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7684849 | CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. patent application Ser. No. 10/334,700 filed Dec. 30, 2002, U.S. patent application Ser. No. 10/382,123, filed Mar. 4, 2003, and U.S. patent application Ser. No. 10/679,801 filed Oct. 6, 2003 all of which are incorporated herein by reference in their entirety.
BACKGROUND
Implantable markers have been used to identify locations within objects, such as a human body. For example, a marker may be implanted in a patient within an organ of interest. As the patient moves, the marker can be used to track the location of the organ. Various techniques have been used to identify the location of such markers.
As described in my co-pending U.S. patent applications noted above, one technique for locating a marker is by measuring the magnetic flux generated by the marker upon excitation from a source. The measurement of the magnetic flux is typically performed by an array of sensing elements that together form a sensing array. In some sensing arrays, each of the sensing elements has their output coupled to their own dedicated amplifier circuit.
The signals from the sensing elements are then output to a receiver that is operative to extract the signal portion from the sensing elements from noise, which may be caused from various sources including the excitation from the source, co-channel or cross-channel interference between sensing elements, radiation sources in the examination environment, etc . . . .
The design of a receiver suitable for use with magnetic flux sensing systems has been problematic and challenging.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. patent application Ser. No. 10/334,700 filed Dec. 30, 2002, U.S. patent application Ser. No. 10/382,123, filed Mar. 4, 2003, and U.S. patent application Ser. No. 10/679,801 filed Oct. 6, 2003 all of which are incorporated herein by reference in their entirety.
BACKGROUND
Implantable markers have been used to identify locations within objects, such as a human body. For example, a marker may be implanted in a patient within an organ of interest. As the patient moves, the marker can be used to track the location of the organ. Various techniques have been used to identify the location of such markers.
As described in my co-pending U.S. patent applications noted above, one technique for locating a marker is by measuring the magnetic flux generated by the marker upon excitation from a source. The measurement of the magnetic flux is typically performed by an array of sensing elements that together form a sensing array. In some sensing arrays, each of the sensing elements has their output coupled to their own dedicated amplifier circuit.
The signals from the sensing elements are then output to a receiver that is operative to extract the signal portion from the sensing elements from noise, which may be caused from various sources including the excitation from the source, co-channel or cross-channel interference between sensing elements, radiation sources in the examination environment, etc . . . .
The design of a receiver suitable for use with magnetic flux sensing systems has been problematic and challenging.
Is this patent green technology? Respond with 'yes' or 'no'. |
7737301 | This application is a National Stage Entry under 35 USC §371 of International application serial number PCT/EP2006/008398, filed on Aug. 28, 2006, which claims priority to CH 1416/05, filed on Aug. 30, 2005, the contents of which are incorporated herein by reference.
The present invention relates to a process for the amination of ortho-bicyclopropyl-substituted halobenzenes and also to intermediates of that process.
Ortho-bicyclopropyl-substituted primary anilines such as, for example, 2-bicyclopropyl-2-yl-phenylamine are valuable intermediates for the preparation of fungicides such as those described, for example, in WO 03/074491.
In general terms, anilines can be prepared from halobenzenes by means of palladium-catalysed cross-coupling reactions. Such palladium-catalysed cross-coupling reactions are described in the following summary articles: Handbook of Organopalladium Chemistry for Organic Synthesis, Vol. 1, 1051-1096, 2002; Journal of Organometallic Chemistry, 576, 125-146, 1999 and Journal of Organometallic Chemistry, 653, 69-82, 2002. The basic disadvantage of palladium-catalysed cross-coupling is that direct preparation of primary anilines is not possible.
Therefore, when using palladium-catalysed cross-coupling, primary anilines have to prepared from the corresponding halobenzenes in synthesis procedures comprising at least two stages.
Such a two-stage process for the preparation of ortho-bicyclopropyl-substituted primary anilines, using imines as nucleophiles, is described in WO 03/074491 (see Scheme 1).
According to WO 03/074491, substituted 2-(2-halophenyl)cyclopropanes of formula (A), wherein Hal is bromine or iodine and R3is, inter alia, unsubstituted or substituted cyclopropyl, are aminated in a two-stage reaction to form the corresponding 2-(2-aminophenyl)cyclopropanes (C). For that purpose, firstly benzophenoneimine, sodium tert-butanolate, tris(dibenzylidene-acetone)dipalladium (Pd2dba3) and racemic 2,2′-bis(diphenylphosphine)-1,1′-binaphthyl (“BINAP”) are added. In the second reaction step, the resulting imines (B) are reacted with, for example, hydroxylamine and sodium acetate to form the corresponding 2-(2-aminophenyl)bicyclopropanes (C). As a further palladium ligand, 1,1′-bis(diphenylphosphino)ferrocene (“dppf”) is proposed in WO 03/074491.
This reaction procedure is described in WO 03/074491 exclusively for bromo- or iodo-benzenes, not for chlorobenzenes. It has been found that the reaction procedure described in WO 03/074491 is poorly suited to the imination of the less reactive but more economically priced 2-(2-chlorophenyl)cyclopropanes in high yields.
The reaction procedure described in WO 03/074491 for the preparation of primary anilines is not suitable for the large-scale preparation of ortho-bicyclopropyl-substituted primary anilines because of the high cost of the benzophenoneimine.
The problem of the present invention is accordingly to provide a new process for the preparation of ortho-bicyclopropyl-substituted primary anilines which avoids the above-mentioned disadvantages of the known process and makes it possible to prepare those compounds at economically reasonable cost and in easily manageable manner in high yields and good quality.
The present invention accordingly relates to a process for the preparation of compounds of formula I
wherein R1, R2and R3are each independently of the others hydrogen or C1-C4alkyl, which process comprises
a) reacting a compound of formula II
wherein R1, R2and R3are as defined for formula I and X is bromine or chlorine, with a compound of formula III
wherein R4is hydrogen or C1-C4alkyl, in the presence of a base and catalytic amounts of at least one palladium complex compound, to form
a compound of formula IV
wherein R1, R2, R3and R4are each independently of the others hydrogen or C1-C4alkyl; and
b) converting that compound, using a reducing agent, into the compound of formula I.
Compounds of formula I occur in various stereoisomeric forms, which are described in formulae II, III, IIIIand IIV:
The process according to the invention includes the preparation of those stereoisomeric forms of formulae II, III, IIIIand IIV, wherein R1, R2and R3are as defined for formula I, and the preparation of mixtures of those stereoisomeric forms in any ratio.
The process according to the invention is suitable preferably for the preparation of compounds of formula I wherein R1is hydrogen or C1-C4alkyl and R2and R3are hydrogen.
The process according to the invention is suitable preferably for the preparation of compounds of formula I wherein R1is hydrogen or methyl and R2and R3are hydrogen.
The process according to the invention is suitable especially for the preparation of compounds of formula I wherein R1, R2and R3are hydrogen.
Compounds of formula II wherein X is bromine are preferably used in the process according to the invention.
Compounds of formula II wherein X is chlorine are preferably used in the process according to the invention.
Process Step a):
Palladium complex compounds which are used in process step (a) are formed from a palladium precursor and at least one suitable ligand. In process step (a), the palladium complex complexes are preferably present in dissolved form as palladium-ligand complexes.
In the context of the present invention, palladium complex compounds are expressly understood to include compounds consisting of cyclic organic palladium compounds, the so-called “palladacycles”, and secondary phosphines.
The palladium complex compounds may be used as already formed complex compounds in process step (a) or are formed in situ in process step (a).
In order to form palladium complex compounds, a palladium precursor is reacted with at least one suitable ligand. In the event of incomplete reaction, it can be the case that minor amounts of palladium precursor or of ligand do not dissolve in the reaction mixture.
Suitable palladium precursors are palladium acetate, palladium dichloride, palladium dichloride solution, palladium2(dibenzylidene-acetone)3or palladium (dibenzylidene-acetone)2, palladium tetrakis(triphenylphosphine), palladium-on-carbon, palladium dichlorobis(benzonitrile), palladium (tris-tert-butylphosphine)2or a mixture of palladium2(dibenzylidene-acetone)3and palladium (tris-tert-butylphosphine)2.
Suitable ligands are tertiary phosphine ligands, N-heterocyclic carbene ligands or phosphinic acid ligands.
In the context of the present invention, tertiary phosphine ligands are sub-divided into monodentate tertiary phosphine ligands and bidentate tertiary phosphine ligands. A “monodentate ligand” is understood to be a ligand able to occupy one co-ordination site of the palladium centre. A “bidentate ligand” is understood to be a ligand which is able to occupy two co-ordination sites of the palladium centre and is accordingly capable of chelating the palladium atom or palladium ion.
Examples of tertiary phosphine ligands are:
(A) monodentate tertiary phosphine ligands:
tri-tert-butyl-phosphine, tri-tert-butyl-phosphonium tetrafluoroborate (“P(tBu)3HBF4”), tris-ortho-tolyl-phosphine (“P(oTol)3”), tris-cyclohexyl-phosphine (“P(Cy)3”), 2-di-tert-butyl-phosphino-1,1′-bisphenyl (“P(tBu)2BiPh”), 2-dicyclohexyl-phosphino-1,1′-bisphenyl (“P(Cy)2BiPh”) or 2-dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-bisphenyl (“x-Phos”), tert-butyl-di-1-adamantyl-phosphine (“P(tBu)(Adam)2”); or
(B) bidentate tertiary phosphine ligands:
(B1) biphosphine ligands:
(B1.1): ferrocenyl biphosphine ligands such as, for example, R(−)-di-tert-butyl-[1-[(S)-2-(dicyclohexylphosphinyl)ferrocenyl]ethyl]phosphine (“Josiphos 1”)
racemic di-tert-butyl-[1-[2-(dicyclohexylphosphinyl)ferrocenyl]ethyl]phosphine (“racemic Josiphos 1”), (R)-1-((S)-2-(di-tert-butylphosphino)ferrocenyl)ethyl-di-ortho-tolylphosphine (“Josiphos 2”)
racemic 1-(2-(di-tert-butylphosphino)ferrocenyl)ethyl-di-ortho-tolylphosphine (“racemic Josiphos 2”), 1,1′-bis(diphenylphosphino)ferrocene (“dppf”), 1,1′-bis(di-tert-butylphosphino)-ferrocene, R-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine, racemic 1-[2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine, R-1-[(S)-2-(2′-diphenyl-phosphinophenyl]ferrocenyl)ethyl-di-tert-butylphosphine or
(B1.2): binaphthyl bisphosphine ligands such as, for example, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (“BINAP”), R-(+)-2,2′-bis(di-p-tolylphosphino)-1,1′-binaphthyl (“Tol-BINAP”), racemic 2,2′-bis(di-p-tolylphosphino)-1,1′-binaphthyl (“racemic Tol-BINAP”); or
(B1.3): 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (“Xantphos”); or
(B2) aminophosphine ligands:
(B2.1): biphenyl ligands such as, for example, 2-dicyclohexylphosphino-(N,N-dimethylamino)-1,1′-biphenyl (“PCy2NMe2BiPh”)
or 2-di-tert-butylphosphino-(N,N-dimethylamino)-1,1′-biphenyl (“P(tBu)2NMe2BiPh”).
Examples of N-heterocyclic carbene ligands are:
1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (“I—Pr”)
1,2-bis(1-adamantyl)imidazolium chloride (“I-Ad”) or 1,3-bis(2,6-methylphenyl)imidazolium chloride (“I-Me”).
An example of a phosphinic acid ligand is:
di-tert-butyl-phosphine oxide.
An example of a palladium complex compound based on a “palladacycle” and secondary phosphine is a compound of formula A-1:
wherein “norb” is norbornyl. Compound A-1 is described in SYNLETT, 2549-2552, 2004 and is given the designation “SK-CC01-A” therein.
A further example of a palladium complex compound based on a “palladacycle” and secondary phosphine is a compound of formula A-2:
Compound A-2 is described in SYNLETT, 2549-2552, 2004 and is given the designation “SK-CC02-A” therein.
Examples of palladium complex compounds using phosphinic acid ligands are described in Journal of Organic Chemistry, 66, 8677-8681 and are given the designations “POPd”, “POPd2” and “POPD1” therein.
Examples of palladium complex compounds using N-heterocyclic carbene ligands are:
naphthoquinone-1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium (“[Pd—NQ-IPr]2”)
divinyl-tetramethylsiloxane-1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium (“Pd—VTS—IPr”)
1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium dichloride (“Pd—Cl—IPr”), 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium diacetate (“Pd—OAc—IPr”), allyl-1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium chloride (“Pd—Al—Cl—IPr”) or a compound of formula A-3:
wherein R5is 2,6-diisopropylphenyl or 2,4,6-trimethylphenyl. [Pd—NQ-IPr]2, Pd—VTS—IPr, Pd—Cl—IPr and Pd—Al—Cl—IPr are described in Organic Letters, 4, 2229-2231, 2002 and in SYNLETT, 275-278, 2005. The compound of formula A-3 is described in Organic Letters, 5, 1479-1482, 2003.
One palladium complex compound or a mixture of palladium complex compounds may be used in the process according to the invention.
For formation of the palladium complex compound, preference is given to the use, as palladium precursor, of palladium acetate, palladium2(dibenzylidene-acetone)3, palladium (dibenzylidene-acetone)2, palladium dichloride solution or a mixture of palladium2(dibenzylidene-acetone)3and palladium (tris-tert-butylphosphine)2. Special preference is given to the use of palladium acetate or palladium dichloride.
At least one ligand is used for formation of the palladium complex compound.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from a monodentate tertiary phosphine ligand, a bidentate tertiary phosphine ligand and an N-heterocyclic carbene ligand.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from an N-heterocyclic carbene ligand, a monodentate tertiary phosphine ligand and a bidentate tertiary phosphine ligand which is selected from a ferrocenyl biphosphine ligand, a binaphthyl bisphosphine ligand and an aminophosphine ligand.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, P(oTol)3, P(Cy)3, P(tBu)2BiPh, P(Cy)2BiPh, x-Phos, P(tBu)(Adam)2, Josiphos 1, racemic Josiphos 1, Josiphos 2, racemic Josiphos 2, dppf, 1,1′-bis(di-tert-butylphosphino)ferrocene, R-1-[(S)-2-(diphenylphosphino)-ferrocenyl]ethyl-dicyclohexylphosphine, racemic 1-[2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine, R-1-[(S)-2-(2′-diphenylphosphinophenyl]ferrocenyl)ethyl-di-tert-butylphosphine, BINAP, Tol-BINAP, racemic Tol-BINAP, Xantphos, PCy2NMe2BiPh, P(tBu)2NMe2BiPh, I—Pr, I-Ad and I-Me, or a palladium complex compound of formula A-3 wherein R5is 2,6-diisopropylphenyl or 2,4,6-trimethylphenyl.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, P(tBu)2BiPh, P(Cy)2BiPh, x-Phos, Josiphos 1, racemic Josiphos 1, Josiphos 2, racemic Josiphos 2, PCy2NMe2BiPh and I—Pr.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, P(tBu)2BiPh, P(Cy)2BiPh, x-Phos, PCy2NMe2BiPh and I—Pr.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, PCy2NMe2BiPh and I—Pr.
Preference is given to the use of palladium complex compounds which comprise the ligand tri-tert-butyl-phosphine or P(tBu)3HBF4.
Preference is given to the use of palladium complex compounds which comprise the ligand PCy2NMe2BiPh.
Preference is given to the use of palladium complex compounds which comprise the ligand I—Pr.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from Josiphos 1 and racemic Josiphos 1.
Preference is given to the use of palladium complex compounds which comprise the ligand racemic Josiphos 1.
Palladium complex compounds, palladium precursors and/or ligands are used in catalytic amounts in the process according to the invention.
Palladium complex compounds are used preferably in a ratio of from 1:10 to 1:10 000 relative to compounds of formula II, especially in a ratio of from 1:100 to 1:1000.
Palladium precursors are used preferably in a ratio of from 1:10 to 1:10 000 relative to compounds of formula II, especially in a ratio of from 1:100 to 1:1000.
Ligands are used preferably in a ratio of from 1:10 to 1:10 000 relative to compounds of formula II, especially in a ratio of from 1:100 to 1:1000.
In the reaction according to the invention, preference is given to the use, as compound of formula III, of a compound of formula III wherein R4is hydrogen (benzylamine).
Compounds of formula III are preferably used in an equimolar amount or in an excess relative to compounds of formula II. Suitable amounts of compounds of formula III for this reaction are, for example, from 1 to 3 equivalents, especially from 1 to 2 equivalents.
Suitable bases are, for example, alcoholates, e.g. sodium tert-butanolate, potassium tert-butanolate, sodium methanolate or sodium ethanolate, or inorganic bases such as carbonates, e.g. K2CO3, Na2CO3or Cs2CO3, hydroxides, e.g. NaOH or KOH, or phosphates, e.g. K3PO4; preference is given to alcoholates and special preference is given to sodium tert-butanolate.
When NaOH or KOH is used as the base, a phase transfer catalyst such as, for example, cetyltrimethylammonium bromide may be used.
Suitable amounts of base for this reaction are, for example, from 1 to 3 equivalents, especially from 1 to 2 equivalents.
The reaction according to the invention may be carried out in an inert solvent.
In one embodiment of the invention, the reaction according to the invention is carried out in an inert solvent. Suitable solvents are, for example, a compound of formula V
wherein R is C1-C6alkyl, preferably methyl; dimethoxyethane; tert-butyl methyl ether; pentane; hexane; cyclohexane; tetrahydrofuran; dioxane; toluene; xylene or trimethylbenzenes such as, for example, mesitylene; and also mixtures thereof. A preferred solvent is dimethoxyethane or xylene.
In that embodiment, the inert solvent is preferably anhydrous.
In a further embodiment of the invention, the reaction is carried out without solvent. In that embodiment, compounds of formula III are preferably used in an excess relative to compounds of formula II.
The reaction according to the invention is carried out at ambient temperature or at elevated temperature, preferably in a temperature range from 50° C. to 180° C., especially in a temperature range from 50° C. to 100° C.
The reaction according to the invention may be carried out at normal, elevated or reduced pressure. In one embodiment, the reaction according to the invention is carried out at normal pressure.
The reaction time of the reaction according to the invention is generally from 1 to 48 hours, preferably from 4 to 30 hours, especially from 4 to 18 hours.
The reaction according to the invention may be carried out in an inert gas atmosphere. For example, nitrogen or argon is used as inert gas.
In one embodiment of the reaction according to the invention, the reaction is carried out in a nitrogen atmosphere.
Process Step b):
A suitable reducing agent for process step b) is, for example, hydrogen in the presence of a metal catalyst.
Amounts of reducing agent suitable for this reaction are, for example, from 1 to 5 equivalents, especially from 1 to 1.3 equivalents.
Suitable metal catalysts are, for example, palladium catalysts such as, for example, palladium-on-carbon catalysts, or rhodium catalysts; special preference is given to palladium catalysts.
Amounts of metal catalyst suitable for this reaction are catalytic amounts such as, for example, from 0.001 to 0.5 equivalent, especially from 0.01 to 0.1 equivalent.
This reaction is preferably carried out in the presence of an inert solvent. Suitable solvents are, for example, alcohols, e.g. methanol, ethanol, propanol or isopropanol, or aprotic solvents, e.g. tetrahydrofuran, tert-butyl methyl ether, dioxane, ethyl acetate or dimethoxyethane, and also mixtures thereof; special preference is given to tetrahydrofuran.
The temperatures are generally from 0° C. to 80° C.; preference is given to a range from 0° C. to 25° C.; special preference is given to carrying out this reaction at ambient temperature.
The reaction time for this reaction is generally from 1 to 48 hours, preferably from 1 to 6 hours.
The reaction according to the invention may be carried out at normal, elevated or reduced pressure. In one embodiment, the reaction according to the invention is carried out at normal pressure.
If suitable reaction conditions are selected, the compound of formula IV obtained in reaction step a) can be directly reacted to form a compound of formula I without isolating intermediates.
The process according to the invention is very especially suitable for the preparation of compounds of formula I wherein R1, R2and R3are each independently of the others hydrogen or C1-C4alkyl, by
a) reaction of a compound of formula II, wherein R1, R2and R3are each independently of the others hydrogen or C1-C4alkyl and X is chlorine, with benzylamine in the presence of sodium tert-butanolate and catalytic amounts of at least one palladium complex compound, wherein the palladium complex compound comprises at least one ligand selected from tri-tert-butyl-phosphine, tri-tert-butyl-phosphonium tetrafluoroborate, 2-dicyclohexylphosphino-(N,N-dimethylamino)-1,1′-biphenyl and 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride, to form a compound of formula IV, wherein R1, R2, R3and R4are each independently of the others hydrogen or C1-C4alkyl, and
b) conversion of the latter compound into the compound of formula I using hydrogen in the presence of a metal catalyst.
Compounds of formula I wherein R1is hydrogen or methyl and R2and R3are hydrogen are especially suitable for that embodiment.
Compounds of formula I wherein R1, R2and R3are hydrogen are very especially suitable for that embodiment.
The compounds of formula II wherein X is bromine are generally known and can be prepared according to the processes described in WO 03/074491.
The compounds of formula II wherein X is chlorine can be prepared in analogous manner to the processes described in WO 03/074491 for the corresponding compounds of formula II wherein X is bromine. For example, the compound of formula II wherein R1, R2and R3are hydrogen and X is chlorine (compound no. B1) can be prepared as shown in Reaction Scheme 1 and as explained by Examples A1-A3 which follow:
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: This application is a National Stage Entry under 35 USC §371 of International application serial number PCT/EP2006/008398, filed on Aug. 28, 2006, which claims priority to CH 1416/05, filed on Aug. 30, 2005, the contents of which are incorporated herein by reference.
The present invention relates to a process for the amination of ortho-bicyclopropyl-substituted halobenzenes and also to intermediates of that process.
Ortho-bicyclopropyl-substituted primary anilines such as, for example, 2-bicyclopropyl-2-yl-phenylamine are valuable intermediates for the preparation of fungicides such as those described, for example, in WO 03/074491.
In general terms, anilines can be prepared from halobenzenes by means of palladium-catalysed cross-coupling reactions. Such palladium-catalysed cross-coupling reactions are described in the following summary articles: Handbook of Organopalladium Chemistry for Organic Synthesis, Vol. 1, 1051-1096, 2002; Journal of Organometallic Chemistry, 576, 125-146, 1999 and Journal of Organometallic Chemistry, 653, 69-82, 2002. The basic disadvantage of palladium-catalysed cross-coupling is that direct preparation of primary anilines is not possible.
Therefore, when using palladium-catalysed cross-coupling, primary anilines have to prepared from the corresponding halobenzenes in synthesis procedures comprising at least two stages.
Such a two-stage process for the preparation of ortho-bicyclopropyl-substituted primary anilines, using imines as nucleophiles, is described in WO 03/074491 (see Scheme 1).
According to WO 03/074491, substituted 2-(2-halophenyl)cyclopropanes of formula (A), wherein Hal is bromine or iodine and R3is, inter alia, unsubstituted or substituted cyclopropyl, are aminated in a two-stage reaction to form the corresponding 2-(2-aminophenyl)cyclopropanes (C). For that purpose, firstly benzophenoneimine, sodium tert-butanolate, tris(dibenzylidene-acetone)dipalladium (Pd2dba3) and racemic 2,2′-bis(diphenylphosphine)-1,1′-binaphthyl (“BINAP”) are added. In the second reaction step, the resulting imines (B) are reacted with, for example, hydroxylamine and sodium acetate to form the corresponding 2-(2-aminophenyl)bicyclopropanes (C). As a further palladium ligand, 1,1′-bis(diphenylphosphino)ferrocene (“dppf”) is proposed in WO 03/074491.
This reaction procedure is described in WO 03/074491 exclusively for bromo- or iodo-benzenes, not for chlorobenzenes. It has been found that the reaction procedure described in WO 03/074491 is poorly suited to the imination of the less reactive but more economically priced 2-(2-chlorophenyl)cyclopropanes in high yields.
The reaction procedure described in WO 03/074491 for the preparation of primary anilines is not suitable for the large-scale preparation of ortho-bicyclopropyl-substituted primary anilines because of the high cost of the benzophenoneimine.
The problem of the present invention is accordingly to provide a new process for the preparation of ortho-bicyclopropyl-substituted primary anilines which avoids the above-mentioned disadvantages of the known process and makes it possible to prepare those compounds at economically reasonable cost and in easily manageable manner in high yields and good quality.
The present invention accordingly relates to a process for the preparation of compounds of formula I
wherein R1, R2and R3are each independently of the others hydrogen or C1-C4alkyl, which process comprises
a) reacting a compound of formula II
wherein R1, R2and R3are as defined for formula I and X is bromine or chlorine, with a compound of formula III
wherein R4is hydrogen or C1-C4alkyl, in the presence of a base and catalytic amounts of at least one palladium complex compound, to form
a compound of formula IV
wherein R1, R2, R3and R4are each independently of the others hydrogen or C1-C4alkyl; and
b) converting that compound, using a reducing agent, into the compound of formula I.
Compounds of formula I occur in various stereoisomeric forms, which are described in formulae II, III, IIIIand IIV:
The process according to the invention includes the preparation of those stereoisomeric forms of formulae II, III, IIIIand IIV, wherein R1, R2and R3are as defined for formula I, and the preparation of mixtures of those stereoisomeric forms in any ratio.
The process according to the invention is suitable preferably for the preparation of compounds of formula I wherein R1is hydrogen or C1-C4alkyl and R2and R3are hydrogen.
The process according to the invention is suitable preferably for the preparation of compounds of formula I wherein R1is hydrogen or methyl and R2and R3are hydrogen.
The process according to the invention is suitable especially for the preparation of compounds of formula I wherein R1, R2and R3are hydrogen.
Compounds of formula II wherein X is bromine are preferably used in the process according to the invention.
Compounds of formula II wherein X is chlorine are preferably used in the process according to the invention.
Process Step a):
Palladium complex compounds which are used in process step (a) are formed from a palladium precursor and at least one suitable ligand. In process step (a), the palladium complex complexes are preferably present in dissolved form as palladium-ligand complexes.
In the context of the present invention, palladium complex compounds are expressly understood to include compounds consisting of cyclic organic palladium compounds, the so-called “palladacycles”, and secondary phosphines.
The palladium complex compounds may be used as already formed complex compounds in process step (a) or are formed in situ in process step (a).
In order to form palladium complex compounds, a palladium precursor is reacted with at least one suitable ligand. In the event of incomplete reaction, it can be the case that minor amounts of palladium precursor or of ligand do not dissolve in the reaction mixture.
Suitable palladium precursors are palladium acetate, palladium dichloride, palladium dichloride solution, palladium2(dibenzylidene-acetone)3or palladium (dibenzylidene-acetone)2, palladium tetrakis(triphenylphosphine), palladium-on-carbon, palladium dichlorobis(benzonitrile), palladium (tris-tert-butylphosphine)2or a mixture of palladium2(dibenzylidene-acetone)3and palladium (tris-tert-butylphosphine)2.
Suitable ligands are tertiary phosphine ligands, N-heterocyclic carbene ligands or phosphinic acid ligands.
In the context of the present invention, tertiary phosphine ligands are sub-divided into monodentate tertiary phosphine ligands and bidentate tertiary phosphine ligands. A “monodentate ligand” is understood to be a ligand able to occupy one co-ordination site of the palladium centre. A “bidentate ligand” is understood to be a ligand which is able to occupy two co-ordination sites of the palladium centre and is accordingly capable of chelating the palladium atom or palladium ion.
Examples of tertiary phosphine ligands are:
(A) monodentate tertiary phosphine ligands:
tri-tert-butyl-phosphine, tri-tert-butyl-phosphonium tetrafluoroborate (“P(tBu)3HBF4”), tris-ortho-tolyl-phosphine (“P(oTol)3”), tris-cyclohexyl-phosphine (“P(Cy)3”), 2-di-tert-butyl-phosphino-1,1′-bisphenyl (“P(tBu)2BiPh”), 2-dicyclohexyl-phosphino-1,1′-bisphenyl (“P(Cy)2BiPh”) or 2-dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-bisphenyl (“x-Phos”), tert-butyl-di-1-adamantyl-phosphine (“P(tBu)(Adam)2”); or
(B) bidentate tertiary phosphine ligands:
(B1) biphosphine ligands:
(B1.1): ferrocenyl biphosphine ligands such as, for example, R(−)-di-tert-butyl-[1-[(S)-2-(dicyclohexylphosphinyl)ferrocenyl]ethyl]phosphine (“Josiphos 1”)
racemic di-tert-butyl-[1-[2-(dicyclohexylphosphinyl)ferrocenyl]ethyl]phosphine (“racemic Josiphos 1”), (R)-1-((S)-2-(di-tert-butylphosphino)ferrocenyl)ethyl-di-ortho-tolylphosphine (“Josiphos 2”)
racemic 1-(2-(di-tert-butylphosphino)ferrocenyl)ethyl-di-ortho-tolylphosphine (“racemic Josiphos 2”), 1,1′-bis(diphenylphosphino)ferrocene (“dppf”), 1,1′-bis(di-tert-butylphosphino)-ferrocene, R-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine, racemic 1-[2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine, R-1-[(S)-2-(2′-diphenyl-phosphinophenyl]ferrocenyl)ethyl-di-tert-butylphosphine or
(B1.2): binaphthyl bisphosphine ligands such as, for example, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (“BINAP”), R-(+)-2,2′-bis(di-p-tolylphosphino)-1,1′-binaphthyl (“Tol-BINAP”), racemic 2,2′-bis(di-p-tolylphosphino)-1,1′-binaphthyl (“racemic Tol-BINAP”); or
(B1.3): 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (“Xantphos”); or
(B2) aminophosphine ligands:
(B2.1): biphenyl ligands such as, for example, 2-dicyclohexylphosphino-(N,N-dimethylamino)-1,1′-biphenyl (“PCy2NMe2BiPh”)
or 2-di-tert-butylphosphino-(N,N-dimethylamino)-1,1′-biphenyl (“P(tBu)2NMe2BiPh”).
Examples of N-heterocyclic carbene ligands are:
1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (“I—Pr”)
1,2-bis(1-adamantyl)imidazolium chloride (“I-Ad”) or 1,3-bis(2,6-methylphenyl)imidazolium chloride (“I-Me”).
An example of a phosphinic acid ligand is:
di-tert-butyl-phosphine oxide.
An example of a palladium complex compound based on a “palladacycle” and secondary phosphine is a compound of formula A-1:
wherein “norb” is norbornyl. Compound A-1 is described in SYNLETT, 2549-2552, 2004 and is given the designation “SK-CC01-A” therein.
A further example of a palladium complex compound based on a “palladacycle” and secondary phosphine is a compound of formula A-2:
Compound A-2 is described in SYNLETT, 2549-2552, 2004 and is given the designation “SK-CC02-A” therein.
Examples of palladium complex compounds using phosphinic acid ligands are described in Journal of Organic Chemistry, 66, 8677-8681 and are given the designations “POPd”, “POPd2” and “POPD1” therein.
Examples of palladium complex compounds using N-heterocyclic carbene ligands are:
naphthoquinone-1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium (“[Pd—NQ-IPr]2”)
divinyl-tetramethylsiloxane-1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium (“Pd—VTS—IPr”)
1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium dichloride (“Pd—Cl—IPr”), 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium diacetate (“Pd—OAc—IPr”), allyl-1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-palladium chloride (“Pd—Al—Cl—IPr”) or a compound of formula A-3:
wherein R5is 2,6-diisopropylphenyl or 2,4,6-trimethylphenyl. [Pd—NQ-IPr]2, Pd—VTS—IPr, Pd—Cl—IPr and Pd—Al—Cl—IPr are described in Organic Letters, 4, 2229-2231, 2002 and in SYNLETT, 275-278, 2005. The compound of formula A-3 is described in Organic Letters, 5, 1479-1482, 2003.
One palladium complex compound or a mixture of palladium complex compounds may be used in the process according to the invention.
For formation of the palladium complex compound, preference is given to the use, as palladium precursor, of palladium acetate, palladium2(dibenzylidene-acetone)3, palladium (dibenzylidene-acetone)2, palladium dichloride solution or a mixture of palladium2(dibenzylidene-acetone)3and palladium (tris-tert-butylphosphine)2. Special preference is given to the use of palladium acetate or palladium dichloride.
At least one ligand is used for formation of the palladium complex compound.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from a monodentate tertiary phosphine ligand, a bidentate tertiary phosphine ligand and an N-heterocyclic carbene ligand.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from an N-heterocyclic carbene ligand, a monodentate tertiary phosphine ligand and a bidentate tertiary phosphine ligand which is selected from a ferrocenyl biphosphine ligand, a binaphthyl bisphosphine ligand and an aminophosphine ligand.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, P(oTol)3, P(Cy)3, P(tBu)2BiPh, P(Cy)2BiPh, x-Phos, P(tBu)(Adam)2, Josiphos 1, racemic Josiphos 1, Josiphos 2, racemic Josiphos 2, dppf, 1,1′-bis(di-tert-butylphosphino)ferrocene, R-1-[(S)-2-(diphenylphosphino)-ferrocenyl]ethyl-dicyclohexylphosphine, racemic 1-[2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine, R-1-[(S)-2-(2′-diphenylphosphinophenyl]ferrocenyl)ethyl-di-tert-butylphosphine, BINAP, Tol-BINAP, racemic Tol-BINAP, Xantphos, PCy2NMe2BiPh, P(tBu)2NMe2BiPh, I—Pr, I-Ad and I-Me, or a palladium complex compound of formula A-3 wherein R5is 2,6-diisopropylphenyl or 2,4,6-trimethylphenyl.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, P(tBu)2BiPh, P(Cy)2BiPh, x-Phos, Josiphos 1, racemic Josiphos 1, Josiphos 2, racemic Josiphos 2, PCy2NMe2BiPh and I—Pr.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, P(tBu)2BiPh, P(Cy)2BiPh, x-Phos, PCy2NMe2BiPh and I—Pr.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from tri-tert-butyl-phosphine, P(tBu)3HBF4, PCy2NMe2BiPh and I—Pr.
Preference is given to the use of palladium complex compounds which comprise the ligand tri-tert-butyl-phosphine or P(tBu)3HBF4.
Preference is given to the use of palladium complex compounds which comprise the ligand PCy2NMe2BiPh.
Preference is given to the use of palladium complex compounds which comprise the ligand I—Pr.
Preference is given to the use of palladium complex compounds which comprise at least one ligand selected from Josiphos 1 and racemic Josiphos 1.
Preference is given to the use of palladium complex compounds which comprise the ligand racemic Josiphos 1.
Palladium complex compounds, palladium precursors and/or ligands are used in catalytic amounts in the process according to the invention.
Palladium complex compounds are used preferably in a ratio of from 1:10 to 1:10 000 relative to compounds of formula II, especially in a ratio of from 1:100 to 1:1000.
Palladium precursors are used preferably in a ratio of from 1:10 to 1:10 000 relative to compounds of formula II, especially in a ratio of from 1:100 to 1:1000.
Ligands are used preferably in a ratio of from 1:10 to 1:10 000 relative to compounds of formula II, especially in a ratio of from 1:100 to 1:1000.
In the reaction according to the invention, preference is given to the use, as compound of formula III, of a compound of formula III wherein R4is hydrogen (benzylamine).
Compounds of formula III are preferably used in an equimolar amount or in an excess relative to compounds of formula II. Suitable amounts of compounds of formula III for this reaction are, for example, from 1 to 3 equivalents, especially from 1 to 2 equivalents.
Suitable bases are, for example, alcoholates, e.g. sodium tert-butanolate, potassium tert-butanolate, sodium methanolate or sodium ethanolate, or inorganic bases such as carbonates, e.g. K2CO3, Na2CO3or Cs2CO3, hydroxides, e.g. NaOH or KOH, or phosphates, e.g. K3PO4; preference is given to alcoholates and special preference is given to sodium tert-butanolate.
When NaOH or KOH is used as the base, a phase transfer catalyst such as, for example, cetyltrimethylammonium bromide may be used.
Suitable amounts of base for this reaction are, for example, from 1 to 3 equivalents, especially from 1 to 2 equivalents.
The reaction according to the invention may be carried out in an inert solvent.
In one embodiment of the invention, the reaction according to the invention is carried out in an inert solvent. Suitable solvents are, for example, a compound of formula V
wherein R is C1-C6alkyl, preferably methyl; dimethoxyethane; tert-butyl methyl ether; pentane; hexane; cyclohexane; tetrahydrofuran; dioxane; toluene; xylene or trimethylbenzenes such as, for example, mesitylene; and also mixtures thereof. A preferred solvent is dimethoxyethane or xylene.
In that embodiment, the inert solvent is preferably anhydrous.
In a further embodiment of the invention, the reaction is carried out without solvent. In that embodiment, compounds of formula III are preferably used in an excess relative to compounds of formula II.
The reaction according to the invention is carried out at ambient temperature or at elevated temperature, preferably in a temperature range from 50° C. to 180° C., especially in a temperature range from 50° C. to 100° C.
The reaction according to the invention may be carried out at normal, elevated or reduced pressure. In one embodiment, the reaction according to the invention is carried out at normal pressure.
The reaction time of the reaction according to the invention is generally from 1 to 48 hours, preferably from 4 to 30 hours, especially from 4 to 18 hours.
The reaction according to the invention may be carried out in an inert gas atmosphere. For example, nitrogen or argon is used as inert gas.
In one embodiment of the reaction according to the invention, the reaction is carried out in a nitrogen atmosphere.
Process Step b):
A suitable reducing agent for process step b) is, for example, hydrogen in the presence of a metal catalyst.
Amounts of reducing agent suitable for this reaction are, for example, from 1 to 5 equivalents, especially from 1 to 1.3 equivalents.
Suitable metal catalysts are, for example, palladium catalysts such as, for example, palladium-on-carbon catalysts, or rhodium catalysts; special preference is given to palladium catalysts.
Amounts of metal catalyst suitable for this reaction are catalytic amounts such as, for example, from 0.001 to 0.5 equivalent, especially from 0.01 to 0.1 equivalent.
This reaction is preferably carried out in the presence of an inert solvent. Suitable solvents are, for example, alcohols, e.g. methanol, ethanol, propanol or isopropanol, or aprotic solvents, e.g. tetrahydrofuran, tert-butyl methyl ether, dioxane, ethyl acetate or dimethoxyethane, and also mixtures thereof; special preference is given to tetrahydrofuran.
The temperatures are generally from 0° C. to 80° C.; preference is given to a range from 0° C. to 25° C.; special preference is given to carrying out this reaction at ambient temperature.
The reaction time for this reaction is generally from 1 to 48 hours, preferably from 1 to 6 hours.
The reaction according to the invention may be carried out at normal, elevated or reduced pressure. In one embodiment, the reaction according to the invention is carried out at normal pressure.
If suitable reaction conditions are selected, the compound of formula IV obtained in reaction step a) can be directly reacted to form a compound of formula I without isolating intermediates.
The process according to the invention is very especially suitable for the preparation of compounds of formula I wherein R1, R2and R3are each independently of the others hydrogen or C1-C4alkyl, by
a) reaction of a compound of formula II, wherein R1, R2and R3are each independently of the others hydrogen or C1-C4alkyl and X is chlorine, with benzylamine in the presence of sodium tert-butanolate and catalytic amounts of at least one palladium complex compound, wherein the palladium complex compound comprises at least one ligand selected from tri-tert-butyl-phosphine, tri-tert-butyl-phosphonium tetrafluoroborate, 2-dicyclohexylphosphino-(N,N-dimethylamino)-1,1′-biphenyl and 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride, to form a compound of formula IV, wherein R1, R2, R3and R4are each independently of the others hydrogen or C1-C4alkyl, and
b) conversion of the latter compound into the compound of formula I using hydrogen in the presence of a metal catalyst.
Compounds of formula I wherein R1is hydrogen or methyl and R2and R3are hydrogen are especially suitable for that embodiment.
Compounds of formula I wherein R1, R2and R3are hydrogen are very especially suitable for that embodiment.
The compounds of formula II wherein X is bromine are generally known and can be prepared according to the processes described in WO 03/074491.
The compounds of formula II wherein X is chlorine can be prepared in analogous manner to the processes described in WO 03/074491 for the corresponding compounds of formula II wherein X is bromine. For example, the compound of formula II wherein R1, R2and R3are hydrogen and X is chlorine (compound no. B1) can be prepared as shown in Reaction Scheme 1 and as explained by Examples A1-A3 which follow:
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7742302 | BACKGROUND OF THE INVENTION
The present invention relates to an axial-flow fan unit and a heat-emitting element cooling apparatus which uses the axial-flow fan unit, for cooling a heat emitting element such as an electronic component.
Such a heat-emitting element cooling apparatus has been know that includes a heat sink having a base and a plurality of radiation fins, and a fan unit. In this apparatus, a heat-emitting element to be cooled is mounted on the rear surface of the base, and the plurality of radiation fins are fixed to the base. The fan unit is disposed above the heat sink, for blowing air along at least the radiation fins to promote heat dissipation from the radiation fins. In this heat-emitting element cooling apparatus, heat generated from the heat-emitting element is transferred from the base to the radiation fins. Then, the air flowing from the fan unit along the radiation fins carries away the heat of the radiation fins, thereby cooling the heat-emitting element.
U.S. Pat. No. 6,407,913 discloses an electronic component cooling apparatus where a heat sink provided with a plurality of radiation fins juxtaposed on a base, is cooled by a fan unit.
Japanese Patent Application No. 267093/2002 (Laid-Open Publication No. 104020/2004), which is the prior application of the applicant of the present invention, discloses an axial-flow fan unit in which the shape of a venturi is so defined that, as seen from the radially outward direction of the revolving shaft of a motor for rotating an impeller, part of a plurality of blades located on the side of the motor can be seen.
Further, U.S. Design Pat. No. 441,724 and U.S. Design Pat. No. 450,306 disclose a heat sink constituted by a radiation group comprising four space-dividing radiation fins and a plurality of subdividing radiation fins. In this heat sink, the four space-dividing radiation fins directly extend from the outer periphery of a base in the radial direction of the revolving shaft of a motor, thereby dividing a space surrounding the outer periphery of the base into four spaces. The plurality of subdividing radiation fins are located within the divided spaces in order to further subdivide the divided spaces. A part of the subdividing radiation fins respectively extend outward from two of the space-dividing radiation fins adjacent to each other, and the remaining subdividing radiation fins respectively extend outward from the outer periphery of the base located between two adjacent space-dividing radiation fins.
Like the axial-flow fan unit as shown in Japanese Patent Application No. 267093/2002 (Laid-Open Publication No. 104020/2004), in which the shape of the venturi is so defined that part of a plurality of blades located on the side of the motor can be seen as viewed from the radially outward direction of the revolving shaft of the motor for rotating the impeller, comparatively large noise might be produced.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an axial-flow fan unit that produces less noise.
Another object of the present invention is to provide a heat-emitting element cooling apparatus that has high cooling performance and also produces less noise.
An axial-flow fan unit of which the present invention aims at improvement includes: a motor having a revolving shaft; an impeller having a plurality of blades and mounted on the revolving shaft; a cylindrical venturi surrounding the impeller in the radial direction of the revolving shaft; and a plurality of webs spaced in the radial direction, for connecting the venturi to the housing of the motor. Then, the shape of the venturi is so defined that part of the blades located on the side of the housing of the motor can be seen, as viewed from the radially outward direction. Further, each of the webs includes: a web leg section extending from the end of the venturi toward a side of the housing of the motor and having an inner surface continuous with the inner periphery surface of the venturi; and a web body located between the housing and the end of the web leg section on the side of the housing. Then, the axial-flow fan unit draws in air from the side of the motor and blows the air into the venturi.
In the axial-flow fan unit according to the present invention, the shape of each of the blades is so defined that a space formed between at least the inner surface of the web leg section and the edge of each of the blades located in the radially outward direction expands toward the end of the web leg section.
Incidentally, the space between the inner periphery surface of the venturi and the edge of each of the blades may be fixed. Then, the shapes of the blades may be so defined that a space formed among the inner periphery surface of the venturi, the inner surface, and the edge of each of the blades located in the radially outward direction expands toward the end of the web leg section.
In other words, the space is gradually expanding toward the end of the web leg section (or each of the web bodies) so as to reduce the noise produced when the edge of each of the blades moves along the inner surface of the web leg section.
According to the present invention, the noise produced when the blades rotates along the web leg sections with part of the blades protruding from the venturi can be greatly reduced. If the space is expanded too much, the volume of airflow is also reduced though the noise is decreased. On the contrary, if the space does not expand enough, the volume of the airflow is not reduced, but a reduction in noise becomes less. Thus, an increase in space expansion should be determined as necessary, based on the required volume of airflow and the desired reduction in noise. The reason why the noise is reduced is uncertain. However, actual tests have confirmed that the noise is reduced. According to the result of the tests, it is preferable that the shapes of the blades are so defined that an angle between the edge of each blade and an inner surface of a virtual cylinder, with which a radially outermost vertex of the edge of each blade is inscribed, becomes approximately 4° or more. If the angle is in this range, the noise can be reduced without substantially decreasing the volume of the airflow. Preferably, the major parts of the respective edges of the blades are formed to be inscribed in a common virtual cone. Generally, the edges of the blades on the side of the housing have arcs (curvatures). It is considered that the curvature of the arcs does not significantly affect the reduction of the noise so much.
Preferably, the inner surface of the web leg section is continuous with the inner periphery surface of the venturi and is curved along the inner periphery surface. In this case, the curvature of the inner surface becomes substantially the same as that of the inner periphery surface of the venturi. With this arrangement, a reduction in noise with respect to an increase in space expansion can be increased.
A heat-emitting element cooling apparatus of which the present invention aims at improvement includes: a heat sink including a base with a heat-emitting element to be cooled mounted on a rear surface thereof and a heat radiation fin group constituted by a plurality of radiation fins, fixed to the base; and an axial-flow fan unit arranged above the heat sink, for blowing air along at least the radiation fins constituting the radiation fin group to promote heat dissipation from the radiation fins. Then, the base of the heat sink has a columnar shape. Further, the radiation fins are disposed outside the base in a radial direction of the base. More specifically, the radiation fins are directly or indirectly fixed to the columnar base, and extend both in the radially outward direction of the base and the height direction of the outer periphery surface of the base or the direction extending from the fan unit to the heat sink. A preferred fan unit is the axial-flow fan unit of the present invention.
The radiation fin group in the heat sink can be constituted by: two or more space-dividing radiation fins directly extending from the outer periphery of the base in the radially outward direction, for dividing a space surrounding the outer periphery of the base into a plurality of divided spaces; and a plurality of subdividing radiation fins located within the divided spaces. A part of the subdividing radiation fins respectively extend outward from two of the space-dividing radiation fins adjacent to each other and the remaining subdividing radiation fins respectively extend outward from the outer periphery of the base arranged between two adjacent space-dividing radiation fins so that the divided spaces are further subdivided. With this arrangement, compared with the case where the radiation fins are radially arranged with respect to the base, the total surface area of the radiation fins can be increased. For this reason, the cooling performance of the apparatus can be improved.
Preferably, the subdividing radiation fins located within each of said divided spaces are inclined in a direction opposite to the rotating direction of the impeller. With this arrangement, the cooling effect of the apparatus can be enhanced. Though the reason for this is not clear, it is considered that the cooling effect can be enhanced because cooling airflow efficiently strikes the fins.
Preferably, the shapes of the two or more space dividing radiation fins may be so defined that enough heat dissipation can be performed through the subdividing radiation fins joined to the respective space dividing radiation fins.
According to the present invention, the noise produced when the blades rotate along the web leg sections with part of the blades protruding from the venturi can be greatly reduced.
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SUMMARY: BACKGROUND OF THE INVENTION
The present invention relates to an axial-flow fan unit and a heat-emitting element cooling apparatus which uses the axial-flow fan unit, for cooling a heat emitting element such as an electronic component.
Such a heat-emitting element cooling apparatus has been know that includes a heat sink having a base and a plurality of radiation fins, and a fan unit. In this apparatus, a heat-emitting element to be cooled is mounted on the rear surface of the base, and the plurality of radiation fins are fixed to the base. The fan unit is disposed above the heat sink, for blowing air along at least the radiation fins to promote heat dissipation from the radiation fins. In this heat-emitting element cooling apparatus, heat generated from the heat-emitting element is transferred from the base to the radiation fins. Then, the air flowing from the fan unit along the radiation fins carries away the heat of the radiation fins, thereby cooling the heat-emitting element.
U.S. Pat. No. 6,407,913 discloses an electronic component cooling apparatus where a heat sink provided with a plurality of radiation fins juxtaposed on a base, is cooled by a fan unit.
Japanese Patent Application No. 267093/2002 (Laid-Open Publication No. 104020/2004), which is the prior application of the applicant of the present invention, discloses an axial-flow fan unit in which the shape of a venturi is so defined that, as seen from the radially outward direction of the revolving shaft of a motor for rotating an impeller, part of a plurality of blades located on the side of the motor can be seen.
Further, U.S. Design Pat. No. 441,724 and U.S. Design Pat. No. 450,306 disclose a heat sink constituted by a radiation group comprising four space-dividing radiation fins and a plurality of subdividing radiation fins. In this heat sink, the four space-dividing radiation fins directly extend from the outer periphery of a base in the radial direction of the revolving shaft of a motor, thereby dividing a space surrounding the outer periphery of the base into four spaces. The plurality of subdividing radiation fins are located within the divided spaces in order to further subdivide the divided spaces. A part of the subdividing radiation fins respectively extend outward from two of the space-dividing radiation fins adjacent to each other, and the remaining subdividing radiation fins respectively extend outward from the outer periphery of the base located between two adjacent space-dividing radiation fins.
Like the axial-flow fan unit as shown in Japanese Patent Application No. 267093/2002 (Laid-Open Publication No. 104020/2004), in which the shape of the venturi is so defined that part of a plurality of blades located on the side of the motor can be seen as viewed from the radially outward direction of the revolving shaft of the motor for rotating the impeller, comparatively large noise might be produced.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an axial-flow fan unit that produces less noise.
Another object of the present invention is to provide a heat-emitting element cooling apparatus that has high cooling performance and also produces less noise.
An axial-flow fan unit of which the present invention aims at improvement includes: a motor having a revolving shaft; an impeller having a plurality of blades and mounted on the revolving shaft; a cylindrical venturi surrounding the impeller in the radial direction of the revolving shaft; and a plurality of webs spaced in the radial direction, for connecting the venturi to the housing of the motor. Then, the shape of the venturi is so defined that part of the blades located on the side of the housing of the motor can be seen, as viewed from the radially outward direction. Further, each of the webs includes: a web leg section extending from the end of the venturi toward a side of the housing of the motor and having an inner surface continuous with the inner periphery surface of the venturi; and a web body located between the housing and the end of the web leg section on the side of the housing. Then, the axial-flow fan unit draws in air from the side of the motor and blows the air into the venturi.
In the axial-flow fan unit according to the present invention, the shape of each of the blades is so defined that a space formed between at least the inner surface of the web leg section and the edge of each of the blades located in the radially outward direction expands toward the end of the web leg section.
Incidentally, the space between the inner periphery surface of the venturi and the edge of each of the blades may be fixed. Then, the shapes of the blades may be so defined that a space formed among the inner periphery surface of the venturi, the inner surface, and the edge of each of the blades located in the radially outward direction expands toward the end of the web leg section.
In other words, the space is gradually expanding toward the end of the web leg section (or each of the web bodies) so as to reduce the noise produced when the edge of each of the blades moves along the inner surface of the web leg section.
According to the present invention, the noise produced when the blades rotates along the web leg sections with part of the blades protruding from the venturi can be greatly reduced. If the space is expanded too much, the volume of airflow is also reduced though the noise is decreased. On the contrary, if the space does not expand enough, the volume of the airflow is not reduced, but a reduction in noise becomes less. Thus, an increase in space expansion should be determined as necessary, based on the required volume of airflow and the desired reduction in noise. The reason why the noise is reduced is uncertain. However, actual tests have confirmed that the noise is reduced. According to the result of the tests, it is preferable that the shapes of the blades are so defined that an angle between the edge of each blade and an inner surface of a virtual cylinder, with which a radially outermost vertex of the edge of each blade is inscribed, becomes approximately 4° or more. If the angle is in this range, the noise can be reduced without substantially decreasing the volume of the airflow. Preferably, the major parts of the respective edges of the blades are formed to be inscribed in a common virtual cone. Generally, the edges of the blades on the side of the housing have arcs (curvatures). It is considered that the curvature of the arcs does not significantly affect the reduction of the noise so much.
Preferably, the inner surface of the web leg section is continuous with the inner periphery surface of the venturi and is curved along the inner periphery surface. In this case, the curvature of the inner surface becomes substantially the same as that of the inner periphery surface of the venturi. With this arrangement, a reduction in noise with respect to an increase in space expansion can be increased.
A heat-emitting element cooling apparatus of which the present invention aims at improvement includes: a heat sink including a base with a heat-emitting element to be cooled mounted on a rear surface thereof and a heat radiation fin group constituted by a plurality of radiation fins, fixed to the base; and an axial-flow fan unit arranged above the heat sink, for blowing air along at least the radiation fins constituting the radiation fin group to promote heat dissipation from the radiation fins. Then, the base of the heat sink has a columnar shape. Further, the radiation fins are disposed outside the base in a radial direction of the base. More specifically, the radiation fins are directly or indirectly fixed to the columnar base, and extend both in the radially outward direction of the base and the height direction of the outer periphery surface of the base or the direction extending from the fan unit to the heat sink. A preferred fan unit is the axial-flow fan unit of the present invention.
The radiation fin group in the heat sink can be constituted by: two or more space-dividing radiation fins directly extending from the outer periphery of the base in the radially outward direction, for dividing a space surrounding the outer periphery of the base into a plurality of divided spaces; and a plurality of subdividing radiation fins located within the divided spaces. A part of the subdividing radiation fins respectively extend outward from two of the space-dividing radiation fins adjacent to each other and the remaining subdividing radiation fins respectively extend outward from the outer periphery of the base arranged between two adjacent space-dividing radiation fins so that the divided spaces are further subdivided. With this arrangement, compared with the case where the radiation fins are radially arranged with respect to the base, the total surface area of the radiation fins can be increased. For this reason, the cooling performance of the apparatus can be improved.
Preferably, the subdividing radiation fins located within each of said divided spaces are inclined in a direction opposite to the rotating direction of the impeller. With this arrangement, the cooling effect of the apparatus can be enhanced. Though the reason for this is not clear, it is considered that the cooling effect can be enhanced because cooling airflow efficiently strikes the fins.
Preferably, the shapes of the two or more space dividing radiation fins may be so defined that enough heat dissipation can be performed through the subdividing radiation fins joined to the respective space dividing radiation fins.
According to the present invention, the noise produced when the blades rotate along the web leg sections with part of the blades protruding from the venturi can be greatly reduced.
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7858239 | TECHNICAL FIELD
The present invention relates to a non-aqueous electrolyte secondary battery, specifically, a negative electrode material for a non-aqueous electrolyte secondary battery having a high input density and output density; a process of producing the negative electrode material; as well as a non-aqueous electrolyte secondary battery using the negative electrode material, specifically a non-aqueous electrolyte secondary battery for hybrid electric vehicles.
BACKGROUND ART
As a secondary battery having high energy density, a non-aqueous electrolyte lithium secondary battery using a carbonaceous material as a negative electrode has been proposed (see, for example, Patent Literature 1 to 4). This utilizes the fact that a lithium-intercalated carbon can be easily formed electrochemically. By charging this battery, the lithium in a positive electrode made of a chalcogen compound such as LiCoO2is electrochemically doped in between layers of negative electrode carbon. The lithium-doped carbon acts as a lithium electrode, and by discharging, the lithium is de-doped from between the carbon layers and is returned into a positive electrode. Since such a non-aqueous electrolyte secondary battery is small and light, and has a high energy density, demand for the battery to be used as a power source of mobile devices is expanding in recent years.
As a negative electrode material for such non-aqueous electrolyte secondary batteries used in small mobile devices, non-graphitizable carbon (also called “hard carbon”) having a discharge capacity of much more than 372 mAh/g carbon, which is the theoretical value of graphite, has been widely used. To increase the capacity, for example, a method, comprising calcinating the non-graphitizable carbon under a condition of flow of inert gas (Patent Literature 5) or under reduced pressure (Patent Literature 6) to remove gas generated in the carbonizing reaction, thereby enhancing development of pores (open pores), has been employed.
However, there was a problem in relation to the above method in that, when the thus formed non-graphitizable carbon is left to stand in the air, an oxidation reaction occurs, resulting in increase in an irreversible capacity or deterioration of cycle performances. As a solution for the problem, a method comprising storing the non-graphitizable carbon in an inert gas atmosphere (Patent Literature 7) has been proposed.
As another method for reducing deterioration of the characteristics, a method comprising depositing a thermally decomposed carbon on a carbon surface to adjust the pore size has been proposed (Patent Literature 8). However, in order to increase a discharge capacity, a large number of open pores are desired.
As a novel use exploiting the small and light character of the non-aqueous electrolyte secondary battery, those used for electric vehicles (EVs) driven by a motor alone and for hybrid electric vehicles (HEVS) combining an internal-combustion engine and a motor has been studied intensively. Among others, HEVs combining an engine and a battery-driven motor are now drawing much attention as cars achieving both economic efficiency and low fuel consumption. Especially, as for HEVs, since the start of their commercial sale in 1997, their environment-friendly concept has been accepted, and their market has been growing year by year. In these cars, since the weight saving, the input density and output density of the battery effect an improvement in fuel consumption, improvements in the characteristics of the battery to be mounted on the cars has been demanded. Some of the non-aqueous electrolyte secondary batteries are already in use for cars.
When HEVs run at a low speed or under a driving mode of low load, a load to a motor having a higher efficiency than an internal combustion engine is increased, and when the HEVs run under a driving mode at a high speed or under a high load, such as the occasion making a quick start or passing at a high speed, the load to the engine having a higher efficiency than the motor is increased. Further, when the cars brake, the motor is used as a generator, and a regenerated electric current is stored in a battery. Thus, the motor is mainly used for start, acceleration and slowdown of HEVs. It is demanded that a battery which supplies electric power to the motor does not have a high energy density to supply small electric power for a long period of time as demanded for a small mobile device, but a high input and output characteristics for supplying and receiving a large electric power in a short time.
Thus, the characteristics demanded for secondary batteries of HEVs, are different from those demanded for secondary batteries of a small mobile device. Most of the studies on negative electrode materials for non-aqueous electrolyte secondary batteries has been directed to making improvements in the characteristics of negative electrode materials of secondary batteries used as an electric source for small mobile devices. However, a negative electrode material having the necessary characteristics for a large current input/output non-aqueous electrolyte secondary batteries such as secondary batteries for HEVs has not been studied.
As a negative electrode material for non-aqueous electrolyte secondary battery having a high durability when used for a long time, and which is capable of high current input/output, a non-graphitizable carbon material whose average interlayer spacing d002is larger than that of graphite, and which has a character that an electric potential changes depending on an amount of doped lithium, is suitable, and various materials have been proposed (Patent Literature 9).
These materials have micropores. Since moisture is adsorbed in the micropores, there are problems in that an irreversible capacity is increased in initial charging, and a capacity of the battery is decreased with progress of a charge-discharge cycle. To address this problem, a method, wherein the carbon material which is once calcinated is subjected to heat treatment again so as to eliminate the adsorbed moisture, has been proposed (Patent Literature 10). However, since the moisture-adsorbing property itself of the material is not improved, there are problems in that care should be taken for the moisture absorption of the material during storage and production; and control of atmosphere is required.
To reduce molecular adsorption of a material, a material in which a thermally decomposed carbon layer is formed on the surface of the carbon particles by a chemical deposition treatment, has been proposed (Patent Literature 11). However, in large scale production, since the thermally decomposed carbon serves as a binder of carbon particles, there is a problem with regard to the production process in that the material coagulates in a reaction bath, or it is difficult to uniformly form the thermally decomposed carbon layer on a large number of particles. There is also a problem in that increase of cost for production cannot be avoided because of addition of a production step.Patent Literature 1: JP 57-208079 APatent Literature 2: JP 62-90863 APatent Literature 3: JP 62-122066 APatent Literature 4: JP 2-66856 APatent Literature 5: JP 3399015 BPatent Literature 6: JP 3427577 BPatent Literature 7: JP 8-298111 APatent Literature 8: JP 2003-3238911 APatent Literature 9: PCT/JP2005/005908Patent Literature 10: JP 3619799 BPatent Literature 11: JP 9-326254 APatent Literature 12: JP 3496901 BPatent Literature 13: JP 7-122300 A
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
A primary object of the present invention is to provide a negative electrode material for non-aqueous electrolyte secondary batteries, which material is best suited for large current input/output of non-aqueous electrolyte secondary batteries such as non-aqueous electrolyte secondary batteries for hybrid electric vehicles (HEVs), and which is unlikely to cause deterioration of battery characteristics due to moisture. A further object of the present invention is to provide a process for producing the material.
Another object of the present invention is to provide a non-aqueous electrolyte secondary battery comprising a negative electrode material which is used for non-aqueous electrolyte secondary batteries and which is unlikely to be influenced by moisture; as well as a non-aqueous electrolyte secondary battery for hybrid electric vehicles (HEVs).
Means for Solving the Problems
The charge-discharge curve of a non-aqueous electrolyte secondary battery, shown inFIG. 1, shifts to a direction of higher electric potential with respect to an open circuit voltage during charging, and shifts to a direction of lower electric potential with respect to an open circuit voltage during discharging. This potential difference is expressed by ΔV (=I(current)×R (internal resistance of battery)). When the internal resistance is constant, the larger ΔV indicates that the battery can be used under a larger electric current. The absolute value of ΔV is expressed as a difference between the upper limit electric potential and the open circuit voltage during charging, and is expressed as a difference between the lower limit electric potential and the open terminal voltage during discharging.
The various negative electrode materials for non-aqueous electrolyte secondary batteries so far proposed have been developed mainly for small mobile devices such as mobile phones and mobile personal computers. For a non-aqueous electrolyte secondary battery used in mobile devices, it is demanded that the battery discharge a small electric current from a fully charged state to the lower limit electric potential (complete discharging), and to repeat the cycle of being charged to a fully charged state and subsequent discharging. Therefore, it is demanded that the battery discharge an electric current keeping an electric potential as high as possible, and attain a change in electric potential (ΔV) as small as possible with respect to a change in a discharge capacity.
A charge-discharge curve of a non-aqueous electrolyte secondary battery for small mobile devices, which has been used, is shown as curve (1) inFIG. 1. The curve (1) is a charge-discharge curve of a non-aqueous electrolyte secondary battery for small mobile devices, which battery employs LiCoO2as a positive electrode as an active material whose change in electric potential (E) is small with respect to change in a discharge capacity (mAh), and employs graphite as a negative electrode. As seen from the curve (1), the upper limit of an electric potential is 4.1V, the lower limit of an electric potential is 3.0V, the battery voltage at the discharge ratio of 50% is 3.8V, and the battery voltage (V) is kept at a high level of not lower than 3.6 V until the discharge ratio is close to 100% of the battery voltage of 4.1V at the fully charged state. In this case, the potential difference ΔV during charging is 0.3V (4.1-3.8), and the potential difference ΔV during discharging is 0.8V (3.8-3.0).
On the other hand, curve (2) inFIG. 1is a charge-discharge curve of a large current input/output non-aqueous electrolyte secondary battery employing LiMn2O4as a positive electrode, and a hard carbon (non-graphitizable carbon) of the present invention as a negative electrode. As seen from the curve (2), the upper limit electric potential is 4.2V, the lower limit electric potential is 2.5V, the battery voltage at the discharge ratio of 50% is 3.7V, and the electric potential is decreased at almost a constant rate from the battery voltage of 4.2V at a fully charged state to that of 2.5 V at the discharge ratio of 100%. In this case, the potential difference ΔV during charging is 0.5V (4.2-3.7), and the potential difference ΔV during discharging is 1.2V (3.7-2.5). Thus, a charge-discharge behavior suitable for large current input/output, which behavior is largely different from that suitable for small current input/output for non-aqueous electrolyte secondary batteries used in small mobile devices, is observed.
The non-aqueous electrolyte secondary battery suited for high current input/output having the curve (2) is preferably used in the condition that the input and output characteristics are well balanced, that is, the charging and discharging are repeated in the charging region at about 50% when the fully charged state is taken as 100%, and is not preferably used in the condition that full charging and complete discharging are repeated. In such an embodiment, it is preferred to use a material whose electric potential (E) largely changes at a constant slope with respect to the discharge capacity (mAh), as a negative electrode material; not a material having a large discharge capacity (mAh/g) per unit weight of the active material, as demanded for the negative electrode material used in small mobile devices. Specifically, non-graphitizable carbon and easily-graphitizable carbon which are active materials having a large change in electric potential (E) with respect to the discharge capacity (mAh) can preferably be used. Non-graphitizable carbon is preferred in view of durability. Since non-graphitizable carbon has excellent input/output characteristics as a negative electrode material for high current input/output non-aqueous electrolyte secondary batteries, as well as high durability at a high temperature and high price competitiveness, it is appropriate as a negative electrode material for large current input/output non-aqueous electrolyte secondary batteries.
However, since the non-graphitizable carbon as a negative electrode material has been studied as a negative electrode material for small mobile devices, it has been studied to have a large discharge capacity, a small potential difference, and a large gas adsorption. A non-graphitizable carbon having many open pores has been proposed as a negative electrode material (Patent Literatures 5, 12 and 13). Such a non-graphitizable carbon having a number of open pores cannot show a charge-discharge behavior demanded for a negative electrode material of large current input/output non-aqueous electrolyte secondary batteries, which is shown as the curve (2) inFIG. 1. Moreover, since many open pores exist, there is a problem in that, due to high water adsorption, characteristics of the non-aqueous electrolyte secondary battery deteriorate.
As a result of intensive study for solving the problem, the present inventors discovered that water adsorption can be decreased by employing a negative electrode material having a number of closed pores. The present inventors also discovered that a negative electrode material having a number of closed pores can be produced by carbonizing a negative electrode material precursor having low oxygen content under a low inert gas flow under normal pressure or under slightly increased pressure.
That is, the present invention provides a negative electrode material for non-aqueous electrolyte secondary batteries, which the negative electrode material has at least one exothermic peak in the range of not lower than 650° C. and lower than 700° C., and at least one exothermic peak in the range of not lower than 700° C. and lower than 760° C., in differential thermal analysis measured under an air flow. The negative electrode material for non-aqueous electrolyte secondary batteries, according to the present invention, preferably has at least one exothermic peak in the range of not lower than 654° C. and lower than 690° C., and at least one exothermic peak in the range of not lower than 700° C. and lower than 758° C., more preferably has at least one exothermic peak in the range of not lower than 660° C. and lower than 690° C., and at least one exothermic peak in the range of not lower than 704° C. and lower than 758° C.
In general, the exothermic peaks measured by differential thermal analysis tend to shift to the side of high temperature as the crystallization proceeds. With the conventional non-graphitizable carbon as the negative electrode material used in small mobile devices, there is a tendency that the exothermic peaks in differential thermal analysis do not emerge in the region of not lower than 700° C. On the other hand, in the differential thermal analysis of graphite, exothermic peaks emerge in the region higher than 750° C. For example, the present inventors have confirmed that, in case of natural graphite, an exothermic peak emerges at 755.8° C., and, in case of artificial graphite, an exothermic peak emerges at 875° C. (seeFIG. 4). Therefore, the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention is thought to have a portion in which the crystallization is proceeded and a portion in which the crystallization has not proceeded, and it is thought that, in the deep portion of a negative electrode material according to the present invention, pores are developed, and that, in the surface, micro pores are closed to form closed pores.
The negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention has an average interlayer spacing d002determined by X-ray diffraction method of not less than 0.355 nm and not more than 0.400 nm, preferably not less than 0.360 nm and not more than 0.375 nm, more preferably not less than 0.365 nm and not more than 0.370 nm. If the average interlayer spacing is within this range, deterioration of the electrode due to expansion/shrinkage of the negative electrode material (carbonaceous material) caused by the repetition of charging and discharging, decrease in cycle durability at high temperature, and increase in the irreversible capacity of the active material defined as a difference between the doping capacity and dedoping capacity of the active material (e.g., lithium) constituting the positive electrode, can be prevented.
The negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention preferably satisfies at least one of the following conditions (1) and (2):(1) The true density (ρH) measured according to the gas displacement method defined in JIS R1620(4) using helium as a displacement medium is not less than 1.5 g/cm3and not more than 1.9 g/cm3, preferably not less than 1.55 g/cm3and not more than 1.85 g/cm3, more preferably not less than 1.60 g/cm3and not more than 1.80 g/cm3;(2) The equilibrium water adsorption at 120 hours later, measured according to JIS K1469, is not more than 1% by weight, preferably not less than 0.0% by weight and not more than 0.5% by weight.
Further, (3) the specific surface area measured by BET method is not less than 0.5 m2/g and not more than 5 m2/g, preferably not less than 0.8 m2/g and not more than 4 m2/g, still more preferably not less than 1.0 m2/g and not more than 3.5 m2/g, most preferably not less than 1.3 m2/g and not more than 2.5 m2/g.
(1) The true density (ρH) measured using helium as a displacement medium is an index of diffusibility of helium gas. The fact that this value is large and close to 2.0 g/cm3means that the diffusibility of helium is very high. The fact that the diffusibility of helium is high means that many open pores exist. On the other hand, since helium has the smallest atomic diameter (0.26 nm), the micro pores smaller than the atomic diameter of helium can be considered as closed pores. Thus, the fact that the diffusibility of helium gas is small means that many closed pores exist. Therefore, the true density measured using helium gas as a displacement medium is not only an index of diffusibility of helium gas, but also an index of closed pores contained in the negative electrode material according to the present invention.(2) If the equilibrium of water adsorption is within the range described above, the non-aqueous electrolyte secondary batteries according to the present invention has a low water adsorption, and deterioration of the battery performances can be prevented. The water adsorption shows good correlation with diffusibility of helium gas and the smaller the diffusibility of helium of the negative electrode material, the smaller the water adsorption.
(3) The smaller specific surface area indicates the smaller outer surface area giving the sites to which water is adsorbed, and simultaneously, it means that the edge sites in which the active material (e.g. lithium) of the positive electrode that can be doped enters are smaller, leading to deterioration of characteristics of the negative electrode. Therefore, considering the balance between the water adsorption and the doping amount of the active material, the specific surface area is preferably within the range described above.
The negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention preferably has a discharge capacity of not less than 60 mAh/g and less than 115 mAh/g per 1 g at an electric potential of 0.1V; has a discharge capacity of not less than 200 mAh/g and less than 300 mAh/g per 1 g at an electric potential of 1.5V in counter electrode lithium evaluation; and has a difference between the capacity required for lithium doping and the capacity required for lithium dedoping (irreversible capacity) not more than 60 mAh/g. Especially, the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention preferably has a difference between the capacity required for lithium doping and the capacity required for lithium dedoping (irreversible capacity) at a current density of 0.5 mA/cm2of not less than 25 mAh/g and not more than 60 mAh/g, more preferably, not less than 29 mAh/g and not more than 55 mAh/g. The irreversible capacity is defined as a difference between the charge capacity and discharge capacity, and the smaller the irreversible capacity, the higher the durability to repetition of charging and discharging. The discharge efficiency (%) (the percentage obtained by dividing the discharge capacity by the charge capacity) of the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention is preferably not less than 86%, more preferably not less than 88%.
As mentioned above, the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention shows the charge-discharge behavior as shown by the curve (2) inFIG. 1, demanded for the negative electrode material for high current input/output non-aqueous electrolyte secondary batteries. Moreover, when compared with negative electrode materials having a small interlayer spacing, the expansion/shrinkage is smaller, so that the high temperature cycle durability is excellent. When compared with negative electrode materials having a large interlayer spacing, the irreversible capacity of the active material defined as the difference between the doping capacity and dedoping capacity of the active material (such as lithium) is smaller, so that discharge efficiency is good. Further, since closed pores are abundant and open pores are few; the water adsorption is low, which can solve the problem of deterioration of the non-aqueous electrolyte secondary battery performances.
The present invention also provides a process of producing the above-described negative electrode material for non-aqueous electrolyte secondary batteries. This process is characterized by carbonizing a carbonaceous material having an oxygen content of not less than 5% by weight and less than 10% by weight, under an inert gas flow at a rate of not more than 120 ml/g·h, under a pressure of normal pressure to 10 kPa, at a temperature higher than 1100° C. and lower than 1500° C.
In the production process according to the present invention, one of the important factors for obtaining a negative electrode material which is a non-graphitizable carbon having a small diffusibility of helium is to control the oxygen content of the carbonaceous material (negative electrode material precursor) to a prescribed range. The oxygen content in the negative electrode material precursor is not less than 5% by weight and less than 10% by weight, preferably not less than 6% by weight and less than 10% by weight, more preferably not less than 7% by weight and less than 9.5% by weight. If the oxygen content in the negative electrode material precursor is less than 5% by weight, when the carbonization of the negative electrode material precursor proceeds, the average interlayer spacing becomes small, development of carbon hexagonal net plane layers is likely to occur, an easily-graphitizable carbon whose butanol true density is not less than 1.70 g/cm3is resulted; and a negative electrode material having an average interlayer spacing d002determined by X-ray diffraction method of not less than 0.355 nm and not more than 0.400 nm cannot be obtained. If the oxygen content in the negative electrode material precursor is not less than 10% by weight, a negative electrode material having a helium true density of more than 1.9 g/cm3and having a large diffusibility of helium is resulted, leading to high water adsorption. In the range of oxygen content of not less than 5% by weight and less than 7% by weight, there is a problem on production in that a large amount of tar components is generated in the carbonization reaction, and, if the temperature is quickly elevated, particles are foamed or the tar serves as a binder so that the particles are likely to be fused. Therefore, in cases where a negative electrode material precursor whose oxygen content is not less than 5% by weight and less than 7% by weight is used, a rate of elevating temperature during carbonization reaction is preferably made low. For example, the rate of elevating temperature is not less than 5° C./h and not more than 300° C./h, preferably not less than 10° C./h and not more than 100° C./h, still more preferably not less than 20° C./h and not more than 70° C./h.
The relationship between the oxygen content and the diffusibility of helium is thought to be as follows. By air-oxidizing petroleum or coal pitch which is a negative electrode material precursor to introduce oxygen-containing functional groups, a (non-meltable) negative electrode material precursor which is not melted by heating is obtained. Analysis of the gas generated during the carbonization reaction has revealed that the introduced oxygen-containing functional groups are eliminated to the outside of the system as carbon monoxide or carbon dioxide in the temperature range of not lower than 500° C. and not higher than 700° C. The oxygen-containing functional groups in the negative electrode material precursor are thought to exist in the forms of carbonyl groups, ether groups, hydroxyl groups and so on, and the negative electrode material precursor is thought to be made to a non-meltable state because these functional groups serve as crosslinking sites directly or through hydrogen bonds so as to interfere with the movements of the molecules in the petroleum or coal pitch. In the carbonaceous material in which the molecular movements are interfered by making the precursor non-meltable, development of mesophase pitch serving as a base of graphite hexagonal net plane layers is reduced, so that the precursor is made into a non-graphitizable carbon which is not graphitized even if subjected to carbonation at a temperature of not lower than 2000° C. In the pitch subjected to the treatment to make the pitch non-meltable, the carbonaceous material is solidified in the range of not lower than 500° C., and carbonization reaction occurs with the raise of treatment temperature accompanying removal of aliphatic functional groups and cyclization of carbon. It is thought that, if the oxygen content in the negative electrode material precursor is not less than 10% by weight, since the action by the oxygen-containing functional groups to interfere with the movements of the molecules in the pitch is too strong, the sites from which the oxygen-containing functional groups were removed remain as micro pores as they are, and the entrances of the pores are open (open pores), resulting in a negative electrode material having a high diffusibility of helium. On the other hand, in a material having a low oxygen content, since the average interlayer spacing between layers is smaller by weight by about 3% at the same temperature than that in the material having an oxygen content of not less than 10%, a stacking structure tends to be more easily developed. Further, since its specific surface area is small, and there is a tendency that a material has a small outer surface area, cyclic structures are likely to be easily developed during heat treatment. Further, exits of the pores generated at the sites from which the oxygen-containing functional groups were removed are closed by the cyclization reaction, so that so called closed pores are formed.
In the production process according to the present invention, one of the important factors for reducing the number of open pores existing in the surface of the negative electrode material is the atmosphere of the gas flow used in the carbonation of the negative electrode material precursor. In this process, inert gas flow rate per 1 g of the negative electrode material precursor and per 1 hour (h) is not more than 120 ml/g·h, preferably not more than 100 ml/g·h, more preferably not more than 80 ml/g·h. If the flow rate of the inert gas during carbonization is high, the low molecular gases (such as hydrogen, methane, carbon monoxide and carbon dioxide) generated from the negative electrode material precursor are quickly removed, and a negative electrode material (the conventional negative electrode material for small mobile devices) having a number of pores (open pores) whose entrances are open is likely to be formed. Such a negative electrode material has a high diffusibility of helium, and has a helium true density of more than 1.9 g/cm3. On the other hand, if the carbonization reaction is carried out under an inert gas flow having a flow rate as low as possible, it is thought that since the low molecular substances once generated from the negative electrode material are thermally decomposed again at the surface of the carbon particles to form carbon coating films, closed pores are formed. Thus obtained negative electrode materials have a low diffusibility of helium and a helium true density of not more than 1.9 g/cm3. Preferred examples of the inert gas which can be used in this process include nitrogen, argon and the like.
In the production process according to the present invention, another important factor for reducing the number of open pores existing in the surface of the negative electrode material is pressure used in the carbonization of the negative electrode material precursor. If the carbonization is carried out under reduced pressure, low molecular gases (hydrogen, methane, carbon dioxide and carbon monoxide) generated from the negative electrode material precursor are quickly aspirated and removed, so that a negative electrode material having pores (open pores) whose entrances are open is likely to be formed. On the other hand, it is thought that if the carbonization is carried out under normal pressure or under a pressure increased by 10 kPa, preferably under normal pressure or under a pressure increased by 3 kPa, more preferably under normal pressure or under a pressure increased by 1 kPa, neither aspiration nor removal of the gases proceeds, and formation of open pores is inhibited.
In the process according to the present invention, carbonization is carried out by calcinating the material at a temperature higher than 1100° C. and lower than 1500° C. under the above-described inert gas flow atmosphere having a low flow rate and under the above-described pressure atmosphere close to the normal pressure. If the temperature of carbonization is not higher than 1100° C., it is thought that the carbonization of the material does not develop sufficiently, so that lithium is trapped by the active sites originated from unsaturated bond-derived radicals existing in the carbon structure and so the irreversible capacity is increased. By using such a material as the negative electrode material, availability of the lithium existing in the battery is decreased, and the energy density of the overall battery is decreased, which are not preferred. On the other hand, if the temperature during the carbonization is not lower than 1500° C., although the carbonization reaction of the material is well developed, since the lithium-doping amount per a unit weight and per a unit volume is decreased, the energy density of the overall battery is decreased, so that it is not preferred. In an industrial process, calcination is preferably carried out, for example, under flow of an inert gas at the above-described low flow rate, in an inert gas fluidized bed, under the above-described pressure close to normal pressure, and in the state that the negative electrode material precursor is deposited to a thickness of not less than about 5 mm in a horizontal baking furnace. In small size productions, calcination can also be carried out in a closed system wherein a crucible containing the negative electrode material precursor is placed in an inert gas atmosphere. In this case, the thickness of the layer of the negative electrode material precursor in the crucible is preferably made as thick as possible.
In the production process according to the present invention, the negative electrode material precursor is preferably produced by a process comprising the steps of: (1) adding to a petroleum pitch or a coal pitch one or more aromatic compounds having a boiling point of not lower than 200° C. and having 2 or 3 rings, melt mixing the mixture under heat, and shaping the resulting mixture to obtain shaped pitch spheres enclosing the aromatic compound(s); (2) extracting and removing the enclosed aromatic compound(s) from the shaped pitch spheres by using a solvent in having a low solubility to the pitch and a high solubility to the aromatic compound(s), thereby obtaining porous shaped pitch spheres; and (3) oxidizing the obtained porous shaped pitch spheres.
In the step (1) of this production process, addition of the aromatic compound(s) is performed for the purpose of extracting and removing the aromatic compound(s) from the shaped pitch spheres to make the shaped spheres porous, making the crosslinking treatment by oxidation easy, and making the negative electrode material precursor obtained after carbonization porous. Preferred examples of the aromatic compounds which can be used in this production process include naphthalene, methylnaphthalene, phenylnaphthalene, benzylnaphthalene, methylanthracene, phenanthrene, biphenyl and the like, as well as mixtures of two or more of these compounds. The amount of the aromatic compound(s) to be added to the pitch is preferably not less than 30 parts by weight and not more than 70 parts by weight based on 100 parts by weight of the pitch.
The mixing of the pitch and the aromatic compound(s) is preferably carried out in a melted condition under heat in order to attain uniform mixing and to obtain shaped pitch spheres enclosing the aromatic compound(s). The shaping to the pitch spheres may be carried out in the melted state or by a method such as pulverizing a mixture of the pitch and the aromatic compound(s) after cooling. Thus formed shaped pitch spheres are preferably in the form of spherical particles having a particle size of not more than 1 mm, which makes the extraction and removal of the aromatic compound(s) in the step (2) easily be carried out.
Preferred examples of the solvent which can be used in the step (2) include aliphatic hydrocarbons such as butane, pentane, hexane and heptane; aliphatic alcohols such as methanol, ethanol, propanol and butanol; and naphtha, kerosine and the like. By treating the shaped pitch spheres with such a solvent, the enclosed aromatic compound(s) alone can be extracted and removed while retaining the sphericalness. Since pores from which the aromatic compound(s) was (were) eliminated in the form of being dissolved in the solvent are formed, porous shaped pitch spheres having a uniform porosity can be formed.
In the step (3), it is preferred to oxidize the porous shaped pitch spheres to make the spheres non-meltable. Oxidation of the porous shaped pitch spheres is preferably carried out using an oxidizing agent at a temperature not lower than 50° C. and not higher than 400° C. Preferred examples of the oxidizing agent include oxidative gases such as O2, O3, NO2, mixed gases obtained by diluting these gases with air or nitrogen, and air; and oxidative liquids such as sulfuric acid, nitric acid and aqueous hydrogen peroxide. In practice, to carry out the oxidation and crosslinking treatment at a temperature not lower than 120° C. and lower than 300° C., use of an oxygen-containing gas such as air or other gas, for example, a mixed gas with combustion gas or the like as an oxidizing agent is convenient and also economically advantageous. In this case, if the softening point of the pitch is low, the pitch is melted during oxidation, and oxidation becomes difficult. Therefore, a pitch having a softening point not lower than 150° C. is preferably employed.
The present invention also provides a negative electrode comprising the above-described negative electrode material for non-aqueous electrolyte secondary batteries. The present invention further provides a non-aqueous electrolyte secondary battery comprising the negative electrode; a positive electrode containing a lithium composite oxide as a positive electrode; and a non-aqueous electrolyte.
The negative electrode according to the present invention can be prepared by adding to the negative electrode material for non-aqueous electrolyte secondary batteries a binder alone or a combination of the binder and an electroconductive assistant comprising an electroconductive carbon black such as acetylene black or furnace black in an amount of not less than 1% by weight and not more than 10% by weight based on the negative electrode material; adding an appropriate solvent in an appropriate amount; kneading the resulting mixture to obtain an electrode blend paste; applying the prepared paste on an electroconductive collector material such as a circular or rectangular metal plate and drying the paste; and then pressure-shaping the dried paste to form a layer with a desired thickness, for example, not less than 10 μm and not more than 100 μm.
As a binder, any material which does not react with the electrolytic solution, such as polyvinylidene fluoride, polytetrafluoroethylene or SBR (styrene-butadiene copolymer rubber), can be employed without limitation. In cases where polyvinylidene fluoride is used as the binder, a polar solvent such as N-methylpyrrolidone (NMP) can preferably be employed. In cases where an aqueous emulsion such as SBR is used as an interparticle binder, water can also be employed as a solvent. The amount of the binder is preferably in the range of not less than 0.5 parts by weight and not more than 10 parts by weight based on 100 parts by weight of the negative electrode material. If the amount of the added binder is too great, both the electric resistance of the obtained electrode and the internal resistance of the battery become high, and the battery performances deteriorate. On the other hand, if the amount of the added binder is too small, the binding between the particles constituting the negative electrode material and between the particle and the collector material, is insufficient.
The positive electrode of the non-aqueous electrolyte secondary battery of the present invention preferably contains a lithium composite oxide as a positive electrode active material. Preferred examples of the lithium composite oxide which can be used include composite metal chalcogenides such as LiCoO2, LiNiO2, LiMnO2and LiMn2O4. The positive electrode can be formed by an ordinary forming method wherein the active material is shaped together with an appropriate binder and a carbon material for giving electro conductivity to the electrode, to form a layer on an electroconductive collector material.
As the electrolytic solution of the non-aqueous electrolyte secondary battery of the present invention, an ordinary non-aqueous electrolytic solution can be used. The non-aqueous electrolytic solution can be formed by dissolving an electrolyte in a non-aqueous solvent. As the non-aqueous solvent, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, dimethoxyethane, diethoxyethane, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, sulfolan or 1,3-dioxolane, can be employed alone or in combination of two or more of these solvents. As the electrolyte, LiClO4, LiPF6, LiBF4, LiCF3SO3, LiAsF6, LiCl, LiBr, LiB(C6H5)5, LiN(SO3CF3)2or the like can be used.
The non-aqueous electrolyte secondary battery according to the present invention may be formed by arranging the above-described negative electrode and positive electrode such that they face each other via a separator, and immersing the resultant in an electrolytic solution. As a separator, a liquid-permeable separator made of a non-woven fabric or other porous material, usually used in secondary batteries, can be used. Alternatively, in place of the separator, or together with the separator, a solid electrolyte made of a polymer gel in which an electrolytic solution is immersed, can also be used.
The non-aqueous electrolyte secondary battery according to the present invention can preferably be used as a non-aqueous electrolyte secondary battery for hybrid electric vehicles.
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SUMMARY: TECHNICAL FIELD
The present invention relates to a non-aqueous electrolyte secondary battery, specifically, a negative electrode material for a non-aqueous electrolyte secondary battery having a high input density and output density; a process of producing the negative electrode material; as well as a non-aqueous electrolyte secondary battery using the negative electrode material, specifically a non-aqueous electrolyte secondary battery for hybrid electric vehicles.
BACKGROUND ART
As a secondary battery having high energy density, a non-aqueous electrolyte lithium secondary battery using a carbonaceous material as a negative electrode has been proposed (see, for example, Patent Literature 1 to 4). This utilizes the fact that a lithium-intercalated carbon can be easily formed electrochemically. By charging this battery, the lithium in a positive electrode made of a chalcogen compound such as LiCoO2is electrochemically doped in between layers of negative electrode carbon. The lithium-doped carbon acts as a lithium electrode, and by discharging, the lithium is de-doped from between the carbon layers and is returned into a positive electrode. Since such a non-aqueous electrolyte secondary battery is small and light, and has a high energy density, demand for the battery to be used as a power source of mobile devices is expanding in recent years.
As a negative electrode material for such non-aqueous electrolyte secondary batteries used in small mobile devices, non-graphitizable carbon (also called “hard carbon”) having a discharge capacity of much more than 372 mAh/g carbon, which is the theoretical value of graphite, has been widely used. To increase the capacity, for example, a method, comprising calcinating the non-graphitizable carbon under a condition of flow of inert gas (Patent Literature 5) or under reduced pressure (Patent Literature 6) to remove gas generated in the carbonizing reaction, thereby enhancing development of pores (open pores), has been employed.
However, there was a problem in relation to the above method in that, when the thus formed non-graphitizable carbon is left to stand in the air, an oxidation reaction occurs, resulting in increase in an irreversible capacity or deterioration of cycle performances. As a solution for the problem, a method comprising storing the non-graphitizable carbon in an inert gas atmosphere (Patent Literature 7) has been proposed.
As another method for reducing deterioration of the characteristics, a method comprising depositing a thermally decomposed carbon on a carbon surface to adjust the pore size has been proposed (Patent Literature 8). However, in order to increase a discharge capacity, a large number of open pores are desired.
As a novel use exploiting the small and light character of the non-aqueous electrolyte secondary battery, those used for electric vehicles (EVs) driven by a motor alone and for hybrid electric vehicles (HEVS) combining an internal-combustion engine and a motor has been studied intensively. Among others, HEVs combining an engine and a battery-driven motor are now drawing much attention as cars achieving both economic efficiency and low fuel consumption. Especially, as for HEVs, since the start of their commercial sale in 1997, their environment-friendly concept has been accepted, and their market has been growing year by year. In these cars, since the weight saving, the input density and output density of the battery effect an improvement in fuel consumption, improvements in the characteristics of the battery to be mounted on the cars has been demanded. Some of the non-aqueous electrolyte secondary batteries are already in use for cars.
When HEVs run at a low speed or under a driving mode of low load, a load to a motor having a higher efficiency than an internal combustion engine is increased, and when the HEVs run under a driving mode at a high speed or under a high load, such as the occasion making a quick start or passing at a high speed, the load to the engine having a higher efficiency than the motor is increased. Further, when the cars brake, the motor is used as a generator, and a regenerated electric current is stored in a battery. Thus, the motor is mainly used for start, acceleration and slowdown of HEVs. It is demanded that a battery which supplies electric power to the motor does not have a high energy density to supply small electric power for a long period of time as demanded for a small mobile device, but a high input and output characteristics for supplying and receiving a large electric power in a short time.
Thus, the characteristics demanded for secondary batteries of HEVs, are different from those demanded for secondary batteries of a small mobile device. Most of the studies on negative electrode materials for non-aqueous electrolyte secondary batteries has been directed to making improvements in the characteristics of negative electrode materials of secondary batteries used as an electric source for small mobile devices. However, a negative electrode material having the necessary characteristics for a large current input/output non-aqueous electrolyte secondary batteries such as secondary batteries for HEVs has not been studied.
As a negative electrode material for non-aqueous electrolyte secondary battery having a high durability when used for a long time, and which is capable of high current input/output, a non-graphitizable carbon material whose average interlayer spacing d002is larger than that of graphite, and which has a character that an electric potential changes depending on an amount of doped lithium, is suitable, and various materials have been proposed (Patent Literature 9).
These materials have micropores. Since moisture is adsorbed in the micropores, there are problems in that an irreversible capacity is increased in initial charging, and a capacity of the battery is decreased with progress of a charge-discharge cycle. To address this problem, a method, wherein the carbon material which is once calcinated is subjected to heat treatment again so as to eliminate the adsorbed moisture, has been proposed (Patent Literature 10). However, since the moisture-adsorbing property itself of the material is not improved, there are problems in that care should be taken for the moisture absorption of the material during storage and production; and control of atmosphere is required.
To reduce molecular adsorption of a material, a material in which a thermally decomposed carbon layer is formed on the surface of the carbon particles by a chemical deposition treatment, has been proposed (Patent Literature 11). However, in large scale production, since the thermally decomposed carbon serves as a binder of carbon particles, there is a problem with regard to the production process in that the material coagulates in a reaction bath, or it is difficult to uniformly form the thermally decomposed carbon layer on a large number of particles. There is also a problem in that increase of cost for production cannot be avoided because of addition of a production step.Patent Literature 1: JP 57-208079 APatent Literature 2: JP 62-90863 APatent Literature 3: JP 62-122066 APatent Literature 4: JP 2-66856 APatent Literature 5: JP 3399015 BPatent Literature 6: JP 3427577 BPatent Literature 7: JP 8-298111 APatent Literature 8: JP 2003-3238911 APatent Literature 9: PCT/JP2005/005908Patent Literature 10: JP 3619799 BPatent Literature 11: JP 9-326254 APatent Literature 12: JP 3496901 BPatent Literature 13: JP 7-122300 A
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
A primary object of the present invention is to provide a negative electrode material for non-aqueous electrolyte secondary batteries, which material is best suited for large current input/output of non-aqueous electrolyte secondary batteries such as non-aqueous electrolyte secondary batteries for hybrid electric vehicles (HEVs), and which is unlikely to cause deterioration of battery characteristics due to moisture. A further object of the present invention is to provide a process for producing the material.
Another object of the present invention is to provide a non-aqueous electrolyte secondary battery comprising a negative electrode material which is used for non-aqueous electrolyte secondary batteries and which is unlikely to be influenced by moisture; as well as a non-aqueous electrolyte secondary battery for hybrid electric vehicles (HEVs).
Means for Solving the Problems
The charge-discharge curve of a non-aqueous electrolyte secondary battery, shown inFIG. 1, shifts to a direction of higher electric potential with respect to an open circuit voltage during charging, and shifts to a direction of lower electric potential with respect to an open circuit voltage during discharging. This potential difference is expressed by ΔV (=I(current)×R (internal resistance of battery)). When the internal resistance is constant, the larger ΔV indicates that the battery can be used under a larger electric current. The absolute value of ΔV is expressed as a difference between the upper limit electric potential and the open circuit voltage during charging, and is expressed as a difference between the lower limit electric potential and the open terminal voltage during discharging.
The various negative electrode materials for non-aqueous electrolyte secondary batteries so far proposed have been developed mainly for small mobile devices such as mobile phones and mobile personal computers. For a non-aqueous electrolyte secondary battery used in mobile devices, it is demanded that the battery discharge a small electric current from a fully charged state to the lower limit electric potential (complete discharging), and to repeat the cycle of being charged to a fully charged state and subsequent discharging. Therefore, it is demanded that the battery discharge an electric current keeping an electric potential as high as possible, and attain a change in electric potential (ΔV) as small as possible with respect to a change in a discharge capacity.
A charge-discharge curve of a non-aqueous electrolyte secondary battery for small mobile devices, which has been used, is shown as curve (1) inFIG. 1. The curve (1) is a charge-discharge curve of a non-aqueous electrolyte secondary battery for small mobile devices, which battery employs LiCoO2as a positive electrode as an active material whose change in electric potential (E) is small with respect to change in a discharge capacity (mAh), and employs graphite as a negative electrode. As seen from the curve (1), the upper limit of an electric potential is 4.1V, the lower limit of an electric potential is 3.0V, the battery voltage at the discharge ratio of 50% is 3.8V, and the battery voltage (V) is kept at a high level of not lower than 3.6 V until the discharge ratio is close to 100% of the battery voltage of 4.1V at the fully charged state. In this case, the potential difference ΔV during charging is 0.3V (4.1-3.8), and the potential difference ΔV during discharging is 0.8V (3.8-3.0).
On the other hand, curve (2) inFIG. 1is a charge-discharge curve of a large current input/output non-aqueous electrolyte secondary battery employing LiMn2O4as a positive electrode, and a hard carbon (non-graphitizable carbon) of the present invention as a negative electrode. As seen from the curve (2), the upper limit electric potential is 4.2V, the lower limit electric potential is 2.5V, the battery voltage at the discharge ratio of 50% is 3.7V, and the electric potential is decreased at almost a constant rate from the battery voltage of 4.2V at a fully charged state to that of 2.5 V at the discharge ratio of 100%. In this case, the potential difference ΔV during charging is 0.5V (4.2-3.7), and the potential difference ΔV during discharging is 1.2V (3.7-2.5). Thus, a charge-discharge behavior suitable for large current input/output, which behavior is largely different from that suitable for small current input/output for non-aqueous electrolyte secondary batteries used in small mobile devices, is observed.
The non-aqueous electrolyte secondary battery suited for high current input/output having the curve (2) is preferably used in the condition that the input and output characteristics are well balanced, that is, the charging and discharging are repeated in the charging region at about 50% when the fully charged state is taken as 100%, and is not preferably used in the condition that full charging and complete discharging are repeated. In such an embodiment, it is preferred to use a material whose electric potential (E) largely changes at a constant slope with respect to the discharge capacity (mAh), as a negative electrode material; not a material having a large discharge capacity (mAh/g) per unit weight of the active material, as demanded for the negative electrode material used in small mobile devices. Specifically, non-graphitizable carbon and easily-graphitizable carbon which are active materials having a large change in electric potential (E) with respect to the discharge capacity (mAh) can preferably be used. Non-graphitizable carbon is preferred in view of durability. Since non-graphitizable carbon has excellent input/output characteristics as a negative electrode material for high current input/output non-aqueous electrolyte secondary batteries, as well as high durability at a high temperature and high price competitiveness, it is appropriate as a negative electrode material for large current input/output non-aqueous electrolyte secondary batteries.
However, since the non-graphitizable carbon as a negative electrode material has been studied as a negative electrode material for small mobile devices, it has been studied to have a large discharge capacity, a small potential difference, and a large gas adsorption. A non-graphitizable carbon having many open pores has been proposed as a negative electrode material (Patent Literatures 5, 12 and 13). Such a non-graphitizable carbon having a number of open pores cannot show a charge-discharge behavior demanded for a negative electrode material of large current input/output non-aqueous electrolyte secondary batteries, which is shown as the curve (2) inFIG. 1. Moreover, since many open pores exist, there is a problem in that, due to high water adsorption, characteristics of the non-aqueous electrolyte secondary battery deteriorate.
As a result of intensive study for solving the problem, the present inventors discovered that water adsorption can be decreased by employing a negative electrode material having a number of closed pores. The present inventors also discovered that a negative electrode material having a number of closed pores can be produced by carbonizing a negative electrode material precursor having low oxygen content under a low inert gas flow under normal pressure or under slightly increased pressure.
That is, the present invention provides a negative electrode material for non-aqueous electrolyte secondary batteries, which the negative electrode material has at least one exothermic peak in the range of not lower than 650° C. and lower than 700° C., and at least one exothermic peak in the range of not lower than 700° C. and lower than 760° C., in differential thermal analysis measured under an air flow. The negative electrode material for non-aqueous electrolyte secondary batteries, according to the present invention, preferably has at least one exothermic peak in the range of not lower than 654° C. and lower than 690° C., and at least one exothermic peak in the range of not lower than 700° C. and lower than 758° C., more preferably has at least one exothermic peak in the range of not lower than 660° C. and lower than 690° C., and at least one exothermic peak in the range of not lower than 704° C. and lower than 758° C.
In general, the exothermic peaks measured by differential thermal analysis tend to shift to the side of high temperature as the crystallization proceeds. With the conventional non-graphitizable carbon as the negative electrode material used in small mobile devices, there is a tendency that the exothermic peaks in differential thermal analysis do not emerge in the region of not lower than 700° C. On the other hand, in the differential thermal analysis of graphite, exothermic peaks emerge in the region higher than 750° C. For example, the present inventors have confirmed that, in case of natural graphite, an exothermic peak emerges at 755.8° C., and, in case of artificial graphite, an exothermic peak emerges at 875° C. (seeFIG. 4). Therefore, the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention is thought to have a portion in which the crystallization is proceeded and a portion in which the crystallization has not proceeded, and it is thought that, in the deep portion of a negative electrode material according to the present invention, pores are developed, and that, in the surface, micro pores are closed to form closed pores.
The negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention has an average interlayer spacing d002determined by X-ray diffraction method of not less than 0.355 nm and not more than 0.400 nm, preferably not less than 0.360 nm and not more than 0.375 nm, more preferably not less than 0.365 nm and not more than 0.370 nm. If the average interlayer spacing is within this range, deterioration of the electrode due to expansion/shrinkage of the negative electrode material (carbonaceous material) caused by the repetition of charging and discharging, decrease in cycle durability at high temperature, and increase in the irreversible capacity of the active material defined as a difference between the doping capacity and dedoping capacity of the active material (e.g., lithium) constituting the positive electrode, can be prevented.
The negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention preferably satisfies at least one of the following conditions (1) and (2):(1) The true density (ρH) measured according to the gas displacement method defined in JIS R1620(4) using helium as a displacement medium is not less than 1.5 g/cm3and not more than 1.9 g/cm3, preferably not less than 1.55 g/cm3and not more than 1.85 g/cm3, more preferably not less than 1.60 g/cm3and not more than 1.80 g/cm3;(2) The equilibrium water adsorption at 120 hours later, measured according to JIS K1469, is not more than 1% by weight, preferably not less than 0.0% by weight and not more than 0.5% by weight.
Further, (3) the specific surface area measured by BET method is not less than 0.5 m2/g and not more than 5 m2/g, preferably not less than 0.8 m2/g and not more than 4 m2/g, still more preferably not less than 1.0 m2/g and not more than 3.5 m2/g, most preferably not less than 1.3 m2/g and not more than 2.5 m2/g.
(1) The true density (ρH) measured using helium as a displacement medium is an index of diffusibility of helium gas. The fact that this value is large and close to 2.0 g/cm3means that the diffusibility of helium is very high. The fact that the diffusibility of helium is high means that many open pores exist. On the other hand, since helium has the smallest atomic diameter (0.26 nm), the micro pores smaller than the atomic diameter of helium can be considered as closed pores. Thus, the fact that the diffusibility of helium gas is small means that many closed pores exist. Therefore, the true density measured using helium gas as a displacement medium is not only an index of diffusibility of helium gas, but also an index of closed pores contained in the negative electrode material according to the present invention.(2) If the equilibrium of water adsorption is within the range described above, the non-aqueous electrolyte secondary batteries according to the present invention has a low water adsorption, and deterioration of the battery performances can be prevented. The water adsorption shows good correlation with diffusibility of helium gas and the smaller the diffusibility of helium of the negative electrode material, the smaller the water adsorption.
(3) The smaller specific surface area indicates the smaller outer surface area giving the sites to which water is adsorbed, and simultaneously, it means that the edge sites in which the active material (e.g. lithium) of the positive electrode that can be doped enters are smaller, leading to deterioration of characteristics of the negative electrode. Therefore, considering the balance between the water adsorption and the doping amount of the active material, the specific surface area is preferably within the range described above.
The negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention preferably has a discharge capacity of not less than 60 mAh/g and less than 115 mAh/g per 1 g at an electric potential of 0.1V; has a discharge capacity of not less than 200 mAh/g and less than 300 mAh/g per 1 g at an electric potential of 1.5V in counter electrode lithium evaluation; and has a difference between the capacity required for lithium doping and the capacity required for lithium dedoping (irreversible capacity) not more than 60 mAh/g. Especially, the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention preferably has a difference between the capacity required for lithium doping and the capacity required for lithium dedoping (irreversible capacity) at a current density of 0.5 mA/cm2of not less than 25 mAh/g and not more than 60 mAh/g, more preferably, not less than 29 mAh/g and not more than 55 mAh/g. The irreversible capacity is defined as a difference between the charge capacity and discharge capacity, and the smaller the irreversible capacity, the higher the durability to repetition of charging and discharging. The discharge efficiency (%) (the percentage obtained by dividing the discharge capacity by the charge capacity) of the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention is preferably not less than 86%, more preferably not less than 88%.
As mentioned above, the negative electrode material for non-aqueous electrolyte secondary batteries according to the present invention shows the charge-discharge behavior as shown by the curve (2) inFIG. 1, demanded for the negative electrode material for high current input/output non-aqueous electrolyte secondary batteries. Moreover, when compared with negative electrode materials having a small interlayer spacing, the expansion/shrinkage is smaller, so that the high temperature cycle durability is excellent. When compared with negative electrode materials having a large interlayer spacing, the irreversible capacity of the active material defined as the difference between the doping capacity and dedoping capacity of the active material (such as lithium) is smaller, so that discharge efficiency is good. Further, since closed pores are abundant and open pores are few; the water adsorption is low, which can solve the problem of deterioration of the non-aqueous electrolyte secondary battery performances.
The present invention also provides a process of producing the above-described negative electrode material for non-aqueous electrolyte secondary batteries. This process is characterized by carbonizing a carbonaceous material having an oxygen content of not less than 5% by weight and less than 10% by weight, under an inert gas flow at a rate of not more than 120 ml/g·h, under a pressure of normal pressure to 10 kPa, at a temperature higher than 1100° C. and lower than 1500° C.
In the production process according to the present invention, one of the important factors for obtaining a negative electrode material which is a non-graphitizable carbon having a small diffusibility of helium is to control the oxygen content of the carbonaceous material (negative electrode material precursor) to a prescribed range. The oxygen content in the negative electrode material precursor is not less than 5% by weight and less than 10% by weight, preferably not less than 6% by weight and less than 10% by weight, more preferably not less than 7% by weight and less than 9.5% by weight. If the oxygen content in the negative electrode material precursor is less than 5% by weight, when the carbonization of the negative electrode material precursor proceeds, the average interlayer spacing becomes small, development of carbon hexagonal net plane layers is likely to occur, an easily-graphitizable carbon whose butanol true density is not less than 1.70 g/cm3is resulted; and a negative electrode material having an average interlayer spacing d002determined by X-ray diffraction method of not less than 0.355 nm and not more than 0.400 nm cannot be obtained. If the oxygen content in the negative electrode material precursor is not less than 10% by weight, a negative electrode material having a helium true density of more than 1.9 g/cm3and having a large diffusibility of helium is resulted, leading to high water adsorption. In the range of oxygen content of not less than 5% by weight and less than 7% by weight, there is a problem on production in that a large amount of tar components is generated in the carbonization reaction, and, if the temperature is quickly elevated, particles are foamed or the tar serves as a binder so that the particles are likely to be fused. Therefore, in cases where a negative electrode material precursor whose oxygen content is not less than 5% by weight and less than 7% by weight is used, a rate of elevating temperature during carbonization reaction is preferably made low. For example, the rate of elevating temperature is not less than 5° C./h and not more than 300° C./h, preferably not less than 10° C./h and not more than 100° C./h, still more preferably not less than 20° C./h and not more than 70° C./h.
The relationship between the oxygen content and the diffusibility of helium is thought to be as follows. By air-oxidizing petroleum or coal pitch which is a negative electrode material precursor to introduce oxygen-containing functional groups, a (non-meltable) negative electrode material precursor which is not melted by heating is obtained. Analysis of the gas generated during the carbonization reaction has revealed that the introduced oxygen-containing functional groups are eliminated to the outside of the system as carbon monoxide or carbon dioxide in the temperature range of not lower than 500° C. and not higher than 700° C. The oxygen-containing functional groups in the negative electrode material precursor are thought to exist in the forms of carbonyl groups, ether groups, hydroxyl groups and so on, and the negative electrode material precursor is thought to be made to a non-meltable state because these functional groups serve as crosslinking sites directly or through hydrogen bonds so as to interfere with the movements of the molecules in the petroleum or coal pitch. In the carbonaceous material in which the molecular movements are interfered by making the precursor non-meltable, development of mesophase pitch serving as a base of graphite hexagonal net plane layers is reduced, so that the precursor is made into a non-graphitizable carbon which is not graphitized even if subjected to carbonation at a temperature of not lower than 2000° C. In the pitch subjected to the treatment to make the pitch non-meltable, the carbonaceous material is solidified in the range of not lower than 500° C., and carbonization reaction occurs with the raise of treatment temperature accompanying removal of aliphatic functional groups and cyclization of carbon. It is thought that, if the oxygen content in the negative electrode material precursor is not less than 10% by weight, since the action by the oxygen-containing functional groups to interfere with the movements of the molecules in the pitch is too strong, the sites from which the oxygen-containing functional groups were removed remain as micro pores as they are, and the entrances of the pores are open (open pores), resulting in a negative electrode material having a high diffusibility of helium. On the other hand, in a material having a low oxygen content, since the average interlayer spacing between layers is smaller by weight by about 3% at the same temperature than that in the material having an oxygen content of not less than 10%, a stacking structure tends to be more easily developed. Further, since its specific surface area is small, and there is a tendency that a material has a small outer surface area, cyclic structures are likely to be easily developed during heat treatment. Further, exits of the pores generated at the sites from which the oxygen-containing functional groups were removed are closed by the cyclization reaction, so that so called closed pores are formed.
In the production process according to the present invention, one of the important factors for reducing the number of open pores existing in the surface of the negative electrode material is the atmosphere of the gas flow used in the carbonation of the negative electrode material precursor. In this process, inert gas flow rate per 1 g of the negative electrode material precursor and per 1 hour (h) is not more than 120 ml/g·h, preferably not more than 100 ml/g·h, more preferably not more than 80 ml/g·h. If the flow rate of the inert gas during carbonization is high, the low molecular gases (such as hydrogen, methane, carbon monoxide and carbon dioxide) generated from the negative electrode material precursor are quickly removed, and a negative electrode material (the conventional negative electrode material for small mobile devices) having a number of pores (open pores) whose entrances are open is likely to be formed. Such a negative electrode material has a high diffusibility of helium, and has a helium true density of more than 1.9 g/cm3. On the other hand, if the carbonization reaction is carried out under an inert gas flow having a flow rate as low as possible, it is thought that since the low molecular substances once generated from the negative electrode material are thermally decomposed again at the surface of the carbon particles to form carbon coating films, closed pores are formed. Thus obtained negative electrode materials have a low diffusibility of helium and a helium true density of not more than 1.9 g/cm3. Preferred examples of the inert gas which can be used in this process include nitrogen, argon and the like.
In the production process according to the present invention, another important factor for reducing the number of open pores existing in the surface of the negative electrode material is pressure used in the carbonization of the negative electrode material precursor. If the carbonization is carried out under reduced pressure, low molecular gases (hydrogen, methane, carbon dioxide and carbon monoxide) generated from the negative electrode material precursor are quickly aspirated and removed, so that a negative electrode material having pores (open pores) whose entrances are open is likely to be formed. On the other hand, it is thought that if the carbonization is carried out under normal pressure or under a pressure increased by 10 kPa, preferably under normal pressure or under a pressure increased by 3 kPa, more preferably under normal pressure or under a pressure increased by 1 kPa, neither aspiration nor removal of the gases proceeds, and formation of open pores is inhibited.
In the process according to the present invention, carbonization is carried out by calcinating the material at a temperature higher than 1100° C. and lower than 1500° C. under the above-described inert gas flow atmosphere having a low flow rate and under the above-described pressure atmosphere close to the normal pressure. If the temperature of carbonization is not higher than 1100° C., it is thought that the carbonization of the material does not develop sufficiently, so that lithium is trapped by the active sites originated from unsaturated bond-derived radicals existing in the carbon structure and so the irreversible capacity is increased. By using such a material as the negative electrode material, availability of the lithium existing in the battery is decreased, and the energy density of the overall battery is decreased, which are not preferred. On the other hand, if the temperature during the carbonization is not lower than 1500° C., although the carbonization reaction of the material is well developed, since the lithium-doping amount per a unit weight and per a unit volume is decreased, the energy density of the overall battery is decreased, so that it is not preferred. In an industrial process, calcination is preferably carried out, for example, under flow of an inert gas at the above-described low flow rate, in an inert gas fluidized bed, under the above-described pressure close to normal pressure, and in the state that the negative electrode material precursor is deposited to a thickness of not less than about 5 mm in a horizontal baking furnace. In small size productions, calcination can also be carried out in a closed system wherein a crucible containing the negative electrode material precursor is placed in an inert gas atmosphere. In this case, the thickness of the layer of the negative electrode material precursor in the crucible is preferably made as thick as possible.
In the production process according to the present invention, the negative electrode material precursor is preferably produced by a process comprising the steps of: (1) adding to a petroleum pitch or a coal pitch one or more aromatic compounds having a boiling point of not lower than 200° C. and having 2 or 3 rings, melt mixing the mixture under heat, and shaping the resulting mixture to obtain shaped pitch spheres enclosing the aromatic compound(s); (2) extracting and removing the enclosed aromatic compound(s) from the shaped pitch spheres by using a solvent in having a low solubility to the pitch and a high solubility to the aromatic compound(s), thereby obtaining porous shaped pitch spheres; and (3) oxidizing the obtained porous shaped pitch spheres.
In the step (1) of this production process, addition of the aromatic compound(s) is performed for the purpose of extracting and removing the aromatic compound(s) from the shaped pitch spheres to make the shaped spheres porous, making the crosslinking treatment by oxidation easy, and making the negative electrode material precursor obtained after carbonization porous. Preferred examples of the aromatic compounds which can be used in this production process include naphthalene, methylnaphthalene, phenylnaphthalene, benzylnaphthalene, methylanthracene, phenanthrene, biphenyl and the like, as well as mixtures of two or more of these compounds. The amount of the aromatic compound(s) to be added to the pitch is preferably not less than 30 parts by weight and not more than 70 parts by weight based on 100 parts by weight of the pitch.
The mixing of the pitch and the aromatic compound(s) is preferably carried out in a melted condition under heat in order to attain uniform mixing and to obtain shaped pitch spheres enclosing the aromatic compound(s). The shaping to the pitch spheres may be carried out in the melted state or by a method such as pulverizing a mixture of the pitch and the aromatic compound(s) after cooling. Thus formed shaped pitch spheres are preferably in the form of spherical particles having a particle size of not more than 1 mm, which makes the extraction and removal of the aromatic compound(s) in the step (2) easily be carried out.
Preferred examples of the solvent which can be used in the step (2) include aliphatic hydrocarbons such as butane, pentane, hexane and heptane; aliphatic alcohols such as methanol, ethanol, propanol and butanol; and naphtha, kerosine and the like. By treating the shaped pitch spheres with such a solvent, the enclosed aromatic compound(s) alone can be extracted and removed while retaining the sphericalness. Since pores from which the aromatic compound(s) was (were) eliminated in the form of being dissolved in the solvent are formed, porous shaped pitch spheres having a uniform porosity can be formed.
In the step (3), it is preferred to oxidize the porous shaped pitch spheres to make the spheres non-meltable. Oxidation of the porous shaped pitch spheres is preferably carried out using an oxidizing agent at a temperature not lower than 50° C. and not higher than 400° C. Preferred examples of the oxidizing agent include oxidative gases such as O2, O3, NO2, mixed gases obtained by diluting these gases with air or nitrogen, and air; and oxidative liquids such as sulfuric acid, nitric acid and aqueous hydrogen peroxide. In practice, to carry out the oxidation and crosslinking treatment at a temperature not lower than 120° C. and lower than 300° C., use of an oxygen-containing gas such as air or other gas, for example, a mixed gas with combustion gas or the like as an oxidizing agent is convenient and also economically advantageous. In this case, if the softening point of the pitch is low, the pitch is melted during oxidation, and oxidation becomes difficult. Therefore, a pitch having a softening point not lower than 150° C. is preferably employed.
The present invention also provides a negative electrode comprising the above-described negative electrode material for non-aqueous electrolyte secondary batteries. The present invention further provides a non-aqueous electrolyte secondary battery comprising the negative electrode; a positive electrode containing a lithium composite oxide as a positive electrode; and a non-aqueous electrolyte.
The negative electrode according to the present invention can be prepared by adding to the negative electrode material for non-aqueous electrolyte secondary batteries a binder alone or a combination of the binder and an electroconductive assistant comprising an electroconductive carbon black such as acetylene black or furnace black in an amount of not less than 1% by weight and not more than 10% by weight based on the negative electrode material; adding an appropriate solvent in an appropriate amount; kneading the resulting mixture to obtain an electrode blend paste; applying the prepared paste on an electroconductive collector material such as a circular or rectangular metal plate and drying the paste; and then pressure-shaping the dried paste to form a layer with a desired thickness, for example, not less than 10 μm and not more than 100 μm.
As a binder, any material which does not react with the electrolytic solution, such as polyvinylidene fluoride, polytetrafluoroethylene or SBR (styrene-butadiene copolymer rubber), can be employed without limitation. In cases where polyvinylidene fluoride is used as the binder, a polar solvent such as N-methylpyrrolidone (NMP) can preferably be employed. In cases where an aqueous emulsion such as SBR is used as an interparticle binder, water can also be employed as a solvent. The amount of the binder is preferably in the range of not less than 0.5 parts by weight and not more than 10 parts by weight based on 100 parts by weight of the negative electrode material. If the amount of the added binder is too great, both the electric resistance of the obtained electrode and the internal resistance of the battery become high, and the battery performances deteriorate. On the other hand, if the amount of the added binder is too small, the binding between the particles constituting the negative electrode material and between the particle and the collector material, is insufficient.
The positive electrode of the non-aqueous electrolyte secondary battery of the present invention preferably contains a lithium composite oxide as a positive electrode active material. Preferred examples of the lithium composite oxide which can be used include composite metal chalcogenides such as LiCoO2, LiNiO2, LiMnO2and LiMn2O4. The positive electrode can be formed by an ordinary forming method wherein the active material is shaped together with an appropriate binder and a carbon material for giving electro conductivity to the electrode, to form a layer on an electroconductive collector material.
As the electrolytic solution of the non-aqueous electrolyte secondary battery of the present invention, an ordinary non-aqueous electrolytic solution can be used. The non-aqueous electrolytic solution can be formed by dissolving an electrolyte in a non-aqueous solvent. As the non-aqueous solvent, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, dimethoxyethane, diethoxyethane, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, sulfolan or 1,3-dioxolane, can be employed alone or in combination of two or more of these solvents. As the electrolyte, LiClO4, LiPF6, LiBF4, LiCF3SO3, LiAsF6, LiCl, LiBr, LiB(C6H5)5, LiN(SO3CF3)2or the like can be used.
The non-aqueous electrolyte secondary battery according to the present invention may be formed by arranging the above-described negative electrode and positive electrode such that they face each other via a separator, and immersing the resultant in an electrolytic solution. As a separator, a liquid-permeable separator made of a non-woven fabric or other porous material, usually used in secondary batteries, can be used. Alternatively, in place of the separator, or together with the separator, a solid electrolyte made of a polymer gel in which an electrolytic solution is immersed, can also be used.
The non-aqueous electrolyte secondary battery according to the present invention can preferably be used as a non-aqueous electrolyte secondary battery for hybrid electric vehicles.
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7643266 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a trigger circuit for an electromagnetic actuator, comprising an energy storage located in the vicinity of the actuator, said energy storage being connected with a remotely arranged supply source via supply lines, at least one electronic switch defining, together with the actuator, a first series circuit, and a sensor responding to danger situations.
2. Description of Related Art
Trigger circuits for electromagnetic actuators are frequently used in the vicinity of potentially explosive areas, for example in the chemical industry. Typical electromagnetic actuators are actuators for valves, e.g. linear actuators for shutoff valves. In protective systems, these valves serve for very rapidly switching on or off mass and volume flows, or for very rapidly pre-controlling suitable shutoff devices and thus performing switching actions. The operation of electromagnetic actuators requires a very high power to be provided for a short time. If the energy required for the switching action must be transmitted through the potentially explosive area, the power involved must be transmitted in an explosion-protected manner.
For preventing high currents from flowing through the supply lines, it is common practice to arrange an energy storage in the vicinity of the electronic switch and, if the sensors responds, to discharge the energy storage via the series circuit defined by the then closed electronic switch and the actuator.
One aspect of the present invention is based on a trigger circuit of EP 1 498 912 A1 of the applicant company. The trigger circuit described here comprises two electronic switches connected in series with the actuator in the form of triacs. The triacs are controlled via optocouplers. The trigger command for operating the actuator has the effect that a polarity inversion of the supply voltage takes place, which is transmitted to the optocoupler. The known trigger circuit is expensive on the one hand, and susceptible to malfunction on the other hand, in particular since light emitting diodes and light-sensitive transistors may fail.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a trigger circuit for an electromagnetic actuator, which has a simple configuration and ensures a reliable switching function and maintenance of an adopted switching state.
In the trigger circuit according to the invention, the sensor defines, together with at least one resistor, a second series circuit arranged in parallel to the first series circuit; a tap of the second series circuit is connected with an ignition electrode of the electronic switch.
The trigger circuit according to the invention is characterized by its great simplicity. Further, said circuit is inexpensive since only a few components are required. In the case of danger, the second series circuit is interrupted by opening the sensor. This leads to a shift of electric potential in the ignition electrode of the electronic switch such that now a current flows via the ignition electrode, said current exceeding a switching threshold, thus igniting the switch. In this manner, a reliable operation of the actuator is performed with only a few components.
If the electronic switch is a thyristor, said thyristor offers the further advantage that it does not extinguish after having been ignited, and cannot be switched off even when the switch is closed again. It is thus ensured that after triggering of the actuator, said actuator stays in the triggered state, independent of the sensor state.
Preferably, the electronic switch is a glass-passivated semiconductor switch. By glass passivation a cover is formed which protects the semiconductor switch against external influences, such as dust and aggressive media.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a trigger circuit for an electromagnetic actuator, comprising an energy storage located in the vicinity of the actuator, said energy storage being connected with a remotely arranged supply source via supply lines, at least one electronic switch defining, together with the actuator, a first series circuit, and a sensor responding to danger situations.
2. Description of Related Art
Trigger circuits for electromagnetic actuators are frequently used in the vicinity of potentially explosive areas, for example in the chemical industry. Typical electromagnetic actuators are actuators for valves, e.g. linear actuators for shutoff valves. In protective systems, these valves serve for very rapidly switching on or off mass and volume flows, or for very rapidly pre-controlling suitable shutoff devices and thus performing switching actions. The operation of electromagnetic actuators requires a very high power to be provided for a short time. If the energy required for the switching action must be transmitted through the potentially explosive area, the power involved must be transmitted in an explosion-protected manner.
For preventing high currents from flowing through the supply lines, it is common practice to arrange an energy storage in the vicinity of the electronic switch and, if the sensors responds, to discharge the energy storage via the series circuit defined by the then closed electronic switch and the actuator.
One aspect of the present invention is based on a trigger circuit of EP 1 498 912 A1 of the applicant company. The trigger circuit described here comprises two electronic switches connected in series with the actuator in the form of triacs. The triacs are controlled via optocouplers. The trigger command for operating the actuator has the effect that a polarity inversion of the supply voltage takes place, which is transmitted to the optocoupler. The known trigger circuit is expensive on the one hand, and susceptible to malfunction on the other hand, in particular since light emitting diodes and light-sensitive transistors may fail.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a trigger circuit for an electromagnetic actuator, which has a simple configuration and ensures a reliable switching function and maintenance of an adopted switching state.
In the trigger circuit according to the invention, the sensor defines, together with at least one resistor, a second series circuit arranged in parallel to the first series circuit; a tap of the second series circuit is connected with an ignition electrode of the electronic switch.
The trigger circuit according to the invention is characterized by its great simplicity. Further, said circuit is inexpensive since only a few components are required. In the case of danger, the second series circuit is interrupted by opening the sensor. This leads to a shift of electric potential in the ignition electrode of the electronic switch such that now a current flows via the ignition electrode, said current exceeding a switching threshold, thus igniting the switch. In this manner, a reliable operation of the actuator is performed with only a few components.
If the electronic switch is a thyristor, said thyristor offers the further advantage that it does not extinguish after having been ignited, and cannot be switched off even when the switch is closed again. It is thus ensured that after triggering of the actuator, said actuator stays in the triggered state, independent of the sensor state.
Preferably, the electronic switch is a glass-passivated semiconductor switch. By glass passivation a cover is formed which protects the semiconductor switch against external influences, such as dust and aggressive media.
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7660808 | FIELD OF THE INVENTION
The present invention generally relates to a method and system for managing user content on a computer system, and more specifically, pertains to automating the indexing of media content in a simplified hierarchical storage scheme and the automated assignment of keywords and other metadata to the media content to facilitate its retrieval.
BACKGROUND OF THE INVENTION
With the increased use of digital cameras, Web site image files, home video editing files, sound files, and other types of user media content stored on a hard drive, there is a clear need to provide a scheme to manage and more efficiently access these files. It is common for users to create a number of different folders at scattered locations on one or more hard drives to hold clip art, digital camera photos, video files and other types of image and sound media files. While the prior art includes programs that search a user's hard drive to identify media files for inclusion in a common listing or index, an efficient technique for automatically creating a hierarchical collection of the media-specific files has not previously been developed. In the past, users have been required to import personal content into an organizer program and manually input keywords and other metadata parameters that would enable a user to subsequently access a desired type or category of media file, or a specific media file.
Once all of the media files on a user's system are indexed and associated with keywords and other identifying metadata, it becomes relatively easy to locate a group of related media files or a specific media file. However, creating such an index and manually entering keywords and other metadata that will then enable the efficient access of media files becomes a daunting task that may involve many hours of a user's time. For this reason, most users are reluctant to take the time necessary to index and enter metadata for media files. As a result, media files are often misplaced, or at the very least, are difficult to locate on most users's hard drives. Without a centralized index and the ability to search through hundreds of media files based on metadata, a user can spend considerable time locating desired media files. The user must locate each potential folder in which one or more desired media file might be stored and then visually search through the files stored therein. While this task may require much less time than manually entering metadata, it is typically repeated so many times that the cumulative time lost can be much greater than that needed to index the files.
Even after a user's media files are manually indexed and associated with metadata, the user must still periodically update the indexing and associate new media files with metadata. This maintenance function also requires considerable time and effort. Accordingly, it will be apparent that an automated technique for both indexing and associating keywords and other metadata with media files on an ongoing basis would be desirable, since the user would then not need to manually implement this task, and would benefit from being able to readily locate one or more desired media files among all of those stored in various folders on the user's computer system. As new media files are stored, it would be desirable to automatically add the files to the index scheme and include the corresponding metadata that will enable a user to find the files when desired. Furthermore, the index scheme should be relatively simple, hierarchical, and avoid including unnecessary path information that relates to the location of non-media files.
SUMMARY OF THE INVENTION
In accord with the present invention, a method is defined for hierarchically organizing files of a selected type that are stored in a storage accessed by a computing device, to enable a user to efficiently access desired files from among the files of the selected type in the storage. The method includes the step of scanning the storage with the computing device to identify any content folders in which files of the selected type are included. (Note that throughout this disclosure and in the claims that follow, the term “folder” and its plural form are used, and these terms are intended to be entirely synonymous with the terms “directory” and its plural form, respectively.) A collection hierarchy is then created based upon the content folders that were thus identified. Each content folder is represented as a collection in the collection hierarchy, and each collection in the collection hierarchy is associated with a folder path that indicates where the collection is located in the storage. Selected empty folders (i.e., folders that do not include any files of the selected type) are also included in the collection hierarchy as necessary to enable the path to each collection to be clearly delineated. These empty folders are selected by applying a “sibling rule” and delineate branches in the collection hierarchy that distinguish between the different folder paths associated with the collections. Finally, files of the selected type that are included in each collection are imported into the collection hierarchy.
The sibling rule provides for selecting an empty folder for inclusion in the collection hierarchy if and only if the empty folder has any subfolder that is a content folder, and has a sibling folder that is either a content folder or has any subfolder that is a content folder.
The step of scanning preferably includes the step of omitting one or more predefined types of folders included in the storage while scanning. These predefined types of folders include at least one of a temporary folder in which substantially all of the files included therein are only temporarily stored, an application program folder in which application program files are stored, a filtered folder to which filters are applied in determining the files included therein, a folder that is designated as hidden, and a folder that is a subfolder under a non-current-user profile.
The method further includes the step of automatically importing a new collection into the collection hierarchy. The new collection corresponds to a new content folder that was created since the storage was previously scanned, in response to a user accessing the collection hierarchy. Preferably, the step of automatically importing is implemented when a user selects a collection in the collection hierarchy for browsing.
In addition, a user is preferably enabled to selectively determine whether to automatically detect and import into the collection hierarchy at least one of any new content folder that includes any files of the selected type by providing a new collection corresponding to the new content folder, and any new file of the selected type. In a preferred form of the invention, only new content folders that are no more than a predefined level below an existing content folder are imported into the collection hierarchy, if the user has selectively determined that any new content folder is to be automatically detected and included in the collection hierarchy.
An important aspect of the method is that metadata are automatically associated with each file in the collection hierarchy. The metadata preferably comprise keywords derived from the folder path associated with each file in the collection hierarchy. A user is enabled to search for desired files of the selected type that may be included in the collection hierarchy by searching the metadata for one or more keywords. Furthermore, any changes in the folder path at which a folder included within the collection hierarchy is stored in the storage are preferably automatically detected. Then, the metadata associated with each file of the specific type stored within the folder thus detected are automatically determined as a function of the changes in the folder path.
A further aspect of the present invention is directed to a machine-readable memory medium having machine instructions that are executable by a computing device to carry out a plurality of functions generally consistent with the steps of the method described above.
Yet another aspect of the present invention is directed to a system for hierarchically organizing files of a selected type that are stored in a storage accessed by a computing device, to enable a user to efficiently locate desired files from among the files of the selected type in the storage. The system includes a computing device having logical processing capabilities, a storage coupled to the computing device that provides non-volatile storage of files and data, and a memory that is coupled to the computing device in which machine instructions are stored. When these machine instructions are executed by the computing device, they cause functions to be implemented that are also generally consistent with the steps of the method discussed above.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention generally relates to a method and system for managing user content on a computer system, and more specifically, pertains to automating the indexing of media content in a simplified hierarchical storage scheme and the automated assignment of keywords and other metadata to the media content to facilitate its retrieval.
BACKGROUND OF THE INVENTION
With the increased use of digital cameras, Web site image files, home video editing files, sound files, and other types of user media content stored on a hard drive, there is a clear need to provide a scheme to manage and more efficiently access these files. It is common for users to create a number of different folders at scattered locations on one or more hard drives to hold clip art, digital camera photos, video files and other types of image and sound media files. While the prior art includes programs that search a user's hard drive to identify media files for inclusion in a common listing or index, an efficient technique for automatically creating a hierarchical collection of the media-specific files has not previously been developed. In the past, users have been required to import personal content into an organizer program and manually input keywords and other metadata parameters that would enable a user to subsequently access a desired type or category of media file, or a specific media file.
Once all of the media files on a user's system are indexed and associated with keywords and other identifying metadata, it becomes relatively easy to locate a group of related media files or a specific media file. However, creating such an index and manually entering keywords and other metadata that will then enable the efficient access of media files becomes a daunting task that may involve many hours of a user's time. For this reason, most users are reluctant to take the time necessary to index and enter metadata for media files. As a result, media files are often misplaced, or at the very least, are difficult to locate on most users's hard drives. Without a centralized index and the ability to search through hundreds of media files based on metadata, a user can spend considerable time locating desired media files. The user must locate each potential folder in which one or more desired media file might be stored and then visually search through the files stored therein. While this task may require much less time than manually entering metadata, it is typically repeated so many times that the cumulative time lost can be much greater than that needed to index the files.
Even after a user's media files are manually indexed and associated with metadata, the user must still periodically update the indexing and associate new media files with metadata. This maintenance function also requires considerable time and effort. Accordingly, it will be apparent that an automated technique for both indexing and associating keywords and other metadata with media files on an ongoing basis would be desirable, since the user would then not need to manually implement this task, and would benefit from being able to readily locate one or more desired media files among all of those stored in various folders on the user's computer system. As new media files are stored, it would be desirable to automatically add the files to the index scheme and include the corresponding metadata that will enable a user to find the files when desired. Furthermore, the index scheme should be relatively simple, hierarchical, and avoid including unnecessary path information that relates to the location of non-media files.
SUMMARY OF THE INVENTION
In accord with the present invention, a method is defined for hierarchically organizing files of a selected type that are stored in a storage accessed by a computing device, to enable a user to efficiently access desired files from among the files of the selected type in the storage. The method includes the step of scanning the storage with the computing device to identify any content folders in which files of the selected type are included. (Note that throughout this disclosure and in the claims that follow, the term “folder” and its plural form are used, and these terms are intended to be entirely synonymous with the terms “directory” and its plural form, respectively.) A collection hierarchy is then created based upon the content folders that were thus identified. Each content folder is represented as a collection in the collection hierarchy, and each collection in the collection hierarchy is associated with a folder path that indicates where the collection is located in the storage. Selected empty folders (i.e., folders that do not include any files of the selected type) are also included in the collection hierarchy as necessary to enable the path to each collection to be clearly delineated. These empty folders are selected by applying a “sibling rule” and delineate branches in the collection hierarchy that distinguish between the different folder paths associated with the collections. Finally, files of the selected type that are included in each collection are imported into the collection hierarchy.
The sibling rule provides for selecting an empty folder for inclusion in the collection hierarchy if and only if the empty folder has any subfolder that is a content folder, and has a sibling folder that is either a content folder or has any subfolder that is a content folder.
The step of scanning preferably includes the step of omitting one or more predefined types of folders included in the storage while scanning. These predefined types of folders include at least one of a temporary folder in which substantially all of the files included therein are only temporarily stored, an application program folder in which application program files are stored, a filtered folder to which filters are applied in determining the files included therein, a folder that is designated as hidden, and a folder that is a subfolder under a non-current-user profile.
The method further includes the step of automatically importing a new collection into the collection hierarchy. The new collection corresponds to a new content folder that was created since the storage was previously scanned, in response to a user accessing the collection hierarchy. Preferably, the step of automatically importing is implemented when a user selects a collection in the collection hierarchy for browsing.
In addition, a user is preferably enabled to selectively determine whether to automatically detect and import into the collection hierarchy at least one of any new content folder that includes any files of the selected type by providing a new collection corresponding to the new content folder, and any new file of the selected type. In a preferred form of the invention, only new content folders that are no more than a predefined level below an existing content folder are imported into the collection hierarchy, if the user has selectively determined that any new content folder is to be automatically detected and included in the collection hierarchy.
An important aspect of the method is that metadata are automatically associated with each file in the collection hierarchy. The metadata preferably comprise keywords derived from the folder path associated with each file in the collection hierarchy. A user is enabled to search for desired files of the selected type that may be included in the collection hierarchy by searching the metadata for one or more keywords. Furthermore, any changes in the folder path at which a folder included within the collection hierarchy is stored in the storage are preferably automatically detected. Then, the metadata associated with each file of the specific type stored within the folder thus detected are automatically determined as a function of the changes in the folder path.
A further aspect of the present invention is directed to a machine-readable memory medium having machine instructions that are executable by a computing device to carry out a plurality of functions generally consistent with the steps of the method described above.
Yet another aspect of the present invention is directed to a system for hierarchically organizing files of a selected type that are stored in a storage accessed by a computing device, to enable a user to efficiently locate desired files from among the files of the selected type in the storage. The system includes a computing device having logical processing capabilities, a storage coupled to the computing device that provides non-volatile storage of files and data, and a memory that is coupled to the computing device in which machine instructions are stored. When these machine instructions are executed by the computing device, they cause functions to be implemented that are also generally consistent with the steps of the method discussed above.
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7688552 | FIELD OF THE INVENTION
The present invention relates to a disk drive unit, and more particularly to a head gimbal assembly (HGA) and its manufacturing method.
BACKGROUND OF THE INVENTION
In the disk drive unit industry today, different methods are used to support a slider with magnetic head to selectively read from and write to a rotating disk, one of which is called CSS (contact start stop), and the other is called load/unload, both kinds of the methods are related with a support structure or design of a suspension of a HGA in the disk drive unit.
FIGS. 1a-1cillustrate a conventional HGA that includes a slider106′, incorporating a magnetic read/write head, and a suspension101′. The suspension101′ includes a load beam102′, a flexure103′, and a base plate105′, all of which are assembled together. The flexure103′ provides a suspension tongue104′ for supporting the slider106′ thereon. A dimple107′ is formed on a distal end of the load beam102′ to support the suspension tongue104of the flexure103′ at a position corresponding to a center of the slider106′, thereby transferring load forces from the load beam102′ to the slider106′. The top of the dimple107′ is cone-shaped, so the flexure103′ can rotate freely around top end of the dimple107′, and the slider106′ mounted on the suspension tongue104′ of the flexure103′, thus the slider106′ can rotate along with the suspension tongue104′.
However, such a dimple is required to use a punch coining die or a pulsed laser energy treatment to manufacture, so the manufacturing processes are rather complicated and easy to cause the dimple geometry asymmetric. Once the dimple is geometry asymmetric, the load beam102′ and the flexure103′ may be misaligned with each other, and the dimple107′ may not match the center of the slider106′ so as not to transfer the loading force to the center of the slider106′, which will cause unbalance of the movement of the slider106′ and, in turn, affect the slider106′ flying stability. Moreover, even if the geometry of the dimple107′ is symmetric, as there is no special positioning mechanism, it is difficult to align the load beam102′ with the flexure103′ in assembly.
In additional, the conventional HGA has a drawback in shock performance. As illustrated inFIGS. 2aand2b, since the slider106′ and the flexure103′ are supported by the dimple107′ only and the other region is free, the suspension tongue104′ of the flexure103′ and the dimple107′ are easy to separate when a shock or a vibration event happens. Even a limiter is provided to the suspension101′ to reduce the movement of the flexure103′, but the movement can not be avoided because the clearance of the limiter gap is difficult to control.
Furthermore, a dimple contact force (DCF) between the dimple107′ and the flexure103′ is a very important parameter to keep a good characteristic of the HGA. Due to the DCF is very small (Normal DCF is 2-4 g for 30% slider and 0.1-0.3 g for 20% slider), it is difficult to test and control the DCF especially for the small size slider (such as 20%, 15%, or 10% slider).
Meanwhile, during the operation of the disk drive unit and the high-speed rotation of the slider106′, the temperature of the slider106′ increases quickly, and the slider106′ endures a profile deformation against the temperature change. The profile deformation, especially the air bearing surface (ABS) profile deformation, affects the slider106′ flying height and stability.FIG. 5ais a graph to show a curve between crown of a slider106′ against temperature. It can be seen fromFIG. 5athat the crown change is quite big. This is because the slider106′ in the conventional HGA is fully mounted on the suspension tongue104′ and the heat generated between the slider106′ and the suspension tongue104′ is not easy to be emitted. This will seriously affect the flying height characteristic and the flying stability of the slider106′.
Therefore, there is a need for an improved head suspension assembly and a disk drive unit to overcome these above-mentioned disadvantages.
SUMMARY OF THE INVENTION
Accordingly, a main object of the present invention is to provide a HGA that has a good shock performance and a good flying performance.
Another object of the present invention is to provide a disk drive unit that has a good shock performance and a good flying performance.
Yet another object of the present invention is to provide a method for manufacturing a HGA to improve shock performance and flying performance of the HGA.
To achieve the above objects, the present invention provides a HGA which includes a slider and a suspension for supporting the slider. The suspension includes a load beam, a base plate, and a flexure, all of which are assembled together. The flexure has a suspension tongue on which the slider is mounted. A suspension through hole is defined in the suspension tongue at a position corresponding to a center area of the slider. The HGA further includes a dimple connecting the suspension tongue with the load beam. The dimple has a first bump, a second bump and a shaft connecting the first and the second bumps. The shaft of the dimple extends through the suspension through hole to limit the suspension tongue between the first and the second bumps.
In the present invention, diameters of the first and the second bumps are bigger than that of the shaft. The slider is partially mounted on the suspension tongue, for example, by sandwiching an adhesive material between the slider and the suspension tongue to adhere the slider to the suspension tongue. Also, the height of the adhesive material is bigger than that of the second bump.
In an embodiment of the present invention, a bow bump is formed on the load beam to support the suspension tongue, and a load beam through hole is formed in the bow bump corresponding to the suspension through hole. The shaft of the dimple extends through the load beam through hole to limit the load beam between the first and the second bumps. In another embodiment, the suspension tongue provides a mounting pattern for applying an adhesive material therein, and a plurality of protruded ribs are formed around the mounting pattern. The mounting pattern is formed at a position corresponding to a leading edge or a trailing edge of the slider.
According to the present invention, a disk drive unit including a HGA, a drive arm connecting with the HGA, a disk, and a spindle motor to spin the disk. The HGA includes a slider and a suspension for supporting the slider. The suspension comprises a load beam, a base plate, and a flexure, which are assembled together. The flexure has a suspension tongue on which the slider is mounted. A suspension through hole is formed in the suspension tongue at a position corresponding to a center area of the slider. The HGA further includes a dimple connecting the suspension tongue and the load beam. The dimple has a first bump, a second bump and a shaft connecting the first and the second bumps. The shaft of the dimple extends through the suspension through hole to limit the suspension tongue between the first and the second bumps.
According to the present invention, a manufacturing method of a HGA comprises the steps of: providing a slider, a load beam, and a flexure having a suspension tongue; forming a suspension through hole in the suspension tongue at a position corresponding to a center area of the slider mounted on the suspension tongue; providing a blank dimple which has a first bump and a shaft extending from the first bump; fixing the first bump to the load beam at a position corresponding to the suspension through hole; extending the shaft of the blank dimple through the suspension through hole of the suspension tongue; forming a second bump at a free end of the shaft so as to connect the load beam with the suspension tongue; and mounting the slider on the suspension tongue at a predetermined position thereon.
According to another embodiment of the present invention, a manufacturing method of a HGA comprises the steps of: providing a slider, a load beam, and a flexure having a suspension tongue; forming a suspension through hole in the suspension tongue at a position corresponding to a center area of the slider mounted on the suspension tongue, and forming a load beam through hole in the load beam at a position corresponding to the suspension through hole; aligning the suspension through hole with the load beam through hole; providing a blank dimple, the blank dimple having a first bump and a shaft extending from the first bump; extending the shaft of the blank dimple through the suspension through hole of the suspension tongue and the load beam through hole of the load beam; forming a second bump at a free end of the shaft so as to connect the load beam and the suspension tongue; and mounting the slider on the suspension tongue at a predetermined position thereon.
Comparing with the prior art, on one hand, the suspension tongue is limited between the first bump and the second bump so that the relative position between the load beam and the suspension tongue can be accurately regulated. Namely, the load beam and the suspension tongue can be kept a high position accuracy and good assembly symmetry so as to make the dimple accurately align with the center of the back surface of the slider without deviation, which keeps the load force from the load beam always evenly transferring to the center of the slider through the dimple when the slider is flying, thus making the slider always keep a good flying attitude and do not cause vibration, and finally ensure the slider have a good fly stability and improve the slider flying characteristic.
On the other hand, the HGA of the present invention has a good shock performance. The dimple and the suspension tongue never separate with each other, and during operation of the disk drive unit, the load force directly apply to the slider through the first dump of the dimple, which ensures an enough dimple contact force between the first bump and the suspension tongue.
In addition, in the present invention, since the slider is partially mounted on the suspension tongue, the heat generated between the slider and the suspension tongue is easy to be emitted so that the crown change of the slider against the temperature is very small, which will keep ABS crown stable so as to keep the slider fly stability during high-speed rotation of the slider.
The dimple of the present invention is very easy to manufacture and has a good assembly symmetry so as to improve the slider flying height characteristic, shock performance of the HGA and enhances the slider fly stability.
Other aspects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of this invention.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates to a disk drive unit, and more particularly to a head gimbal assembly (HGA) and its manufacturing method.
BACKGROUND OF THE INVENTION
In the disk drive unit industry today, different methods are used to support a slider with magnetic head to selectively read from and write to a rotating disk, one of which is called CSS (contact start stop), and the other is called load/unload, both kinds of the methods are related with a support structure or design of a suspension of a HGA in the disk drive unit.
FIGS. 1a-1cillustrate a conventional HGA that includes a slider106′, incorporating a magnetic read/write head, and a suspension101′. The suspension101′ includes a load beam102′, a flexure103′, and a base plate105′, all of which are assembled together. The flexure103′ provides a suspension tongue104′ for supporting the slider106′ thereon. A dimple107′ is formed on a distal end of the load beam102′ to support the suspension tongue104of the flexure103′ at a position corresponding to a center of the slider106′, thereby transferring load forces from the load beam102′ to the slider106′. The top of the dimple107′ is cone-shaped, so the flexure103′ can rotate freely around top end of the dimple107′, and the slider106′ mounted on the suspension tongue104′ of the flexure103′, thus the slider106′ can rotate along with the suspension tongue104′.
However, such a dimple is required to use a punch coining die or a pulsed laser energy treatment to manufacture, so the manufacturing processes are rather complicated and easy to cause the dimple geometry asymmetric. Once the dimple is geometry asymmetric, the load beam102′ and the flexure103′ may be misaligned with each other, and the dimple107′ may not match the center of the slider106′ so as not to transfer the loading force to the center of the slider106′, which will cause unbalance of the movement of the slider106′ and, in turn, affect the slider106′ flying stability. Moreover, even if the geometry of the dimple107′ is symmetric, as there is no special positioning mechanism, it is difficult to align the load beam102′ with the flexure103′ in assembly.
In additional, the conventional HGA has a drawback in shock performance. As illustrated inFIGS. 2aand2b, since the slider106′ and the flexure103′ are supported by the dimple107′ only and the other region is free, the suspension tongue104′ of the flexure103′ and the dimple107′ are easy to separate when a shock or a vibration event happens. Even a limiter is provided to the suspension101′ to reduce the movement of the flexure103′, but the movement can not be avoided because the clearance of the limiter gap is difficult to control.
Furthermore, a dimple contact force (DCF) between the dimple107′ and the flexure103′ is a very important parameter to keep a good characteristic of the HGA. Due to the DCF is very small (Normal DCF is 2-4 g for 30% slider and 0.1-0.3 g for 20% slider), it is difficult to test and control the DCF especially for the small size slider (such as 20%, 15%, or 10% slider).
Meanwhile, during the operation of the disk drive unit and the high-speed rotation of the slider106′, the temperature of the slider106′ increases quickly, and the slider106′ endures a profile deformation against the temperature change. The profile deformation, especially the air bearing surface (ABS) profile deformation, affects the slider106′ flying height and stability.FIG. 5ais a graph to show a curve between crown of a slider106′ against temperature. It can be seen fromFIG. 5athat the crown change is quite big. This is because the slider106′ in the conventional HGA is fully mounted on the suspension tongue104′ and the heat generated between the slider106′ and the suspension tongue104′ is not easy to be emitted. This will seriously affect the flying height characteristic and the flying stability of the slider106′.
Therefore, there is a need for an improved head suspension assembly and a disk drive unit to overcome these above-mentioned disadvantages.
SUMMARY OF THE INVENTION
Accordingly, a main object of the present invention is to provide a HGA that has a good shock performance and a good flying performance.
Another object of the present invention is to provide a disk drive unit that has a good shock performance and a good flying performance.
Yet another object of the present invention is to provide a method for manufacturing a HGA to improve shock performance and flying performance of the HGA.
To achieve the above objects, the present invention provides a HGA which includes a slider and a suspension for supporting the slider. The suspension includes a load beam, a base plate, and a flexure, all of which are assembled together. The flexure has a suspension tongue on which the slider is mounted. A suspension through hole is defined in the suspension tongue at a position corresponding to a center area of the slider. The HGA further includes a dimple connecting the suspension tongue with the load beam. The dimple has a first bump, a second bump and a shaft connecting the first and the second bumps. The shaft of the dimple extends through the suspension through hole to limit the suspension tongue between the first and the second bumps.
In the present invention, diameters of the first and the second bumps are bigger than that of the shaft. The slider is partially mounted on the suspension tongue, for example, by sandwiching an adhesive material between the slider and the suspension tongue to adhere the slider to the suspension tongue. Also, the height of the adhesive material is bigger than that of the second bump.
In an embodiment of the present invention, a bow bump is formed on the load beam to support the suspension tongue, and a load beam through hole is formed in the bow bump corresponding to the suspension through hole. The shaft of the dimple extends through the load beam through hole to limit the load beam between the first and the second bumps. In another embodiment, the suspension tongue provides a mounting pattern for applying an adhesive material therein, and a plurality of protruded ribs are formed around the mounting pattern. The mounting pattern is formed at a position corresponding to a leading edge or a trailing edge of the slider.
According to the present invention, a disk drive unit including a HGA, a drive arm connecting with the HGA, a disk, and a spindle motor to spin the disk. The HGA includes a slider and a suspension for supporting the slider. The suspension comprises a load beam, a base plate, and a flexure, which are assembled together. The flexure has a suspension tongue on which the slider is mounted. A suspension through hole is formed in the suspension tongue at a position corresponding to a center area of the slider. The HGA further includes a dimple connecting the suspension tongue and the load beam. The dimple has a first bump, a second bump and a shaft connecting the first and the second bumps. The shaft of the dimple extends through the suspension through hole to limit the suspension tongue between the first and the second bumps.
According to the present invention, a manufacturing method of a HGA comprises the steps of: providing a slider, a load beam, and a flexure having a suspension tongue; forming a suspension through hole in the suspension tongue at a position corresponding to a center area of the slider mounted on the suspension tongue; providing a blank dimple which has a first bump and a shaft extending from the first bump; fixing the first bump to the load beam at a position corresponding to the suspension through hole; extending the shaft of the blank dimple through the suspension through hole of the suspension tongue; forming a second bump at a free end of the shaft so as to connect the load beam with the suspension tongue; and mounting the slider on the suspension tongue at a predetermined position thereon.
According to another embodiment of the present invention, a manufacturing method of a HGA comprises the steps of: providing a slider, a load beam, and a flexure having a suspension tongue; forming a suspension through hole in the suspension tongue at a position corresponding to a center area of the slider mounted on the suspension tongue, and forming a load beam through hole in the load beam at a position corresponding to the suspension through hole; aligning the suspension through hole with the load beam through hole; providing a blank dimple, the blank dimple having a first bump and a shaft extending from the first bump; extending the shaft of the blank dimple through the suspension through hole of the suspension tongue and the load beam through hole of the load beam; forming a second bump at a free end of the shaft so as to connect the load beam and the suspension tongue; and mounting the slider on the suspension tongue at a predetermined position thereon.
Comparing with the prior art, on one hand, the suspension tongue is limited between the first bump and the second bump so that the relative position between the load beam and the suspension tongue can be accurately regulated. Namely, the load beam and the suspension tongue can be kept a high position accuracy and good assembly symmetry so as to make the dimple accurately align with the center of the back surface of the slider without deviation, which keeps the load force from the load beam always evenly transferring to the center of the slider through the dimple when the slider is flying, thus making the slider always keep a good flying attitude and do not cause vibration, and finally ensure the slider have a good fly stability and improve the slider flying characteristic.
On the other hand, the HGA of the present invention has a good shock performance. The dimple and the suspension tongue never separate with each other, and during operation of the disk drive unit, the load force directly apply to the slider through the first dump of the dimple, which ensures an enough dimple contact force between the first bump and the suspension tongue.
In addition, in the present invention, since the slider is partially mounted on the suspension tongue, the heat generated between the slider and the suspension tongue is easy to be emitted so that the crown change of the slider against the temperature is very small, which will keep ABS crown stable so as to keep the slider fly stability during high-speed rotation of the slider.
The dimple of the present invention is very easy to manufacture and has a good assembly symmetry so as to improve the slider flying height characteristic, shock performance of the HGA and enhances the slider fly stability.
Other aspects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of this invention.
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7809336 | BACKGROUND
I. Field
The present disclosure relates generally to data communication, and more specifically to rate selection for a communication system.
II. Background
A wireless multiple-access communication system can concurrently communicate with multiple terminals on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. Multiple terminals may simultaneously transmit data on the reverse link and/or receive data on the forward link. This is often achieved by multiplexing the transmissions on each link to be orthogonal to one another in time, frequency and/or code domain.
The terminals may be distributed throughout the system and may experience different channel conditions (e.g., different fading, multipath, and interference effects). Consequently, these terminals may achieve different signal-to-noise-and-interference ratios (SINRs). The SINR of a traffic channel determines its transmission capability, which is typically quantified by a particular data rate that may be reliably transmitted on the traffic channel. If the SINR varies from terminal to terminal, then the supported data rate would also vary from terminal to terminal. Moreover, since the channel conditions typically vary with time, the supported data rates for the terminals would also vary with time.
Rate control is a major challenge in a multiple-access communication system. Rate control entails controlling the data rate of each terminal based on the channel conditions for the terminal. The goal of rate control should be to maximize the overall throughput while meeting certain quality objectives, which may be quantified by a target packet error rate (PER) and/or some other criterion.
There is therefore a need in the art for techniques to effectively perform rate control in a multiple-access communication system.
SUMMARY
Techniques for selecting a rate for a transmitter in a communication system are described herein. A receiver obtains a channel response estimate and a received SINR estimate for the transmitter, e.g., based on a pilot received from the transmitter. The receiver computes a hypothesized SINR for the transmitter based on the channel response estimate and the received SINR estimate. The receiver then selects a rate for the transmitter based on the hypothesized SINR and characterized statistics of noise and interference at the receiver for the transmitter.
The noise and interference for the transmitter is dependent on various factors such as the number of other transmitters causing interference to this transmitter (which are called co-channel transmitters), the spatial processing technique used by the receiver to recover data transmissions sent by the transmitters, the number of antennas at the receiver, and so on. The characterized statistics of the noise and interference for the transmitter may be given by a probability density function (PDF) of SINR loss with respect to the hypothesized SINR for the transmitter. A look-up table of rate versus hypothesized SINR may be generated a priori for the PDF of SINR loss. For each hypothesized SINR value, a capacity may be computed based on the hypothesized SINR value, the PDF of SINR loss, and a capacity function. The computed capacity may be quantized to a rate supported by the system, and the rate and hypothesized SINR value may be stored in the look-up table. The receiver may then apply the hypothesized SINR for the transmitter to the look-up table, which would provide the rate for the transmitter.
The rate selection techniques described herein are well suited for a quasi-orthogonal communication system in which (1) multiple transmitters can transmit simultaneously on the same frequency subband in the same time interval and (2) the exact noise and interference for the transmitter are not known and only statistics of the noise and interference are available. The exact noise and interference may not be known because, e.g., the channel responses and the transmit powers of the co-channel transmitters are not known.
Various aspects and embodiments of the disclosure are described in further detail below.
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SUMMARY: BACKGROUND
I. Field
The present disclosure relates generally to data communication, and more specifically to rate selection for a communication system.
II. Background
A wireless multiple-access communication system can concurrently communicate with multiple terminals on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. Multiple terminals may simultaneously transmit data on the reverse link and/or receive data on the forward link. This is often achieved by multiplexing the transmissions on each link to be orthogonal to one another in time, frequency and/or code domain.
The terminals may be distributed throughout the system and may experience different channel conditions (e.g., different fading, multipath, and interference effects). Consequently, these terminals may achieve different signal-to-noise-and-interference ratios (SINRs). The SINR of a traffic channel determines its transmission capability, which is typically quantified by a particular data rate that may be reliably transmitted on the traffic channel. If the SINR varies from terminal to terminal, then the supported data rate would also vary from terminal to terminal. Moreover, since the channel conditions typically vary with time, the supported data rates for the terminals would also vary with time.
Rate control is a major challenge in a multiple-access communication system. Rate control entails controlling the data rate of each terminal based on the channel conditions for the terminal. The goal of rate control should be to maximize the overall throughput while meeting certain quality objectives, which may be quantified by a target packet error rate (PER) and/or some other criterion.
There is therefore a need in the art for techniques to effectively perform rate control in a multiple-access communication system.
SUMMARY
Techniques for selecting a rate for a transmitter in a communication system are described herein. A receiver obtains a channel response estimate and a received SINR estimate for the transmitter, e.g., based on a pilot received from the transmitter. The receiver computes a hypothesized SINR for the transmitter based on the channel response estimate and the received SINR estimate. The receiver then selects a rate for the transmitter based on the hypothesized SINR and characterized statistics of noise and interference at the receiver for the transmitter.
The noise and interference for the transmitter is dependent on various factors such as the number of other transmitters causing interference to this transmitter (which are called co-channel transmitters), the spatial processing technique used by the receiver to recover data transmissions sent by the transmitters, the number of antennas at the receiver, and so on. The characterized statistics of the noise and interference for the transmitter may be given by a probability density function (PDF) of SINR loss with respect to the hypothesized SINR for the transmitter. A look-up table of rate versus hypothesized SINR may be generated a priori for the PDF of SINR loss. For each hypothesized SINR value, a capacity may be computed based on the hypothesized SINR value, the PDF of SINR loss, and a capacity function. The computed capacity may be quantized to a rate supported by the system, and the rate and hypothesized SINR value may be stored in the look-up table. The receiver may then apply the hypothesized SINR for the transmitter to the look-up table, which would provide the rate for the transmitter.
The rate selection techniques described herein are well suited for a quasi-orthogonal communication system in which (1) multiple transmitters can transmit simultaneously on the same frequency subband in the same time interval and (2) the exact noise and interference for the transmitter are not known and only statistics of the noise and interference are available. The exact noise and interference may not be known because, e.g., the channel responses and the transmit powers of the co-channel transmitters are not known.
Various aspects and embodiments of the disclosure are described in further detail below.
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7802859 | BACKGROUND
Refill kiosks are becoming popular with printer users for refilling used inkjet print cartridges. Inkjet print cartridges are also sometimes called ink cartridges, inkjet cartridges or ink pens. One factor that can affect the performance and use of a refill kiosk is the extent to which the cartridge can be accurately or completely filled. The amount of ink needed to completely fill a used cartridge depends on the amount of ink left in the cartridge. This leftover ink typically varies from cartridge to cartridge. One method currently used to control the accuracy of the fill level is to print or otherwise extract all of the ink from the used cartridge and then refill the cartridge, thus eliminating the varying amount of left over ink as a factor in the refill method. This method, however, adds undesirable labor costs and reduces automation of the refill method, and wastes ink.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND
Refill kiosks are becoming popular with printer users for refilling used inkjet print cartridges. Inkjet print cartridges are also sometimes called ink cartridges, inkjet cartridges or ink pens. One factor that can affect the performance and use of a refill kiosk is the extent to which the cartridge can be accurately or completely filled. The amount of ink needed to completely fill a used cartridge depends on the amount of ink left in the cartridge. This leftover ink typically varies from cartridge to cartridge. One method currently used to control the accuracy of the fill level is to print or otherwise extract all of the ink from the used cartridge and then refill the cartridge, thus eliminating the varying amount of left over ink as a factor in the refill method. This method, however, adds undesirable labor costs and reduces automation of the refill method, and wastes ink.
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7648334 | FIELD OF THE INVENTION
The present invention relates to improved airfoil geometry, and more particularly to a high efficiency airfoil for a turbine nozzle guide vane in a gas turbine engine.
BACKGROUND
Gas turbine engine designers continuously work to improve engine efficiency, to reduce operating costs of the engine, and to reduce specific exhaust gas emissions such as NOx, CO2, CO, unburnt hydrocarbons, and particulate matter. The specific fuel consumption (SFC) of an engine is inversely proportional to the overall thermal efficiency of the engine, thus, as the SFC decreases the fuel efficiency of the engine increases. Furthermore, specific exhaust gas emissions typically decrease as the engine becomes more efficient. The thermal efficiency of the engine is a function of component efficiencies, cycle pressure ratio and turbine inlet temperature. The present invention contemplates increased thermal efficiency for a gas turbine engine by improving turbine efficiency through a new aerodynamic design of an airfoil for a second stage turbine nozzle guide vane.
SUMMARY
The present invention provides an airfoil with an external surface having first and second sides, the external surface extends spanwise between a hub and a tip and streamwise between a leading edge and a trailing edge. The external surface has a contour substantially defined by Table 1 as listed in the specification.
In another aspect of the present invention, a turbine nozzle guide vane assembly for a gas turbine engine can include an inner shroud having an upper surface and a lower surface, the upper surface of the inner shroud partially defining an inner flow path wall. An airfoil can extend radially outward from the upper surface of the inner shroud relative to an axis of rotation of the gas turbine engine. The airfoil includes first and second three-dimensional external surfaces that extend between a hub and a tip in a spanwise direction and between a leading edge and a trailing edge in a streamwise direction. A Cartesian coordinate array having X,Y and Z axis coordinates listed in Table 1 of the specification defines the first and second external surfaces of the airfoil.
Another aspect of the present invention provides for a method of forming an airfoil for a turbine nozzle guide vane. The method includes forming a contoured three-dimensional external surface of an airfoil defined by Cartesian (X, Y and Z) coordinates listed in the specification as Table 1, wherein the Z axis coordinates are generally measured in a radial direction from a longitudinal axis, the X axis coordinates are generally measured normal to the Z axis in a streamwise direction, and the Y axis coordinates are generally measured normal to the Z axis and normal to the X axis.
Another aspect of the present invention provides for a method of forming an airfoil for a turbine nozzle guide vane. The method includes forming a contoured three-dimensional external surface of an airfoil defined by Cartesian (X, Y and Z) coordinates listed in the specification as Table 1, wherein the Z axis coordinates are generally measured from an engine centerline axis, the X axis coordinates are generally measured normal to the Z axis in a streamwise direction, and the Y axis coordinates are generally measured normal to the Z axis and normal to the X axis.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention relates to improved airfoil geometry, and more particularly to a high efficiency airfoil for a turbine nozzle guide vane in a gas turbine engine.
BACKGROUND
Gas turbine engine designers continuously work to improve engine efficiency, to reduce operating costs of the engine, and to reduce specific exhaust gas emissions such as NOx, CO2, CO, unburnt hydrocarbons, and particulate matter. The specific fuel consumption (SFC) of an engine is inversely proportional to the overall thermal efficiency of the engine, thus, as the SFC decreases the fuel efficiency of the engine increases. Furthermore, specific exhaust gas emissions typically decrease as the engine becomes more efficient. The thermal efficiency of the engine is a function of component efficiencies, cycle pressure ratio and turbine inlet temperature. The present invention contemplates increased thermal efficiency for a gas turbine engine by improving turbine efficiency through a new aerodynamic design of an airfoil for a second stage turbine nozzle guide vane.
SUMMARY
The present invention provides an airfoil with an external surface having first and second sides, the external surface extends spanwise between a hub and a tip and streamwise between a leading edge and a trailing edge. The external surface has a contour substantially defined by Table 1 as listed in the specification.
In another aspect of the present invention, a turbine nozzle guide vane assembly for a gas turbine engine can include an inner shroud having an upper surface and a lower surface, the upper surface of the inner shroud partially defining an inner flow path wall. An airfoil can extend radially outward from the upper surface of the inner shroud relative to an axis of rotation of the gas turbine engine. The airfoil includes first and second three-dimensional external surfaces that extend between a hub and a tip in a spanwise direction and between a leading edge and a trailing edge in a streamwise direction. A Cartesian coordinate array having X,Y and Z axis coordinates listed in Table 1 of the specification defines the first and second external surfaces of the airfoil.
Another aspect of the present invention provides for a method of forming an airfoil for a turbine nozzle guide vane. The method includes forming a contoured three-dimensional external surface of an airfoil defined by Cartesian (X, Y and Z) coordinates listed in the specification as Table 1, wherein the Z axis coordinates are generally measured in a radial direction from a longitudinal axis, the X axis coordinates are generally measured normal to the Z axis in a streamwise direction, and the Y axis coordinates are generally measured normal to the Z axis and normal to the X axis.
Another aspect of the present invention provides for a method of forming an airfoil for a turbine nozzle guide vane. The method includes forming a contoured three-dimensional external surface of an airfoil defined by Cartesian (X, Y and Z) coordinates listed in the specification as Table 1, wherein the Z axis coordinates are generally measured from an engine centerline axis, the X axis coordinates are generally measured normal to the Z axis in a streamwise direction, and the Y axis coordinates are generally measured normal to the Z axis and normal to the X axis.
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7721709 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel injection control apparatus and method for an internal combustion engine which is supplied with a fuel by an in-cylinder fuel injection valve for injecting the fuel into a cylinder, and a port fuel injection valve for injecting the fuel into an intake system including an intake port.
2. Description of the Prior Art
Conventionally, as this type of fuel injection control apparatus for an internal combustion engine, one described, for example, in Laid-open Japanese Patent Application No. 2005-337102 is known. In this fuel injection control apparatus, the proportion of an in-cylinder injection amount injected from an in-cylinder fuel injection valve to a port injection amount injected from a port fuel injection valve is set in accordance with a detected operating condition of an internal combustion engine. Also, when the proportion of the port injection amount decreases while the proportion of the port injection amount increases, an increased amount of the port injection amount is divided into a primary injection for injecting an amount of fuel in accordance with the operating condition of the internal combustion engine, and a secondary injection which precedes the primary injection. Also, the amount of fuel injected in the secondary injection is set to the amount of fuel sticking to the inner wall of an intake passage, thereby compensating for a lack of fuel supplied to a combustion chamber due to the fuel sticking to the inner wall of the intake passage.
When a port fuel injection valve is provided in conjunction with an in-cylinder fuel injection valve, as is the case with the foregoing conventional internal combustion engine, the sticking of fuel is not limited to a fuel injected from the port fuel injection valve, but is involved in a fuel injected from the in-cylinder fuel injection valve, where the fuel can stick to the inner wall surface of a combustion chamber, for example, the inner wall surface of a cylinder, the top surface of a piston, and the like. However, in the conventional fuel injection control apparatus, a correction against the sticking is made only for a fuel injected from the port fuel injection valve, so that a fuel transport behavior of the whole cylinder, including the sticking of a fuel injected from the in-cylinder fuel injection valve, is not reflected. As a result, the amount of fuel actually used in the combustion in the combustion chamber cannot be appropriately controlled, failing to achieve a desired air-fuel ratio.
Also, in this fuel injection control apparatus, the correction against the sticking is performed exclusively in an operating condition in which the proportion of the port injection amount is increasing, so that an appropriate fuel injection amount reflecting a fuel transport behavior cannot be set in other operating conditions of the internal combustion engine. Further, since fuel injection amounts are set by control approaches different from each other between the operating condition in which the proportion of the port injection amount is increasing and other operating conditions, the entire control logic is complicated, and the air-fuel ratio is more likely to vary before and after switching between the control approaches.
SUMMARY OF THE INVENTION
The present invention has been made to solve the problems as mentioned above, and it is an object of the invention to provide a fuel injection control apparatus and method for an internal combustion engine which are capable of appropriately controlling the amounts of fuel supplied from an in-cylinder fuel injection valve and a port fuel injection valve to a cylinder in a simple control approach while satisfactorily reflecting a fuel transport behavior as a whole cylinder.
To achieve the above object, according to a first aspect of the present invention, there is provided a fuel injection control apparatus for an internal combustion engine which is supplied with a fuel by an in-cylinder fuel injection vale for injecting the fuel into a cylinder, and a port fuel injection valve for injecting the fuel into an intake system including an intake port. The fuel injection control apparatus is characterized by comprising required in-cylinder injection amount calculating means for calculating a required in-cylinder injection amount required for the in-cylinder fuel injection valve; required port injection amount calculating means for calculating a required port injection amount required for the port fuel injection valve; in-cylinder injected fuel behavior parameter calculating means for calculating an in-cylinder injected fuel behavior parameter indicative of a transport behavior of a fuel injected by the in-cylinder fuel injection valve; port injected fuel behavior parameter calculating means for calculating a port injected fuel behavior parameter indicative of a transport behavior of the fuel injected by the port fuel injection valve; net in-cylinder injection amount determining means for determining a net in-cylinder injection amount which should be injected from the in-cylinder fuel injection valve in accordance with the calculated in-cylinder injected fuel behavior parameter and port injected fuel behavior parameter based on the calculated required in-cylinder injection amount; and net port injection amount determining means for determining a net port injection amount which should be injected from the port fuel injection valve in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the calculated required port injection amount.
According to this fuel injection control apparatus for an internal combustion engine, the required in-cylinder injection amount required for the in-cylinder fuel injection valve, and the required port injection amount required for the port fuel injection valve are calculated, respectively. Also, the in-cylinder injected fuel behavior parameter indicative of a transport behavior of a fuel injected from the in-cylinder fuel injection valve, and the port injected fuel behavior parameter indicative of a transport behavior of the fuel injected from the port fuel injection valve are calculated, respectively. Then, the net in-cylinder injection amount which should be actually injected from the in-cylinder fuel injection valve is determined in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the required in-cylinder injection amount. Also, the net port injection amount which should be actually injected from the port fuel injection valve is determined in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the required port injected amount.
As described above, according to the present invention, the net in-cylinder injection amount from the in-cylinder fuel injection valve and the net port injection amount from the port fuel injection valve are determined in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter. Accordingly, the amount of fuel actually used in a combustion chamber for combustion can be appropriately controlled while satisfactorily reflecting fuel transport behaviors as the whole cylinder including not only a transport delay due to the sticking of the fuel injected from the port fuel injection valve onto the inner wall surface of an intake system, but also a transport delay due to the sticking of the fuel injected from the in-cylinder fuel injection valve onto the inner wall surface of the combustion chamber, and the like, thereby making it possible to accurately control the air-fuel ratio to a desired value.
Also, since the control approach described above can be applied irrespective of the operating condition of the internal combustion engine, the control logic can be simplified, and the air-fuel ratio can be controlled with stability, as compared with the aforementioned conventional control apparatus which needs to switch control approaches in accordance with a particular operating condition.
To achieve the above object, according to a second aspect of the present invention, there is provided a fuel injection control method for an internal combustion engine which is supplied with a fuel by an in-cylinder fuel injection vale for injecting the fuel into a cylinder, and a port fuel injection valve for injecting the fuel into an intake system including an intake port. The fuel injection control method is characterized by comprising the steps of calculating a required in-cylinder injection amount required for the in-cylinder fuel injection valve; calculating a required port injection amount required for the port fuel injection valve; calculating an in-cylinder injected fuel behavior parameter indicative of a transport behavior of a fuel injected by the in-cylinder fuel injection valve; calculating a port injected fuel behavior parameter indicative of a transport behavior of the fuel injected by the port fuel injection valve; determining a net in-cylinder injection amount which should be injected from the in-cylinder fuel injection valve in accordance with the calculated in-cylinder injected fuel behavior parameter and port injected fuel behavior parameter based on the calculated required in-cylinder injection amount; and determining a net port injection amount which should be injected from the port fuel injection valve in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the calculated required port injection amount.
This method provides the same advantageous effects as described above concerning the abnormality determining apparatus according to the first aspect of the invention.
Preferably, the fuel injection control apparatus for an internal combustion engine further comprises load detecting means for detecting a load of the internal combustion engine; total required fuel amount calculating means for calculating a total required fuel amount required for the whole cylinder based on the detected load of the internal combustion engine; and engine temperature detecting means for detecting a temperature of the internal combustion engine, wherein the in-cylinder injected fuel behavior parameter calculating means calculates the in-cylinder injected fuel behavior parameter in accordance with one of the calculated total required fuel amount and the required in-cylinder injection amount and the detected temperature of the internal combustion engine, and the port injected fuel behavior parameter calculating means calculates the port injected fuel behavior parameter in accordance with one of the total required fuel amount and the required port injection amount and the temperature of the internal combustion engine.
Generally, a degree to which the fuel sticks to the inner wall surfaces of the intake system and combustion chamber is largely affected by the temperature of the internal combustion engine, and is larger as the temperature is lower because the fuel is less apt to vaporize. Also, the required fuel injection amount represents a load on the internal combustion engine, and additionally reflects the thickness of a fuel film sticking to the inner wall surface of the intake system, and the like, unlike other load parameters. Therefore, according to the present invention, the in-cylinder injected fuel behavior parameter can be appropriately calculated in accordance with one of the total required fuel amount and the required in-cylinder injection amount and the temperature of the internal combustion engine. Also, the in-cylinder injected fuel behavior parameter can be appropriately calculated in accordance with one of the total required fuel amount and the required port injection amount and the temperature of the internal combustion engine. Consequently, it is possible to more appropriately determine the net in-cylinder injection amount and the net port injection amount in accordance with both fuel behavior parameters.
Preferably, the fuel injection control method for an internal combustion engine further comprises the step of detecting a load of the internal combustion engine; calculating a total required fuel amount required for the whole cylinder based on the detected load of the internal combustion engine; and detecting a temperature of the internal combustion engine, wherein the in-cylinder injected fuel behavior parameter calculating step includes calculating the in-cylinder injected fuel behavior parameter in accordance with one of the calculated total required fuel amount and the required in-cylinder injection amount and the detected temperature of the internal combustion engine, and the port injected fuel behavior parameter calculating step includes calculating the port injected fuel behavior parameter in accordance with one of the total required fuel amount and the required port injection amount and the temperature of the internal combustion engine.
This preferred embodiment of the fuel injection control method provides the same advantageous effects as described above concerning the fuel injection control apparatus according to the first aspect of the invention.
Preferably, the fuel injection control apparatus for an internal combustion engine further comprises total fuel behavior parameter calculating means for calculating a total fuel behavior parameter indicative of a transport behavior of the fuel as the whole cylinder by weight averaging the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter in accordance with ratios of the required in-cylinder injection amount and the required port injection amount to the total required fuel amount; and total net injection amount calculating means for calculating a total net injection amount which is a sum total of fuel amounts that should be injected from the in-cylinder fuel injection valve and the port fuel injection valve in accordance with the calculated total fuel behavior parameter, wherein the net in-cylinder injection amount determining means and the net port injection amount determining means determine the net in-cylinder injection amount and the net port injection amount, respectively, by proportionally distributing the calculated total net injection amount in accordance with ratios of the required in-cylinder injection amount and the required port injection amount.
According to this preferred embodiment of the fuel injection control apparatus for an internal combustion engine, the total fuel behavior parameter as the whole cylinder is calculated by weight averaging the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter in accordance with the ratios of the required in-cylinder injection amount and the required port injection amount to the total required fuel amount. Therefore, the calculated total fuel behavior parameter satisfactorily reflects a transport behavior of the fuel as the whole cylinder. Also, the total net injection amount is calculated in accordance with the total fuel behavior parameter, and the net in-cylinder injection amount and the net port injection amount are determined respectively by proportionally distributing the calculated total net injection amount in accordance with the ratios of the required in-cylinder injection amount and the required port injection amount.
Accordingly, it is possible to appropriately determine the net in-cylinder injection amount and the net port injection amount, while satisfactorily reflecting the transport behavior of the fuel as the whole cylinder, to accurately control the air-fuel ratio to a desired value. Also, since the final net in-cylinder injection amount and net port injection amount can be calculated simply by calculating the total fuel behavior parameter by the weighted average of the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter, and proportionally distributing the calculated total net injection amount in accordance with the total fuel behavior parameter, the foregoing actions can be provided by such an extremely simple processing approach.
Preferably, the fuel injection control method for an internal combustion engine further comprises the step of calculating a total fuel behavior parameter indicative of a transport behavior of the fuel as the whole cylinder by weight averaging the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter in accordance with ratios of the required in-cylinder injection amount and the required port injection amount to the total required fuel amount; and calculating a total net injection amount which is a sum total of fuel amounts that should be injected from the in-cylinder fuel injection valve and the port fuel injection valve in accordance with the calculated total fuel behavior parameter, wherein the net in-cylinder injection amount determining step and the net port injection amount determining step include determining the net in-cylinder injection amount and the net port injection amount, respectively, by proportionally distributing the calculated total net injection amount in accordance with ratios of the required in-cylinder injection amount and the required port injection amount.
This preferred embodiment of the fuel injection control method provides the same advantageous effects as described above concerning the fuel injection control apparatus according to the first aspect of the invention.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel injection control apparatus and method for an internal combustion engine which is supplied with a fuel by an in-cylinder fuel injection valve for injecting the fuel into a cylinder, and a port fuel injection valve for injecting the fuel into an intake system including an intake port.
2. Description of the Prior Art
Conventionally, as this type of fuel injection control apparatus for an internal combustion engine, one described, for example, in Laid-open Japanese Patent Application No. 2005-337102 is known. In this fuel injection control apparatus, the proportion of an in-cylinder injection amount injected from an in-cylinder fuel injection valve to a port injection amount injected from a port fuel injection valve is set in accordance with a detected operating condition of an internal combustion engine. Also, when the proportion of the port injection amount decreases while the proportion of the port injection amount increases, an increased amount of the port injection amount is divided into a primary injection for injecting an amount of fuel in accordance with the operating condition of the internal combustion engine, and a secondary injection which precedes the primary injection. Also, the amount of fuel injected in the secondary injection is set to the amount of fuel sticking to the inner wall of an intake passage, thereby compensating for a lack of fuel supplied to a combustion chamber due to the fuel sticking to the inner wall of the intake passage.
When a port fuel injection valve is provided in conjunction with an in-cylinder fuel injection valve, as is the case with the foregoing conventional internal combustion engine, the sticking of fuel is not limited to a fuel injected from the port fuel injection valve, but is involved in a fuel injected from the in-cylinder fuel injection valve, where the fuel can stick to the inner wall surface of a combustion chamber, for example, the inner wall surface of a cylinder, the top surface of a piston, and the like. However, in the conventional fuel injection control apparatus, a correction against the sticking is made only for a fuel injected from the port fuel injection valve, so that a fuel transport behavior of the whole cylinder, including the sticking of a fuel injected from the in-cylinder fuel injection valve, is not reflected. As a result, the amount of fuel actually used in the combustion in the combustion chamber cannot be appropriately controlled, failing to achieve a desired air-fuel ratio.
Also, in this fuel injection control apparatus, the correction against the sticking is performed exclusively in an operating condition in which the proportion of the port injection amount is increasing, so that an appropriate fuel injection amount reflecting a fuel transport behavior cannot be set in other operating conditions of the internal combustion engine. Further, since fuel injection amounts are set by control approaches different from each other between the operating condition in which the proportion of the port injection amount is increasing and other operating conditions, the entire control logic is complicated, and the air-fuel ratio is more likely to vary before and after switching between the control approaches.
SUMMARY OF THE INVENTION
The present invention has been made to solve the problems as mentioned above, and it is an object of the invention to provide a fuel injection control apparatus and method for an internal combustion engine which are capable of appropriately controlling the amounts of fuel supplied from an in-cylinder fuel injection valve and a port fuel injection valve to a cylinder in a simple control approach while satisfactorily reflecting a fuel transport behavior as a whole cylinder.
To achieve the above object, according to a first aspect of the present invention, there is provided a fuel injection control apparatus for an internal combustion engine which is supplied with a fuel by an in-cylinder fuel injection vale for injecting the fuel into a cylinder, and a port fuel injection valve for injecting the fuel into an intake system including an intake port. The fuel injection control apparatus is characterized by comprising required in-cylinder injection amount calculating means for calculating a required in-cylinder injection amount required for the in-cylinder fuel injection valve; required port injection amount calculating means for calculating a required port injection amount required for the port fuel injection valve; in-cylinder injected fuel behavior parameter calculating means for calculating an in-cylinder injected fuel behavior parameter indicative of a transport behavior of a fuel injected by the in-cylinder fuel injection valve; port injected fuel behavior parameter calculating means for calculating a port injected fuel behavior parameter indicative of a transport behavior of the fuel injected by the port fuel injection valve; net in-cylinder injection amount determining means for determining a net in-cylinder injection amount which should be injected from the in-cylinder fuel injection valve in accordance with the calculated in-cylinder injected fuel behavior parameter and port injected fuel behavior parameter based on the calculated required in-cylinder injection amount; and net port injection amount determining means for determining a net port injection amount which should be injected from the port fuel injection valve in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the calculated required port injection amount.
According to this fuel injection control apparatus for an internal combustion engine, the required in-cylinder injection amount required for the in-cylinder fuel injection valve, and the required port injection amount required for the port fuel injection valve are calculated, respectively. Also, the in-cylinder injected fuel behavior parameter indicative of a transport behavior of a fuel injected from the in-cylinder fuel injection valve, and the port injected fuel behavior parameter indicative of a transport behavior of the fuel injected from the port fuel injection valve are calculated, respectively. Then, the net in-cylinder injection amount which should be actually injected from the in-cylinder fuel injection valve is determined in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the required in-cylinder injection amount. Also, the net port injection amount which should be actually injected from the port fuel injection valve is determined in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the required port injected amount.
As described above, according to the present invention, the net in-cylinder injection amount from the in-cylinder fuel injection valve and the net port injection amount from the port fuel injection valve are determined in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter. Accordingly, the amount of fuel actually used in a combustion chamber for combustion can be appropriately controlled while satisfactorily reflecting fuel transport behaviors as the whole cylinder including not only a transport delay due to the sticking of the fuel injected from the port fuel injection valve onto the inner wall surface of an intake system, but also a transport delay due to the sticking of the fuel injected from the in-cylinder fuel injection valve onto the inner wall surface of the combustion chamber, and the like, thereby making it possible to accurately control the air-fuel ratio to a desired value.
Also, since the control approach described above can be applied irrespective of the operating condition of the internal combustion engine, the control logic can be simplified, and the air-fuel ratio can be controlled with stability, as compared with the aforementioned conventional control apparatus which needs to switch control approaches in accordance with a particular operating condition.
To achieve the above object, according to a second aspect of the present invention, there is provided a fuel injection control method for an internal combustion engine which is supplied with a fuel by an in-cylinder fuel injection vale for injecting the fuel into a cylinder, and a port fuel injection valve for injecting the fuel into an intake system including an intake port. The fuel injection control method is characterized by comprising the steps of calculating a required in-cylinder injection amount required for the in-cylinder fuel injection valve; calculating a required port injection amount required for the port fuel injection valve; calculating an in-cylinder injected fuel behavior parameter indicative of a transport behavior of a fuel injected by the in-cylinder fuel injection valve; calculating a port injected fuel behavior parameter indicative of a transport behavior of the fuel injected by the port fuel injection valve; determining a net in-cylinder injection amount which should be injected from the in-cylinder fuel injection valve in accordance with the calculated in-cylinder injected fuel behavior parameter and port injected fuel behavior parameter based on the calculated required in-cylinder injection amount; and determining a net port injection amount which should be injected from the port fuel injection valve in accordance with the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter based on the calculated required port injection amount.
This method provides the same advantageous effects as described above concerning the abnormality determining apparatus according to the first aspect of the invention.
Preferably, the fuel injection control apparatus for an internal combustion engine further comprises load detecting means for detecting a load of the internal combustion engine; total required fuel amount calculating means for calculating a total required fuel amount required for the whole cylinder based on the detected load of the internal combustion engine; and engine temperature detecting means for detecting a temperature of the internal combustion engine, wherein the in-cylinder injected fuel behavior parameter calculating means calculates the in-cylinder injected fuel behavior parameter in accordance with one of the calculated total required fuel amount and the required in-cylinder injection amount and the detected temperature of the internal combustion engine, and the port injected fuel behavior parameter calculating means calculates the port injected fuel behavior parameter in accordance with one of the total required fuel amount and the required port injection amount and the temperature of the internal combustion engine.
Generally, a degree to which the fuel sticks to the inner wall surfaces of the intake system and combustion chamber is largely affected by the temperature of the internal combustion engine, and is larger as the temperature is lower because the fuel is less apt to vaporize. Also, the required fuel injection amount represents a load on the internal combustion engine, and additionally reflects the thickness of a fuel film sticking to the inner wall surface of the intake system, and the like, unlike other load parameters. Therefore, according to the present invention, the in-cylinder injected fuel behavior parameter can be appropriately calculated in accordance with one of the total required fuel amount and the required in-cylinder injection amount and the temperature of the internal combustion engine. Also, the in-cylinder injected fuel behavior parameter can be appropriately calculated in accordance with one of the total required fuel amount and the required port injection amount and the temperature of the internal combustion engine. Consequently, it is possible to more appropriately determine the net in-cylinder injection amount and the net port injection amount in accordance with both fuel behavior parameters.
Preferably, the fuel injection control method for an internal combustion engine further comprises the step of detecting a load of the internal combustion engine; calculating a total required fuel amount required for the whole cylinder based on the detected load of the internal combustion engine; and detecting a temperature of the internal combustion engine, wherein the in-cylinder injected fuel behavior parameter calculating step includes calculating the in-cylinder injected fuel behavior parameter in accordance with one of the calculated total required fuel amount and the required in-cylinder injection amount and the detected temperature of the internal combustion engine, and the port injected fuel behavior parameter calculating step includes calculating the port injected fuel behavior parameter in accordance with one of the total required fuel amount and the required port injection amount and the temperature of the internal combustion engine.
This preferred embodiment of the fuel injection control method provides the same advantageous effects as described above concerning the fuel injection control apparatus according to the first aspect of the invention.
Preferably, the fuel injection control apparatus for an internal combustion engine further comprises total fuel behavior parameter calculating means for calculating a total fuel behavior parameter indicative of a transport behavior of the fuel as the whole cylinder by weight averaging the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter in accordance with ratios of the required in-cylinder injection amount and the required port injection amount to the total required fuel amount; and total net injection amount calculating means for calculating a total net injection amount which is a sum total of fuel amounts that should be injected from the in-cylinder fuel injection valve and the port fuel injection valve in accordance with the calculated total fuel behavior parameter, wherein the net in-cylinder injection amount determining means and the net port injection amount determining means determine the net in-cylinder injection amount and the net port injection amount, respectively, by proportionally distributing the calculated total net injection amount in accordance with ratios of the required in-cylinder injection amount and the required port injection amount.
According to this preferred embodiment of the fuel injection control apparatus for an internal combustion engine, the total fuel behavior parameter as the whole cylinder is calculated by weight averaging the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter in accordance with the ratios of the required in-cylinder injection amount and the required port injection amount to the total required fuel amount. Therefore, the calculated total fuel behavior parameter satisfactorily reflects a transport behavior of the fuel as the whole cylinder. Also, the total net injection amount is calculated in accordance with the total fuel behavior parameter, and the net in-cylinder injection amount and the net port injection amount are determined respectively by proportionally distributing the calculated total net injection amount in accordance with the ratios of the required in-cylinder injection amount and the required port injection amount.
Accordingly, it is possible to appropriately determine the net in-cylinder injection amount and the net port injection amount, while satisfactorily reflecting the transport behavior of the fuel as the whole cylinder, to accurately control the air-fuel ratio to a desired value. Also, since the final net in-cylinder injection amount and net port injection amount can be calculated simply by calculating the total fuel behavior parameter by the weighted average of the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter, and proportionally distributing the calculated total net injection amount in accordance with the total fuel behavior parameter, the foregoing actions can be provided by such an extremely simple processing approach.
Preferably, the fuel injection control method for an internal combustion engine further comprises the step of calculating a total fuel behavior parameter indicative of a transport behavior of the fuel as the whole cylinder by weight averaging the in-cylinder injected fuel behavior parameter and the port injected fuel behavior parameter in accordance with ratios of the required in-cylinder injection amount and the required port injection amount to the total required fuel amount; and calculating a total net injection amount which is a sum total of fuel amounts that should be injected from the in-cylinder fuel injection valve and the port fuel injection valve in accordance with the calculated total fuel behavior parameter, wherein the net in-cylinder injection amount determining step and the net port injection amount determining step include determining the net in-cylinder injection amount and the net port injection amount, respectively, by proportionally distributing the calculated total net injection amount in accordance with ratios of the required in-cylinder injection amount and the required port injection amount.
This preferred embodiment of the fuel injection control method provides the same advantageous effects as described above concerning the fuel injection control apparatus according to the first aspect of the invention.
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7792660 | FIELD OF INVENTION
The current invention relates to monitoring multiple channels of data from real time processes, and more particularly to detecting recent abnormal behavior using the data monitored.
BACKGROUND OF THE INVENTION
The monitoring of multiple channels of real-time data plays a key role in business processes in various domains. For example, in the production context (say, in the Oil and Gas Industry) sensors monitor various parameters and produce information at various temporal granularities. An important reason for this monitoring is to detect abnormal situations in a timely fashion to take corrective action. This monitoring can be done by domain experts but that can be an expensive and inconvenient process especially when this has to be done round-the-clock. For each situation, one can envision building a new system from scratch that mimics the monitoring done by the human expert as a possible solution to this problem. This can be an expensive proposition if there are multiple situations to be considered in each domain. Also, one has to find a way to incorporate domain knowledge related to the channels being monitored and the notion of abnormality in the detection process.
In U.S. Pat. No. 6,131,076 a method and system is disclosed for automatically establishing operational parameters of a statistical surveillance system. This is done using transformations of the time dependent data into the frequency domain and using sequential probability ratio test (SPRT).
In U.S. Pat. No. 6,859,739 a model-based surveillance system is disclosed for monitoring or controlling a process or machine. This system uses model-based estimates of operational parameters to indicate whether the process or machine is operating in a stable state or is in a transition from one state to another.
In some domains, the partial domain knowledge may be available on the relationships between various sensor values. It is important to be able to perform monitoring even in this scenario in a robust fashion detecting recent abnormal behavior in a timely fashion without too many false alarms. Also, training data containing examples of abnormal behavior may not exist. Therefore a need exists for a system to detect recent abnormal behavior using data from multiple channels in a domain with these characteristics.
SUMMARY
Therefore, the present invention provides methods systems and apparatus for monitoring multiple channels of data from real time processes, and more particularly for detecting recent abnormal behavior using the monitored data.
It is therefore an aspect of the present invention to present a method and apparatus to generate alerts indicating abnormal behavior by monitoring multiple channels of raw data from a monitored entity. In an example embodiment alerts are generated by processing raw channel data to form time dependent signals based on user customization in the form of processing rules. The time dependent signals from a set of channels are used to compute deviations in behavior by considering varying time intervals and comparing the signals with historically normal baseline signals. The computed deviations are used to produce alerts indicating abnormal behavior in one or more channels.
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SUMMARY: FIELD OF INVENTION
The current invention relates to monitoring multiple channels of data from real time processes, and more particularly to detecting recent abnormal behavior using the data monitored.
BACKGROUND OF THE INVENTION
The monitoring of multiple channels of real-time data plays a key role in business processes in various domains. For example, in the production context (say, in the Oil and Gas Industry) sensors monitor various parameters and produce information at various temporal granularities. An important reason for this monitoring is to detect abnormal situations in a timely fashion to take corrective action. This monitoring can be done by domain experts but that can be an expensive and inconvenient process especially when this has to be done round-the-clock. For each situation, one can envision building a new system from scratch that mimics the monitoring done by the human expert as a possible solution to this problem. This can be an expensive proposition if there are multiple situations to be considered in each domain. Also, one has to find a way to incorporate domain knowledge related to the channels being monitored and the notion of abnormality in the detection process.
In U.S. Pat. No. 6,131,076 a method and system is disclosed for automatically establishing operational parameters of a statistical surveillance system. This is done using transformations of the time dependent data into the frequency domain and using sequential probability ratio test (SPRT).
In U.S. Pat. No. 6,859,739 a model-based surveillance system is disclosed for monitoring or controlling a process or machine. This system uses model-based estimates of operational parameters to indicate whether the process or machine is operating in a stable state or is in a transition from one state to another.
In some domains, the partial domain knowledge may be available on the relationships between various sensor values. It is important to be able to perform monitoring even in this scenario in a robust fashion detecting recent abnormal behavior in a timely fashion without too many false alarms. Also, training data containing examples of abnormal behavior may not exist. Therefore a need exists for a system to detect recent abnormal behavior using data from multiple channels in a domain with these characteristics.
SUMMARY
Therefore, the present invention provides methods systems and apparatus for monitoring multiple channels of data from real time processes, and more particularly for detecting recent abnormal behavior using the monitored data.
It is therefore an aspect of the present invention to present a method and apparatus to generate alerts indicating abnormal behavior by monitoring multiple channels of raw data from a monitored entity. In an example embodiment alerts are generated by processing raw channel data to form time dependent signals based on user customization in the form of processing rules. The time dependent signals from a set of channels are used to compute deviations in behavior by considering varying time intervals and comparing the signals with historically normal baseline signals. The computed deviations are used to produce alerts indicating abnormal behavior in one or more channels.
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7678282 | FIELD OF THE INVENTION
The object of the present invention is to provide a method to determine the conditions of exhaustion of a filtering cartridge for filtering carafes with a replaceable cartridge, and to provide a carafe operating in compliance with such method.
BACKGROUND
Filtering carafes including a system of determination of the conditions of exhaustion of a filtering cartridge are familiar, for example by U.S. Pat. No. 5,900,138 of the same applicant.
In filtering carafes the problem of pointing out to the user the need to replace the cartridge once it is exhausted is very common. Typically, exhaustion of the cartridge is monitored through the use of two parameters, the number of filtering cycles carried out from initial activation and/or the amount of time from said activation. It is clear that the filtering material contained in the cartridge progressively loses its capacity of purifying water through use and time.
Even if these two factors represent efficient parameters in order to evaluate the conditions of efficiency of the filtering cartridge, the indication based on these factors only may turn out to be unsatisfactory. There is in fact a third important factor for calculation of the lifespan of the cartridge: the quality of the water to be filtered and the concentration of pollutants that it contains.
The filtering power of the cartridge does not vary only according to the quantity of water treated but also according to its quality.
The filtering carafes available up until today include a counting system of the filtering cycles carried out from initial activation of the cartridge, identified for example according to the counting of the number of accesses to the first water collection basin to be filtered. In some cases there is also an auxiliary counting system which counts the amount of time from the initial activation of the cartridge, compared with a time limit of lifespan of the cartridge, in order to calculate the exhaustion of the cartridge according to the first of the two events (exhaustion of time from the first activation—counting of the filtered water) that is verified.
Carafes capable of calculating the exhaustion of the cartridge according to the quality of the water treated are not currently known
SUMMARY
A main objective of the invention is to provide a method of determination of the conditions of exhaustion of a filter cartridge for filtering carafes with replaceable cartridge in which the condition of exhaustion is established in an accurate and reliable manner.
Another objective of the invention is to provide a filtering carafe with a replaceable cartridge operating in compliance with said method and at the same time built in a simple and functional way.
Another objective of the findings is to provide a carafe that, in one single device, incorporates all of the indicators desired for an accurate determination of the conditions of exhaustion of the cartridge.
These objectives and more, which will be described in further detail here below, are achieved from a carafe made in compliance with the following claims.
The characteristics and the advantages of the invention are described in the detailed description of some illustrative examples of activation, provided purely as an indicative and not restricted example, in the drawings attached.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The object of the present invention is to provide a method to determine the conditions of exhaustion of a filtering cartridge for filtering carafes with a replaceable cartridge, and to provide a carafe operating in compliance with such method.
BACKGROUND
Filtering carafes including a system of determination of the conditions of exhaustion of a filtering cartridge are familiar, for example by U.S. Pat. No. 5,900,138 of the same applicant.
In filtering carafes the problem of pointing out to the user the need to replace the cartridge once it is exhausted is very common. Typically, exhaustion of the cartridge is monitored through the use of two parameters, the number of filtering cycles carried out from initial activation and/or the amount of time from said activation. It is clear that the filtering material contained in the cartridge progressively loses its capacity of purifying water through use and time.
Even if these two factors represent efficient parameters in order to evaluate the conditions of efficiency of the filtering cartridge, the indication based on these factors only may turn out to be unsatisfactory. There is in fact a third important factor for calculation of the lifespan of the cartridge: the quality of the water to be filtered and the concentration of pollutants that it contains.
The filtering power of the cartridge does not vary only according to the quantity of water treated but also according to its quality.
The filtering carafes available up until today include a counting system of the filtering cycles carried out from initial activation of the cartridge, identified for example according to the counting of the number of accesses to the first water collection basin to be filtered. In some cases there is also an auxiliary counting system which counts the amount of time from the initial activation of the cartridge, compared with a time limit of lifespan of the cartridge, in order to calculate the exhaustion of the cartridge according to the first of the two events (exhaustion of time from the first activation—counting of the filtered water) that is verified.
Carafes capable of calculating the exhaustion of the cartridge according to the quality of the water treated are not currently known
SUMMARY
A main objective of the invention is to provide a method of determination of the conditions of exhaustion of a filter cartridge for filtering carafes with replaceable cartridge in which the condition of exhaustion is established in an accurate and reliable manner.
Another objective of the invention is to provide a filtering carafe with a replaceable cartridge operating in compliance with said method and at the same time built in a simple and functional way.
Another objective of the findings is to provide a carafe that, in one single device, incorporates all of the indicators desired for an accurate determination of the conditions of exhaustion of the cartridge.
These objectives and more, which will be described in further detail here below, are achieved from a carafe made in compliance with the following claims.
The characteristics and the advantages of the invention are described in the detailed description of some illustrative examples of activation, provided purely as an indicative and not restricted example, in the drawings attached.
Is this patent green technology? Respond with 'yes' or 'no'. |
7660457 | FIELD OF THE INVENTION
The field of the invention relates to a method for determining the change in position of an item of luggage in order to examine a suspect region in this item of luggage.
BACKGROUND
Currently it is possible to analyze items of luggage completely for explosives. The underlying analysis methods prove very reliable but also laborious. Such a laborious analysis can take place in airports only in so-called third-stage apparatuses. There, the quantity of items of luggage processed is much smaller than with the first- and second-stage apparatuses. With these third-stage apparatuses a high detection rate and a low false alarm rate is required. In order to be able to use such a third-stage apparatus as a second-stage apparatus also, the analysis time must be clearly reduced.
This problem has been solved to date by allowing no physical separation between a first-stage and a second-stage apparatus (see U.S. Pat. No. 5,182,764) or preventing a physical movement or rotation of the item of luggage (see WO 03/065077 A2). However this is very costly and hardly feasible in practice.
SUMMARY
The object of the invention is therefore to provide a method which on the one hand has a high detection rate with simultaneously low false alarm rate, but has a much shorter examination time compared with the known methods with the abovementioned framework conditions.
The object is achieved by a method with the features of claim1. With the method according to the invention the relative change in position of the item of luggage is calculated by comparing two pictures of the same item of luggage which have been recorded in different examination systems. Because the coordinates of a suspect region, which have been obtained in the first examination system are known, it is possible in the second examination system to examine in more detail only this suspect region, the coordinates of which from the first examination system have now been converted to the coordinates in the second examination system. As a result, the time spent analyzing once again all the parts of the item of luggage that have already been identified as a non-suspect region is saved. Any imaging system is possible as first and second examination systems, provided the calculation of the angles of rotation is to take place about the vertical and horizontal axes and also the translation. These include both video images and transmission images, for example by means of X-ray radiation. How the suspect region is obtained in the first examination system is not essential to the invention, with the result that for the first examination system and the second examination system, apparatuses can be used that operate on completely different technological principles. For the second examination machine, a transmission system is preferred in respect of the examination of the suspect region, but the invention is by no means limited to this. It is equally possible to use e.g. magnetic resonance tomography. In addition, the two examination systems can also be far apart. The item of luggage to be examined can be carried by hand or transported via a vehicle with the result that even a conveyor belt between them can be dispensed with. Consequently, there is an enormous saving as a result of the method according to the invention in analysis time with a simultaneously high detection rate and low false alarm rate. An advantageous development of the invention provides that an optical and/or geometrical pre-processing of the first and/or second transmission image takes place before determination of the change in position. By an optical pre-processing it is meant within the scope of this invention that the image information of a transmission image is manipulated such that the function of the image registration is improved in respect of accuracy and reliability. This can be achieved for example by carrying out a local averaging and median formation to reduce the noise. In addition, non-linear scale filters (see G. Aubert & P. Komprobst: Mathematical Problems in Image Processing: Partial Differential Equations and the Calculus of Variations. Springer, N.Y., 2002) can also be used. These filters reduce the image information content inside image segments, but retain edges so that the position of the image segments does not change. As a result, perspective changes due to different viewing angles in the two examination systems can be compensated. A further possibility is to use look-up tables, gamma filters or histogram filters, as a result of which identical absorptions also look the same within the transmission image, which is necessary in particular if the two examination systems are constructed or operate differently. Local features, e.g. edges, points or massive objects, can also be highlighted. Finally, by geometric pre-processing is meant within the framework of this application a geometric rectification. This is necessary whenever the two examination systems have different geometries. In such a case, different representations result even if the examined item of luggage is in the same position. Optical pre-processing makes possible a better basis for comparing the pictures of the item of luggage of the first and second examination systems. This leads to a simpler determination of the first angle of rotation about the vertical axis, the second angle of rotation about the horizontal axis and the translation.
A further advantageous development of the invention provides that several sets of first and/or second angles of rotation are issued in the case of ambiguities. Although it is necessary as a result to examine several suspect regions, as a rule only a few regions are left over, with the result that there is a clear reduction in the regions to be examined in the item of luggage. At the same time the detection rate is kept high and the false alarm rate remains low. The two hypotheses used are that the item of luggage has or has not been flipped, i.e. that it is lying on the same side or on its opposite side. Ambiguities occur if the method cannot decide clearly between these two hypotheses. Preferred is the input in each case of a probability value or a confidence value (a number or a vector of numbers which provides information about the reliability of a result) for the first and/or second angles of rotation. As a result, an appraisal of the suspect regions found is carried out and an examination can be carried out first of the region for which the angles with the highest probability value have been found. As a result it is more probable that dangerous contents of the item of luggage will be discovered more quickly. By a probability value is meant in the present application a value which provides information as to how high the reliability of the determined values for translation and angles of rotation is (which also indicates whether the item of luggage has been flipped over or not). This probability value can be used to allow other entities (both a person and a machine) to decide on the quality of the image registration. For example, a threshold value is used which, if not reached, causes the whole item of luggage to be scanned once again in the second examination system. A further advantageous development of the invention provides that the change in position of the item of luggage is determined using global features, in particular correlation, “mutual information” (see description relating toFIG. 3) or radial dimensional variables. One of the two pictures of the item of luggage is rotated until it is most similar to the other picture. The point of rotation must be defined in both pictures. Preferably the centre of gravity of the image of the item of luggage is used. Iijis the intensity value of the image at point (i,j). The resultant coordinates of the centre of gravity of the image (xg, yg) are then:
xg=∑i,jx,Ii,j∑i,jIi,j,yg=∑i,jy,Ii,j∑i,jIi,j,
In addition to the use of correlation and “mutual information”, the use of radial dimensional variables is also possible. The picture is divided into N angle segments (the evaluation takes place in each case in an angle range between φ and φ+Δφ) which are appraised with different values, e.g. statistical moments. The values of the Nth segments are then compared with the values of the N+nth segment, n corresponding to the angle increment. This measurement is preferably coupled with a scale analysis. The results on different linear scales, i.e. at different resolutions, are compared and these findings are combined, as a result of which a reduced calculation time is obtained. Thus the calculation time is reduced by a factor of 4 if the resolution is halved, as fewer image spots must be analyzed. Preferably different comparison values can also be used and their result taken jointly into account. By a comparison value is meant within the framework of the application a function which has the two pictures as input parameters and provides a number or a vector. This issued value is then related to the difference between the two images. The simplest example of this is the difference between the two image spots. If this is small, the two pictures are identical. By global features is meant within the framework of this application that all image spots of the image are used for image registration. This differs from the local features given below which are used as a subset of all these image spots. The respective subset must be determined. One possibility for this is the detection of corners and edges.
A further advantageous development of the invention provides that the change in position of the item of luggage is determined using local features, in particular using “Random Sample Consensus” (RANSAC), robust estimation methods, Hough transformations or least-square methods. Suitable local features are sought in both pictures, e.g. corners, edges, lines, significant points or small, easily-identifiable objects (such as metal buttons) inside the item of luggage. These features are allocated to one another by ascertaining where a specific feature in one picture is to be found in the second picture. As a result it is possible to determine the information necessary for the transformation of the coordinates of the suspect region—namely the first angle of rotation about the vertical axis, the second angle of rotation about the horizontal axis and the translation—by which the features can be changed into one another. This method delivers more accurate results if the mapping geometries of the two imaging systems are known. The question of which of the preferred methods—RANSAC (see also on this: “Random Sample Consensus: A Paradigm for Model Fitting with Applications to Image Analysis and Automated Cartography” in Comm. of the ACM, Vol. 24, p. 381-395, 1981), robust estimation methods, Hough transformations or least-square methods—is used depends on the calculation speed and the quality of the allocation of the features. For the allocation of the features, reference can be made to the same values as for global image information.
Particularly preferably the determination of the change in position of the item of luggage is carried out using a coupling of the analysis by means of global features with an analysis by means of local features. Such a coupling can take place for example by using both image registration methods and forming a weighted average of the two results. This weighted average can then serve as a function of the probability value. Another coupling can also take place by using the local features only when the probability value of the global features is not high enough. As a result particularly reliable and rapidly obtainable information on the transformation of the coordinates is obtained.
A further advantageous development of the invention provides that the determination of the change in position using local features takes place on different linear scales. For example, this can take place in that the calculation is carried out on one linear scale and the results compared with a comparable analysis on another linear scale. Preferably, the local features are chosen according to the linear scale. On each linear scale the features are chosen which can best be measured there. This leads to a simplification of the determination of the change in position of the item of luggage. For example, the original image of the picture is used as linear scale 1. Linear scale 2 then corresponds to the original image with lower resolution (see on this point also Skalenpyramide [Scale Pyramids] in Jahne, Digitale Bildverarbeitung [Digital Image Processing], Springer 1997). By a scale analysis is meant within the framework of this application that the resolution of the pictures is successively increased. Image registration is then carried out at each resolution stage. Firstly, the image registration of a coarse resolution begins, for example the linear scale 4. This produces a position with a confidence interval. Then the resolution is increased, for example to the linear scale 3, and the image registration is operated only in the confidence interval. These steps are then carried out up to maximum resolution (original image of the linear scale 1). The advantage comprises on the one hand the reduced calculation time and on the other hand the robustness of this method vis-a-vis geometric distortions which can lead to incorrect registrations, in particular at higher resolutions.
A further advantageous development of the invention provides that only the local features are used which do not contradict the analysis using the global features. As a result the allocation of the local features is improved.
Further advantageous developments of the invention are the subject of the dependent claims.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The field of the invention relates to a method for determining the change in position of an item of luggage in order to examine a suspect region in this item of luggage.
BACKGROUND
Currently it is possible to analyze items of luggage completely for explosives. The underlying analysis methods prove very reliable but also laborious. Such a laborious analysis can take place in airports only in so-called third-stage apparatuses. There, the quantity of items of luggage processed is much smaller than with the first- and second-stage apparatuses. With these third-stage apparatuses a high detection rate and a low false alarm rate is required. In order to be able to use such a third-stage apparatus as a second-stage apparatus also, the analysis time must be clearly reduced.
This problem has been solved to date by allowing no physical separation between a first-stage and a second-stage apparatus (see U.S. Pat. No. 5,182,764) or preventing a physical movement or rotation of the item of luggage (see WO 03/065077 A2). However this is very costly and hardly feasible in practice.
SUMMARY
The object of the invention is therefore to provide a method which on the one hand has a high detection rate with simultaneously low false alarm rate, but has a much shorter examination time compared with the known methods with the abovementioned framework conditions.
The object is achieved by a method with the features of claim1. With the method according to the invention the relative change in position of the item of luggage is calculated by comparing two pictures of the same item of luggage which have been recorded in different examination systems. Because the coordinates of a suspect region, which have been obtained in the first examination system are known, it is possible in the second examination system to examine in more detail only this suspect region, the coordinates of which from the first examination system have now been converted to the coordinates in the second examination system. As a result, the time spent analyzing once again all the parts of the item of luggage that have already been identified as a non-suspect region is saved. Any imaging system is possible as first and second examination systems, provided the calculation of the angles of rotation is to take place about the vertical and horizontal axes and also the translation. These include both video images and transmission images, for example by means of X-ray radiation. How the suspect region is obtained in the first examination system is not essential to the invention, with the result that for the first examination system and the second examination system, apparatuses can be used that operate on completely different technological principles. For the second examination machine, a transmission system is preferred in respect of the examination of the suspect region, but the invention is by no means limited to this. It is equally possible to use e.g. magnetic resonance tomography. In addition, the two examination systems can also be far apart. The item of luggage to be examined can be carried by hand or transported via a vehicle with the result that even a conveyor belt between them can be dispensed with. Consequently, there is an enormous saving as a result of the method according to the invention in analysis time with a simultaneously high detection rate and low false alarm rate. An advantageous development of the invention provides that an optical and/or geometrical pre-processing of the first and/or second transmission image takes place before determination of the change in position. By an optical pre-processing it is meant within the scope of this invention that the image information of a transmission image is manipulated such that the function of the image registration is improved in respect of accuracy and reliability. This can be achieved for example by carrying out a local averaging and median formation to reduce the noise. In addition, non-linear scale filters (see G. Aubert & P. Komprobst: Mathematical Problems in Image Processing: Partial Differential Equations and the Calculus of Variations. Springer, N.Y., 2002) can also be used. These filters reduce the image information content inside image segments, but retain edges so that the position of the image segments does not change. As a result, perspective changes due to different viewing angles in the two examination systems can be compensated. A further possibility is to use look-up tables, gamma filters or histogram filters, as a result of which identical absorptions also look the same within the transmission image, which is necessary in particular if the two examination systems are constructed or operate differently. Local features, e.g. edges, points or massive objects, can also be highlighted. Finally, by geometric pre-processing is meant within the framework of this application a geometric rectification. This is necessary whenever the two examination systems have different geometries. In such a case, different representations result even if the examined item of luggage is in the same position. Optical pre-processing makes possible a better basis for comparing the pictures of the item of luggage of the first and second examination systems. This leads to a simpler determination of the first angle of rotation about the vertical axis, the second angle of rotation about the horizontal axis and the translation.
A further advantageous development of the invention provides that several sets of first and/or second angles of rotation are issued in the case of ambiguities. Although it is necessary as a result to examine several suspect regions, as a rule only a few regions are left over, with the result that there is a clear reduction in the regions to be examined in the item of luggage. At the same time the detection rate is kept high and the false alarm rate remains low. The two hypotheses used are that the item of luggage has or has not been flipped, i.e. that it is lying on the same side or on its opposite side. Ambiguities occur if the method cannot decide clearly between these two hypotheses. Preferred is the input in each case of a probability value or a confidence value (a number or a vector of numbers which provides information about the reliability of a result) for the first and/or second angles of rotation. As a result, an appraisal of the suspect regions found is carried out and an examination can be carried out first of the region for which the angles with the highest probability value have been found. As a result it is more probable that dangerous contents of the item of luggage will be discovered more quickly. By a probability value is meant in the present application a value which provides information as to how high the reliability of the determined values for translation and angles of rotation is (which also indicates whether the item of luggage has been flipped over or not). This probability value can be used to allow other entities (both a person and a machine) to decide on the quality of the image registration. For example, a threshold value is used which, if not reached, causes the whole item of luggage to be scanned once again in the second examination system. A further advantageous development of the invention provides that the change in position of the item of luggage is determined using global features, in particular correlation, “mutual information” (see description relating toFIG. 3) or radial dimensional variables. One of the two pictures of the item of luggage is rotated until it is most similar to the other picture. The point of rotation must be defined in both pictures. Preferably the centre of gravity of the image of the item of luggage is used. Iijis the intensity value of the image at point (i,j). The resultant coordinates of the centre of gravity of the image (xg, yg) are then:
xg=∑i,jx,Ii,j∑i,jIi,j,yg=∑i,jy,Ii,j∑i,jIi,j,
In addition to the use of correlation and “mutual information”, the use of radial dimensional variables is also possible. The picture is divided into N angle segments (the evaluation takes place in each case in an angle range between φ and φ+Δφ) which are appraised with different values, e.g. statistical moments. The values of the Nth segments are then compared with the values of the N+nth segment, n corresponding to the angle increment. This measurement is preferably coupled with a scale analysis. The results on different linear scales, i.e. at different resolutions, are compared and these findings are combined, as a result of which a reduced calculation time is obtained. Thus the calculation time is reduced by a factor of 4 if the resolution is halved, as fewer image spots must be analyzed. Preferably different comparison values can also be used and their result taken jointly into account. By a comparison value is meant within the framework of the application a function which has the two pictures as input parameters and provides a number or a vector. This issued value is then related to the difference between the two images. The simplest example of this is the difference between the two image spots. If this is small, the two pictures are identical. By global features is meant within the framework of this application that all image spots of the image are used for image registration. This differs from the local features given below which are used as a subset of all these image spots. The respective subset must be determined. One possibility for this is the detection of corners and edges.
A further advantageous development of the invention provides that the change in position of the item of luggage is determined using local features, in particular using “Random Sample Consensus” (RANSAC), robust estimation methods, Hough transformations or least-square methods. Suitable local features are sought in both pictures, e.g. corners, edges, lines, significant points or small, easily-identifiable objects (such as metal buttons) inside the item of luggage. These features are allocated to one another by ascertaining where a specific feature in one picture is to be found in the second picture. As a result it is possible to determine the information necessary for the transformation of the coordinates of the suspect region—namely the first angle of rotation about the vertical axis, the second angle of rotation about the horizontal axis and the translation—by which the features can be changed into one another. This method delivers more accurate results if the mapping geometries of the two imaging systems are known. The question of which of the preferred methods—RANSAC (see also on this: “Random Sample Consensus: A Paradigm for Model Fitting with Applications to Image Analysis and Automated Cartography” in Comm. of the ACM, Vol. 24, p. 381-395, 1981), robust estimation methods, Hough transformations or least-square methods—is used depends on the calculation speed and the quality of the allocation of the features. For the allocation of the features, reference can be made to the same values as for global image information.
Particularly preferably the determination of the change in position of the item of luggage is carried out using a coupling of the analysis by means of global features with an analysis by means of local features. Such a coupling can take place for example by using both image registration methods and forming a weighted average of the two results. This weighted average can then serve as a function of the probability value. Another coupling can also take place by using the local features only when the probability value of the global features is not high enough. As a result particularly reliable and rapidly obtainable information on the transformation of the coordinates is obtained.
A further advantageous development of the invention provides that the determination of the change in position using local features takes place on different linear scales. For example, this can take place in that the calculation is carried out on one linear scale and the results compared with a comparable analysis on another linear scale. Preferably, the local features are chosen according to the linear scale. On each linear scale the features are chosen which can best be measured there. This leads to a simplification of the determination of the change in position of the item of luggage. For example, the original image of the picture is used as linear scale 1. Linear scale 2 then corresponds to the original image with lower resolution (see on this point also Skalenpyramide [Scale Pyramids] in Jahne, Digitale Bildverarbeitung [Digital Image Processing], Springer 1997). By a scale analysis is meant within the framework of this application that the resolution of the pictures is successively increased. Image registration is then carried out at each resolution stage. Firstly, the image registration of a coarse resolution begins, for example the linear scale 4. This produces a position with a confidence interval. Then the resolution is increased, for example to the linear scale 3, and the image registration is operated only in the confidence interval. These steps are then carried out up to maximum resolution (original image of the linear scale 1). The advantage comprises on the one hand the reduced calculation time and on the other hand the robustness of this method vis-a-vis geometric distortions which can lead to incorrect registrations, in particular at higher resolutions.
A further advantageous development of the invention provides that only the local features are used which do not contradict the analysis using the global features. As a result the allocation of the local features is improved.
Further advantageous developments of the invention are the subject of the dependent claims.
Is this patent green technology? Respond with 'yes' or 'no'. |
7666234 | FIELD OF THE INVENTION
The present invention relates to an improved process for the preparation of biodiesel from triglyceride oils obtained from plant materials by transesterification. More specifically, the present invention relates to preparation of fatty acid methyl ester of oil expelled from whole seeds ofJatropha curcas, a plant that has potential for cultivation on wasteland in India and other countries.
BACKGROUND OF THE INVENTION
The depletion of fossil fuel and their polluting effect has spurred interest in renewable sources of energy, e.g., solar energy, wind energy, tidal energy, draught animal power, and energy that can be derived from plant sources.
Reference is made to a review article titled “Biodiesel fuel production by transesterification of oils” by H. Fukuda et al. (Journal of Bioscience and Bioengineering, vol. 92, No. 5, (2001), 405-416) that discusses the drawbacks of using vegetable oils directly in place of fossil diesel and the three approaches being investigated to overcome these drawbacks, namely, pyrolysis, micro-emulsification and transesterification. This article further states that transesterification is the preferred approach, and that such transesterification of oils can be effected by three routes, namely, acid catalysis, base catalysis and enzyme catalysis. While each route has its merits, base catalysis is the most industrially acceptable route presently in view of the much faster rate of reaction and inexpensive nature of the catalyst. The drawbacks of the current alkali-catalysed process as reported are: higher than ambient reaction temperature (60-70° C.), problems encountered with free fatty acid in the raw oil, difficulty encountered in recovering glycerol and methanol, and need for repeated washing of the methyl ester with water to effect its purification. No mention is made about the fate of the catalyst and the manner of effluent disposal.
Reference is made to the same review article above wherein it is stated that in a report entitled “An overview of biodiesel and petroleum diesel life cycles” by Sheehan et al. (Report of National Renewable Energy Laboratory (NREL) and US-Department of Energy (DOE) Task No. BF886002, May (1998)), it has been shown that the benefit of using biodiesel is proportionate to the level of blending with petroleum diesel. The overall life cycle emissions of CO2from 100% biodiesel fuel are 78.45% lower than those of petroleum diesel, and a blend with 20% biodiesel fuel reduces net CO2emissions by 15.66%.
Reference is made to the article entitled “Biodiesel: A Renewable Energy Fuel” by N. S. K. Prasad (Chemical Weekly, Aug. 17, 2004, p 183-188) wherein it is mentioned on p 186 that: “Biodiesel is widely used in Europe. Germany has more than 1500 filling stations selling biodiesel at the pump. France is the world's largest producer. All French Diesel fuel contains between 2-5% biodiesel that will soon apply to the whole of Europe. In the 1990s, France launched the local production of biodiesel fuel (known locally as diester) obtained by the transesterification of rape seed oil. It is mixed to the proportion of 5% into regular diesel fuel, and to the proportion of 30% into the diesel fuel used by captive fleets (public transportation). Renault, Peugeot and other manufacturers have certified truck engines for use with up to this partial biodiesel. Experiments with 50% biodiesel are underway.”
Reference is made to a Google search:
http://www.google.co.in/search?hl=en&q=Biodiesel+preparation&btnG=Google+Search&meta, that yielded 13,200 different results related to biodiesel preparation.
Reference is made to the paper entitled “Integrated biodiesel production: a comparison of different homogeneous catalysts systems” by Vicente et al. (Bioresource Technology92 (2004) 297-305) wherein the process of transesterification of vegetable oils with different base catalysts is described. The authors report that the maximum yield of biodiesel obtained by them using alkali catalysed methanolysis is ca. 85.32% and 90.54% for NaOH and KOH-catalysed reactions, respectively, for laboratory scale experiments with oil having <0.5% FFA. Besides less than desirable yield, other drawbacks of the process are the need to carry out the transesterification reaction at higher than ambient conditions and the lack of any suitable solution to the problem of catalyst disposal and effluent management.
U.S. Pat. No. 6,489,496, describes a process for transesterification of triglycerides with continuous removal of glycerol produced during the reaction using centrifugal separator to enhance the reaction rate. The major draw back of the process is that the transesterification reaction is carried out at 70° C. The process does not describe the removal of catalyst from the glycerol, removal of methanol from the ester product, and recycling the excess ethanol; and hence the process is rendered uneconomical for industrial practice.
U.S. Pat. No. 6,712,867 discloses a process for production of fatty acid methyl esters from fatty acid triglycerides wherein the process of transesterification of triglycerides using methanol and/or ethanol, alkali catalyst and cosolvent like ether. The major drawbacks of the process are: (i) the use of cosolvent, higher than ambient transesterification temperature, and lack of any attempt to deal with the problem of spent catalyst discharge.
The Internet site http://www.svlele.com/biodiesel_in_india, discloses a detailed project report on Biodiesel manufacturing unit of 10 kl per day capacity. The project report is based on known prior art which, as mentioned above, has important limitations.
US Patent Application No. 20030229238 dated Dec. 11, 2003 relates to a continuous transesterification process, wherein the process includes a continuous, plug-flow environment with a single-pass residence time as low as about 10 seconds, and a conversion of at least 70 percent. The major draw back of the process is that it employs high temperature and pressure for transesterification reaction.
In another article W. Zhou et al, titled “Ethyl esters from the Single-Phase Base-Catalyzed Ethanolysis of Vegetable Oils” (JAOCS vol. 80, 367-371, 2003) the base catalyzed transesterification of vegetable oils has been carried out using co-solvent tetrahydrofuran (THF) and ethanol at elevated temperature. The draw backs of this publication are: the transesterification is carried out at elevated temperatures, and the use of additional solvent in the system renders the process complicated and expensive. Further, the article is silent on the recovery of the catalyst in any form and that of excess alcohol used in the reaction.
There are several literature reports wherein lipases have been used as catalysts in industrial processes for producing Biodiesel; for example Bradin (U.S. Pat. No. 6,398,707) uses a pretreated immobilized lipase to catalyze the transesterification or esterification. Further, the pretreated immobilized lipase is prepared by immersing an immobilized lipase in an alcohol having a carbon atom number not less than 3 and the pretreatment of lipase requires time up to 48 hours. Such processes are time consuming for industrial production. In another article published by Watanabe, et al., [“Continuous Production of Biodiesel Fuel from Vegetable Oil Using Immobilized Candida antarctica Lipase”, JAOCS,vol. 77, pp. 355-360, 2000], there are three major difficulties in using lipase to produce Biodiesel. The first difficulty is that price of lipase is much higher than price of alkali. Secondly lipase process requires up to 48 hours to complete the reaction which is significantly longer than with base catalysis. The third difficulty is that the activity of lipase is relatively low, and it requires pretreatment with an alcohol having a carbon atom number not less than 3. Another difficulty with enzyme catalysis not alluded to in the article is that, for transesterification with methanol which is the preferred alcohol for biodiesel preparation, the reaction is extremely sluggish and proceeds in most cases with only low conversion efficiency, if at all.
Although ways of circumventing the problems associated with alkali-catalysed biodiesel preparation through use of alternative catalysts such as enzymes, acids and heterogeneous catalysts are described, it would be greatly beneficial if the base-catalysed process itself could be improved to overcome the current drawbacks. One such reported improvement is 2-stage transesterification but, here again, this slows down the overall throughput of the reaction and it would be desirable if high quality biodiesel, such as that conforming to EN14214 specifications, can be produced in a single stage. There are also no reports of any suitable means of overcoming the problem of messy work up of the crude fatty acid methyl ester obtained on transesterification of triglyceride with methanol, and losses of product/reagents in aqueous effluent. Moreover, given that biodiesel is about promoting green technology, it would be highly desirable if the entire process of producing such biodiesel from raw oil is carried out under ambient conditions. Another limitation of the prior art is that in attempting to maximize biodiesel yield, the process sometimes can be more complex than desirable and it would be of interest to have a simpler process where useful co-products are obtained along with biodiesel and, in the process, the overall method of production is maintained as simple as possible.
A Google search:
http://www.google.co.in/search?hl=en&q=Biodiesel+preparation+from+Jatropba+oil&btnG=Google+Search&meta provided 141 results related to biodiesel fromJatropha curcasoil. The oil obtained from the non-traditionalJatropha curcasplant is non-edible.
Reference is made to a book titledBiofuels and Industrial Products from Jatropha curcas, G. M. Gublitz, M. Mittelbach, M. Trabi, Eds. (1997), wherein it is reported by G. D. Sharma et al. that theJ. curcasplant can be grown over a wide range of arid or semi-arid climatic conditions, is hardy to weather conditions, easy to propagate by seed or cuttings, and not browsed by goat or cattle. Reference is also be made to an article by B. Schmook and L. Serralta-Peraza in the same book wherein the authors state that “Taking into account the climatic and edaphic conditions of the Yucatan Peninsula, which are not very favorable for modern agriculture,J. curcascould be an option.” It will be evident that the plant is suitable for cultivation on wasteland and large quantities of biodiesel may become available from wasteland in future if biodiesel of desired quality can be produced in simple and cost-effective manner. Reference is also be made to articles in the above book by E. Zamora et al. and M. N. Eisa on transesterification ofJ. curcasoil. The articles do not disclose much of the details of the process adopted. Reference is also made to the same book above wherein the utility ofJatrophaoil cake, soap cake and glycerol have been reported in different chapters.
Reference is made to the Petroleum Conservation Research Association web site (http://www.pcra.org/petroleum16.html) wherein it is stated that triglycerides, includingJatrophaoil, are “readily transesterified in the presence of alkaline catalyst (Lye) at atmospheric pressure and temperature of approximately 60-70° C. with an excess of methanol The mixture at the end of reaction is allowed to settle. The excess methanol is recovered by distillation and sent to a rectifying column for purification and recycled. The lower glycerol layer is drawn off while the upper methyl ester layer is washed with water to remove entrained glycerol Methyl esters of fatty acids are termed as bio-diesel.” Apart from the fact that transesterification is conducted at higher than ambient temperature, no mention is made of the layer from which methanol is recovered or what is done with the alkali. There is also no mention of the complications expected to be encountered when water is added into the crude biodiesel layer.
The Minutes of Meeting of Adhoc Panel of experts of PCD 3 constituted by Bureau of Indian Standards for finalising Specifications of Biodiesel held on 17 Jun. 2004 which has been circulated for comments, wherein it is stated that: “On bio-diesel there are two important overseas standards, namely, EN 14214 and ASTM D 6751. The scope of EN 14214 covers the requirements of bio-diesel for its use as 100% and also for blending with diesel whereas the scope of ASTMD 6751 covers the requirements of bio-diesel only blend stocks.” The report further states that: “Considering the fact that the bio-diesel in India is expected to be manufactured from non edible vegetable oils, members felt that it would be extremely difficult to meet the EN specifications.”
Reference is made to an article by M. N. Eisa, titled “Production of ethyl esters as diesel fuel substitutes in the developing countries” (pp 110-112), inProceedings on Biofuels and Industrial Products from Jatropha curcas,23-27 Feb. 1997, held in Managua, Nicaragua. The article discloses the preparation of ethyl ester of oil by base catalyzed transesterification. The draw backs of this process are that they use large excess of ethyl alcohol (up to 70 parts per 100 parts of oil) and they did not recover the catalyst and the reaction temperature is also at around 70° C.
Reference is also be made to a publication by N. Foidl et al, titled “Jatropha Curcas L as a Source For The Production of Biofuel in Nicaragua” (Bioresource Technology,58, 1996, pp 77-82) wherein it is stated that for developing countries like Nicaragua,Jatropha curcasis a very promising energy plant since the plant can be grown on very poor soils and gives a high average yield of seeds. The publication further describes the method of producing methyl ester of the oil, effectively by the 2-step base-catalysed transesterification process. The oil having 0.60-1.27% FFA is expelled from the seed kernel ofJatropha curcasseeds and then processed with 1.5 equivalents of MeOH and 1.3% KOH in a continuous reactor, with recycling of 90-93% of the methyl ester with fresh oil. The remaining ester phase is mixed with 5% of warm water and then centrifuged to eliminate excess methanol, remaining soaps and glycerol. The main disadvantages of the process are: (i) the need to decorticate the seeds, (ii) the low throughput because of high recycle ratio, and (iii) the high phosphorous (17.5 ppm) and moisture (0.16%) levels which would make the product unsuitable for use as neat biodiesel. No mention is also made of the complications of work up of the crude methyl ester, effluent management and the fate of the catalyst used.
Reference is made to the composition of the oil fromJ. Curcasseeds of Caboverde variety and Nicaragua variety reported in the above article. It is stated that the oil contains 290 ppm of phosphorous, and its level in biodiesel can be reduced to 17.5 ppm in the adopted process but degumming is necessary to produce biodiesel with <10 ppm of phosphorous as mandated in the EN14214 specifications for B100 biodiesel.
It will be evident from the prior art that there is no report wherein pure biodiesel of EN14214 specification has been prepared fromJatropha curcasoil, not to mention preparation of such premium quality biodiesel from oil expelled directly from whole seeds. Moreover, there is no report of biodiesel preparation under ambient conditions of processing which would minimize generation of greenhouse gases during processing. There is also little indication in the prior art of the economics of production and any attempts to value add effluents and flue gases. Lack of a suitable solution to the problem of spent alkali catalyst value addition, coupled with the cost of catalyst, may compel lower than optimum quantities of catalyst to be otherwise used that can adversely affect the process. There is also no report wherein the process has been optimized keeping the value of all products in mind.
Reference may be made to H. Scherzberg et al. who in their paper entitled ‘Messo pilots new potassium sulphate process’, (Phosphorous & Potassium, 178, March-April 1992, p-20) describe the utility of potassium sulphate as a superior fertilizer having both potassium and sulphur as plant nutrients and additionally having low chloride index.
Reference is made to an article on Potassium Compounds by H. Schultz et al. in Ullmann's Encyclopedia, 6thEdition, 2002, wherein the preparation of potassium carbonate from caustic potash and carbon dioxide is reported to be the most popular. It is further stated that: “the glass industry is the most important consumer of K2CO3. Large amounts are also required for potassium silicate manufacture.” Besides many other applications, potassium carbonate is used as a fertilizer for acidic soil.
Reference is made to U.S. Pat. No. 6,174,501, by H. Noureddini discloses a system and process for producing biodiesel fuel with reduced viscosity and a cloud point below thirty-two (32) degrees Fahrenheit in which the utility of crude glycerol for preparation of glycerol ethers. These ethers are shown to lower the cloud point of the biodiesel obtained through based catalysed transesterification of triglycerides.
OBJECTS OF THE INVENTION
The main object of the invention is to provide an improved process for the preparation of fatty acid methyl ester (biodiesel) from triglyceride oil through transestrification
Another object of the present invention is to provide an improved process for the preparation of biodiesel from triglyceride oil obtained from plant materials.
Another object of the present invention is to provide an improved process for the preparation of biodiesel ofJatrophaoil that complies with EN14214 specifications and is suitable for use as biodiesel in neat form in mobile and stationary engines without any engine modification.
Another object of the present invention is to produce biodiesel under ambient conditions from raw oil expelled from whole seeds ofJatropha curcas.
Another object of the present invention is to produce biodiesel with least energy input and minimum effluent formation.
Another object of the present invention is to reduce the FFA content of oil to <0.5% by treating the raw oil under ambient conditions with required quantity of caustic soda solution of optimum concentration and to simultaneously eliminate pigments, phospholipids and other impurities in the raw oil along with the soap cake.
Another object of the present invention is to convert the soap cake containing 15-20% residual oil into a laundry bar.
Another object of the present invention is to sparge the neutralized oil with dry air to reduce the moisture content of the oil.
Another object of the present invention is to dry the methanolic-KOH used for transesterification of the oil with anhydrous sodium sulphate.
Another object of the present invention is to improve the method of work up of crude fatty acid methyl ester after tranesterification of the oil.
Another object of the present invention is to wash crude methyl ester after separation of glycerol layer with additional amounts of glycerol so as to extract out much of the methanol, catalyst and other impurities in methyl ester into the glycerol layer and thereby eliminate the problem of emulsion and froth formation, as also undesirable impurity-forming reactions, when the methyl ester is washed with water.
Another object of the present invention is to use water having <50 ppm total dissolved solids for washing the fatty acid methyl ester.
Another object is to add an antioxidant to the water-washed biodiesel and sparge with dry air to reduce the moisture content to <500 ppm.
Another object of the present invention is to take advantage of the improved process and work up procedure to produce biodiesel with 96% yield (w.r.t. neutralized oil) and ≦0.15% total glycerol through one-step transesterification of neutralized oil.
Another object of the present invention is to minimize COD and TDS of aqueous washings.
Another object of the present invention is to confine all of the KOH and excess methanol used in the reaction in the glycerol layers produced during reaction and used for washing of the crude fatty acid methyl ester.
Another object of the present invention is to treat the alkaline glycerol layer with SOxor concentrated sulphuric acid so as to convert the spent catalyst into solid fertilizer grade potassium sulphate that can be filtered and washed.
Another object of the present invention is to treat the alkaline glycerol layer with flue gases from the boiler in the biodiesel plant so as to convert the spent catalyst into potassium carbonate that can be filtered and washed.
Another object of the present invention is to distill the methanol in the glycerol layer for reuse after drying.
Another object of the present invention is to recycle a part of the crude glycerol remaining after methanol distillation for washing of crude methyl ester as described above.
Another object of the present invention is to utilize a part of the crude glycerol for preparation of glycerol ether to reduce the cloud point of the biodiesel as described in the prior art.
Another object of the present invention is to distill the balance amount of crude glycerol having low water content so as to produce refined glycerol cost-effectively.
Another object of the present invention is to provide a model of biodiesel production wherein biodiesel is produced in rural areas in the vicinity of the cultivation site and both the biodiesel as also by-products of the biodiesel process can be utilized locally to the maximum extent possible.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide an improved process for the preparation of fatty acid methyl ester (biodiesel) from oil expelled mechanically from whole seeds ofJatropha curcas. Biodiesel is produced from raw oil under ambient conditions by first removing FFA and other impurities from the oil and thereafter using a single step KOH-catalysed transesterification followed by a novel work up based on initial washing of crude fatty acid methyl ester with glycerol followed by washing with water to remove traces of remaining impurities. The work up confines all the excess methanol and alkali in glycerol, which is then processed with greater cost-effectiveness and energy-efficiency to recover individual constituents (methanol, glycerol, potash) from the mixture. A further novelty is the use of flue gases in the above process. Biodiesel complying with EN14214 specification is obtained in >96% yield (w/w) w.r.t. neutralized oil and all by-products obtained are of commercial value. As a result of the above inventions, the effluent load is at a minimum.
Inventive Steps
(1) The main inventive step is the recognition that improving the process of work up of the methyl ester ofJatrophaoil after transesterification is the key to improving the overall process economics and biodiesel quality.(2) Another inventive step is the recognition that, whereas methanol is poorly soluble inJatrophaoil, it is much more soluble in the methyl ester ofJatrophaoil, i.e., in the biodiesel, and as a result considerable quantities of methanol and alkali catalyst used in the transesterification reaction, as also soaps, remain solubilised in the biodiesel at the end of the reaction.(3) Another inventive step is the recognition that, whereas it is desirable to have methanol and catalyst solubilised in the biodiesel to allow the transesterification reaction to proceed to completion, their subsequent removal from biodiesel by washing with water poses the following difficulties: (i) the methyl ester gets partially hydrolysed in presence of water and alkali to produce a soap which can promote emulsification of biodiesel and water, necesssitating long period of standing to break the emulsion, (ii) the yield and quality of biodiesel can be adversely affected as a result, (iii) biodiesel can be lost in aqueous effluent if clear separation of the layers is not achieved, (iv) methanol consumption will increase since methanol that remains dissolved in biodiesel will be lost in the water, (v) a part of the alkali catalyst will be wasted in the aqueous effluent, and (vi) treatment of the alkaline aqueous effluent will be costly and problematic.(4) Another inventive step is the recognition that retention of methanol, catalyst, and soaps in methyl ester will be higher when 2-step transesterification is carried out since the relative proportion of glycerol formed in the second step of transesterification tends to be less and, consequently, the pulling out of methanol, catalyst and soap is less effective. By contrast, the weight of glycerol layer separated is approximately the same as the weight of methanolic KOH used when an optimum amount of methanol and KOH is used in a single step transesterification, as a result of which there is little residual impurities that need to be removed from the fatty acid methyl ester layer.(5) Another inventive step is use of additional glycerol—obtained through recovery of glycerol from previous batches of biodiesel production—to pull off residual methanol, catalyst and other impurities remaining in biodiesel at the end of transesterification reaction, such glycerol layer cleanly separating from the ester layer upon standing for short duration.(6) Another inventive step is washing off any residual methanol, catalyst and free glycerol in the methyl ester with water without encountering any problem of ester hydrolysis and emulsion formation, resulting in a methyl ester layer (biodiesel) that can be cleanly separated and has FFA, methanol, alkali metal, total glycerol and free glycerol impurity levels well below those specified in the EN14214 specifications.(7) Another inventive step is sparging water-washed biodiesel with dry nitrogen or air at ambient temperature to drive off moisture and achieve residual moisture level <500 ppm.(8) Another inventive step is incorporation of an antioxidant into the biodiesel after water washing to minimise oxidative degradation while sparging with air and subsequently on storage of the product.(9) Another inventive step is producing clear, golden yellow biodiesel from dark brown, turbid rawJatrophaoil under ambient condition by taking advantage of the neutralization step of FFA reduction wherein the majority of other impurities in oil such as pigments, phospholipids and insoluble matter are eliminated along with soap cake.(10) Another inventive step is the near-quantitative recovery of spent KOH catalyst confined in the glycerol layer in the form of solid sulphate of potash fertilizer or potassium carbonate.(11) Another inventive step is the cost-effective recovery of methanol and glycerol from glycerol layer by keeping moisture content of the layer to a bare minimum as produced stoichiometrically during the neutralization of KOH.(12) Another inventive step is treating the saponified mass obtained on removal of free fatty acid fromJatrophaoil with additional quantity of caustic lye to convert all trapped oil into soap, and further upgrading the soap, if desired, by incorporating by-product glycerol generated in the biodiesel process.(13) Another inventive step is the processing of oil for biodiesel entirely under ambient condition and economizing on energy by confining heating operations only to the small volume of glycerol layer.(14) Another inventive step is the minimization of aqueous effluent load by cleaning up the methyl ester with glycerol prior to water wash and also by reusing the second lot of washings in the first water wash of subsequent batch and also by utilizing a part of the first water wash for preparation of NaOH solution required for the oil neutralization and soap making steps.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention relates to an improved process for the preparation of biodiesel from triglyceride oils obtained from plant materials by transesterification. More specifically, the present invention relates to preparation of fatty acid methyl ester of oil expelled from whole seeds ofJatropha curcas, a plant that has potential for cultivation on wasteland in India and other countries.
BACKGROUND OF THE INVENTION
The depletion of fossil fuel and their polluting effect has spurred interest in renewable sources of energy, e.g., solar energy, wind energy, tidal energy, draught animal power, and energy that can be derived from plant sources.
Reference is made to a review article titled “Biodiesel fuel production by transesterification of oils” by H. Fukuda et al. (Journal of Bioscience and Bioengineering, vol. 92, No. 5, (2001), 405-416) that discusses the drawbacks of using vegetable oils directly in place of fossil diesel and the three approaches being investigated to overcome these drawbacks, namely, pyrolysis, micro-emulsification and transesterification. This article further states that transesterification is the preferred approach, and that such transesterification of oils can be effected by three routes, namely, acid catalysis, base catalysis and enzyme catalysis. While each route has its merits, base catalysis is the most industrially acceptable route presently in view of the much faster rate of reaction and inexpensive nature of the catalyst. The drawbacks of the current alkali-catalysed process as reported are: higher than ambient reaction temperature (60-70° C.), problems encountered with free fatty acid in the raw oil, difficulty encountered in recovering glycerol and methanol, and need for repeated washing of the methyl ester with water to effect its purification. No mention is made about the fate of the catalyst and the manner of effluent disposal.
Reference is made to the same review article above wherein it is stated that in a report entitled “An overview of biodiesel and petroleum diesel life cycles” by Sheehan et al. (Report of National Renewable Energy Laboratory (NREL) and US-Department of Energy (DOE) Task No. BF886002, May (1998)), it has been shown that the benefit of using biodiesel is proportionate to the level of blending with petroleum diesel. The overall life cycle emissions of CO2from 100% biodiesel fuel are 78.45% lower than those of petroleum diesel, and a blend with 20% biodiesel fuel reduces net CO2emissions by 15.66%.
Reference is made to the article entitled “Biodiesel: A Renewable Energy Fuel” by N. S. K. Prasad (Chemical Weekly, Aug. 17, 2004, p 183-188) wherein it is mentioned on p 186 that: “Biodiesel is widely used in Europe. Germany has more than 1500 filling stations selling biodiesel at the pump. France is the world's largest producer. All French Diesel fuel contains between 2-5% biodiesel that will soon apply to the whole of Europe. In the 1990s, France launched the local production of biodiesel fuel (known locally as diester) obtained by the transesterification of rape seed oil. It is mixed to the proportion of 5% into regular diesel fuel, and to the proportion of 30% into the diesel fuel used by captive fleets (public transportation). Renault, Peugeot and other manufacturers have certified truck engines for use with up to this partial biodiesel. Experiments with 50% biodiesel are underway.”
Reference is made to a Google search:
http://www.google.co.in/search?hl=en&q=Biodiesel+preparation&btnG=Google+Search&meta, that yielded 13,200 different results related to biodiesel preparation.
Reference is made to the paper entitled “Integrated biodiesel production: a comparison of different homogeneous catalysts systems” by Vicente et al. (Bioresource Technology92 (2004) 297-305) wherein the process of transesterification of vegetable oils with different base catalysts is described. The authors report that the maximum yield of biodiesel obtained by them using alkali catalysed methanolysis is ca. 85.32% and 90.54% for NaOH and KOH-catalysed reactions, respectively, for laboratory scale experiments with oil having <0.5% FFA. Besides less than desirable yield, other drawbacks of the process are the need to carry out the transesterification reaction at higher than ambient conditions and the lack of any suitable solution to the problem of catalyst disposal and effluent management.
U.S. Pat. No. 6,489,496, describes a process for transesterification of triglycerides with continuous removal of glycerol produced during the reaction using centrifugal separator to enhance the reaction rate. The major draw back of the process is that the transesterification reaction is carried out at 70° C. The process does not describe the removal of catalyst from the glycerol, removal of methanol from the ester product, and recycling the excess ethanol; and hence the process is rendered uneconomical for industrial practice.
U.S. Pat. No. 6,712,867 discloses a process for production of fatty acid methyl esters from fatty acid triglycerides wherein the process of transesterification of triglycerides using methanol and/or ethanol, alkali catalyst and cosolvent like ether. The major drawbacks of the process are: (i) the use of cosolvent, higher than ambient transesterification temperature, and lack of any attempt to deal with the problem of spent catalyst discharge.
The Internet site http://www.svlele.com/biodiesel_in_india, discloses a detailed project report on Biodiesel manufacturing unit of 10 kl per day capacity. The project report is based on known prior art which, as mentioned above, has important limitations.
US Patent Application No. 20030229238 dated Dec. 11, 2003 relates to a continuous transesterification process, wherein the process includes a continuous, plug-flow environment with a single-pass residence time as low as about 10 seconds, and a conversion of at least 70 percent. The major draw back of the process is that it employs high temperature and pressure for transesterification reaction.
In another article W. Zhou et al, titled “Ethyl esters from the Single-Phase Base-Catalyzed Ethanolysis of Vegetable Oils” (JAOCS vol. 80, 367-371, 2003) the base catalyzed transesterification of vegetable oils has been carried out using co-solvent tetrahydrofuran (THF) and ethanol at elevated temperature. The draw backs of this publication are: the transesterification is carried out at elevated temperatures, and the use of additional solvent in the system renders the process complicated and expensive. Further, the article is silent on the recovery of the catalyst in any form and that of excess alcohol used in the reaction.
There are several literature reports wherein lipases have been used as catalysts in industrial processes for producing Biodiesel; for example Bradin (U.S. Pat. No. 6,398,707) uses a pretreated immobilized lipase to catalyze the transesterification or esterification. Further, the pretreated immobilized lipase is prepared by immersing an immobilized lipase in an alcohol having a carbon atom number not less than 3 and the pretreatment of lipase requires time up to 48 hours. Such processes are time consuming for industrial production. In another article published by Watanabe, et al., [“Continuous Production of Biodiesel Fuel from Vegetable Oil Using Immobilized Candida antarctica Lipase”, JAOCS,vol. 77, pp. 355-360, 2000], there are three major difficulties in using lipase to produce Biodiesel. The first difficulty is that price of lipase is much higher than price of alkali. Secondly lipase process requires up to 48 hours to complete the reaction which is significantly longer than with base catalysis. The third difficulty is that the activity of lipase is relatively low, and it requires pretreatment with an alcohol having a carbon atom number not less than 3. Another difficulty with enzyme catalysis not alluded to in the article is that, for transesterification with methanol which is the preferred alcohol for biodiesel preparation, the reaction is extremely sluggish and proceeds in most cases with only low conversion efficiency, if at all.
Although ways of circumventing the problems associated with alkali-catalysed biodiesel preparation through use of alternative catalysts such as enzymes, acids and heterogeneous catalysts are described, it would be greatly beneficial if the base-catalysed process itself could be improved to overcome the current drawbacks. One such reported improvement is 2-stage transesterification but, here again, this slows down the overall throughput of the reaction and it would be desirable if high quality biodiesel, such as that conforming to EN14214 specifications, can be produced in a single stage. There are also no reports of any suitable means of overcoming the problem of messy work up of the crude fatty acid methyl ester obtained on transesterification of triglyceride with methanol, and losses of product/reagents in aqueous effluent. Moreover, given that biodiesel is about promoting green technology, it would be highly desirable if the entire process of producing such biodiesel from raw oil is carried out under ambient conditions. Another limitation of the prior art is that in attempting to maximize biodiesel yield, the process sometimes can be more complex than desirable and it would be of interest to have a simpler process where useful co-products are obtained along with biodiesel and, in the process, the overall method of production is maintained as simple as possible.
A Google search:
http://www.google.co.in/search?hl=en&q=Biodiesel+preparation+from+Jatropba+oil&btnG=Google+Search&meta provided 141 results related to biodiesel fromJatropha curcasoil. The oil obtained from the non-traditionalJatropha curcasplant is non-edible.
Reference is made to a book titledBiofuels and Industrial Products from Jatropha curcas, G. M. Gublitz, M. Mittelbach, M. Trabi, Eds. (1997), wherein it is reported by G. D. Sharma et al. that theJ. curcasplant can be grown over a wide range of arid or semi-arid climatic conditions, is hardy to weather conditions, easy to propagate by seed or cuttings, and not browsed by goat or cattle. Reference is also be made to an article by B. Schmook and L. Serralta-Peraza in the same book wherein the authors state that “Taking into account the climatic and edaphic conditions of the Yucatan Peninsula, which are not very favorable for modern agriculture,J. curcascould be an option.” It will be evident that the plant is suitable for cultivation on wasteland and large quantities of biodiesel may become available from wasteland in future if biodiesel of desired quality can be produced in simple and cost-effective manner. Reference is also be made to articles in the above book by E. Zamora et al. and M. N. Eisa on transesterification ofJ. curcasoil. The articles do not disclose much of the details of the process adopted. Reference is also made to the same book above wherein the utility ofJatrophaoil cake, soap cake and glycerol have been reported in different chapters.
Reference is made to the Petroleum Conservation Research Association web site (http://www.pcra.org/petroleum16.html) wherein it is stated that triglycerides, includingJatrophaoil, are “readily transesterified in the presence of alkaline catalyst (Lye) at atmospheric pressure and temperature of approximately 60-70° C. with an excess of methanol The mixture at the end of reaction is allowed to settle. The excess methanol is recovered by distillation and sent to a rectifying column for purification and recycled. The lower glycerol layer is drawn off while the upper methyl ester layer is washed with water to remove entrained glycerol Methyl esters of fatty acids are termed as bio-diesel.” Apart from the fact that transesterification is conducted at higher than ambient temperature, no mention is made of the layer from which methanol is recovered or what is done with the alkali. There is also no mention of the complications expected to be encountered when water is added into the crude biodiesel layer.
The Minutes of Meeting of Adhoc Panel of experts of PCD 3 constituted by Bureau of Indian Standards for finalising Specifications of Biodiesel held on 17 Jun. 2004 which has been circulated for comments, wherein it is stated that: “On bio-diesel there are two important overseas standards, namely, EN 14214 and ASTM D 6751. The scope of EN 14214 covers the requirements of bio-diesel for its use as 100% and also for blending with diesel whereas the scope of ASTMD 6751 covers the requirements of bio-diesel only blend stocks.” The report further states that: “Considering the fact that the bio-diesel in India is expected to be manufactured from non edible vegetable oils, members felt that it would be extremely difficult to meet the EN specifications.”
Reference is made to an article by M. N. Eisa, titled “Production of ethyl esters as diesel fuel substitutes in the developing countries” (pp 110-112), inProceedings on Biofuels and Industrial Products from Jatropha curcas,23-27 Feb. 1997, held in Managua, Nicaragua. The article discloses the preparation of ethyl ester of oil by base catalyzed transesterification. The draw backs of this process are that they use large excess of ethyl alcohol (up to 70 parts per 100 parts of oil) and they did not recover the catalyst and the reaction temperature is also at around 70° C.
Reference is also be made to a publication by N. Foidl et al, titled “Jatropha Curcas L as a Source For The Production of Biofuel in Nicaragua” (Bioresource Technology,58, 1996, pp 77-82) wherein it is stated that for developing countries like Nicaragua,Jatropha curcasis a very promising energy plant since the plant can be grown on very poor soils and gives a high average yield of seeds. The publication further describes the method of producing methyl ester of the oil, effectively by the 2-step base-catalysed transesterification process. The oil having 0.60-1.27% FFA is expelled from the seed kernel ofJatropha curcasseeds and then processed with 1.5 equivalents of MeOH and 1.3% KOH in a continuous reactor, with recycling of 90-93% of the methyl ester with fresh oil. The remaining ester phase is mixed with 5% of warm water and then centrifuged to eliminate excess methanol, remaining soaps and glycerol. The main disadvantages of the process are: (i) the need to decorticate the seeds, (ii) the low throughput because of high recycle ratio, and (iii) the high phosphorous (17.5 ppm) and moisture (0.16%) levels which would make the product unsuitable for use as neat biodiesel. No mention is also made of the complications of work up of the crude methyl ester, effluent management and the fate of the catalyst used.
Reference is made to the composition of the oil fromJ. Curcasseeds of Caboverde variety and Nicaragua variety reported in the above article. It is stated that the oil contains 290 ppm of phosphorous, and its level in biodiesel can be reduced to 17.5 ppm in the adopted process but degumming is necessary to produce biodiesel with <10 ppm of phosphorous as mandated in the EN14214 specifications for B100 biodiesel.
It will be evident from the prior art that there is no report wherein pure biodiesel of EN14214 specification has been prepared fromJatropha curcasoil, not to mention preparation of such premium quality biodiesel from oil expelled directly from whole seeds. Moreover, there is no report of biodiesel preparation under ambient conditions of processing which would minimize generation of greenhouse gases during processing. There is also little indication in the prior art of the economics of production and any attempts to value add effluents and flue gases. Lack of a suitable solution to the problem of spent alkali catalyst value addition, coupled with the cost of catalyst, may compel lower than optimum quantities of catalyst to be otherwise used that can adversely affect the process. There is also no report wherein the process has been optimized keeping the value of all products in mind.
Reference may be made to H. Scherzberg et al. who in their paper entitled ‘Messo pilots new potassium sulphate process’, (Phosphorous & Potassium, 178, March-April 1992, p-20) describe the utility of potassium sulphate as a superior fertilizer having both potassium and sulphur as plant nutrients and additionally having low chloride index.
Reference is made to an article on Potassium Compounds by H. Schultz et al. in Ullmann's Encyclopedia, 6thEdition, 2002, wherein the preparation of potassium carbonate from caustic potash and carbon dioxide is reported to be the most popular. It is further stated that: “the glass industry is the most important consumer of K2CO3. Large amounts are also required for potassium silicate manufacture.” Besides many other applications, potassium carbonate is used as a fertilizer for acidic soil.
Reference is made to U.S. Pat. No. 6,174,501, by H. Noureddini discloses a system and process for producing biodiesel fuel with reduced viscosity and a cloud point below thirty-two (32) degrees Fahrenheit in which the utility of crude glycerol for preparation of glycerol ethers. These ethers are shown to lower the cloud point of the biodiesel obtained through based catalysed transesterification of triglycerides.
OBJECTS OF THE INVENTION
The main object of the invention is to provide an improved process for the preparation of fatty acid methyl ester (biodiesel) from triglyceride oil through transestrification
Another object of the present invention is to provide an improved process for the preparation of biodiesel from triglyceride oil obtained from plant materials.
Another object of the present invention is to provide an improved process for the preparation of biodiesel ofJatrophaoil that complies with EN14214 specifications and is suitable for use as biodiesel in neat form in mobile and stationary engines without any engine modification.
Another object of the present invention is to produce biodiesel under ambient conditions from raw oil expelled from whole seeds ofJatropha curcas.
Another object of the present invention is to produce biodiesel with least energy input and minimum effluent formation.
Another object of the present invention is to reduce the FFA content of oil to <0.5% by treating the raw oil under ambient conditions with required quantity of caustic soda solution of optimum concentration and to simultaneously eliminate pigments, phospholipids and other impurities in the raw oil along with the soap cake.
Another object of the present invention is to convert the soap cake containing 15-20% residual oil into a laundry bar.
Another object of the present invention is to sparge the neutralized oil with dry air to reduce the moisture content of the oil.
Another object of the present invention is to dry the methanolic-KOH used for transesterification of the oil with anhydrous sodium sulphate.
Another object of the present invention is to improve the method of work up of crude fatty acid methyl ester after tranesterification of the oil.
Another object of the present invention is to wash crude methyl ester after separation of glycerol layer with additional amounts of glycerol so as to extract out much of the methanol, catalyst and other impurities in methyl ester into the glycerol layer and thereby eliminate the problem of emulsion and froth formation, as also undesirable impurity-forming reactions, when the methyl ester is washed with water.
Another object of the present invention is to use water having <50 ppm total dissolved solids for washing the fatty acid methyl ester.
Another object is to add an antioxidant to the water-washed biodiesel and sparge with dry air to reduce the moisture content to <500 ppm.
Another object of the present invention is to take advantage of the improved process and work up procedure to produce biodiesel with 96% yield (w.r.t. neutralized oil) and ≦0.15% total glycerol through one-step transesterification of neutralized oil.
Another object of the present invention is to minimize COD and TDS of aqueous washings.
Another object of the present invention is to confine all of the KOH and excess methanol used in the reaction in the glycerol layers produced during reaction and used for washing of the crude fatty acid methyl ester.
Another object of the present invention is to treat the alkaline glycerol layer with SOxor concentrated sulphuric acid so as to convert the spent catalyst into solid fertilizer grade potassium sulphate that can be filtered and washed.
Another object of the present invention is to treat the alkaline glycerol layer with flue gases from the boiler in the biodiesel plant so as to convert the spent catalyst into potassium carbonate that can be filtered and washed.
Another object of the present invention is to distill the methanol in the glycerol layer for reuse after drying.
Another object of the present invention is to recycle a part of the crude glycerol remaining after methanol distillation for washing of crude methyl ester as described above.
Another object of the present invention is to utilize a part of the crude glycerol for preparation of glycerol ether to reduce the cloud point of the biodiesel as described in the prior art.
Another object of the present invention is to distill the balance amount of crude glycerol having low water content so as to produce refined glycerol cost-effectively.
Another object of the present invention is to provide a model of biodiesel production wherein biodiesel is produced in rural areas in the vicinity of the cultivation site and both the biodiesel as also by-products of the biodiesel process can be utilized locally to the maximum extent possible.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide an improved process for the preparation of fatty acid methyl ester (biodiesel) from oil expelled mechanically from whole seeds ofJatropha curcas. Biodiesel is produced from raw oil under ambient conditions by first removing FFA and other impurities from the oil and thereafter using a single step KOH-catalysed transesterification followed by a novel work up based on initial washing of crude fatty acid methyl ester with glycerol followed by washing with water to remove traces of remaining impurities. The work up confines all the excess methanol and alkali in glycerol, which is then processed with greater cost-effectiveness and energy-efficiency to recover individual constituents (methanol, glycerol, potash) from the mixture. A further novelty is the use of flue gases in the above process. Biodiesel complying with EN14214 specification is obtained in >96% yield (w/w) w.r.t. neutralized oil and all by-products obtained are of commercial value. As a result of the above inventions, the effluent load is at a minimum.
Inventive Steps
(1) The main inventive step is the recognition that improving the process of work up of the methyl ester ofJatrophaoil after transesterification is the key to improving the overall process economics and biodiesel quality.(2) Another inventive step is the recognition that, whereas methanol is poorly soluble inJatrophaoil, it is much more soluble in the methyl ester ofJatrophaoil, i.e., in the biodiesel, and as a result considerable quantities of methanol and alkali catalyst used in the transesterification reaction, as also soaps, remain solubilised in the biodiesel at the end of the reaction.(3) Another inventive step is the recognition that, whereas it is desirable to have methanol and catalyst solubilised in the biodiesel to allow the transesterification reaction to proceed to completion, their subsequent removal from biodiesel by washing with water poses the following difficulties: (i) the methyl ester gets partially hydrolysed in presence of water and alkali to produce a soap which can promote emulsification of biodiesel and water, necesssitating long period of standing to break the emulsion, (ii) the yield and quality of biodiesel can be adversely affected as a result, (iii) biodiesel can be lost in aqueous effluent if clear separation of the layers is not achieved, (iv) methanol consumption will increase since methanol that remains dissolved in biodiesel will be lost in the water, (v) a part of the alkali catalyst will be wasted in the aqueous effluent, and (vi) treatment of the alkaline aqueous effluent will be costly and problematic.(4) Another inventive step is the recognition that retention of methanol, catalyst, and soaps in methyl ester will be higher when 2-step transesterification is carried out since the relative proportion of glycerol formed in the second step of transesterification tends to be less and, consequently, the pulling out of methanol, catalyst and soap is less effective. By contrast, the weight of glycerol layer separated is approximately the same as the weight of methanolic KOH used when an optimum amount of methanol and KOH is used in a single step transesterification, as a result of which there is little residual impurities that need to be removed from the fatty acid methyl ester layer.(5) Another inventive step is use of additional glycerol—obtained through recovery of glycerol from previous batches of biodiesel production—to pull off residual methanol, catalyst and other impurities remaining in biodiesel at the end of transesterification reaction, such glycerol layer cleanly separating from the ester layer upon standing for short duration.(6) Another inventive step is washing off any residual methanol, catalyst and free glycerol in the methyl ester with water without encountering any problem of ester hydrolysis and emulsion formation, resulting in a methyl ester layer (biodiesel) that can be cleanly separated and has FFA, methanol, alkali metal, total glycerol and free glycerol impurity levels well below those specified in the EN14214 specifications.(7) Another inventive step is sparging water-washed biodiesel with dry nitrogen or air at ambient temperature to drive off moisture and achieve residual moisture level <500 ppm.(8) Another inventive step is incorporation of an antioxidant into the biodiesel after water washing to minimise oxidative degradation while sparging with air and subsequently on storage of the product.(9) Another inventive step is producing clear, golden yellow biodiesel from dark brown, turbid rawJatrophaoil under ambient condition by taking advantage of the neutralization step of FFA reduction wherein the majority of other impurities in oil such as pigments, phospholipids and insoluble matter are eliminated along with soap cake.(10) Another inventive step is the near-quantitative recovery of spent KOH catalyst confined in the glycerol layer in the form of solid sulphate of potash fertilizer or potassium carbonate.(11) Another inventive step is the cost-effective recovery of methanol and glycerol from glycerol layer by keeping moisture content of the layer to a bare minimum as produced stoichiometrically during the neutralization of KOH.(12) Another inventive step is treating the saponified mass obtained on removal of free fatty acid fromJatrophaoil with additional quantity of caustic lye to convert all trapped oil into soap, and further upgrading the soap, if desired, by incorporating by-product glycerol generated in the biodiesel process.(13) Another inventive step is the processing of oil for biodiesel entirely under ambient condition and economizing on energy by confining heating operations only to the small volume of glycerol layer.(14) Another inventive step is the minimization of aqueous effluent load by cleaning up the methyl ester with glycerol prior to water wash and also by reusing the second lot of washings in the first water wash of subsequent batch and also by utilizing a part of the first water wash for preparation of NaOH solution required for the oil neutralization and soap making steps.
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7685593 | FIELD OF THE INVENTION
The invention is directed to systems and methods for distributing software updates to software systems in a virtual machine (VM) environment and, more particularly, the invention is directed to systems and methods for distributing updates to runtime systems and storing multiple versions of the runtime systems that may be accessed based on the version of the runtime system that is needed to run a particular software application.
BACKGROUND OF THE INVENTION
When updating hardware architectures of computer systems such as game consoles to implement faster, more feature rich hardware, developers are faced with the issue of backwards compatibility to the legacy computer system for application programs or games developed for the legacy computer system platform. In particular, it is commercially desirable that the updated hardware architecture support application programs or games developed for the legacy hardware architecture. However, if the updated hardware architecture differs substantially, or radically, from that of the legacy hardware architecture, architectural differences between the two systems may make it very difficult, or even impossible, for legacy application programs or games to operate on the new hardware architecture without substantial hardware modification and/or software patches. Since customers generally expect such backwards compatibility, a solution to these problems is critical to the success of the updated hardware architecture.
To assure that a new hardware architecture provides complete backwards compatibility to a legacy hardware architecture, one solution is to validate the operation of every application program or game written for the legacy hardware architecture in the new hardware architecture. In the case of a game system such as Xbox, for example, over 750 Xbox games would have to be validated at extraordinary expense with an associated time delay to product release. This problem is shared by any software application platform, and no computer system developer relishes the thought of testing an entire library of application programs or games each time the hardware architecture is changed. A technique to avoid this costly validation process, while still providing support to legacy application programs or games, is desired.
Cost and lack of sufficient technology prevent the solution of the backwards compatibility problems using hardware. Also, re-mastering an existing library of legacy application programs or games is extraordinarily cumbersome and expensive, and thus also undesirable. On the other hand, one approach to this problem that has been successfully used is to emulate the legacy hardware on the new hardware using hardware emulation techniques whereby one or more actual legacy hardware components is included in the new hardware device. For example, the Sony PlayStation 2 game system runs PlayStation 1 games by invoking a hardware emulator that emulates the hardware of the PlayStation 1 architecture. Unfortunately, this approach also has its problems in that it requires the legacy hardware and new hardware to be quite similar and may not be modified once shipped, thereby significantly limiting the upgrade path for the hardware platform.
Fortunately, recent advances in PC architecture and software emulation have provided hardware architectures for computers, even game consoles, that are powerful enough to enable the emulation of legacy application programs or games in software rather than hardware. Such software emulators translate the title instructions for the application program or game on the fly into device instructions understandable by the new hardware architecture. This software emulation approach is particularly useful for backwards compatibility for computer game consoles since the developer of the game console maintains control over both the hardware and software platforms and is quite familiar with the legacy games.
However, a problem remains with the use of software emulators for backwards compatibility. Problems may develop with backwards compatibility for certain legacy application programs or games whereby changing the underlying software platform may destabilize the software emulation of the legacy application program or game. Unfortunately, the fixes themselves could destabilize legacy application programs and games in unexpected ways. As noted above, re-certifying the emulation software against all of the application programs and games is not a desirable option. Accordingly, a solution is required that enables the developer of the computer hardware architecture or game system to change the emulation software, the application programs, or the games without destabilizing the compatibility between the legacy system and the new system. Also, it is desired to enable emulation of only a subset of legacy application programs or games at launch of the emulator product and to enable addition of emulation support for additional application programs or games at a later time so that launch of the emulation product need not be held up until all legacy products are certified. The present invention addresses these needs in the art.
SUMMARY OF THE INVENTION
The invention avoids the backwards compatibility problems outlined above by devising an update protocol that avoids such problems. Rather than updating the software emulation system binary in place to address software bugs and the like, multiple versions of the software emulation application are allowed to co-exist in the persistent memory of the new hardware architecture. Operating system software reads configuration data from a database or table to decide which version of the emulator is desirable for an application program or game that is being loaded or is currently running, and, if a match is found, only that emulator is invoked. In this fashion, future changes only need to be tested for the relevant target application programs or games.
To reduce storage footprint, the different versions of the emulator may be stored using “differential patching” techniques. In other words, the operating system will always launch the same basic emulator binary, but it will select a different differential patch to apply at run-time based on the title under emulation as determined during the database lookup.
Those skilled in the art will appreciate that the invention may be used to update all sorts of middleware, not just emulators. Moreover, while any application platform may benefit from the invention, it will be appreciated that the invention is especially useful for hardware platforms that have a moderate to large number of applications and a significant investment in making sure those applications continue to work. A computer game console is a good example of such a device, but other consumer electronics may also benefit from the techniques of the invention. Additional characteristics of the invention will be apparent to those skilled in the art based on the following detailed description.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The invention is directed to systems and methods for distributing software updates to software systems in a virtual machine (VM) environment and, more particularly, the invention is directed to systems and methods for distributing updates to runtime systems and storing multiple versions of the runtime systems that may be accessed based on the version of the runtime system that is needed to run a particular software application.
BACKGROUND OF THE INVENTION
When updating hardware architectures of computer systems such as game consoles to implement faster, more feature rich hardware, developers are faced with the issue of backwards compatibility to the legacy computer system for application programs or games developed for the legacy computer system platform. In particular, it is commercially desirable that the updated hardware architecture support application programs or games developed for the legacy hardware architecture. However, if the updated hardware architecture differs substantially, or radically, from that of the legacy hardware architecture, architectural differences between the two systems may make it very difficult, or even impossible, for legacy application programs or games to operate on the new hardware architecture without substantial hardware modification and/or software patches. Since customers generally expect such backwards compatibility, a solution to these problems is critical to the success of the updated hardware architecture.
To assure that a new hardware architecture provides complete backwards compatibility to a legacy hardware architecture, one solution is to validate the operation of every application program or game written for the legacy hardware architecture in the new hardware architecture. In the case of a game system such as Xbox, for example, over 750 Xbox games would have to be validated at extraordinary expense with an associated time delay to product release. This problem is shared by any software application platform, and no computer system developer relishes the thought of testing an entire library of application programs or games each time the hardware architecture is changed. A technique to avoid this costly validation process, while still providing support to legacy application programs or games, is desired.
Cost and lack of sufficient technology prevent the solution of the backwards compatibility problems using hardware. Also, re-mastering an existing library of legacy application programs or games is extraordinarily cumbersome and expensive, and thus also undesirable. On the other hand, one approach to this problem that has been successfully used is to emulate the legacy hardware on the new hardware using hardware emulation techniques whereby one or more actual legacy hardware components is included in the new hardware device. For example, the Sony PlayStation 2 game system runs PlayStation 1 games by invoking a hardware emulator that emulates the hardware of the PlayStation 1 architecture. Unfortunately, this approach also has its problems in that it requires the legacy hardware and new hardware to be quite similar and may not be modified once shipped, thereby significantly limiting the upgrade path for the hardware platform.
Fortunately, recent advances in PC architecture and software emulation have provided hardware architectures for computers, even game consoles, that are powerful enough to enable the emulation of legacy application programs or games in software rather than hardware. Such software emulators translate the title instructions for the application program or game on the fly into device instructions understandable by the new hardware architecture. This software emulation approach is particularly useful for backwards compatibility for computer game consoles since the developer of the game console maintains control over both the hardware and software platforms and is quite familiar with the legacy games.
However, a problem remains with the use of software emulators for backwards compatibility. Problems may develop with backwards compatibility for certain legacy application programs or games whereby changing the underlying software platform may destabilize the software emulation of the legacy application program or game. Unfortunately, the fixes themselves could destabilize legacy application programs and games in unexpected ways. As noted above, re-certifying the emulation software against all of the application programs and games is not a desirable option. Accordingly, a solution is required that enables the developer of the computer hardware architecture or game system to change the emulation software, the application programs, or the games without destabilizing the compatibility between the legacy system and the new system. Also, it is desired to enable emulation of only a subset of legacy application programs or games at launch of the emulator product and to enable addition of emulation support for additional application programs or games at a later time so that launch of the emulation product need not be held up until all legacy products are certified. The present invention addresses these needs in the art.
SUMMARY OF THE INVENTION
The invention avoids the backwards compatibility problems outlined above by devising an update protocol that avoids such problems. Rather than updating the software emulation system binary in place to address software bugs and the like, multiple versions of the software emulation application are allowed to co-exist in the persistent memory of the new hardware architecture. Operating system software reads configuration data from a database or table to decide which version of the emulator is desirable for an application program or game that is being loaded or is currently running, and, if a match is found, only that emulator is invoked. In this fashion, future changes only need to be tested for the relevant target application programs or games.
To reduce storage footprint, the different versions of the emulator may be stored using “differential patching” techniques. In other words, the operating system will always launch the same basic emulator binary, but it will select a different differential patch to apply at run-time based on the title under emulation as determined during the database lookup.
Those skilled in the art will appreciate that the invention may be used to update all sorts of middleware, not just emulators. Moreover, while any application platform may benefit from the invention, it will be appreciated that the invention is especially useful for hardware platforms that have a moderate to large number of applications and a significant investment in making sure those applications continue to work. A computer game console is a good example of such a device, but other consumer electronics may also benefit from the techniques of the invention. Additional characteristics of the invention will be apparent to those skilled in the art based on the following detailed description.
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7849332 | FIELD OF THE INVENTION
The present invention relates to the field of processor operation. More particularly, the present invention relates to a system and method for adjusting graphics processor performance.
BACKGROUND OF THE INVENTION
Electronic systems and circuits have made a significant contribution towards the advancement of modern society and are utilized in a number of applications to achieve advantageous results. Numerous electronic technologies such as digital computers, calculators, audio devices, video equipment, and telephone systems facilitate increased productivity and cost reduction in analyzing and communicating data, ideas and trends in most areas of business, science, education and entertainment. Frequently, these activities involve significant information processing. However, the speed at which a processor can reliably provide accurate results is limited and typically degrades over time. Most systems limit processor operation within conservative boundaries and sacrifice possible increased performance so that the processor can meet reliability standards.
Advanced applications are creating ever greater demands for faster processor performance. For example, the desired objective of numerous applications is to provide a visual presentation to a user (e.g., on a display monitor). Displaying information in a visual presentation is usually a convenient and effective method of conveying the information. Display devices (cathode ray tube monitors, liquid crystal displays, etc.) usually present images by coordinating the illumination characteristics of numerous picture elements (pixels). However, many graphics presentations, especially interactive 3D graphics presentations, usually require significant processing of large amounts of data at a rapid rate. Providing image information for each pixel is very data intensive and consumes a significant amount of processing resources. Advanced graphics applications such as three dimensional graphics utilized in modern gaming applications require significant amounts of information associated with each pixel (e.g., primary color intensity, transparency, brightness, texture and shading) to be produced at rates fast enough to provide a smooth and interactive presentation.
Graphics information generation is often best performed by dedicated graphics subsystem resources including graphics processor units. Separate graphics processors relieve the central processor of performing many of the graphics processing tasks. Graphics processors are usually specifically configured for performance of graphics activities enabling a graphics processor to perform many graphics operations faster and more efficiently than a central processor.
The amount of information and speed at which it is processed by a processor is determined by a variety of factors. For example, the number of transistors and their configuration on the chip usually affect the bandwidth and speed at which the processing can occur. Generally, a larger number of transistors can process information quicker than a smaller number of transistors operating at the same clock frequency. However, at some point increasing the number of transistors becomes cost prohibitive. Another factor that affects the processing speed is the clock frequency. A processor typically performs operations in a sequence of events (e.g., fetching, decoding and executing instructions), the order and timing of which are usually critical. A processor typically relies upon a clock signal to provide appropriate synchronization and satisfy requisite timing constraints. However, increasing the clock frequency is often limited by the characteristics of the transistors utilized to perform the processing. Higher voltages can be used to sustain operations at a higher clock frequency, and higher clock frequencies and voltage supplies cause a processor to consume more power, thereby increasing the temperature of the processor. However, higher temperatures generally cause transistors to operate more slowly, causing a lower operational transistor speed. Continually running a processor at a high temperature stresses the semiconductor device and reduces long term reliability of the device.
The basic electronic component for performing most of the switching operations in a processor is a transistor. There are a number of factors that can affect the degradation of a transistor's ability to quickly and reliably perform switching operations. For example, the drain current saturation (Id,sat) is one of the underlying physical mechanisms involved in transistor switching operations and is often utilized to indicate how fast a transistor can perform switching operations. The drain current saturation rating of a transistor can be adversely impacted by the temperature and voltage level at which the transistor is operating, causing deterioration in the transistor switching speed. These limitations impact maximum clock frequencies since transistor reliability is often degraded over time by increased voltage levels and temperatures associated with relatively high clock frequencies.
Most processors are identified by a particular fixed nominal clock frequency at which the processor is expected to provide reliable results over a specific life span (e.g., 10 years). Numerous systems operate the processor at the fixed nominal clock frequency continuously for the life of the processor even though a task does not require the level of processing speed provided by the fixed nominal clock frequency. The fixed nominal frequency is typically not the fastest frequency the processor can possibly operate at and resource utilization is not maximized. To the extent traditional processing systems attempt clock frequency adjustment, they are usually limited to downward adjustments from the fixed nominal clock frequency to achieve power conservation, further limiting the maximization of processor performance speed. Some traditional processing systems also attempt to make various adjustments in response to temperature measurements. These attempts are also typically limited in scope (such as a single specific adjustment) and usually have limited or no consideration for impacts on processing performance (e.g., maximized processing speed) or environment (e.g., noise level). Traditional attempts at processor control typically have limited or no consideration for impacts of frequency, voltage and/or temperature adjustments on maximizing performance while maintaining overall lifetime reliability.
SUMMARY
The present invention facilitates maintenance of processor speed by voltage level adjustment. In one embodiment, a present invention voltage adjustment system includes a speed analysis component that compares an actual speed of a processing unit to a directed speed. If the actual speed is lower than the directed speed, a voltage control component directs offset adjustments in a voltage level of a power signal to the processor. For example, the voltage control component directs an increase in a voltage level of a power signal. The voltage level can be altered to compensate for hardware tolerance variations. In one embodiment of the present invention, a voltage sensor measures the actual voltage of the processing unit.
The present invention also facilitates maintenance of a processor temperature within acceptable ranges that minimize overheating damage to the processor. In one embodiment, a present invention temperature maintenance system includes a temperature sensor that senses the temperature of the processor. This sensor can take the form of an on-chip diode and an off-chip voltage-to-temperature measuring device, the device being programmable to set an indicator when any of a plurality of temperature thresholds is crossed. When the temperature sensor senses the processor temperature approaching undesirable levels one or more adjustments are performed. For example, the adjustment can include automatically modulating the frequency of a clock signal associated with the processor. The frequency can be decreased (without software intervention) if the temperature rises beyond a predetermined value or the frequency can be increased to achieve greater performance if the temperature drops below the predetermined value. Voltage can be similarly increased or decreased in response to crossing a temperature threshold. In addition, an interrupt can be generated that causes software to take additional actions to tune the clock frequency in response to temperature measurements.
Adjustments to the fan operations can also be made to increase cooling when required (e.g., temperature increases beyond predetermined values) or to run in a quiet mode when cooling is not required. In one embodiment, a processor can be configured to run in at least two modes, a quiet mode and a performance mode. In the quiet mode performance is reduced to minimize fan operation as much as possible. In performance mode the fan is directed to operate in a manner that facilitates achievement of maximum performance. In one exemplary implementation, a driver can automatically select between the modes depending on the type of application programs that are running. Alternatively, a user can select the mode via a control panel.
In one embodiment the present invention provides temperature control via pulse width modulation of the clock signal. For example, a clock speed adjustment circuit picks a variable amount of clock pulses out of 256 clock pulses and removes the rest. This allows an almost continuously variable clock rate, and allows smooth transitions between clock frequencies.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention relates to the field of processor operation. More particularly, the present invention relates to a system and method for adjusting graphics processor performance.
BACKGROUND OF THE INVENTION
Electronic systems and circuits have made a significant contribution towards the advancement of modern society and are utilized in a number of applications to achieve advantageous results. Numerous electronic technologies such as digital computers, calculators, audio devices, video equipment, and telephone systems facilitate increased productivity and cost reduction in analyzing and communicating data, ideas and trends in most areas of business, science, education and entertainment. Frequently, these activities involve significant information processing. However, the speed at which a processor can reliably provide accurate results is limited and typically degrades over time. Most systems limit processor operation within conservative boundaries and sacrifice possible increased performance so that the processor can meet reliability standards.
Advanced applications are creating ever greater demands for faster processor performance. For example, the desired objective of numerous applications is to provide a visual presentation to a user (e.g., on a display monitor). Displaying information in a visual presentation is usually a convenient and effective method of conveying the information. Display devices (cathode ray tube monitors, liquid crystal displays, etc.) usually present images by coordinating the illumination characteristics of numerous picture elements (pixels). However, many graphics presentations, especially interactive 3D graphics presentations, usually require significant processing of large amounts of data at a rapid rate. Providing image information for each pixel is very data intensive and consumes a significant amount of processing resources. Advanced graphics applications such as three dimensional graphics utilized in modern gaming applications require significant amounts of information associated with each pixel (e.g., primary color intensity, transparency, brightness, texture and shading) to be produced at rates fast enough to provide a smooth and interactive presentation.
Graphics information generation is often best performed by dedicated graphics subsystem resources including graphics processor units. Separate graphics processors relieve the central processor of performing many of the graphics processing tasks. Graphics processors are usually specifically configured for performance of graphics activities enabling a graphics processor to perform many graphics operations faster and more efficiently than a central processor.
The amount of information and speed at which it is processed by a processor is determined by a variety of factors. For example, the number of transistors and their configuration on the chip usually affect the bandwidth and speed at which the processing can occur. Generally, a larger number of transistors can process information quicker than a smaller number of transistors operating at the same clock frequency. However, at some point increasing the number of transistors becomes cost prohibitive. Another factor that affects the processing speed is the clock frequency. A processor typically performs operations in a sequence of events (e.g., fetching, decoding and executing instructions), the order and timing of which are usually critical. A processor typically relies upon a clock signal to provide appropriate synchronization and satisfy requisite timing constraints. However, increasing the clock frequency is often limited by the characteristics of the transistors utilized to perform the processing. Higher voltages can be used to sustain operations at a higher clock frequency, and higher clock frequencies and voltage supplies cause a processor to consume more power, thereby increasing the temperature of the processor. However, higher temperatures generally cause transistors to operate more slowly, causing a lower operational transistor speed. Continually running a processor at a high temperature stresses the semiconductor device and reduces long term reliability of the device.
The basic electronic component for performing most of the switching operations in a processor is a transistor. There are a number of factors that can affect the degradation of a transistor's ability to quickly and reliably perform switching operations. For example, the drain current saturation (Id,sat) is one of the underlying physical mechanisms involved in transistor switching operations and is often utilized to indicate how fast a transistor can perform switching operations. The drain current saturation rating of a transistor can be adversely impacted by the temperature and voltage level at which the transistor is operating, causing deterioration in the transistor switching speed. These limitations impact maximum clock frequencies since transistor reliability is often degraded over time by increased voltage levels and temperatures associated with relatively high clock frequencies.
Most processors are identified by a particular fixed nominal clock frequency at which the processor is expected to provide reliable results over a specific life span (e.g., 10 years). Numerous systems operate the processor at the fixed nominal clock frequency continuously for the life of the processor even though a task does not require the level of processing speed provided by the fixed nominal clock frequency. The fixed nominal frequency is typically not the fastest frequency the processor can possibly operate at and resource utilization is not maximized. To the extent traditional processing systems attempt clock frequency adjustment, they are usually limited to downward adjustments from the fixed nominal clock frequency to achieve power conservation, further limiting the maximization of processor performance speed. Some traditional processing systems also attempt to make various adjustments in response to temperature measurements. These attempts are also typically limited in scope (such as a single specific adjustment) and usually have limited or no consideration for impacts on processing performance (e.g., maximized processing speed) or environment (e.g., noise level). Traditional attempts at processor control typically have limited or no consideration for impacts of frequency, voltage and/or temperature adjustments on maximizing performance while maintaining overall lifetime reliability.
SUMMARY
The present invention facilitates maintenance of processor speed by voltage level adjustment. In one embodiment, a present invention voltage adjustment system includes a speed analysis component that compares an actual speed of a processing unit to a directed speed. If the actual speed is lower than the directed speed, a voltage control component directs offset adjustments in a voltage level of a power signal to the processor. For example, the voltage control component directs an increase in a voltage level of a power signal. The voltage level can be altered to compensate for hardware tolerance variations. In one embodiment of the present invention, a voltage sensor measures the actual voltage of the processing unit.
The present invention also facilitates maintenance of a processor temperature within acceptable ranges that minimize overheating damage to the processor. In one embodiment, a present invention temperature maintenance system includes a temperature sensor that senses the temperature of the processor. This sensor can take the form of an on-chip diode and an off-chip voltage-to-temperature measuring device, the device being programmable to set an indicator when any of a plurality of temperature thresholds is crossed. When the temperature sensor senses the processor temperature approaching undesirable levels one or more adjustments are performed. For example, the adjustment can include automatically modulating the frequency of a clock signal associated with the processor. The frequency can be decreased (without software intervention) if the temperature rises beyond a predetermined value or the frequency can be increased to achieve greater performance if the temperature drops below the predetermined value. Voltage can be similarly increased or decreased in response to crossing a temperature threshold. In addition, an interrupt can be generated that causes software to take additional actions to tune the clock frequency in response to temperature measurements.
Adjustments to the fan operations can also be made to increase cooling when required (e.g., temperature increases beyond predetermined values) or to run in a quiet mode when cooling is not required. In one embodiment, a processor can be configured to run in at least two modes, a quiet mode and a performance mode. In the quiet mode performance is reduced to minimize fan operation as much as possible. In performance mode the fan is directed to operate in a manner that facilitates achievement of maximum performance. In one exemplary implementation, a driver can automatically select between the modes depending on the type of application programs that are running. Alternatively, a user can select the mode via a control panel.
In one embodiment the present invention provides temperature control via pulse width modulation of the clock signal. For example, a clock speed adjustment circuit picks a variable amount of clock pulses out of 256 clock pulses and removes the rest. This allows an almost continuously variable clock rate, and allows smooth transitions between clock frequencies.
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7815113 | BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to digital image capturing and processing scanners of ultra-compact design capable of reading bar code symbols in point-of-sale (POS) and other demanding scanning environments.
2. Brief Description of the State of Knowledge in the Art
The use of bar code symbols for product and article identification is well known in the art. Presently, various types of bar code symbol scanners have been developed for reading bar code symbols at retail points of sale (POS). In general, these bar code symbol readers can be classified into two (2) distinct classes.
The first class of bar code symbol reader uses a focused light beam, typically a focused laser beam, to sequentially scan the bars and spaces of a bar code symbol to be read. This type of bar code symbol scanner is commonly called a “flying spot” scanner as the focused laser beam appears as “a spot of light that flies” across the bar code symbol being read. In general, laser bar code symbol scanners are sub-classified further by the type of mechanism used to focus and scan the laser beam across bar code symbols.
The second class of bar code symbol readers simultaneously illuminate all of the bars and spaces of a bar code symbol with light of a specific wavelength(s) in order to capture an image thereof for recognition and decoding purposes.
The majority of laser scanners in the first class employ lenses and moving (i.e. rotating or oscillating) mirrors and/or other optical elements in order to focus and scan laser beams across bar code symbols during code symbol reading operations. Examples of hand-held laser scanning bar code readers are described in U.S. Pat. Nos. 7,007,849 and 7,028,904, each incorporated herein by reference in its entirety. Examples of laser scanning presentation bar code readers are described in U.S. Pat. No. 5,557,093, incorporated herein by reference in its entirety. Other examples of bar code symbol readers using multiple laser scanning mechanisms are described in U.S. Pat. No. 5,019,714, incorporated herein by reference in its entirety.
In demanding retail environments, such as supermarkets and high-volume department stores, where high check-out throughput is critical to achieving store profitability and customer satisfaction, it is common for laser scanning bar code reading systems to have both bottom and side-scanning windows to enable highly aggressive scanner performance. In such systems, the cashier need only drag a bar coded product past these scanning windows for the bar code thereon to be automatically read with minimal assistance of the cashier or checkout personal. Such dual scanning window systems are typically referred to as “bioptical” laser scanning systems as such systems employ two sets of optics disposed behind the bottom and side-scanning windows thereof. Examples of polygon-based bioptical laser scanning systems are disclosed in U.S. Pat. Nos.: 4,229,588; 4,652,732 and 6,814,292; each incorporated herein by reference in its entirety.
Commercial examples of bioptical laser scanners include: the PSC 8500-6-sided laser based scanning by PSC Inc.; PSC 8100/8200, 5-sided laser based scanning by PSC Inc.; the NCR 7876-6-sided laser based scanning by NCR; the NCR7872, 5-sided laser based scanning by NCR; and the MS232x Stratos®H, and MS2122 Stratos® E Stratos 6 sided laser based scanning systems by Metrologic Instruments, Inc., and the MS2200 Stratos®S 5-sided laser based scanning system by Metrologic Instruments, Inc.
In general, prior art bioptical laser scanning systems are generally more aggressive that conventional single scanning window systems. However, while prior art bioptical scanning systems represent a technological advance over most single scanning window system, prior art bioptical scanning systems in general suffer from various shortcomings and drawbacks. In particular, the scanning coverage and performance of prior art bioptical laser scanning systems are not optimized. These systems are generally expensive to manufacture by virtue of the large number of optical components presently required to construct such laser scanning systems. Also, they require heavy and expensive motors which consume significant amounts of electrical power and generate significant amounts of heat.
In the second class of bar code symbol readers, early forms of linear imaging scanners were commonly known as CCD scanners because they used CCD image detectors to detect images of the bar code symbols being read. Examples of such scanners are disclosed in U.S. Pat. Nos. 4,282,425, and 4,570,057; each incorporated herein by reference in its entirety.
In more recent times, hand-held imaging-based bar code readers employing area-type image sensing arrays based on CCD and CMOS sensor technologies have gained increasing popularity.
In U.S. patent application Ser. No. 10/712,787, a detailed history of hand-hand imaging—based bar code symbol readers is provided, explaining the many problems that had to be overcome to make imaging-based scanners competitive against laser-scanning based bar code readers. Metrologic Instruments' Focus® Hand-Held Imager is representative of an advance in the art which has overcome such historical problems. An advantage of 2D imaging-based bar code symbol readers is that they are omni-directional by nature of image capturing and processing based decode processing software that is commercially available from various vendors.
U.S. Pat. No. 6,766,954 to Barkan et al. proposes a combination of linear image sensing arrays in a hand-held unit to form an omni-directional imaging-based bar code symbol reader. However, this hand-held imager has limited application to 1D bar code symbols, and is extremely challenged in reading 2D bar code symbologies at POS applications.
And yet despite the increasing popularity in area-type hand-held and presentation type imaging-based bar code symbol reading systems, such systems still cannot complete with the performance characteristics of conventional laser scanning bioptical bar code symbol readers in POS environments.
Thus, there is a great need in the art for an improved bar code symbol reading system that is capable of competing with conventional laser scanning bioptical bar code readers employed in demanding POS environments, and providing the many advantages offered by imaging-based bar code symbol readers, while avoiding the shortcomings and drawbacks of such prior art systems and methodologies.
OBJECTS AND SUMMARY OF THE PRESENT INVENTION
Accordingly, a primary object of the present invention is to provide an improved digital image capturing and processing apparatus for use in POS environments, which is free of the shortcomings and drawbacks of prior art bioptical laser scanning systems and methodologies.
Another object of the present invention is to provide such a digital image capturing and processing apparatus in the form of an omni-directional image capturing and processing based bar code symbol reading system that employs advanced coplanar illumination and imaging technologies.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, comprising a plurality of coplanar illumination and imaging stations (i.e. subsystems), generating a plurality of coplanar light illumination beams and field of views (FOVs), that are projected through and intersect above an imaging window to generate a complex of linear-imaging planes within a 3D imaging volume for omni-directional imaging of objects passed therethrough.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the plurality of coplanar light illumination beams can be generated by an array of coherent or incoherent light sources.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the array of coherent light sources comprises an array of visible laser diodes (VLDs).
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the array of incoherent light sources comprises an array of light emitting diodes (LEDs).
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein is capable of reading (i) bar code symbols having bar code elements (i.e., ladder type bar code symbols) that are oriented substantially horizontal with respect to the imaging window, as well as (ii) bar code symbols having bar code elements (i.e., picket-fence type bar code symbols) that are oriented substantially vertical with respect to the imaging window.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, which comprises a plurality of coplanar illumination and imaging stations (i.e. subsystems), each of which produces a coplanar PLIB/FOV within predetermined regions of space contained within a 3-D imaging volume defined above the imaging window of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein each coplanar illumination and imaging station comprises a planar light illumination module (PLIM) that generates a planar light illumination beam (PLIB) and a linear image sensing array and field of view (FOV) forming optics for generating a planar FOV which is coplanar with its respective PLIB.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, comprising a plurality of coplanar illumination and imaging stations, each employing a linear array of laser light emitting devices configured together, with a linear imaging array with substantially planar FOV forming optics, producing a substantially planar beam of laser illumination which extends in substantially the same plane as the field of view of the linear array of the station, within the working distance of the 3D imaging volume.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, having an electronic weigh scale integrated within the system housing.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, comprising a plurality of coplanar illumination and imaging stations strategically arranged within an ultra-compact housing, so as to project out through an imaging window a plurality of coplanar illumination and imaging planes that capture omni-directional views of objects passing through a 3D imaging volume supported above the imaging window.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system comprising a plurality of coplanar illumination and imaging stations, each employing an array of planar laser illumination modules (PLIMs).
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein at each coplanar illumination and imaging station, an array of VLDs concentrate their output power into a thin illumination plane which spatially coincides exactly with the field of view of the imaging optics of the coplanar illumination and imaging station, so very little light energy is wasted.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein each planar illumination beam is focused so that the minimum width thereof occurs at a point or plane which is the farthest object distance at which the system is designed to capture images within the 3D imaging volume of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein at each coplanar illumination and imaging station, an object need only be illuminated along a single plane which is coplanar with a planar section of the field of view of the image formation and detection module being used in the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein low-power, light-weight, high-response, ultra-compact, high-efficiency solid-state illumination producing devices, such as visible laser diodes (VLDs), are used to selectively illuminate ultra-narrow sections of a target object during image formation and detection operations.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein the planar laser illumination technique enables modulation of the spatial and/or temporal intensity of the transmitted planar laser illumination beam, and use of simple (i.e. substantially monochromatic) lens designs for substantially monochromatic optical illumination and image formation and detection operations.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein intelligent object presence detection, motion and trajectory detection techniques are employed to automatically determined when and where an object is being moved through the 3D imaging volume of the system, and to selectively activate only those light emitting sources when an object is being moved within the spatial extent of its substantially planar laser beam so as to minimize the illumination of consumers who might be present along the lines of projected illumination/imaging during the operation of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein such intelligent object presence detection, motion and trajectory detection includes the use of an imaging-based motion sensor, at each coplanar illumination and imaging subsystem, and having a field of view that is spatially aligned with at least a portion of the field of view of the linear image sensing array employed in the coplanar illumination and imaging subsystem.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the imaging-based motion sensor employed at each coplanar illumination and imaging subsystem therein employs the laser illumination array of the coplanar illumination and imaging subsystem, operated at a lower operating power, to illuminate objects while the system is operating in its object motion/velocity detection mode.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the imaging-based motion sensor is used to determine the velocity of objects moving though the field of view (FOV) of a particular coplanar illumination and imaging station, and automatically control the frequency at which pixel data, associated with captured linear images, is transferred out of the linear image sensing array and into buffer memory.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing a plurality of coplanar illumination and imaging stations, wherein each such station includes a linear imaging module realized as an array of electronic image detection cells (e.g. CCD) having programmable integration time settings, responsive to the automatically detected velocity of an object being imaged, for enabling high-speed image capture operations.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing a plurality of coplanar illumination and imaging stations, wherein at each such station, a pair of planar laser illumination arrays are mounted about an image formation and detection module having a field of view, so as to produce a substantially planar laser illumination beam which is coplanar with the field of view during object illumination and imaging operations, and one or more beam/FOV folding mirrors are used to direct the resulting coplanar illumination and imaging plane through the imaging window of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing a plurality of coplanar illumination and imaging stations, wherein each such station supports an independent image generation and processing channel that receives frames of linear (1D) images from the linear image sensing array and automatically buffers these linear images in video memory and automatically assembles these linear images to construct 2D images of the object taken along the field of view of the coplanar illumination and imaging plane associated with the station, and then processes these images using exposure quality analysis algorithms, bar code decoding algorithms, and the like.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system capable of reading PDF bar codes for age verification, credit card application and other productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system capable of reading PDF and 2D bar codes on produce—eliminating keyboard entry and enjoying productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system supporting image capture and processing for produce automatic produce recognition and price lookup support—eliminating keyboard entry and enjoying productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system supporting image capture and processing for analyzing cashier scanning tendencies, and providing cashier training to help achieve productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system supporting image capture and processing for automatic item look up when there is no bar code or price tag on an item, thereby achieving productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a very fast wakeup from sleep mode—ready to scan first item—to achieve productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), each supporting an object motion/velocity sensing mode of operation.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein each coplanar illumination and imaging subsystem (i.e. station) employs an illumination control method that may involve the control of parameters selected from the group consisting of: illumination source (e.g. ambient, LED, VLD); illumination intensity (e.g. low-power, half-power, full power); illumination beam width (e.g. narrow, wide); and illumination beam thickness (e.g. beam thickness).
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the different illumination control methods that can be implemented at each illumination and imaging station in the system, include:
(1) Ambient Control Method, wherein ambient lighting is used to illuminate the FOV of the image sensing array in the object motion/velocity sensing subsystem during the object motion/velocity detection mode and bar code symbol reading mode of subsystem operation;
(2) Partial-Power Illumination Method, wherein illumination produced from the LED or VLD array is operated at half, fractional or otherwise partial power, and directed into the field of view (FOV) of the image sensing array employed in the object motion/velocity sensing subsystem;
(3) Full-Power Illumination Method, wherein illumination produced by the LED or VLD array is operated at half or fractional power, and directed in the field of view (FOV) of the image sensing array employed in the object motion/velocity sensing subsystem.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein each coplanar illumination and imaging station employs an Illumination Beam Width Method, such that the thickness of the planar illumination beam (PLIB) is increased so as to illuminate more pixels (e.g. 3 or more pixels) on the image sensing array of object motion when the station is operated in its object motion/velocity detection mode.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Distributed Local Control is employed, such that at each illumination and imaging station, the local control subsystem controls the function and operation of the components of the illumination and imaging subsystem, and sends state data to the global control subsystem for state management at the level of system operation.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Distributed Local Control, with Global Over-Ride Control, is employed, such that the local control subsystem controls the function and operation of the components of the illumination and imaging subsystem, and sends state data to the global control subsystem for state management at the level of system operation, as well as for over-riding the control functions of nearest neighboring local control subsystems employed within other illumination and imaging stations in the system, thereby allowing the global control subsystem to drive one or more other stations in the system to the bar code reading state upon receiving state data from a local control subsystem that an object has been detected and its velocity computed/estimated.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Distributed Local Control, with Global Over-Ride Control, is employed, such that the local control subsystem controls the function and operation of the components of the illumination and imaging subsystem, and sends state data to the global control subsystem for state management at the level of system operation, as well as for over-riding the control functions of all neighboring local control subsystems employed within other illumination and imaging stations in the system, thereby allowing the global control subsystem to drive one or more other stations in the system to the bar code reading state upon receiving state data from a local control subsystem that an object has been detected and its velocity computed/estimated.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Global Control is employed, such that the local control subsystem in each illumination and imaging station controls the operation of the subcomponents in the station, except for “state control” which is managed at the system level by the global control subsystem using “state data” generated by one or more object motion sensors (e.g. imaging based, IR Pulse-Doppler LIDAR-based, ultra-sonic energy based, etc.) provided at the system level within the 3D imaging volume of the system, in various possible locations.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein one or more Pulse-Doppler LIDAR subsystems, or Pulse-Doppler SONAR subsystems, are employed in the system so that real-time object velocity sensing can be achieved within the 3D imaging volume, or across a major section or diagonal thereof, so that object velocity data can be captured and distributed (in real-time) to each illumination and imaging station (via the global control subsystem) for purposes of adjusting the illumination and/or exposure control parameters therein (e.g. the frequency of the clock signal used to read out image data from the linear image sensing array within the IFD subsystem in the station).
Another object of the present invention is to provide a digital image capturing and processing system having an integrated electronic weigh scale, wherein its image capturing and processing module electrically interfaces with its electronic weigh scale module by way of a pair of touch-fit electrical interconnectors that automatically establish all electrical interconnections between the two modules when the image capturing and processing module is placed onto the electronic weigh scale module, and its electronic load cell bears the weight of the image capturing and processing module.
Another object of the present invention is to provide a digital image capturing and processing bar code reading system, with an integrated electronic weigh scale subsystem, suitable for POS applications, wherein the load cell of the electronic weigh scale module directly bears substantially all of the weight of the image capturing and processing module (and any produce articles placed thereon during weighing operations), while a touch-fit electrical interconnector arrangement automatically establishes all electrical interconnections between the two modules.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the 2D images produced from the multiple image generation and processing channels are managed by an image processing management processor programmed to optimize image processing flows.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system which supports intelligent image-based object recognition processes that can be used to automate the recognition of objects such as produce and fruit in supermarket environments.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having an integrated electronic weight scale, an RFID module, and modular support of wireless technology (e.g. BlueTooth and IEEE 802.11(g)).
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system capable of reading bar code symbologies independent of bar code orientation.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a 5 mil read capability.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a below counter depth not to exceed 3.5″ (89 mm).
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having direct connect power for PlusPower USB Ports.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having an integrated scale with its load cell positioned substantially in the center of weighing platform.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having an integrated Sensormatic® deactivation device, and an integrated Checkpoint® EAS antenna.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing cashier training software, and productivity measurement software showing how an operator actually oriented packages as they were scanned by the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having flash ROM capability.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system that can power a hand held scanner.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a mechanism for weighing oversized produce.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having excellent debris deflecting capabilities.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system that is capable of reading all types of poor quality codes—eliminating keyboard entry and enjoying productivity gains.
Another object of the present invention is to provide an image capturing and processing scanner based high throughput scanner that can address the needs of the supermarket/hypermarket and grocery store market segment.
Another object of the present invention is to provide an image capturing and processing scanner having a performance advantage that leads to quicker customer checkout times and productivity gain that cannot be matched by the conventional bioptic laser scanners.
Another object of the present invention is to provide a high throughput image capturing and processing scanner which can assist in lowering operational costs by exceptional First Pass Read Rate scanning and one product pass performance, enabling sales transactions to be executed with no manual keyboard entry required by the operator.
Another object of the present invention is to provide a high performance image capturing and processing checkout scanner that can meet the emerging needs of retailers to scan PDF and 2D bar codes for age verification and produce items.
Another object of the present invention is to provide high performance image capturing and processing scanner capable of capturing the images of produce and products for price lookup applications.
Another object of the present invention is to provide a digital image capturing and processing scanner that provides a measurable advancement in First Pass Read Rate scanning with the end result leading to noticeable gains in worker productivity and checkout speed.
Another object of the present invention is to provide a digital image capturing and processing scanner that employs no moving parts technology, has a light weight design and offers a low cost solution that translate easily into a lower cost of ownership.
These and other objects of the present invention will become apparent hereinafter and in the Claims to Invention.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to digital image capturing and processing scanners of ultra-compact design capable of reading bar code symbols in point-of-sale (POS) and other demanding scanning environments.
2. Brief Description of the State of Knowledge in the Art
The use of bar code symbols for product and article identification is well known in the art. Presently, various types of bar code symbol scanners have been developed for reading bar code symbols at retail points of sale (POS). In general, these bar code symbol readers can be classified into two (2) distinct classes.
The first class of bar code symbol reader uses a focused light beam, typically a focused laser beam, to sequentially scan the bars and spaces of a bar code symbol to be read. This type of bar code symbol scanner is commonly called a “flying spot” scanner as the focused laser beam appears as “a spot of light that flies” across the bar code symbol being read. In general, laser bar code symbol scanners are sub-classified further by the type of mechanism used to focus and scan the laser beam across bar code symbols.
The second class of bar code symbol readers simultaneously illuminate all of the bars and spaces of a bar code symbol with light of a specific wavelength(s) in order to capture an image thereof for recognition and decoding purposes.
The majority of laser scanners in the first class employ lenses and moving (i.e. rotating or oscillating) mirrors and/or other optical elements in order to focus and scan laser beams across bar code symbols during code symbol reading operations. Examples of hand-held laser scanning bar code readers are described in U.S. Pat. Nos. 7,007,849 and 7,028,904, each incorporated herein by reference in its entirety. Examples of laser scanning presentation bar code readers are described in U.S. Pat. No. 5,557,093, incorporated herein by reference in its entirety. Other examples of bar code symbol readers using multiple laser scanning mechanisms are described in U.S. Pat. No. 5,019,714, incorporated herein by reference in its entirety.
In demanding retail environments, such as supermarkets and high-volume department stores, where high check-out throughput is critical to achieving store profitability and customer satisfaction, it is common for laser scanning bar code reading systems to have both bottom and side-scanning windows to enable highly aggressive scanner performance. In such systems, the cashier need only drag a bar coded product past these scanning windows for the bar code thereon to be automatically read with minimal assistance of the cashier or checkout personal. Such dual scanning window systems are typically referred to as “bioptical” laser scanning systems as such systems employ two sets of optics disposed behind the bottom and side-scanning windows thereof. Examples of polygon-based bioptical laser scanning systems are disclosed in U.S. Pat. Nos.: 4,229,588; 4,652,732 and 6,814,292; each incorporated herein by reference in its entirety.
Commercial examples of bioptical laser scanners include: the PSC 8500-6-sided laser based scanning by PSC Inc.; PSC 8100/8200, 5-sided laser based scanning by PSC Inc.; the NCR 7876-6-sided laser based scanning by NCR; the NCR7872, 5-sided laser based scanning by NCR; and the MS232x Stratos®H, and MS2122 Stratos® E Stratos 6 sided laser based scanning systems by Metrologic Instruments, Inc., and the MS2200 Stratos®S 5-sided laser based scanning system by Metrologic Instruments, Inc.
In general, prior art bioptical laser scanning systems are generally more aggressive that conventional single scanning window systems. However, while prior art bioptical scanning systems represent a technological advance over most single scanning window system, prior art bioptical scanning systems in general suffer from various shortcomings and drawbacks. In particular, the scanning coverage and performance of prior art bioptical laser scanning systems are not optimized. These systems are generally expensive to manufacture by virtue of the large number of optical components presently required to construct such laser scanning systems. Also, they require heavy and expensive motors which consume significant amounts of electrical power and generate significant amounts of heat.
In the second class of bar code symbol readers, early forms of linear imaging scanners were commonly known as CCD scanners because they used CCD image detectors to detect images of the bar code symbols being read. Examples of such scanners are disclosed in U.S. Pat. Nos. 4,282,425, and 4,570,057; each incorporated herein by reference in its entirety.
In more recent times, hand-held imaging-based bar code readers employing area-type image sensing arrays based on CCD and CMOS sensor technologies have gained increasing popularity.
In U.S. patent application Ser. No. 10/712,787, a detailed history of hand-hand imaging—based bar code symbol readers is provided, explaining the many problems that had to be overcome to make imaging-based scanners competitive against laser-scanning based bar code readers. Metrologic Instruments' Focus® Hand-Held Imager is representative of an advance in the art which has overcome such historical problems. An advantage of 2D imaging-based bar code symbol readers is that they are omni-directional by nature of image capturing and processing based decode processing software that is commercially available from various vendors.
U.S. Pat. No. 6,766,954 to Barkan et al. proposes a combination of linear image sensing arrays in a hand-held unit to form an omni-directional imaging-based bar code symbol reader. However, this hand-held imager has limited application to 1D bar code symbols, and is extremely challenged in reading 2D bar code symbologies at POS applications.
And yet despite the increasing popularity in area-type hand-held and presentation type imaging-based bar code symbol reading systems, such systems still cannot complete with the performance characteristics of conventional laser scanning bioptical bar code symbol readers in POS environments.
Thus, there is a great need in the art for an improved bar code symbol reading system that is capable of competing with conventional laser scanning bioptical bar code readers employed in demanding POS environments, and providing the many advantages offered by imaging-based bar code symbol readers, while avoiding the shortcomings and drawbacks of such prior art systems and methodologies.
OBJECTS AND SUMMARY OF THE PRESENT INVENTION
Accordingly, a primary object of the present invention is to provide an improved digital image capturing and processing apparatus for use in POS environments, which is free of the shortcomings and drawbacks of prior art bioptical laser scanning systems and methodologies.
Another object of the present invention is to provide such a digital image capturing and processing apparatus in the form of an omni-directional image capturing and processing based bar code symbol reading system that employs advanced coplanar illumination and imaging technologies.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, comprising a plurality of coplanar illumination and imaging stations (i.e. subsystems), generating a plurality of coplanar light illumination beams and field of views (FOVs), that are projected through and intersect above an imaging window to generate a complex of linear-imaging planes within a 3D imaging volume for omni-directional imaging of objects passed therethrough.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the plurality of coplanar light illumination beams can be generated by an array of coherent or incoherent light sources.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the array of coherent light sources comprises an array of visible laser diodes (VLDs).
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the array of incoherent light sources comprises an array of light emitting diodes (LEDs).
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein is capable of reading (i) bar code symbols having bar code elements (i.e., ladder type bar code symbols) that are oriented substantially horizontal with respect to the imaging window, as well as (ii) bar code symbols having bar code elements (i.e., picket-fence type bar code symbols) that are oriented substantially vertical with respect to the imaging window.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, which comprises a plurality of coplanar illumination and imaging stations (i.e. subsystems), each of which produces a coplanar PLIB/FOV within predetermined regions of space contained within a 3-D imaging volume defined above the imaging window of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein each coplanar illumination and imaging station comprises a planar light illumination module (PLIM) that generates a planar light illumination beam (PLIB) and a linear image sensing array and field of view (FOV) forming optics for generating a planar FOV which is coplanar with its respective PLIB.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, comprising a plurality of coplanar illumination and imaging stations, each employing a linear array of laser light emitting devices configured together, with a linear imaging array with substantially planar FOV forming optics, producing a substantially planar beam of laser illumination which extends in substantially the same plane as the field of view of the linear array of the station, within the working distance of the 3D imaging volume.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, having an electronic weigh scale integrated within the system housing.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, comprising a plurality of coplanar illumination and imaging stations strategically arranged within an ultra-compact housing, so as to project out through an imaging window a plurality of coplanar illumination and imaging planes that capture omni-directional views of objects passing through a 3D imaging volume supported above the imaging window.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system comprising a plurality of coplanar illumination and imaging stations, each employing an array of planar laser illumination modules (PLIMs).
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein at each coplanar illumination and imaging station, an array of VLDs concentrate their output power into a thin illumination plane which spatially coincides exactly with the field of view of the imaging optics of the coplanar illumination and imaging station, so very little light energy is wasted.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein each planar illumination beam is focused so that the minimum width thereof occurs at a point or plane which is the farthest object distance at which the system is designed to capture images within the 3D imaging volume of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein at each coplanar illumination and imaging station, an object need only be illuminated along a single plane which is coplanar with a planar section of the field of view of the image formation and detection module being used in the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein low-power, light-weight, high-response, ultra-compact, high-efficiency solid-state illumination producing devices, such as visible laser diodes (VLDs), are used to selectively illuminate ultra-narrow sections of a target object during image formation and detection operations.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein the planar laser illumination technique enables modulation of the spatial and/or temporal intensity of the transmitted planar laser illumination beam, and use of simple (i.e. substantially monochromatic) lens designs for substantially monochromatic optical illumination and image formation and detection operations.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein intelligent object presence detection, motion and trajectory detection techniques are employed to automatically determined when and where an object is being moved through the 3D imaging volume of the system, and to selectively activate only those light emitting sources when an object is being moved within the spatial extent of its substantially planar laser beam so as to minimize the illumination of consumers who might be present along the lines of projected illumination/imaging during the operation of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system, wherein such intelligent object presence detection, motion and trajectory detection includes the use of an imaging-based motion sensor, at each coplanar illumination and imaging subsystem, and having a field of view that is spatially aligned with at least a portion of the field of view of the linear image sensing array employed in the coplanar illumination and imaging subsystem.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the imaging-based motion sensor employed at each coplanar illumination and imaging subsystem therein employs the laser illumination array of the coplanar illumination and imaging subsystem, operated at a lower operating power, to illuminate objects while the system is operating in its object motion/velocity detection mode.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the imaging-based motion sensor is used to determine the velocity of objects moving though the field of view (FOV) of a particular coplanar illumination and imaging station, and automatically control the frequency at which pixel data, associated with captured linear images, is transferred out of the linear image sensing array and into buffer memory.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing a plurality of coplanar illumination and imaging stations, wherein each such station includes a linear imaging module realized as an array of electronic image detection cells (e.g. CCD) having programmable integration time settings, responsive to the automatically detected velocity of an object being imaged, for enabling high-speed image capture operations.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing a plurality of coplanar illumination and imaging stations, wherein at each such station, a pair of planar laser illumination arrays are mounted about an image formation and detection module having a field of view, so as to produce a substantially planar laser illumination beam which is coplanar with the field of view during object illumination and imaging operations, and one or more beam/FOV folding mirrors are used to direct the resulting coplanar illumination and imaging plane through the imaging window of the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing a plurality of coplanar illumination and imaging stations, wherein each such station supports an independent image generation and processing channel that receives frames of linear (1D) images from the linear image sensing array and automatically buffers these linear images in video memory and automatically assembles these linear images to construct 2D images of the object taken along the field of view of the coplanar illumination and imaging plane associated with the station, and then processes these images using exposure quality analysis algorithms, bar code decoding algorithms, and the like.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system capable of reading PDF bar codes for age verification, credit card application and other productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system capable of reading PDF and 2D bar codes on produce—eliminating keyboard entry and enjoying productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system supporting image capture and processing for produce automatic produce recognition and price lookup support—eliminating keyboard entry and enjoying productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system supporting image capture and processing for analyzing cashier scanning tendencies, and providing cashier training to help achieve productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system supporting image capture and processing for automatic item look up when there is no bar code or price tag on an item, thereby achieving productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a very fast wakeup from sleep mode—ready to scan first item—to achieve productivity gains.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), each supporting an object motion/velocity sensing mode of operation.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein each coplanar illumination and imaging subsystem (i.e. station) employs an illumination control method that may involve the control of parameters selected from the group consisting of: illumination source (e.g. ambient, LED, VLD); illumination intensity (e.g. low-power, half-power, full power); illumination beam width (e.g. narrow, wide); and illumination beam thickness (e.g. beam thickness).
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the different illumination control methods that can be implemented at each illumination and imaging station in the system, include:
(1) Ambient Control Method, wherein ambient lighting is used to illuminate the FOV of the image sensing array in the object motion/velocity sensing subsystem during the object motion/velocity detection mode and bar code symbol reading mode of subsystem operation;
(2) Partial-Power Illumination Method, wherein illumination produced from the LED or VLD array is operated at half, fractional or otherwise partial power, and directed into the field of view (FOV) of the image sensing array employed in the object motion/velocity sensing subsystem;
(3) Full-Power Illumination Method, wherein illumination produced by the LED or VLD array is operated at half or fractional power, and directed in the field of view (FOV) of the image sensing array employed in the object motion/velocity sensing subsystem.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein each coplanar illumination and imaging station employs an Illumination Beam Width Method, such that the thickness of the planar illumination beam (PLIB) is increased so as to illuminate more pixels (e.g. 3 or more pixels) on the image sensing array of object motion when the station is operated in its object motion/velocity detection mode.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Distributed Local Control is employed, such that at each illumination and imaging station, the local control subsystem controls the function and operation of the components of the illumination and imaging subsystem, and sends state data to the global control subsystem for state management at the level of system operation.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Distributed Local Control, with Global Over-Ride Control, is employed, such that the local control subsystem controls the function and operation of the components of the illumination and imaging subsystem, and sends state data to the global control subsystem for state management at the level of system operation, as well as for over-riding the control functions of nearest neighboring local control subsystems employed within other illumination and imaging stations in the system, thereby allowing the global control subsystem to drive one or more other stations in the system to the bar code reading state upon receiving state data from a local control subsystem that an object has been detected and its velocity computed/estimated.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Distributed Local Control, with Global Over-Ride Control, is employed, such that the local control subsystem controls the function and operation of the components of the illumination and imaging subsystem, and sends state data to the global control subsystem for state management at the level of system operation, as well as for over-riding the control functions of all neighboring local control subsystems employed within other illumination and imaging stations in the system, thereby allowing the global control subsystem to drive one or more other stations in the system to the bar code reading state upon receiving state data from a local control subsystem that an object has been detected and its velocity computed/estimated.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein a method of Global Control is employed, such that the local control subsystem in each illumination and imaging station controls the operation of the subcomponents in the station, except for “state control” which is managed at the system level by the global control subsystem using “state data” generated by one or more object motion sensors (e.g. imaging based, IR Pulse-Doppler LIDAR-based, ultra-sonic energy based, etc.) provided at the system level within the 3D imaging volume of the system, in various possible locations.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system having a plurality of coplanar illumination and imaging subsystems (i.e. stations), wherein one or more Pulse-Doppler LIDAR subsystems, or Pulse-Doppler SONAR subsystems, are employed in the system so that real-time object velocity sensing can be achieved within the 3D imaging volume, or across a major section or diagonal thereof, so that object velocity data can be captured and distributed (in real-time) to each illumination and imaging station (via the global control subsystem) for purposes of adjusting the illumination and/or exposure control parameters therein (e.g. the frequency of the clock signal used to read out image data from the linear image sensing array within the IFD subsystem in the station).
Another object of the present invention is to provide a digital image capturing and processing system having an integrated electronic weigh scale, wherein its image capturing and processing module electrically interfaces with its electronic weigh scale module by way of a pair of touch-fit electrical interconnectors that automatically establish all electrical interconnections between the two modules when the image capturing and processing module is placed onto the electronic weigh scale module, and its electronic load cell bears the weight of the image capturing and processing module.
Another object of the present invention is to provide a digital image capturing and processing bar code reading system, with an integrated electronic weigh scale subsystem, suitable for POS applications, wherein the load cell of the electronic weigh scale module directly bears substantially all of the weight of the image capturing and processing module (and any produce articles placed thereon during weighing operations), while a touch-fit electrical interconnector arrangement automatically establishes all electrical interconnections between the two modules.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system, wherein the 2D images produced from the multiple image generation and processing channels are managed by an image processing management processor programmed to optimize image processing flows.
Another object of the present invention is to provide such an omni-directional image capturing and processing based bar code symbol reading system which supports intelligent image-based object recognition processes that can be used to automate the recognition of objects such as produce and fruit in supermarket environments.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having an integrated electronic weight scale, an RFID module, and modular support of wireless technology (e.g. BlueTooth and IEEE 802.11(g)).
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system capable of reading bar code symbologies independent of bar code orientation.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a 5 mil read capability.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a below counter depth not to exceed 3.5″ (89 mm).
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having direct connect power for PlusPower USB Ports.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having an integrated scale with its load cell positioned substantially in the center of weighing platform.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having an integrated Sensormatic® deactivation device, and an integrated Checkpoint® EAS antenna.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system employing cashier training software, and productivity measurement software showing how an operator actually oriented packages as they were scanned by the system.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having flash ROM capability.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system that can power a hand held scanner.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having a mechanism for weighing oversized produce.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system having excellent debris deflecting capabilities.
Another object of the present invention is to provide an omni-directional image capturing and processing based bar code symbol reading system that is capable of reading all types of poor quality codes—eliminating keyboard entry and enjoying productivity gains.
Another object of the present invention is to provide an image capturing and processing scanner based high throughput scanner that can address the needs of the supermarket/hypermarket and grocery store market segment.
Another object of the present invention is to provide an image capturing and processing scanner having a performance advantage that leads to quicker customer checkout times and productivity gain that cannot be matched by the conventional bioptic laser scanners.
Another object of the present invention is to provide a high throughput image capturing and processing scanner which can assist in lowering operational costs by exceptional First Pass Read Rate scanning and one product pass performance, enabling sales transactions to be executed with no manual keyboard entry required by the operator.
Another object of the present invention is to provide a high performance image capturing and processing checkout scanner that can meet the emerging needs of retailers to scan PDF and 2D bar codes for age verification and produce items.
Another object of the present invention is to provide high performance image capturing and processing scanner capable of capturing the images of produce and products for price lookup applications.
Another object of the present invention is to provide a digital image capturing and processing scanner that provides a measurable advancement in First Pass Read Rate scanning with the end result leading to noticeable gains in worker productivity and checkout speed.
Another object of the present invention is to provide a digital image capturing and processing scanner that employs no moving parts technology, has a light weight design and offers a low cost solution that translate easily into a lower cost of ownership.
These and other objects of the present invention will become apparent hereinafter and in the Claims to Invention.
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7858253 | FIELD OF THE INVENTION
The present invention relates to fuel cell systems. More particularly, the present invention relates to a time-based fuel cell purge method in which a fuel cell system is purged based on the total current supplied to the system during an operating cycle of the fuel cell.
BACKGROUND OF THE INVENTION
During the operation of a hydrogen-based fuel cell, there is an accumulation of impurities in the anode side due to cross-leaks and diffusion through membrane from the cathode side of the fuel cell. One of the methods which is used to reduce the impact of such accumulation is purging of the anode loop, wherein purging involves the removal of hydrogen from the anode loop. As can be appreciated by one skilled in the art, this can be done, for example, by the low cell purge, the differential pressure purge and the time-based purge, the latter of which is a preventive purge.
One of the problems associated with the time-based purge is determining the time and duration of the purge. The higher the load on the fuel cell, the more rapidly impurities accumulate in the anode loop of the fuel cell. Therefore, a time-based purge method is needed which is based on the average load on a fuel cell during a fuel cell operating cycle, and therefore, removes impurities from the anode loop in an efficient and timely manner.
SUMMARY OF THE INVENTION
The present invention is generally directed to a method of purging a fuel cell. The method includes determining a running average current load on the fuel cell, a standard deviation of cell voltages of the fuel cell stack and/or a maximum change in cell voltage of the fuel cell. The fuel cell is purged if the running average current load exceeds an average current load standard, the standard deviation of cell voltages exceeds a standard deviation threshold value, or the maximum change in cell voltage exceeds a maximum allowed cell voltage change rate.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates to fuel cell systems. More particularly, the present invention relates to a time-based fuel cell purge method in which a fuel cell system is purged based on the total current supplied to the system during an operating cycle of the fuel cell.
BACKGROUND OF THE INVENTION
During the operation of a hydrogen-based fuel cell, there is an accumulation of impurities in the anode side due to cross-leaks and diffusion through membrane from the cathode side of the fuel cell. One of the methods which is used to reduce the impact of such accumulation is purging of the anode loop, wherein purging involves the removal of hydrogen from the anode loop. As can be appreciated by one skilled in the art, this can be done, for example, by the low cell purge, the differential pressure purge and the time-based purge, the latter of which is a preventive purge.
One of the problems associated with the time-based purge is determining the time and duration of the purge. The higher the load on the fuel cell, the more rapidly impurities accumulate in the anode loop of the fuel cell. Therefore, a time-based purge method is needed which is based on the average load on a fuel cell during a fuel cell operating cycle, and therefore, removes impurities from the anode loop in an efficient and timely manner.
SUMMARY OF THE INVENTION
The present invention is generally directed to a method of purging a fuel cell. The method includes determining a running average current load on the fuel cell, a standard deviation of cell voltages of the fuel cell stack and/or a maximum change in cell voltage of the fuel cell. The fuel cell is purged if the running average current load exceeds an average current load standard, the standard deviation of cell voltages exceeds a standard deviation threshold value, or the maximum change in cell voltage exceeds a maximum allowed cell voltage change rate.
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7681988 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording head adapted to perform recording on a recording medium by discharging ink from a discharge port, and to an ink jet recording apparatus including the ink jet recording head.
2. Description of the Related Art
An ink jet recording apparatus performs recording by discharging ink droplets from a discharge port provided in an ink jet recording head, and applying the ink droplets to a recording medium such as paper or resin sheet. A conventional ink jet recording head includes a substrate bearing an energy generating element, a flow path member bonded to the substrate for forming ink flow paths, and an orifice plate bonded to the flow path member and having an ink discharge port. The energy generating element is provided in a position corresponding to the ink flow path, which is used to generate energy to discharge ink. Examples of the energy generating element include an electrothermal converting element such as a heating resistance element, a piezoelectric element, and so forth.
Ink mist accompanying the discharged ink droplets is also generated by the inkjet recording head when ink is repeatedly discharged. Ink mist may cause the problem of displacing an ink discharge direction when the ink mist adheres to the discharge port face of the inkjet recording head.FIGS. 8A to 8Dillustrate this problem.
FIG. 8Ashows a state of ink mist110aadhering on the discharge port face surface (100a) near a discharge port101on an orifice plate100. When ink110is discharged in this state, the ink110is drawn towards and combined with the ink mist110athat adheres to the discharge port face100a, after passing through the discharge port101, as shown inFIG. 8B. As a result, a displacement in the ink discharge direction of the ink110occurs at the discharge port101as shown inFIGS. 8C and 8D. When the ink discharge direction is displaced, an impact position of the ink110onto a recording medium is displaced, thus degrading the image quality. The displacement of the ink discharge direction is also referred to as a “drag”.
In order to prevent the displacement of the ink discharge direction caused by ink adhering to the discharge port face, a conventional ink jet recording apparatus is configured to perform a wiping process for wiping off the ink adhering to the discharge port face of the ink jet recording head using a blade made of rubber. However, the ink that adheres to the discharge port face cannot be completely wiped off even after the wiping process, so that the some ink still remains on the discharge port face in some cases.
Japanese Patent Application Laid-Open No. 2000-326515 discusses applying a water-repellent (ink-repellent) treatment to the discharge port face in order to effectively wipe off the ink adhering to the discharge port face. Moreover, Japanese Patent Application Laid-Open No. 2001-71510 discusses an ink jet recording head having an orifice plate in which a protective film having an ink-repellent property is formed at an inner side of the discharge port, a top end portion of the protective film is made to protrude from the discharge port face, and an ink-repellent film is formed throughout the discharge port face. The protective film protruding from the discharge port face is configured, during the process for forming the orifice plate, by forming a protective film having an ink-repellent property on the inner wall of the discharge port, and then performing etching to remove a surface of the orifice plate while leaving the protective film.
In general, ink for use with an ink jet recording head includes dye ink (dye-based ink) and pigment ink (pigment-based ink). The dye ink is used to print a high-resolution image such as photographs. The pigment ink is used to print characters or the like. The pigment ink has a characteristic that it can firmly adhere to a material surface compared to the dye ink. Accordingly, a contact angle of an ink-repellent layer of the ink jet recording head using the pigment ink is made larger than that using the dye ink, so that ink can be prevented from adhering to the orifice plate surface.
On the other hand, in recent years, the pigment ink is often used to achieve high-resolution printed matter and improve its preservation. In this case, compared with the case of printing characters, the amount of discharge of ink drops is very small such as about several pl (pico liter), and the nozzle array density is about 1200 dpi. Here, when a conventional ink-repellent layer is provided on the orifice plate, it is newly found that the contact angle decreases in part in some places adjacent the discharge port, that is, a deterioration of the ink-repellent layer occurs near the discharge port, regardless of the presence of ink firmly adhering to the orifice plate.
This phenomenon is not observed in ink jet recording heads using dye ink. The problem has recently been detected in a recording head having a high density array for discharging minute droplets using pigment ink to record a high-resolution image as described above.
SUMMARY OF THE INVENTION
The present invention is directed to an ink jet recording head and an ink jet recording apparatus in which an ink discharge direction can be made stable by preventing or reducing the deterioration of an ink-repellent layer even in a case where pigment ink is discharged from a recording head having a high array density for discharging minute ink droplets.
According to an aspect of the present invention, an ink jet recording head using pigment ink as discharged ink includes a nozzle member having one or more nozzles for discharging ink, the nozzle member having an ink-repellent layer forming a discharge port face having a discharge port that is an open end of the one or more nozzles, and a projection portion positioned around the discharge port and protruding along a central axis direction of the one or more nozzles away from the discharge port face, wherein the one or more nozzles, in a cross section passing through the central axis of the nozzle, has an outline shape provided with a curved line having a changing radius of curvature, and wherein a point at which the radius of curvature of the curved line is a minimum is included in the projection portion and is located at a maximum height from the discharge port face in the central axis direction.
According to another aspect of the present invention, an ink jet recording head using pigment ink as discharged ink includes a nozzle member having a nozzle for discharging ink, the nozzle member having an ink-repellent layer forming a discharge port face having a discharge port that is an open end of the nozzle, and a projection portion positioned around the discharge port and protruding along a central axis direction of the nozzle with respect to the discharge port face, wherein the nozzle, in a cross section passing through the central axis of the nozzle, has an outline shape provided with a curved line having a changing radius of curvature, wherein an angle defined by tangent lines at points at which the curvature radius of the curved line is maximum and which are nearest to a boundary point at which the curvature radius of the curved line is minimum inside and outside the nozzle with respect to the boundary point is equal to or greater than 40° and equal to or less than 75°, and wherein a height of the projection portion from the discharge port face along the central axis direction of the nozzle is equal to or greater than 0.05 μm and less than 0.5 μm.
According to an aspect of the present invention, since the projection portion is provided around the discharge port as described above, ink coagulation can hardly be generated in the nozzle even if pigment ink is used. Thus, the ink-repellent layer on the discharge port face is excellently maintained even if the wiping processing on the discharge port face is repeated. As a result, the displacement of a ink discharge direction caused by ink adhering to the discharge port face can effectively be prevented or reduced to facilitate stably discharging ink.
Further features of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording head adapted to perform recording on a recording medium by discharging ink from a discharge port, and to an ink jet recording apparatus including the ink jet recording head.
2. Description of the Related Art
An ink jet recording apparatus performs recording by discharging ink droplets from a discharge port provided in an ink jet recording head, and applying the ink droplets to a recording medium such as paper or resin sheet. A conventional ink jet recording head includes a substrate bearing an energy generating element, a flow path member bonded to the substrate for forming ink flow paths, and an orifice plate bonded to the flow path member and having an ink discharge port. The energy generating element is provided in a position corresponding to the ink flow path, which is used to generate energy to discharge ink. Examples of the energy generating element include an electrothermal converting element such as a heating resistance element, a piezoelectric element, and so forth.
Ink mist accompanying the discharged ink droplets is also generated by the inkjet recording head when ink is repeatedly discharged. Ink mist may cause the problem of displacing an ink discharge direction when the ink mist adheres to the discharge port face of the inkjet recording head.FIGS. 8A to 8Dillustrate this problem.
FIG. 8Ashows a state of ink mist110aadhering on the discharge port face surface (100a) near a discharge port101on an orifice plate100. When ink110is discharged in this state, the ink110is drawn towards and combined with the ink mist110athat adheres to the discharge port face100a, after passing through the discharge port101, as shown inFIG. 8B. As a result, a displacement in the ink discharge direction of the ink110occurs at the discharge port101as shown inFIGS. 8C and 8D. When the ink discharge direction is displaced, an impact position of the ink110onto a recording medium is displaced, thus degrading the image quality. The displacement of the ink discharge direction is also referred to as a “drag”.
In order to prevent the displacement of the ink discharge direction caused by ink adhering to the discharge port face, a conventional ink jet recording apparatus is configured to perform a wiping process for wiping off the ink adhering to the discharge port face of the ink jet recording head using a blade made of rubber. However, the ink that adheres to the discharge port face cannot be completely wiped off even after the wiping process, so that the some ink still remains on the discharge port face in some cases.
Japanese Patent Application Laid-Open No. 2000-326515 discusses applying a water-repellent (ink-repellent) treatment to the discharge port face in order to effectively wipe off the ink adhering to the discharge port face. Moreover, Japanese Patent Application Laid-Open No. 2001-71510 discusses an ink jet recording head having an orifice plate in which a protective film having an ink-repellent property is formed at an inner side of the discharge port, a top end portion of the protective film is made to protrude from the discharge port face, and an ink-repellent film is formed throughout the discharge port face. The protective film protruding from the discharge port face is configured, during the process for forming the orifice plate, by forming a protective film having an ink-repellent property on the inner wall of the discharge port, and then performing etching to remove a surface of the orifice plate while leaving the protective film.
In general, ink for use with an ink jet recording head includes dye ink (dye-based ink) and pigment ink (pigment-based ink). The dye ink is used to print a high-resolution image such as photographs. The pigment ink is used to print characters or the like. The pigment ink has a characteristic that it can firmly adhere to a material surface compared to the dye ink. Accordingly, a contact angle of an ink-repellent layer of the ink jet recording head using the pigment ink is made larger than that using the dye ink, so that ink can be prevented from adhering to the orifice plate surface.
On the other hand, in recent years, the pigment ink is often used to achieve high-resolution printed matter and improve its preservation. In this case, compared with the case of printing characters, the amount of discharge of ink drops is very small such as about several pl (pico liter), and the nozzle array density is about 1200 dpi. Here, when a conventional ink-repellent layer is provided on the orifice plate, it is newly found that the contact angle decreases in part in some places adjacent the discharge port, that is, a deterioration of the ink-repellent layer occurs near the discharge port, regardless of the presence of ink firmly adhering to the orifice plate.
This phenomenon is not observed in ink jet recording heads using dye ink. The problem has recently been detected in a recording head having a high density array for discharging minute droplets using pigment ink to record a high-resolution image as described above.
SUMMARY OF THE INVENTION
The present invention is directed to an ink jet recording head and an ink jet recording apparatus in which an ink discharge direction can be made stable by preventing or reducing the deterioration of an ink-repellent layer even in a case where pigment ink is discharged from a recording head having a high array density for discharging minute ink droplets.
According to an aspect of the present invention, an ink jet recording head using pigment ink as discharged ink includes a nozzle member having one or more nozzles for discharging ink, the nozzle member having an ink-repellent layer forming a discharge port face having a discharge port that is an open end of the one or more nozzles, and a projection portion positioned around the discharge port and protruding along a central axis direction of the one or more nozzles away from the discharge port face, wherein the one or more nozzles, in a cross section passing through the central axis of the nozzle, has an outline shape provided with a curved line having a changing radius of curvature, and wherein a point at which the radius of curvature of the curved line is a minimum is included in the projection portion and is located at a maximum height from the discharge port face in the central axis direction.
According to another aspect of the present invention, an ink jet recording head using pigment ink as discharged ink includes a nozzle member having a nozzle for discharging ink, the nozzle member having an ink-repellent layer forming a discharge port face having a discharge port that is an open end of the nozzle, and a projection portion positioned around the discharge port and protruding along a central axis direction of the nozzle with respect to the discharge port face, wherein the nozzle, in a cross section passing through the central axis of the nozzle, has an outline shape provided with a curved line having a changing radius of curvature, wherein an angle defined by tangent lines at points at which the curvature radius of the curved line is maximum and which are nearest to a boundary point at which the curvature radius of the curved line is minimum inside and outside the nozzle with respect to the boundary point is equal to or greater than 40° and equal to or less than 75°, and wherein a height of the projection portion from the discharge port face along the central axis direction of the nozzle is equal to or greater than 0.05 μm and less than 0.5 μm.
According to an aspect of the present invention, since the projection portion is provided around the discharge port as described above, ink coagulation can hardly be generated in the nozzle even if pigment ink is used. Thus, the ink-repellent layer on the discharge port face is excellently maintained even if the wiping processing on the discharge port face is repeated. As a result, the displacement of a ink discharge direction caused by ink adhering to the discharge port face can effectively be prevented or reduced to facilitate stably discharging ink.
Further features of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings.
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7776516 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a graded anti-reflective coating, its use in integrated circuit fabrication, and a method for depositing the graded anti-reflective coating.
2. Description of the Related Art
In recent years integrated circuits have evolved into complex devices that commonly include millions of transistors, capacitors, resistors, and other electronic components on a single chip. Therefore, there is an inherent demand for increased circuit densities, as well as a continual demand for faster and more efficient circuit components. The combined demands for faster circuits having greater circuit densities imposes corresponding demands on the materials used to fabricate such integrated circuits. This demand for faster circuits with greater circuit densities has led to the use of low resistivity conductive materials, such as copper and/or low dielectric constant insulating materials having a dielectric constant less than about 3.8.
The demands for faster components having greater circuit densities also imposes demands on process sequences used for integrated circuit manufacture. For example, in process sequences using conventional lithographic techniques, a layer of energy sensitive resist is generally formed over a stack of material layers on a substrate. An image of a pattern may then be introduced into the energy sensitive resist layer. Thereafter, the pattern introduced into the energy sensitive resist layer may be transferred into one or more layers of the material stack formed on the substrate using the layer of energy sensitive resist as a mask. The pattern introduced into the energy sensitive resist may then be transferred into a material layer(s) using a chemical and/or physical etchant. A chemical etchant is generally designed to have a greater etch selectivity for the material layer(s) than for the energy sensitive resist, which generally indicates that the chemical etchant will etch the material layer(s) at a faster rate than it etches the energy sensitive resist. The faster etch rate for the one or more material layers of the stack typically prevents the energy sensitive resist material from being consumed prior to completion of the pattern transfer.
Lithographic imaging tools used in the manufacture of integrated circuits employ deep ultraviolet (DUV) imaging wavelengths, i.e., wavelengths of 248 nm or 193 nm, to generate resist patterns. The DUV imaging wavelengths are generally known to improve resist pattern resolution as a result of the diffraction effects being reduced at the shorter wavelengths. However, the increased reflective nature of many underlying materials, i.e., polysilicon and metal silicides, for example, may operate to degrade the resulting resist patterns at DUV wavelengths. Furthermore, for printing features with smaller pitches (≦250-300 nm) immersion lithography using lenses with a high numerical aperture is typically used. As the numerical aperture (NA) increases beyond 0.9, and pitch sizes decrease to less than 100 nm, light reflectance from non-normal incidence angles becomes a significant source of reflection.
One technique proposed to minimize reflections from an underlying material layer uses an anti-reflective coating (ARC). The ARC is formed over the reflective material layer prior to resist patterning. The ARC generally suppresses the reflections off the underlying material layer during resist imaging, thereby providing more accurate pattern replication in the layer of energy sensitive resist. However, currently available anti-reflective coating techniques fail to account for the light reflectance from non-normal incidence angles.
In view of conventional photolithographic techniques, there exists a need in the art for an anti-reflective coating that reduces light reflectance from non-normal incidence angles.
SUMMARY OF THE INVENTION
Embodiments of the invention pertain to forming a graded anti-reflective coating. According to one embodiment one or more amorphous carbon layers are formed on a substrate. An anti-reflective coating (ARC) is formed on the one or more amorphous carbon layers wherein the ARC layer has an absorption coefficient that varies across the thickness of the ARC layer. An energy sensitive resist material is formed on the ARC layer. An image of a pattern is introduced into the layer of energy sensitive resist material by exposing the energy sensitive resist material to patterned radiation. The image of the pattern introduced into the layer of energy sensitive resist material is developed. In another embodiment, the ARC layer and the amorphous carbon layer are deposited in-situ in the same processing system or the same processing chamber without breaking vacuum.
According to another embodiment, a method of forming a device is provided. The method comprises forming one or more amorphous carbon layers on a substrate. An ARC layer is formed on the one or more amorphous carbon layers wherein the ARC layer has an absorption coefficient that varies across the thickness of the ARC layer, wherein the one or more amorphous carbon layers and the ARC layer are deposited in-situ in the same processing system or the same processing chamber without breaking vacuum.
According to another embodiment, a layer of antireflective coating (ARC) material for use in a photolithographic process is provided. The ARC layer is formed from a gas mixture comprising one or more carbon sources, a silicon source, and an oxygen source wherein the ARC layer has an absorption coefficient that varies across the thickness of the ARC layer. In another embodiment, the gas mixture further comprises an inert gas.
In additional embodiments, the ARC layer has an absorption coefficient in a range between about 0 and about 1.0. In another embodiment, the ARC layer is formed by modulating the flow of one or more carbon sources, an inert gas, a silicon source, and an oxygen source.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a graded anti-reflective coating, its use in integrated circuit fabrication, and a method for depositing the graded anti-reflective coating.
2. Description of the Related Art
In recent years integrated circuits have evolved into complex devices that commonly include millions of transistors, capacitors, resistors, and other electronic components on a single chip. Therefore, there is an inherent demand for increased circuit densities, as well as a continual demand for faster and more efficient circuit components. The combined demands for faster circuits having greater circuit densities imposes corresponding demands on the materials used to fabricate such integrated circuits. This demand for faster circuits with greater circuit densities has led to the use of low resistivity conductive materials, such as copper and/or low dielectric constant insulating materials having a dielectric constant less than about 3.8.
The demands for faster components having greater circuit densities also imposes demands on process sequences used for integrated circuit manufacture. For example, in process sequences using conventional lithographic techniques, a layer of energy sensitive resist is generally formed over a stack of material layers on a substrate. An image of a pattern may then be introduced into the energy sensitive resist layer. Thereafter, the pattern introduced into the energy sensitive resist layer may be transferred into one or more layers of the material stack formed on the substrate using the layer of energy sensitive resist as a mask. The pattern introduced into the energy sensitive resist may then be transferred into a material layer(s) using a chemical and/or physical etchant. A chemical etchant is generally designed to have a greater etch selectivity for the material layer(s) than for the energy sensitive resist, which generally indicates that the chemical etchant will etch the material layer(s) at a faster rate than it etches the energy sensitive resist. The faster etch rate for the one or more material layers of the stack typically prevents the energy sensitive resist material from being consumed prior to completion of the pattern transfer.
Lithographic imaging tools used in the manufacture of integrated circuits employ deep ultraviolet (DUV) imaging wavelengths, i.e., wavelengths of 248 nm or 193 nm, to generate resist patterns. The DUV imaging wavelengths are generally known to improve resist pattern resolution as a result of the diffraction effects being reduced at the shorter wavelengths. However, the increased reflective nature of many underlying materials, i.e., polysilicon and metal silicides, for example, may operate to degrade the resulting resist patterns at DUV wavelengths. Furthermore, for printing features with smaller pitches (≦250-300 nm) immersion lithography using lenses with a high numerical aperture is typically used. As the numerical aperture (NA) increases beyond 0.9, and pitch sizes decrease to less than 100 nm, light reflectance from non-normal incidence angles becomes a significant source of reflection.
One technique proposed to minimize reflections from an underlying material layer uses an anti-reflective coating (ARC). The ARC is formed over the reflective material layer prior to resist patterning. The ARC generally suppresses the reflections off the underlying material layer during resist imaging, thereby providing more accurate pattern replication in the layer of energy sensitive resist. However, currently available anti-reflective coating techniques fail to account for the light reflectance from non-normal incidence angles.
In view of conventional photolithographic techniques, there exists a need in the art for an anti-reflective coating that reduces light reflectance from non-normal incidence angles.
SUMMARY OF THE INVENTION
Embodiments of the invention pertain to forming a graded anti-reflective coating. According to one embodiment one or more amorphous carbon layers are formed on a substrate. An anti-reflective coating (ARC) is formed on the one or more amorphous carbon layers wherein the ARC layer has an absorption coefficient that varies across the thickness of the ARC layer. An energy sensitive resist material is formed on the ARC layer. An image of a pattern is introduced into the layer of energy sensitive resist material by exposing the energy sensitive resist material to patterned radiation. The image of the pattern introduced into the layer of energy sensitive resist material is developed. In another embodiment, the ARC layer and the amorphous carbon layer are deposited in-situ in the same processing system or the same processing chamber without breaking vacuum.
According to another embodiment, a method of forming a device is provided. The method comprises forming one or more amorphous carbon layers on a substrate. An ARC layer is formed on the one or more amorphous carbon layers wherein the ARC layer has an absorption coefficient that varies across the thickness of the ARC layer, wherein the one or more amorphous carbon layers and the ARC layer are deposited in-situ in the same processing system or the same processing chamber without breaking vacuum.
According to another embodiment, a layer of antireflective coating (ARC) material for use in a photolithographic process is provided. The ARC layer is formed from a gas mixture comprising one or more carbon sources, a silicon source, and an oxygen source wherein the ARC layer has an absorption coefficient that varies across the thickness of the ARC layer. In another embodiment, the gas mixture further comprises an inert gas.
In additional embodiments, the ARC layer has an absorption coefficient in a range between about 0 and about 1.0. In another embodiment, the ARC layer is formed by modulating the flow of one or more carbon sources, an inert gas, a silicon source, and an oxygen source.
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7772837 | FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for coding an output signal of a sensor of an apparatus for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having associated with it at least one differential sensor encompassing two sensor elements, the differential sensor generating an output signal that is a difference of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value. The present invention furthermore relates to a computer program for carrying out such a method.
BACKGROUND INFORMATION
A determination of the crankshaft angle is of central importance in terms of controlling internal combustion engines. Approaches known in the existing art utilize, in particular, incremental sensors on the crankshaft and/or camshaft. Sensor disks having increment marks encompassing teeth and tooth gaps, which in coaction with the signals from the crankshaft and camshaft enable a determination of the engine position, are usual.
Sensor systems of this kind allow a determination of the absolute position of the crankshaft by way of a non-uniform placement of the increment marks. A typical implementation is a sensor wheel having 60 minus 2 teeth, i.e. 58 teeth, and a two-tooth sensor-wheel gap.
A disadvantage of such a gap is the absence of increments for exact determination of the crankshaft angle within the gap. Within the gap, an extrapolation of the crankshaft angle is performed by the engine controller, although that extrapolation is error-prone because of the non-uniformity of the crankshaft angle speed. Modern working methods for internal combustion engines impose more stringent requirements in terms of accuracy, in particular for determining the location of injection operations, for both Otto-cycle and diesel engines.
It is possible to avoid the sensor-wheel gap by an asymmetrical pitch of the increment markings and thus an asymmetrical pitch of the teeth with respect to tooth gaps. Instead of a sensor-wheel gap, here the pitch between teeth and tooth gaps is modified over one or more tooth/tooth-gap pairs. To increase the accuracy with which this modification is detected, usually the teeth and tooth gaps together are already configured asymmetrically, and the asymmetry in the region replacing the previous sensor-wheel gap is, for example, simply turned around. For example, if the teeth extend over a crankshaft angle of 4°, and the tooth gaps over a crankshaft angle of 2°, then the sensor-wheel gap is replaced by a reversal of this ratio, i.e. by teeth of, for example, 2° and tooth gaps of, for example, 4°.
With evaluation of the trailing tooth edges, a signal is available for an engine controller every 6° of crankshaft angle, even in the former gap, and in addition a demonstrable position of the sensor wheel is detected by evaluating the ratio between the tooth time and gap time.
Additional evaluation of the ratio between tooth time and gap time is complicated by what is today the typical embodiment of the crankshaft angle sensor. As a rule, these sensors are so-called differential sensors, in which signal processing encompasses appropriate calculation of a difference between sensor elements that are spatially separated from one another. An important advantage as compared with a so-called single sensor having only one sensor element is greatly improved reproducibility of the sensor signal. Improved reproducibility means a decrease in statistical errors upon acquisition and sampling of the sensor wheel's increment markings. Any changes in the magnetic field due to external interference fields or changes in the air gap of the sensor wheel have an effect on the switching threshold of the sensor in the case of a single sensor, but cancel each other out in the case of a differential sensor. The differential sensor is therefore more robust in terms of installation positions and external magnetic fields. The differential sensor switches at the center of the tooth or tooth gap at the zero transition of the differential signal. An asymmetrically apportioned sensor wheel generates an asymmetrical output signal only once, upon the transition from one tooth-to-space pitch to a different tooth-to-space pitch. A ratio of tooth time to gap time that is not equal to one is therefore available to an evaluation function in the engine controller only at the beginning and the end of the modified tooth pitch replacing the previous sensor-wheel gap. In terms of sensing of the rest of the sensor wheel, the tooth-to-gap time is approximately the same despite the asymmetrical tooth pitch.
It is furthermore known additionally to evaluate the rotation direction of the crankshaft. One known approach to transferring this information to an engine control unit is to use a variable pulse length. Because the engine control unit employs only one of the edges, usually the leading edge, for incremental determination of the angle traveled by the crankshaft, the other edge can be used to code further data. The rotation direction is transferred in this case by way of a change in the pulse length.
The existing art is disadvantageous in that evaluation of a sensor-wheel gap, or of a modified pitch of the sensor wheel replacing the sensor-wheel gap, is possible only on the basis of detection of the leading edges that are transmitted to an engine control unit.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method that enables improved detection of a modified pitch of a sensor wheel replacing the sensor-wheel gap.
This problem is solved by a method for coding an output signal of a sensor of an apparatus for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having associated with it at least one differential sensor encompassing two sensor elements, the differential sensor generating an output signal that is a difference of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value, the rotation direction of the shaft, as well as a pitch ratio of a tooth sweeping past the sensor with respect to an adjacent tooth gap, being ascertained from the signals of the two sensor elements, and the rotation direction as well as the pitch being coded as a pulse width coded output signal.
Provision is preferably made that the pitch be an angle segment of one tooth with respect to an angle segment of a succeeding tooth gap. The angle segment of a tooth and the angle segment of a tooth gap are the angle swept out by them on the sensor wheel. In the case of sensor wheels known in the existing art and having a 6-degree pitch, the two add up in each case to 6°.
Provision is further preferably made that the sweeping of a leading tooth edge of the sensor wheel past the sensor be coded in real time as an edge, and that a counter-edge following the edge be generated at an offset in time from the edge, which offset codes the rotation direction as well as the pitch. “Edge” and “counter-edge” are understood here as the combination of a leading edge with a trailing edge. If the edge is a leading edge, the counter-edge is therefore a trailing edge, and vice versa.
Provision is further preferably made that the rotation direction be ascertained from the sequence in time of the signals of the sensor elements. The signals of the sensor elements follow one another in time, since they are arranged next to one another when viewed in the rotation direction of the sensor wheel. Provision is preferably further made that the pitch be ascertained from the signal of one of the sensor elements.
The aforesaid problem is also solved by a sensor of an assemblage for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having at least one sensor associated with it, the sensor encompassing two sensor elements and generating at least one output signal that is a difference signal of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value, wherein the rotation direction of the shaft, as well as a pitch ratio of a tooth sweeping past the sensor with respect to an adjacent tooth gap, is ascertained from the signals of the two sensor elements, and the rotation direction as well as the pitch are coded as a pulse width coded output signal.
The aforesaid problem is also solved by a computer program having program code for carrying out all the steps in accordance with the method according to the present invention when the program is executed in a computer.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for coding an output signal of a sensor of an apparatus for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having associated with it at least one differential sensor encompassing two sensor elements, the differential sensor generating an output signal that is a difference of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value. The present invention furthermore relates to a computer program for carrying out such a method.
BACKGROUND INFORMATION
A determination of the crankshaft angle is of central importance in terms of controlling internal combustion engines. Approaches known in the existing art utilize, in particular, incremental sensors on the crankshaft and/or camshaft. Sensor disks having increment marks encompassing teeth and tooth gaps, which in coaction with the signals from the crankshaft and camshaft enable a determination of the engine position, are usual.
Sensor systems of this kind allow a determination of the absolute position of the crankshaft by way of a non-uniform placement of the increment marks. A typical implementation is a sensor wheel having 60 minus 2 teeth, i.e. 58 teeth, and a two-tooth sensor-wheel gap.
A disadvantage of such a gap is the absence of increments for exact determination of the crankshaft angle within the gap. Within the gap, an extrapolation of the crankshaft angle is performed by the engine controller, although that extrapolation is error-prone because of the non-uniformity of the crankshaft angle speed. Modern working methods for internal combustion engines impose more stringent requirements in terms of accuracy, in particular for determining the location of injection operations, for both Otto-cycle and diesel engines.
It is possible to avoid the sensor-wheel gap by an asymmetrical pitch of the increment markings and thus an asymmetrical pitch of the teeth with respect to tooth gaps. Instead of a sensor-wheel gap, here the pitch between teeth and tooth gaps is modified over one or more tooth/tooth-gap pairs. To increase the accuracy with which this modification is detected, usually the teeth and tooth gaps together are already configured asymmetrically, and the asymmetry in the region replacing the previous sensor-wheel gap is, for example, simply turned around. For example, if the teeth extend over a crankshaft angle of 4°, and the tooth gaps over a crankshaft angle of 2°, then the sensor-wheel gap is replaced by a reversal of this ratio, i.e. by teeth of, for example, 2° and tooth gaps of, for example, 4°.
With evaluation of the trailing tooth edges, a signal is available for an engine controller every 6° of crankshaft angle, even in the former gap, and in addition a demonstrable position of the sensor wheel is detected by evaluating the ratio between the tooth time and gap time.
Additional evaluation of the ratio between tooth time and gap time is complicated by what is today the typical embodiment of the crankshaft angle sensor. As a rule, these sensors are so-called differential sensors, in which signal processing encompasses appropriate calculation of a difference between sensor elements that are spatially separated from one another. An important advantage as compared with a so-called single sensor having only one sensor element is greatly improved reproducibility of the sensor signal. Improved reproducibility means a decrease in statistical errors upon acquisition and sampling of the sensor wheel's increment markings. Any changes in the magnetic field due to external interference fields or changes in the air gap of the sensor wheel have an effect on the switching threshold of the sensor in the case of a single sensor, but cancel each other out in the case of a differential sensor. The differential sensor is therefore more robust in terms of installation positions and external magnetic fields. The differential sensor switches at the center of the tooth or tooth gap at the zero transition of the differential signal. An asymmetrically apportioned sensor wheel generates an asymmetrical output signal only once, upon the transition from one tooth-to-space pitch to a different tooth-to-space pitch. A ratio of tooth time to gap time that is not equal to one is therefore available to an evaluation function in the engine controller only at the beginning and the end of the modified tooth pitch replacing the previous sensor-wheel gap. In terms of sensing of the rest of the sensor wheel, the tooth-to-gap time is approximately the same despite the asymmetrical tooth pitch.
It is furthermore known additionally to evaluate the rotation direction of the crankshaft. One known approach to transferring this information to an engine control unit is to use a variable pulse length. Because the engine control unit employs only one of the edges, usually the leading edge, for incremental determination of the angle traveled by the crankshaft, the other edge can be used to code further data. The rotation direction is transferred in this case by way of a change in the pulse length.
The existing art is disadvantageous in that evaluation of a sensor-wheel gap, or of a modified pitch of the sensor wheel replacing the sensor-wheel gap, is possible only on the basis of detection of the leading edges that are transmitted to an engine control unit.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method that enables improved detection of a modified pitch of a sensor wheel replacing the sensor-wheel gap.
This problem is solved by a method for coding an output signal of a sensor of an apparatus for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having associated with it at least one differential sensor encompassing two sensor elements, the differential sensor generating an output signal that is a difference of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value, the rotation direction of the shaft, as well as a pitch ratio of a tooth sweeping past the sensor with respect to an adjacent tooth gap, being ascertained from the signals of the two sensor elements, and the rotation direction as well as the pitch being coded as a pulse width coded output signal.
Provision is preferably made that the pitch be an angle segment of one tooth with respect to an angle segment of a succeeding tooth gap. The angle segment of a tooth and the angle segment of a tooth gap are the angle swept out by them on the sensor wheel. In the case of sensor wheels known in the existing art and having a 6-degree pitch, the two add up in each case to 6°.
Provision is further preferably made that the sweeping of a leading tooth edge of the sensor wheel past the sensor be coded in real time as an edge, and that a counter-edge following the edge be generated at an offset in time from the edge, which offset codes the rotation direction as well as the pitch. “Edge” and “counter-edge” are understood here as the combination of a leading edge with a trailing edge. If the edge is a leading edge, the counter-edge is therefore a trailing edge, and vice versa.
Provision is further preferably made that the rotation direction be ascertained from the sequence in time of the signals of the sensor elements. The signals of the sensor elements follow one another in time, since they are arranged next to one another when viewed in the rotation direction of the sensor wheel. Provision is preferably further made that the pitch be ascertained from the signal of one of the sensor elements.
The aforesaid problem is also solved by a sensor of an assemblage for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having at least one sensor associated with it, the sensor encompassing two sensor elements and generating at least one output signal that is a difference signal of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value, wherein the rotation direction of the shaft, as well as a pitch ratio of a tooth sweeping past the sensor with respect to an adjacent tooth gap, is ascertained from the signals of the two sensor elements, and the rotation direction as well as the pitch are coded as a pulse width coded output signal.
The aforesaid problem is also solved by a computer program having program code for carrying out all the steps in accordance with the method according to the present invention when the program is executed in a computer.
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7740925 | FIELD
The present disclosure relates generally to composite materials and to methods of manufacturing the composite materials. In particular, the composite material of the present invention includes a thermoplastic material having a relatively low coefficient of friction such as ultra-high molecular weight polyethylene (UHMWPE) which is bonded by use of a porous material such as a fibrous mat to a substrate.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
While not limited in any way to food processing equipment, the present invention was conceived in part to meet a need in the industry. Heretofore, food processing equipment has largely been manufactured from stainless steel due to its known strength and relative durability. It has been discovered that at least certain pieces of stainless steel food processing equipment, particularly those involved in high temperature and vibration environments, tend to be susceptible to stress cracking over time. Further, the cleaning of such food processing equipment manufactured from stainless steel is unnecessarily labor intensive, often requiring at least two people.
In contrast, the composite material of the present invention is resistant to stress cracking, is relatively easy to clean, and tends to be lightweight (generally at least 50% lighter than all stainless steel embodiments). Further perceived advantages include less sticking of food components, reduced noise associated with the product, and speedy assembly and disassembly times, among a host of other advantages.
SUMMARY
The present invention relates to composite materials having a first layer including a thermoplastic material having a static coefficient of friction of less than about 0.25 at 23° C. as measured against chromium plated steel, a second layer comprising a porous material to which the first layer is intimately bonded, and a third layer which is a substrate.
The present invention also relates to methods of manufacturing the composite materials for specific applications. The method generally comprises the steps of:a) providing a substrate;b) applying a porous layer onto the substrate;c) applying a thermoplastic material having a static coefficient of friction of less than about 0.25 at 23° C. over the porous layer; andd) joining the materials under vacuum, pressure or a combination of vacuum and pressure.
Further details and advantages of the composite according to the invention, of the method and of the device, are described with reference to the embodiment illustrated in the drawings.
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SUMMARY: FIELD
The present disclosure relates generally to composite materials and to methods of manufacturing the composite materials. In particular, the composite material of the present invention includes a thermoplastic material having a relatively low coefficient of friction such as ultra-high molecular weight polyethylene (UHMWPE) which is bonded by use of a porous material such as a fibrous mat to a substrate.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
While not limited in any way to food processing equipment, the present invention was conceived in part to meet a need in the industry. Heretofore, food processing equipment has largely been manufactured from stainless steel due to its known strength and relative durability. It has been discovered that at least certain pieces of stainless steel food processing equipment, particularly those involved in high temperature and vibration environments, tend to be susceptible to stress cracking over time. Further, the cleaning of such food processing equipment manufactured from stainless steel is unnecessarily labor intensive, often requiring at least two people.
In contrast, the composite material of the present invention is resistant to stress cracking, is relatively easy to clean, and tends to be lightweight (generally at least 50% lighter than all stainless steel embodiments). Further perceived advantages include less sticking of food components, reduced noise associated with the product, and speedy assembly and disassembly times, among a host of other advantages.
SUMMARY
The present invention relates to composite materials having a first layer including a thermoplastic material having a static coefficient of friction of less than about 0.25 at 23° C. as measured against chromium plated steel, a second layer comprising a porous material to which the first layer is intimately bonded, and a third layer which is a substrate.
The present invention also relates to methods of manufacturing the composite materials for specific applications. The method generally comprises the steps of:a) providing a substrate;b) applying a porous layer onto the substrate;c) applying a thermoplastic material having a static coefficient of friction of less than about 0.25 at 23° C. over the porous layer; andd) joining the materials under vacuum, pressure or a combination of vacuum and pressure.
Further details and advantages of the composite according to the invention, of the method and of the device, are described with reference to the embodiment illustrated in the drawings.
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7668412 | BACKGROUND
The present disclosure relates to electric partial discharge detection, and more particularly, to a system and method for detection and measuring electric partial discharge using an optical fiber.
As electrical wires age, insulation may become brittle and crack leading to arcing or shorts. Small arcs can carbonize the insulation, leading to bigger arcs and the potential for fire. Control of electrical discharge is necessary to avoid degrading the insulation in electrical wires in air or in insulating oil. The need for reliable monitoring is increased when the cable is used in high altitude where ambient pressures may be well below one atmosphere such at flight altitudes. The inception level for discharges is reduced as pressure decreases. Therefore, intermittent partial discharge or arcing that can occur in flight may not be reproducible during ground maintenance.
Intermittent discharges can occur from a wire with cracked or faulty insulation. Such partial discharges are in the form of pulses having time durations as short as a few nanoseconds or less. The pulses form because, once a discharge initiates, electrons quickly become depleted in the gap by buildup of space charge between the electrodes.
This extinguishes the discharge until the space charge dissipates sufficiently for a fresh discharge to occur. The presence of residual space charge along with surface charges and meta-stable excited gases act as a memory thus affecting ensuing pulse amplitudes and times of onset. Such discharges create an avalanche of electrons whose collisions with nitrogen molecules in air produce spectrum from near-UV photons to visible as shown inFIG. 1.
In order to detect the presence of cable defects in air or in oil, various imaging systems or electrical reflectometry techniques have been used to monitor entire wiring systems. But these devices provide limited coverage or require direct electrical connection, which can be inconvenient or even unsafe in some applications.
One potential detection concept that has been reported is photoluminescence. Photoluminescence is the emission of near or visible light from any substance under external excitation and it can be categorized into fluorescence and phosphorescence. The emission rates of fluorescence are typically 108/sec and its lifetime is near 10 nsec. Phosphorescence is emission of light from triplet-excited states, in which the electron in an excited orbital has the same spin orientation as the ground state electron. The transitions to ground are forbidden and the emission rates are slow (103-100), so phosphorescence lifetimes are typically milliseconds to seconds.
When an electron is excited to an upper state, it decays non-radiatively to a lower meta-stable state. From this meta-stable state the, electron decays radiatively emitting a photon. The energy of the emission, which is described as E=hν (where h is Plancks constant and ν is the frequency of the light) is typically less than that of absorption.
Sarkozi, U.S. Pat. No. 7,142,291, proposed a system for detecting partial discharges in wiring using a fluorescence optical fiber. The system required large diameter plastic core fiber optic cables embedded into the insulation material surrounding the wiring. The large core diameter optical fiber had a fluorescent material incorporated into the fiber core. Upon exposure of that fluorescent material to a discharge frequency it generates light that travels in both directions in the optical fiber. Optical detectors at each end of the fiber record the arrival of that light and a processor calculates a location of the discharge from the arrival times.
McSherry, et. al. (IEEE Sensors Journal October 2004) proposed a coated sensor model for measuring germicidal UV irradiation in which a large core diameter plastic optical fiber had its cladding removed and replaced by a fluorescent coating. When placed near a UV lamp the fluorescent coating would generate light that would travel down the optical fiber core to be detected.
Both of these prior art systems made use of large (1000 micro-meter) core diameter plastic optical fibers. Plastic fibers usually have cores of polymethylmethacrylate (PMMA) and typically have core diameters close to 1000 micro-meters. Such fibers have a limited transmission distance and poorer resistance to environmental conditions than optical fibers of a silica (glass) core. Silica glass core fibers typically have silica cores of between 50-500 micro-meters. Thus the plastic core fibers of these prior art references are significantly limited to very short sensor systems (around 10 m range) in favorable environments. In addition less complex detection systems than the two optical detector system of Sarkozi are needed. A silica core based sensor system with a hard plastic cladding for electric partial discharge would enable sensor systems based on large distances (potentially up to 1 kilometer with attenuation of less than 1 dB/100 m at the 550 nm emission band) and in more stringent environmental conditions.
In addition there is a need is for a distributed system that is easily deployable in close proximity to the objects being monitored without the need to incorporate them into the structural design as in the Sarkozi reference. And there is a need to decrease bend related attenuation in the fibers, which is possible with much smaller (<500 micro-meter) core diameter fibers with silica cores.
SUMMARY OF THE INVENTION
One aspect of the invention is a distributed sensing system for detecting partial electric discharge along the length of an extended object or objects on which a single line of silica core optical sensing fiber is deployed in close proximity comprising: a optical sensing fiber comprising: a silica core; a cladding surrounding the core; wherein a luminescent material is integrated into the cladding surrounding the core; and wherein the luminescent material is selected to interact with the photons of any electric discharge so that the photons are converted to near UV to visible light when exposed to electric discharge of the extended object or objects; and wherein the optical sensing fiber is coated at a first end to provide a mirror reflecting surface for any specific emission light; and wherein a transparent protection layer is coated over the cladding; and wherein the silica core of the optical sensing fiber is less than 500 micro-meters in diameter; a photo detector positioned at a second end of the optical sensing fiber for receiving and measuring a first emission light from an electric partial discharge event and a second emission light reflected from the first end of the optical sensing fiber; a signal processor for receiving outputs from the photo detector for determining electric discharge location and magnitude.
In another aspect of the instant invention there is a method for detecting, locating, and measuring electric discharge along the length of an extended object or objects on which a single line of optical sensing fiber is deployed in close proximity comprising the steps of: providing an optical sensing fiber comprising a core, and a cladding surrounding the core, providing a reflecting finish on a first end of the optical sensing fiber; providing a luminescent material integrated into the cladding surrounding the core; the luminescent material selected to interact with electric discharge so that photons from the electric discharge are converted to near UV and visible light; deploying the optical sensing fiber in proximity to the extended object or objects; collecting emission light from the optical sensing fiber at a second end of the optical sensing fiber; providing a photo detector at the second end of the optical sensing fiber to measure intensities and arrival times of the emission light; providing the outputs from the photo detectors to a signal processor and the signal processor then utilizes the photo detector outputs to determine electric discharge location and magnitude.
In another aspect of the instant invention the luminescent material is integrated in the optical sensing fiber by uniformly integrating it into the entire length of the cladding of the optical sensing fiber.
In another aspect of the instant invention the integration of luminescent material is achieved by removing the cladding surrounding the core at discrete locations on the core and replacing it with the luminescent material and a coating of a transparent protection layer.
In another aspect of the instant invention outputs from the photo detector are fed to the signal processor and used to locate the electric discharge source along the fiber by determining the time difference between the first emission light from an electric partial discharge event and a second emission light reflected from the first end of the optical sensing fiber.
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SUMMARY: BACKGROUND
The present disclosure relates to electric partial discharge detection, and more particularly, to a system and method for detection and measuring electric partial discharge using an optical fiber.
As electrical wires age, insulation may become brittle and crack leading to arcing or shorts. Small arcs can carbonize the insulation, leading to bigger arcs and the potential for fire. Control of electrical discharge is necessary to avoid degrading the insulation in electrical wires in air or in insulating oil. The need for reliable monitoring is increased when the cable is used in high altitude where ambient pressures may be well below one atmosphere such at flight altitudes. The inception level for discharges is reduced as pressure decreases. Therefore, intermittent partial discharge or arcing that can occur in flight may not be reproducible during ground maintenance.
Intermittent discharges can occur from a wire with cracked or faulty insulation. Such partial discharges are in the form of pulses having time durations as short as a few nanoseconds or less. The pulses form because, once a discharge initiates, electrons quickly become depleted in the gap by buildup of space charge between the electrodes.
This extinguishes the discharge until the space charge dissipates sufficiently for a fresh discharge to occur. The presence of residual space charge along with surface charges and meta-stable excited gases act as a memory thus affecting ensuing pulse amplitudes and times of onset. Such discharges create an avalanche of electrons whose collisions with nitrogen molecules in air produce spectrum from near-UV photons to visible as shown inFIG. 1.
In order to detect the presence of cable defects in air or in oil, various imaging systems or electrical reflectometry techniques have been used to monitor entire wiring systems. But these devices provide limited coverage or require direct electrical connection, which can be inconvenient or even unsafe in some applications.
One potential detection concept that has been reported is photoluminescence. Photoluminescence is the emission of near or visible light from any substance under external excitation and it can be categorized into fluorescence and phosphorescence. The emission rates of fluorescence are typically 108/sec and its lifetime is near 10 nsec. Phosphorescence is emission of light from triplet-excited states, in which the electron in an excited orbital has the same spin orientation as the ground state electron. The transitions to ground are forbidden and the emission rates are slow (103-100), so phosphorescence lifetimes are typically milliseconds to seconds.
When an electron is excited to an upper state, it decays non-radiatively to a lower meta-stable state. From this meta-stable state the, electron decays radiatively emitting a photon. The energy of the emission, which is described as E=hν (where h is Plancks constant and ν is the frequency of the light) is typically less than that of absorption.
Sarkozi, U.S. Pat. No. 7,142,291, proposed a system for detecting partial discharges in wiring using a fluorescence optical fiber. The system required large diameter plastic core fiber optic cables embedded into the insulation material surrounding the wiring. The large core diameter optical fiber had a fluorescent material incorporated into the fiber core. Upon exposure of that fluorescent material to a discharge frequency it generates light that travels in both directions in the optical fiber. Optical detectors at each end of the fiber record the arrival of that light and a processor calculates a location of the discharge from the arrival times.
McSherry, et. al. (IEEE Sensors Journal October 2004) proposed a coated sensor model for measuring germicidal UV irradiation in which a large core diameter plastic optical fiber had its cladding removed and replaced by a fluorescent coating. When placed near a UV lamp the fluorescent coating would generate light that would travel down the optical fiber core to be detected.
Both of these prior art systems made use of large (1000 micro-meter) core diameter plastic optical fibers. Plastic fibers usually have cores of polymethylmethacrylate (PMMA) and typically have core diameters close to 1000 micro-meters. Such fibers have a limited transmission distance and poorer resistance to environmental conditions than optical fibers of a silica (glass) core. Silica glass core fibers typically have silica cores of between 50-500 micro-meters. Thus the plastic core fibers of these prior art references are significantly limited to very short sensor systems (around 10 m range) in favorable environments. In addition less complex detection systems than the two optical detector system of Sarkozi are needed. A silica core based sensor system with a hard plastic cladding for electric partial discharge would enable sensor systems based on large distances (potentially up to 1 kilometer with attenuation of less than 1 dB/100 m at the 550 nm emission band) and in more stringent environmental conditions.
In addition there is a need is for a distributed system that is easily deployable in close proximity to the objects being monitored without the need to incorporate them into the structural design as in the Sarkozi reference. And there is a need to decrease bend related attenuation in the fibers, which is possible with much smaller (<500 micro-meter) core diameter fibers with silica cores.
SUMMARY OF THE INVENTION
One aspect of the invention is a distributed sensing system for detecting partial electric discharge along the length of an extended object or objects on which a single line of silica core optical sensing fiber is deployed in close proximity comprising: a optical sensing fiber comprising: a silica core; a cladding surrounding the core; wherein a luminescent material is integrated into the cladding surrounding the core; and wherein the luminescent material is selected to interact with the photons of any electric discharge so that the photons are converted to near UV to visible light when exposed to electric discharge of the extended object or objects; and wherein the optical sensing fiber is coated at a first end to provide a mirror reflecting surface for any specific emission light; and wherein a transparent protection layer is coated over the cladding; and wherein the silica core of the optical sensing fiber is less than 500 micro-meters in diameter; a photo detector positioned at a second end of the optical sensing fiber for receiving and measuring a first emission light from an electric partial discharge event and a second emission light reflected from the first end of the optical sensing fiber; a signal processor for receiving outputs from the photo detector for determining electric discharge location and magnitude.
In another aspect of the instant invention there is a method for detecting, locating, and measuring electric discharge along the length of an extended object or objects on which a single line of optical sensing fiber is deployed in close proximity comprising the steps of: providing an optical sensing fiber comprising a core, and a cladding surrounding the core, providing a reflecting finish on a first end of the optical sensing fiber; providing a luminescent material integrated into the cladding surrounding the core; the luminescent material selected to interact with electric discharge so that photons from the electric discharge are converted to near UV and visible light; deploying the optical sensing fiber in proximity to the extended object or objects; collecting emission light from the optical sensing fiber at a second end of the optical sensing fiber; providing a photo detector at the second end of the optical sensing fiber to measure intensities and arrival times of the emission light; providing the outputs from the photo detectors to a signal processor and the signal processor then utilizes the photo detector outputs to determine electric discharge location and magnitude.
In another aspect of the instant invention the luminescent material is integrated in the optical sensing fiber by uniformly integrating it into the entire length of the cladding of the optical sensing fiber.
In another aspect of the instant invention the integration of luminescent material is achieved by removing the cladding surrounding the core at discrete locations on the core and replacing it with the luminescent material and a coating of a transparent protection layer.
In another aspect of the instant invention outputs from the photo detector are fed to the signal processor and used to locate the electric discharge source along the fiber by determining the time difference between the first emission light from an electric partial discharge event and a second emission light reflected from the first end of the optical sensing fiber.
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7765421 | FIELD
Various embodiments relate to powered devices and data processing systems. More particularly, embodiments relate to methods and apparatuses that operate in a data processing network.
COPYRIGHT NOTICE/PERMISSION
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The following notice applies to the software, modules, and data as described below and in the drawings hereto: Copyright © 2005, Apple Computer, Inc., All Rights Reserved.
BACKGROUND
A network involves a number of devices linked together to form a communications system for information and device sharing. Local Area Networks (“LAN”) are small (e.g., currently limited to about 500 meters though in the future may be longer), and are commonly deployed in corporate offices to facilitate information transfer. Cities and other metropolitan regions can be connected via Metropolitan Area Networks (“MAN”s). Wide Area Networks (“WAN”s) involve systems communicating across large geographic regions, for example, states and countries. Globally, computers in networks interlink to form “the Internet.”
Wireless networking is the use of Radio Frequency (“RF”) technology to connect workstations in a LAN and/or LAN's in WAN's. Use of this technology allows for high-speed network links with a limited amount or no wired connections. Wireless networking transmits and receives information over the air. The benefits of wireless networking include increased mobility, flexible installation, and easy scalability. Easy scalability means that wireless networks can support large physical areas by adding wireless access points to boost and extend coverage. Wireless networking also adds the aspect of mobility for laptop users. Since a LAN may have wireless capabilities, a user needs to be within a RF range of an access point device, instead of physically connected to an electrical power outlet through a cable.
Electronic devices (e.g., an internet phone, a building appliance such as a smoke detector, a computer, a data processing equipment, a networking device, etc.) may receive electrical power from an external source (e.g., an electrical power outlet, a 9V or other size batteries, etc.). Certain types of electronic devices (e.g., which may be access point devices such as base stations, modems, routers, etc.) connect wireless network devices of a wireless network to the wired network. Wireless network devices may communicate with each other by transmitting and receiving signals on a specific frequency of the radio band through one or more devices. Wireless network devices may have wireless adapters and/or PC cards (“wireless interfaces”) to provide direct wireless connection to each other and/or through electronic devices. In one example, an electronic device may be an Airport Express™ manufactured by Apple Computer, Inc., which combines a shared wireless Internet connection, music streaming, printing, and wireless bridging capabilities into a single, portable size mobile unit to use in various environments, for example, in homes, businesses, and campuses around the world.
A local power source (e.g., an electrical power outlet physically near to the electronic device or an internal battery) is usually required to deliver power to the electronic device. Without a dependable local power source, a particular electronic device may not be able to communicate with the network and/or provide any transmission and bridging functionality to other devices. Furthermore, if power is delivered from a non-local power source, problems such as energy waste, delay, and service interruptions may arise.
SUMMARY
Apparatuses and methods are described for automatic power management of a network powered device. In one aspect, a system delivers power to a powered device through a local area network using a power sourcing equipment which also processes data of an interconnected network and to receive power from a first power source coupled to the power sourcing equipment. The system may include the powered device connected at a distance away from the power sourcing equipment through a local area network (LAN) to process the data of the interconnected network through the power sourcing equipment. The powered device may include a modular power over LAN circuit to enable power to the powered device through the LAN when the modular power over LAN circuit is coupled to the powered device.
In one aspect, an optionally powered subsystem of the powered device may be altered (e.g., altered meaning disabled and/or enabled) (e.g., or may disable at least one port and/or function) when the powered device receives power through the LAN. In addition, an isolation circuit (e.g., an optical isolation circuit) of the powered device may be used to control the operation of a converter and/or power conversion circuit of the powered device. The powered device may draw power from a local power source when the modular power over LAN circuit is not coupled to the powered device or power is otherwise unavailable from the LAN (e.g., the power sourcing equipment is overloaded such that the maximum amount of power which it can distribute is already being distributed). In another aspect, a power source detection and control circuit of the powered device may transmit a LAN power disable control signal when power is received through the local power source. Furthermore, a report generator module of the powered device may create at least one detailed summary report of activity monitored by the power source detection and control circuit, where the at least one detailed summary report is transmittable to at least one interested party.
The powered device may include a converter of the powered device coupled to the power source detection and control circuit to transform an input voltage to an output voltage when the modular power over LAN circuit is coupled to the powered device and when power is received through the LAN. In one aspect, the converter may be disabled when power is received through the local power source.
A powered device may include a power source detection and control circuit to transmit a LAN power disable control signal to an optical isolation circuit when power is received through a local power source. The powered device may also include a converter coupled to the optical isolation circuit to transform an input voltage to an output voltage when a modular power over LAN circuit is coupled to the powered device and when power is received through the LAN. In addition, an optionally powered subsystem of the powered device may be disabled (e.g., or may disable power to at least one port of the powered device) when the modular power over LAN circuit is coupled to the powered device and when power is received through the LAN. In some embodiments, if the local power source is minimal, such as a battery, some functions of the device may only be powered if LAN power is available. The powered device may also include a transmitter circuit to transmit data received from the processing system to at least one wireless device.
In another aspect, a transmitter circuit of the powered device may deliver at least one status report generated by a report generator module of the powered device to the at least one wireless device. The converter may be disabled and power may be directly supplied to a processing system when power is received through the local power source. The powered device may also include an optical isolation circuit to control the operation of the converter. The powered device may draw power from the local power source when the modular power over LAN circuit is not coupled to the powered device. In an alternate aspect, the powered device may, through automatic or other means, preferentially determine how to draw power when both local and LAN power are available. Additionally, power may be supplied through the LAN from a remote power source when the modular power over LAN circuit is coupled to the powered device and the local power source is unavailable.
In one aspect, a method of managing power of a powered device may include automatically detecting power from at least one of a remote power source and a local power source; selecting the remote power source when the local power source is unavailable; and conserving power by disabling at least one port and/or function of the powered device when the remote power source is selected. The method may also transmit data indicating a status of at least one of the remote power source and the local power source to at least one interested party (e.g., at least one of a wireless device and/or a power sourcing equipment). The method may restrict power from the remote power source when a modular power over local area network (LAN) circuit is disconnected from the powered device. The method may disable an internal converter and supply power directly to a processing system when power is received from the local power source. Furthermore, the method may control an internal power converter using an optical isolation circuit.
The present invention describes systems, methods, and machine-readable media of varying scope. In addition to the aspects of the present invention described in this summary, further aspects of the invention will become apparent by reference to the drawings and by reading the detailed description that follows.
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SUMMARY: FIELD
Various embodiments relate to powered devices and data processing systems. More particularly, embodiments relate to methods and apparatuses that operate in a data processing network.
COPYRIGHT NOTICE/PERMISSION
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The following notice applies to the software, modules, and data as described below and in the drawings hereto: Copyright © 2005, Apple Computer, Inc., All Rights Reserved.
BACKGROUND
A network involves a number of devices linked together to form a communications system for information and device sharing. Local Area Networks (“LAN”) are small (e.g., currently limited to about 500 meters though in the future may be longer), and are commonly deployed in corporate offices to facilitate information transfer. Cities and other metropolitan regions can be connected via Metropolitan Area Networks (“MAN”s). Wide Area Networks (“WAN”s) involve systems communicating across large geographic regions, for example, states and countries. Globally, computers in networks interlink to form “the Internet.”
Wireless networking is the use of Radio Frequency (“RF”) technology to connect workstations in a LAN and/or LAN's in WAN's. Use of this technology allows for high-speed network links with a limited amount or no wired connections. Wireless networking transmits and receives information over the air. The benefits of wireless networking include increased mobility, flexible installation, and easy scalability. Easy scalability means that wireless networks can support large physical areas by adding wireless access points to boost and extend coverage. Wireless networking also adds the aspect of mobility for laptop users. Since a LAN may have wireless capabilities, a user needs to be within a RF range of an access point device, instead of physically connected to an electrical power outlet through a cable.
Electronic devices (e.g., an internet phone, a building appliance such as a smoke detector, a computer, a data processing equipment, a networking device, etc.) may receive electrical power from an external source (e.g., an electrical power outlet, a 9V or other size batteries, etc.). Certain types of electronic devices (e.g., which may be access point devices such as base stations, modems, routers, etc.) connect wireless network devices of a wireless network to the wired network. Wireless network devices may communicate with each other by transmitting and receiving signals on a specific frequency of the radio band through one or more devices. Wireless network devices may have wireless adapters and/or PC cards (“wireless interfaces”) to provide direct wireless connection to each other and/or through electronic devices. In one example, an electronic device may be an Airport Express™ manufactured by Apple Computer, Inc., which combines a shared wireless Internet connection, music streaming, printing, and wireless bridging capabilities into a single, portable size mobile unit to use in various environments, for example, in homes, businesses, and campuses around the world.
A local power source (e.g., an electrical power outlet physically near to the electronic device or an internal battery) is usually required to deliver power to the electronic device. Without a dependable local power source, a particular electronic device may not be able to communicate with the network and/or provide any transmission and bridging functionality to other devices. Furthermore, if power is delivered from a non-local power source, problems such as energy waste, delay, and service interruptions may arise.
SUMMARY
Apparatuses and methods are described for automatic power management of a network powered device. In one aspect, a system delivers power to a powered device through a local area network using a power sourcing equipment which also processes data of an interconnected network and to receive power from a first power source coupled to the power sourcing equipment. The system may include the powered device connected at a distance away from the power sourcing equipment through a local area network (LAN) to process the data of the interconnected network through the power sourcing equipment. The powered device may include a modular power over LAN circuit to enable power to the powered device through the LAN when the modular power over LAN circuit is coupled to the powered device.
In one aspect, an optionally powered subsystem of the powered device may be altered (e.g., altered meaning disabled and/or enabled) (e.g., or may disable at least one port and/or function) when the powered device receives power through the LAN. In addition, an isolation circuit (e.g., an optical isolation circuit) of the powered device may be used to control the operation of a converter and/or power conversion circuit of the powered device. The powered device may draw power from a local power source when the modular power over LAN circuit is not coupled to the powered device or power is otherwise unavailable from the LAN (e.g., the power sourcing equipment is overloaded such that the maximum amount of power which it can distribute is already being distributed). In another aspect, a power source detection and control circuit of the powered device may transmit a LAN power disable control signal when power is received through the local power source. Furthermore, a report generator module of the powered device may create at least one detailed summary report of activity monitored by the power source detection and control circuit, where the at least one detailed summary report is transmittable to at least one interested party.
The powered device may include a converter of the powered device coupled to the power source detection and control circuit to transform an input voltage to an output voltage when the modular power over LAN circuit is coupled to the powered device and when power is received through the LAN. In one aspect, the converter may be disabled when power is received through the local power source.
A powered device may include a power source detection and control circuit to transmit a LAN power disable control signal to an optical isolation circuit when power is received through a local power source. The powered device may also include a converter coupled to the optical isolation circuit to transform an input voltage to an output voltage when a modular power over LAN circuit is coupled to the powered device and when power is received through the LAN. In addition, an optionally powered subsystem of the powered device may be disabled (e.g., or may disable power to at least one port of the powered device) when the modular power over LAN circuit is coupled to the powered device and when power is received through the LAN. In some embodiments, if the local power source is minimal, such as a battery, some functions of the device may only be powered if LAN power is available. The powered device may also include a transmitter circuit to transmit data received from the processing system to at least one wireless device.
In another aspect, a transmitter circuit of the powered device may deliver at least one status report generated by a report generator module of the powered device to the at least one wireless device. The converter may be disabled and power may be directly supplied to a processing system when power is received through the local power source. The powered device may also include an optical isolation circuit to control the operation of the converter. The powered device may draw power from the local power source when the modular power over LAN circuit is not coupled to the powered device. In an alternate aspect, the powered device may, through automatic or other means, preferentially determine how to draw power when both local and LAN power are available. Additionally, power may be supplied through the LAN from a remote power source when the modular power over LAN circuit is coupled to the powered device and the local power source is unavailable.
In one aspect, a method of managing power of a powered device may include automatically detecting power from at least one of a remote power source and a local power source; selecting the remote power source when the local power source is unavailable; and conserving power by disabling at least one port and/or function of the powered device when the remote power source is selected. The method may also transmit data indicating a status of at least one of the remote power source and the local power source to at least one interested party (e.g., at least one of a wireless device and/or a power sourcing equipment). The method may restrict power from the remote power source when a modular power over local area network (LAN) circuit is disconnected from the powered device. The method may disable an internal converter and supply power directly to a processing system when power is received from the local power source. Furthermore, the method may control an internal power converter using an optical isolation circuit.
The present invention describes systems, methods, and machine-readable media of varying scope. In addition to the aspects of the present invention described in this summary, further aspects of the invention will become apparent by reference to the drawings and by reading the detailed description that follows.
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7690020 | FIELD OF THE INVENTION
The present invention relates to content delivery systems and, more particularly, to content delivery systems having video on demand capability.
BACKGROUND OF THE INVENTION
Video on demand (VOD) is not a new concept. It has been implemented in small scale, closed systems for a number of years (as used in this application, closed system means additional users cannot be added after the system has been installed). In particular, VOD has been used in hotels, on airplanes, and in other, similar closed systems. Recently, larger scale television services have begun implementing VOD services on larger, open television systems (as used in this application, open system means additional users can be added after the system has been installed). U.S. Pat. No. 5,850,218, issued Dec. 15, 1998, to Lajoie et al. for “Inter-Active Program Guide with Default Selection Control,” incorporated herein by reference, describes one possible television network capable of supplying VOD services. A television system in Orlando, Fl. has implemented a VOD system similar to the one described in U.S. Pat. No. 5,850,218.
As is evident in the above examples, conventional wisdom for implementing VOD services in television systems contemplated a centralized service. The centralized VOD service model placed (or housed) the computers and media servers necessary to implement and control the VOD services in the central or headend location. Customers would access the servers through their set-top boxes. The set-top boxes would communicate with the media server at the headend to establish a video stream for the requested video. On a smaller scale with a limited number of users, such as the hotel system mentioned above, the centralized service works fairly well. Centralized VOD services work in the smaller environment partially due to the predictable and limited number of video streams that are necessary to satisfy expected peak demand for VOD services. Additionally, the content of the smaller centralized server is typically limited to “new release” types of movies.
However, implementing the centralized system on a large and potentially ever increasing open network system is prohibitively expensive because of the large size of the content transport network required to support the number of interactive video sessions. For example, in a network with 500,000 customers and assuming 10% (50,000) are simultaneous users, 20,000 Mbps must be available from the headend to the hubs to support the expected peak demand of the VOD services. Increasing demand causes a corresponding increase in the number of video streams that the centralized server needs to provide. Furthermore, in the typical wide area television network, the number of subscribers continually increases. As the number of subscribers increases or the demand expands, it becomes increasingly difficult to provide the server streaming capacity and the bandwidth and switching capability of the interactive transport network to accommodate the increase in users. It would therefore be beneficial to develop a content delivery system having VOD services that was not reliant solely on the centralized media source.
By distributing servers to hubs (closer to the customers), the size of the fiber transport network can be reduced, which significantly reduces the costs associated with implementing a large-scale interactive VOD service. A purely distributed system, however, has some of its own disadvantages. As all servers must provide all and any content that is promoted as available on the system, each server must provide a large storage capacity that must include low-demand library titles. Such content numbering in hundreds or thousands of titles consumes the vast majority of storage capacity, yet it generates very limited revenues. It can be documented that 90% of such content generates only 10% of the earnings, while the current 10% of the high-demand content generates 90% of the total revenues. In addition, a purely distributed system cannot realistically support interactive VOD functionality for real time events that would provide personal video recorder (PVR) experience for live events. Therefore, it is desirous to develop and engineer a hybrid central/distributed VOD system with a tiered content structure that would provide a vastly superior technical and economical performance. It segregates the content according to its demand and makes each of the high and low demand content available in a most economic and reliable fashion to the users. It would further enable fully interactive real time event VOD services, providing PVR functionality. The hybrid central/distributed VOD system with a tiered content structure is applicable to interactive content delivery systems used in cable systems, as well as geographically larger delivery systems such as internet, satellite or regional DSL service systems. For example, as set top boxes and satellite receivers with record and replay capability are becoming available, the term “hub server” as it relates to high demand content storage may be supplemented by any of these home devices. One may assume high demand content to be pushed to homes (as it is now file transferred to the hub servers) while the low demand content is ordered on an individual basis (as it is now from central server).
SUMMARY OF THE INVENTION
To attain the advantages of and in accordance with the purpose of the present invention, as embodied and broadly described herein, content delivery systems for supplying video on demand in a broadband environment include a headend station having a central media server and at least one hub station having a hub media server. The headend and the hub stations also have tiered content storage capability and radio frequency management infrastructure. Video on demand content is supplied via a distribution network to the set-top boxes preferably from a nearby high-demand content hub server and secondary from the central media server over a content transport network. The radio frequency management infrastructure modulates and directs the content streams. It further groups the channels for delivery of video on demand services from the radio frequency management infrastructure to the set-top boxes over a distribution network.
Other embodiments of the present invention provide methods of interactive delivering video on demand services. These methods include requesting a video on demand service. After requesting the service, a video on demand asset database is accessed to identify available delivery assets and data stream paths. Particular assets are determined, identified, and assigned to deliver the requested video on demand service to the set-top box. After the assignment of the assets, the video on demand service is supplied over the assigned data stream path.
Still other embodiments of the present invention provide computer program products having computer readable code for delivering video on demand service. The computer program product may include a requesting module configured to receive requests for video on demand services from a viewer. A determining module may be configured to access a video on demand asset database to identify assets capable of being used to deliver the requested video on demand service and to determine whether assets are available to deliver the requested service. An identifying module then identifies a particular data stream path from the assets determined to be available. An assigning module may be configured to assign the identified data stream path to deliver the requested video on demand service and to update the asset database to indicate the assets are no longer available. Finally, a supplying module may be configured to supply the requested VOD service over the assigned data stream path.
The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates to content delivery systems and, more particularly, to content delivery systems having video on demand capability.
BACKGROUND OF THE INVENTION
Video on demand (VOD) is not a new concept. It has been implemented in small scale, closed systems for a number of years (as used in this application, closed system means additional users cannot be added after the system has been installed). In particular, VOD has been used in hotels, on airplanes, and in other, similar closed systems. Recently, larger scale television services have begun implementing VOD services on larger, open television systems (as used in this application, open system means additional users can be added after the system has been installed). U.S. Pat. No. 5,850,218, issued Dec. 15, 1998, to Lajoie et al. for “Inter-Active Program Guide with Default Selection Control,” incorporated herein by reference, describes one possible television network capable of supplying VOD services. A television system in Orlando, Fl. has implemented a VOD system similar to the one described in U.S. Pat. No. 5,850,218.
As is evident in the above examples, conventional wisdom for implementing VOD services in television systems contemplated a centralized service. The centralized VOD service model placed (or housed) the computers and media servers necessary to implement and control the VOD services in the central or headend location. Customers would access the servers through their set-top boxes. The set-top boxes would communicate with the media server at the headend to establish a video stream for the requested video. On a smaller scale with a limited number of users, such as the hotel system mentioned above, the centralized service works fairly well. Centralized VOD services work in the smaller environment partially due to the predictable and limited number of video streams that are necessary to satisfy expected peak demand for VOD services. Additionally, the content of the smaller centralized server is typically limited to “new release” types of movies.
However, implementing the centralized system on a large and potentially ever increasing open network system is prohibitively expensive because of the large size of the content transport network required to support the number of interactive video sessions. For example, in a network with 500,000 customers and assuming 10% (50,000) are simultaneous users, 20,000 Mbps must be available from the headend to the hubs to support the expected peak demand of the VOD services. Increasing demand causes a corresponding increase in the number of video streams that the centralized server needs to provide. Furthermore, in the typical wide area television network, the number of subscribers continually increases. As the number of subscribers increases or the demand expands, it becomes increasingly difficult to provide the server streaming capacity and the bandwidth and switching capability of the interactive transport network to accommodate the increase in users. It would therefore be beneficial to develop a content delivery system having VOD services that was not reliant solely on the centralized media source.
By distributing servers to hubs (closer to the customers), the size of the fiber transport network can be reduced, which significantly reduces the costs associated with implementing a large-scale interactive VOD service. A purely distributed system, however, has some of its own disadvantages. As all servers must provide all and any content that is promoted as available on the system, each server must provide a large storage capacity that must include low-demand library titles. Such content numbering in hundreds or thousands of titles consumes the vast majority of storage capacity, yet it generates very limited revenues. It can be documented that 90% of such content generates only 10% of the earnings, while the current 10% of the high-demand content generates 90% of the total revenues. In addition, a purely distributed system cannot realistically support interactive VOD functionality for real time events that would provide personal video recorder (PVR) experience for live events. Therefore, it is desirous to develop and engineer a hybrid central/distributed VOD system with a tiered content structure that would provide a vastly superior technical and economical performance. It segregates the content according to its demand and makes each of the high and low demand content available in a most economic and reliable fashion to the users. It would further enable fully interactive real time event VOD services, providing PVR functionality. The hybrid central/distributed VOD system with a tiered content structure is applicable to interactive content delivery systems used in cable systems, as well as geographically larger delivery systems such as internet, satellite or regional DSL service systems. For example, as set top boxes and satellite receivers with record and replay capability are becoming available, the term “hub server” as it relates to high demand content storage may be supplemented by any of these home devices. One may assume high demand content to be pushed to homes (as it is now file transferred to the hub servers) while the low demand content is ordered on an individual basis (as it is now from central server).
SUMMARY OF THE INVENTION
To attain the advantages of and in accordance with the purpose of the present invention, as embodied and broadly described herein, content delivery systems for supplying video on demand in a broadband environment include a headend station having a central media server and at least one hub station having a hub media server. The headend and the hub stations also have tiered content storage capability and radio frequency management infrastructure. Video on demand content is supplied via a distribution network to the set-top boxes preferably from a nearby high-demand content hub server and secondary from the central media server over a content transport network. The radio frequency management infrastructure modulates and directs the content streams. It further groups the channels for delivery of video on demand services from the radio frequency management infrastructure to the set-top boxes over a distribution network.
Other embodiments of the present invention provide methods of interactive delivering video on demand services. These methods include requesting a video on demand service. After requesting the service, a video on demand asset database is accessed to identify available delivery assets and data stream paths. Particular assets are determined, identified, and assigned to deliver the requested video on demand service to the set-top box. After the assignment of the assets, the video on demand service is supplied over the assigned data stream path.
Still other embodiments of the present invention provide computer program products having computer readable code for delivering video on demand service. The computer program product may include a requesting module configured to receive requests for video on demand services from a viewer. A determining module may be configured to access a video on demand asset database to identify assets capable of being used to deliver the requested video on demand service and to determine whether assets are available to deliver the requested service. An identifying module then identifies a particular data stream path from the assets determined to be available. An assigning module may be configured to assign the identified data stream path to deliver the requested video on demand service and to update the asset database to indicate the assets are no longer available. Finally, a supplying module may be configured to supply the requested VOD service over the assigned data stream path.
The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
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7661494 | BACKGROUND OF THE INVENTION
Priority is claimed on Japanese Patent Application No. 2006-146882, filed May 26, 2006, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relate to a power supply system of a fuel cell vehicle.
2. Description of the Related Art
A conventional power supply system of a fuel cell vehicle is known which increases the output voltage of a fuel cell using a first DC-DC converter and input it to a load, wherein if the output electrical power from the fuel cell is insufficient for the requirement by the load, then the deficiency is compensated by inputting additional electrical power to the load from a power storage device via a second DC-DC converter, while if the output electrical power from the fuel cell is excessive for the requirement by the load, then the excessive electrical power is supplied from the fuel cell to the power storage device via the first DC-DC converter and the second DC-DC converter, to charge the power storage device (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2003-208913).
The power supply system of a fuel cell vehicle having the above-mentioned construction needs cooperative operations of the two DC-DC converters to supply stable current and voltage to the load; and it has been an object to establish a control method therefore.
The present invention was made in view of the above-mentioned circumstances and has an object of providing a power supply system of a fuel cell vehicle which enables a cooperative control of two DC-DC converters to supply stable current and voltage to a load.
SUMMARY OF THE INVENTION
A power supply system of a fuel cell vehicle of the present invention employed the followings in order to achieve the above object.
That is, a power supply system of a fuel cell vehicle of the present invention includes: a load mounted on a vehicle; a fuel cell and a power storage device which are connected to the load so as to be parallel with each other; a first DC-DC converter provided between the fuel cell and the load; a second DC-DC converter provided between the power storage device and the load; a current-measuring device which measures one of an input current and an output current of the first DC-DC converter; a voltage-measuring device which measures one of an input voltage and an output voltage of the second DC-DC converter; and a controller which performs a feedback control of the first DC-DC converter such that the input current or the output current measured by the current-measuring device becomes a target current, and also performs a feedback control of the second DC-DC converter such that the input voltage or the output voltage measured by the voltage-measuring device becomes a target voltage.
According to the power supply system of a fuel cell vehicle, the first DC-DC converter is controlled by controlling current, while the second DC-DC converter is controlled by controlling the voltage. Since control parameters between the first DC-DC converter and the second DC-DC converter differ from each other, controlling of the first DC-DC converter and controlling of the second DC-DC converter will not interfere with each other. Accordingly, the output current of the fuel cell can be controlled so as to be stable, while enabling controlling the input voltage to the load so as to be stable.
It may be arranged such that: the load be a motor for traveling the vehicle; and the controller increase the target voltage of the second DC-DC converter in response to an increasing target output power of the motor.
In this case, the output power control of the motor for traveling the vehicle can be performed stably, and thereby enabling securing desired motor output power reliably.
The controller may be provided with: a motor target output power calculation device which calculates the target output power of the motor; a load target voltage calculation device which calculates a target voltage of the motor in response to the target output power of the motor; a fuel cell target current calculation device which calculates a target output current of the fuel cell; a first DC-DC converter controller which performs a feedback control of the first DC-DC converter referring to the target output current of the fuel cell calculated by the fuel cell target current calculation device, as the target current of the first DC-DC converter; and a second DC-DC converter controller which performs a feedback control of the second DC-DC converter employing the target voltage of the motor calculated by the load target voltage calculation device as the target voltage of the second DC-DC converter.
In this case, the voltage to the motor can be stably controlled in response to the motor output power, while the current of the fuel cell can be stably controlled so as to be the desired current.
It may be arranged such that: the controller include an output power distribution device which distributes the target output power of the motor into an output electrical power to be generated by the fuel cell and another output electrical power to be generated by the power storage device; and the fuel cell target current calculation device calculate the target output current of the fuel cell based on the output electrical power to be generated by the fuel cell, which is distributed by the output power distribution device.
In this case, the output current of the fuel cell can be controlled in response to the distributed electrical power.
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SUMMARY: BACKGROUND OF THE INVENTION
Priority is claimed on Japanese Patent Application No. 2006-146882, filed May 26, 2006, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relate to a power supply system of a fuel cell vehicle.
2. Description of the Related Art
A conventional power supply system of a fuel cell vehicle is known which increases the output voltage of a fuel cell using a first DC-DC converter and input it to a load, wherein if the output electrical power from the fuel cell is insufficient for the requirement by the load, then the deficiency is compensated by inputting additional electrical power to the load from a power storage device via a second DC-DC converter, while if the output electrical power from the fuel cell is excessive for the requirement by the load, then the excessive electrical power is supplied from the fuel cell to the power storage device via the first DC-DC converter and the second DC-DC converter, to charge the power storage device (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2003-208913).
The power supply system of a fuel cell vehicle having the above-mentioned construction needs cooperative operations of the two DC-DC converters to supply stable current and voltage to the load; and it has been an object to establish a control method therefore.
The present invention was made in view of the above-mentioned circumstances and has an object of providing a power supply system of a fuel cell vehicle which enables a cooperative control of two DC-DC converters to supply stable current and voltage to a load.
SUMMARY OF THE INVENTION
A power supply system of a fuel cell vehicle of the present invention employed the followings in order to achieve the above object.
That is, a power supply system of a fuel cell vehicle of the present invention includes: a load mounted on a vehicle; a fuel cell and a power storage device which are connected to the load so as to be parallel with each other; a first DC-DC converter provided between the fuel cell and the load; a second DC-DC converter provided between the power storage device and the load; a current-measuring device which measures one of an input current and an output current of the first DC-DC converter; a voltage-measuring device which measures one of an input voltage and an output voltage of the second DC-DC converter; and a controller which performs a feedback control of the first DC-DC converter such that the input current or the output current measured by the current-measuring device becomes a target current, and also performs a feedback control of the second DC-DC converter such that the input voltage or the output voltage measured by the voltage-measuring device becomes a target voltage.
According to the power supply system of a fuel cell vehicle, the first DC-DC converter is controlled by controlling current, while the second DC-DC converter is controlled by controlling the voltage. Since control parameters between the first DC-DC converter and the second DC-DC converter differ from each other, controlling of the first DC-DC converter and controlling of the second DC-DC converter will not interfere with each other. Accordingly, the output current of the fuel cell can be controlled so as to be stable, while enabling controlling the input voltage to the load so as to be stable.
It may be arranged such that: the load be a motor for traveling the vehicle; and the controller increase the target voltage of the second DC-DC converter in response to an increasing target output power of the motor.
In this case, the output power control of the motor for traveling the vehicle can be performed stably, and thereby enabling securing desired motor output power reliably.
The controller may be provided with: a motor target output power calculation device which calculates the target output power of the motor; a load target voltage calculation device which calculates a target voltage of the motor in response to the target output power of the motor; a fuel cell target current calculation device which calculates a target output current of the fuel cell; a first DC-DC converter controller which performs a feedback control of the first DC-DC converter referring to the target output current of the fuel cell calculated by the fuel cell target current calculation device, as the target current of the first DC-DC converter; and a second DC-DC converter controller which performs a feedback control of the second DC-DC converter employing the target voltage of the motor calculated by the load target voltage calculation device as the target voltage of the second DC-DC converter.
In this case, the voltage to the motor can be stably controlled in response to the motor output power, while the current of the fuel cell can be stably controlled so as to be the desired current.
It may be arranged such that: the controller include an output power distribution device which distributes the target output power of the motor into an output electrical power to be generated by the fuel cell and another output electrical power to be generated by the power storage device; and the fuel cell target current calculation device calculate the target output current of the fuel cell based on the output electrical power to be generated by the fuel cell, which is distributed by the output power distribution device.
In this case, the output current of the fuel cell can be controlled in response to the distributed electrical power.
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7785145 | The present invention concerns an electrical connector designed to be coupled with a connector counterpart by elastic interlocking along a coupling direction, and comprising for this purpose a device that locks by elastic interlocking and has an axial stop surface provided in order to create, together with a stop surface associated with a complementary locking device of the counterpart, a mutual support opposing a disconnection of the connector and the counterpart.
In certain applications in severe environments, as is the case particularly for connection technology in the engine compartment of motor vehicles, the quality of the electrical contacts can be rapidly degraded and malfunctioning can be generated.
In the particular example of a connection device for an internal combustion engine injector, the connection base made in one piece with the engine is subjected to high levels of vibration and is also subjected to temperature levels that are also very high.
With connectors and bases of the known type, locking devices that offer a great simplicity of mounting of the connector onto the base, however, undergo significant wear and a loss of efficacy over the lifetime of the vehicle, due to these severe operating conditions. The progressive wear of the locking devices leads to an increase of the axial play between the connector and the base, so that friction is produced between the complementary contacts of the base and the connector.
Thus the functioning of known connection devices of the type disclosed above is affected in an amplified manner over time, since the appearance of play generates wear, which itself increases the play, etc.
The object of the invention is to resolve this problem without increasing the complexity of the locking devices of the connector and the base, and without increasing the difficulty of positioning the connector on the base.
For this purpose, the subject of the invention is an electrical connector of the above-mentioned type, characterized in that it comprises an elastic component for attenuating vibrations, arranged in such a way as to create an elastic force of mutual support for the stop surfaces, when the connector and its counterpart are coupled.
According to other characteristics of the invention:the electrical connector comprises a peripheral seal, provided in order to assure tightness between the connector and its counterpart when they are coupled, and the elastic attenuating component makes up part of said seal;the peripheral seal is a lip seal; andthe seal is made in one piece, particularly of an elastomer.
According to a first embodiment of the invention, the electrical connector comprises a casing on which is provided the locking device, and a contact-bearing module, which is mounted inside the casing by interlocking with the possibility of axial play, and the elastic attenuating component is arranged so as to be compressed axially between the module and the casing, when the module is mounted in the casing, with the effect of locking the connector onto the counterpart.
Preferably, the peripheral seal is mounted on said contact-bearing module.
According to a second embodiment of the invention, the connector comprises a contact-receiving casing, on which is provided the locking device, and the elastic component is provided so as to be compressed axially between the casing and the counterpart, with the effect of locking the connector onto the counterpart.
Preferably, the peripheral seal is mounted on said casing.
The invention also pertains to a device for electrical connection comprising an electrical connector such as defined above, and a base forming a counterpart for said connector, said base being a base of a motor vehicle part.
In particular, the base can be a base of an internal combustion engine part of a motor vehicle, particularly a base for the fuel injector.
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SUMMARY: The present invention concerns an electrical connector designed to be coupled with a connector counterpart by elastic interlocking along a coupling direction, and comprising for this purpose a device that locks by elastic interlocking and has an axial stop surface provided in order to create, together with a stop surface associated with a complementary locking device of the counterpart, a mutual support opposing a disconnection of the connector and the counterpart.
In certain applications in severe environments, as is the case particularly for connection technology in the engine compartment of motor vehicles, the quality of the electrical contacts can be rapidly degraded and malfunctioning can be generated.
In the particular example of a connection device for an internal combustion engine injector, the connection base made in one piece with the engine is subjected to high levels of vibration and is also subjected to temperature levels that are also very high.
With connectors and bases of the known type, locking devices that offer a great simplicity of mounting of the connector onto the base, however, undergo significant wear and a loss of efficacy over the lifetime of the vehicle, due to these severe operating conditions. The progressive wear of the locking devices leads to an increase of the axial play between the connector and the base, so that friction is produced between the complementary contacts of the base and the connector.
Thus the functioning of known connection devices of the type disclosed above is affected in an amplified manner over time, since the appearance of play generates wear, which itself increases the play, etc.
The object of the invention is to resolve this problem without increasing the complexity of the locking devices of the connector and the base, and without increasing the difficulty of positioning the connector on the base.
For this purpose, the subject of the invention is an electrical connector of the above-mentioned type, characterized in that it comprises an elastic component for attenuating vibrations, arranged in such a way as to create an elastic force of mutual support for the stop surfaces, when the connector and its counterpart are coupled.
According to other characteristics of the invention:the electrical connector comprises a peripheral seal, provided in order to assure tightness between the connector and its counterpart when they are coupled, and the elastic attenuating component makes up part of said seal;the peripheral seal is a lip seal; andthe seal is made in one piece, particularly of an elastomer.
According to a first embodiment of the invention, the electrical connector comprises a casing on which is provided the locking device, and a contact-bearing module, which is mounted inside the casing by interlocking with the possibility of axial play, and the elastic attenuating component is arranged so as to be compressed axially between the module and the casing, when the module is mounted in the casing, with the effect of locking the connector onto the counterpart.
Preferably, the peripheral seal is mounted on said contact-bearing module.
According to a second embodiment of the invention, the connector comprises a contact-receiving casing, on which is provided the locking device, and the elastic component is provided so as to be compressed axially between the casing and the counterpart, with the effect of locking the connector onto the counterpart.
Preferably, the peripheral seal is mounted on said casing.
The invention also pertains to a device for electrical connection comprising an electrical connector such as defined above, and a base forming a counterpart for said connector, said base being a base of a motor vehicle part.
In particular, the base can be a base of an internal combustion engine part of a motor vehicle, particularly a base for the fuel injector.
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7697294 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The disclosure relates generally to a heat dissipation device, and more particularly to a heat dissipation device having a plurality of fins to remove heat from an electronic heat-generating component, wherein the fins have an improved structure.
2. Description of Related Art
Heat sinks are usually used to remove heat from heat-generating electronic components, such as central processing units (CPUs), power transistors, etc., to keep the components in stable operation. A typical heat sink comprises a base for contacting a heat-generating component to absorb heat generated by the heat-generating component and a plurality of parallel planar fins attached to the base by soldering or adhering. The fins are used for dissipating the heat to the ambient environment.
Typically, the heat sink is a parallel fined heat sink, which is fabricated by processes including an extrusion process, a gang sawing process and a bonding process. It is known that thickness and number of the fins produced by the extrusion process is restricted by the structure limitation and stress loading limitation of a die. If the number of the fins increases, the die fingers become weaker thus easily break off. Therefore, the extrusion process is not suitable for fabricating the high-density fin heat sink. The gang sawing process is performed by cutting off portions of a metal block to produce fins having predetermined thickness, number, depth and gap, which results in a great loss of material. In the bonding process, each fin is individually bonded into a base of the heat sink, which is time-consuming and labor intensive. In addiction, the fins that are not well-bonded into the base are likely to fall and thus be detached from the base.
A current thermal resolution to overcome the problems mentioned above is to provide a composite fin unit having a plurality of individual fins assembled together. The fins each have at least a flange extending perpendicularly from at least an edge thereof. Each flange of the fins is provided with a locking structure thereon. The locking structure of each fin engages with the locking structures of the rear and front fins to assemble the fins together with their flanges oriented in a same direction. The density of the fins can be predetermined by width of the flanges and able to be increased dramatically. However, the fins which are usually rectangular sheets have sharp angles in their corners, and the flanges of the fins all have exposed sharp edges. The sharp corners and edges of the flanges and the fins are in a high risk of damaging components surrounding the heat-generating component and hurting an operator during installation.
What is needed is a heat sink which has a plurality of individual fins assembled together to obtain a fin unit which has a high density of fins and is safe in installation and in use.
SUMMARY OF THE INVENTION
The present invention relates to a heat dissipation device adapted for dissipating heat from a heat-generating electronic element, includes a plurality of fins assembled together. Each of the fins has a rectangular body and four arch-shaped flanges extending from edges of the body to form four round corners in four corners of the body. Each main body of the fins defines a plurality of locking members thereon to engage with corresponding locking members of a corresponding front fin. The arch-shaped flanges in four respective corners of the fins cooperate with each other to form four arced faces in four corners of the assembled fins along an entire length of the assembled fins.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The disclosure relates generally to a heat dissipation device, and more particularly to a heat dissipation device having a plurality of fins to remove heat from an electronic heat-generating component, wherein the fins have an improved structure.
2. Description of Related Art
Heat sinks are usually used to remove heat from heat-generating electronic components, such as central processing units (CPUs), power transistors, etc., to keep the components in stable operation. A typical heat sink comprises a base for contacting a heat-generating component to absorb heat generated by the heat-generating component and a plurality of parallel planar fins attached to the base by soldering or adhering. The fins are used for dissipating the heat to the ambient environment.
Typically, the heat sink is a parallel fined heat sink, which is fabricated by processes including an extrusion process, a gang sawing process and a bonding process. It is known that thickness and number of the fins produced by the extrusion process is restricted by the structure limitation and stress loading limitation of a die. If the number of the fins increases, the die fingers become weaker thus easily break off. Therefore, the extrusion process is not suitable for fabricating the high-density fin heat sink. The gang sawing process is performed by cutting off portions of a metal block to produce fins having predetermined thickness, number, depth and gap, which results in a great loss of material. In the bonding process, each fin is individually bonded into a base of the heat sink, which is time-consuming and labor intensive. In addiction, the fins that are not well-bonded into the base are likely to fall and thus be detached from the base.
A current thermal resolution to overcome the problems mentioned above is to provide a composite fin unit having a plurality of individual fins assembled together. The fins each have at least a flange extending perpendicularly from at least an edge thereof. Each flange of the fins is provided with a locking structure thereon. The locking structure of each fin engages with the locking structures of the rear and front fins to assemble the fins together with their flanges oriented in a same direction. The density of the fins can be predetermined by width of the flanges and able to be increased dramatically. However, the fins which are usually rectangular sheets have sharp angles in their corners, and the flanges of the fins all have exposed sharp edges. The sharp corners and edges of the flanges and the fins are in a high risk of damaging components surrounding the heat-generating component and hurting an operator during installation.
What is needed is a heat sink which has a plurality of individual fins assembled together to obtain a fin unit which has a high density of fins and is safe in installation and in use.
SUMMARY OF THE INVENTION
The present invention relates to a heat dissipation device adapted for dissipating heat from a heat-generating electronic element, includes a plurality of fins assembled together. Each of the fins has a rectangular body and four arch-shaped flanges extending from edges of the body to form four round corners in four corners of the body. Each main body of the fins defines a plurality of locking members thereon to engage with corresponding locking members of a corresponding front fin. The arch-shaped flanges in four respective corners of the fins cooperate with each other to form four arced faces in four corners of the assembled fins along an entire length of the assembled fins.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
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7851971 | FIELD
This disclosure relates to quartz based MEMS resonators, and in particular to low frequency quartz based MEMS resonators and methods for fabricating them.
BACKGROUND
The resonant frequency for a quartz resonator is determined by the thickness of the quartz between two electrodes of the resonator. U.S. Pat. No. 7,237,315 to Kubena et al. for a Method for Fabricating a Resonator, which is incorporated herein by reference and commonly assigned with the present application, describes a method for fabricating a quartz resonator. In that prior art, plasma dry etching technology is used to form the resonator structure with soft photoresist used for masking. However, there is a substantial difference in the quartz thickness required for quartz resonators with greater than 100 MHz resonant frequencies (several microns) and the quartz thickness required for quartz resonators at lower frequencies at or below the VHF frequency band (several tens or hundreds of microns). Low frequency quartz resonators have much greater quartz thicknesses and so the fabrication methods used for high frequency quartz resonators are not always appropriate for low frequency quartz resonators.
FIGS. 1ato1lshow a prior art method of fabricating quartz resonators. Although the method fabricates many resonators at once,FIG. 1shows only one resonator being fabricated. The starting materials are a single-crystal quartz wafer20, a silicon handle wafer30, and a host substrate40as shown inFIG. 1a. The process begins by defining and etching a cavity32in a silicon handle wafer30, as shown inFIG. 1b. Then, a top-side electrode22and tuning pad metal (Al or Au)25and26are deposited onto the single-crystal quartz wafer20inFIG. 1c. Next, the two wafers are brought together using a direct bonding process using low temperature bonding/annealing inFIG. 1d. A series of processes including wafer grinding/lapping, chemical-mechanical-planarization (CMP), plasma etching and chemical polishing are used to thin the quartz wafer20down to a thickness of typically less than 10 microns, for a desired resonant frequency, inFIG. 1e. The 10 microns or less thickness is appropriate for quartz resonators with resonant frequencies above 100 MHz. Next, photolithography is used to pattern via holes28and29in the quartz wafer20and holes are etched through the quartz wafer to stop on top-side metal25and26of aluminum (Al) or gold (Au) and then metallized to form through-wafer conductive vias28and29inFIG. 1f. A bottom-side electrode24and bottom-side metal34and35are then metallized inFIG. 1g. Then the quartz wafer20is patterned and etched to form a resonator inFIG. 1h. Protrusions41are etched into the host substrate40inFIG. 1i, and metallization patterns, including bonding pads42and44, are defined on the host substrate inFIG. 1j. The quartz/silicon pair produced inFIG. 1his then bonded to the host substrate40using either a gold to gold (Au—Au) or gold to indium (Au—In) compression bonding scheme inFIG. 1k. Then the silicon handle wafer30is removed with a combination of dry and wet etches, resulting in the quartz resonators being attached only to the host wafer40, as shown inFIG. 1l.
This prior art method uses spin coating of a soft mask (photoresist) for patterning metal, quartz and silicon structures. For example, photolithography is used to pattern via holes28and29in the quartz wafer20and holes28and29are etched through the quartz wafer to stop on top-side metal25and26of aluminum (Al) or gold (Au), as shown inFIG. 1f. However, for low frequency resonators that require thick quartz substrates, the aluminum or gold metal layer is no longer an adequate etch stop layer due to the long plasma etching required to form via holes in a thick quartz substrate.
Commercially available low frequency quartz resonators are fabricated as separate discrete components due to the conventional processes employed to make them. Fabrication as separate discrete components increase their cost.
Some commercially available low frequency quartz resonators are fabricated using wet etching. Wet etching of quartz is notoriously slow and only allows circular or rectangular quartz blanks to be fabricated due to the asymmetrical etching profiles that result from preferential crystallographic etching rates. For example, a Z-axis etch rate is at least 500 times faster than those of x- and y-axis etch rates. Also, if the crystals are rotated to form various cuts for temperature compensation, then there are further limits on the shapes that can be formed using wet etching. Dry etching allows arbitrary shaped resonators to be formed and provides 3-4× improvement in etch throughput. However, in either case the methods of the prior art to fabricate low frequency quartz resonators are not amenable to wafer or chip scale integration of quartz resonators with other electronic circuits to form, for example, oscillator circuits. This raises the cost of using prior art low frequency quartz resonators.
What is needed is a method of making low frequency quartz resonators that is amenable to wafer production to thereby lower cost and allow chip scale integration of quartz resonators with other electronic circuits. The embodiments of the present disclosure answer these and other needs.
SUMMARY
In a first embodiment disclosed herein, a method for fabricating a low frequency quartz resonator comprises forming a first cavity in a silicon handle, metalizing a top-side of a quartz wafer with a metal etch stop, depositing a first metal layer over the top-side of the quartz wafer and over the metal etch stop, patterning the first metal layer to form a top electrode for the low frequency quartz resonator, aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle, thinning the quartz wafer to a desired thickness, depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer, etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode, removing the hard etch mask without removing the metal etch stop, depositing a third metal layer on the bottom side of the quartz wafer, applying and patterning photoresist over the third metal layer to form a soft mask, etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator, removing the photoresist to form a quartz resonator on the silicon handle, depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer, aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad, and removing the silicon handle.
In another embodiment disclosed herein, a low frequency quartz resonator comprises a quartz wafer having a thickness of tens of microns or greater, a metal etch stop comprising nickel on a top-side of the quartz wafer, a top electrode on the top-side of the quartz wafer and electrically coupled to the metal etch stop, a bottom metal area on the bottom-side of the quartz wafer, a conductive via through the quartz wafer for electrically connecting to the metal etch stop and the bottom metal area, a bottom electrode for the low frequency quartz resonator on the bottom-side of the quartz wafer opposite the top electrode, a host substrate, and a substrate bond pad on the host substrate wafer bonded to the bottom metal area.
In yet another embodiment disclosed herein, a method for fabricating a plurality of low frequency quartz resonators on a host substrate starting with a silicon handle and a quartz wafer is provided. The method for forming each of the low frequency quartz resonators of the plurality of low frequency quartz resonators on the host substrate comprises forming a first cavity in the silicon handle, metalizing a top-side of a quartz wafer with a metal etch stop, depositing a first metal layer over a top-side of the quartz wafer and over the metal etch stop, patterning the first metal layer to form a top electrode for the low frequency quartz resonator, aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle, thinning the quartz wafer to a desired thickness, depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer, etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode, removing the hard etch mask without removing the metal etch stop, depositing a third metal layer on the bottom side of the quartz wafer, applying and patterning photoresist over the third metal layer to form a soft mask, etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator, removing the photoresist to form a quartz resonator on the silicon handle, depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer, aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad, and removing the silicon handle.
These and other features and advantages will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features, like numerals referring to like features throughout both the drawings and the description.
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SUMMARY: FIELD
This disclosure relates to quartz based MEMS resonators, and in particular to low frequency quartz based MEMS resonators and methods for fabricating them.
BACKGROUND
The resonant frequency for a quartz resonator is determined by the thickness of the quartz between two electrodes of the resonator. U.S. Pat. No. 7,237,315 to Kubena et al. for a Method for Fabricating a Resonator, which is incorporated herein by reference and commonly assigned with the present application, describes a method for fabricating a quartz resonator. In that prior art, plasma dry etching technology is used to form the resonator structure with soft photoresist used for masking. However, there is a substantial difference in the quartz thickness required for quartz resonators with greater than 100 MHz resonant frequencies (several microns) and the quartz thickness required for quartz resonators at lower frequencies at or below the VHF frequency band (several tens or hundreds of microns). Low frequency quartz resonators have much greater quartz thicknesses and so the fabrication methods used for high frequency quartz resonators are not always appropriate for low frequency quartz resonators.
FIGS. 1ato1lshow a prior art method of fabricating quartz resonators. Although the method fabricates many resonators at once,FIG. 1shows only one resonator being fabricated. The starting materials are a single-crystal quartz wafer20, a silicon handle wafer30, and a host substrate40as shown inFIG. 1a. The process begins by defining and etching a cavity32in a silicon handle wafer30, as shown inFIG. 1b. Then, a top-side electrode22and tuning pad metal (Al or Au)25and26are deposited onto the single-crystal quartz wafer20inFIG. 1c. Next, the two wafers are brought together using a direct bonding process using low temperature bonding/annealing inFIG. 1d. A series of processes including wafer grinding/lapping, chemical-mechanical-planarization (CMP), plasma etching and chemical polishing are used to thin the quartz wafer20down to a thickness of typically less than 10 microns, for a desired resonant frequency, inFIG. 1e. The 10 microns or less thickness is appropriate for quartz resonators with resonant frequencies above 100 MHz. Next, photolithography is used to pattern via holes28and29in the quartz wafer20and holes are etched through the quartz wafer to stop on top-side metal25and26of aluminum (Al) or gold (Au) and then metallized to form through-wafer conductive vias28and29inFIG. 1f. A bottom-side electrode24and bottom-side metal34and35are then metallized inFIG. 1g. Then the quartz wafer20is patterned and etched to form a resonator inFIG. 1h. Protrusions41are etched into the host substrate40inFIG. 1i, and metallization patterns, including bonding pads42and44, are defined on the host substrate inFIG. 1j. The quartz/silicon pair produced inFIG. 1his then bonded to the host substrate40using either a gold to gold (Au—Au) or gold to indium (Au—In) compression bonding scheme inFIG. 1k. Then the silicon handle wafer30is removed with a combination of dry and wet etches, resulting in the quartz resonators being attached only to the host wafer40, as shown inFIG. 1l.
This prior art method uses spin coating of a soft mask (photoresist) for patterning metal, quartz and silicon structures. For example, photolithography is used to pattern via holes28and29in the quartz wafer20and holes28and29are etched through the quartz wafer to stop on top-side metal25and26of aluminum (Al) or gold (Au), as shown inFIG. 1f. However, for low frequency resonators that require thick quartz substrates, the aluminum or gold metal layer is no longer an adequate etch stop layer due to the long plasma etching required to form via holes in a thick quartz substrate.
Commercially available low frequency quartz resonators are fabricated as separate discrete components due to the conventional processes employed to make them. Fabrication as separate discrete components increase their cost.
Some commercially available low frequency quartz resonators are fabricated using wet etching. Wet etching of quartz is notoriously slow and only allows circular or rectangular quartz blanks to be fabricated due to the asymmetrical etching profiles that result from preferential crystallographic etching rates. For example, a Z-axis etch rate is at least 500 times faster than those of x- and y-axis etch rates. Also, if the crystals are rotated to form various cuts for temperature compensation, then there are further limits on the shapes that can be formed using wet etching. Dry etching allows arbitrary shaped resonators to be formed and provides 3-4× improvement in etch throughput. However, in either case the methods of the prior art to fabricate low frequency quartz resonators are not amenable to wafer or chip scale integration of quartz resonators with other electronic circuits to form, for example, oscillator circuits. This raises the cost of using prior art low frequency quartz resonators.
What is needed is a method of making low frequency quartz resonators that is amenable to wafer production to thereby lower cost and allow chip scale integration of quartz resonators with other electronic circuits. The embodiments of the present disclosure answer these and other needs.
SUMMARY
In a first embodiment disclosed herein, a method for fabricating a low frequency quartz resonator comprises forming a first cavity in a silicon handle, metalizing a top-side of a quartz wafer with a metal etch stop, depositing a first metal layer over the top-side of the quartz wafer and over the metal etch stop, patterning the first metal layer to form a top electrode for the low frequency quartz resonator, aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle, thinning the quartz wafer to a desired thickness, depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer, etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode, removing the hard etch mask without removing the metal etch stop, depositing a third metal layer on the bottom side of the quartz wafer, applying and patterning photoresist over the third metal layer to form a soft mask, etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator, removing the photoresist to form a quartz resonator on the silicon handle, depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer, aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad, and removing the silicon handle.
In another embodiment disclosed herein, a low frequency quartz resonator comprises a quartz wafer having a thickness of tens of microns or greater, a metal etch stop comprising nickel on a top-side of the quartz wafer, a top electrode on the top-side of the quartz wafer and electrically coupled to the metal etch stop, a bottom metal area on the bottom-side of the quartz wafer, a conductive via through the quartz wafer for electrically connecting to the metal etch stop and the bottom metal area, a bottom electrode for the low frequency quartz resonator on the bottom-side of the quartz wafer opposite the top electrode, a host substrate, and a substrate bond pad on the host substrate wafer bonded to the bottom metal area.
In yet another embodiment disclosed herein, a method for fabricating a plurality of low frequency quartz resonators on a host substrate starting with a silicon handle and a quartz wafer is provided. The method for forming each of the low frequency quartz resonators of the plurality of low frequency quartz resonators on the host substrate comprises forming a first cavity in the silicon handle, metalizing a top-side of a quartz wafer with a metal etch stop, depositing a first metal layer over a top-side of the quartz wafer and over the metal etch stop, patterning the first metal layer to form a top electrode for the low frequency quartz resonator, aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle, thinning the quartz wafer to a desired thickness, depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer, etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode, removing the hard etch mask without removing the metal etch stop, depositing a third metal layer on the bottom side of the quartz wafer, applying and patterning photoresist over the third metal layer to form a soft mask, etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator, removing the photoresist to form a quartz resonator on the silicon handle, depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer, aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad, and removing the silicon handle.
These and other features and advantages will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features, like numerals referring to like features throughout both the drawings and the description.
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7860503 | TECHNICAL FIELD
The present invention relates to a radio network controller, a mobile station, and a mobile communication method.
BACKGROUND ART
Heretofore, a service (Multimedia Broadcast Multicast Service, hereinafter referred to as “MBMS”) has been provided in which multimedia contents are transmitted by broadcast or multicast to a plurality of mobile stations (e.g., 3GPP TSG-RAN, “TS25.346 V6.1.0 Introduction of Multimedia broadcast multicast service (MBMS) in Radio access network (RAN),” June). In MBMS, the frequency at which the MBMS data is transmitted, is notified to mobile stations through a Radio Access Network (RAN). Thus, mobile stations which are not currently receiving the MBMS data can also perform frequency handovers to the notified frequency and receive the MBMS data.
DISCLOSURE OF INVENTION
However, mobile stations, which have started using a specific frequency used to transmit MBMS data, stay at the frequency even after receiving the MBMS data unless the communication quality of the frequency deteriorates. Accordingly, traffic is concentrated at a specific frequency, and traffic is distributed unevenly among frequencies. Such a problem is not limited to MBMS. For example, in the case where mobile stations receive data transmitted using a specific frequency as in High Speed Downlink Packet Access (HSDPA) and the like, similar problems may also occur. Traffic locally concentrated as described above results in ineffective utilization of radio resources.
According to one aspect of the present invention, a radio network controller includes a selection decision unit configured to decide whether or not to perform a selection of cells which are used by mobile stations after data reception, and a mobile station controller configured to instruct the mobile stations to select the cells which are used after the data reception, according to a result of a decision by the selection decision unit.
According to one aspect of the present invention, a radio network controller includes a selection decision unit configured to decide whether or not to perform a selection of cells which are allowed to be used by mobile stations after data reception, a cell selector configured to select the cells which are allowed to be used by mobile stations after the data reception, according to a result of a decision by the selection decision unit, and a mobile station controller configured to control the mobile stations to perform wireless communications using the cells selected by the cell selector, after the data reception.
According to one aspect of the present invention, a mobile station includes a wireless communication unit configured to perform a wireless communication, a selection decision unit configured to decide whether or not to perform a selection of a cell which is used after data reception, and a communication controller configured to control the wireless communication unit to select the cell which is used after the data reception, according to a result of a decision by the selection decision unit, and perform the wireless communication using the cell selected, after the data reception.
According to one aspect of the present invention, a mobile communication method includes deciding whether or not to perform a selection of cells which are used by mobile stations after data reception, selecting the cells which are used by the mobile stations after the data reception, and performing wireless communications using the cells selected, after the data reception by the mobile stations.
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SUMMARY: TECHNICAL FIELD
The present invention relates to a radio network controller, a mobile station, and a mobile communication method.
BACKGROUND ART
Heretofore, a service (Multimedia Broadcast Multicast Service, hereinafter referred to as “MBMS”) has been provided in which multimedia contents are transmitted by broadcast or multicast to a plurality of mobile stations (e.g., 3GPP TSG-RAN, “TS25.346 V6.1.0 Introduction of Multimedia broadcast multicast service (MBMS) in Radio access network (RAN),” June). In MBMS, the frequency at which the MBMS data is transmitted, is notified to mobile stations through a Radio Access Network (RAN). Thus, mobile stations which are not currently receiving the MBMS data can also perform frequency handovers to the notified frequency and receive the MBMS data.
DISCLOSURE OF INVENTION
However, mobile stations, which have started using a specific frequency used to transmit MBMS data, stay at the frequency even after receiving the MBMS data unless the communication quality of the frequency deteriorates. Accordingly, traffic is concentrated at a specific frequency, and traffic is distributed unevenly among frequencies. Such a problem is not limited to MBMS. For example, in the case where mobile stations receive data transmitted using a specific frequency as in High Speed Downlink Packet Access (HSDPA) and the like, similar problems may also occur. Traffic locally concentrated as described above results in ineffective utilization of radio resources.
According to one aspect of the present invention, a radio network controller includes a selection decision unit configured to decide whether or not to perform a selection of cells which are used by mobile stations after data reception, and a mobile station controller configured to instruct the mobile stations to select the cells which are used after the data reception, according to a result of a decision by the selection decision unit.
According to one aspect of the present invention, a radio network controller includes a selection decision unit configured to decide whether or not to perform a selection of cells which are allowed to be used by mobile stations after data reception, a cell selector configured to select the cells which are allowed to be used by mobile stations after the data reception, according to a result of a decision by the selection decision unit, and a mobile station controller configured to control the mobile stations to perform wireless communications using the cells selected by the cell selector, after the data reception.
According to one aspect of the present invention, a mobile station includes a wireless communication unit configured to perform a wireless communication, a selection decision unit configured to decide whether or not to perform a selection of a cell which is used after data reception, and a communication controller configured to control the wireless communication unit to select the cell which is used after the data reception, according to a result of a decision by the selection decision unit, and perform the wireless communication using the cell selected, after the data reception.
According to one aspect of the present invention, a mobile communication method includes deciding whether or not to perform a selection of cells which are used by mobile stations after data reception, selecting the cells which are used by the mobile stations after the data reception, and performing wireless communications using the cells selected, after the data reception by the mobile stations.
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7810217 | FIELD OF THE INVENTION
This invention relates to a novel gin saw stand for ginning seed cotton. In particular, this invention relates to a gin saw stand having a powered roll box door and an adjustable seed roll retaining member that allow for adjustment of the shape of the roll box during operation of the gin saw stand and for automatic extension to retain the seed roll when the breast is opened.
BACKGROUND OF THE INVENTION
The process of picking cotton and removing seeds, trash and other foreign materials from the seed cotton is well known. Freshly picked seed cotton is transported from the field to a cotton gin. The cotton gin has apparatus for receiving the seed cotton, removing the seeds from the long cotton fiber or lint, cleaning the lint, and pressing the lint into bales for sale and further processing.
Central to this process is a saw type gin stand (referred to herein as a gin saw stand or gin). The gin saw stand separates the cotton fiber from the seeds. Before the seed cotton is fed into the gin saw stand, it is processed with other apparatus to remove heavier foreign materials such as rocks and larger sticks, etc., and dried to desired moisture levels. After drying and cleaning, the seed cotton is fed at a controlled rate into a gin saw stand. From the gin saw stand, the cotton fiber is next transported to lint cleaners for further cleaning or processing before bailing.
A commercial gin saw stand which is currently in use is shown in cross section inFIG. 1. Referring to the figure, conventional gin saw stands10typically comprise an inlet cotton chute11wherein the cotton is deposited. A gin saw cylinder12, composed of a large number of spaced apart circular blades13rotating having serrated outer edges15about a common axis14, is combined with operably associated ribs26positioned between the blades13of the saw in order to strip the lint from the seed.
Delivery of the seed cotton into contact with the teeth of the first saw is assisted by a rotating toothed cylinder, referred to as the picker roller21, which throws the cotton from the inlet cotton chute11onto the saw12. This picker roller21is generally positioned with its axis22approximately lateral to the axis14of the saw12, with its outer periphery23spaced apart from the serrated outer periphery15or teeth of the saw12. The locks of cotton are drawn upwardly by the saw12, through a passage called the seed discharge shaft31and into the lower portion of a roll box25positioned above the axis14of the saw12where the seeds with attached cotton accumulate in a large mass. This mass of seeds and/or seed cotton is commonly referred to as the roll or seed roll (not shown inFIG. 1). Most of the interior of the seed roll is made up of lint-free seed, and the exterior primarily comprises partially ginned seed and un-ginned seed.
The roll box25is typically of somewhat distorted cylindrical configuration and its structure is shaped by the exposed, inwardly facing (relative to the roll box) surfaces of a plurality of different members of the gin saw stand10, such as, in the illustrated example, the upper portions26aof the ginning ribs26, the upper rib support34, one or more upper gin-side sheet members38(which may further comprise the inner surface37of door member36), one or more concave partition or sheet members39of the breast18and adjustable sheet member20. Prior art gin saw stands10did employ an adjustable sheet member20though previously such sheet members have had a very limited degree of actuation, limited to the function and path of travel as that obtained with the cam shaft assembly as discussed herein. Prior art sheet members20did not serve the function of retaining the seed roll with in the roll box as is accomplished by the greater range of motion of the seed roll retaining member of the present invention (discussed below).
In some prior art gin saw stands (not shown), the roll box may also comprise an alternate additional set of ginning ribs for one or more additional saw cylinders.
While the roll box door member36of some prior art gin saw stands10do not form part of the roll box25, it is not uncommon for at least a portion of the roll box25to be formed by the concave inner surface37of the roll box door member36as illustrated inFIG. 1. Typically there is a gap or space35in the upper portion of the roll box25to allow the seed roll to be viewed or even touched as the gin is operating. It will be noted that at the gap35, the seed roll will maintain its generally circular shape because the centrifugal force will tend for it to move horizontally at this point, but gravity and the cohesive qualities of the fibers within the exterior regions of the seed roll tends to pull it down.
As gin saw capacities have increased, gin saw stands have become wider. At the same time, the increased capacities and density of the seed rolls within these larger machines have resulted in the need for the reinforcement of the roll box surfaces shaping the seed roll. As a result, the surfaces forming the roll box, including the roll box door member36, have been made sturdier and more rigid, and thus thicker and heavier. This has resulted in roll box doors36that are cumbersome and may require the efforts of two or more individuals to open.
The actual separation of the seed from lint takes place in the roll box25of the gin saw stand10. In the prior art gin saw stand10illustrated inFIG. 1, a set of ribs, referred to as the ginning ribs26, are located in the spaces between the blades13of the saw12at the downstream end of the roll box25, and extend from a position above the periphery15of the saw12downward through the spaces between the blades13to near or below the bottom of the saw12. Cotton fibers in the roll box25are caught by the teeth of the first saw and passed toward the ginning ribs26. As the teeth of the saw12pass between the ginning ribs26, they pull the lint from the seeds, which are too large to pass between adjacent ribs26. The seed-free lint proceeds past the ginning ribs26where it is removed from the teeth of the blades13by the faster moving brushes of the doffing brush27and passed out of the gin stand10through the doffing outlet29for transferral to the lint cotton cleaners and/or the battery condenser and bailing press depending upon the design of the installation.
As the seeds in the seed roll become substantially free of lint or in a substantially completely “ginned” state, they are of appropriate size and character to pass gravitationally downward adjacent the ginning ribs26between the saw blades13through the seed discharge shaft31and into a seed collection area32in the front lower portion of the gin saw stand10, to be picked up by the usual seed discharge screw conveyor33and delivered to the discharge point (not shown). Lint-free seeds are not held firmly within the surface of the seed roll and often escape the seed roll along the relatively sharp curve or bulge in the seed roll that is formed at the bottom of the seed roll over the seed discharge shaft31immediately prior to being pulled upward by the periphery15of the saw12. The seed discharge shaft31is defined by the space between the ginning ribs26and the closest, lower breast-side edge45of the roll box25. Note, however, that when the breast18is in the closed position, the blades13extend through the ginning ribs26and into the seed discharge shaft31.
In contrast to the substantially lint-free seeds, seeds which retain cotton fibers thereon generally remain on the surface of the mass of seeds and seed cotton (the seed roll) in the roll box25, awaiting to be caught by the saw12and repeat the ginning operation.
In some models of gin saw stands, one or more rotating agitators75transversely spanning the gin saw stand10substantially parallel to the axis14of the saw12and having a serrated outer edge or periphery76, have been placed in the roll box25to assist the gin saw12in turning the roll of material within the roll box25. Typically, such agitators75comprise a plurality of discs77about the agitator axis78, said discs77having serrated teeth about the periphery76and being canted at an angle relative to the gin saw blades13to cause some side to side action within the seed roll. The agitator75spins in a direction counter to the direction of the spinning saw12. The agitator75is typically not located in the exact center of the roll box cavity25, but is somewhat offset, and its periphery76is closer to the periphery15of the saw12than to the other surfaces defining the roll box25. In some designs (not shown inFIG. 1), the agitator axis78further comprises or may be replaced by a perforated tube containing an auger which provides an additional path for seed to leave the seed roll.
The gin stand10typically comprises a casing or housing comprising a main gin frame17supporting the gin saw cylinder12and doffing brush27, and a separable front, forwardly movable breast18including inlet cotton chute11and the supports for ginning ribs26, picker roller21, roll box door member36, and (if any) agitator75, permitting the breast structure18to be drawn away from the main gin frame17. The breast18is typically attached to the main gin frame17in such a manner that it may be pulled away from the frame17. In the prior art gin saw stand10shown inFIG. 1, the breast18is moved away from the frame17substantially laterally along the surface of an integrated rail or track49on opposing sides of the frame17by powered gears or a pneumatic cylinder (not shown inFIG. 1) or other common means. Another typical configuration is shown inFIG. 2wherein the breast18is attached to the frame17at a pivot point19located near the front bottom of the main gin frame17so that the breast18may be tilted away from the main gin frame17, thereby creating greater space between the breast18and the main gin frame17at the top of the breast18than at the lower regions. The breast18is typically attached to the main gin frame17at the top by a pneumatic or hydraulic cylinder47to power the movement of the breast between a fully-open, non-ginning position and closed, ginning position.
Moving or tilting the breast18or otherwise withdrawing it from the main gin frame17may be used as a method of interrupting the ginning process instead of stopping the saw12from turning. As the breast18is withdrawn to a fully-open position, the ginning ribs26move even with, or preferably beyond or outside the periphery15of the saw12, thereby preventing the saw cylinder12from removing lint from the seed roll25. This is important because it is much more efficient to simply move the breast18away from the main gin frame17than to stop the relatively massive saw cylinder12from spinning, then having to bring it back up to speed when the ginning process is to be re-started. As a practical matter, it is impossible to restart a motionless saw12with a full seed roll if the breast18is in the ginning position. The saws will encounter so much resistance, that the motor cannot start without over loading the motor starter.
Over the years, the capacities of gin saws12have increased, with the stands becoming wider and wider and with higher density seed rolls. As capacities have increased, the width of the seed discharge shaft31between the ginning ribs26and the lower, breast-side edge45of the roll box25immediately above the picker roller21has also increased to allow more cotton into the roll box and more ginned seed out. A drawback to this approach is that when the breast18is moved away from the main gin frame17, an relatively larger open gap is created between the lower, breast-side edge45of the roll box25and the ginning ribs26as the blades13of the saw12are withdrawn from between the ginning ribs26. When in operation, this gap is occupied by the portion of the saw blades13that extends through the ginning ribs26and the spin of the saw blades13provides an upward current in the mass of seeds and seed cotton in the roll box such that there is little likelihood that seed cotton will fall down the seed discharge shaft31. However, as progressive models of saw stands have moved the lower, breast-side edge45of the roll box25higher and higher above the picker roller21to allow for greater cotton flow, the width of the open gap created when the breast18is opened has also increased because as seen inFIG. 1, the ginning ribs26typically have a curvature that mirrors an arc of the periphery15of the circular saw blades13. Therefore, the higher the bottom edge45of the seed box25is positioned relative to the periphery15of the saw12, the further the ginning ribs26curve away from the bottom edge45at that same relative height.
The larger gaps created when the breast18is opened combined with the bigger and more dense seed rolls in current gin saw stands, has led to an increase in the occurrence of seed roll breakage, with parts of the roll, and sometimes even the entire seed roll, including un-ginned seeds with usable cotton, breaking off and falling into the seed discharge shaft31when the breast18is opened because it is no longer supported by the saw12or the lower edge45of roll box25and/or seed vanes40(if any). Obviously, the loss of un-ginned cotton down the seed discharge shaft31is undesirable in that it is either wasted or reclaiming it requires a separate operation, resulting in lower productivity and higher expense.
Efforts have been made in the past to manipulate the shape of the roll box for the purpose of accelerating the removal of fully ginned seed from the seed roll. An example is shown in U.S. Pat. Reg. No. 4,974,294 issued to Vandergriff entitled Cotton Gin Seed Vanes and Seed Roll Box, wherein a set of spaced-apart vanes are attached to an adjustable finger shaft thereby allowing for the increased width of the seed passage which aids in increasing the rate of discharge of ginned seeds. The vanes extend from the finger shaft mounted across the breast below the bottom edge of a flat or planar surface of the roll box. The vanes extend from the breast into the seed passage when the breast is closed for operation to prevent the seed roll from sagging too deeply into the seed passage and to purposefully slice into the seed roll with the intent of rupturing the lint-covered surface of the seed roll to more easily allow ginned seeds from the interior of the seed roll to escape. The vanes are spaced apart on the finger shaft to allow ginned seed to fall between them down through the seed passage.
A thorough description of a variety of commercially available gin saw stands and their operation is provided by Anthony and Mayfield (ed.), Cotton Ginner's Handbook, Agricultural Handbook No. 503, United States Department of Agriculture, Agricultural Research Service, Washington, D.C., 1994, the contents of which are incorporated in their entirety by reference herein.
SUMMARY OF THE INVENTION
The present invention relates to a novel gin saw stand having a roll box, the shape of which may be adjusted during operation of the gin saw. Adjustment is possible through movement of one or more members making up one or more segments of the roll box surface. Specifically, the present invention provides a power operated roll box door that may be moved and stopped at any point between fully-opened and fully-closed positions. The roll box door may be adjusted manually or may be operatively connected to a powered means for movement. The present invention also proves a seed roll retaining member that many be adjusted during operation of the gin saw to re-shape the roll box. The seed roll retaining member may be adjusted manually or may be operatively connected to a powered means for movement.
The seed roll retaining member is further biased to extend to its fullest extent towards the cylindrical saw when the breast of the gin saw stand is opened to provide support for and substantially retain the seed roll in place above the saw. When closed, the seed roll retaining member is not extendable to the maximum extent, and is only capable of such extension when the breast is opened.
It is therefore an object of the present invention to provide an improved gin saw stand having a roll box with one or more surfaces that are adjustable to reconfigure the size of the roll box during ginning operations.
It is another object of the present invention to provide a gin saw stand having a powered roll box door positionable anywhere between its fully-opened and fully-closed positions.
A further object of the present invention is to provide a gin saw stand having a roll box retainer member which is adjustable during ginning operations to modify the shape of the roll box and which automatically extends even further into the seed discharge shaft to provide support for the seed roll when the breast is opened.
Another object of the present invention is to provide a gin saw stand having a cam shaft assembly allowing for fine adjustment of the seed roll retaining member to enhance the performance of the gin saw by adjusting the width of the seed discharge shaft.
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SUMMARY: FIELD OF THE INVENTION
This invention relates to a novel gin saw stand for ginning seed cotton. In particular, this invention relates to a gin saw stand having a powered roll box door and an adjustable seed roll retaining member that allow for adjustment of the shape of the roll box during operation of the gin saw stand and for automatic extension to retain the seed roll when the breast is opened.
BACKGROUND OF THE INVENTION
The process of picking cotton and removing seeds, trash and other foreign materials from the seed cotton is well known. Freshly picked seed cotton is transported from the field to a cotton gin. The cotton gin has apparatus for receiving the seed cotton, removing the seeds from the long cotton fiber or lint, cleaning the lint, and pressing the lint into bales for sale and further processing.
Central to this process is a saw type gin stand (referred to herein as a gin saw stand or gin). The gin saw stand separates the cotton fiber from the seeds. Before the seed cotton is fed into the gin saw stand, it is processed with other apparatus to remove heavier foreign materials such as rocks and larger sticks, etc., and dried to desired moisture levels. After drying and cleaning, the seed cotton is fed at a controlled rate into a gin saw stand. From the gin saw stand, the cotton fiber is next transported to lint cleaners for further cleaning or processing before bailing.
A commercial gin saw stand which is currently in use is shown in cross section inFIG. 1. Referring to the figure, conventional gin saw stands10typically comprise an inlet cotton chute11wherein the cotton is deposited. A gin saw cylinder12, composed of a large number of spaced apart circular blades13rotating having serrated outer edges15about a common axis14, is combined with operably associated ribs26positioned between the blades13of the saw in order to strip the lint from the seed.
Delivery of the seed cotton into contact with the teeth of the first saw is assisted by a rotating toothed cylinder, referred to as the picker roller21, which throws the cotton from the inlet cotton chute11onto the saw12. This picker roller21is generally positioned with its axis22approximately lateral to the axis14of the saw12, with its outer periphery23spaced apart from the serrated outer periphery15or teeth of the saw12. The locks of cotton are drawn upwardly by the saw12, through a passage called the seed discharge shaft31and into the lower portion of a roll box25positioned above the axis14of the saw12where the seeds with attached cotton accumulate in a large mass. This mass of seeds and/or seed cotton is commonly referred to as the roll or seed roll (not shown inFIG. 1). Most of the interior of the seed roll is made up of lint-free seed, and the exterior primarily comprises partially ginned seed and un-ginned seed.
The roll box25is typically of somewhat distorted cylindrical configuration and its structure is shaped by the exposed, inwardly facing (relative to the roll box) surfaces of a plurality of different members of the gin saw stand10, such as, in the illustrated example, the upper portions26aof the ginning ribs26, the upper rib support34, one or more upper gin-side sheet members38(which may further comprise the inner surface37of door member36), one or more concave partition or sheet members39of the breast18and adjustable sheet member20. Prior art gin saw stands10did employ an adjustable sheet member20though previously such sheet members have had a very limited degree of actuation, limited to the function and path of travel as that obtained with the cam shaft assembly as discussed herein. Prior art sheet members20did not serve the function of retaining the seed roll with in the roll box as is accomplished by the greater range of motion of the seed roll retaining member of the present invention (discussed below).
In some prior art gin saw stands (not shown), the roll box may also comprise an alternate additional set of ginning ribs for one or more additional saw cylinders.
While the roll box door member36of some prior art gin saw stands10do not form part of the roll box25, it is not uncommon for at least a portion of the roll box25to be formed by the concave inner surface37of the roll box door member36as illustrated inFIG. 1. Typically there is a gap or space35in the upper portion of the roll box25to allow the seed roll to be viewed or even touched as the gin is operating. It will be noted that at the gap35, the seed roll will maintain its generally circular shape because the centrifugal force will tend for it to move horizontally at this point, but gravity and the cohesive qualities of the fibers within the exterior regions of the seed roll tends to pull it down.
As gin saw capacities have increased, gin saw stands have become wider. At the same time, the increased capacities and density of the seed rolls within these larger machines have resulted in the need for the reinforcement of the roll box surfaces shaping the seed roll. As a result, the surfaces forming the roll box, including the roll box door member36, have been made sturdier and more rigid, and thus thicker and heavier. This has resulted in roll box doors36that are cumbersome and may require the efforts of two or more individuals to open.
The actual separation of the seed from lint takes place in the roll box25of the gin saw stand10. In the prior art gin saw stand10illustrated inFIG. 1, a set of ribs, referred to as the ginning ribs26, are located in the spaces between the blades13of the saw12at the downstream end of the roll box25, and extend from a position above the periphery15of the saw12downward through the spaces between the blades13to near or below the bottom of the saw12. Cotton fibers in the roll box25are caught by the teeth of the first saw and passed toward the ginning ribs26. As the teeth of the saw12pass between the ginning ribs26, they pull the lint from the seeds, which are too large to pass between adjacent ribs26. The seed-free lint proceeds past the ginning ribs26where it is removed from the teeth of the blades13by the faster moving brushes of the doffing brush27and passed out of the gin stand10through the doffing outlet29for transferral to the lint cotton cleaners and/or the battery condenser and bailing press depending upon the design of the installation.
As the seeds in the seed roll become substantially free of lint or in a substantially completely “ginned” state, they are of appropriate size and character to pass gravitationally downward adjacent the ginning ribs26between the saw blades13through the seed discharge shaft31and into a seed collection area32in the front lower portion of the gin saw stand10, to be picked up by the usual seed discharge screw conveyor33and delivered to the discharge point (not shown). Lint-free seeds are not held firmly within the surface of the seed roll and often escape the seed roll along the relatively sharp curve or bulge in the seed roll that is formed at the bottom of the seed roll over the seed discharge shaft31immediately prior to being pulled upward by the periphery15of the saw12. The seed discharge shaft31is defined by the space between the ginning ribs26and the closest, lower breast-side edge45of the roll box25. Note, however, that when the breast18is in the closed position, the blades13extend through the ginning ribs26and into the seed discharge shaft31.
In contrast to the substantially lint-free seeds, seeds which retain cotton fibers thereon generally remain on the surface of the mass of seeds and seed cotton (the seed roll) in the roll box25, awaiting to be caught by the saw12and repeat the ginning operation.
In some models of gin saw stands, one or more rotating agitators75transversely spanning the gin saw stand10substantially parallel to the axis14of the saw12and having a serrated outer edge or periphery76, have been placed in the roll box25to assist the gin saw12in turning the roll of material within the roll box25. Typically, such agitators75comprise a plurality of discs77about the agitator axis78, said discs77having serrated teeth about the periphery76and being canted at an angle relative to the gin saw blades13to cause some side to side action within the seed roll. The agitator75spins in a direction counter to the direction of the spinning saw12. The agitator75is typically not located in the exact center of the roll box cavity25, but is somewhat offset, and its periphery76is closer to the periphery15of the saw12than to the other surfaces defining the roll box25. In some designs (not shown inFIG. 1), the agitator axis78further comprises or may be replaced by a perforated tube containing an auger which provides an additional path for seed to leave the seed roll.
The gin stand10typically comprises a casing or housing comprising a main gin frame17supporting the gin saw cylinder12and doffing brush27, and a separable front, forwardly movable breast18including inlet cotton chute11and the supports for ginning ribs26, picker roller21, roll box door member36, and (if any) agitator75, permitting the breast structure18to be drawn away from the main gin frame17. The breast18is typically attached to the main gin frame17in such a manner that it may be pulled away from the frame17. In the prior art gin saw stand10shown inFIG. 1, the breast18is moved away from the frame17substantially laterally along the surface of an integrated rail or track49on opposing sides of the frame17by powered gears or a pneumatic cylinder (not shown inFIG. 1) or other common means. Another typical configuration is shown inFIG. 2wherein the breast18is attached to the frame17at a pivot point19located near the front bottom of the main gin frame17so that the breast18may be tilted away from the main gin frame17, thereby creating greater space between the breast18and the main gin frame17at the top of the breast18than at the lower regions. The breast18is typically attached to the main gin frame17at the top by a pneumatic or hydraulic cylinder47to power the movement of the breast between a fully-open, non-ginning position and closed, ginning position.
Moving or tilting the breast18or otherwise withdrawing it from the main gin frame17may be used as a method of interrupting the ginning process instead of stopping the saw12from turning. As the breast18is withdrawn to a fully-open position, the ginning ribs26move even with, or preferably beyond or outside the periphery15of the saw12, thereby preventing the saw cylinder12from removing lint from the seed roll25. This is important because it is much more efficient to simply move the breast18away from the main gin frame17than to stop the relatively massive saw cylinder12from spinning, then having to bring it back up to speed when the ginning process is to be re-started. As a practical matter, it is impossible to restart a motionless saw12with a full seed roll if the breast18is in the ginning position. The saws will encounter so much resistance, that the motor cannot start without over loading the motor starter.
Over the years, the capacities of gin saws12have increased, with the stands becoming wider and wider and with higher density seed rolls. As capacities have increased, the width of the seed discharge shaft31between the ginning ribs26and the lower, breast-side edge45of the roll box25immediately above the picker roller21has also increased to allow more cotton into the roll box and more ginned seed out. A drawback to this approach is that when the breast18is moved away from the main gin frame17, an relatively larger open gap is created between the lower, breast-side edge45of the roll box25and the ginning ribs26as the blades13of the saw12are withdrawn from between the ginning ribs26. When in operation, this gap is occupied by the portion of the saw blades13that extends through the ginning ribs26and the spin of the saw blades13provides an upward current in the mass of seeds and seed cotton in the roll box such that there is little likelihood that seed cotton will fall down the seed discharge shaft31. However, as progressive models of saw stands have moved the lower, breast-side edge45of the roll box25higher and higher above the picker roller21to allow for greater cotton flow, the width of the open gap created when the breast18is opened has also increased because as seen inFIG. 1, the ginning ribs26typically have a curvature that mirrors an arc of the periphery15of the circular saw blades13. Therefore, the higher the bottom edge45of the seed box25is positioned relative to the periphery15of the saw12, the further the ginning ribs26curve away from the bottom edge45at that same relative height.
The larger gaps created when the breast18is opened combined with the bigger and more dense seed rolls in current gin saw stands, has led to an increase in the occurrence of seed roll breakage, with parts of the roll, and sometimes even the entire seed roll, including un-ginned seeds with usable cotton, breaking off and falling into the seed discharge shaft31when the breast18is opened because it is no longer supported by the saw12or the lower edge45of roll box25and/or seed vanes40(if any). Obviously, the loss of un-ginned cotton down the seed discharge shaft31is undesirable in that it is either wasted or reclaiming it requires a separate operation, resulting in lower productivity and higher expense.
Efforts have been made in the past to manipulate the shape of the roll box for the purpose of accelerating the removal of fully ginned seed from the seed roll. An example is shown in U.S. Pat. Reg. No. 4,974,294 issued to Vandergriff entitled Cotton Gin Seed Vanes and Seed Roll Box, wherein a set of spaced-apart vanes are attached to an adjustable finger shaft thereby allowing for the increased width of the seed passage which aids in increasing the rate of discharge of ginned seeds. The vanes extend from the finger shaft mounted across the breast below the bottom edge of a flat or planar surface of the roll box. The vanes extend from the breast into the seed passage when the breast is closed for operation to prevent the seed roll from sagging too deeply into the seed passage and to purposefully slice into the seed roll with the intent of rupturing the lint-covered surface of the seed roll to more easily allow ginned seeds from the interior of the seed roll to escape. The vanes are spaced apart on the finger shaft to allow ginned seed to fall between them down through the seed passage.
A thorough description of a variety of commercially available gin saw stands and their operation is provided by Anthony and Mayfield (ed.), Cotton Ginner's Handbook, Agricultural Handbook No. 503, United States Department of Agriculture, Agricultural Research Service, Washington, D.C., 1994, the contents of which are incorporated in their entirety by reference herein.
SUMMARY OF THE INVENTION
The present invention relates to a novel gin saw stand having a roll box, the shape of which may be adjusted during operation of the gin saw. Adjustment is possible through movement of one or more members making up one or more segments of the roll box surface. Specifically, the present invention provides a power operated roll box door that may be moved and stopped at any point between fully-opened and fully-closed positions. The roll box door may be adjusted manually or may be operatively connected to a powered means for movement. The present invention also proves a seed roll retaining member that many be adjusted during operation of the gin saw to re-shape the roll box. The seed roll retaining member may be adjusted manually or may be operatively connected to a powered means for movement.
The seed roll retaining member is further biased to extend to its fullest extent towards the cylindrical saw when the breast of the gin saw stand is opened to provide support for and substantially retain the seed roll in place above the saw. When closed, the seed roll retaining member is not extendable to the maximum extent, and is only capable of such extension when the breast is opened.
It is therefore an object of the present invention to provide an improved gin saw stand having a roll box with one or more surfaces that are adjustable to reconfigure the size of the roll box during ginning operations.
It is another object of the present invention to provide a gin saw stand having a powered roll box door positionable anywhere between its fully-opened and fully-closed positions.
A further object of the present invention is to provide a gin saw stand having a roll box retainer member which is adjustable during ginning operations to modify the shape of the roll box and which automatically extends even further into the seed discharge shaft to provide support for the seed roll when the breast is opened.
Another object of the present invention is to provide a gin saw stand having a cam shaft assembly allowing for fine adjustment of the seed roll retaining member to enhance the performance of the gin saw by adjusting the width of the seed discharge shaft.
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7674985 | CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2007-140343, filed May 28, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND
1. Field
One embodiment of the present invention relates to a printed wiring board assembly having components, such as ball grid arrays (BGA) and the like, mounted on both surfaces of the board.
2. Description of the Related Art
An electronic apparatus, such as a personal computer, is equipped with a printed wiring board on which various semiconductor circuit components are mounted to configure desired functional circuits. The semiconductor circuit component includes a CPU chip, a CPU family chip, and an IO chip. Since a BGA component is large in size and produces much heat, and since the BGA component is bonded to a printed wiring board by means of solder balls arranged in the form of an array on its package back surface, when the printed wiring board is placed in a casing as a circuit board, the printed wiring board will warp due to the thermal deformation or external stress. In the event of such a warp, the solder-mounting surface of the BGA component will be subjected to excessive stress, resulting in failure of the normal bonded condition of the bonded portions. In order to avoid such a disadvantage, a technique has been proposed by which the BGA component solder-mounting surface is reinforced by means of a back plate provided on the other surface (see JP-A No. 2006-210852: KOKAI).
With such a printed wiring board on which a large sized BGA component producing much heat is mounted, when BGA components are each to be mounted on a respective one of the surfaces of the board so that they overlap each other, the solder-mounting surface of the BGA component cannot be reinforced by a back plate with sufficient strength. This problem will also occur when a BGA component is mounted on one surface of a printed wiring board and another circuit component is mounted on the other surface so that they overlap each other.
As described above, when BGA components are each mounted on respective surfaces of a printed wiring board so that they overlap each other, there arises a problem that a back plate to reinforce the BGA component solder-mounting surface cannot be provided. The same problem also arises in a case where a BGA component is mounted on one surface of a printed wiring board and another circuit component is mounted on the other surface so that they overlap each other.
According to one aspect of the present invention, there is provided a printed wiring board assembly comprising: a printed wiring board; a first component mounting portion provided on a first surface of the printed wiring board; a second component mounting portion provided on a second surface of the printed wiring board so that it overlaps the first component mounting portion; a BGA component mounted on the first component mounting portion; a circuit component mounted on the second component mounting portion; and a supplementary component which is provided on the second surface of the printed wiring board and functions as a heat-sink portion to remove heat produced from the circuit component and as a reinforcement portion to reinforce the first component mounting portion.
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SUMMARY: CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2007-140343, filed May 28, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND
1. Field
One embodiment of the present invention relates to a printed wiring board assembly having components, such as ball grid arrays (BGA) and the like, mounted on both surfaces of the board.
2. Description of the Related Art
An electronic apparatus, such as a personal computer, is equipped with a printed wiring board on which various semiconductor circuit components are mounted to configure desired functional circuits. The semiconductor circuit component includes a CPU chip, a CPU family chip, and an IO chip. Since a BGA component is large in size and produces much heat, and since the BGA component is bonded to a printed wiring board by means of solder balls arranged in the form of an array on its package back surface, when the printed wiring board is placed in a casing as a circuit board, the printed wiring board will warp due to the thermal deformation or external stress. In the event of such a warp, the solder-mounting surface of the BGA component will be subjected to excessive stress, resulting in failure of the normal bonded condition of the bonded portions. In order to avoid such a disadvantage, a technique has been proposed by which the BGA component solder-mounting surface is reinforced by means of a back plate provided on the other surface (see JP-A No. 2006-210852: KOKAI).
With such a printed wiring board on which a large sized BGA component producing much heat is mounted, when BGA components are each to be mounted on a respective one of the surfaces of the board so that they overlap each other, the solder-mounting surface of the BGA component cannot be reinforced by a back plate with sufficient strength. This problem will also occur when a BGA component is mounted on one surface of a printed wiring board and another circuit component is mounted on the other surface so that they overlap each other.
As described above, when BGA components are each mounted on respective surfaces of a printed wiring board so that they overlap each other, there arises a problem that a back plate to reinforce the BGA component solder-mounting surface cannot be provided. The same problem also arises in a case where a BGA component is mounted on one surface of a printed wiring board and another circuit component is mounted on the other surface so that they overlap each other.
According to one aspect of the present invention, there is provided a printed wiring board assembly comprising: a printed wiring board; a first component mounting portion provided on a first surface of the printed wiring board; a second component mounting portion provided on a second surface of the printed wiring board so that it overlaps the first component mounting portion; a BGA component mounted on the first component mounting portion; a circuit component mounted on the second component mounting portion; and a supplementary component which is provided on the second surface of the printed wiring board and functions as a heat-sink portion to remove heat produced from the circuit component and as a reinforcement portion to reinforce the first component mounting portion.
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7769643 | FIELD OF THE INVENTION
The present invention relates to inventory control systems and methods and, more particularly, to lean inventory control systems and methods employing a minimum and a maximum inventory level.
BACKGROUND OF THE INVENTION
Everyday, businesses in product industries deal with inventory, generally consisting all of the goods and materials held by a business for future sale, use or other type of transfer. Typically, these businesses must engage in some type of inventory control to manage and maintain the proper amount of each good in stock or to provide the required service level of a product at a minimum cost. In one type of traditional inventory control system, a push system, an order for goods is issued for fulfillment in specified quantities, by specified due dates, based on estimated lead-times. In another type of traditional inventory control system, a pull (consumption based) system, an order is placed with the supplier when the on-hand inventory balance reaches a specified level.
These traditional methodologies of inventory procurement and management are generally transaction intensive, requiring many manual processes in order to keep customers supplied with the stock they need for future sale, use, or other type of transfer. Changes originating from engineering, define, and manufacturing result in a mismatch between the scheduled date and quantity, and the actual needed date and quantity. Due to changes in scheduling, engineering, and line stoppages, a mismatch often exists between the scheduled due date and/or the quantity, and the actual need date and quantity.
Administrative transactions, such as those entailing Change Orders and/or new Purchase Orders, adjust existing orders to account for these mismatches. New Purchase Orders may also be created to realign the needs of the customer with the inventory received from the supplier. While these administrative transactions seek to help control inventory and satisfy customer demand, the transactions themselves are expensive and wasteful in terms of resources. As an overhead cost, these transactions add no value to the end products of the customer.
In order to keep from running out of stock of a needed good and missing the delivery of a product incorporating the good to the customer as a result, it is common for suppliers to build excess inventory into their inventory control system to serve as a buffer to protect the supplier from being unable to deliver the required products. Additionally, the customer simultaneously orders and stores extra inventory to buffer the suppliers inability to consistently deliver the required products. This excess inventory is an economic liability for a number of reasons. First, excess inventory is costly for both the supplier and customer, as it ties up valuable, limited resources, such as space, materials, money, capacity, etc. Second, excess inventory exposes the manufacturer of the products to scrapage and rework in the event of a change in the configuration of a good. Third, excess inventory can pose a safety risk in terms of blocking aisles in storage areas or warehouses, as well as slowing down work flow, and reducing the efficiency at which the products can be produced and supplied.
Lean inventory systems, developed from lean manufacturing principles, can help address some of the problems associated with excess inventory and the waste created thereby. In lean inventory management systems, the emphasis is on real customer demand, which pulls products through the system, as they are needed. As such, lean inventory systems are a type of pull system. In traditional lean inventory systems, the time required to produce a particular good is matched as closely as possible with the rate of customer demand, thus, reducing excess inventory. Generally, the rate of customer demand is based upon projections, such as usage from a previous measured time period. But because the rate of customer demand can be more dynamic than a given projection, it is difficult, if not impossible, to always match production delivery dates and quantities with actual customer demand.
SUMMARY OF THE INVENTION
In light of the foregoing background, the present invention provides an improved lean inventory control system, method, and computer program product that employ a minimum and a maximum inventory level (min/max inventory) and a customer located warehouse. The system allows the supplier to monitor the customer's inventory levels and deliver needed products based on the customer consumption. By monitoring the inventory of the customer as the inventory changes, the supplier can better eliminate both the supplier and customer's wasteful excess inventory, and better match product supply with customer demand. Also, by providing additional products to the customer, based upon monitored inventory levels instead of schedule or separate Purchase Orders from the customer, expensive and wasteful administrative transactions are reduced. Additionally, the min/max inventory system allows the supplier to provide products to the customer from a warehouse as the customer's inventory level changes. Providing products to the customer from a warehouse near the customer's location reduces wasteful transportation time to better match product delivery with customer demand.
To facilitate communication between the supplier and the customer, the present invention also provides a system, method and computer program product for transferring at least one electronic file from a first location. The system for transferring electronic files improves the transfer of electronic files by providing a displayable reference electronic file including a pointer to the transferred electronic files. The displayable reference electronic file allows users to verify the location of a transferred file and, thereby access the transferred electronic file. Additionally, the reference electronic file can provide users with information relative to the date and/or time the electronic files were transferred. To facilitate the creation of composite electronic files which can further improve communication between the supplier and the customer, the present invention also provides a system, method and computer program product for generating composite electronic files, including pointers to one or more component electronic files. The system for creating composite electronic files allows originators of component electronic files to have their electronic files formatted and compiled into the composite electronic file without special training, and allows the composite electronic file to be updated each time it is accessed.
The min/max inventory system of the present invention typically operates in conjunction with a supplier/customer relationship whereby the supplier provides at least one product to the customer, who is often remote from the supplier. According to one embodiment of the present invention, the supplier and the customer have an open purchase order contract or agreement that includes a quantity of each product the supplier is to provide to the customer. The open purchase order contract or agreement also includes an acceptable inventory range bounded by a minimum and maximum amount for each product that the supplier provides to the customer that in order to defines delivery needs of the products to the customer. The system includes a processing unit disposed near the customer for storing a product inventory count associated with an initial amount of the products as the customer receives the initial amount. The customer's processing unit also maintains the product inventory count for each product representative of the amount of the product that is maintained in inventory. For example, the customer's processing unit can store the product inventory count in an electronic file, such as in a hypertext markup language (HTML) format or an extensible markup language (XML) format. The product inventory count is maintained by the customer's processing unit by decreasing the product inventory count as the customer sells, uses, transfers or otherwise ships out each product, and by increasing the product inventory count as the customer receives additional amounts of each product.
The system also includes a storage unit disposed remote from the supplier and proximate to the customer for storing a supply amount of the products provided to the customer. The products provided to the customer are drawn from the supply amount and, in one embodiment, the supply amount is bounded by the minimum and maximum amounts of the acceptable inventory range. Additionally, the system includes a processing unit disposed near the supplier for monitoring the product inventory count. For example, in embodiments where the customer's processing unit stores the product inventory count in an electronic file, the customer's processing unit may additionally be capable of transferring the electronic file to the supplier's processing unit, such as over the World Wide Web. The supplier's processing unit monitor's the product inventory count so that the supplier and/or the supplier's processing unit can detect product inventory counts that approach the respective lower limit, as evidenced by product inventory counts falling below a notification level between the upper and lower limits. When the supplier and/or supplier's processing unit detects that a product inventory count for a particular product is approaching the lower limit, supplier's processing unit can automatically send a shipment request to the supplier so that the supplier can provide the customer with an additional amount of the respective product. Because of the open purchase order, the supplier can provide the additional amount without a new purchase order associated with the additional amount, as long as the product inventory count is within the acceptable inventory range after the customer receives the additional amount. In one embodiment, the minimum amount is one below the maximum amount so that the supplier can provide the additional amount equal to the decrease in the product inventory count as the product inventory count decreases. Therefore, a constant product inventory count can be maintained by the supplier. Also, in this embodiment, the customer has at least one point-of-use location capable of receiving and shipping out each product. In this manner, the supplier can better match the delivery of the additional products with the customer demand by providing the products to the customer at the respective point-of-use location for the products. This simplifies receipt of the product and reduces the number of steps required for shipment of the required products.
In another embodiment, each product provided to the customer includes an electronic identifier for tracking the product. In this embodiment, the customer's processing unit can read each electronic identifier as the customer ships out the respective product and immediately thereafter decrease the product inventory count by the number of products shipped out as identified by the electronic identifiers. Additionally, the customer's processing unit can read each electronic identifier as the customer receives the respective product and immediately thereafter increase the product inventory count by the number of products received as identified by the electronic identifiers.
To facilitate communication between the supplier and the customer, the present invention also provides a system, method and computer program product for transferring at least one electronic file from a first location. The system includes a first processing unit, typically disposed at the customer location or otherwise under the control of the customer, on which the electronic files are stored. The first processing unit is capable of transferring the electronic files, such as by file transfer protocol (FTP), to a remote location, typically disposed at the supplier location or otherwise under the control of the supplier. After the first processing unit transfers the electronic files, the first processing unit generates at least one pointer, such as a hypertext link, associated with the transferred electronic files and the remote location. The first processing unit then generates a reference electronic file and thereafter includes the pointers in the reference electronic file. Additionally, in one embodiment the reference electronic file includes a date and/or time stamp identifying the date and/or time the electronic files were transferred from the first processing unit. The reference electronic file is capable of being displayed, such as an HTML or XML formatted electronic file. The system also includes a second processing unit disposed remote from the first processing unit, such as at the supplier location. Typically, the remote processing unit and the second processing unit are electrically connected, such as over a local area network (LAN). The second processing unit is capable displaying the reference electronic file, including the pointers, so that a user located proximate the second processing unit is capable of locating the electronic files at the remote location based upon the pointers. For example, by including pointers for the electronic files on a reference electronic file, the supplier can locate the electronic files, previously transferred from the customer, on a supplier accessible computer without additional notification from the customer as to the transfer. In one embodiment, the second processing unit displays the reference electronic file, including the pointers, for a predefined period of time. By displaying the reference electronic file, including the pointers, for a predefined period of time, the reference electronic file can be updated with removed or different pointers to take into account any change in file location, as well as any subsequent electronic file transfers to the second processing unit.
To further facilitate communication between the supplier and the customer, the present invention also provides a system, method and computer program product for generating at least one composite electronic file, such as an HTML or XML formatted electronic file. The system includes a first processing unit having at least one composite location capable of storing at least one component electronic file. The first processing unit may additionally be capable of receiving the component electronic files into the respective composite locations. In one embodiment, the system further includes a remote processing unit, such as a computer connected to the first processing unit over a LAN, having at least one composite location capable of storing, and possibly receiving, the component electronic files. In another embodiment, the first processing unit also includes a master electronic file, such as an HTML or XML formatted electronic file, having a composite pointer, such as a hypertext link, associated with each composite location so that each composite location is accessible via the respective composite pointer.
The first processing unit is capable of generating the composite electronic files when the respective composite locations are accessed from a second processing unit. The composite electronic files include at least one component pointer, such as a hypertext link, associated with the component electronic files in the respective composite locations. The composite electronic files are capable of being displayed through an interface, such as a graphical user interface (GUI), so that the information within component electronic files are accessible via the interface, based upon the component pointers. When a component electronic file is removed from the respective composite location, the first processing unit generates the respective composite electronic file without the component pointer associated with the respective component electronic file. Automatically generating the composite electronic files as the composite locations are accessed allows users at the customer location, for example, who may comprise users from multiple sectors within the customer's business, to create, delete and otherwise modify electronic files pertaining to their particular sector for display by the supplier.
The present invention therefore provides an improved lean inventory control system that employs minimum and maximum inventory levels and a customer located warehouse or point-of-use (POU) inventory. The min/max inventory system allows the supplier to monitor the inventory and to provide additional products to the customer as the customer's inventory changes. Monitoring the inventory of the customer as the inventory changes reduces wasteful excess inventory, and facilitates a better match between the production of products and customer demand for the products. Providing additional products to the customer, based upon monitored inventory levels instead of based upon a schedule or separate purchase orders from the customer, reduces expensive and wasteful administrative transactions. Also, the min/max inventory system of the present invention allows the supplier to provide products to the customer from a warehouse at or near the customer's location as the customer's inventory level changes, which reduces wasteful transportation time to better match product delivery with customer demand.
The present invention also provides a system, method and computer program product for transferring at least one electronic file from a first location. The system provides a displayable reference electronic file including a pointer to the transferred electronic files that allows users to verify the location of a transferred file and, thereby, access the transferred electronic file. The present invention further includes a system for creating composite electronic files that allows originators of component electronic files to have their electronic files formatted and compiled into the composite electronic file without special training.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates to inventory control systems and methods and, more particularly, to lean inventory control systems and methods employing a minimum and a maximum inventory level.
BACKGROUND OF THE INVENTION
Everyday, businesses in product industries deal with inventory, generally consisting all of the goods and materials held by a business for future sale, use or other type of transfer. Typically, these businesses must engage in some type of inventory control to manage and maintain the proper amount of each good in stock or to provide the required service level of a product at a minimum cost. In one type of traditional inventory control system, a push system, an order for goods is issued for fulfillment in specified quantities, by specified due dates, based on estimated lead-times. In another type of traditional inventory control system, a pull (consumption based) system, an order is placed with the supplier when the on-hand inventory balance reaches a specified level.
These traditional methodologies of inventory procurement and management are generally transaction intensive, requiring many manual processes in order to keep customers supplied with the stock they need for future sale, use, or other type of transfer. Changes originating from engineering, define, and manufacturing result in a mismatch between the scheduled date and quantity, and the actual needed date and quantity. Due to changes in scheduling, engineering, and line stoppages, a mismatch often exists between the scheduled due date and/or the quantity, and the actual need date and quantity.
Administrative transactions, such as those entailing Change Orders and/or new Purchase Orders, adjust existing orders to account for these mismatches. New Purchase Orders may also be created to realign the needs of the customer with the inventory received from the supplier. While these administrative transactions seek to help control inventory and satisfy customer demand, the transactions themselves are expensive and wasteful in terms of resources. As an overhead cost, these transactions add no value to the end products of the customer.
In order to keep from running out of stock of a needed good and missing the delivery of a product incorporating the good to the customer as a result, it is common for suppliers to build excess inventory into their inventory control system to serve as a buffer to protect the supplier from being unable to deliver the required products. Additionally, the customer simultaneously orders and stores extra inventory to buffer the suppliers inability to consistently deliver the required products. This excess inventory is an economic liability for a number of reasons. First, excess inventory is costly for both the supplier and customer, as it ties up valuable, limited resources, such as space, materials, money, capacity, etc. Second, excess inventory exposes the manufacturer of the products to scrapage and rework in the event of a change in the configuration of a good. Third, excess inventory can pose a safety risk in terms of blocking aisles in storage areas or warehouses, as well as slowing down work flow, and reducing the efficiency at which the products can be produced and supplied.
Lean inventory systems, developed from lean manufacturing principles, can help address some of the problems associated with excess inventory and the waste created thereby. In lean inventory management systems, the emphasis is on real customer demand, which pulls products through the system, as they are needed. As such, lean inventory systems are a type of pull system. In traditional lean inventory systems, the time required to produce a particular good is matched as closely as possible with the rate of customer demand, thus, reducing excess inventory. Generally, the rate of customer demand is based upon projections, such as usage from a previous measured time period. But because the rate of customer demand can be more dynamic than a given projection, it is difficult, if not impossible, to always match production delivery dates and quantities with actual customer demand.
SUMMARY OF THE INVENTION
In light of the foregoing background, the present invention provides an improved lean inventory control system, method, and computer program product that employ a minimum and a maximum inventory level (min/max inventory) and a customer located warehouse. The system allows the supplier to monitor the customer's inventory levels and deliver needed products based on the customer consumption. By monitoring the inventory of the customer as the inventory changes, the supplier can better eliminate both the supplier and customer's wasteful excess inventory, and better match product supply with customer demand. Also, by providing additional products to the customer, based upon monitored inventory levels instead of schedule or separate Purchase Orders from the customer, expensive and wasteful administrative transactions are reduced. Additionally, the min/max inventory system allows the supplier to provide products to the customer from a warehouse as the customer's inventory level changes. Providing products to the customer from a warehouse near the customer's location reduces wasteful transportation time to better match product delivery with customer demand.
To facilitate communication between the supplier and the customer, the present invention also provides a system, method and computer program product for transferring at least one electronic file from a first location. The system for transferring electronic files improves the transfer of electronic files by providing a displayable reference electronic file including a pointer to the transferred electronic files. The displayable reference electronic file allows users to verify the location of a transferred file and, thereby access the transferred electronic file. Additionally, the reference electronic file can provide users with information relative to the date and/or time the electronic files were transferred. To facilitate the creation of composite electronic files which can further improve communication between the supplier and the customer, the present invention also provides a system, method and computer program product for generating composite electronic files, including pointers to one or more component electronic files. The system for creating composite electronic files allows originators of component electronic files to have their electronic files formatted and compiled into the composite electronic file without special training, and allows the composite electronic file to be updated each time it is accessed.
The min/max inventory system of the present invention typically operates in conjunction with a supplier/customer relationship whereby the supplier provides at least one product to the customer, who is often remote from the supplier. According to one embodiment of the present invention, the supplier and the customer have an open purchase order contract or agreement that includes a quantity of each product the supplier is to provide to the customer. The open purchase order contract or agreement also includes an acceptable inventory range bounded by a minimum and maximum amount for each product that the supplier provides to the customer that in order to defines delivery needs of the products to the customer. The system includes a processing unit disposed near the customer for storing a product inventory count associated with an initial amount of the products as the customer receives the initial amount. The customer's processing unit also maintains the product inventory count for each product representative of the amount of the product that is maintained in inventory. For example, the customer's processing unit can store the product inventory count in an electronic file, such as in a hypertext markup language (HTML) format or an extensible markup language (XML) format. The product inventory count is maintained by the customer's processing unit by decreasing the product inventory count as the customer sells, uses, transfers or otherwise ships out each product, and by increasing the product inventory count as the customer receives additional amounts of each product.
The system also includes a storage unit disposed remote from the supplier and proximate to the customer for storing a supply amount of the products provided to the customer. The products provided to the customer are drawn from the supply amount and, in one embodiment, the supply amount is bounded by the minimum and maximum amounts of the acceptable inventory range. Additionally, the system includes a processing unit disposed near the supplier for monitoring the product inventory count. For example, in embodiments where the customer's processing unit stores the product inventory count in an electronic file, the customer's processing unit may additionally be capable of transferring the electronic file to the supplier's processing unit, such as over the World Wide Web. The supplier's processing unit monitor's the product inventory count so that the supplier and/or the supplier's processing unit can detect product inventory counts that approach the respective lower limit, as evidenced by product inventory counts falling below a notification level between the upper and lower limits. When the supplier and/or supplier's processing unit detects that a product inventory count for a particular product is approaching the lower limit, supplier's processing unit can automatically send a shipment request to the supplier so that the supplier can provide the customer with an additional amount of the respective product. Because of the open purchase order, the supplier can provide the additional amount without a new purchase order associated with the additional amount, as long as the product inventory count is within the acceptable inventory range after the customer receives the additional amount. In one embodiment, the minimum amount is one below the maximum amount so that the supplier can provide the additional amount equal to the decrease in the product inventory count as the product inventory count decreases. Therefore, a constant product inventory count can be maintained by the supplier. Also, in this embodiment, the customer has at least one point-of-use location capable of receiving and shipping out each product. In this manner, the supplier can better match the delivery of the additional products with the customer demand by providing the products to the customer at the respective point-of-use location for the products. This simplifies receipt of the product and reduces the number of steps required for shipment of the required products.
In another embodiment, each product provided to the customer includes an electronic identifier for tracking the product. In this embodiment, the customer's processing unit can read each electronic identifier as the customer ships out the respective product and immediately thereafter decrease the product inventory count by the number of products shipped out as identified by the electronic identifiers. Additionally, the customer's processing unit can read each electronic identifier as the customer receives the respective product and immediately thereafter increase the product inventory count by the number of products received as identified by the electronic identifiers.
To facilitate communication between the supplier and the customer, the present invention also provides a system, method and computer program product for transferring at least one electronic file from a first location. The system includes a first processing unit, typically disposed at the customer location or otherwise under the control of the customer, on which the electronic files are stored. The first processing unit is capable of transferring the electronic files, such as by file transfer protocol (FTP), to a remote location, typically disposed at the supplier location or otherwise under the control of the supplier. After the first processing unit transfers the electronic files, the first processing unit generates at least one pointer, such as a hypertext link, associated with the transferred electronic files and the remote location. The first processing unit then generates a reference electronic file and thereafter includes the pointers in the reference electronic file. Additionally, in one embodiment the reference electronic file includes a date and/or time stamp identifying the date and/or time the electronic files were transferred from the first processing unit. The reference electronic file is capable of being displayed, such as an HTML or XML formatted electronic file. The system also includes a second processing unit disposed remote from the first processing unit, such as at the supplier location. Typically, the remote processing unit and the second processing unit are electrically connected, such as over a local area network (LAN). The second processing unit is capable displaying the reference electronic file, including the pointers, so that a user located proximate the second processing unit is capable of locating the electronic files at the remote location based upon the pointers. For example, by including pointers for the electronic files on a reference electronic file, the supplier can locate the electronic files, previously transferred from the customer, on a supplier accessible computer without additional notification from the customer as to the transfer. In one embodiment, the second processing unit displays the reference electronic file, including the pointers, for a predefined period of time. By displaying the reference electronic file, including the pointers, for a predefined period of time, the reference electronic file can be updated with removed or different pointers to take into account any change in file location, as well as any subsequent electronic file transfers to the second processing unit.
To further facilitate communication between the supplier and the customer, the present invention also provides a system, method and computer program product for generating at least one composite electronic file, such as an HTML or XML formatted electronic file. The system includes a first processing unit having at least one composite location capable of storing at least one component electronic file. The first processing unit may additionally be capable of receiving the component electronic files into the respective composite locations. In one embodiment, the system further includes a remote processing unit, such as a computer connected to the first processing unit over a LAN, having at least one composite location capable of storing, and possibly receiving, the component electronic files. In another embodiment, the first processing unit also includes a master electronic file, such as an HTML or XML formatted electronic file, having a composite pointer, such as a hypertext link, associated with each composite location so that each composite location is accessible via the respective composite pointer.
The first processing unit is capable of generating the composite electronic files when the respective composite locations are accessed from a second processing unit. The composite electronic files include at least one component pointer, such as a hypertext link, associated with the component electronic files in the respective composite locations. The composite electronic files are capable of being displayed through an interface, such as a graphical user interface (GUI), so that the information within component electronic files are accessible via the interface, based upon the component pointers. When a component electronic file is removed from the respective composite location, the first processing unit generates the respective composite electronic file without the component pointer associated with the respective component electronic file. Automatically generating the composite electronic files as the composite locations are accessed allows users at the customer location, for example, who may comprise users from multiple sectors within the customer's business, to create, delete and otherwise modify electronic files pertaining to their particular sector for display by the supplier.
The present invention therefore provides an improved lean inventory control system that employs minimum and maximum inventory levels and a customer located warehouse or point-of-use (POU) inventory. The min/max inventory system allows the supplier to monitor the inventory and to provide additional products to the customer as the customer's inventory changes. Monitoring the inventory of the customer as the inventory changes reduces wasteful excess inventory, and facilitates a better match between the production of products and customer demand for the products. Providing additional products to the customer, based upon monitored inventory levels instead of based upon a schedule or separate purchase orders from the customer, reduces expensive and wasteful administrative transactions. Also, the min/max inventory system of the present invention allows the supplier to provide products to the customer from a warehouse at or near the customer's location as the customer's inventory level changes, which reduces wasteful transportation time to better match product delivery with customer demand.
The present invention also provides a system, method and computer program product for transferring at least one electronic file from a first location. The system provides a displayable reference electronic file including a pointer to the transferred electronic files that allows users to verify the location of a transferred file and, thereby, access the transferred electronic file. The present invention further includes a system for creating composite electronic files that allows originators of component electronic files to have their electronic files formatted and compiled into the composite electronic file without special training.
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7738201 | TECHNICAL FIELD
The invention relates to data storage devices and, more particularly, to read error recovery in data storage devices.
BACKGROUND
Data storage devices, such as disc drives, store information on a storage medium. For example, in the case of disc drives data is stored on a magnetic disc medium. The magnetic disc medium includes a number of concentric circles, i.e., tracks, onto which data is stored. Each of the tracks is divided into a number of sectors, each sector including a predefined portion of the track. The disc drive reads and writes information to the sectors of the disc medium. Disc drives may encounter a read error during an attempt to read data from a sector of the disc medium. Read errors may occur, for example, due to poor magnetic head placement during read operations, adjacent track noise during read operations, poorly written data in the sector of interest, foreign matter on the disc surface or the like. Upon detecting a read error, the disc drive typically implements some sort of read retry scheme to successfully read the data from the disc medium.
SUMMARY
In general, this disclosure describes read error recovery techniques in data storage devices. The read error recovery techniques utilize soft information associated with multiple read operations. For example, a data storage medium, such as a disc drive may attempt to read a sector of a storage medium during a first read operation. In response to detecting an uncorrectable read error, the disc drive implements a read retry scheme (i.e., second read operation) to successfully read the information from the sector of the disc medium. The disc drive computes soft information for each bit detected during the first and second read operations. In one embodiment, the soft information is computed after synchronization and timing recovery have been performed. The disc drive averages the soft information for each bit computed during the first and second read operations to determine the value of each of the bits. In this manner, the disc drive implements a read retry scheme that improves detection performance of the disc drive with little or no impact on the data transfer rate. Moreover, by averaging soft information that is computed after synchronization and timing recovery, the disc drive reduces the SNR loss due to time and frequency offset differences between the two read operations.
In one embodiment, a method comprises averaging soft information associated with a first and second read operation of a data storage medium of a data storage device to determine a value of each bit of data read during the read operations.
In another embodiment, a disc drive comprises a disc medium that stores data and a magnetic head that reads data from the disc medium. The disc drive also includes a read channel that receives the data read by the magnetic head, computes soft information for each bit of the data detected during a first read operation, computes soft information for each bit of the data detected during a second read operation, and averages the soft information corresponding to each bit to determine the value of each of the bits.
In a further embodiment, a data storage device comprises a data storage medium and a read channel that receives data read from the storage medium, computes soft information for each bit of data read during a first and second read operation of a first sector of a data storage medium, and averages, for each bit, the soft information computed during the first and second read operations to determine the value of each of the bits.
In another embodiment, a method comprises performing a first read operation of a data storage medium of a data storage device, performing synchronization and timing recovery on information obtained during the first read operation and computing soft information for each bit detected during the first read operation after the synchronization and timing recovery. The method also comprises performing a second read operation of the data storage medium, performing synchronization and timing recovery on information obtained during the second read operation, and computing soft information for each bit detected during the second read operation after the synchronization and timing recovery. Additionally the method comprises averaging, for each bit, the soft information computed during the first and second read operations to determine the value of each of the bits.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: TECHNICAL FIELD
The invention relates to data storage devices and, more particularly, to read error recovery in data storage devices.
BACKGROUND
Data storage devices, such as disc drives, store information on a storage medium. For example, in the case of disc drives data is stored on a magnetic disc medium. The magnetic disc medium includes a number of concentric circles, i.e., tracks, onto which data is stored. Each of the tracks is divided into a number of sectors, each sector including a predefined portion of the track. The disc drive reads and writes information to the sectors of the disc medium. Disc drives may encounter a read error during an attempt to read data from a sector of the disc medium. Read errors may occur, for example, due to poor magnetic head placement during read operations, adjacent track noise during read operations, poorly written data in the sector of interest, foreign matter on the disc surface or the like. Upon detecting a read error, the disc drive typically implements some sort of read retry scheme to successfully read the data from the disc medium.
SUMMARY
In general, this disclosure describes read error recovery techniques in data storage devices. The read error recovery techniques utilize soft information associated with multiple read operations. For example, a data storage medium, such as a disc drive may attempt to read a sector of a storage medium during a first read operation. In response to detecting an uncorrectable read error, the disc drive implements a read retry scheme (i.e., second read operation) to successfully read the information from the sector of the disc medium. The disc drive computes soft information for each bit detected during the first and second read operations. In one embodiment, the soft information is computed after synchronization and timing recovery have been performed. The disc drive averages the soft information for each bit computed during the first and second read operations to determine the value of each of the bits. In this manner, the disc drive implements a read retry scheme that improves detection performance of the disc drive with little or no impact on the data transfer rate. Moreover, by averaging soft information that is computed after synchronization and timing recovery, the disc drive reduces the SNR loss due to time and frequency offset differences between the two read operations.
In one embodiment, a method comprises averaging soft information associated with a first and second read operation of a data storage medium of a data storage device to determine a value of each bit of data read during the read operations.
In another embodiment, a disc drive comprises a disc medium that stores data and a magnetic head that reads data from the disc medium. The disc drive also includes a read channel that receives the data read by the magnetic head, computes soft information for each bit of the data detected during a first read operation, computes soft information for each bit of the data detected during a second read operation, and averages the soft information corresponding to each bit to determine the value of each of the bits.
In a further embodiment, a data storage device comprises a data storage medium and a read channel that receives data read from the storage medium, computes soft information for each bit of data read during a first and second read operation of a first sector of a data storage medium, and averages, for each bit, the soft information computed during the first and second read operations to determine the value of each of the bits.
In another embodiment, a method comprises performing a first read operation of a data storage medium of a data storage device, performing synchronization and timing recovery on information obtained during the first read operation and computing soft information for each bit detected during the first read operation after the synchronization and timing recovery. The method also comprises performing a second read operation of the data storage medium, performing synchronization and timing recovery on information obtained during the second read operation, and computing soft information for each bit detected during the second read operation after the synchronization and timing recovery. Additionally the method comprises averaging, for each bit, the soft information computed during the first and second read operations to determine the value of each of the bits.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
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7727613 | FIELD OF THE INVENTION
The present invention relates to a ceramic honeycomb structure with a peripheral wall layer, which neither suffers from cracking nor peels off from a honeycomb body, and its production method. It particularly relates to a ceramic honeycomb structure having sufficient mechanical strength to avoid cracking, chipping, etc. by vibration, etc., when used in exhaust gas-cleaning catalytic converters or in particulates-capturing filters, which are likely to be subjected to thermal shock at high temperatures, and a production method thereof.
BACKGROUND OF THE INVENTION
From the aspect of protecting the environment not only in local areas but also in the entire globe, exhaust gas-cleaning catalytic converters and particulates-capturing filters with ceramic honeycombs are used to remove harmful substances such as carbon particulates, etc. from exhaust gases emitted from diesel engines. As shown inFIG. 1, a honeycomb structure1integrally comprises a peripheral wall3and cell walls4defining a large number of cells6. The honeycomb structure1is strongly gripped by a grip member disposed between an inner surface of a metal container (not shown) and the peripheral wall3of the honeycomb structure1.
The honeycomb structure1is conventionally produced according to the following steps. Cordierite-producing ingredient powder, a shaping aid, a pore-forming agent and water are kneaded to produce a soft ceramic material, which is shaped by extrusion to provide a green body having a honeycomb structure, in which the peripheral wall3and the cell walls4are integral with each other. After drying and removing the shaping aid such as a binder, etc. by heating, this green body is fired to provide a honeycomb structure1integrally composed of a finely porous peripheral wall3and finely porous cell walls4, which have the predetermined shape and strength.
However, in the case of producing large ceramic honeycomb structures of 150 mm or more in outer diameter and 150 mm or more in height for diesel engines, and thin honeycomb structures with cell walls4as thin as 0.2 mm or less, for instance, the green bodies are too heavy or insufficient in strength to support themselves, causing the problem that the cell walls4near the peripheral wall3are collapsed or deformed.
As a method for solving this problem, Japanese Patent 2,604,876 discloses a method of kneading cordierite ingredients with a shaping aid and/or a pore-forming agent, shaping the resultant soft ceramic material by extrusion, drying and firing the resultant green body to provide a fired body having a honeycomb structure, removing a peripheral wall3and nearby cell walls from this fired body having a honeycomb structure by grinding, coating the exposed cell walls with a coating material, drying and curing it to form a peripheral wall layer. In this method, because the peripheral wall3and the nearby cell walls4are removed from the fired body having a honeycomb structure by grinding, the peripheral wall3and nearby deformed cells can be removed. When a fired body having a honeycomb structure has low roundness, the peripheral wall layer is formed after increasing the roundness by grinding. Accordingly, it is possible to improve the dimensional accuracy of the honeycomb structure. If coating materials containing ceramic fibers and inorganic binders were used, it would be possible to provide the peripheral wall layer with high strength.
As a ceramic honeycomb structure having a peripheral wall layer with improved peeling resistance, Japanese Patent 2,613,729 discloses a ceramic honeycomb structure having a peripheral wall layer composed of cordierite particles and/or ceramic fibers, and an amorphous oxide matrix comprising colloidal silica or colloidal alumina.
One example of the structure of a ceramic honeycomb1is shown inFIGS. 2 and 3. A ceramic honeycomb body10comprises a large number of cells6partitioned by cell walls4, and axial grooves14formed on the outermost circumference of the ceramic honeycomb body10, the grooves14being coated with a peripheral wall layer12, which does not peel off from the honeycomb body10during use, while suppressing decrease in the thermal shock strength of the honeycomb structure1.
It has been found, however, that when the ceramic honeycomb structures described in Japanese Patents 2,604,876 and 2,613,729 are used for catalytic converters for cleaning an exhaust gas and filters for capturing particulates, there arise the following problems.
When the ceramic honeycomb structure is used as a catalyst carrier and a particulate-capturing filter, the ceramic honeycomb structure is firmly gripped by a grip member in a metal container. Because a high-temperature exhaust gas flows through a larger number of flow paths in the ceramic honeycomb structure, rapid temperature elevation locally occurs particularly at the time of starting operation, causing temperature difference between the center portion and the peripheral wall layer of the ceramic honeycomb body, and thus generating thermal stress in the ceramic honeycomb structure, which sometimes leads to cracking in the peripheral wall layer. Also, when used as a particulate-capturing filter, local temperature elevation occurs particularly near the center portion of the honeycomb structure in which a large amount of particulates are accumulated, by heat generated by a regeneration treatment for burning particulates accumulated in the filter, resulting in cracking in the peripheral wall layer by thermal stress.
If cracking occurs in the peripheral wall layer and propagates to the cell walls, the cell walls are detached, resulting in decrease in the performance of cleaning an exhaust gas, and also decrease in a particulates-capturing rate because of the communication of flow paths between the inlet and outlet.
When a large honeycomb structure having an outer diameter of 150 mm or more and a length of 150 mm or more or a thin honeycomb structure with cell walls having a thickness of 0.15 mm or less is produced, an extrusion-shaped green body is likely to have defects such as breakage or deformation in cells near the peripheral wall. As a result, it has a remaining stress provided by shaping and drying. If firing is carried out with such defects, cracking is likely to propagate to free the remaining stress from defective portions, and spread in the entire fired body. Some cracks are not completely eliminated by removing the peripheral wall and the nearby cell walls from the fired body, resulting in decrease in a production yield.
Because the fired ceramic honeycomb is hard and brittle, as shown inFIG. 4, chipping4aeasily occurs in the outermost cell walls4constituting the grooves14, and part of the cell walls4are easily cracked, resulting in defective grooves14a. Because the grooves14on the circumference have a small contact area with the cell walls4, the honeycomb structure1is likely to suffer from decrease in isostatic strength and the peeling of the peripheral wall layer12. When such a honeycomb structure is used for catalytic converters and particulate-capturing filters, the peripheral wall layer peels off from the honeycomb structure by the vibration of an engine and vibration by contact with the road, so that a proper holding force cannot be maintained in the container, failing to keep the honeycomb structure from moving in the container, and thus resulting in the breakage of the honeycomb structure.
Japanese Patent 2,604,876 uses a grinder rotating at a high peripheral speed of 750 to 2100 m/minute to remove the peripheral wall from the fired ceramic honeycomb, to conduct grinding at a speed of 0.7 to 0.9 mm/minute. However, because the grinding of the cell walls of the honeycomb structure is an intermittent working, in which a tool impinges the cell walls intermittently, the extent of working such as feed and depth of cutting, etc. must be kept small, resulting in the long working time. In addition, because the fired body is hard and brittle, an expensive grinder such as a diamond grinder should be used.
In the above prior art, because a coating material comprising cordierite particles and an inorganic binder is applied to the outer surface of the honeycomb body made of cordierite to form the peripheral wall layer, the peripheral wall layer has a larger thermal expansion coefficient than that of the honeycomb body, resulting in a tensile stress remaining in the peripheral wall layer and a compression stress remaining in the cell walls after drying and firing. The reason why the peripheral wall layer has a larger thermal expansion coefficient than that of the honeycomb body is that because kaolin particles (hexagonal planar crystal) in the material passing through the narrow slits of an extrusion die slit are oriented in plane (in the walls), and because a hexagonal columnar cordierite crystal is orientated perpendicularly to the orientation direction of kaolin by firing, the cell walls have a small thermal expansion coefficient, while the peripheral wall layer is composed of the randomly orientated cordierite particles and the inorganic binder having a large thermal expansion coefficient.
When the honeycomb structure is gripped for the purpose of being introduced into the container, too, tensile stress may occur in the peripheral wall layer. When rapid temperature elevation occurs in the center portion of the honeycomb structure while the tensile stress exerting onto the peripheral wall layer, tensile stress in the peripheral wall layer increases due to the temperature difference between the cell walls and the peripheral wall layer, making it likely that cracking occurs in the peripheral wall layer.
OBJECT OF THE INVENTION
Accordingly, an object of the present invention is to provide a ceramic honeycomb structure having such excellent thermal shock resistance and reliability that cracking is not likely to occur in cell walls by thermal shock.
Another object of the present invention is to provide a ceramic honeycomb structure, in which cracking is not likely to occur by thermal shock when used in a catalytic converter for cleaning an exhaust gas or in a particulate-capturing filter.
A further object of the present invention is to provide a ceramic honeycomb structure with a peripheral wall layer not easily peeling off from a honeycomb body and thus having excellent isostatic strength, which can be produced efficiently.
A still further object of the present invention is to provide a method for producing such a ceramic honeycomb structure.
DISCLOSURE OF THE INVENTION
The first ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, wherein the ceramic honeycomb body comprises stress release portions at least in a portion of the peripheral wall layer and/or in a portion between the peripheral wall layer and the grooves.
The above stress release portions are preferably voids open on the outer surface of the peripheral wall layer, or voids defined between the peripheral wall layer and the grooves. When the voids are formed in the peripheral wall layer, the total length of the voids is preferably one time or more the full length of the ceramic honeycomb structure. The voids are preferably slits, more preferably cracks in the peripheral wall layer. When the voids are present between the peripheral wall layer and the grooves, the number of the grooves having voids is preferably 5% or more of the number of the total grooves.
The second ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, wherein the thermal expansion coefficient of the peripheral wall layer is smaller than those of the cell walls in a radial direction. The second ceramic honeycomb structure may comprise the features of the first ceramic honeycomb structure at the same time.
In the first and second ceramic honeycomb structures, the ceramic honeycomb bodies are preferably formed by the extrusion, drying and firing of a soft ceramic material, and their peripheral walls are preferably removed before or after firing.
The third ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, the ceramic honeycomb body being obtained by removing a peripheral wall before firing.
The fourth ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, wherein the peripheral wall layer is made of a mixture containing amorphous silica particles and an amorphous oxide matrix.
The amorphous oxide matrix is preferably formed from colloidal silica and/or colloidal alumina. The peripheral wall layer is more preferably made of a composition comprising 100 parts by mass of amorphous silica particles and 2 to 35 parts by mass of the amorphous oxide matrix.
The peripheral wall layer is preferably formed before or after firing the ceramic honeycomb body. When the peripheral wall layer is formed before firing, the peripheral wall layer preferably has a composition identical with or extremely close to that of the ceramic honeycomb body.
In the preferred embodiment of the present invention, the ceramic honeycomb structure has an isostatic strength of 1.5 MPa or more. The cell walls of the ceramic honeycomb structure have a porosity of 50 to 80% and an average pore size of 10 to 50 μm.
The method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having grooves axially-extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves according to the present invention comprises the steps of shaping by extrusion and drying a soft ceramic material to form a ceramic honeycomb green body, removing a peripheral wall from the ceramic honeycomb green body to form a ceramic honeycomb body, and forming a peripheral wall layer on the ceramic honeycomb body before or after firing the ceramic honeycomb body.
It is preferable to fire the ceramic honeycomb green body on a table with its one opening end abutting the table, and then cut off a portion of the resultant fired body close to the table. The peripheral wall in a portion of the green body close to the table may be removed depending on the predicted dimensional change by firing.
The coating material of the present invention for forming the peripheral wall layer of the ceramic honeycomb structure comprises 100 parts by mass of amorphous silica particles and 2 to 35 parts by mass of colloidal silica and/or colloidal alumina on a solid basis. The fired ceramic honeycomb is preferably coated with this coating material and fired again to form the peripheral wall layer.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates to a ceramic honeycomb structure with a peripheral wall layer, which neither suffers from cracking nor peels off from a honeycomb body, and its production method. It particularly relates to a ceramic honeycomb structure having sufficient mechanical strength to avoid cracking, chipping, etc. by vibration, etc., when used in exhaust gas-cleaning catalytic converters or in particulates-capturing filters, which are likely to be subjected to thermal shock at high temperatures, and a production method thereof.
BACKGROUND OF THE INVENTION
From the aspect of protecting the environment not only in local areas but also in the entire globe, exhaust gas-cleaning catalytic converters and particulates-capturing filters with ceramic honeycombs are used to remove harmful substances such as carbon particulates, etc. from exhaust gases emitted from diesel engines. As shown inFIG. 1, a honeycomb structure1integrally comprises a peripheral wall3and cell walls4defining a large number of cells6. The honeycomb structure1is strongly gripped by a grip member disposed between an inner surface of a metal container (not shown) and the peripheral wall3of the honeycomb structure1.
The honeycomb structure1is conventionally produced according to the following steps. Cordierite-producing ingredient powder, a shaping aid, a pore-forming agent and water are kneaded to produce a soft ceramic material, which is shaped by extrusion to provide a green body having a honeycomb structure, in which the peripheral wall3and the cell walls4are integral with each other. After drying and removing the shaping aid such as a binder, etc. by heating, this green body is fired to provide a honeycomb structure1integrally composed of a finely porous peripheral wall3and finely porous cell walls4, which have the predetermined shape and strength.
However, in the case of producing large ceramic honeycomb structures of 150 mm or more in outer diameter and 150 mm or more in height for diesel engines, and thin honeycomb structures with cell walls4as thin as 0.2 mm or less, for instance, the green bodies are too heavy or insufficient in strength to support themselves, causing the problem that the cell walls4near the peripheral wall3are collapsed or deformed.
As a method for solving this problem, Japanese Patent 2,604,876 discloses a method of kneading cordierite ingredients with a shaping aid and/or a pore-forming agent, shaping the resultant soft ceramic material by extrusion, drying and firing the resultant green body to provide a fired body having a honeycomb structure, removing a peripheral wall3and nearby cell walls from this fired body having a honeycomb structure by grinding, coating the exposed cell walls with a coating material, drying and curing it to form a peripheral wall layer. In this method, because the peripheral wall3and the nearby cell walls4are removed from the fired body having a honeycomb structure by grinding, the peripheral wall3and nearby deformed cells can be removed. When a fired body having a honeycomb structure has low roundness, the peripheral wall layer is formed after increasing the roundness by grinding. Accordingly, it is possible to improve the dimensional accuracy of the honeycomb structure. If coating materials containing ceramic fibers and inorganic binders were used, it would be possible to provide the peripheral wall layer with high strength.
As a ceramic honeycomb structure having a peripheral wall layer with improved peeling resistance, Japanese Patent 2,613,729 discloses a ceramic honeycomb structure having a peripheral wall layer composed of cordierite particles and/or ceramic fibers, and an amorphous oxide matrix comprising colloidal silica or colloidal alumina.
One example of the structure of a ceramic honeycomb1is shown inFIGS. 2 and 3. A ceramic honeycomb body10comprises a large number of cells6partitioned by cell walls4, and axial grooves14formed on the outermost circumference of the ceramic honeycomb body10, the grooves14being coated with a peripheral wall layer12, which does not peel off from the honeycomb body10during use, while suppressing decrease in the thermal shock strength of the honeycomb structure1.
It has been found, however, that when the ceramic honeycomb structures described in Japanese Patents 2,604,876 and 2,613,729 are used for catalytic converters for cleaning an exhaust gas and filters for capturing particulates, there arise the following problems.
When the ceramic honeycomb structure is used as a catalyst carrier and a particulate-capturing filter, the ceramic honeycomb structure is firmly gripped by a grip member in a metal container. Because a high-temperature exhaust gas flows through a larger number of flow paths in the ceramic honeycomb structure, rapid temperature elevation locally occurs particularly at the time of starting operation, causing temperature difference between the center portion and the peripheral wall layer of the ceramic honeycomb body, and thus generating thermal stress in the ceramic honeycomb structure, which sometimes leads to cracking in the peripheral wall layer. Also, when used as a particulate-capturing filter, local temperature elevation occurs particularly near the center portion of the honeycomb structure in which a large amount of particulates are accumulated, by heat generated by a regeneration treatment for burning particulates accumulated in the filter, resulting in cracking in the peripheral wall layer by thermal stress.
If cracking occurs in the peripheral wall layer and propagates to the cell walls, the cell walls are detached, resulting in decrease in the performance of cleaning an exhaust gas, and also decrease in a particulates-capturing rate because of the communication of flow paths between the inlet and outlet.
When a large honeycomb structure having an outer diameter of 150 mm or more and a length of 150 mm or more or a thin honeycomb structure with cell walls having a thickness of 0.15 mm or less is produced, an extrusion-shaped green body is likely to have defects such as breakage or deformation in cells near the peripheral wall. As a result, it has a remaining stress provided by shaping and drying. If firing is carried out with such defects, cracking is likely to propagate to free the remaining stress from defective portions, and spread in the entire fired body. Some cracks are not completely eliminated by removing the peripheral wall and the nearby cell walls from the fired body, resulting in decrease in a production yield.
Because the fired ceramic honeycomb is hard and brittle, as shown inFIG. 4, chipping4aeasily occurs in the outermost cell walls4constituting the grooves14, and part of the cell walls4are easily cracked, resulting in defective grooves14a. Because the grooves14on the circumference have a small contact area with the cell walls4, the honeycomb structure1is likely to suffer from decrease in isostatic strength and the peeling of the peripheral wall layer12. When such a honeycomb structure is used for catalytic converters and particulate-capturing filters, the peripheral wall layer peels off from the honeycomb structure by the vibration of an engine and vibration by contact with the road, so that a proper holding force cannot be maintained in the container, failing to keep the honeycomb structure from moving in the container, and thus resulting in the breakage of the honeycomb structure.
Japanese Patent 2,604,876 uses a grinder rotating at a high peripheral speed of 750 to 2100 m/minute to remove the peripheral wall from the fired ceramic honeycomb, to conduct grinding at a speed of 0.7 to 0.9 mm/minute. However, because the grinding of the cell walls of the honeycomb structure is an intermittent working, in which a tool impinges the cell walls intermittently, the extent of working such as feed and depth of cutting, etc. must be kept small, resulting in the long working time. In addition, because the fired body is hard and brittle, an expensive grinder such as a diamond grinder should be used.
In the above prior art, because a coating material comprising cordierite particles and an inorganic binder is applied to the outer surface of the honeycomb body made of cordierite to form the peripheral wall layer, the peripheral wall layer has a larger thermal expansion coefficient than that of the honeycomb body, resulting in a tensile stress remaining in the peripheral wall layer and a compression stress remaining in the cell walls after drying and firing. The reason why the peripheral wall layer has a larger thermal expansion coefficient than that of the honeycomb body is that because kaolin particles (hexagonal planar crystal) in the material passing through the narrow slits of an extrusion die slit are oriented in plane (in the walls), and because a hexagonal columnar cordierite crystal is orientated perpendicularly to the orientation direction of kaolin by firing, the cell walls have a small thermal expansion coefficient, while the peripheral wall layer is composed of the randomly orientated cordierite particles and the inorganic binder having a large thermal expansion coefficient.
When the honeycomb structure is gripped for the purpose of being introduced into the container, too, tensile stress may occur in the peripheral wall layer. When rapid temperature elevation occurs in the center portion of the honeycomb structure while the tensile stress exerting onto the peripheral wall layer, tensile stress in the peripheral wall layer increases due to the temperature difference between the cell walls and the peripheral wall layer, making it likely that cracking occurs in the peripheral wall layer.
OBJECT OF THE INVENTION
Accordingly, an object of the present invention is to provide a ceramic honeycomb structure having such excellent thermal shock resistance and reliability that cracking is not likely to occur in cell walls by thermal shock.
Another object of the present invention is to provide a ceramic honeycomb structure, in which cracking is not likely to occur by thermal shock when used in a catalytic converter for cleaning an exhaust gas or in a particulate-capturing filter.
A further object of the present invention is to provide a ceramic honeycomb structure with a peripheral wall layer not easily peeling off from a honeycomb body and thus having excellent isostatic strength, which can be produced efficiently.
A still further object of the present invention is to provide a method for producing such a ceramic honeycomb structure.
DISCLOSURE OF THE INVENTION
The first ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, wherein the ceramic honeycomb body comprises stress release portions at least in a portion of the peripheral wall layer and/or in a portion between the peripheral wall layer and the grooves.
The above stress release portions are preferably voids open on the outer surface of the peripheral wall layer, or voids defined between the peripheral wall layer and the grooves. When the voids are formed in the peripheral wall layer, the total length of the voids is preferably one time or more the full length of the ceramic honeycomb structure. The voids are preferably slits, more preferably cracks in the peripheral wall layer. When the voids are present between the peripheral wall layer and the grooves, the number of the grooves having voids is preferably 5% or more of the number of the total grooves.
The second ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, wherein the thermal expansion coefficient of the peripheral wall layer is smaller than those of the cell walls in a radial direction. The second ceramic honeycomb structure may comprise the features of the first ceramic honeycomb structure at the same time.
In the first and second ceramic honeycomb structures, the ceramic honeycomb bodies are preferably formed by the extrusion, drying and firing of a soft ceramic material, and their peripheral walls are preferably removed before or after firing.
The third ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, the ceramic honeycomb body being obtained by removing a peripheral wall before firing.
The fourth ceramic honeycomb structure of the present invention comprises a ceramic honeycomb body having grooves axially extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves, wherein the peripheral wall layer is made of a mixture containing amorphous silica particles and an amorphous oxide matrix.
The amorphous oxide matrix is preferably formed from colloidal silica and/or colloidal alumina. The peripheral wall layer is more preferably made of a composition comprising 100 parts by mass of amorphous silica particles and 2 to 35 parts by mass of the amorphous oxide matrix.
The peripheral wall layer is preferably formed before or after firing the ceramic honeycomb body. When the peripheral wall layer is formed before firing, the peripheral wall layer preferably has a composition identical with or extremely close to that of the ceramic honeycomb body.
In the preferred embodiment of the present invention, the ceramic honeycomb structure has an isostatic strength of 1.5 MPa or more. The cell walls of the ceramic honeycomb structure have a porosity of 50 to 80% and an average pore size of 10 to 50 μm.
The method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having grooves axially-extending on its outer surface and cell walls constituting a large number of flow paths inside the grooves, and a peripheral wall layer covering the grooves according to the present invention comprises the steps of shaping by extrusion and drying a soft ceramic material to form a ceramic honeycomb green body, removing a peripheral wall from the ceramic honeycomb green body to form a ceramic honeycomb body, and forming a peripheral wall layer on the ceramic honeycomb body before or after firing the ceramic honeycomb body.
It is preferable to fire the ceramic honeycomb green body on a table with its one opening end abutting the table, and then cut off a portion of the resultant fired body close to the table. The peripheral wall in a portion of the green body close to the table may be removed depending on the predicted dimensional change by firing.
The coating material of the present invention for forming the peripheral wall layer of the ceramic honeycomb structure comprises 100 parts by mass of amorphous silica particles and 2 to 35 parts by mass of colloidal silica and/or colloidal alumina on a solid basis. The fired ceramic honeycomb is preferably coated with this coating material and fired again to form the peripheral wall layer.
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7851506 | BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates generally to the fields of pharmaceutical compositions to be used in treatments, such as, sleeping disorders, such as, e.g., narcolepsy (particularly cataplexy), drug abuse, alcohol and opiate withdrawal, a reduced level of growth hormone, anxiety, analgesia, effects in certain neurological disorders such as Parkinson's Disease, depression, certain endocrine disturbances and tissue protection following hypoxia/anoxia such as in stroke or myocardial infarction, or for an increased level of intracranial pressure or the like. The present invention particularly relates to the field of pharmaceutical production of microbiologically resistant and chemically stable preparations or solutions of gamma-hydroxybutyrate (GHB), also known as 4-hydroxybutyrate, and the sodium salt of GHB (sodium oxybate) and other salts such as magnesium, ammonium and calcium, e.g.
II. Description of Related Art
GHB is an endogenous compound with hypnotic properties that is found in many human body tissues. GHB is present, for example, in the mammalian brain and other tissues. In brain the highest GHB concentration is found in the hypothalamus and basal ganglia and GHB is postulated to function as a neurotransmitter (Snead and Moriey, 1981). The neuropharmacologic effects of GHB include increases in brain acetylcholine, increases in brain dopamine, inhibition of GABA-ketoglutarate transaminase and depression of glucose utilization but not oxygen consumption in the brain. GHB is converted to succinate and then metabolized via the Krebs cycle. Clinical trials have shown that GHB increases delta sleep and improves the continuity of sleep (Ladinsky et al., 1983; Anden and Stock, 1973; Stock et al., 1973; Laborit, 1973; Lapierre et al., 1988; Lapierre et al., 1990; Yamda et al., 1967; Grove-White and Kelman, 1971; Scharf, 1985).
GHB has typically been administered in clinical trials as an oral solution (Lee, 1977; Mamelak, 1977; Hoes, 1980; Scharf, 1985; Scrima, 1990; Gallimberti, 1992; Series, 1992; Lammers, 1993). GHB treatment substantially reduces the signs and symptoms of narcolepsy, i.e. daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. In addition, GHB increases total sleep time and REM sleep, and it decreases REM latency (Mamelak et al, 1973; Yamada et al., 1967; Bedard et al., 1989), reduces sleep apnea (Series et al, 1992; Scrima et al., 1987), and improves general anesthesia (Hasenbos and Gielen, 1985).
GHB has several clinical applications other than narcolepsy and sleep disorders. GHB has been reported to reduce alcohol craving, the number of daily drinks consumed, and the symptoms of alcohol withdrawal in patients (Gallimberti et al., 1989; Gallimberti et al., 1992; Gessa et al., 1992). GHB has been used to decrease the symptoms of opiate withdrawal, including both heroin and methadone withdrawal (Gallimberti et al, 1994; Gallimberti et al., 1993). It has analgesic effects that make it suitable as a pain reliever (U.S. Pat. No. 4,393,236). Intravenous administration of GHB has been reported to reduce intracranial pressure in patients (Strong, A. 1984). Also, administration of GHB was reported to increase growth hormone levels in patients (Gerra et al, 1994; Oyama et al., 1970).
A good safety profile for GHB consumption, when used long term for treatment of narcolepsy, has been reported. Patients have been safely treated for many years with GHB without development of tolerance (Scharf, 1985). Clinical laboratory tests carried out periodically on many patients have not indicated organ or other toxicities (Lammers, 1993; Scrima, 1990; Scharf, 1985; Mamelack, 1977; Mamelak, 1979; Gallimberti, 1989; Gallimberti, 1992; Gessa, 1992). The side effects of GHB treatment have been minimal in incidence and degree of severity, though they include sleepwalking, enuresis, headache, nausea and dizziness (Broughton and Mamelak, 1979; Mamelak et al., 1981; Mamelak et al., 1977; Scrima et al., 1989; Scrima et al., 1990; Scharf et al., 1985).
The pharmacokinetics of GHB have been investigated in alcohol dependent patients (Ferrara et al., 1992) and in normal healthy males (Palatini et al., 1993) after oral administration. GHB possesses a rapid onset and short pharmacological effect (Ferrara et al., 1992; Palatine et al., 1993; Lee, C., 1977; van der Bogert; Gallimberti, 1989; Gallimberti, 1992; Lettieri and Fung, 1978; Arena and Fung, 1980; Roth and Giarman, 1966; Vickers, 1969; Lee, 1977). In alcohol dependent patients, GHB absorption into and elimination from the systemic circulation were fast processes. Virtually no unchanged drug could be recovered in the urine. There were preliminary indications that the pharmacokinetics of GHB might be non-linear or dose-dependent (Ferrara et al., 1992). In the healthy volunteers study, the pharmacokinetics of three rising GHB doses (12.5, 25, and 50 mg/kg) were investigated. These findings indicate that both the oral absorption and elimination processes of GHB were capacity-limited though the degree of dose dependency was moderate (Palatini et al., 1993).
Organic salts and amides of GHB have been produced to reduce the physiological side effects of GHB (U.S. Pat. No. 5,380,937). Magnesium and calcium salt have been produced to reduce the hygroscopic nature of GHB or powdered forms (U.S. Pat. No. 4,393,236; British Patent No. 922,029). However, problems with the storage of GHB solutions still exist. GHB degrades into gamma-butyrolactone (GBL) and possibly other degradants in solution depending upon the pH and other factors. Also, the contamination by microorganisms in GHB solutions rapidly surpass acceptable limits, and preservatives can adversely affect the pH and thus, GHB's stability. As a chronically used product which requires high levels of drug, the volume of a non-concentrated product creates cost and handling issues. Thus, there is an immediate need for effective solutions of GHB that are stable to biological or chemical degradation.
SUMMARY OF THE INVENTION
The present invention overcomes deficiencies in the prior art by providing compositions of GHB in an aqueous medium that are resistant to microbial growth. These compositions are also resistant to the uncontrolled degradation of GHB into GBL or other substances. The compositions of the present invention are stable compositions of GHB that improve shelf-life, and provide a titratable formulation of GHB for easy dose measurement. In addition, the concentrated solutions embodied in this invention reduce shipping and storage requirements and allow patients to carry more drugs for their convenience. The present invention provides methods to treat a number of conditions treatable by GHB, referred to herein as “therapeutic categories.” Therapeutic categories for the present invention include, but are not limited to, sleeping disorders, drug abuse, alcohol and opiate withdrawal, a reduced level of growth hormone, anxiety, analgesia, effects in certain neurological disorders, such as Parkinson's Disease, depression, certain endocrine disturbances and tissue protection following hypoxia/anoxia such as in stroke or myocardial infarction, or an increased level of intracranial pressure or other conditions treatable with GHB.
The invention first provides a pharmaceutical composition of GHB rendered chemically stable and/or resistant to microbial growth in an aqueous medium. Preferred GHB salts of the present invention include sodium, ammonium and calcium. As used herein in certain embodiments, “stable” may mean resistant to degradation of GHB into its known or unknown decomposition elements. The level of GBL that is acceptable can be up to 0.1% of the formulation as per the ICH guidelines for shelf-life determination. As used herein in certain embodiments, “resistant to microbial growth” or “resistant to microbial challenge” means that the formulations meet the criteria set by the Food and Drug Administration and the U.S. Pharmacopoeia for products made with aqueous bases or vehicles, which for bacteria means not less than a 1.0 log reduction from the initial count at 14 days, and no increase from the 14 days count at 28 days, and for yeast and molds, no increase from the initial calculated count at 14 and 28 days. As used herein in certain embodiments, an “aqueous medium” may mean a liquid comprising more than about 50% water. In certain preferred embodiments, an “aqueous medium” may be a solution, suspension, gel or emulsion of GHB, with a solution of GHB being most preferred. Preferred gels are thixotropic gels. Compositions that are resistant to microbial growth are created by dissolving or mixing GHB in an aqueous medium to a concentration or content of greater than of about 150 mg/ml GHB to the maximal solubility of GHB. The solubility of GHB is up to about 750 mg/ml at room temperature (20° C. to about 25° C.), however, heating the aqueous medium during preparation up to 100° C. will increase GHB solubility to at least about 1000 mg/ml. A preferred concentration or content of GHB is about 500 mg/ml.
The amount of GHB that may be mixed or dissolved into an aqueous medium and still be resistant to microbial growth depends upon the pH of the aqueous medium. In certain embodiments the presence of a preservative may allow the amount of GHB contained in the compositions of the present invention to be increased and still maintain resistance to chemical degradation and/or microbial growth. In one embodiment of the present invention, the pH of the aqueous medium of the pharmaceutical composition is about 3 to about 10.
In a preferred embodiment, the pH of said aqueous medium is about 6 to about 7.5. The pH may be from about 3.0 to about 10.3, namely of about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6; about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, about 10.0, about 10.1, about 10.2, or about 10.3, and all pH values between each of the listed pH values, of the aqueous media. This will produce a GHB composition that is resistant to microbial growth as defined by the test described herein. As used herein, the term “about” generally means within about 10-20%.
These pH values will produce compositions resistant to microbial growth in an aqueous medium if the amount of GHB added, admixed, or dissolved is from above about 150 mg/ml to about 450 mg/ml, namely, above about 150 mg/ml, about 160 mg/ml, about 170 mg/ml, about 180 mg/ml, about 190 mg/ml, about 200 mg/ml, about 210 mg/ml, about 220 mg/ml, about 230 mg/ml, about 240 mg/ml, about 250 mg/ml, about 260 mg/ml, about 270 mg/ml, about 280 mg/ml, about 290 mg/ml, about 300 mg/ml, about 310 mg/ml, about 320 mg/ml, about 330 mg/ml, about 340 mg/ml, about 350 mg/ml, about 360 mg/ml, about 370 mg/ml, about 380 mg/ml, about 390 mg/ml, about 400 mg/ml, about 410 mg/ml, about 420 mg/ml, about 430 mg/ml, about 440 mg/ml, to about 450 mg/ml, and all amounts of GHB between the values listed.
At the medium to high end of the concentration or content of GHB that may be dissolved or mixed in the aqueous medium, the maximal pH that may be used is reduced at room temperature. This is shown inFIG. 1, a graphical presentation of acceptable formulation ranges. At a concentration or content of about 450 mg/ml GHB, the pH may be of about 3.9 to about 10.3. At a concentration or content of about 500 mg/ml GHB, the pH may be of about 4.75 to about 10.3. At a concentration or content of about 600 mg/ml GHB, the pH may be of about 6.1 to about 10.3. At a concentration or content of about 750 mg/ml GHB, the pH may be of about 7.0 to about 10.3. Of course, all pH and concentration or content values in between each of the listed pH and concentration or content values are encompassed by the invention.
Certain embodiments may be selected as sub-ranges from these values of GHB content and aqueous medium pH. For example, a specific embodiment may be selected as a content of about 170 mg/ml to about 440 mg/ml GHB in an aqueous medium, at a pH range of about pH 5.5 to about pH 8.7. Another example of how a range may be selected in an embodiment would be the selection of a content of about 155 mg/ml of GHB, which is a value between the above listed values, to a content of about 350 mg/ml of GHB, and the selection of a pH range of the aqueous medium, such as a pH range of about 8.87, which is a value between the listed pH values, to a pH of about 8.93, which is another value between the listed values of pH. A third example of ranges that may be selected for a specific embodiment would be selection of a single content or concentration of GHB, such as about 200 mg/ml of GHB, and the selection of a pH range, such as a pH of about 3.5 to about 8.2. A fourth example of ranges that may be selected for a specific embodiment would be selection of a content or concentration of GHB over a range, such as about 300 mg/ml to about 400 mg/ml, and the selection of a single pH value for the aqueous medium, such as a pH of about 3. Another example of a range selected for an embodiment may be the selection of a single content or concentration of GHB, such as 400 mg/ml GHB, and a single pH value of the aqueous medium, such as pH 7.7.
Other examples of how a range of an embodiment of GHB content or concentration may be selected include a range of GHB content or concentration from about 200 mg/ml to about 460 mg/ml GHB, encompassing the ranges for GHB described herein, and a range of pH for the aqueous medium may be from about pH 4.3 to about pH 7, encompassing ranges for GHB in an aqueous medium at room temperature described herein. Another example would be the selection of a range of GHB content or concentration from about 153 mg/ml to about 750 mg/ml, and a pH range of about 7 to about 9, encompassing ranges between the listed values of GHB content and pH described herein. An example may be the selection as a GHB concentration or content of about 170 mg/ml to about 640 mg/ml in an aqueous medium, at a pH range of about pH 6.5 to about pH 7.7. Another example of how a range may be selected in an embodiment would be a content or concentration of about 185 mg/ml of GHB, which is a value between the listed values, to a content or concentration of about 750 mg/ml of GHB, at a pH range of about 7.87, which is a value between the listed pH values, to a pH of about 8.91, which is another value between the listed values of pH. An additional example of ranges that may be selected for a specific embodiment would be a content or concentration of about 200 mg/ml of GHB at a pH of about 7 to about 8.2. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 750 mg/ml to about 400 mg/ml at a pH of about 7. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 300 mg/ml to about 750 mg/ml at a pH of about 8.5 to about 7. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 400 mg/ml to about 600 mg/ml at a pH of about 9 to about 5.8. And so forth. Thus, all ranges of pH and GHB concentration or content that can be selected from the values herein and as would be understood by those of ordinary skill in the art, are encompassed by the present invention.
The chemical stability of GHB is affected by pH, with compositions of GHB in an aqueous medium with a pH below about 6 being less effective in maintaining the chemical stability of GHB. Compositions with a pH of greater than about 6.0 are preferred to produce chemically stable formulations of GHB. Thus, a preferred range to produce chemically stable GHB would be from about pH 6 to about pH 9. However, all concentrations or content of GHB in an aqueous medium, as described herein, and as would be understood by those of ordinary skill in the art, may be selected to produce compositions of the present invention.
Additionally, the ranges described above are for a composition at room temperature, which is defined herein as from about 20° C. to about 25° C., namely, about 20° C. about 21° C., about 22° C., about 23° C., about 24° C., to about 25° C. Within the values and ranges of pH described above, the ranges of concentration or content of GHB may increase at temperatures greater than room temperature. Thus, the maximal content or concentration of GHB in an aqueous medium at a temperature of from about 26° C. to about 100° C., namely about 26° C., about 27° C., about 28° C., about 29° C., about 30° C., about 31° C., about 32° C., about 33° C., about 34° C., about 35° C., about 36° C., about 37° C., about 38° C., about 39° C., about 40° C., about 41° C., about 42° C., about 43° C., about 44° C., about 45° C., about 46° C., about 47° C., about 48° C., about 49° C., about 50° C., about 51° C., about 52° C., about 53° C., about 54° C., about 55° C., about 56° C., about 57° C., about 58° C., about 59° C., about 60° C., about 61° C., about 62° C., about 63° C., about 64° C., about 65° C., about 66° C., about 67° C., about 68° C., about 69° C., about 70° C., about 71° C., about 72° C., about 73° C., about 74° C., about 75° C., about 76° C., about 77° C., about 78° C., about 79° C., about 80° C., about 81° C., about 82° C., about 83° C., about 84° C., about 85° C., about 86° C., about 87° C., about 88° C., about 89° C., about 90° C., about 91° C., about 92° C., about 93° C., about 94° C., about 95° C., about 96° C., about 97° C., about 98° C., about 99° C., to about 100° C. may be from about 750 to about 1 g/ml, namely to about 751 mg/ml, about 760 mg/ml, about 770 mg/ml, about 780 mg/ml, about 790 mg/ml, about 800 mg/ml, about 810 mg/ml, about 820 mg/ml, about 830 mg/ml, about 840 mg/ml, about 850 mg/ml, about 860 mg/ml, about 870 mg/ml, about 880 mg/ml, about 890 mg/ml, about 900 mg/ml, about 910 mg/ml, about 920 mg/ml, about 930 mg/ml, about 940 mg/ml, about 950 mg/ml, about 960 mg/ml, about 970 mg/ml, about 980 mg/ml, about 990 mg/ml, to about 1000 mg/ml. At temperatures below room temperature, the solubility of GHB may decrease, and compositions at lower temperature and solubility of GHB at the pH values and ranges described herein are also encompassed by the invention. Additionally, differences of atmospheric pressure may also increase or decrease the solubility of GHB within the ranges described, and embodiments of the invention with an increased or decreased content of GHB due to changes in pressure are also encompassed by the invention. Of course, it is understood that the present invention encompasses embodiments of GHB concentration or content in an aqueous medium at higher or lower temperature within the values described herein, such as about 980 mg/ml to about 200 mg/ml at 95° C. GHB at a pH of about 9 to about 7.5. Or about 150 mg/ml GHB at about 17° C. at about pH 6 to about pH 7. And so forth. Thus, all ranges of pH and GHB content that can be selected at various temperatures and pressures from the values above, and as would be understood by those of ordinary skill in the art, are encompassed by the present invention.
In certain other embodiments of the present invention, the pharmaceutical composition may comprise a pH adjusting or buffering agent. Such agents may be acids, bases, or combinations thereof. In certain embodiments, the acid may be an organic acid, preferably a carboxylic acid or alphahydroxy carboxylic acid. In certain other embodiments, the acid is selected from the group including, but not limited to, acetic, acetylsalicylic, barbital, barbituric, benzoic, benzyl penicillin, boric, caffeine, carbonic, citric, dichloroacetic, ethylenediaminetetra-acetic acid (EDTA), formic, glycerophosphoric, glycine, lactic, malic, mandelic, monochloroacetic, oxalic, phenobarbital, phenol, picric, propionic, saccharin, salicylic, sodium dihydrogen phosphate, succinic, sulfadiazine, sulfamerazine, sulfapyridine, sulfathiazole, tartaric, trichloroacetic, and the like, or inorganic acids such as hydrochloric, nitric, phosphoric or sulfuric, and the like. In a preferred embodiment, the acid is malic or hydrochloric acid. In certain other embodiments, the pH adjusting agent may be a base selected from the group including, but not limited to, acetanilide, ammonia, apomorphine, atropine, benzocaine, caffeine, calcium hydroxide, cocaine, codeine, ephedrine, morphine, papaverine, physostigmine, pilocarpine, potassium bicarbonate, potassium hydroxide, procaine, quinine, reserpine, sodium bicarbonate, sodium dihydrogen phosphate, sodium citrate, sodium taitrate, sodium carbonate, sodium hydroxide, theobromine, thiourea or urea. In certain other embodiments, the pH adjusting agent may be a mixture of more than one acid and/or more than one base. In other preferred embodiments, a weak acid and its conjugate base are used to form a buffering agent to help stabilize the composition's pH.
In certain embodiments, the composition may contain one or more salts. A “salt” is understood herein to mean certain embodiments to mean a compound formed by the interaction of an acid and a base, the hydrogen atoms of the acid being replaced by the positive ion of the base. Various salts, including salts of GHB, are also encompassed by the invention, particularly as pH adjusting or buffering agents. Pharmaceutically acceptable salts, include inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as malic, acetic, oxalic, tartaric, mandelic, and the like. Salts formed can also be derived from inorganic bases such as, for example, sodium, potassium, silicates, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, histidine, procaine and the like. Alkali metal salts, such as lithium, potassium, sodium, and the like may be used, preferably with an acid to form a pH adjusting agent. Other salts may comprise ammonium, calcium, magnesium and the like. In one embodiment, a salt of GHB comprising an alkali metal may be combined with an acid to create a composition that achieves the desired pH when admixed with an aqueous medium. In another embodiment, a weak base may be combined with GHB to create a composition that achieves the desired pH when admixed with an aqueous solution. Of course, other salts can be formed from compounds disclosed herein, or as would be known to one of ordinary skill in the art, and all such salts are encompassed by the invention.
In certain embodiments, excipients may be added to the invention. An “excipient” as used herein shall mean certain embodiments which are more or less inert substances added as diluents or vehicles or to give form or consistency when the remedy is in a solid form, though they may be contained in liquid form preparations, e.g. syrups, aromatic powders, honey, and various elixirs. Excipients may also enhance resistance to microbial growth, and thus act as a preservative. Such excipients include, but are not limited to, xylitol, mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, cellulose derivatives, magnesium carbonate and the like.
In certain embodiments, the pharmaceutical composition may contain a preservative. A “preservative” is understood herein to mean certain embodiments which are substances added to inhibit chemical change or microbial action. Such preservatives may include, but are not limited to, xylitol, sodium benzoate, methylparaben, propyl gallate BP, sorbic acid, chlorobutanol, dihydroacetic acid, monothioglycerol, potassium benzoate, propylparaben, benzoic acid, benzalkonium chloride, alcohol, benzoic acid, benzalkonium chloride, benzethonium chloride, benzyl alcohol, butylparaben, cetylpyridinium chloride, ethylenediamine, ethylparaben, ethyl vanillin, glycerin, hypophosphorus acid, methylparaben, phenol, phenylethyl alcohol, phenylmercuric nitrate, propylparaben, sassafras oil, sodium benzoate, sodium propionate, thimerosal and potassium sorbate. Preferred preservatives may be selected from the group comprising, but not limited to, xylitol, sodium benzoate, methylparaben, propylparaben and potassium sorbate. Xylitol is particularly preferred in certain compositions of the invention, because it acts as an preservative and a sweetener, is a caries preventative, is less laxative than other sweeteners, and is recommended for diabetics.
In certain embodiments, the pharmaceutical composition may also contain an antioxidant. An “antioxidant” is understood herein to mean certain embodiments which are substances that inhibits oxidation. Such antioxidants include, but are not limited to, ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, potassium metabisulfite, sodium metabisulfite, anoxomer and maleic acid BP.
In certain embodiments, the pharmaceutical composition may also contain a flavoring agent. A “flavoring agent” is understood herein to mean certain embodiments which are substances that alters the flavor of the composition during oral consumption. A type of “flavoring agent” would be a sweetener. Preferred sweeteners or flavoring agents would be microbially non-metabolizable. Especially preferred sweeteners or flavoring agents would be carbohydrates such as xylitol and sorbitol. Such flavoring agents include, but are not limited to, acacia syrup, anethole, anise oil, aromatic elixir, benzaldehyde, benzaldehyde elixir-compound, caraway, caraway oil, cardamom oil, cardamom seed, cardamom spirit, cardamom tincture-compound, cherry juice, cherry syrup, cinnamon, cinnamon oil, cinnamon water, citric acid, citric acid syrup, clove oil, coca, coca syrup, coriander oil, dextrose, eriodictyon, eriodictyon fluidextract, eriodictyon syrup-aromatic, ethyl acetate, ethyl vanillin, fennel oil, ginger, ginger fluidextract, ginger oleoresin, glucose, glycerin, glycyrrhiza, glycyrrhiza elixir, glycyrrhiza extract, glycyrrhiza extract-pure, glycyrrhiza fluidextract, glycyrrhiza syrup, honey, non-alcoholic elixir, lavender oil, citrus extract or oil, lemon oil, lemon tincture, mannitol, methyl salicylate, nutmeg oil, orange-bitter-elixir, orange-bitter-oil, orange flower oil, orange flower water, orange oil, orange peel-bitter, orange-peel-sweet-tincture, orange spirit-compound, compound, orange syrup, peppermint, peppermint oil, peppermint spirit, peppermint water, phenylethyl alcohol, raspberry juice, raspberry syrup, rosemary oil, rose oil, rose water, saccharin, saccharin calcium, saccharin sodium, sarsaparilla syrup, sorbitol solution, spearmint, spearmint oil, sucrose, syrup, thyme oil, tolu balsam, tolu balsam syrup, vanilla, vanilla tincture, vanillin or wild cherry syrup.
Salts, excipients, pH adjusting agents such as acids, bases and buffering agents, flavoring agents, and other agents that may be combined with the compositions of the present invention, or may be used to prepare the compositions of the present invention, are well known in the art, (see for example, “Remington's Pharmaceutical Sciences” 8th and 15th Editions, and Nema et al., 1997, incorporated herein in their entirety), and are encompassed by the invention.
In certain other embodiments, the pharmaceutical composition comprises GHB, a pH adjusting or buffering agent, and an aqueous medium, wherein the components are admixed (sequentially or simultaneously) to prepare said pharmaceutical composition. The pH adjusting or buffering agent and aqueous medium may be any described herein.
The invention also provides a method of preparing a chemically stable and microbial growth-resistant pharmaceutical composition for the treatment of a condition responsive to GHB, comprising admixing GHB and a pH-adjusting or buffering agent in an aqueous medium. In certain embodiments, the method of preparing the pharmaceutical composition further comprises admixing a preservative with the pharmaceutical composition. Other components, such as flavoring agents, salts, and the like, may be added to the composition. The pH adjusting or buffering agent, aqueous medium, preservative, flavoring agents, salts, or other ingredient may be any described herein.
In certain other embodiments, the method of preparing the pharmaceutical composition comprises admixing GHB, a pH adjusting or buffering agent, and an aqueous medium soon before administration to a patient suspected of having a condition responsive to GHB.
The invention also provides a method of treating any therapeutic category of disorder responsive to GHB, comprising administering to a patient suspected of having such a condition a therapeutic amount of a pharmaceutical composition comprising chemically stable GHB (e.g. 1-10 gms.) in an aqueous medium resistant to microbial growth. In certain embodiments, the method of treating a condition responsive to GHB comprises a patient taking a first dosage of from about 0.1 g to about 10 g, namely about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1-9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, to about 10 grams of GHB, or as needed by the patient as would be recognized by one of skill in the art. Of course, it will be understood that all values in between those listed, such as 9.45 grams, 6.32 grams, etc. may be administered, and those values are encompassed well. In preferred embodiments, the first dose is administered within an hour of sleep. In preferred embodiments, a second dose of GHB within the values described above may be administered. This second dose is administered preferably within about 2.0 to about 5.0 hrs, namely about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, to about 5.0 hours after the first dose, though it may be administered at a time outside of the preferred range.
In certain embodiments, a second pharmaceutical may be administered with the composition of GHB. Such a second pharmaceutical may be e.g., a stimulant administered within the same 24 hour period as the first dose of GHB. The stimulant may be, e.g., but not limited to, methylphenidate or pemoline to counter the residual effects of GHB treatment during periods of wakefulness. In certain embodiments, the method of treating a sleep disorder may include the discontinuation of other second pharmaceuticals used to control a sleep disorder. Such second pharmaceuticals may include, but are not limited to, a tricyclic antidepressant.
In certain embodiments, the invention provides a method of treating any appropriate therapeutic category of disorder, by administration of GHB compositions of the present invention as described above for the treatment of sleep disorders. When GHB is used in methods of treating any therapeutic category of disorder, the GHB composition of the present invention may be mixed with the aqueous medium, and optionally pH adjusting or buffering agent or other additives, by the patient or administrator soon before consumption. The patient may prepare the composition within a few minutes to hours before administration. Alternatively, one or more of the components may be premixed for ready use. The components of the GHB composition of the present invention, GHB, an aqueous medium, pH adjusting or buffering agent, excipients, preservatives, flavoring agents, and/or other components or additives may be stored in a container means suitable to aid preservation. Preferably, the container means is in the form of a set. A “set” as used herein certain embodiments is one or more components of the composition packaged in a container or other suitable storage means.
The present invention also provides a set for the treatment of a condition responsive to GHB comprising, in suitable storage means, GHB and a pH adjusting or buffering agent. In certain embodiments, the GHB and the pH adjusting or buffering agent are separately packaged. In certain other embodiments the GHB and the pH-adjusting or buffering agent may be mixed. The set may contain an aqueous medium. In certain other embodiments, at least one component selected from the group including, but not limited to, GHB, the pH-adjusting or buffering agent and/or an aqueous medium is separately, packaged. In certain other embodiments, at least two of the components selected from the group comprising GHB, a pH adjusting or buffering agent and an aqueous medium are mixed together. In some embodiments, the set further contains a preservative. Such a set may have one, two, or more components from the group comprising, GHB, a pH-adjusting or buffering agent, an aqueous medium or a preservative packaged separately. Such a set may have two or more components mixed together. Thus, both liquid and dry formulations of GHB and other components may be packaged in a set for mixing before administration, or one or more components may be premixed and packaged together with other components, or all the components may be premixed and packaged in a set.
It is understood that the compositions of the present invention, including those in a set, may be dispersed in a pharmaceutically acceptable carrier solution as described below. Such a solution would be sterile or aseptic and may include water, co-solvent vehicle buffers, isotonic agents, pharmaceutical aids or other ingredients known to those of skill in the art that would cause no allergic or other harmful reaction when administered to an animal or human subject. Therefore, the present invention may also be described as a pharmaceutical composition of GHB with increased stability in a pharmaceutically acceptable carrier solution.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Also as used herein, the term “a” “an” or “the” is understood to include the meaning “one or more”. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described.
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SUMMARY: BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates generally to the fields of pharmaceutical compositions to be used in treatments, such as, sleeping disorders, such as, e.g., narcolepsy (particularly cataplexy), drug abuse, alcohol and opiate withdrawal, a reduced level of growth hormone, anxiety, analgesia, effects in certain neurological disorders such as Parkinson's Disease, depression, certain endocrine disturbances and tissue protection following hypoxia/anoxia such as in stroke or myocardial infarction, or for an increased level of intracranial pressure or the like. The present invention particularly relates to the field of pharmaceutical production of microbiologically resistant and chemically stable preparations or solutions of gamma-hydroxybutyrate (GHB), also known as 4-hydroxybutyrate, and the sodium salt of GHB (sodium oxybate) and other salts such as magnesium, ammonium and calcium, e.g.
II. Description of Related Art
GHB is an endogenous compound with hypnotic properties that is found in many human body tissues. GHB is present, for example, in the mammalian brain and other tissues. In brain the highest GHB concentration is found in the hypothalamus and basal ganglia and GHB is postulated to function as a neurotransmitter (Snead and Moriey, 1981). The neuropharmacologic effects of GHB include increases in brain acetylcholine, increases in brain dopamine, inhibition of GABA-ketoglutarate transaminase and depression of glucose utilization but not oxygen consumption in the brain. GHB is converted to succinate and then metabolized via the Krebs cycle. Clinical trials have shown that GHB increases delta sleep and improves the continuity of sleep (Ladinsky et al., 1983; Anden and Stock, 1973; Stock et al., 1973; Laborit, 1973; Lapierre et al., 1988; Lapierre et al., 1990; Yamda et al., 1967; Grove-White and Kelman, 1971; Scharf, 1985).
GHB has typically been administered in clinical trials as an oral solution (Lee, 1977; Mamelak, 1977; Hoes, 1980; Scharf, 1985; Scrima, 1990; Gallimberti, 1992; Series, 1992; Lammers, 1993). GHB treatment substantially reduces the signs and symptoms of narcolepsy, i.e. daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. In addition, GHB increases total sleep time and REM sleep, and it decreases REM latency (Mamelak et al, 1973; Yamada et al., 1967; Bedard et al., 1989), reduces sleep apnea (Series et al, 1992; Scrima et al., 1987), and improves general anesthesia (Hasenbos and Gielen, 1985).
GHB has several clinical applications other than narcolepsy and sleep disorders. GHB has been reported to reduce alcohol craving, the number of daily drinks consumed, and the symptoms of alcohol withdrawal in patients (Gallimberti et al., 1989; Gallimberti et al., 1992; Gessa et al., 1992). GHB has been used to decrease the symptoms of opiate withdrawal, including both heroin and methadone withdrawal (Gallimberti et al, 1994; Gallimberti et al., 1993). It has analgesic effects that make it suitable as a pain reliever (U.S. Pat. No. 4,393,236). Intravenous administration of GHB has been reported to reduce intracranial pressure in patients (Strong, A. 1984). Also, administration of GHB was reported to increase growth hormone levels in patients (Gerra et al, 1994; Oyama et al., 1970).
A good safety profile for GHB consumption, when used long term for treatment of narcolepsy, has been reported. Patients have been safely treated for many years with GHB without development of tolerance (Scharf, 1985). Clinical laboratory tests carried out periodically on many patients have not indicated organ or other toxicities (Lammers, 1993; Scrima, 1990; Scharf, 1985; Mamelack, 1977; Mamelak, 1979; Gallimberti, 1989; Gallimberti, 1992; Gessa, 1992). The side effects of GHB treatment have been minimal in incidence and degree of severity, though they include sleepwalking, enuresis, headache, nausea and dizziness (Broughton and Mamelak, 1979; Mamelak et al., 1981; Mamelak et al., 1977; Scrima et al., 1989; Scrima et al., 1990; Scharf et al., 1985).
The pharmacokinetics of GHB have been investigated in alcohol dependent patients (Ferrara et al., 1992) and in normal healthy males (Palatini et al., 1993) after oral administration. GHB possesses a rapid onset and short pharmacological effect (Ferrara et al., 1992; Palatine et al., 1993; Lee, C., 1977; van der Bogert; Gallimberti, 1989; Gallimberti, 1992; Lettieri and Fung, 1978; Arena and Fung, 1980; Roth and Giarman, 1966; Vickers, 1969; Lee, 1977). In alcohol dependent patients, GHB absorption into and elimination from the systemic circulation were fast processes. Virtually no unchanged drug could be recovered in the urine. There were preliminary indications that the pharmacokinetics of GHB might be non-linear or dose-dependent (Ferrara et al., 1992). In the healthy volunteers study, the pharmacokinetics of three rising GHB doses (12.5, 25, and 50 mg/kg) were investigated. These findings indicate that both the oral absorption and elimination processes of GHB were capacity-limited though the degree of dose dependency was moderate (Palatini et al., 1993).
Organic salts and amides of GHB have been produced to reduce the physiological side effects of GHB (U.S. Pat. No. 5,380,937). Magnesium and calcium salt have been produced to reduce the hygroscopic nature of GHB or powdered forms (U.S. Pat. No. 4,393,236; British Patent No. 922,029). However, problems with the storage of GHB solutions still exist. GHB degrades into gamma-butyrolactone (GBL) and possibly other degradants in solution depending upon the pH and other factors. Also, the contamination by microorganisms in GHB solutions rapidly surpass acceptable limits, and preservatives can adversely affect the pH and thus, GHB's stability. As a chronically used product which requires high levels of drug, the volume of a non-concentrated product creates cost and handling issues. Thus, there is an immediate need for effective solutions of GHB that are stable to biological or chemical degradation.
SUMMARY OF THE INVENTION
The present invention overcomes deficiencies in the prior art by providing compositions of GHB in an aqueous medium that are resistant to microbial growth. These compositions are also resistant to the uncontrolled degradation of GHB into GBL or other substances. The compositions of the present invention are stable compositions of GHB that improve shelf-life, and provide a titratable formulation of GHB for easy dose measurement. In addition, the concentrated solutions embodied in this invention reduce shipping and storage requirements and allow patients to carry more drugs for their convenience. The present invention provides methods to treat a number of conditions treatable by GHB, referred to herein as “therapeutic categories.” Therapeutic categories for the present invention include, but are not limited to, sleeping disorders, drug abuse, alcohol and opiate withdrawal, a reduced level of growth hormone, anxiety, analgesia, effects in certain neurological disorders, such as Parkinson's Disease, depression, certain endocrine disturbances and tissue protection following hypoxia/anoxia such as in stroke or myocardial infarction, or an increased level of intracranial pressure or other conditions treatable with GHB.
The invention first provides a pharmaceutical composition of GHB rendered chemically stable and/or resistant to microbial growth in an aqueous medium. Preferred GHB salts of the present invention include sodium, ammonium and calcium. As used herein in certain embodiments, “stable” may mean resistant to degradation of GHB into its known or unknown decomposition elements. The level of GBL that is acceptable can be up to 0.1% of the formulation as per the ICH guidelines for shelf-life determination. As used herein in certain embodiments, “resistant to microbial growth” or “resistant to microbial challenge” means that the formulations meet the criteria set by the Food and Drug Administration and the U.S. Pharmacopoeia for products made with aqueous bases or vehicles, which for bacteria means not less than a 1.0 log reduction from the initial count at 14 days, and no increase from the 14 days count at 28 days, and for yeast and molds, no increase from the initial calculated count at 14 and 28 days. As used herein in certain embodiments, an “aqueous medium” may mean a liquid comprising more than about 50% water. In certain preferred embodiments, an “aqueous medium” may be a solution, suspension, gel or emulsion of GHB, with a solution of GHB being most preferred. Preferred gels are thixotropic gels. Compositions that are resistant to microbial growth are created by dissolving or mixing GHB in an aqueous medium to a concentration or content of greater than of about 150 mg/ml GHB to the maximal solubility of GHB. The solubility of GHB is up to about 750 mg/ml at room temperature (20° C. to about 25° C.), however, heating the aqueous medium during preparation up to 100° C. will increase GHB solubility to at least about 1000 mg/ml. A preferred concentration or content of GHB is about 500 mg/ml.
The amount of GHB that may be mixed or dissolved into an aqueous medium and still be resistant to microbial growth depends upon the pH of the aqueous medium. In certain embodiments the presence of a preservative may allow the amount of GHB contained in the compositions of the present invention to be increased and still maintain resistance to chemical degradation and/or microbial growth. In one embodiment of the present invention, the pH of the aqueous medium of the pharmaceutical composition is about 3 to about 10.
In a preferred embodiment, the pH of said aqueous medium is about 6 to about 7.5. The pH may be from about 3.0 to about 10.3, namely of about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6; about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, about 10.0, about 10.1, about 10.2, or about 10.3, and all pH values between each of the listed pH values, of the aqueous media. This will produce a GHB composition that is resistant to microbial growth as defined by the test described herein. As used herein, the term “about” generally means within about 10-20%.
These pH values will produce compositions resistant to microbial growth in an aqueous medium if the amount of GHB added, admixed, or dissolved is from above about 150 mg/ml to about 450 mg/ml, namely, above about 150 mg/ml, about 160 mg/ml, about 170 mg/ml, about 180 mg/ml, about 190 mg/ml, about 200 mg/ml, about 210 mg/ml, about 220 mg/ml, about 230 mg/ml, about 240 mg/ml, about 250 mg/ml, about 260 mg/ml, about 270 mg/ml, about 280 mg/ml, about 290 mg/ml, about 300 mg/ml, about 310 mg/ml, about 320 mg/ml, about 330 mg/ml, about 340 mg/ml, about 350 mg/ml, about 360 mg/ml, about 370 mg/ml, about 380 mg/ml, about 390 mg/ml, about 400 mg/ml, about 410 mg/ml, about 420 mg/ml, about 430 mg/ml, about 440 mg/ml, to about 450 mg/ml, and all amounts of GHB between the values listed.
At the medium to high end of the concentration or content of GHB that may be dissolved or mixed in the aqueous medium, the maximal pH that may be used is reduced at room temperature. This is shown inFIG. 1, a graphical presentation of acceptable formulation ranges. At a concentration or content of about 450 mg/ml GHB, the pH may be of about 3.9 to about 10.3. At a concentration or content of about 500 mg/ml GHB, the pH may be of about 4.75 to about 10.3. At a concentration or content of about 600 mg/ml GHB, the pH may be of about 6.1 to about 10.3. At a concentration or content of about 750 mg/ml GHB, the pH may be of about 7.0 to about 10.3. Of course, all pH and concentration or content values in between each of the listed pH and concentration or content values are encompassed by the invention.
Certain embodiments may be selected as sub-ranges from these values of GHB content and aqueous medium pH. For example, a specific embodiment may be selected as a content of about 170 mg/ml to about 440 mg/ml GHB in an aqueous medium, at a pH range of about pH 5.5 to about pH 8.7. Another example of how a range may be selected in an embodiment would be the selection of a content of about 155 mg/ml of GHB, which is a value between the above listed values, to a content of about 350 mg/ml of GHB, and the selection of a pH range of the aqueous medium, such as a pH range of about 8.87, which is a value between the listed pH values, to a pH of about 8.93, which is another value between the listed values of pH. A third example of ranges that may be selected for a specific embodiment would be selection of a single content or concentration of GHB, such as about 200 mg/ml of GHB, and the selection of a pH range, such as a pH of about 3.5 to about 8.2. A fourth example of ranges that may be selected for a specific embodiment would be selection of a content or concentration of GHB over a range, such as about 300 mg/ml to about 400 mg/ml, and the selection of a single pH value for the aqueous medium, such as a pH of about 3. Another example of a range selected for an embodiment may be the selection of a single content or concentration of GHB, such as 400 mg/ml GHB, and a single pH value of the aqueous medium, such as pH 7.7.
Other examples of how a range of an embodiment of GHB content or concentration may be selected include a range of GHB content or concentration from about 200 mg/ml to about 460 mg/ml GHB, encompassing the ranges for GHB described herein, and a range of pH for the aqueous medium may be from about pH 4.3 to about pH 7, encompassing ranges for GHB in an aqueous medium at room temperature described herein. Another example would be the selection of a range of GHB content or concentration from about 153 mg/ml to about 750 mg/ml, and a pH range of about 7 to about 9, encompassing ranges between the listed values of GHB content and pH described herein. An example may be the selection as a GHB concentration or content of about 170 mg/ml to about 640 mg/ml in an aqueous medium, at a pH range of about pH 6.5 to about pH 7.7. Another example of how a range may be selected in an embodiment would be a content or concentration of about 185 mg/ml of GHB, which is a value between the listed values, to a content or concentration of about 750 mg/ml of GHB, at a pH range of about 7.87, which is a value between the listed pH values, to a pH of about 8.91, which is another value between the listed values of pH. An additional example of ranges that may be selected for a specific embodiment would be a content or concentration of about 200 mg/ml of GHB at a pH of about 7 to about 8.2. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 750 mg/ml to about 400 mg/ml at a pH of about 7. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 300 mg/ml to about 750 mg/ml at a pH of about 8.5 to about 7. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 400 mg/ml to about 600 mg/ml at a pH of about 9 to about 5.8. And so forth. Thus, all ranges of pH and GHB concentration or content that can be selected from the values herein and as would be understood by those of ordinary skill in the art, are encompassed by the present invention.
The chemical stability of GHB is affected by pH, with compositions of GHB in an aqueous medium with a pH below about 6 being less effective in maintaining the chemical stability of GHB. Compositions with a pH of greater than about 6.0 are preferred to produce chemically stable formulations of GHB. Thus, a preferred range to produce chemically stable GHB would be from about pH 6 to about pH 9. However, all concentrations or content of GHB in an aqueous medium, as described herein, and as would be understood by those of ordinary skill in the art, may be selected to produce compositions of the present invention.
Additionally, the ranges described above are for a composition at room temperature, which is defined herein as from about 20° C. to about 25° C., namely, about 20° C. about 21° C., about 22° C., about 23° C., about 24° C., to about 25° C. Within the values and ranges of pH described above, the ranges of concentration or content of GHB may increase at temperatures greater than room temperature. Thus, the maximal content or concentration of GHB in an aqueous medium at a temperature of from about 26° C. to about 100° C., namely about 26° C., about 27° C., about 28° C., about 29° C., about 30° C., about 31° C., about 32° C., about 33° C., about 34° C., about 35° C., about 36° C., about 37° C., about 38° C., about 39° C., about 40° C., about 41° C., about 42° C., about 43° C., about 44° C., about 45° C., about 46° C., about 47° C., about 48° C., about 49° C., about 50° C., about 51° C., about 52° C., about 53° C., about 54° C., about 55° C., about 56° C., about 57° C., about 58° C., about 59° C., about 60° C., about 61° C., about 62° C., about 63° C., about 64° C., about 65° C., about 66° C., about 67° C., about 68° C., about 69° C., about 70° C., about 71° C., about 72° C., about 73° C., about 74° C., about 75° C., about 76° C., about 77° C., about 78° C., about 79° C., about 80° C., about 81° C., about 82° C., about 83° C., about 84° C., about 85° C., about 86° C., about 87° C., about 88° C., about 89° C., about 90° C., about 91° C., about 92° C., about 93° C., about 94° C., about 95° C., about 96° C., about 97° C., about 98° C., about 99° C., to about 100° C. may be from about 750 to about 1 g/ml, namely to about 751 mg/ml, about 760 mg/ml, about 770 mg/ml, about 780 mg/ml, about 790 mg/ml, about 800 mg/ml, about 810 mg/ml, about 820 mg/ml, about 830 mg/ml, about 840 mg/ml, about 850 mg/ml, about 860 mg/ml, about 870 mg/ml, about 880 mg/ml, about 890 mg/ml, about 900 mg/ml, about 910 mg/ml, about 920 mg/ml, about 930 mg/ml, about 940 mg/ml, about 950 mg/ml, about 960 mg/ml, about 970 mg/ml, about 980 mg/ml, about 990 mg/ml, to about 1000 mg/ml. At temperatures below room temperature, the solubility of GHB may decrease, and compositions at lower temperature and solubility of GHB at the pH values and ranges described herein are also encompassed by the invention. Additionally, differences of atmospheric pressure may also increase or decrease the solubility of GHB within the ranges described, and embodiments of the invention with an increased or decreased content of GHB due to changes in pressure are also encompassed by the invention. Of course, it is understood that the present invention encompasses embodiments of GHB concentration or content in an aqueous medium at higher or lower temperature within the values described herein, such as about 980 mg/ml to about 200 mg/ml at 95° C. GHB at a pH of about 9 to about 7.5. Or about 150 mg/ml GHB at about 17° C. at about pH 6 to about pH 7. And so forth. Thus, all ranges of pH and GHB content that can be selected at various temperatures and pressures from the values above, and as would be understood by those of ordinary skill in the art, are encompassed by the present invention.
In certain other embodiments of the present invention, the pharmaceutical composition may comprise a pH adjusting or buffering agent. Such agents may be acids, bases, or combinations thereof. In certain embodiments, the acid may be an organic acid, preferably a carboxylic acid or alphahydroxy carboxylic acid. In certain other embodiments, the acid is selected from the group including, but not limited to, acetic, acetylsalicylic, barbital, barbituric, benzoic, benzyl penicillin, boric, caffeine, carbonic, citric, dichloroacetic, ethylenediaminetetra-acetic acid (EDTA), formic, glycerophosphoric, glycine, lactic, malic, mandelic, monochloroacetic, oxalic, phenobarbital, phenol, picric, propionic, saccharin, salicylic, sodium dihydrogen phosphate, succinic, sulfadiazine, sulfamerazine, sulfapyridine, sulfathiazole, tartaric, trichloroacetic, and the like, or inorganic acids such as hydrochloric, nitric, phosphoric or sulfuric, and the like. In a preferred embodiment, the acid is malic or hydrochloric acid. In certain other embodiments, the pH adjusting agent may be a base selected from the group including, but not limited to, acetanilide, ammonia, apomorphine, atropine, benzocaine, caffeine, calcium hydroxide, cocaine, codeine, ephedrine, morphine, papaverine, physostigmine, pilocarpine, potassium bicarbonate, potassium hydroxide, procaine, quinine, reserpine, sodium bicarbonate, sodium dihydrogen phosphate, sodium citrate, sodium taitrate, sodium carbonate, sodium hydroxide, theobromine, thiourea or urea. In certain other embodiments, the pH adjusting agent may be a mixture of more than one acid and/or more than one base. In other preferred embodiments, a weak acid and its conjugate base are used to form a buffering agent to help stabilize the composition's pH.
In certain embodiments, the composition may contain one or more salts. A “salt” is understood herein to mean certain embodiments to mean a compound formed by the interaction of an acid and a base, the hydrogen atoms of the acid being replaced by the positive ion of the base. Various salts, including salts of GHB, are also encompassed by the invention, particularly as pH adjusting or buffering agents. Pharmaceutically acceptable salts, include inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as malic, acetic, oxalic, tartaric, mandelic, and the like. Salts formed can also be derived from inorganic bases such as, for example, sodium, potassium, silicates, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, histidine, procaine and the like. Alkali metal salts, such as lithium, potassium, sodium, and the like may be used, preferably with an acid to form a pH adjusting agent. Other salts may comprise ammonium, calcium, magnesium and the like. In one embodiment, a salt of GHB comprising an alkali metal may be combined with an acid to create a composition that achieves the desired pH when admixed with an aqueous medium. In another embodiment, a weak base may be combined with GHB to create a composition that achieves the desired pH when admixed with an aqueous solution. Of course, other salts can be formed from compounds disclosed herein, or as would be known to one of ordinary skill in the art, and all such salts are encompassed by the invention.
In certain embodiments, excipients may be added to the invention. An “excipient” as used herein shall mean certain embodiments which are more or less inert substances added as diluents or vehicles or to give form or consistency when the remedy is in a solid form, though they may be contained in liquid form preparations, e.g. syrups, aromatic powders, honey, and various elixirs. Excipients may also enhance resistance to microbial growth, and thus act as a preservative. Such excipients include, but are not limited to, xylitol, mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, cellulose derivatives, magnesium carbonate and the like.
In certain embodiments, the pharmaceutical composition may contain a preservative. A “preservative” is understood herein to mean certain embodiments which are substances added to inhibit chemical change or microbial action. Such preservatives may include, but are not limited to, xylitol, sodium benzoate, methylparaben, propyl gallate BP, sorbic acid, chlorobutanol, dihydroacetic acid, monothioglycerol, potassium benzoate, propylparaben, benzoic acid, benzalkonium chloride, alcohol, benzoic acid, benzalkonium chloride, benzethonium chloride, benzyl alcohol, butylparaben, cetylpyridinium chloride, ethylenediamine, ethylparaben, ethyl vanillin, glycerin, hypophosphorus acid, methylparaben, phenol, phenylethyl alcohol, phenylmercuric nitrate, propylparaben, sassafras oil, sodium benzoate, sodium propionate, thimerosal and potassium sorbate. Preferred preservatives may be selected from the group comprising, but not limited to, xylitol, sodium benzoate, methylparaben, propylparaben and potassium sorbate. Xylitol is particularly preferred in certain compositions of the invention, because it acts as an preservative and a sweetener, is a caries preventative, is less laxative than other sweeteners, and is recommended for diabetics.
In certain embodiments, the pharmaceutical composition may also contain an antioxidant. An “antioxidant” is understood herein to mean certain embodiments which are substances that inhibits oxidation. Such antioxidants include, but are not limited to, ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, potassium metabisulfite, sodium metabisulfite, anoxomer and maleic acid BP.
In certain embodiments, the pharmaceutical composition may also contain a flavoring agent. A “flavoring agent” is understood herein to mean certain embodiments which are substances that alters the flavor of the composition during oral consumption. A type of “flavoring agent” would be a sweetener. Preferred sweeteners or flavoring agents would be microbially non-metabolizable. Especially preferred sweeteners or flavoring agents would be carbohydrates such as xylitol and sorbitol. Such flavoring agents include, but are not limited to, acacia syrup, anethole, anise oil, aromatic elixir, benzaldehyde, benzaldehyde elixir-compound, caraway, caraway oil, cardamom oil, cardamom seed, cardamom spirit, cardamom tincture-compound, cherry juice, cherry syrup, cinnamon, cinnamon oil, cinnamon water, citric acid, citric acid syrup, clove oil, coca, coca syrup, coriander oil, dextrose, eriodictyon, eriodictyon fluidextract, eriodictyon syrup-aromatic, ethyl acetate, ethyl vanillin, fennel oil, ginger, ginger fluidextract, ginger oleoresin, glucose, glycerin, glycyrrhiza, glycyrrhiza elixir, glycyrrhiza extract, glycyrrhiza extract-pure, glycyrrhiza fluidextract, glycyrrhiza syrup, honey, non-alcoholic elixir, lavender oil, citrus extract or oil, lemon oil, lemon tincture, mannitol, methyl salicylate, nutmeg oil, orange-bitter-elixir, orange-bitter-oil, orange flower oil, orange flower water, orange oil, orange peel-bitter, orange-peel-sweet-tincture, orange spirit-compound, compound, orange syrup, peppermint, peppermint oil, peppermint spirit, peppermint water, phenylethyl alcohol, raspberry juice, raspberry syrup, rosemary oil, rose oil, rose water, saccharin, saccharin calcium, saccharin sodium, sarsaparilla syrup, sorbitol solution, spearmint, spearmint oil, sucrose, syrup, thyme oil, tolu balsam, tolu balsam syrup, vanilla, vanilla tincture, vanillin or wild cherry syrup.
Salts, excipients, pH adjusting agents such as acids, bases and buffering agents, flavoring agents, and other agents that may be combined with the compositions of the present invention, or may be used to prepare the compositions of the present invention, are well known in the art, (see for example, “Remington's Pharmaceutical Sciences” 8th and 15th Editions, and Nema et al., 1997, incorporated herein in their entirety), and are encompassed by the invention.
In certain other embodiments, the pharmaceutical composition comprises GHB, a pH adjusting or buffering agent, and an aqueous medium, wherein the components are admixed (sequentially or simultaneously) to prepare said pharmaceutical composition. The pH adjusting or buffering agent and aqueous medium may be any described herein.
The invention also provides a method of preparing a chemically stable and microbial growth-resistant pharmaceutical composition for the treatment of a condition responsive to GHB, comprising admixing GHB and a pH-adjusting or buffering agent in an aqueous medium. In certain embodiments, the method of preparing the pharmaceutical composition further comprises admixing a preservative with the pharmaceutical composition. Other components, such as flavoring agents, salts, and the like, may be added to the composition. The pH adjusting or buffering agent, aqueous medium, preservative, flavoring agents, salts, or other ingredient may be any described herein.
In certain other embodiments, the method of preparing the pharmaceutical composition comprises admixing GHB, a pH adjusting or buffering agent, and an aqueous medium soon before administration to a patient suspected of having a condition responsive to GHB.
The invention also provides a method of treating any therapeutic category of disorder responsive to GHB, comprising administering to a patient suspected of having such a condition a therapeutic amount of a pharmaceutical composition comprising chemically stable GHB (e.g. 1-10 gms.) in an aqueous medium resistant to microbial growth. In certain embodiments, the method of treating a condition responsive to GHB comprises a patient taking a first dosage of from about 0.1 g to about 10 g, namely about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1-9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, to about 10 grams of GHB, or as needed by the patient as would be recognized by one of skill in the art. Of course, it will be understood that all values in between those listed, such as 9.45 grams, 6.32 grams, etc. may be administered, and those values are encompassed well. In preferred embodiments, the first dose is administered within an hour of sleep. In preferred embodiments, a second dose of GHB within the values described above may be administered. This second dose is administered preferably within about 2.0 to about 5.0 hrs, namely about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, to about 5.0 hours after the first dose, though it may be administered at a time outside of the preferred range.
In certain embodiments, a second pharmaceutical may be administered with the composition of GHB. Such a second pharmaceutical may be e.g., a stimulant administered within the same 24 hour period as the first dose of GHB. The stimulant may be, e.g., but not limited to, methylphenidate or pemoline to counter the residual effects of GHB treatment during periods of wakefulness. In certain embodiments, the method of treating a sleep disorder may include the discontinuation of other second pharmaceuticals used to control a sleep disorder. Such second pharmaceuticals may include, but are not limited to, a tricyclic antidepressant.
In certain embodiments, the invention provides a method of treating any appropriate therapeutic category of disorder, by administration of GHB compositions of the present invention as described above for the treatment of sleep disorders. When GHB is used in methods of treating any therapeutic category of disorder, the GHB composition of the present invention may be mixed with the aqueous medium, and optionally pH adjusting or buffering agent or other additives, by the patient or administrator soon before consumption. The patient may prepare the composition within a few minutes to hours before administration. Alternatively, one or more of the components may be premixed for ready use. The components of the GHB composition of the present invention, GHB, an aqueous medium, pH adjusting or buffering agent, excipients, preservatives, flavoring agents, and/or other components or additives may be stored in a container means suitable to aid preservation. Preferably, the container means is in the form of a set. A “set” as used herein certain embodiments is one or more components of the composition packaged in a container or other suitable storage means.
The present invention also provides a set for the treatment of a condition responsive to GHB comprising, in suitable storage means, GHB and a pH adjusting or buffering agent. In certain embodiments, the GHB and the pH adjusting or buffering agent are separately packaged. In certain other embodiments the GHB and the pH-adjusting or buffering agent may be mixed. The set may contain an aqueous medium. In certain other embodiments, at least one component selected from the group including, but not limited to, GHB, the pH-adjusting or buffering agent and/or an aqueous medium is separately, packaged. In certain other embodiments, at least two of the components selected from the group comprising GHB, a pH adjusting or buffering agent and an aqueous medium are mixed together. In some embodiments, the set further contains a preservative. Such a set may have one, two, or more components from the group comprising, GHB, a pH-adjusting or buffering agent, an aqueous medium or a preservative packaged separately. Such a set may have two or more components mixed together. Thus, both liquid and dry formulations of GHB and other components may be packaged in a set for mixing before administration, or one or more components may be premixed and packaged together with other components, or all the components may be premixed and packaged in a set.
It is understood that the compositions of the present invention, including those in a set, may be dispersed in a pharmaceutically acceptable carrier solution as described below. Such a solution would be sterile or aseptic and may include water, co-solvent vehicle buffers, isotonic agents, pharmaceutical aids or other ingredients known to those of skill in the art that would cause no allergic or other harmful reaction when administered to an animal or human subject. Therefore, the present invention may also be described as a pharmaceutical composition of GHB with increased stability in a pharmaceutically acceptable carrier solution.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Also as used herein, the term “a” “an” or “the” is understood to include the meaning “one or more”. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described.
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7704731 | CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. application Ser. No. 11/586,747, filed Oct. 10, 2006, entitled “Method for Stimulation of Bioluminescent Organisms Via Turbulence Created by Gas Bubbles” (Navy Case #98122).
BACKGROUND OF THE INVENTION
Current systems for quantifying toxicity in water, soil, and sediments tend to be complex, expensive, time consuming, and imprecise. A need exists for an easier to use, less expensive, quicker, and more precise system for quantifying toxicity in soils, sediments, and water.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. application Ser. No. 11/586,747, filed Oct. 10, 2006, entitled “Method for Stimulation of Bioluminescent Organisms Via Turbulence Created by Gas Bubbles” (Navy Case #98122).
BACKGROUND OF THE INVENTION
Current systems for quantifying toxicity in water, soil, and sediments tend to be complex, expensive, time consuming, and imprecise. A need exists for an easier to use, less expensive, quicker, and more precise system for quantifying toxicity in soils, sediments, and water.
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7793505 | TECHNICAL FIELD
The invention relates to gas turbine engines, in more particularly to a method for lubricating a gas turbine engine.
BACKGROUND
A gas turbine engine comprises a plurality of rotating elements, such as shafts, rotating at a very high rotation speed when the engine is running. These rotating elements are supported by bearings provided at various strategic locations in the engine. These bearings are lubricated using pressurized oil. Oil is sent to the bearing cavities using oil pumps that are mechanically driven and as a result will start to pump oil to the bearings as soon as the engine starter is engaged. One drawback is that when starting the engine or during the run down, the air-oil seals of bearing cavities are inefficient because of the lack of sufficient air pressure. This may result in oil leaks, which is undesirable.
SUMMARY
In one aspect, the present invention provides a method of operating a gas turbine engine having a combustor and at least one turbine shaft drivingly connected to an electric machine, the engine also having an oil system communicating with an electric oil pump, at least one bearing cavity of the engine and a coolant passage of the electric machine, the method comprising: rotating the shaft while the combustor is unlit; controlling the oil pump to intermittently provide oil flow to the oil system for cooling the electric machine.
In another aspect, the present invention provides a method of operating a gas turbine engine having a motor/generator drivingly connected to a turbine shaft, the engine having an oil system communicating with an electric oil pump, at least one bearing cavity of the engine and a coolant passage of the motor/generator, the method comprising: rotating the shaft with the motor/generator; pumping oil to provide an intermittent oil flow to the oil system; providing pumped oil to the motor/generator for cooling; lighting the engine; and then pumping oil to provide a continuous oil flow to the oil system.
In another aspect, the present invention provides a method of operating a gas turbine engine having a combustor and at least one electric machine, the engine having an oil system communicating with an electric oil pump, at least one bearing cavity of the engine and a coolant passage of the electric machine, the method comprising the step of pumping oil intermittently to the oil system to cool the electric machine.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: TECHNICAL FIELD
The invention relates to gas turbine engines, in more particularly to a method for lubricating a gas turbine engine.
BACKGROUND
A gas turbine engine comprises a plurality of rotating elements, such as shafts, rotating at a very high rotation speed when the engine is running. These rotating elements are supported by bearings provided at various strategic locations in the engine. These bearings are lubricated using pressurized oil. Oil is sent to the bearing cavities using oil pumps that are mechanically driven and as a result will start to pump oil to the bearings as soon as the engine starter is engaged. One drawback is that when starting the engine or during the run down, the air-oil seals of bearing cavities are inefficient because of the lack of sufficient air pressure. This may result in oil leaks, which is undesirable.
SUMMARY
In one aspect, the present invention provides a method of operating a gas turbine engine having a combustor and at least one turbine shaft drivingly connected to an electric machine, the engine also having an oil system communicating with an electric oil pump, at least one bearing cavity of the engine and a coolant passage of the electric machine, the method comprising: rotating the shaft while the combustor is unlit; controlling the oil pump to intermittently provide oil flow to the oil system for cooling the electric machine.
In another aspect, the present invention provides a method of operating a gas turbine engine having a motor/generator drivingly connected to a turbine shaft, the engine having an oil system communicating with an electric oil pump, at least one bearing cavity of the engine and a coolant passage of the motor/generator, the method comprising: rotating the shaft with the motor/generator; pumping oil to provide an intermittent oil flow to the oil system; providing pumped oil to the motor/generator for cooling; lighting the engine; and then pumping oil to provide a continuous oil flow to the oil system.
In another aspect, the present invention provides a method of operating a gas turbine engine having a combustor and at least one electric machine, the engine having an oil system communicating with an electric oil pump, at least one bearing cavity of the engine and a coolant passage of the electric machine, the method comprising the step of pumping oil intermittently to the oil system to cool the electric machine.
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7851841 | The following application is related to the grandparent patent U.S. Pat. No. 7,067,867, has the same filing date as the grandparent patent, and is herein incorporated by reference in its entirety:
“Integrated Displays Using Nanowire Transistors,” Atty. Dkt. No. 2132.0080001, Ser. No. 10/673,669, now U.S. Pat. No. 7,102,605.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor devices, and more particularly, to the use of thin films of nanowires in semiconductor devices.
2. Background Art
An interest exists in industry in developing low cost electronics, and in particular, in developing low cost, large area electronic devices. Availability of such large area electronic devices could revolutionize a variety of technology areas, ranging from civil to military applications. Example applications for such devices include driving circuitry for active matrix liquid crystal displays (LCDs) and other types of matrix displays, smart libraries, credit cards, radio-frequency identification tags for smart price and inventory tags, security screening/surveillance or highway traffic monitoring systems, large area sensor arrays, and the like.
The advancement of electronics has been moving towards two extremes in terms of physical scale. Rapid miniaturization of microelectronics according to Moore's law has led to increases in computing power while at the same time enabling reductions in cost. At the same time, progress has been made in the area of macroelectronics, in which electronic devices are integrated over large area substrates (e.g., having sizes measured in square meters). Current macroelectronics are primarily based on amorphous silicon (a-Si) or polycrystalline silicon (p-Si) thin film transistors (TFTs) on glass, and are finding important applications in various areas, including flat panel display (FPD), solar cells, image sensor arrays and digital x-ray imagers.
The current technology, however, is limited in what applications to which it can be applied. For example, there has been growing interest in the use of plastic as a substrate for macroelectronics due to various beneficial attributes of plastic, including flexibility, shock resistance, low weight, and low cost. However, the fabrication of high performance TFTs on plastics is difficult because process steps must be carried out below the glass transition temperature of the plastic. Significant efforts have been devoted to search for new materials (such as organics and organic-inorganic hybrids) or new fabrication strategies suitable for TFTs on plastics, but only with limited success. Organic TFTs have the potential for roll-to-roll fabrication process on plastic substrates, but with only a limited carrier mobility of about 1 cm2/V·s (centimeter squared per volt second). The limitations posed by materials and/or substrate process temperature (particularly on plastic) lead to low device performance, restricting devices to low-frequency applications. Therefore, applications that require even modest computation, control, or communication functions cannot be addressed by the existing TFT technology.
Individual semiconductor nanowires (NWs) and single walled carbon nanotubes can be used to fabricate nanoscale field effect transistors (FETs) with electronic performance comparable to and in some case exceeding that of the highest-quality single-crystal materials. In particular, carrier mobility of 300 cm2/V·s has been demonstrated for p-Si NWs, 2000-4000 cm2/V·s for n-indium InP NWs and up to 20,000 cm2/V·s for single walled carbon nanotubes. These nano-FETs are extending Moore's law toward the molecular level. They are, however, currently difficult to implement for production-scale nanoelectronics due to the complexity and limited scalability of the device fabrication processes.
Accordingly, what is needed are higher performance conductive or semiconductive materials and devices, and methods and systems for producing lower-cost, high performance electronic devices and components.
Furthermore, what is needed are high performance TFTs that can be applied to plastics and other substrates requiring low process temperatures.
What is also needed is a production scalable method for fabrication of nanoscale semiconductor devices than can be used as high performance TFTs.
BRIEF SUMMARY OF THE INVENTION
Methods, systems, and apparatuses for an electronic substrate having one or more semiconductor devices formed thereon is described. A thin film of semiconductor nanowires is formed on a substrate. The thin film of nanowires is formed to have a sufficient density of nanowires to achieve an operational current level. A plurality of semiconductor regions are defined in the thin film of nanowires. Contacts are formed at the semiconductor device regions to thereby provide electrical connectivity to the plurality of semiconductor devices.
In a first aspect of the present invention, a semiconductor device is formed. A plurality of nanowires are deposited onto a substrate in a thin film. First and second electrical contacts are formed on the substrate. At least one of the nanowires couples the first electrical contact to the second electrical contact. In aspects of the present invention, the deposited nanowires can be semiconducting, magnetic, ferroelectric, thermoelectric, piezoelectric, metallic or transition metal oxide nanowires.
In another aspect of the present invention, a thin film for use in one or more semiconductor devices is fabricated. A first plurality of nanowires that are p-doped are formed. A second plurality of nanowires that are n-doped are formed. The first plurality of nanowires and second plurality of nanowires are deposited onto a substrate to form a thin film of nanowires that includes n-doped and p-doped nanowires. The thin film of nanowires exhibits characteristics of both n-doped and p-doped nanowires.
In another aspect of the present invention, an electrical device is formed incorporating nanowire heterostructures. A plurality of nanowires are formed so that each nanowire has along its long axis at least one first portion doped with a first dopant and at least one second portion doped with a second dopant. Each nanowire has a spacing between consecutive junctions of the first and second portions substantially equal to a first distance. A pair of electrical contacts are formed on the substrate. A distance between the electrical contacts is approximately equal to the first distance. The plurality of nanowires are deposited onto the substrate. At least one nanowire of the plurality of nanowires couples the first electrical contact to the second electrical contact.
In another aspect of the present invention, a light emitting thin film is fabricated incorporating nanowire heterostructures. At least one light emitting semiconductor material. A plurality of nanowires are formed from the selected at least one light emitting semiconductor material. Each nanowire is doped so that each nanowire includes at least one P-N junction. The plurality of nanowires are deposited onto a substrate.
In still another aspect of the present invention, nanowires are positioned on a target surface. A first surface of a flow mask is mated with the target surface such that at least one channel formed in the first surface of the flow mask covers a portion of the target surface. A liquid that contains a plurality of nanowires is flowed through the at least one channel. Nanowires contained in the liquid flowing through the at least one channel are permitted to become positioned on the portion of the target surface covered by the at least one channel.
In still another aspect of the present invention, nanowires are applied to a target surface. A solution source provides a nanowire solution. The nanowire solution comprises a liquid containing a plurality of nanowires. A nozzle is coupled to the solution source. The nozzle has at least one output opening. The nozzle directs the nanowire solution through the output opening(s) onto the target surface. The nanowires of the nanowire solution are directed onto the target surface to be aligned on said target surface substantially parallel to each other, or to be randomly oriented with respect to each other.
In still another aspect of the present invention, conducting nanowires having high mobility of electrons are designed. A semiconductor material is selected. A maximum diameter for a nanowire made from the selected semiconductor material that provides substantial quantum confinement of electrons is determined.
In an example aspect, the diameter is determined by calculating the maximum diameter as follows:
themaximumdiameter=NkbT(8.9)ℏ22meff
wherein:
h=Planck's constant=4.14×10−15eV-sec;
meff=effective mass of the selected semiconductor material;
N=a predetermined factor;
kb=Boltzmann's constant=8.62×10−5eV/° K; and
T=operating temperature;wherein at room temperature, kbT=0.0259 eV.
In still another aspect of the present invention, nanowires are configured to use electrons as conducting carriers to substantially reduce or entirely eliminate phonon scattering of electrons in the nanowires. In one aspect, the nanowires are doped with an n-type dopant material to be configured to use electrons as conducting carriers. In another aspect, the nanowires are doped with an p-type dopant material. The nanowires are operated in an inversion mode by applying a sufficient bias voltage to a thin film of the nanowires so that electrons are used as conducting carriers.
In still another aspect of the present invention, nanowires having reduced surface scattering are fabricated. A semiconductor material is selected. A plurality of nanowires are formed from the selected semiconductor material. A circumferential surface of each nanowire of the plurality of nanowires is coated with an insulating layer.
In still another aspect of the present invention, nanowires having reduced surface scattering are fabricated. A semiconductor material is selected. A plurality of nanowires are formed from the selected semiconductor material. Each nanowire of the plurality of nanowires is doped so that each nanowire comprises a core-shell structure. The shell is a doped outer layer of each nanowire surrounding a respective core. Carriers of each nanowire are thereby caused to be substantially confined to the core during operation.
In a further aspect, the present invention is directed to thin film transistors using nanowires, nanorods, or nanoribbons, and to production scalable methods for producing such transistors on a variety of substrates. In particular, an entirely new concept of macroelectronics has been developed by using oriented semiconductor nanowire or nanoribbon thin films to produce thin film transistors (TFTs) with the conducting channel parallel to the wire/ribbon axis. These new TFTs have a conducting channel formed by multiple single crystal nanowires in parallel (like a log bridge) or a single crystal nanoribbon, which crosses all the way from source to drain electrode for high carrier mobility.
In another aspect of the present invention, a NW-TFT fabrication method is provided in which a high-temperature active semiconductor materials synthesis process (e.g., used to form nanowires or nanoribbons) is carried out before the active semiconductor materials are applied to a device substrate. Subsequently, the formed NW-TFTs are applied to the device substrate via a solution assembly process, providing a general technique for applying any semiconductor material to any substrate type, including a plastic substrate.
According to aspects of the invention, both p-channel and n-channel TFTs can be formed. In an example aspect, a complementary inverter is described herein that is assembled from p-channel and n-channel TFTs using a combination of nanowires and nanoribbons.
Systems and methods to further improve performance are described herein, according to further aspects of the present invention. For example, aspects of the present invention allow NW-TFT performance to match or exceed that of bulk single crystal materials. In an example aspect, by fabricating novel core-shell NW structures and fully exploiting quantum electronic effects at reduced dimensions, carrier mobility can be enhanced to exceed that of bulk single crystal materials. In addition, approaches to fabricating NW-TFTs, according to aspects of the present invention, represent a general platform for a variety of macroelectronic applications. In aspects of the present invention, NWs made of optically active materials with various bandgaps are used to produce high performance, optically active thin films for multiple color solid-state light emitting diode (LED) displays. Furthermore, according to aspects of the present invention, NW-TFTs can be deposited from solution onto large area substrates using low-cost, low-temperature processes including micro-contact or ink-jet printing technology, for example.
In another aspect of this invention, electrical devices can be formed using a structure that includes multiple nanowire thin film layers. A first plurality of nanowires are deposited on a substrate to form a first nanowire thin film layer. A second plurality of nanowires are deposited on the first nanowire thin film layer to form a second nanowire thin film layer. Junctions, such as p-n junctions, are thereby formed at the cross points between the nanowires of the first and second thin film layers. Contacts can be formed to create electrical devices based on the properties of the junctions. Nanowires of the first thin film layer are preferably aligned parallel to each other, and nanowires of the second thin film layer are preferably aligned parallel to each other. However, in alternative aspects, the nanowires of the first and/or second thin film layers can be randomly oriented.
In another aspect of this invention, an electrical device is formed that includes a hybrid nanowire-single crystal semiconductor structure. A single-crystal semiconductor strip/thin film is formed. A plurality of nanowires are deposited on the top of the strip. Junctions, such as p-n junctions, are formed at the cross points between the nanowires and the single crystal semiconductor strip. Contacts can be formed to create electrical devices based on the properties of these junctions. The nanowires of the plurality of nanowires are preferably aligned parallel to each other, but can alternatively be randomly oriented.
In another aspect of the present invention, an electrical device is formed that includes a hybrid nanowire-amorphous/polycrystalline semiconductor structure. An amorphous or polycrystalline semiconductor thin film is deposited on a substrate. A plurality of nanowires are deposited on the thin film pattern. Junctions, such as p-n junctions, are formed at the cross points between the nanowires and the amorphous/polycrystalline semiconductor thin film pattern. Contacts can be formed to create electrical devices based on the properties of these junctions. The nanowires of the plurality of nanowires are preferably aligned parallel to each other, but can alternatively be randomly oriented.
In another aspect of the present invention, semiconductor nanowires emitting red, green and blue light in a predetermined ratio can be mixed in a solution. The wire mixture is flowed across a single-crystal, amorphous, or polycrystalline semiconductor strip/thin film. Contacts are formed to create a light emitting electrical device. Depending on the mixture of light emitting nanowires, any color of light can be emitted by the light emitting electrical device, including white light.
Thus, according to aspects of the present invention, nanowire, nanorod, nanoribbon, and nanotube thin films enable a variety of new capabilities. In aspects, these include: moving microelectronics from single crystal substrates to glass and plastic substrates; integrating macroelectronics, microelectronics and nanoelectronics at the device level; and, integrating different semiconductor materials on a single substrate. These aspects of the present invention impact a broad range of existing applications, from flat-panel displays to image sensor arrays, and enable a whole new range of universal flexible, wearable, disposable electronics for computing, storage and communication.
These and other objects, advantages and features will become readily apparent in view of the following detailed description of the invention.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: The following application is related to the grandparent patent U.S. Pat. No. 7,067,867, has the same filing date as the grandparent patent, and is herein incorporated by reference in its entirety:
“Integrated Displays Using Nanowire Transistors,” Atty. Dkt. No. 2132.0080001, Ser. No. 10/673,669, now U.S. Pat. No. 7,102,605.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor devices, and more particularly, to the use of thin films of nanowires in semiconductor devices.
2. Background Art
An interest exists in industry in developing low cost electronics, and in particular, in developing low cost, large area electronic devices. Availability of such large area electronic devices could revolutionize a variety of technology areas, ranging from civil to military applications. Example applications for such devices include driving circuitry for active matrix liquid crystal displays (LCDs) and other types of matrix displays, smart libraries, credit cards, radio-frequency identification tags for smart price and inventory tags, security screening/surveillance or highway traffic monitoring systems, large area sensor arrays, and the like.
The advancement of electronics has been moving towards two extremes in terms of physical scale. Rapid miniaturization of microelectronics according to Moore's law has led to increases in computing power while at the same time enabling reductions in cost. At the same time, progress has been made in the area of macroelectronics, in which electronic devices are integrated over large area substrates (e.g., having sizes measured in square meters). Current macroelectronics are primarily based on amorphous silicon (a-Si) or polycrystalline silicon (p-Si) thin film transistors (TFTs) on glass, and are finding important applications in various areas, including flat panel display (FPD), solar cells, image sensor arrays and digital x-ray imagers.
The current technology, however, is limited in what applications to which it can be applied. For example, there has been growing interest in the use of plastic as a substrate for macroelectronics due to various beneficial attributes of plastic, including flexibility, shock resistance, low weight, and low cost. However, the fabrication of high performance TFTs on plastics is difficult because process steps must be carried out below the glass transition temperature of the plastic. Significant efforts have been devoted to search for new materials (such as organics and organic-inorganic hybrids) or new fabrication strategies suitable for TFTs on plastics, but only with limited success. Organic TFTs have the potential for roll-to-roll fabrication process on plastic substrates, but with only a limited carrier mobility of about 1 cm2/V·s (centimeter squared per volt second). The limitations posed by materials and/or substrate process temperature (particularly on plastic) lead to low device performance, restricting devices to low-frequency applications. Therefore, applications that require even modest computation, control, or communication functions cannot be addressed by the existing TFT technology.
Individual semiconductor nanowires (NWs) and single walled carbon nanotubes can be used to fabricate nanoscale field effect transistors (FETs) with electronic performance comparable to and in some case exceeding that of the highest-quality single-crystal materials. In particular, carrier mobility of 300 cm2/V·s has been demonstrated for p-Si NWs, 2000-4000 cm2/V·s for n-indium InP NWs and up to 20,000 cm2/V·s for single walled carbon nanotubes. These nano-FETs are extending Moore's law toward the molecular level. They are, however, currently difficult to implement for production-scale nanoelectronics due to the complexity and limited scalability of the device fabrication processes.
Accordingly, what is needed are higher performance conductive or semiconductive materials and devices, and methods and systems for producing lower-cost, high performance electronic devices and components.
Furthermore, what is needed are high performance TFTs that can be applied to plastics and other substrates requiring low process temperatures.
What is also needed is a production scalable method for fabrication of nanoscale semiconductor devices than can be used as high performance TFTs.
BRIEF SUMMARY OF THE INVENTION
Methods, systems, and apparatuses for an electronic substrate having one or more semiconductor devices formed thereon is described. A thin film of semiconductor nanowires is formed on a substrate. The thin film of nanowires is formed to have a sufficient density of nanowires to achieve an operational current level. A plurality of semiconductor regions are defined in the thin film of nanowires. Contacts are formed at the semiconductor device regions to thereby provide electrical connectivity to the plurality of semiconductor devices.
In a first aspect of the present invention, a semiconductor device is formed. A plurality of nanowires are deposited onto a substrate in a thin film. First and second electrical contacts are formed on the substrate. At least one of the nanowires couples the first electrical contact to the second electrical contact. In aspects of the present invention, the deposited nanowires can be semiconducting, magnetic, ferroelectric, thermoelectric, piezoelectric, metallic or transition metal oxide nanowires.
In another aspect of the present invention, a thin film for use in one or more semiconductor devices is fabricated. A first plurality of nanowires that are p-doped are formed. A second plurality of nanowires that are n-doped are formed. The first plurality of nanowires and second plurality of nanowires are deposited onto a substrate to form a thin film of nanowires that includes n-doped and p-doped nanowires. The thin film of nanowires exhibits characteristics of both n-doped and p-doped nanowires.
In another aspect of the present invention, an electrical device is formed incorporating nanowire heterostructures. A plurality of nanowires are formed so that each nanowire has along its long axis at least one first portion doped with a first dopant and at least one second portion doped with a second dopant. Each nanowire has a spacing between consecutive junctions of the first and second portions substantially equal to a first distance. A pair of electrical contacts are formed on the substrate. A distance between the electrical contacts is approximately equal to the first distance. The plurality of nanowires are deposited onto the substrate. At least one nanowire of the plurality of nanowires couples the first electrical contact to the second electrical contact.
In another aspect of the present invention, a light emitting thin film is fabricated incorporating nanowire heterostructures. At least one light emitting semiconductor material. A plurality of nanowires are formed from the selected at least one light emitting semiconductor material. Each nanowire is doped so that each nanowire includes at least one P-N junction. The plurality of nanowires are deposited onto a substrate.
In still another aspect of the present invention, nanowires are positioned on a target surface. A first surface of a flow mask is mated with the target surface such that at least one channel formed in the first surface of the flow mask covers a portion of the target surface. A liquid that contains a plurality of nanowires is flowed through the at least one channel. Nanowires contained in the liquid flowing through the at least one channel are permitted to become positioned on the portion of the target surface covered by the at least one channel.
In still another aspect of the present invention, nanowires are applied to a target surface. A solution source provides a nanowire solution. The nanowire solution comprises a liquid containing a plurality of nanowires. A nozzle is coupled to the solution source. The nozzle has at least one output opening. The nozzle directs the nanowire solution through the output opening(s) onto the target surface. The nanowires of the nanowire solution are directed onto the target surface to be aligned on said target surface substantially parallel to each other, or to be randomly oriented with respect to each other.
In still another aspect of the present invention, conducting nanowires having high mobility of electrons are designed. A semiconductor material is selected. A maximum diameter for a nanowire made from the selected semiconductor material that provides substantial quantum confinement of electrons is determined.
In an example aspect, the diameter is determined by calculating the maximum diameter as follows:
themaximumdiameter=NkbT(8.9)ℏ22meff
wherein:
h=Planck's constant=4.14×10−15eV-sec;
meff=effective mass of the selected semiconductor material;
N=a predetermined factor;
kb=Boltzmann's constant=8.62×10−5eV/° K; and
T=operating temperature;wherein at room temperature, kbT=0.0259 eV.
In still another aspect of the present invention, nanowires are configured to use electrons as conducting carriers to substantially reduce or entirely eliminate phonon scattering of electrons in the nanowires. In one aspect, the nanowires are doped with an n-type dopant material to be configured to use electrons as conducting carriers. In another aspect, the nanowires are doped with an p-type dopant material. The nanowires are operated in an inversion mode by applying a sufficient bias voltage to a thin film of the nanowires so that electrons are used as conducting carriers.
In still another aspect of the present invention, nanowires having reduced surface scattering are fabricated. A semiconductor material is selected. A plurality of nanowires are formed from the selected semiconductor material. A circumferential surface of each nanowire of the plurality of nanowires is coated with an insulating layer.
In still another aspect of the present invention, nanowires having reduced surface scattering are fabricated. A semiconductor material is selected. A plurality of nanowires are formed from the selected semiconductor material. Each nanowire of the plurality of nanowires is doped so that each nanowire comprises a core-shell structure. The shell is a doped outer layer of each nanowire surrounding a respective core. Carriers of each nanowire are thereby caused to be substantially confined to the core during operation.
In a further aspect, the present invention is directed to thin film transistors using nanowires, nanorods, or nanoribbons, and to production scalable methods for producing such transistors on a variety of substrates. In particular, an entirely new concept of macroelectronics has been developed by using oriented semiconductor nanowire or nanoribbon thin films to produce thin film transistors (TFTs) with the conducting channel parallel to the wire/ribbon axis. These new TFTs have a conducting channel formed by multiple single crystal nanowires in parallel (like a log bridge) or a single crystal nanoribbon, which crosses all the way from source to drain electrode for high carrier mobility.
In another aspect of the present invention, a NW-TFT fabrication method is provided in which a high-temperature active semiconductor materials synthesis process (e.g., used to form nanowires or nanoribbons) is carried out before the active semiconductor materials are applied to a device substrate. Subsequently, the formed NW-TFTs are applied to the device substrate via a solution assembly process, providing a general technique for applying any semiconductor material to any substrate type, including a plastic substrate.
According to aspects of the invention, both p-channel and n-channel TFTs can be formed. In an example aspect, a complementary inverter is described herein that is assembled from p-channel and n-channel TFTs using a combination of nanowires and nanoribbons.
Systems and methods to further improve performance are described herein, according to further aspects of the present invention. For example, aspects of the present invention allow NW-TFT performance to match or exceed that of bulk single crystal materials. In an example aspect, by fabricating novel core-shell NW structures and fully exploiting quantum electronic effects at reduced dimensions, carrier mobility can be enhanced to exceed that of bulk single crystal materials. In addition, approaches to fabricating NW-TFTs, according to aspects of the present invention, represent a general platform for a variety of macroelectronic applications. In aspects of the present invention, NWs made of optically active materials with various bandgaps are used to produce high performance, optically active thin films for multiple color solid-state light emitting diode (LED) displays. Furthermore, according to aspects of the present invention, NW-TFTs can be deposited from solution onto large area substrates using low-cost, low-temperature processes including micro-contact or ink-jet printing technology, for example.
In another aspect of this invention, electrical devices can be formed using a structure that includes multiple nanowire thin film layers. A first plurality of nanowires are deposited on a substrate to form a first nanowire thin film layer. A second plurality of nanowires are deposited on the first nanowire thin film layer to form a second nanowire thin film layer. Junctions, such as p-n junctions, are thereby formed at the cross points between the nanowires of the first and second thin film layers. Contacts can be formed to create electrical devices based on the properties of the junctions. Nanowires of the first thin film layer are preferably aligned parallel to each other, and nanowires of the second thin film layer are preferably aligned parallel to each other. However, in alternative aspects, the nanowires of the first and/or second thin film layers can be randomly oriented.
In another aspect of this invention, an electrical device is formed that includes a hybrid nanowire-single crystal semiconductor structure. A single-crystal semiconductor strip/thin film is formed. A plurality of nanowires are deposited on the top of the strip. Junctions, such as p-n junctions, are formed at the cross points between the nanowires and the single crystal semiconductor strip. Contacts can be formed to create electrical devices based on the properties of these junctions. The nanowires of the plurality of nanowires are preferably aligned parallel to each other, but can alternatively be randomly oriented.
In another aspect of the present invention, an electrical device is formed that includes a hybrid nanowire-amorphous/polycrystalline semiconductor structure. An amorphous or polycrystalline semiconductor thin film is deposited on a substrate. A plurality of nanowires are deposited on the thin film pattern. Junctions, such as p-n junctions, are formed at the cross points between the nanowires and the amorphous/polycrystalline semiconductor thin film pattern. Contacts can be formed to create electrical devices based on the properties of these junctions. The nanowires of the plurality of nanowires are preferably aligned parallel to each other, but can alternatively be randomly oriented.
In another aspect of the present invention, semiconductor nanowires emitting red, green and blue light in a predetermined ratio can be mixed in a solution. The wire mixture is flowed across a single-crystal, amorphous, or polycrystalline semiconductor strip/thin film. Contacts are formed to create a light emitting electrical device. Depending on the mixture of light emitting nanowires, any color of light can be emitted by the light emitting electrical device, including white light.
Thus, according to aspects of the present invention, nanowire, nanorod, nanoribbon, and nanotube thin films enable a variety of new capabilities. In aspects, these include: moving microelectronics from single crystal substrates to glass and plastic substrates; integrating macroelectronics, microelectronics and nanoelectronics at the device level; and, integrating different semiconductor materials on a single substrate. These aspects of the present invention impact a broad range of existing applications, from flat-panel displays to image sensor arrays, and enable a whole new range of universal flexible, wearable, disposable electronics for computing, storage and communication.
These and other objects, advantages and features will become readily apparent in view of the following detailed description of the invention.
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7792903 | FIELD OF THE INVENTION
The present invention relates to online services and communications tools and, more particularly, to identity management in social networks.
BACKGROUND OF THE INVENTION
In its short history, Internet usage has been mainly driven by portals and search engines, such as Yahoo! and Google. Recently, the rapid growth of social networking sites, such as MySpace and Facebook, has revealed a new trend of Internet usage. Social networking generally relates to services and tools that help users maintain and expand their circles of friends usually by exploiting existing relationships. Social networking sites have shown potential to become the places on the Internet where many people spend most of their time, thus making these sites the main entry point for online activity. Often times, these social networking sites can become the focal point of sharing information, such as links, multimedia, music, and the like.
In general, social networking sites and other online services of the Internet offer a mix of features and tools, such as message boards, games, journals or web logs (“blogs”). Many of these sites try to build communities around multi-media or popular culture, such as television, film, music, etc. These sites and their features are designed to keep users clicking on advertising-supported pages of the site. Thus, the known social networking sites employ a closed platform of services that attempt to keep their user-base captive to the site.
Unfortunately, it can be difficult for users to maintain their multiplicity of accounts for their social networks. For example, users can have multiple profiles at multiple sites for their music, email, instant messaging, etc. However, most users eventually do not keep up with all of their accounts. For example, many users have four or five e-mail addresses, but essentially may use only one or two of them.
In addition, the Internet is crowded with a large number of social networking sites and sharing tools. For example, the recent supremacy of iTunes has triggered a plethora of music service offerings. As another example, the recent success of YouTube and Google Video has sparked an explosion of video-sharing sites.
Unfortunately, due to their current business model, the known social network sites are vulnerable to spammers and other forms of fraud. Thus, many closed social networking sites will likely become abandoned or a major hassle for users to maintain.
Accordingly, it may be desirable to provide methods and systems that serve as an open platform for users to maintain their personas across a plurality of social networking sites and online services. It may also be desirable to provide methods and systems that serve as an open overlay that serves as a consistent context by which users interact with social networking sites and online services.
SUMMARY OF THE INVENTION
In accordance with one feature of the present invention, a method of forming a social network of users is provided. It is determined when a user has invited a new user to join the social network. A temporary group is formed that includes the new user in response to the invitation. Information is provided to the temporary group that indicates existing groups of the social network. An existing group is selected based on input received from the new user. Information is then distributed about the new user among users of the existing group selected by the new user.
In accordance with another feature of the present invention, a method of forming a social network of users is provided. Multiple invitations to a new user are identified. The new user is assigned a temporary identity. The temporary identity for the new user is distributed until the new user completes registration into the social network. All inviters of the new user are notified when the new user completes registration. The temporary identity is then converted into a permanent identity when the new user completes registration into the social network.
In accordance with another feature of the present invention, a method of viewing a user's identity in a social network is provided. The user has a plurality of associated identity resources known by only some of the other users in the social network. A request is received from another user to contact the user based on one of associated identity resources of the user. Views of the other user are restricted for the identity of the user to the associated identity resource used by that other user.
Additional features of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention relates to online services and communications tools and, more particularly, to identity management in social networks.
BACKGROUND OF THE INVENTION
In its short history, Internet usage has been mainly driven by portals and search engines, such as Yahoo! and Google. Recently, the rapid growth of social networking sites, such as MySpace and Facebook, has revealed a new trend of Internet usage. Social networking generally relates to services and tools that help users maintain and expand their circles of friends usually by exploiting existing relationships. Social networking sites have shown potential to become the places on the Internet where many people spend most of their time, thus making these sites the main entry point for online activity. Often times, these social networking sites can become the focal point of sharing information, such as links, multimedia, music, and the like.
In general, social networking sites and other online services of the Internet offer a mix of features and tools, such as message boards, games, journals or web logs (“blogs”). Many of these sites try to build communities around multi-media or popular culture, such as television, film, music, etc. These sites and their features are designed to keep users clicking on advertising-supported pages of the site. Thus, the known social networking sites employ a closed platform of services that attempt to keep their user-base captive to the site.
Unfortunately, it can be difficult for users to maintain their multiplicity of accounts for their social networks. For example, users can have multiple profiles at multiple sites for their music, email, instant messaging, etc. However, most users eventually do not keep up with all of their accounts. For example, many users have four or five e-mail addresses, but essentially may use only one or two of them.
In addition, the Internet is crowded with a large number of social networking sites and sharing tools. For example, the recent supremacy of iTunes has triggered a plethora of music service offerings. As another example, the recent success of YouTube and Google Video has sparked an explosion of video-sharing sites.
Unfortunately, due to their current business model, the known social network sites are vulnerable to spammers and other forms of fraud. Thus, many closed social networking sites will likely become abandoned or a major hassle for users to maintain.
Accordingly, it may be desirable to provide methods and systems that serve as an open platform for users to maintain their personas across a plurality of social networking sites and online services. It may also be desirable to provide methods and systems that serve as an open overlay that serves as a consistent context by which users interact with social networking sites and online services.
SUMMARY OF THE INVENTION
In accordance with one feature of the present invention, a method of forming a social network of users is provided. It is determined when a user has invited a new user to join the social network. A temporary group is formed that includes the new user in response to the invitation. Information is provided to the temporary group that indicates existing groups of the social network. An existing group is selected based on input received from the new user. Information is then distributed about the new user among users of the existing group selected by the new user.
In accordance with another feature of the present invention, a method of forming a social network of users is provided. Multiple invitations to a new user are identified. The new user is assigned a temporary identity. The temporary identity for the new user is distributed until the new user completes registration into the social network. All inviters of the new user are notified when the new user completes registration. The temporary identity is then converted into a permanent identity when the new user completes registration into the social network.
In accordance with another feature of the present invention, a method of viewing a user's identity in a social network is provided. The user has a plurality of associated identity resources known by only some of the other users in the social network. A request is received from another user to contact the user based on one of associated identity resources of the user. Views of the other user are restricted for the identity of the user to the associated identity resource used by that other user.
Additional features of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.
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7701100 | Applicant claims, under 35 U.S.C. §§120 and 365, the benefit of priority of the filing date of May 3, 2005 of a Patent Cooperation Treaty patent application, copy attached, Serial Number PCT/EP2005/004767, filed on the aforementioned date, the entire contents of which are incorporated herein by reference, wherein Patent Cooperation Treaty patent application Serial Number PCT/EP2005/004767 was not published under PCT Article 21(2) in English.
Applicant claims, under 35 U.S.C. §119, the benefit of priority of the filing date of Jun. 2, 2004 of a German patent application, copy attached, Serial Number 10 2004 027 036.8, filed on the aforementioned date, the entire contents of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a synchronous motor that employs magnets.
2. Description of the Related Art
Synchronous motors in the form of linear or rotary direct drive mechanisms play an increasingly important role in technology. Such direct drive mechanisms do not require any mechanical transmissions, they themselves move the useful load.
An example of such a direct drive mechanism is described in EP 0 793 870 B1. A stator supports teeth wound with coils, a rotor supports evenly arranged permanent magnets. These magnets are customarily glued onto a magnetic flux conductor. For certain applications, for example in connection with a turntable of a machine tool, very high numbers of revolutions are demanded of such a direct drive. Because of centrifugal forces, it is possible that the adherence of such a magnet to its substrate becomes detached at high numbers of revolutions. Waste heat occurring at high numbers of revolutions heats the motor excessively and in this way further contributes to the fact that it is no longer sufficient to glue the magnets on when encountering high numbers of revolutions.
Eddy currents are also responsible for heating the motor. Therefore the coils of the stator are wound on a laminated core, whose individual laminations are insulated against each other. The flux conductor of the rotor is occasionally designed in the form of a laminated core. For stopping eddy currents in the magnets themselves, JP04079741A has already proposed segmented magnets for motors, which are put together from several layers or segments which are insulated against each other. However, at high numbers of revolutions these steps alone do no result in a sufficiently stable connection between the magnet and rotor.
It has also already been proposed to clamp the magnets in addition to gluing. DE 100 53 694 A1 describes such a synchronous motor. Clamping of the magnets in place is achieved by clamping elements alt ached to the front of the rotor, which initially have individual clamping claws, and clamping the magnets in place on the rotor is achieved by bending the clamping claws in an axial orientation. However, additional components are required for this solution, moreover, the magnets are only clamped in place at the ends of the rotor.
SUMMARY AND OBJECTS OF THE INVENTION
It is therefore an object of the present invention to disclose a synchronous motor whose magnets are well protected against detachment from the rotor by clamping and which can be simply produced.
This object is attained by a synchronous motor having a rotor that includes: a body, a plurality of magnets positioned on the body of the rotor. For each of the plurality of magnets, a corresponding clamping element fixes a corresponding one of the plurality of magnets on the body of the rotor, wherein the corresponding clamping element includes a web arranged between the corresponding one of the plurality of magnets and the body of the rotor. The synchronous motor further including a stator including a coil that receives an electric current and generates a magnetic field that generates a torque on the rotor.
A synchronous motor with a rotor is proposed, on which magnets have been fixed by clamping elements, wherein the clamping elements are embodied in the form of webs which are arranged on the rotor between the magnets. Since the webs substantially extend over the entire axial length of the rotor, the magnets are well fastened to the rotor. This is of particularly great importance in case where magnets are employed which are segmented in the axial direction in order to reduce eddy current losses, and therefore heat generation in the magnets themselves.
Further advantages, as well as details of the present invention ensue from the following description of a preferred embodiment by the drawing figures. Shown here are in:
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: Applicant claims, under 35 U.S.C. §§120 and 365, the benefit of priority of the filing date of May 3, 2005 of a Patent Cooperation Treaty patent application, copy attached, Serial Number PCT/EP2005/004767, filed on the aforementioned date, the entire contents of which are incorporated herein by reference, wherein Patent Cooperation Treaty patent application Serial Number PCT/EP2005/004767 was not published under PCT Article 21(2) in English.
Applicant claims, under 35 U.S.C. §119, the benefit of priority of the filing date of Jun. 2, 2004 of a German patent application, copy attached, Serial Number 10 2004 027 036.8, filed on the aforementioned date, the entire contents of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a synchronous motor that employs magnets.
2. Description of the Related Art
Synchronous motors in the form of linear or rotary direct drive mechanisms play an increasingly important role in technology. Such direct drive mechanisms do not require any mechanical transmissions, they themselves move the useful load.
An example of such a direct drive mechanism is described in EP 0 793 870 B1. A stator supports teeth wound with coils, a rotor supports evenly arranged permanent magnets. These magnets are customarily glued onto a magnetic flux conductor. For certain applications, for example in connection with a turntable of a machine tool, very high numbers of revolutions are demanded of such a direct drive. Because of centrifugal forces, it is possible that the adherence of such a magnet to its substrate becomes detached at high numbers of revolutions. Waste heat occurring at high numbers of revolutions heats the motor excessively and in this way further contributes to the fact that it is no longer sufficient to glue the magnets on when encountering high numbers of revolutions.
Eddy currents are also responsible for heating the motor. Therefore the coils of the stator are wound on a laminated core, whose individual laminations are insulated against each other. The flux conductor of the rotor is occasionally designed in the form of a laminated core. For stopping eddy currents in the magnets themselves, JP04079741A has already proposed segmented magnets for motors, which are put together from several layers or segments which are insulated against each other. However, at high numbers of revolutions these steps alone do no result in a sufficiently stable connection between the magnet and rotor.
It has also already been proposed to clamp the magnets in addition to gluing. DE 100 53 694 A1 describes such a synchronous motor. Clamping of the magnets in place is achieved by clamping elements alt ached to the front of the rotor, which initially have individual clamping claws, and clamping the magnets in place on the rotor is achieved by bending the clamping claws in an axial orientation. However, additional components are required for this solution, moreover, the magnets are only clamped in place at the ends of the rotor.
SUMMARY AND OBJECTS OF THE INVENTION
It is therefore an object of the present invention to disclose a synchronous motor whose magnets are well protected against detachment from the rotor by clamping and which can be simply produced.
This object is attained by a synchronous motor having a rotor that includes: a body, a plurality of magnets positioned on the body of the rotor. For each of the plurality of magnets, a corresponding clamping element fixes a corresponding one of the plurality of magnets on the body of the rotor, wherein the corresponding clamping element includes a web arranged between the corresponding one of the plurality of magnets and the body of the rotor. The synchronous motor further including a stator including a coil that receives an electric current and generates a magnetic field that generates a torque on the rotor.
A synchronous motor with a rotor is proposed, on which magnets have been fixed by clamping elements, wherein the clamping elements are embodied in the form of webs which are arranged on the rotor between the magnets. Since the webs substantially extend over the entire axial length of the rotor, the magnets are well fastened to the rotor. This is of particularly great importance in case where magnets are employed which are segmented in the axial direction in order to reduce eddy current losses, and therefore heat generation in the magnets themselves.
Further advantages, as well as details of the present invention ensue from the following description of a preferred embodiment by the drawing figures. Shown here are in:
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7827962 | CROSS-REFERENCE TO RELATED APPLICATION
This application is a 35 USC 371 application of PCT/EP 2006/069147 filed on Nov. 30, 2006.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a fuel injection system for a multi-cylinder internal combustion engine.
2. Description of the Prior Art
DE 100 60 785 A1 relates to a fuel injection apparatus equipped with a high-pressure fuel accumulator. Branch lines can be screwed to the high-pressure fuel accumulator, each containing a throttle for reducing pressure pulsations in the fuel injection apparatus. The throttles are each composed of a tube element that is either mounted to an end of the branch line to which a connecting head is attached or is accommodated inside the branch line, close to that end. Throttle elements in high-pressure accumulators (common rails) are used for pressure wave damping inside the body of the high-pressure accumulator. To achieve this, for example cylindrical throttle elements are press-fitted into connecting bores of the high-pressure accumulator (common rail) that lead to the individual fuel injectors or also to the high-pressure pump acting on the high-pressure accumulator. The throttle elements press-fitted into the connecting bores serve to improve the damping of pressure pulsations inside the fuel injection system, thus permitting an increase in the pressure-tightness of the individual components.
DE 20 2004 019 820.7 relates to a fuel injection apparatus for a diesel engine. A fuel injection apparatus includes a high-pressure fuel accumulator and a number of branch lines serving to convey fuel out of the high-pressure fuel accumulator. These branch lines each have a connecting head at their one respective end for connecting the branch line to an associated connection fitting of the high-pressure fuel accumulator, while a throttle is mounted in each of the branch lines. The throttle is embodied in a support element that is mounted in the region of the connecting head by means of attaching elements, which are embodied with the same design as the connecting head and which narrow an internal diameter of the branch line at the two ends of the support element. The throttle is provided in the support element and is embodied in the form of a through bore with a first partial bore and a second partial bore, i.e. it has two stages. During the upsetting of the connecting head, the through bore is protected by a stepped, cylindrical inner mandrel that is inserted into it and is embodied as recoverable. The support element preferably has a cylindrical circumference surface.
In internal combustion engines with six and more cylinders, two high-pressure accumulators are used, each of which supplies fuel to the fuel injectors of the cylinders of a respective cylinder bank. The two high-pressure accumulators (common rails) are connected to each other by a connecting line that provides for a pressure compensation between the high-pressure accumulators. In order to damp the pressure pulsations that occur in the two high-pressure accumulators, it is also possible for a distributor block to be provided. The distributor block is acted on by a high-pressure pump that compresses the fuel to the system pressure and maintains this system pressure in the two high-pressure accumulators. The two high-pressure accumulators are supplied with fuel by the distributor block, which is acted on by the high-pressure pump and in which pulsations are damped.
SUMMARY AND ADVANTAGES OF THE INVENTION
According to the embodiment proposed by the invention, the distributor block, which was previously embodied in the form of a separate component, is integrated into one of the two high-pressure accumulators that supply fuel to the multicylinder internal combustion engine. In particular, this is implemented by integrating a throttle into the cavity of the relevant high-pressure accumulator (common rail). By integrating the throttle into the cavity, which is embodied for example as a bore, of the relevant high-pressure accumulator, the volume of the high-pressure accumulator is divided into two individual volumes. The smaller of the two individual volumes of the relevant high-pressure accumulator (common rail) fulfills the function of the distributor block that was previously embodied in the form of a separate component. The smaller volume of the relevant high-pressure accumulator representing the distributor block is preferably situated at the end of the high-pressure accumulator to which the high-pressure lines are connected, which are connected to the high-pressure pump and supply fuel to the relevant high-pressure accumulator. This high-pressure accumulator into which the distributor block is integrated supplies fuel the other high-pressure accumulator via a connecting line, which has a damping throttle integrated into its end that opens into the other high-pressure accumulator.
On the one hand, the embodiment proposed according to the invention—in which the distributor block, which was previously embodied in the form of a separate component, is integrated into one of the high-pressure accumulators—avoids the use of a bulky separate component between the two high-pressure accumulators so that the fuel injection system proposed according to the invention takes up less space in the cylinder head region of the multicylinder internal combustion engine. In addition, eliminating a separate component that must be embodied as pressure-tight achieves a not insignificant cost advantage. According to the invention, the distributor block integrated into one of the high-pressure accumulators likewise damps pressure fluctuations that can occur in the fuel injection system and is therefore equivalent in function to a distributor block that was previously produced as a separate component.
There are a number of embodiment variations for implementation of the integrated throttle and the resulting division of the high-pressure accumulator volume into two individual volumes:
The integrated throttle can, for example, be embodied in the form of a bore in a diametrical partition wall of the high-pressure accumulator (common rail). According to this embodiment variation, the cavity is delimited by a deep-hole bore introduced into the two ends of the tubular high-pressure accumulator. A throttle equipped with a stepped throttle conduit can then be introduced into the partition wall that separates the two deep-hole bore sections. In a modification of this embodiment variation, the end regions of the deep-hole bores introduced into the two ends of the high-pressure accumulator can also be rounded in order to improve the flow properties of the fuel inside the cavity of the high-pressure accumulator. In another embodiment variation, a continuous cavity, which can be embodied for example in the form of a through bore in the body of the high-pressure accumulator, can have a sleeve-shaped component mounted in it, whose one end, preferably the end oriented toward the middle region of the high-pressure accumulator, has a throttle opening provided in its end surface. This sleeve-shaped insert can be mounted in the cavity of the high-pressure accumulator by means of a fitting to which the pressure line from the high-pressure pump is connected. In a modification of this embodiment variation, the connection, which is acted on by the high-pressure pump, and the sleeve, which has a throttle bore at the end and is mounted in the cavity of the high-pressure accumulator, can also be produced in the form of a single insert component that can, for example, be mounted at an end surface in the high-pressure accumulator by means of a biting edge.
In another embodiment variation of the integrated throttle proposed according to the invention, the throttle can also be integrated into the cavity of the high-pressure accumulator in the form of a press-fitted throttle that includes a ring element and a throttle element. According to this embodiment variation, the integrated throttle can also be embodied in the form of a multipart component that includes a ring element and a throttle element. In lieu of a press-fitted throttle that is press-fitted into the cavity of the high-pressure accumulator the integrated throttle can also be embodied in the form of a clamped throttle that is mounted in the cavity of the relevant high-pressure accumulator (common rail) by means of an annular clamping element. According to this embodiment variation, the position of the integrated throttle inside the cavity of the high-pressure accumulator can be selectively chosen so that it is also possible to freely select and freely predetermine the two individual volumes inside the high-pressure accumulator.
In another embodiment variation, the integrated throttle can be embodied in the form of a two-part component that includes a screw part and a threaded part; the threaded part and the screw part both rest against a diametrical step on the inner wall of the cavity of the high-pressure accumulator and are screw-connected to each other. The screw connection integrates the integrated throttle into the cavity of the relevant high-pressure accumulator (common rail).
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SUMMARY: CROSS-REFERENCE TO RELATED APPLICATION
This application is a 35 USC 371 application of PCT/EP 2006/069147 filed on Nov. 30, 2006.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a fuel injection system for a multi-cylinder internal combustion engine.
2. Description of the Prior Art
DE 100 60 785 A1 relates to a fuel injection apparatus equipped with a high-pressure fuel accumulator. Branch lines can be screwed to the high-pressure fuel accumulator, each containing a throttle for reducing pressure pulsations in the fuel injection apparatus. The throttles are each composed of a tube element that is either mounted to an end of the branch line to which a connecting head is attached or is accommodated inside the branch line, close to that end. Throttle elements in high-pressure accumulators (common rails) are used for pressure wave damping inside the body of the high-pressure accumulator. To achieve this, for example cylindrical throttle elements are press-fitted into connecting bores of the high-pressure accumulator (common rail) that lead to the individual fuel injectors or also to the high-pressure pump acting on the high-pressure accumulator. The throttle elements press-fitted into the connecting bores serve to improve the damping of pressure pulsations inside the fuel injection system, thus permitting an increase in the pressure-tightness of the individual components.
DE 20 2004 019 820.7 relates to a fuel injection apparatus for a diesel engine. A fuel injection apparatus includes a high-pressure fuel accumulator and a number of branch lines serving to convey fuel out of the high-pressure fuel accumulator. These branch lines each have a connecting head at their one respective end for connecting the branch line to an associated connection fitting of the high-pressure fuel accumulator, while a throttle is mounted in each of the branch lines. The throttle is embodied in a support element that is mounted in the region of the connecting head by means of attaching elements, which are embodied with the same design as the connecting head and which narrow an internal diameter of the branch line at the two ends of the support element. The throttle is provided in the support element and is embodied in the form of a through bore with a first partial bore and a second partial bore, i.e. it has two stages. During the upsetting of the connecting head, the through bore is protected by a stepped, cylindrical inner mandrel that is inserted into it and is embodied as recoverable. The support element preferably has a cylindrical circumference surface.
In internal combustion engines with six and more cylinders, two high-pressure accumulators are used, each of which supplies fuel to the fuel injectors of the cylinders of a respective cylinder bank. The two high-pressure accumulators (common rails) are connected to each other by a connecting line that provides for a pressure compensation between the high-pressure accumulators. In order to damp the pressure pulsations that occur in the two high-pressure accumulators, it is also possible for a distributor block to be provided. The distributor block is acted on by a high-pressure pump that compresses the fuel to the system pressure and maintains this system pressure in the two high-pressure accumulators. The two high-pressure accumulators are supplied with fuel by the distributor block, which is acted on by the high-pressure pump and in which pulsations are damped.
SUMMARY AND ADVANTAGES OF THE INVENTION
According to the embodiment proposed by the invention, the distributor block, which was previously embodied in the form of a separate component, is integrated into one of the two high-pressure accumulators that supply fuel to the multicylinder internal combustion engine. In particular, this is implemented by integrating a throttle into the cavity of the relevant high-pressure accumulator (common rail). By integrating the throttle into the cavity, which is embodied for example as a bore, of the relevant high-pressure accumulator, the volume of the high-pressure accumulator is divided into two individual volumes. The smaller of the two individual volumes of the relevant high-pressure accumulator (common rail) fulfills the function of the distributor block that was previously embodied in the form of a separate component. The smaller volume of the relevant high-pressure accumulator representing the distributor block is preferably situated at the end of the high-pressure accumulator to which the high-pressure lines are connected, which are connected to the high-pressure pump and supply fuel to the relevant high-pressure accumulator. This high-pressure accumulator into which the distributor block is integrated supplies fuel the other high-pressure accumulator via a connecting line, which has a damping throttle integrated into its end that opens into the other high-pressure accumulator.
On the one hand, the embodiment proposed according to the invention—in which the distributor block, which was previously embodied in the form of a separate component, is integrated into one of the high-pressure accumulators—avoids the use of a bulky separate component between the two high-pressure accumulators so that the fuel injection system proposed according to the invention takes up less space in the cylinder head region of the multicylinder internal combustion engine. In addition, eliminating a separate component that must be embodied as pressure-tight achieves a not insignificant cost advantage. According to the invention, the distributor block integrated into one of the high-pressure accumulators likewise damps pressure fluctuations that can occur in the fuel injection system and is therefore equivalent in function to a distributor block that was previously produced as a separate component.
There are a number of embodiment variations for implementation of the integrated throttle and the resulting division of the high-pressure accumulator volume into two individual volumes:
The integrated throttle can, for example, be embodied in the form of a bore in a diametrical partition wall of the high-pressure accumulator (common rail). According to this embodiment variation, the cavity is delimited by a deep-hole bore introduced into the two ends of the tubular high-pressure accumulator. A throttle equipped with a stepped throttle conduit can then be introduced into the partition wall that separates the two deep-hole bore sections. In a modification of this embodiment variation, the end regions of the deep-hole bores introduced into the two ends of the high-pressure accumulator can also be rounded in order to improve the flow properties of the fuel inside the cavity of the high-pressure accumulator. In another embodiment variation, a continuous cavity, which can be embodied for example in the form of a through bore in the body of the high-pressure accumulator, can have a sleeve-shaped component mounted in it, whose one end, preferably the end oriented toward the middle region of the high-pressure accumulator, has a throttle opening provided in its end surface. This sleeve-shaped insert can be mounted in the cavity of the high-pressure accumulator by means of a fitting to which the pressure line from the high-pressure pump is connected. In a modification of this embodiment variation, the connection, which is acted on by the high-pressure pump, and the sleeve, which has a throttle bore at the end and is mounted in the cavity of the high-pressure accumulator, can also be produced in the form of a single insert component that can, for example, be mounted at an end surface in the high-pressure accumulator by means of a biting edge.
In another embodiment variation of the integrated throttle proposed according to the invention, the throttle can also be integrated into the cavity of the high-pressure accumulator in the form of a press-fitted throttle that includes a ring element and a throttle element. According to this embodiment variation, the integrated throttle can also be embodied in the form of a multipart component that includes a ring element and a throttle element. In lieu of a press-fitted throttle that is press-fitted into the cavity of the high-pressure accumulator the integrated throttle can also be embodied in the form of a clamped throttle that is mounted in the cavity of the relevant high-pressure accumulator (common rail) by means of an annular clamping element. According to this embodiment variation, the position of the integrated throttle inside the cavity of the high-pressure accumulator can be selectively chosen so that it is also possible to freely select and freely predetermine the two individual volumes inside the high-pressure accumulator.
In another embodiment variation, the integrated throttle can be embodied in the form of a two-part component that includes a screw part and a threaded part; the threaded part and the screw part both rest against a diametrical step on the inner wall of the cavity of the high-pressure accumulator and are screw-connected to each other. The screw connection integrates the integrated throttle into the cavity of the relevant high-pressure accumulator (common rail).
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7694365 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a pillow for supporting and fixing the shoulders of an examination subject in the housing of a shoulder coil in a magnetic resonance apparatus.
2. Description of the Prior Art
In magnetic resonance data acquisitions, the shoulders of the subject must be supported and fixed comfortably. Furthermore it is important for a specific distance to be maintained between the inner surface of a shoulder coil and the shoulders, in order to minimize unwanted signals that originate from the subcutaneous fat layer of the shoulders. There have previously been no standardized, commercially produced solutions in order to satisfy the above conditions. Makeshift solutions such as hand towels or foam padding that were not tailored to the shape of the inner surface of the shoulder coil have been used.
The problem is thus that the aforementioned makeshift solutions do not represent uniform, reproducible devices in order to fix the shoulders at a fixed, optimal distance from the inner surface of the shoulder coil.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a device with which the shoulders of a patient can be comfortably supported, fixed and held at a fixed distance from the inner surface of the shoulder coil during a magnetic resonance acquisition.
The above object is achieved in accordance with the invention by a pillow for supporting and fixing the shoulders in the housings of shoulder coils in magnetic resonance apparatuses, that snugly fills the inner area of the shoulder coil with at least three, and preferably four lobes, with and the lobes not laterally overlapping each other in the housing.
The present invention is advantageous for a number of reasons. The basis of the invention is a pillow that enables the comfortable support of the shoulders of patients at a fixed distance from the inner side of the shoulder coil of a magnetic resonance system. The pillow has a unit size that fits all shoulder coil sizes and shoulder sizes. The pillow is thus universally usable and can be industrially produced in a large quantity and in a uniform shape size. Furthermore, the pillow exhibits a good filling factor due to its structure composed of a number of lobes.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a pillow for supporting and fixing the shoulders of an examination subject in the housing of a shoulder coil in a magnetic resonance apparatus.
2. Description of the Prior Art
In magnetic resonance data acquisitions, the shoulders of the subject must be supported and fixed comfortably. Furthermore it is important for a specific distance to be maintained between the inner surface of a shoulder coil and the shoulders, in order to minimize unwanted signals that originate from the subcutaneous fat layer of the shoulders. There have previously been no standardized, commercially produced solutions in order to satisfy the above conditions. Makeshift solutions such as hand towels or foam padding that were not tailored to the shape of the inner surface of the shoulder coil have been used.
The problem is thus that the aforementioned makeshift solutions do not represent uniform, reproducible devices in order to fix the shoulders at a fixed, optimal distance from the inner surface of the shoulder coil.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a device with which the shoulders of a patient can be comfortably supported, fixed and held at a fixed distance from the inner surface of the shoulder coil during a magnetic resonance acquisition.
The above object is achieved in accordance with the invention by a pillow for supporting and fixing the shoulders in the housings of shoulder coils in magnetic resonance apparatuses, that snugly fills the inner area of the shoulder coil with at least three, and preferably four lobes, with and the lobes not laterally overlapping each other in the housing.
The present invention is advantageous for a number of reasons. The basis of the invention is a pillow that enables the comfortable support of the shoulders of patients at a fixed distance from the inner side of the shoulder coil of a magnetic resonance system. The pillow has a unit size that fits all shoulder coil sizes and shoulder sizes. The pillow is thus universally usable and can be industrially produced in a large quantity and in a uniform shape size. Furthermore, the pillow exhibits a good filling factor due to its structure composed of a number of lobes.
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7665936 | The invention concerns a wood drill bit with a cylindrical drilling head and a connecting portion adjoining the drilling head in opposite relationship to the drilling direction for connection to a drive means, wherein the drilling head has at its end a centering tip which is disposed on the longitudinal axis of the drill and which projects in the drilling direction for centering the wood drill bit, at least two main cutters which are arranged diametrically and radially or substantially radially and have main cutting edges, and a part-cylindrical guide bell and adjoining each main cutter is a chip ejection space which is partially open towards the connecting portion.
Wood drill bits of that kind, which are generally known as Forstner drill bits, are designed in particular for drilled holes of large diameters, such as for example for cupboard hinges. The amount of material to be cut away, which is comparatively large as a result, easily gives rise to the generation of a high level of heat in the drilled hole which, amplified when a high feed speed is involved, easily results in charring of material in the bottom of the hole, requires frequent re-sharpening of the cutting edges and ultimately reduces the operating lives of a wood drill bit of that kind. In addition it is necessary to manage a large amount of wood chips and this contributes to an increased drilling pressure in the drilled hole, which in turn can cause an increase in temperature with the above-indicated risks, and in addition increases the risk of easily chipping off wood at a side face of material being drilled, that is remote from the entry side when producing through holes or blind holes. That in turn allows only low feed speeds when performing drilling operations.
For that purpose, DE 299 11 945 U1 puts forward the proposal of breaking the chips over their width by grooves which are formed in the main cutters and which interrupt the main cutting edges, in order thereby to produce narrower wood chips which are easier to transport away, which represents a certain advance in terms of resolving the problem involved.
Therefore the object of the invention is to provide a wood drill bit of the kind set forth in the opening part of this specification, which permits an increased feed speed without its operating lives being reduced at the same time.
According to the invention that object is attained in that the main cutter extends with a radially inwardly disposed portion into the centering tip and the chip ejection space is enlarged into the centering tip by means of a pre-chip ejection groove.
In that case the pre-chip ejection groove is preferably disposed downstream of the respective main cutting edge which has the respective portion, in a direction of drilling rotation. The pre-chip ejection groove can be ground into the centering tip in one working operation together with the portion. In that way the cutting action can be implemented into the centering tip. As mentioned above, when drilling inter alia through resistant material, a drilling pressure can be built up at the bottom of a drilled hole, which can be increased by the material which has been cut away being accumulated or backing up. As a result an increased pressure on the wood drill bit in the drilling direction is necessary to produce the feed, whereby the temperature in the drilled hole can be further increased. Both these factors can increase the amount of wear of the drilling head, necessitate premature re-grinding of the main cutter and thus reduce the service life of the wood drill bit. In addition the risk of the wood splitting away at an exit side of the drilled hole, that is to say a side surface of the drilled hole which is at the rear in the drilling direction, can be increased. As a result material which accumulates at the centering tip when using conventional wood drill bits in the feed procedure can be partially cut away, whereby the drilling pressure is reduced. Furthermore the pressure can be further reduced by the pre-chip ejection groove by virtue of the material being cut away, insofar as the groove enlarges the chip ejection space into which it opens, and insofar as the material can be more easily transported away. Furthermore the area of the centering tip in perpendicular relationship to the drilling direction is reduced, whereby a force which contributes to determining the drilling pressure and with which the centering tip has to be pressed into the material which is still to be cut away in the bottom of the drilled hole in the drilling operation is reduced. The measure according to the invention completely attains the specified object.
Preferably the main cutter extends to close to a drill bit longitudinal axis of the drilling head or to the drill bit longitudinal axis or is extended by a small amount beyond the drill bit longitudinal axis. In that case the main cutter with said portion can be extended at a maximum as far as the side wall or side wall portion of the centering tip, which is beyond the drill bit center in a prolongation of the main cutting edge.
The main cutter can form in the portion a side face in the centering tip, which faces radially outwardly and axially in opposite relationship to the drilling direction. In that way the main cutters can each extend into the centering tip, forming an undercut configuration, and can acquire a cutting action and by virtue of the simultaneous provision of the pre-chip ejection groove, can increase the respectively adjoining chip ejection space into the centering tip. The orientation of the undercut configuration provides that with the rotation of the wood drill bit the centering tip can twist itself virtually in a spiral configuration into the material at the bottom of the drilled hole or can exert a feed force on the wood drill bit in the drilling direction, whereby a necessary external drilling force can be reduced.
In a preferred development of the wood drill bit the chip ejection space adjoining a respective main cutter can be enlarged into the centering tip. In that case allocated to the chip ejection space is also a space which in the drilled hole is delimited by the bottom of the drilled hole and the respective relief surface following a main cutter. Accordingly, by virtue of this measure according to the invention, the relief space behind the main cutters can extend into the centering tip so that the wood chips can already be guided away here into the chip ejection space. In that way once again the drilling pressure can be reduced so that just by virtue thereof the object of the invention can be completely attained. In that respect it is possible to attain an enlargement in part or completely by way of a radially inward enlargement of a relief surface following the respective main cutter.
Preferably the centering tip is of a pyramidal configuration with a base in parallelogram form, wherein sides of the base include an acute first angle and an obtuse second angle and the main cutters are respectively arranged to extend into a region of the centering tip with the acute angle in the base. In that way a free space which is associated with a main cutter and thus the chip ejection space can be enlarged. It is possible for chips which are cut off in the portion of the main cutter in the centering tip to be more easily guided away into the chip ejection space. The consequence of that is in turn that friction and temperature at the bottom of the drilled hole as well as the drilling pressure can be reduced in comparison with a conventional wood drill bit configuration and thus higher feed times and/or service lives are possible so that the object can be attained thereby.
On the geometrical premise that both angles are 180 degrees, the first angle can be between 55 degrees and 85 degrees and the second angle can be between 95 degrees and 125 degrees. Preferably the first angle is between 60 degrees and 80 degrees and the second angle is between 100 degrees and 120 degrees. As an optimum the first angle is 70 degrees and the second angle is 110 degrees. Tests have admittedly shown that here an optimum with the drill bit geometries involved can be achieved with 70° for the first angle and 110° for the second angle. It will be appreciated that it is possible that other angle values can be found to be optimum, with modified drill bit geometries. The diagonals of the base are preferably in mutually perpendicular relationship. That can be afforded if an originally square centering tip is laterally ground away in order to produce the centering tip according to the invention, as will be described in further detail hereinafter.
Preferably the first sides of the base extend approximately in the direction of the main cutters and the second sides of the base extend approximately perpendicularly or perpendicularly to the main cutters. Preferably the first sides are shorter than the second sides. In that respect the first sides and the second sides of the base denote the sides of the centering tip which are notionally afforded from the pyramidal centering tip with a parallelogram as the base and which have not yet been notionally shortened by the portion of the main cutters, which projects into the centering tip. Accordingly a conventional square centering tip can be reduced in its extent in perpendicular relationship to the main cutter so that as a result the main cutters extend further towards the drill bit longitudinal axis and can work freely. Furthermore a lateral flattening of the centering tip, which is effected thereby, can provide that the free space is increased in size in the region of the lateral flattening whereby chips which have been cut away have more available space and can thus reduce the drilling pressure at the bottom of the drilled hole.
The wood drill bit can additionally or solely have a chip divider device for dividing and/or breaking off chips which are to be cut away or which have been cut away by the main cutters in respect of their width over the longitudinal extent of the main cutters, wherein the chip divider device is preferably operative over the radial extent of at least one of the main cutters. In that way the chips can be divided at least once in respect of their chip width at least one of the main cutters over the radial extent thereof so that the chip width of individual chips can be correspondingly reduced. In that way the chips in question can be transported into the chip ejection space in opposite relationship to the drilling direction or the feed direction more easily, and further transported toward the connection portion. The specified object can be completely attained by that feature.
In a development of the wood drill bit at least one of the main cutters can be provided with at least one peak or tip projecting in the drilling direction. In that case the tip can be arranged disposed radially outwardly whereby, similarly to the pre-cutter referred to in greater detail hereinafter, it can cut an outer peripheral circle into the material which is to be cut away. Preferably however the tip is arranged spaced radially inwardly from the outer periphery of the drilling head. That projecting and thus leading tip can thus implement division of the material before the chip is cut away from the bottom of the drilled hole and thereby definedly reduce the chip width. By virtue of that measure the chips which are reduced in respect of their width can be more easily guided away into the chip ejection space and further towards the connecting portion so that this alone can attain the specified object.
The main cutters in respect of their longitudinal cross-sections can be of a curved profile, similarly to the configuration of a usual cycloid, with in each case at least one wave trough which trails or which is at the front in the drilling direction and/or at least one peak which leads or is at the rear in the drilling direction. A usual cycloid is the curve defined by a point rolling on an outer peripheral circle of a wheel and affords a succession of wave troughs which adjoin each other laterally converging to peaks. The profile can be ground into the main cutter for example by a suitably profiled grinding stone. If the tip is arranged radially outwardly or inwardly it can be incomplete as then it laterally delimits only one wave trough. In the region of the wave trough the chip can be cut away from the bottom of the drilled hole while the tip can implement division of the chip whereby the specified object can be completely attained. Preferably the wave troughs are of a respectively symmetrical configuration so that the main cutting edge extends in the radial center of a wave trough in perpendicular relationship to the drilling direction or in a cross-sectional plane of the drilling head and otherwise inclinedly and in leading relationship thereto. By virtue of the curved profile the main cutting edge can correspondingly cut inclinedly into the material in the bottom of the drilled hole and can thereby effectively operate in portion-wise manner in part like a saw. Other profile shapes are also possible such as for example a sawtooth or a wave profile of a configuration similar to a sine curve. The profile can also be similar to that of a toothed spatula, wherein the projecting “teeth” have a cutting edge and the “teeth” of both main cutters are staggered with respect to the peripheral circles.
Preferably the one main cutter has a wave trough and/or a peak more than the other main cutter. It can further be provided that the wave trough and the peak of the one main cutter are so arranged on peripheral circles that the wave trough of the one main cutter is arranged in a peripheral circle region like the peak of the other main cutter and/or that the peak of the one main cutter is arranged in a peripheral circle region on the same peripheral circle region as the wave trough of the other main cutter. Accordingly a peak of the one main cutter can engage into the peripheral region of the wave trough of the other main cutter, and can therefore be “staggered”, whereby the bottom of the drilled hole can be cut away in the form of chips over the entire longitudinal extent of both main cutters, the widths of the chips being reduced corresponding to the positioning of the peaks on the main cutters.
In order to achieve a uniformly minimal chip width the peak of the one main cutter is arranged on a peripheral circle, on which a central region or preferably the geometrical center of the wave trough associated therewith of the other main cutter is arranged. It will be appreciated that this also applies conversely with cyclic interchange of the terms. In that way the chip to be cut away can be divided centrally in its width.
In addition the main cutters can each have at least one groove for breaking away chips, which is spaced from the outer peripheral circle of the drilling head and extends approximately perpendicularly to the main cutting edge of the respective main cutter, and the groove interrupts the respective main cutting edge. For that purpose, in accordance with the state of the art referred to in the opening part of this specification, DE 299 11 945 U1 to which reference is directed here, the groove of the one main cutter can be arranged on a peripheral circle which is radially spaced relative to the circumcircle on which the groove of the other main cutter is arranged. Accordingly the grooves are arranged on different peripheral circles, like previously peaks or wave troughs, each implementing a chip breaking effect in the drilling operation. In that way the cutting of a chip by means of a main cutter is interrupted radially at a different location, from the cutting of a chip by means of the other main cutter. The side walls of the groove can each project by a slight amount beyond the associated main cutting edge and thus, axially leading, implement preliminary separation of the chip which is to be cut away.
Preferably the one groove is arranged on a circumcircle at a third of an outside radius of the wood drill bit and the other groove is arranged on two-thirds of the outside radius of the wood drill bit. Preferably, in an arrangement with a plurality of grooves on the respective main cutters, one groove of the one main cutter is arranged on the peripheral circle which is approximately equal or equal to the peripheral circle on which a center of a main cutter portion is arranged between two grooves of the other main cutter. Minimally for attaining the specified object it can be provided that only one of the main cutters has a groove while no groove is provided in respect of the other main cutter. In that way the chip is divided at the one main cutter and not divided at the other main cutter, which however already signifies an alleviation in terms of guiding away the chip volume which occurs.
As a usual measure, the guide bell can have at least two part-peripheral pre-cutters with pre-cutting edges. Advantageously however, in comparison with conventional pre-cutters, the pre-cutters can be set back axially with respect to the main cutters inoperatively in respect of pre-cutting except for a respective pre-cutting portion which is operative in respect of pre-cutting. The reduction in both pre-cutters to only one respective pre-cutting portion which is operative in respect of pre-cutting means that it is possible to effectively reduce friction which is generated in the drilling operation by the pre-cutters, and that completely attains the specified object. Furthermore grinding of the pre-cutter which is limited operatively in respect of pre-cutting to the pre-cutter portion can be facilitated.
Preferably the pre-cutting portion can be respectively arranged peripherally from the radially outer edge of the associated main cutter approximately by between a quarter and a third of the outer peripheral circle of the drilling head in opposite relationship to a direction of drilling rotation. Usually the guide bell of a Forstner drill has two peripheral openings, of which a respective one is arranged preceding a main cutter in the direction of drilling rotation, and which serve for tool engagement for producing the main cutters. In that respect it is preferably provided that the pre-cutter portion is arranged on the guide bell in such a way that it delimits the peripheral opening at the side in opposite relationship to the main cutter. Accordingly cutting by means of the pre-cutting edges is displaced with respect to the main cutters in the direction of drilling rotation so that the cutting forces to be applied for drilling a drilled hole are distributed uniformly over the end face of the drilling head and permit smoother drilling which counteracts tilting in the drilled hole. In addition grinding the pre-cutters or the pre-cutter portions can be facilitated. Preferably the guide bell, in accordance with the state of the art, is open radially outwardly in the peripheral region which in opposite relationship to the direction of drilling rotation is arranged between the pre-cutter portion and the following main cutter.
Preferably the pre-cutting portion narrows radially outwardly and/or axially in the drilling direction. That can achieve a mechanically stable base for the pre-cutting portion in relation to cutting forces which occur and at the same time a pre-cutting edge which is further reduced in size, whereby frictional forces which occur at the pre-cutting edge can be further reduced in the drilling procedure. As is generally usual the pre-cutting edge can be arranged at the outer peripheral circle of the drilling head. In a development of the pre-cutter or the pre-cutting portion the pre-cutting edge, in the direction of drilling rotation, can be designed to rise slightly axially in the drilling direction. By virtue of that arrangement the pre-cutter or the pre-cutting portion can gradually engage with a pre-cutting action with the pre-cutting edge into the material which is to be cut away in the bottom of the drilled hole, whereby frictional forces which occur can be further minimized. In addition the pre-cutting portion is more vigorously supported in the direction of the forces which load it in the pre-cutting situation. In that way the pre-cutting portion can be further reduced in respect of its peripheral cutting length, which once again permits a reduction in possible frictional forces in the cutting operation and completely attains the object involved.
The cutting head can be coated at least in the region of the centering tip, the main cutters and/or the side cutters with a wear-resistant layer of hard material, in particular with a titanium nitride layer, whereby its service life can be enhanced.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: The invention concerns a wood drill bit with a cylindrical drilling head and a connecting portion adjoining the drilling head in opposite relationship to the drilling direction for connection to a drive means, wherein the drilling head has at its end a centering tip which is disposed on the longitudinal axis of the drill and which projects in the drilling direction for centering the wood drill bit, at least two main cutters which are arranged diametrically and radially or substantially radially and have main cutting edges, and a part-cylindrical guide bell and adjoining each main cutter is a chip ejection space which is partially open towards the connecting portion.
Wood drill bits of that kind, which are generally known as Forstner drill bits, are designed in particular for drilled holes of large diameters, such as for example for cupboard hinges. The amount of material to be cut away, which is comparatively large as a result, easily gives rise to the generation of a high level of heat in the drilled hole which, amplified when a high feed speed is involved, easily results in charring of material in the bottom of the hole, requires frequent re-sharpening of the cutting edges and ultimately reduces the operating lives of a wood drill bit of that kind. In addition it is necessary to manage a large amount of wood chips and this contributes to an increased drilling pressure in the drilled hole, which in turn can cause an increase in temperature with the above-indicated risks, and in addition increases the risk of easily chipping off wood at a side face of material being drilled, that is remote from the entry side when producing through holes or blind holes. That in turn allows only low feed speeds when performing drilling operations.
For that purpose, DE 299 11 945 U1 puts forward the proposal of breaking the chips over their width by grooves which are formed in the main cutters and which interrupt the main cutting edges, in order thereby to produce narrower wood chips which are easier to transport away, which represents a certain advance in terms of resolving the problem involved.
Therefore the object of the invention is to provide a wood drill bit of the kind set forth in the opening part of this specification, which permits an increased feed speed without its operating lives being reduced at the same time.
According to the invention that object is attained in that the main cutter extends with a radially inwardly disposed portion into the centering tip and the chip ejection space is enlarged into the centering tip by means of a pre-chip ejection groove.
In that case the pre-chip ejection groove is preferably disposed downstream of the respective main cutting edge which has the respective portion, in a direction of drilling rotation. The pre-chip ejection groove can be ground into the centering tip in one working operation together with the portion. In that way the cutting action can be implemented into the centering tip. As mentioned above, when drilling inter alia through resistant material, a drilling pressure can be built up at the bottom of a drilled hole, which can be increased by the material which has been cut away being accumulated or backing up. As a result an increased pressure on the wood drill bit in the drilling direction is necessary to produce the feed, whereby the temperature in the drilled hole can be further increased. Both these factors can increase the amount of wear of the drilling head, necessitate premature re-grinding of the main cutter and thus reduce the service life of the wood drill bit. In addition the risk of the wood splitting away at an exit side of the drilled hole, that is to say a side surface of the drilled hole which is at the rear in the drilling direction, can be increased. As a result material which accumulates at the centering tip when using conventional wood drill bits in the feed procedure can be partially cut away, whereby the drilling pressure is reduced. Furthermore the pressure can be further reduced by the pre-chip ejection groove by virtue of the material being cut away, insofar as the groove enlarges the chip ejection space into which it opens, and insofar as the material can be more easily transported away. Furthermore the area of the centering tip in perpendicular relationship to the drilling direction is reduced, whereby a force which contributes to determining the drilling pressure and with which the centering tip has to be pressed into the material which is still to be cut away in the bottom of the drilled hole in the drilling operation is reduced. The measure according to the invention completely attains the specified object.
Preferably the main cutter extends to close to a drill bit longitudinal axis of the drilling head or to the drill bit longitudinal axis or is extended by a small amount beyond the drill bit longitudinal axis. In that case the main cutter with said portion can be extended at a maximum as far as the side wall or side wall portion of the centering tip, which is beyond the drill bit center in a prolongation of the main cutting edge.
The main cutter can form in the portion a side face in the centering tip, which faces radially outwardly and axially in opposite relationship to the drilling direction. In that way the main cutters can each extend into the centering tip, forming an undercut configuration, and can acquire a cutting action and by virtue of the simultaneous provision of the pre-chip ejection groove, can increase the respectively adjoining chip ejection space into the centering tip. The orientation of the undercut configuration provides that with the rotation of the wood drill bit the centering tip can twist itself virtually in a spiral configuration into the material at the bottom of the drilled hole or can exert a feed force on the wood drill bit in the drilling direction, whereby a necessary external drilling force can be reduced.
In a preferred development of the wood drill bit the chip ejection space adjoining a respective main cutter can be enlarged into the centering tip. In that case allocated to the chip ejection space is also a space which in the drilled hole is delimited by the bottom of the drilled hole and the respective relief surface following a main cutter. Accordingly, by virtue of this measure according to the invention, the relief space behind the main cutters can extend into the centering tip so that the wood chips can already be guided away here into the chip ejection space. In that way once again the drilling pressure can be reduced so that just by virtue thereof the object of the invention can be completely attained. In that respect it is possible to attain an enlargement in part or completely by way of a radially inward enlargement of a relief surface following the respective main cutter.
Preferably the centering tip is of a pyramidal configuration with a base in parallelogram form, wherein sides of the base include an acute first angle and an obtuse second angle and the main cutters are respectively arranged to extend into a region of the centering tip with the acute angle in the base. In that way a free space which is associated with a main cutter and thus the chip ejection space can be enlarged. It is possible for chips which are cut off in the portion of the main cutter in the centering tip to be more easily guided away into the chip ejection space. The consequence of that is in turn that friction and temperature at the bottom of the drilled hole as well as the drilling pressure can be reduced in comparison with a conventional wood drill bit configuration and thus higher feed times and/or service lives are possible so that the object can be attained thereby.
On the geometrical premise that both angles are 180 degrees, the first angle can be between 55 degrees and 85 degrees and the second angle can be between 95 degrees and 125 degrees. Preferably the first angle is between 60 degrees and 80 degrees and the second angle is between 100 degrees and 120 degrees. As an optimum the first angle is 70 degrees and the second angle is 110 degrees. Tests have admittedly shown that here an optimum with the drill bit geometries involved can be achieved with 70° for the first angle and 110° for the second angle. It will be appreciated that it is possible that other angle values can be found to be optimum, with modified drill bit geometries. The diagonals of the base are preferably in mutually perpendicular relationship. That can be afforded if an originally square centering tip is laterally ground away in order to produce the centering tip according to the invention, as will be described in further detail hereinafter.
Preferably the first sides of the base extend approximately in the direction of the main cutters and the second sides of the base extend approximately perpendicularly or perpendicularly to the main cutters. Preferably the first sides are shorter than the second sides. In that respect the first sides and the second sides of the base denote the sides of the centering tip which are notionally afforded from the pyramidal centering tip with a parallelogram as the base and which have not yet been notionally shortened by the portion of the main cutters, which projects into the centering tip. Accordingly a conventional square centering tip can be reduced in its extent in perpendicular relationship to the main cutter so that as a result the main cutters extend further towards the drill bit longitudinal axis and can work freely. Furthermore a lateral flattening of the centering tip, which is effected thereby, can provide that the free space is increased in size in the region of the lateral flattening whereby chips which have been cut away have more available space and can thus reduce the drilling pressure at the bottom of the drilled hole.
The wood drill bit can additionally or solely have a chip divider device for dividing and/or breaking off chips which are to be cut away or which have been cut away by the main cutters in respect of their width over the longitudinal extent of the main cutters, wherein the chip divider device is preferably operative over the radial extent of at least one of the main cutters. In that way the chips can be divided at least once in respect of their chip width at least one of the main cutters over the radial extent thereof so that the chip width of individual chips can be correspondingly reduced. In that way the chips in question can be transported into the chip ejection space in opposite relationship to the drilling direction or the feed direction more easily, and further transported toward the connection portion. The specified object can be completely attained by that feature.
In a development of the wood drill bit at least one of the main cutters can be provided with at least one peak or tip projecting in the drilling direction. In that case the tip can be arranged disposed radially outwardly whereby, similarly to the pre-cutter referred to in greater detail hereinafter, it can cut an outer peripheral circle into the material which is to be cut away. Preferably however the tip is arranged spaced radially inwardly from the outer periphery of the drilling head. That projecting and thus leading tip can thus implement division of the material before the chip is cut away from the bottom of the drilled hole and thereby definedly reduce the chip width. By virtue of that measure the chips which are reduced in respect of their width can be more easily guided away into the chip ejection space and further towards the connecting portion so that this alone can attain the specified object.
The main cutters in respect of their longitudinal cross-sections can be of a curved profile, similarly to the configuration of a usual cycloid, with in each case at least one wave trough which trails or which is at the front in the drilling direction and/or at least one peak which leads or is at the rear in the drilling direction. A usual cycloid is the curve defined by a point rolling on an outer peripheral circle of a wheel and affords a succession of wave troughs which adjoin each other laterally converging to peaks. The profile can be ground into the main cutter for example by a suitably profiled grinding stone. If the tip is arranged radially outwardly or inwardly it can be incomplete as then it laterally delimits only one wave trough. In the region of the wave trough the chip can be cut away from the bottom of the drilled hole while the tip can implement division of the chip whereby the specified object can be completely attained. Preferably the wave troughs are of a respectively symmetrical configuration so that the main cutting edge extends in the radial center of a wave trough in perpendicular relationship to the drilling direction or in a cross-sectional plane of the drilling head and otherwise inclinedly and in leading relationship thereto. By virtue of the curved profile the main cutting edge can correspondingly cut inclinedly into the material in the bottom of the drilled hole and can thereby effectively operate in portion-wise manner in part like a saw. Other profile shapes are also possible such as for example a sawtooth or a wave profile of a configuration similar to a sine curve. The profile can also be similar to that of a toothed spatula, wherein the projecting “teeth” have a cutting edge and the “teeth” of both main cutters are staggered with respect to the peripheral circles.
Preferably the one main cutter has a wave trough and/or a peak more than the other main cutter. It can further be provided that the wave trough and the peak of the one main cutter are so arranged on peripheral circles that the wave trough of the one main cutter is arranged in a peripheral circle region like the peak of the other main cutter and/or that the peak of the one main cutter is arranged in a peripheral circle region on the same peripheral circle region as the wave trough of the other main cutter. Accordingly a peak of the one main cutter can engage into the peripheral region of the wave trough of the other main cutter, and can therefore be “staggered”, whereby the bottom of the drilled hole can be cut away in the form of chips over the entire longitudinal extent of both main cutters, the widths of the chips being reduced corresponding to the positioning of the peaks on the main cutters.
In order to achieve a uniformly minimal chip width the peak of the one main cutter is arranged on a peripheral circle, on which a central region or preferably the geometrical center of the wave trough associated therewith of the other main cutter is arranged. It will be appreciated that this also applies conversely with cyclic interchange of the terms. In that way the chip to be cut away can be divided centrally in its width.
In addition the main cutters can each have at least one groove for breaking away chips, which is spaced from the outer peripheral circle of the drilling head and extends approximately perpendicularly to the main cutting edge of the respective main cutter, and the groove interrupts the respective main cutting edge. For that purpose, in accordance with the state of the art referred to in the opening part of this specification, DE 299 11 945 U1 to which reference is directed here, the groove of the one main cutter can be arranged on a peripheral circle which is radially spaced relative to the circumcircle on which the groove of the other main cutter is arranged. Accordingly the grooves are arranged on different peripheral circles, like previously peaks or wave troughs, each implementing a chip breaking effect in the drilling operation. In that way the cutting of a chip by means of a main cutter is interrupted radially at a different location, from the cutting of a chip by means of the other main cutter. The side walls of the groove can each project by a slight amount beyond the associated main cutting edge and thus, axially leading, implement preliminary separation of the chip which is to be cut away.
Preferably the one groove is arranged on a circumcircle at a third of an outside radius of the wood drill bit and the other groove is arranged on two-thirds of the outside radius of the wood drill bit. Preferably, in an arrangement with a plurality of grooves on the respective main cutters, one groove of the one main cutter is arranged on the peripheral circle which is approximately equal or equal to the peripheral circle on which a center of a main cutter portion is arranged between two grooves of the other main cutter. Minimally for attaining the specified object it can be provided that only one of the main cutters has a groove while no groove is provided in respect of the other main cutter. In that way the chip is divided at the one main cutter and not divided at the other main cutter, which however already signifies an alleviation in terms of guiding away the chip volume which occurs.
As a usual measure, the guide bell can have at least two part-peripheral pre-cutters with pre-cutting edges. Advantageously however, in comparison with conventional pre-cutters, the pre-cutters can be set back axially with respect to the main cutters inoperatively in respect of pre-cutting except for a respective pre-cutting portion which is operative in respect of pre-cutting. The reduction in both pre-cutters to only one respective pre-cutting portion which is operative in respect of pre-cutting means that it is possible to effectively reduce friction which is generated in the drilling operation by the pre-cutters, and that completely attains the specified object. Furthermore grinding of the pre-cutter which is limited operatively in respect of pre-cutting to the pre-cutter portion can be facilitated.
Preferably the pre-cutting portion can be respectively arranged peripherally from the radially outer edge of the associated main cutter approximately by between a quarter and a third of the outer peripheral circle of the drilling head in opposite relationship to a direction of drilling rotation. Usually the guide bell of a Forstner drill has two peripheral openings, of which a respective one is arranged preceding a main cutter in the direction of drilling rotation, and which serve for tool engagement for producing the main cutters. In that respect it is preferably provided that the pre-cutter portion is arranged on the guide bell in such a way that it delimits the peripheral opening at the side in opposite relationship to the main cutter. Accordingly cutting by means of the pre-cutting edges is displaced with respect to the main cutters in the direction of drilling rotation so that the cutting forces to be applied for drilling a drilled hole are distributed uniformly over the end face of the drilling head and permit smoother drilling which counteracts tilting in the drilled hole. In addition grinding the pre-cutters or the pre-cutter portions can be facilitated. Preferably the guide bell, in accordance with the state of the art, is open radially outwardly in the peripheral region which in opposite relationship to the direction of drilling rotation is arranged between the pre-cutter portion and the following main cutter.
Preferably the pre-cutting portion narrows radially outwardly and/or axially in the drilling direction. That can achieve a mechanically stable base for the pre-cutting portion in relation to cutting forces which occur and at the same time a pre-cutting edge which is further reduced in size, whereby frictional forces which occur at the pre-cutting edge can be further reduced in the drilling procedure. As is generally usual the pre-cutting edge can be arranged at the outer peripheral circle of the drilling head. In a development of the pre-cutter or the pre-cutting portion the pre-cutting edge, in the direction of drilling rotation, can be designed to rise slightly axially in the drilling direction. By virtue of that arrangement the pre-cutter or the pre-cutting portion can gradually engage with a pre-cutting action with the pre-cutting edge into the material which is to be cut away in the bottom of the drilled hole, whereby frictional forces which occur can be further minimized. In addition the pre-cutting portion is more vigorously supported in the direction of the forces which load it in the pre-cutting situation. In that way the pre-cutting portion can be further reduced in respect of its peripheral cutting length, which once again permits a reduction in possible frictional forces in the cutting operation and completely attains the object involved.
The cutting head can be coated at least in the region of the centering tip, the main cutters and/or the side cutters with a wear-resistant layer of hard material, in particular with a titanium nitride layer, whereby its service life can be enhanced.
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7641215 | BACKGROUND
Prior art ski and snowboard boots are generally made of an upper cuff and a lower boot that are connected together to restrict a user's lateral movement. These boots can vary in forward flexibility and stiffness, and they have proven popular because lateral flexibility in a ski or snowboard boot would reduce the user's ability to quickly turn the ski or snowboard. When a user leans into a traditional boot, the whole boot and ski (or snowboard) move as a single unit; this may allow the user to easily turn at high speeds or in other circumstances where fast direction changes are needed.
People sliding (also referred to as “grinding”) on rails and other objects with skis and snowboards is becoming increasingly popular.
SUMMARY
Gliding board equipment systems are disclosed herein. A system of one embodiment includes a gliding board, a boot having an upper cuff and a lower boot, and a binding selectively attaching the boot to the gliding board. The upper cuff defines opposed slots, and a respective pin passes through each slot to couple the upper cuff to the lower boot and allow the upper cuff to move laterally relative to the lower boot.
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SUMMARY: BACKGROUND
Prior art ski and snowboard boots are generally made of an upper cuff and a lower boot that are connected together to restrict a user's lateral movement. These boots can vary in forward flexibility and stiffness, and they have proven popular because lateral flexibility in a ski or snowboard boot would reduce the user's ability to quickly turn the ski or snowboard. When a user leans into a traditional boot, the whole boot and ski (or snowboard) move as a single unit; this may allow the user to easily turn at high speeds or in other circumstances where fast direction changes are needed.
People sliding (also referred to as “grinding”) on rails and other objects with skis and snowboards is becoming increasingly popular.
SUMMARY
Gliding board equipment systems are disclosed herein. A system of one embodiment includes a gliding board, a boot having an upper cuff and a lower boot, and a binding selectively attaching the boot to the gliding board. The upper cuff defines opposed slots, and a respective pin passes through each slot to couple the upper cuff to the lower boot and allow the upper cuff to move laterally relative to the lower boot.
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7795846 | TECHNICAL FIELD
The subject matter of this disclosure relates to power supply circuits, and more particularly to circuitry and methodology for determining average output current in an inductive DC-DC converter.
BACKGROUND
In some application, it may be desirable to accurately determine average output current of an inductor-based DC-DC converter in order to use this information to either limit the output current to a safe level or to disable the converter to preserve battery life when a certain output current level is reached.
For example, in USB-ON-THE-GO applications, a portable converter may supply a regulated 5V boosted voltage to an external connector using a lower voltage Li-Ion battery. Since the output of the converter is exposed, via the connector, to an influence of an external device, the converter may experience fault conditions, such as a short circuit to ground. Therefore, it may be necessary to limit the output current of such a converter or to disable it for preserving battery life.
Furthermore, it would be desirable to measure the average output current fairly accurately so that a converter can always deliver a minimum required current but not a current produced at a level significantly higher than necessary due to a less accurate current measuring technique. For example, a converter may be required to deliver a 500 mA minimum amount of current required by the USB-ON-THE-GO specification.
Moreover, in accordance with a conventional technique, output current may be directly sensed using a current sensing resistor. However, a conventional current sensing resistor has a very large size. Therefore, it occupies substantial space on a circuit board increasing the cost of a converter and causing significant power loss. Accordingly, it would be desirable to determine the output current without the use of a current sensing resistor.
SUMMARY OF THE DISCLOSURE
In accordance with one aspect of the present disclosure, a switching circuit for converting an input voltage into an output voltage comprises an input terminal for receiving the input voltage. A power switching element is coupled to the input terminal and has duty cycle d controllable to adjust the output voltage with respect to a desired level using inductor current representing current in an inductor element connectable to the power switching element. An average and hold circuit is responsive to a voltage at an output of the power switching element to produce an average switch voltage during the ON phase of the switching cycle of the power switching element. A voltage-to-current converter is responsive to the average switch voltage for producing representation of an average inductor current over one or more switching cycles of the power switching element. A current modulator having a duty cycle equal to 1-d modulates the representation of the average inductor current to produce a signal proportional to an average output current of the switching circuit over one or more switching cycles of the power switching element.
For example, the switching circuit may be a boost converter that produces the output voltage exceeding the input voltage.
In accordance with another aspect of the present disclosure, resistance of the power switching element, instead of a current sensing resistor, may be used to determine the inductor current.
In accordance with a further aspect of the disclosure, the average and hold circuit may comprise a first switching element operating in phase with the power switching element. A resistor-capacitor (RC) circuit may be coupled to the output of the first switching element.
In accordance with an embodiment of the disclosure, the voltage-to-current converter may comprise a sense switching element coupled to the input terminal and having resistance proportional to the resistance of the power switching element. An operational amplifier may have a first input responsive to the average switch voltage and a second input coupled to the sense switching element. A driver may be coupled to the output of the operational amplifier for supplying an output signal of the operational amplifier to the sense switching element.
The current modulator may comprise a second switching element having an input responsive to the representation of the average inductor current and an output for producing the signal proportional to the average output current. The input of the second switching element may be connected to the output when the power switching element is in off-state, or may be grounded when the power switching element is in on-state.
A current mirror circuit may be coupled between the voltage-to-current converter and the current modulator.
In accordance with a method of the present disclosure, the following steps are carried out to determine average output current in a switching circuit for converting an input voltage into an output voltage and having a power switching element connectable to an inductor element:producing an average value of a voltage at an output of the power switching element over the ON phase of the switching cycle of the power switching element,converting the average value of the voltage into representation of an average inductor current, the inductor current may be determined using resistance of the power switching element, andmodulating the representation of average inductor current with a duty cycle equal to 1-d, where d is a duty cycle of the power switching element, to produce a signal representing the average output current.
In accordance with a further aspect of the disclosure, a converter for producing a DC output voltage in response to a DC input voltage comprises a power switching element having a duty cycle d controllable to produce the output voltage at a desired level using an inductor current representing current in an inductor element connectable to the power switching element, and a current determining circuit for determining an average output current of the converter. The current determining circuit may include a current generator for producing an average current signal representing an average value of the inductor current over the ON phase of the switching cycle of the power switching element, and an output switching element responsive to the average current signal to produce a signal representing the average output current. The output switching circuit may have a duty cycle equal to 1-d.
The current generator may include an average and hold circuit responsive to a voltage at the output of the power switching element for producing an average switch voltage over the ON phase of the switching cycle of the power switching element.
Also, the current generator may include a voltage-to-current converter responsive to the average switch voltage for producing the average current signal. As the resistance of the power switching element is used to determine the inductor current, the voltage-to-current converter may include a sense switching element having resistance representing the resistance of the power switching element.
Additional advantages and aspects of the disclosure will become readily apparent to those skilled in the art from the following detailed description, wherein embodiments of the present disclosure are shown and described, simply by way of illustration of the best mode contemplated for practicing the present disclosure. As will be described, the disclosure is capable of other and different embodiments, and its several details are susceptible of modification in various obvious respects, all without departing from the spirit of the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as limitative.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: TECHNICAL FIELD
The subject matter of this disclosure relates to power supply circuits, and more particularly to circuitry and methodology for determining average output current in an inductive DC-DC converter.
BACKGROUND
In some application, it may be desirable to accurately determine average output current of an inductor-based DC-DC converter in order to use this information to either limit the output current to a safe level or to disable the converter to preserve battery life when a certain output current level is reached.
For example, in USB-ON-THE-GO applications, a portable converter may supply a regulated 5V boosted voltage to an external connector using a lower voltage Li-Ion battery. Since the output of the converter is exposed, via the connector, to an influence of an external device, the converter may experience fault conditions, such as a short circuit to ground. Therefore, it may be necessary to limit the output current of such a converter or to disable it for preserving battery life.
Furthermore, it would be desirable to measure the average output current fairly accurately so that a converter can always deliver a minimum required current but not a current produced at a level significantly higher than necessary due to a less accurate current measuring technique. For example, a converter may be required to deliver a 500 mA minimum amount of current required by the USB-ON-THE-GO specification.
Moreover, in accordance with a conventional technique, output current may be directly sensed using a current sensing resistor. However, a conventional current sensing resistor has a very large size. Therefore, it occupies substantial space on a circuit board increasing the cost of a converter and causing significant power loss. Accordingly, it would be desirable to determine the output current without the use of a current sensing resistor.
SUMMARY OF THE DISCLOSURE
In accordance with one aspect of the present disclosure, a switching circuit for converting an input voltage into an output voltage comprises an input terminal for receiving the input voltage. A power switching element is coupled to the input terminal and has duty cycle d controllable to adjust the output voltage with respect to a desired level using inductor current representing current in an inductor element connectable to the power switching element. An average and hold circuit is responsive to a voltage at an output of the power switching element to produce an average switch voltage during the ON phase of the switching cycle of the power switching element. A voltage-to-current converter is responsive to the average switch voltage for producing representation of an average inductor current over one or more switching cycles of the power switching element. A current modulator having a duty cycle equal to 1-d modulates the representation of the average inductor current to produce a signal proportional to an average output current of the switching circuit over one or more switching cycles of the power switching element.
For example, the switching circuit may be a boost converter that produces the output voltage exceeding the input voltage.
In accordance with another aspect of the present disclosure, resistance of the power switching element, instead of a current sensing resistor, may be used to determine the inductor current.
In accordance with a further aspect of the disclosure, the average and hold circuit may comprise a first switching element operating in phase with the power switching element. A resistor-capacitor (RC) circuit may be coupled to the output of the first switching element.
In accordance with an embodiment of the disclosure, the voltage-to-current converter may comprise a sense switching element coupled to the input terminal and having resistance proportional to the resistance of the power switching element. An operational amplifier may have a first input responsive to the average switch voltage and a second input coupled to the sense switching element. A driver may be coupled to the output of the operational amplifier for supplying an output signal of the operational amplifier to the sense switching element.
The current modulator may comprise a second switching element having an input responsive to the representation of the average inductor current and an output for producing the signal proportional to the average output current. The input of the second switching element may be connected to the output when the power switching element is in off-state, or may be grounded when the power switching element is in on-state.
A current mirror circuit may be coupled between the voltage-to-current converter and the current modulator.
In accordance with a method of the present disclosure, the following steps are carried out to determine average output current in a switching circuit for converting an input voltage into an output voltage and having a power switching element connectable to an inductor element:producing an average value of a voltage at an output of the power switching element over the ON phase of the switching cycle of the power switching element,converting the average value of the voltage into representation of an average inductor current, the inductor current may be determined using resistance of the power switching element, andmodulating the representation of average inductor current with a duty cycle equal to 1-d, where d is a duty cycle of the power switching element, to produce a signal representing the average output current.
In accordance with a further aspect of the disclosure, a converter for producing a DC output voltage in response to a DC input voltage comprises a power switching element having a duty cycle d controllable to produce the output voltage at a desired level using an inductor current representing current in an inductor element connectable to the power switching element, and a current determining circuit for determining an average output current of the converter. The current determining circuit may include a current generator for producing an average current signal representing an average value of the inductor current over the ON phase of the switching cycle of the power switching element, and an output switching element responsive to the average current signal to produce a signal representing the average output current. The output switching circuit may have a duty cycle equal to 1-d.
The current generator may include an average and hold circuit responsive to a voltage at the output of the power switching element for producing an average switch voltage over the ON phase of the switching cycle of the power switching element.
Also, the current generator may include a voltage-to-current converter responsive to the average switch voltage for producing the average current signal. As the resistance of the power switching element is used to determine the inductor current, the voltage-to-current converter may include a sense switching element having resistance representing the resistance of the power switching element.
Additional advantages and aspects of the disclosure will become readily apparent to those skilled in the art from the following detailed description, wherein embodiments of the present disclosure are shown and described, simply by way of illustration of the best mode contemplated for practicing the present disclosure. As will be described, the disclosure is capable of other and different embodiments, and its several details are susceptible of modification in various obvious respects, all without departing from the spirit of the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as limitative.
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7836588 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an article and process for producing electronic devices. More particularly the invention relates to an article and process for fabricating patterns of electrically conductive materials on non-electrically conductive substrates by laser ablation. Such an article and process find use in the production of RFID devices, antennae, electrical circuits, microwave susceptors, contacts, leads, conductors, sensors, interactive displays, electrostatic shielding devices, heating elements and the like.
2. Description of the Related Art
There is great commercial interest in a new generation of data transmitting electronic devices such as transponders, sensors, etc. The use of electronic components in everyday items, particularly in packaging, in the form of traceable tags, heating elements, security elements, sensors etc, is growing rapidly.
Recently, Radio Frequency Identification Devices or RFID's have found use in providing tagging and traceability for the packaging industry. RFID refers to technologies that use radio waves to identify and transmit information remotely from tagged objects. In a typical RFID tag, a microchip is attached to an antenna. The antenna is typically made of conductive metal, e.g., silver, copper, etc., and can have various shapes and geometries based on the radio frequency used. The chip and the antenna together constitute an RFID transponder or a tag. The chip contains the necessary information for identifying a tagged item. The function of the antenna is to communicate remotely through radio wave signals from a reader and establish the identity of the object. The ability to remotely monitor the flow of items from one place to another makes RFID an attractive technology. Its use in inventory control, security, etc. for packaged goods has serious financial ramifications. The ultimate goal is to implement an item level tagging. However, there are several roadblocks to the commercial use of RFID technology. A key factor is the inability to mass produce tags with required functionalities in a simple, reliable, and consistent manner, and producing them cost effectively, for making widespread applications feasible. At present, the cost of RFID transponders ranges from 50 cents to several dollars each, depending on their functional requirements. However, for item level tagging to be feasible, which would require billions of tags, the cost of the transponders has to be significantly less. Unfortunately, the currently available methods of tag manufacturing are not capable of meeting these requirements and therefore, the industry and the market, are at a stand still. The cost of a transponder is primarily dictated by (1) the cost of the antenna (2) the cost of the base material used (3) the cost of the chip (4) the cost of fabrication (5) the cost of quality control (6) the final yield value and (7) the overall capital investment required. The cost of the antennae has been identified to be one of the key limiting variables and therefore, an intense effort is being made to overcome this problem. Currently a method of chemical etching is used to produce an antenna from a conductive metal base. The process involves selective chemical etching of a conductive metal like silver or copper, with a strong acid or base to produce antennae of selective geometries. In subsequent multiple steps the antenna is attached to a chip via a conductive adhesive and is encased in an appropriate casing. The process is old, well understood and broadly practiced, however, wasteful, environmentally harmful, expensive, and therefore it is not able to take the industry to the next level. Several other methods e.g., metal stamping, selective electrolytic metal deposition, etc. have been tried as alternatives. However, none has been successful as a solution.
It is known in the art to produce electronic devices such as antennae by a technique generally described as “plating on plastics” The “plating on plastics” technology deposits an adherent coating of a metal or metal-based material onto the surface of a plastic substrate. “Plating on plastic” envisions the deposition of an initial metal coating using “electroless” plating followed by an optional deposition of metal using electrodeposition. Electroless plating involves chemically coating a nonconductive surface such as a plastic with a continuous metallic film. In this regard, U.S. Patent Application 20020135519 describes a radio frequency identification device (RFID) and many different ways of manufacturing such RFID antennae and transponders. An RFID transponder device is essentially composed of a small antenna attached to a programmable computer chip. Such transponders are required for transmitting electromagnetic radiation between the device and its surroundings, e.g., a reader or negotiator. Together, a transponder and a reader constitute a working RFID system. An RFID transponder may be passive, which can be used for transmission short range transmission. However, they may also be active and used for longer range transmission when a battery is attached to the transponder. Typically an RFID antenna is a flat metallic structure comprising of conductive and non-conductive areas. Its appropriate geometrical form is dictated by the frequencies used by the readers, typically in the kilohertz to megahertz ranges. An active or passive transponder is typically encased in a plastic laminated structure, e.g., a label, which is then attached to a pallet, case or boxes to obtain non-contact and remote “tag and traceability” features for inventory control, logistics, security and various other functions. However, most of the solid state electronic circuitry is rigid and therefore, not suitable for use on packaging items, as most such items are flexible materials. Therefore, a tremendous amount of effort is being used developing so called “printed electronics.” The goal of printed electronics is to print the required elements of an electrical circuitry onto the flexible substrate itself. The printed substrate with required elements can then be put onto the finished packaging as an added label, or as part of the packaging itself, or the item itself, thereby imparting the appropriate functionalities to the packaging and packaged items.
An essential element of an electronic circuit is geometric patterns of conductive and nonconductive (dielectric) areas. Typically this is done in a semiconductor circuit via the doped metal layers and dielectric layers. In a printed circuit, printing inks made with conductive particles, typically silver, are printed in respective patterns on a nonconductive (dielectric) film surface. Majority of commercially manufactured antennas today are based on selective chemical etching of metals in appropriate geometries. However, this process poses serious environmental and health and safety hazards.
Recently printing of RFID antennae with conductive inks is being developed as an environmentally friendly approach. Typically, inks containing expensive metals like silver powder, are printed onto dielectric substrates, e.g., plastic or paper, forming a conductive pattern. After printing, the printed structure requires a high temperature annealing process to sinter all the conductive particles together and form continuous conductive elements, in order to achieve necessary levels of conductivity. This limits the number of substrates that can be used to print on, since only expensive substrates with high softening temperature may be used to avoid any deformation. High temperature requirement also seriously reduces the overall productivity of the process. In addition, certain amount of ink film thickness must be deposited in order to obtain required conductivity levels. Moreover, due to high loading of silver powder requirement, the ink formulations must contain extraneous additives, including volatile organic compounds (VOC), to produce inks in a printable fashion. This makes the inks either less conductive or environmentally unfriendly. Printing of a substrate surface with a metal catalyst or “seed layer” and subsequent electrodeposition of copper metal in a bath onto the printed areas is another approach that is being studied. Although this process avoids any high temperature processing, it is a slow and wet process, with their inherent disadvantages.
German Patent DE 19951721 teaches a process of selective ablation of a thin, less than 250 nm metal layer, with UV lasers emitting between 248 nm and 532 nm. After ablation an additional step of metal electrodeposition is required in order to achieve required electrical conductivity. While this approach promises to yield silver free, less expensive antennae, the productivity of such process is very low since UV laser irradiation has a limited energy level for ablating thicker metal layers and electrodeposition process is extremely slow and requires utilization of wet chemistry.
All of these prior approaches also require subsequent multiple steps to convert the formed antennae into actual functional transponders. For example, a programmable computer chip must be attached to the antenna in a precise manner to obtain appropriate connection to the circuitry. Lack of connection would further reduce the yield of the process and above all, reliability of the transponders itself. For transponders with longer ranges, a battery must also be attached in a subsequent step.
Overall, the limitations of all the current and available approaches make the RFID antennae and transponders produced expensive, and limit their viability as commercially successful processes to satisfy projected industry needs for billions of inexpensive RFID transponders, for all types of applications including tagging of individual items. Similarly, commercial manufacturing of microwave susceptors or sensors also face similar limitations. These industries require a new, efficient, effective, environmentally friendly, robust, economical, and reliable manufacturing process to achieve their projected growth potentials.
At present the industry is focused on developing a printing method as a solution to this quandary. An ink made with conductive metal powder is printed on a flexible web substrate in the form of an antenna pattern. Next the printed patterns are heated to a high temperature, e.g., 130° C., to anneal the metal particles and form a continuous and conductive pathway. Subsequently, a suitable chip is attached in-line to the antenna via a conductive adhesive; quality controlled for right contacts and functionality, and the structure encased in an appropriate package for final assembly. However, this approach is complex. In order to achieve a high enough conductivity at printed film thickness, mainly silver is used as metal, which is expensive. The metal must also be in powder form with particle size ranging from micrometer to nanometer with their associated processing cost, further increasing the material cost. The substrate must be able to withstand high bake temperature ˜130° C. without thermal distortion, and therefore can primarily be expensive polyesters with high glass transition temperature (Tg). High web surface temperature requirement also slows down the overall printing process, increasing cost.
In order to convert the metal powder to an ink composition, resins, solvents, additives etc. must be added, most of which being non-conductive are not desired to remain with the printed antennae. Therefore, materials are selected which would volatilize during the baking step, which in turn create undesired environmental (VOC) and health & safety issues. In addition, despite the high heating step, the metal particles in the printed antenna simply do not attain their original metallic crystal structure and therefore results in printed antennae with somewhat reduced metal conductivity compared to their original value.
Attachment of computer chips onto the printed antennae is also a critical step. The chip connectors must be properly aligned right onto the antenna pads for appropriate coupling. Any misalignment would increase waste factor and above all would increase unreliability of the system, increasing potential risks and security breaches in several sensitive application areas. In order to minimize such risk factors “straps,” which are webs containing pre-positioned chips, can be positioned and aligned in a film lamination arrangement and chips transferred from the “strap” to the printed antenna web in-line. However, even with this approach there is at least 1-3% unreliability factor, which for mass adoption poses a great disadvantage.
The overall complexity, unreliability and economics of the current “printed antenna” process simply does not lend itself to be a solution to preventing the RFID market from achieving intended commercial success and there is a serious need for a new fabrication method for RFID antenna. The present invention discloses such an RFID antenna manufacturing process. The invented process starts with a metallized film which is provided with several computer chips in any pre-determined pattern via a conductive adhesive. This step can be done in-line or off-line. Next, an infrared (IR) laser ablates a portion of the metal layer in a predetermined manner to create an appropriate antenna form. A CAD/CAM or similar computer-hardware interface software can direct this exposure step. The process offers an increased in creating almost any possible antenna shape or form in one step. Since there is no baking step involved, an expensive high Tg film is no longer necessary. The metal layer can be almost any thin conductive metal layer, e.g., aluminum, silver, copper etc. However, a metallized Al layer is the most economical. The thickness of the Al layer can be adjusted easily to obtain a desired level of conductivity.
The present invention for mass manufacturing RFID devices avoids the roadblocks faced by the printing approach. The process does not require an expensive substrate, expensive conductive inks, no heat is required, no wet chemistry is involved and does not produce any VOC and/or health and safety issues. The process does not require a separate step of attaching computer chips to the formed antenna, thereby significantly improving the reliability, yield and robustness of the manufacturing process. The individual RFID devices, i.e., an antenna attached to a chip can be packaged in-line to produce a finished RFID tag in one single step.
Geometric patterns produced may be “passive,” e.g., an antenna for radio frequency identification device (RFID); a microwave susceptor; a circuit etc. They can also be “active” or “functional,” e.g., a complete transponder for RFID or a sensor or similar devices, when a metallized substrate, pre-fabricated with computer chip and a battery, is ablated. Any geometric form on a flat surface can be produced in a sheet or roll form. The conductive articles can be folded into a three dimensional architecture. Such production of fully active or passive devices, with high reliability and in high yield, produced in one step, is unique.
SUMMARY OF THE INVENTION
The invention provides a process for producing an electronic device which comprises,a) providing an electrically conductive metal layer on an electrically non-conductive substrate;b) thereafter electrically connecting an electronic circuit to the electrically conductive metal layer; andc) thereafter ablating a portion of the electrically conductive metal layer with infrared laser radiation to thereby form a pattern of electrically conductive areas and electrically non-conductive areas on the substrate, wherein at least a portion of the electrically conductive areas are electrically connected to the electronic circuit.
The invention also provides an article for producing an electronic device which comprises an electrically non-conductive substrate, a continuous, unpatterned, electrically conductive metal layer on the electrically non-conductive substrate, a continuous, unpatterned, infrared radiation sensitive composition layer between the electrically non-conductive substrate and the electrically conductive metal layer, and an electronic circuit electrically connected to the electrically conductive metal layer.
The invention also offers an alternative to the “printed electronics” approach to form electronic circuitry or devices.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an article and process for producing electronic devices. More particularly the invention relates to an article and process for fabricating patterns of electrically conductive materials on non-electrically conductive substrates by laser ablation. Such an article and process find use in the production of RFID devices, antennae, electrical circuits, microwave susceptors, contacts, leads, conductors, sensors, interactive displays, electrostatic shielding devices, heating elements and the like.
2. Description of the Related Art
There is great commercial interest in a new generation of data transmitting electronic devices such as transponders, sensors, etc. The use of electronic components in everyday items, particularly in packaging, in the form of traceable tags, heating elements, security elements, sensors etc, is growing rapidly.
Recently, Radio Frequency Identification Devices or RFID's have found use in providing tagging and traceability for the packaging industry. RFID refers to technologies that use radio waves to identify and transmit information remotely from tagged objects. In a typical RFID tag, a microchip is attached to an antenna. The antenna is typically made of conductive metal, e.g., silver, copper, etc., and can have various shapes and geometries based on the radio frequency used. The chip and the antenna together constitute an RFID transponder or a tag. The chip contains the necessary information for identifying a tagged item. The function of the antenna is to communicate remotely through radio wave signals from a reader and establish the identity of the object. The ability to remotely monitor the flow of items from one place to another makes RFID an attractive technology. Its use in inventory control, security, etc. for packaged goods has serious financial ramifications. The ultimate goal is to implement an item level tagging. However, there are several roadblocks to the commercial use of RFID technology. A key factor is the inability to mass produce tags with required functionalities in a simple, reliable, and consistent manner, and producing them cost effectively, for making widespread applications feasible. At present, the cost of RFID transponders ranges from 50 cents to several dollars each, depending on their functional requirements. However, for item level tagging to be feasible, which would require billions of tags, the cost of the transponders has to be significantly less. Unfortunately, the currently available methods of tag manufacturing are not capable of meeting these requirements and therefore, the industry and the market, are at a stand still. The cost of a transponder is primarily dictated by (1) the cost of the antenna (2) the cost of the base material used (3) the cost of the chip (4) the cost of fabrication (5) the cost of quality control (6) the final yield value and (7) the overall capital investment required. The cost of the antennae has been identified to be one of the key limiting variables and therefore, an intense effort is being made to overcome this problem. Currently a method of chemical etching is used to produce an antenna from a conductive metal base. The process involves selective chemical etching of a conductive metal like silver or copper, with a strong acid or base to produce antennae of selective geometries. In subsequent multiple steps the antenna is attached to a chip via a conductive adhesive and is encased in an appropriate casing. The process is old, well understood and broadly practiced, however, wasteful, environmentally harmful, expensive, and therefore it is not able to take the industry to the next level. Several other methods e.g., metal stamping, selective electrolytic metal deposition, etc. have been tried as alternatives. However, none has been successful as a solution.
It is known in the art to produce electronic devices such as antennae by a technique generally described as “plating on plastics” The “plating on plastics” technology deposits an adherent coating of a metal or metal-based material onto the surface of a plastic substrate. “Plating on plastic” envisions the deposition of an initial metal coating using “electroless” plating followed by an optional deposition of metal using electrodeposition. Electroless plating involves chemically coating a nonconductive surface such as a plastic with a continuous metallic film. In this regard, U.S. Patent Application 20020135519 describes a radio frequency identification device (RFID) and many different ways of manufacturing such RFID antennae and transponders. An RFID transponder device is essentially composed of a small antenna attached to a programmable computer chip. Such transponders are required for transmitting electromagnetic radiation between the device and its surroundings, e.g., a reader or negotiator. Together, a transponder and a reader constitute a working RFID system. An RFID transponder may be passive, which can be used for transmission short range transmission. However, they may also be active and used for longer range transmission when a battery is attached to the transponder. Typically an RFID antenna is a flat metallic structure comprising of conductive and non-conductive areas. Its appropriate geometrical form is dictated by the frequencies used by the readers, typically in the kilohertz to megahertz ranges. An active or passive transponder is typically encased in a plastic laminated structure, e.g., a label, which is then attached to a pallet, case or boxes to obtain non-contact and remote “tag and traceability” features for inventory control, logistics, security and various other functions. However, most of the solid state electronic circuitry is rigid and therefore, not suitable for use on packaging items, as most such items are flexible materials. Therefore, a tremendous amount of effort is being used developing so called “printed electronics.” The goal of printed electronics is to print the required elements of an electrical circuitry onto the flexible substrate itself. The printed substrate with required elements can then be put onto the finished packaging as an added label, or as part of the packaging itself, or the item itself, thereby imparting the appropriate functionalities to the packaging and packaged items.
An essential element of an electronic circuit is geometric patterns of conductive and nonconductive (dielectric) areas. Typically this is done in a semiconductor circuit via the doped metal layers and dielectric layers. In a printed circuit, printing inks made with conductive particles, typically silver, are printed in respective patterns on a nonconductive (dielectric) film surface. Majority of commercially manufactured antennas today are based on selective chemical etching of metals in appropriate geometries. However, this process poses serious environmental and health and safety hazards.
Recently printing of RFID antennae with conductive inks is being developed as an environmentally friendly approach. Typically, inks containing expensive metals like silver powder, are printed onto dielectric substrates, e.g., plastic or paper, forming a conductive pattern. After printing, the printed structure requires a high temperature annealing process to sinter all the conductive particles together and form continuous conductive elements, in order to achieve necessary levels of conductivity. This limits the number of substrates that can be used to print on, since only expensive substrates with high softening temperature may be used to avoid any deformation. High temperature requirement also seriously reduces the overall productivity of the process. In addition, certain amount of ink film thickness must be deposited in order to obtain required conductivity levels. Moreover, due to high loading of silver powder requirement, the ink formulations must contain extraneous additives, including volatile organic compounds (VOC), to produce inks in a printable fashion. This makes the inks either less conductive or environmentally unfriendly. Printing of a substrate surface with a metal catalyst or “seed layer” and subsequent electrodeposition of copper metal in a bath onto the printed areas is another approach that is being studied. Although this process avoids any high temperature processing, it is a slow and wet process, with their inherent disadvantages.
German Patent DE 19951721 teaches a process of selective ablation of a thin, less than 250 nm metal layer, with UV lasers emitting between 248 nm and 532 nm. After ablation an additional step of metal electrodeposition is required in order to achieve required electrical conductivity. While this approach promises to yield silver free, less expensive antennae, the productivity of such process is very low since UV laser irradiation has a limited energy level for ablating thicker metal layers and electrodeposition process is extremely slow and requires utilization of wet chemistry.
All of these prior approaches also require subsequent multiple steps to convert the formed antennae into actual functional transponders. For example, a programmable computer chip must be attached to the antenna in a precise manner to obtain appropriate connection to the circuitry. Lack of connection would further reduce the yield of the process and above all, reliability of the transponders itself. For transponders with longer ranges, a battery must also be attached in a subsequent step.
Overall, the limitations of all the current and available approaches make the RFID antennae and transponders produced expensive, and limit their viability as commercially successful processes to satisfy projected industry needs for billions of inexpensive RFID transponders, for all types of applications including tagging of individual items. Similarly, commercial manufacturing of microwave susceptors or sensors also face similar limitations. These industries require a new, efficient, effective, environmentally friendly, robust, economical, and reliable manufacturing process to achieve their projected growth potentials.
At present the industry is focused on developing a printing method as a solution to this quandary. An ink made with conductive metal powder is printed on a flexible web substrate in the form of an antenna pattern. Next the printed patterns are heated to a high temperature, e.g., 130° C., to anneal the metal particles and form a continuous and conductive pathway. Subsequently, a suitable chip is attached in-line to the antenna via a conductive adhesive; quality controlled for right contacts and functionality, and the structure encased in an appropriate package for final assembly. However, this approach is complex. In order to achieve a high enough conductivity at printed film thickness, mainly silver is used as metal, which is expensive. The metal must also be in powder form with particle size ranging from micrometer to nanometer with their associated processing cost, further increasing the material cost. The substrate must be able to withstand high bake temperature ˜130° C. without thermal distortion, and therefore can primarily be expensive polyesters with high glass transition temperature (Tg). High web surface temperature requirement also slows down the overall printing process, increasing cost.
In order to convert the metal powder to an ink composition, resins, solvents, additives etc. must be added, most of which being non-conductive are not desired to remain with the printed antennae. Therefore, materials are selected which would volatilize during the baking step, which in turn create undesired environmental (VOC) and health & safety issues. In addition, despite the high heating step, the metal particles in the printed antenna simply do not attain their original metallic crystal structure and therefore results in printed antennae with somewhat reduced metal conductivity compared to their original value.
Attachment of computer chips onto the printed antennae is also a critical step. The chip connectors must be properly aligned right onto the antenna pads for appropriate coupling. Any misalignment would increase waste factor and above all would increase unreliability of the system, increasing potential risks and security breaches in several sensitive application areas. In order to minimize such risk factors “straps,” which are webs containing pre-positioned chips, can be positioned and aligned in a film lamination arrangement and chips transferred from the “strap” to the printed antenna web in-line. However, even with this approach there is at least 1-3% unreliability factor, which for mass adoption poses a great disadvantage.
The overall complexity, unreliability and economics of the current “printed antenna” process simply does not lend itself to be a solution to preventing the RFID market from achieving intended commercial success and there is a serious need for a new fabrication method for RFID antenna. The present invention discloses such an RFID antenna manufacturing process. The invented process starts with a metallized film which is provided with several computer chips in any pre-determined pattern via a conductive adhesive. This step can be done in-line or off-line. Next, an infrared (IR) laser ablates a portion of the metal layer in a predetermined manner to create an appropriate antenna form. A CAD/CAM or similar computer-hardware interface software can direct this exposure step. The process offers an increased in creating almost any possible antenna shape or form in one step. Since there is no baking step involved, an expensive high Tg film is no longer necessary. The metal layer can be almost any thin conductive metal layer, e.g., aluminum, silver, copper etc. However, a metallized Al layer is the most economical. The thickness of the Al layer can be adjusted easily to obtain a desired level of conductivity.
The present invention for mass manufacturing RFID devices avoids the roadblocks faced by the printing approach. The process does not require an expensive substrate, expensive conductive inks, no heat is required, no wet chemistry is involved and does not produce any VOC and/or health and safety issues. The process does not require a separate step of attaching computer chips to the formed antenna, thereby significantly improving the reliability, yield and robustness of the manufacturing process. The individual RFID devices, i.e., an antenna attached to a chip can be packaged in-line to produce a finished RFID tag in one single step.
Geometric patterns produced may be “passive,” e.g., an antenna for radio frequency identification device (RFID); a microwave susceptor; a circuit etc. They can also be “active” or “functional,” e.g., a complete transponder for RFID or a sensor or similar devices, when a metallized substrate, pre-fabricated with computer chip and a battery, is ablated. Any geometric form on a flat surface can be produced in a sheet or roll form. The conductive articles can be folded into a three dimensional architecture. Such production of fully active or passive devices, with high reliability and in high yield, produced in one step, is unique.
SUMMARY OF THE INVENTION
The invention provides a process for producing an electronic device which comprises,a) providing an electrically conductive metal layer on an electrically non-conductive substrate;b) thereafter electrically connecting an electronic circuit to the electrically conductive metal layer; andc) thereafter ablating a portion of the electrically conductive metal layer with infrared laser radiation to thereby form a pattern of electrically conductive areas and electrically non-conductive areas on the substrate, wherein at least a portion of the electrically conductive areas are electrically connected to the electronic circuit.
The invention also provides an article for producing an electronic device which comprises an electrically non-conductive substrate, a continuous, unpatterned, electrically conductive metal layer on the electrically non-conductive substrate, a continuous, unpatterned, infrared radiation sensitive composition layer between the electrically non-conductive substrate and the electrically conductive metal layer, and an electronic circuit electrically connected to the electrically conductive metal layer.
The invention also offers an alternative to the “printed electronics” approach to form electronic circuitry or devices.
Is this patent green technology? Respond with 'yes' or 'no'. |
7719328 | CROSS-REFERENCE TO RELATED APPLICATION
This application is related to a co-pending U.S. application Ser. No. 12/189,085, assigned to the same assignee as this application.
This application claims the priority of Chinese Patent Application No. 200810038056.0, filed May 23, 2008, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to the field of phase locked loop, and in particular to a self-biased phase locked loop.
BACKGROUND OF THE INVENTION
A Phase Locked Loop (PLL) is widely applied in a System on Chip (SOC) to constitute a frequency synthesizer, a clock generator and the like.FIG. 1is a basic structure of a PLL, in which a Phase Frequency Detector (PFD)10detects a frequency difference and a phase difference between an input signal Frefand a feedback signal Ffb, and generates pulse control signals UP and DN and sends them to a Charge Pump (CP)20. In the CP20, the pulse control signals UP and DN are converted into a current IPso as to charge or discharge a capacitor CPin a Loop Filter (LP)30, the LP30generates and sends a control voltage Vctrlto a Voltage Control Oscillator (VCO)40. The VCO40increases an oscillation frequency as the control voltage Vctrlis boosted, and the VCO40decreases the oscillation frequency as the control voltage Vctrlis dropped. An output signal Foutof the VCO40results in the feedback signal Ffbvia a divider50, so that the entire system forms a feedback system, and the frequency and phase of the output signal Foutare locked to a fixed frequency and phase.
A loop damping factor ξ of the PLL illustrated inFIG. 1is denoted by Equation (1) and a loop bandwidth ωnis denoted by Equation (2):
ξ=Rp2IpKvCpN(1)ωn=KvIpNCp(2)
where CPdenotes the capacitor of the LF30, RPdenotes a resistor of the LF30, IPdenotes a current for charging or discharging the capacitor CP(that is, the charging or discharging current output from the CP20), Kvdenotes a gain of the VCO40, and N denotes a frequency division factor of the divider50.
A high performance PLL should have advantages as follows: insusceptibility to variations of process, voltage and temperature (PVT), a wide frequency band, a low phase jitter and a small frequency change after being locked, a monolithic integrated filter, low power consumption for circuit and the like. However, it may be difficult to design a PLL satisfying all the requirements. A conventional PLL based on a VCO has a phase jitter caused by the noise of a power source and a substrate. The loop acts as a low-pass filter for the noise, and the narrower the loop bandwidth is, the lower the jitter will be. On the other hand, the capacitor of the filter can not be manufactured largely in size due to the requirement of monolithic integration, and at the same time, the bandwidth may be restricted by the loop stability condition. These restrictive conditions may result in the designed PLL with a narrow operation band and poor jitter performance.
A method for improving a bandwidth and lowering a jitter is to vary the bandwidth of the PLL to follow the operation frequency of the PLL. The loop has a narrow bandwidth and a low jitter in each operation status, but the varying bandwidth of the PLL may result in a very wide frequency range while reducing phase and frequency jitters introduced by the noise. An example of the method is a self-biased method to design a PLL with a loop damping factor ξ of a fixed value (typically 1). The damping factor ξ and the ratio of the loop width ωnto an angular frequency of an input signal ωref(hereinafter, referred to as an input frequency, ωref=2πFref, where Frefdenotes a frequency of the input signal) are determined only by a relative value of a capacitor during a fabrication process.
The technical document titled “Low-Jitter Process-Independent DLL and PLL Based on Self-Biased Techniques” (John G Maneatis,IEEE Journal OF Solid-State Circuits, VOL. 31, NO. 11, NOVEMBER 1996) discloses a basic structure of a self-biased PLL. As illustrated inFIG. 2, a capacitor C1and a bias generator60constitute a LF31, that is, the bias generator60creates a resistor of the LF31, and a current output from an additional CP21is applied at the output terminal of a bias voltage VBPof the bias generator60, so that a CP20charges and discharges the capacitor C1and the CP21charges and discharges the resistor created by the bias generator60.
The bias generator60generates bias voltages VBPand VPNfrom a control voltage VCTRLto provide input voltages to a VCO41. As illustrated inFIG. 3, the bias generator60includes a bias initialization circuit601, an amplifier bias circuit602, a differential amplifier circuit603, a half-buffer replication circuit604and a control voltage buffer circuit605. The amplifier bias circuit602provides the differential amplifier circuit603with a bias, and the differential amplifier circuit603adjusts the bias voltage VBN, so that the half-buffer replication circuit604and the control voltage buffer circuit605replicate the control voltage VCTRLto the bias voltage VBPat the output terminal, that is, VBP=VCTRL.
The VCO41includes n (n≧3) differential buffer delay stages with symmetric loads, for example, the VCO41including three differential buffer delay stages410with symmetric loads as illustrated inFIG. 4. The bias voltage VBNprovides the symmetric loads411and412with a bias current2ID(IDdenotes a current flowing through the symmetric load411or412). The bias voltage VBPof the symmetric loads411and412equals to the control voltage VCTRL, and an equivalent resistance of the symmetric loads411and412equals to ½ gm, where gmdenotes a transconductance of one transistor in the symmetric loads. A resistance of the symmetric loads411and412, a time delay of the buffer stages and a frequency of the output signal (CK+ or CK−) of the VCO41change with the variation of the control voltage VCTRL.
It is assumed that the current IPoutput from the CPs20and21is x times than the bias current2IDof the VCO41, that is, IP=x·2ID, and the resistance RPof the LF31created by the symmetric load606in the bias generator60is y times than an equivalent resistance Roof the buffer stages410of the VCO41, that is, Rp=yRo=y/2 gm. Therefore, a loop damping factor ξ of the self-biased PLL illustrated inFIG. 2is denoted by Equation (3) and the ratio of an loop bandwidth ωnto an input frequency ωrefis denoted by Equation (4):
ξ=y4xNC1CB(3)ωnωref=xN2πCBC1(4)
where CBdenotes a parasitic capacitor of the VCO41. Thus, parameters x and y and the frequency division factor N may satisfy a certain ratio relationship through a circuit design so as to counteract the frequency division factor N, so that the damping factor ξ of the PLL and the ratio ωn/ωrefof the loop bandwidth to the input frequency only depends on a relative value of the capacitors CBand C1in a fabrication process.
Based on the above structure of the self-biased PLL, John G. Maneatis et. al. propose a self-biased PLL (see, “Self-Biased High-Bandwidth Low-Jitter 1-to-4096 Multiplier Clock Generator PLL”, IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 38, NO. 11, NOVEMBER 2003) in which the parameters x and y in the formulas 3) and 4) are obtained. Moreover, this document also discloses that two NMOS transistors are added between the differential buffer delay stages with symmetric load in the VCO so as to clamp the phase difference between two output signals to be 180° and ensure that the VCO is able to oscillate (see, page 1801 and FIG. 11).
Compared with a basic PLL, the existing self-biased PLL has the following differences.
1. Two charge pumps are used to discharge and charge the capacitor and the resistor, while in the basic PLL only one charge pump is used.
2. The VCO includes differential buffer delay stages with symmetric loads, while in VCO of the basic PLL, the ring oscillator such as the differential ring oscillator is used. Thus, the NMOS transistor between the differential buffer delay stages with symmetric load may affect the frequency of the output signal from the VCO.
3. A bias generator is added to generate the bias voltage from the control voltage so as to provide the input voltage of the VCO. The circuit structure of the bias generator is complex.
Therefore, in order to meet the requirement that the damping factor of the loop needs to be kept as a fixed value, a large modification is made to the basic PLL to construct the existing self-biased PLL and the structure of the existing self-biased PLL is complex.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a self-biased PLL with simple structure which has a small modification with respect to the basic PLL.
In order to achieve the object, the present invention provides a self-biased PLL including:
a PFD adapted to detect a frequency difference and a phrase difference between an input signal and a feedback signal and generate a pulse control signal;
a CP adapted to generate a charging or discharging current which equals to a first control current input to the CP according to the pulse control signal output from the PFD;
an LF adapted to output the first control voltage so as to raise the first control voltage when the CP outputs a charging current and lower the first control voltage when the CP outputs a discharging current, the resistance of the LF is controlled by the first control voltage and a second control voltage which is adjusted according to the first control voltage and a second control current input to the LF;
a VCO adapted to generate an oscillation voltage and a bias current according to the first control voltage output from the LF, that is, increase an oscillation frequency of an output signal when the oscillation voltage is increased and decrease the oscillation frequency of the output signal when the oscillation voltage is lowered;
a divider adapted to perform a frequency division on the output signal of the VCO and generate the feedback signal input to the PFD; and
a bias current converter adapted to convert the bias current generated by the VCO into the first control current input to the CP and the second control current input to the LF, where the first control current equals to the ratio of the bias current to a constant, and the second control current equals to the ratio of the bias current to a frequency division factor of the divider.
Optionally, the LF further includes a filter unit adapted to increase the first control voltage when the CP outputs the charging current and lowers the first control voltage when the CP outputs the discharging current; and a filter bias unit adapted to the adjust the second control voltage according to the first control voltage and the second control current input to the LF.
In one embodiment, the filter bias unit includes a first voltage follower, a first NMOS transistor and a first current source, where, the first control voltage is input to one input terminal of the first voltage follower and the other input terminal of the first voltage follower is connected with an output terminal of the first voltage follower and a source of the first NMOS transistor. A gate and a drain of first NMOS transistor are provided with the second control voltage. The drain-source current of the first NMOS transistor are provided by the first current source. The current provided by the first current source is the second control current output from the bias current converter.
The filter unit further includes a resistor, a capacitor and a second current source. The resistor of the filter unit constructs the resistance of the LF and includes the second NMOS transistor, and the capacitor includes a first capacitor and a second capacitor. One terminal of the first capacitor is connected with a source of the second NMOS transistor. One terminal of the second capacitor is connected with a drain of the second NMOS and the other terminal is connected with the other terminal of the first capacitor and is provided with the first voltage. The drain voltage of the second NMOS transistor is the first control voltage and the gate voltage is the second control voltage. The second current source is connected with the second capacitor and the current of the second current source is the charging or discharging current output from the CP.
Optionally, the VCO includes an oscillation unit adapted to increase the oscillation frequency of the output signal when the oscillation voltage is increased and decrease the oscillation frequency of the output signal when the oscillation voltage is lowered; and an oscillation voltage and bias current generating unit, adapted to generate the bias current and the oscillation voltage provided to the oscillation unit according to the first control voltage.
In one embodiment, the oscillation unit includes at least two differential buffer delay stages connected in series. The positive input terminal of the back differential buffer delay stage is connected with the negative output terminal of the front differential buffer delay stage and the negative input terminal of the back differential buffer delay stage is connected with the positive output terminal of the front differential buffer delay stage. The positive input terminal of the first differential buffer delay stage is connected with the positive output terminal of the last differential buffer delay stage and the negative input terminal of the first differential buffer delay stage is connected with the negative output terminal of the last differential buffer delay stage. The oscillation frequency of the differential buffer delay stage is controlled by the oscillation voltage input.
The differential buffer delay stage includes a third NMOS transistor, a fourth NMOS transistor, a first PMOS transistor, a fifth NMOS transistor, a sixth NMOS transistor and a second PMOS transistor. The gate of the third NMOS transistor and the gate of the first PMOS transistor are positive input terminals and the drain of the third NMOS transistor, the drain of the fourth NMOS transistor, the drain of the first PMOS transistor and the gate of the sixth NMOS transistor are negative output terminals. The gate of the fifth NMOS transistor and the gate of the second PMOS transistor are negative input terminals. The drain of the fifth NMOS transistor, the drain of the sixth NMOS transistor, the drain of the second PMOS transistor and the gate of the fourth NMOS transistor are positive output terminals. The oscillation voltage is provided to the sources of the first PMOS transistor and the second PMOS transistor and the first voltage is provided to the sources of the third NMOS transistor, the fourth NMOS transistor, the fifth NMOS transistor and the sixth NMOS transistor.
The oscillation voltage and bias current unit includes a seventh NMOS transistor, an eighth NMOS transistor, a ninth NMOS transistor, a second voltage follower, a third PMOS transistor and a fourth PMOS transistor. The gate voltage of the seventh NMOS transistor is the first control voltage and the source voltage is the oscillation voltage. The drain of the eighth NMOS transistor is provided with the second voltage and the gate is connected with the RC filter circuit. The drain of the seventh NMOS transistor is connected with the source of the eighth NMOS transistor. The gate of the ninth NMOS transistor is connected with the gate of the seventh NMOS transistor and the source of the ninth NMOS transistor is connected with the output terminal of the second voltage follower. One input terminal of the second voltage follower is provided with the oscillation voltage and the other input terminal is connected with the output terminal of the second voltage follower. The drain of the third PMOS transistor is connected with the drain of the ninth NMOS transistor. The third PMOS transistor and the fourth PMOS transistor construct a current mirror. The current output from the drain of the fourth PMOS transistor is the bias current.
Optionally, the bias current converter includes a first current mirror adapted to be provided with the bias current and output the first control current which is 1/x times than the input current, where x is a constant; and a second current mirror adapted to be provided with the bias current and output the second control current which is 1/N times than the input current, where N is a frequency division factor of the divider.
Compared with the conventional technical means, in the technical solution according to one embedment of the present invention, only one CP is needed to meet the requirement for the self-biased PLL that the damping factor of the loop needs to be kept as a fixed value. Compared with the existing self-biased PLL which includes two CPs, the circuit structure of the self-biased PLL is simplified. Because the oscillation unit of the VCO may directly employ the existing differential ring oscillator, the modification to the basic PLL is very small. Compared with the existing self-biased PLL in which the NMOS transistor is added between the differential buffer delay stages with symmetric load, because no NMOS transistor is added between the differential buffer delay stages to ensure that the oscillation unit is able to oscillate, the frequency of the output signal of the VCO will not be affected and the circuit structure is simplified.
In addition, the technical solution according to the present invention also provides the following advantages.
Because the complex bias generator circuit is omitted, the circuit structure of the self-biased PLL is further simplified. Moreover, because the circuit structures of the LF, VCO and the bias current generator are simple, they are easy to be implemented.
The circuit of VCO may restrain the power supply noise. The power supply noise may affect the oscillation voltage. If the noise of the oscillation voltage is small, the frequency of the output signal of the VCO is stable and has a low jitter. Thus, the phase noise of the PLL is also small.
The loop bandwidth of the PLL is optimized. The loop bandwidth will not be too narrow when the input frequency is low and the loop bandwidth will not be too wide when the input frequency is high. Thus, the low frequency noise at the input terminal and the high frequency noise from the VCO can be restrained as far as possible.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: CROSS-REFERENCE TO RELATED APPLICATION
This application is related to a co-pending U.S. application Ser. No. 12/189,085, assigned to the same assignee as this application.
This application claims the priority of Chinese Patent Application No. 200810038056.0, filed May 23, 2008, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to the field of phase locked loop, and in particular to a self-biased phase locked loop.
BACKGROUND OF THE INVENTION
A Phase Locked Loop (PLL) is widely applied in a System on Chip (SOC) to constitute a frequency synthesizer, a clock generator and the like.FIG. 1is a basic structure of a PLL, in which a Phase Frequency Detector (PFD)10detects a frequency difference and a phase difference between an input signal Frefand a feedback signal Ffb, and generates pulse control signals UP and DN and sends them to a Charge Pump (CP)20. In the CP20, the pulse control signals UP and DN are converted into a current IPso as to charge or discharge a capacitor CPin a Loop Filter (LP)30, the LP30generates and sends a control voltage Vctrlto a Voltage Control Oscillator (VCO)40. The VCO40increases an oscillation frequency as the control voltage Vctrlis boosted, and the VCO40decreases the oscillation frequency as the control voltage Vctrlis dropped. An output signal Foutof the VCO40results in the feedback signal Ffbvia a divider50, so that the entire system forms a feedback system, and the frequency and phase of the output signal Foutare locked to a fixed frequency and phase.
A loop damping factor ξ of the PLL illustrated inFIG. 1is denoted by Equation (1) and a loop bandwidth ωnis denoted by Equation (2):
ξ=Rp2IpKvCpN(1)ωn=KvIpNCp(2)
where CPdenotes the capacitor of the LF30, RPdenotes a resistor of the LF30, IPdenotes a current for charging or discharging the capacitor CP(that is, the charging or discharging current output from the CP20), Kvdenotes a gain of the VCO40, and N denotes a frequency division factor of the divider50.
A high performance PLL should have advantages as follows: insusceptibility to variations of process, voltage and temperature (PVT), a wide frequency band, a low phase jitter and a small frequency change after being locked, a monolithic integrated filter, low power consumption for circuit and the like. However, it may be difficult to design a PLL satisfying all the requirements. A conventional PLL based on a VCO has a phase jitter caused by the noise of a power source and a substrate. The loop acts as a low-pass filter for the noise, and the narrower the loop bandwidth is, the lower the jitter will be. On the other hand, the capacitor of the filter can not be manufactured largely in size due to the requirement of monolithic integration, and at the same time, the bandwidth may be restricted by the loop stability condition. These restrictive conditions may result in the designed PLL with a narrow operation band and poor jitter performance.
A method for improving a bandwidth and lowering a jitter is to vary the bandwidth of the PLL to follow the operation frequency of the PLL. The loop has a narrow bandwidth and a low jitter in each operation status, but the varying bandwidth of the PLL may result in a very wide frequency range while reducing phase and frequency jitters introduced by the noise. An example of the method is a self-biased method to design a PLL with a loop damping factor ξ of a fixed value (typically 1). The damping factor ξ and the ratio of the loop width ωnto an angular frequency of an input signal ωref(hereinafter, referred to as an input frequency, ωref=2πFref, where Frefdenotes a frequency of the input signal) are determined only by a relative value of a capacitor during a fabrication process.
The technical document titled “Low-Jitter Process-Independent DLL and PLL Based on Self-Biased Techniques” (John G Maneatis,IEEE Journal OF Solid-State Circuits, VOL. 31, NO. 11, NOVEMBER 1996) discloses a basic structure of a self-biased PLL. As illustrated inFIG. 2, a capacitor C1and a bias generator60constitute a LF31, that is, the bias generator60creates a resistor of the LF31, and a current output from an additional CP21is applied at the output terminal of a bias voltage VBPof the bias generator60, so that a CP20charges and discharges the capacitor C1and the CP21charges and discharges the resistor created by the bias generator60.
The bias generator60generates bias voltages VBPand VPNfrom a control voltage VCTRLto provide input voltages to a VCO41. As illustrated inFIG. 3, the bias generator60includes a bias initialization circuit601, an amplifier bias circuit602, a differential amplifier circuit603, a half-buffer replication circuit604and a control voltage buffer circuit605. The amplifier bias circuit602provides the differential amplifier circuit603with a bias, and the differential amplifier circuit603adjusts the bias voltage VBN, so that the half-buffer replication circuit604and the control voltage buffer circuit605replicate the control voltage VCTRLto the bias voltage VBPat the output terminal, that is, VBP=VCTRL.
The VCO41includes n (n≧3) differential buffer delay stages with symmetric loads, for example, the VCO41including three differential buffer delay stages410with symmetric loads as illustrated inFIG. 4. The bias voltage VBNprovides the symmetric loads411and412with a bias current2ID(IDdenotes a current flowing through the symmetric load411or412). The bias voltage VBPof the symmetric loads411and412equals to the control voltage VCTRL, and an equivalent resistance of the symmetric loads411and412equals to ½ gm, where gmdenotes a transconductance of one transistor in the symmetric loads. A resistance of the symmetric loads411and412, a time delay of the buffer stages and a frequency of the output signal (CK+ or CK−) of the VCO41change with the variation of the control voltage VCTRL.
It is assumed that the current IPoutput from the CPs20and21is x times than the bias current2IDof the VCO41, that is, IP=x·2ID, and the resistance RPof the LF31created by the symmetric load606in the bias generator60is y times than an equivalent resistance Roof the buffer stages410of the VCO41, that is, Rp=yRo=y/2 gm. Therefore, a loop damping factor ξ of the self-biased PLL illustrated inFIG. 2is denoted by Equation (3) and the ratio of an loop bandwidth ωnto an input frequency ωrefis denoted by Equation (4):
ξ=y4xNC1CB(3)ωnωref=xN2πCBC1(4)
where CBdenotes a parasitic capacitor of the VCO41. Thus, parameters x and y and the frequency division factor N may satisfy a certain ratio relationship through a circuit design so as to counteract the frequency division factor N, so that the damping factor ξ of the PLL and the ratio ωn/ωrefof the loop bandwidth to the input frequency only depends on a relative value of the capacitors CBand C1in a fabrication process.
Based on the above structure of the self-biased PLL, John G. Maneatis et. al. propose a self-biased PLL (see, “Self-Biased High-Bandwidth Low-Jitter 1-to-4096 Multiplier Clock Generator PLL”, IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 38, NO. 11, NOVEMBER 2003) in which the parameters x and y in the formulas 3) and 4) are obtained. Moreover, this document also discloses that two NMOS transistors are added between the differential buffer delay stages with symmetric load in the VCO so as to clamp the phase difference between two output signals to be 180° and ensure that the VCO is able to oscillate (see, page 1801 and FIG. 11).
Compared with a basic PLL, the existing self-biased PLL has the following differences.
1. Two charge pumps are used to discharge and charge the capacitor and the resistor, while in the basic PLL only one charge pump is used.
2. The VCO includes differential buffer delay stages with symmetric loads, while in VCO of the basic PLL, the ring oscillator such as the differential ring oscillator is used. Thus, the NMOS transistor between the differential buffer delay stages with symmetric load may affect the frequency of the output signal from the VCO.
3. A bias generator is added to generate the bias voltage from the control voltage so as to provide the input voltage of the VCO. The circuit structure of the bias generator is complex.
Therefore, in order to meet the requirement that the damping factor of the loop needs to be kept as a fixed value, a large modification is made to the basic PLL to construct the existing self-biased PLL and the structure of the existing self-biased PLL is complex.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a self-biased PLL with simple structure which has a small modification with respect to the basic PLL.
In order to achieve the object, the present invention provides a self-biased PLL including:
a PFD adapted to detect a frequency difference and a phrase difference between an input signal and a feedback signal and generate a pulse control signal;
a CP adapted to generate a charging or discharging current which equals to a first control current input to the CP according to the pulse control signal output from the PFD;
an LF adapted to output the first control voltage so as to raise the first control voltage when the CP outputs a charging current and lower the first control voltage when the CP outputs a discharging current, the resistance of the LF is controlled by the first control voltage and a second control voltage which is adjusted according to the first control voltage and a second control current input to the LF;
a VCO adapted to generate an oscillation voltage and a bias current according to the first control voltage output from the LF, that is, increase an oscillation frequency of an output signal when the oscillation voltage is increased and decrease the oscillation frequency of the output signal when the oscillation voltage is lowered;
a divider adapted to perform a frequency division on the output signal of the VCO and generate the feedback signal input to the PFD; and
a bias current converter adapted to convert the bias current generated by the VCO into the first control current input to the CP and the second control current input to the LF, where the first control current equals to the ratio of the bias current to a constant, and the second control current equals to the ratio of the bias current to a frequency division factor of the divider.
Optionally, the LF further includes a filter unit adapted to increase the first control voltage when the CP outputs the charging current and lowers the first control voltage when the CP outputs the discharging current; and a filter bias unit adapted to the adjust the second control voltage according to the first control voltage and the second control current input to the LF.
In one embodiment, the filter bias unit includes a first voltage follower, a first NMOS transistor and a first current source, where, the first control voltage is input to one input terminal of the first voltage follower and the other input terminal of the first voltage follower is connected with an output terminal of the first voltage follower and a source of the first NMOS transistor. A gate and a drain of first NMOS transistor are provided with the second control voltage. The drain-source current of the first NMOS transistor are provided by the first current source. The current provided by the first current source is the second control current output from the bias current converter.
The filter unit further includes a resistor, a capacitor and a second current source. The resistor of the filter unit constructs the resistance of the LF and includes the second NMOS transistor, and the capacitor includes a first capacitor and a second capacitor. One terminal of the first capacitor is connected with a source of the second NMOS transistor. One terminal of the second capacitor is connected with a drain of the second NMOS and the other terminal is connected with the other terminal of the first capacitor and is provided with the first voltage. The drain voltage of the second NMOS transistor is the first control voltage and the gate voltage is the second control voltage. The second current source is connected with the second capacitor and the current of the second current source is the charging or discharging current output from the CP.
Optionally, the VCO includes an oscillation unit adapted to increase the oscillation frequency of the output signal when the oscillation voltage is increased and decrease the oscillation frequency of the output signal when the oscillation voltage is lowered; and an oscillation voltage and bias current generating unit, adapted to generate the bias current and the oscillation voltage provided to the oscillation unit according to the first control voltage.
In one embodiment, the oscillation unit includes at least two differential buffer delay stages connected in series. The positive input terminal of the back differential buffer delay stage is connected with the negative output terminal of the front differential buffer delay stage and the negative input terminal of the back differential buffer delay stage is connected with the positive output terminal of the front differential buffer delay stage. The positive input terminal of the first differential buffer delay stage is connected with the positive output terminal of the last differential buffer delay stage and the negative input terminal of the first differential buffer delay stage is connected with the negative output terminal of the last differential buffer delay stage. The oscillation frequency of the differential buffer delay stage is controlled by the oscillation voltage input.
The differential buffer delay stage includes a third NMOS transistor, a fourth NMOS transistor, a first PMOS transistor, a fifth NMOS transistor, a sixth NMOS transistor and a second PMOS transistor. The gate of the third NMOS transistor and the gate of the first PMOS transistor are positive input terminals and the drain of the third NMOS transistor, the drain of the fourth NMOS transistor, the drain of the first PMOS transistor and the gate of the sixth NMOS transistor are negative output terminals. The gate of the fifth NMOS transistor and the gate of the second PMOS transistor are negative input terminals. The drain of the fifth NMOS transistor, the drain of the sixth NMOS transistor, the drain of the second PMOS transistor and the gate of the fourth NMOS transistor are positive output terminals. The oscillation voltage is provided to the sources of the first PMOS transistor and the second PMOS transistor and the first voltage is provided to the sources of the third NMOS transistor, the fourth NMOS transistor, the fifth NMOS transistor and the sixth NMOS transistor.
The oscillation voltage and bias current unit includes a seventh NMOS transistor, an eighth NMOS transistor, a ninth NMOS transistor, a second voltage follower, a third PMOS transistor and a fourth PMOS transistor. The gate voltage of the seventh NMOS transistor is the first control voltage and the source voltage is the oscillation voltage. The drain of the eighth NMOS transistor is provided with the second voltage and the gate is connected with the RC filter circuit. The drain of the seventh NMOS transistor is connected with the source of the eighth NMOS transistor. The gate of the ninth NMOS transistor is connected with the gate of the seventh NMOS transistor and the source of the ninth NMOS transistor is connected with the output terminal of the second voltage follower. One input terminal of the second voltage follower is provided with the oscillation voltage and the other input terminal is connected with the output terminal of the second voltage follower. The drain of the third PMOS transistor is connected with the drain of the ninth NMOS transistor. The third PMOS transistor and the fourth PMOS transistor construct a current mirror. The current output from the drain of the fourth PMOS transistor is the bias current.
Optionally, the bias current converter includes a first current mirror adapted to be provided with the bias current and output the first control current which is 1/x times than the input current, where x is a constant; and a second current mirror adapted to be provided with the bias current and output the second control current which is 1/N times than the input current, where N is a frequency division factor of the divider.
Compared with the conventional technical means, in the technical solution according to one embedment of the present invention, only one CP is needed to meet the requirement for the self-biased PLL that the damping factor of the loop needs to be kept as a fixed value. Compared with the existing self-biased PLL which includes two CPs, the circuit structure of the self-biased PLL is simplified. Because the oscillation unit of the VCO may directly employ the existing differential ring oscillator, the modification to the basic PLL is very small. Compared with the existing self-biased PLL in which the NMOS transistor is added between the differential buffer delay stages with symmetric load, because no NMOS transistor is added between the differential buffer delay stages to ensure that the oscillation unit is able to oscillate, the frequency of the output signal of the VCO will not be affected and the circuit structure is simplified.
In addition, the technical solution according to the present invention also provides the following advantages.
Because the complex bias generator circuit is omitted, the circuit structure of the self-biased PLL is further simplified. Moreover, because the circuit structures of the LF, VCO and the bias current generator are simple, they are easy to be implemented.
The circuit of VCO may restrain the power supply noise. The power supply noise may affect the oscillation voltage. If the noise of the oscillation voltage is small, the frequency of the output signal of the VCO is stable and has a low jitter. Thus, the phase noise of the PLL is also small.
The loop bandwidth of the PLL is optimized. The loop bandwidth will not be too narrow when the input frequency is low and the loop bandwidth will not be too wide when the input frequency is high. Thus, the low frequency noise at the input terminal and the high frequency noise from the VCO can be restrained as far as possible.
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7719109 | FIELD OF INVENTION
The invention relates to the field of microelectronics, and more particularly to the packaging of microelectronics.
PRIOR AND RELATED ART
To make a system with an integrated circuit, such as a microprocessor, a microelectronic die is often bonded to a mounting substrate. The mounting substrate may be coupled to another component such as a printed circuit board. Electrical contacts on the die may be connected to corresponding contacts on the side of the mounting substrate facing the die.
As increasingly complex microelectronic dies consume more power, the need for decoupling capacitors near the die also increases. Accordingly, decoupling capacitors are often mounted close to the die on the same mounting substrate surface to which the die is attached. The number and size of surface mounted capacitors that can be placed near the die is limited by the footprint of the capacitors and space available on the mounting substrate.
Materials used to construct the dies and mounting substrates have a wide range of thermal expansion properties. The linear coefficient of thermal expansion (CTE) relates a change in a material's linear dimension to a corresponding change in temperature. The CTE of a material is given in parts per million per degree of temperature change (ppm/K°). Often, integrated circuits (IC) are fabricated on silicon which has a CTE of about 3 ppm/K°. Organic mounting substrates commonly comprise a fiber reinforced glass core having a CTE between about 15-20 ppm/K°. Organic mounting substrates are often used because of their physical strength, good electrical qualities, and relatively low cost. The CTE mismatch between two or more materials, such as between a microelectronic die and a mounting substrate, induces stress at the interface of the materials during manufacture and operation.
Controlled Collapsible Chip Connection (C4) is one popular method of electrically and mechanically attaching a die to a mounting substrate. Conductive solder bumps (C4 joints) are placed on contacts on the die at portions corresponding to contacts on the mounting substrate. The surface of the die having C4 joints is then placed onto the mounting substrate and attached using a re-flow process. During the re-flow process, the temperature is raised to the melting point of the solder bumps. As long as the temperature remains above the melting point of the solder bumps, both the die and mounting substrate are free to expand independently.
However, as the temperature drops below the melting point of the solder relative motion between the die and mounting substrate is prevented and they are forced to contract together. The mounting substrate, due to its larger CTE, contracts more than the die. Consequently, the C4 joints are stressed and often crack. Stresses on the C4 joints tend to be greatest near the edges of the die where the relative movement between the die and the mounting substrate is greatest. This problem is exacerbated by large dies and thick, stiff substrates, such as those used in high end servers.
Presently, the problem of C4 joint cracking due to CTE mismatch is addressed by using entirely ceramic mounting substrates that have CTEs more closely matching the CTE of silicon. This solution is not ideal because of the high cost of ceramic substrates. Alternatively, sacrificial C4 joints may be introduced around the periphery of the die. This alternative, however, reduces the total amount of power and input/output (I/O) available under the die. Likewise, increasing the pitch between C4 joints reduces the amount of power and I/O available to a chip.
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SUMMARY: FIELD OF INVENTION
The invention relates to the field of microelectronics, and more particularly to the packaging of microelectronics.
PRIOR AND RELATED ART
To make a system with an integrated circuit, such as a microprocessor, a microelectronic die is often bonded to a mounting substrate. The mounting substrate may be coupled to another component such as a printed circuit board. Electrical contacts on the die may be connected to corresponding contacts on the side of the mounting substrate facing the die.
As increasingly complex microelectronic dies consume more power, the need for decoupling capacitors near the die also increases. Accordingly, decoupling capacitors are often mounted close to the die on the same mounting substrate surface to which the die is attached. The number and size of surface mounted capacitors that can be placed near the die is limited by the footprint of the capacitors and space available on the mounting substrate.
Materials used to construct the dies and mounting substrates have a wide range of thermal expansion properties. The linear coefficient of thermal expansion (CTE) relates a change in a material's linear dimension to a corresponding change in temperature. The CTE of a material is given in parts per million per degree of temperature change (ppm/K°). Often, integrated circuits (IC) are fabricated on silicon which has a CTE of about 3 ppm/K°. Organic mounting substrates commonly comprise a fiber reinforced glass core having a CTE between about 15-20 ppm/K°. Organic mounting substrates are often used because of their physical strength, good electrical qualities, and relatively low cost. The CTE mismatch between two or more materials, such as between a microelectronic die and a mounting substrate, induces stress at the interface of the materials during manufacture and operation.
Controlled Collapsible Chip Connection (C4) is one popular method of electrically and mechanically attaching a die to a mounting substrate. Conductive solder bumps (C4 joints) are placed on contacts on the die at portions corresponding to contacts on the mounting substrate. The surface of the die having C4 joints is then placed onto the mounting substrate and attached using a re-flow process. During the re-flow process, the temperature is raised to the melting point of the solder bumps. As long as the temperature remains above the melting point of the solder bumps, both the die and mounting substrate are free to expand independently.
However, as the temperature drops below the melting point of the solder relative motion between the die and mounting substrate is prevented and they are forced to contract together. The mounting substrate, due to its larger CTE, contracts more than the die. Consequently, the C4 joints are stressed and often crack. Stresses on the C4 joints tend to be greatest near the edges of the die where the relative movement between the die and the mounting substrate is greatest. This problem is exacerbated by large dies and thick, stiff substrates, such as those used in high end servers.
Presently, the problem of C4 joint cracking due to CTE mismatch is addressed by using entirely ceramic mounting substrates that have CTEs more closely matching the CTE of silicon. This solution is not ideal because of the high cost of ceramic substrates. Alternatively, sacrificial C4 joints may be introduced around the periphery of the die. This alternative, however, reduces the total amount of power and input/output (I/O) available under the die. Likewise, increasing the pitch between C4 joints reduces the amount of power and I/O available to a chip.
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7677942 | CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on 7 Oct. 2005 and there duly assigned Serial No. 10-2005-0094251.
FIELD OF THE INVENTION
The present invention relates to a method of making a plasma display panel. More particularly, the present invention relates to a method of making a plasma display panel in which a dielectric layer to cover an address electrode and a dielectric layer covering display electrodes are formed in a singular process using a two-layer green sheet, and which thereby simplifies a manufacturing process and reduces manufacturing time and inferior products.
BACKGROUND OF THE INVENTION
A plasma display panel (herein referred to as a “PDP”) is a display apparatus using plasma discharge. Vacuum ultraviolet (herein referred to as “VUV”) rays emitted by the plasma discharge excite phosphor layers, and in turn, the phosphor layers emit visible light. The visible light is used to display images. Recently, the PDP has been implemented as a thin wide screen apparatus having a screen size of 60 inches or more and a thickness of 10 cm or less. In addition, since it is a spontaneous light emitting apparatus like a cathode ray tube (CRT), the PDP has excellent color reproducibility. Further, the PDP has no image distortion associated with its viewing angle.
Moreover, the PDP can be manufactured by a simpler method than a liquid crystal display (LCD) can, so the PDP can be produced with a low production cost and high productivity. Therefore, the PDP is expected to be the next generation of flat display apparatus for industry and home televisions.
Since the 1970s, various structures of the PDP have been developed. In recent years, a three-electrode surface-discharge type PDP has been widely used. In the three-electrode surface-discharge PDP, two electrodes including scan and sustain electrodes are disposed on one substrate, and one address electrode is disposed on the other substrate in a direction intersecting the scan and sustain electrodes. The two substrates are separated from each other so as to provide a discharge cell. The discharge cell is filled with a discharge gas. In general, in the three-electrode surface-discharge PDP, the presence of a discharge is determined by an address discharge. Specifically, the address discharge is generated as a facing discharge between the scan electrode controlled separately and the address electrode opposite to the scan electrode, and a sustain discharge related to brightness is generated as a surface discharge between the scan and sustain electrodes disposed on the same substrate.
A general AC three-electrode surface-discharge PDP includes a front substrate and a rear substrate facing each other. Address electrodes are disposed on the rear substrate along one direction, and a dielectric layer is disposed on the entire the front substrate so as to cover the address electrodes. A plurality of barrier ribs are disposed on the dielectric layer so as to define discharge cells. Red (R), green (G), and blue (B) phosphor layers are disposed in the respective discharge cells partitioned by the barrier ribs. Pairs of display electrodes are disposed on the front substrate in a direction intersecting the direction of address electrodes. Each pair of display electrodes includes a transparent electrode and a bus electrode. A dielectric layer and a protection layer made of magnesium oxide (MgO) are sequentially formed on the entire surface of the front substrate so as to cover the display electrodes. The intersections between the address electrodes of the rear substrate and the pairs of display electrodes correspond to the discharge cells.
A metal electrode in such a structure of a plasma display panel is generally formed using a pattern-printing method. The pattern-printing method is relatively simple and can make a metal electrode with narrow intervals. However, there is a limit for forming a fine width of electrodes, and the method is not suitable for large screens and the high-definition of high resolution PDPs.
SUMMARY OF THE INVENTION
An exemplary embodiment of the present invention provides a method of making a plasma display panel which simplifies a manufacturing process, and reduces manufacturing time and inferior products.
According to an embodiment of the present invention, a method of making a plasma display panel includes the following steps. An address electrode is formed on a front substrate, a green sheet is formed to cover the address electrode, a dielectric layer pattern is formed by exposing, developing, and firing the green sheet, a composition for a display electrode is filled in the dielectric layer pattern and then fired to form a patterned display electrode, and a dielectric layer is formed to cover the patterned display electrode. The green sheet includes a first green sheet that is formed using a dielectric composition (i.e., a composition for a first dielectric layer), and a second green sheet that is formed on the first green sheet and that uses a photosensitive dielectric composition (i.e., a photosensitive composition for a second dielectric layer).
The composition for a first dielectric layer may include 50 to 70 wt % of a glass powder with respect to the total weight of the composition for the first dielectric layer.
The glass powder may include at least one selected from the group consisting of ZnO, B2O3, Al2O3, SiO2, SnO, P2O5, Sb2O3, and Bi2O3. The glass powder may further include at least one material selected from the group consisting of oxides of group 1 to group 5 metal elements, oxides of lanthanum-based elements, and fluorides of group 1 metal elements.
The photosensitive composition for the second dielectric layer may include a glass powder, a photosensitive binder, a cross-linking compound having at least two ethylene-based double bonds, a photopolymerization initiator, and a solvent.
According to another embodiment of the present invention, a method of making a plasma display panel includes the following steps. An address electrode is formed on a front substrate, a green sheet is formed to cover the address electrode, a dielectric layer pattern is formed by exposing, developing, and firing the green sheet, a composition for a display electrode is filled in the dielectric layer pattern and then fired to form a patterned display electrode, a dielectric layer is formed to cover the patterned display electrode, thereby fabricating a front substrate, a patterned barrier rib is formed on a rear substrate, phosphor layers are formed on the barrier rib, and the fabricated front substrate and rear substrate are assembled, evacuated, and sealed. The green sheet includes a first green sheet that is formed using a composition for a first dielectric layer, and a second green sheet that is formed on the first green sheet and that uses a photosensitive composition for a second dielectric layer.
According to yet another embodiment of the present invention, a green sheet for forming dielectric layers of a plasma display panel, including a first green sheet comprising a dielectric composition and a second green sheet formed on the first green sheet, and the second green sheet comprising a photosensitive dielectric composition.
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SUMMARY: CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on 7 Oct. 2005 and there duly assigned Serial No. 10-2005-0094251.
FIELD OF THE INVENTION
The present invention relates to a method of making a plasma display panel. More particularly, the present invention relates to a method of making a plasma display panel in which a dielectric layer to cover an address electrode and a dielectric layer covering display electrodes are formed in a singular process using a two-layer green sheet, and which thereby simplifies a manufacturing process and reduces manufacturing time and inferior products.
BACKGROUND OF THE INVENTION
A plasma display panel (herein referred to as a “PDP”) is a display apparatus using plasma discharge. Vacuum ultraviolet (herein referred to as “VUV”) rays emitted by the plasma discharge excite phosphor layers, and in turn, the phosphor layers emit visible light. The visible light is used to display images. Recently, the PDP has been implemented as a thin wide screen apparatus having a screen size of 60 inches or more and a thickness of 10 cm or less. In addition, since it is a spontaneous light emitting apparatus like a cathode ray tube (CRT), the PDP has excellent color reproducibility. Further, the PDP has no image distortion associated with its viewing angle.
Moreover, the PDP can be manufactured by a simpler method than a liquid crystal display (LCD) can, so the PDP can be produced with a low production cost and high productivity. Therefore, the PDP is expected to be the next generation of flat display apparatus for industry and home televisions.
Since the 1970s, various structures of the PDP have been developed. In recent years, a three-electrode surface-discharge type PDP has been widely used. In the three-electrode surface-discharge PDP, two electrodes including scan and sustain electrodes are disposed on one substrate, and one address electrode is disposed on the other substrate in a direction intersecting the scan and sustain electrodes. The two substrates are separated from each other so as to provide a discharge cell. The discharge cell is filled with a discharge gas. In general, in the three-electrode surface-discharge PDP, the presence of a discharge is determined by an address discharge. Specifically, the address discharge is generated as a facing discharge between the scan electrode controlled separately and the address electrode opposite to the scan electrode, and a sustain discharge related to brightness is generated as a surface discharge between the scan and sustain electrodes disposed on the same substrate.
A general AC three-electrode surface-discharge PDP includes a front substrate and a rear substrate facing each other. Address electrodes are disposed on the rear substrate along one direction, and a dielectric layer is disposed on the entire the front substrate so as to cover the address electrodes. A plurality of barrier ribs are disposed on the dielectric layer so as to define discharge cells. Red (R), green (G), and blue (B) phosphor layers are disposed in the respective discharge cells partitioned by the barrier ribs. Pairs of display electrodes are disposed on the front substrate in a direction intersecting the direction of address electrodes. Each pair of display electrodes includes a transparent electrode and a bus electrode. A dielectric layer and a protection layer made of magnesium oxide (MgO) are sequentially formed on the entire surface of the front substrate so as to cover the display electrodes. The intersections between the address electrodes of the rear substrate and the pairs of display electrodes correspond to the discharge cells.
A metal electrode in such a structure of a plasma display panel is generally formed using a pattern-printing method. The pattern-printing method is relatively simple and can make a metal electrode with narrow intervals. However, there is a limit for forming a fine width of electrodes, and the method is not suitable for large screens and the high-definition of high resolution PDPs.
SUMMARY OF THE INVENTION
An exemplary embodiment of the present invention provides a method of making a plasma display panel which simplifies a manufacturing process, and reduces manufacturing time and inferior products.
According to an embodiment of the present invention, a method of making a plasma display panel includes the following steps. An address electrode is formed on a front substrate, a green sheet is formed to cover the address electrode, a dielectric layer pattern is formed by exposing, developing, and firing the green sheet, a composition for a display electrode is filled in the dielectric layer pattern and then fired to form a patterned display electrode, and a dielectric layer is formed to cover the patterned display electrode. The green sheet includes a first green sheet that is formed using a dielectric composition (i.e., a composition for a first dielectric layer), and a second green sheet that is formed on the first green sheet and that uses a photosensitive dielectric composition (i.e., a photosensitive composition for a second dielectric layer).
The composition for a first dielectric layer may include 50 to 70 wt % of a glass powder with respect to the total weight of the composition for the first dielectric layer.
The glass powder may include at least one selected from the group consisting of ZnO, B2O3, Al2O3, SiO2, SnO, P2O5, Sb2O3, and Bi2O3. The glass powder may further include at least one material selected from the group consisting of oxides of group 1 to group 5 metal elements, oxides of lanthanum-based elements, and fluorides of group 1 metal elements.
The photosensitive composition for the second dielectric layer may include a glass powder, a photosensitive binder, a cross-linking compound having at least two ethylene-based double bonds, a photopolymerization initiator, and a solvent.
According to another embodiment of the present invention, a method of making a plasma display panel includes the following steps. An address electrode is formed on a front substrate, a green sheet is formed to cover the address electrode, a dielectric layer pattern is formed by exposing, developing, and firing the green sheet, a composition for a display electrode is filled in the dielectric layer pattern and then fired to form a patterned display electrode, a dielectric layer is formed to cover the patterned display electrode, thereby fabricating a front substrate, a patterned barrier rib is formed on a rear substrate, phosphor layers are formed on the barrier rib, and the fabricated front substrate and rear substrate are assembled, evacuated, and sealed. The green sheet includes a first green sheet that is formed using a composition for a first dielectric layer, and a second green sheet that is formed on the first green sheet and that uses a photosensitive composition for a second dielectric layer.
According to yet another embodiment of the present invention, a green sheet for forming dielectric layers of a plasma display panel, including a first green sheet comprising a dielectric composition and a second green sheet formed on the first green sheet, and the second green sheet comprising a photosensitive dielectric composition.
Is this patent green technology? Respond with 'yes' or 'no'. |
7785342 | INTRODUCTION
The Invention relates to an embolic protection device.
The term “STROKE” is used to describe a medical event whereby blood supply to the brain or specific areas of the brain is restricted or blocked to the extent that the supply is inadequate to provide the required flow of oxygenated blood to maintain function. The brain will be impaired either temporarily or permanently, with the patient experiencing a loss of function such as sight, speech or control of limbs. There are two distinct types of stroke, haemorrhagic and embolic. This invention addresses embolic stroke.
Medical literature describes carotid artery disease as a significant source of embolic material. Typically, an atherosclerotic plaque builds up in the carotid arteries. The nature of the plaque varies considerably, but in a significant number of cases pieces of the plaque can break away and flow distally and block bloodflow to specific areas of the brain and cause neurological impairment. Treatment of the disease is classically by way of surgical carotid endarterectomy whereby, the carotid artery is cut and the plaque is physically removed from the vessel. The procedure has broad acceptance with neurological complication rates quoted as being low, somewhere in the order of 6% although claims vary widely on this.
Not all patients are candidates for surgery. A number of reasons may exist such that the patients could not tolerate surgical intervention. In these cases and an increasing number of candidates that are surgical candidates are being treated using transcatheter techniques. In this case, the evolving approach uses devices inserted in the femoral artery and manipulated to the site of the stenosis. A balloon angioplasty catheter is inflated to open the artery and an intravascular stent is sometimes deployed at the site of the stenosis. The action of these devices as with surgery can dislodge embolic material which will flow with the arterial blood and if large enough, eventually block a blood vessel and cause a stroke.
It is known to permanently implant a filter in human vasculature to catch embolic material. It is also known to use a removable filter for this purpose. Such removable filters typically comprise umbrella type filters comprising a filter membrane supported on a collapsible frame on a guidewire for movement of the filter membrane between a collapsed position against the guidewire and a laterally extending position occluding a vessel. Examples of such filters are shown in U.S. Pat. No. 4,723,549, 5,053,008, 5,108,419 and WO 98/33443. Various deployment and/or collapsing arrangements are provided for the umbrella filter. However, as the filter collapses, the captured embolic material tends to be squeezed outwardly towards an open end of the filter and pieces of embolic material may escape from the filter with potentially catastrophic results. More usually, the filter umbrella is collapsed against the guidewire before removal through a catheter or the like. Again, as the filter membrane is collapsed, it will tend to squeeze out the embolic material. Further, the umbrella filter is generally fixed to the guidewire and any inadvertent movement of the guidewire during an interventional procedure can dislodge the filter.
The present invention is directed towards overcoming these problems.
There is a need for an embolic protection device which will overcome this problem.
STATEMENTS OF INVENTION
According to the invention, there is provided an embolic protection device comprising:a collapsible filter element mounted on a filter carrier for delivery through a vascular system of a patient,the filter element being movable between a collapsed stored position against the filter carrier for movement through the vascular system, and an expanded position for occluding a blood vessel such that blood passing through the blood vessel is delivered through the filter element,the filter element comprising a collapsible filter body having an inlet end and an outlet end,the inlet end of the filter body having one or more inlet openings sized to allow blood and embolic material enter the filter body,the outlet end of the filter body having a plurality of outlet openings sized to allow through passage of blood but to retain undesired embolic material within the filter body,means for closing the inlet openings at the inlet end of the filter body, andmeans for collapsing the filter body on the support.
Advantageously, the inlet openings in the filter are closed before the filter is collapsed ensuring retention of all embolic material within the filter element.
In a particularly preferred embodiment of the invention, the means for closing the inlet comprises:a tubular filter retrieval device having an open distal end for reception of the filter element,said distal end being engagable with a proximal inlet end of the filter body to close the inlet openings and being slidable over the filter body from the inlet end to the outlet end to progressively collapse the filter body on the filter carrier and receive the filter body within the retrieval device.
Conveniently, the retrieval device which may be a catheter or pod or the like which engages and collapses the filter element firstly closing the inlet openings to prevent any escape of embolic material and then collapsing the remainder of the filter, being slid from the proximal end over the filter to the distal end of the filter.
In a particularly preferred embodiment, the collapsible filter element is slidably mounted on the filter carrier between the a pair of spaced-apart stops on the filter carrier for axial movement of the filter element along the filter carrier between the stops.
Advantageously, the filter carrier which may for example be a guidewire can be moved independently of the filter element and thus accidental movement of the guidewire is accommodated without unintentionally moving the filter, for example, during exchange of medical devices.
In a further embodiment, the filter element is rotatably mounted on the filter carrier.
In a preferred embodiment, a sleeve is slidably mounted on the filter carrier between the stops, the length of the sleeve being less than the distance between the stops, the filter element being mounted on the sleeve.
In a particularly preferred embodiment, the filter element comprises:a collapsible filter net mounted on the filter carrier,the filter net being movable between a collapsed stored position against the filter carrier and an expanded position extending outwardly of the filter carrier for deployment across a blood vessel.
Preferably, the tubular filter retrieval device comprises a catheter slidable along the filter carrier, an open distal end of the catheter forming a housing for reception of the filter element.
In another embodiment, a proximal inlet end of the filter body is fixed to the filter carrier and a distal end of the filter body is slidably mounted on the filter carrier, although this arrangement may be reversed.
In a further embodiment, the distal end of the filter body is attached to a collar which is slidable along the filter carrier.
In a preferred embodiment, a filter support frame is mounted on the filter carrier, the support frame being movable between a collapsed position along the filter carrier and an extended outwardly projecting position to support the filter body in the expanded position.
In another embodiment, the filter support frame is fixed on the filter carrier at a proximal end of the filter body.
Preferably, the filter support frame slidably engages the filter carrier at a distal end of the filter body. Ideally, the filter support frame is biased into a normally extended position.
In a further embodiment, a circumferential groove is provided in the filter body intermediate the ends of the filter body.
In another embodiment, a guide olive is provided on the filter carrier distally of the filter body, the guide olive having a cylindrical body with a tapered distal end, the cylindrical body being engagable within a distal end of a deployment catheter, said tapered distal end projecting outwardly of the deployment catheter to provide a smooth transition between the catheter and the filter carrier.
In a further embodiment, the net is gathered into the filter carrier at each end of the net.
In another embodiment of the invention, there is provided an embolic protection device comprising a filter element for placing in a desired position, the filter element providing a pathway for blood and having means for capturing, retaining and removing undesired embolic material.
In one embodiment of the invention, the pathway has means for constricting flow to capture undesired embolic material.
In another embodiment of the invention, the filter has a proximal end and a distal end, openings in the proximal end being larger than openings in the distal end, the proximal end openings being sized to allow the flow of blood and embolic material to enter the filter element and the distal end openings being sized to allow the flow of blood while capturing undesired emboli within the filter element.
In a further embodiment of the invention, the filter element includes storage means to store captured undesired embolic material in the filter element. Preferably, the storage means comprises additional storage pathways within the filter element. Preferably, the filter element defines a three dimensional matrix.
In another embodiment of the invention, the filter element is of a polymeric porous structure. In a further embodiment of the invention, the matrix comprises a porous structure dimensioned to entrap embolic material which typically ranges in size from about 100 microns to 3500 microns. In a still further embodiment of the invention, the filter element is compressible and/or foldable for loading into a delivery device to deliver the filter element to a desired location in the compressed or folded state.
In one embodiment of the invention, the filter element has material removed from its structure to aid compressibility.
In another embodiment of the invention, the filter element has material removed from its structure to provide specific sizing in relation to the size of embolic material to be trapped.
In a further embodiment of the invention, the filter element has pathways through the filter body that are inter-linked such that the flow rate through the filter may be tailored.
In another embodiment of the invention, the filter element has a distal end which is tapered such that there is a smooth transition in lateral stiffness to improve the manoeuvrabillty of the filter element in the vascular system.
In a further embodiment of the invention, the filter element has a soft distal portion to aid in atraumatic transport through the vascular system. Preferably, the filter element has circumferential grooves to reduce the lateral flexibility of the filter element.
In one embodiment of the invention, the filter element has a tapered proximal end to facilitate retrieval by a removal catheter.
In another embodiment of the invention, the filter element has inlet holes that close on pulling back into a retrieval catheter to ensure retention of any collected emboli.
In a further embodiment of the invention, the filter element has outlet openings sized to capture embolic material of a size large enough to impair the function of the organ receiving the blood downstream of the filter body element. Preferably, the filter element is sized to capture embolic material of a size greater than 100 microns. Most preferably, the filter element is sized to capture embolic material of a size greater than 200 microns. Most preferably, the filter element is sized to capture embolic material of a size greater than 500 microns.
In one embodiment of the invention, the filter element is sized for complete coverage of a vessel cross-section that allows passage of blood and blood components.
In a still further embodiment of the invention, there is provided a device having means for placing over a medical guidewire.
In another embodiment of the invention, there is provided a device which may be placed under a balloon or stent delivery catheter.
In a further embodiment of the invention, there is provided a device having means for insertion through, femoral, brachial, radial, subclavian or other arterial puncture by means of a transcatheter approach.
In one embodiment of the invention, there is provided a device for protection of neurological function which is inserted for the duration of a surgical intervention at or near the site of surgical opening.
It is envisaged that two devices could be used bi-laterally in left and right carotid arteries allowing sufficient cerebral blood flow to maintain neurological function during procedures with a high risk of generating clot such as electrophysiological treatment of coronary arrhythmias.
In a further embodiment of the invention, there is provided a device including a delivery catheter in which an external sheath is engagable with the filter element or filter carrier to provide push during delivery and is removable to allow maximum space in the vascular cross-section during an interventional procedure.
In one embodiment of the invention, the external sheath is joined to the filter element or filter carrier by a joining means. The joining means may be a removable shrink tube or a removable clip. Preferably the joining means is a compression connector such as a Tuohy Borst adapter.
In another embodiment of the invention, the delivery catheter has a central lumen for at least part of it's length to allow it to track over a steerable guidewire.
in a further embodiment of the invention, the external sheath is sufficiently long to extend to the outside of the vasculature and is movable proximally to release the filter element from the catheter.
In one embodiment of the invention, the delivery catheter has an external covering which extends beyond the push element to define a filter retention sleeve.
In another embodiment of the invention, the delivery catheter has a spring component with a localised stepwise increasing pitch to alter stiffness characteristics to suit the target vasculature.
In a further embodiment of the invention, the delivery catheter has a spring component with a localised gradually increasing pitch to alter stiffness characteristics to suit the target vasculature.
In one embodiment of the invention, the filter element is mounted on a collapsible support structure which is movable between a collapsed position for deployment and an extended in-use position, means being provided for retaining the support structure in the collapsed position. Preferably, the support structure comprises support arms. Preferably, the support arms are formed from a shape memory or elastic memory material. Most preferably, the support arms are formed from Nitinol.
In one embodiment of the invention, the support arms are configured to open co-axially with the filter carrier such that they may be restrained for removal by pulling the filter element proximally into an appropriately dimensioned sheath.
In another embodiment of the invention, the filter element has an associated support structure with a pre-shaped spiral arrangement such that it provides radial support to the filter element.
In a further embodiment of the invention, the filter support structure is adapted to fold into the collapsed position when pulled into a retrieval catheter.
In one embodiment of the invention, the filter element comprises a flexible shaped polymeric component.
In another embodiment of the invention, the shaped polymeric component is constructed such that fluid flow through the component assists in opening the component from the collapsed position.
In a further embodiment of the invention, the shaped polymeric component is flexible and opens to make circumferential contact with the vessel wall by way of using the pressure drop across the exit filter face.
In a further embodiment of the invention the filter element is mounted on a guidewire such that the guidewire has freedom to rotate and/or move axially independently of the filter. More preferably the wire has complete freedom to rotate independently of the filter and has limited axial movement. The limit of axial movement is determined by stops mounted on or connected to the wire. Ideally the wire can move 100 mm in the axial direction independent of the filter. More ideally the wire can move less than 50 mm independently of the filter. This embodiment facilitates the maintenance of filter position during the exchange of catheters and permits the steering of the wire independent of the filter.
In a further embodiment of this invention the filter element is bonded to the filter mount at its proximal end and its distal end is free to move relative to the filter mount and proximal bond so as to aid the collapse of the filter for deployment.
In a further embodiment of the invention the filter element is tapered over part or all of its length such that it is accurately sized to the vessel over some portion of its length.
In a further embodiment of the invention the shaped polymeric component contains one or more circumferential grooves along its body to maintain the circular shape of the filter element in an under sized artery.
In one embodiment of the invention, the filter element is directly bonded onto a steerable medical guide wire incorporating a slidable sheath that is movable to deploy the filter.
In another embodiment of the invention, there is provided a device incorporating a medical guidewire with a flexible segment of wire distal to the filter so as to provide steerability of the wire particularly prior to it being deployed.
In a further embodiment of the invention, there is provided a device incorporating a medical guide wire with a soft distal segment so as to provide a tip section that will be atraumatic.
In a still further embodiment of the invention, there is provided a device with a porous coating on a distal end of the filter element only with a means for opening and closing the filter by slidable motion.
In one embodiment of the invention, the filter element incorporates proximal tapering such that it may be pulled proximally into a sheath for removal in order that such pulling action will effectively reduce the diameter of the filter and assist retrieval.
In another embodiment of the invention, the filter element has a porous structure that can be deployed and closed by way of a slidable motion, the closure thereof caused by way of snap-fit to a protruding rim that allows the support elements be pulled proximally, thus closing the structure with the filter membrane attached.
In a further embodiment of the invention, there is provided a device having a filter element which permits the incorporation of a medical guide wire in the outer wall of the filter element to facilitate the incorporation of large inlet holes on the proximal inlet end of the filter element.
In one embodiment of the invention, the filter element comprises a mesh work structure with large proximal inlet holes and small distal outlet holes wherein the mesh structure is collapsible into a small diameter delivery catheter and is expandable upon deployment to a shape which is remembered by the mesh structure either through shape memory characteristics or elastic memory characteristics.
In another embodiment of the invention, the filter element comprises a mesh work structure wherein the expansion of the filter element within the vessel causes blood flowing through the vessel to flow through the filter element due to the filter element engaging with the wall of the vessel to conform to the shape of the vessel bore.
In another embodiment, the filter element comprises a braided fibrous mesh work. Preferably, distal outlet openings are defined by an area enclosed by a series of crossing interwoven fibres. Larger proximal inlet holes are provided by the convergence of the fibres of the braid into a few bundles which are mounted to the filter carrier. Preferably, the fibrous meshwork material is an elastic or shape memory material such that it can be collapsed into a delivery catheter and recover its enlarged shape upon deployment. The fibres of the meshwork are bonded at the points where they cross one another. The fibres may be made from either a polymer or metal or a composite material.
In a further embodiment, the distal end of the filter element has the facility to move in the axial direction relative to the proximal end of the filter element so as to take up the exact shape of the blood vessel.
In a further embodiment, the device has a porous coating on a distal end of the filter element only with means for opening and closing the filter element by slidable motion. Preferably, the filter element comprises a collapsible wire frame having a plurality of wires, outer ends of the wires being hingedly mounted on the filter carrier, the wires being hinged intermediate their ends, at one end the wires being fixed on the filter carrier and at the other end the wires being mounted on a collar which is slidable along the filter carrier, a porous filter mesh being mounted on the wire frame. An actuating sleeve is slidable over the filter carrier to push the collar towards the fixed end of the filter element, and a collapsing device is engagable with the collar to pull back the collar away from the fixed end of the filter element to collapse the wire frame against the filter carrier for retrieval of the filter element.
In a still further embodiment of the invention, there is provided a filter retrieval system for use with the device comprising a longitudinal catheter with a radially deformable or elastic tip to assist the pull back of the filter into the tip.
In another embodiment of the invention, there is provided a system incorporating a filter, a delivery catheter and a retrieval catheter for temporary filtration of the vascular system during an interventional procedure.
In another aspect the invention provides an embolic protection device comprising:a collapsible filter element mounted on a filter carrier for delivery through a vascular system of a patient,the filter element being movable between a collapsed stored position against the filter carrier for movement through the vascular system, and an expanded position for occluding a blood vessel such that blood passing through the blood vessel is delivered through the filter element, a pair of spaced-apart stops on the filter carrier, the collapsible filter element being slidably mounted on the filter carrier for axial movement along the filter carrier between the stops, and means for collapsing the filter element on the filter carrier.
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SUMMARY: INTRODUCTION
The Invention relates to an embolic protection device.
The term “STROKE” is used to describe a medical event whereby blood supply to the brain or specific areas of the brain is restricted or blocked to the extent that the supply is inadequate to provide the required flow of oxygenated blood to maintain function. The brain will be impaired either temporarily or permanently, with the patient experiencing a loss of function such as sight, speech or control of limbs. There are two distinct types of stroke, haemorrhagic and embolic. This invention addresses embolic stroke.
Medical literature describes carotid artery disease as a significant source of embolic material. Typically, an atherosclerotic plaque builds up in the carotid arteries. The nature of the plaque varies considerably, but in a significant number of cases pieces of the plaque can break away and flow distally and block bloodflow to specific areas of the brain and cause neurological impairment. Treatment of the disease is classically by way of surgical carotid endarterectomy whereby, the carotid artery is cut and the plaque is physically removed from the vessel. The procedure has broad acceptance with neurological complication rates quoted as being low, somewhere in the order of 6% although claims vary widely on this.
Not all patients are candidates for surgery. A number of reasons may exist such that the patients could not tolerate surgical intervention. In these cases and an increasing number of candidates that are surgical candidates are being treated using transcatheter techniques. In this case, the evolving approach uses devices inserted in the femoral artery and manipulated to the site of the stenosis. A balloon angioplasty catheter is inflated to open the artery and an intravascular stent is sometimes deployed at the site of the stenosis. The action of these devices as with surgery can dislodge embolic material which will flow with the arterial blood and if large enough, eventually block a blood vessel and cause a stroke.
It is known to permanently implant a filter in human vasculature to catch embolic material. It is also known to use a removable filter for this purpose. Such removable filters typically comprise umbrella type filters comprising a filter membrane supported on a collapsible frame on a guidewire for movement of the filter membrane between a collapsed position against the guidewire and a laterally extending position occluding a vessel. Examples of such filters are shown in U.S. Pat. No. 4,723,549, 5,053,008, 5,108,419 and WO 98/33443. Various deployment and/or collapsing arrangements are provided for the umbrella filter. However, as the filter collapses, the captured embolic material tends to be squeezed outwardly towards an open end of the filter and pieces of embolic material may escape from the filter with potentially catastrophic results. More usually, the filter umbrella is collapsed against the guidewire before removal through a catheter or the like. Again, as the filter membrane is collapsed, it will tend to squeeze out the embolic material. Further, the umbrella filter is generally fixed to the guidewire and any inadvertent movement of the guidewire during an interventional procedure can dislodge the filter.
The present invention is directed towards overcoming these problems.
There is a need for an embolic protection device which will overcome this problem.
STATEMENTS OF INVENTION
According to the invention, there is provided an embolic protection device comprising:a collapsible filter element mounted on a filter carrier for delivery through a vascular system of a patient,the filter element being movable between a collapsed stored position against the filter carrier for movement through the vascular system, and an expanded position for occluding a blood vessel such that blood passing through the blood vessel is delivered through the filter element,the filter element comprising a collapsible filter body having an inlet end and an outlet end,the inlet end of the filter body having one or more inlet openings sized to allow blood and embolic material enter the filter body,the outlet end of the filter body having a plurality of outlet openings sized to allow through passage of blood but to retain undesired embolic material within the filter body,means for closing the inlet openings at the inlet end of the filter body, andmeans for collapsing the filter body on the support.
Advantageously, the inlet openings in the filter are closed before the filter is collapsed ensuring retention of all embolic material within the filter element.
In a particularly preferred embodiment of the invention, the means for closing the inlet comprises:a tubular filter retrieval device having an open distal end for reception of the filter element,said distal end being engagable with a proximal inlet end of the filter body to close the inlet openings and being slidable over the filter body from the inlet end to the outlet end to progressively collapse the filter body on the filter carrier and receive the filter body within the retrieval device.
Conveniently, the retrieval device which may be a catheter or pod or the like which engages and collapses the filter element firstly closing the inlet openings to prevent any escape of embolic material and then collapsing the remainder of the filter, being slid from the proximal end over the filter to the distal end of the filter.
In a particularly preferred embodiment, the collapsible filter element is slidably mounted on the filter carrier between the a pair of spaced-apart stops on the filter carrier for axial movement of the filter element along the filter carrier between the stops.
Advantageously, the filter carrier which may for example be a guidewire can be moved independently of the filter element and thus accidental movement of the guidewire is accommodated without unintentionally moving the filter, for example, during exchange of medical devices.
In a further embodiment, the filter element is rotatably mounted on the filter carrier.
In a preferred embodiment, a sleeve is slidably mounted on the filter carrier between the stops, the length of the sleeve being less than the distance between the stops, the filter element being mounted on the sleeve.
In a particularly preferred embodiment, the filter element comprises:a collapsible filter net mounted on the filter carrier,the filter net being movable between a collapsed stored position against the filter carrier and an expanded position extending outwardly of the filter carrier for deployment across a blood vessel.
Preferably, the tubular filter retrieval device comprises a catheter slidable along the filter carrier, an open distal end of the catheter forming a housing for reception of the filter element.
In another embodiment, a proximal inlet end of the filter body is fixed to the filter carrier and a distal end of the filter body is slidably mounted on the filter carrier, although this arrangement may be reversed.
In a further embodiment, the distal end of the filter body is attached to a collar which is slidable along the filter carrier.
In a preferred embodiment, a filter support frame is mounted on the filter carrier, the support frame being movable between a collapsed position along the filter carrier and an extended outwardly projecting position to support the filter body in the expanded position.
In another embodiment, the filter support frame is fixed on the filter carrier at a proximal end of the filter body.
Preferably, the filter support frame slidably engages the filter carrier at a distal end of the filter body. Ideally, the filter support frame is biased into a normally extended position.
In a further embodiment, a circumferential groove is provided in the filter body intermediate the ends of the filter body.
In another embodiment, a guide olive is provided on the filter carrier distally of the filter body, the guide olive having a cylindrical body with a tapered distal end, the cylindrical body being engagable within a distal end of a deployment catheter, said tapered distal end projecting outwardly of the deployment catheter to provide a smooth transition between the catheter and the filter carrier.
In a further embodiment, the net is gathered into the filter carrier at each end of the net.
In another embodiment of the invention, there is provided an embolic protection device comprising a filter element for placing in a desired position, the filter element providing a pathway for blood and having means for capturing, retaining and removing undesired embolic material.
In one embodiment of the invention, the pathway has means for constricting flow to capture undesired embolic material.
In another embodiment of the invention, the filter has a proximal end and a distal end, openings in the proximal end being larger than openings in the distal end, the proximal end openings being sized to allow the flow of blood and embolic material to enter the filter element and the distal end openings being sized to allow the flow of blood while capturing undesired emboli within the filter element.
In a further embodiment of the invention, the filter element includes storage means to store captured undesired embolic material in the filter element. Preferably, the storage means comprises additional storage pathways within the filter element. Preferably, the filter element defines a three dimensional matrix.
In another embodiment of the invention, the filter element is of a polymeric porous structure. In a further embodiment of the invention, the matrix comprises a porous structure dimensioned to entrap embolic material which typically ranges in size from about 100 microns to 3500 microns. In a still further embodiment of the invention, the filter element is compressible and/or foldable for loading into a delivery device to deliver the filter element to a desired location in the compressed or folded state.
In one embodiment of the invention, the filter element has material removed from its structure to aid compressibility.
In another embodiment of the invention, the filter element has material removed from its structure to provide specific sizing in relation to the size of embolic material to be trapped.
In a further embodiment of the invention, the filter element has pathways through the filter body that are inter-linked such that the flow rate through the filter may be tailored.
In another embodiment of the invention, the filter element has a distal end which is tapered such that there is a smooth transition in lateral stiffness to improve the manoeuvrabillty of the filter element in the vascular system.
In a further embodiment of the invention, the filter element has a soft distal portion to aid in atraumatic transport through the vascular system. Preferably, the filter element has circumferential grooves to reduce the lateral flexibility of the filter element.
In one embodiment of the invention, the filter element has a tapered proximal end to facilitate retrieval by a removal catheter.
In another embodiment of the invention, the filter element has inlet holes that close on pulling back into a retrieval catheter to ensure retention of any collected emboli.
In a further embodiment of the invention, the filter element has outlet openings sized to capture embolic material of a size large enough to impair the function of the organ receiving the blood downstream of the filter body element. Preferably, the filter element is sized to capture embolic material of a size greater than 100 microns. Most preferably, the filter element is sized to capture embolic material of a size greater than 200 microns. Most preferably, the filter element is sized to capture embolic material of a size greater than 500 microns.
In one embodiment of the invention, the filter element is sized for complete coverage of a vessel cross-section that allows passage of blood and blood components.
In a still further embodiment of the invention, there is provided a device having means for placing over a medical guidewire.
In another embodiment of the invention, there is provided a device which may be placed under a balloon or stent delivery catheter.
In a further embodiment of the invention, there is provided a device having means for insertion through, femoral, brachial, radial, subclavian or other arterial puncture by means of a transcatheter approach.
In one embodiment of the invention, there is provided a device for protection of neurological function which is inserted for the duration of a surgical intervention at or near the site of surgical opening.
It is envisaged that two devices could be used bi-laterally in left and right carotid arteries allowing sufficient cerebral blood flow to maintain neurological function during procedures with a high risk of generating clot such as electrophysiological treatment of coronary arrhythmias.
In a further embodiment of the invention, there is provided a device including a delivery catheter in which an external sheath is engagable with the filter element or filter carrier to provide push during delivery and is removable to allow maximum space in the vascular cross-section during an interventional procedure.
In one embodiment of the invention, the external sheath is joined to the filter element or filter carrier by a joining means. The joining means may be a removable shrink tube or a removable clip. Preferably the joining means is a compression connector such as a Tuohy Borst adapter.
In another embodiment of the invention, the delivery catheter has a central lumen for at least part of it's length to allow it to track over a steerable guidewire.
in a further embodiment of the invention, the external sheath is sufficiently long to extend to the outside of the vasculature and is movable proximally to release the filter element from the catheter.
In one embodiment of the invention, the delivery catheter has an external covering which extends beyond the push element to define a filter retention sleeve.
In another embodiment of the invention, the delivery catheter has a spring component with a localised stepwise increasing pitch to alter stiffness characteristics to suit the target vasculature.
In a further embodiment of the invention, the delivery catheter has a spring component with a localised gradually increasing pitch to alter stiffness characteristics to suit the target vasculature.
In one embodiment of the invention, the filter element is mounted on a collapsible support structure which is movable between a collapsed position for deployment and an extended in-use position, means being provided for retaining the support structure in the collapsed position. Preferably, the support structure comprises support arms. Preferably, the support arms are formed from a shape memory or elastic memory material. Most preferably, the support arms are formed from Nitinol.
In one embodiment of the invention, the support arms are configured to open co-axially with the filter carrier such that they may be restrained for removal by pulling the filter element proximally into an appropriately dimensioned sheath.
In another embodiment of the invention, the filter element has an associated support structure with a pre-shaped spiral arrangement such that it provides radial support to the filter element.
In a further embodiment of the invention, the filter support structure is adapted to fold into the collapsed position when pulled into a retrieval catheter.
In one embodiment of the invention, the filter element comprises a flexible shaped polymeric component.
In another embodiment of the invention, the shaped polymeric component is constructed such that fluid flow through the component assists in opening the component from the collapsed position.
In a further embodiment of the invention, the shaped polymeric component is flexible and opens to make circumferential contact with the vessel wall by way of using the pressure drop across the exit filter face.
In a further embodiment of the invention the filter element is mounted on a guidewire such that the guidewire has freedom to rotate and/or move axially independently of the filter. More preferably the wire has complete freedom to rotate independently of the filter and has limited axial movement. The limit of axial movement is determined by stops mounted on or connected to the wire. Ideally the wire can move 100 mm in the axial direction independent of the filter. More ideally the wire can move less than 50 mm independently of the filter. This embodiment facilitates the maintenance of filter position during the exchange of catheters and permits the steering of the wire independent of the filter.
In a further embodiment of this invention the filter element is bonded to the filter mount at its proximal end and its distal end is free to move relative to the filter mount and proximal bond so as to aid the collapse of the filter for deployment.
In a further embodiment of the invention the filter element is tapered over part or all of its length such that it is accurately sized to the vessel over some portion of its length.
In a further embodiment of the invention the shaped polymeric component contains one or more circumferential grooves along its body to maintain the circular shape of the filter element in an under sized artery.
In one embodiment of the invention, the filter element is directly bonded onto a steerable medical guide wire incorporating a slidable sheath that is movable to deploy the filter.
In another embodiment of the invention, there is provided a device incorporating a medical guidewire with a flexible segment of wire distal to the filter so as to provide steerability of the wire particularly prior to it being deployed.
In a further embodiment of the invention, there is provided a device incorporating a medical guide wire with a soft distal segment so as to provide a tip section that will be atraumatic.
In a still further embodiment of the invention, there is provided a device with a porous coating on a distal end of the filter element only with a means for opening and closing the filter by slidable motion.
In one embodiment of the invention, the filter element incorporates proximal tapering such that it may be pulled proximally into a sheath for removal in order that such pulling action will effectively reduce the diameter of the filter and assist retrieval.
In another embodiment of the invention, the filter element has a porous structure that can be deployed and closed by way of a slidable motion, the closure thereof caused by way of snap-fit to a protruding rim that allows the support elements be pulled proximally, thus closing the structure with the filter membrane attached.
In a further embodiment of the invention, there is provided a device having a filter element which permits the incorporation of a medical guide wire in the outer wall of the filter element to facilitate the incorporation of large inlet holes on the proximal inlet end of the filter element.
In one embodiment of the invention, the filter element comprises a mesh work structure with large proximal inlet holes and small distal outlet holes wherein the mesh structure is collapsible into a small diameter delivery catheter and is expandable upon deployment to a shape which is remembered by the mesh structure either through shape memory characteristics or elastic memory characteristics.
In another embodiment of the invention, the filter element comprises a mesh work structure wherein the expansion of the filter element within the vessel causes blood flowing through the vessel to flow through the filter element due to the filter element engaging with the wall of the vessel to conform to the shape of the vessel bore.
In another embodiment, the filter element comprises a braided fibrous mesh work. Preferably, distal outlet openings are defined by an area enclosed by a series of crossing interwoven fibres. Larger proximal inlet holes are provided by the convergence of the fibres of the braid into a few bundles which are mounted to the filter carrier. Preferably, the fibrous meshwork material is an elastic or shape memory material such that it can be collapsed into a delivery catheter and recover its enlarged shape upon deployment. The fibres of the meshwork are bonded at the points where they cross one another. The fibres may be made from either a polymer or metal or a composite material.
In a further embodiment, the distal end of the filter element has the facility to move in the axial direction relative to the proximal end of the filter element so as to take up the exact shape of the blood vessel.
In a further embodiment, the device has a porous coating on a distal end of the filter element only with means for opening and closing the filter element by slidable motion. Preferably, the filter element comprises a collapsible wire frame having a plurality of wires, outer ends of the wires being hingedly mounted on the filter carrier, the wires being hinged intermediate their ends, at one end the wires being fixed on the filter carrier and at the other end the wires being mounted on a collar which is slidable along the filter carrier, a porous filter mesh being mounted on the wire frame. An actuating sleeve is slidable over the filter carrier to push the collar towards the fixed end of the filter element, and a collapsing device is engagable with the collar to pull back the collar away from the fixed end of the filter element to collapse the wire frame against the filter carrier for retrieval of the filter element.
In a still further embodiment of the invention, there is provided a filter retrieval system for use with the device comprising a longitudinal catheter with a radially deformable or elastic tip to assist the pull back of the filter into the tip.
In another embodiment of the invention, there is provided a system incorporating a filter, a delivery catheter and a retrieval catheter for temporary filtration of the vascular system during an interventional procedure.
In another aspect the invention provides an embolic protection device comprising:a collapsible filter element mounted on a filter carrier for delivery through a vascular system of a patient,the filter element being movable between a collapsed stored position against the filter carrier for movement through the vascular system, and an expanded position for occluding a blood vessel such that blood passing through the blood vessel is delivered through the filter element, a pair of spaced-apart stops on the filter carrier, the collapsible filter element being slidably mounted on the filter carrier for axial movement along the filter carrier between the stops, and means for collapsing the filter element on the filter carrier.
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7781103 | CROSS-REFERENCES TO RELATED APPLICATION
This application claims the benefit of and priority to Korean Patent Application Nos. 10-2004-0024867 and 10-2004-0025768 filed on Apr. 12, 2004 and Apr. 14, 2004, respectively, in the Korean Intellectual Property Office, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a negative active material for a lithium secondary battery, and a negative electrode and a lithium secondary battery comprising the same. It more particularly relates to a negative active material for a lithium secondary battery having good compression strength, wetability for an electrolyte, and discharge characteristics at a low temperature, and that is capable of providing a high density electrode plate, and a negative electrode and a lithium secondary battery comprising the same.
BACKGROUND OF THE INVENTION
Lithium secondary batteries comprise a positive electrode and a negative electrode comprising materials capable of reversibly intercalating lithium ions, with an organic electrolyte or a polymer electrolyte injected between the positive electrode and the negative electrode. The battery produces electrical energy as a result of a redox reaction upon intercalating/deintercalating the lithium ions.
The positive active material for the lithium secondary battery employs a chalcogenide compound such as a metal composite compound of LiCoO2, LiMnO2, LiMn2O4, LiNiO2, or LiNi1−xCoxO2(where 0<x<1).
The negative active material typically comprises a lithium metal, but a battery short circuit may occur in a battery using such a material as the negative active material due to dendrite formation. Therefore, the lithium metal may be substituted with a carbonaceous material. Crystalline carbon such as natural graphite or synthetic graphite and amorphous carbon such as soft carbon or hard carbon have been mentioned for this purpose. While amorphous carbon has a very large capacity, it may cause problems in that it is hard to reverse intercalation during the charge and the discharge. Crystalline carbon, when used for the negative active material, is generally in the form of a natural graphite since it has a high capacity with a theoretical limit capacity of 372 mA h/g, but it has a problem in that the cycle life of the resultant battery is remarkably degenerated.
The negative active material for a negative electrode for a lithium secondary battery is prepared by mixing carbon materials and a binder, and a conductive agent if required, and agitating them to provide a slurry. Then, the slurry is coated on a metal current collector and dried to form a negative electrode. The negative active material is further compressed onto the current collector in order to obtain a uniformly thick electrode plate and increase the capacity of the electrode plate. However, the carbon material tends to crack upon compressing the electrode plate, so the electrode plate may lose its uniformity, which causes the reaction with the electrolyte to lose uniformity and the life of the electrolyte plate to degenerate. Furthermore, if a crack develops, an edge portion thereof is exposed by the pulverized crack so as to increase a side reaction with the electrolyte, and the viscosity of the electrolyte is remarkably increased at a low temperature such as −20° C. because the electrolyte is soaked into the fine cracks by capillary action and the electrolyte taking part in the battery reaction is decreased. Thereby, the discharge characteristic at the low temperature is degenerated.
SUMMARY OF THE INVENTION
In one embodiment of the present invention, a negative active material is provided for a lithium secondary battery capable of providing an electrode plate having a high density and a good compression strength of the particle, a negative electrode, and a lithium secondary battery comprising the same.
In an embodiment of the present invention, a negative active material comprises a plurality of negative active material particles, each including a plurality of plate-shaped carbon powder particles agglomerated in a primary structure in which the plate-shaped particles are oriented in a plane direction and laminated to one another with fine pores formed on the surface of the negative active material particle.
In still another embodiment of the present invention, a negative electrode for a lithium secondary battery comprises such a negative active material.
In yet another embodiment of the present invention, a lithium secondary battery is provided comprising the negative electrode.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: CROSS-REFERENCES TO RELATED APPLICATION
This application claims the benefit of and priority to Korean Patent Application Nos. 10-2004-0024867 and 10-2004-0025768 filed on Apr. 12, 2004 and Apr. 14, 2004, respectively, in the Korean Intellectual Property Office, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a negative active material for a lithium secondary battery, and a negative electrode and a lithium secondary battery comprising the same. It more particularly relates to a negative active material for a lithium secondary battery having good compression strength, wetability for an electrolyte, and discharge characteristics at a low temperature, and that is capable of providing a high density electrode plate, and a negative electrode and a lithium secondary battery comprising the same.
BACKGROUND OF THE INVENTION
Lithium secondary batteries comprise a positive electrode and a negative electrode comprising materials capable of reversibly intercalating lithium ions, with an organic electrolyte or a polymer electrolyte injected between the positive electrode and the negative electrode. The battery produces electrical energy as a result of a redox reaction upon intercalating/deintercalating the lithium ions.
The positive active material for the lithium secondary battery employs a chalcogenide compound such as a metal composite compound of LiCoO2, LiMnO2, LiMn2O4, LiNiO2, or LiNi1−xCoxO2(where 0<x<1).
The negative active material typically comprises a lithium metal, but a battery short circuit may occur in a battery using such a material as the negative active material due to dendrite formation. Therefore, the lithium metal may be substituted with a carbonaceous material. Crystalline carbon such as natural graphite or synthetic graphite and amorphous carbon such as soft carbon or hard carbon have been mentioned for this purpose. While amorphous carbon has a very large capacity, it may cause problems in that it is hard to reverse intercalation during the charge and the discharge. Crystalline carbon, when used for the negative active material, is generally in the form of a natural graphite since it has a high capacity with a theoretical limit capacity of 372 mA h/g, but it has a problem in that the cycle life of the resultant battery is remarkably degenerated.
The negative active material for a negative electrode for a lithium secondary battery is prepared by mixing carbon materials and a binder, and a conductive agent if required, and agitating them to provide a slurry. Then, the slurry is coated on a metal current collector and dried to form a negative electrode. The negative active material is further compressed onto the current collector in order to obtain a uniformly thick electrode plate and increase the capacity of the electrode plate. However, the carbon material tends to crack upon compressing the electrode plate, so the electrode plate may lose its uniformity, which causes the reaction with the electrolyte to lose uniformity and the life of the electrolyte plate to degenerate. Furthermore, if a crack develops, an edge portion thereof is exposed by the pulverized crack so as to increase a side reaction with the electrolyte, and the viscosity of the electrolyte is remarkably increased at a low temperature such as −20° C. because the electrolyte is soaked into the fine cracks by capillary action and the electrolyte taking part in the battery reaction is decreased. Thereby, the discharge characteristic at the low temperature is degenerated.
SUMMARY OF THE INVENTION
In one embodiment of the present invention, a negative active material is provided for a lithium secondary battery capable of providing an electrode plate having a high density and a good compression strength of the particle, a negative electrode, and a lithium secondary battery comprising the same.
In an embodiment of the present invention, a negative active material comprises a plurality of negative active material particles, each including a plurality of plate-shaped carbon powder particles agglomerated in a primary structure in which the plate-shaped particles are oriented in a plane direction and laminated to one another with fine pores formed on the surface of the negative active material particle.
In still another embodiment of the present invention, a negative electrode for a lithium secondary battery comprises such a negative active material.
In yet another embodiment of the present invention, a lithium secondary battery is provided comprising the negative electrode.
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7667090 | BACKGROUND OF THE INVENTION
Acute leukemia is a rapidly progressive malignant disease of the bone marrow and blood that results in the accumulation of immature, functionless cells, called blast cells, in the marrow and blood. The accumulation of blast cells in the marrow blocks normal blood cell development. As a result, red cells, white cells and platelets are not produced in sufficient numbers. When the disease originates in a marrow lymphocyte progenitor cell, it results in acute lymphoblastic leukemia (ALL) and when the disease originates in a myeloid progenitor, it results in acute myelogenous leukemia (AML).
ALL is a rapidly progressive cancer that starts by the malignant transformation of a marrow lymphocyte. ALL is the most common type of childhood leukemia, with 3,000 new cases per year in all age groups. The transformed, now malignant, cell multiplies and accumulates in the marrow as leukemic lymphoblasts. The lymphoblasts block normal blood cell-formation in the marrow, resulting in insufficient production of red cells, white cells and platelets.
High-grade lymphomas, also known as aggressive lymphoma, include several subtypes of lymphoma that progress relatively rapidly if untreated. These subtypes include, e.g., AIDS-associated lymphoma, anaplastic large cell lymphoma, Burkitt's lymphoma, diffuse large cell lymphoma, immunoblastic lymphoma, lymphoblastic lymphoma and small noncleaved cell lymphomas. Compared to diffuse large B-cell lymphomas, high-grade lymphomas behave more aggressively, require more intensive chemotherapy, and occur more often in children. Because rapidly dividing cells are more sensitive to anti-cancer agents and because the young patients usually lack other health problems, some of these lymphomas show a dramatic response to therapy. Acute lymphoblastic leukemia and high-grade lymphoma are the most common leukemias and lymphomas in children. These diseases are, for the most part, polyclonal, suggesting that only a few genetic changes are sufficient to induce malignancy.
MicroRNAs (miRNAs) represent a new class of abundant small RNAs that play important regulatory roles at the post-transcriptional level by binding to targeted mRNAs and either blocking their translation or initiating their degradation, according to the degree of complementarity with the target. Since their discovery in 1993 inCaenorhabditis elegans(Lee, R. et al.,Cell75:843-854 (1993)), there have been numerous reports that implicated these tiny molecules in the posttranscriptional regulation of a large array of proteins with very diverse roles, ranging from cell proliferation and differentiation to lipid metabolism (Nairz, K., et al.,Dev. Biol.291:314-324 (2006); Chen, J. F., et al.,Nat. Genet.38:228-233 (2006); Naguibneva, I., et al.,Nat. Cell Biol.8:278-284 (2006); Esau, C., et al.,Cell Metab.3:87-98 (2006); and Gauthier, B. R., et al.,Nat. Med.12:36-18 (2006)).
miRNA profiling of hematopoietic lineages in humans and mice showed that miRNAs are differentially expressed in the course of hematopoietic development, suggesting a potential role in hematopoietic differentiation (Chen, C. Z., et al.,Science303:83-86 (2004); Chen, C. Z., et al.,Semin. Immunol.17:155-165 (2005); and Ramkissoon, S. H., et al.,Leuk. Res.30:643-647 (2006)). We have shown that miR-15a and miR-16-1 are deleted or down-regulated in 68% of cases of chronic lymphocytic leukemia (CLL) (Calin, G. A., et al.,Proc. Natl. Acad. Sci. USA99:15524-15529 (2002); and Calin, G. A., et al.,Proc. Natl. Acad. Sci. USA101:11755-11760 (2004)), and that miRNAs genes are frequently located at fragile sites and genomic regions involved in cancers (Calin, G. A., et al,Proc. Natl. Acad. Sci. USA101:2999-3004 (2004)). miR155 and BIC (its host gene) transcripts have been shown to accumulate in human B cell lymphomas, especially diffuse large B cell lymphomas (Eis, P. S., et al,Proc. Natl. Acad. Sci. USA102:3627-3632 (2005)), Hodgkin lymphomas (Kluvier, J., et al.,J. Pathol207:243-249 (2006)), and certain types of Burkitt lymphomas (latency type III Epstein-Barr virus-positive Burkitt lymphoma) (Kluvier, J., et al,Genes Chromosomes Cancer45: 147-153 (2006)).
Currently, there is an urgent need to produce animal models that can be used to screen for, and identify, candidate agents that have therapeutic potential for the treatment of lymphoproliferative disorders, such as B cell malignancies (e.g., B cell leukemias, B cell lymphomas).
SUMMARY OF THE INVENTION
The present invention is based on the discovery that transgenic mice carrying a miR155 transgene, whose expression is targeted to B cells (e.g., using an Ig heavy chain-Eμ enhancer), initially exhibit a preleukemic pre-B cell proliferation, evident in spleen and bone marrow, and later develop B cell malignancies. Transgenic mice that overexpress miR155 develop a lymphoproliferative disease resembling human lymphoproliferative diseases, thus strongly implicating miR155 in the initiation and/or progression of these diseases. The Eμ-mmu-miR155 transgenic mice are useful for devising new therapeutic approaches to treat different forms of lymphoproliferative disorders, such as B cell malignancies (e.g., acute lymphoblastic leukemia, high-grade lymphomas) in humans.
Accordingly, in one aspect, there is provided herein, novel animal models for lymphoproliferative disorders. Specifically, according to one aspect, animal models for B cell malignancies (e.g., leukemias (e.g., acute lymphoblastic leukemia), lymphomas (e.g., high-grade lymphoma), and neoplasms) are provided.
In one embodiment, there is provided herein a transgenic non-human animal (e.g., a mouse) whose genome comprises a nucleic acid construct comprising at least one transcriptional regulatory sequence capable of directing expression in B cells of the animal, operably linked to a nucleic acid encoding a miR155 gene product. In a particular embodiment, the miR155 gene product comprises a nucleotide sequence having at least 90% sequence identity to SEQ ID NO:1 and/or SEQ ID NO:2. In another embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:1. In still another embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:2.
According to one embodiment, the at least one transcriptional regulatory sequence can be any sequence capable of directing expression in B cells of the animal. In one embodiment, the transcriptional regulatory sequence comprises a VHpromoter (e.g., a VHpromoter derived from mouse). In another embodiment the transcriptional regulatory sequence comprises an Ig heavy chain-Eμ enhancer (e.g., an Ig heavy chain-Eμ enhancer derived from mouse). In a related embodiment, the nucleic acid construct comprises the 3′ UTR and poly(A) sequence of a β-globin gene (e.g., a β-globin gene derived from human or other mammalian species).
There is also provided herein a transgenic non-human animal whose genome comprises a nucleic acid construct comprising a VHpromoter and an Ig heavy chain-Eμ enhancer, operably linked to a nucleic acid encoding a miR155 gene product comprising SEQ ID NO:1 and/or SEQ ID NO:2. In a particular embodiment, the transgenic non-human animal's genome comprises a nucleic acid construct comprising a VHpromoter and an Ig heavy chain-Eμ enhancer, operably linked to a nucleic acid encoding a miR155 gene product comprising a nucleotide sequence having at least 90% sequence identity to SEQ ID NO:1 and/or SEQ ID NO:2.
In a particular embodiment, the transgenic non-human animal has an expanded population of B220low/CD19low/CD10low/IgM−/TCR−/CD43−lymphoid cells in the spleen, the bone marrow or both the spleen and bone marrow, relative to this population in a suitable control animal. In a related embodiment, the transgenic non-human animal exhibits a lymphoproliferative condition. In a certain embodiment, the lymphoproliferative condition is a B cell malignancy (e.g., a B cell leukemia, for example, acute lymphoblastic leukemia; a B cell lymphoma, a B cell neoplasm). In a further embodiment, the B cell malignancy exhibits characteristics of human acute lymphoblastic leukemia, human lymphoblastic lymphoma or a combination thereof. In yet another embodiment, the lymphoproliferative condition is a preleukemic state (e.g., pre-B cell proliferation). In additional embodiments, the transgenic non-human animal exhibits an enlarged abdomen, splenomegaly, bone marrow replacement, lymphopenia, or a combination thereof.
There is also provided herein a method of testing the therapeutic efficacy of an agent in treating or preventing a lymphoproliferative condition in a subject. According to one embodiment, the method comprises administering the agent to a transgenic non-human animal (e.g., a mouse) whose genome comprises a nucleic acid construct comprising at least one transcriptional regulatory sequence capable of directing expression in B cells of the animal (e.g., a VHpromoter, an Ig heavy chain-Eμ enhancer, a combination thereof), wherein the transcriptional regulatory sequence is operably linked to a nucleic acid encoding a miR155 gene product comprising a nucleotide sequence having at least 90% sequence identity to SEQ ID NO:1 and/or SEQ ID NO:2. In a particular embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:1. In another embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:2.
After the agent has been administered to the transgenic animal, one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal are compared with those of a control animal of the same genotype, which has not been administered the agent. If the agent inhibits, prevents and/or reduces one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal to which it has been administered, relative to the control animal, then the agent is considered to have therapeutic efficacy in treating or preventing a lymphoproliferative condition. In a certain embodiment, the one or more symptoms and/or indications of the lymphoproliferative condition are selected from the group consisting of: an expanded population of B220low/cD19low/CD10low/IgM−/TCR−/CD43−lymphoid cells, an enlarged abdomen, splenomegaly, bone marrow replacement, lymphopenia and a combination thereof.
In another embodiment, there is provided herein a method of determining whether an agent affects a lymphoproliferative condition in a subject (e.g., affecting a difference in the detectability and/or rate of appearance of one or more symptoms and/or indications of a lymphoproliferative condition). The method comprises administering an agent to a transgenic non-human animal described herein and comparing one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal to those of a control animal of the same genotype, wherein the control animal has not been administered the agent. Detection of a difference in the detectability and/or rate of appearance of one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal, relative to the control animal, is indicative of the agent affecting the lymphoproliferative condition.
In one embodiment, the lymphoproliferative condition is a B cell malignancy. In a particular embodiment, the B cell malignancy is selected from the group consisting of acute lymphoblastic leukemia, B cell lymphoma (e.g., high-grade lymphoma), B cell neoplasm and a combination thereof. The B cell malignancy may exhibit characteristics of human acute lymphoblastic leukemia, human lymphoblastic lymphoma or both. In another embodiment, the lymphoproliferative condition is a preleukemic state, such as a state characterized by pre-B cell proliferation.
These as well as other important aspects of the invention will become more apparent from the following detailed description.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
Acute leukemia is a rapidly progressive malignant disease of the bone marrow and blood that results in the accumulation of immature, functionless cells, called blast cells, in the marrow and blood. The accumulation of blast cells in the marrow blocks normal blood cell development. As a result, red cells, white cells and platelets are not produced in sufficient numbers. When the disease originates in a marrow lymphocyte progenitor cell, it results in acute lymphoblastic leukemia (ALL) and when the disease originates in a myeloid progenitor, it results in acute myelogenous leukemia (AML).
ALL is a rapidly progressive cancer that starts by the malignant transformation of a marrow lymphocyte. ALL is the most common type of childhood leukemia, with 3,000 new cases per year in all age groups. The transformed, now malignant, cell multiplies and accumulates in the marrow as leukemic lymphoblasts. The lymphoblasts block normal blood cell-formation in the marrow, resulting in insufficient production of red cells, white cells and platelets.
High-grade lymphomas, also known as aggressive lymphoma, include several subtypes of lymphoma that progress relatively rapidly if untreated. These subtypes include, e.g., AIDS-associated lymphoma, anaplastic large cell lymphoma, Burkitt's lymphoma, diffuse large cell lymphoma, immunoblastic lymphoma, lymphoblastic lymphoma and small noncleaved cell lymphomas. Compared to diffuse large B-cell lymphomas, high-grade lymphomas behave more aggressively, require more intensive chemotherapy, and occur more often in children. Because rapidly dividing cells are more sensitive to anti-cancer agents and because the young patients usually lack other health problems, some of these lymphomas show a dramatic response to therapy. Acute lymphoblastic leukemia and high-grade lymphoma are the most common leukemias and lymphomas in children. These diseases are, for the most part, polyclonal, suggesting that only a few genetic changes are sufficient to induce malignancy.
MicroRNAs (miRNAs) represent a new class of abundant small RNAs that play important regulatory roles at the post-transcriptional level by binding to targeted mRNAs and either blocking their translation or initiating their degradation, according to the degree of complementarity with the target. Since their discovery in 1993 inCaenorhabditis elegans(Lee, R. et al.,Cell75:843-854 (1993)), there have been numerous reports that implicated these tiny molecules in the posttranscriptional regulation of a large array of proteins with very diverse roles, ranging from cell proliferation and differentiation to lipid metabolism (Nairz, K., et al.,Dev. Biol.291:314-324 (2006); Chen, J. F., et al.,Nat. Genet.38:228-233 (2006); Naguibneva, I., et al.,Nat. Cell Biol.8:278-284 (2006); Esau, C., et al.,Cell Metab.3:87-98 (2006); and Gauthier, B. R., et al.,Nat. Med.12:36-18 (2006)).
miRNA profiling of hematopoietic lineages in humans and mice showed that miRNAs are differentially expressed in the course of hematopoietic development, suggesting a potential role in hematopoietic differentiation (Chen, C. Z., et al.,Science303:83-86 (2004); Chen, C. Z., et al.,Semin. Immunol.17:155-165 (2005); and Ramkissoon, S. H., et al.,Leuk. Res.30:643-647 (2006)). We have shown that miR-15a and miR-16-1 are deleted or down-regulated in 68% of cases of chronic lymphocytic leukemia (CLL) (Calin, G. A., et al.,Proc. Natl. Acad. Sci. USA99:15524-15529 (2002); and Calin, G. A., et al.,Proc. Natl. Acad. Sci. USA101:11755-11760 (2004)), and that miRNAs genes are frequently located at fragile sites and genomic regions involved in cancers (Calin, G. A., et al,Proc. Natl. Acad. Sci. USA101:2999-3004 (2004)). miR155 and BIC (its host gene) transcripts have been shown to accumulate in human B cell lymphomas, especially diffuse large B cell lymphomas (Eis, P. S., et al,Proc. Natl. Acad. Sci. USA102:3627-3632 (2005)), Hodgkin lymphomas (Kluvier, J., et al.,J. Pathol207:243-249 (2006)), and certain types of Burkitt lymphomas (latency type III Epstein-Barr virus-positive Burkitt lymphoma) (Kluvier, J., et al,Genes Chromosomes Cancer45: 147-153 (2006)).
Currently, there is an urgent need to produce animal models that can be used to screen for, and identify, candidate agents that have therapeutic potential for the treatment of lymphoproliferative disorders, such as B cell malignancies (e.g., B cell leukemias, B cell lymphomas).
SUMMARY OF THE INVENTION
The present invention is based on the discovery that transgenic mice carrying a miR155 transgene, whose expression is targeted to B cells (e.g., using an Ig heavy chain-Eμ enhancer), initially exhibit a preleukemic pre-B cell proliferation, evident in spleen and bone marrow, and later develop B cell malignancies. Transgenic mice that overexpress miR155 develop a lymphoproliferative disease resembling human lymphoproliferative diseases, thus strongly implicating miR155 in the initiation and/or progression of these diseases. The Eμ-mmu-miR155 transgenic mice are useful for devising new therapeutic approaches to treat different forms of lymphoproliferative disorders, such as B cell malignancies (e.g., acute lymphoblastic leukemia, high-grade lymphomas) in humans.
Accordingly, in one aspect, there is provided herein, novel animal models for lymphoproliferative disorders. Specifically, according to one aspect, animal models for B cell malignancies (e.g., leukemias (e.g., acute lymphoblastic leukemia), lymphomas (e.g., high-grade lymphoma), and neoplasms) are provided.
In one embodiment, there is provided herein a transgenic non-human animal (e.g., a mouse) whose genome comprises a nucleic acid construct comprising at least one transcriptional regulatory sequence capable of directing expression in B cells of the animal, operably linked to a nucleic acid encoding a miR155 gene product. In a particular embodiment, the miR155 gene product comprises a nucleotide sequence having at least 90% sequence identity to SEQ ID NO:1 and/or SEQ ID NO:2. In another embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:1. In still another embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:2.
According to one embodiment, the at least one transcriptional regulatory sequence can be any sequence capable of directing expression in B cells of the animal. In one embodiment, the transcriptional regulatory sequence comprises a VHpromoter (e.g., a VHpromoter derived from mouse). In another embodiment the transcriptional regulatory sequence comprises an Ig heavy chain-Eμ enhancer (e.g., an Ig heavy chain-Eμ enhancer derived from mouse). In a related embodiment, the nucleic acid construct comprises the 3′ UTR and poly(A) sequence of a β-globin gene (e.g., a β-globin gene derived from human or other mammalian species).
There is also provided herein a transgenic non-human animal whose genome comprises a nucleic acid construct comprising a VHpromoter and an Ig heavy chain-Eμ enhancer, operably linked to a nucleic acid encoding a miR155 gene product comprising SEQ ID NO:1 and/or SEQ ID NO:2. In a particular embodiment, the transgenic non-human animal's genome comprises a nucleic acid construct comprising a VHpromoter and an Ig heavy chain-Eμ enhancer, operably linked to a nucleic acid encoding a miR155 gene product comprising a nucleotide sequence having at least 90% sequence identity to SEQ ID NO:1 and/or SEQ ID NO:2.
In a particular embodiment, the transgenic non-human animal has an expanded population of B220low/CD19low/CD10low/IgM−/TCR−/CD43−lymphoid cells in the spleen, the bone marrow or both the spleen and bone marrow, relative to this population in a suitable control animal. In a related embodiment, the transgenic non-human animal exhibits a lymphoproliferative condition. In a certain embodiment, the lymphoproliferative condition is a B cell malignancy (e.g., a B cell leukemia, for example, acute lymphoblastic leukemia; a B cell lymphoma, a B cell neoplasm). In a further embodiment, the B cell malignancy exhibits characteristics of human acute lymphoblastic leukemia, human lymphoblastic lymphoma or a combination thereof. In yet another embodiment, the lymphoproliferative condition is a preleukemic state (e.g., pre-B cell proliferation). In additional embodiments, the transgenic non-human animal exhibits an enlarged abdomen, splenomegaly, bone marrow replacement, lymphopenia, or a combination thereof.
There is also provided herein a method of testing the therapeutic efficacy of an agent in treating or preventing a lymphoproliferative condition in a subject. According to one embodiment, the method comprises administering the agent to a transgenic non-human animal (e.g., a mouse) whose genome comprises a nucleic acid construct comprising at least one transcriptional regulatory sequence capable of directing expression in B cells of the animal (e.g., a VHpromoter, an Ig heavy chain-Eμ enhancer, a combination thereof), wherein the transcriptional regulatory sequence is operably linked to a nucleic acid encoding a miR155 gene product comprising a nucleotide sequence having at least 90% sequence identity to SEQ ID NO:1 and/or SEQ ID NO:2. In a particular embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:1. In another embodiment, the miR155 gene product comprises the nucleotide sequence of SEQ ID NO:2.
After the agent has been administered to the transgenic animal, one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal are compared with those of a control animal of the same genotype, which has not been administered the agent. If the agent inhibits, prevents and/or reduces one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal to which it has been administered, relative to the control animal, then the agent is considered to have therapeutic efficacy in treating or preventing a lymphoproliferative condition. In a certain embodiment, the one or more symptoms and/or indications of the lymphoproliferative condition are selected from the group consisting of: an expanded population of B220low/cD19low/CD10low/IgM−/TCR−/CD43−lymphoid cells, an enlarged abdomen, splenomegaly, bone marrow replacement, lymphopenia and a combination thereof.
In another embodiment, there is provided herein a method of determining whether an agent affects a lymphoproliferative condition in a subject (e.g., affecting a difference in the detectability and/or rate of appearance of one or more symptoms and/or indications of a lymphoproliferative condition). The method comprises administering an agent to a transgenic non-human animal described herein and comparing one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal to those of a control animal of the same genotype, wherein the control animal has not been administered the agent. Detection of a difference in the detectability and/or rate of appearance of one or more symptoms and/or indications of the lymphoproliferative condition in the transgenic animal, relative to the control animal, is indicative of the agent affecting the lymphoproliferative condition.
In one embodiment, the lymphoproliferative condition is a B cell malignancy. In a particular embodiment, the B cell malignancy is selected from the group consisting of acute lymphoblastic leukemia, B cell lymphoma (e.g., high-grade lymphoma), B cell neoplasm and a combination thereof. The B cell malignancy may exhibit characteristics of human acute lymphoblastic leukemia, human lymphoblastic lymphoma or both. In another embodiment, the lymphoproliferative condition is a preleukemic state, such as a state characterized by pre-B cell proliferation.
These as well as other important aspects of the invention will become more apparent from the following detailed description.
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7736176 | BACKGROUND OF THE INVENTION
The present application is related to commonly assigned patent application entitled “MODULAR JACK ASSEMBLY HAVING IMPROVED BASE ELEMENT”.
FIELD OF THE INVENTION
The present invention relates to a modular jack assembly and particularly to a modular jack assembly comprising an improved connecting terminal.
DESCRIPTION OF THE PRIOR ART
Modular jack assembly is commonly used in the computer or network appliance as input/output port for transmitting data or signals. An example of such a connector is disclosed in U.S. Pat. No. 7,052,315 issued on May 30, 2006. The modular jack assembly engages with a mating plug and includes an insulative housing, a terminal module received in the housing, a main board mounted to the rear of the insulative housing and a power over ethernet assembly. The terminal module includes a base element defining a receiving room and a conductive portion assembled to a front wall of the base element. The base element comprises a printed circuit board positioned on a top thereof. The terminal module has a plurality of L-shaped signal contacts and power contacts. The L-shaped contacts have first ends routed through the printed circuit board and second ends extending outwardly from a rear wall of the connecting portion and then through the main board for electrically connecting with the power over ethernet assembly.
However, during assembling, the first ends and the second ends of the L-shaped contacts are respectively inserted through the printed circuit board and the main board by strong mechanical force that would result in cracks of the contacts and would complicate the manufacture of the modular jack assembly.
Hence, an improved modular jack assembly is needed to solve the above problem.
BRIEF SUMMARY OF THE INVENTION
One object of the present invention is to provide a modular jack assembly comprising a terminal module having an improved connecting terminal adapted for being assembled to the terminal module easily and being fixed in corresponding terminal slots firmly.
The present invention provides a modular jack assembly for being mounted on a mother board and engaging with a mating plug. The modular jack assembly comprises a plurality of terminal modules, an outer shield surrounding the insulative housing, a power over ethernet assembly mounted rearwardly. The terminal module comprises a contacting module, a base element, a connecting element, a pair of daughter boards assembled to opposite sides of the base element and a plurality of connecting terminals mounted to the base element. The base element defines a plurality of terminal slots at an outer face thereof for receiving the connecting terminals. Each connecting terminal has a first end exposed at a side of the base element, a second end connected with the power over ethernet assembly and a plurality of protrusions disposed thereon for interfering with the terminal slots.
Thus, the connecting terminals are easy to be mounted into the terminal slot in an outer-to-inner direction and firmly fixed in the terminal slots by the interference between the protrusions of the connecting terminals and the terminal slots.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiments when taken in conjunction with the accompanying drawings.
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SUMMARY: BACKGROUND OF THE INVENTION
The present application is related to commonly assigned patent application entitled “MODULAR JACK ASSEMBLY HAVING IMPROVED BASE ELEMENT”.
FIELD OF THE INVENTION
The present invention relates to a modular jack assembly and particularly to a modular jack assembly comprising an improved connecting terminal.
DESCRIPTION OF THE PRIOR ART
Modular jack assembly is commonly used in the computer or network appliance as input/output port for transmitting data or signals. An example of such a connector is disclosed in U.S. Pat. No. 7,052,315 issued on May 30, 2006. The modular jack assembly engages with a mating plug and includes an insulative housing, a terminal module received in the housing, a main board mounted to the rear of the insulative housing and a power over ethernet assembly. The terminal module includes a base element defining a receiving room and a conductive portion assembled to a front wall of the base element. The base element comprises a printed circuit board positioned on a top thereof. The terminal module has a plurality of L-shaped signal contacts and power contacts. The L-shaped contacts have first ends routed through the printed circuit board and second ends extending outwardly from a rear wall of the connecting portion and then through the main board for electrically connecting with the power over ethernet assembly.
However, during assembling, the first ends and the second ends of the L-shaped contacts are respectively inserted through the printed circuit board and the main board by strong mechanical force that would result in cracks of the contacts and would complicate the manufacture of the modular jack assembly.
Hence, an improved modular jack assembly is needed to solve the above problem.
BRIEF SUMMARY OF THE INVENTION
One object of the present invention is to provide a modular jack assembly comprising a terminal module having an improved connecting terminal adapted for being assembled to the terminal module easily and being fixed in corresponding terminal slots firmly.
The present invention provides a modular jack assembly for being mounted on a mother board and engaging with a mating plug. The modular jack assembly comprises a plurality of terminal modules, an outer shield surrounding the insulative housing, a power over ethernet assembly mounted rearwardly. The terminal module comprises a contacting module, a base element, a connecting element, a pair of daughter boards assembled to opposite sides of the base element and a plurality of connecting terminals mounted to the base element. The base element defines a plurality of terminal slots at an outer face thereof for receiving the connecting terminals. Each connecting terminal has a first end exposed at a side of the base element, a second end connected with the power over ethernet assembly and a plurality of protrusions disposed thereon for interfering with the terminal slots.
Thus, the connecting terminals are easy to be mounted into the terminal slot in an outer-to-inner direction and firmly fixed in the terminal slots by the interference between the protrusions of the connecting terminals and the terminal slots.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiments when taken in conjunction with the accompanying drawings.
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7826502 | FIELD OF THE INVENTION
The present invention relates in general to the stabilization of the output of a laser system and more particularly to lessening noise in the output of a diode-laser pumped, solid-state, externally frequency-converted laser system.
BACKGROUND OF THE INVENTION
There is considerable demand for short-wavelength laser sources such as green, blue and UV lasers. One known approach to create such a light source is to utilize red or infra-red laser diodes, which are widely available in a variety of configurations. These diodes, in combination with nonlinear elements made of optically nonlinear materials, can produce short-wavelength frequency-doubled radiation by means of second harmonic generation (SHG) in the nonlinear element.
A laser source for frequency doubling requires (a) high power, (b) stable, narrow-line operation, (c) simple, low-cost optics and assembly, and, importantly (d) some means of fine-tuning the spectrum to match it to a doubling material to optimize efficiency. This invention particularly relates to a method and circuit to minimize noise in the frequency doubled output signal.
A number of prior art designs for frequency doubling of laser diode emission have been disclosed. For example, U.S. Pat. No. 5,384,797, in the names of Welch et al., describes a monolithic multi-wavelength laser diode array having output light that can be coupled into a ferroelectric frequency doubler integrally formed on an array substrate. U.S. Pat. No. 5,644,584, in the names of Nam et al. describes a tunable blue laser diode having a distributed Bragg reflector (DBR) or distributed feedback (DFB) tunable diode laser coupled to a quasi-phase-matched waveguide of optically nonlinear material. U.S. Pat. No. 6,370,168 to Spinelli describes an intracavity frequency-converted optically-pumped semiconductor laser based on surface-emitting gain-structure surmounting a Bragg mirror, and an external concaved mirror. U.S. Pat. No. 6,393,038 to Raymond et al. describes a frequency-doubled vertical-external-cavity surface-emitting laser; and, U.S. Pat. No. 6,438,153 to Caprara et al. describes an intracavity-converted optically-pumped semiconductor laser. Although these aforementioned inventions appear to perform their intended function, many provide solutions wherein power and frequency stabilization requirements are met through the use of complex laser structures or complex nonlinear element arrangements. Furthermore, since complex laser designs usually lead to somewhat reduced power and increase in noise, these prior art solutions either use an intra-cavity nonlinear doubling arrangement to benefit from the intra-cavity resonance power enhancement, at the expense of yet more complex cavity control, or use single-pass doubling with relatively low output powers. U.S. Pat. No. 7,242,700 to Wang discloses a circuit for stabilizing a laser frequency doubled output signal. Although this circuit to some degree achieves its goal, a more reliable solution having less noise in the output laser frequency doubled signal is being sought after.
In an attempt to overcome some of the limitations of the prior art, U.S. Pat. No. 7,177,340 to Lang et al. assigned to JDS Uniphase Corporation describes an extended cavity laser device with bulk transmission grating. The system of Lang et al. uses a semi-conductor, high power, lasers of simple cavity design, such as edge emitting 980 nm laser diodes commonly used to pump erbium-doped fiber amplifiers, in an external cavity arrangement with frequency stabilization provided by an external frequency selective reflector. This patent attempts to provide a simple Littrow-type external cavity configuration for a diode laser, which substantially maximizes output power and enables frequency tuning without angular tuning of the output beam. An interesting aspect of U.S. Pat. No. 7,177,340 is that spectral noise of the laser diode radiation is substantially mitigated by providing an additional electric dither current to the laser diode to cause frequency modulation of the laser diode radiation with amplitude exceeding mode spacing. Such dithering results in a continuous scrambling of the laser light to increase stability of time-averaged spectrum of the laser diode radiation and therefore to stabilize a time-averaged power of the frequency-doubled radiation.
SHG is routinely used to double the frequency and halve the wavelength of near-IR fundamental radiation having a wavelength near 1000 nanometers (nm) to produce visible light having a wavelength near 500 nm. In this context, SHG commonly involves propagating an IR output beam from a diode-pumped solid-state (DPSS) laser resonator through an appropriate optically nonlinear crystal, for example a crystal of lithium triborate (LBO). When such a crystal is properly tuned by establishing an appropriate orientation and temperature, visible light is generated and exits the crystal, usually accompanied by some residual fundamental-wavelength light. The efficiency of converting power from the fundamental wavelength to the desired frequency-converted wavelength (conversion efficiency) is defined by the ratio of the net power transferred to the frequency-converted output divided by the power contained in the fundamental-wavelength source beam. IR-to-visible conversion efficiencies exceeding 50% in LBO are readily demonstrated.
As noted above, optimization of a frequency converter generally involves establishing an appropriate wavelength-dependent crystal orientation and operating temperature. Operating parameters that optimize conversion efficiency for a particular frequency converter may be determined during a preliminary characterization or calibration phase of system operation. Optimal operating parameters might be determined once and thereafter be left unchanged in anticipation of retaining the demonstrated performance without subsequent intervention by a system operator.
However, such an optimistic approach typically encounters problems. Over time, the frequency-converted output power of a DPSS laser, even given constant input power, tends to degrade as optical components age and accumulate damage. In addition, as the laser system power level or operating duty factor change, re-tuning of the frequency converter often becomes necessary and some method of monitoring conversion efficiency becomes advisable.
One method to compensate for deteriorating frequency-converted output power involves monitoring the frequency-converted output power level and increasing pump power as needed to boost the output while also monitoring the fundamental power level to allow determination of the conversion efficiency. Adjustments may then be made to the frequency converter to maintain or recover the desired efficiency. This approach does not always give satisfactory results.
The time-averaged power and perhaps even the position of the frequency-converted output may change so much over time that no reasonable adjustment of the diode drive current alone can recover the desired operating condition. Further, when fundamental and frequency-converted beams are sampled and detected separately, components exposed to the different beams may degrade at different rates. Such differential aging may bias the assessment of conversion efficiency. In addition, verifying that peak conversion efficiency is being maintained, when the output power may be slowly varying due to changes in the laser resonator, necessitates detuning the frequency converter away from an optimal condition, checking for a corresponding roll-off in performance, then re-tuning back to the optimal value.
In many instances, it is desirous to provide a frequency doubling laser circuit that maximizes output power regardless of the noise generated. However in other particular instances, where output power is of less of a concern, it is desired to minimize the noise present in the frequency doubled signal. Although maximizing output power and lessening noise typically occur to some degree together, they most often do not track perfectly with one another. For example achieving the lowest possible noise in the output signal does not ensure that maximum power will be attained. Furthermore, achieving maximum power output from the frequency doubling crystal does not ensure that the lowest noise will be achieved.
This invention is primarily concerned with the lessening of noise in the frequency doubled output signal and provides a novel way in which to achieve this as the laser and frequency doubling crystal physically change by aging over time.
It is an object of this invention to provide a method and circuit for frequency converting an optical signal to a shorter wavelength while minimizing noise in the output signal.
It is an object of this invention to continuously dither the temperature of a frequency doubling crystal and search for an optimized crystal temperature by varying the temperature in predetermined steps based on input from an RMS noise detector and current monitor.
It is an object of the invention to optimize the crystal temperature to minimize noise as the laser ages, as current driving the laser changes, as ambient temperature changes, and as stress and release of stress occurs within the crystal.
SUMMARY OF THE INVENTION
The present invention is directed to providing a low noise frequency-converted laser signal. In a general aspect, the inventive laser system comprises a current driven laser diode to generate and deliver a beam of fundamental radiation having a first (fundamental) wavelength. The laser system includes a frequency converting crystal located separate from the laser and aligned to receive light from the laser. The frequency converting crystal converts a portion of the fundamental-wavelength beam to a frequency-converted beam. One or more detectors are provided for monitoring the noise present on the frequency-converted beam. A controller is arranged cooperative with the detectors to adjust the temperature of the frequency converting crystal by repeatedly dithering the temperature while monitoring the noise so as to lessen it. The position of the frequency-converted beam and the conversion efficiency of the frequency converter are to some degree dependent on the temperature of the optically nonlinear crystal.
In accordance with the invention, there is provided a method of controlling the output signal generated by a frequency converting crystal comprising the steps of:
providing a frequency converting crystal with light of a first wavelength at an input end thereof;
detecting a portion of frequency converted light exiting an output end of the frequency converting crystal and converting the portion of frequency converted light to an electrical signal;
determining from the electrical signal, a level of noise present in the detected portion of the frequency converted light; and
repeatedly varying the temperature of the frequency converting crystal upward and downward within limits in increments, while continuing to perform steps (b) and (c) so as to minimize the RMS noise present in the frequency converted light.
A circuit for generating a low noise short wavelength signal comprising:
a laser for providing a first optical signal having a first wavelength;
a frequency converting element positioned to receive the first optical signal from the laser and for converting the first optical signal into a second optical signal having a shorter wavelength than the first wavelength;
a detector for detecting a portion of the second optical signal and for providing a first electrical signal having characteristics dependent upon the second optical signal;
a first control circuit responsive to the first electrical signal and for determining an optical power value and a noise value corresponding to power and noise present in the second optical signal in dependence upon characteristics of the first electrical signal;
a second control responsive to input from the first control circuit in communication with the laser for maintaining the power of the laser at a constant value;
a third control circuit responsive to input from the first control circuit for varying the temperature in a continuous manner so as to lessen noise present in the second optical signal.
In accordance with the invention there is provided a circuit for generating a low noise short wavelength optical signal comprising:
a laser for providing a first optical signal having a first wavelength longer than the short wavelength signal;
a frequency converting element positioned to receive the first optical signal from the laser and for converting the first optical signal into the short wavelength signal;
a feedback circuit for detecting a portion of the second optical signal and for adjusting the temperature of the frequency converting element upward one or more temperature increments and downward one or more temperature increments continuously so as to lessen noise present in the short wavelength signal, wherein said increases upward and downward in temperature are based on an amount of detected noise in the short wavelength signal; and,
a control circuit for maintaining the power level of the short wavelength signal to be at a constant value while the feedback circuit lessens noise present in the short wavelength signal.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates in general to the stabilization of the output of a laser system and more particularly to lessening noise in the output of a diode-laser pumped, solid-state, externally frequency-converted laser system.
BACKGROUND OF THE INVENTION
There is considerable demand for short-wavelength laser sources such as green, blue and UV lasers. One known approach to create such a light source is to utilize red or infra-red laser diodes, which are widely available in a variety of configurations. These diodes, in combination with nonlinear elements made of optically nonlinear materials, can produce short-wavelength frequency-doubled radiation by means of second harmonic generation (SHG) in the nonlinear element.
A laser source for frequency doubling requires (a) high power, (b) stable, narrow-line operation, (c) simple, low-cost optics and assembly, and, importantly (d) some means of fine-tuning the spectrum to match it to a doubling material to optimize efficiency. This invention particularly relates to a method and circuit to minimize noise in the frequency doubled output signal.
A number of prior art designs for frequency doubling of laser diode emission have been disclosed. For example, U.S. Pat. No. 5,384,797, in the names of Welch et al., describes a monolithic multi-wavelength laser diode array having output light that can be coupled into a ferroelectric frequency doubler integrally formed on an array substrate. U.S. Pat. No. 5,644,584, in the names of Nam et al. describes a tunable blue laser diode having a distributed Bragg reflector (DBR) or distributed feedback (DFB) tunable diode laser coupled to a quasi-phase-matched waveguide of optically nonlinear material. U.S. Pat. No. 6,370,168 to Spinelli describes an intracavity frequency-converted optically-pumped semiconductor laser based on surface-emitting gain-structure surmounting a Bragg mirror, and an external concaved mirror. U.S. Pat. No. 6,393,038 to Raymond et al. describes a frequency-doubled vertical-external-cavity surface-emitting laser; and, U.S. Pat. No. 6,438,153 to Caprara et al. describes an intracavity-converted optically-pumped semiconductor laser. Although these aforementioned inventions appear to perform their intended function, many provide solutions wherein power and frequency stabilization requirements are met through the use of complex laser structures or complex nonlinear element arrangements. Furthermore, since complex laser designs usually lead to somewhat reduced power and increase in noise, these prior art solutions either use an intra-cavity nonlinear doubling arrangement to benefit from the intra-cavity resonance power enhancement, at the expense of yet more complex cavity control, or use single-pass doubling with relatively low output powers. U.S. Pat. No. 7,242,700 to Wang discloses a circuit for stabilizing a laser frequency doubled output signal. Although this circuit to some degree achieves its goal, a more reliable solution having less noise in the output laser frequency doubled signal is being sought after.
In an attempt to overcome some of the limitations of the prior art, U.S. Pat. No. 7,177,340 to Lang et al. assigned to JDS Uniphase Corporation describes an extended cavity laser device with bulk transmission grating. The system of Lang et al. uses a semi-conductor, high power, lasers of simple cavity design, such as edge emitting 980 nm laser diodes commonly used to pump erbium-doped fiber amplifiers, in an external cavity arrangement with frequency stabilization provided by an external frequency selective reflector. This patent attempts to provide a simple Littrow-type external cavity configuration for a diode laser, which substantially maximizes output power and enables frequency tuning without angular tuning of the output beam. An interesting aspect of U.S. Pat. No. 7,177,340 is that spectral noise of the laser diode radiation is substantially mitigated by providing an additional electric dither current to the laser diode to cause frequency modulation of the laser diode radiation with amplitude exceeding mode spacing. Such dithering results in a continuous scrambling of the laser light to increase stability of time-averaged spectrum of the laser diode radiation and therefore to stabilize a time-averaged power of the frequency-doubled radiation.
SHG is routinely used to double the frequency and halve the wavelength of near-IR fundamental radiation having a wavelength near 1000 nanometers (nm) to produce visible light having a wavelength near 500 nm. In this context, SHG commonly involves propagating an IR output beam from a diode-pumped solid-state (DPSS) laser resonator through an appropriate optically nonlinear crystal, for example a crystal of lithium triborate (LBO). When such a crystal is properly tuned by establishing an appropriate orientation and temperature, visible light is generated and exits the crystal, usually accompanied by some residual fundamental-wavelength light. The efficiency of converting power from the fundamental wavelength to the desired frequency-converted wavelength (conversion efficiency) is defined by the ratio of the net power transferred to the frequency-converted output divided by the power contained in the fundamental-wavelength source beam. IR-to-visible conversion efficiencies exceeding 50% in LBO are readily demonstrated.
As noted above, optimization of a frequency converter generally involves establishing an appropriate wavelength-dependent crystal orientation and operating temperature. Operating parameters that optimize conversion efficiency for a particular frequency converter may be determined during a preliminary characterization or calibration phase of system operation. Optimal operating parameters might be determined once and thereafter be left unchanged in anticipation of retaining the demonstrated performance without subsequent intervention by a system operator.
However, such an optimistic approach typically encounters problems. Over time, the frequency-converted output power of a DPSS laser, even given constant input power, tends to degrade as optical components age and accumulate damage. In addition, as the laser system power level or operating duty factor change, re-tuning of the frequency converter often becomes necessary and some method of monitoring conversion efficiency becomes advisable.
One method to compensate for deteriorating frequency-converted output power involves monitoring the frequency-converted output power level and increasing pump power as needed to boost the output while also monitoring the fundamental power level to allow determination of the conversion efficiency. Adjustments may then be made to the frequency converter to maintain or recover the desired efficiency. This approach does not always give satisfactory results.
The time-averaged power and perhaps even the position of the frequency-converted output may change so much over time that no reasonable adjustment of the diode drive current alone can recover the desired operating condition. Further, when fundamental and frequency-converted beams are sampled and detected separately, components exposed to the different beams may degrade at different rates. Such differential aging may bias the assessment of conversion efficiency. In addition, verifying that peak conversion efficiency is being maintained, when the output power may be slowly varying due to changes in the laser resonator, necessitates detuning the frequency converter away from an optimal condition, checking for a corresponding roll-off in performance, then re-tuning back to the optimal value.
In many instances, it is desirous to provide a frequency doubling laser circuit that maximizes output power regardless of the noise generated. However in other particular instances, where output power is of less of a concern, it is desired to minimize the noise present in the frequency doubled signal. Although maximizing output power and lessening noise typically occur to some degree together, they most often do not track perfectly with one another. For example achieving the lowest possible noise in the output signal does not ensure that maximum power will be attained. Furthermore, achieving maximum power output from the frequency doubling crystal does not ensure that the lowest noise will be achieved.
This invention is primarily concerned with the lessening of noise in the frequency doubled output signal and provides a novel way in which to achieve this as the laser and frequency doubling crystal physically change by aging over time.
It is an object of this invention to provide a method and circuit for frequency converting an optical signal to a shorter wavelength while minimizing noise in the output signal.
It is an object of this invention to continuously dither the temperature of a frequency doubling crystal and search for an optimized crystal temperature by varying the temperature in predetermined steps based on input from an RMS noise detector and current monitor.
It is an object of the invention to optimize the crystal temperature to minimize noise as the laser ages, as current driving the laser changes, as ambient temperature changes, and as stress and release of stress occurs within the crystal.
SUMMARY OF THE INVENTION
The present invention is directed to providing a low noise frequency-converted laser signal. In a general aspect, the inventive laser system comprises a current driven laser diode to generate and deliver a beam of fundamental radiation having a first (fundamental) wavelength. The laser system includes a frequency converting crystal located separate from the laser and aligned to receive light from the laser. The frequency converting crystal converts a portion of the fundamental-wavelength beam to a frequency-converted beam. One or more detectors are provided for monitoring the noise present on the frequency-converted beam. A controller is arranged cooperative with the detectors to adjust the temperature of the frequency converting crystal by repeatedly dithering the temperature while monitoring the noise so as to lessen it. The position of the frequency-converted beam and the conversion efficiency of the frequency converter are to some degree dependent on the temperature of the optically nonlinear crystal.
In accordance with the invention, there is provided a method of controlling the output signal generated by a frequency converting crystal comprising the steps of:
providing a frequency converting crystal with light of a first wavelength at an input end thereof;
detecting a portion of frequency converted light exiting an output end of the frequency converting crystal and converting the portion of frequency converted light to an electrical signal;
determining from the electrical signal, a level of noise present in the detected portion of the frequency converted light; and
repeatedly varying the temperature of the frequency converting crystal upward and downward within limits in increments, while continuing to perform steps (b) and (c) so as to minimize the RMS noise present in the frequency converted light.
A circuit for generating a low noise short wavelength signal comprising:
a laser for providing a first optical signal having a first wavelength;
a frequency converting element positioned to receive the first optical signal from the laser and for converting the first optical signal into a second optical signal having a shorter wavelength than the first wavelength;
a detector for detecting a portion of the second optical signal and for providing a first electrical signal having characteristics dependent upon the second optical signal;
a first control circuit responsive to the first electrical signal and for determining an optical power value and a noise value corresponding to power and noise present in the second optical signal in dependence upon characteristics of the first electrical signal;
a second control responsive to input from the first control circuit in communication with the laser for maintaining the power of the laser at a constant value;
a third control circuit responsive to input from the first control circuit for varying the temperature in a continuous manner so as to lessen noise present in the second optical signal.
In accordance with the invention there is provided a circuit for generating a low noise short wavelength optical signal comprising:
a laser for providing a first optical signal having a first wavelength longer than the short wavelength signal;
a frequency converting element positioned to receive the first optical signal from the laser and for converting the first optical signal into the short wavelength signal;
a feedback circuit for detecting a portion of the second optical signal and for adjusting the temperature of the frequency converting element upward one or more temperature increments and downward one or more temperature increments continuously so as to lessen noise present in the short wavelength signal, wherein said increases upward and downward in temperature are based on an amount of detected noise in the short wavelength signal; and,
a control circuit for maintaining the power level of the short wavelength signal to be at a constant value while the feedback circuit lessens noise present in the short wavelength signal.
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7811557 | TECHNICAL FIELD
This invention relates to methods of improving central nervous system functioning.
BACKGROUND
The central nervous system is a complex system of tissues, including cells, fluids and chemicals that interact in concert to enable a wide variety of functions, including movement, navigation, cognition, speech, vision and emotion. Unfortunately, a variety of debilitating malfunctions of the central nervous system may occur and disrupt some or all of these functions. These malfunctions are broad in range and include, for example, missing genetic elements, e.g., genetic diseases such as Tay-Sachs; malfunctioning cellular processes, e.g., Parkinson's Disease; trauma, e.g., head injury; degenerative diseases, e.g., Alzheimer's Disease; and damage due to lack of oxygen, e.g., caused by stroke or asphyxiation.
Typically, treatments for restoring central nervous system function after damage by the above malfunctions have been limited to drugs, and to adaptive or behavioral therapies. These approaches are generally limited in their ability to reverse damage (or stop degeneration) and restore normal function.
Recent research has explored the possibility of using cells to restore function to the central nervous system. Data using animal models suggests that cell implantation or transplantation may be an effective means for restoring central nervous system function after damage. Cells that have been used in this research have included various nonhematopoietic precursor cells, for example, fetal or embryonic neural cells from porcine and human sources (see, e.g., Nairne, S. P.,Animal-to-Human transplants; the ethics of Xenotransplantation.London: Nuffield Council of Bioethics, 1996); immortalized fetal neural cells (Ren et al.,Co-Administration of Neural Stem Cells and bFGF Enhances Funcational Recovery Following Focal Cerebral Infarction in Rat.Soc. Neurosci. Abstr., 26:2291, 2000); mesenchymal bone marrow stem and progenitor cells (Chen et al.,Intracerebral Transplantation with Cultured Bone Marrow Stroma Cells after MCAO in Rats.American Society for Neural Transplantation & Repair, Program and Abstracts, Volume 7: 2000, A-3) including multipotent adult stem cells (see, e.g., Keene et al.,Phenotypic Expression of Transplanted Human Bone Marrow-Derived Multipotent Adult Stem Cells into the Rat CNS.American Society for Neural Transplantation & Repair, Program and Abstracts, Volume 7: 2000, 6-3); murine neural stem cells (Marciniak,Neural Stem Cells, In Combination with Basic Fibro-Blast Growth Factor(bFGF)May Represent a Treatment for Stroke,supra, A-1), including immortalized murine neuroepithelial stem cells (Modo et al.,Implantation Site of Stem Cells in MCAO Rats Influences the Recovery on Different Behavioral Tests,supra, 8-2); adult mouse and human neural stem and progenitor cells (see, e.g., Steindler et al.,Stem Cells in the Human Brain.,supra, 8-3); fetal mesencephalic cells (Mendez et al.,Simultaneous Intraputaminal and Instranigral Fetal Dopaminergic Grafts in Parkinson's Disease: First Clinical Trails,supra, 5-3); testis-derived Sertoli cells (Cameron et al.,Formation of SNACs by Simulated Microgravity Coculture of Sertoli Cells and NT2Cells,supra, C-), and crude bone marrow extract (Mahmood et al.,Effects of Transplantation of Bone Marrow Cells on Wistar Rats Following Traumatic Brain Injury,supra, A-4). To overcome the lack of availability of many of these types of cells, researchers have even resorted to studying the possibility of administering cancer cells such as teratacarcinomal cells (Kondziolka et al.,Transplantation of Cultured Human Neuronal Cells for Patients with Stroke,Neurology 2000, 55: 565-569), despite the inherent dangers of the use of cancerous cells. Some research into cellular therapies has reached the clinical stage. Generally, the cells that have been used in the research described above pose potential hazards to patients, and/or are difficult to obtain.
SUMMARY
The present invention features methods of enhancing recovery of central nervous system function by administering cells derived from blood, e.g., cells derived from cord blood. By “cord blood”, we mean blood that is derived from the placenta or umbilical cord around the time of the birth of a human infant. Advantageously, there is a readily available supply of such cells, without resort to fetal or embryonic sources or to harvesting the patient's own brain cells. For example, cord blood cells are currently banked for autologous or allogeneic administration in other applications. As a result, these cells need not be immortalized, and therefore there is a reduced risk of possible cancerous outgrowths or other detrimental complications that may result from the use of immortalized cells. Because these cells are primarily cells, they also are less likely to be carcinogenic or cause other related problems. Also, the use of autologous or immunologically matched cord blood cells reduces the risk of rejection.
Moreover, in some cases, e.g., if a large supply of cord blood is not readily available, a suitable cell population can be obtained using a relatively small sample of cord blood or other source of relatively undifferentiated precursor cells, e.g., as described in U.S. Pat. Nos. 5,674,750 and 5,925,567, the entire disclosures of which are incorporated herein by reference.
A method of causing an improvement in function of the central nervous system of a subject, comprising administering to the subject an aliquot of cells derived from umbilical cord blood.
In one aspect, the invention features a method of causing an improvement in a function of the central nervous system of a subject, comprising administering to the subject an aliquot of cells derived from blood, the aliquot containing stem cells.
In another aspect, the invention features a method of causing an improvement in a function of the central nervous system of a subject, comprising administering to the subject an aliquot of cells derived from blood and a growth factor.
Implementations of the invention may include one or more of the following features.
The cells are derived from umbilical cord blood. The cells are derived from peripheral blood. The method further includes obtaining the aliquot of cells by separating a desired cell population from the cord blood. The growth factor is selected from the group consisting of oncostatin M and growth factors from the following families: FGF, neurotrophin, IGF, CNTF, EGF, TGF-beta, LIF, interleukins, PDGF and VEGF. The method further includes obtaining a sample of cells and purifying the sample to obtain the aliquot. The method further includes obtaining a sample of cells and expanding at least a selected population of cells in the sample ex vivo to obtain the aliquot. The aliquot of cells includes allogeneic cells. Alternatively, or in addition, the aliquot of cells includes autologous cells. The improvement results in recovery from a central nervous system trauma, repair of central nervous system damage or disease, and/or regeneration of central nervous system tissue. The improvement includes measurable stroke recovery. The improvement is the result of stroke repair. The improvement results from tissue regeneration after a stroke. The improvement results from a genetic element contained in the administered cells. The genetic element is endogenous to the administered cells. The genetic element has been exogenously added to the administered cells. The improvement includes head trauma recovery and/or repair. The improvement results from tissue regeneration after head trauma. The cells are administered intercerebrally. The cells are CD 34+/−, Lin-cells or precursor cells. The cells are characterized as: CD2−, CD3−, CD14−, CD16−, CD19−, CD24−, CD56−, CD66b−, glycophorin A−, flk-1+, CD45+, CXCR4+, MDR+. The improvement results from treatment of one of the following diseases: Parkinson's Disease, Alzheimer's Disease, Huntington's Disease, ALS, MS, Tay-Sacks, and cerebral palsy. The method further includes administering to the subject a cell differentiation factor or a neural guidance molecule.
In a further aspect, the invention features a method of causing an improvement in central nervous system function of a patient including (i) obtaining an aliquot containing a predetermined target population of cells by (a) introducing a starting sample of cells into a growth medium; (b) causing cells of the predetermined target population to divide; and (c) concurrently with, intermittently during, or following step (b), contacting the cells in the growth medium with a selection element, so as to select cells of the target population from other cells in the growth medium; and (ii) administering the aliquot to the patient.
The selection element may include a plurality of selective binding molecules with affinity either for target cells or for a first population of non-target cells. The starting sample may be cord blood or be derived from cord blood. The aliquot of cells may include CD 34+/−, Lin-cells. Expansion may be clonogenic.
The term “blood”, as used herein, refers to peripheral, fetal and cord blood, and is not meant to include bone marrow.
The phrase “blood-derived cells” refers to relatively undifferentiated cells, and is not intended to include differentiated lymphoid cells such as T or B cells.
Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
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SUMMARY: TECHNICAL FIELD
This invention relates to methods of improving central nervous system functioning.
BACKGROUND
The central nervous system is a complex system of tissues, including cells, fluids and chemicals that interact in concert to enable a wide variety of functions, including movement, navigation, cognition, speech, vision and emotion. Unfortunately, a variety of debilitating malfunctions of the central nervous system may occur and disrupt some or all of these functions. These malfunctions are broad in range and include, for example, missing genetic elements, e.g., genetic diseases such as Tay-Sachs; malfunctioning cellular processes, e.g., Parkinson's Disease; trauma, e.g., head injury; degenerative diseases, e.g., Alzheimer's Disease; and damage due to lack of oxygen, e.g., caused by stroke or asphyxiation.
Typically, treatments for restoring central nervous system function after damage by the above malfunctions have been limited to drugs, and to adaptive or behavioral therapies. These approaches are generally limited in their ability to reverse damage (or stop degeneration) and restore normal function.
Recent research has explored the possibility of using cells to restore function to the central nervous system. Data using animal models suggests that cell implantation or transplantation may be an effective means for restoring central nervous system function after damage. Cells that have been used in this research have included various nonhematopoietic precursor cells, for example, fetal or embryonic neural cells from porcine and human sources (see, e.g., Nairne, S. P.,Animal-to-Human transplants; the ethics of Xenotransplantation.London: Nuffield Council of Bioethics, 1996); immortalized fetal neural cells (Ren et al.,Co-Administration of Neural Stem Cells and bFGF Enhances Funcational Recovery Following Focal Cerebral Infarction in Rat.Soc. Neurosci. Abstr., 26:2291, 2000); mesenchymal bone marrow stem and progenitor cells (Chen et al.,Intracerebral Transplantation with Cultured Bone Marrow Stroma Cells after MCAO in Rats.American Society for Neural Transplantation & Repair, Program and Abstracts, Volume 7: 2000, A-3) including multipotent adult stem cells (see, e.g., Keene et al.,Phenotypic Expression of Transplanted Human Bone Marrow-Derived Multipotent Adult Stem Cells into the Rat CNS.American Society for Neural Transplantation & Repair, Program and Abstracts, Volume 7: 2000, 6-3); murine neural stem cells (Marciniak,Neural Stem Cells, In Combination with Basic Fibro-Blast Growth Factor(bFGF)May Represent a Treatment for Stroke,supra, A-1), including immortalized murine neuroepithelial stem cells (Modo et al.,Implantation Site of Stem Cells in MCAO Rats Influences the Recovery on Different Behavioral Tests,supra, 8-2); adult mouse and human neural stem and progenitor cells (see, e.g., Steindler et al.,Stem Cells in the Human Brain.,supra, 8-3); fetal mesencephalic cells (Mendez et al.,Simultaneous Intraputaminal and Instranigral Fetal Dopaminergic Grafts in Parkinson's Disease: First Clinical Trails,supra, 5-3); testis-derived Sertoli cells (Cameron et al.,Formation of SNACs by Simulated Microgravity Coculture of Sertoli Cells and NT2Cells,supra, C-), and crude bone marrow extract (Mahmood et al.,Effects of Transplantation of Bone Marrow Cells on Wistar Rats Following Traumatic Brain Injury,supra, A-4). To overcome the lack of availability of many of these types of cells, researchers have even resorted to studying the possibility of administering cancer cells such as teratacarcinomal cells (Kondziolka et al.,Transplantation of Cultured Human Neuronal Cells for Patients with Stroke,Neurology 2000, 55: 565-569), despite the inherent dangers of the use of cancerous cells. Some research into cellular therapies has reached the clinical stage. Generally, the cells that have been used in the research described above pose potential hazards to patients, and/or are difficult to obtain.
SUMMARY
The present invention features methods of enhancing recovery of central nervous system function by administering cells derived from blood, e.g., cells derived from cord blood. By “cord blood”, we mean blood that is derived from the placenta or umbilical cord around the time of the birth of a human infant. Advantageously, there is a readily available supply of such cells, without resort to fetal or embryonic sources or to harvesting the patient's own brain cells. For example, cord blood cells are currently banked for autologous or allogeneic administration in other applications. As a result, these cells need not be immortalized, and therefore there is a reduced risk of possible cancerous outgrowths or other detrimental complications that may result from the use of immortalized cells. Because these cells are primarily cells, they also are less likely to be carcinogenic or cause other related problems. Also, the use of autologous or immunologically matched cord blood cells reduces the risk of rejection.
Moreover, in some cases, e.g., if a large supply of cord blood is not readily available, a suitable cell population can be obtained using a relatively small sample of cord blood or other source of relatively undifferentiated precursor cells, e.g., as described in U.S. Pat. Nos. 5,674,750 and 5,925,567, the entire disclosures of which are incorporated herein by reference.
A method of causing an improvement in function of the central nervous system of a subject, comprising administering to the subject an aliquot of cells derived from umbilical cord blood.
In one aspect, the invention features a method of causing an improvement in a function of the central nervous system of a subject, comprising administering to the subject an aliquot of cells derived from blood, the aliquot containing stem cells.
In another aspect, the invention features a method of causing an improvement in a function of the central nervous system of a subject, comprising administering to the subject an aliquot of cells derived from blood and a growth factor.
Implementations of the invention may include one or more of the following features.
The cells are derived from umbilical cord blood. The cells are derived from peripheral blood. The method further includes obtaining the aliquot of cells by separating a desired cell population from the cord blood. The growth factor is selected from the group consisting of oncostatin M and growth factors from the following families: FGF, neurotrophin, IGF, CNTF, EGF, TGF-beta, LIF, interleukins, PDGF and VEGF. The method further includes obtaining a sample of cells and purifying the sample to obtain the aliquot. The method further includes obtaining a sample of cells and expanding at least a selected population of cells in the sample ex vivo to obtain the aliquot. The aliquot of cells includes allogeneic cells. Alternatively, or in addition, the aliquot of cells includes autologous cells. The improvement results in recovery from a central nervous system trauma, repair of central nervous system damage or disease, and/or regeneration of central nervous system tissue. The improvement includes measurable stroke recovery. The improvement is the result of stroke repair. The improvement results from tissue regeneration after a stroke. The improvement results from a genetic element contained in the administered cells. The genetic element is endogenous to the administered cells. The genetic element has been exogenously added to the administered cells. The improvement includes head trauma recovery and/or repair. The improvement results from tissue regeneration after head trauma. The cells are administered intercerebrally. The cells are CD 34+/−, Lin-cells or precursor cells. The cells are characterized as: CD2−, CD3−, CD14−, CD16−, CD19−, CD24−, CD56−, CD66b−, glycophorin A−, flk-1+, CD45+, CXCR4+, MDR+. The improvement results from treatment of one of the following diseases: Parkinson's Disease, Alzheimer's Disease, Huntington's Disease, ALS, MS, Tay-Sacks, and cerebral palsy. The method further includes administering to the subject a cell differentiation factor or a neural guidance molecule.
In a further aspect, the invention features a method of causing an improvement in central nervous system function of a patient including (i) obtaining an aliquot containing a predetermined target population of cells by (a) introducing a starting sample of cells into a growth medium; (b) causing cells of the predetermined target population to divide; and (c) concurrently with, intermittently during, or following step (b), contacting the cells in the growth medium with a selection element, so as to select cells of the target population from other cells in the growth medium; and (ii) administering the aliquot to the patient.
The selection element may include a plurality of selective binding molecules with affinity either for target cells or for a first population of non-target cells. The starting sample may be cord blood or be derived from cord blood. The aliquot of cells may include CD 34+/−, Lin-cells. Expansion may be clonogenic.
The term “blood”, as used herein, refers to peripheral, fetal and cord blood, and is not meant to include bone marrow.
The phrase “blood-derived cells” refers to relatively undifferentiated cells, and is not intended to include differentiated lymphoid cells such as T or B cells.
Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
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7723740 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a light emitting device that uses a light emitting element and fluorescent material, and can be used for such applications as a signal light, illumination, display, indicator and other light sources, and particularly to a light emitting device that can emit light of white and other color tones by using fluorescent material that is excited by light emitted by a light emitting element, which emits in an ultraviolet to visible light region, and emits light in the visible light region.
2. Description of the Related Art
Various light emitting diodes (LED) and laser diodes (LD) have been developed as light emitting elements. These light emitting elements are replacing part of electric bulbs and cold cathode ray tubes that are used as light sources for display, back light and indicator, and the like by taking advantage of such features as a capability to run on low voltage, compact construction, light weight, small thickness, long life, high reliability and low power consumption. What deserves attention in this context are LEDs capable of emitting blue or green light with at least 10 candela luminous intensity that have been recently developed and commercialized by using an activation (light emission) layer of a quantum well structure made of a nitride semiconductor (for example, mixed crystal of InGaN). It has also been made possible to emit light of various colors including white light by combining light emitted by such LED chips and light emitted by fluorescent materials that are excited by light of the LED chips, thereby to produce fluorescence (principle of blending light colors).
An example of such devices is a light emitting device that uses a light emitting element which emits blue light and a YAG fluorescent material which is excited by the light emitted by the light emitting element and emits yellow light, so as to generate white light. This device emits white light by blending a transmitted part of the blue light from the light emitting element and yellow light emitted by the YAG fluorescent material that is excited by a part of the blue light from the light emitting element. This light emitting device has advantages of simple structure and ease of increasing output power.
There is also a device that emits white light by using a light emitting element, which emits an ultraviolet ray, and fluorescent materials capable of emitting light of RGB (red, green and blue) colors. There is also such a device that emits white light or other colors, wherein a fluorescent material which emits blue light when excited by a UV light emitting element and another fluorescent material which is excited by the blue light from the former fluorescent material emits yellow light (for example, refer to Patent Document 1). In this case, light color can be adjusted relatively easily since only the light emitted by the fluorescent materials is substantially used. When a light emitting element that emits an ultraviolet ray is used, in particular, mass productivity can be improved since color deviation due to wavelength of light emitted by this semiconductor light emitting element can be accommodated somewhat and chromaticity can be determined only by color of light emitted by the fluorescent materials, unlike a case of using a light emitting element that emits visible light.
[Patent Document 1]
Japanese Unexamined Patent Publication (Kokai) No. 2003-147351
However, there are demands for further improvement in a color rendering property for blended light emitted by a light emitting device that combines a blue light emitting element and YAG fluorescent material. There is a problem, in particular, that light emitted by such a device has an insufficient red component and a low value of a special color rendering index R9 that represents the red component. There is also such a problem that, since the device can emit light of only such colors that lie on a line connecting blue and a color of light emitted by YAG material on a chromaticity diagram, it is difficult to obtain light of a desired color by adjusting amounts of fluorescent materials; namely it is difficult to obtain a multi-color light emitting device.
A light emitting device that employs a light emitting element which emits an ultraviolet ray such as that described in Patent Document 1 has low intensity of emitted light at wavelengths around 500 nm, resulting in a low color rendering property.
It has also been attempted to improve a color rendering property by using at least two kinds of fluorescent material, such as combining a light emitting element which emits an ultraviolet ray and fluorescent materials capable of emitting light of RGB (red, green and blue) colors. But these attempts have been facing such a problem that difference in excitation characteristics among the fluorescent materials results in color deviation and/or variation in a color rendering property. For example, changing drive current density in the light emitting element causes a plurality of fluorescent materials to change light emitting characteristics differently, thus resulting in variations in color of emitted light.
SUMMARY OF THE INVENTION
With the background described above, an object of the present invention is to solve at least one of the problems described above and to provide a light emitting device having excellent light emitting characteristics.
The light emitting device of the present invention contains a light emitting element, that emits light with principal emission wavelength in a region ranging from near ultraviolet to blue light (300-490 nm), and fluorescent material, wherein the fluorescent material comprises at least two kinds of fluorescent material each having a luminescence center of a direct transition type. The light emitting device of the present invention having such a constitution can easily emit light of a desired color with a high color rendering property due to use of at least two kinds of fluorescent material and has, since each of the at least two kinds of fluorescent material has a luminescence center of the direct transition type, a short response time of excitation, so that there is no difference in color of emitted light between DC drive and pulse drive. Also, because a fluorescent material of a direct transition type has high linearity of light emission intensity with respect to intensity of excitation light, proportions of light emission intensity among a plurality of fluorescent materials can be maintained constant so as to prevent color deviation and deterioration of a color rendering property from occurring even when a drive current density of the light emitting element is changed.
Thus, according to the present invention, such a light emitting device can be provided that does not experience color deviation even when intensity of light emitted by a light emitting element is changed or a light emission spectrum is altered slightly by a change in current density supplied to the light emitting element that serves as an excitation light source or the emission spectrum is slightly changed, since fluorescent materials having a luminescence center of the direct transition type are used. That the device does not experience color deviation herein means that there occurs no significant change in color tone which can be visibly recognized.
Specifically, according to the present invention, variation in values of both chromaticity coordinates x and y (JIS 28110) can be restricted within 0.03 when current density in the light emitting element is changed from 2.0 A/cm2to 50.0 A/cm2. Also according to the light emitting device of the present invention, variations in the values of chromaticity coordinates x and y can also be restricted in a range from 0.01 to 0.02, or even below 0.1 by selection of the florescent materials. Also, because the light emitting device of the present invention uses fluorescent materials of direct transition type that have a short response time from excitation to stable light emission and short 1/10 afterglow period (for example, at most 200 μsec), stable emission of light is ensured even when the light emitting device is driven with pulsed power, and there is no difference in color of emitted light between DC drive and pulse drive. In other words, the light emitting device of the present invention can emit light of the same color regardless of whether operated by DC drive or pulse drive, or even when a driving condition of the light emitting device is changed from low current to high current. Moreover, light of stable color can be emitted with less changes in light color and a color rendering property even when the current density in the light emitting device changes. Since the human eye has high sensitivity to recognize a slight change in color of light in a white region, such features as variations in light color and in the color rendering property are extremely small, that are characteristic of the present invention, are very advantageous when making a device that emits white light.
It goes without saying that a number of different kinds of fluorescent materials used in the light emitting device of the present invention is not limited to two or three, and may be four (BGYR: blue, green, yellow and red) or more than four.
In the light emitting device of the present invention, response time from excitation to stable light emission and 1/10 afterglow period of the fluorescent material is preferably at most 200 μsec. Response time is a period of time required for fluorescent material to release supplied energy as light emission after absorbing the energy, and undergoes transition from a ground state to an excited state. Specifically, the response time is a period from the time immediately after supply of energy to the fluorescent material has begun to a time when the fluorescent material emits light. Afterglow refers to light emission that ensues after excitation of luminescence has stopped. The 1/10 afterglow period is a period of time taken for the luminance to decrease to 1/10 after excitation of luminescence has stopped.
The fluorescent material preferably has a luminescence center of the direct transition type of 4f-4d. The fluorescent material preferably has a luminescence center that contains at least Eu, Ce or Yb.
The light emitting device of the present invention may have such a constitution that uses a light emitting element which emits light with a principal-emission-peak wavelength in a region ranging from near ultraviolet to visible light region of short wavelengths, and at least three kinds of fluorescent material each having a peak emission wavelength in the visible light region. Such a constitution enables color of light emission to be set by blending light emitted by at least three kinds of fluorescent material that are of the direct transition type and exhibit a fast excitation response characteristic. Thus, the light emitting device can emit light with a higher color rendering property while avoiding variation in color of emitted light regardless of whether the device is operated by DC drive or pulse drive, and preventing color deviation and deterioration of a color rendering property from occurring when drive current density in the light emitting device changes.
The light emitting element operating in such a wavelength region preferably has a nitride semiconductor that contains Al and Ga in a light emitting layer, which enables a light emitting element having high luminance. The region ranging from near ultraviolet to visible light region of short wavelengths herein means a wavelength region approximately from 300 nm to 420 nm where light is difficult to recognize by the eye.
According to the present invention, the fluorescent material preferably comprises at least two kinds selected from among the group consisting of alkaline earth metal halogen apatite fluorescent material activated with at least Eu, alkaline earth metal boric acid halide salt fluorescent material, alkaline earth metal aluminate fluorescent material, rare earth aluminate fluorescent material having a garnet structure and activated with at least Ce, alkaline earth silicon oxynitride fluorescent material, alkaline earth silicate fluorescent material and alkaline earth silicon nitride fluorescent material activated with at least Eu.
When at least three kinds of fluorescent material are used, white light of a high color rendering property can be emitted by using a first fluorescent material that emits light having at least one peak emission wavelength in a region from blue-purple to blue region, a second fluorescent material that emits light having at least one peak emission wavelength in a region from blue-green to yellow-green region, and a third fluorescent material that emits light having at least one peak emission wavelength in a region from yellow to red region. Wavelengths of the blue region (=pure blue region) are from 455 nm to 485 nm, wavelengths of the blue-green region are from 485 nm to 495 nm, wavelengths of the green region are from 495 nm to 548 nm, wavelengths of the yellow-green region are from 548 nm to 573 nm, wavelengths of the yellow region are from 573 nm to 584 nm, wavelengths of the yellow-red region are from 584 nm to 610 nm, and wavelengths of the red region are from 610 nm to 780 nm. Correspondence of these color notations and chromatic coordinates is based on JIS 28110.
According to the present invention, the first fluorescent material is preferably at least one selected from among the group consisting of alkaline earth metal halogen apatite fluorescent material activated with at least Eu, alkaline earth metal boric acid halide salt fluorescent material and alkaline earth metal aluminate fluorescent material.
The second fluorescent material is preferably at least one selected from among the group consisting of rare earth aluminate fluorescent material having a garnet structure and activated with at least Ce, alkaline earth metal aluminate fluorescent material activated with at least Eu, alkaline earth silicon oxynitride fluorescent material and alkaline earth silicate fluorescent material.
The third fluorescent material is preferably at least one selected from among a group of alkaline earth silicon nitride fluorescent material activated with at least Eu.
The light emitting device according to the present invention can emit light of desired color with a high color rendering property while preventing color deviation and deterioration of the color rendering property from occurring in case drive current density in the light emitting device changes, also when a light emitting element having a principal-emission-peak wavelength in blue region (420-490 nm) is used and a YAG fluorescent material is included in the fluorescent material. Here, the term YAG fluorescent material is used to collectively represent rare earth aluminate fluorescent materials that have a garnet structure and are activated with a rare earth element. It is preferable that the light emitting element operating in such a wavelength region has a nitride semiconductor that contains In and Ga in a light emission layer thereof.
The light emitting device according to the present invention uses at least two kinds of fluorescent material that are substantially directly excited by light emitted by an excitation source having a principal emission peak in a range from 250 nm to 420 nm, so as to generate light of various colors through blending of light emitted by the at least two kinds of fluorescent material. The at least two kinds of fluorescent material may include at least one kind of oxynitride-based fluorescent material or nitride-based fluorescent material having crystallinity. With this constitution, a light emitting device having fluorescent material of high light emission efficiency can be provided. Combining at least two kinds of fluorescent material enables a light emitting device to be provided having a broad range of color tones. Moreover, since an excitation light source that is difficult to recognize with the eye is used, a light emitting device that is free of color deviation with no recognizable color deviation of the excitation source can be provided.
The light emitting device according to the present invention may also have such a constitution which uses at least two kinds of fluorescent material that are substantially directly excited by light emitted by an excitation source having a principal emission peak in a range from 420 nm to 500 nm, so as to generate light of various colors through blending of light emitted by the at least two kinds of fluorescent material, wherein the at least two kinds of fluorescent material may include at least one kind of oxynitride-based fluorescent material having crystallinity. With this constitution, a light emitting device that has less health hazards relative to humans and high light emission efficiency can be provided. Also, combining at least two kinds of fluorescent material enables to be provided a light emitting device having a broad range of color tones.
The light emitting device according to the present invention may also use at least two kinds of direct-excitation fluorescent material (first fluorescent material) that are substantially directly excited by light emitted from an excitation source having a principal emission peak in a range from 250 nm to 420 nm, and indirect-excitation fluorescent material (a second fluorescent material) that is excited by a part of light emitted by the at least two kinds of the direct-excitation fluorescent material, so as to generate light of various colors through blending of the light emitted by the at least two kinds of the direct-excitation fluorescent material and light emitted by the indirect-excitation fluorescent material, wherein the at least two kinds of the direct-excitation fluorescent material may include at least one kind of oxynitride-based fluorescent material or nitride-based fluorescent material having crystallinity. With this constitution, a light emitting device having a direct-excitation fluorescent material of high light emission efficiency and indirect-excitation fluorescent material of high light emission efficiency can be provided. Combining at least two kinds of the direct-excitation fluorescent material and the indirect-excitation fluorescent material enables to be provided a light emitting device having an even broader range of color tones.
The at least two kinds of direct-excitation fluorescent material that are directly excited by the light emitted by the excitation source preferably have efficiency of converting energy received from the excitation source not lower than 60% of a maximum light emission efficiency over an entire wavelength region. This enables to be provided a light emitting device that uses fluorescent material having high excitation efficiency. In case indirect-excitation fluorescent material is used, intensity of light emitted by the indirect-excitation fluorescent material can be increased with high-efficiency light emission from direct-excitation fluorescent material.
The at least two kinds of fluorescent material that are directly excited by the light emitted by an excitation light source (direct-excitation fluorescent material) may be such that exhibits maximum light emission efficiency in a region from 250 nm to 550 nm when excited by light. This enables to be manufactured a light emitting device that is less harmful to the human body and has high light emission efficiency. By using at least two kinds of fluorescent material that exhibit maximum emission efficiency in a wavelength region of an excitation light source in use, it is made possible to provide a light emitting device having a broad range of color tones and high luminance of emitted light that makes maximum use of characteristics of the fluorescent material to a highest efficiency possible.
The oxynitride-based fluorescent material having crystallinity preferably contains at least one Group II element selected from among the group consisting of Be, Mg, Ca, Sr, Ba and Zn, at least one Group IV element selected from among the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf, and a rare earth element used as an activator R. Use of this novel fluorescent material makes it possible to provide a light emitting device having a broad range of color tones and high luminance of emitted light. When the fluorescent material is excited by an excitation source that emits an ultraviolet ray, in particular, a light emitting device having high luminance of emitted light can be provided by using a fluorescent material of high luminance having a peak emission wavelength in the region from blue-green to yellow.
The nitride-based fluorescent material preferably contains at least one Group II element selected from among the group consisting of Be, Mg, Ca, Sr, Ba and Zn, at least Group IV element selected from among the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf, and a rare earth element used as an activator R. Use of this novel fluorescent material makes it possible to provide a light emitting device having a broader range of color tones and high luminance of emitted light. When the fluorescent material is excited by an excitation source that emits an ultraviolet ray, in particular, a light emitting device having high luminance of emitted light can be provided by using a fluorescent material of high luminance having an emission peak wavelength in the region from yellow-red to red. A light emitting device having a high color rendering property can also be provided. Especially because the nitride-based fluorescent material is excited to emit light in a region from yellow-red to red by absorbing light in a short wavelength region from ultraviolet to visible light region of short wavelengths, a light emitting device having a high color rendering property that has a high red component by supplementing the red component can also be provided.
The indirect-excitation fluorescent material is preferably aluminate-based fluorescent material that contains a rare earth element as the activator R. This enables to be provided a light emitting device having high luminance of emitted light.
The excitation light source is preferably a light emitting element. This enables to be provided a light emitting device that is compact, high in power efficiency and emits light of clear color. A wavelength of light emission from an excitation light source may be within a region from ultraviolet to visible light. If the excitation light source has a principal emission peak in the ultraviolet region that has low visibility to human eyes, a color deviation caused by wavelength deviation of the light emitting device can be reduced. There is a visual sensitivity characteristic in sensitivity of the human eye to wavelengths of light, which dictates a highest sensitivity to light of 555 nm in wavelength, with the sensitivity decreasing toward shorter and longer wavelengths. For example, the human eye has lower visual sensitivity to ultraviolet rays used as an excitation source, and color of light emitted by the light emitting device is substantially determined by a light color emitted by fluorescent material that is employed. Also, because color deviation of light emitted by fluorescent material that emits light in the visible light region is restricted to an extremely small level even when the light emitting element undergoes color deviation due to a change in supplied current or other cause, a light emitting device having less variation in color tone can be provided. Here, “ultraviolet region” means a wavelength range shorter than visible light, specifically a wavelength range shorter than 400 nm. In the ultraviolet region, a wavelength range longer than 250 nm is preferable, and a near ultraviolet region (over 300 nm) is more preferable. A shorter wavelength region in the visible light (under 420 nm) has a similar effect as the above ultraviolet region.
On the other hand, if the excitation light source has a principal emission peak in the visible region, deterioration of phosphors caused by light emitted from light emitting devices can be reduced. Also, as light emitted from light emitting devices could be utilized to form a desired emission spectrum, less kinds of phosphors are required than a case with ultraviolet light emitting elements. In the visible light region, a light having a wavelength longer than 420 nm is preferable because of its high visibility to human eyes. However, as a light having too long a wavelength has lower efficiency for exciting phosphors, a light of a wavelength shorter than 500 nm is preferable. More preferably, “a blue region” in a broad sense (420-490 nm) is used. In this specification, terms like “a blue region” or “a blue series region” means the blue region in a broad sense, i.e. 420-490 nm in absence of any specific limitation.
In the light emitting device of the present invention, emission of white light can be easily achieved when the device has at least two emission peaks in the visible light region and wavelengths of at least two of the at least two emission peaks are in complementary color relation with each other. Here, white color includes (purplish) white, (bluish) white, (greenish) white, (yellowish) white, (light) pink, as well as (light) violet, (light) blue violet, (light) blue, (light) blue green, (light) green, (light) yellow green, (light) yellow, (light) yellow red, (orangish) pink, pink and (purplish) pink.
In the light emitting device of the present invention, general color rendering index (Ra) can be set to at least 80 and can be maintained at least 80 even when drive current density of the light emitting element fluctuates. In the light emitting device of the present invention, general color rendering index (Ra) can be maintained at least 80, for example, when drive current density of the light emitting element changes from 2.0 A/cm2to 50.0 A/cm2. Special color rendering index (R9), in particular, is preferably at least 50. This enables to be provided a light emitting device having a broad range of color tones, as well as a light emitting device having an excellent color rendering property. General color rendering index (Ra) is a special color rendering index averaged over eight test color chips No. 1 to No. 8, specified in CIE and JIS.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a light emitting device that uses a light emitting element and fluorescent material, and can be used for such applications as a signal light, illumination, display, indicator and other light sources, and particularly to a light emitting device that can emit light of white and other color tones by using fluorescent material that is excited by light emitted by a light emitting element, which emits in an ultraviolet to visible light region, and emits light in the visible light region.
2. Description of the Related Art
Various light emitting diodes (LED) and laser diodes (LD) have been developed as light emitting elements. These light emitting elements are replacing part of electric bulbs and cold cathode ray tubes that are used as light sources for display, back light and indicator, and the like by taking advantage of such features as a capability to run on low voltage, compact construction, light weight, small thickness, long life, high reliability and low power consumption. What deserves attention in this context are LEDs capable of emitting blue or green light with at least 10 candela luminous intensity that have been recently developed and commercialized by using an activation (light emission) layer of a quantum well structure made of a nitride semiconductor (for example, mixed crystal of InGaN). It has also been made possible to emit light of various colors including white light by combining light emitted by such LED chips and light emitted by fluorescent materials that are excited by light of the LED chips, thereby to produce fluorescence (principle of blending light colors).
An example of such devices is a light emitting device that uses a light emitting element which emits blue light and a YAG fluorescent material which is excited by the light emitted by the light emitting element and emits yellow light, so as to generate white light. This device emits white light by blending a transmitted part of the blue light from the light emitting element and yellow light emitted by the YAG fluorescent material that is excited by a part of the blue light from the light emitting element. This light emitting device has advantages of simple structure and ease of increasing output power.
There is also a device that emits white light by using a light emitting element, which emits an ultraviolet ray, and fluorescent materials capable of emitting light of RGB (red, green and blue) colors. There is also such a device that emits white light or other colors, wherein a fluorescent material which emits blue light when excited by a UV light emitting element and another fluorescent material which is excited by the blue light from the former fluorescent material emits yellow light (for example, refer to Patent Document 1). In this case, light color can be adjusted relatively easily since only the light emitted by the fluorescent materials is substantially used. When a light emitting element that emits an ultraviolet ray is used, in particular, mass productivity can be improved since color deviation due to wavelength of light emitted by this semiconductor light emitting element can be accommodated somewhat and chromaticity can be determined only by color of light emitted by the fluorescent materials, unlike a case of using a light emitting element that emits visible light.
[Patent Document 1]
Japanese Unexamined Patent Publication (Kokai) No. 2003-147351
However, there are demands for further improvement in a color rendering property for blended light emitted by a light emitting device that combines a blue light emitting element and YAG fluorescent material. There is a problem, in particular, that light emitted by such a device has an insufficient red component and a low value of a special color rendering index R9 that represents the red component. There is also such a problem that, since the device can emit light of only such colors that lie on a line connecting blue and a color of light emitted by YAG material on a chromaticity diagram, it is difficult to obtain light of a desired color by adjusting amounts of fluorescent materials; namely it is difficult to obtain a multi-color light emitting device.
A light emitting device that employs a light emitting element which emits an ultraviolet ray such as that described in Patent Document 1 has low intensity of emitted light at wavelengths around 500 nm, resulting in a low color rendering property.
It has also been attempted to improve a color rendering property by using at least two kinds of fluorescent material, such as combining a light emitting element which emits an ultraviolet ray and fluorescent materials capable of emitting light of RGB (red, green and blue) colors. But these attempts have been facing such a problem that difference in excitation characteristics among the fluorescent materials results in color deviation and/or variation in a color rendering property. For example, changing drive current density in the light emitting element causes a plurality of fluorescent materials to change light emitting characteristics differently, thus resulting in variations in color of emitted light.
SUMMARY OF THE INVENTION
With the background described above, an object of the present invention is to solve at least one of the problems described above and to provide a light emitting device having excellent light emitting characteristics.
The light emitting device of the present invention contains a light emitting element, that emits light with principal emission wavelength in a region ranging from near ultraviolet to blue light (300-490 nm), and fluorescent material, wherein the fluorescent material comprises at least two kinds of fluorescent material each having a luminescence center of a direct transition type. The light emitting device of the present invention having such a constitution can easily emit light of a desired color with a high color rendering property due to use of at least two kinds of fluorescent material and has, since each of the at least two kinds of fluorescent material has a luminescence center of the direct transition type, a short response time of excitation, so that there is no difference in color of emitted light between DC drive and pulse drive. Also, because a fluorescent material of a direct transition type has high linearity of light emission intensity with respect to intensity of excitation light, proportions of light emission intensity among a plurality of fluorescent materials can be maintained constant so as to prevent color deviation and deterioration of a color rendering property from occurring even when a drive current density of the light emitting element is changed.
Thus, according to the present invention, such a light emitting device can be provided that does not experience color deviation even when intensity of light emitted by a light emitting element is changed or a light emission spectrum is altered slightly by a change in current density supplied to the light emitting element that serves as an excitation light source or the emission spectrum is slightly changed, since fluorescent materials having a luminescence center of the direct transition type are used. That the device does not experience color deviation herein means that there occurs no significant change in color tone which can be visibly recognized.
Specifically, according to the present invention, variation in values of both chromaticity coordinates x and y (JIS 28110) can be restricted within 0.03 when current density in the light emitting element is changed from 2.0 A/cm2to 50.0 A/cm2. Also according to the light emitting device of the present invention, variations in the values of chromaticity coordinates x and y can also be restricted in a range from 0.01 to 0.02, or even below 0.1 by selection of the florescent materials. Also, because the light emitting device of the present invention uses fluorescent materials of direct transition type that have a short response time from excitation to stable light emission and short 1/10 afterglow period (for example, at most 200 μsec), stable emission of light is ensured even when the light emitting device is driven with pulsed power, and there is no difference in color of emitted light between DC drive and pulse drive. In other words, the light emitting device of the present invention can emit light of the same color regardless of whether operated by DC drive or pulse drive, or even when a driving condition of the light emitting device is changed from low current to high current. Moreover, light of stable color can be emitted with less changes in light color and a color rendering property even when the current density in the light emitting device changes. Since the human eye has high sensitivity to recognize a slight change in color of light in a white region, such features as variations in light color and in the color rendering property are extremely small, that are characteristic of the present invention, are very advantageous when making a device that emits white light.
It goes without saying that a number of different kinds of fluorescent materials used in the light emitting device of the present invention is not limited to two or three, and may be four (BGYR: blue, green, yellow and red) or more than four.
In the light emitting device of the present invention, response time from excitation to stable light emission and 1/10 afterglow period of the fluorescent material is preferably at most 200 μsec. Response time is a period of time required for fluorescent material to release supplied energy as light emission after absorbing the energy, and undergoes transition from a ground state to an excited state. Specifically, the response time is a period from the time immediately after supply of energy to the fluorescent material has begun to a time when the fluorescent material emits light. Afterglow refers to light emission that ensues after excitation of luminescence has stopped. The 1/10 afterglow period is a period of time taken for the luminance to decrease to 1/10 after excitation of luminescence has stopped.
The fluorescent material preferably has a luminescence center of the direct transition type of 4f-4d. The fluorescent material preferably has a luminescence center that contains at least Eu, Ce or Yb.
The light emitting device of the present invention may have such a constitution that uses a light emitting element which emits light with a principal-emission-peak wavelength in a region ranging from near ultraviolet to visible light region of short wavelengths, and at least three kinds of fluorescent material each having a peak emission wavelength in the visible light region. Such a constitution enables color of light emission to be set by blending light emitted by at least three kinds of fluorescent material that are of the direct transition type and exhibit a fast excitation response characteristic. Thus, the light emitting device can emit light with a higher color rendering property while avoiding variation in color of emitted light regardless of whether the device is operated by DC drive or pulse drive, and preventing color deviation and deterioration of a color rendering property from occurring when drive current density in the light emitting device changes.
The light emitting element operating in such a wavelength region preferably has a nitride semiconductor that contains Al and Ga in a light emitting layer, which enables a light emitting element having high luminance. The region ranging from near ultraviolet to visible light region of short wavelengths herein means a wavelength region approximately from 300 nm to 420 nm where light is difficult to recognize by the eye.
According to the present invention, the fluorescent material preferably comprises at least two kinds selected from among the group consisting of alkaline earth metal halogen apatite fluorescent material activated with at least Eu, alkaline earth metal boric acid halide salt fluorescent material, alkaline earth metal aluminate fluorescent material, rare earth aluminate fluorescent material having a garnet structure and activated with at least Ce, alkaline earth silicon oxynitride fluorescent material, alkaline earth silicate fluorescent material and alkaline earth silicon nitride fluorescent material activated with at least Eu.
When at least three kinds of fluorescent material are used, white light of a high color rendering property can be emitted by using a first fluorescent material that emits light having at least one peak emission wavelength in a region from blue-purple to blue region, a second fluorescent material that emits light having at least one peak emission wavelength in a region from blue-green to yellow-green region, and a third fluorescent material that emits light having at least one peak emission wavelength in a region from yellow to red region. Wavelengths of the blue region (=pure blue region) are from 455 nm to 485 nm, wavelengths of the blue-green region are from 485 nm to 495 nm, wavelengths of the green region are from 495 nm to 548 nm, wavelengths of the yellow-green region are from 548 nm to 573 nm, wavelengths of the yellow region are from 573 nm to 584 nm, wavelengths of the yellow-red region are from 584 nm to 610 nm, and wavelengths of the red region are from 610 nm to 780 nm. Correspondence of these color notations and chromatic coordinates is based on JIS 28110.
According to the present invention, the first fluorescent material is preferably at least one selected from among the group consisting of alkaline earth metal halogen apatite fluorescent material activated with at least Eu, alkaline earth metal boric acid halide salt fluorescent material and alkaline earth metal aluminate fluorescent material.
The second fluorescent material is preferably at least one selected from among the group consisting of rare earth aluminate fluorescent material having a garnet structure and activated with at least Ce, alkaline earth metal aluminate fluorescent material activated with at least Eu, alkaline earth silicon oxynitride fluorescent material and alkaline earth silicate fluorescent material.
The third fluorescent material is preferably at least one selected from among a group of alkaline earth silicon nitride fluorescent material activated with at least Eu.
The light emitting device according to the present invention can emit light of desired color with a high color rendering property while preventing color deviation and deterioration of the color rendering property from occurring in case drive current density in the light emitting device changes, also when a light emitting element having a principal-emission-peak wavelength in blue region (420-490 nm) is used and a YAG fluorescent material is included in the fluorescent material. Here, the term YAG fluorescent material is used to collectively represent rare earth aluminate fluorescent materials that have a garnet structure and are activated with a rare earth element. It is preferable that the light emitting element operating in such a wavelength region has a nitride semiconductor that contains In and Ga in a light emission layer thereof.
The light emitting device according to the present invention uses at least two kinds of fluorescent material that are substantially directly excited by light emitted by an excitation source having a principal emission peak in a range from 250 nm to 420 nm, so as to generate light of various colors through blending of light emitted by the at least two kinds of fluorescent material. The at least two kinds of fluorescent material may include at least one kind of oxynitride-based fluorescent material or nitride-based fluorescent material having crystallinity. With this constitution, a light emitting device having fluorescent material of high light emission efficiency can be provided. Combining at least two kinds of fluorescent material enables a light emitting device to be provided having a broad range of color tones. Moreover, since an excitation light source that is difficult to recognize with the eye is used, a light emitting device that is free of color deviation with no recognizable color deviation of the excitation source can be provided.
The light emitting device according to the present invention may also have such a constitution which uses at least two kinds of fluorescent material that are substantially directly excited by light emitted by an excitation source having a principal emission peak in a range from 420 nm to 500 nm, so as to generate light of various colors through blending of light emitted by the at least two kinds of fluorescent material, wherein the at least two kinds of fluorescent material may include at least one kind of oxynitride-based fluorescent material having crystallinity. With this constitution, a light emitting device that has less health hazards relative to humans and high light emission efficiency can be provided. Also, combining at least two kinds of fluorescent material enables to be provided a light emitting device having a broad range of color tones.
The light emitting device according to the present invention may also use at least two kinds of direct-excitation fluorescent material (first fluorescent material) that are substantially directly excited by light emitted from an excitation source having a principal emission peak in a range from 250 nm to 420 nm, and indirect-excitation fluorescent material (a second fluorescent material) that is excited by a part of light emitted by the at least two kinds of the direct-excitation fluorescent material, so as to generate light of various colors through blending of the light emitted by the at least two kinds of the direct-excitation fluorescent material and light emitted by the indirect-excitation fluorescent material, wherein the at least two kinds of the direct-excitation fluorescent material may include at least one kind of oxynitride-based fluorescent material or nitride-based fluorescent material having crystallinity. With this constitution, a light emitting device having a direct-excitation fluorescent material of high light emission efficiency and indirect-excitation fluorescent material of high light emission efficiency can be provided. Combining at least two kinds of the direct-excitation fluorescent material and the indirect-excitation fluorescent material enables to be provided a light emitting device having an even broader range of color tones.
The at least two kinds of direct-excitation fluorescent material that are directly excited by the light emitted by the excitation source preferably have efficiency of converting energy received from the excitation source not lower than 60% of a maximum light emission efficiency over an entire wavelength region. This enables to be provided a light emitting device that uses fluorescent material having high excitation efficiency. In case indirect-excitation fluorescent material is used, intensity of light emitted by the indirect-excitation fluorescent material can be increased with high-efficiency light emission from direct-excitation fluorescent material.
The at least two kinds of fluorescent material that are directly excited by the light emitted by an excitation light source (direct-excitation fluorescent material) may be such that exhibits maximum light emission efficiency in a region from 250 nm to 550 nm when excited by light. This enables to be manufactured a light emitting device that is less harmful to the human body and has high light emission efficiency. By using at least two kinds of fluorescent material that exhibit maximum emission efficiency in a wavelength region of an excitation light source in use, it is made possible to provide a light emitting device having a broad range of color tones and high luminance of emitted light that makes maximum use of characteristics of the fluorescent material to a highest efficiency possible.
The oxynitride-based fluorescent material having crystallinity preferably contains at least one Group II element selected from among the group consisting of Be, Mg, Ca, Sr, Ba and Zn, at least one Group IV element selected from among the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf, and a rare earth element used as an activator R. Use of this novel fluorescent material makes it possible to provide a light emitting device having a broad range of color tones and high luminance of emitted light. When the fluorescent material is excited by an excitation source that emits an ultraviolet ray, in particular, a light emitting device having high luminance of emitted light can be provided by using a fluorescent material of high luminance having a peak emission wavelength in the region from blue-green to yellow.
The nitride-based fluorescent material preferably contains at least one Group II element selected from among the group consisting of Be, Mg, Ca, Sr, Ba and Zn, at least Group IV element selected from among the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf, and a rare earth element used as an activator R. Use of this novel fluorescent material makes it possible to provide a light emitting device having a broader range of color tones and high luminance of emitted light. When the fluorescent material is excited by an excitation source that emits an ultraviolet ray, in particular, a light emitting device having high luminance of emitted light can be provided by using a fluorescent material of high luminance having an emission peak wavelength in the region from yellow-red to red. A light emitting device having a high color rendering property can also be provided. Especially because the nitride-based fluorescent material is excited to emit light in a region from yellow-red to red by absorbing light in a short wavelength region from ultraviolet to visible light region of short wavelengths, a light emitting device having a high color rendering property that has a high red component by supplementing the red component can also be provided.
The indirect-excitation fluorescent material is preferably aluminate-based fluorescent material that contains a rare earth element as the activator R. This enables to be provided a light emitting device having high luminance of emitted light.
The excitation light source is preferably a light emitting element. This enables to be provided a light emitting device that is compact, high in power efficiency and emits light of clear color. A wavelength of light emission from an excitation light source may be within a region from ultraviolet to visible light. If the excitation light source has a principal emission peak in the ultraviolet region that has low visibility to human eyes, a color deviation caused by wavelength deviation of the light emitting device can be reduced. There is a visual sensitivity characteristic in sensitivity of the human eye to wavelengths of light, which dictates a highest sensitivity to light of 555 nm in wavelength, with the sensitivity decreasing toward shorter and longer wavelengths. For example, the human eye has lower visual sensitivity to ultraviolet rays used as an excitation source, and color of light emitted by the light emitting device is substantially determined by a light color emitted by fluorescent material that is employed. Also, because color deviation of light emitted by fluorescent material that emits light in the visible light region is restricted to an extremely small level even when the light emitting element undergoes color deviation due to a change in supplied current or other cause, a light emitting device having less variation in color tone can be provided. Here, “ultraviolet region” means a wavelength range shorter than visible light, specifically a wavelength range shorter than 400 nm. In the ultraviolet region, a wavelength range longer than 250 nm is preferable, and a near ultraviolet region (over 300 nm) is more preferable. A shorter wavelength region in the visible light (under 420 nm) has a similar effect as the above ultraviolet region.
On the other hand, if the excitation light source has a principal emission peak in the visible region, deterioration of phosphors caused by light emitted from light emitting devices can be reduced. Also, as light emitted from light emitting devices could be utilized to form a desired emission spectrum, less kinds of phosphors are required than a case with ultraviolet light emitting elements. In the visible light region, a light having a wavelength longer than 420 nm is preferable because of its high visibility to human eyes. However, as a light having too long a wavelength has lower efficiency for exciting phosphors, a light of a wavelength shorter than 500 nm is preferable. More preferably, “a blue region” in a broad sense (420-490 nm) is used. In this specification, terms like “a blue region” or “a blue series region” means the blue region in a broad sense, i.e. 420-490 nm in absence of any specific limitation.
In the light emitting device of the present invention, emission of white light can be easily achieved when the device has at least two emission peaks in the visible light region and wavelengths of at least two of the at least two emission peaks are in complementary color relation with each other. Here, white color includes (purplish) white, (bluish) white, (greenish) white, (yellowish) white, (light) pink, as well as (light) violet, (light) blue violet, (light) blue, (light) blue green, (light) green, (light) yellow green, (light) yellow, (light) yellow red, (orangish) pink, pink and (purplish) pink.
In the light emitting device of the present invention, general color rendering index (Ra) can be set to at least 80 and can be maintained at least 80 even when drive current density of the light emitting element fluctuates. In the light emitting device of the present invention, general color rendering index (Ra) can be maintained at least 80, for example, when drive current density of the light emitting element changes from 2.0 A/cm2to 50.0 A/cm2. Special color rendering index (R9), in particular, is preferably at least 50. This enables to be provided a light emitting device having a broad range of color tones, as well as a light emitting device having an excellent color rendering property. General color rendering index (Ra) is a special color rendering index averaged over eight test color chips No. 1 to No. 8, specified in CIE and JIS.
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7772211 | FIELD OF THE INVENTION
The present invention is directed to carrageenan products, methods of preparing such carrageenan products, and to formulations containing carrageenan products according to the present invention.
BACKGROUND OF THE INVENTION
Carrageenan is a complex mixture of sulfated polysaccharides comprising linear polymers of 1,3 bound α-D-galactose units and 1,4 bound α-D-galactose units with the general formula:
→3α)A(1→4β)B(1→3α)A(1→4β)B(1→3α)A(1→4β)B(1→
wherein A and B represent galactose residues derived from two different groups.
Carrageenan is extracted from red seaweeds and constitutes the principal structure of the seaweed. It is located within the cell wall and intracellular matrix of the plant tissue. The carrageenan content of commercially harvested seaweeds is generally between 30% and 80% based on the seaweed dry weight.
Carrageenan finds wide applicability as a food ingredient and is functional in foods such as dairy products, water dessert gels, meat products, confections, beverages, dressings and other such products. Carrageenan is also used in non-food products such as cosmetics, toothpaste, and other personal care products. The molecular weight of commercial carrageenan products is typically from about 100,000 to 1,000,000 Daltons. Carrageenans have the unique ability to form an almost infinite variety of gels at room temperature, with a variety of gelling and melting points. These gels require no refrigeration, and can be made stable through repeated freeze-thaw cycles. Carrageenan solutions can thicken, suspend, and stabilize particulates, colloidal dispersions and water/oil emulsions. The solutions shear thin, which allows them to be pumped easily. Also, the solutions rapidly rebuild viscosity and suspending power on standing. Depending upon the food application, carrageenan present in a few percent by weight or less provides gelling, thickening, and binding, and also helps in imparting appropriate texture to the food product. Owing to these qualities, carrageenan is particularly desirable as a fat replacement in low fat foods.
Carrageenan is generally soluble in warm water, in which it forms viscous solutions. It is insoluble in most organic solvents, and typically forms complexes with proteins. The major types of carrageenan are designated as kappa, iota, lambda, nu and mu. These are differentiated based on the nature of the repeating galactose units contained in the carrageenan. The polymer chains in carrageenan can be cleaved by hydrolytic depolymerization upon treatment with an acid, or by oxidative depolymerization upon treatment with hydrogen peroxide. Upon cleavage of the polymer chains, carrageenan products having optimum gelling properties and viscosity can be obtained.
In a typical process for making pure carrageenan, crude seaweed is first washed with cold water to remove sand and other particulates that may be present after the seaweed has been harvested. Carrageenan typically does not swell during the cold wash, primarily because carrageenan in seaweed is associated with the structural components of the seaweed, generally cellulose. Depending on the seaweed species, following the cold wash a hot water extraction procedure is typically performed in which the extracted carrageenan is treated with aqueous base at high temperature. Generally, the base used is an alkali or alkaline earth metal hydroxide such as, for example, NaOH, Ca(OH)2, or KOH. This high temperature aqueous base modification leads to the formation of 3,6-anhydro linkages in the galactose units of the carrageenan polysaccharide. After base modification, the hot extract is filtered to remove insoluble material such as cellulose, hemicellulose and other particulates, and acid is added to adjust the pH to 9 or lower. The filtrate can then be concentrated to about4% carrageenan for further processing. Optional procedural steps after extraction may include centrifugation and bleaching. Pure carrageenan is typically obtained by precipitation of the extract from the aqueous solution with KCl or an alcohol such as isopropanol.
Preparation of pure carrageenan by extraction on a commercial scale is expensive because of viscosity and gelling properties that limit the rate at which such carrageenan products can be processed. After the extraction step, a hot aqueous stream can typically only contain low concentrations of carrageenan, typically up to about 4%. At higher concentrations of carrageenan, the aqueous stream becomes too viscous to be processed efficiently. Therefore, a relatively low proportion of carrageenan is obtained per unit volume of the aqueous process stream.
There has been an ongoing search for more cost-effective methods of preparing semi-refined carrageenan and other products as lower cost replacements for conventional carrageenan. Semi-refined carrageenan (SRC) products are those in which few or none of the structural components of the seaweed, principally cellulose, have been removed. During the preparation of SRC, a salt such as KCl or NaCl typically is added during base modification along with the base. The presence of sufficient amounts of salt prevents disintegration of the seaweed structure and inhibits extraction of carrageenan from the seaweed. An alcohol, such as isopropanol, can also be used to inhibit extraction during the high temperature base modification step. Following the base modification step, with the seaweed structure still intact, the processed seaweed mixture is typically dried to afford SRC. When the seaweed is a member of the Eucheuma family, the SRC obtained is known as processedEucheumaseaweed (PES).
U.S. Pat. No. 5,502,179 is directed to processes wherein the seaweed starting (feed) material is mixed with a base and a solvent in which carrageenan is insoluble. This base-treated mixture is washed with an aqueous solution and then subjected to shear stress treatment (such as an extrusion process or by means of a shear mixer). The shear stress treatment is said to be performed on seaweed material having a solids content of at least 25%, at a temperature between iooaC and 175° C., for about 10 to 200 seconds. The carrageenan material resulting from the shear stress treatment may be dried and subjected to comminution, grinding or milling to obtain a powder with a particle size in the range of 0.05 to 0.5 mm.
Conventional carrageenans typically have some advantages relative to SRC obtained from the same seaweed. One such advantage is that they typically begin to hydrate, i.e., they begin to swell and solubilize, at a lower temperatures than does SRC. For example, conventional iota carrageenan obtained fromEucheuma spinosumwill hydrate, swell, and solubilize at room temperature. PES derived fromEucheuma spinosum,however, does not hydrate, swell and solubilize until first heated to above about 60° C. Another such advantage is that because SRC contains cellulosic and other materials which are absent in conventional carrageenan, gels formed from SRC have reduced clarity relative to pure carrageenan gels. Therefore, utility of SRC products has been limited to those applications where the food product is not required to be clear and can be readily prepared at the high temperatures required for hydration and solubility of carrageenan to occur. For many applications, however, it is desirable to have an SRC which provides gelling without the need for such high temperatures. It is also important that SRC have acceptable color and appearance suitable for use in products made for human consumption such as, for example, cream, ice cream, other dairy products, and beverages, as well as non-food products such as, for example, cosmetics, tooth paste, and other personal care products.
Therefore, there is a need in the art for a low cost processes for producing carrageenan products with improved hydration characteristics while maintaining acceptable color and appearance suitable for use in food products.
SUMMARY OF THE INVENTION
The present invention provides methods for preparing a carrageenan product comprising the steps of providing a carrageenan-containing seaweed material having a seaweed solids content of less than 25% by weight, and subjecting this seaweed material to shear stress treatment. The carrageenan-containing seaweed material optionally is treated with base prior to extrusion.
In one embodiment, the carrageenan-containing seaweed material is prepared by a process comprising the steps of washing the seaweed with water to produce washed seaweed; rinsing the seaweed with water to form rinsed seaweed; and washing the rinsed seaweed with water or an aqueous solution to form the carrageenan-containing seaweed material.
In another embodiment, the methods of the present invention comprise washing the seaweed with water, treating the seaweed with a base at a temperature of about 25° C. to about 65° C. to form base-modified seaweed; rinsing the base-modified seaweed with water, washing this base-modified seaweed with an aqueous solution of a salt; rinsing this base-modified seaweed with water to form processed seaweed, wherein the processed seaweed comprises less than 25% solids; extruding this processed seaweed to form extruded seaweed; and drying the extruded seaweed to form a carrageenan product.
In yet another embodiment, the concentration of the aqueous salt solution is less than about 40%. It is preferred that the concentration of the aqueous salt solution be less than about 15%. It is more preferred that the concentration of the aqueous salt solution be between about 2% and about 15%.
The present invention also includes carrageenan products that preferably comprise at least about 60% by weight of carrageenan and at least about 2% by weight of acid insoluble material, and have an onset of hydration below about 50° C. In a preferred embodiment, the carrageenan product is derived fromEucheuma spinosum,or any other species containing iota-carrageenan. In another preferred embodiment, the carrageenan product further comprises about 2% to about 15% by weight of a salt. A preferred salt is sodium chloride.
The present invention further includes foods and other products containing a carrageenan product or products produced by the foregoing methods. The carrageenan product preferably comprises at least about 60% by weight of carrageenan and at least about 2% by weight of acid insoluble material. For such carrageenan products produced fromEucheuma cottonii,the onset of hydration can be as low as below about 50° C. For such carrageenan products produced fromEucheuma spinosum,the onset of hydration can be as low as below about 30° C.
Other products include toothpaste formulations comprising a binder, a humectant, an abrasive, and water, wherein the binder is a carrageenan product according to the present invention. It is preferred that the concentration of the binder be from about 0.5 to about 1.5% by weight of the toothpaste formulation.
The present invention further includes methods of making articles containing one or more carrageenan products produced by the methods of the invention. In one embodiment, a solution comprising the carrageenan-containing product of the invention is heated and at least a portion of the heated solution is then subjected to conditions effective to transform it into a barrier material. Films can be formed, for example, by casting the solution on a cooled rotating drum. Optionally, the carrageenan-containing film can be fed through a series of rollers to counter rotating dies which form, cut, and fill capsules of various sizes.
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SUMMARY: FIELD OF THE INVENTION
The present invention is directed to carrageenan products, methods of preparing such carrageenan products, and to formulations containing carrageenan products according to the present invention.
BACKGROUND OF THE INVENTION
Carrageenan is a complex mixture of sulfated polysaccharides comprising linear polymers of 1,3 bound α-D-galactose units and 1,4 bound α-D-galactose units with the general formula:
→3α)A(1→4β)B(1→3α)A(1→4β)B(1→3α)A(1→4β)B(1→
wherein A and B represent galactose residues derived from two different groups.
Carrageenan is extracted from red seaweeds and constitutes the principal structure of the seaweed. It is located within the cell wall and intracellular matrix of the plant tissue. The carrageenan content of commercially harvested seaweeds is generally between 30% and 80% based on the seaweed dry weight.
Carrageenan finds wide applicability as a food ingredient and is functional in foods such as dairy products, water dessert gels, meat products, confections, beverages, dressings and other such products. Carrageenan is also used in non-food products such as cosmetics, toothpaste, and other personal care products. The molecular weight of commercial carrageenan products is typically from about 100,000 to 1,000,000 Daltons. Carrageenans have the unique ability to form an almost infinite variety of gels at room temperature, with a variety of gelling and melting points. These gels require no refrigeration, and can be made stable through repeated freeze-thaw cycles. Carrageenan solutions can thicken, suspend, and stabilize particulates, colloidal dispersions and water/oil emulsions. The solutions shear thin, which allows them to be pumped easily. Also, the solutions rapidly rebuild viscosity and suspending power on standing. Depending upon the food application, carrageenan present in a few percent by weight or less provides gelling, thickening, and binding, and also helps in imparting appropriate texture to the food product. Owing to these qualities, carrageenan is particularly desirable as a fat replacement in low fat foods.
Carrageenan is generally soluble in warm water, in which it forms viscous solutions. It is insoluble in most organic solvents, and typically forms complexes with proteins. The major types of carrageenan are designated as kappa, iota, lambda, nu and mu. These are differentiated based on the nature of the repeating galactose units contained in the carrageenan. The polymer chains in carrageenan can be cleaved by hydrolytic depolymerization upon treatment with an acid, or by oxidative depolymerization upon treatment with hydrogen peroxide. Upon cleavage of the polymer chains, carrageenan products having optimum gelling properties and viscosity can be obtained.
In a typical process for making pure carrageenan, crude seaweed is first washed with cold water to remove sand and other particulates that may be present after the seaweed has been harvested. Carrageenan typically does not swell during the cold wash, primarily because carrageenan in seaweed is associated with the structural components of the seaweed, generally cellulose. Depending on the seaweed species, following the cold wash a hot water extraction procedure is typically performed in which the extracted carrageenan is treated with aqueous base at high temperature. Generally, the base used is an alkali or alkaline earth metal hydroxide such as, for example, NaOH, Ca(OH)2, or KOH. This high temperature aqueous base modification leads to the formation of 3,6-anhydro linkages in the galactose units of the carrageenan polysaccharide. After base modification, the hot extract is filtered to remove insoluble material such as cellulose, hemicellulose and other particulates, and acid is added to adjust the pH to 9 or lower. The filtrate can then be concentrated to about4% carrageenan for further processing. Optional procedural steps after extraction may include centrifugation and bleaching. Pure carrageenan is typically obtained by precipitation of the extract from the aqueous solution with KCl or an alcohol such as isopropanol.
Preparation of pure carrageenan by extraction on a commercial scale is expensive because of viscosity and gelling properties that limit the rate at which such carrageenan products can be processed. After the extraction step, a hot aqueous stream can typically only contain low concentrations of carrageenan, typically up to about 4%. At higher concentrations of carrageenan, the aqueous stream becomes too viscous to be processed efficiently. Therefore, a relatively low proportion of carrageenan is obtained per unit volume of the aqueous process stream.
There has been an ongoing search for more cost-effective methods of preparing semi-refined carrageenan and other products as lower cost replacements for conventional carrageenan. Semi-refined carrageenan (SRC) products are those in which few or none of the structural components of the seaweed, principally cellulose, have been removed. During the preparation of SRC, a salt such as KCl or NaCl typically is added during base modification along with the base. The presence of sufficient amounts of salt prevents disintegration of the seaweed structure and inhibits extraction of carrageenan from the seaweed. An alcohol, such as isopropanol, can also be used to inhibit extraction during the high temperature base modification step. Following the base modification step, with the seaweed structure still intact, the processed seaweed mixture is typically dried to afford SRC. When the seaweed is a member of the Eucheuma family, the SRC obtained is known as processedEucheumaseaweed (PES).
U.S. Pat. No. 5,502,179 is directed to processes wherein the seaweed starting (feed) material is mixed with a base and a solvent in which carrageenan is insoluble. This base-treated mixture is washed with an aqueous solution and then subjected to shear stress treatment (such as an extrusion process or by means of a shear mixer). The shear stress treatment is said to be performed on seaweed material having a solids content of at least 25%, at a temperature between iooaC and 175° C., for about 10 to 200 seconds. The carrageenan material resulting from the shear stress treatment may be dried and subjected to comminution, grinding or milling to obtain a powder with a particle size in the range of 0.05 to 0.5 mm.
Conventional carrageenans typically have some advantages relative to SRC obtained from the same seaweed. One such advantage is that they typically begin to hydrate, i.e., they begin to swell and solubilize, at a lower temperatures than does SRC. For example, conventional iota carrageenan obtained fromEucheuma spinosumwill hydrate, swell, and solubilize at room temperature. PES derived fromEucheuma spinosum,however, does not hydrate, swell and solubilize until first heated to above about 60° C. Another such advantage is that because SRC contains cellulosic and other materials which are absent in conventional carrageenan, gels formed from SRC have reduced clarity relative to pure carrageenan gels. Therefore, utility of SRC products has been limited to those applications where the food product is not required to be clear and can be readily prepared at the high temperatures required for hydration and solubility of carrageenan to occur. For many applications, however, it is desirable to have an SRC which provides gelling without the need for such high temperatures. It is also important that SRC have acceptable color and appearance suitable for use in products made for human consumption such as, for example, cream, ice cream, other dairy products, and beverages, as well as non-food products such as, for example, cosmetics, tooth paste, and other personal care products.
Therefore, there is a need in the art for a low cost processes for producing carrageenan products with improved hydration characteristics while maintaining acceptable color and appearance suitable for use in food products.
SUMMARY OF THE INVENTION
The present invention provides methods for preparing a carrageenan product comprising the steps of providing a carrageenan-containing seaweed material having a seaweed solids content of less than 25% by weight, and subjecting this seaweed material to shear stress treatment. The carrageenan-containing seaweed material optionally is treated with base prior to extrusion.
In one embodiment, the carrageenan-containing seaweed material is prepared by a process comprising the steps of washing the seaweed with water to produce washed seaweed; rinsing the seaweed with water to form rinsed seaweed; and washing the rinsed seaweed with water or an aqueous solution to form the carrageenan-containing seaweed material.
In another embodiment, the methods of the present invention comprise washing the seaweed with water, treating the seaweed with a base at a temperature of about 25° C. to about 65° C. to form base-modified seaweed; rinsing the base-modified seaweed with water, washing this base-modified seaweed with an aqueous solution of a salt; rinsing this base-modified seaweed with water to form processed seaweed, wherein the processed seaweed comprises less than 25% solids; extruding this processed seaweed to form extruded seaweed; and drying the extruded seaweed to form a carrageenan product.
In yet another embodiment, the concentration of the aqueous salt solution is less than about 40%. It is preferred that the concentration of the aqueous salt solution be less than about 15%. It is more preferred that the concentration of the aqueous salt solution be between about 2% and about 15%.
The present invention also includes carrageenan products that preferably comprise at least about 60% by weight of carrageenan and at least about 2% by weight of acid insoluble material, and have an onset of hydration below about 50° C. In a preferred embodiment, the carrageenan product is derived fromEucheuma spinosum,or any other species containing iota-carrageenan. In another preferred embodiment, the carrageenan product further comprises about 2% to about 15% by weight of a salt. A preferred salt is sodium chloride.
The present invention further includes foods and other products containing a carrageenan product or products produced by the foregoing methods. The carrageenan product preferably comprises at least about 60% by weight of carrageenan and at least about 2% by weight of acid insoluble material. For such carrageenan products produced fromEucheuma cottonii,the onset of hydration can be as low as below about 50° C. For such carrageenan products produced fromEucheuma spinosum,the onset of hydration can be as low as below about 30° C.
Other products include toothpaste formulations comprising a binder, a humectant, an abrasive, and water, wherein the binder is a carrageenan product according to the present invention. It is preferred that the concentration of the binder be from about 0.5 to about 1.5% by weight of the toothpaste formulation.
The present invention further includes methods of making articles containing one or more carrageenan products produced by the methods of the invention. In one embodiment, a solution comprising the carrageenan-containing product of the invention is heated and at least a portion of the heated solution is then subjected to conditions effective to transform it into a barrier material. Films can be formed, for example, by casting the solution on a cooled rotating drum. Optionally, the carrageenan-containing film can be fed through a series of rollers to counter rotating dies which form, cut, and fill capsules of various sizes.
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7769240 | CROSS REFERENCE TO RELATED APPLICATIONS
This application relates to the following co-pending and commonly-assigned applications, with each application incorporated herein by reference: U.S. application Ser. No. 11/300,125, filed Dec. 14, 2005 and entitled “Presence Detection in a Bandwidth Management System”); U.S. application Ser. No. 11/300,061, filed Dec. 14, 2005 and entitled “Methods, Systems, and Devices for Bandwidth Conservation”; U.S. application Ser. No. 11/178,075, filed Jul. 8, 2005 and entitled “Methods, Systems, and Devices for Securing Content”; U.S. application Ser. No. 11/304,264, filed Dec. 14, 2005 and entitled “Methods, Systems, and Computer Program Products For Providing Traffic Control Services”; U.S. application Ser. No. 11/703,573, concurrently filed and entitled “Methods, Systems, and Products for Conserving Bandwidth”; U.S. application Ser. No. 11/413,886, concurrently filed and entitled “Methods, Systems, and Products for Recording Media”; U.S. application Ser. No. 11/413,885, concurrently filed and entitled “Methods, Systems, and Products for Recording Media”; U.S. application Ser. No. 12/726,441, concurrently filed and entitled “Methods, Systems, and Products for Targeting Media”; and U.S. application Ser. No. 12/630,895, concurrently filed and entitled “Methods, Systems, and Products for Restoring Media”.
NOTICE OF COPYRIGHT PROTECTION
A portion of the disclosure of this patent document and its figures contain material subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, but otherwise reserves all copyrights whatsoever.
BACKGROUND
This application generally relates to interactive multimedia distribution systems and, more particularly, to distributing video data streams having varying resolutions in such systems.
Multimedia streaming systems are limited by wireless bandwidth and multimedia delivery systems. For example, each subscriber's multimedia device may have different display formats, power settings, communications capabilities, and computational capabilities. Still further, each content distribution network that delivers or otherwise communicates media content to the multimedia device may have different maximum bandwidths, quality levels, time-varying characteristics, delivery reliability features, and delivery costs. And, as subscribers demand more and more content, higher definition services, interactive services, and data services, the existing network infrastructures have trouble supplying and utilizing adequate bandwidth. The industry is hard at work identifying new ways of utilizing bandwidth. The industry is also striving to reduce wasted bandwidth.
Conventional interactive multimedia distribution systems make use of a display device (coupled or otherwise integrated with the multimedia device) for presentation of video and/or graphical content. In order to enlarge or otherwise “zoom” to a selected image of the video and/or graphical content, the selected area is targeted and presented on the display device at a higher magnification. However, if an image plane becomes larger on the display device and the number of display pixels in a longitudinal direction is the same as that in a lateral direction, then the space between the pixels becomes larger. And, the displayed resolution appears lowered, thus the “definition” of the zoomed, selected image is lowered for a subscriber viewing the display device.
Consequently, the subscriber may desire to raise horizontal and vertical scanning frequencies of the video and/or graphical images to implement a higher resolution of the zoomed, selected image to the display device and provide an improved definition of the selected image plane. However, as briefly mentioned above, high-grade delivery techniques and increased costs are typically required to raise the quality of the image plane.
Accordingly, needs exist for image processing systems and methods that enable video or graphical data enlargement (i.e., “zooming”) to the display device and that also effectively leverage higher resolution data streams. Similarly, needs exist for image processing systems and methods to selectively control image plane presentation of zoomed content. Still further, a need exists for image processing systems and methods that recapture a lower resolution data stream of the video or graphical data when the zoom feature is deactivated.
SUMMARY
The aforementioned problems, and other problems, are addressed, according to exemplary embodiments, by methods, systems, and devices that conserve bandwidth in communications networks. These exemplary embodiments describe tools that can reduce the occurrences of wasted bandwidth. Because each subscriber's multimedia device may have limited presentation capabilities and because each content distribution network may have different maximum bandwidths and delivery features, these exemplary embodiments selectively upgrade resolution of multimedia content when the subscriber activates commands to zoom and/or to pan the displayed content. If the zoom and/or pan command is deactivated, then the exemplary embodiments restore standard resolution of a stream of data for the multimedia content. According to exemplary embodiments, the standard resolution data stream may be supplanted with the upgraded resolution data stream. And, further exemplary embodiments degrade the standard resolution data stream during presentation of the upgraded resolution data stream (e.g., multiple data streams may be delivered and selectively filtered for presentation according to selection and use of the zoom command and/or pan command.)
The exemplary embodiments conserve bandwidth. A standard resolution is predetermined for the delivery of multimedia content to a multimedia device. During presentation of the data stream having the predetermined, standard resolution (also referred to herein as the “standard data stream”), if the zoom command is activated, then an upgraded stream of data (also referred to herein as the “upgraded data stream”) having a higher resolution for a zoomed image plane supplants the standard data stream and the upgraded data stream is delivered to the multimedia device over a content distribution network. And, if during delivery of the upgraded data stream, the pan command is activated, then the upgraded data stream is refreshed for zoomed, spherical panorama presentation to the multimedia device (also referred to herein as the “refreshed data stream”). When the zoom command and/or the pan command are deactivated or when a restoration command is detected, the standard resolution stream of data may be restored (also referred to herein as the “restored data stream”) such that available bandwidth is conserved.
According to alternative exemplary embodiments, the content distribution network may deliver multiple data streams having different resolutions, such that the multimedia device itself and/or a local network component (e.g., a residential gateway) controls selection and presentation of either the standard data stream or the upgraded data stream.
Some of the exemplary embodiments include a device that conserves bandwidth. The device comprises a processor communicating with means for detecting a zoom command. The processor commands communication of a first stream of data for presentation to a multimedia device. According to some of the embodiments, the resolution of the first stream of data is predetermined based upon the capabilities of the multimedia device and/or the capabilities of the content distribution network. When the zoom command is activated, the processor accesses a second stream of data for a zoomed image plane of the first stream of data and commands communication of the second stream of data for presentation to the multimedia device. This second stream of data has a higher resolution of the zoomed image plane such that the definition of the zoomed image plane is comparable or better to the definition of the full image plane of the first stream of data. The processor may then degrade, discontinue, or otherwise discard the first stream of data during presentation of the upgraded data stream. When the zoom command is deactivated or when a restoration command is detected, the processor restores the standard data stream. Consequently, the device controls selection and delivery of media content having variable data streams of different resolutions to conserve bandwidth.
Further exemplary embodiments describe a computer program product for conserving bandwidth. The computer program product comprises a computer-readable medium and a zoom and pan application stored on the computer-readable medium. The zoom and pan application includes instructions for: i) displaying a first video stream having a sequence of frames of video data, each frame having an image plane with a predetermined image pixel density wherein the image pixel density comprises an x-dimension of a predetermined number of pixels and a y-dimension of a predetermined number of pixels, ii) detecting a zoom command from the multimedia device, the zoom command comprising an instruction to magnify a selected portion of the image plane, iii) supplanting the first video stream with a second video stream having a synchronized sequence of zoomed frames for the selected portion of image plane, each zoomed frame having a higher image pixel density than the predetermined pixel density of the first video stream for the selected portion of the image plane, wherein the higher image pixel density comprises an x-dimension of an increased number of pixels for the selected portion of the image plane and a y-dimension of an increased number of pixels for the selected portion of the image plane, and iv) displaying the second video stream.
Other systems, methods, and/or computer program products according to the exemplary embodiments will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such additional systems, methods, and/or computer program products be included within and protected by this description and be within the scope of this invention.
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SUMMARY: CROSS REFERENCE TO RELATED APPLICATIONS
This application relates to the following co-pending and commonly-assigned applications, with each application incorporated herein by reference: U.S. application Ser. No. 11/300,125, filed Dec. 14, 2005 and entitled “Presence Detection in a Bandwidth Management System”); U.S. application Ser. No. 11/300,061, filed Dec. 14, 2005 and entitled “Methods, Systems, and Devices for Bandwidth Conservation”; U.S. application Ser. No. 11/178,075, filed Jul. 8, 2005 and entitled “Methods, Systems, and Devices for Securing Content”; U.S. application Ser. No. 11/304,264, filed Dec. 14, 2005 and entitled “Methods, Systems, and Computer Program Products For Providing Traffic Control Services”; U.S. application Ser. No. 11/703,573, concurrently filed and entitled “Methods, Systems, and Products for Conserving Bandwidth”; U.S. application Ser. No. 11/413,886, concurrently filed and entitled “Methods, Systems, and Products for Recording Media”; U.S. application Ser. No. 11/413,885, concurrently filed and entitled “Methods, Systems, and Products for Recording Media”; U.S. application Ser. No. 12/726,441, concurrently filed and entitled “Methods, Systems, and Products for Targeting Media”; and U.S. application Ser. No. 12/630,895, concurrently filed and entitled “Methods, Systems, and Products for Restoring Media”.
NOTICE OF COPYRIGHT PROTECTION
A portion of the disclosure of this patent document and its figures contain material subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, but otherwise reserves all copyrights whatsoever.
BACKGROUND
This application generally relates to interactive multimedia distribution systems and, more particularly, to distributing video data streams having varying resolutions in such systems.
Multimedia streaming systems are limited by wireless bandwidth and multimedia delivery systems. For example, each subscriber's multimedia device may have different display formats, power settings, communications capabilities, and computational capabilities. Still further, each content distribution network that delivers or otherwise communicates media content to the multimedia device may have different maximum bandwidths, quality levels, time-varying characteristics, delivery reliability features, and delivery costs. And, as subscribers demand more and more content, higher definition services, interactive services, and data services, the existing network infrastructures have trouble supplying and utilizing adequate bandwidth. The industry is hard at work identifying new ways of utilizing bandwidth. The industry is also striving to reduce wasted bandwidth.
Conventional interactive multimedia distribution systems make use of a display device (coupled or otherwise integrated with the multimedia device) for presentation of video and/or graphical content. In order to enlarge or otherwise “zoom” to a selected image of the video and/or graphical content, the selected area is targeted and presented on the display device at a higher magnification. However, if an image plane becomes larger on the display device and the number of display pixels in a longitudinal direction is the same as that in a lateral direction, then the space between the pixels becomes larger. And, the displayed resolution appears lowered, thus the “definition” of the zoomed, selected image is lowered for a subscriber viewing the display device.
Consequently, the subscriber may desire to raise horizontal and vertical scanning frequencies of the video and/or graphical images to implement a higher resolution of the zoomed, selected image to the display device and provide an improved definition of the selected image plane. However, as briefly mentioned above, high-grade delivery techniques and increased costs are typically required to raise the quality of the image plane.
Accordingly, needs exist for image processing systems and methods that enable video or graphical data enlargement (i.e., “zooming”) to the display device and that also effectively leverage higher resolution data streams. Similarly, needs exist for image processing systems and methods to selectively control image plane presentation of zoomed content. Still further, a need exists for image processing systems and methods that recapture a lower resolution data stream of the video or graphical data when the zoom feature is deactivated.
SUMMARY
The aforementioned problems, and other problems, are addressed, according to exemplary embodiments, by methods, systems, and devices that conserve bandwidth in communications networks. These exemplary embodiments describe tools that can reduce the occurrences of wasted bandwidth. Because each subscriber's multimedia device may have limited presentation capabilities and because each content distribution network may have different maximum bandwidths and delivery features, these exemplary embodiments selectively upgrade resolution of multimedia content when the subscriber activates commands to zoom and/or to pan the displayed content. If the zoom and/or pan command is deactivated, then the exemplary embodiments restore standard resolution of a stream of data for the multimedia content. According to exemplary embodiments, the standard resolution data stream may be supplanted with the upgraded resolution data stream. And, further exemplary embodiments degrade the standard resolution data stream during presentation of the upgraded resolution data stream (e.g., multiple data streams may be delivered and selectively filtered for presentation according to selection and use of the zoom command and/or pan command.)
The exemplary embodiments conserve bandwidth. A standard resolution is predetermined for the delivery of multimedia content to a multimedia device. During presentation of the data stream having the predetermined, standard resolution (also referred to herein as the “standard data stream”), if the zoom command is activated, then an upgraded stream of data (also referred to herein as the “upgraded data stream”) having a higher resolution for a zoomed image plane supplants the standard data stream and the upgraded data stream is delivered to the multimedia device over a content distribution network. And, if during delivery of the upgraded data stream, the pan command is activated, then the upgraded data stream is refreshed for zoomed, spherical panorama presentation to the multimedia device (also referred to herein as the “refreshed data stream”). When the zoom command and/or the pan command are deactivated or when a restoration command is detected, the standard resolution stream of data may be restored (also referred to herein as the “restored data stream”) such that available bandwidth is conserved.
According to alternative exemplary embodiments, the content distribution network may deliver multiple data streams having different resolutions, such that the multimedia device itself and/or a local network component (e.g., a residential gateway) controls selection and presentation of either the standard data stream or the upgraded data stream.
Some of the exemplary embodiments include a device that conserves bandwidth. The device comprises a processor communicating with means for detecting a zoom command. The processor commands communication of a first stream of data for presentation to a multimedia device. According to some of the embodiments, the resolution of the first stream of data is predetermined based upon the capabilities of the multimedia device and/or the capabilities of the content distribution network. When the zoom command is activated, the processor accesses a second stream of data for a zoomed image plane of the first stream of data and commands communication of the second stream of data for presentation to the multimedia device. This second stream of data has a higher resolution of the zoomed image plane such that the definition of the zoomed image plane is comparable or better to the definition of the full image plane of the first stream of data. The processor may then degrade, discontinue, or otherwise discard the first stream of data during presentation of the upgraded data stream. When the zoom command is deactivated or when a restoration command is detected, the processor restores the standard data stream. Consequently, the device controls selection and delivery of media content having variable data streams of different resolutions to conserve bandwidth.
Further exemplary embodiments describe a computer program product for conserving bandwidth. The computer program product comprises a computer-readable medium and a zoom and pan application stored on the computer-readable medium. The zoom and pan application includes instructions for: i) displaying a first video stream having a sequence of frames of video data, each frame having an image plane with a predetermined image pixel density wherein the image pixel density comprises an x-dimension of a predetermined number of pixels and a y-dimension of a predetermined number of pixels, ii) detecting a zoom command from the multimedia device, the zoom command comprising an instruction to magnify a selected portion of the image plane, iii) supplanting the first video stream with a second video stream having a synchronized sequence of zoomed frames for the selected portion of image plane, each zoomed frame having a higher image pixel density than the predetermined pixel density of the first video stream for the selected portion of the image plane, wherein the higher image pixel density comprises an x-dimension of an increased number of pixels for the selected portion of the image plane and a y-dimension of an increased number of pixels for the selected portion of the image plane, and iv) displaying the second video stream.
Other systems, methods, and/or computer program products according to the exemplary embodiments will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such additional systems, methods, and/or computer program products be included within and protected by this description and be within the scope of this invention.
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7857090 | FIELD OF THE INVENTION
The present disclosure includes a console for controlling a construction vehicle, such as a motor grader.
BACKGROUND OF THE INVENTION
Skilled motor grader operators have learned to operate the motor grader based on a learned “feel” of the machine, and can accurately control numerous controls simultaneously to provide accurate grades at high productivity. Highly skilled grader operators have a preferred control pattern for motor graders such that nearly all graders have similar lever arrangements, including lever and knob size, lever efforts and lever travel. These traditional motor grader controls are a series of individual levers arranged on either side of the steering wheel. Each lever individually controls a single function on the motor grader through a mechanical linkage system connected to a hydraulic valve.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a motor grader is provided including a chassis; a plurality of traction devices positioned to support the chassis and including at least one front traction device and at least one rear traction device; a motor grader circle supported by the chassis; a grader blade supported by the motor grader circle and positioned between the at least one front traction device and the at least one rear traction device; and an operator seat assembly supported by the chassis. The operator seat assembly includes a frame, a seat, and a back support. The vehicle further includes a control system including primary joysticks controlling at least one of the grader blade position, the grader blade orientation, and the lean of the at least one front traction device. The control system further includes at least one auxiliary input controlling at least one of the position or orientation of an accessory adapted to attach to a front end, rear end, or lateral side of the chassis. The vehicle further includes a console supported by the operator seat assembly and supporting the plurality of primary joysticks and the at least one auxiliary input.
According to another aspect of the present invention, a motor grader is provided including a chassis; a plurality of traction devices positioned to support the chassis and including at least one front traction device and at least one rear traction device; a motor grader circle supported by the chassis; a grader blade supported by the motor grader circle and positioned between the at least one front traction device and the at least one rear traction device; and an operator seat assembly supported by the chassis. The operator seat assembly includes a frame, a seat, and a back support. The vehicle further includes a control system including primary joysticks controlling at least one of the grader blade position, the grader blade orientation, and the lean of the at least one front traction device. The control system further includes at least one auxiliary input controlling at least one of the position or orientation of an accessory adapted to attach to a front end, rear end, or lateral side of the chassis. The at least one auxiliary input is positioned forward of at least a portion of the plurality of primary joysticks. The vehicle further includes a console supported by the operator seat assembly and supporting the plurality of primary joysticks.
According to another aspect of the present invention, a motor grader is provided including a chassis; a plurality of traction devices positioned to support the chassis and including at least one front traction device and at least one rear traction device; a motor grader circle supported by the chassis; a grader blade supported by the motor grader circle and positioned between the at least one front traction device and the at least one rear traction device; and an operator seat assembly supported by the chassis. The operator seat assembly includes a frame, a seat, and a back support. The vehicle further includes a control system including primary control means controlling at least one of the grader blade position, the grader blade orientation, and the lean of the at least one front traction device. The control system further includes auxiliary control means controlling at least one of the position or orientation of an accessory adapted to attach to a front end, rear end, or lateral side of the chassis. The vehicle further includes a console supported by the operator seat assembly and supporting the primary control means and the auxiliary control means.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present disclosure includes a console for controlling a construction vehicle, such as a motor grader.
BACKGROUND OF THE INVENTION
Skilled motor grader operators have learned to operate the motor grader based on a learned “feel” of the machine, and can accurately control numerous controls simultaneously to provide accurate grades at high productivity. Highly skilled grader operators have a preferred control pattern for motor graders such that nearly all graders have similar lever arrangements, including lever and knob size, lever efforts and lever travel. These traditional motor grader controls are a series of individual levers arranged on either side of the steering wheel. Each lever individually controls a single function on the motor grader through a mechanical linkage system connected to a hydraulic valve.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a motor grader is provided including a chassis; a plurality of traction devices positioned to support the chassis and including at least one front traction device and at least one rear traction device; a motor grader circle supported by the chassis; a grader blade supported by the motor grader circle and positioned between the at least one front traction device and the at least one rear traction device; and an operator seat assembly supported by the chassis. The operator seat assembly includes a frame, a seat, and a back support. The vehicle further includes a control system including primary joysticks controlling at least one of the grader blade position, the grader blade orientation, and the lean of the at least one front traction device. The control system further includes at least one auxiliary input controlling at least one of the position or orientation of an accessory adapted to attach to a front end, rear end, or lateral side of the chassis. The vehicle further includes a console supported by the operator seat assembly and supporting the plurality of primary joysticks and the at least one auxiliary input.
According to another aspect of the present invention, a motor grader is provided including a chassis; a plurality of traction devices positioned to support the chassis and including at least one front traction device and at least one rear traction device; a motor grader circle supported by the chassis; a grader blade supported by the motor grader circle and positioned between the at least one front traction device and the at least one rear traction device; and an operator seat assembly supported by the chassis. The operator seat assembly includes a frame, a seat, and a back support. The vehicle further includes a control system including primary joysticks controlling at least one of the grader blade position, the grader blade orientation, and the lean of the at least one front traction device. The control system further includes at least one auxiliary input controlling at least one of the position or orientation of an accessory adapted to attach to a front end, rear end, or lateral side of the chassis. The at least one auxiliary input is positioned forward of at least a portion of the plurality of primary joysticks. The vehicle further includes a console supported by the operator seat assembly and supporting the plurality of primary joysticks.
According to another aspect of the present invention, a motor grader is provided including a chassis; a plurality of traction devices positioned to support the chassis and including at least one front traction device and at least one rear traction device; a motor grader circle supported by the chassis; a grader blade supported by the motor grader circle and positioned between the at least one front traction device and the at least one rear traction device; and an operator seat assembly supported by the chassis. The operator seat assembly includes a frame, a seat, and a back support. The vehicle further includes a control system including primary control means controlling at least one of the grader blade position, the grader blade orientation, and the lean of the at least one front traction device. The control system further includes auxiliary control means controlling at least one of the position or orientation of an accessory adapted to attach to a front end, rear end, or lateral side of the chassis. The vehicle further includes a console supported by the operator seat assembly and supporting the primary control means and the auxiliary control means.
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7655956 | This application claims priority from Japanese Patent application No. 2005-375901, filed Dec. 27, 2005, the contents of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device having a substrate mounted with a light emitting element and a method for manufacturing the semiconductor device.
2. Description of the Related Art
Recently, various structures have been proposed as a semiconductor device having a substrate mounted with a light emitting element. For example, as an example of a semiconductor device mounted with a light emitting element, a semiconductor device mounted with a light emitting diode (LED) as described in JP-A-H11-177136 has been proposed.
FIG. 1is a cross-sectional view showing a frame format of a semiconductor device10mounted with the LED as a light emitting element14. Referring toFIG. 1, the semiconductor device10includes a structure having a substrate11mounted with the light emitting element14.
In addition, the substrate11is formed with wirings12,13that extend from one side of the substrate, where the light emitting element14is mounted, to the opposite side of the substrate. The light emitting element14is arranged to be connected to the wirings12,13respectively through wires15,16.
Further, a cavity17is formed on the substrate11, and the light emitting element14is arranged in a concave portion of the cavity17. If an internal surface17aof the cavity17is coated with a metal plating, it is possible to use the internal surface as a reflector.
If necessary, it is possible to use a combination of LED light emitted and phosphor light emitted so as to obtain desired light emitting color by coating a phosphor film on the light emitting element14.
However, the semiconductor device has the following problems. In the semiconductor device, the light emitting element is connected to the substrate through the wires. For this reason, a space is needed for bonding wires. As the result, a problem is caused in that it becomes difficult to downsize the semiconductor device.
Further, when a reflector is formed in the semiconductor device or when a phosphor film is formed in the semiconductor device, it is necessary to form the reflector and the phosphor film in every package respectively. As a result, there have been such problems that not only the structure of the semiconductor device is complex, but also it is difficult to form a structure to improve light emitting efficiency.
SUMMARY OF THE INVENTION
The invention is accomplished in view of the above problems. Objects of the present invention are to provide a novel and useful semiconductor device, and a method for manufacturing the semiconductor device, which solve the above-mentioned problems.
More specifically, objects of the present invention are to provide a semiconductor device mounted with a light emitting element, which can be downsized easily, improve light emitting efficiency and be formed easily, and a method for manufacturing the semiconductor device effectively.
In a first aspect of the present invention, the above-mentioned problems can be solved by providing a semiconductor device comprising a substrate, a light emitting element mounted on the substrate by flip chip bonding and a sealing structure sealing the light emitting element, wherein the sealing structure includes a blocking portion which is formed to surround the light emitting element on the substrate through plating and is bonded to a cover portion which is arranged on top of the blocking portion. A phosphor film is also formed on an internal surface of the sealing structure and the blocking portion functions as a reflector that reflects a light emitted from the light emitting element.
The semiconductor device is able to be downsized easily, to improve light emitting efficiency and to be formed easily.
When the light emitting element is an LED, it is preferable that a desired light emitting color can be obtained by combining of an LED light emission and a phosphor light emission.
When the semiconductor device includes a through wiring which is formed to pass through the substrate and is electrically connected to the light emitting element, the light emitting element can be easily connected to a connection object.
When a bonding portion of the cover portion, which is bonded to the blocking portion, is formed by patterning, the cover portion can be easily bonded to the blocking portion. Further, in a second aspect of the present invention, the above-mentioned problems can be solved by providing a method for manufacturing a semiconductor device in which a light emitting element mounted on a substrate is sealed, said method comprises steps of forming a blocking portion on the substrate through plating, mounting the light emitting element by flip chip bonding in a region surrounded by the blocking portion on the substrate, coating a phosphor film on an internal surface of a sealing structure and sealing the light emitting element by bonding a cover portion coated with a phosphor film to the blocking portion.
According to the method for manufacturing the semiconductor device, it is possible to effectively manufacture the semiconductor device mounted with a light emitting element, which can be downsized easily and improves light emitting efficiency.
Further, when the light emitting element is an LED, it is preferable that a desired light emitting color can be obtained by combining an LED light emission and a phosphor light emission.
When the method for manufacturing the semiconductor device further comprises a step of forming a through wiring which is formed to pass through the substrate, wherein the light emitting element is mounted to be connected to the through wiring, it is possible to manufacture the semiconductor device in which the light emitting element can be easily connected to a connection object.
When the blocking portion functions as a reflector that reflects a light emitted from the light emitting element, the light emitting efficiency of the semiconductor device can be improved.
When a bonding portion of the cover portion, which is bonded to the blocking portion, is formed by patterning, the cover portion can be easily bonded to the blocking portion.
According to the present invention, it is possible to provide a semiconductor device mounted with a light emitting element, which can be downsized easily, improve light emitting efficiency and also be formed easily, and a method for manufacturing the semiconductor device effectively.
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SUMMARY: This application claims priority from Japanese Patent application No. 2005-375901, filed Dec. 27, 2005, the contents of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device having a substrate mounted with a light emitting element and a method for manufacturing the semiconductor device.
2. Description of the Related Art
Recently, various structures have been proposed as a semiconductor device having a substrate mounted with a light emitting element. For example, as an example of a semiconductor device mounted with a light emitting element, a semiconductor device mounted with a light emitting diode (LED) as described in JP-A-H11-177136 has been proposed.
FIG. 1is a cross-sectional view showing a frame format of a semiconductor device10mounted with the LED as a light emitting element14. Referring toFIG. 1, the semiconductor device10includes a structure having a substrate11mounted with the light emitting element14.
In addition, the substrate11is formed with wirings12,13that extend from one side of the substrate, where the light emitting element14is mounted, to the opposite side of the substrate. The light emitting element14is arranged to be connected to the wirings12,13respectively through wires15,16.
Further, a cavity17is formed on the substrate11, and the light emitting element14is arranged in a concave portion of the cavity17. If an internal surface17aof the cavity17is coated with a metal plating, it is possible to use the internal surface as a reflector.
If necessary, it is possible to use a combination of LED light emitted and phosphor light emitted so as to obtain desired light emitting color by coating a phosphor film on the light emitting element14.
However, the semiconductor device has the following problems. In the semiconductor device, the light emitting element is connected to the substrate through the wires. For this reason, a space is needed for bonding wires. As the result, a problem is caused in that it becomes difficult to downsize the semiconductor device.
Further, when a reflector is formed in the semiconductor device or when a phosphor film is formed in the semiconductor device, it is necessary to form the reflector and the phosphor film in every package respectively. As a result, there have been such problems that not only the structure of the semiconductor device is complex, but also it is difficult to form a structure to improve light emitting efficiency.
SUMMARY OF THE INVENTION
The invention is accomplished in view of the above problems. Objects of the present invention are to provide a novel and useful semiconductor device, and a method for manufacturing the semiconductor device, which solve the above-mentioned problems.
More specifically, objects of the present invention are to provide a semiconductor device mounted with a light emitting element, which can be downsized easily, improve light emitting efficiency and be formed easily, and a method for manufacturing the semiconductor device effectively.
In a first aspect of the present invention, the above-mentioned problems can be solved by providing a semiconductor device comprising a substrate, a light emitting element mounted on the substrate by flip chip bonding and a sealing structure sealing the light emitting element, wherein the sealing structure includes a blocking portion which is formed to surround the light emitting element on the substrate through plating and is bonded to a cover portion which is arranged on top of the blocking portion. A phosphor film is also formed on an internal surface of the sealing structure and the blocking portion functions as a reflector that reflects a light emitted from the light emitting element.
The semiconductor device is able to be downsized easily, to improve light emitting efficiency and to be formed easily.
When the light emitting element is an LED, it is preferable that a desired light emitting color can be obtained by combining of an LED light emission and a phosphor light emission.
When the semiconductor device includes a through wiring which is formed to pass through the substrate and is electrically connected to the light emitting element, the light emitting element can be easily connected to a connection object.
When a bonding portion of the cover portion, which is bonded to the blocking portion, is formed by patterning, the cover portion can be easily bonded to the blocking portion. Further, in a second aspect of the present invention, the above-mentioned problems can be solved by providing a method for manufacturing a semiconductor device in which a light emitting element mounted on a substrate is sealed, said method comprises steps of forming a blocking portion on the substrate through plating, mounting the light emitting element by flip chip bonding in a region surrounded by the blocking portion on the substrate, coating a phosphor film on an internal surface of a sealing structure and sealing the light emitting element by bonding a cover portion coated with a phosphor film to the blocking portion.
According to the method for manufacturing the semiconductor device, it is possible to effectively manufacture the semiconductor device mounted with a light emitting element, which can be downsized easily and improves light emitting efficiency.
Further, when the light emitting element is an LED, it is preferable that a desired light emitting color can be obtained by combining an LED light emission and a phosphor light emission.
When the method for manufacturing the semiconductor device further comprises a step of forming a through wiring which is formed to pass through the substrate, wherein the light emitting element is mounted to be connected to the through wiring, it is possible to manufacture the semiconductor device in which the light emitting element can be easily connected to a connection object.
When the blocking portion functions as a reflector that reflects a light emitted from the light emitting element, the light emitting efficiency of the semiconductor device can be improved.
When a bonding portion of the cover portion, which is bonded to the blocking portion, is formed by patterning, the cover portion can be easily bonded to the blocking portion.
According to the present invention, it is possible to provide a semiconductor device mounted with a light emitting element, which can be downsized easily, improve light emitting efficiency and also be formed easily, and a method for manufacturing the semiconductor device effectively.
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7711899 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an information processing device comprising a plurality of processing units and a data control method in the information processing device.
2. Description of the Related Art
Information processing devices such as servers have been widely used in recent years in a variety of fields. Web servers processing millions of accesses per day and transaction servers used in financial institutions or communication companies are the typical servers.
Because such information processing devices are required to have a high processing capability, they most often have a multiprocessor configuration carrying a plurality of processing units (CPU (Central Processing Unit), MPU (Micro Processing Unit) etc.) in one information processing device. In the information processing devices with a multiprocessor configuration, control has to be conducted to maintain consistency (memory consistency, cache coherency) of data stored in a main memory and a cache provided in each processing unit so that each processing unit can independently access the main memory.
In the information processing devices with a multiprocessor configuration, the consistency is most often controlled with a system controller conducting intermediate processing of the main memory and each processing unit. Further, as a control for maintaining the consistency, for example, in the case where a read request relating to the same request is generated, while the system controller stores data (write data) that will be written into the main memory, the system controller waits till writing of the write data into the main memory is completed and then processes the read request.
As a result, the execution time required for processing the read requests is increased and the processing capability of the information processing device is degraded. Accordingly, a technology for improving the processing capability of read requests in an information processing device by using a store buffer for storing temporarily the data immediately prior to writing to the main memory or cache memory has been suggested as prior art technology (Japanese Patent Application Laid-open No. H6-301600 and H3-288245).
However, data stored in the store buffer is stored as a result of arbitration relating to read requests and write requests from each processing unit that are stored in a read cue or write cue provided in the previous stage. Therefore, the problem is that it is necessary to wait for arbitration in order to use the store buffer (and data stored therein).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an information processing device of a multiprocessor configuration that can process read requests, without waiting for arbitration relating to the store buffer.
This object can be attained by providing as the first aspect of the present invention an information processing device, comprising a plurality of processing units, a plurality of cache memories corresponding to the plurality of processing units, for storing temporarily the data read by the plurality of processing units from a main memory, and a system controller for controlling the access of the plurality of processing units to the main memories, wherein the system controller comprises a tag copy unit for holding the tag information, of the tag information and data contained in the cache memory, a plurality of write cues corresponding to the plurality of processing units, for storing write requests outputted respectively by the plurality of processing units, and a store buffer for storing the arbitration results relating to a plurality of write requests that will be stored in the plurality of write cues, and the system controller, in the case where the tag information contained in the cache memory and the tag information contained in the tag copy unit are asynchronous when a read request from one processing unit of the plurality of processing units is inputted, searches the plurality of write cues to find whether a write request relating to the address corresponding to the read request has been inputted by another processing unit that is different from the one processing unit and, if such a request has been inputted in any of the plurality of write cues, acknowledges the data contained in the write request relating to the address corresponding to the read request.
With the more preferred embodiment of this aspect of the present invention, the system controller cancels the write request relating to the address corresponding to the read request.
Further, with the more preferred embodiment of this aspect of the present invention, the plurality of processors are divided into a plurality of groups, the system controller is present for each group, the first system controller corresponding to one group of the plurality of groups, in the case where the tag information contained in a cache memory of the first system controller and the tag information contained in a tag copy unit of the first system controller are asynchronous when a read reference request from a second system controller different from the first system controller is inputted, searches the plurality of write cues provided in the first system controller to find whether a write request relating to the address corresponding to the read reference request has been inputted and, if such a request has been inputted in any of the plurality of write cues, acknowledges the data contained in the corresponding write request.
Further, with the more preferred embodiment of this aspect of the present invention, the first system controller cancels the write request relating to the address corresponding to the read request.
With the more preferred embodiment of this aspect of the present invention, the second system controller adds to the write cue of the second system controller a write request for writing data acknowledged in response to the read reference request in the address corresponding to the read reference request.
With the more preferred embodiment of this aspect of the present invention, the system controller, when there follows a separate write request to the address corresponding to any write request contained in the plurality of write cues, cancels the write request that preceded this request.
Further, the aforementioned object can be attained by providing as the second aspect of the present invention a data control method in an information processing device comprising a plurality of processing units, a plurality of cache memories corresponding to the plurality of processing units, for storing temporarily the data read by the plurality of processing units from a main memory in combination with tag information indicating the state of said data that will be stored, and a system controller for controlling the access of the plurality of processing units to the main memory, where the system controller comprises a tag copy unit for holding the tag information, of the tag information and data contained in the cache memory, a plurality of write cues corresponding to the plurality of processing units, for storing write requests outputted respectively by the plurality of processing units, and a store buffer for storing the arbitration results relating to a plurality of write requests that will be stored in the plurality of write cues, wherein the information processing device verifies whether the tag information contained in the cache memory and the tag information contained in the tag copy unit are asynchronous when a read request from one processing unit of a plurality of processing units is inputted, the information processing device, when they are asynchronous, searches the plurality of write cues to find whether a write request relating to the address corresponding to the read request has been inputted by another processing unit that is different from the one processing unit, and the information processing device, if a write request relating to the address corresponding to the read request has been inputted in any of the plurality of write cues, acknowledges the data contained in the write request relating to the address corresponding to the read request.
With the embodiments of the present invention an information processing device of a multiprocessor configuration can be provided that can increase significantly the processing capability of read requests, without waiting for arbitration.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an information processing device comprising a plurality of processing units and a data control method in the information processing device.
2. Description of the Related Art
Information processing devices such as servers have been widely used in recent years in a variety of fields. Web servers processing millions of accesses per day and transaction servers used in financial institutions or communication companies are the typical servers.
Because such information processing devices are required to have a high processing capability, they most often have a multiprocessor configuration carrying a plurality of processing units (CPU (Central Processing Unit), MPU (Micro Processing Unit) etc.) in one information processing device. In the information processing devices with a multiprocessor configuration, control has to be conducted to maintain consistency (memory consistency, cache coherency) of data stored in a main memory and a cache provided in each processing unit so that each processing unit can independently access the main memory.
In the information processing devices with a multiprocessor configuration, the consistency is most often controlled with a system controller conducting intermediate processing of the main memory and each processing unit. Further, as a control for maintaining the consistency, for example, in the case where a read request relating to the same request is generated, while the system controller stores data (write data) that will be written into the main memory, the system controller waits till writing of the write data into the main memory is completed and then processes the read request.
As a result, the execution time required for processing the read requests is increased and the processing capability of the information processing device is degraded. Accordingly, a technology for improving the processing capability of read requests in an information processing device by using a store buffer for storing temporarily the data immediately prior to writing to the main memory or cache memory has been suggested as prior art technology (Japanese Patent Application Laid-open No. H6-301600 and H3-288245).
However, data stored in the store buffer is stored as a result of arbitration relating to read requests and write requests from each processing unit that are stored in a read cue or write cue provided in the previous stage. Therefore, the problem is that it is necessary to wait for arbitration in order to use the store buffer (and data stored therein).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an information processing device of a multiprocessor configuration that can process read requests, without waiting for arbitration relating to the store buffer.
This object can be attained by providing as the first aspect of the present invention an information processing device, comprising a plurality of processing units, a plurality of cache memories corresponding to the plurality of processing units, for storing temporarily the data read by the plurality of processing units from a main memory, and a system controller for controlling the access of the plurality of processing units to the main memories, wherein the system controller comprises a tag copy unit for holding the tag information, of the tag information and data contained in the cache memory, a plurality of write cues corresponding to the plurality of processing units, for storing write requests outputted respectively by the plurality of processing units, and a store buffer for storing the arbitration results relating to a plurality of write requests that will be stored in the plurality of write cues, and the system controller, in the case where the tag information contained in the cache memory and the tag information contained in the tag copy unit are asynchronous when a read request from one processing unit of the plurality of processing units is inputted, searches the plurality of write cues to find whether a write request relating to the address corresponding to the read request has been inputted by another processing unit that is different from the one processing unit and, if such a request has been inputted in any of the plurality of write cues, acknowledges the data contained in the write request relating to the address corresponding to the read request.
With the more preferred embodiment of this aspect of the present invention, the system controller cancels the write request relating to the address corresponding to the read request.
Further, with the more preferred embodiment of this aspect of the present invention, the plurality of processors are divided into a plurality of groups, the system controller is present for each group, the first system controller corresponding to one group of the plurality of groups, in the case where the tag information contained in a cache memory of the first system controller and the tag information contained in a tag copy unit of the first system controller are asynchronous when a read reference request from a second system controller different from the first system controller is inputted, searches the plurality of write cues provided in the first system controller to find whether a write request relating to the address corresponding to the read reference request has been inputted and, if such a request has been inputted in any of the plurality of write cues, acknowledges the data contained in the corresponding write request.
Further, with the more preferred embodiment of this aspect of the present invention, the first system controller cancels the write request relating to the address corresponding to the read request.
With the more preferred embodiment of this aspect of the present invention, the second system controller adds to the write cue of the second system controller a write request for writing data acknowledged in response to the read reference request in the address corresponding to the read reference request.
With the more preferred embodiment of this aspect of the present invention, the system controller, when there follows a separate write request to the address corresponding to any write request contained in the plurality of write cues, cancels the write request that preceded this request.
Further, the aforementioned object can be attained by providing as the second aspect of the present invention a data control method in an information processing device comprising a plurality of processing units, a plurality of cache memories corresponding to the plurality of processing units, for storing temporarily the data read by the plurality of processing units from a main memory in combination with tag information indicating the state of said data that will be stored, and a system controller for controlling the access of the plurality of processing units to the main memory, where the system controller comprises a tag copy unit for holding the tag information, of the tag information and data contained in the cache memory, a plurality of write cues corresponding to the plurality of processing units, for storing write requests outputted respectively by the plurality of processing units, and a store buffer for storing the arbitration results relating to a plurality of write requests that will be stored in the plurality of write cues, wherein the information processing device verifies whether the tag information contained in the cache memory and the tag information contained in the tag copy unit are asynchronous when a read request from one processing unit of a plurality of processing units is inputted, the information processing device, when they are asynchronous, searches the plurality of write cues to find whether a write request relating to the address corresponding to the read request has been inputted by another processing unit that is different from the one processing unit, and the information processing device, if a write request relating to the address corresponding to the read request has been inputted in any of the plurality of write cues, acknowledges the data contained in the write request relating to the address corresponding to the read request.
With the embodiments of the present invention an information processing device of a multiprocessor configuration can be provided that can increase significantly the processing capability of read requests, without waiting for arbitration.
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7655664 | CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national phase application under 35 U.S.C. § 371 of PCT International Application No. PCT/SE2005/001917, filed Dec. 14. 2005, which claims priority to Swedish Application Serial No. 0403085-4, filed Dec. 17, 2004.
The present invention relates to novel hydantoin derivatives, processes for their preparation, pharmaceutical compositions containing them and their use in therapy.
Metalloproteinases are a superfamily of proteinases (enzymes) whose numbers in recent years have increased dramatically. Based on structural and functional considerations these enzymes have been classified into families and subfamilies as described in N. M. Hooper (1994) FEBS Letters 354:1-6. Examples of metalloproteinases include the matrix metalloproteinases (MMPs) such as the collagenases (MMP1, MMP8, MMP13), the gelatinases (MMP2, MMP9), the stromelysins (MMP3, MMP10, MMP11), matrilysin (MMP7), metalloelastase (MMP12), enamelysin (MMP19), the MT-MMPs (MMP14, MMP15, MMP16, MMP17); the reprolysin or adamalysin or MDC family which includes the secretases and sheddases such as TNF converting enzymes (ADAM10 and TACE); the astacin family which include enzymes such as procollagen processing proteinase (PCP); and other metalloproteinases such as aggrecanase, the endothelin converting enzyme family and the angiotensin converting enzyme family.
Metalloproteinases are believed to be important in a plethora of physiological disease processes that involve tissue remodelling such as embryonic development, bone formation and uterine remodelling during menstruation. This is based on the ability of the metalloproteinases to cleave a broad range of matrix substrates such as collagen, proteoglycan and fibronectin. Metalloproteinases are also believed to be important in the processing, or secretion, of biological important cell mediators, such as tumour necrosis factor (TNF); and the post translational proteolysis processing, or shedding, of biologically important membrane proteins, such as the low affinity IgE receptor CD23 (for a more complete list see N. M. Hooper et al., (1997) Biochem. J. 321:265-279).
Metalloproteinases have been associated with many diseases or conditions. Inhibition of the activity of one or more metalloproteinases may well be of benefit in these diseases or conditions, for example: various inflammatory and allergic diseases such as, inflammation of the joint (especially rheumatoid arthritis, osteoarthritis and gout), inflammation of the gastro-intestinal tract (especially inflammatory bowel disease, ulcerative colitis and gastritis), inflammation of the skin (especially psoriasis, eczema, dermatitis); in tumour metastasis or invasion; in disease associated with uncontrolled degradation of the extracellular matrix such as osteoarthritis; in bone resorptive disease (such as osteoporosis and Paget's disease); in diseases associated with aberrant angiogenesis; the enhanced collagen remodelling associated with diabetes, periodontal disease (such as gingivitis), corneal ulceration, ulceration of the skin, post-operative conditions (such as colonic anastomosis) and dermal wound healing; demyelinating diseases of the central and peripheral nervous systems (such as multiple sclerosis); Alzheimer's disease; extracellular matrix remodelling observed in cardiovascular diseases such as restenosis and atherosclerosis; asthma; rhinitis; and chronic obstructive pulmonary diseases (COPD).
MMP12, also known as macrophage elastase or metalloelastase, was initially cloned in the mouse by Shapiro et al [1992, Journal of Biological Chemistry 267: 4664] and in man by is the same group in 1995. MMP12 is preferentially expressed in activated macrophages, and has been shown to be secreted from alveolar macrophages from smokers [Shapiro et al, 1993, Journal of Biological Chemistry, 268: 23824] as well as in foam cells in atherosclerotic lesions [Matsumoto et al, 1998, Am. J. Pathol. 153: 109]. A mouse model of COPD is based on challenge of mice with cigarette smoke for six months, two cigarettes a day six days a week. Wild-type mice developed pulmonary emphysema after this treatment. When MMP12 knock-out mice were tested in this model they developed no significant emphysema, strongly indicating that MMP12 is a key enzyme in the COPD pathogenesis. The role of MMPs such as MMP12 in COPD (emphysema and bronchitis) is discussed in Anderson and Shinagawa, 1999, Current Opinion in Anti-inflammatory and Immunomodulatory Investigational Drugs 1(1): 29-38. It was recently discovered that smoking increases macrophage infiltration and macrophage-derived MMP-12 expression in human carotid artery plaques Kangavari [Matetzky S, Fishbein M C et al., Circulation 102:(18, 36-39 Suppl. S, Oct. 31, 2000].
MMP9 (Gelatinase B; 92 kDa TypeIV Collagenase; 92 kDa Gelatinase) is a secreted protein which was first purified, then cloned and sequenced, in 1989 [S. M. Wilhelm et al (1989) J. Biol. Chem. 264 (29): 17213-17221; published erratum in J. Biol. Chem. (1990) 265 (36): 22570]. A recent review of MMP9 provides an excellent source for detailed information and references on this protease: T. H. Vu & Z. Werb (1998) (In: Matrix Metalloproteinases, 1998, edited by W. C. Parks & R. P. Mecham, pp. 115-148, Academic Press. ISBN 0-12-545090-7). The following points are drawn from that review by T. H. Vu & Z. Werb (1998).
The expression of MMP9 is restricted normally to a few cell types, including trophoblasts, osteoclasts, neutrophils and macrophages. However, the expression can be induced in these same cells and in other cell types by several mediators, including exposure of the cells to growth factors or cytokines. These are the same mediators often implicated in initiating an inflammatory response. As with other secreted MMPs, MMP9 is released as an inactive Pro-enzyme which is subsequently cleaved to form the enzymatically active enzyme. The proteases required for this activation in vivo are not known. The balance of active MMP9 versus inactive enzyme is further regulated in vivo by interaction with is TIMP-1 (Tissue Inhibitor of Metalloproteinases-1), a naturally-occurring protein. TIMP-1 binds to the C-terminal region of MMP9, leading to inhibition of the catalytic domain of MMP9. The balance of induced expression of ProMMP9, cleavage of Pro- to active MMP9 and the presence of TIMP-1 combine to determine the amount of catalytically active MMP9 which is present at a local site. Proteolytically active MMP9 attacks substrates which include gelatin, elastin, and native Type IV and Type V collagens; it has no activity against native Type I collagen, proteoglycans or laminins.
There has been a growing body of data implicating roles for MMP9 in various physiological and pathological processes. Physiological roles include the invasion of embryonic trophoblasts through the uterine epithelium in the early stages of embryonic implantation; some role in the growth and development of bones; and migration of inflammatory cells from the vasculature into tissues.
MMP9 release, measured using enzyme immunoassay, was significantly enhanced in fluids and in AM supernantants from untreated asthmatics compared with those from other populations [Am. J. Resp. Cell & Mol. Biol., November 1997, 17 (5):583-591]. Also, increased MMP9 expression has been observed in certain other pathological conditions, thereby implicating MMP9 in disease processes such as COPD, arthritis, tumour metastasis, Alzheimer's disease, multiple sclerosis, and plaque rupture in atherosclerosis leading to acute coronary conditions such as myocardial infarction.
A number of metalloproteinase inhibitors are known (see, for example, the reviews of MMP inhibitors by Beckett R. P. and Whittaker M., 1998, Exp. Opin. Ther. Patents, 8(3):259-282; and by Whittaker M. et al, 1999, Chemical Reviews 99(9):2735-2776).
WO 02/074767 discloses hydantoin derivatives of formula
that are useful as MMP inhibitors, particularly as potent MMP12 inhibitors.
We now disclose a further group of hydantoin derivatives that are inhibitors of metalloproteinases and are of particular interest in inhibiting MMPs such as MMP12 and MMP9. The compounds of the present invention have beneficial potency, selectivity and/or pharmacokinetic properties.
In accordance with the present invention, there are provided compounds of formula (I)
whereinR1represents cyclobutyl or cyclopropyl; said cyclopropyl group being optionally further substituted by CH3, CN or one or two fluoro atoms;R2represents C1 to 3 alkyl or cyclopropyl; andA, A1and B independently represent CH or N;
and pharmaceutically acceptable salts thereof.
The compounds of formula (I) may exist in enantiomeric forms. It is to be understood that all enantiomers, diastereomers, racemates and mixtures thereof are included within the scope of the invention.
Compounds of formula (I) may also exist in various tautomeric forms. All possible tautomeric forms and mixtures thereof are included within the scope of the invention.
In one embodiment, R1represents cyclopropyl; said cyclopropyl group being optionally further substituted by one or two fluoro atoms.
In one embodiment, R1represents cyclopropyl.
In one embodiment, R2represents methyl or ethyl. In one embodiment, R2represents methyl.
In one embodiment, A and A1each represent N. In another embodiment, A represents N and A1represents-CH.
In one embodiment, B represents N. In another embodiment, B represents CH.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A and A1each represent N; and B represents CH.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A and A1each represent N; and B represents N.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A represents N and A1represents CH; and B represents N.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A represents N and A1represents CH; and B represents CH.
In one embodiment, R1represents cyclopropyl; said cyclopropyl group being optionally is further substituted by CH3, CN or one or two fluoro atoms; R2represents C1 to 3 alkyl; and A, A1and B independently represent CH or N.
Unless otherwise indicated, the term “C1 to 3 alkyl” referred to herein denotes a straight or branched chain alkyl group having from 1 to 3 carbon atoms. Examples of such groups include methyl, ethyl, n-propyl and i-propyl.
Examples of a cyclopropyl ring optionally further substituted by one or two fluoro atoms include 1-fluoro-1-cyclopropyl, 2,2-difluoro-1-cyclopropyl and 2,3-difluoro-1-cyclopropyl:
Examples of compounds of the invention include:(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-({[6-(6-cyclopropylpyridin-3-yl)-3,4-dihydro-2,7-naphthyridin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydro-2,7-naphthyridin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydro-2,7-naphthyridin-2(1H)-yl]sulfonyl}methyl)-5-ethylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)-5-ethylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclobutylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-methyl-5-({[6-[2-(1-methylcyclopropyl)pyrimidin-5-yl]-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione;(5S)-5-Cyclopropyl-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione;
and pharmaceutically acceptable salts thereof.
Each exemplified compound represents a particular and independent aspect of the invention.
The compounds of formula (I) may exist in enantiomeric forms. Therefore, all enantiomers, diastereomers, racemates and mixtures thereof are included within the scope of the invention. The various optical isomers may be isolated by separation of a racemic mixture of the compounds using conventional techniques, for example, fractional crystallisation, or HPLC. Alternatively the optical isomers may be obtained by asymmetric synthesis, or by synthesis from optically active starting materials.
Where optically isomers exist in the compounds of the invention, we disclose all individual optically active forms and combinations of these as individual specific embodiments of the invention, as well as their corresponding racemates.
Preferably the compounds of formula (I) have (5S)-stereochemistry as shown below:
Where tautomers exist in the compounds of the invention, we disclose all individual tautomeric forms and combinations of these as individual specific embodiments of the invention.
The present invention includes compounds of formula (I) in the form of salts. Suitable salts include those formed with organic or inorganic acids or organic or inorganic bases. Such is salts will normally be pharmaceutically acceptable salts although non-pharmaceutically acceptable salts may be of utility in the preparation and purification of particular compounds. Such salts include acid addition salts such as hydrochloride, hydrobromide, citrate, tosylate and maleate salts and salts formed with phosphoric acid or sulphuric acid.
In another aspect suitable salts are base salts such as an alkali metal salt, for example, sodium or potassium, an alkaline earth metal salt, for example, calcium or magnesium, or an organic amine salt, for example, triethylamine.
Salts of compounds of formula (I) may be formed by reacting the free base or another salt thereof with one or more equivalents of an appropriate acid or base.
The compounds of formula (I) are useful because they possess pharmacological activity in animals and are thus potentially useful as pharmaceuticals. In particular, the compounds of the invention are metalloproteinase inhibitors and may thus be used in the treatment of diseases or conditions mediated by MMP12 and/or MMP9 such as asthma, rhinitis, chronic obstructive pulmonary diseases (COPD), arthritis (such as rheumatoid arthritis and osteoarthritis), atherosclerosis and restenosis, cancer, invasion and metastasis, diseases involving tissue destruction, loosening of hip joint replacements, periodontal disease, fibrotic disease, infarction and heart disease, liver and renal fibrosis, endometriosis, diseases related to the weakening of the extracellular matrix, heart failure, aortic aneurysms, CNS related diseases such as Alzheimer's disease and multiple sclerosis (MS), and haematological disorders.
In general, the compounds of the present invention are potent inhibitors of MMP9 and MMP12. The compounds of the present invention also show good selectivity with respect to a relative lack of inhibition of various other MMPs such as MMP8, MMP14 and MMP19.
Accordingly, the present invention provides a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined for use in therapy.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in therapy.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of diseases or conditions in which inhibition of MMP12 and/or MMP9 is beneficial.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of inflammatory disease.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of an obstructive airways disease such as asthma or COPD.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of rheumatoid arthritis, osteoarthritis, atherosclerosis, cancer or multiple sclerosis.
In the context of the present specification, the term “therapy” also includes “prophylaxis” unless there are specific indications to the contrary. The terms “therapeutic” and “therapeutically” should be construed accordingly.
Prophylaxis is expected to be particularly relevant to the treatment of persons who have suffered a previous episode of, or are otherwise considered to be at increased risk of, the disease or condition in question. Persons at risk of developing a particular disease or condition generally include those having a family history of the disease or condition, or those who have been identified by genetic testing or screening to be particularly susceptible to developing the disease or condition.
The invention further provides a method of treating a disease or condition in which inhibition of MMP12 and/or MMP9 is beneficial which comprises administering to a patient a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined.
The invention also provides a method of treating an obstructive airways disease, for example, asthma or COPD, which comprises administering to a patient a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined.
For the above-mentioned therapeutic uses the dosage administered will, of course, vary with the compound employed, the mode of administration, the treatment desired and the disorder to be treated. The daily dosage of the compound of formula (I)/salt (active ingredient) may be in the range from 0.001 mg/kg to 75 mg/kg, in particular from 0.5 mg/kg to 30 mg/kg. This daily dose may be given in divided doses as necessary. Typically unit dosage forms will contain about 1 mg to 500 mg of a compound of this invention.
The compounds of formula (I) and pharmaceutically acceptable salts thereof may be used on their own but will generally be administered in the form of a pharmaceutical composition in which the formula (I) compound/salt (active ingredient) is in association with a pharmaceutically acceptable adjuvant, diluent or carrier. Depending on the mode of administration, the pharmaceutical composition will preferably comprise from 0.05 to 99% w (percent by weight), more preferably from 0.10 to 70% w, of active ingredient, and, from 1 to 99.95% w, more preferably from 30 to 99.90% w, of a pharmaceutically acceptable adjuvant, diluent or carrier, all percentages by weight being based on total composition. Conventional procedures for the selection and preparation of suitable pharmaceutical formulations are described in, for example, “Pharmaceuticals—The Science of Dosage Form Designs”, M. E. Aulton, Churchill Livingstone, 1988.
Thus, the present invention also provides a pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined in association with a pharmaceutically acceptable adjuvant, diluent or carrier.
The invention further provides a process for the preparation of a pharmaceutical composition of the invention which comprises mixing a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined with a pharmaceutically acceptable adjuvant, diluent or carrier.
The pharmaceutical compositions of this invention may be administered in a standard manner for the disease or condition that it is desired to treat, for example by oral, topical, parenteral, buccal, nasal, vaginal or rectal administration or by inhalation. For these purposes the compounds of this invention may be formulated by means known in the art into the form of, for example, tablets, capsules, aqueous or oily solutions, suspensions, emulsions, creams, ointments, gels, nasal sprays, suppositories, finely divided powders or aerosols for inhalation, and for parenteral use (including intravenous, intramuscular or infusion) sterile aqueous or oily solutions or suspensions or sterile emulsions.
In addition to the compounds of the present invention the pharmaceutical composition of this invention may also contain, or be co-administered (simultaneously or sequentially) with, one or more pharmacological agents of value in treating one or more diseases or conditions referred to hereinabove such as “Symbicort” (trade mark) product.
The present invention further provides a process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof as defined above which, comprises:a) reaction of a compound of formula (II)
wherein R2is as defined in formula (I) and L1represents a leaving group, with a compound of formula (III) (or a salt thereof)
wherein R1, A, A1and B are as defined in formula (I); orb) reaction of a compound of formula (V)
wherein R2and B are as defined in formula (I) and LG is a leaving group; with a boronic acid derivative of formula (XII)
wherein R1, A and A1are as defined in formula (I); orc) reaction of a compound of formula (IX)
wherein R1, R2, A, A1and B are as defined in formula (I); with ammonium carbonate and potassium cyanide;
and optionally thereafter forming a pharmaceutically acceptable salt thereof.
In the above process (a), suitable leaving groups L1include halo, particularly chloro or trifluoromethylsulfonate. The reaction is preferably performed in a suitable solvent optionally in the presence of an added base for a suitable period of time, typically 0.5 to 16 h, at ambient to reflux temperature. Typically solvents such as N,N-dimethylformamide, pyridine, tetrahydrofuran, acetonitrile, N-methylpyrrolidine or dichloromethane are used. When used, the added base may be an organic base such as triethylamine, N,N-diisopropylethylamine, N-methylmorpholine or pyridine, or an inorganic base such as an alkali metal carbonate. The reaction is typically conducted at ambient temperature for 0.5 to 16 h, or until completion of the reaction has been achieved, as determined by chromatographic or spectroscopic methods. Reactions of sulfonyl halides with various primary and secondary amines are well known in the literature, and the variations of the conditions will be evident for those skilled in the art.
Sulfonylchlorides of formula (II) wherein L1represents chloro and R2represents Me are disclosed in WO 02/074767 and references cited therein. Corresponding compounds wherein R2represents C1 to 3 alkyl may be prepared using analogous methods.
Suitable processes for the preparation of compounds of formula (I) are described in a retrosynthetic way in Scheme 1.
In Scheme 1, protecting groups (PG) can be either carbamates (e.g. tert-butoxycarbamate), amides (e.g. trifluoroacetyl) or alkyl (e.g. tert-butyl or benzyl). Leaving groups (LG) can be either chloride, bromide, iodide or trifluoromethylsulfonate. In the palladium-catalysed Suzuki couplings, either boronic acids or pinacolboronates may be used. Intermediate (IVa-c) can be prepared by standard Suzuki coupling (Chem. Rev.1995, 95, 2457) between an electrophile (VIIa-c) and a boron reagent (XII), or the other way around, between an electrophile (XI) and a boron reagent (VIIIa-c). The latter can be obtained from (VIIa-c) using standard Miyaura conditions (J. Org. Chem.1995, 60, 7508-7510). Deprotection of (IVa-c) either by hydrogen chloride in methanol (PG=tert-butoxycarbonyl) or refluxing 1-chloroethyl chloroformate/refluxing methanol (PG=tert-butyl or benzyl) (Synlett.1993, 195-196) gives amine (IIIa-c) as a hydrochloride salt. The free base can be obtained by treatment of (IIIa-c) with base and extraction with an organic solvent such as ethyl acetate is or toluene. Reacting (IIIa-c) either as a salt or base in a suitable solvent (e.g. acetonitrile, tetrahydrofuran, N-methylpyrrolidine or N,N-dimethylformamide) with the sulfonyl chloride (II) in the presence of a tertiary amine (e.g. triethylamine, pyridine or N,N-diisopropylethylamine) for 0.5 to 16 hours produces compounds of formula (I).
An alternative route to compounds of formula (I) from intermediate (IIIa-c) via methanesulfonamide (Xa-c) and ketone (IXa-c) has been previously described (WO 02/074767). Briefly, treatment of (IIIa-c) with methansulfonyl chloride and a tertiary amine (e.g. triethylamine, pyridine or N,N-diisopropylethylamine) in a suitable solvent (e.g. dichloromethane or tetrahydrofuran) produces the methansulfonamide (Xa-c) which in turn can be transformed into the ketone (IXa-c) using standard procedures. Heating ketone (IXa-c) with ammonium carbonate and potassium cyanide in 50% aqueous ethanol in a sealed vial at 80-90° C. for 1 to 5 hours gives a racemic hydantoin that can be resolved by chiral chromatography (e.g. on OD-H with 100% ethanol).
In a third route, intermediate (VIIa-c) is deprotected as described above to give amine (VIa-c) as a hydrochloride salt. The free base can be isolated by treatment with base and extraction with an organic solvent e.g. ethyl acetate or toluene. Reacting (Via-c) either as a salt or base in a suitable solvent (e.g. acetonitrile, tetrahydrofuran, N-methylpyrrolidine or N,N-dimethylformamide) with sulfonyl chloride (II) in the presence of a tertiary amine (e.g. triethylamine, pyridine or N,N-diisopropylethylamine) for 0.5 to 16 hours produces chiral sulfonamide (Va-c). The latter can be coupled with boron reagent (XII) using standard Suzuki conditions to give compounds of formula (I).
Intermediates (VIIa-b) are conveniently prepared using the following methods.
The 1,2,3,4-tetrahydroisoquinoline Intermediate (VIIa)
Methods for the synthesis of 1,2,3,4-tetrahydroisoquinolines are well known in the literature. The classical route is the Pomeranz-Fritz reaction of benzaldehydes with a diacetal protected aminoacetaldehyde (Org. React.1951, 6, 191) yielding the isoquinoline nucleus which upon catalytical reduction gives 1,2,3,4-tetrahydro-isoquinolines. Another route is the Bischler-Napieralski reaction (Org. React.1951, 6, 74) of a carbamate of 2-phenylethanamines with phosphoryl chloride in refluxing toluene or xylenes. Reduction of the resulting cyclic benzamide with lithium aluminium hydride in tetrahydrofuran (J. Med. Chem.1987, 30(12), 2208-2216) or diborane in tetrahydrofuran (J. Med. Chem.1980, 23(5), 506-511) affords the 1,2,3,4-tetrahydroisoquinoline. A variation of the Bischler-Napieralski reaction is the Pictet-Spengler synthesis (Org. React.1951, 6, 151). In this reaction amides, carbamates or sulfonamides of 2-phenylethanamines are heated with paraformaldehyde and strong proton acids (e.g. trifluoroacetic acid, sulfuric acid) or Lewis acids in a solvent (e.g. dichloromethane, toluene, formic acid) to give the 1,2,3,4-tetrahydroisoquinoline in a single step (Tetrahedron2002, 58(8), 1471-1478).
Preferably the 1,2,3,4-tetrahydroisoquinoline intermediate (VIIa) is synthesised by Route A shown in Scheme 2. This route is a Friedel-Craft-type reaction of N-[2-(3-bromophenyl)ethyl]-2,2,2-trifluoroacetamide with formaldehyde and sulfuric acid in acetic acid (Tetrahedron Lett.1996, 37(31), 5453-5456) giving a mixture of the 6-bromo- and 8-bromoisomer in a ratio of 3 to 1. Replacement of the trifluoroacetamide group with a BOC-group gives (VIIa). The regioisomers are not conveniently separated at this stage.
The 1,2,3,4-tetrahydro-2,7-naphthyridine Intermediate (VIIB)
In contrast to the 1,2,3,4-tetrahydroisoquinolines, there are rather few examples of synthetic methods for 1,2,3,4-tetrahydro-2,7-naphthyridines in the literature. One important method to prepare 1,2,3,4-tetrahydro-2,7-naphthyridine is the regio-selective catalytic reduction of 2,7-naphthyridine (Eur. J. Med. Chem. Ther.1996, 31(11), 875-888). The synthesis of 2,7-naphthyridine and some derivatives thereof has been described in the literature. One classical route involves several steps and starts with the acid catalysed condensation of malononitrile with diethyl 1,3-acetonedicarboxylate (J. Chem. Soc.1960, 3513-3515; see alsoJ. Heterocycl. Chem.1970, 7, 419-421). A slightly different route to 2,7-naphthyridine involves oxidation of 4-formyl-2,7-naphthyridine to give 2,7-naphthyridine-4-carboxylic acid followed by decarboxylation (Synthesis 1973, 46-47). A completely different method is based on the internal Diels-Alder reaction of N-(ethoxycarbonyl)-N-(but-3-ynyl)amino-methylpyrazine and gives a mixture of 1,2,3,4-tetrahydro-2,7-naphthyridine and 5,6,7,8-tetrahydro-1,7-naphthyridine after hydrolysis of the carbamate group (WO 02/064574).
Preferably the 1,2,3,4-tetrahydro-2,7-naphthyridine intermediate (VIIb) can be synthesised as shown in Schemes 3 and 4. In Route B, commercially available 6-methoxynicotinaldehyde is treated successively with the lithium salt of N,N,N′-trimethylethylenediamine, then n-BuLi in hexanes and finally iodine to afford the 4-iodo-6-methoxynicotinaldehyde (cf.Tetrahedron Lett.1993, 34(39), 6173-6176). The iodo compound is coupled with trimethylsilylacetylene under usual Sonagashira-Hagihara conditions (Synthesis1980, 627-630) and the resulting 6-methoxy-4-[(trimethylsilyl)ethynyl]nicotinaldehyde is condensed with ammonium hydroxide in ethanol to give 3-methoxy-2,7-naphthyridine (Synthesis1999, 2, 306-311). Regioselective catalytical reduction (cf.Eur. J. Med. Chem. Ther.1996, 31(11), 875-888) affords 6-methoxy-1,2,3,4-tetrahydro-2,7-naphthyridine. Demethylation and N-protection with BOC-anhydride and finally treatment of the resulting tert-butyl 6-hydroxy-3,4-dihydro-2,7-naphthyridine-2(1H)-carboxylate with triflic anhydride in a two-phase system gives (VIIb).
In Route C, commercially available 5-bromo-2-methoxy-4-methylpyridine in anhydrous tetrahydrofuran is metallated with n-BuLi and then treated with N,N-dimethylformamide to afford 6-methoxy-4-methylnicotinaldehyde. This was converted to the tert-butylimine with tert-butylamine in dichloromethane. Metallation with lithium 2,2,6,6-tetramethylpiperidide (Li-TMP) (cf.J. Org. Chem.1993, 58, 2463-2467) and addition of N,N-dimethylformamide affords the iminoacetaldehyde which is reduced with sodium cyanoborohydride in methanol to give 2-tert-butyl-6-methoxy-1,2,3,4-tetrahydro-2,7-naphthyridine. Cleavage of the methyl group with refluxing 48% hydrobromic acid and treatment with triflic anhydride in the presence of base gives (VIIb) protected as the tert-butylamine.
It will be appreciated by those skilled in the art that in the processes of the present invention certain potentially reactive functional groups such as hydroxyl or amino groups in the starting reagents or intermediate compounds may need to be protected by suitable protecting groups. Thus, the preparation of the compounds of the invention may involve, at various stages, the addition and removal of one or more protecting groups.
Suitable protecting groups and details of processes for adding and removing such groups are described in ‘Protective Groups in Organic Chemistry’, edited by J. W. F. McOmie, Plenum Press (1973) and ‘Protective Groups in Organic Synthesis’, 3rd edition, T. W. Greene and P. G. M. Wuts, Wiley-Interscience (1999).
The compounds of the invention and intermediates thereto may be isolated from their reaction mixtures and, if necessary further purified, by using standard techniques.
The present invention will now be further explained by reference to the following illustrative examples.
General Methods
1H NMR and13C NMR spectra were recorded on a Varian Inova 400 MHz or a Varian Mercury-VX 300 MHz instrument. The central peaks of chloroform-d (δH7.27 ppm), dimethylsulfoxide-d6(δH2.50 ppm), acetonitrile-d3(δH1.95 ppm) or methanol-d4(δH3.31 ppm) were used as internal references. Column chromatography was carried out using silica gel (0.040-0.063 mm, Merck) with a slight over-pressure (0.2-0.4 bars) applied on the column. A Kromasil KR-100-5-C18column (250×20 mm, Akzo Nobel) and mixtures of acetonitrile/water with 0.1% TFA at a flow rate of 10 mL/min were used for preparative HPLC. Unless stated otherwise, starting materials were commercially available. All solvents and commercial reagents were of laboratory grade and were used as received. The organic phases from extractions were dried over anhydrous sodium sulfate if not stated otherwise. Organic phases or solutions were concentrated by rotary evaporation. Yields were not optimised.
The Following Method was Used for LC-MS Analysis:
Instrument Agilent 1100; Column Waters Symmetry 2.1×30 mm; Mass APCI; Flow rate 0.7 mL/min; Wavelength 254 or 220 nm; Solvent A: water+0.1% TFA; Solvent B: acetonitrile+0.1% TFA; Gradient 15-95%/B 2.7 min, 95% B 0.3 min.
The Following Method was Used for GC-MS Analysis:
Instrument Hewlett Packard 5890 Series II; Column Agilent HP-5 (30 m×0.32 mm ID); Mass selective detector Hewlett Packard 5971 Series; Pressure 55 kPa He; Oven program 100° C. (3 min) to 300° C., 25° C./min.
Abbreviations:BOC-anhydridedi-tert-butyl dicarbonaten-BuLin-butyl lithiumDCMdichloromethaneDIPEAN,N-diisopropylethylamineDMFN,N-dimethylformamideDMSOdimethylsulfoxideEtOAcethyl acetateEtOHethanolGC-MSgas chromatography-mass spectrometryLDAlithium diisopropylamideMeOHmethanolLC-MSliquid chromatography-mass spectroscopyPdCl2× dppf1,1′-bis(diphenylphosphino)ferrocenepalladium(II)dichlorideRTroom temperature, normally 20 to 22° C.TEAtriethylamineTHFtetrahydrofuranTBMEtert-butyl methyl etherTFAtrifluoroacetic acidTriflic anhydridetrifluoromethanesulfonic anhydride (Tf2O)
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SUMMARY: CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national phase application under 35 U.S.C. § 371 of PCT International Application No. PCT/SE2005/001917, filed Dec. 14. 2005, which claims priority to Swedish Application Serial No. 0403085-4, filed Dec. 17, 2004.
The present invention relates to novel hydantoin derivatives, processes for their preparation, pharmaceutical compositions containing them and their use in therapy.
Metalloproteinases are a superfamily of proteinases (enzymes) whose numbers in recent years have increased dramatically. Based on structural and functional considerations these enzymes have been classified into families and subfamilies as described in N. M. Hooper (1994) FEBS Letters 354:1-6. Examples of metalloproteinases include the matrix metalloproteinases (MMPs) such as the collagenases (MMP1, MMP8, MMP13), the gelatinases (MMP2, MMP9), the stromelysins (MMP3, MMP10, MMP11), matrilysin (MMP7), metalloelastase (MMP12), enamelysin (MMP19), the MT-MMPs (MMP14, MMP15, MMP16, MMP17); the reprolysin or adamalysin or MDC family which includes the secretases and sheddases such as TNF converting enzymes (ADAM10 and TACE); the astacin family which include enzymes such as procollagen processing proteinase (PCP); and other metalloproteinases such as aggrecanase, the endothelin converting enzyme family and the angiotensin converting enzyme family.
Metalloproteinases are believed to be important in a plethora of physiological disease processes that involve tissue remodelling such as embryonic development, bone formation and uterine remodelling during menstruation. This is based on the ability of the metalloproteinases to cleave a broad range of matrix substrates such as collagen, proteoglycan and fibronectin. Metalloproteinases are also believed to be important in the processing, or secretion, of biological important cell mediators, such as tumour necrosis factor (TNF); and the post translational proteolysis processing, or shedding, of biologically important membrane proteins, such as the low affinity IgE receptor CD23 (for a more complete list see N. M. Hooper et al., (1997) Biochem. J. 321:265-279).
Metalloproteinases have been associated with many diseases or conditions. Inhibition of the activity of one or more metalloproteinases may well be of benefit in these diseases or conditions, for example: various inflammatory and allergic diseases such as, inflammation of the joint (especially rheumatoid arthritis, osteoarthritis and gout), inflammation of the gastro-intestinal tract (especially inflammatory bowel disease, ulcerative colitis and gastritis), inflammation of the skin (especially psoriasis, eczema, dermatitis); in tumour metastasis or invasion; in disease associated with uncontrolled degradation of the extracellular matrix such as osteoarthritis; in bone resorptive disease (such as osteoporosis and Paget's disease); in diseases associated with aberrant angiogenesis; the enhanced collagen remodelling associated with diabetes, periodontal disease (such as gingivitis), corneal ulceration, ulceration of the skin, post-operative conditions (such as colonic anastomosis) and dermal wound healing; demyelinating diseases of the central and peripheral nervous systems (such as multiple sclerosis); Alzheimer's disease; extracellular matrix remodelling observed in cardiovascular diseases such as restenosis and atherosclerosis; asthma; rhinitis; and chronic obstructive pulmonary diseases (COPD).
MMP12, also known as macrophage elastase or metalloelastase, was initially cloned in the mouse by Shapiro et al [1992, Journal of Biological Chemistry 267: 4664] and in man by is the same group in 1995. MMP12 is preferentially expressed in activated macrophages, and has been shown to be secreted from alveolar macrophages from smokers [Shapiro et al, 1993, Journal of Biological Chemistry, 268: 23824] as well as in foam cells in atherosclerotic lesions [Matsumoto et al, 1998, Am. J. Pathol. 153: 109]. A mouse model of COPD is based on challenge of mice with cigarette smoke for six months, two cigarettes a day six days a week. Wild-type mice developed pulmonary emphysema after this treatment. When MMP12 knock-out mice were tested in this model they developed no significant emphysema, strongly indicating that MMP12 is a key enzyme in the COPD pathogenesis. The role of MMPs such as MMP12 in COPD (emphysema and bronchitis) is discussed in Anderson and Shinagawa, 1999, Current Opinion in Anti-inflammatory and Immunomodulatory Investigational Drugs 1(1): 29-38. It was recently discovered that smoking increases macrophage infiltration and macrophage-derived MMP-12 expression in human carotid artery plaques Kangavari [Matetzky S, Fishbein M C et al., Circulation 102:(18, 36-39 Suppl. S, Oct. 31, 2000].
MMP9 (Gelatinase B; 92 kDa TypeIV Collagenase; 92 kDa Gelatinase) is a secreted protein which was first purified, then cloned and sequenced, in 1989 [S. M. Wilhelm et al (1989) J. Biol. Chem. 264 (29): 17213-17221; published erratum in J. Biol. Chem. (1990) 265 (36): 22570]. A recent review of MMP9 provides an excellent source for detailed information and references on this protease: T. H. Vu & Z. Werb (1998) (In: Matrix Metalloproteinases, 1998, edited by W. C. Parks & R. P. Mecham, pp. 115-148, Academic Press. ISBN 0-12-545090-7). The following points are drawn from that review by T. H. Vu & Z. Werb (1998).
The expression of MMP9 is restricted normally to a few cell types, including trophoblasts, osteoclasts, neutrophils and macrophages. However, the expression can be induced in these same cells and in other cell types by several mediators, including exposure of the cells to growth factors or cytokines. These are the same mediators often implicated in initiating an inflammatory response. As with other secreted MMPs, MMP9 is released as an inactive Pro-enzyme which is subsequently cleaved to form the enzymatically active enzyme. The proteases required for this activation in vivo are not known. The balance of active MMP9 versus inactive enzyme is further regulated in vivo by interaction with is TIMP-1 (Tissue Inhibitor of Metalloproteinases-1), a naturally-occurring protein. TIMP-1 binds to the C-terminal region of MMP9, leading to inhibition of the catalytic domain of MMP9. The balance of induced expression of ProMMP9, cleavage of Pro- to active MMP9 and the presence of TIMP-1 combine to determine the amount of catalytically active MMP9 which is present at a local site. Proteolytically active MMP9 attacks substrates which include gelatin, elastin, and native Type IV and Type V collagens; it has no activity against native Type I collagen, proteoglycans or laminins.
There has been a growing body of data implicating roles for MMP9 in various physiological and pathological processes. Physiological roles include the invasion of embryonic trophoblasts through the uterine epithelium in the early stages of embryonic implantation; some role in the growth and development of bones; and migration of inflammatory cells from the vasculature into tissues.
MMP9 release, measured using enzyme immunoassay, was significantly enhanced in fluids and in AM supernantants from untreated asthmatics compared with those from other populations [Am. J. Resp. Cell & Mol. Biol., November 1997, 17 (5):583-591]. Also, increased MMP9 expression has been observed in certain other pathological conditions, thereby implicating MMP9 in disease processes such as COPD, arthritis, tumour metastasis, Alzheimer's disease, multiple sclerosis, and plaque rupture in atherosclerosis leading to acute coronary conditions such as myocardial infarction.
A number of metalloproteinase inhibitors are known (see, for example, the reviews of MMP inhibitors by Beckett R. P. and Whittaker M., 1998, Exp. Opin. Ther. Patents, 8(3):259-282; and by Whittaker M. et al, 1999, Chemical Reviews 99(9):2735-2776).
WO 02/074767 discloses hydantoin derivatives of formula
that are useful as MMP inhibitors, particularly as potent MMP12 inhibitors.
We now disclose a further group of hydantoin derivatives that are inhibitors of metalloproteinases and are of particular interest in inhibiting MMPs such as MMP12 and MMP9. The compounds of the present invention have beneficial potency, selectivity and/or pharmacokinetic properties.
In accordance with the present invention, there are provided compounds of formula (I)
whereinR1represents cyclobutyl or cyclopropyl; said cyclopropyl group being optionally further substituted by CH3, CN or one or two fluoro atoms;R2represents C1 to 3 alkyl or cyclopropyl; andA, A1and B independently represent CH or N;
and pharmaceutically acceptable salts thereof.
The compounds of formula (I) may exist in enantiomeric forms. It is to be understood that all enantiomers, diastereomers, racemates and mixtures thereof are included within the scope of the invention.
Compounds of formula (I) may also exist in various tautomeric forms. All possible tautomeric forms and mixtures thereof are included within the scope of the invention.
In one embodiment, R1represents cyclopropyl; said cyclopropyl group being optionally further substituted by one or two fluoro atoms.
In one embodiment, R1represents cyclopropyl.
In one embodiment, R2represents methyl or ethyl. In one embodiment, R2represents methyl.
In one embodiment, A and A1each represent N. In another embodiment, A represents N and A1represents-CH.
In one embodiment, B represents N. In another embodiment, B represents CH.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A and A1each represent N; and B represents CH.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A and A1each represent N; and B represents N.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A represents N and A1represents CH; and B represents N.
In one embodiment, R1represents cyclopropyl; R2represents methyl or ethyl; A represents N and A1represents CH; and B represents CH.
In one embodiment, R1represents cyclopropyl; said cyclopropyl group being optionally is further substituted by CH3, CN or one or two fluoro atoms; R2represents C1 to 3 alkyl; and A, A1and B independently represent CH or N.
Unless otherwise indicated, the term “C1 to 3 alkyl” referred to herein denotes a straight or branched chain alkyl group having from 1 to 3 carbon atoms. Examples of such groups include methyl, ethyl, n-propyl and i-propyl.
Examples of a cyclopropyl ring optionally further substituted by one or two fluoro atoms include 1-fluoro-1-cyclopropyl, 2,2-difluoro-1-cyclopropyl and 2,3-difluoro-1-cyclopropyl:
Examples of compounds of the invention include:(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-({[6-(6-cyclopropylpyridin-3-yl)-3,4-dihydro-2,7-naphthyridin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydro-2,7-naphthyridin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydro-2,7-naphthyridin-2(1H)-yl]sulfonyl}methyl)-5-ethylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)-5-ethylimidazolidine-2,4-dione;(5S)-5-({[6-(2-cyclobutylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;(5S)-5-methyl-5-({[6-[2-(1-methylcyclopropyl)pyrimidin-5-yl]-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione;(5S)-5-Cyclopropyl-5-({[6-(2-cyclopropylpyrimidin-5-yl)-3,4-dihydroisoquinolin-2(1H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione;
and pharmaceutically acceptable salts thereof.
Each exemplified compound represents a particular and independent aspect of the invention.
The compounds of formula (I) may exist in enantiomeric forms. Therefore, all enantiomers, diastereomers, racemates and mixtures thereof are included within the scope of the invention. The various optical isomers may be isolated by separation of a racemic mixture of the compounds using conventional techniques, for example, fractional crystallisation, or HPLC. Alternatively the optical isomers may be obtained by asymmetric synthesis, or by synthesis from optically active starting materials.
Where optically isomers exist in the compounds of the invention, we disclose all individual optically active forms and combinations of these as individual specific embodiments of the invention, as well as their corresponding racemates.
Preferably the compounds of formula (I) have (5S)-stereochemistry as shown below:
Where tautomers exist in the compounds of the invention, we disclose all individual tautomeric forms and combinations of these as individual specific embodiments of the invention.
The present invention includes compounds of formula (I) in the form of salts. Suitable salts include those formed with organic or inorganic acids or organic or inorganic bases. Such is salts will normally be pharmaceutically acceptable salts although non-pharmaceutically acceptable salts may be of utility in the preparation and purification of particular compounds. Such salts include acid addition salts such as hydrochloride, hydrobromide, citrate, tosylate and maleate salts and salts formed with phosphoric acid or sulphuric acid.
In another aspect suitable salts are base salts such as an alkali metal salt, for example, sodium or potassium, an alkaline earth metal salt, for example, calcium or magnesium, or an organic amine salt, for example, triethylamine.
Salts of compounds of formula (I) may be formed by reacting the free base or another salt thereof with one or more equivalents of an appropriate acid or base.
The compounds of formula (I) are useful because they possess pharmacological activity in animals and are thus potentially useful as pharmaceuticals. In particular, the compounds of the invention are metalloproteinase inhibitors and may thus be used in the treatment of diseases or conditions mediated by MMP12 and/or MMP9 such as asthma, rhinitis, chronic obstructive pulmonary diseases (COPD), arthritis (such as rheumatoid arthritis and osteoarthritis), atherosclerosis and restenosis, cancer, invasion and metastasis, diseases involving tissue destruction, loosening of hip joint replacements, periodontal disease, fibrotic disease, infarction and heart disease, liver and renal fibrosis, endometriosis, diseases related to the weakening of the extracellular matrix, heart failure, aortic aneurysms, CNS related diseases such as Alzheimer's disease and multiple sclerosis (MS), and haematological disorders.
In general, the compounds of the present invention are potent inhibitors of MMP9 and MMP12. The compounds of the present invention also show good selectivity with respect to a relative lack of inhibition of various other MMPs such as MMP8, MMP14 and MMP19.
Accordingly, the present invention provides a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined for use in therapy.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in therapy.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of diseases or conditions in which inhibition of MMP12 and/or MMP9 is beneficial.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of inflammatory disease.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of an obstructive airways disease such as asthma or COPD.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, as hereinbefore defined in the manufacture of a medicament for use in the treatment of rheumatoid arthritis, osteoarthritis, atherosclerosis, cancer or multiple sclerosis.
In the context of the present specification, the term “therapy” also includes “prophylaxis” unless there are specific indications to the contrary. The terms “therapeutic” and “therapeutically” should be construed accordingly.
Prophylaxis is expected to be particularly relevant to the treatment of persons who have suffered a previous episode of, or are otherwise considered to be at increased risk of, the disease or condition in question. Persons at risk of developing a particular disease or condition generally include those having a family history of the disease or condition, or those who have been identified by genetic testing or screening to be particularly susceptible to developing the disease or condition.
The invention further provides a method of treating a disease or condition in which inhibition of MMP12 and/or MMP9 is beneficial which comprises administering to a patient a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined.
The invention also provides a method of treating an obstructive airways disease, for example, asthma or COPD, which comprises administering to a patient a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined.
For the above-mentioned therapeutic uses the dosage administered will, of course, vary with the compound employed, the mode of administration, the treatment desired and the disorder to be treated. The daily dosage of the compound of formula (I)/salt (active ingredient) may be in the range from 0.001 mg/kg to 75 mg/kg, in particular from 0.5 mg/kg to 30 mg/kg. This daily dose may be given in divided doses as necessary. Typically unit dosage forms will contain about 1 mg to 500 mg of a compound of this invention.
The compounds of formula (I) and pharmaceutically acceptable salts thereof may be used on their own but will generally be administered in the form of a pharmaceutical composition in which the formula (I) compound/salt (active ingredient) is in association with a pharmaceutically acceptable adjuvant, diluent or carrier. Depending on the mode of administration, the pharmaceutical composition will preferably comprise from 0.05 to 99% w (percent by weight), more preferably from 0.10 to 70% w, of active ingredient, and, from 1 to 99.95% w, more preferably from 30 to 99.90% w, of a pharmaceutically acceptable adjuvant, diluent or carrier, all percentages by weight being based on total composition. Conventional procedures for the selection and preparation of suitable pharmaceutical formulations are described in, for example, “Pharmaceuticals—The Science of Dosage Form Designs”, M. E. Aulton, Churchill Livingstone, 1988.
Thus, the present invention also provides a pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined in association with a pharmaceutically acceptable adjuvant, diluent or carrier.
The invention further provides a process for the preparation of a pharmaceutical composition of the invention which comprises mixing a compound of formula (I) or a pharmaceutically acceptable salt thereof as hereinbefore defined with a pharmaceutically acceptable adjuvant, diluent or carrier.
The pharmaceutical compositions of this invention may be administered in a standard manner for the disease or condition that it is desired to treat, for example by oral, topical, parenteral, buccal, nasal, vaginal or rectal administration or by inhalation. For these purposes the compounds of this invention may be formulated by means known in the art into the form of, for example, tablets, capsules, aqueous or oily solutions, suspensions, emulsions, creams, ointments, gels, nasal sprays, suppositories, finely divided powders or aerosols for inhalation, and for parenteral use (including intravenous, intramuscular or infusion) sterile aqueous or oily solutions or suspensions or sterile emulsions.
In addition to the compounds of the present invention the pharmaceutical composition of this invention may also contain, or be co-administered (simultaneously or sequentially) with, one or more pharmacological agents of value in treating one or more diseases or conditions referred to hereinabove such as “Symbicort” (trade mark) product.
The present invention further provides a process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof as defined above which, comprises:a) reaction of a compound of formula (II)
wherein R2is as defined in formula (I) and L1represents a leaving group, with a compound of formula (III) (or a salt thereof)
wherein R1, A, A1and B are as defined in formula (I); orb) reaction of a compound of formula (V)
wherein R2and B are as defined in formula (I) and LG is a leaving group; with a boronic acid derivative of formula (XII)
wherein R1, A and A1are as defined in formula (I); orc) reaction of a compound of formula (IX)
wherein R1, R2, A, A1and B are as defined in formula (I); with ammonium carbonate and potassium cyanide;
and optionally thereafter forming a pharmaceutically acceptable salt thereof.
In the above process (a), suitable leaving groups L1include halo, particularly chloro or trifluoromethylsulfonate. The reaction is preferably performed in a suitable solvent optionally in the presence of an added base for a suitable period of time, typically 0.5 to 16 h, at ambient to reflux temperature. Typically solvents such as N,N-dimethylformamide, pyridine, tetrahydrofuran, acetonitrile, N-methylpyrrolidine or dichloromethane are used. When used, the added base may be an organic base such as triethylamine, N,N-diisopropylethylamine, N-methylmorpholine or pyridine, or an inorganic base such as an alkali metal carbonate. The reaction is typically conducted at ambient temperature for 0.5 to 16 h, or until completion of the reaction has been achieved, as determined by chromatographic or spectroscopic methods. Reactions of sulfonyl halides with various primary and secondary amines are well known in the literature, and the variations of the conditions will be evident for those skilled in the art.
Sulfonylchlorides of formula (II) wherein L1represents chloro and R2represents Me are disclosed in WO 02/074767 and references cited therein. Corresponding compounds wherein R2represents C1 to 3 alkyl may be prepared using analogous methods.
Suitable processes for the preparation of compounds of formula (I) are described in a retrosynthetic way in Scheme 1.
In Scheme 1, protecting groups (PG) can be either carbamates (e.g. tert-butoxycarbamate), amides (e.g. trifluoroacetyl) or alkyl (e.g. tert-butyl or benzyl). Leaving groups (LG) can be either chloride, bromide, iodide or trifluoromethylsulfonate. In the palladium-catalysed Suzuki couplings, either boronic acids or pinacolboronates may be used. Intermediate (IVa-c) can be prepared by standard Suzuki coupling (Chem. Rev.1995, 95, 2457) between an electrophile (VIIa-c) and a boron reagent (XII), or the other way around, between an electrophile (XI) and a boron reagent (VIIIa-c). The latter can be obtained from (VIIa-c) using standard Miyaura conditions (J. Org. Chem.1995, 60, 7508-7510). Deprotection of (IVa-c) either by hydrogen chloride in methanol (PG=tert-butoxycarbonyl) or refluxing 1-chloroethyl chloroformate/refluxing methanol (PG=tert-butyl or benzyl) (Synlett.1993, 195-196) gives amine (IIIa-c) as a hydrochloride salt. The free base can be obtained by treatment of (IIIa-c) with base and extraction with an organic solvent such as ethyl acetate is or toluene. Reacting (IIIa-c) either as a salt or base in a suitable solvent (e.g. acetonitrile, tetrahydrofuran, N-methylpyrrolidine or N,N-dimethylformamide) with the sulfonyl chloride (II) in the presence of a tertiary amine (e.g. triethylamine, pyridine or N,N-diisopropylethylamine) for 0.5 to 16 hours produces compounds of formula (I).
An alternative route to compounds of formula (I) from intermediate (IIIa-c) via methanesulfonamide (Xa-c) and ketone (IXa-c) has been previously described (WO 02/074767). Briefly, treatment of (IIIa-c) with methansulfonyl chloride and a tertiary amine (e.g. triethylamine, pyridine or N,N-diisopropylethylamine) in a suitable solvent (e.g. dichloromethane or tetrahydrofuran) produces the methansulfonamide (Xa-c) which in turn can be transformed into the ketone (IXa-c) using standard procedures. Heating ketone (IXa-c) with ammonium carbonate and potassium cyanide in 50% aqueous ethanol in a sealed vial at 80-90° C. for 1 to 5 hours gives a racemic hydantoin that can be resolved by chiral chromatography (e.g. on OD-H with 100% ethanol).
In a third route, intermediate (VIIa-c) is deprotected as described above to give amine (VIa-c) as a hydrochloride salt. The free base can be isolated by treatment with base and extraction with an organic solvent e.g. ethyl acetate or toluene. Reacting (Via-c) either as a salt or base in a suitable solvent (e.g. acetonitrile, tetrahydrofuran, N-methylpyrrolidine or N,N-dimethylformamide) with sulfonyl chloride (II) in the presence of a tertiary amine (e.g. triethylamine, pyridine or N,N-diisopropylethylamine) for 0.5 to 16 hours produces chiral sulfonamide (Va-c). The latter can be coupled with boron reagent (XII) using standard Suzuki conditions to give compounds of formula (I).
Intermediates (VIIa-b) are conveniently prepared using the following methods.
The 1,2,3,4-tetrahydroisoquinoline Intermediate (VIIa)
Methods for the synthesis of 1,2,3,4-tetrahydroisoquinolines are well known in the literature. The classical route is the Pomeranz-Fritz reaction of benzaldehydes with a diacetal protected aminoacetaldehyde (Org. React.1951, 6, 191) yielding the isoquinoline nucleus which upon catalytical reduction gives 1,2,3,4-tetrahydro-isoquinolines. Another route is the Bischler-Napieralski reaction (Org. React.1951, 6, 74) of a carbamate of 2-phenylethanamines with phosphoryl chloride in refluxing toluene or xylenes. Reduction of the resulting cyclic benzamide with lithium aluminium hydride in tetrahydrofuran (J. Med. Chem.1987, 30(12), 2208-2216) or diborane in tetrahydrofuran (J. Med. Chem.1980, 23(5), 506-511) affords the 1,2,3,4-tetrahydroisoquinoline. A variation of the Bischler-Napieralski reaction is the Pictet-Spengler synthesis (Org. React.1951, 6, 151). In this reaction amides, carbamates or sulfonamides of 2-phenylethanamines are heated with paraformaldehyde and strong proton acids (e.g. trifluoroacetic acid, sulfuric acid) or Lewis acids in a solvent (e.g. dichloromethane, toluene, formic acid) to give the 1,2,3,4-tetrahydroisoquinoline in a single step (Tetrahedron2002, 58(8), 1471-1478).
Preferably the 1,2,3,4-tetrahydroisoquinoline intermediate (VIIa) is synthesised by Route A shown in Scheme 2. This route is a Friedel-Craft-type reaction of N-[2-(3-bromophenyl)ethyl]-2,2,2-trifluoroacetamide with formaldehyde and sulfuric acid in acetic acid (Tetrahedron Lett.1996, 37(31), 5453-5456) giving a mixture of the 6-bromo- and 8-bromoisomer in a ratio of 3 to 1. Replacement of the trifluoroacetamide group with a BOC-group gives (VIIa). The regioisomers are not conveniently separated at this stage.
The 1,2,3,4-tetrahydro-2,7-naphthyridine Intermediate (VIIB)
In contrast to the 1,2,3,4-tetrahydroisoquinolines, there are rather few examples of synthetic methods for 1,2,3,4-tetrahydro-2,7-naphthyridines in the literature. One important method to prepare 1,2,3,4-tetrahydro-2,7-naphthyridine is the regio-selective catalytic reduction of 2,7-naphthyridine (Eur. J. Med. Chem. Ther.1996, 31(11), 875-888). The synthesis of 2,7-naphthyridine and some derivatives thereof has been described in the literature. One classical route involves several steps and starts with the acid catalysed condensation of malononitrile with diethyl 1,3-acetonedicarboxylate (J. Chem. Soc.1960, 3513-3515; see alsoJ. Heterocycl. Chem.1970, 7, 419-421). A slightly different route to 2,7-naphthyridine involves oxidation of 4-formyl-2,7-naphthyridine to give 2,7-naphthyridine-4-carboxylic acid followed by decarboxylation (Synthesis 1973, 46-47). A completely different method is based on the internal Diels-Alder reaction of N-(ethoxycarbonyl)-N-(but-3-ynyl)amino-methylpyrazine and gives a mixture of 1,2,3,4-tetrahydro-2,7-naphthyridine and 5,6,7,8-tetrahydro-1,7-naphthyridine after hydrolysis of the carbamate group (WO 02/064574).
Preferably the 1,2,3,4-tetrahydro-2,7-naphthyridine intermediate (VIIb) can be synthesised as shown in Schemes 3 and 4. In Route B, commercially available 6-methoxynicotinaldehyde is treated successively with the lithium salt of N,N,N′-trimethylethylenediamine, then n-BuLi in hexanes and finally iodine to afford the 4-iodo-6-methoxynicotinaldehyde (cf.Tetrahedron Lett.1993, 34(39), 6173-6176). The iodo compound is coupled with trimethylsilylacetylene under usual Sonagashira-Hagihara conditions (Synthesis1980, 627-630) and the resulting 6-methoxy-4-[(trimethylsilyl)ethynyl]nicotinaldehyde is condensed with ammonium hydroxide in ethanol to give 3-methoxy-2,7-naphthyridine (Synthesis1999, 2, 306-311). Regioselective catalytical reduction (cf.Eur. J. Med. Chem. Ther.1996, 31(11), 875-888) affords 6-methoxy-1,2,3,4-tetrahydro-2,7-naphthyridine. Demethylation and N-protection with BOC-anhydride and finally treatment of the resulting tert-butyl 6-hydroxy-3,4-dihydro-2,7-naphthyridine-2(1H)-carboxylate with triflic anhydride in a two-phase system gives (VIIb).
In Route C, commercially available 5-bromo-2-methoxy-4-methylpyridine in anhydrous tetrahydrofuran is metallated with n-BuLi and then treated with N,N-dimethylformamide to afford 6-methoxy-4-methylnicotinaldehyde. This was converted to the tert-butylimine with tert-butylamine in dichloromethane. Metallation with lithium 2,2,6,6-tetramethylpiperidide (Li-TMP) (cf.J. Org. Chem.1993, 58, 2463-2467) and addition of N,N-dimethylformamide affords the iminoacetaldehyde which is reduced with sodium cyanoborohydride in methanol to give 2-tert-butyl-6-methoxy-1,2,3,4-tetrahydro-2,7-naphthyridine. Cleavage of the methyl group with refluxing 48% hydrobromic acid and treatment with triflic anhydride in the presence of base gives (VIIb) protected as the tert-butylamine.
It will be appreciated by those skilled in the art that in the processes of the present invention certain potentially reactive functional groups such as hydroxyl or amino groups in the starting reagents or intermediate compounds may need to be protected by suitable protecting groups. Thus, the preparation of the compounds of the invention may involve, at various stages, the addition and removal of one or more protecting groups.
Suitable protecting groups and details of processes for adding and removing such groups are described in ‘Protective Groups in Organic Chemistry’, edited by J. W. F. McOmie, Plenum Press (1973) and ‘Protective Groups in Organic Synthesis’, 3rd edition, T. W. Greene and P. G. M. Wuts, Wiley-Interscience (1999).
The compounds of the invention and intermediates thereto may be isolated from their reaction mixtures and, if necessary further purified, by using standard techniques.
The present invention will now be further explained by reference to the following illustrative examples.
General Methods
1H NMR and13C NMR spectra were recorded on a Varian Inova 400 MHz or a Varian Mercury-VX 300 MHz instrument. The central peaks of chloroform-d (δH7.27 ppm), dimethylsulfoxide-d6(δH2.50 ppm), acetonitrile-d3(δH1.95 ppm) or methanol-d4(δH3.31 ppm) were used as internal references. Column chromatography was carried out using silica gel (0.040-0.063 mm, Merck) with a slight over-pressure (0.2-0.4 bars) applied on the column. A Kromasil KR-100-5-C18column (250×20 mm, Akzo Nobel) and mixtures of acetonitrile/water with 0.1% TFA at a flow rate of 10 mL/min were used for preparative HPLC. Unless stated otherwise, starting materials were commercially available. All solvents and commercial reagents were of laboratory grade and were used as received. The organic phases from extractions were dried over anhydrous sodium sulfate if not stated otherwise. Organic phases or solutions were concentrated by rotary evaporation. Yields were not optimised.
The Following Method was Used for LC-MS Analysis:
Instrument Agilent 1100; Column Waters Symmetry 2.1×30 mm; Mass APCI; Flow rate 0.7 mL/min; Wavelength 254 or 220 nm; Solvent A: water+0.1% TFA; Solvent B: acetonitrile+0.1% TFA; Gradient 15-95%/B 2.7 min, 95% B 0.3 min.
The Following Method was Used for GC-MS Analysis:
Instrument Hewlett Packard 5890 Series II; Column Agilent HP-5 (30 m×0.32 mm ID); Mass selective detector Hewlett Packard 5971 Series; Pressure 55 kPa He; Oven program 100° C. (3 min) to 300° C., 25° C./min.
Abbreviations:BOC-anhydridedi-tert-butyl dicarbonaten-BuLin-butyl lithiumDCMdichloromethaneDIPEAN,N-diisopropylethylamineDMFN,N-dimethylformamideDMSOdimethylsulfoxideEtOAcethyl acetateEtOHethanolGC-MSgas chromatography-mass spectrometryLDAlithium diisopropylamideMeOHmethanolLC-MSliquid chromatography-mass spectroscopyPdCl2× dppf1,1′-bis(diphenylphosphino)ferrocenepalladium(II)dichlorideRTroom temperature, normally 20 to 22° C.TEAtriethylamineTHFtetrahydrofuranTBMEtert-butyl methyl etherTFAtrifluoroacetic acidTriflic anhydridetrifluoromethanesulfonic anhydride (Tf2O)
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7709816 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor fabrication, and more particularly to systems and methods for monitoring and controlling the operation of extreme ultraviolet (EUV) light sources used in semiconductor fabrication.
2. Description of Related Art
Semiconductor fabrication typically involves dozens, or even hundreds of individual operations. In general terms, these operations can be classified as: layering, patterning, doping, and heat treatments. Among these, patterning (also referred to as “lithography”) is considered to be the most critical operation because it sets the physical dimensions of the resulting devices on the semiconductor wafer.
Patterning comprises a series of steps by which selected portions of material deposited on the wafer surface are removed, thus leaving a “pattern” thereon. The sequence of steps may be described as follows. First, a pattern is formed on a photomask or reticle—e.g., a glass or quartz plate having a thin layer of chrome thereon. Then, the photomask is imaged or printed onto a layer of photoresist deposited on the wafer. Etching agents remove portions of the wafer not covered by the photoresist, and the photoresist itself is removed in subsequent steps. The transfer of the pattern from the photomask onto the photoresist is performed using some form of light source or electromagnetic radiation.
The wavelength of the light source used during the lithography process is directly proportional to the size of the features that can ultimately be fabricated on the semiconductor wafer. Hence, the continuous desire to create increasingly small semiconductor devices has created a need for light sources capable of emitting very short wavelength radiation. One such light source is the Extreme Ultraviolet (EUV) plasma source. EUV radiation may be generated in the 13.5 nm wavelength range by a plasma-based process whereby a fuel material such as xenon, lithium, indium, tin, etc. is heated to high temperatures. This intense heat may be achieved through the use of a focused laser beam, plasma pinch electrodes applying high-energy, short-duration pulses, or the like.
Light produced by EUV sources provides a printing resolution in the order of nanometers. Extremely small features down to 25 nm have been satisfactorily imaged. It is, however, very difficult to monitor the performance of these sources. U.S. Patent Application Publication No. 2003/0058429 discloses an apparatus that attempts to measure the energy of an EUV photon system. The apparatus is designed to detect the in-band power of a pulsed or continuous source—i. e., at a wavelength between 11 and 15 nm—and filtering out the out-of-band radiation by several orders of magnitude.
The inventors hereof have recognized several significant drawbacks with existing EUV monitoring systems such as the one referred to above. First, multi-layer mirrors used in these systems quickly lose their reflectivity over time and frequently need to undergo expensive and time consuming calibration procedures, thus decreasing the overall productivity. Moreover, existing EUV systems must perform measurements in a high vacuum, which further adds to the cost and complexity of the system.
The shortcomings mentioned above are not intended to be exhaustive, but rather are among many that tend to impair the effectiveness of previously known techniques for monitoring energy from EUV sources. The problems listed above are sufficient to demonstrate that the methodologies appearing in the art have not been satisfactory, and that a significant need exists for the systems and methods described and claimed herein.
BRIEF SUMMARY OF THE INVENTION
The present invention provides systems and methods for monitoring and controlling the operation of light sources used in semiconductor fabrication. In one embodiment, a method comprises providing a semiconductor fabrication apparatus having a light source that emits in-band and out-of-band radiation, taking a first out-of-band radiation measurement, taking a second out-of-band radiation measurement, and controlling the in-band radiation of the light source, at least in part, based upon a comparison of the first and second out-of-band measurements.
In another embodiment, an apparatus comprises an electromagnetic detector operable to detect out-of-band EUV radiation emitted by an EUV plasma source, a spectrometer coupled to the electromagnetic detector and operable to measure at least one out-of-band radiation parameter based upon the out-of-band EUV radiation detected by the electromagnetic detector, and a controller coupled to the spectrometer and operable to monitor and control the operation of the plasma based EUV sources upon the at least one out-of-band radiation parameter measured by the spectrometer.
In yet another embodiment, a computer readable medium has a computer program recorded thereon that causes a computer to perform the steps of monitoring a first out-of-band radiation parameter collected from a first point of a light source apparatus used in a semiconductor fabrication process, monitoring a second out-of-band radiation parameter collected from a second point of the light source apparatus, and controlling an in-band output of the light source, at least in part, based upon a comparison of first and second out-of-band radiation parameters.
The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially,” “approximately,” “about,” and variations thereof are defined as being largely but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. In one non-limiting embodiment, the term substantially refers to ranges within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5% of what is specified.
The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways other than those specifically described herein.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor fabrication, and more particularly to systems and methods for monitoring and controlling the operation of extreme ultraviolet (EUV) light sources used in semiconductor fabrication.
2. Description of Related Art
Semiconductor fabrication typically involves dozens, or even hundreds of individual operations. In general terms, these operations can be classified as: layering, patterning, doping, and heat treatments. Among these, patterning (also referred to as “lithography”) is considered to be the most critical operation because it sets the physical dimensions of the resulting devices on the semiconductor wafer.
Patterning comprises a series of steps by which selected portions of material deposited on the wafer surface are removed, thus leaving a “pattern” thereon. The sequence of steps may be described as follows. First, a pattern is formed on a photomask or reticle—e.g., a glass or quartz plate having a thin layer of chrome thereon. Then, the photomask is imaged or printed onto a layer of photoresist deposited on the wafer. Etching agents remove portions of the wafer not covered by the photoresist, and the photoresist itself is removed in subsequent steps. The transfer of the pattern from the photomask onto the photoresist is performed using some form of light source or electromagnetic radiation.
The wavelength of the light source used during the lithography process is directly proportional to the size of the features that can ultimately be fabricated on the semiconductor wafer. Hence, the continuous desire to create increasingly small semiconductor devices has created a need for light sources capable of emitting very short wavelength radiation. One such light source is the Extreme Ultraviolet (EUV) plasma source. EUV radiation may be generated in the 13.5 nm wavelength range by a plasma-based process whereby a fuel material such as xenon, lithium, indium, tin, etc. is heated to high temperatures. This intense heat may be achieved through the use of a focused laser beam, plasma pinch electrodes applying high-energy, short-duration pulses, or the like.
Light produced by EUV sources provides a printing resolution in the order of nanometers. Extremely small features down to 25 nm have been satisfactorily imaged. It is, however, very difficult to monitor the performance of these sources. U.S. Patent Application Publication No. 2003/0058429 discloses an apparatus that attempts to measure the energy of an EUV photon system. The apparatus is designed to detect the in-band power of a pulsed or continuous source—i. e., at a wavelength between 11 and 15 nm—and filtering out the out-of-band radiation by several orders of magnitude.
The inventors hereof have recognized several significant drawbacks with existing EUV monitoring systems such as the one referred to above. First, multi-layer mirrors used in these systems quickly lose their reflectivity over time and frequently need to undergo expensive and time consuming calibration procedures, thus decreasing the overall productivity. Moreover, existing EUV systems must perform measurements in a high vacuum, which further adds to the cost and complexity of the system.
The shortcomings mentioned above are not intended to be exhaustive, but rather are among many that tend to impair the effectiveness of previously known techniques for monitoring energy from EUV sources. The problems listed above are sufficient to demonstrate that the methodologies appearing in the art have not been satisfactory, and that a significant need exists for the systems and methods described and claimed herein.
BRIEF SUMMARY OF THE INVENTION
The present invention provides systems and methods for monitoring and controlling the operation of light sources used in semiconductor fabrication. In one embodiment, a method comprises providing a semiconductor fabrication apparatus having a light source that emits in-band and out-of-band radiation, taking a first out-of-band radiation measurement, taking a second out-of-band radiation measurement, and controlling the in-band radiation of the light source, at least in part, based upon a comparison of the first and second out-of-band measurements.
In another embodiment, an apparatus comprises an electromagnetic detector operable to detect out-of-band EUV radiation emitted by an EUV plasma source, a spectrometer coupled to the electromagnetic detector and operable to measure at least one out-of-band radiation parameter based upon the out-of-band EUV radiation detected by the electromagnetic detector, and a controller coupled to the spectrometer and operable to monitor and control the operation of the plasma based EUV sources upon the at least one out-of-band radiation parameter measured by the spectrometer.
In yet another embodiment, a computer readable medium has a computer program recorded thereon that causes a computer to perform the steps of monitoring a first out-of-band radiation parameter collected from a first point of a light source apparatus used in a semiconductor fabrication process, monitoring a second out-of-band radiation parameter collected from a second point of the light source apparatus, and controlling an in-band output of the light source, at least in part, based upon a comparison of first and second out-of-band radiation parameters.
The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially,” “approximately,” “about,” and variations thereof are defined as being largely but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. In one non-limiting embodiment, the term substantially refers to ranges within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5% of what is specified.
The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways other than those specifically described herein.
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7645046 | CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not applicable.
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable.
SEQUENCE LISTING
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Present Disclosure
This disclosure relates generally to devices for redirecting light from a camera flash unit, and more particularly to a reflector unit capable of adapting camera flash light output as to direction, scope, color and other features and more especially to producing a softer but wider light beam.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Hughes, U.S. Pat. No. 7,360,909, discloses and teaches a new and improved photographic flash attachment, a light reflecting apparatus that is lightweight, flexible, easily attached and/or detached from a camera flash and conveniently stored in a rolled or folded configuration. The disclosed flash reflector is configured from a thin, flexible, planar polyurethane foam material, or any other suitable material, into an adjustable, generally concave configuration whereby adjusting the reflectors shape adjusts the power of the light it reflects to balance with the existing natural light or bounce off a ceiling thereby eliminating and/or reducing shadows about the photographic subject.
Petitjean, U.S. Pat. No. 6,094,545, discloses an illumination directing apparatus for use with photographic cameras having a lens and a flash, and including at least one reflecting member for reflecting light from the flash of the camera toward a subject to be photographed. The apparatus is configured so as to provide light directly from the flash (either diffused or not) as well as reflected light from the flash (either diffused or not) directed at the subject and essentially from respective sides of the lens of the camera to thereby provide more even illumination on the subject.
Kean, U.S. Pat. No. 5,778,264, discloses a photographic reflector to convert a forward-illuminating flash unit into one which produces reflected light or for use directly with a bounce-head flash unit. The reflector includes an internal reflective hood with an attachment so as to enable it to be secured to a flash unit. A mirror is provided which is angled between thirty degrees and sixty degrees inclusive with respect to a forward facing light-emitting surface of the flash unit when the reflector is secured thereto. In this way, the flash of light is directed upwardly by the mirror into the internally reflective hood so as to produce a reflected flash of light for illumination of a photographic subject.
Stephenson, U.S. Pat. No. 5,406,343, discloses a main light reflector supported for movement between a direct flash position for reflecting light output from a source of flash illumination directly towards a subject to be photographed and an indirect flash position for reflecting light output from the flash source onto a nearby surface and thence directly towards a subject to be photographed. A supplementary light reflector is supported for movement to a direct flash position for reflecting light output from the flash source directly towards a subject to be photographed. The supplementary reflector is moved to its direct flash position in response to movement of the main reflector to its indirect flash position, whereby combined direct and indirect illumination of a subject to be photographed can be achieved.
Smith et al., U.S. Pat. No. 5,337,104, discloses an apparatus for redirecting beams of light emanating from the flash of a camera so as to avoid the creation of “red-eye” in a photograph. The apparatus redirects the beams of lights so as to be distanced even further from the central axis of the camera lens. To provide the full effect of the flash, the apparatus redirects the beams of light in a direction parallel to the original direction the light beams travel off from the flash and to the central axis of the lens. The apparatus includes a main body which forms an enclosure with an inlet and outlet opening and is attached to the camera such that the inlet opening is aligned with and covers the camera's flash. The main body includes at least two reflective surfaces for redirecting the flash beam from a first direction to a second direction and then from the second direction to a third direction exiting the main body. The device can be releasably mounted to existing flash cameras (including pop-out flash members). It can also be built into new compact cameras and act as a sliding lens cover and power switch. With the built-in design, the flash of the camera can be directed either vertically or to one side of the camera and a built-in light shifter with single reflective surface is provided to redirect the light parallel and far removed from the central axis of the lens.
Crouse, U.S. Pat. No. 4,122,333, discloses a reflective device for use with a source of flash illumination, and method, for providing indirect, or, simultaneous direct and indirect illumination of a scene to be photographed. A reflective member, interposed at an angle between the flash source and scene, intercepts flash illumination and reflectively redirects at least a percentage of it for indirect illumination. Reflective member passing means allow some flash illumination therethrough for simultaneous direct illumination, the amount being variable by regulating means such as movable shutters or polarizer sheets mounted on the reflective member. Means are provided for varying the angle of interposition of and for rotating the reflective member. Mounting means for mounting reflective members onto flash units accommodate various removable reflective members.
Sloop, U.S. Pat. No. 4,078,170, discloses an apparatus for use with a camera and flash unit to provide diffused light, including a support frame for holding a flash unit so it emits light upwardly, and for holding a reflector screen above the flash unit and facing forwardly and downwardly to reflect light from the flash unit in a largely forward direction. The reflector screen includes a sheet of flexible reflective material and a resilient wire reflector frame for holding the reflective sheet taut and for mounting it on the support frame.
Blizzard, U.S. Pat. No. 3,258,586, discloses a bounce light beam deflector for flash and strobe lights.
The related art described above discloses camera accessories capable of expanding a flash beam, of redirecting a flash beam and of softening a flash beam. However, the prior art fails to disclose a reflector system that may be integrated with a hot or cold camera shoe to place reflectors in an optimal position for greatly broadening the flash light beam, changing its color, intensity, redirecting its path and other adjustments and lighting effects. The present disclosure distinguishes over the prior art providing heretofore unknown advantages as described in the following summary.
BRIEF SUMMARY OF THE INVENTION
This disclosure teaches certain benefits in construction and use which give rise to the objectives described below.
With the advent of digital technology in relatively inexpensive cameras that provide fully automated operation, i.e., auto-focus and aperture setting, taking pictures has become a common past time. Most cameras have built-in flash devices making indoor and low-light photography easily mastered by even the most inexperienced amateur. However, with the miniaturization of cameras both the flash mechanism and its reflector have also become quite small although light output has increased through technical improvements. Large light output from relatively small built-in reflectors tends to produce a flat image since little, if any, gray tones appear around the edges of objects. Built-in camera flash devices have many limitations including the inability to: select flash direction other then at the point of focus, produce bounce lighting, change lighting color, throttle flash magnitude, increase or restrict breath of field, soften lighting, and other effects.
The present invention is a camera accessory that provides a solution to the many needs in flash photography not presently available. A reflector system provides a pair of reflector assemblies mounted on a strut in mutually facing positions. The strut is enabled for mounting in the accessory shoe of the camera, and with those cameras that have built-in flash devices that can be positioned above the camera shoe, the strut permits a smaller one of the reflector assemblies (forward reflector) to be positioned facing the built-in flash device, while a much larger one of the reflectors (rearward reflector is positioned behind the flash device and is therefore able to receive light bounced off the forward reflector and then direct the light toward the photographic subject.
The reflector assemblies have snap-in reflectors that may be quickly and easily changed so that one may use a reflector set that selects flash direction other then at the point of focus, produces bounce lighting, changes lighting color, throttles flash magnitude, increases or restricts breath of field, softens lighting, or produces other desired light effects. The reflector assemblies are adjustable as to the height and can easily be adjustable also for changing the direction of light reflection. The invention is easily assembled and broken down for convenience in use and comprises inexpensively manufactured parts. The camera's flash beam is directed at a first one of the reflectors, which then directs the flash beam to the second one of the reflectors, which, in turn, directs the flash beam outwardly toward the subject of the photograph. The first and second reflectors expand the beam so that the final outgoing flash beam is many times broader then the beam that would proceed from the camera's flash unit alone.
A primary objective inherent in the above described apparatus and method of use is to provide advantages not taught by the prior art.
Another objective is provide a device that improves flash lighting effects for ordinary commercial camera equipment.
A further objective is to provide such a device that is able to be easily assembled and mounted onto a camera utilizing the camera's existing accessory shoe.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described apparatus and method of its use.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not applicable.
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable.
SEQUENCE LISTING
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Present Disclosure
This disclosure relates generally to devices for redirecting light from a camera flash unit, and more particularly to a reflector unit capable of adapting camera flash light output as to direction, scope, color and other features and more especially to producing a softer but wider light beam.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Hughes, U.S. Pat. No. 7,360,909, discloses and teaches a new and improved photographic flash attachment, a light reflecting apparatus that is lightweight, flexible, easily attached and/or detached from a camera flash and conveniently stored in a rolled or folded configuration. The disclosed flash reflector is configured from a thin, flexible, planar polyurethane foam material, or any other suitable material, into an adjustable, generally concave configuration whereby adjusting the reflectors shape adjusts the power of the light it reflects to balance with the existing natural light or bounce off a ceiling thereby eliminating and/or reducing shadows about the photographic subject.
Petitjean, U.S. Pat. No. 6,094,545, discloses an illumination directing apparatus for use with photographic cameras having a lens and a flash, and including at least one reflecting member for reflecting light from the flash of the camera toward a subject to be photographed. The apparatus is configured so as to provide light directly from the flash (either diffused or not) as well as reflected light from the flash (either diffused or not) directed at the subject and essentially from respective sides of the lens of the camera to thereby provide more even illumination on the subject.
Kean, U.S. Pat. No. 5,778,264, discloses a photographic reflector to convert a forward-illuminating flash unit into one which produces reflected light or for use directly with a bounce-head flash unit. The reflector includes an internal reflective hood with an attachment so as to enable it to be secured to a flash unit. A mirror is provided which is angled between thirty degrees and sixty degrees inclusive with respect to a forward facing light-emitting surface of the flash unit when the reflector is secured thereto. In this way, the flash of light is directed upwardly by the mirror into the internally reflective hood so as to produce a reflected flash of light for illumination of a photographic subject.
Stephenson, U.S. Pat. No. 5,406,343, discloses a main light reflector supported for movement between a direct flash position for reflecting light output from a source of flash illumination directly towards a subject to be photographed and an indirect flash position for reflecting light output from the flash source onto a nearby surface and thence directly towards a subject to be photographed. A supplementary light reflector is supported for movement to a direct flash position for reflecting light output from the flash source directly towards a subject to be photographed. The supplementary reflector is moved to its direct flash position in response to movement of the main reflector to its indirect flash position, whereby combined direct and indirect illumination of a subject to be photographed can be achieved.
Smith et al., U.S. Pat. No. 5,337,104, discloses an apparatus for redirecting beams of light emanating from the flash of a camera so as to avoid the creation of “red-eye” in a photograph. The apparatus redirects the beams of lights so as to be distanced even further from the central axis of the camera lens. To provide the full effect of the flash, the apparatus redirects the beams of light in a direction parallel to the original direction the light beams travel off from the flash and to the central axis of the lens. The apparatus includes a main body which forms an enclosure with an inlet and outlet opening and is attached to the camera such that the inlet opening is aligned with and covers the camera's flash. The main body includes at least two reflective surfaces for redirecting the flash beam from a first direction to a second direction and then from the second direction to a third direction exiting the main body. The device can be releasably mounted to existing flash cameras (including pop-out flash members). It can also be built into new compact cameras and act as a sliding lens cover and power switch. With the built-in design, the flash of the camera can be directed either vertically or to one side of the camera and a built-in light shifter with single reflective surface is provided to redirect the light parallel and far removed from the central axis of the lens.
Crouse, U.S. Pat. No. 4,122,333, discloses a reflective device for use with a source of flash illumination, and method, for providing indirect, or, simultaneous direct and indirect illumination of a scene to be photographed. A reflective member, interposed at an angle between the flash source and scene, intercepts flash illumination and reflectively redirects at least a percentage of it for indirect illumination. Reflective member passing means allow some flash illumination therethrough for simultaneous direct illumination, the amount being variable by regulating means such as movable shutters or polarizer sheets mounted on the reflective member. Means are provided for varying the angle of interposition of and for rotating the reflective member. Mounting means for mounting reflective members onto flash units accommodate various removable reflective members.
Sloop, U.S. Pat. No. 4,078,170, discloses an apparatus for use with a camera and flash unit to provide diffused light, including a support frame for holding a flash unit so it emits light upwardly, and for holding a reflector screen above the flash unit and facing forwardly and downwardly to reflect light from the flash unit in a largely forward direction. The reflector screen includes a sheet of flexible reflective material and a resilient wire reflector frame for holding the reflective sheet taut and for mounting it on the support frame.
Blizzard, U.S. Pat. No. 3,258,586, discloses a bounce light beam deflector for flash and strobe lights.
The related art described above discloses camera accessories capable of expanding a flash beam, of redirecting a flash beam and of softening a flash beam. However, the prior art fails to disclose a reflector system that may be integrated with a hot or cold camera shoe to place reflectors in an optimal position for greatly broadening the flash light beam, changing its color, intensity, redirecting its path and other adjustments and lighting effects. The present disclosure distinguishes over the prior art providing heretofore unknown advantages as described in the following summary.
BRIEF SUMMARY OF THE INVENTION
This disclosure teaches certain benefits in construction and use which give rise to the objectives described below.
With the advent of digital technology in relatively inexpensive cameras that provide fully automated operation, i.e., auto-focus and aperture setting, taking pictures has become a common past time. Most cameras have built-in flash devices making indoor and low-light photography easily mastered by even the most inexperienced amateur. However, with the miniaturization of cameras both the flash mechanism and its reflector have also become quite small although light output has increased through technical improvements. Large light output from relatively small built-in reflectors tends to produce a flat image since little, if any, gray tones appear around the edges of objects. Built-in camera flash devices have many limitations including the inability to: select flash direction other then at the point of focus, produce bounce lighting, change lighting color, throttle flash magnitude, increase or restrict breath of field, soften lighting, and other effects.
The present invention is a camera accessory that provides a solution to the many needs in flash photography not presently available. A reflector system provides a pair of reflector assemblies mounted on a strut in mutually facing positions. The strut is enabled for mounting in the accessory shoe of the camera, and with those cameras that have built-in flash devices that can be positioned above the camera shoe, the strut permits a smaller one of the reflector assemblies (forward reflector) to be positioned facing the built-in flash device, while a much larger one of the reflectors (rearward reflector is positioned behind the flash device and is therefore able to receive light bounced off the forward reflector and then direct the light toward the photographic subject.
The reflector assemblies have snap-in reflectors that may be quickly and easily changed so that one may use a reflector set that selects flash direction other then at the point of focus, produces bounce lighting, changes lighting color, throttles flash magnitude, increases or restricts breath of field, softens lighting, or produces other desired light effects. The reflector assemblies are adjustable as to the height and can easily be adjustable also for changing the direction of light reflection. The invention is easily assembled and broken down for convenience in use and comprises inexpensively manufactured parts. The camera's flash beam is directed at a first one of the reflectors, which then directs the flash beam to the second one of the reflectors, which, in turn, directs the flash beam outwardly toward the subject of the photograph. The first and second reflectors expand the beam so that the final outgoing flash beam is many times broader then the beam that would proceed from the camera's flash unit alone.
A primary objective inherent in the above described apparatus and method of use is to provide advantages not taught by the prior art.
Another objective is provide a device that improves flash lighting effects for ordinary commercial camera equipment.
A further objective is to provide such a device that is able to be easily assembled and mounted onto a camera utilizing the camera's existing accessory shoe.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described apparatus and method of its use.
Is this patent green technology? Respond with 'yes' or 'no'. |
7690125 | FIELD OF THE INVENTION
The present invention relates generally to layout devices or tools commonly used to provide straight line runs, accurate angles and stability to alignment means such as lasers, chalk lines, wires and other media suitable for establishing floor, wall and associated orientation for the construction of residential, industrial and commercial objects of construction including but not limited to floors, walls, plumbing and electrical layouts, parking lot lines, street medians, markings and others.
BACKGROUND OF THE INVENTION
Presently, in the field of layout tools, many solutions have been offered, in many cases including multiple means of scribing or indicating lines, means for attaching chalk lines or wires, leveling means, laser emitters and fixtures for attaching same, indexes for measuring small distances, holders for tape measures and more.
U.S. Pat. No. 5,022,158 for a WALL MARKING LAYOUT DEVICE issued to Beyer on Jun. 11, 1991, disclosing a layout device with an elongated rectangular body. The Beyer patent disclosed a device fashioned from dense material and was provided with vertical alignment pins to enable vertical adjustments. Further, grooves were provided to allow the use of chalk lines during the layout procedure.
Beyer, while providing a device of substantial weight for use in performing layout procedures, is somewhat simple, providing the predominant function necessary for solo use, but carries with it some limitations as will be more fully discussed below.
U.S. Pat. No. 6,578,274 B1 for a CONSTRUCTION LAYOUT BLOCK issued to Tango, Jr. et al. on Jun. 17, 2003, also shares the commonality of substantial weight and a handle, but as well tries to include so many features for alignment that it actually limits its usage in the industrial or commercial setting as being too precise for the typically rugged duty experienced by such tools.
Beyer and Tango, Jr. et al. may be considered the two “ends of the spectrum” from the simple to the complex as far as layout tools are concerned.
In the case of Breyer, the unit appears to be quite rugged and simple. The basic function of a weighty tool which may stay in place is present. The propensity to stay in place during use is somewhat compromised, however by the provision of elevation pins. With the pins extended, the amount of surface area in contact with the work surface underneath becomes inherently limited in the amount of adhesion which can be transmitted to the work surface, thereby affecting the amount of pull which might cause the unit to move, thereby limiting the length of line which may be employed and the distance traversed.
What is needed then is a device which may provide vertical indexing but which also may be stable for use with string or wire pulls of substantial tension, the device being resistant to movement during operation, such as long lines in commercial environments, including large diameter lines such as those used for parking lot layouts, street median lines, striping and the like.
Further, with the body in such an elongated shape as disclosed by Breyer, constant use of the device causes a great deal of torque to be experience by the user's hand and wrist, putting undue stress on the wrist, which may become fatigued over time and subject to injury or sprain if lifted too abruptly or without smooth, deliberate movement.
What is needed is a device which has substantial weight or other provision to prevent slippage, but which also is more ergonomically friendly for the user.
On the other hand, Tonga, Jr. discloses a layout tool which has some weight, but which also has some precise features such as a laser alignment target notch and an intrinsic level. These are provisions which are not without some precision which means that the device must be cared for with a relative amount of safety to assure that the device does not require constant calibration. When a level bulb is provided on a device, the device must be guarded from impact and jarring to keep the level bulb in correct position relative to the device. Further, an alignment notch for a laser must be kept safe from debris buildup, galling, dents, etc. When precision features are included in a layout tool, the tool must then be cared for either in its own case or separate from other tools which may by their interaction; e.g., being tossed into a gangbox or truck bed, damage each other.
What is needed is a layout tool which accomplishes the major layout tasks commonly used, and which may also be stored and transported in a tool or gang box, essentially impervious to being bumped by or underneath other heavy industrial tools.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a rugged but useful layout device which is substantially ergonomic and easy to use, resistant to movement during operation, impervious to common, heavy duty industrial usage, and sufficiently precise for the intended job.
Applicant's device is compact compared to the device of Breyer. The preferred embodiment is typically fabricated from 1″ thick mild steel or iron plate, with typically two base pads having at least one rubber pad fastened thereto, providing substantial friction with the work surface underneath, and resistant to movement during use.
Typically, a plurality of protrusions are, or at a minimum, one is supplied at typically right angles to one another where downwardly oriented pointers are adjustably secured for attached snap lines or wires in order to locate anticipated structures or lines. The pointers are replaceable over time if damaged, and are useful to assist in a degree of vertical alignment without the limitation of affecting pull resistance as in the Breyer device. The pointer may be oriented in a downward or upward direction.
Easy fabrication by welding makes production of the device economical. The only surfaces which might be desired to be accurately indexed relative to one another are the lower surface of the base pads, and the bores in the aforementioned protrusions which will house the adjustable pointers.
The stout nature of the device lends itself to heavy usage, and its nature of manufacture and the rugged pointers and protrusions are resistant to damage from being tossed into the bed of a truck or into a gangbox wherein other tools will be stored and transported.
Applicant's preferred embodiment also utilizes a handle which is oriented in such a way that it is easily manipulated by the user, allowing a natural twist to occur during the typical lift, thereby reducing the work done by the wrist in moving the device, an improvement over the prior art.
Applicant's device typically weighs approximately 30 to 40 pounds. However, by using the embodiment shown inFIGS. 4 and 5, even heavier tools may be employed to handle increased duty which includes higher snap line tension. By its weight the device avoids the necessity for pins, nails or other means to locate and fix the device in a desired position, particularly helpful in situations where the device may be used on concrete, tile or wood floors which should not be damaged.
As opposed to Breyer, applicant's tool utilizes rubber pads on the underside which not only protect the floor or work surface underneath, but also prevents slippage or damage when the tool is subjected to high snap line loading or tension.
Applicant's invention provides a clear solution to the needs as described above, yielding a rugged yet sufficiently precise layout device that is resistant to moving, ergonomically designed, non-damaging to sensitive surfaces and up to the task of withstanding heavy industrial use.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates generally to layout devices or tools commonly used to provide straight line runs, accurate angles and stability to alignment means such as lasers, chalk lines, wires and other media suitable for establishing floor, wall and associated orientation for the construction of residential, industrial and commercial objects of construction including but not limited to floors, walls, plumbing and electrical layouts, parking lot lines, street medians, markings and others.
BACKGROUND OF THE INVENTION
Presently, in the field of layout tools, many solutions have been offered, in many cases including multiple means of scribing or indicating lines, means for attaching chalk lines or wires, leveling means, laser emitters and fixtures for attaching same, indexes for measuring small distances, holders for tape measures and more.
U.S. Pat. No. 5,022,158 for a WALL MARKING LAYOUT DEVICE issued to Beyer on Jun. 11, 1991, disclosing a layout device with an elongated rectangular body. The Beyer patent disclosed a device fashioned from dense material and was provided with vertical alignment pins to enable vertical adjustments. Further, grooves were provided to allow the use of chalk lines during the layout procedure.
Beyer, while providing a device of substantial weight for use in performing layout procedures, is somewhat simple, providing the predominant function necessary for solo use, but carries with it some limitations as will be more fully discussed below.
U.S. Pat. No. 6,578,274 B1 for a CONSTRUCTION LAYOUT BLOCK issued to Tango, Jr. et al. on Jun. 17, 2003, also shares the commonality of substantial weight and a handle, but as well tries to include so many features for alignment that it actually limits its usage in the industrial or commercial setting as being too precise for the typically rugged duty experienced by such tools.
Beyer and Tango, Jr. et al. may be considered the two “ends of the spectrum” from the simple to the complex as far as layout tools are concerned.
In the case of Breyer, the unit appears to be quite rugged and simple. The basic function of a weighty tool which may stay in place is present. The propensity to stay in place during use is somewhat compromised, however by the provision of elevation pins. With the pins extended, the amount of surface area in contact with the work surface underneath becomes inherently limited in the amount of adhesion which can be transmitted to the work surface, thereby affecting the amount of pull which might cause the unit to move, thereby limiting the length of line which may be employed and the distance traversed.
What is needed then is a device which may provide vertical indexing but which also may be stable for use with string or wire pulls of substantial tension, the device being resistant to movement during operation, such as long lines in commercial environments, including large diameter lines such as those used for parking lot layouts, street median lines, striping and the like.
Further, with the body in such an elongated shape as disclosed by Breyer, constant use of the device causes a great deal of torque to be experience by the user's hand and wrist, putting undue stress on the wrist, which may become fatigued over time and subject to injury or sprain if lifted too abruptly or without smooth, deliberate movement.
What is needed is a device which has substantial weight or other provision to prevent slippage, but which also is more ergonomically friendly for the user.
On the other hand, Tonga, Jr. discloses a layout tool which has some weight, but which also has some precise features such as a laser alignment target notch and an intrinsic level. These are provisions which are not without some precision which means that the device must be cared for with a relative amount of safety to assure that the device does not require constant calibration. When a level bulb is provided on a device, the device must be guarded from impact and jarring to keep the level bulb in correct position relative to the device. Further, an alignment notch for a laser must be kept safe from debris buildup, galling, dents, etc. When precision features are included in a layout tool, the tool must then be cared for either in its own case or separate from other tools which may by their interaction; e.g., being tossed into a gangbox or truck bed, damage each other.
What is needed is a layout tool which accomplishes the major layout tasks commonly used, and which may also be stored and transported in a tool or gang box, essentially impervious to being bumped by or underneath other heavy industrial tools.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a rugged but useful layout device which is substantially ergonomic and easy to use, resistant to movement during operation, impervious to common, heavy duty industrial usage, and sufficiently precise for the intended job.
Applicant's device is compact compared to the device of Breyer. The preferred embodiment is typically fabricated from 1″ thick mild steel or iron plate, with typically two base pads having at least one rubber pad fastened thereto, providing substantial friction with the work surface underneath, and resistant to movement during use.
Typically, a plurality of protrusions are, or at a minimum, one is supplied at typically right angles to one another where downwardly oriented pointers are adjustably secured for attached snap lines or wires in order to locate anticipated structures or lines. The pointers are replaceable over time if damaged, and are useful to assist in a degree of vertical alignment without the limitation of affecting pull resistance as in the Breyer device. The pointer may be oriented in a downward or upward direction.
Easy fabrication by welding makes production of the device economical. The only surfaces which might be desired to be accurately indexed relative to one another are the lower surface of the base pads, and the bores in the aforementioned protrusions which will house the adjustable pointers.
The stout nature of the device lends itself to heavy usage, and its nature of manufacture and the rugged pointers and protrusions are resistant to damage from being tossed into the bed of a truck or into a gangbox wherein other tools will be stored and transported.
Applicant's preferred embodiment also utilizes a handle which is oriented in such a way that it is easily manipulated by the user, allowing a natural twist to occur during the typical lift, thereby reducing the work done by the wrist in moving the device, an improvement over the prior art.
Applicant's device typically weighs approximately 30 to 40 pounds. However, by using the embodiment shown inFIGS. 4 and 5, even heavier tools may be employed to handle increased duty which includes higher snap line tension. By its weight the device avoids the necessity for pins, nails or other means to locate and fix the device in a desired position, particularly helpful in situations where the device may be used on concrete, tile or wood floors which should not be damaged.
As opposed to Breyer, applicant's tool utilizes rubber pads on the underside which not only protect the floor or work surface underneath, but also prevents slippage or damage when the tool is subjected to high snap line loading or tension.
Applicant's invention provides a clear solution to the needs as described above, yielding a rugged yet sufficiently precise layout device that is resistant to moving, ergonomically designed, non-damaging to sensitive surfaces and up to the task of withstanding heavy industrial use.
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7730246 | FIELD OF INVENTION
The field of invention relates generally to the monitoring of computing systems, and, more specifically, to the opportunistic transmission of software state information within a link based computing system.
BACKGROUND
FIG. 1ashows a depiction of a bus120. A bus120is a “shared medium” communication structure that is used to transport communications between electronic components101a-10Na and110a. Shared medium means that the components101a-10Na and110athat communicate with one another physically share and are connected to the same electronic wiring120. Thus, for example, if component101awished to communicate to component10Na, component101awould send information along wiring120to component10Na; if component103awished to communicate to component110a, component103awould send information along the same wiring120to component110a, etc.
Computing systems have traditionally made use of busses. With respect to certain IBM compatible PCs, bus120may correspond to a PCI bus where components101a-10Na correspond to “I/O” components (e.g., LAN networking adapter cards, MODEMs, hard disk storage devices, etc.) and component110acorresponds to an I/O Control Hub (ICH). As another example, with respect to certain multiprocessor computing systems, bus120may correspond to a “front side” bus where components101a-10Na correspond to microprocessors and component110acorresponds to a memory controller.
In the past, when computing system clock speeds were relatively slow, the capacitive loading on the computing system's busses was not a serious issue because the degraded maximum speed of the bus wiring (owing to capacitive loading) still far exceeded the computing system's internal clock speeds. The same cannot be said for at least some of today's computing systems. With the continual increase in computing system clock speeds over the years, the speed of today's computing systems are reaching (and/or perhaps exceeding) the maximum speed of wires that are heavily loaded with capacitance such as bus wiring120.
Therefore computing systems are migrating to a “link-based” component-to-component interconnection scheme.FIG. 1bshows a comparative example vis-à-visFIG. 1a. According to the approach ofFIG. 1b, computing system components101a-10Na and110aare interconnected through a mesh140of high speed bidirectional point-to-point links1301through130N. A bidirectional point-to-point link typically comprises a first unidirectional point-to-point link that transmits information in a first direction and a second unidirectional point-to-point link that transmits information is a second direction that is opposite that of the first direction.
Each point-to-point link can be constructed with copper or fiber optic cabling and appropriate drivers and receivers (e.g., single or differential line drivers and receivers for copper based cables; and LASER or LED E/O transmitters and O/E receivers for fiber optic cables;, etc.). The mesh140observed inFIG. 1bis simplistic in that each component is connected by a bidirectional point-to-point link to every other component. In more complicated schemes, the mesh140is a network having routing/switching nodes. Here, every component need not be coupled by a point-to-point link to every other component.
Instead, hops across a plurality of links may take place through routing/switching nodes in order to transport information from a source component to a destination component. Depending on implementation, the routing/switching function may be a stand alone function within the mesh network or may be integrated into a substantive component of the computing system (e.g., processor, memory controller, I/O unit, etc.). According to one perspective, the term “link agent” is used to refer to a component of a link based computing system that includes any such substantive component.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF INVENTION
The field of invention relates generally to the monitoring of computing systems, and, more specifically, to the opportunistic transmission of software state information within a link based computing system.
BACKGROUND
FIG. 1ashows a depiction of a bus120. A bus120is a “shared medium” communication structure that is used to transport communications between electronic components101a-10Na and110a. Shared medium means that the components101a-10Na and110athat communicate with one another physically share and are connected to the same electronic wiring120. Thus, for example, if component101awished to communicate to component10Na, component101awould send information along wiring120to component10Na; if component103awished to communicate to component110a, component103awould send information along the same wiring120to component110a, etc.
Computing systems have traditionally made use of busses. With respect to certain IBM compatible PCs, bus120may correspond to a PCI bus where components101a-10Na correspond to “I/O” components (e.g., LAN networking adapter cards, MODEMs, hard disk storage devices, etc.) and component110acorresponds to an I/O Control Hub (ICH). As another example, with respect to certain multiprocessor computing systems, bus120may correspond to a “front side” bus where components101a-10Na correspond to microprocessors and component110acorresponds to a memory controller.
In the past, when computing system clock speeds were relatively slow, the capacitive loading on the computing system's busses was not a serious issue because the degraded maximum speed of the bus wiring (owing to capacitive loading) still far exceeded the computing system's internal clock speeds. The same cannot be said for at least some of today's computing systems. With the continual increase in computing system clock speeds over the years, the speed of today's computing systems are reaching (and/or perhaps exceeding) the maximum speed of wires that are heavily loaded with capacitance such as bus wiring120.
Therefore computing systems are migrating to a “link-based” component-to-component interconnection scheme.FIG. 1bshows a comparative example vis-à-visFIG. 1a. According to the approach ofFIG. 1b, computing system components101a-10Na and110aare interconnected through a mesh140of high speed bidirectional point-to-point links1301through130N. A bidirectional point-to-point link typically comprises a first unidirectional point-to-point link that transmits information in a first direction and a second unidirectional point-to-point link that transmits information is a second direction that is opposite that of the first direction.
Each point-to-point link can be constructed with copper or fiber optic cabling and appropriate drivers and receivers (e.g., single or differential line drivers and receivers for copper based cables; and LASER or LED E/O transmitters and O/E receivers for fiber optic cables;, etc.). The mesh140observed inFIG. 1bis simplistic in that each component is connected by a bidirectional point-to-point link to every other component. In more complicated schemes, the mesh140is a network having routing/switching nodes. Here, every component need not be coupled by a point-to-point link to every other component.
Instead, hops across a plurality of links may take place through routing/switching nodes in order to transport information from a source component to a destination component. Depending on implementation, the routing/switching function may be a stand alone function within the mesh network or may be integrated into a substantive component of the computing system (e.g., processor, memory controller, I/O unit, etc.). According to one perspective, the term “link agent” is used to refer to a component of a link based computing system that includes any such substantive component.
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7697369 | BACKGROUND OF THE INVENTION
This invention relates to a system having a controller and a memory and, more particularly, to a data sending/receiving operation between the controller and the memory.
In a conventional data sending/receiving operation between the controller and the memory, either the controller or the memory who serves as a sender generates a data strobe signal which is synchronized with a clock signal. Data signals are sent out from the sender is synchronized with the data strobe signal as disclosed in U.S. Pat. No. 6,789,209B1, Description of the Related Art, the contents of U.S. Pat. No. 6,789,209B1 being incorporated herein by reference in their entireties.
U.S. Pat. No. 6,789,209B1 points out some problems on the use of the data strobe signal and, alternative to the data strobe signal, proposes a system which sends/receives the data in synchronization with the clock signal.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system based on a new protocol which is different from the above-described conventional techniques.
One aspect of the present invention provides a system comprising a controller adapted to send out a first data strobe signal and a write data signal in a write operation. The write data signal is synchronized with the first data strobe signal. The controller is adapted, in a read operation, to send out a second data strobe signal and to receive a read data signal in synchronization with a read data strobe (RDQS) signal. The read data strobe signal corresponds to the second data strobe signal. The system also comprises a memory adapted to receive the write data signal in synchronization with the first data strobe signal in the write operation. The memory is adapted, in the read operation, to send out the read data strobe signal in response to the second data strobe signal and to send out the read data signal synchronized with the read data strobe signal.
The controller may be further adapted to produce a clock signal and to send the clock signal to the memory. Each of the first and the second data strobe signals and the read data strobe signal may be independent of and separated from the clock signal.
Each of the first and the second data strobe signals and the read data strobe signal may has a frequency different from the clock signal.
Each of the first and the second data strobe signals and the read data strobe signal may not be in synchronization with the clock signal.
Another aspect of the present invention provides a system wherein the memory comprises a low speed memory and a high speed memory. The controller sends out a clock signal having a clock frequency. The controller also sends out first and second lower data strobe signals as the first and the second data strobe signals for the low speed memory and receives lower read data strobe signal as the read data strobe signal from the low speed memory. Each of the first and the second lower data strobe signals and the lower read data strobe signal has a frequency equal to or lower than the clock frequency. The controller sends out first and second higher data strobe signals as the first and the second data strobe signals for the high speed memory and receives higher read data strobe signal as the read data strobe signal from the high speed memory. Each of the first and the second higher data strobe signals and the higher read data strobe signal has a frequency equal to or 2ntimes (n being an integer) as the clock frequency.
An appreciation of the objectives of the present invention and a more complete understanding of its structure may be had by studying the following description of the preferred embodiment and by referring to the accompanying drawings.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
This invention relates to a system having a controller and a memory and, more particularly, to a data sending/receiving operation between the controller and the memory.
In a conventional data sending/receiving operation between the controller and the memory, either the controller or the memory who serves as a sender generates a data strobe signal which is synchronized with a clock signal. Data signals are sent out from the sender is synchronized with the data strobe signal as disclosed in U.S. Pat. No. 6,789,209B1, Description of the Related Art, the contents of U.S. Pat. No. 6,789,209B1 being incorporated herein by reference in their entireties.
U.S. Pat. No. 6,789,209B1 points out some problems on the use of the data strobe signal and, alternative to the data strobe signal, proposes a system which sends/receives the data in synchronization with the clock signal.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system based on a new protocol which is different from the above-described conventional techniques.
One aspect of the present invention provides a system comprising a controller adapted to send out a first data strobe signal and a write data signal in a write operation. The write data signal is synchronized with the first data strobe signal. The controller is adapted, in a read operation, to send out a second data strobe signal and to receive a read data signal in synchronization with a read data strobe (RDQS) signal. The read data strobe signal corresponds to the second data strobe signal. The system also comprises a memory adapted to receive the write data signal in synchronization with the first data strobe signal in the write operation. The memory is adapted, in the read operation, to send out the read data strobe signal in response to the second data strobe signal and to send out the read data signal synchronized with the read data strobe signal.
The controller may be further adapted to produce a clock signal and to send the clock signal to the memory. Each of the first and the second data strobe signals and the read data strobe signal may be independent of and separated from the clock signal.
Each of the first and the second data strobe signals and the read data strobe signal may has a frequency different from the clock signal.
Each of the first and the second data strobe signals and the read data strobe signal may not be in synchronization with the clock signal.
Another aspect of the present invention provides a system wherein the memory comprises a low speed memory and a high speed memory. The controller sends out a clock signal having a clock frequency. The controller also sends out first and second lower data strobe signals as the first and the second data strobe signals for the low speed memory and receives lower read data strobe signal as the read data strobe signal from the low speed memory. Each of the first and the second lower data strobe signals and the lower read data strobe signal has a frequency equal to or lower than the clock frequency. The controller sends out first and second higher data strobe signals as the first and the second data strobe signals for the high speed memory and receives higher read data strobe signal as the read data strobe signal from the high speed memory. Each of the first and the second higher data strobe signals and the higher read data strobe signal has a frequency equal to or 2ntimes (n being an integer) as the clock frequency.
An appreciation of the objectives of the present invention and a more complete understanding of its structure may be had by studying the following description of the preferred embodiment and by referring to the accompanying drawings.
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7717255 | BACKGROUND
The conveying, alignment, and transport of articles, especially oddly shaped and difficult to engage packages, is problematic. For example, the process of engaging and transporting bagged items, such as bags of olives or candies, into shipping or transportation containers such as boxes or cartons poses unique problems.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND
The conveying, alignment, and transport of articles, especially oddly shaped and difficult to engage packages, is problematic. For example, the process of engaging and transporting bagged items, such as bags of olives or candies, into shipping or transportation containers such as boxes or cartons poses unique problems.
Is this patent green technology? Respond with 'yes' or 'no'. |
7839845 | BACKGROUND
Wireless networks and wireless communication have become prevalent throughout society creating the need for increased capacity and faster and more reliable wireless communication techniques. TGn Sync is a multi-industry group working together to rapidly introduce a unified proposal for the next generation of high performance wireless networks.
A proposal to 802.11 TGn may dramatically improve the capabilities of wireless networks while supporting the antenna configurations, product designs and protocol requirements of hundreds of millions of cellular handsets, enterprise base stations, and Wi-Fi enabled computers already in use. Key Features of the TGn Sync Proposal may include: MIMO Spatial Division Multiplexing to support 315 Mbps reliably with two antennas, up to 630 Mbps with larger systems; Scalable Architecture for different spatial stream (2 to 4) and spectrum configurations (10, 20, 40 MHz); seamless interoperability between 802.11a/b/g and new modes of operation; timed receive mode switching and multiple receiver addressing to reduce power for battery-operated devices; and flexible architecture offering product compliance for all major regulatory domains while preserving interoperability.
In the TGnSync proposal, there is included a Media Access Control Service Data Units (A-MSDU) aggregation, which is a way of “batching together” multiple higher-layer packets (MSDUs) into a single transmission unit, such as Media Access Control Protocol Data Units (MPDU). However, the subframe header in this proposal may be a fixed length and may contain information that is redundant if the A-MSDU contains multiple MSDUs for the same destination address/source address (DAISA) pair.
Thus, a strong need exists for the ability to remove the redundant information by providing an apparatus, system and method capable of aggregate compression in a wireless local area network (WLAN).
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND
Wireless networks and wireless communication have become prevalent throughout society creating the need for increased capacity and faster and more reliable wireless communication techniques. TGn Sync is a multi-industry group working together to rapidly introduce a unified proposal for the next generation of high performance wireless networks.
A proposal to 802.11 TGn may dramatically improve the capabilities of wireless networks while supporting the antenna configurations, product designs and protocol requirements of hundreds of millions of cellular handsets, enterprise base stations, and Wi-Fi enabled computers already in use. Key Features of the TGn Sync Proposal may include: MIMO Spatial Division Multiplexing to support 315 Mbps reliably with two antennas, up to 630 Mbps with larger systems; Scalable Architecture for different spatial stream (2 to 4) and spectrum configurations (10, 20, 40 MHz); seamless interoperability between 802.11a/b/g and new modes of operation; timed receive mode switching and multiple receiver addressing to reduce power for battery-operated devices; and flexible architecture offering product compliance for all major regulatory domains while preserving interoperability.
In the TGnSync proposal, there is included a Media Access Control Service Data Units (A-MSDU) aggregation, which is a way of “batching together” multiple higher-layer packets (MSDUs) into a single transmission unit, such as Media Access Control Protocol Data Units (MPDU). However, the subframe header in this proposal may be a fixed length and may contain information that is redundant if the A-MSDU contains multiple MSDUs for the same destination address/source address (DAISA) pair.
Thus, a strong need exists for the ability to remove the redundant information by providing an apparatus, system and method capable of aggregate compression in a wireless local area network (WLAN).
Is this patent green technology? Respond with 'yes' or 'no'. |
7809628 | FIELD OF INVENTION
The present invention is directed towards electronic trading. Specifically, the present invention is directed to tools for trading tradeable objects that can be traded with quantities and/or prices.
BACKGROUND
An electronic exchange typically provides an automatic matching process between traders, or more specifically, between buyers and sellers. Traders are connected to an electronic exchange by way of a communication link to facilitate electronic messaging between themselves and the exchange. Included in the messaging are buy and sell orders sent from the traders to the exchange. Of course, other types of well-known financial transaction messages are also communicated.
Generally, when a buy order or a sell order is submitted to an exchange, the exchange's logic checks the conditions associated with the order, for example price and quantity, and determines if a match exists. If a match does not exist, the exchange's logic prioritizes the order into an exchange order book with other orders of the same price. When the order conditions are satisfied in the market, or equivalently, a match exists, a trade occurs and trade information is then often relayed in some fashion to one or more client devices. To do this, the exchange would typically publish a data feed to the client devices to inform the traders of the most recent market changes.
The contents of the data feed, however, are often limited in information. Generally, the data feed only presents enough information to provide total aggregate quantities available at particular prices. In other words, an exchange usually provides in its data feed the total buy or the total sell quantity available in the market at a particular price level. Trading software installed on a computer can receive the data feed, and after that, the information contained in the date feed is displayed to a trader. Then, the trader attempts to use this information to spot opportunities in the market and to determine where to place orders. However, because this information is limited and oftentimes inadequate to fully characterize a market's activity, it can essentially force the trader to guess as to what is actually happening in the market. As a result, the trader may not be making the best possible trades.
Despite the limitations of the informational content provided by an exchange, traders want to characterize the markets to the best of their abilities. It is therefore desirable to offer tools that can provide a trader with more information to better assess a market at an electronic exchange. Such additional information may be helpful in, for example, spotting opportunities in the market and ultimately may be used to help traders make more informed and desirable trades.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF INVENTION
The present invention is directed towards electronic trading. Specifically, the present invention is directed to tools for trading tradeable objects that can be traded with quantities and/or prices.
BACKGROUND
An electronic exchange typically provides an automatic matching process between traders, or more specifically, between buyers and sellers. Traders are connected to an electronic exchange by way of a communication link to facilitate electronic messaging between themselves and the exchange. Included in the messaging are buy and sell orders sent from the traders to the exchange. Of course, other types of well-known financial transaction messages are also communicated.
Generally, when a buy order or a sell order is submitted to an exchange, the exchange's logic checks the conditions associated with the order, for example price and quantity, and determines if a match exists. If a match does not exist, the exchange's logic prioritizes the order into an exchange order book with other orders of the same price. When the order conditions are satisfied in the market, or equivalently, a match exists, a trade occurs and trade information is then often relayed in some fashion to one or more client devices. To do this, the exchange would typically publish a data feed to the client devices to inform the traders of the most recent market changes.
The contents of the data feed, however, are often limited in information. Generally, the data feed only presents enough information to provide total aggregate quantities available at particular prices. In other words, an exchange usually provides in its data feed the total buy or the total sell quantity available in the market at a particular price level. Trading software installed on a computer can receive the data feed, and after that, the information contained in the date feed is displayed to a trader. Then, the trader attempts to use this information to spot opportunities in the market and to determine where to place orders. However, because this information is limited and oftentimes inadequate to fully characterize a market's activity, it can essentially force the trader to guess as to what is actually happening in the market. As a result, the trader may not be making the best possible trades.
Despite the limitations of the informational content provided by an exchange, traders want to characterize the markets to the best of their abilities. It is therefore desirable to offer tools that can provide a trader with more information to better assess a market at an electronic exchange. Such additional information may be helpful in, for example, spotting opportunities in the market and ultimately may be used to help traders make more informed and desirable trades.
Is this patent green technology? Respond with 'yes' or 'no'. |
7858263 | INCORPORATION BY REFERENCE
Priority is claimed on Japanese Patent Application No. 2004-209216, filed Jul. 15, 2004, and Japanese Patent Application No. 2005-111742, filed Apr. 8, 2005, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention is related to a solid polymer electrolyte fuel cell and a method for manufacturing thereof, in particular, a solid polymer electrolyte fuel cell in which the output varies according to a demand load.
RELATED ART
A fuel cell uses hydrogen gas as a fuel gas and generates energy by an electrochemical reaction of hydrogen and oxygen. There are various types of fuel cells including a phosphoric acid fuel cell, a molten carbonate fuel cell, a solid electrolyte type fuel cell, and a solid polymer electrolyte fuel cell. Among these, a solid polymer electrolyte fuel cell can start operation at a normal temperature and can also provide higher output with small configuration, and thus holds great promise as a power source for two-wheeled or four-wheeled vehicles, or portable power supply. In the case where such a solid polymer electrolyte fuel cell is actually used, a electrode structure, a basic unit of a fuel cell, is held between separators to make a single cell, and then combined with several tens to hundreds of single cells to be used as a stack (battery).
As shown inFIGS. 9A and 9B, there are two kinds of fuel cell systems that combine the above-mentioned fuel cell with a motor. One of these is a fuel cell-storage element (battery) hybrid system (shown inFIG. 9A), and the other is a fuel cell direct connection system (shown inFIG. 9B) in which a fuel cell is directly linked with a motor. A conventional fuel cell system ofFIG. 9Ais configured in such a way that a fuel cell6is connected to a storage element8, and the storage element8is connected to a motor7in series. This allows the fuel cell6in a vehicle to continuously feed a constant amount of electric current without being influenced by a change in acceleration. As in the case with a fuel cell direct connection system ofFIG. 9B, the fuel cell6and the storage element8for storing electricity is directly connected in parallel to the motor7and mounted to a vehicle, it is necessary at the anode side to supply hydrogen flexibly corresponding to changes in the output generated according to changes in the acceleration of the vehicle, however, the hydrogen supplied as a fuel is in a state of gas, and poorly responds in controlling the amount of supply. It is therefore difficult for the system to supply hydrogen corresponding to the increase in the amount of current, and to deal flexibly with the changes in the output. As a result, fuel shortage arises temporarily in an electrode structure.
In connection with the fuel shortage, electrolysis of water advances in the anode in order to compensate the decreased supply amount of electrons, and the so-called reverse voltage arises. When the electrolysis of water occurs in the anode, it will cause a corrosion of the carbon used for the catalyst carrier in the catalyst layer which constitutes the anode, and will result in a deterioration of the performance. The deterioration of the performance of the anode will lead to a deterioration of the power generation performance of the fuel cell as a whole.
In order to solve these problems, two roughly divided methods have been examined. One of these is a method of promoting electrolysis of water (refer to Patent document 1 (International Publication No. WO01/15274), Patent Document 2 (International Publication No. WO01/15249), and Patent Document 3 (International Publication No. WO01/15255)), and the other is a method of improving the corrosion resistance of the material used for an electrode (refer to Patent document 4 (International Publication No. WO01/15254)).
Patent document 1 discloses that a catalyst layer of the anode is mixed with a catalyst which promotes the electrolysis of water. This prevents oxidization of the carbon by the reverse voltage generated by a fuel shortage. Patent document 2 discloses that a foundation layer or catalyst layer of the anode is added with a PTFE resin (Teflon: registered trademark) or graphite to increase the water content of the anode. The electrolysis of water arising in a priority basis at the time of generation of the reverse voltage prevents the corrosion of the carbon of the catalyst carrier. Patent document 3 further discloses that the catalyst layer of the anode is mixed with a catalyst that promotes electrolysis of water and then the foundation layer or catalyst layer in the anode is added with the PTFE resin or a carbon in a form of graphite. This increases the amount of water in the anode catalyst layer and to control the oxidization of carbon generated by reverse voltage. Patent document 4 further discloses that the increase in the rate of catalyst support in the catalyst layer or the improvement in the corrosion resistance of the catalyst carrier controls the degradation of the anode component.
The methods disclosed in Patent Documents 1 through 4 control the corrosion of carbon, however, does not fully satisfy the resistance property to the reverse voltage. These methods are effective in the case of a temporary fuel shortage, however, in actual operation, speed fluctuation is conducted rapidly and repeatedly and the fuel shortage incurs, and resulting in the degradation of the power generation performance due to a development of corrosion reaction of carbon.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide, for a fuel cell of which output varies according to the demand load, an electrode for a fuel cell and a fuel cell which can hold a property of high power generation and has a sufficient durability even when the reverse voltage is generated by a fuel shortage accompanied by a rapid change in the output.
More specifically, the present invention provides the followings:
(1) A solid polymer electrolyte fuel cell which varies an output according to a demand load, comprising: a plurality of electrode structures comprising an anode and a cathode, each having a diffusion layer and a catalyst layer, and polymer electrolyte membrane held between the anode and the cathode; and a plurality of separators for holding the respective electrode structures, comprising a fuel gas passage for supplying and discharging fuel gas containing hydrogen on a surface opposing the anode; and an oxidant gas passage for supplying and discharging oxidant gas on a surface opposing the cathode, the electrode structures between the separators being stacked, wherein the catalyst layer of the anode comprises a mixture of an ion conductive material, a platinum powder and/or platinum alloy powder and a carbon, the platinum powder and/or platinum alloy powder and carbon substantially exist independently from each other, and the catalyst layer of the cathode comprises a metal support mixture in which the ion conductive material and the electro-conductive material which has the supported catalyst material are mixed.
According to the invention shown in (1), the use of a mixture of an ion conductive material, a platinum powder and/or platinum alloy powder, and a carbon in the catalyst layer of the anode (negative electrode) makes it possible for the catalyst reaction and electronic conduction to be performed in an aggregate of platinum powder and/or platinum alloy powder. Since the platinum powder and/or platinum alloy powder and carbon substantially exist independently from each other, a contact ratio with carbon, platinum powder and/or platinum alloy powder can be made smaller. Since carbon securest the passages for gas and water in the catalyst layer, the water and oxygen generated by the reverse voltage can efficiently be discharged. This advances the electrolysis of water at the time of fuel shortage without having the corrosion of carbon.
Hereinafter, the “ion conductive material” is referred to as a polymer electrolyte. The “platinum alloy powder” includes, for example, a platinum-ruthenium alloy. The state of “substantially independent” is referred to as a platinum powder and/or platinum alloy powder in a state not supported by carbon. The state indicates the powder that exists separately from each other, however, the state also includes the powder that is mutually in contact with each other. Further, it is not intended to exclude a material which entraps impurities. In a fuel cell according to the present invention, the electrode structures comprising the anodes; the cathode; and the polymer electrolyte membrane held between the anode and the cathode, and the separators holding the electrode structures, are stacked. Preferably, the separators hold individual electrode structure from the anode side or the cathode side, however, one separator may have a shape with the anode and the cathode of the next electrode structure.
(2) A solid polymer electrolyte fuel cell according to (1) wherein the platinum alloy powder is a platinum ruthenium alloy having an average particle size of 3 nm to 10 nm.
According to the invention shown in (2), by setting a mean particle size of a platinum ruthenium alloy to a range described above, the solid polymer electrolyte fuel cell enables to yield a higher durability with higher terminal voltage.
From a viewpoint of preventing carbon monoxide poisoning, it is particularly preferable to use platinum ruthenium alloy instead of a single use of platinum powder for the catalyst layer in the anode layer. However, the ruthenium ingredient (alloy ingredient) will be eluted when fuel shortage arises during the use of the platinum ruthenium alloy. The range of the average particle size of platinum alloy is thus important when platinum alloy is used for the catalyst layer. For example, when the average particle size is less than 3 nm in which the specific surface area is larger and more activity points exist, the terminal voltage is inevitably higher. On the other hand, at the time of fuel shortage, the dissolution reaction of alloy ingredient progresses faster than the corrosion reaction of a carbon material and leads to a decreased durability. When an average particle size is not less than 10 nm in which the specific surface area is smaller and fewer activity points exist, the terminal voltage is inevitably lower.
(3) The solid polymer electrolyte fuel cell according to (1) or (2) wherein the specific surface area of the carbon is in a range of no less than 50 m2/g and no more than 800 m2/g.
According to the invention described in (3), setting the specific surface area of carbon to a range of no less than 50 m2/g and no more than 800 m2/g allows more efficient discharge of the generated gas and water. When the specific surface area is no more than 50 m2/g, it is difficult to secure the diffusion passage of the gas and rapidly reduces the power generation performance.
(4) The solid polymer electrolyte fuel cell according to any one of (1) to (3) in which no less than 40% and no more than 100% of particles exist with a distance of no less than 100 nm between the electro-conductive material and the noble metal powder.
According to the invention described in (4), setting the distance at 100 nm and more between the electro-conductive material and the noble metal powder allows the electronic conduction path to be supported only by noble metal powder. When the distance is set at 100 nm or less, however, the portion of electronic conduction path through electro-conductive material becomes larger, and the rate at which the electronic conduction path is intercepted due to the corrosion of an electro-conductive material upon occurrence of reverse voltage becomes higher.
(5) A method for manufacturing a solid polymer electrolyte fuel cell which varies according to a demand load, comprising the steps of: manufacturing an anode and a cathode each having a diffusion layer and a catalyst layer; manufacturing a plurality of electrode structures in which polymer electrolyte membrane is held between the anode and the cathode; holding the electrode structures between a plurality of separators comprising a fuel gas passage for supply and discharge of fuel gas containing hydrogen on a surface opposing the anode; and a passage for oxidant gas for supply and discharge of oxidant gas on a surface opposing the cathode and stacking the electrode structures held between the separators; manufacturing a paste by mixing an ion conductive material, platinum powder and/or platinum alloy powder, and carbon, and forming an electrode sheet by applying the paste onto a substrate formed in a continuous sheet, to form the catalyst layer of the anode.
According to the invention described in (5), a catalyst layer can be manufactured without conducting complicated manufacturing steps by providing the manufacturing step of the catalyst layer of the anode with the paste manufacturing step and the sheet formation step. The substrate in the above sheet formation step is not specifically limited to, but is preferably, a carbon, a carbon paper, or a Teflon sheet. When using the Teflon sheet, it is preferred that the Teflon sheet is firstly applied with a paste, and then transferred on a membrane in the transferring process.
In the solid polymer electrolyte fuel cell according to the present invention, the use of a mixture of an ion conductive material, carbon, platinum powder and/or platinum alloy powder for the catalyst layer of the anode secures an electronic conduction path and passages for gas and water respectively in an independent condition. This allows efficient discharge of oxygen and water generated by the reverse voltage, and also allows the electrolysis of water without corrosion of the electro-conductive material.
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SUMMARY: INCORPORATION BY REFERENCE
Priority is claimed on Japanese Patent Application No. 2004-209216, filed Jul. 15, 2004, and Japanese Patent Application No. 2005-111742, filed Apr. 8, 2005, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention is related to a solid polymer electrolyte fuel cell and a method for manufacturing thereof, in particular, a solid polymer electrolyte fuel cell in which the output varies according to a demand load.
RELATED ART
A fuel cell uses hydrogen gas as a fuel gas and generates energy by an electrochemical reaction of hydrogen and oxygen. There are various types of fuel cells including a phosphoric acid fuel cell, a molten carbonate fuel cell, a solid electrolyte type fuel cell, and a solid polymer electrolyte fuel cell. Among these, a solid polymer electrolyte fuel cell can start operation at a normal temperature and can also provide higher output with small configuration, and thus holds great promise as a power source for two-wheeled or four-wheeled vehicles, or portable power supply. In the case where such a solid polymer electrolyte fuel cell is actually used, a electrode structure, a basic unit of a fuel cell, is held between separators to make a single cell, and then combined with several tens to hundreds of single cells to be used as a stack (battery).
As shown inFIGS. 9A and 9B, there are two kinds of fuel cell systems that combine the above-mentioned fuel cell with a motor. One of these is a fuel cell-storage element (battery) hybrid system (shown inFIG. 9A), and the other is a fuel cell direct connection system (shown inFIG. 9B) in which a fuel cell is directly linked with a motor. A conventional fuel cell system ofFIG. 9Ais configured in such a way that a fuel cell6is connected to a storage element8, and the storage element8is connected to a motor7in series. This allows the fuel cell6in a vehicle to continuously feed a constant amount of electric current without being influenced by a change in acceleration. As in the case with a fuel cell direct connection system ofFIG. 9B, the fuel cell6and the storage element8for storing electricity is directly connected in parallel to the motor7and mounted to a vehicle, it is necessary at the anode side to supply hydrogen flexibly corresponding to changes in the output generated according to changes in the acceleration of the vehicle, however, the hydrogen supplied as a fuel is in a state of gas, and poorly responds in controlling the amount of supply. It is therefore difficult for the system to supply hydrogen corresponding to the increase in the amount of current, and to deal flexibly with the changes in the output. As a result, fuel shortage arises temporarily in an electrode structure.
In connection with the fuel shortage, electrolysis of water advances in the anode in order to compensate the decreased supply amount of electrons, and the so-called reverse voltage arises. When the electrolysis of water occurs in the anode, it will cause a corrosion of the carbon used for the catalyst carrier in the catalyst layer which constitutes the anode, and will result in a deterioration of the performance. The deterioration of the performance of the anode will lead to a deterioration of the power generation performance of the fuel cell as a whole.
In order to solve these problems, two roughly divided methods have been examined. One of these is a method of promoting electrolysis of water (refer to Patent document 1 (International Publication No. WO01/15274), Patent Document 2 (International Publication No. WO01/15249), and Patent Document 3 (International Publication No. WO01/15255)), and the other is a method of improving the corrosion resistance of the material used for an electrode (refer to Patent document 4 (International Publication No. WO01/15254)).
Patent document 1 discloses that a catalyst layer of the anode is mixed with a catalyst which promotes the electrolysis of water. This prevents oxidization of the carbon by the reverse voltage generated by a fuel shortage. Patent document 2 discloses that a foundation layer or catalyst layer of the anode is added with a PTFE resin (Teflon: registered trademark) or graphite to increase the water content of the anode. The electrolysis of water arising in a priority basis at the time of generation of the reverse voltage prevents the corrosion of the carbon of the catalyst carrier. Patent document 3 further discloses that the catalyst layer of the anode is mixed with a catalyst that promotes electrolysis of water and then the foundation layer or catalyst layer in the anode is added with the PTFE resin or a carbon in a form of graphite. This increases the amount of water in the anode catalyst layer and to control the oxidization of carbon generated by reverse voltage. Patent document 4 further discloses that the increase in the rate of catalyst support in the catalyst layer or the improvement in the corrosion resistance of the catalyst carrier controls the degradation of the anode component.
The methods disclosed in Patent Documents 1 through 4 control the corrosion of carbon, however, does not fully satisfy the resistance property to the reverse voltage. These methods are effective in the case of a temporary fuel shortage, however, in actual operation, speed fluctuation is conducted rapidly and repeatedly and the fuel shortage incurs, and resulting in the degradation of the power generation performance due to a development of corrosion reaction of carbon.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide, for a fuel cell of which output varies according to the demand load, an electrode for a fuel cell and a fuel cell which can hold a property of high power generation and has a sufficient durability even when the reverse voltage is generated by a fuel shortage accompanied by a rapid change in the output.
More specifically, the present invention provides the followings:
(1) A solid polymer electrolyte fuel cell which varies an output according to a demand load, comprising: a plurality of electrode structures comprising an anode and a cathode, each having a diffusion layer and a catalyst layer, and polymer electrolyte membrane held between the anode and the cathode; and a plurality of separators for holding the respective electrode structures, comprising a fuel gas passage for supplying and discharging fuel gas containing hydrogen on a surface opposing the anode; and an oxidant gas passage for supplying and discharging oxidant gas on a surface opposing the cathode, the electrode structures between the separators being stacked, wherein the catalyst layer of the anode comprises a mixture of an ion conductive material, a platinum powder and/or platinum alloy powder and a carbon, the platinum powder and/or platinum alloy powder and carbon substantially exist independently from each other, and the catalyst layer of the cathode comprises a metal support mixture in which the ion conductive material and the electro-conductive material which has the supported catalyst material are mixed.
According to the invention shown in (1), the use of a mixture of an ion conductive material, a platinum powder and/or platinum alloy powder, and a carbon in the catalyst layer of the anode (negative electrode) makes it possible for the catalyst reaction and electronic conduction to be performed in an aggregate of platinum powder and/or platinum alloy powder. Since the platinum powder and/or platinum alloy powder and carbon substantially exist independently from each other, a contact ratio with carbon, platinum powder and/or platinum alloy powder can be made smaller. Since carbon securest the passages for gas and water in the catalyst layer, the water and oxygen generated by the reverse voltage can efficiently be discharged. This advances the electrolysis of water at the time of fuel shortage without having the corrosion of carbon.
Hereinafter, the “ion conductive material” is referred to as a polymer electrolyte. The “platinum alloy powder” includes, for example, a platinum-ruthenium alloy. The state of “substantially independent” is referred to as a platinum powder and/or platinum alloy powder in a state not supported by carbon. The state indicates the powder that exists separately from each other, however, the state also includes the powder that is mutually in contact with each other. Further, it is not intended to exclude a material which entraps impurities. In a fuel cell according to the present invention, the electrode structures comprising the anodes; the cathode; and the polymer electrolyte membrane held between the anode and the cathode, and the separators holding the electrode structures, are stacked. Preferably, the separators hold individual electrode structure from the anode side or the cathode side, however, one separator may have a shape with the anode and the cathode of the next electrode structure.
(2) A solid polymer electrolyte fuel cell according to (1) wherein the platinum alloy powder is a platinum ruthenium alloy having an average particle size of 3 nm to 10 nm.
According to the invention shown in (2), by setting a mean particle size of a platinum ruthenium alloy to a range described above, the solid polymer electrolyte fuel cell enables to yield a higher durability with higher terminal voltage.
From a viewpoint of preventing carbon monoxide poisoning, it is particularly preferable to use platinum ruthenium alloy instead of a single use of platinum powder for the catalyst layer in the anode layer. However, the ruthenium ingredient (alloy ingredient) will be eluted when fuel shortage arises during the use of the platinum ruthenium alloy. The range of the average particle size of platinum alloy is thus important when platinum alloy is used for the catalyst layer. For example, when the average particle size is less than 3 nm in which the specific surface area is larger and more activity points exist, the terminal voltage is inevitably higher. On the other hand, at the time of fuel shortage, the dissolution reaction of alloy ingredient progresses faster than the corrosion reaction of a carbon material and leads to a decreased durability. When an average particle size is not less than 10 nm in which the specific surface area is smaller and fewer activity points exist, the terminal voltage is inevitably lower.
(3) The solid polymer electrolyte fuel cell according to (1) or (2) wherein the specific surface area of the carbon is in a range of no less than 50 m2/g and no more than 800 m2/g.
According to the invention described in (3), setting the specific surface area of carbon to a range of no less than 50 m2/g and no more than 800 m2/g allows more efficient discharge of the generated gas and water. When the specific surface area is no more than 50 m2/g, it is difficult to secure the diffusion passage of the gas and rapidly reduces the power generation performance.
(4) The solid polymer electrolyte fuel cell according to any one of (1) to (3) in which no less than 40% and no more than 100% of particles exist with a distance of no less than 100 nm between the electro-conductive material and the noble metal powder.
According to the invention described in (4), setting the distance at 100 nm and more between the electro-conductive material and the noble metal powder allows the electronic conduction path to be supported only by noble metal powder. When the distance is set at 100 nm or less, however, the portion of electronic conduction path through electro-conductive material becomes larger, and the rate at which the electronic conduction path is intercepted due to the corrosion of an electro-conductive material upon occurrence of reverse voltage becomes higher.
(5) A method for manufacturing a solid polymer electrolyte fuel cell which varies according to a demand load, comprising the steps of: manufacturing an anode and a cathode each having a diffusion layer and a catalyst layer; manufacturing a plurality of electrode structures in which polymer electrolyte membrane is held between the anode and the cathode; holding the electrode structures between a plurality of separators comprising a fuel gas passage for supply and discharge of fuel gas containing hydrogen on a surface opposing the anode; and a passage for oxidant gas for supply and discharge of oxidant gas on a surface opposing the cathode and stacking the electrode structures held between the separators; manufacturing a paste by mixing an ion conductive material, platinum powder and/or platinum alloy powder, and carbon, and forming an electrode sheet by applying the paste onto a substrate formed in a continuous sheet, to form the catalyst layer of the anode.
According to the invention described in (5), a catalyst layer can be manufactured without conducting complicated manufacturing steps by providing the manufacturing step of the catalyst layer of the anode with the paste manufacturing step and the sheet formation step. The substrate in the above sheet formation step is not specifically limited to, but is preferably, a carbon, a carbon paper, or a Teflon sheet. When using the Teflon sheet, it is preferred that the Teflon sheet is firstly applied with a paste, and then transferred on a membrane in the transferring process.
In the solid polymer electrolyte fuel cell according to the present invention, the use of a mixture of an ion conductive material, carbon, platinum powder and/or platinum alloy powder for the catalyst layer of the anode secures an electronic conduction path and passages for gas and water respectively in an independent condition. This allows efficient discharge of oxygen and water generated by the reverse voltage, and also allows the electrolysis of water without corrosion of the electro-conductive material.
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7763041 | FIELD OF THE INVENTION
The present invention relates generally to surgical instruments and methods, and more specifically to devices and methods for surgical wound closure, tissue approximation and attachment, and vascular anastomosis, especially coronary artery anastomosis.
BACKGROUND OF THE INVENTION
In coronary artery disease, one or more of the coronary arteries which supply oxygenated blood to the heart are partially or entirely blocked by a build-up of atherosclerotic plaque within the artery. This deprives the heart muscle of oxygen and nutrients, leading to myocardial infarction and even death.
Coronary artery bypass grafting remains the gold standard for the surgical treatment of severe coronary artery disease. In coronary artery bypass grafting, or CABG, a graft vessel is used to bypass a blockage in a coronary artery by connecting the distal end of the graft vessel to the coronary artery downstream of the blockage and connecting the proximal end of the graft vessel to a source of arterial blood upstream of the blockage. Various types of graft vessels may be used, including a saphenous vein taken from the patient's leg, a radial artery removed from the patient's forearm, or a prosthetic graft made of expanded polytetrafluoroethylene, Dacron, or other suitable material. Additionally, the left or right internal mammary arteries, which originate from the subclavian artery and reside on the top of the chest wall, may be resected at a distal location and left intact proximally, the free distal end then being connected to the diseased coronary artery downstream of the blockage. Similarly, the gastroepiploic artery, which originates from the gastroduodenal artery in the abdomen, may be resected at a distal location in the abdomen and passed into the thorax through a puncture in the diaphragm for attachment to the diseased coronary artery. Other types of graft vessels may also be used, as well as combinations of several different types of graft vessels in order to bypass multiple coronary blockages.
The surgical interconnection of two vascular structures, such as a graft vessel and a coronary artery, is a process known as anastomosis. In CABG, the anastomosis of a graft vessel to a coronary artery is particularly challenging. Several factors contribute to this challenge. First, the scale of the vessels is extremely small, the coronary arteries having a diameter on the order of about 1-5 mm, and the graft vessels having a diameter on the order of about 1-4 mm for an arterial graft such as a mammary artery, or about 4-8 mm for a vein graft. In addition, the completed anastomosis must not only provide a sealed connection and a patent blood flow path between the graft vessel and the coronary artery, but must further provide a connection which minimizes the exposure of the blood to foreign material or external vessel surfaces which can cause thrombosis at the anastomosis site. Moreover, recent studies suggests that the anastomosis site should not be dramatically different in compliance relative to either the coronary artery or the vascular graft, since such a “compliance mismatch” may also cause thrombus to form at the anastomosis.
Suturing is the technique of choice for coronary anastomosis in the vast majority of CABG cases today. The anastomosis is performed by creating a small opening, or arteriotomy, in the coronary artery, and passing a series of running stitches through the walls of the graft vessel and the coronary artery, respectively, around the perimeter of the arteriotomy so as to compress the end of the graft vessel against the side wall of the coronary artery. The surgeon has a great deal of flexibility in selecting the optimum location for each stitch, based on the shape, structure and condition of the two vessels. The suture needle may be placed initially through the graft vessel wall, and, before the two vessels are closely approximated, the needle then independently placed through the desired location in the target vessel wall. The suture is then tensioned to approximate the two vessels and create a tight, hemostatic seal. The sutured anastomosis thus offers a secure, sealed and patent connection between the two vessels, while having a substantial degree of compliance due to the flexible nature of the suture material.
A drawback of the sutured anastomosis is, however, the high degree of skill, dexterity, and acute visualization required. In addition, the completion of the anastomosis takes a significant amount of time, during which the patient is maintained under cardioplegic arrest and cardiopulmonary bypass. The period of cardioplegic arrest should generally be minimized in order to minimize damage to the heart muscle. Further, in recent years, some attempts have been made at reducing the invasiveness and trauma of CABG surgery by working through smaller incisions or “ports” between the ribs and using endoscopic surgical techniques. Performing microvascular anastomoses with conventional sutures is extremely difficulty when working through small ports, particularly if direct vision of the anastomosis site is not possible and reliance upon endoscopic visualization techniques is necessitated.
Various ideas have been proposed for simplifying and accelerating the process of coronary anastomosis using sutureless anastomosis devices. For example, in U.S. Pat. No. 4,350,160 to Kolesov et al., a device is disclosed for creating an end-to-end anastomosis by everting each vessel end over a split bushing and driving a plurality of staples through the everted vessel ends. For coronary anastomosis, this device requires that the coronary artery be severed downstream of the blockage and the downstream end dissected away from the surface of the heart in order to allow it to be connected end-to-end to the graft vessel. This adds an undesirable increase in time, difficulty and risk to the procedure. In addition, the staples in the Kolesov device are always positioned in a fixed pattern, allowing no flexibility in selecting the location in which each staple is to be driven through the vessels.
In U.S. Pat. No. 4,624,257 to Berggren et al., a device is disclosed for creating either end-to-end or end-to-side anastomoses. The device consists of a pair of rigid rings each having a central opening through which the end of the coronary or graft vessel may be drawn through and everted over the ring. A set of sharp pins extend outwardly from the face of each ring and pierce through the vessel wall to maintain the vessel in the everted configuration. The rings are then joined together to align the end of the graft vessel with the opening in the target vessel. While this device may be suitable for end-to-side anastomosis, eliminating the need to sever and isolate a free end of the coronary artery, the device requires that the side wall of the coronary artery be everted through the central opening of the ring, a maneuver which is likely to be extremely difficult in coronary anastomosis due to the structure and size of the coronary arteries. Moreover, the use of rigid rings that completely encircle the graft vessel and the arteriotomy creates a severe compliance mismatch at the anastomosis site which could lead to thrombosis.
An additional device which has been proposed for end-to-side anastomosis is seen in U.S. Pat. No. 5,234,447 to Kaster et al. This device consists of a rigid ring having a plurality of pointed legs extending from the ring axially in the distal direction and a plurality of angled legs extending axially from the ring in the proximal direction. The graft vessel is placed through the middle of the ring and the end is everted over the pointed legs, which puncture the vessel wall and retain it on the ring. The pointed legs are then bent outwardly, and the everted end of the graft vessel and the outwardly-oriented pointed legs are inserted through an arteriotomy in the target vessel so that the pointed legs engage the interior wall of the target vessel. The angled legs on the proximal end of the ring are then bent toward the target vessel to penetrate the outer wall thereof. While the Kaster device has a simple one-piece design and avoids the need to evert the wall of the target vessel over the device as proposed in Berggren, the device maintains a rigid ring structure which results in inadequate compliance at the anastomosis. In addition, the rigidity of Kaster's device leaves the surgeon little flexibility in selecting the optimum location where each leg of the device should be driven into the graft and target vessels, in contrast to the flexibility available when placing suture stitches.
U.S. Pat. No. 4,586,503 to Kirsch et al. discloses an alternative scheme for creating microvascular anastomoses. The Kirsch device consists of a plurality of individual clips each consisting of a pair of arcuate legs interconnected by a bridging section. The edges of the vascular tissue to be anastomosed are approximated and everted outwardly so that a clip can be placed over the tissue edges, and the clip is then crimped to permanently deform the legs in an inward position. The clip thereby retains the edges of the tissue together without puncturing the tissue. A plurality of clips are placed around the graft vessel in this manner to accomplish the anastomosis. The Kirsch device eliminates the compliance problems of rigid ring-type devices, and allows the surgeon the flexibility to select the optimum location for the placement of each clip. However, the Kirsch clips suffer from several disadvantages. For example, placement of the clips while maintaining eversion and approximation of the tissue edges is difficult and time-consuming. Typically, two pairs of forceps are needed to hold the tissue edges in approximation while a third hand applies the clip, in contrast to suturing, where only one tissue edge needs to be held at one time while the suture needle is driven through it. The Kirsch clips are especially awkward in endoscopic applications, where access, visualization, and maneuverability of instruments are limited. Moreover, in end-to-side anastomosis, the tissue edges along the arteriotomy must be everted outwardly and approximated with the everted end of the graft vessel, a maneuver which becomes increasingly difficult as the ends of the arteriotomy are approached. In addition, due to variation in vessel size and structure, variation in the crimping force applied, and other factors, the clips may not reliably maintain the anastomotic connection.
In view of the foregoing, devices and methods are needed which facilitate the performance of vascular anastomosis, especially coronary anastomosis, but which eliminate the various drawbacks of prior devices. The devices and methods should allow the surgeon to select the specific locations on the graft and target vessels where the device is to be applied, similar to selecting the location of each stitch in a sutured anastomosis. The devices and methods should be relatively simple to utilize without requiring an undue degree of skill and dexterity, even at the small scale of the coronary arteries, and even in endoscopic applications. The devices and methods should be useful for performing end-to-side, end-to-end and side-to-side anastomoses. Further, the devices and methods should produce an anastomosis which is reliably sealed and patent, with a degree of compliance comparable to sutured anastomosis.
SUMMARY OF THE INVENTION
The invention provides surgical clips and methods that meet the foregoing needs, and that are useful not only for coronary anastomosis, but for anastomosis of a variety of other vascular structures, as well as in ligation, wound closure and other tissue approximation and attachment applications. The invention offers a simple and convenient solution to coronary anastomosis, allowing the anastomosis to be performed using only two hands more quickly and easily than existing devices, but with the hemostasis, patency, compliance and reliability of sutures. The devices and methods of the invention are useful not only in conventional open surgical procedures, but in endoscopic, laparoscopic, thoracoscopic and other minimally-invasive procedures as well.
In a first embodiment of the invention, a surgical clip is provided for approximating or attaching a first tissue layer to a second tissue layer. The first and second tissue layers may be any of various tissue structures, such as flaps of tissue adjacent to a wound or incision in a vessel, organ or body wall, but the invention is particularly suitable for vascular anastomosis, wherein a graft vessel is joined to a target vessel. The graft vessel has a free end and a graft vessel wall defining a graft lumen. The target vessel has a target vessel wall defining a target lumen and has an opening in the target vessel wall, which may be an incision or other opening formed in the target vessel wall (for end-to-side or side-to-side anastomoses), or an opening at a free end of the target vessel (for end-to-end anastomoses). The surgical clip includes a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end. The distal end is configured to penetrate through the graft vessel wall near the free end and through the target vessel wall near the opening such that both the distal and proximal ends of the clip body are outside the graft and target vessels. At least a portion of the clip body is shapable so as to compress the graft vessel wall against the target vessel wall with the target vessel lumen in communication with the graft vessel lumen.
By penetrating the graft and target vessel walls, the surgical clip provides the long-term reliability of a sutured connection. In addition, maintaining both ends of the clip outside of both the graft and target vessels minimizes the amount of foreign material contacting blood, eliminates the need for an internal anvil which must be removed after clip application, facilitates visual confirmation of successful application of the clip, and permits manipulation of the ends of the clip to re-apply, reposition or remove the clip. Further, the surgical clip provides a reliable hemostatic seal by having a deformable portion which compresses the graft vessel wall against the target vessel wall. Moreover, through the use of a plurality of individual surgical clips, the invention provides the surgeon with the flexibility to select the ideal location on both the target and graft vessel walls to which each clip should be applied, depending upon vessel structure, condition and shape. The use of multiple independent clips also produces an anastomotic connection having compliance comparable to a sutured anastomosis.
The surgical clip may have a variety of configurations. The clip body will generally have an outer surface against which the graft and target vessel walls are compressed. In one embodiment, the proximal extremity comprises a leg extending from the clip body that is movable between an open position spaced apart from the distal extremity and a closed position closer to the distal extremity. The proximal extremity has an inner surface which faces the outer surface of the clip body in the closed position. The clip body is thus “shaped” by moving the proximal extremity into the closed position, thereby compressing the graft and target vessel walls between the inner and outer surfaces. The proximal extremity may be hingedly coupled to the clip body to facilitate movement thereof, but is preferably configured to be inelastically deformed from the open into the closed position.
The movable proximal extremity may also be configured to contact or to extend across the distal extremity in the closed position. In one configuration, the proximal extremity has an end portion which includes two generally parallel segments which extend across the distal extremity in the closed position and a slot between the parallel segments for receiving the distal extremity. The proximal extremity may also be configured to shield the distal end of the distal extremity in the closed position to prevent inadvertent injury to tissue. Preferably, the proximal extremity is configured to prevent its passage through the graft and target vessel walls. For example, the proximal extremity may have a cross-sectional area which is substantially larger than that of the distal extremity so that it cannot pass through the puncture created by the distal extremity. The proximal extremity may also be oriented at an angle, usually at least about 90°, relative to the distal extremity to inhibit its passage through the vessel walls.
In another embodiment, the distal extremity is movable between an open position spaced apart from the proximal extremity and a closed position closer to the proximal extremity, and the distal extremity has an inner surface which compresses the graft and target vessel walls against the outer surface of the clip body in the closed position. Preferably, the distal extremity is inelastically deformable into the closed position.
The distal extremity is preferably oriented such that its inner surface is at an angle of at most about 90° relative to the outer surface of the clip body. The inner surface (or the entire distal extremity) may also be arcuate in shape. The distal extremity is usually tapered to a sharp point at its distal end to facilitate penetration of the graft and target vessel walls. One or more barbs may be provided near the distal end to maintain the graft and target vessel walls on the distal extremity.
The invention also provides an applier for applying the surgical clip. The applier includes a holding mechanism for releasably holding a surgical clip and a shaping mechanism for shaping the clip so as to compress the graft vessel wall against the target vessel wall. Although a variety of holding mechanisms are possible, in one embodiment the holding mechanism comprises a pin at the distal end of the applier, in which case the surgical clip includes a middle portion having an aperture for receiving the pin. Various types of shaping mechanisms are also possible, but in an exemplary configuration, the clip applier includes an inner shaft and an outer shaft axially movable with respect to each other. The clip is held by a first of the inner and outer shafts, and the clip body is shaped by engagement with a second of the inner and outer shafts. In a particularly preferred aspect, the clip applier is configured for endoscopic, laparoscopic, thoracoscopic, or other minimally-invasive procedures, by holding the clip at the end of a small-profile elongated shaft suitable for positioning through a small incision, trocar sleeve, tubular port, cannula or the like. An actuator at the proximal end of the shaft permits remote application of the clip from outside the body cavity.
In another embodiment, the surgical clip of the invention comprises a clip body, a needle portion extending from the clip body that has a distal end configured to penetrated the graft and target vessel walls and to extend outside of the graft and target vessels. The clip body is configured to prevent its passage through the graft and target vessel walls so that it remains outside of the graft and target vessels. A retainer is further provided on the clip for retaining the graft and target vessel walls on the needle portion.
In one configuration, the retainer comprises a leg attached to the clip body and movable from an open position spaced apart from the needle portion to a closed position closer to the needle portion. The leg may be hingedly movable or inelastically deformable into the closed position. Preferably, the retainer is configured to compress the graft vessel wall against the target vessel wall for reliable hemostasis. The leg may also be configured to shield the distal end of the needle portion in the closed position.
Alternatively, the retainer may comprise a barb or other retention device on the needle portion itself. A plurality of barbs may be provided at spaced apart positions along the extremity of the needle portion so that the needle portion may be passed through the graft and target vessel walls a desired amount and the barbs will prevent the needle portion from backing out of the vessel walls. As an alternative to barbs, a retainer which is unidirectionally slidable or threadable onto the needle portion may be provided which is placed on the needle portion after it has been passed through the graft and target vessel walls. The needle portion is preferably hook-shaped, J-shaped or oriented at an angle of at least about 90° relative to the clip body so that the needle portion may be advanced through the vessel walls until its curved portion or the clip body engages the vessel wall. The barbs or other retaining devices are positioned relative to the clip body so as to maintain the graft vessel wall in compression against the target vessel wall.
In an additional embodiment, the surgical clips of the invention are configured to be coupled to a flexible ring-shaped band, which is preferably a continuous ring of suture, metal or plastic wire or strip, or other flexible material. The band defines a central opening through which the graft vessel may be received. Each clip has a first portion for engaging the graft vessel wall, and a second portion for engaging the target vessel wall, the first and second portions being configured to retain the graft vessel wall in sealing engagement with the target vessel wall. A plurality of clips are positionable at spaced-apart locations around the band. In this way, application of the clips to the vessels is accomplished by simply placing the band over the end of the graft vessel and applying each clip to the vessel wall. The graft vessel may then be positioned adjacent to the opening in the target vessel and each clip applied to the target vessel wall to create a sealed anastomotic connection. The band may be either left in place, or configured for removal by cutting or other wise detaching the ring from the clips.
Preferably, the clips are coupled to the band so as to be slidable to the desired position around the perimeter of the band. In one configuration, the clips have a loop or eyelet through which the band may be slidably received. The clips in this embodiment may have any of various configurations suitable for vascular anastomosis, including those described above, as well as other configurations not specifically described.
In a preferred embodiment, a method of joining a graft vessel to a target vessel according to the invention comprises providing a plurality of surgical clips each including a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end; penetrating the graft vessel wall and the target vessel wall with the distal extremity of each surgical clip such that the distal and proximal ends are disposed outside of the graft and target vessels; and shaping a portion of each clip body outside of the graft and target vessels so as to compress the graft vessel wall against the target vessel wall with the graft lumen in communication with the target lumen. In this way, a robust, reliable and hemostatic anastomosis is provided which is simple and convenient to perform using only two hands, which minimizes the amount of foreign material in contact with the blood stream, which allows the surgeon to place each clip in the optimum location based on the size, shape and condition of the vessels, and which provides a degree of compliance in the completed anastomosis comparable to that of sutured anastomoses. The invention thus combines the ease of application, flexibility of position, reliability, and compliance of sutures, with the convenience and quickness of surgical clips.
Because of its simplicity and convenience, the invention is particularly well-adapted for use in endoscopic, laparoscopic, thoracoscopic and other minimally-invasive applications. The clips may be applied to a body structure using slender instruments positioned through percutaneous ports such as trocar sleeves, tubular cannulas, or small incisions, under direct visualization through such ports or under video-based visualization by means of an endoscope positioned through a port.
The nature and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates generally to surgical instruments and methods, and more specifically to devices and methods for surgical wound closure, tissue approximation and attachment, and vascular anastomosis, especially coronary artery anastomosis.
BACKGROUND OF THE INVENTION
In coronary artery disease, one or more of the coronary arteries which supply oxygenated blood to the heart are partially or entirely blocked by a build-up of atherosclerotic plaque within the artery. This deprives the heart muscle of oxygen and nutrients, leading to myocardial infarction and even death.
Coronary artery bypass grafting remains the gold standard for the surgical treatment of severe coronary artery disease. In coronary artery bypass grafting, or CABG, a graft vessel is used to bypass a blockage in a coronary artery by connecting the distal end of the graft vessel to the coronary artery downstream of the blockage and connecting the proximal end of the graft vessel to a source of arterial blood upstream of the blockage. Various types of graft vessels may be used, including a saphenous vein taken from the patient's leg, a radial artery removed from the patient's forearm, or a prosthetic graft made of expanded polytetrafluoroethylene, Dacron, or other suitable material. Additionally, the left or right internal mammary arteries, which originate from the subclavian artery and reside on the top of the chest wall, may be resected at a distal location and left intact proximally, the free distal end then being connected to the diseased coronary artery downstream of the blockage. Similarly, the gastroepiploic artery, which originates from the gastroduodenal artery in the abdomen, may be resected at a distal location in the abdomen and passed into the thorax through a puncture in the diaphragm for attachment to the diseased coronary artery. Other types of graft vessels may also be used, as well as combinations of several different types of graft vessels in order to bypass multiple coronary blockages.
The surgical interconnection of two vascular structures, such as a graft vessel and a coronary artery, is a process known as anastomosis. In CABG, the anastomosis of a graft vessel to a coronary artery is particularly challenging. Several factors contribute to this challenge. First, the scale of the vessels is extremely small, the coronary arteries having a diameter on the order of about 1-5 mm, and the graft vessels having a diameter on the order of about 1-4 mm for an arterial graft such as a mammary artery, or about 4-8 mm for a vein graft. In addition, the completed anastomosis must not only provide a sealed connection and a patent blood flow path between the graft vessel and the coronary artery, but must further provide a connection which minimizes the exposure of the blood to foreign material or external vessel surfaces which can cause thrombosis at the anastomosis site. Moreover, recent studies suggests that the anastomosis site should not be dramatically different in compliance relative to either the coronary artery or the vascular graft, since such a “compliance mismatch” may also cause thrombus to form at the anastomosis.
Suturing is the technique of choice for coronary anastomosis in the vast majority of CABG cases today. The anastomosis is performed by creating a small opening, or arteriotomy, in the coronary artery, and passing a series of running stitches through the walls of the graft vessel and the coronary artery, respectively, around the perimeter of the arteriotomy so as to compress the end of the graft vessel against the side wall of the coronary artery. The surgeon has a great deal of flexibility in selecting the optimum location for each stitch, based on the shape, structure and condition of the two vessels. The suture needle may be placed initially through the graft vessel wall, and, before the two vessels are closely approximated, the needle then independently placed through the desired location in the target vessel wall. The suture is then tensioned to approximate the two vessels and create a tight, hemostatic seal. The sutured anastomosis thus offers a secure, sealed and patent connection between the two vessels, while having a substantial degree of compliance due to the flexible nature of the suture material.
A drawback of the sutured anastomosis is, however, the high degree of skill, dexterity, and acute visualization required. In addition, the completion of the anastomosis takes a significant amount of time, during which the patient is maintained under cardioplegic arrest and cardiopulmonary bypass. The period of cardioplegic arrest should generally be minimized in order to minimize damage to the heart muscle. Further, in recent years, some attempts have been made at reducing the invasiveness and trauma of CABG surgery by working through smaller incisions or “ports” between the ribs and using endoscopic surgical techniques. Performing microvascular anastomoses with conventional sutures is extremely difficulty when working through small ports, particularly if direct vision of the anastomosis site is not possible and reliance upon endoscopic visualization techniques is necessitated.
Various ideas have been proposed for simplifying and accelerating the process of coronary anastomosis using sutureless anastomosis devices. For example, in U.S. Pat. No. 4,350,160 to Kolesov et al., a device is disclosed for creating an end-to-end anastomosis by everting each vessel end over a split bushing and driving a plurality of staples through the everted vessel ends. For coronary anastomosis, this device requires that the coronary artery be severed downstream of the blockage and the downstream end dissected away from the surface of the heart in order to allow it to be connected end-to-end to the graft vessel. This adds an undesirable increase in time, difficulty and risk to the procedure. In addition, the staples in the Kolesov device are always positioned in a fixed pattern, allowing no flexibility in selecting the location in which each staple is to be driven through the vessels.
In U.S. Pat. No. 4,624,257 to Berggren et al., a device is disclosed for creating either end-to-end or end-to-side anastomoses. The device consists of a pair of rigid rings each having a central opening through which the end of the coronary or graft vessel may be drawn through and everted over the ring. A set of sharp pins extend outwardly from the face of each ring and pierce through the vessel wall to maintain the vessel in the everted configuration. The rings are then joined together to align the end of the graft vessel with the opening in the target vessel. While this device may be suitable for end-to-side anastomosis, eliminating the need to sever and isolate a free end of the coronary artery, the device requires that the side wall of the coronary artery be everted through the central opening of the ring, a maneuver which is likely to be extremely difficult in coronary anastomosis due to the structure and size of the coronary arteries. Moreover, the use of rigid rings that completely encircle the graft vessel and the arteriotomy creates a severe compliance mismatch at the anastomosis site which could lead to thrombosis.
An additional device which has been proposed for end-to-side anastomosis is seen in U.S. Pat. No. 5,234,447 to Kaster et al. This device consists of a rigid ring having a plurality of pointed legs extending from the ring axially in the distal direction and a plurality of angled legs extending axially from the ring in the proximal direction. The graft vessel is placed through the middle of the ring and the end is everted over the pointed legs, which puncture the vessel wall and retain it on the ring. The pointed legs are then bent outwardly, and the everted end of the graft vessel and the outwardly-oriented pointed legs are inserted through an arteriotomy in the target vessel so that the pointed legs engage the interior wall of the target vessel. The angled legs on the proximal end of the ring are then bent toward the target vessel to penetrate the outer wall thereof. While the Kaster device has a simple one-piece design and avoids the need to evert the wall of the target vessel over the device as proposed in Berggren, the device maintains a rigid ring structure which results in inadequate compliance at the anastomosis. In addition, the rigidity of Kaster's device leaves the surgeon little flexibility in selecting the optimum location where each leg of the device should be driven into the graft and target vessels, in contrast to the flexibility available when placing suture stitches.
U.S. Pat. No. 4,586,503 to Kirsch et al. discloses an alternative scheme for creating microvascular anastomoses. The Kirsch device consists of a plurality of individual clips each consisting of a pair of arcuate legs interconnected by a bridging section. The edges of the vascular tissue to be anastomosed are approximated and everted outwardly so that a clip can be placed over the tissue edges, and the clip is then crimped to permanently deform the legs in an inward position. The clip thereby retains the edges of the tissue together without puncturing the tissue. A plurality of clips are placed around the graft vessel in this manner to accomplish the anastomosis. The Kirsch device eliminates the compliance problems of rigid ring-type devices, and allows the surgeon the flexibility to select the optimum location for the placement of each clip. However, the Kirsch clips suffer from several disadvantages. For example, placement of the clips while maintaining eversion and approximation of the tissue edges is difficult and time-consuming. Typically, two pairs of forceps are needed to hold the tissue edges in approximation while a third hand applies the clip, in contrast to suturing, where only one tissue edge needs to be held at one time while the suture needle is driven through it. The Kirsch clips are especially awkward in endoscopic applications, where access, visualization, and maneuverability of instruments are limited. Moreover, in end-to-side anastomosis, the tissue edges along the arteriotomy must be everted outwardly and approximated with the everted end of the graft vessel, a maneuver which becomes increasingly difficult as the ends of the arteriotomy are approached. In addition, due to variation in vessel size and structure, variation in the crimping force applied, and other factors, the clips may not reliably maintain the anastomotic connection.
In view of the foregoing, devices and methods are needed which facilitate the performance of vascular anastomosis, especially coronary anastomosis, but which eliminate the various drawbacks of prior devices. The devices and methods should allow the surgeon to select the specific locations on the graft and target vessels where the device is to be applied, similar to selecting the location of each stitch in a sutured anastomosis. The devices and methods should be relatively simple to utilize without requiring an undue degree of skill and dexterity, even at the small scale of the coronary arteries, and even in endoscopic applications. The devices and methods should be useful for performing end-to-side, end-to-end and side-to-side anastomoses. Further, the devices and methods should produce an anastomosis which is reliably sealed and patent, with a degree of compliance comparable to sutured anastomosis.
SUMMARY OF THE INVENTION
The invention provides surgical clips and methods that meet the foregoing needs, and that are useful not only for coronary anastomosis, but for anastomosis of a variety of other vascular structures, as well as in ligation, wound closure and other tissue approximation and attachment applications. The invention offers a simple and convenient solution to coronary anastomosis, allowing the anastomosis to be performed using only two hands more quickly and easily than existing devices, but with the hemostasis, patency, compliance and reliability of sutures. The devices and methods of the invention are useful not only in conventional open surgical procedures, but in endoscopic, laparoscopic, thoracoscopic and other minimally-invasive procedures as well.
In a first embodiment of the invention, a surgical clip is provided for approximating or attaching a first tissue layer to a second tissue layer. The first and second tissue layers may be any of various tissue structures, such as flaps of tissue adjacent to a wound or incision in a vessel, organ or body wall, but the invention is particularly suitable for vascular anastomosis, wherein a graft vessel is joined to a target vessel. The graft vessel has a free end and a graft vessel wall defining a graft lumen. The target vessel has a target vessel wall defining a target lumen and has an opening in the target vessel wall, which may be an incision or other opening formed in the target vessel wall (for end-to-side or side-to-side anastomoses), or an opening at a free end of the target vessel (for end-to-end anastomoses). The surgical clip includes a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end. The distal end is configured to penetrate through the graft vessel wall near the free end and through the target vessel wall near the opening such that both the distal and proximal ends of the clip body are outside the graft and target vessels. At least a portion of the clip body is shapable so as to compress the graft vessel wall against the target vessel wall with the target vessel lumen in communication with the graft vessel lumen.
By penetrating the graft and target vessel walls, the surgical clip provides the long-term reliability of a sutured connection. In addition, maintaining both ends of the clip outside of both the graft and target vessels minimizes the amount of foreign material contacting blood, eliminates the need for an internal anvil which must be removed after clip application, facilitates visual confirmation of successful application of the clip, and permits manipulation of the ends of the clip to re-apply, reposition or remove the clip. Further, the surgical clip provides a reliable hemostatic seal by having a deformable portion which compresses the graft vessel wall against the target vessel wall. Moreover, through the use of a plurality of individual surgical clips, the invention provides the surgeon with the flexibility to select the ideal location on both the target and graft vessel walls to which each clip should be applied, depending upon vessel structure, condition and shape. The use of multiple independent clips also produces an anastomotic connection having compliance comparable to a sutured anastomosis.
The surgical clip may have a variety of configurations. The clip body will generally have an outer surface against which the graft and target vessel walls are compressed. In one embodiment, the proximal extremity comprises a leg extending from the clip body that is movable between an open position spaced apart from the distal extremity and a closed position closer to the distal extremity. The proximal extremity has an inner surface which faces the outer surface of the clip body in the closed position. The clip body is thus “shaped” by moving the proximal extremity into the closed position, thereby compressing the graft and target vessel walls between the inner and outer surfaces. The proximal extremity may be hingedly coupled to the clip body to facilitate movement thereof, but is preferably configured to be inelastically deformed from the open into the closed position.
The movable proximal extremity may also be configured to contact or to extend across the distal extremity in the closed position. In one configuration, the proximal extremity has an end portion which includes two generally parallel segments which extend across the distal extremity in the closed position and a slot between the parallel segments for receiving the distal extremity. The proximal extremity may also be configured to shield the distal end of the distal extremity in the closed position to prevent inadvertent injury to tissue. Preferably, the proximal extremity is configured to prevent its passage through the graft and target vessel walls. For example, the proximal extremity may have a cross-sectional area which is substantially larger than that of the distal extremity so that it cannot pass through the puncture created by the distal extremity. The proximal extremity may also be oriented at an angle, usually at least about 90°, relative to the distal extremity to inhibit its passage through the vessel walls.
In another embodiment, the distal extremity is movable between an open position spaced apart from the proximal extremity and a closed position closer to the proximal extremity, and the distal extremity has an inner surface which compresses the graft and target vessel walls against the outer surface of the clip body in the closed position. Preferably, the distal extremity is inelastically deformable into the closed position.
The distal extremity is preferably oriented such that its inner surface is at an angle of at most about 90° relative to the outer surface of the clip body. The inner surface (or the entire distal extremity) may also be arcuate in shape. The distal extremity is usually tapered to a sharp point at its distal end to facilitate penetration of the graft and target vessel walls. One or more barbs may be provided near the distal end to maintain the graft and target vessel walls on the distal extremity.
The invention also provides an applier for applying the surgical clip. The applier includes a holding mechanism for releasably holding a surgical clip and a shaping mechanism for shaping the clip so as to compress the graft vessel wall against the target vessel wall. Although a variety of holding mechanisms are possible, in one embodiment the holding mechanism comprises a pin at the distal end of the applier, in which case the surgical clip includes a middle portion having an aperture for receiving the pin. Various types of shaping mechanisms are also possible, but in an exemplary configuration, the clip applier includes an inner shaft and an outer shaft axially movable with respect to each other. The clip is held by a first of the inner and outer shafts, and the clip body is shaped by engagement with a second of the inner and outer shafts. In a particularly preferred aspect, the clip applier is configured for endoscopic, laparoscopic, thoracoscopic, or other minimally-invasive procedures, by holding the clip at the end of a small-profile elongated shaft suitable for positioning through a small incision, trocar sleeve, tubular port, cannula or the like. An actuator at the proximal end of the shaft permits remote application of the clip from outside the body cavity.
In another embodiment, the surgical clip of the invention comprises a clip body, a needle portion extending from the clip body that has a distal end configured to penetrated the graft and target vessel walls and to extend outside of the graft and target vessels. The clip body is configured to prevent its passage through the graft and target vessel walls so that it remains outside of the graft and target vessels. A retainer is further provided on the clip for retaining the graft and target vessel walls on the needle portion.
In one configuration, the retainer comprises a leg attached to the clip body and movable from an open position spaced apart from the needle portion to a closed position closer to the needle portion. The leg may be hingedly movable or inelastically deformable into the closed position. Preferably, the retainer is configured to compress the graft vessel wall against the target vessel wall for reliable hemostasis. The leg may also be configured to shield the distal end of the needle portion in the closed position.
Alternatively, the retainer may comprise a barb or other retention device on the needle portion itself. A plurality of barbs may be provided at spaced apart positions along the extremity of the needle portion so that the needle portion may be passed through the graft and target vessel walls a desired amount and the barbs will prevent the needle portion from backing out of the vessel walls. As an alternative to barbs, a retainer which is unidirectionally slidable or threadable onto the needle portion may be provided which is placed on the needle portion after it has been passed through the graft and target vessel walls. The needle portion is preferably hook-shaped, J-shaped or oriented at an angle of at least about 90° relative to the clip body so that the needle portion may be advanced through the vessel walls until its curved portion or the clip body engages the vessel wall. The barbs or other retaining devices are positioned relative to the clip body so as to maintain the graft vessel wall in compression against the target vessel wall.
In an additional embodiment, the surgical clips of the invention are configured to be coupled to a flexible ring-shaped band, which is preferably a continuous ring of suture, metal or plastic wire or strip, or other flexible material. The band defines a central opening through which the graft vessel may be received. Each clip has a first portion for engaging the graft vessel wall, and a second portion for engaging the target vessel wall, the first and second portions being configured to retain the graft vessel wall in sealing engagement with the target vessel wall. A plurality of clips are positionable at spaced-apart locations around the band. In this way, application of the clips to the vessels is accomplished by simply placing the band over the end of the graft vessel and applying each clip to the vessel wall. The graft vessel may then be positioned adjacent to the opening in the target vessel and each clip applied to the target vessel wall to create a sealed anastomotic connection. The band may be either left in place, or configured for removal by cutting or other wise detaching the ring from the clips.
Preferably, the clips are coupled to the band so as to be slidable to the desired position around the perimeter of the band. In one configuration, the clips have a loop or eyelet through which the band may be slidably received. The clips in this embodiment may have any of various configurations suitable for vascular anastomosis, including those described above, as well as other configurations not specifically described.
In a preferred embodiment, a method of joining a graft vessel to a target vessel according to the invention comprises providing a plurality of surgical clips each including a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end; penetrating the graft vessel wall and the target vessel wall with the distal extremity of each surgical clip such that the distal and proximal ends are disposed outside of the graft and target vessels; and shaping a portion of each clip body outside of the graft and target vessels so as to compress the graft vessel wall against the target vessel wall with the graft lumen in communication with the target lumen. In this way, a robust, reliable and hemostatic anastomosis is provided which is simple and convenient to perform using only two hands, which minimizes the amount of foreign material in contact with the blood stream, which allows the surgeon to place each clip in the optimum location based on the size, shape and condition of the vessels, and which provides a degree of compliance in the completed anastomosis comparable to that of sutured anastomoses. The invention thus combines the ease of application, flexibility of position, reliability, and compliance of sutures, with the convenience and quickness of surgical clips.
Because of its simplicity and convenience, the invention is particularly well-adapted for use in endoscopic, laparoscopic, thoracoscopic and other minimally-invasive applications. The clips may be applied to a body structure using slender instruments positioned through percutaneous ports such as trocar sleeves, tubular cannulas, or small incisions, under direct visualization through such ports or under video-based visualization by means of an endoscope positioned through a port.
The nature and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
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7734273 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to DC offset compensation in a frequency mixer device that mixes an input signal and a switching signal, and outputs a multiplied signal. It is particularly related to a frequency mixer device having a DC offset compensating function suitable for compensating DC offset generated when an interfering waveband signal is input when using a direct conversion wireless receiver, and a method for compensating the DC offset.
2. Description of Related Art
In recent years, technology that uses a direct-conversion system has been proposed in connection with the miniaturization and price reduction of wireless receivers. In this system an input RF (wireless frequency) signal is converted directly to a low frequency baseband signal, and so in comparison to a super heterodyne system that requires a high frequency IF (intermediate frequency) signal, it has the advantage that an intermediate frequency filter becomes unnecessary. A direct conversion system is also referred to as a zero IF system, because the center frequency of the IF signal is DC.
Frequency conversion is performed by mixing (compositing) the frequency of an input RF signal with a local signal having the same frequency using a mixer circuit. However, in a direct conversion system, when the input signal level is large, DC offset occurs in the output baseband signal when second order nonlinear distortion is present in the mixer circuit. This condition will be explained in detail with reference toFIG. 7andFIG. 8.
FIG. 7shows the spectrum of an input RF signal, with numeral101denoting a weak-level desired waveband signal with the center frequency being the same as a local signal frequency fLO, and numeral102indicating a high-level interfering waveband signal that is present at a higher frequency fINT. As a result of inputting an RF signal that accompanies this sort of high-level interfering waveband signal to a mixer circuit, the spectrum of the output signal appearing in the mixer output becomes as shown inFIG. 8. Numerals103and104respectively indicate the components that appear in the mixer output after frequency conversion of the desired waveband signal101and the interfering waveband signal102of the RF input. Numeral105indicates the DC offset generated by the high-level interfering waveband signal when second order nonlinear distortion is present in the mixer circuit.
Accordingly, in a direct conversion system, there is the problem that receiver sensitivity decreases due to the DC offset105generated in the frequency range of the desired waveband signal103of the mixer output. If the mixer circuit is composed of a differential circuit and the differential balance is completely symmetrical, second order nonlinear distortion will not be present. However, because the components constituting the differential circuit cannot be made completely symmetrical due to manufacturing irregularities, it is not possible to eliminate second order nonlinear distortion. Therefore, technology has been proposed that compensates the DC offset generated by second order nonlinear distortion.
A method for detecting an interfering waveband signal included in the input RF signal and compensating DC offset generated in the mixer output, disclosed in U.S. Pat. No. 6,535,725, is explained below with reference toFIG. 9.
InFIG. 9, numeral106indicates a mixer circuit, which is composed of a switching cell107and an RF input cell108. The switching cell107is composed of bipolar transistors Q1, Q2, Q3, and Q4. The RF input cell108is composed of bipolar transistors Q5and Q6, and resistors R. The RF signal input from RF input terminals109and110is amplified by the RF input cell108. The amplified RF signal is converted to an IF signal by being mixed with a local signal input from local input terminals111and112in the switching cell107, and this converted IF signal is output from output terminals113and114.
If all of the transistors Q1, Q2, Q3, and Q4constituting the switching cell107have exactly the same characteristics, balance as a differential circuit will be completely symmetrical. However, because the bipolar transistors Q1, Q2, Q3, and Q4each individually have properties that differ from the ideal properties due to manufacturing irregularities, second order nonlinear distortion is generated when the input RF signal is converted to an IF signal. Therefore, DC offset is generated in the mixer output as shown inFIG. 8. As is well known, because the DC offset is proportional to the square of the input signal strength, the higher the level of the interfering waveband signal included in the input signal, the greater the output DC offset will become.
On the other hand, the circuit shown inFIG. 9is provided with a DC offset compensator115. The DC offset compensator115is composed of a detector116, a controller117, and a correction generator118. The detector116detects an input RF signal and outputs a detection signal. The controller117generates a control signal in response to the detection signal. The correction generator118generates a compensation signal in response to the control signal from the controller117such that it reduces the DC offset of the mixer output terminals113and114. By this operation of the DC offset compensator115, the compensation signal that the correction generator118outputs to the mixer circuit106changes in response to the strength of the RF signal input, and the DC offset of the mixer output is cancelled. Further, in the mixer circuit106, because the second order nonlinear distortion properties of each individual element differ due to manufacturing irregularities, a function of a user interface119is also provided in the DC offset compensator115in order to adjust the control signal produced by the controller117.
However, in the method that adds a compensation signal in order to compensate the DC offset included in the mixer output signal, a low frequency noise generated within the DC offset compensator is superimposed on the compensation signal that is used. Therefore, not only the DC offset included in the mixer output signal being compensated, but also a noise signal is newly added in the frequency range of the desired waveband signal. In order to explain this condition, the spectrum of the mixer output after DC offset compensation is shown inFIG. 10. Numerals103and104respectively indicate the desired waveband signal and the interfering waveband signal appearing in the mixer output after frequency conversion in the mixer circuit, as shown inFIG. 8. A numeral120indicates the low frequency noise included in the compensation signal generated by the DC offset compensator, which ranges over the desired waveband. Therefore, the degradation of receiving sensitivity when inputting a high-level interfering waveband signal is not improved even when DC offset is compensated.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is an object of the present invention to provide a frequency mixer device that can compensate DC offset such that low frequency noise included in the DC offset compensation signal does not range over the desired waveband of the mixer output, and a DC offset compensating method, that solve the problems in the conventional technology described above.
A frequency mixer device according to the present invention is provided with a mixer circuit having an input cell that amplifies an input signal, and a switching cell that mixes the amplified input signal with a switching signal and outputs a multiplied signal; and a DC offset compensator that detects the input level of the input signal and outputs a compensation signal based on that detection signal, the compensation signal being supplied to the mixer circuit so as to compensate a DC offset included in the multiplied signal. In order to realize the objective described above, the compensation signal that the DC offset compensator outputs is added to the output signal of the input cell so as to compensate the DC offset.
A method according to the present invention is for compensating a DC offset included in a multiplied signal obtained by amplifying an input signal by an input cell and mixing the amplified input signal with a switching signal by a switching cell. In order to achieve the objective described above, the method includes: detecting a level of the input signal; generating a compensation signal for compensating the DC offset based on the level detection signal; supplying the compensation signal to the input cell, the compensation signal being added to the amplified input signal; and mixing the output of the input cell with the switching signal by the switching cell, so as to output the multiplied signal.
With the configuration described above, the low frequency noise included in the DC offset compensation signal is converted in the mixer output to a frequency near that of the switching signal, and therefore it is possible to compensate the DC offset such that the low frequency noise does not range over the desired waveband of the mixer output.
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SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to DC offset compensation in a frequency mixer device that mixes an input signal and a switching signal, and outputs a multiplied signal. It is particularly related to a frequency mixer device having a DC offset compensating function suitable for compensating DC offset generated when an interfering waveband signal is input when using a direct conversion wireless receiver, and a method for compensating the DC offset.
2. Description of Related Art
In recent years, technology that uses a direct-conversion system has been proposed in connection with the miniaturization and price reduction of wireless receivers. In this system an input RF (wireless frequency) signal is converted directly to a low frequency baseband signal, and so in comparison to a super heterodyne system that requires a high frequency IF (intermediate frequency) signal, it has the advantage that an intermediate frequency filter becomes unnecessary. A direct conversion system is also referred to as a zero IF system, because the center frequency of the IF signal is DC.
Frequency conversion is performed by mixing (compositing) the frequency of an input RF signal with a local signal having the same frequency using a mixer circuit. However, in a direct conversion system, when the input signal level is large, DC offset occurs in the output baseband signal when second order nonlinear distortion is present in the mixer circuit. This condition will be explained in detail with reference toFIG. 7andFIG. 8.
FIG. 7shows the spectrum of an input RF signal, with numeral101denoting a weak-level desired waveband signal with the center frequency being the same as a local signal frequency fLO, and numeral102indicating a high-level interfering waveband signal that is present at a higher frequency fINT. As a result of inputting an RF signal that accompanies this sort of high-level interfering waveband signal to a mixer circuit, the spectrum of the output signal appearing in the mixer output becomes as shown inFIG. 8. Numerals103and104respectively indicate the components that appear in the mixer output after frequency conversion of the desired waveband signal101and the interfering waveband signal102of the RF input. Numeral105indicates the DC offset generated by the high-level interfering waveband signal when second order nonlinear distortion is present in the mixer circuit.
Accordingly, in a direct conversion system, there is the problem that receiver sensitivity decreases due to the DC offset105generated in the frequency range of the desired waveband signal103of the mixer output. If the mixer circuit is composed of a differential circuit and the differential balance is completely symmetrical, second order nonlinear distortion will not be present. However, because the components constituting the differential circuit cannot be made completely symmetrical due to manufacturing irregularities, it is not possible to eliminate second order nonlinear distortion. Therefore, technology has been proposed that compensates the DC offset generated by second order nonlinear distortion.
A method for detecting an interfering waveband signal included in the input RF signal and compensating DC offset generated in the mixer output, disclosed in U.S. Pat. No. 6,535,725, is explained below with reference toFIG. 9.
InFIG. 9, numeral106indicates a mixer circuit, which is composed of a switching cell107and an RF input cell108. The switching cell107is composed of bipolar transistors Q1, Q2, Q3, and Q4. The RF input cell108is composed of bipolar transistors Q5and Q6, and resistors R. The RF signal input from RF input terminals109and110is amplified by the RF input cell108. The amplified RF signal is converted to an IF signal by being mixed with a local signal input from local input terminals111and112in the switching cell107, and this converted IF signal is output from output terminals113and114.
If all of the transistors Q1, Q2, Q3, and Q4constituting the switching cell107have exactly the same characteristics, balance as a differential circuit will be completely symmetrical. However, because the bipolar transistors Q1, Q2, Q3, and Q4each individually have properties that differ from the ideal properties due to manufacturing irregularities, second order nonlinear distortion is generated when the input RF signal is converted to an IF signal. Therefore, DC offset is generated in the mixer output as shown inFIG. 8. As is well known, because the DC offset is proportional to the square of the input signal strength, the higher the level of the interfering waveband signal included in the input signal, the greater the output DC offset will become.
On the other hand, the circuit shown inFIG. 9is provided with a DC offset compensator115. The DC offset compensator115is composed of a detector116, a controller117, and a correction generator118. The detector116detects an input RF signal and outputs a detection signal. The controller117generates a control signal in response to the detection signal. The correction generator118generates a compensation signal in response to the control signal from the controller117such that it reduces the DC offset of the mixer output terminals113and114. By this operation of the DC offset compensator115, the compensation signal that the correction generator118outputs to the mixer circuit106changes in response to the strength of the RF signal input, and the DC offset of the mixer output is cancelled. Further, in the mixer circuit106, because the second order nonlinear distortion properties of each individual element differ due to manufacturing irregularities, a function of a user interface119is also provided in the DC offset compensator115in order to adjust the control signal produced by the controller117.
However, in the method that adds a compensation signal in order to compensate the DC offset included in the mixer output signal, a low frequency noise generated within the DC offset compensator is superimposed on the compensation signal that is used. Therefore, not only the DC offset included in the mixer output signal being compensated, but also a noise signal is newly added in the frequency range of the desired waveband signal. In order to explain this condition, the spectrum of the mixer output after DC offset compensation is shown inFIG. 10. Numerals103and104respectively indicate the desired waveband signal and the interfering waveband signal appearing in the mixer output after frequency conversion in the mixer circuit, as shown inFIG. 8. A numeral120indicates the low frequency noise included in the compensation signal generated by the DC offset compensator, which ranges over the desired waveband. Therefore, the degradation of receiving sensitivity when inputting a high-level interfering waveband signal is not improved even when DC offset is compensated.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is an object of the present invention to provide a frequency mixer device that can compensate DC offset such that low frequency noise included in the DC offset compensation signal does not range over the desired waveband of the mixer output, and a DC offset compensating method, that solve the problems in the conventional technology described above.
A frequency mixer device according to the present invention is provided with a mixer circuit having an input cell that amplifies an input signal, and a switching cell that mixes the amplified input signal with a switching signal and outputs a multiplied signal; and a DC offset compensator that detects the input level of the input signal and outputs a compensation signal based on that detection signal, the compensation signal being supplied to the mixer circuit so as to compensate a DC offset included in the multiplied signal. In order to realize the objective described above, the compensation signal that the DC offset compensator outputs is added to the output signal of the input cell so as to compensate the DC offset.
A method according to the present invention is for compensating a DC offset included in a multiplied signal obtained by amplifying an input signal by an input cell and mixing the amplified input signal with a switching signal by a switching cell. In order to achieve the objective described above, the method includes: detecting a level of the input signal; generating a compensation signal for compensating the DC offset based on the level detection signal; supplying the compensation signal to the input cell, the compensation signal being added to the amplified input signal; and mixing the output of the input cell with the switching signal by the switching cell, so as to output the multiplied signal.
With the configuration described above, the low frequency noise included in the DC offset compensation signal is converted in the mixer output to a frequency near that of the switching signal, and therefore it is possible to compensate the DC offset such that the low frequency noise does not range over the desired waveband of the mixer output.
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7821884 | CLAIM OF PRIORITY
The present application claims priority from Japanese application JP 2007-058024 filed on Mar. 8, 2007, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an information recording and retrieval method for optically recording and retrieving information in recording media, and also relates to an information recording and retrieval apparatus.
2. Description of the Related Art
Optical disks have the following prominent features. Semiconductor lasers can be used as a light source. Recording media (disks) can be removed from the recording and retrieval apparatus. Optical disks cost lower per bit of the recording media. Accordingly, a desirable optical disk apparatus is a higher-density, higher-speed one that still has the above-mentioned features. Conventionally, an optical disk has a single recording layer, but, to record a larger-volume data, double-layer, triple-layer optical disks have been developed. The number of recording layers has reached eight for a read-only type multiple-layer optical disk. As other types of multiple-layer recording media, a data-recordable type optical disk is disclosed. In this type of optical disk, a plurality of data-recording layers and a single servo layer are combined, and light sources are provided respectively for recording data purpose and for servo purpose. The light beams eradiated from the light source for servo form a minute beam spot on the servo layer, and always following the track formed in the surface of servo layer. The light beams eradiated from the light source for data recording maintain a constant geometrical arrangement relationship with the beam spot formed in the servo layer, and thus data is recorded in a plurality of recording layers. The retrieval of data from each of the layers is carried out by moving the spot for retrieving data in the vertical direction of the disk, and by detecting the signal in the data layer while the cross-talk from other layers is reduced by use of a pinhole (U.S. Pat. No. 6,540,397).
SUMMARY OF THE INVENTION
In a multi-layer optical disk, recording layers and intermediate layers are alternately laminated. When each recording layer and each intermediate layer have different refraction indices, multiple reflections occur at boundary surface. While the light beam reflected from the target data layer is focused on a spot on the photodetector surface, the multiple reflected light beams from other data layers are also focused on the same spot, which results in a difficulty in separating the signal of the target data layer from multiple reflected light beams of other layers. In addition, detecting a track error signal and a focus error signal needs a plurality of photodetectors placed at positions deviated from the converging spot of the reflected light beam, and also needs a detection of the balance between the quantities of light that the photodetectors received. The structure of this photodetector, however, needs another separation method because light beams from other layers get mixed again.
A wider interval between layers helps separating reflected lights from the respective layers even with a photodetector with a certain dimensions and thus helps reduce layer cross-talk. The interval between layers has to be made narrower to achieve a larger recording capacity for multi-layer optical disks in the future. This results in a difficulty in separating reflected light beams of the respective layers. A method, therefore, is needed to retrieve only the information of the desired layer among all the received light beams reflected from layers.
To meet the demand, the present invention provides an information recording and retrieval method, and an information recording and retrieval apparatus for a multi-layer optical disk.
In the present invention, using a multi-layer optical disk into which a plurality of recording layers and a single servo layer are combined, and a light-beam spot is eradiated to the servo layer and a selected one of the recording layers in a time-sharing manner. While following a desired track is carried out by acquiring servo information from the servo layer, the recording data in and retrieving data from the recording layer are carried out.
In a multi-layer optical disk according to an aspect of the present invention, a plurality of recording layers and a single servo layer are combined to form a set. In the servo layer, servo areas for detecting a track error signal and a focus error signal are formed discretely along a track, and in the recording layer, non-recording areas are formed discretely. Non-recording areas in the recording layer and servo areas in the servo layer are arranged so as to overlap each other when viewed from the light incident side. In a case where the servo layer is positioned farther than the plurality of recording layers when viewed form the light incident side, non-recording areas in the recording layer are transparent areas. Alternatively, in a case where servo layer is positioned nearer than the plurality of recording layers when viewed form the light incident side, the servo layer, except for the servo areas, are transparent.
An information recording and retrieval method according to an aspect of the present invention uses the above-described multi-layer optical disk. The method includes a step of making a first laser beam and a second laser beam enter a multi-layer optical disk along the optical axis of a single objective lens, and then making the beams converge at respective positions, which are different from each other, on the optical axis. Also included are a step of detecting the first laser beam interacting with the servo layer, a step of generating a sampling logic signal from a first laser beam detection signal, a step of alternately turning on the first laser beam and the second laser beam in accordance with the sampling logic signal, a step of deriving a track error signal and a focus error signal for the servo layer while the first laser beam is turned on, a step of controlling the relative position of the objective lens to the multi-layer optical disk using the track error signal and the focus error signal, and then making the spot of the first laser beam follow a desired track in the servo layer, a step of detecting the second laser beam interacting with one of the plurality of recording layers while the second laser beam is turned on, and then deriving a focus error signal of the second laser beam for the recording layer, and a step of focusing the spot of the second laser beam on the recording layer using the focus error signal of the second laser beam.
An information recording and retrieval apparatus of an aspect of the present invention uses the above-mentioned multi-layer optical disk. The apparatus includes a first laser beam generating means, and a second laser beam generating means. The apparatus also includes an optical system for linking the first laser beam and the second laser beam on a single axis. Also included is an objective lens for converging the linked first laser beam onto the servo layer, and for converging the second laser beam onto one of the plurality of recording layers. In addition, the apparatus includes an actuator for driving the objective lens, a photodetector having a focus error detector and a track error detector, and a timing generation circuit for generating a timing signal for eradiating alternately the first laser beam and the second laser beam in accordance with the output of the track error detector. Moreover, the apparatus includes a first focus servo block for driving the actuator in the optical axis direction in accordance with the output of the track error detector while the first laser beam is turned on, and a tracking servo block for driving the actuator in a direction perpendicular to the optical axis in accordance with the output while the first laser beam is turned on. Furthermore the apparatus includes a second focus servo block for driving the spot of the second laser beam in the optical axis direction in accordance with the output of the focus detector while the second laser beam is turned on.
According to the present invention, use of two light-beam spots enables a single photodetector to detect signals from a plurality of recording layers in a multi-layer optical disk.
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SUMMARY: CLAIM OF PRIORITY
The present application claims priority from Japanese application JP 2007-058024 filed on Mar. 8, 2007, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an information recording and retrieval method for optically recording and retrieving information in recording media, and also relates to an information recording and retrieval apparatus.
2. Description of the Related Art
Optical disks have the following prominent features. Semiconductor lasers can be used as a light source. Recording media (disks) can be removed from the recording and retrieval apparatus. Optical disks cost lower per bit of the recording media. Accordingly, a desirable optical disk apparatus is a higher-density, higher-speed one that still has the above-mentioned features. Conventionally, an optical disk has a single recording layer, but, to record a larger-volume data, double-layer, triple-layer optical disks have been developed. The number of recording layers has reached eight for a read-only type multiple-layer optical disk. As other types of multiple-layer recording media, a data-recordable type optical disk is disclosed. In this type of optical disk, a plurality of data-recording layers and a single servo layer are combined, and light sources are provided respectively for recording data purpose and for servo purpose. The light beams eradiated from the light source for servo form a minute beam spot on the servo layer, and always following the track formed in the surface of servo layer. The light beams eradiated from the light source for data recording maintain a constant geometrical arrangement relationship with the beam spot formed in the servo layer, and thus data is recorded in a plurality of recording layers. The retrieval of data from each of the layers is carried out by moving the spot for retrieving data in the vertical direction of the disk, and by detecting the signal in the data layer while the cross-talk from other layers is reduced by use of a pinhole (U.S. Pat. No. 6,540,397).
SUMMARY OF THE INVENTION
In a multi-layer optical disk, recording layers and intermediate layers are alternately laminated. When each recording layer and each intermediate layer have different refraction indices, multiple reflections occur at boundary surface. While the light beam reflected from the target data layer is focused on a spot on the photodetector surface, the multiple reflected light beams from other data layers are also focused on the same spot, which results in a difficulty in separating the signal of the target data layer from multiple reflected light beams of other layers. In addition, detecting a track error signal and a focus error signal needs a plurality of photodetectors placed at positions deviated from the converging spot of the reflected light beam, and also needs a detection of the balance between the quantities of light that the photodetectors received. The structure of this photodetector, however, needs another separation method because light beams from other layers get mixed again.
A wider interval between layers helps separating reflected lights from the respective layers even with a photodetector with a certain dimensions and thus helps reduce layer cross-talk. The interval between layers has to be made narrower to achieve a larger recording capacity for multi-layer optical disks in the future. This results in a difficulty in separating reflected light beams of the respective layers. A method, therefore, is needed to retrieve only the information of the desired layer among all the received light beams reflected from layers.
To meet the demand, the present invention provides an information recording and retrieval method, and an information recording and retrieval apparatus for a multi-layer optical disk.
In the present invention, using a multi-layer optical disk into which a plurality of recording layers and a single servo layer are combined, and a light-beam spot is eradiated to the servo layer and a selected one of the recording layers in a time-sharing manner. While following a desired track is carried out by acquiring servo information from the servo layer, the recording data in and retrieving data from the recording layer are carried out.
In a multi-layer optical disk according to an aspect of the present invention, a plurality of recording layers and a single servo layer are combined to form a set. In the servo layer, servo areas for detecting a track error signal and a focus error signal are formed discretely along a track, and in the recording layer, non-recording areas are formed discretely. Non-recording areas in the recording layer and servo areas in the servo layer are arranged so as to overlap each other when viewed from the light incident side. In a case where the servo layer is positioned farther than the plurality of recording layers when viewed form the light incident side, non-recording areas in the recording layer are transparent areas. Alternatively, in a case where servo layer is positioned nearer than the plurality of recording layers when viewed form the light incident side, the servo layer, except for the servo areas, are transparent.
An information recording and retrieval method according to an aspect of the present invention uses the above-described multi-layer optical disk. The method includes a step of making a first laser beam and a second laser beam enter a multi-layer optical disk along the optical axis of a single objective lens, and then making the beams converge at respective positions, which are different from each other, on the optical axis. Also included are a step of detecting the first laser beam interacting with the servo layer, a step of generating a sampling logic signal from a first laser beam detection signal, a step of alternately turning on the first laser beam and the second laser beam in accordance with the sampling logic signal, a step of deriving a track error signal and a focus error signal for the servo layer while the first laser beam is turned on, a step of controlling the relative position of the objective lens to the multi-layer optical disk using the track error signal and the focus error signal, and then making the spot of the first laser beam follow a desired track in the servo layer, a step of detecting the second laser beam interacting with one of the plurality of recording layers while the second laser beam is turned on, and then deriving a focus error signal of the second laser beam for the recording layer, and a step of focusing the spot of the second laser beam on the recording layer using the focus error signal of the second laser beam.
An information recording and retrieval apparatus of an aspect of the present invention uses the above-mentioned multi-layer optical disk. The apparatus includes a first laser beam generating means, and a second laser beam generating means. The apparatus also includes an optical system for linking the first laser beam and the second laser beam on a single axis. Also included is an objective lens for converging the linked first laser beam onto the servo layer, and for converging the second laser beam onto one of the plurality of recording layers. In addition, the apparatus includes an actuator for driving the objective lens, a photodetector having a focus error detector and a track error detector, and a timing generation circuit for generating a timing signal for eradiating alternately the first laser beam and the second laser beam in accordance with the output of the track error detector. Moreover, the apparatus includes a first focus servo block for driving the actuator in the optical axis direction in accordance with the output of the track error detector while the first laser beam is turned on, and a tracking servo block for driving the actuator in a direction perpendicular to the optical axis in accordance with the output while the first laser beam is turned on. Furthermore the apparatus includes a second focus servo block for driving the spot of the second laser beam in the optical axis direction in accordance with the output of the focus detector while the second laser beam is turned on.
According to the present invention, use of two light-beam spots enables a single photodetector to detect signals from a plurality of recording layers in a multi-layer optical disk.
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7674058 | BACKGROUND OF THE INVENTION
Disposable finger covers or wipes are known and used in the art for a variety of purposes. A common use of finger wipes (also know as “finger gloves” in the art) is for applying ointments, medications, alcohol, oral anesthetics, and the like, to various body parts. Such devices may also be utilized to remove various substances, such as makeup, or to clean body parts or other objects.
Finger wipes have proven particularly useful in the field of dental hygiene in that they provide a portable and efficient means for more frequent dental care, and as a cleaning device that can be easily used in public. In particular, a number of finger-mounted teeth cleaning devices have been developed that can be placed over a finger and wiped over the teeth and gums. These devices are typically small, portable, and disposable.
Examples of dental hygiene cleaning devices and finger wipes are disclosed, for instance, in U.S. Pat. No. 6,721,987 to McDevitt, et al. and in U.S. Pat. No. 6,647,549 also to McDevitt, et al., which are incorporated herein by reference. A dental hygiene finger device is also described in U.S. Pat. No. 5,445,825 to Copelan et al. Other finger-mounted teeth cleaning devices were developed to contain an elastomeric material to help prevent the device from slipping or falling off the user's finger during cleaning. Examples of such teeth cleaning devices are disclosed in U.S. Pat. No. 5,068,941 to Dunn; U.S. Pat. No. 5,348,153 to Cole; U.S. Pat. No. 5,524,764 to Kaufman et al.; and PCT Publication No. WO 95/31154 to Mittiga et al.
Finger wipes that incorporate an integral additive or composition are a convenient and desirable product. However, it may be difficult to incorporate an adequate supply of the desired composition with conventional finger wipe constructions. Consumers often resort to using multiple wipes to achieve a desired application of the composition.
DEFINITIONS
As used herein, the terms “elastic” and “elastomeric” are generally used to refer to materials that, upon application of a force, are stretchable to a stretched, biased length, and which will retract at least about 50% of its elongation upon release of the stretching, biasing force.
As used herein, “meltblown fibers” refers to fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin, et al. Meltblown fibers may be continuous or discontinuous, are generally smaller than 10 microns in average diameter, and are generally tacky when deposited on a collecting surface.
As used herein, the term “neck-bonded” refers to an elastic member being bonded to a non-elastic member while the non-elastic member is extended in the machine direction creating a necked material. “Neck-bonded laminate” refers to a composite material having at least two layers in which one layer is a necked, non-elastic layer and the other layer is an elastic layer thereby creating a material that is elastic in the cross direction. Examples of neck-bonded laminates are such as those described in U.S. Pat. Nos. 5,226,992; 4,981,747; 4,965,122; and 5,336,545, all to Morman, all of which are incorporated herein by reference thereto.
As used herein, “spunbond fibers” refers to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appel, et al.; U.S. Pat. No. 3,692,618 to Dorschner, et al.; U.S. Pat. No. 3,802,817 to Matsuki, et al.; U.S. Pat. No. 3,338,992 to Kinney; U.S. Pat. No. 3,341,394 to Kinney; U.S. Pat. No. 3,502,763 to Hartman; and U.S. Pat. No. 3,542,615 to Dobo, et al. Spunbond fibers are generally not tacky when they are deposited on a collecting surface. Spunbond fibers are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns, and more particularly, between about 10 and 40 microns.
As used herein, the term “stretch-bonded” refers to a composite material having at least two layers in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in an extended condition so that upon relaxing the layers, the gatherable layer is gathered. For example, one elastic member can be bonded to another member while the elastic member is extended at least about 25 percent of its relaxed length. Such a multilayer composite elastic material may be stretched until the nonelastic layer is fully extended. One type of stretch-bonded laminate is disclosed, for example, in U.S. Pat. No. 4,720,415 to Vander Wielen, et al., which is incorporated herein by reference. Other composite elastic materials are described and disclosed in U.S. Pat. No. 4,789,699 to Kieffer, et al.: U.S. Pat. No. 4,781,966 to Taylor: U.S. Pat. No. 4,657,802 to Morman; and U.S. Pat. No. 4,655,760 to Morman, et al., all of which are incorporated herein by reference thereto.
As used herein, the term “texturized” refers to a base web having projections from a surface of the web in the Z-direction. The projections can have a length, for instance, from about 0.1 mm to about 25 mm, particularly from about 0.1 mm to about 5 mm, and more particularly from about 0.1 mm to about 3 mm. The projections can take on many forms and can be, for instance, bristles, tufts, loop structures such as the loops used in hook and loop attachment structures, and the like.
SUMMARY
Objects and advantages of the invention will be set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The present disclosure is directed generally to an article used to deliver a composition from a container configured with the article. The article may be a generally flat member, such as a disposable towel or the like, or may be in the form of a tubular structure designed to fit over a user's hand or one or more fingers. The article is collectively referred to herein as a “wipe”, and for ease of description only, aspects of the invention are explained by reference to finger wipe embodiments that fit over one or more fingers. However, it should be appreciated that the invention is not limited to such finger wipes, and includes all embodiments of wipes incorporating the novel aspects of the invention.
A wipe of the present invention can also be used in various applications. For instance, the wipe may be used to clean or treat parts of the body such as the eyes, the ears, the nose, and the like. The wipe may be used to apply a medicine, lotion, ointment, cleaning agent, or the like to any part of the body, or any other object. In still other embodiments, the wipe can be used to clean various utensils, objects or surfaces and/or to polish various items with any number of compositions or agents carried by the wipe. For example, in one embodiment, the wipe can be used to polish silver with a polish carried by the wipe.
In a particular embodiment, the wipe includes a substrate having an application side and an opposite back side. The substrate may be formed as a tubular structure having an open end for the insertion of one or more fingers, or may be a component of such a tubular structure. A pouch is configured on the application side of the substrate and includes an access opening into the pouch. The opening can be located anywhere on the pouch. In a particular embodiment, the opening is oriented towards the closed end of the tubular structure, or towards the open end of the tubular structure.
Any manner of desired composition or additive intended to be delivered by the wipe upon use of the product is stored in a container that is insertable into the pouch through the access opening. In use of the wipe, the container releases the composition within the pouch and the composition migrates through the pouch material for application by the wipe. The pouch material may be a liquid permeable material, or an impermeable material that has been altered, for example with slits or holes, so as to be permeable to the composition
The composition container may be any one of a number of suitable devices. In a particular embodiment, the container is formed of a shell designed to rupture upon application of pressure to the pouch. For example, the container may be a gel capsule that ruptures to release the composition held therein. In an alternate embodiment, the container may be a relatively hard-sided vial or like device that is crushed upon application of pressure, with the vial components being retained within the pouch during use of the wipe. With still another embodiment, the container may be formed by a shell or membrane that dissolves upon exposure to a liquid during use of the finger wipe such that the composition is released and mixes with the liquid.
It should be appreciated that the invention is not limited to any particular type of composition or intended use of the wipe. The composition may be a liquid or cream agent. In an alternate embodiment, the composition may be in a powder or granular form that mixes with a liquid upon use of the finger wipe.
The components of the wipe may be made of various suitable materials. In a particular embodiment, the substrate may be formed from a laminate of a liquid impermeable material and an outer nonwoven cover material. The pouch may be formed by a liquid permeable nonwoven patch of material that is attached to the cover layer. In this manner, the laminate material defines a back surface of the pouch and the access opening is defined between the laminate material and the patch. In a finger wipe embodiment, the liquid impermeable layer of the laminate prevents the composition from migrating through the tubular structure to the wearer's finger.
In an alternate embodiment, the pouch may be a separately formed member having a liquid impermeable backing layer that is attached to the application side of the substrate.
The pouch may be formed of an elastomeric material that stretches to accommodate the composition container, and then contracts to maintain the container within the pouch.
It may be desired to incorporate a seal with the pouch opening so as to minimize migration of the composition out of the access opening upon application of pressure to the pouch. In a particular embodiment, the seal may include a releasable adhesive applied between the pouch material and substrate along the access opening. A peel strip may be used to protect the adhesive prior to use of the wipe. In an alternate embodiment, the seal may be a hook-and-loop type of mechanism. For example, the substrate may include a nonwoven material, and the pouch may include a strip of microhook material along the access opening that releasably secures to the nonwoven material.
The pouch may be configured to retain a single composition container, or a plurality of containers. The containers may be stored within the pouch prior to use of the wipe, or may be stored separately from the wipe. For example, a plurality of the wipes and a selection of composition containers may be provided in a kit format wherein the consumer chooses an appropriate composition depending on the intended use of the wipe.
Because the composition is applied through the pouch material, it may be desired that the pouch material include a texturized outwardly facing surface, particularly if the wipe is intended as a cleaning or dental hygiene device. In this regard, the pouch may be formed from a nonwoven material layer that has been texturized by any one of a number of conventional processes.
The tubular structure component of finger wipe embodiments can be made from numerous different types of materials. For instance, in one embodiment, nonwoven webs made from synthetic and/or pulp fibers may be used. The material may include a texturized surface adapted to enhance scrubbing or cleaning with the finger wipe. Further, a material can also include an elastic component for providing the tubular structure with form-fitting properties. A moisture barrier, such as a liquid impermeable layer, may be incorporated into the finger wipe to prevent any fluids from contacting the wearer's fingers. In general, a moisture barrier refers to any barrier, layer, or film that is relatively liquid impervious. The moisture barrier prevents the flow of liquid through the finger wipe so that a user's finger remains dry when the wipe is being used. In some embodiments, the moisture barrier can remain breathable, i.e., permeable to vapors, such that a finger within the wipe is more comfortable. Examples of suitable moisture barriers can include films, fibrous materials, laminates, and the like. The wipe may include an elastic nonwoven material having form-fitting properties to help the wipe effectively remain on a finger in use. Suitable materials will be described in greater detail below.
A finger wipe of the present invention can generally be formed in a variety of ways. For instance, the tubular structure can be formed from two or more sections of the same or a different substrates, depending on the desired characteristics of the finger wipe. For example, in one embodiment, the tubular structure is formed from two substrate sections, wherein one section may be formed from a textured nonwoven material and the other section may be formed from an elastomeric nonwoven material. A seam is formed around the closed periphery portion of the wipe to define the elongated closed-end tubular structure having the finger insertion opening at one end. The pouch may be formed with the tubular structure during the seaming process. For example, the pouch may be defined by a patch of material that is sealed along a portion of the periphery of the tubular structure.
Besides the composition contained within the pouch, various other additives can also be applied to other portions of the cover layer during manufacturing and/or by the consumer. For example, cationic materials, such as chitosan (poly-N-acetylglucosamine), chitosan salts, cationic starches, etc., can be applied to a wipe of the present invention to help attract negatively charged bacteria and deleterious acidic byproducts that accumulate in plaque. Examples of other suitable additives include, but are not limited to, dental agents, such as fluorides, peppermint oil, mint oil and alcohol mixtures; flavoring agents, such as xylitol; anti-microbial agents; polishing agents; hemostatic agents; surfactants; anti-ulcer components; and the like.
Additives can be applied to the substrate material in the form of an aqueous solution, non-aqueous solution (e.g., oil), lotions, creams, suspensions, gels, etc. When utilized, the aqueous solution may be coated, saturated, sprayed, or impregnated into the material. In some embodiments, the additives can be applied asymmetrically. Moreover, in some instances, it may be desired that the additives comprise less than about 100% by weight of the wipe, and in some embodiments, less than about 50% by weight of the wipe, and particularly less than 10% by weight of the wipe.
The invention also encompasses any manner of kit or other compilation that includes a plurality of the wipes and containers in a common package, wherein the containers are filled with the same or different compositions. For example, a package may be provided to consumers that contains a number of disposable finger wipe embodiments with a plurality of rupturable containers having the same or different oral hygiene compositions.
It should be noted that any given range presented herein is intended to include any and all lesser included ranges. For example, a range of from 45-90 would also include 50-90; 45-80; 46-89 and the like. Thus, the range of 95% to 99.999% also includes, for example, the ranges of 96% to 99.1%, 96.3% to 99.7%, and 99.91 to 99.999%.
Various features and aspects of the present invention are discussed in greater detail below.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
Disposable finger covers or wipes are known and used in the art for a variety of purposes. A common use of finger wipes (also know as “finger gloves” in the art) is for applying ointments, medications, alcohol, oral anesthetics, and the like, to various body parts. Such devices may also be utilized to remove various substances, such as makeup, or to clean body parts or other objects.
Finger wipes have proven particularly useful in the field of dental hygiene in that they provide a portable and efficient means for more frequent dental care, and as a cleaning device that can be easily used in public. In particular, a number of finger-mounted teeth cleaning devices have been developed that can be placed over a finger and wiped over the teeth and gums. These devices are typically small, portable, and disposable.
Examples of dental hygiene cleaning devices and finger wipes are disclosed, for instance, in U.S. Pat. No. 6,721,987 to McDevitt, et al. and in U.S. Pat. No. 6,647,549 also to McDevitt, et al., which are incorporated herein by reference. A dental hygiene finger device is also described in U.S. Pat. No. 5,445,825 to Copelan et al. Other finger-mounted teeth cleaning devices were developed to contain an elastomeric material to help prevent the device from slipping or falling off the user's finger during cleaning. Examples of such teeth cleaning devices are disclosed in U.S. Pat. No. 5,068,941 to Dunn; U.S. Pat. No. 5,348,153 to Cole; U.S. Pat. No. 5,524,764 to Kaufman et al.; and PCT Publication No. WO 95/31154 to Mittiga et al.
Finger wipes that incorporate an integral additive or composition are a convenient and desirable product. However, it may be difficult to incorporate an adequate supply of the desired composition with conventional finger wipe constructions. Consumers often resort to using multiple wipes to achieve a desired application of the composition.
DEFINITIONS
As used herein, the terms “elastic” and “elastomeric” are generally used to refer to materials that, upon application of a force, are stretchable to a stretched, biased length, and which will retract at least about 50% of its elongation upon release of the stretching, biasing force.
As used herein, “meltblown fibers” refers to fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin, et al. Meltblown fibers may be continuous or discontinuous, are generally smaller than 10 microns in average diameter, and are generally tacky when deposited on a collecting surface.
As used herein, the term “neck-bonded” refers to an elastic member being bonded to a non-elastic member while the non-elastic member is extended in the machine direction creating a necked material. “Neck-bonded laminate” refers to a composite material having at least two layers in which one layer is a necked, non-elastic layer and the other layer is an elastic layer thereby creating a material that is elastic in the cross direction. Examples of neck-bonded laminates are such as those described in U.S. Pat. Nos. 5,226,992; 4,981,747; 4,965,122; and 5,336,545, all to Morman, all of which are incorporated herein by reference thereto.
As used herein, “spunbond fibers” refers to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appel, et al.; U.S. Pat. No. 3,692,618 to Dorschner, et al.; U.S. Pat. No. 3,802,817 to Matsuki, et al.; U.S. Pat. No. 3,338,992 to Kinney; U.S. Pat. No. 3,341,394 to Kinney; U.S. Pat. No. 3,502,763 to Hartman; and U.S. Pat. No. 3,542,615 to Dobo, et al. Spunbond fibers are generally not tacky when they are deposited on a collecting surface. Spunbond fibers are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns, and more particularly, between about 10 and 40 microns.
As used herein, the term “stretch-bonded” refers to a composite material having at least two layers in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in an extended condition so that upon relaxing the layers, the gatherable layer is gathered. For example, one elastic member can be bonded to another member while the elastic member is extended at least about 25 percent of its relaxed length. Such a multilayer composite elastic material may be stretched until the nonelastic layer is fully extended. One type of stretch-bonded laminate is disclosed, for example, in U.S. Pat. No. 4,720,415 to Vander Wielen, et al., which is incorporated herein by reference. Other composite elastic materials are described and disclosed in U.S. Pat. No. 4,789,699 to Kieffer, et al.: U.S. Pat. No. 4,781,966 to Taylor: U.S. Pat. No. 4,657,802 to Morman; and U.S. Pat. No. 4,655,760 to Morman, et al., all of which are incorporated herein by reference thereto.
As used herein, the term “texturized” refers to a base web having projections from a surface of the web in the Z-direction. The projections can have a length, for instance, from about 0.1 mm to about 25 mm, particularly from about 0.1 mm to about 5 mm, and more particularly from about 0.1 mm to about 3 mm. The projections can take on many forms and can be, for instance, bristles, tufts, loop structures such as the loops used in hook and loop attachment structures, and the like.
SUMMARY
Objects and advantages of the invention will be set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The present disclosure is directed generally to an article used to deliver a composition from a container configured with the article. The article may be a generally flat member, such as a disposable towel or the like, or may be in the form of a tubular structure designed to fit over a user's hand or one or more fingers. The article is collectively referred to herein as a “wipe”, and for ease of description only, aspects of the invention are explained by reference to finger wipe embodiments that fit over one or more fingers. However, it should be appreciated that the invention is not limited to such finger wipes, and includes all embodiments of wipes incorporating the novel aspects of the invention.
A wipe of the present invention can also be used in various applications. For instance, the wipe may be used to clean or treat parts of the body such as the eyes, the ears, the nose, and the like. The wipe may be used to apply a medicine, lotion, ointment, cleaning agent, or the like to any part of the body, or any other object. In still other embodiments, the wipe can be used to clean various utensils, objects or surfaces and/or to polish various items with any number of compositions or agents carried by the wipe. For example, in one embodiment, the wipe can be used to polish silver with a polish carried by the wipe.
In a particular embodiment, the wipe includes a substrate having an application side and an opposite back side. The substrate may be formed as a tubular structure having an open end for the insertion of one or more fingers, or may be a component of such a tubular structure. A pouch is configured on the application side of the substrate and includes an access opening into the pouch. The opening can be located anywhere on the pouch. In a particular embodiment, the opening is oriented towards the closed end of the tubular structure, or towards the open end of the tubular structure.
Any manner of desired composition or additive intended to be delivered by the wipe upon use of the product is stored in a container that is insertable into the pouch through the access opening. In use of the wipe, the container releases the composition within the pouch and the composition migrates through the pouch material for application by the wipe. The pouch material may be a liquid permeable material, or an impermeable material that has been altered, for example with slits or holes, so as to be permeable to the composition
The composition container may be any one of a number of suitable devices. In a particular embodiment, the container is formed of a shell designed to rupture upon application of pressure to the pouch. For example, the container may be a gel capsule that ruptures to release the composition held therein. In an alternate embodiment, the container may be a relatively hard-sided vial or like device that is crushed upon application of pressure, with the vial components being retained within the pouch during use of the wipe. With still another embodiment, the container may be formed by a shell or membrane that dissolves upon exposure to a liquid during use of the finger wipe such that the composition is released and mixes with the liquid.
It should be appreciated that the invention is not limited to any particular type of composition or intended use of the wipe. The composition may be a liquid or cream agent. In an alternate embodiment, the composition may be in a powder or granular form that mixes with a liquid upon use of the finger wipe.
The components of the wipe may be made of various suitable materials. In a particular embodiment, the substrate may be formed from a laminate of a liquid impermeable material and an outer nonwoven cover material. The pouch may be formed by a liquid permeable nonwoven patch of material that is attached to the cover layer. In this manner, the laminate material defines a back surface of the pouch and the access opening is defined between the laminate material and the patch. In a finger wipe embodiment, the liquid impermeable layer of the laminate prevents the composition from migrating through the tubular structure to the wearer's finger.
In an alternate embodiment, the pouch may be a separately formed member having a liquid impermeable backing layer that is attached to the application side of the substrate.
The pouch may be formed of an elastomeric material that stretches to accommodate the composition container, and then contracts to maintain the container within the pouch.
It may be desired to incorporate a seal with the pouch opening so as to minimize migration of the composition out of the access opening upon application of pressure to the pouch. In a particular embodiment, the seal may include a releasable adhesive applied between the pouch material and substrate along the access opening. A peel strip may be used to protect the adhesive prior to use of the wipe. In an alternate embodiment, the seal may be a hook-and-loop type of mechanism. For example, the substrate may include a nonwoven material, and the pouch may include a strip of microhook material along the access opening that releasably secures to the nonwoven material.
The pouch may be configured to retain a single composition container, or a plurality of containers. The containers may be stored within the pouch prior to use of the wipe, or may be stored separately from the wipe. For example, a plurality of the wipes and a selection of composition containers may be provided in a kit format wherein the consumer chooses an appropriate composition depending on the intended use of the wipe.
Because the composition is applied through the pouch material, it may be desired that the pouch material include a texturized outwardly facing surface, particularly if the wipe is intended as a cleaning or dental hygiene device. In this regard, the pouch may be formed from a nonwoven material layer that has been texturized by any one of a number of conventional processes.
The tubular structure component of finger wipe embodiments can be made from numerous different types of materials. For instance, in one embodiment, nonwoven webs made from synthetic and/or pulp fibers may be used. The material may include a texturized surface adapted to enhance scrubbing or cleaning with the finger wipe. Further, a material can also include an elastic component for providing the tubular structure with form-fitting properties. A moisture barrier, such as a liquid impermeable layer, may be incorporated into the finger wipe to prevent any fluids from contacting the wearer's fingers. In general, a moisture barrier refers to any barrier, layer, or film that is relatively liquid impervious. The moisture barrier prevents the flow of liquid through the finger wipe so that a user's finger remains dry when the wipe is being used. In some embodiments, the moisture barrier can remain breathable, i.e., permeable to vapors, such that a finger within the wipe is more comfortable. Examples of suitable moisture barriers can include films, fibrous materials, laminates, and the like. The wipe may include an elastic nonwoven material having form-fitting properties to help the wipe effectively remain on a finger in use. Suitable materials will be described in greater detail below.
A finger wipe of the present invention can generally be formed in a variety of ways. For instance, the tubular structure can be formed from two or more sections of the same or a different substrates, depending on the desired characteristics of the finger wipe. For example, in one embodiment, the tubular structure is formed from two substrate sections, wherein one section may be formed from a textured nonwoven material and the other section may be formed from an elastomeric nonwoven material. A seam is formed around the closed periphery portion of the wipe to define the elongated closed-end tubular structure having the finger insertion opening at one end. The pouch may be formed with the tubular structure during the seaming process. For example, the pouch may be defined by a patch of material that is sealed along a portion of the periphery of the tubular structure.
Besides the composition contained within the pouch, various other additives can also be applied to other portions of the cover layer during manufacturing and/or by the consumer. For example, cationic materials, such as chitosan (poly-N-acetylglucosamine), chitosan salts, cationic starches, etc., can be applied to a wipe of the present invention to help attract negatively charged bacteria and deleterious acidic byproducts that accumulate in plaque. Examples of other suitable additives include, but are not limited to, dental agents, such as fluorides, peppermint oil, mint oil and alcohol mixtures; flavoring agents, such as xylitol; anti-microbial agents; polishing agents; hemostatic agents; surfactants; anti-ulcer components; and the like.
Additives can be applied to the substrate material in the form of an aqueous solution, non-aqueous solution (e.g., oil), lotions, creams, suspensions, gels, etc. When utilized, the aqueous solution may be coated, saturated, sprayed, or impregnated into the material. In some embodiments, the additives can be applied asymmetrically. Moreover, in some instances, it may be desired that the additives comprise less than about 100% by weight of the wipe, and in some embodiments, less than about 50% by weight of the wipe, and particularly less than 10% by weight of the wipe.
The invention also encompasses any manner of kit or other compilation that includes a plurality of the wipes and containers in a common package, wherein the containers are filled with the same or different compositions. For example, a package may be provided to consumers that contains a number of disposable finger wipe embodiments with a plurality of rupturable containers having the same or different oral hygiene compositions.
It should be noted that any given range presented herein is intended to include any and all lesser included ranges. For example, a range of from 45-90 would also include 50-90; 45-80; 46-89 and the like. Thus, the range of 95% to 99.999% also includes, for example, the ranges of 96% to 99.1%, 96.3% to 99.7%, and 99.91 to 99.999%.
Various features and aspects of the present invention are discussed in greater detail below.
Is this patent green technology? Respond with 'yes' or 'no'. |
7810403 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to motors, and more particularly, to gear engagement mechanisms for motors.
2. Description of the Related Art
Starter motors for internal combustion engines are designed to engage a pinion gear, a first rotatable element, with a flywheel gear, a second rotatable element. When engaged and power is applied to the starter motor, the flywheel is turned to start the engine. The conventional starter motor comprises a hold-in winding1, a pull-in winding2, a return spring3, an engaging lever4, a meshing spring5, a driver6, a roller-type overrunning clutch7, a pinion8, an armature shaft9, a stop ring10, a spiral spline11, a guide ring12, a terminal13, a contact14, a contact break spring15, a moving contact16, a solenoid switch17, a commutator end shield18, a brush holder19, a carbon brush20, a commutator21, a pole shoe22, an armature23, a field frame24, and an excitation winding25. The arrangement and assembly of these components is well known in the art.
Conventional starter motors, for example as depicted inFIG. 1, typically require a starter assembly to be placed offset/behind the flywheel, taking up valuable envelope space in the engine. The current design further requires a heavy starter, thereby affecting vehicle's fuel economy. More importantly however, the present designs require the drive gear to advance axially forward and engage the flywheel before the starter turns. The advancement of the drive gear requires that the armature shaft be journaled on a nose casting, adding weight and complexity; requires expensive heat treat and helicoidal lamination of the armature shaft splines; requires a large solenoid to advance and hold the large mass of the drive gear; and requires a more complex offset lever system.
The large solenoid required to advance and hold the large mass of the drive gear needs extensive copper coils (2 of them) adding mass and cost. Moreover, the extensive coils require more amp draw from the electrical system, and more power wasted in order to have the starter perform its function. The large solenoid requires complex design with expensive terminals and contacts which tent to weld and wear over time. In addition, the solenoid phenolic caps tend to crack and break due to handling or thermal issues. The large solenoid design further leads to moisture accumulation and contact freezing, leading to a non-starting (click-no-crank) condition. Also, coil gassing creates deposits on the contacts, leading to electrical insulation deterioration and non-function of the starter system.
In addition, the drive gear advance results in frequent impacts with the flywheel, leading to both drive gear and flywheel damage. Accordingly, expensive heat treatments of both components are incurred to help improve component life. Moreover, the large axial travel, time, and energy expended for starting cycle to initiate and ignite engine reduces the efficiency of the operation of the starter motor and leads to premature wear and/or failure of the starter motor.
Therefore, there is a need in the art for an improved starter motor.
SUMMARY OF THE INVENTION
Methods and apparatus for engaging gears in motors are provided herein. In some embodiments, an apparatus for engaging gears in a motor includes an actuator; and an engagement assembly having at least one pawl axially movably configured to selectively couple the engagement assembly with a gear via operation of the actuator. The actuator may be a solenoid, and may further be a single-coil solenoid. The apparatus may further include a shaft having the actuator and engagement assembly disposed thereon; and a gear disposed on the shaft adjacent the engagement assembly.
In another aspect of the invention, a gear assembly is provided. In some embodiments, a gear assembly may include a shaft; a gear disposed on the shaft; an engagement assembly disposed on the shaft and having at least one pawl movably configured axially along the shaft to selectively couple the engagement assembly with the gear; and an actuator configured to selectively couple the engagement assembly to the gear.
In another aspect of the invention, a method for coupling torque to a rotatable element is provided. In some embodiments, a method for coupling torque to a rotatable element includes providing a rotatable element having at least one recess and an engagement assembly having at least one pawl; axially advancing the engagement assembly to interface with the rotatable element; and rotating the engagement assembly to engage the at least one pawl with an inner surface of the at least one recess of the rotatable element.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to motors, and more particularly, to gear engagement mechanisms for motors.
2. Description of the Related Art
Starter motors for internal combustion engines are designed to engage a pinion gear, a first rotatable element, with a flywheel gear, a second rotatable element. When engaged and power is applied to the starter motor, the flywheel is turned to start the engine. The conventional starter motor comprises a hold-in winding1, a pull-in winding2, a return spring3, an engaging lever4, a meshing spring5, a driver6, a roller-type overrunning clutch7, a pinion8, an armature shaft9, a stop ring10, a spiral spline11, a guide ring12, a terminal13, a contact14, a contact break spring15, a moving contact16, a solenoid switch17, a commutator end shield18, a brush holder19, a carbon brush20, a commutator21, a pole shoe22, an armature23, a field frame24, and an excitation winding25. The arrangement and assembly of these components is well known in the art.
Conventional starter motors, for example as depicted inFIG. 1, typically require a starter assembly to be placed offset/behind the flywheel, taking up valuable envelope space in the engine. The current design further requires a heavy starter, thereby affecting vehicle's fuel economy. More importantly however, the present designs require the drive gear to advance axially forward and engage the flywheel before the starter turns. The advancement of the drive gear requires that the armature shaft be journaled on a nose casting, adding weight and complexity; requires expensive heat treat and helicoidal lamination of the armature shaft splines; requires a large solenoid to advance and hold the large mass of the drive gear; and requires a more complex offset lever system.
The large solenoid required to advance and hold the large mass of the drive gear needs extensive copper coils (2 of them) adding mass and cost. Moreover, the extensive coils require more amp draw from the electrical system, and more power wasted in order to have the starter perform its function. The large solenoid requires complex design with expensive terminals and contacts which tent to weld and wear over time. In addition, the solenoid phenolic caps tend to crack and break due to handling or thermal issues. The large solenoid design further leads to moisture accumulation and contact freezing, leading to a non-starting (click-no-crank) condition. Also, coil gassing creates deposits on the contacts, leading to electrical insulation deterioration and non-function of the starter system.
In addition, the drive gear advance results in frequent impacts with the flywheel, leading to both drive gear and flywheel damage. Accordingly, expensive heat treatments of both components are incurred to help improve component life. Moreover, the large axial travel, time, and energy expended for starting cycle to initiate and ignite engine reduces the efficiency of the operation of the starter motor and leads to premature wear and/or failure of the starter motor.
Therefore, there is a need in the art for an improved starter motor.
SUMMARY OF THE INVENTION
Methods and apparatus for engaging gears in motors are provided herein. In some embodiments, an apparatus for engaging gears in a motor includes an actuator; and an engagement assembly having at least one pawl axially movably configured to selectively couple the engagement assembly with a gear via operation of the actuator. The actuator may be a solenoid, and may further be a single-coil solenoid. The apparatus may further include a shaft having the actuator and engagement assembly disposed thereon; and a gear disposed on the shaft adjacent the engagement assembly.
In another aspect of the invention, a gear assembly is provided. In some embodiments, a gear assembly may include a shaft; a gear disposed on the shaft; an engagement assembly disposed on the shaft and having at least one pawl movably configured axially along the shaft to selectively couple the engagement assembly with the gear; and an actuator configured to selectively couple the engagement assembly to the gear.
In another aspect of the invention, a method for coupling torque to a rotatable element is provided. In some embodiments, a method for coupling torque to a rotatable element includes providing a rotatable element having at least one recess and an engagement assembly having at least one pawl; axially advancing the engagement assembly to interface with the rotatable element; and rotating the engagement assembly to engage the at least one pawl with an inner surface of the at least one recess of the rotatable element.
Is this patent green technology? Respond with 'yes' or 'no'. |
7796411 | FIELD OF THE INVENTION
The invention relates generally to the field of power converter controllers, and more particularly to systems and methods for the control of power converters with a controller.
BACKGROUND INFORMATION
Switched power converters are circuits having numerous applications in distributed generation (DG) power systems.FIGS. 1-4depict four types of commonly used switched power converters.FIG. 1Adepicts a two level power factor corrected (PFC) rectifier102. Here, PFC rectifier102is used to shape the line currents ia, iband icto be proportional to the corresponding line voltages Va, Vband Vc.FIG. 1Bdepicts an example graph of the line voltage versus time, and the line current versus time, where j is used to denote a, b or c. Here, it can be seen that the line current ijis kept proportional to the line voltage Vj.
FIG. 2Adepicts a two level active power filter (APF)104, which is another example power converter. Here, APF104is used to generate anti-harmonic and reactive currents to suppress or cancel harmonics in the power lines.FIG. 2Bdepicts an example graph of the system line voltage, Vj, versus time.FIG. 2Cdepicts an example graph of the line current, ij, versus time prior to adjustment by the APF104.FIG. 2Ddepicts an example graph of the anti-harmonic or reactive current, icj, versus time andFIG. 2Edepicts an exemplary graph of the resulting line current, ilj, after adjustment by the APF104.
FIG. 3Adepicts a two level pulse width modulated (PWM) static volt-ampere-reactive (VAR) compensator (SVC)106, which is another example of a power converter. Here, SVC106is used to generate a 90 degree phase offset, either leading or lagging, of the line current from the line voltage so as to control power flow from a power grid. The power grid is typically a power system, or power utility, which is a network of transmission lines, transformers, loads, power generators, motors and the like.FIG. 3Bdepicts an example graph of the line voltage, Vj, and the line current, ij, versus time where ijlags VjandFIG. 3Cdepicts an example graph of the line voltage, Vj, and the line current, ij, versus time where ijleads Vj. An example of a similar type of power converter is a static synchronous compensator (STATCOM).
FIG. 4Adepicts a two level grid connected inverter (GCI)108, which is another example of a power converter. Here, GCI108is used to convert time-static, or direct current (DC), power into time-varying, or alternating current (AC), power flowing into the power grid, where the generated current (ij) has a polarity opposite that of the line voltage (Vj). The power grid is typically a power system, or power utility, which is a network of transmission lines, transformers, loads, power generators, motors and the like.FIG. 4Bdepicts a graph of Vjand ijversus time, where Vjand ijhave opposite polarities. GCI108is typically used to convert DC energy from renewable or alternative energy sources such as fuel cells, photovoltaic sources, batteries and the like.
Each of the power converters102-108are operating by controlling the state (opened or closed) of each of the various switches110. Some conventional control methods employ DQ conversion and real-time reference current calculation. These methods require a high-speed digital microprocessor and high performance A/D converters and result in a higher cost, higher complexity and lower reliability. Another conventional control method is referred to as one cycle control (OCC).
OCC is a unified pulse width modulation (PWM) control method that is capable of controlling basic power converters with relatively lower costs, lower complexity and higher reliability. OCC is described in more detail in U.S. Pat. No. 5,278,490, issued Jan. 11, 1994, which is fully incorporated by reference herein. Many previous OCC controllers were not capable of operation with different types of power converters102-108. The design of separate OCC controllers was required for each type of power converter102-108.
More recently, OCC controllers were developed capable of controlling more than one type of power converter. For instance, three phase two-level OCC controllers capable of controlling a PFC102, APF104and GCI108were described in U.S. Pat. No. 6,297,980 issued on Oct. 2, 2001 and U.S. Pat. No. 6,545,887, issued on Apr. 8, 2003, both of which are fully incorporated by reference herein. However, these OCC controllers were not capable of operation with each type of power converter102-108.
Accordingly, a universal controller capable of controlling multiple types of two and three level power converters is needed.
SUMMARY
The systems and methods described herein provide for modulation methods for controlling a three phase three level power converter with a controller. In one exemplary embodiment of a modulation method, the power converter includes a first, a second and a third voltage source where each voltage source is configured to output a time-varying signal and is inductively coupled to a separate input node. Each input node is preferably connectable to a first output node, a second output node and a third output node. The power converter also includes a first capacitive element coupled between the first and the second output node and a second capacitive element coupled between the second output node and the third output node. Each time-varying voltage signal has substantially the same period and a different phase.
The method includes determining which voltage signal has the highest voltage, the lowest voltage and the intermediate voltage higher than one of the voltage signals and lower than the other voltage signal for each of a plurality of sub-periods. Then connecting the voltage signal having the intermediate voltage to only the first output node during each sub-period, connecting the voltage signal having the highest voltage to one of the second or third output nodes during each sub-period; and connecting the voltage signal having the lowest voltage to one of the second or third output nodes during each sub-period.
In another exemplary embodiment, the modulation method includes providing a power converter having a first, a second and a third voltage source each configured to output a time-varying signal. The first and second voltage sources are each preferably inductively coupled to a separate input node. The input nodes can be connectable to a first and second output node. The third voltage source is preferably inductively coupled to a third output node. The power converter also includes a first capacitive element coupled between the first and the second output node, and a second capacitive element coupled between the second output node and the third output node. Each time-varying voltage signal preferably has substantially the same period and a different phase. The method also includes providing a controller configured to control the connection of the second and third voltage sources to the second and third output nodes.
In yet another exemplary embodiment of a modulation method, the power converter includes a first, a second and a third voltage source where each voltage source is configured to output a time-varying signal and is inductively coupled to a separate input node. Each input node is preferably connectable to a first output node, a second output node and a third output node. The converter can further include a first capacitive element coupled between the first and the second output node and a second capacitive element coupled between the second output node and the third output node. Each time-varying voltage signal preferably has substantially the same period and a different phase.
The method preferably includes determining which voltage signal has the highest voltage, the lowest voltage and the intermediate voltage higher than one of the voltage signals and lower than the other voltage signal for each of a plurality of sub-periods, determining which voltage signal is dominant for each of the plurality of sub-periods, connecting the voltage signal having the lowest voltage to only the third output node when the dominant voltage signal is lower than the non-dominant voltage signals, connecting the voltage signal having the highest voltage to one of the first output node and the second output node during each sub-period where the dominant voltage signal is lower than the non-dominant voltage signals, connecting the voltage signal having the intermediate voltage to one of the second output node and the third output node during each sub-period where the dominant voltage signal is lower than the non-dominant voltage signals, connecting the voltage signal having the highest voltage to only the second output node when the dominant voltage signal is higher than the non-dominant voltage signals, connecting the voltage signal having the lowest voltage to one of the first output node and the second output node during each sub-period where the dominant voltage signal is higher than the non-dominant voltage signals and connecting the voltage signal having the intermediate voltage to one of the second output node and the third output node during each sub-period where the dominant voltage signal is higher than the non-dominant voltage signals.
The systems and methods described herein also provide for a universal controller capable of controlling numerous types of three phase, two and three level power converters. Any type of power converter can be controlled in any of the four quadrants of the PQ domain (the domain of real and imaginary power). The universal controller can include a region selection unit, a signal selection unit, a reference signal source unit, a drive signal distribution unit and a control core. The control core can be implemented with one-cycle control, average current mode control, current mode control, sliding mode control and the like. The controller can be configured to control numerous types of power converters by adjusting the reference signal source unit. Also provided are multiple embodiments of control cores suitable for use with the various modulation methods.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. It is also intended that the invention is not limited to require the details of the example embodiments.
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SUMMARY: FIELD OF THE INVENTION
The invention relates generally to the field of power converter controllers, and more particularly to systems and methods for the control of power converters with a controller.
BACKGROUND INFORMATION
Switched power converters are circuits having numerous applications in distributed generation (DG) power systems.FIGS. 1-4depict four types of commonly used switched power converters.FIG. 1Adepicts a two level power factor corrected (PFC) rectifier102. Here, PFC rectifier102is used to shape the line currents ia, iband icto be proportional to the corresponding line voltages Va, Vband Vc.FIG. 1Bdepicts an example graph of the line voltage versus time, and the line current versus time, where j is used to denote a, b or c. Here, it can be seen that the line current ijis kept proportional to the line voltage Vj.
FIG. 2Adepicts a two level active power filter (APF)104, which is another example power converter. Here, APF104is used to generate anti-harmonic and reactive currents to suppress or cancel harmonics in the power lines.FIG. 2Bdepicts an example graph of the system line voltage, Vj, versus time.FIG. 2Cdepicts an example graph of the line current, ij, versus time prior to adjustment by the APF104.FIG. 2Ddepicts an example graph of the anti-harmonic or reactive current, icj, versus time andFIG. 2Edepicts an exemplary graph of the resulting line current, ilj, after adjustment by the APF104.
FIG. 3Adepicts a two level pulse width modulated (PWM) static volt-ampere-reactive (VAR) compensator (SVC)106, which is another example of a power converter. Here, SVC106is used to generate a 90 degree phase offset, either leading or lagging, of the line current from the line voltage so as to control power flow from a power grid. The power grid is typically a power system, or power utility, which is a network of transmission lines, transformers, loads, power generators, motors and the like.FIG. 3Bdepicts an example graph of the line voltage, Vj, and the line current, ij, versus time where ijlags VjandFIG. 3Cdepicts an example graph of the line voltage, Vj, and the line current, ij, versus time where ijleads Vj. An example of a similar type of power converter is a static synchronous compensator (STATCOM).
FIG. 4Adepicts a two level grid connected inverter (GCI)108, which is another example of a power converter. Here, GCI108is used to convert time-static, or direct current (DC), power into time-varying, or alternating current (AC), power flowing into the power grid, where the generated current (ij) has a polarity opposite that of the line voltage (Vj). The power grid is typically a power system, or power utility, which is a network of transmission lines, transformers, loads, power generators, motors and the like.FIG. 4Bdepicts a graph of Vjand ijversus time, where Vjand ijhave opposite polarities. GCI108is typically used to convert DC energy from renewable or alternative energy sources such as fuel cells, photovoltaic sources, batteries and the like.
Each of the power converters102-108are operating by controlling the state (opened or closed) of each of the various switches110. Some conventional control methods employ DQ conversion and real-time reference current calculation. These methods require a high-speed digital microprocessor and high performance A/D converters and result in a higher cost, higher complexity and lower reliability. Another conventional control method is referred to as one cycle control (OCC).
OCC is a unified pulse width modulation (PWM) control method that is capable of controlling basic power converters with relatively lower costs, lower complexity and higher reliability. OCC is described in more detail in U.S. Pat. No. 5,278,490, issued Jan. 11, 1994, which is fully incorporated by reference herein. Many previous OCC controllers were not capable of operation with different types of power converters102-108. The design of separate OCC controllers was required for each type of power converter102-108.
More recently, OCC controllers were developed capable of controlling more than one type of power converter. For instance, three phase two-level OCC controllers capable of controlling a PFC102, APF104and GCI108were described in U.S. Pat. No. 6,297,980 issued on Oct. 2, 2001 and U.S. Pat. No. 6,545,887, issued on Apr. 8, 2003, both of which are fully incorporated by reference herein. However, these OCC controllers were not capable of operation with each type of power converter102-108.
Accordingly, a universal controller capable of controlling multiple types of two and three level power converters is needed.
SUMMARY
The systems and methods described herein provide for modulation methods for controlling a three phase three level power converter with a controller. In one exemplary embodiment of a modulation method, the power converter includes a first, a second and a third voltage source where each voltage source is configured to output a time-varying signal and is inductively coupled to a separate input node. Each input node is preferably connectable to a first output node, a second output node and a third output node. The power converter also includes a first capacitive element coupled between the first and the second output node and a second capacitive element coupled between the second output node and the third output node. Each time-varying voltage signal has substantially the same period and a different phase.
The method includes determining which voltage signal has the highest voltage, the lowest voltage and the intermediate voltage higher than one of the voltage signals and lower than the other voltage signal for each of a plurality of sub-periods. Then connecting the voltage signal having the intermediate voltage to only the first output node during each sub-period, connecting the voltage signal having the highest voltage to one of the second or third output nodes during each sub-period; and connecting the voltage signal having the lowest voltage to one of the second or third output nodes during each sub-period.
In another exemplary embodiment, the modulation method includes providing a power converter having a first, a second and a third voltage source each configured to output a time-varying signal. The first and second voltage sources are each preferably inductively coupled to a separate input node. The input nodes can be connectable to a first and second output node. The third voltage source is preferably inductively coupled to a third output node. The power converter also includes a first capacitive element coupled between the first and the second output node, and a second capacitive element coupled between the second output node and the third output node. Each time-varying voltage signal preferably has substantially the same period and a different phase. The method also includes providing a controller configured to control the connection of the second and third voltage sources to the second and third output nodes.
In yet another exemplary embodiment of a modulation method, the power converter includes a first, a second and a third voltage source where each voltage source is configured to output a time-varying signal and is inductively coupled to a separate input node. Each input node is preferably connectable to a first output node, a second output node and a third output node. The converter can further include a first capacitive element coupled between the first and the second output node and a second capacitive element coupled between the second output node and the third output node. Each time-varying voltage signal preferably has substantially the same period and a different phase.
The method preferably includes determining which voltage signal has the highest voltage, the lowest voltage and the intermediate voltage higher than one of the voltage signals and lower than the other voltage signal for each of a plurality of sub-periods, determining which voltage signal is dominant for each of the plurality of sub-periods, connecting the voltage signal having the lowest voltage to only the third output node when the dominant voltage signal is lower than the non-dominant voltage signals, connecting the voltage signal having the highest voltage to one of the first output node and the second output node during each sub-period where the dominant voltage signal is lower than the non-dominant voltage signals, connecting the voltage signal having the intermediate voltage to one of the second output node and the third output node during each sub-period where the dominant voltage signal is lower than the non-dominant voltage signals, connecting the voltage signal having the highest voltage to only the second output node when the dominant voltage signal is higher than the non-dominant voltage signals, connecting the voltage signal having the lowest voltage to one of the first output node and the second output node during each sub-period where the dominant voltage signal is higher than the non-dominant voltage signals and connecting the voltage signal having the intermediate voltage to one of the second output node and the third output node during each sub-period where the dominant voltage signal is higher than the non-dominant voltage signals.
The systems and methods described herein also provide for a universal controller capable of controlling numerous types of three phase, two and three level power converters. Any type of power converter can be controlled in any of the four quadrants of the PQ domain (the domain of real and imaginary power). The universal controller can include a region selection unit, a signal selection unit, a reference signal source unit, a drive signal distribution unit and a control core. The control core can be implemented with one-cycle control, average current mode control, current mode control, sliding mode control and the like. The controller can be configured to control numerous types of power converters by adjusting the reference signal source unit. Also provided are multiple embodiments of control cores suitable for use with the various modulation methods.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. It is also intended that the invention is not limited to require the details of the example embodiments.
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7646574 | REFERENCE TO THE RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP2007-118815 filed Apr. 27, 2007, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a voltage regulator that outputs a constant voltage, and more particularly to an overcurrent protective circuit that reduces an output current to protect a circuit when an overcurrent flows into an output terminal.
2. Description of the Related Art
Voltage regulators have been employed as voltage supply sources of circuits in diverse electronic devices. The function of the voltage regulator is to output a constant voltage to the output terminal without being affected by a voltage variation of an input terminal. Also, it is important that the voltage regulator functions as overcurrent protection that reduces an output current to protect a circuit when a current that is supplied to a load from the output terminal increases and exceeds a largest current (for example, refer to JP 2003-29856 A).
FIG. 5shows a circuit diagram showing a voltage regulator having an overcurrent protective circuit. The conventional voltage regulator having the overcurrent protective circuit includes an output voltage divider circuit2that divides a voltage at an output terminal VOUT, a reference voltage circuit3that outputs a reference voltage, an error amplifier4that compares the divided voltage with the reference voltage, an output transistor1that is controlled by an output voltage of the error amplifier4, and an overcurrent protective circuit100. The overcurrent protective circuit100includes an output current detection transistor5and a detection resistor6which are an output current detector circuit that is connected in parallel to the output transistor1, and a transistor7, a resistor8, and an output current control transistor9which constitute an output current limiter circuit that is controlled by a voltage of the detection resistor6.
The above overcurrent protective circuit100has a function of protecting a circuit from the overcurrent with the following operation.
In the case where the output current of the output terminal VOUT increases, the detection current that is in proportion to the output current flows in the output current detection transistor5. The detection current flows in the resistor6, thereby allowing a voltage between the gate and the source of the transistor7to rise. In this case, when the overcurrent flows in the output terminal VOUT, and the voltage between the gate and the source of the transistor7exceeds a threshold voltage due to the detection current that is proportional to the overcurrent, a drain current flows in the transistor7. Accordingly, the voltage between the gate and the source of the output current control transistor9drops, and a drain current flows in the output current control transistor9, thereby allowing the voltage between the gate and the source of the output transistor1to rise. With the execution of feedback as described above, the gate of the output transistor1is so controlled as to hold the drain current of the output current detection transistor5constant. As a result, an increase in the output current is suppressed.
However, the output current detection transistor5of the overcurrent protective circuit100suffers from such a problem that because the drain voltage changes according to the input voltage, a relationship of current between the output current detection transistor5and the output transistor1is collapsed due to the channel length modulation effect, to thereby deteriorate a precision in the detection of the overcurrent.
Accordingly, the overcurrent protective circuit100needs to make a voltage VAat the drain (point A) of the output current detection transistor5identical with a voltage VBat the drain (point B) of the output transistor1, and uses a current mirror circuit as a circuit for achieving the above requirement.
The operation will be described below. A current of the same amount as that of the detection current flows by the transistor11that is identical in size with the output current detection transistor5. The current is reflexed by a first current mirror circuit, and flows in transistors14,15, and16that constitute a second current mirror circuit, thereby making the voltage VAat the point A identical with the voltage VBat the point B.
However, the circuit using the above current mirror circuit has a drawback that a current consumption increases because the same current as that of the detection current flows in two paths that pass through transistors11,15, and12and transistors14and13, respectively.
The present invention has been made to solve the above problems, and an object of the present invention is to provide an overcurrent protective circuit that is high in detection precision without increasing the current consumption.
SUMMARY OF THE INVENTION
In order to solve the conventional problems, a voltage regulator having the overcurrent protective circuit according to the present invention is configured as follows. That is, the present invention provides:
(1) a voltage regulator, including: an overcurrent protective circuit including: an output current detection transistor that is controlled by an output voltage of the error amplifier circuit, and allows a detection current to flow therein; a detection resistor that generates a detection voltage by the detection current; an output current limiter circuit that is controlled by the voltage of the detection resistor, and controls the gate voltage of the output transistor; and a regulated cascode circuit that is connected between the drain of the output transistor and the drain of the output current detection transistor, and makes a voltage at the drain of the output transistor equal to a voltage at the drain of the output current detection transistor, in which the voltage regulator, the operating current of the regulated cascode circuit is supplied by the operating current supply transistor that is controlled by the output voltage of the error amplifier circuit.
(2) a voltage regulator, in which the regulated cascode circuit further includes a current limiter circuit that is connected in series to the operating current supply transistor, and the upper limit of the operating current is limited by the current limiter circuit.
(3) a voltage regulator, in which the regulated cascode circuit further includes a minimum operating current supply circuit that is connected in parallel to the operating current supply transistor, and the minimum operating current is compensated by the minimum operating current supply circuit.
According to the voltage regulator having the overcurrent protective circuit of the present invention, since the regulated cascode circuit is used in order to make the voltage VAat the drain (point A) of the output current detection transistor5identical with the voltage VBat the drain (point B) of the output transistor1, the current flows in one path as compared with the current mirror circuit. This causes such an advantage that the current consumption can be reduced.
Also, even if there occurs the overcurrent that exceeds the operating current required for the regulated cascode circuit, the operating current is limited. As a result, an unnecessary current is prevented from flowing, thereby making it possible to reduce the current consumption more.
Further, even if the current is lower than the operating current required for the regulated cascode circuit, the minimum operating current can be supplied. As a result, the operation of the regulated cascode circuit is prevented from getting unstable, thereby making it possible to maintain the detection precision.
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SUMMARY: REFERENCE TO THE RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP2007-118815 filed Apr. 27, 2007, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a voltage regulator that outputs a constant voltage, and more particularly to an overcurrent protective circuit that reduces an output current to protect a circuit when an overcurrent flows into an output terminal.
2. Description of the Related Art
Voltage regulators have been employed as voltage supply sources of circuits in diverse electronic devices. The function of the voltage regulator is to output a constant voltage to the output terminal without being affected by a voltage variation of an input terminal. Also, it is important that the voltage regulator functions as overcurrent protection that reduces an output current to protect a circuit when a current that is supplied to a load from the output terminal increases and exceeds a largest current (for example, refer to JP 2003-29856 A).
FIG. 5shows a circuit diagram showing a voltage regulator having an overcurrent protective circuit. The conventional voltage regulator having the overcurrent protective circuit includes an output voltage divider circuit2that divides a voltage at an output terminal VOUT, a reference voltage circuit3that outputs a reference voltage, an error amplifier4that compares the divided voltage with the reference voltage, an output transistor1that is controlled by an output voltage of the error amplifier4, and an overcurrent protective circuit100. The overcurrent protective circuit100includes an output current detection transistor5and a detection resistor6which are an output current detector circuit that is connected in parallel to the output transistor1, and a transistor7, a resistor8, and an output current control transistor9which constitute an output current limiter circuit that is controlled by a voltage of the detection resistor6.
The above overcurrent protective circuit100has a function of protecting a circuit from the overcurrent with the following operation.
In the case where the output current of the output terminal VOUT increases, the detection current that is in proportion to the output current flows in the output current detection transistor5. The detection current flows in the resistor6, thereby allowing a voltage between the gate and the source of the transistor7to rise. In this case, when the overcurrent flows in the output terminal VOUT, and the voltage between the gate and the source of the transistor7exceeds a threshold voltage due to the detection current that is proportional to the overcurrent, a drain current flows in the transistor7. Accordingly, the voltage between the gate and the source of the output current control transistor9drops, and a drain current flows in the output current control transistor9, thereby allowing the voltage between the gate and the source of the output transistor1to rise. With the execution of feedback as described above, the gate of the output transistor1is so controlled as to hold the drain current of the output current detection transistor5constant. As a result, an increase in the output current is suppressed.
However, the output current detection transistor5of the overcurrent protective circuit100suffers from such a problem that because the drain voltage changes according to the input voltage, a relationship of current between the output current detection transistor5and the output transistor1is collapsed due to the channel length modulation effect, to thereby deteriorate a precision in the detection of the overcurrent.
Accordingly, the overcurrent protective circuit100needs to make a voltage VAat the drain (point A) of the output current detection transistor5identical with a voltage VBat the drain (point B) of the output transistor1, and uses a current mirror circuit as a circuit for achieving the above requirement.
The operation will be described below. A current of the same amount as that of the detection current flows by the transistor11that is identical in size with the output current detection transistor5. The current is reflexed by a first current mirror circuit, and flows in transistors14,15, and16that constitute a second current mirror circuit, thereby making the voltage VAat the point A identical with the voltage VBat the point B.
However, the circuit using the above current mirror circuit has a drawback that a current consumption increases because the same current as that of the detection current flows in two paths that pass through transistors11,15, and12and transistors14and13, respectively.
The present invention has been made to solve the above problems, and an object of the present invention is to provide an overcurrent protective circuit that is high in detection precision without increasing the current consumption.
SUMMARY OF THE INVENTION
In order to solve the conventional problems, a voltage regulator having the overcurrent protective circuit according to the present invention is configured as follows. That is, the present invention provides:
(1) a voltage regulator, including: an overcurrent protective circuit including: an output current detection transistor that is controlled by an output voltage of the error amplifier circuit, and allows a detection current to flow therein; a detection resistor that generates a detection voltage by the detection current; an output current limiter circuit that is controlled by the voltage of the detection resistor, and controls the gate voltage of the output transistor; and a regulated cascode circuit that is connected between the drain of the output transistor and the drain of the output current detection transistor, and makes a voltage at the drain of the output transistor equal to a voltage at the drain of the output current detection transistor, in which the voltage regulator, the operating current of the regulated cascode circuit is supplied by the operating current supply transistor that is controlled by the output voltage of the error amplifier circuit.
(2) a voltage regulator, in which the regulated cascode circuit further includes a current limiter circuit that is connected in series to the operating current supply transistor, and the upper limit of the operating current is limited by the current limiter circuit.
(3) a voltage regulator, in which the regulated cascode circuit further includes a minimum operating current supply circuit that is connected in parallel to the operating current supply transistor, and the minimum operating current is compensated by the minimum operating current supply circuit.
According to the voltage regulator having the overcurrent protective circuit of the present invention, since the regulated cascode circuit is used in order to make the voltage VAat the drain (point A) of the output current detection transistor5identical with the voltage VBat the drain (point B) of the output transistor1, the current flows in one path as compared with the current mirror circuit. This causes such an advantage that the current consumption can be reduced.
Also, even if there occurs the overcurrent that exceeds the operating current required for the regulated cascode circuit, the operating current is limited. As a result, an unnecessary current is prevented from flowing, thereby making it possible to reduce the current consumption more.
Further, even if the current is lower than the operating current required for the regulated cascode circuit, the minimum operating current can be supplied. As a result, the operation of the regulated cascode circuit is prevented from getting unstable, thereby making it possible to maintain the detection precision.
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7669736 | FIELD OF THE INVENTION
This invention relates generally to resealable polymeric packets designed to hold and disperse multiple doses of a useful fluid. Specifically, the present invention discloses a simple and reliable fold closure technique for resealing small, disposable, bi-chambered, multidose packets of liquid.
BACKGROUND OF THE INVENTION
The packaging of liquids and particularly the resealing of opened liquid packets has always had the twin challenges of operational simplicity and reliable leak prevention. Whatever the design it must be intuitively easy to operate by users with widely ranging physical abilities; equally important is absolute leakage control which not only prevents product loss but also avoids damage to surrounding materials and circumstances. Above all, the design must provide these features in the form of a very low cost, small, disposable packet. Numerous inventive designs have been put forth over many years to meet these well recognized challenges. The following are representative of the current art.
Salfisberg, U.S. Pat. No. 2,325,921 (1943) describes a polymeric packet for distribution of tablets or liquids. The design includes a material reservoir, a discharge neck, a matchbook-style cover that when closed and held folds the discharge neck so as to prevent accidental discharge. This design has no controlling barrier feature or restrictive passage so the relatively large discharge channel permits substantial leakage whenever even minor incidental external pressure is applied to the liquid reservoir.
Schneider, U.S. Pat. No. 2,976,988 (1961) describes a polymeric packet for distribution of tablets or liquids. Two chambers, reservoir and distribution, are connected by a passage designed to control liquid exchange by simple stretch tension produced by the polymeric walls of the packet, opened under fluidic pressure, and resealing when the fluidic pressure is released. No other resealing features such as a fold are provided and application of inadvertent pressure to the liquid through the walls, such as found in a purse or pocket, is more than sufficient to produce a substantial product discharge with subsequent loss and damage.
Schneider, U.S. Pat. No. 3,224,640 (1965) describes a flexible polymeric packet with an extended discharge channel that is folded over and held against the packet by placing the discharge end in a slit pocket formed as part of the packet wall. This one chamber design absent a controlling barrier feature and restrictive passage is very prone to leakage particular along the channel edges where the fold and side seals meet but fail to provide effective closure.
Amneus, U.S. Pat. No. 4,163,509 (1979) describes a dispensing container with an elongated discharge spout ending in a tension curl valve designed to uncurl and release fluid when a stripping action is applied to the length of the discharge spout. Due to the relatively stiff tension required to maintain the curl for leakage control, the design is better adapted to wall hanging and mechanical operation and precludes the convenience of a pocket carried version.
Herzig, U.S. Pat. No. 4,252,257 (1981) describes a flexible container employing a transverse pinch-off valve at the discharge slit that opens when pressure is applied to key areas of the container adjacent to a pinch-off line. Practice has shown the tension of the valve quickly fatigues and leakage results. Ease of manipulation has also proven problematic.
Imer, U.S. Pat. No. 5,228,782 (1993) describes a polymeric sachet with a liquid reservoir and narrow outlet channel through which the liquid is discharged. The sachet is resealed by folding the strap in which the narrow channel is located at a 45° angle and fitting the strap extension into a holding slit thus sealing the channel. In practice the strap manipulation is cumbersome to operate and prone to accidental discharge and leakage. Additionally the lack of a distribution chamber to control pressure discharge and dose measurement makes dispersement messy and erratic.
Farmer, U.S. Pat. No. 6,244,468 (2001) describes a liquid sachet with two chambers formed by seals, a connecting inlet, and an exit point resealable by twin tension folds traversing the opening that unfold under hydraulic pressure to disperse the liquid. The tension necessary to hold the folds shut is necessary slight so as to appropriately respond to an opening pressure that needs to remain within moderate limits, this requirement and the lack of any fold holding means makes the folds vulnerable to accidental opening, discharge, and leakage when inadvertently manipulated by movements and conditions typically found in a pocket, briefcase, or purse.
Harper, U.S. Pat. No. 7,004,354 (2006) describes a self-sealing polymer packet with reservoir and dispersement chambers, a traversing barrier seam forming the chambers, and an active choke valve in the barrier seam that restricts pressurized liquid passage unless opened by intentional contortion of the packet walls. In practice the design presents operational challenges to users with small hands, arthritic fingers, or limited dexterity. Additionally, some users disbelieve a miniscule choke valve can adequately reseal the packet, preferring a more obvious and robust closure system to prevent leakage.
The present invention recognizes the numerous seal variations found in the foregoing prior art and specifically addresses their individual and collective disadvantages and shortcomings. Salfisberg's matchbook packaging with a fold closure held in place by a cover is simple, somewhat intuitive, cost effective, but leaks badly. Schneider '640 and Imer disclosed fold-and-hold designs that are both cumbersome to operate and prone to leakage and discharge. Schneider '988 introduced the bi-chamber and contolling barrier features together with cost effectiveness but failed to provide a robust closure system against leakage. Amneus, Herzig and Farmer all employed spout closure designs that relied upon material tension to control leakage, such designs are prone to accidental external manipulation that allows leakage, particularly in small packets intended for pocket or purse carrying. The Harper packet with the active choke seal design provides effective measurement and dose dispersal, together with cost effectiveness and good leak protection, but opening the seal is not easy for all users. Despite all these efforts there is still an unmet need for a novel closure system that makes secure, resealable liquid packets a simple reality for all users.
SUMMARY OF THE INVENTION
All the elements for creating a small, disposable, resealable, leak proof packet exist in the prior art, however these elements must be carefully selected out of the general clutter and then arranged in a new and novel way to achieve a truly effective result, a result so far not yet achieved despite continuous efforts by numerous skilled designers over many years. A key component of the present invention is to provide a closure means where a controlling barrier and restrictive passage interact with a proximate parallel fold to alternatively permit or prevent fluid passage between two chambers and subsequent exit of the packet. The packet is formed of opposing walls of a supple imperforate material interconnected along at least one edge by a seam. The walls define a space bisected by a controlling barrier seam containing a restrictive passage connecting a larger reservoir and smaller distribution chamber. Contained within the packet is a liquid in fluidic communication between the chambers and capable of exiting the distribution chamber in multiple measured doses though a user created tear in the periphery of the distribution chamber. Resealing the open packet is accomplished by folding the packet at a fold line immediately adjacent to the controlling barrier creating an effective seal closing the restrictive passage by the immediate proximity of packet fold bringing the two opposing walls into a crimped closure system. The controlling barrier effectively prevents leakage across the width of the packet that has defeated much of the earlier art, and the relatively narrow restrictive passage which focuses flow movement, working in concert with the fold, tightly shuts and prevents fluidic exchange between chambers and subsequent measured dispersement. The fold can be held shut by various techniques; four representative examples of fold holding means are described as cover, tab, case, and slide.
A primary object of the present invention is to provide a fluid dispensing apparatus in the form of a packet which employs a controlling barrier, a restrictive passage, and an immediate fold working in concert to provide reliable resealing which makes possible a small, flat, multidose, easy use, reliable, cost effective tool for carrying about small quantities of useful liquids, specifically a hand sanitizing fluid for control of sickness and infectious disease in a human population.
Another object of the present invention is to provide a method for allocating multiple varied measured doses of a useful liquid as needed.
Another object of the present invention is to provide a means by way of a resealable packet for promoting better health by access to a hand sanitizing fluid making possible clean hands when and where needed.
Another object of the present invention is to provide surfaces and/or chambers that bear meaningful communications which encourages distribution and use of resealable packets of useful liquids.
A final object of the present invention is to provide liquid packets with an intuitively simple and easily manipulated resealing means for the immature or impaired user.
Other objects and advantages of the present invention will become apparent from the following description taken in conjunction where appropriate with the accompanying drawings wherein are set forth, by way of illustrations and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
This invention relates generally to resealable polymeric packets designed to hold and disperse multiple doses of a useful fluid. Specifically, the present invention discloses a simple and reliable fold closure technique for resealing small, disposable, bi-chambered, multidose packets of liquid.
BACKGROUND OF THE INVENTION
The packaging of liquids and particularly the resealing of opened liquid packets has always had the twin challenges of operational simplicity and reliable leak prevention. Whatever the design it must be intuitively easy to operate by users with widely ranging physical abilities; equally important is absolute leakage control which not only prevents product loss but also avoids damage to surrounding materials and circumstances. Above all, the design must provide these features in the form of a very low cost, small, disposable packet. Numerous inventive designs have been put forth over many years to meet these well recognized challenges. The following are representative of the current art.
Salfisberg, U.S. Pat. No. 2,325,921 (1943) describes a polymeric packet for distribution of tablets or liquids. The design includes a material reservoir, a discharge neck, a matchbook-style cover that when closed and held folds the discharge neck so as to prevent accidental discharge. This design has no controlling barrier feature or restrictive passage so the relatively large discharge channel permits substantial leakage whenever even minor incidental external pressure is applied to the liquid reservoir.
Schneider, U.S. Pat. No. 2,976,988 (1961) describes a polymeric packet for distribution of tablets or liquids. Two chambers, reservoir and distribution, are connected by a passage designed to control liquid exchange by simple stretch tension produced by the polymeric walls of the packet, opened under fluidic pressure, and resealing when the fluidic pressure is released. No other resealing features such as a fold are provided and application of inadvertent pressure to the liquid through the walls, such as found in a purse or pocket, is more than sufficient to produce a substantial product discharge with subsequent loss and damage.
Schneider, U.S. Pat. No. 3,224,640 (1965) describes a flexible polymeric packet with an extended discharge channel that is folded over and held against the packet by placing the discharge end in a slit pocket formed as part of the packet wall. This one chamber design absent a controlling barrier feature and restrictive passage is very prone to leakage particular along the channel edges where the fold and side seals meet but fail to provide effective closure.
Amneus, U.S. Pat. No. 4,163,509 (1979) describes a dispensing container with an elongated discharge spout ending in a tension curl valve designed to uncurl and release fluid when a stripping action is applied to the length of the discharge spout. Due to the relatively stiff tension required to maintain the curl for leakage control, the design is better adapted to wall hanging and mechanical operation and precludes the convenience of a pocket carried version.
Herzig, U.S. Pat. No. 4,252,257 (1981) describes a flexible container employing a transverse pinch-off valve at the discharge slit that opens when pressure is applied to key areas of the container adjacent to a pinch-off line. Practice has shown the tension of the valve quickly fatigues and leakage results. Ease of manipulation has also proven problematic.
Imer, U.S. Pat. No. 5,228,782 (1993) describes a polymeric sachet with a liquid reservoir and narrow outlet channel through which the liquid is discharged. The sachet is resealed by folding the strap in which the narrow channel is located at a 45° angle and fitting the strap extension into a holding slit thus sealing the channel. In practice the strap manipulation is cumbersome to operate and prone to accidental discharge and leakage. Additionally the lack of a distribution chamber to control pressure discharge and dose measurement makes dispersement messy and erratic.
Farmer, U.S. Pat. No. 6,244,468 (2001) describes a liquid sachet with two chambers formed by seals, a connecting inlet, and an exit point resealable by twin tension folds traversing the opening that unfold under hydraulic pressure to disperse the liquid. The tension necessary to hold the folds shut is necessary slight so as to appropriately respond to an opening pressure that needs to remain within moderate limits, this requirement and the lack of any fold holding means makes the folds vulnerable to accidental opening, discharge, and leakage when inadvertently manipulated by movements and conditions typically found in a pocket, briefcase, or purse.
Harper, U.S. Pat. No. 7,004,354 (2006) describes a self-sealing polymer packet with reservoir and dispersement chambers, a traversing barrier seam forming the chambers, and an active choke valve in the barrier seam that restricts pressurized liquid passage unless opened by intentional contortion of the packet walls. In practice the design presents operational challenges to users with small hands, arthritic fingers, or limited dexterity. Additionally, some users disbelieve a miniscule choke valve can adequately reseal the packet, preferring a more obvious and robust closure system to prevent leakage.
The present invention recognizes the numerous seal variations found in the foregoing prior art and specifically addresses their individual and collective disadvantages and shortcomings. Salfisberg's matchbook packaging with a fold closure held in place by a cover is simple, somewhat intuitive, cost effective, but leaks badly. Schneider '640 and Imer disclosed fold-and-hold designs that are both cumbersome to operate and prone to leakage and discharge. Schneider '988 introduced the bi-chamber and contolling barrier features together with cost effectiveness but failed to provide a robust closure system against leakage. Amneus, Herzig and Farmer all employed spout closure designs that relied upon material tension to control leakage, such designs are prone to accidental external manipulation that allows leakage, particularly in small packets intended for pocket or purse carrying. The Harper packet with the active choke seal design provides effective measurement and dose dispersal, together with cost effectiveness and good leak protection, but opening the seal is not easy for all users. Despite all these efforts there is still an unmet need for a novel closure system that makes secure, resealable liquid packets a simple reality for all users.
SUMMARY OF THE INVENTION
All the elements for creating a small, disposable, resealable, leak proof packet exist in the prior art, however these elements must be carefully selected out of the general clutter and then arranged in a new and novel way to achieve a truly effective result, a result so far not yet achieved despite continuous efforts by numerous skilled designers over many years. A key component of the present invention is to provide a closure means where a controlling barrier and restrictive passage interact with a proximate parallel fold to alternatively permit or prevent fluid passage between two chambers and subsequent exit of the packet. The packet is formed of opposing walls of a supple imperforate material interconnected along at least one edge by a seam. The walls define a space bisected by a controlling barrier seam containing a restrictive passage connecting a larger reservoir and smaller distribution chamber. Contained within the packet is a liquid in fluidic communication between the chambers and capable of exiting the distribution chamber in multiple measured doses though a user created tear in the periphery of the distribution chamber. Resealing the open packet is accomplished by folding the packet at a fold line immediately adjacent to the controlling barrier creating an effective seal closing the restrictive passage by the immediate proximity of packet fold bringing the two opposing walls into a crimped closure system. The controlling barrier effectively prevents leakage across the width of the packet that has defeated much of the earlier art, and the relatively narrow restrictive passage which focuses flow movement, working in concert with the fold, tightly shuts and prevents fluidic exchange between chambers and subsequent measured dispersement. The fold can be held shut by various techniques; four representative examples of fold holding means are described as cover, tab, case, and slide.
A primary object of the present invention is to provide a fluid dispensing apparatus in the form of a packet which employs a controlling barrier, a restrictive passage, and an immediate fold working in concert to provide reliable resealing which makes possible a small, flat, multidose, easy use, reliable, cost effective tool for carrying about small quantities of useful liquids, specifically a hand sanitizing fluid for control of sickness and infectious disease in a human population.
Another object of the present invention is to provide a method for allocating multiple varied measured doses of a useful liquid as needed.
Another object of the present invention is to provide a means by way of a resealable packet for promoting better health by access to a hand sanitizing fluid making possible clean hands when and where needed.
Another object of the present invention is to provide surfaces and/or chambers that bear meaningful communications which encourages distribution and use of resealable packets of useful liquids.
A final object of the present invention is to provide liquid packets with an intuitively simple and easily manipulated resealing means for the immature or impaired user.
Other objects and advantages of the present invention will become apparent from the following description taken in conjunction where appropriate with the accompanying drawings wherein are set forth, by way of illustrations and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
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7765498 | FIELD OF THE INVENTION
The invention relates to integrated circuit devices (ICs). More particularly, the invention relates to IC layouts and netlists, and methods of modifying the netlists to reflect behavioral changes resulting from semiconductor fabrication of the IC layouts.
BACKGROUND
Integrated circuits are typically manufactured using “layouts”, which are collections of polygons and/or other shapes in two-dimensions. These polygons might be physically incorporated into “masks”, with one or more masks being used to define the locations of each fabrication layer, e.g., diffusion, contacts, polysilicon (also known as “poly”), vias, metal1, metal2, and so forth. Alternatively or additionally, the polygons might form a database that is used to directly control the application of a layer to the surface of the wafer, without the use of a physical mask. In either case, the polygons define the areas of the polysilicon to which a new layer will be applied or from which an existing layer will be removed during the semiconductor fabrication process.
Although IC circuits are typically simulated prior to layout, it is desirable to simulate a circuit after layout as well, a process known as “post-layout simulation”. Post-layout simulation provides a more accurate depiction of the circuit behavior than a simulation of the circuit prior to layout, and may detect, for example, discrepancies between the layout and the original circuit design. To perform a post-layout simulation, a netlist is extracted from the layout and the simulation is performed upon this netlist. The extracted netlist may include, for example, a specification of transistors implemented by the layout, interconnections between the transistors, width and length values for each transistor, parasitics for each transistor, and parasitic capacitances and resistances for the interconnections between the transistors.
However, the semiconductor fabrication process typically alters some characteristics of an IC layout, such as the length and/or width of transistors, and these effects become more pronounced for nanometer processes at smaller dimensions. It is common practice to account for this discrepancy during post-layout simulation by using complicated simulation models designed to predict the behavior of post-fabrication transistors. While these transistor models can be quite accurate, their development is time-consuming, and changes to the fabrication process typically require what may be extensive modification of each transistor model. Further, the use of these models complicates the simulation process to the point where post-layout simulation requires extensive amounts of time and computing power.
Therefore, it is desirable to find alternative computer-implemented methods of performing post-layout simulation that reduce the amount of time and computing-power required to perform post-layout simulation, while retaining a sufficient level of accuracy to provide confidence in the result.
SUMMARY
The invention provides computer-implemented methods of generating netlists for use in post-layout simulation procedures. In one embodiment, a lookup table includes a predetermined set of features (e.g., transistors of specified sizes and shapes) supported by an integrated circuit (IC) fabrication process, with dimensions and process induced dimension variations being included for each feature. A netlist is extracted from an IC layout, the extracted netlist specifying circuit elements (e.g., transistors) implemented by the IC layout and interconnections between the circuit elements. A search pattern is run on the IC layout to identify features in the IC layout corresponding to features included in the lookup table. Circuit elements in the extracted netlist that correspond to the identified features are then modified using values from the lookup table, and the modified netlist is output, e.g., to a user, to a file, or to a post-layout simulation tool.
According to another embodiment, the extracted netlist is generated with reference to the lookup table, rather than being modified after its initial generation. In this embodiment, a lookup table includes a predetermined set of features (e.g., transistors of specified sizes and shapes) supported by an IC fabrication process, with dimensions and process induced dimension variations being included for each feature. A netlist is extracted from an IC layout, where the extracted netlist includes a specification of circuit elements (e.g., transistors) implemented by the IC layout and connectivity information specifying interconnections between the circuit elements. The extracted netlist also includes effective dimensions for each circuit element implemented by the IC layout, the effective dimensions comprising actual dimensions taken from the IC layout modified by process induced dimension variations taken from the lookup table. The netlist is then output, e.g., to a user, to a file, or to a post-layout simulation tool.
The invention also provides media that store code for performing the methods of the invention.
Thus, the invention provides methods by which the frequent process modifications in advanced deep sub-micron development can be simulated during the design phase of an integrated circuit, before the IC is actually in production.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The invention relates to integrated circuit devices (ICs). More particularly, the invention relates to IC layouts and netlists, and methods of modifying the netlists to reflect behavioral changes resulting from semiconductor fabrication of the IC layouts.
BACKGROUND
Integrated circuits are typically manufactured using “layouts”, which are collections of polygons and/or other shapes in two-dimensions. These polygons might be physically incorporated into “masks”, with one or more masks being used to define the locations of each fabrication layer, e.g., diffusion, contacts, polysilicon (also known as “poly”), vias, metal1, metal2, and so forth. Alternatively or additionally, the polygons might form a database that is used to directly control the application of a layer to the surface of the wafer, without the use of a physical mask. In either case, the polygons define the areas of the polysilicon to which a new layer will be applied or from which an existing layer will be removed during the semiconductor fabrication process.
Although IC circuits are typically simulated prior to layout, it is desirable to simulate a circuit after layout as well, a process known as “post-layout simulation”. Post-layout simulation provides a more accurate depiction of the circuit behavior than a simulation of the circuit prior to layout, and may detect, for example, discrepancies between the layout and the original circuit design. To perform a post-layout simulation, a netlist is extracted from the layout and the simulation is performed upon this netlist. The extracted netlist may include, for example, a specification of transistors implemented by the layout, interconnections between the transistors, width and length values for each transistor, parasitics for each transistor, and parasitic capacitances and resistances for the interconnections between the transistors.
However, the semiconductor fabrication process typically alters some characteristics of an IC layout, such as the length and/or width of transistors, and these effects become more pronounced for nanometer processes at smaller dimensions. It is common practice to account for this discrepancy during post-layout simulation by using complicated simulation models designed to predict the behavior of post-fabrication transistors. While these transistor models can be quite accurate, their development is time-consuming, and changes to the fabrication process typically require what may be extensive modification of each transistor model. Further, the use of these models complicates the simulation process to the point where post-layout simulation requires extensive amounts of time and computing power.
Therefore, it is desirable to find alternative computer-implemented methods of performing post-layout simulation that reduce the amount of time and computing-power required to perform post-layout simulation, while retaining a sufficient level of accuracy to provide confidence in the result.
SUMMARY
The invention provides computer-implemented methods of generating netlists for use in post-layout simulation procedures. In one embodiment, a lookup table includes a predetermined set of features (e.g., transistors of specified sizes and shapes) supported by an integrated circuit (IC) fabrication process, with dimensions and process induced dimension variations being included for each feature. A netlist is extracted from an IC layout, the extracted netlist specifying circuit elements (e.g., transistors) implemented by the IC layout and interconnections between the circuit elements. A search pattern is run on the IC layout to identify features in the IC layout corresponding to features included in the lookup table. Circuit elements in the extracted netlist that correspond to the identified features are then modified using values from the lookup table, and the modified netlist is output, e.g., to a user, to a file, or to a post-layout simulation tool.
According to another embodiment, the extracted netlist is generated with reference to the lookup table, rather than being modified after its initial generation. In this embodiment, a lookup table includes a predetermined set of features (e.g., transistors of specified sizes and shapes) supported by an IC fabrication process, with dimensions and process induced dimension variations being included for each feature. A netlist is extracted from an IC layout, where the extracted netlist includes a specification of circuit elements (e.g., transistors) implemented by the IC layout and connectivity information specifying interconnections between the circuit elements. The extracted netlist also includes effective dimensions for each circuit element implemented by the IC layout, the effective dimensions comprising actual dimensions taken from the IC layout modified by process induced dimension variations taken from the lookup table. The netlist is then output, e.g., to a user, to a file, or to a post-layout simulation tool.
The invention also provides media that store code for performing the methods of the invention.
Thus, the invention provides methods by which the frequent process modifications in advanced deep sub-micron development can be simulated during the design phase of an integrated circuit, before the IC is actually in production.
Is this patent green technology? Respond with 'yes' or 'no'. |
7678470 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a reinforced matrix for a molten carbonate fuel cell using a porous aluminum support and to a method for preparing the molten carbonate fuel cell comprising the reinforced matrix.
2. Description of the Related Art
A matrix in a molten carbonate fuel cell (MCFC) serves to prevent a cross-over of a reaction gas, to provide a conduction channel of a CO32−ion with a molten carbonate impregnated in the porous structure of the matrix and to insulate a cathode and an anode electrically.
Since the matrix is not an element participating in an electrochemical reaction but serves just as a support for an electrolyte, a pore size, a porosity, a stability for the electrolyte and a mechanical strength are very important in the matrix.
In particular, fracture and crack of the matrix due to a difference between coefficients of thermal expansion of the matrix and of the electrolyte according to a thermal cycle, and a change of a micro structure due to a long time operation are main causes of a degradation of performance and a reduction of life of a unit cell.
To solve the above problems, there have been suggested methods of dispersing a secondary phase of ceramic fibers or coarse particles as a retardant of crack propagation in γ-LiAlO2matrix to reinforce the matrix. As a result, it is known that an addition of alumina fibers is relatively efficient for reinforcing the matrix.
However, it is very expensive to manufacture the matrix using the alumina fibers. In view of that, the method using the alumina fibers is not suitable for a commercialization of the MCFC.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art. The object of the present invention is to provide a reinforced matrix for a molten carbonate fuel cell using a porous aluminum support and a method for preparing the molten carbonate fuel cell comprising the reinforced matrix, where the method is simple and economic contrary to the prior art which uses the alumina fibers and takes very high costs, and where the mass production of the matrix is easy, and where strength of the matrix can be increased effectively and therefore there is no worry about fracture or crack.
In order to accomplish the object, there is provided a reinforced matrix for a molten carbonate fuel cell comprising a porous aluminum support, and a lithium aluminate, which is tape-cast on the porous aluminum support.
In the reinforced matrix for a molten carbonate fuel cell according to the present invention, the porous aluminum support is a reticulate aluminum support.
In the reinforced matrix for a molten carbonate fuel cell according to the present invention, the porous aluminum support is an aluminum support having a three-dimensional network structure.
In order to achieve the above object, there is provided a method for preparing a molten carbonate fuel cell comprising steps of tape-casting a lithium aluminate on a porous aluminum support so as to prepare a reinforced matrix (S1); making a unit cell or a stack of the unit cells using the reinforced matrix (S2); and heat treating the unit cell or the stack so as to oxidize the aluminum in the support into the lithium aluminate (S3).
In the method according to the present invention, the porous aluminum support is a reticulate aluminum support.
In the method according to the present invention, the porous aluminum support is an aluminum support having a three-dimensional network structure.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a reinforced matrix for a molten carbonate fuel cell using a porous aluminum support and to a method for preparing the molten carbonate fuel cell comprising the reinforced matrix.
2. Description of the Related Art
A matrix in a molten carbonate fuel cell (MCFC) serves to prevent a cross-over of a reaction gas, to provide a conduction channel of a CO32−ion with a molten carbonate impregnated in the porous structure of the matrix and to insulate a cathode and an anode electrically.
Since the matrix is not an element participating in an electrochemical reaction but serves just as a support for an electrolyte, a pore size, a porosity, a stability for the electrolyte and a mechanical strength are very important in the matrix.
In particular, fracture and crack of the matrix due to a difference between coefficients of thermal expansion of the matrix and of the electrolyte according to a thermal cycle, and a change of a micro structure due to a long time operation are main causes of a degradation of performance and a reduction of life of a unit cell.
To solve the above problems, there have been suggested methods of dispersing a secondary phase of ceramic fibers or coarse particles as a retardant of crack propagation in γ-LiAlO2matrix to reinforce the matrix. As a result, it is known that an addition of alumina fibers is relatively efficient for reinforcing the matrix.
However, it is very expensive to manufacture the matrix using the alumina fibers. In view of that, the method using the alumina fibers is not suitable for a commercialization of the MCFC.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art. The object of the present invention is to provide a reinforced matrix for a molten carbonate fuel cell using a porous aluminum support and a method for preparing the molten carbonate fuel cell comprising the reinforced matrix, where the method is simple and economic contrary to the prior art which uses the alumina fibers and takes very high costs, and where the mass production of the matrix is easy, and where strength of the matrix can be increased effectively and therefore there is no worry about fracture or crack.
In order to accomplish the object, there is provided a reinforced matrix for a molten carbonate fuel cell comprising a porous aluminum support, and a lithium aluminate, which is tape-cast on the porous aluminum support.
In the reinforced matrix for a molten carbonate fuel cell according to the present invention, the porous aluminum support is a reticulate aluminum support.
In the reinforced matrix for a molten carbonate fuel cell according to the present invention, the porous aluminum support is an aluminum support having a three-dimensional network structure.
In order to achieve the above object, there is provided a method for preparing a molten carbonate fuel cell comprising steps of tape-casting a lithium aluminate on a porous aluminum support so as to prepare a reinforced matrix (S1); making a unit cell or a stack of the unit cells using the reinforced matrix (S2); and heat treating the unit cell or the stack so as to oxidize the aluminum in the support into the lithium aluminate (S3).
In the method according to the present invention, the porous aluminum support is a reticulate aluminum support.
In the method according to the present invention, the porous aluminum support is an aluminum support having a three-dimensional network structure.
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7694773 | The invention relates to hybrid electric motor vehicles, particularly but not exclusively of the kind where an internal combustion (IC) engine provides power to a four wheel drive transmission which has an electric motor/generator in the drive to one pair of wheels.
It is known from EP0584090 to provide a hybrid electric motor vehicle in which a motor/generator is mounted on the nose of a rear final drive unit where a propshaft connects an engine and transmission unit to the rear final drive unit, the motor/generator providing additional drive torque or braking torque as required. It is also known from U.S. Pat. No. 5,443,130 to provide an electric motor drive in which an electric traction motor is arranged transversely on a final drive unit, the motor having a hollow rotor which drives a differential through an epicyclic reduction gear, the differential driving one of the wheels through a shaft which extends concentrically through the rotor.
The present invention has an object of providing a hybrid electric motor vehicle in which a motor/generator unit is mounted in a final drive unit and wherein the final drive unit with the motor/generator unit has a reduced number of component parts.
According to one aspect of the invention there is provided a hybrid electric motor vehicle having an internal combustion engine, a transmission to transmit power from the engine to a front pair of wheels through a front final drive unit and to a rear pair of wheels through a rear final drive unit and an electric motor/generator in the drive to one of said pairs of wheels, the motor/generator being arranged in one of the final drive units and comprising a casing, a stator and a rotor, the stator being fast with the casing and the rotor driving said one pair of wheels through a reduction gear and a differential and the motor/generator being arranged transversely in said one final drive unit, the rotor of the motor/generator being hollow such that a drive shaft connecting the differential to one of said one pair of wheels extends concentrically through the rotor, wherein the reduction gear comprises a layshaft reduction gear train including a spur input gear driven by the motor/generator, a large diameter spur gear and a small diameter spur gear fixed on a layshaft and a large diameter driving gear fast with the differential, the large diameter spur gear meshing with the input gear and the small diameter spur gear meshing with the driving gear.
The invention also provides, according to another aspect thereof, a final drive unit for a hybrid electric motor vehicle having an internal combustion engine, a transmission to transmit power from the engine to a front pair of wheels through a front final drive unit and to a rear pair of wheels through a rear final drive unit and an electric motor/generator in the drive to one of said pairs of wheels, the motor/generator being arranged in one of the final drive units, wherein said one final drive unit comprises a casing, a stator and a rotor, the stator being fast with the casing and the rotor arranged to drive said one pair of wheels through a reduction gear and a differential, the motor/generator being arranged transversely in said one final drive unit and the rotor of the motor/generator being hollow such that a drive shaft which in use connects the differential to one of said one pair of wheels extends concentrically through the rotor, wherein the reduction gear comprises a layshaft reduction gear train including a spur input gear driven by the motor/generator, a large diameter spur gear and a small diameter spur gear fixed on a layshaft and a large diameter driving gear fast with the differential, the large diameter spur gear meshing with the input gear and the small diameter spur gear meshing with the driving gear.
Said one final drive unit may include an input shaft arranged longitudinally in the vehicle to transmit power, typically via a propshaft, from the transmission to the differential, the input shaft having a final drive bevel pinion which meshes with a crownwheel fast with the large diameter spur gear. Preferably, the layshaft spur gears are adjacent each other with the crown wheel facing away from the small diameter spur gear towards the final drive bevel pinion.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: The invention relates to hybrid electric motor vehicles, particularly but not exclusively of the kind where an internal combustion (IC) engine provides power to a four wheel drive transmission which has an electric motor/generator in the drive to one pair of wheels.
It is known from EP0584090 to provide a hybrid electric motor vehicle in which a motor/generator is mounted on the nose of a rear final drive unit where a propshaft connects an engine and transmission unit to the rear final drive unit, the motor/generator providing additional drive torque or braking torque as required. It is also known from U.S. Pat. No. 5,443,130 to provide an electric motor drive in which an electric traction motor is arranged transversely on a final drive unit, the motor having a hollow rotor which drives a differential through an epicyclic reduction gear, the differential driving one of the wheels through a shaft which extends concentrically through the rotor.
The present invention has an object of providing a hybrid electric motor vehicle in which a motor/generator unit is mounted in a final drive unit and wherein the final drive unit with the motor/generator unit has a reduced number of component parts.
According to one aspect of the invention there is provided a hybrid electric motor vehicle having an internal combustion engine, a transmission to transmit power from the engine to a front pair of wheels through a front final drive unit and to a rear pair of wheels through a rear final drive unit and an electric motor/generator in the drive to one of said pairs of wheels, the motor/generator being arranged in one of the final drive units and comprising a casing, a stator and a rotor, the stator being fast with the casing and the rotor driving said one pair of wheels through a reduction gear and a differential and the motor/generator being arranged transversely in said one final drive unit, the rotor of the motor/generator being hollow such that a drive shaft connecting the differential to one of said one pair of wheels extends concentrically through the rotor, wherein the reduction gear comprises a layshaft reduction gear train including a spur input gear driven by the motor/generator, a large diameter spur gear and a small diameter spur gear fixed on a layshaft and a large diameter driving gear fast with the differential, the large diameter spur gear meshing with the input gear and the small diameter spur gear meshing with the driving gear.
The invention also provides, according to another aspect thereof, a final drive unit for a hybrid electric motor vehicle having an internal combustion engine, a transmission to transmit power from the engine to a front pair of wheels through a front final drive unit and to a rear pair of wheels through a rear final drive unit and an electric motor/generator in the drive to one of said pairs of wheels, the motor/generator being arranged in one of the final drive units, wherein said one final drive unit comprises a casing, a stator and a rotor, the stator being fast with the casing and the rotor arranged to drive said one pair of wheels through a reduction gear and a differential, the motor/generator being arranged transversely in said one final drive unit and the rotor of the motor/generator being hollow such that a drive shaft which in use connects the differential to one of said one pair of wheels extends concentrically through the rotor, wherein the reduction gear comprises a layshaft reduction gear train including a spur input gear driven by the motor/generator, a large diameter spur gear and a small diameter spur gear fixed on a layshaft and a large diameter driving gear fast with the differential, the large diameter spur gear meshing with the input gear and the small diameter spur gear meshing with the driving gear.
Said one final drive unit may include an input shaft arranged longitudinally in the vehicle to transmit power, typically via a propshaft, from the transmission to the differential, the input shaft having a final drive bevel pinion which meshes with a crownwheel fast with the large diameter spur gear. Preferably, the layshaft spur gears are adjacent each other with the crown wheel facing away from the small diameter spur gear towards the final drive bevel pinion.
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7666152 | FIELD OF THE INVENTION
The present invention relates generally to generation and focusing of acoustic waves, and specifically to generation and focusing of acoustic waves with electromagnetic energy.
BACKGROUND OF THE INVENTION
Focused acoustic waves (or shockwaves, the terms being used interchangeably throughout) are being used increasingly in medical applications. For example, acoustic waves are used for tissue ablation, diagnostic imaging, drug delivery, breaking up concretions in the body such as kidney stones, treating orthopedic diseases, combating soft tissue complaints and pain, and other therapies which employ heat, cavitation, shock waves, and other thermal and/or mechanical effects for therapeutic purposes.
The prior art typically converts electrical energy into acoustic waves, such as by generating a strong pulse of an electric or magnetic field, usually by capacitor discharge, converting the electromagnetic field into acoustic energy, and directing the energy to a target by means of an associated focusing apparatus.
Point sources for the generation of acoustic waves in a lithotripter are described in various patents, such as U.S. Pat. No. 3,942,531 to Hoff et al., and U.S. Pat. No. 4,539,989 to Forsemann et al. A planar source for generation of acoustic waves is described, for example, in U.S. Pat. No. 4,674,505 to Pauli et al.
Cylindrical sources for generation of acoustic waves are described, for example, in U.S. Pat. No. 5,058,569 to Hassler et al., and U.S. Pat. No. 5,174,280 to Gruenwald et al. Spherical sources are also mentioned in the background of U.S. Pat. No. 5,174,280.
A truncated conical acoustic wave source is described in U.S. Pat. No. 6,869,407 to Ein-Gal, the disclosure of which is incorporated herein by reference. The background section of U.S. Pat. No. 6,869,407 includes a brief description of the manner by which acoustic waves are produced by point, spherical, planar, and cylindrical sources and a description of the limitations of each of these prior art acoustic wave generation apparatuses.
SUMMARY OF THE INVENTION
It is an object of some aspects of the present invention to provide an acoustic wave generation and focusing device comprising an acoustic wave transducer and an acoustic lens that provides improved focusing capability for ultrasonic energy deposition in body tissue, and provides a more efficient and cost-effective apparatus for ultrasonic energy deposition.
Acoustic waves may be generated in a variety of ways. By way of example and not limitation, acoustic waves may be generated by an area transducer, such as a truncated conical area transducer. A coil may repel or vibrate a conical membrane to produce acoustic waves. In another example, a conducting surface electrode may be mounted on the inner contour of the conical transducer. A perforated insulator may at least partially cover the surface electrode, and may be sandwiched between the surface electrode and a return electrode. A multiplicity of electrical currents may flow through the perforations of the perforated insulator, which give rise to point sources of ultrasonic energy in the form of spherical waves emanating from the perforations.
There is thus provided in accordance with a non-limiting embodiment of the present invention an acoustic wave device an acoustic wave transducer adapted to generate an acoustic wave in a propagation liquid, said acoustic wave transducer having an inner contour defined by rotating a curve about a rotation axis of symmetry, wherein the curve and the acoustic wave are not parallel to the rotation axis of symmetry, and a focusing lens arranged with respect to said acoustic wave transducer so as to focus the acoustic wave emanating from said acoustic wave transducer to a focal point. The focusing lens may have an inner contour that defines an inner volume axisymmetric about the rotation axis of symmetry and at least partially filled with the propagation liquid, wherein an outer volume defined between an outer contour of said focusing lens and said acoustic wave transducer is at least partially filled with the propagation liquid, the inner and outer volumes being bounded by a membrane.
There is also provided in accordance with a non-limiting embodiment of the present invention, apparatus for generating highly focused acoustic waves including a non-planar axisymmetric conducting membrane and associated electromagnetic coil obtained by rotating a membrane line-segment about a rotation axis. Said rotation axis intersects the focal point to which the acoustic waves will be targeted. The conducting membrane surface is monotonous (monotonically increasing in the symmetry axis for increasing radial distance from the symmetry axis) and the distance from any membrane point to a plane perpendicular to the rotation axis and intersecting the focal point is inversely proportional to the distance of said membrane point to the rotation axis. An axisymmetric acoustic lens surface associated with said membrane is obtained by rotating a lens cross-section segment about said rotation axis. Said lens cross-section-segment is determined by the relative propagation speeds in the acoustic lens material and the propagating liquid subject to the requirement that the waves produced by the vibrating membrane are focused by the lens onto the focal region.
In some embodiments of the present invention, the focal point is located closer to the larger cone base of a truncated conical membrane surface. Said surface is produced by rotating a linear membrane line-segment about a rotation axis wherein said membrane line-segment and said rotation axis are on the same plane and are not orthogonal so as not to form a planar membrane. A lens associated with said conical membrane surface is formed by rotating a generally concave circular lens cross-section-segment about said rotation axis. Said lens cross-section-segment is generally concave since the propagation speed of the lens is faster than that of the propagating liquid.
In other embodiments of the present invention, a non-conical membrane surface may be obtained by rotating a substantially circular membrane line segment about a rotation axis. The acoustic lens associated with said non-conical membrane surface is obtained by rotation of a lens circular cross-section about the said rotation axis.
There is also provided in accordance with an embodiment of the present invention, an acoustic wave device including an electrical element disposable on an inner contour of a support of an acoustic wave transducer, the inner contour having a non-cylindrical and non-flat shape, the electrical element being a really configured on the inner contour for radiating acoustic waves inwardly from the inner contour.
Further, in accordance with an embodiment of this invention, the electrical element includes a coil mountable on an inner contour of a support of an acoustic wave transducer and a membrane shaped to conform to the inner contour, wherein the coil is adapted to move the membrane inwards from the support.
Further in accordance with an embodiment of this invention the electrical element includes a coil mountable on an inner contour of a support of an acoustic wave transducer and a magnet disposable on the support adapted to generate a magnetic field that repels the coil inwards from the support.
Still further in accordance with an embodiment of this invention the electrical element includes a conducting surface electrode mountable on the inner contour, a perforated insulator that at least partially covers the conducting surface electrode, and a return electrode disposed on a side of the perforated insulator opposite to the conducting surface electrode.
There is also provided in accordance with an embodiment of the invention an acoustic wave device including an electrical element disposable on an inner contour of a support of an acoustic wave transducer, the electrical element being areally configured on the inner contour for radiating acoustic waves inwardly from the inner contour, and a magnet disposable on the support adapted to generate a magnetic field that repels the electrical element inwards from the support. The electrical element may be a coil, for example. The support may be non-cylindrical and non-flat.
There is also provided in accordance with an embodiment of this invention an acoustic wave device including an electrical element disposable on an inner contour of a support of an acoustic wave transducer, the electrical element being areally configured on the inner contour for radiating acoustic waves inwardly from the inner contour, and a perforated insulator that at least partially covers the electrical element. The support may be non-cylindrical and non-flat.
In accordance with an embodiment of the invention the electrical element includes a conducting surface electrode mountable on the inner contour, and a return electrode disposed on a side of the perforated insulator opposite to the conducting surface electrode.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates generally to generation and focusing of acoustic waves, and specifically to generation and focusing of acoustic waves with electromagnetic energy.
BACKGROUND OF THE INVENTION
Focused acoustic waves (or shockwaves, the terms being used interchangeably throughout) are being used increasingly in medical applications. For example, acoustic waves are used for tissue ablation, diagnostic imaging, drug delivery, breaking up concretions in the body such as kidney stones, treating orthopedic diseases, combating soft tissue complaints and pain, and other therapies which employ heat, cavitation, shock waves, and other thermal and/or mechanical effects for therapeutic purposes.
The prior art typically converts electrical energy into acoustic waves, such as by generating a strong pulse of an electric or magnetic field, usually by capacitor discharge, converting the electromagnetic field into acoustic energy, and directing the energy to a target by means of an associated focusing apparatus.
Point sources for the generation of acoustic waves in a lithotripter are described in various patents, such as U.S. Pat. No. 3,942,531 to Hoff et al., and U.S. Pat. No. 4,539,989 to Forsemann et al. A planar source for generation of acoustic waves is described, for example, in U.S. Pat. No. 4,674,505 to Pauli et al.
Cylindrical sources for generation of acoustic waves are described, for example, in U.S. Pat. No. 5,058,569 to Hassler et al., and U.S. Pat. No. 5,174,280 to Gruenwald et al. Spherical sources are also mentioned in the background of U.S. Pat. No. 5,174,280.
A truncated conical acoustic wave source is described in U.S. Pat. No. 6,869,407 to Ein-Gal, the disclosure of which is incorporated herein by reference. The background section of U.S. Pat. No. 6,869,407 includes a brief description of the manner by which acoustic waves are produced by point, spherical, planar, and cylindrical sources and a description of the limitations of each of these prior art acoustic wave generation apparatuses.
SUMMARY OF THE INVENTION
It is an object of some aspects of the present invention to provide an acoustic wave generation and focusing device comprising an acoustic wave transducer and an acoustic lens that provides improved focusing capability for ultrasonic energy deposition in body tissue, and provides a more efficient and cost-effective apparatus for ultrasonic energy deposition.
Acoustic waves may be generated in a variety of ways. By way of example and not limitation, acoustic waves may be generated by an area transducer, such as a truncated conical area transducer. A coil may repel or vibrate a conical membrane to produce acoustic waves. In another example, a conducting surface electrode may be mounted on the inner contour of the conical transducer. A perforated insulator may at least partially cover the surface electrode, and may be sandwiched between the surface electrode and a return electrode. A multiplicity of electrical currents may flow through the perforations of the perforated insulator, which give rise to point sources of ultrasonic energy in the form of spherical waves emanating from the perforations.
There is thus provided in accordance with a non-limiting embodiment of the present invention an acoustic wave device an acoustic wave transducer adapted to generate an acoustic wave in a propagation liquid, said acoustic wave transducer having an inner contour defined by rotating a curve about a rotation axis of symmetry, wherein the curve and the acoustic wave are not parallel to the rotation axis of symmetry, and a focusing lens arranged with respect to said acoustic wave transducer so as to focus the acoustic wave emanating from said acoustic wave transducer to a focal point. The focusing lens may have an inner contour that defines an inner volume axisymmetric about the rotation axis of symmetry and at least partially filled with the propagation liquid, wherein an outer volume defined between an outer contour of said focusing lens and said acoustic wave transducer is at least partially filled with the propagation liquid, the inner and outer volumes being bounded by a membrane.
There is also provided in accordance with a non-limiting embodiment of the present invention, apparatus for generating highly focused acoustic waves including a non-planar axisymmetric conducting membrane and associated electromagnetic coil obtained by rotating a membrane line-segment about a rotation axis. Said rotation axis intersects the focal point to which the acoustic waves will be targeted. The conducting membrane surface is monotonous (monotonically increasing in the symmetry axis for increasing radial distance from the symmetry axis) and the distance from any membrane point to a plane perpendicular to the rotation axis and intersecting the focal point is inversely proportional to the distance of said membrane point to the rotation axis. An axisymmetric acoustic lens surface associated with said membrane is obtained by rotating a lens cross-section segment about said rotation axis. Said lens cross-section-segment is determined by the relative propagation speeds in the acoustic lens material and the propagating liquid subject to the requirement that the waves produced by the vibrating membrane are focused by the lens onto the focal region.
In some embodiments of the present invention, the focal point is located closer to the larger cone base of a truncated conical membrane surface. Said surface is produced by rotating a linear membrane line-segment about a rotation axis wherein said membrane line-segment and said rotation axis are on the same plane and are not orthogonal so as not to form a planar membrane. A lens associated with said conical membrane surface is formed by rotating a generally concave circular lens cross-section-segment about said rotation axis. Said lens cross-section-segment is generally concave since the propagation speed of the lens is faster than that of the propagating liquid.
In other embodiments of the present invention, a non-conical membrane surface may be obtained by rotating a substantially circular membrane line segment about a rotation axis. The acoustic lens associated with said non-conical membrane surface is obtained by rotation of a lens circular cross-section about the said rotation axis.
There is also provided in accordance with an embodiment of the present invention, an acoustic wave device including an electrical element disposable on an inner contour of a support of an acoustic wave transducer, the inner contour having a non-cylindrical and non-flat shape, the electrical element being a really configured on the inner contour for radiating acoustic waves inwardly from the inner contour.
Further, in accordance with an embodiment of this invention, the electrical element includes a coil mountable on an inner contour of a support of an acoustic wave transducer and a membrane shaped to conform to the inner contour, wherein the coil is adapted to move the membrane inwards from the support.
Further in accordance with an embodiment of this invention the electrical element includes a coil mountable on an inner contour of a support of an acoustic wave transducer and a magnet disposable on the support adapted to generate a magnetic field that repels the coil inwards from the support.
Still further in accordance with an embodiment of this invention the electrical element includes a conducting surface electrode mountable on the inner contour, a perforated insulator that at least partially covers the conducting surface electrode, and a return electrode disposed on a side of the perforated insulator opposite to the conducting surface electrode.
There is also provided in accordance with an embodiment of the invention an acoustic wave device including an electrical element disposable on an inner contour of a support of an acoustic wave transducer, the electrical element being areally configured on the inner contour for radiating acoustic waves inwardly from the inner contour, and a magnet disposable on the support adapted to generate a magnetic field that repels the electrical element inwards from the support. The electrical element may be a coil, for example. The support may be non-cylindrical and non-flat.
There is also provided in accordance with an embodiment of this invention an acoustic wave device including an electrical element disposable on an inner contour of a support of an acoustic wave transducer, the electrical element being areally configured on the inner contour for radiating acoustic waves inwardly from the inner contour, and a perforated insulator that at least partially covers the electrical element. The support may be non-cylindrical and non-flat.
In accordance with an embodiment of the invention the electrical element includes a conducting surface electrode mountable on the inner contour, and a return electrode disposed on a side of the perforated insulator opposite to the conducting surface electrode.
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7836898 | BACKGROUND OF THE INVENTION
The present invention relates generally to a wrapper for a smoking article to create a reduced ignition propensity (IP) smoking article and, more particularly, to a smoking article having the ability to freeburn in a static state and reduced IP. Under some circumstances cigarettes may ignite fire-prone substrates if the article is laid or accidentally contacts the substrate. Therefore, a cigarette prepared from a wrapper, which diminishes the ability of the article to ignite a substrate, may have the desirable effect of reducing cigarette-initiated fires. Furthermore, a wrapper that concurrently confers on the cigarette the ability to freeburn in a static state and reduced IP character allows a beneficial reduction in the tendency of the article to ignite fire-prone substrates while maintaining consumer acceptability.
There have been various attempts to create a cigarette that has reduced IP and consumer acceptable attributes particularly taste and the ability to freeburn in the static state. Technologies that appear to provide such cigarettes are described in the patent literature. Cigarettes claiming to possess reduced IP are commercially available.
A factor that manufacturers consider in preparing a smoking article having reduced IP is whether currently used processes and equipment will remain substantially unchanged. One method for preparing a reduced IP paper involves the addition of elaborate equipment on a conventional papermaking machine. Cellulose fibers or particles suspended in water are sprayed from angular moving nozzles moving at an angle to a continuous forming moist web. This approach involves the coordinated angular movement of the spray nozzle and the about 400 feet per minute moving web to create spaced apart bands transverse to the web. The above-mentioned technology suffers from a number of deficiencies that limit consumer acceptability, IP reduction, and ease of manufacture. The technology requires expensive add-on equipment including a spray nozzle system and an associated slurry distribution system, pressure regulating system, and a means for carefully synchronizing the angular material distribution system with the underlying papermaking machine.
The reduced consumer acceptable properties of the prepared cigarettes are due to factors including reduced ability of the cigarette to freeburn in the static state, poor ash appearance, and variable taste profile.
The poor IP reduction performance achieved by cigarettes prepared with wrappers made using this technology is believed to be caused by a number of factors including difficulty in depositing an even layer of the cellulose fibers or particles, low efficiency of the cellulose fibers or particles to reduce the permeability of the underlying web, and poor reproducibility caused by fanning out of the sprayed material. Deficiencies in the approach that limit ease of manufacture include the difficulty in synchronizing the angular moving cellulose fibers and particles distribution apparatus with the underlying web forming apparatus and difficulty in reducing the banded moist web to dryness without disrupting the structure of the web.
Another technology involves adding discrete material regions to the dry web using organic solvent-based printing equipment. Organic solvents and non-aqueous soluble solutes are used to make the discrete regions on the web. The presence of organic solvents requires hoods to capture the solvent vapors and the corresponding further expenses.
In regard to commercially available cigarettes claiming to possess reduced IP, consumers may find their organoleptic experience wanting. Some technologies that are based on discretely treated areas for reduced IP cigarettes create a varying organoleptic experience as the consumption of the smoking article moves from treated area to non-treated areas.
One commercial product claiming to possess reduced IP is characterized by a tendency to extinguish when left burning in the static state—that is reduced freeburn. The article displays a less desirable taste when relit after being extinguished. Thus, although the cigarette may possess the reduced IP, the reduced freeburn property decreases consumer acceptability of the article.
Other factors affecting consumer acceptability are product appearance, including pleasing and consistent wrapper and ash character. Moreover, it is important that the construction of the smoking article exhibit a reasonable shelf-life while maintaining reduced IP.
Thus, there remains a need for a new and improved wrapper and smoking article having reduced IP while at the same time possessing a sufficient free burn. Also, there remains a need for a new and improved method for making a wrapper that can be used to create a smoking article having reduced IP and sufficient freeburn.
SUMMARY OF THE INVENTION
The present invention is directed to a smoking article having reduced IP. The smoking article includes a tobacco column, a wrapper surrounding the tobacco column and, optionally, a filter element. The wrapper has a base permeability, an untreated area and a least one discrete area treated with a composition to reduce the base permeability. The discretely treated area interacts with a coal of a burning tobacco firecone as it advances to self-extinguish the smoking article if the smoking article is left on a surface or causes the cigarette not to ignite the surface.
The tendency of a cigarette to self-extinguish or not ignite surfaces can be measured by the use of IP tests such as those published by the Consumer Products Safety Commission and developed by the National Institute of Standards and Technology (NIST) or the American Society of Testing and Materials (ASTM). See Ohlemiller, T. J. et al., “Test Methods for Quantifying the Propensity of Cigarettes to Ignite Soft Furnishings. Volume 2,” NIST SP 851; volume 2; 166 pages [also includes: Cigarette Extinction Test Method, see pp. 153-160] August 1993 available from U.S. Consumer Product Safety Commission, Washington, D.C. 20207 as order number PB94-108644, the subject matter of which is herein incorporated by reference. One NIST IP test, the “cotton duck test”, involves placing a smoldering cigarette on a test assembly composed of a cellulosic fabric over a foam block. Variations of the test use fabrics of various weights and polyethylene sheet backing. A test failure occurs when the fabric ignites. Another NIST IP test, the “filter paper test”, involves placing a smoldering cigarette on a test assembly composed of layered filter paper sheets. Various forms of the test use 3, 10, and 15 layered filter paper sheets. A successful test result occurs when the cigarette self extinguishes before the whole tobacco column is consumed.
The composition of the treated area includes at least a permeability reducing substance. Another substance in the treated are includes a burn rate retarding substance. Yet another substance in the treated area includes a burn rate accelerating substance. Either the burn rate retarding substance or the burn rate accelerating substance or both preferably acts as an organoleptic enhancing substance. In this way a smoker's experience when smoking either the at least one treated area or the untreated area is substantially the same. Additionally, the composition of the treated area may include a filler component.
In a wrapper making process, the applied amount of the permeability reducing substance, the burn rate retarding substance, and the burn rate accelerating substance is such as to give the desired freeburn character and IP reduction to a finished article made from the wrapper. The quantity and the concentration of the applied composition will depend on factors including the absorbency of the web, polymer properties of the permeability reducing substance, whether the web is wet or dry, and the operating conditions of the application equipment.
The burn rate accelerating substance may be an alkali metal or alkali earth containing salt. Preferably, the burn rate accelerating substance may be an alkali metal salt of a carboxylic acid such as acetic acid, citric acid, malic acid, lactic acid, tartaric acid and the like. Preferably, the salt of the carboxylic acid is a salt of citric acid. Also, the alkali metal containing compound is preferably at least one of a sodium containing compound and a potassium containing compound. Alternatively, the burn rate accelerating substance may be monoammonium phosphate.
The burn rate retarding substance may be a phosphate, preferably a phosphate of ammonium and more preferably a diammonium phosphate.
The permeability reducing substance may be a pore filling substance, a film forming substance or combination thereof. The permeability reducing substance may be a polymer and, preferably, a polysaccharide. Among the contemplated polysaccharides are starch, including various mixtures of amylose, amylopectin and dextrin, modified starch and starch derivatives. The starch and starch derivatives may be water dispersible and, preferably, water soluble. Other contemplated polysaccharides include cellulose, cellulose derivatives, chitosan, chitosan derivatives, chitin, chitin derivatives, alginate, alginate derivatives and combinations thereof. These polysaccharides are preferably water dispersible and, more preferably, are water-soluble.
In one embodiment, the discretely treated area is a circumferential band about the body of the article. The band has a sufficient width so as to deprive the coal of the burning tobacco firecone of oxygen from behind a char line of the wrapper when the smoking article is placed on a surface. That may be achieved by a band width typically of at least about 3 millimeters.
In an alternative embodiment, the discretely treated area includes at least two bands spaced sufficiently to reduce the IP of the smoking article. In this case, the two bands preferably have a center-to-center spacing of between about 10 millimeters to about 30 millimeters. The two bands may have a width of about 3 millimeters to about 10 millimeters. A center-to-center spacing is preferably about 25 millimeters.
The discretely treated area preferably has a thickness and properties so a bobbin of the wrapper is useable in a commercially available smoking article manufacturing machine. Also, the discretely treated area is preferably visually substantially the same as the untreated area.
Still another aspect of the present invention is to provide a population of smoking articles having a reduced IP. Each smoking article within the population includes a tobacco column, wrapper surrounding the tobacco column so that the smoking article includes an ignition end and a distal end, and at least one banded region, preferably at least two spaced apart banded regions, between the ignition end and the distal end having a combustion characteristic substantially different from that of an non-banded, untreated, region. A distance from the ignition end to the at least one of the banded region of each smoking article may be sequentially related, random, or quasi-random within a selected population.
In one embodiment, the selected population is a package of smoking articles and in another embodiment a grab sample of smoking articles.
In another embodiment, the distance from the ignition end to the at least one of the banded regions of each smoking article are sequentially related, random, or quasi-random.
In a preferred embodiment, the IP of the selected population is between about 50 and about 100 percent for the population.
The invention also provides a method of making a wrapper, of making a smoking article having reduced IP, and a composition for application to a paper to make a wrapper and a smoking article.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
The present invention relates generally to a wrapper for a smoking article to create a reduced ignition propensity (IP) smoking article and, more particularly, to a smoking article having the ability to freeburn in a static state and reduced IP. Under some circumstances cigarettes may ignite fire-prone substrates if the article is laid or accidentally contacts the substrate. Therefore, a cigarette prepared from a wrapper, which diminishes the ability of the article to ignite a substrate, may have the desirable effect of reducing cigarette-initiated fires. Furthermore, a wrapper that concurrently confers on the cigarette the ability to freeburn in a static state and reduced IP character allows a beneficial reduction in the tendency of the article to ignite fire-prone substrates while maintaining consumer acceptability.
There have been various attempts to create a cigarette that has reduced IP and consumer acceptable attributes particularly taste and the ability to freeburn in the static state. Technologies that appear to provide such cigarettes are described in the patent literature. Cigarettes claiming to possess reduced IP are commercially available.
A factor that manufacturers consider in preparing a smoking article having reduced IP is whether currently used processes and equipment will remain substantially unchanged. One method for preparing a reduced IP paper involves the addition of elaborate equipment on a conventional papermaking machine. Cellulose fibers or particles suspended in water are sprayed from angular moving nozzles moving at an angle to a continuous forming moist web. This approach involves the coordinated angular movement of the spray nozzle and the about 400 feet per minute moving web to create spaced apart bands transverse to the web. The above-mentioned technology suffers from a number of deficiencies that limit consumer acceptability, IP reduction, and ease of manufacture. The technology requires expensive add-on equipment including a spray nozzle system and an associated slurry distribution system, pressure regulating system, and a means for carefully synchronizing the angular material distribution system with the underlying papermaking machine.
The reduced consumer acceptable properties of the prepared cigarettes are due to factors including reduced ability of the cigarette to freeburn in the static state, poor ash appearance, and variable taste profile.
The poor IP reduction performance achieved by cigarettes prepared with wrappers made using this technology is believed to be caused by a number of factors including difficulty in depositing an even layer of the cellulose fibers or particles, low efficiency of the cellulose fibers or particles to reduce the permeability of the underlying web, and poor reproducibility caused by fanning out of the sprayed material. Deficiencies in the approach that limit ease of manufacture include the difficulty in synchronizing the angular moving cellulose fibers and particles distribution apparatus with the underlying web forming apparatus and difficulty in reducing the banded moist web to dryness without disrupting the structure of the web.
Another technology involves adding discrete material regions to the dry web using organic solvent-based printing equipment. Organic solvents and non-aqueous soluble solutes are used to make the discrete regions on the web. The presence of organic solvents requires hoods to capture the solvent vapors and the corresponding further expenses.
In regard to commercially available cigarettes claiming to possess reduced IP, consumers may find their organoleptic experience wanting. Some technologies that are based on discretely treated areas for reduced IP cigarettes create a varying organoleptic experience as the consumption of the smoking article moves from treated area to non-treated areas.
One commercial product claiming to possess reduced IP is characterized by a tendency to extinguish when left burning in the static state—that is reduced freeburn. The article displays a less desirable taste when relit after being extinguished. Thus, although the cigarette may possess the reduced IP, the reduced freeburn property decreases consumer acceptability of the article.
Other factors affecting consumer acceptability are product appearance, including pleasing and consistent wrapper and ash character. Moreover, it is important that the construction of the smoking article exhibit a reasonable shelf-life while maintaining reduced IP.
Thus, there remains a need for a new and improved wrapper and smoking article having reduced IP while at the same time possessing a sufficient free burn. Also, there remains a need for a new and improved method for making a wrapper that can be used to create a smoking article having reduced IP and sufficient freeburn.
SUMMARY OF THE INVENTION
The present invention is directed to a smoking article having reduced IP. The smoking article includes a tobacco column, a wrapper surrounding the tobacco column and, optionally, a filter element. The wrapper has a base permeability, an untreated area and a least one discrete area treated with a composition to reduce the base permeability. The discretely treated area interacts with a coal of a burning tobacco firecone as it advances to self-extinguish the smoking article if the smoking article is left on a surface or causes the cigarette not to ignite the surface.
The tendency of a cigarette to self-extinguish or not ignite surfaces can be measured by the use of IP tests such as those published by the Consumer Products Safety Commission and developed by the National Institute of Standards and Technology (NIST) or the American Society of Testing and Materials (ASTM). See Ohlemiller, T. J. et al., “Test Methods for Quantifying the Propensity of Cigarettes to Ignite Soft Furnishings. Volume 2,” NIST SP 851; volume 2; 166 pages [also includes: Cigarette Extinction Test Method, see pp. 153-160] August 1993 available from U.S. Consumer Product Safety Commission, Washington, D.C. 20207 as order number PB94-108644, the subject matter of which is herein incorporated by reference. One NIST IP test, the “cotton duck test”, involves placing a smoldering cigarette on a test assembly composed of a cellulosic fabric over a foam block. Variations of the test use fabrics of various weights and polyethylene sheet backing. A test failure occurs when the fabric ignites. Another NIST IP test, the “filter paper test”, involves placing a smoldering cigarette on a test assembly composed of layered filter paper sheets. Various forms of the test use 3, 10, and 15 layered filter paper sheets. A successful test result occurs when the cigarette self extinguishes before the whole tobacco column is consumed.
The composition of the treated area includes at least a permeability reducing substance. Another substance in the treated are includes a burn rate retarding substance. Yet another substance in the treated area includes a burn rate accelerating substance. Either the burn rate retarding substance or the burn rate accelerating substance or both preferably acts as an organoleptic enhancing substance. In this way a smoker's experience when smoking either the at least one treated area or the untreated area is substantially the same. Additionally, the composition of the treated area may include a filler component.
In a wrapper making process, the applied amount of the permeability reducing substance, the burn rate retarding substance, and the burn rate accelerating substance is such as to give the desired freeburn character and IP reduction to a finished article made from the wrapper. The quantity and the concentration of the applied composition will depend on factors including the absorbency of the web, polymer properties of the permeability reducing substance, whether the web is wet or dry, and the operating conditions of the application equipment.
The burn rate accelerating substance may be an alkali metal or alkali earth containing salt. Preferably, the burn rate accelerating substance may be an alkali metal salt of a carboxylic acid such as acetic acid, citric acid, malic acid, lactic acid, tartaric acid and the like. Preferably, the salt of the carboxylic acid is a salt of citric acid. Also, the alkali metal containing compound is preferably at least one of a sodium containing compound and a potassium containing compound. Alternatively, the burn rate accelerating substance may be monoammonium phosphate.
The burn rate retarding substance may be a phosphate, preferably a phosphate of ammonium and more preferably a diammonium phosphate.
The permeability reducing substance may be a pore filling substance, a film forming substance or combination thereof. The permeability reducing substance may be a polymer and, preferably, a polysaccharide. Among the contemplated polysaccharides are starch, including various mixtures of amylose, amylopectin and dextrin, modified starch and starch derivatives. The starch and starch derivatives may be water dispersible and, preferably, water soluble. Other contemplated polysaccharides include cellulose, cellulose derivatives, chitosan, chitosan derivatives, chitin, chitin derivatives, alginate, alginate derivatives and combinations thereof. These polysaccharides are preferably water dispersible and, more preferably, are water-soluble.
In one embodiment, the discretely treated area is a circumferential band about the body of the article. The band has a sufficient width so as to deprive the coal of the burning tobacco firecone of oxygen from behind a char line of the wrapper when the smoking article is placed on a surface. That may be achieved by a band width typically of at least about 3 millimeters.
In an alternative embodiment, the discretely treated area includes at least two bands spaced sufficiently to reduce the IP of the smoking article. In this case, the two bands preferably have a center-to-center spacing of between about 10 millimeters to about 30 millimeters. The two bands may have a width of about 3 millimeters to about 10 millimeters. A center-to-center spacing is preferably about 25 millimeters.
The discretely treated area preferably has a thickness and properties so a bobbin of the wrapper is useable in a commercially available smoking article manufacturing machine. Also, the discretely treated area is preferably visually substantially the same as the untreated area.
Still another aspect of the present invention is to provide a population of smoking articles having a reduced IP. Each smoking article within the population includes a tobacco column, wrapper surrounding the tobacco column so that the smoking article includes an ignition end and a distal end, and at least one banded region, preferably at least two spaced apart banded regions, between the ignition end and the distal end having a combustion characteristic substantially different from that of an non-banded, untreated, region. A distance from the ignition end to the at least one of the banded region of each smoking article may be sequentially related, random, or quasi-random within a selected population.
In one embodiment, the selected population is a package of smoking articles and in another embodiment a grab sample of smoking articles.
In another embodiment, the distance from the ignition end to the at least one of the banded regions of each smoking article are sequentially related, random, or quasi-random.
In a preferred embodiment, the IP of the selected population is between about 50 and about 100 percent for the population.
The invention also provides a method of making a wrapper, of making a smoking article having reduced IP, and a composition for application to a paper to make a wrapper and a smoking article.
Is this patent green technology? Respond with 'yes' or 'no'. |
7852088 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of geophysical exploration, and more particularly to a high resolution magnetotelluric method for removing a static frequency domain.
2. Description of the Related Art
A magnetotelluric method is an important geophysical exploration method widely used in energy, metal ores, groundwater, engineering and marine resources exploration and many other fields. The frequency-domain magnetotelluric method is the most widely used method of the magnetotelluric method.
The frequency-domain magnetotelluric method tests vertical variation of underground medium via a pair of static electric field observation-electrodes disposed at the surface of the area to be explored, a pair of magnetic probes corresponding and perpendicular to the static electric field observation-electrodes, a magnetic probe disposed in a vertical direction, and a sampling device connected to the electrodes and probe, whereby bringing great convenient for construction and improving production efficiency.
However, the existing frequency-domain magnetotelluric method has the following problems: a static effect is generated, which causes electric false anomaly of a horizontal and continuous geoelectric geologic body, and makes it possible to treat and analysis the geologic body; moreover, the method selects frequency points that are uniformly distributed on a logarithmic coordinate as observation frequency points, which decreases vertical resolution.
BRIEF SUMMARY OF THE INVENTION
In view of the above-described problems, it is one objective of the invention to provide a high resolution magnetotelluric method capable of removing a static frequency domain and improving vertical resolution.
To achieve the above objective, in accordance with one embodiment of the invention, provided is a high resolution magnetotelluric method for removing a static frequency domain, comprising steps of: (1) installing multiple sampling devices at the surface of the area to be explored in a form of an array, adjacent observation points sharing a same electrode; (2) performing conventional processing on all observation results whereby obtaining conventional observation curves of the observation points; (3) for the time series data of the original observation value of the electric field along the same direction of all observation points, adding electric-filed components of two adjacent observation points, those of three adjacent observation points, . . . , and those of all points whereby obtaining electric fields of different polar distance, i.e. a sequence of electric field components of topology points and encrypted topology points; (4) using the sequence of the electric field components of the topology points sequence and the encrypted topology points sequence obtained above as an observation field value to perform power spectrum analysis and impedance tensor estimate, whereby obtaining a series of topological observation curves of a same record point; (5) drawing a resistance—variation of polar distance curve of a single frequency point of the record point; observing and analyzing a variation rule of resistivity, editing and deleting static interference resistance, whereby obtaining a resistivity value of the point at the frequency; and (6) repeating the previous step to complete edition of all frequency points of all record points, whereby obtaining observation results without the static frequency domain.
In certain classes of this embodiment, the step of using said sequence of the electric field components of the topology points sequence and the encrypted topology points sequence obtained above as an observation field value to perform power spectrum analysis and impedance tensor estimate: sampling using cascade decimation; extracting a reference frequency point with a cycle of 2iT0, T0being 32-time sampling interval, and i being a sub-sample series; and performing Fourier transformation between a time interval of 2iT1to 2i+1T1, whereby obtaining the eighth harmonic wave as an encrypted power spectrum and improving vertical resolution.
The high resolution magnetotelluric method for removing a static frequency domain of the invention has the following advantages:
(1) the static effect is removed via topology processing;
(2) the vertical resolution is improved by increasing observation cycle at an equal interval;
(3) an geological effect more closer to an actual one is obtained and thus comprehensive underground information can be directly indicated; and
(4) interference and false anomaly are removed.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of geophysical exploration, and more particularly to a high resolution magnetotelluric method for removing a static frequency domain.
2. Description of the Related Art
A magnetotelluric method is an important geophysical exploration method widely used in energy, metal ores, groundwater, engineering and marine resources exploration and many other fields. The frequency-domain magnetotelluric method is the most widely used method of the magnetotelluric method.
The frequency-domain magnetotelluric method tests vertical variation of underground medium via a pair of static electric field observation-electrodes disposed at the surface of the area to be explored, a pair of magnetic probes corresponding and perpendicular to the static electric field observation-electrodes, a magnetic probe disposed in a vertical direction, and a sampling device connected to the electrodes and probe, whereby bringing great convenient for construction and improving production efficiency.
However, the existing frequency-domain magnetotelluric method has the following problems: a static effect is generated, which causes electric false anomaly of a horizontal and continuous geoelectric geologic body, and makes it possible to treat and analysis the geologic body; moreover, the method selects frequency points that are uniformly distributed on a logarithmic coordinate as observation frequency points, which decreases vertical resolution.
BRIEF SUMMARY OF THE INVENTION
In view of the above-described problems, it is one objective of the invention to provide a high resolution magnetotelluric method capable of removing a static frequency domain and improving vertical resolution.
To achieve the above objective, in accordance with one embodiment of the invention, provided is a high resolution magnetotelluric method for removing a static frequency domain, comprising steps of: (1) installing multiple sampling devices at the surface of the area to be explored in a form of an array, adjacent observation points sharing a same electrode; (2) performing conventional processing on all observation results whereby obtaining conventional observation curves of the observation points; (3) for the time series data of the original observation value of the electric field along the same direction of all observation points, adding electric-filed components of two adjacent observation points, those of three adjacent observation points, . . . , and those of all points whereby obtaining electric fields of different polar distance, i.e. a sequence of electric field components of topology points and encrypted topology points; (4) using the sequence of the electric field components of the topology points sequence and the encrypted topology points sequence obtained above as an observation field value to perform power spectrum analysis and impedance tensor estimate, whereby obtaining a series of topological observation curves of a same record point; (5) drawing a resistance—variation of polar distance curve of a single frequency point of the record point; observing and analyzing a variation rule of resistivity, editing and deleting static interference resistance, whereby obtaining a resistivity value of the point at the frequency; and (6) repeating the previous step to complete edition of all frequency points of all record points, whereby obtaining observation results without the static frequency domain.
In certain classes of this embodiment, the step of using said sequence of the electric field components of the topology points sequence and the encrypted topology points sequence obtained above as an observation field value to perform power spectrum analysis and impedance tensor estimate: sampling using cascade decimation; extracting a reference frequency point with a cycle of 2iT0, T0being 32-time sampling interval, and i being a sub-sample series; and performing Fourier transformation between a time interval of 2iT1to 2i+1T1, whereby obtaining the eighth harmonic wave as an encrypted power spectrum and improving vertical resolution.
The high resolution magnetotelluric method for removing a static frequency domain of the invention has the following advantages:
(1) the static effect is removed via topology processing;
(2) the vertical resolution is improved by increasing observation cycle at an equal interval;
(3) an geological effect more closer to an actual one is obtained and thus comprehensive underground information can be directly indicated; and
(4) interference and false anomaly are removed.
Is this patent green technology? Respond with 'yes' or 'no'. |
7674786 | BACKGROUND OF THE INVENTION
Ocular hypotensive agents are useful in the treatment of a number of various ocular hypertensive conditions, such as post-surgical and post-laser trabeculectomy ocular hypertensive episodes, glaucoma, and as presurgical adjuncts.
Glaucoma is a disease of the eye characterized by increased intraocular pressure. On the basis of its etiology, glaucoma has been classified as primary or secondary. For example, primary glaucoma in adults (congenital glaucoma) may be either open-angle or acute or chronic angle-closure. Secondary glaucoma results from pre-existing ocular diseases such as uveitis, intraocular tumor or an enlarged cataract.
The underlying causes of primary glaucoma are not yet known. The increased intraocular tension is due to the obstruction of aqueous humor outflow. In chronic open-angle glaucoma, the anterior chamber and its anatomic structures appear normal, but drainage of the aqueous humor is impeded. In acute or chronic angle-closure glaucoma, the anterior chamber is shallow, the filtration angle is narrowed, and the iris may obstruct the trabecular meshwork at the entrance of the canal of Schlemm. Dilation of the pupil may push the root of the iris forward against the angle, and may produce pupilary block and thus precipitate an acute attack. Eyes with narrow anterior chamber angles are predisposed to acute angle-closure glaucoma attacks of various degrees of severity.
Secondary glaucoma is caused by any interference with the flow of aqueous humor from the posterior chamber into the anterior chamber and subsequently, into the canal of Schlemm. Inflammatory disease of the anterior segment may prevent aqueous escape by causing complete posterior synechia in iris bombe, and may plug the drainage channel with exudates. Other common causes are intraocular tumors, enlarged cataracts, central retinal vein occlusion, trauma to the eye, operative procedures and intraocular hemorrhage.
Considering all types together, glaucoma occurs in about 2% of all persons over the age of 40 and may be asymptotic for years before progressing to rapid loss of vision. In cases where surgery is not indicated, topical β-adrenoreceptor antagonists have traditionally been the drugs of choice for treating glaucoma.
Certain eicosanoids and their derivatives are currently commercially available for use in glaucoma management. Eicosanoids and derivatives include numerous biologically important compounds such as prostaglandins and their derivatives. Prostaglandins can be described as derivatives of prostanoic acid which have the following structural formula:
Various types of prostaglandins are known, depending on the structure and substituents carried on the alicyclic ring of the prostanoic acid skeleton. Further classification is based on the number of unsaturated bonds in the side chain indicated by numerical subscripts after the generic type of prostaglandin [e.g. prostaglandin E1(PGE1), prostaglandin E2(PGE2)], and on the configuration of the substituents on the alicyclic ring indicated by α or β [e.g. prostaglandin F2α(PGF2β)].
The prostaglandin E analog shown below is disclosed in the following documents, expressly incorporated herein by reference: U.S. Pat. No. 5,462,968; U.S. Pat. No. 5,698,598; and U.S. Pat. No. 6,090,847.
Other EP2selective agonists are disclosed in U.S. patent application Ser. No. 11/009,298, filed Dec. 10, 2004 (now U.S. Pat. No. 7,091,231 issued Aug. 15, 2006). Prostaglandin EP2selective agonists are believed to have several medical uses. For example, U.S. Pat. No. 6,437,146 teaches the use of prostaglandin EP2selective agonists “for treating or preventing inflammation and pain in joint and muscle (e.g., rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis, juvenile arthritis, etc.), inflammatory skin condition (e.g., sunburn, burns, eczema, dermatitis, etc.), inflammatory eye condition (e.g., conjunctivitis, etc.), lung disorder in which inflammation is involved (e.g., asthma, bronchitis, pigeon fancier's disease, farmer's lung, etc.), condition of the gastrointestinal tract associated with inflammation (e.g., aphthous ulcer, Chrohn's disease, atrophic gastritis, gastritis varialoforme, ulcerative colitis, coeliac disease, regional ileitis, irritable bowel syndrome, etc.), gingivitis, inflammation, pain and tumescence after operation or injury, pyrexia, pain and other conditions associated with inflammation, allergic disease, systemic lupus crythematosus, scleroderma, polymyositis, tendinitis, bursitis, periarteritis nodose, rheumatic fever, Sjgren's syndrome, Behcet disease, thyroiditis, type I diabetes, diabetic complication (diabetic microangiopathy, diabetic retinopathy, diabetic neohropathy, etc.), nephrotic syndrome, aplastic anemia, myasthenia gravis, uveitis contact dermatitis, psoriasis, Kawasaki disease, sarcoidosis, Hodgkin's disease, Alzheimers disease, kidney dysfunction (nephritis, nephritic syndrome, etc.), liver dysfunction (hepatitis, cirrhosis, etc.), gastrointestinal dysfunction (diarrhea, inflammatory bowel disease, etc.) shock, bone disease characterized by abnormal bone metabolism such as osteoporosis (especially, postmenopausal osteoporosis), hypercalcemia, hyperparathyroidism, Paget's bone diseases, osteolysis, hypercalcemia of malignancy with or without bone metastases, rheumatoid arthritis, periodonritis, osteoarthritis, ostealgia, osteopenia, cancer cachexia, calculosis, lithiasis (especially, urolithiasis), solid carcinoma, mesangial proliferative glomerulonephritis, edema (e.g. cardiac edema, cerebral edema, etc.), hypertension such as malignant hypertension or the like, premenstrual tension, urinary calculus, oliguria such as the one caused by acute or chronic failure, hyperphosphaturia, or the like.”
U.S. Pat. No. 6,710,072 teaches the use of EP2 agonists for the treatment or prevention of “osteoporosis, constipation, renal disorders, sexual dysfunction, baldness, diabetes, cancer and in disorder of immune regulation . . . various pathophysiological diseases including acute myocardial infarction, vascular thrombosis, hypertension, pulmonary hypertension, ischemic heart disease, congestive heart failure, and angina pectoris.”
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
Ocular hypotensive agents are useful in the treatment of a number of various ocular hypertensive conditions, such as post-surgical and post-laser trabeculectomy ocular hypertensive episodes, glaucoma, and as presurgical adjuncts.
Glaucoma is a disease of the eye characterized by increased intraocular pressure. On the basis of its etiology, glaucoma has been classified as primary or secondary. For example, primary glaucoma in adults (congenital glaucoma) may be either open-angle or acute or chronic angle-closure. Secondary glaucoma results from pre-existing ocular diseases such as uveitis, intraocular tumor or an enlarged cataract.
The underlying causes of primary glaucoma are not yet known. The increased intraocular tension is due to the obstruction of aqueous humor outflow. In chronic open-angle glaucoma, the anterior chamber and its anatomic structures appear normal, but drainage of the aqueous humor is impeded. In acute or chronic angle-closure glaucoma, the anterior chamber is shallow, the filtration angle is narrowed, and the iris may obstruct the trabecular meshwork at the entrance of the canal of Schlemm. Dilation of the pupil may push the root of the iris forward against the angle, and may produce pupilary block and thus precipitate an acute attack. Eyes with narrow anterior chamber angles are predisposed to acute angle-closure glaucoma attacks of various degrees of severity.
Secondary glaucoma is caused by any interference with the flow of aqueous humor from the posterior chamber into the anterior chamber and subsequently, into the canal of Schlemm. Inflammatory disease of the anterior segment may prevent aqueous escape by causing complete posterior synechia in iris bombe, and may plug the drainage channel with exudates. Other common causes are intraocular tumors, enlarged cataracts, central retinal vein occlusion, trauma to the eye, operative procedures and intraocular hemorrhage.
Considering all types together, glaucoma occurs in about 2% of all persons over the age of 40 and may be asymptotic for years before progressing to rapid loss of vision. In cases where surgery is not indicated, topical β-adrenoreceptor antagonists have traditionally been the drugs of choice for treating glaucoma.
Certain eicosanoids and their derivatives are currently commercially available for use in glaucoma management. Eicosanoids and derivatives include numerous biologically important compounds such as prostaglandins and their derivatives. Prostaglandins can be described as derivatives of prostanoic acid which have the following structural formula:
Various types of prostaglandins are known, depending on the structure and substituents carried on the alicyclic ring of the prostanoic acid skeleton. Further classification is based on the number of unsaturated bonds in the side chain indicated by numerical subscripts after the generic type of prostaglandin [e.g. prostaglandin E1(PGE1), prostaglandin E2(PGE2)], and on the configuration of the substituents on the alicyclic ring indicated by α or β [e.g. prostaglandin F2α(PGF2β)].
The prostaglandin E analog shown below is disclosed in the following documents, expressly incorporated herein by reference: U.S. Pat. No. 5,462,968; U.S. Pat. No. 5,698,598; and U.S. Pat. No. 6,090,847.
Other EP2selective agonists are disclosed in U.S. patent application Ser. No. 11/009,298, filed Dec. 10, 2004 (now U.S. Pat. No. 7,091,231 issued Aug. 15, 2006). Prostaglandin EP2selective agonists are believed to have several medical uses. For example, U.S. Pat. No. 6,437,146 teaches the use of prostaglandin EP2selective agonists “for treating or preventing inflammation and pain in joint and muscle (e.g., rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis, juvenile arthritis, etc.), inflammatory skin condition (e.g., sunburn, burns, eczema, dermatitis, etc.), inflammatory eye condition (e.g., conjunctivitis, etc.), lung disorder in which inflammation is involved (e.g., asthma, bronchitis, pigeon fancier's disease, farmer's lung, etc.), condition of the gastrointestinal tract associated with inflammation (e.g., aphthous ulcer, Chrohn's disease, atrophic gastritis, gastritis varialoforme, ulcerative colitis, coeliac disease, regional ileitis, irritable bowel syndrome, etc.), gingivitis, inflammation, pain and tumescence after operation or injury, pyrexia, pain and other conditions associated with inflammation, allergic disease, systemic lupus crythematosus, scleroderma, polymyositis, tendinitis, bursitis, periarteritis nodose, rheumatic fever, Sjgren's syndrome, Behcet disease, thyroiditis, type I diabetes, diabetic complication (diabetic microangiopathy, diabetic retinopathy, diabetic neohropathy, etc.), nephrotic syndrome, aplastic anemia, myasthenia gravis, uveitis contact dermatitis, psoriasis, Kawasaki disease, sarcoidosis, Hodgkin's disease, Alzheimers disease, kidney dysfunction (nephritis, nephritic syndrome, etc.), liver dysfunction (hepatitis, cirrhosis, etc.), gastrointestinal dysfunction (diarrhea, inflammatory bowel disease, etc.) shock, bone disease characterized by abnormal bone metabolism such as osteoporosis (especially, postmenopausal osteoporosis), hypercalcemia, hyperparathyroidism, Paget's bone diseases, osteolysis, hypercalcemia of malignancy with or without bone metastases, rheumatoid arthritis, periodonritis, osteoarthritis, ostealgia, osteopenia, cancer cachexia, calculosis, lithiasis (especially, urolithiasis), solid carcinoma, mesangial proliferative glomerulonephritis, edema (e.g. cardiac edema, cerebral edema, etc.), hypertension such as malignant hypertension or the like, premenstrual tension, urinary calculus, oliguria such as the one caused by acute or chronic failure, hyperphosphaturia, or the like.”
U.S. Pat. No. 6,710,072 teaches the use of EP2 agonists for the treatment or prevention of “osteoporosis, constipation, renal disorders, sexual dysfunction, baldness, diabetes, cancer and in disorder of immune regulation . . . various pathophysiological diseases including acute myocardial infarction, vascular thrombosis, hypertension, pulmonary hypertension, ischemic heart disease, congestive heart failure, and angina pectoris.”
Is this patent green technology? Respond with 'yes' or 'no'. |
7744121 | BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an airbag which deploys, for example, along a side window inside a vehicle compartment, an airbag apparatus having the airbag, and a method for folding the airbag.
2. Description of the Related Art
With regard to an airbag apparatus having an airbag which is inflated and deployed by inflation gas, a curtain airbag apparatus has been known. The curtain airbag apparatus has an airbag which deploys planarly along side windows inside a vehicle compartment. In this kind of the airbag apparatus, an airbag is folded and assembled elongatedly and installed along an upper edge of the side windows inside the vehicle compartment. When the vehicle receives impact by side impact or rollover, an inflator infuses gas into the airbag. The gas is infused into a bag-shaped inflating portion via a tubular infusion portion of the airbag. Then, the airbag is inflated and deployed downwardly along the side windows.
In this kind of airbag, a separated fabric (flow control fabric) is attached from a gas infusion portion to an inflating portion to protect the gas infusion portion from heat of gas (see Japanese Laid-open Patent Application No. 2003-146174 [page. 5, FIGS. 4 and 6]).
Furthermore, method for folding a curtain airbag is also known (see U.S. Patent Application Publication No. 2005/0110256 [FIGS. 1 and 2D]). In the above method, the airbag is rolled from the lower edge and the upper potion of the rolled potion is formed as a pair of flattened pleats. The pair of pleats wraps the rolled potion. With this folding pattern, the pair of flattened pleats is quickly inflated, and then the rolled portion is deployed.
SUMMARY OF THE INVENTION
However, if the fabric, which is attached from the gas infusion portion to the inflating portion, is adapted to the above-mentioned structure, edge of the fabric is rolled with the inflating portion or folded haphazardly.
The present invention has been made in view of the point of view as described above. An object of the present invention is to provide an airbag, an airbag apparatus, or method for folding an airbag which can improve deployment performance of an airbag.
A first aspect of the present invention provides an airbag which comprises (a) an airbag main portion and (b) an inner tube. The airbag main body includes (x) a gas infusion portion through which gas is infused into an inside of the airbag main portion, and (y) an inflating portion which is communicated with the gas infusion portion and has first and second fabrics between which the gas is infused through the gas infusion potion to inflate the inflating portion. The inner tube is provided from the inside of the gas infusion portion to the inside of an upstream portion of the inflating portion. The upstream portion of the inflating portion is pleated to form a pleated portion in which the first and second fabrics form a pair of pleats extending counter directions each other. The inner tube is folded with any one of the pleats.
With the first aspect of the present invention, when the gas is infused into the gas infusion portion, the pleated portion, which is communicated with the infusion portion and formed by pleating the inflating portion, is firstly deployed. In addition, the inner tube protects the airbag main portion from heat of the infused gas. Furthermore, since the inner tube is folded with any one of the pleats, folded pattern of the inner tube constantly becomes a uniform pattern and the infused gas is firmly infused into the pleated portion to stabilize the deployment performance.
A second aspect of the present invention provides an airbag which has all the features of the above-mentioned first aspect of the present invention. Furthermore, a downstream portion of the inflating portion is folded to form a folded portion which is folded to be wrapped by the pleated portion. The pleated portion is an upstream portion of the inflating portion and is pleated so that the first and second fabrics form a pair of pleats extending counter directions each other. And, the folded portion is a downstream portion of the inflating portion and is wrapped by the pleated portion.
With the second aspect of the present invention, when the gas is infused into the gas infusion portion, the pleated portion, which is communicated with the infusion portion and formed by pleating the inflating portion, is firstly deployed. The deploying pleated portion guides ejection of the folded portion to the desired direction. Then, the folded portion is inflated and deployed to achieve quick and smooth deployment of the airbag. In addition, the inner tube protects the airbag main portion from heat of the infused gas. Furthermore, since the inner tube is folded with any one of the pleats, folded pattern of the inner tube constantly becomes a uniform pattern and the infused gas is firmly infused into the pleated portion to stabilize the deployment performance.
A third aspect of the present invention provides an airbag apparatus which comprises (i) an airbag of the above-mentioned airbag of the second aspect of the present invention and (ii) an inflator. The airbag deploys along a side window inside a vehicle compartment. The inflator infuses gas into the gas infusion portion of the airbag. And, the first fabric of the airbag is developed so that the surface of the first fabric faces the inside of the vehicle compartment. Furthermore, the inner tube of the airbag is folded with the pleat of the first fabric.
With the third aspect of the present invention, since it comprises the airbag of the second aspect of the present invention, the deployment performance, that the airbag deploys quickly and smoothly along the side window inside the vehicle compartment, is achieved. In addition, since the inner tube of the airbag is folded with the pleat of the first fabric (the surface of the first fabric faces the inside of the vehicle compartment at the deployment), the inside pleat of the pleated portion inflates more quickly than the outside pleat of the pleated portion at the initial stage of the deployment. Then, the deployment direction of the folded portion is regulated outward (to the direction along the side window) to achieve the good and stable deployment performance of the airbag.
A fourth aspect of the present invention provides a method of folding the airbag of the above-mentioned first aspect of the present invention. The method comprises (1) infusing fluid into the inside of the inner tube from a prescribed direction to inflate the inflating portion and detach the first and second fabrics each other, and (2) pleating the inflating portion to form the pleated portion under the condition where the inner tube is positioned along any one of the first or second fabric by the infused fluid.
With the fourth aspect of the present invention, the pleated portion is pleated so that the first and second fabrics form the pair of pleats extending counter directions each other. The preferred folding pattern to fold the inner tube with any one of the pleats is achieved.
A fifth aspect of the present invention provides a method of folding an airbag of the above-mentioned second aspect of the present invention. The method comprises (1) folding the inflating portion to form the folded portion which is apart from the gas infusion portion, (2) infusing fluid into the inside of the inner tube from a prescribed direction to inflate the inflating portion except the folded portion and detach the first and second fabrics each other, and (3) pleating the inflating portion except the folded portion to form the pleated portion under the condition where the inner tube is positioned along any one of the first or second fabric by the infused fluid.
With the fifth aspect of the present invention, the preferred folding pattern for stable deployment performance to deploy the airbag quickly and smoothly is achieved.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an airbag which deploys, for example, along a side window inside a vehicle compartment, an airbag apparatus having the airbag, and a method for folding the airbag.
2. Description of the Related Art
With regard to an airbag apparatus having an airbag which is inflated and deployed by inflation gas, a curtain airbag apparatus has been known. The curtain airbag apparatus has an airbag which deploys planarly along side windows inside a vehicle compartment. In this kind of the airbag apparatus, an airbag is folded and assembled elongatedly and installed along an upper edge of the side windows inside the vehicle compartment. When the vehicle receives impact by side impact or rollover, an inflator infuses gas into the airbag. The gas is infused into a bag-shaped inflating portion via a tubular infusion portion of the airbag. Then, the airbag is inflated and deployed downwardly along the side windows.
In this kind of airbag, a separated fabric (flow control fabric) is attached from a gas infusion portion to an inflating portion to protect the gas infusion portion from heat of gas (see Japanese Laid-open Patent Application No. 2003-146174 [page. 5, FIGS. 4 and 6]).
Furthermore, method for folding a curtain airbag is also known (see U.S. Patent Application Publication No. 2005/0110256 [FIGS. 1 and 2D]). In the above method, the airbag is rolled from the lower edge and the upper potion of the rolled potion is formed as a pair of flattened pleats. The pair of pleats wraps the rolled potion. With this folding pattern, the pair of flattened pleats is quickly inflated, and then the rolled portion is deployed.
SUMMARY OF THE INVENTION
However, if the fabric, which is attached from the gas infusion portion to the inflating portion, is adapted to the above-mentioned structure, edge of the fabric is rolled with the inflating portion or folded haphazardly.
The present invention has been made in view of the point of view as described above. An object of the present invention is to provide an airbag, an airbag apparatus, or method for folding an airbag which can improve deployment performance of an airbag.
A first aspect of the present invention provides an airbag which comprises (a) an airbag main portion and (b) an inner tube. The airbag main body includes (x) a gas infusion portion through which gas is infused into an inside of the airbag main portion, and (y) an inflating portion which is communicated with the gas infusion portion and has first and second fabrics between which the gas is infused through the gas infusion potion to inflate the inflating portion. The inner tube is provided from the inside of the gas infusion portion to the inside of an upstream portion of the inflating portion. The upstream portion of the inflating portion is pleated to form a pleated portion in which the first and second fabrics form a pair of pleats extending counter directions each other. The inner tube is folded with any one of the pleats.
With the first aspect of the present invention, when the gas is infused into the gas infusion portion, the pleated portion, which is communicated with the infusion portion and formed by pleating the inflating portion, is firstly deployed. In addition, the inner tube protects the airbag main portion from heat of the infused gas. Furthermore, since the inner tube is folded with any one of the pleats, folded pattern of the inner tube constantly becomes a uniform pattern and the infused gas is firmly infused into the pleated portion to stabilize the deployment performance.
A second aspect of the present invention provides an airbag which has all the features of the above-mentioned first aspect of the present invention. Furthermore, a downstream portion of the inflating portion is folded to form a folded portion which is folded to be wrapped by the pleated portion. The pleated portion is an upstream portion of the inflating portion and is pleated so that the first and second fabrics form a pair of pleats extending counter directions each other. And, the folded portion is a downstream portion of the inflating portion and is wrapped by the pleated portion.
With the second aspect of the present invention, when the gas is infused into the gas infusion portion, the pleated portion, which is communicated with the infusion portion and formed by pleating the inflating portion, is firstly deployed. The deploying pleated portion guides ejection of the folded portion to the desired direction. Then, the folded portion is inflated and deployed to achieve quick and smooth deployment of the airbag. In addition, the inner tube protects the airbag main portion from heat of the infused gas. Furthermore, since the inner tube is folded with any one of the pleats, folded pattern of the inner tube constantly becomes a uniform pattern and the infused gas is firmly infused into the pleated portion to stabilize the deployment performance.
A third aspect of the present invention provides an airbag apparatus which comprises (i) an airbag of the above-mentioned airbag of the second aspect of the present invention and (ii) an inflator. The airbag deploys along a side window inside a vehicle compartment. The inflator infuses gas into the gas infusion portion of the airbag. And, the first fabric of the airbag is developed so that the surface of the first fabric faces the inside of the vehicle compartment. Furthermore, the inner tube of the airbag is folded with the pleat of the first fabric.
With the third aspect of the present invention, since it comprises the airbag of the second aspect of the present invention, the deployment performance, that the airbag deploys quickly and smoothly along the side window inside the vehicle compartment, is achieved. In addition, since the inner tube of the airbag is folded with the pleat of the first fabric (the surface of the first fabric faces the inside of the vehicle compartment at the deployment), the inside pleat of the pleated portion inflates more quickly than the outside pleat of the pleated portion at the initial stage of the deployment. Then, the deployment direction of the folded portion is regulated outward (to the direction along the side window) to achieve the good and stable deployment performance of the airbag.
A fourth aspect of the present invention provides a method of folding the airbag of the above-mentioned first aspect of the present invention. The method comprises (1) infusing fluid into the inside of the inner tube from a prescribed direction to inflate the inflating portion and detach the first and second fabrics each other, and (2) pleating the inflating portion to form the pleated portion under the condition where the inner tube is positioned along any one of the first or second fabric by the infused fluid.
With the fourth aspect of the present invention, the pleated portion is pleated so that the first and second fabrics form the pair of pleats extending counter directions each other. The preferred folding pattern to fold the inner tube with any one of the pleats is achieved.
A fifth aspect of the present invention provides a method of folding an airbag of the above-mentioned second aspect of the present invention. The method comprises (1) folding the inflating portion to form the folded portion which is apart from the gas infusion portion, (2) infusing fluid into the inside of the inner tube from a prescribed direction to inflate the inflating portion except the folded portion and detach the first and second fabrics each other, and (3) pleating the inflating portion except the folded portion to form the pleated portion under the condition where the inner tube is positioned along any one of the first or second fabric by the infused fluid.
With the fifth aspect of the present invention, the preferred folding pattern for stable deployment performance to deploy the airbag quickly and smoothly is achieved.
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7711574 | BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention generally relates to financial systems and to systems and methods for processing financial information. More particularly, the invention relates to systems and methods for evaluating the likelihood that an appraisal of property is faulty.
II. Background and Material Information
When an application for a mortgage loan is processed by a financial entity such as a lender, bank, mortgage bank, mortgage broker, or mortgage originator, the property securing the mortgage is usually appraised. Since various financial entities have an interest in knowing the true (or fair) market value of the property securing the mortgage, the appraisal of a property is an important part of the mortgage loan application process.
An appraisal provides a property value estimate indicating a market value for a property. The appraisal may be performed in various ways including, for example, an in-person property appraisal performed by an appraiser. During the in-person appraisal, the appraiser physically inspects the property. With or without a physical inspection of the property, recent sales information for comparable properties may be used to generate an appraisal.
Alternatively, an automated valuation model serves as a tool that utilizes various factors (e.g., ZIP code, lot size, number of bedrooms, etc.) to appraise a property. Examples of automated valuation models may be found in one or more of the following applications: U.S. patent application Ser. No. 08/730,289, filed on Oct. 11, 1996, entitled “METHOD FOR COMBINING HOUSE PRICE FORECASTS”; U.S. patent application Ser. No. 09/115,831, filed on Jul. 15, 1998, entitled “SYSTEM AND METHOD FOR PROVIDING HOUSE PRICE FORECASTS BASED ON REPEAT SALES MODEL” (now U.S. Pat. No. 6,401,070); U.S. patent application Ser. No. 09/134,161, filed on Aug. 14, 1998, entitled “SYSTEM AND METHOD FOR PROVIDING PROPERTY VALUE ESTIMATES”; U.S. patent application Ser. No. 09/728,061, filed on Dec. 4, 2000, entitled “METHOD FOR FORECASTING HOUSE PRICES USING A DYNAMIC ERROR CORRECTION MODEL”; all of which are hereby incorporated by reference in their entirety. Other types of appraisals that provide an informed estimate of property value may also be used to appraise a property. Because of the various forms that an appraisal may take, an appraisal may be burdensome for a financial entity to process and/or interpret. For example, a financial entity may find it difficult to readily assess the reliability of an appraisal and, as a result, order an unnecessary reappraisal of the property.
A financial entity may use an appraisal as part of its mortgage loan approval process. For example, when a borrower applies for a mortgage loan, the appraisal may be used by a bank to verify the value of the underlying property. The bank uses the property value as a factor in approving or rejecting the mortgage loan application. For example, when an appraisal indicates that a property is worth less than the mortgage amount, a bank may not be willing to accept the financial risk and will therefore reject the mortgage loan application. On the other hand, the bank may simply tell the borrower that the maximum amount borrowed cannot exceed the appraised property value, or a percentage thereof. For these and other reasons, the appraisal is usually considered an important part of the mortgage loan application process.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to systems and methods for processing financial information and, more particularly, systems and methods for evaluating the likelihood that an appraisal of property is faulty.
A financial system consistent with the systems and methods of the present invention may provide, based on a model, an indication that an appraisal value for a property is likely to be faulty including, for example, receiving information representative of at least one of a borrower, a property, or one or more demographics; receiving the appraisal value of the property; and determining a score based on the received information, received appraisal, and the model, such that the score provides the indication of the likelihood that the appraisal value for the property is faulty.
Additional features and advantages of the invention will be set forth in part in the following description and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and advantages of the invention may be realized and attained by the system and method particularly described in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is also provided a method for providing an indication, based on a model, that an appraisal value for a property, which is secured by a mortgage loan, was likely to be faulty. The method includes, for example, receiving a date; receiving information representative of at least one of a borrower, a property, or one or more demographics, such that the received information corresponds to the date; receiving the appraisal value based on the date; and determining a score based on the received information, received appraisal, and the model, such that the score provides the indication of the likelihood that the appraisal value was faulty on the date.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as described. Further features and/or variations may be provided in addition to those set forth herein. For example, the present invention may be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed below in the detailed description.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention generally relates to financial systems and to systems and methods for processing financial information. More particularly, the invention relates to systems and methods for evaluating the likelihood that an appraisal of property is faulty.
II. Background and Material Information
When an application for a mortgage loan is processed by a financial entity such as a lender, bank, mortgage bank, mortgage broker, or mortgage originator, the property securing the mortgage is usually appraised. Since various financial entities have an interest in knowing the true (or fair) market value of the property securing the mortgage, the appraisal of a property is an important part of the mortgage loan application process.
An appraisal provides a property value estimate indicating a market value for a property. The appraisal may be performed in various ways including, for example, an in-person property appraisal performed by an appraiser. During the in-person appraisal, the appraiser physically inspects the property. With or without a physical inspection of the property, recent sales information for comparable properties may be used to generate an appraisal.
Alternatively, an automated valuation model serves as a tool that utilizes various factors (e.g., ZIP code, lot size, number of bedrooms, etc.) to appraise a property. Examples of automated valuation models may be found in one or more of the following applications: U.S. patent application Ser. No. 08/730,289, filed on Oct. 11, 1996, entitled “METHOD FOR COMBINING HOUSE PRICE FORECASTS”; U.S. patent application Ser. No. 09/115,831, filed on Jul. 15, 1998, entitled “SYSTEM AND METHOD FOR PROVIDING HOUSE PRICE FORECASTS BASED ON REPEAT SALES MODEL” (now U.S. Pat. No. 6,401,070); U.S. patent application Ser. No. 09/134,161, filed on Aug. 14, 1998, entitled “SYSTEM AND METHOD FOR PROVIDING PROPERTY VALUE ESTIMATES”; U.S. patent application Ser. No. 09/728,061, filed on Dec. 4, 2000, entitled “METHOD FOR FORECASTING HOUSE PRICES USING A DYNAMIC ERROR CORRECTION MODEL”; all of which are hereby incorporated by reference in their entirety. Other types of appraisals that provide an informed estimate of property value may also be used to appraise a property. Because of the various forms that an appraisal may take, an appraisal may be burdensome for a financial entity to process and/or interpret. For example, a financial entity may find it difficult to readily assess the reliability of an appraisal and, as a result, order an unnecessary reappraisal of the property.
A financial entity may use an appraisal as part of its mortgage loan approval process. For example, when a borrower applies for a mortgage loan, the appraisal may be used by a bank to verify the value of the underlying property. The bank uses the property value as a factor in approving or rejecting the mortgage loan application. For example, when an appraisal indicates that a property is worth less than the mortgage amount, a bank may not be willing to accept the financial risk and will therefore reject the mortgage loan application. On the other hand, the bank may simply tell the borrower that the maximum amount borrowed cannot exceed the appraised property value, or a percentage thereof. For these and other reasons, the appraisal is usually considered an important part of the mortgage loan application process.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to systems and methods for processing financial information and, more particularly, systems and methods for evaluating the likelihood that an appraisal of property is faulty.
A financial system consistent with the systems and methods of the present invention may provide, based on a model, an indication that an appraisal value for a property is likely to be faulty including, for example, receiving information representative of at least one of a borrower, a property, or one or more demographics; receiving the appraisal value of the property; and determining a score based on the received information, received appraisal, and the model, such that the score provides the indication of the likelihood that the appraisal value for the property is faulty.
Additional features and advantages of the invention will be set forth in part in the following description and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and advantages of the invention may be realized and attained by the system and method particularly described in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is also provided a method for providing an indication, based on a model, that an appraisal value for a property, which is secured by a mortgage loan, was likely to be faulty. The method includes, for example, receiving a date; receiving information representative of at least one of a borrower, a property, or one or more demographics, such that the received information corresponds to the date; receiving the appraisal value based on the date; and determining a score based on the received information, received appraisal, and the model, such that the score provides the indication of the likelihood that the appraisal value was faulty on the date.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as described. Further features and/or variations may be provided in addition to those set forth herein. For example, the present invention may be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed below in the detailed description.
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7835756 | BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a mobile communications system, a mobile communications network controller, a mobile communications terminal, and a method of controlling a mobile communications network.
2. Description of the Related Art
As conventional mobile communications systems, known are information provision systems in which servers such as WWW servers on the Internet provide various kinds of information to users of mobile terminals (mobile stations). The information provision systems include, for example, the “i-mode service (a service name)” provided by NTT DoCoMo, Inc.
The conventional information provision systems have a problem that users cannot obtain information to receive desired services. For example, although a nearby café has equipment for making a high-quality picture phone call, a user who wants to make such phone call when being in the street cannot get the fact. In another example, even though some fifty meters' walk results in improved radio conditions and relatively higher image quality, a user cannot obtain the information.
Further, the conventional information provision system cannot predict the movement of users. When communications conditions worsen with the movement of a user, that is, when a train bringing the user is about to enter a tunnel, for example, the conventional information providing system cannot enable to know the fact in advance and also cannot provide a seamless service.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above problems, and thus has an object of obtaining in advance information on communications environments in a mobile communications system and providing users with the information regarding communications environments. Another object of the present invention is to predict the movement of users and provide seamless services based on the predictions.
According first aspect of the present invention, there is provided a mobile communications system which comprises: a mobile communications terminal; and a mobile communications network controller; the mobile communications network controller comprising: an information acquisition unit for obtaining information regarding resources of a given object; an information memory for storing the obtained information regarding resources of a given object; and an information provision unit for searching the information memory in response to a request for provision of the information regarding resources of a given object transmitted from the mobile communications terminal and providing the information regarding resources of a given object found in the search to the mobile communications terminal; and the mobile communications terminal comprising: an information provision request transmitter for transmitting the request for provision of the information regarding resources of a given object; and an indicator for indicating the information regarding resources of a given object provided from the mobile communications network controller.
According to a second aspect of the present invention, there is provided a mobile communications network controller which comprises: a history information memory for storing history of movement of a mobile communications terminal to a given place; a notification unit for detecting and notifying the movement of said mobile communications terminal to a given place; and a processing unit for performing predetermined processing to a service to be provided to said mobile communications terminal in response to said notification.
According to a third aspect of the present invention, there is provided a mobile communications network controller which comprises: an information acquisition unit for obtaining information regarding resources of a given object; an information memory for storing the obtained information regarding resources of a given object; and an information provision unit for searching the information memory in response to a request for provision of the information regarding resources of a given object and providing the information regarding resources of a given object found in the search.
According to a forth aspect of the present invention, there is provided a mobile communications terminal which comprises: an information provision request transmitter for transmitting a request for provision of information regarding resources of a given object; and an indicator for indicating the information regarding resources of a given object provided by the request.
According to a fifth aspect of the present invention, there is provided a method of controlling a mobile communications network, which comprises the steps of: A) obtaining information regarding resources of a given object at a mobile communications network controller; B) storing the obtained information regarding resources of a given object at the mobile communications network controller; and C) providing, at the mobile communications network controller, a mobile communications terminal with the information regarding resources of a given object searched in response to a request for provision of the information regarding resources of a given object transmitted from the mobile communications terminal.
According to a sixth aspect of the present invention, there is provided a method of controlling a mobile communications network, which comprises the steps of: A) storing, at a mobile communications network controller, history of movement of a mobile communications terminal to a given place; B) detecting and notifying, at the mobile communications network controller, the movement of the mobile communications terminal to a given place; and C) performing predetermined processing, at the mobile communications network controller, to a service to be provided to the mobile communications terminal, in response to the notification.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a mobile communications system, a mobile communications network controller, a mobile communications terminal, and a method of controlling a mobile communications network.
2. Description of the Related Art
As conventional mobile communications systems, known are information provision systems in which servers such as WWW servers on the Internet provide various kinds of information to users of mobile terminals (mobile stations). The information provision systems include, for example, the “i-mode service (a service name)” provided by NTT DoCoMo, Inc.
The conventional information provision systems have a problem that users cannot obtain information to receive desired services. For example, although a nearby café has equipment for making a high-quality picture phone call, a user who wants to make such phone call when being in the street cannot get the fact. In another example, even though some fifty meters' walk results in improved radio conditions and relatively higher image quality, a user cannot obtain the information.
Further, the conventional information provision system cannot predict the movement of users. When communications conditions worsen with the movement of a user, that is, when a train bringing the user is about to enter a tunnel, for example, the conventional information providing system cannot enable to know the fact in advance and also cannot provide a seamless service.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above problems, and thus has an object of obtaining in advance information on communications environments in a mobile communications system and providing users with the information regarding communications environments. Another object of the present invention is to predict the movement of users and provide seamless services based on the predictions.
According first aspect of the present invention, there is provided a mobile communications system which comprises: a mobile communications terminal; and a mobile communications network controller; the mobile communications network controller comprising: an information acquisition unit for obtaining information regarding resources of a given object; an information memory for storing the obtained information regarding resources of a given object; and an information provision unit for searching the information memory in response to a request for provision of the information regarding resources of a given object transmitted from the mobile communications terminal and providing the information regarding resources of a given object found in the search to the mobile communications terminal; and the mobile communications terminal comprising: an information provision request transmitter for transmitting the request for provision of the information regarding resources of a given object; and an indicator for indicating the information regarding resources of a given object provided from the mobile communications network controller.
According to a second aspect of the present invention, there is provided a mobile communications network controller which comprises: a history information memory for storing history of movement of a mobile communications terminal to a given place; a notification unit for detecting and notifying the movement of said mobile communications terminal to a given place; and a processing unit for performing predetermined processing to a service to be provided to said mobile communications terminal in response to said notification.
According to a third aspect of the present invention, there is provided a mobile communications network controller which comprises: an information acquisition unit for obtaining information regarding resources of a given object; an information memory for storing the obtained information regarding resources of a given object; and an information provision unit for searching the information memory in response to a request for provision of the information regarding resources of a given object and providing the information regarding resources of a given object found in the search.
According to a forth aspect of the present invention, there is provided a mobile communications terminal which comprises: an information provision request transmitter for transmitting a request for provision of information regarding resources of a given object; and an indicator for indicating the information regarding resources of a given object provided by the request.
According to a fifth aspect of the present invention, there is provided a method of controlling a mobile communications network, which comprises the steps of: A) obtaining information regarding resources of a given object at a mobile communications network controller; B) storing the obtained information regarding resources of a given object at the mobile communications network controller; and C) providing, at the mobile communications network controller, a mobile communications terminal with the information regarding resources of a given object searched in response to a request for provision of the information regarding resources of a given object transmitted from the mobile communications terminal.
According to a sixth aspect of the present invention, there is provided a method of controlling a mobile communications network, which comprises the steps of: A) storing, at a mobile communications network controller, history of movement of a mobile communications terminal to a given place; B) detecting and notifying, at the mobile communications network controller, the movement of the mobile communications terminal to a given place; and C) performing predetermined processing, at the mobile communications network controller, to a service to be provided to the mobile communications terminal, in response to the notification.
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7685825 | BACKGROUND OF THE INVENTION
This application relates to liners for the convergent flaps and seals which are part of a convergent/divergent nozzle for a gas turbine engine, and wherein the liners are formed of two separate plates.
A gas turbine engine typically includes a plurality of sections, which are positioned in series. A fan section moves air downstream towards a compressor section. The compressor section compresses the air and delivers it into a combustion section. In the combustion section, air and fuel are mixed and combusted. Products of combustion pass downstream over turbines, and then outwardly through a nozzle.
It is known in the prior art to vary the cross-sectional area of the nozzle by having flaps that pivot inwardly and outwardly. Typically, a plurality of circumferentially spaced flaps and seals are positioned upstream of a throat, and are called the convergent flaps and seals. Downstream of the throat are divergent flaps and seals. The convergent flaps and seals not only move to define the throat area, but they also provide a block for the products of combustion reaching a housing outboard of the flaps and seals.
In the structure for the convergent flaps and seals, a liner typically faces the products of combustion. The liner is connected by a bracket to the flap or seal.
In the prior art, the liners have been subject to high thermal and external loads. In particular, the liner extends over a portion of the length of the nozzle, and as one moves downstream in the nozzle, the liner is subject to greater heat. This is true for several reasons, one being the fact that cooling air is mixed into the nozzle at a position upstream. This cooling air has lesser and lesser effects as one moves downstream.
The liner is subjected to thermal stresses from this thermal gradient along its length. An aft, or downstream edge, of the liner is hotter than a forward curled edge. Thermal stress from the more aft portion is transferred forward toward the forward edge. On the other hand, external loads such as from structure for moving the liner and the associated seal or flap are largely on the upstream of forward portion. These external loads are transferred back toward the aft portion.
Typically, a backing sheet has been attached to the liner by rivets, which are in tension. It is undesirable to have rivets loaded in tension.
In the prior art, a separate plate has been utilized to provide a flow blocker to maintain a higher pressure forward, or upstream, of the flow blocker, and the lower pressure downstream of the flow blocker. The requirement of this separate flow blocker plate adds additional structure, which is undesirable.
SUMMARY OF THE INVENTION
In a disclosed embodiment of this invention, a liner for being connected to a convergent flap and seal is formed of two plates that are split along an axial span-wise flange. By splitting the liner into two plates, the thermal stresses on an aft plate are separated from the external stresses on a forward plate. A break between the two is provided.
In disclosed embodiments, the two plates of the liner, along with the backing sheet, all have abutting faces that provide openings for rivets to secure the three plates. Generally, the rivets extend parallel to the direction of the thermal gradient. These rivets are loaded in shear, which is preferable to loading rivets in tension. Further, the abutting faces of the three plates form the flow blocker such that a separate flow blocker is not necessary.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: BACKGROUND OF THE INVENTION
This application relates to liners for the convergent flaps and seals which are part of a convergent/divergent nozzle for a gas turbine engine, and wherein the liners are formed of two separate plates.
A gas turbine engine typically includes a plurality of sections, which are positioned in series. A fan section moves air downstream towards a compressor section. The compressor section compresses the air and delivers it into a combustion section. In the combustion section, air and fuel are mixed and combusted. Products of combustion pass downstream over turbines, and then outwardly through a nozzle.
It is known in the prior art to vary the cross-sectional area of the nozzle by having flaps that pivot inwardly and outwardly. Typically, a plurality of circumferentially spaced flaps and seals are positioned upstream of a throat, and are called the convergent flaps and seals. Downstream of the throat are divergent flaps and seals. The convergent flaps and seals not only move to define the throat area, but they also provide a block for the products of combustion reaching a housing outboard of the flaps and seals.
In the structure for the convergent flaps and seals, a liner typically faces the products of combustion. The liner is connected by a bracket to the flap or seal.
In the prior art, the liners have been subject to high thermal and external loads. In particular, the liner extends over a portion of the length of the nozzle, and as one moves downstream in the nozzle, the liner is subject to greater heat. This is true for several reasons, one being the fact that cooling air is mixed into the nozzle at a position upstream. This cooling air has lesser and lesser effects as one moves downstream.
The liner is subjected to thermal stresses from this thermal gradient along its length. An aft, or downstream edge, of the liner is hotter than a forward curled edge. Thermal stress from the more aft portion is transferred forward toward the forward edge. On the other hand, external loads such as from structure for moving the liner and the associated seal or flap are largely on the upstream of forward portion. These external loads are transferred back toward the aft portion.
Typically, a backing sheet has been attached to the liner by rivets, which are in tension. It is undesirable to have rivets loaded in tension.
In the prior art, a separate plate has been utilized to provide a flow blocker to maintain a higher pressure forward, or upstream, of the flow blocker, and the lower pressure downstream of the flow blocker. The requirement of this separate flow blocker plate adds additional structure, which is undesirable.
SUMMARY OF THE INVENTION
In a disclosed embodiment of this invention, a liner for being connected to a convergent flap and seal is formed of two plates that are split along an axial span-wise flange. By splitting the liner into two plates, the thermal stresses on an aft plate are separated from the external stresses on a forward plate. A break between the two is provided.
In disclosed embodiments, the two plates of the liner, along with the backing sheet, all have abutting faces that provide openings for rivets to secure the three plates. Generally, the rivets extend parallel to the direction of the thermal gradient. These rivets are loaded in shear, which is preferable to loading rivets in tension. Further, the abutting faces of the three plates form the flow blocker such that a separate flow blocker is not necessary.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
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7711943 | BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to a computer and, more particularly, to a method for saving electricity consumed by a computer.
2. Related Prior Art
Traditionally, a computer cannot immediately provide any service to a user after it is turned on. Only after the loading of an operating system is completed can the computer provide service such as TV, radio, games, internet browsing, web phone, emails, music and movies. One problem is that a lot time elapses before the loading of the operating system is completed. Another problem is that a lot of electricity is consumed during the executing of the operating system.
There have been techniques based on changes in software and/or hardware to enable a computer, when turned on or before the loading of an operating system, to provide a single item of service. The single item of service may be music or movies. However, each of these techniques cannot cause the computer to provide a plurality of items of service.
Disclosed in Patent Application Publication US20040006690 is a computer that executes a first operating system or a second operating system. As required, the second operating system executes an application selected from a DVD application, a TV application, a digital device application, a remote control application, a voice-recording application and an audio application. This technique discloses the provision of several applications, but fails to mention how to enable a user to choose from the applications. Moreover, during the executing of the second operating system, the devices of the computer irrelevant to a chosen application also consume electricity, and this is a waste.
Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.
SUMMARY OF INVENTION
It is an objective of the present invention to provide a method for enabling a computer to provide a plurality of items of service so that a user can select one of the items of service to execute at least one application corresponding to the selected item of service only, to turn on at least one device corresponding to the selected item of service only, and to turn off devices that are irrelevant to the selected item of service. Thus, the computer provides service corresponding to the selected item of service while consuming a reduced amount of electricity.
According to the present invention, a method for saving electricity consumed by a computer includes the steps of defining a plurality of items of service so that a user can select one of the items of service, identifying at least one device, driver and application corresponding to the selected item of service and providing a simplified process for actuating the device, driver and application corresponding to the selected item of service.
In an aspect, the simplified process includes the steps of executing the basic input and out system (hereinafter referred to as “BIOS”) of the computer, turning on all of the devices of the computer and inviting the user to select from a normal mode and an electricity-saving mode, allowing the BIOS to execute an operating system of the computer if the normal mode is selected, stopping the BIOS temporarily if the electricity-saving mode is selected, providing the items of service so that the user to select one of the items of service, executing the driver corresponding to the selected item of service, executing the application corresponding to the selected item of service to provide service corresponding to the selected item of service and turning off the other devices, which are irrelevant to the selected item of service.
The method may include the step of defining several modes for the operation of a central processing device of the computer corresponding to the items of service. The simplified process may include the step of operating the central processing device of the computer in one of the modes corresponding to the selected item of service.
It is another objective of the present invention to provide a computer including a central processing device, a plurality of peripherals, a power supply and a switch circuit. The central processing device includes a CPU, a chip set, a memory and a BIOS chip for storing a BIOS. The peripherals are connected to the chip set. The peripherals include one for storing an operating system, an electricity-saving system, a plurality of drivers and a plurality of applications. The power supply provides electricity to the central processing device and the peripherals. The switch circuit is provided for controlling the supply of electricity to the peripherals. The BIOS loads the electricity-saving system to the memory when the power supply normally provides the electricity. The electricity-saving system provides a plurality of items of service so that a user can select one of the items of service to execute the driver and application corresponding to the selected item of service, and to turn off some of the peripherals which are irrelevant to the selected item of service via the switch circuit.
It is still another objective of the present invention to provide a computer including a central processing device, a plurality of peripherals, a power supply, a switch circuit and a plurality of buttons. The central processing device includes a CPU, a chip set, a memory and a BIOS chip for storing a BIOS. The peripherals are connected to the chip set and comprise one for storing an operating system, an electricity-saving system, a plurality of drivers and a plurality of applications. The power supply provides electricity to the central processing device and the peripherals. The switch circuit is provided for controlling the supply of electricity to the peripherals. The buttons are connected to the chip set so that one of items of service is selected and the BIOS is executed when a corresponding one of the buttons is pushed. The BIOS loads the electricity-saving system to the memory when the power supply normally provides the electricity. The electricity-saving system executes the driver and application corresponding to the selected item of service, and turns off some of the peripherals which are irrelevant to the selected item of service via the switch circuit.
Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings.
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SUMMARY: BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to a computer and, more particularly, to a method for saving electricity consumed by a computer.
2. Related Prior Art
Traditionally, a computer cannot immediately provide any service to a user after it is turned on. Only after the loading of an operating system is completed can the computer provide service such as TV, radio, games, internet browsing, web phone, emails, music and movies. One problem is that a lot time elapses before the loading of the operating system is completed. Another problem is that a lot of electricity is consumed during the executing of the operating system.
There have been techniques based on changes in software and/or hardware to enable a computer, when turned on or before the loading of an operating system, to provide a single item of service. The single item of service may be music or movies. However, each of these techniques cannot cause the computer to provide a plurality of items of service.
Disclosed in Patent Application Publication US20040006690 is a computer that executes a first operating system or a second operating system. As required, the second operating system executes an application selected from a DVD application, a TV application, a digital device application, a remote control application, a voice-recording application and an audio application. This technique discloses the provision of several applications, but fails to mention how to enable a user to choose from the applications. Moreover, during the executing of the second operating system, the devices of the computer irrelevant to a chosen application also consume electricity, and this is a waste.
Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.
SUMMARY OF INVENTION
It is an objective of the present invention to provide a method for enabling a computer to provide a plurality of items of service so that a user can select one of the items of service to execute at least one application corresponding to the selected item of service only, to turn on at least one device corresponding to the selected item of service only, and to turn off devices that are irrelevant to the selected item of service. Thus, the computer provides service corresponding to the selected item of service while consuming a reduced amount of electricity.
According to the present invention, a method for saving electricity consumed by a computer includes the steps of defining a plurality of items of service so that a user can select one of the items of service, identifying at least one device, driver and application corresponding to the selected item of service and providing a simplified process for actuating the device, driver and application corresponding to the selected item of service.
In an aspect, the simplified process includes the steps of executing the basic input and out system (hereinafter referred to as “BIOS”) of the computer, turning on all of the devices of the computer and inviting the user to select from a normal mode and an electricity-saving mode, allowing the BIOS to execute an operating system of the computer if the normal mode is selected, stopping the BIOS temporarily if the electricity-saving mode is selected, providing the items of service so that the user to select one of the items of service, executing the driver corresponding to the selected item of service, executing the application corresponding to the selected item of service to provide service corresponding to the selected item of service and turning off the other devices, which are irrelevant to the selected item of service.
The method may include the step of defining several modes for the operation of a central processing device of the computer corresponding to the items of service. The simplified process may include the step of operating the central processing device of the computer in one of the modes corresponding to the selected item of service.
It is another objective of the present invention to provide a computer including a central processing device, a plurality of peripherals, a power supply and a switch circuit. The central processing device includes a CPU, a chip set, a memory and a BIOS chip for storing a BIOS. The peripherals are connected to the chip set. The peripherals include one for storing an operating system, an electricity-saving system, a plurality of drivers and a plurality of applications. The power supply provides electricity to the central processing device and the peripherals. The switch circuit is provided for controlling the supply of electricity to the peripherals. The BIOS loads the electricity-saving system to the memory when the power supply normally provides the electricity. The electricity-saving system provides a plurality of items of service so that a user can select one of the items of service to execute the driver and application corresponding to the selected item of service, and to turn off some of the peripherals which are irrelevant to the selected item of service via the switch circuit.
It is still another objective of the present invention to provide a computer including a central processing device, a plurality of peripherals, a power supply, a switch circuit and a plurality of buttons. The central processing device includes a CPU, a chip set, a memory and a BIOS chip for storing a BIOS. The peripherals are connected to the chip set and comprise one for storing an operating system, an electricity-saving system, a plurality of drivers and a plurality of applications. The power supply provides electricity to the central processing device and the peripherals. The switch circuit is provided for controlling the supply of electricity to the peripherals. The buttons are connected to the chip set so that one of items of service is selected and the BIOS is executed when a corresponding one of the buttons is pushed. The BIOS loads the electricity-saving system to the memory when the power supply normally provides the electricity. The electricity-saving system executes the driver and application corresponding to the selected item of service, and turns off some of the peripherals which are irrelevant to the selected item of service via the switch circuit.
Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings.
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7722880 | FIELD OF THE INVENTION
The present invention relates generally to the fields of cellular biology, molecular biology, pathology, clinical microbiology, and medicine. Specifically, the present invention concerns the molecular biology ofEhrlichia, includingEhrlichia canis. More specifically, the present invention relates to molecular cloning and characterization of a 38-kDa immunoreactive ferric binding protein (Fbp) polynucleotide and the encoded product fromEhrlichia canis, as well as uses thereof.
BACKGROUND OF THE INVENTION
Ehrlichiaspp. are obligately intracellular gram-negative bacteria that reside in endosomes within hematopoietic cells and infect various hosts including humans, domestic and wild canidae, deer, horses, sheep, cattle, and wild rodents. Each member of the family Anaplasmataceae has its own particular primary target cell tropism. Most species ofEhrlichiaare either monocytotropic (e.g.E. canis, E. chaffeensis, andE. muris) or granulocytotropic (e.g.Anaplasma phagocytophilum, andE. ewingii) with the exceptions ofEhrlichia ruminantium, which grows in the endothelial cells of the host,Anaplasma marginale, a red blood cell parasite, andAnaplasma platys, a platelet parasite.
AlthoughEhrlichiaewere described in the early part of the 20thcentury, they received very little attention because they were considered pathogens of only veterinary importance in the United States until the recent two decades. The renewed interest inEhrlichiais due to the emergence of ehrlichioses affecting humans. Since 1987, three emerging human ehrlichial pathogens (E. chaffeensis, E. ewingii, andA. phagocytophilum) have been discovered in the United States.
Ehrlichia canis, the prototype species of the genus, is the etiologic agent of canine monocytotropic ehrlichiosis (CME). CME, also known as canine tropical pancytopenia, is a worldwide disease transmitted by the brown dog tick,Rhipicephalus sanguineus. The progression of canine ehrlichiosis occurs in three phases: acute, sub-clinical and chronic. The acute phase is characterized by fever, anorexia, depression, lymphadenopathy and mild thrombocytopenia. Dogs typically recover from the acute phase, but become persistently infected carriers of the organism without clinical signs of disease for months or even years. A chronic phase develops in some cases that is characterized by thrombocytopenia, hyperglobulinemia, anorexia, emaciation, and hemorrhage, particularly epistaxis, followed by death. Each year it costs millions of dollars worldwide for treating companion and working dogs infected withE. canis. Ehrlichia caniswas isolated from a human recently, and thus may be an emerging public health threat.
One aspect ofE. canisbiology concerns the need for iron, which is a necessity for survival of nearly all prokaryotes and eukaryotes. For the obligate intracellular bacteriumEhrlichia chaffeensis, the importance of iron for intracellular survival has been demonstrated by inhibition ofEhrlichiaproliferation in the presence of the intracytoplasmic iron chelator deferoxamine (Barnewall et al., 1997). Early endosomes containing the bacteria (morulae) upregulate and accumulate the mammalian transferrin receptor (Barnewall et al., 1997), suggesting that the organism has developed specific strategies for iron acquisition. The cytoplasmic vacuole where theEhrlichiaresides is acidic, which may promote the release of free iron into the compartment (Barnewall et al., 1997). AnE. chaffeensisprotein with homology to known ferric binding proteins has been previously reported (Yu et al., 1999), but the mechanisms of iron acquisition byEhrlichiaspp. are unknown and functional demonstration of iron binding properties ofEhrlichiaFbps has not been experimentally demonstrated. Furthermore, theE. chaffeensisFbp polypeptide is not immunoreactive.
Iron is involved in many key metabolic functions of the cell, but insoluble Fe(OH)3(rust) forms at a physiological pH and thus must be stored and transferred via iron binding proteins (Andrews et al., 2003; Mietzner et al., 1998). In eukaryotic systems, extracellular iron-binding proteins include transferrin and lactoferrin, while ferritin binds and sequesters intracellular iron. Protein-bound iron also inhibits the interaction of Fe(II) with O2, preventing the formation of free radicals that are damaging to cells (Andrews et al., 2003; Mietzner et al., 1998). The availability of iron has been demonstrated to increase the virulence of many diverse pathogenic bacteria (Raymond et al., 2003). Limiting the availability of free iron is a mechanism to naturally suppress growth of bacteria. However, under the selective pressure of the limited iron available in the host, pathogenic bacteria have evolved specific iron acquisition mechanisms including iron binding molecules and proteins.
Bacteria commonly utilize siderophores as means of iron mobilization. These molecules are nonproteinaceous iron chelators that are expressed, secreted, and bound by surface receptors that enable the transport of free iron from the environment (Andrews et al., 2003; Mietzner et al., 1998). Another means of iron uptake involves iron acquisition from the host iron binding proteins transferrin and lactoferrin (Andrews et al., 2003; Mietzner et al., 1998). This mechanism, used by many gram-negative pathogens involves a conserved system by which iron is competed away from transferrin or lactoferrin at the outer membrane of the bacterium and the iron is shuttled across the membrane and into the periplasm (Andrews et al., 2003). Mobilization of iron into the cytoplasm involves three proteins that belong to the ATP-binding cassette (ABC) transporter family, the ferric binding protein (Fbp), a cytoplasmic permease, and an ATP-binding protein (Adhikari et al., 1996; Adhikari et al., 1995; Andrews et al., 2003; Clarke et al., 2001; Mietzner et al., 1998), all encoded by an operon system that is shared among many diverse bacterial species includingNeisseria gonorrhoeae, Haemophilus influenzae, Mannheimia(Pasteurella)haemolytica, Serratia marcescens, Salmonella typhimurium, andYersinia pestis(Adhikari et al., 1996; Adhikari et al., 1995 Angerer et al., 1990; Bearden and Perry, 1999; Bearden et al., 1998; Janakiraman and Slauch, 2000; Kirby et al., 1998). The operon system ofNeisseria gonorrhoeaehas been demonstrated to be under the control of the iron regulatory element Fur (ferric uptake regulator)(Desai et al., 1996).
Identifying the genetic and antigenic compositions ofE. canisis essential for studying the pathogenesis of canine ehrlichiosis and developing an effective vaccine. Although Yu et al. (1999) describe anE. chaffeensis37-kDa protein that is homologous to the iron (III)-binding periplasmic protein precursor of gram-negative bacteria, the prior art is deficient in the cloning and characterization of immunoreactive gene ofEhrlichia canis. The present invention fulfills this long-standing need and desire in the art by cloning an immunoreactive Fbp ofEhrlichia canis.
BRIEF SUMMARY OF THE INVENTION
The present invention describes the molecular cloning, sequencing, expression, and characterization of a 38-kDa immunoreactive ferric binding protein gene ofEhrlichia canis.
In particular, the present invention represents the first functional characterization of a ferric binding protein (Fbp) ortholog in any obligate intracellular bacteria. The present inventors have identified an immunoreactive 38-kDa Fbp fromEhrlichia canisthat shares homology with a known family of periplasmic Fbps involved in iron acquisition in extracellular bacterium. Structural modeling of theE. canisFbp identified an iron-binding motif conserved among the Fbp family, and the present inventors demonstrated the ability ofE. canisFbp to bind free iron.E. canisFbp was observed primarily in the cytoplasm of bacteria with reticulate morphology, while surface and extracellular distribution on morula fibers and the membrane of morulae was observed on the dense-coredEhrlichialform. Notably,E. canisfbp was not organized with other prototypical iron acquisition genes in an operon system.
The exemplaryE. canisFbp protein sequence provided herein had homology (˜25-60%) with a known family of ferric binding proteins (Fbp), indicating that it plays a role in iron acquisition known to be essential forEhrlichiasurvival, in specific embodiments of the invention. The predicted three-dimensional structure ofE. canisFbp demonstrated conservation of Fbp structural motifs. In the presence of iron, the recombinant Fbp exhibited visible absorbance spectrum compared to the unbound form, indicative of iron binding.
The gene encoding the orthologous Fbp fromE. chaffeensis, the closely related causative agent of human disease, exhibits 87% homology to the Fbp protein ofE. canis. A recombinantE. canisFbp fusion protein reacted with antibodies in sera from dogs with canine ehrlichiosis, and antisera produced against recombinantE. canisFbp recognized a native protein of similar molecular mass (38-kDa) fromE. caniswhole cell lysates. In particular embodiments of the invention, these studies demonstrate that Fbp is a highly conserved iron binding protein that is important for its survival and also is a viable target for vaccine use.
In one embodiment of the present invention, there is DNA sequence encoding a 38-kDa immunoreactive Fbp ofEhrlichia canis. In particular embodiments, the protein has an amino acid sequence of SEQ ID NO:2 and the gene has a nucleic acid sequence of SEQ ID NO:1. In specific embodiments of the invention, theE. canisFbp polypeptide comprises one or more of the following characteristics: 1) it is immunoreactive; 2) it binds iron, such as Fe(III), although in alternative embodiments it binds Fe(II) instead or in addition to; 3) it comprises an N-terminal sequence, which may be referred to as a signal sequence, and which may be cleaved after post-translational modification resulting in the production of a mature protein (predicted to be about 35.8-kDa); 4) it comprises a tyrosine at positions 201, 202, or both; 5) it comprises a lysine at position 14; 5) it comprises a tyrosine at 145 and/or an arginine at positions 13, 105, and 139; 6) it may be cytoplasmically localized and/or localized on the surface and extracellular morula fibers; and 7) it comprises two domains each comprised of a central β-sheet surrounded by multiple α-helices, which are thereby connected with a hinge of antiparallel β-strands. In specific embodiments, the polypeptide is isolated and/or purified.
In specific embodiments of the present invention, there is the polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide. As used herein, the term “relatedE. canisFbp polypeptide” refers to a polypeptide having similar sequence with SEQ ID NO:2, such as described below, and the related polypeptide is not necessarily naturally present inE. canisbut may be derived from SEQ ID NO:2 and/or may be generated synthetically. In specific embodiments, mutations to SEQ ID NO:2, either by mutating an amino acid or by mutating a polynucleotide that encodes SEQ ID NO:2, are encompassed in the invention. Such mutations may be produced either chemically or by site-directed mutagenesis, for example. In specific embodiments, the relatedE. canisFbp polypeptide comprises one or more of the same characteristics as native SEQ ID NO:2, including immunoreactivity and iron-binding capability, for example.
TheE. canisFbp of the present invention may comprise sequence identity with the polypeptide of SEQ ID NO:2. For example, a polypeptide of the invention may be about 70% identical to SEQ ID NO:2, about 75% identical to SEQ ID NO:2, about 80% identical to SEQ ID NO:2, about 85% identical to SEQ ID NO:2, about 90% identical to SEQ ID NO:2, about 95% identical to SEQ ID NO:2, about 97% identical to SEQ ID NO:2, about 99% identical to SEQ ID NO:2, and so forth. In other embodiments, an Fbp polypeptide of the invention comprises at least about 325 contiguous amino acids from SEQ ID NO:2, at least about 300 contiguous amino acids from SEQ ID NO:2, at least about 250 contiguous amino acids from SEQ ID NO:2, at least about 200 contiguous amino acids from SEQ ID NO:2, at least about 150 contiguous amino acids from SEQ ID NO:2, at least about 125 contiguous amino acids from SEQ ID NO:2, at least about 100 contiguous amino acids from SEQ ID NO:2, at least about 75 contiguous amino acids from SEQ ID NO:2, at least about 50 contiguous amino acids from SEQ ID NO:2, or at least about 25 contiguous amino acids from SEQ ID NO:2, for example.
Polynucleotides that encode SEQ ID NO:2, such as the exemplary SEQ ID NO:1 polynucleotide, or that encode related proteins as discussed above, are embodiments of the invention and may comprise one or more of the following characteristics: 1) it comprises an iron-regulatory element, such as the exemplary ferric uptake regulator (Fur)-binding site; an exemplaryE. coliFur recognition consensus, for example, comprises ATA/TAT; 2) it encodes a polypeptide comprising one or more of theE. canisFbp polypeptide characteristics described herein; and 3) it is not comprised on an operon.
In particular embodiments of the invention, there is a polynucleotide that comprises sequence identity with SEQ ID NO:1. For example, a polynucleotide of the invention may be about 70% identical to SEQ ID NO:1, about 75% identical to SEQ ID NO:1, about 80% identical to SEQ ID NO:1, about 85% identical to SEQ ID NO:1, about 90% identical to SEQ ID NO:1, about 95% identical to SEQ ID NO:1, and so forth. In other embodiments, an Fbp polynucleotide of the invention comprises at least about 1000 contiguous nucleotides from SEQ ID NO:1, at least about 750 contiguous nucleotides from SEQ ID NO:1, at least about 500 contiguous nucleotides from SEQ ID NO:1, at least about 300 contiguous nucleotides from SEQ ID NO:1, at least about 250 contiguous nucleotides from SEQ ID NO:1, at least about 200 contiguous nucleotides from SEQ ID NO:1, at least about 150 contiguous nucleotides from SEQ ID NO:1, at least about 100 contiguous nucleotides from SEQ ID NO:1, at least about 75 contiguous nucleotides from SEQ ID NO:1, at least about 50 contiguous nucleotides from SEQ ID NO:1, at least about 25 contiguous nucleotides from SEQ ID NO:1, or at least about 12 contiguous nucleotides from SEQ ID NO:1.
In specific aspects of the invention, there is an isolated polynucleotide that specifically hybridizes under highly stringent conditions to the complement of the sequence set forth in SEQ ID NO:1.
In another embodiment of the present invention, there is provided an expression vector comprising a polynucleotide of the invention encoding a 38-kDa immunoreactive Fbp ofE. canis, and the vector is capable of expressing the polynucleotide, such as when the vector is introduced into a cell. The cell into which the vector is introduced may be a prokaryotic cell or it may be a eukaryotic cell, and any elements comprised on the vector, such as regulatory elements, are capable of expressing the Fbp polynucleotide therein. Exemplary regulatory elements include iron-binding elements, promoters, enhancers, origin of replication, and so forth, for example.
In still another embodiment of the present invention, there is provided a recombinant protein comprising an amino acid sequence of SEQ ID NO:2. In specific embodiments, the amino acid sequence is encoded by a nucleic acid sequence of SEQ ID NO:1. The recombinant protein may be useful as an antigen. In specific embodiments, the polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide is employed as an immunogen, and in specific embodiments it induces an immune response in an individual to which the polypeptide is delivered. In specific embodiments, the polypeptide induces an immune response such that it provides immunity to subsequent challenge, such as fromE. canisinfection.
Immunogenic compositions of the present invention may comprise an immunoreactive polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide; it may comprise antibodies to a polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide; or it may comprise both. The present invention provides a considerable advantage forE. canisprotection overE. chaffeensisprotection, wherein the orthologous Fbp polypeptide ofE. chaffeensisis not immunoreactive and it has not been demonstrated to bind iron. Thus, in specific embodiments of the invention, there is a vaccine comprising SEQ ID NO:2 or a relatedE. canisFbp polypeptide. In particular aspects of the invention, the vaccine is a subunit vaccine and does not comprise theE. canisorganism as a whole.
In particular aspects of the invention, theE. canisFbp polypeptide of the invention is immunoreactive. That is, in specific embodiments the polypeptide binds to, which may be referred to as reacts with, an antibody, such as the antibodies in the serum of an individual, for example. One of skill in the art recognizes that there are multiple ways to demonstrate immunoreactivity, such as, for example, by providing a recombinant protein suspected of being immunoreactive, introducing the protein into an animal, such as a rabbit or dog, collecting the antiserum, and then determining if antibodies in the antisera recognize the recombinant protein, such as on a western blot. In another exemplary embodiment, serum from anE. canis-infected animal, such as a dog, is probed to a blot comprising a protein suspected of being immunoreactive to determine if there is binding therebetween. Detection of binding indicates that the protein suspected of being immunoreactive is in fact immunoreactive. Lymphoproliferative responses to an antigen may be employed. Immunoreactivity assays may employ ELISA or cytometric beads, for example.
In particular embodiments, immunogenic compositions of the present invention comprise the native conformation of the polypeptide, as opposed to a denatured form, thereby preserving a conformation which comprises an epitope. In particular embodiments, the conformational epitope is an epitope that comprises a particular three-dimensional structure on the outside of the protein, for example part or all of an alpha helix, a beta sheet, a beta strand, a hinge region, two or more antiparallel beta strands, part or all of an iron-binding domain, or a combination thereof. In specific embodiments, a conformational epitope comprises tyrosine 201, tyrosine 202, tyrosine 145, arginine 13, arginine 105, arginine 139, or a combination thereof. A skilled artisan recognizes that there is software available to determine which residues of a folded polypeptide are located on the outside.
In a preferred embodiment of the present invention, there is provided a method of producing the polypeptide, comprising the steps of obtaining a vector that comprises an expression construct comprising a sequence encoding the amino acid sequence of SEQ ID NO:2 or a related polypeptide operatively linked to a promoter; transfecting the vector into a cell; and culturing the cell under suitable conditions effective for expression of the polypeptide. The polypeptide may be further defined as recombinant.
The invention may also be described in certain embodiments as a method of inhibitingEhrlichia canisinfection in a subject comprising the steps of: identifying a subject prior to exposure or suspected of being exposed. to or suspected of being infected withEhrlichia canis; and administering a composition comprising a Fbp ofEhrlichia canisin an amount effective to inhibitEhrlichia canisinfection. The inhibition may occur through any means such as e.g., the stimulation of the subject's humoral or cellular immune responses, or by other means such as inhibiting the normal function of the Fbp, or even competing with the antigen for interaction with some agent in the subject's body, for example.
In still yet another embodiment of the present invention, there is provided a method of targeting therapy to an individual, comprising the step of administering a compound to an individual, wherein the compound has a targeting moiety and a therapeutic moiety, wherein the targeting moiety is specific for Fbp.
In an embodiment of the present invention, there is an isolated DNA sequence encoding anEhrlichia canisFbp, wherein said protein is immunoreactive with anti-Ehrlichia canisserum, and wherein said 38-kilodalton Fbp has amino acid sequence of SEQ ID NO:2. In particular embodiments, the DNA comprises the sequence of SEQ ID NO:1. In specific embodiments, the protein comprises an N-terminal signal sequence, an iron-binding motif, or both. The iron binding motif of the protein comprises multiple amino acids suitable for iron co-ordination including two tyrosine residues, in particular aspects of the invention. In specific embodiments, the tyrosine residues in the iron binding motif are at positions 201 and 202 of the mature protein.
In another aspect of the invention, there is a vector comprising a DNA sequence of the present invention, such as, for example, one comprising SEQ ID NO:1. In particular aspects of the invention, the vector is an expression vector capable of expressing a peptide or polypeptide comprising SEQ ID NO:1 when said expression vector is introduced into a cell. In other aspects of the invention, there is a host cell comprising a vector of the present invention, such as one comprising SEQ ID NO:1, for example.
In particular embodiments, there is a recombinant protein having the amino acid sequence of SEQ ID NO:2. In specific aspects of the invention, the amino acid sequence is encoded by a nucleic acid segment comprising sequence of SEQ ID NO:1. The recombinant protein of the invention may be comprised, such as formulated, in a pharmaceutically acceptable carrier, in some embodiments. Further embodiments include an antibody immunoreactive with a recombinant protein of the invention.
In another embodiment of the invention, there is a method of producing the recombinant protein of the invention, comprising the steps of obtaining a vector that comprises an expression construct comprising sequence encoding the amino acid sequence of SEQ ID NO:2 operatively linked to a promoter; transfecting said vector into a cell; and culturing the cell under conditions effective for expression of the sequence encoding the amino acid sequence of SEQ ID NO:2.
In an additional embodiment of the invention, there is a method of inhibitingEhrlichia canisinfection in an individual comprising the steps of identifying a subject prior to exposure or suspected of being exposed to or infected withEhrlichia canis; and administering a composition comprising a 38-kDaEhrlichia canisFbp in an amount effective to inhibitEhrlichia canisinfection. In particular aspects of the invention, the Fbp is a recombinant protein comprising an amino acid sequence of SEQ ID NO:2, for example. The recombinant protein is encoded by a gene comprising of sequence of SEQ ID NO:1, in particular aspects of the invention. The composition comprising a 38-kDa antigen may be dispersed in a pharmaceutically acceptable carrier, for example.
In an additional embodiment of the present invention, there is a method of targeted therapy to an individual, comprising the step of administering a composition to an individual, wherein the composition has a therapeutic moiety and a targeting moiety specific for 38-kDaEhrlichia canisFbp protein. In specific embodiments, the targeting moiety is selected from the group consisting of an antibody specific for 38-kDaEhrlichia canisFbp and a ligand or ligand binding domain that binds 38-kDaEhrlichia canisFbp. In additional specific embodiments, the therapeutic moiety is selected from the group consisting of a radioisotope, a toxin, a chemotherapeutic agent, an immune stimulant and a cytotoxic agent.
Other and further aspects, features, and advantages of the present invention will be apparent from the following description of the presently preferred embodiments of the invention given for the purpose of disclosure.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
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SUMMARY: FIELD OF THE INVENTION
The present invention relates generally to the fields of cellular biology, molecular biology, pathology, clinical microbiology, and medicine. Specifically, the present invention concerns the molecular biology ofEhrlichia, includingEhrlichia canis. More specifically, the present invention relates to molecular cloning and characterization of a 38-kDa immunoreactive ferric binding protein (Fbp) polynucleotide and the encoded product fromEhrlichia canis, as well as uses thereof.
BACKGROUND OF THE INVENTION
Ehrlichiaspp. are obligately intracellular gram-negative bacteria that reside in endosomes within hematopoietic cells and infect various hosts including humans, domestic and wild canidae, deer, horses, sheep, cattle, and wild rodents. Each member of the family Anaplasmataceae has its own particular primary target cell tropism. Most species ofEhrlichiaare either monocytotropic (e.g.E. canis, E. chaffeensis, andE. muris) or granulocytotropic (e.g.Anaplasma phagocytophilum, andE. ewingii) with the exceptions ofEhrlichia ruminantium, which grows in the endothelial cells of the host,Anaplasma marginale, a red blood cell parasite, andAnaplasma platys, a platelet parasite.
AlthoughEhrlichiaewere described in the early part of the 20thcentury, they received very little attention because they were considered pathogens of only veterinary importance in the United States until the recent two decades. The renewed interest inEhrlichiais due to the emergence of ehrlichioses affecting humans. Since 1987, three emerging human ehrlichial pathogens (E. chaffeensis, E. ewingii, andA. phagocytophilum) have been discovered in the United States.
Ehrlichia canis, the prototype species of the genus, is the etiologic agent of canine monocytotropic ehrlichiosis (CME). CME, also known as canine tropical pancytopenia, is a worldwide disease transmitted by the brown dog tick,Rhipicephalus sanguineus. The progression of canine ehrlichiosis occurs in three phases: acute, sub-clinical and chronic. The acute phase is characterized by fever, anorexia, depression, lymphadenopathy and mild thrombocytopenia. Dogs typically recover from the acute phase, but become persistently infected carriers of the organism without clinical signs of disease for months or even years. A chronic phase develops in some cases that is characterized by thrombocytopenia, hyperglobulinemia, anorexia, emaciation, and hemorrhage, particularly epistaxis, followed by death. Each year it costs millions of dollars worldwide for treating companion and working dogs infected withE. canis. Ehrlichia caniswas isolated from a human recently, and thus may be an emerging public health threat.
One aspect ofE. canisbiology concerns the need for iron, which is a necessity for survival of nearly all prokaryotes and eukaryotes. For the obligate intracellular bacteriumEhrlichia chaffeensis, the importance of iron for intracellular survival has been demonstrated by inhibition ofEhrlichiaproliferation in the presence of the intracytoplasmic iron chelator deferoxamine (Barnewall et al., 1997). Early endosomes containing the bacteria (morulae) upregulate and accumulate the mammalian transferrin receptor (Barnewall et al., 1997), suggesting that the organism has developed specific strategies for iron acquisition. The cytoplasmic vacuole where theEhrlichiaresides is acidic, which may promote the release of free iron into the compartment (Barnewall et al., 1997). AnE. chaffeensisprotein with homology to known ferric binding proteins has been previously reported (Yu et al., 1999), but the mechanisms of iron acquisition byEhrlichiaspp. are unknown and functional demonstration of iron binding properties ofEhrlichiaFbps has not been experimentally demonstrated. Furthermore, theE. chaffeensisFbp polypeptide is not immunoreactive.
Iron is involved in many key metabolic functions of the cell, but insoluble Fe(OH)3(rust) forms at a physiological pH and thus must be stored and transferred via iron binding proteins (Andrews et al., 2003; Mietzner et al., 1998). In eukaryotic systems, extracellular iron-binding proteins include transferrin and lactoferrin, while ferritin binds and sequesters intracellular iron. Protein-bound iron also inhibits the interaction of Fe(II) with O2, preventing the formation of free radicals that are damaging to cells (Andrews et al., 2003; Mietzner et al., 1998). The availability of iron has been demonstrated to increase the virulence of many diverse pathogenic bacteria (Raymond et al., 2003). Limiting the availability of free iron is a mechanism to naturally suppress growth of bacteria. However, under the selective pressure of the limited iron available in the host, pathogenic bacteria have evolved specific iron acquisition mechanisms including iron binding molecules and proteins.
Bacteria commonly utilize siderophores as means of iron mobilization. These molecules are nonproteinaceous iron chelators that are expressed, secreted, and bound by surface receptors that enable the transport of free iron from the environment (Andrews et al., 2003; Mietzner et al., 1998). Another means of iron uptake involves iron acquisition from the host iron binding proteins transferrin and lactoferrin (Andrews et al., 2003; Mietzner et al., 1998). This mechanism, used by many gram-negative pathogens involves a conserved system by which iron is competed away from transferrin or lactoferrin at the outer membrane of the bacterium and the iron is shuttled across the membrane and into the periplasm (Andrews et al., 2003). Mobilization of iron into the cytoplasm involves three proteins that belong to the ATP-binding cassette (ABC) transporter family, the ferric binding protein (Fbp), a cytoplasmic permease, and an ATP-binding protein (Adhikari et al., 1996; Adhikari et al., 1995; Andrews et al., 2003; Clarke et al., 2001; Mietzner et al., 1998), all encoded by an operon system that is shared among many diverse bacterial species includingNeisseria gonorrhoeae, Haemophilus influenzae, Mannheimia(Pasteurella)haemolytica, Serratia marcescens, Salmonella typhimurium, andYersinia pestis(Adhikari et al., 1996; Adhikari et al., 1995 Angerer et al., 1990; Bearden and Perry, 1999; Bearden et al., 1998; Janakiraman and Slauch, 2000; Kirby et al., 1998). The operon system ofNeisseria gonorrhoeaehas been demonstrated to be under the control of the iron regulatory element Fur (ferric uptake regulator)(Desai et al., 1996).
Identifying the genetic and antigenic compositions ofE. canisis essential for studying the pathogenesis of canine ehrlichiosis and developing an effective vaccine. Although Yu et al. (1999) describe anE. chaffeensis37-kDa protein that is homologous to the iron (III)-binding periplasmic protein precursor of gram-negative bacteria, the prior art is deficient in the cloning and characterization of immunoreactive gene ofEhrlichia canis. The present invention fulfills this long-standing need and desire in the art by cloning an immunoreactive Fbp ofEhrlichia canis.
BRIEF SUMMARY OF THE INVENTION
The present invention describes the molecular cloning, sequencing, expression, and characterization of a 38-kDa immunoreactive ferric binding protein gene ofEhrlichia canis.
In particular, the present invention represents the first functional characterization of a ferric binding protein (Fbp) ortholog in any obligate intracellular bacteria. The present inventors have identified an immunoreactive 38-kDa Fbp fromEhrlichia canisthat shares homology with a known family of periplasmic Fbps involved in iron acquisition in extracellular bacterium. Structural modeling of theE. canisFbp identified an iron-binding motif conserved among the Fbp family, and the present inventors demonstrated the ability ofE. canisFbp to bind free iron.E. canisFbp was observed primarily in the cytoplasm of bacteria with reticulate morphology, while surface and extracellular distribution on morula fibers and the membrane of morulae was observed on the dense-coredEhrlichialform. Notably,E. canisfbp was not organized with other prototypical iron acquisition genes in an operon system.
The exemplaryE. canisFbp protein sequence provided herein had homology (˜25-60%) with a known family of ferric binding proteins (Fbp), indicating that it plays a role in iron acquisition known to be essential forEhrlichiasurvival, in specific embodiments of the invention. The predicted three-dimensional structure ofE. canisFbp demonstrated conservation of Fbp structural motifs. In the presence of iron, the recombinant Fbp exhibited visible absorbance spectrum compared to the unbound form, indicative of iron binding.
The gene encoding the orthologous Fbp fromE. chaffeensis, the closely related causative agent of human disease, exhibits 87% homology to the Fbp protein ofE. canis. A recombinantE. canisFbp fusion protein reacted with antibodies in sera from dogs with canine ehrlichiosis, and antisera produced against recombinantE. canisFbp recognized a native protein of similar molecular mass (38-kDa) fromE. caniswhole cell lysates. In particular embodiments of the invention, these studies demonstrate that Fbp is a highly conserved iron binding protein that is important for its survival and also is a viable target for vaccine use.
In one embodiment of the present invention, there is DNA sequence encoding a 38-kDa immunoreactive Fbp ofEhrlichia canis. In particular embodiments, the protein has an amino acid sequence of SEQ ID NO:2 and the gene has a nucleic acid sequence of SEQ ID NO:1. In specific embodiments of the invention, theE. canisFbp polypeptide comprises one or more of the following characteristics: 1) it is immunoreactive; 2) it binds iron, such as Fe(III), although in alternative embodiments it binds Fe(II) instead or in addition to; 3) it comprises an N-terminal sequence, which may be referred to as a signal sequence, and which may be cleaved after post-translational modification resulting in the production of a mature protein (predicted to be about 35.8-kDa); 4) it comprises a tyrosine at positions 201, 202, or both; 5) it comprises a lysine at position 14; 5) it comprises a tyrosine at 145 and/or an arginine at positions 13, 105, and 139; 6) it may be cytoplasmically localized and/or localized on the surface and extracellular morula fibers; and 7) it comprises two domains each comprised of a central β-sheet surrounded by multiple α-helices, which are thereby connected with a hinge of antiparallel β-strands. In specific embodiments, the polypeptide is isolated and/or purified.
In specific embodiments of the present invention, there is the polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide. As used herein, the term “relatedE. canisFbp polypeptide” refers to a polypeptide having similar sequence with SEQ ID NO:2, such as described below, and the related polypeptide is not necessarily naturally present inE. canisbut may be derived from SEQ ID NO:2 and/or may be generated synthetically. In specific embodiments, mutations to SEQ ID NO:2, either by mutating an amino acid or by mutating a polynucleotide that encodes SEQ ID NO:2, are encompassed in the invention. Such mutations may be produced either chemically or by site-directed mutagenesis, for example. In specific embodiments, the relatedE. canisFbp polypeptide comprises one or more of the same characteristics as native SEQ ID NO:2, including immunoreactivity and iron-binding capability, for example.
TheE. canisFbp of the present invention may comprise sequence identity with the polypeptide of SEQ ID NO:2. For example, a polypeptide of the invention may be about 70% identical to SEQ ID NO:2, about 75% identical to SEQ ID NO:2, about 80% identical to SEQ ID NO:2, about 85% identical to SEQ ID NO:2, about 90% identical to SEQ ID NO:2, about 95% identical to SEQ ID NO:2, about 97% identical to SEQ ID NO:2, about 99% identical to SEQ ID NO:2, and so forth. In other embodiments, an Fbp polypeptide of the invention comprises at least about 325 contiguous amino acids from SEQ ID NO:2, at least about 300 contiguous amino acids from SEQ ID NO:2, at least about 250 contiguous amino acids from SEQ ID NO:2, at least about 200 contiguous amino acids from SEQ ID NO:2, at least about 150 contiguous amino acids from SEQ ID NO:2, at least about 125 contiguous amino acids from SEQ ID NO:2, at least about 100 contiguous amino acids from SEQ ID NO:2, at least about 75 contiguous amino acids from SEQ ID NO:2, at least about 50 contiguous amino acids from SEQ ID NO:2, or at least about 25 contiguous amino acids from SEQ ID NO:2, for example.
Polynucleotides that encode SEQ ID NO:2, such as the exemplary SEQ ID NO:1 polynucleotide, or that encode related proteins as discussed above, are embodiments of the invention and may comprise one or more of the following characteristics: 1) it comprises an iron-regulatory element, such as the exemplary ferric uptake regulator (Fur)-binding site; an exemplaryE. coliFur recognition consensus, for example, comprises ATA/TAT; 2) it encodes a polypeptide comprising one or more of theE. canisFbp polypeptide characteristics described herein; and 3) it is not comprised on an operon.
In particular embodiments of the invention, there is a polynucleotide that comprises sequence identity with SEQ ID NO:1. For example, a polynucleotide of the invention may be about 70% identical to SEQ ID NO:1, about 75% identical to SEQ ID NO:1, about 80% identical to SEQ ID NO:1, about 85% identical to SEQ ID NO:1, about 90% identical to SEQ ID NO:1, about 95% identical to SEQ ID NO:1, and so forth. In other embodiments, an Fbp polynucleotide of the invention comprises at least about 1000 contiguous nucleotides from SEQ ID NO:1, at least about 750 contiguous nucleotides from SEQ ID NO:1, at least about 500 contiguous nucleotides from SEQ ID NO:1, at least about 300 contiguous nucleotides from SEQ ID NO:1, at least about 250 contiguous nucleotides from SEQ ID NO:1, at least about 200 contiguous nucleotides from SEQ ID NO:1, at least about 150 contiguous nucleotides from SEQ ID NO:1, at least about 100 contiguous nucleotides from SEQ ID NO:1, at least about 75 contiguous nucleotides from SEQ ID NO:1, at least about 50 contiguous nucleotides from SEQ ID NO:1, at least about 25 contiguous nucleotides from SEQ ID NO:1, or at least about 12 contiguous nucleotides from SEQ ID NO:1.
In specific aspects of the invention, there is an isolated polynucleotide that specifically hybridizes under highly stringent conditions to the complement of the sequence set forth in SEQ ID NO:1.
In another embodiment of the present invention, there is provided an expression vector comprising a polynucleotide of the invention encoding a 38-kDa immunoreactive Fbp ofE. canis, and the vector is capable of expressing the polynucleotide, such as when the vector is introduced into a cell. The cell into which the vector is introduced may be a prokaryotic cell or it may be a eukaryotic cell, and any elements comprised on the vector, such as regulatory elements, are capable of expressing the Fbp polynucleotide therein. Exemplary regulatory elements include iron-binding elements, promoters, enhancers, origin of replication, and so forth, for example.
In still another embodiment of the present invention, there is provided a recombinant protein comprising an amino acid sequence of SEQ ID NO:2. In specific embodiments, the amino acid sequence is encoded by a nucleic acid sequence of SEQ ID NO:1. The recombinant protein may be useful as an antigen. In specific embodiments, the polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide is employed as an immunogen, and in specific embodiments it induces an immune response in an individual to which the polypeptide is delivered. In specific embodiments, the polypeptide induces an immune response such that it provides immunity to subsequent challenge, such as fromE. canisinfection.
Immunogenic compositions of the present invention may comprise an immunoreactive polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide; it may comprise antibodies to a polypeptide of SEQ ID NO:2 or a relatedE. canisFbp polypeptide; or it may comprise both. The present invention provides a considerable advantage forE. canisprotection overE. chaffeensisprotection, wherein the orthologous Fbp polypeptide ofE. chaffeensisis not immunoreactive and it has not been demonstrated to bind iron. Thus, in specific embodiments of the invention, there is a vaccine comprising SEQ ID NO:2 or a relatedE. canisFbp polypeptide. In particular aspects of the invention, the vaccine is a subunit vaccine and does not comprise theE. canisorganism as a whole.
In particular aspects of the invention, theE. canisFbp polypeptide of the invention is immunoreactive. That is, in specific embodiments the polypeptide binds to, which may be referred to as reacts with, an antibody, such as the antibodies in the serum of an individual, for example. One of skill in the art recognizes that there are multiple ways to demonstrate immunoreactivity, such as, for example, by providing a recombinant protein suspected of being immunoreactive, introducing the protein into an animal, such as a rabbit or dog, collecting the antiserum, and then determining if antibodies in the antisera recognize the recombinant protein, such as on a western blot. In another exemplary embodiment, serum from anE. canis-infected animal, such as a dog, is probed to a blot comprising a protein suspected of being immunoreactive to determine if there is binding therebetween. Detection of binding indicates that the protein suspected of being immunoreactive is in fact immunoreactive. Lymphoproliferative responses to an antigen may be employed. Immunoreactivity assays may employ ELISA or cytometric beads, for example.
In particular embodiments, immunogenic compositions of the present invention comprise the native conformation of the polypeptide, as opposed to a denatured form, thereby preserving a conformation which comprises an epitope. In particular embodiments, the conformational epitope is an epitope that comprises a particular three-dimensional structure on the outside of the protein, for example part or all of an alpha helix, a beta sheet, a beta strand, a hinge region, two or more antiparallel beta strands, part or all of an iron-binding domain, or a combination thereof. In specific embodiments, a conformational epitope comprises tyrosine 201, tyrosine 202, tyrosine 145, arginine 13, arginine 105, arginine 139, or a combination thereof. A skilled artisan recognizes that there is software available to determine which residues of a folded polypeptide are located on the outside.
In a preferred embodiment of the present invention, there is provided a method of producing the polypeptide, comprising the steps of obtaining a vector that comprises an expression construct comprising a sequence encoding the amino acid sequence of SEQ ID NO:2 or a related polypeptide operatively linked to a promoter; transfecting the vector into a cell; and culturing the cell under suitable conditions effective for expression of the polypeptide. The polypeptide may be further defined as recombinant.
The invention may also be described in certain embodiments as a method of inhibitingEhrlichia canisinfection in a subject comprising the steps of: identifying a subject prior to exposure or suspected of being exposed. to or suspected of being infected withEhrlichia canis; and administering a composition comprising a Fbp ofEhrlichia canisin an amount effective to inhibitEhrlichia canisinfection. The inhibition may occur through any means such as e.g., the stimulation of the subject's humoral or cellular immune responses, or by other means such as inhibiting the normal function of the Fbp, or even competing with the antigen for interaction with some agent in the subject's body, for example.
In still yet another embodiment of the present invention, there is provided a method of targeting therapy to an individual, comprising the step of administering a compound to an individual, wherein the compound has a targeting moiety and a therapeutic moiety, wherein the targeting moiety is specific for Fbp.
In an embodiment of the present invention, there is an isolated DNA sequence encoding anEhrlichia canisFbp, wherein said protein is immunoreactive with anti-Ehrlichia canisserum, and wherein said 38-kilodalton Fbp has amino acid sequence of SEQ ID NO:2. In particular embodiments, the DNA comprises the sequence of SEQ ID NO:1. In specific embodiments, the protein comprises an N-terminal signal sequence, an iron-binding motif, or both. The iron binding motif of the protein comprises multiple amino acids suitable for iron co-ordination including two tyrosine residues, in particular aspects of the invention. In specific embodiments, the tyrosine residues in the iron binding motif are at positions 201 and 202 of the mature protein.
In another aspect of the invention, there is a vector comprising a DNA sequence of the present invention, such as, for example, one comprising SEQ ID NO:1. In particular aspects of the invention, the vector is an expression vector capable of expressing a peptide or polypeptide comprising SEQ ID NO:1 when said expression vector is introduced into a cell. In other aspects of the invention, there is a host cell comprising a vector of the present invention, such as one comprising SEQ ID NO:1, for example.
In particular embodiments, there is a recombinant protein having the amino acid sequence of SEQ ID NO:2. In specific aspects of the invention, the amino acid sequence is encoded by a nucleic acid segment comprising sequence of SEQ ID NO:1. The recombinant protein of the invention may be comprised, such as formulated, in a pharmaceutically acceptable carrier, in some embodiments. Further embodiments include an antibody immunoreactive with a recombinant protein of the invention.
In another embodiment of the invention, there is a method of producing the recombinant protein of the invention, comprising the steps of obtaining a vector that comprises an expression construct comprising sequence encoding the amino acid sequence of SEQ ID NO:2 operatively linked to a promoter; transfecting said vector into a cell; and culturing the cell under conditions effective for expression of the sequence encoding the amino acid sequence of SEQ ID NO:2.
In an additional embodiment of the invention, there is a method of inhibitingEhrlichia canisinfection in an individual comprising the steps of identifying a subject prior to exposure or suspected of being exposed to or infected withEhrlichia canis; and administering a composition comprising a 38-kDaEhrlichia canisFbp in an amount effective to inhibitEhrlichia canisinfection. In particular aspects of the invention, the Fbp is a recombinant protein comprising an amino acid sequence of SEQ ID NO:2, for example. The recombinant protein is encoded by a gene comprising of sequence of SEQ ID NO:1, in particular aspects of the invention. The composition comprising a 38-kDa antigen may be dispersed in a pharmaceutically acceptable carrier, for example.
In an additional embodiment of the present invention, there is a method of targeted therapy to an individual, comprising the step of administering a composition to an individual, wherein the composition has a therapeutic moiety and a targeting moiety specific for 38-kDaEhrlichia canisFbp protein. In specific embodiments, the targeting moiety is selected from the group consisting of an antibody specific for 38-kDaEhrlichia canisFbp and a ligand or ligand binding domain that binds 38-kDaEhrlichia canisFbp. In additional specific embodiments, the therapeutic moiety is selected from the group consisting of a radioisotope, a toxin, a chemotherapeutic agent, an immune stimulant and a cytotoxic agent.
Other and further aspects, features, and advantages of the present invention will be apparent from the following description of the presently preferred embodiments of the invention given for the purpose of disclosure.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
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7808597 | CROSS-REFERENCE TO RELATED APPLICATION
This application is the U.S. national stage application of International Patent Application No. PCT/KR2007/000888, filed Feb. 21, 2007, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
Embodiments relate to a display module.
BACKGROUND ART
A flat panel display (FPD) module is used in mobile devices as well as large-sized display devices.
The FPD module includes a panel displaying images, a printed circuit board (PCB) driving the panel, and a flexible printed circuit board (FPCB) electrically connecting the panel to the PCB.
Various flat display devices are used as the panel. Especially, liquid crystal panels are used in small-sized mobile devices.
Meanwhile, the PCB may be in a different plane from that of the panel. For example, the PCB may be located behind the panel. Flexible member such as the FPCB is appropriate for connecting the panel to the PCB.
The FPCB has a restoring force since the FPCB is flexible. When the FPCB is folded, it tends to be unfolded by the restoring force.
Therefore, when the PCB is located behind the panel, the gap between the panel and the PCB is generated by the restoring force of the FPCB.
DISCLOSURE OF INVENTION
Technical Problem
Embodiments of the present invention provide a display module prevent a panel from coming off a PCB when the panel is electrically connected to the PCB using a FPCB.
Technical Solution
An embodiment of the present invention provides a display module comprising a panel displaying images, a printed circuit board (PCB) supplying driving signals to the panel, a flexible printed circuit board (FPCB) electrically connecting the PCB to the panel, and a support member formed on the FPCB.
An embodiment of the present invention provides a display module comprising a panel displaying images, a printed circuit board (PCB) supplying driving signals to the panel, and a flexible printed circuit board (FPCB) electrically connecting the PCB to the panel, wherein the FPCB includes a base layer, a first copper foil pattern and a first cover layer formed on a first surface of the base layer, and a second copper foil pattern and a second cover layer formed on a second surface of the base layer, and the first cover layer formed on an outer surface of the folded FPCB is partially removed.
An embodiment of the present invention provides a device comprising a first electric device, a printed circuit board (PCB) supplying driving signals to the first electric device, a flexible printed circuit board (FPCB) electrically connecting the PCB to the first electric device, and a support member formed on the FPCB.
Advantageous Effects
Embodiments prevent a panel from coming off a PCB caused by a FPCB.
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SUMMARY: CROSS-REFERENCE TO RELATED APPLICATION
This application is the U.S. national stage application of International Patent Application No. PCT/KR2007/000888, filed Feb. 21, 2007, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
Embodiments relate to a display module.
BACKGROUND ART
A flat panel display (FPD) module is used in mobile devices as well as large-sized display devices.
The FPD module includes a panel displaying images, a printed circuit board (PCB) driving the panel, and a flexible printed circuit board (FPCB) electrically connecting the panel to the PCB.
Various flat display devices are used as the panel. Especially, liquid crystal panels are used in small-sized mobile devices.
Meanwhile, the PCB may be in a different plane from that of the panel. For example, the PCB may be located behind the panel. Flexible member such as the FPCB is appropriate for connecting the panel to the PCB.
The FPCB has a restoring force since the FPCB is flexible. When the FPCB is folded, it tends to be unfolded by the restoring force.
Therefore, when the PCB is located behind the panel, the gap between the panel and the PCB is generated by the restoring force of the FPCB.
DISCLOSURE OF INVENTION
Technical Problem
Embodiments of the present invention provide a display module prevent a panel from coming off a PCB when the panel is electrically connected to the PCB using a FPCB.
Technical Solution
An embodiment of the present invention provides a display module comprising a panel displaying images, a printed circuit board (PCB) supplying driving signals to the panel, a flexible printed circuit board (FPCB) electrically connecting the PCB to the panel, and a support member formed on the FPCB.
An embodiment of the present invention provides a display module comprising a panel displaying images, a printed circuit board (PCB) supplying driving signals to the panel, and a flexible printed circuit board (FPCB) electrically connecting the PCB to the panel, wherein the FPCB includes a base layer, a first copper foil pattern and a first cover layer formed on a first surface of the base layer, and a second copper foil pattern and a second cover layer formed on a second surface of the base layer, and the first cover layer formed on an outer surface of the folded FPCB is partially removed.
An embodiment of the present invention provides a device comprising a first electric device, a printed circuit board (PCB) supplying driving signals to the first electric device, a flexible printed circuit board (FPCB) electrically connecting the PCB to the first electric device, and a support member formed on the FPCB.
Advantageous Effects
Embodiments prevent a panel from coming off a PCB caused by a FPCB.
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7704442 | TECHNICAL FIELD
The present invention relates to a process for producing a honeycomb structure. More particularly, the present invention relates to a process for producing a honeycomb structure of high porosity which is useful as a filter for exhaust gas, particularly a diesel particulate filter (DPF) for trapping the particulate matter, etc., present in the exhaust gas of diesel engine.
A requirement for removal of particulate matter and harmful substances present in the exhaust gases of internal combustion engine, boiler, etc., is growing in view of their influence on environment. The regulation with respect to, in particular, the removal of the particulate matter (hereinafter may be referred to as “PM”) discharged from diesel engine is being intensified worldwide; and it is drawing attention to use, as a filter for removing the PM (a diesel particulate filter, this may hereinafter be referred to as “DPF”), a filter made of a honeycomb structure (a honeycomb filter), and various systems have been proposed.
The DPF ordinarily has a structure in which a plurality of cells functioning as fluid passages are separated and formed by porous partition walls and the cells are plugged alternately so that each porous partition wall forming the cells may function as a filter.
As the material for DPF, there is preferably used cordierite which is small in thermal expansion coefficient and high in thermal shock resistance.
Such a cordierite-based honeycomb structure is produced, for example, by mixing and kneading a cordierite-forming raw material, water, a binder, a pore former, etc., to prepare clay, and subjecting the clay to extrusion forming into a honeycomb shape (see, for example, Patent Documents 1 and 2).
A honeycomb filter using such a honeycomb structure is required to have a high porosity in order to reduce pressure loss so that, when it has been fitted into the exhaust gas system of diesel engine or the like and used, a sufficient engine performance can be obtained. Hence, in producing the honeycomb structure, it is being conducted to increase the amount of pore former in clay to be formed in order to raise the porosity of honeycomb structure obtained. In addition, it is required to form pores in a small range at a high rate, that is, to sharpen the pore diameter distribution in order to increase trapping efficiency and inhibit pressure loss due to clogging in pores from increasing.
Patent Document 1: JP-A-2002-219319
Patent Document 2: JP-A-2002-301323
DISCLOSURE OF THE INVENTION
Meanwhile, in recent years, a rise in demand for DPF has necessitated the continuous production of honeycomb structure by use of a continuous forming machine or the like. However, such continuous production by a continuous forming machine brings about higher kneading of clay. This induces easy collapse of the pore former contained in the clay and makes difficult the production of a honeycomb structure of high porosity, or, in view of the collapse of the pore former, it is necessary to use a large amount of a pore former, which is relatively expensive, in the clay to be formed. These have been problems. In addition, due to variance in particle size distribution of the pore former and collapse generation upon production, it has been difficult to stably mass-produce a honeycomb structure having a sharp pore diameter distribution.
The present invention has been made in view of the above-mentioned problems of the prior art and aims at providing a process for producing a honeycomb structure having a high porosity and a sharp pore diameter distribution which is useful as a filter for exhaust gas, particularly a diesel particulate filter (DPF) for trapping the particulate matter, etc., present in the exhaust gas of diesel engine.
The present inventors made a keen study in order to achieve the above aim. As a result, it was found that a honeycomb structure having a high porosity and a sharp pore diameter distribution can be produced by using, as each of an alumina source, a silica source and a magnesia source (all of which constitute a cordierite-forming raw material used for preparation of clay to be formed into a honeycomb structure), a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 1 to 25 μm and, as the cordierite-forming raw material, a material having, in its volume particle size distribution of the whole cordierite-forming raw material, a ratio of 90 volume % particle size (Vall90) [μm] to 10 volume % particle size (Vall10) [μm] [a volume particle size distribution ratio (Vall90/Vall10)] of 10 or less and a difference (Vall90−Vall10) between 90 volume % particle size (Vall90) and 10 volume % particle size (Vall10) of 25 μm or less. The finding has led to the completion of the present invention.
That is, according to the present invention, the is provided a process for producing a honeycomb structure shown below.
[1] A method for producing a honeycomb structure produced via a step of forming clay obtained from a cordierite-forming raw material which contains an alumina source, a silica source, and a magnesia source into a honeycomb shape, wherein there is used, as each of the alumina source, the silica source, and the magnesia source, a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 1 to 25 μm, and there is used, as the cordierite-forming raw material, a material having, in its volume particle size distribution of the whole cordierite-forming raw material, a ratio of 90 volume % particle size (Vall90) [μm] to 10 volume % particle size (Vall10) [μm] [a volume particle size distribution ratio (Vall90/Vall))] of 10 or less and a difference (Vall90−Vall10) between 90 volume % particle size (Vall90) [μm] and 10 volume % particle size (Vall10) [μm] of 25 μm or less.
[2] A process for producing a honeycomb structure according to the above [1] wherein there is used, as each of the alumina source, the silica source and the magnesia source, a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 5 to 20 μm.
[3] A process for producing a honeycomb structure according to the above [2], wherein there is used, as each of the alumina source, the silica source and the magnesia source, a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 10 to 20 μm.
[4] A process for producing a honeycomb structure according to any of the above [1] to [3], wherein the clay is prepared using no pore former and formed to produce a honeycomb structure.
[5] A process for producing a honeycomb structure according to the above [4], which has a porosity of 40% or more.
According to the present invention there can be provided a process for producing a honeycomb structure having a high porosity and a sharp pore diameter distribution which is useful as a filter for exhaust gas, particularly a diesel particulate filter (DPF) for trapping the particulate, etc., present in the exhaust gas of diesel engine.
It is noteworthy that, in a process for producing a honeycomb structure of the present invention, as the clay used for forming of the honeycomb structure of the present invention, there is used a cordierite-forming raw material which has a controlled particle size distribution with each of the components constituting the cordierite-forming raw material having as well a controlled particle size distribution, whereby the closest packing of the cordierite-forming raw material can be avoided, and pores are formed in the honeycomb structure based on the packed condition of each component. As a result, a honeycomb structure of high porosity can be obtained, for example, even by using no pore former in the clay. In addition, since no pore former is used, sharpening of a pore diameter distribution of the honeycomb structure can be realized with maintaining high porosity.
| 1 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: TECHNICAL FIELD
The present invention relates to a process for producing a honeycomb structure. More particularly, the present invention relates to a process for producing a honeycomb structure of high porosity which is useful as a filter for exhaust gas, particularly a diesel particulate filter (DPF) for trapping the particulate matter, etc., present in the exhaust gas of diesel engine.
A requirement for removal of particulate matter and harmful substances present in the exhaust gases of internal combustion engine, boiler, etc., is growing in view of their influence on environment. The regulation with respect to, in particular, the removal of the particulate matter (hereinafter may be referred to as “PM”) discharged from diesel engine is being intensified worldwide; and it is drawing attention to use, as a filter for removing the PM (a diesel particulate filter, this may hereinafter be referred to as “DPF”), a filter made of a honeycomb structure (a honeycomb filter), and various systems have been proposed.
The DPF ordinarily has a structure in which a plurality of cells functioning as fluid passages are separated and formed by porous partition walls and the cells are plugged alternately so that each porous partition wall forming the cells may function as a filter.
As the material for DPF, there is preferably used cordierite which is small in thermal expansion coefficient and high in thermal shock resistance.
Such a cordierite-based honeycomb structure is produced, for example, by mixing and kneading a cordierite-forming raw material, water, a binder, a pore former, etc., to prepare clay, and subjecting the clay to extrusion forming into a honeycomb shape (see, for example, Patent Documents 1 and 2).
A honeycomb filter using such a honeycomb structure is required to have a high porosity in order to reduce pressure loss so that, when it has been fitted into the exhaust gas system of diesel engine or the like and used, a sufficient engine performance can be obtained. Hence, in producing the honeycomb structure, it is being conducted to increase the amount of pore former in clay to be formed in order to raise the porosity of honeycomb structure obtained. In addition, it is required to form pores in a small range at a high rate, that is, to sharpen the pore diameter distribution in order to increase trapping efficiency and inhibit pressure loss due to clogging in pores from increasing.
Patent Document 1: JP-A-2002-219319
Patent Document 2: JP-A-2002-301323
DISCLOSURE OF THE INVENTION
Meanwhile, in recent years, a rise in demand for DPF has necessitated the continuous production of honeycomb structure by use of a continuous forming machine or the like. However, such continuous production by a continuous forming machine brings about higher kneading of clay. This induces easy collapse of the pore former contained in the clay and makes difficult the production of a honeycomb structure of high porosity, or, in view of the collapse of the pore former, it is necessary to use a large amount of a pore former, which is relatively expensive, in the clay to be formed. These have been problems. In addition, due to variance in particle size distribution of the pore former and collapse generation upon production, it has been difficult to stably mass-produce a honeycomb structure having a sharp pore diameter distribution.
The present invention has been made in view of the above-mentioned problems of the prior art and aims at providing a process for producing a honeycomb structure having a high porosity and a sharp pore diameter distribution which is useful as a filter for exhaust gas, particularly a diesel particulate filter (DPF) for trapping the particulate matter, etc., present in the exhaust gas of diesel engine.
The present inventors made a keen study in order to achieve the above aim. As a result, it was found that a honeycomb structure having a high porosity and a sharp pore diameter distribution can be produced by using, as each of an alumina source, a silica source and a magnesia source (all of which constitute a cordierite-forming raw material used for preparation of clay to be formed into a honeycomb structure), a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 1 to 25 μm and, as the cordierite-forming raw material, a material having, in its volume particle size distribution of the whole cordierite-forming raw material, a ratio of 90 volume % particle size (Vall90) [μm] to 10 volume % particle size (Vall10) [μm] [a volume particle size distribution ratio (Vall90/Vall10)] of 10 or less and a difference (Vall90−Vall10) between 90 volume % particle size (Vall90) and 10 volume % particle size (Vall10) of 25 μm or less. The finding has led to the completion of the present invention.
That is, according to the present invention, the is provided a process for producing a honeycomb structure shown below.
[1] A method for producing a honeycomb structure produced via a step of forming clay obtained from a cordierite-forming raw material which contains an alumina source, a silica source, and a magnesia source into a honeycomb shape, wherein there is used, as each of the alumina source, the silica source, and the magnesia source, a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 1 to 25 μm, and there is used, as the cordierite-forming raw material, a material having, in its volume particle size distribution of the whole cordierite-forming raw material, a ratio of 90 volume % particle size (Vall90) [μm] to 10 volume % particle size (Vall10) [μm] [a volume particle size distribution ratio (Vall90/Vall))] of 10 or less and a difference (Vall90−Vall10) between 90 volume % particle size (Vall90) [μm] and 10 volume % particle size (Vall10) [μm] of 25 μm or less.
[2] A process for producing a honeycomb structure according to the above [1] wherein there is used, as each of the alumina source, the silica source and the magnesia source, a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 5 to 20 μm.
[3] A process for producing a honeycomb structure according to the above [2], wherein there is used, as each of the alumina source, the silica source and the magnesia source, a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 10 to 20 μm.
[4] A process for producing a honeycomb structure according to any of the above [1] to [3], wherein the clay is prepared using no pore former and formed to produce a honeycomb structure.
[5] A process for producing a honeycomb structure according to the above [4], which has a porosity of 40% or more.
According to the present invention there can be provided a process for producing a honeycomb structure having a high porosity and a sharp pore diameter distribution which is useful as a filter for exhaust gas, particularly a diesel particulate filter (DPF) for trapping the particulate, etc., present in the exhaust gas of diesel engine.
It is noteworthy that, in a process for producing a honeycomb structure of the present invention, as the clay used for forming of the honeycomb structure of the present invention, there is used a cordierite-forming raw material which has a controlled particle size distribution with each of the components constituting the cordierite-forming raw material having as well a controlled particle size distribution, whereby the closest packing of the cordierite-forming raw material can be avoided, and pores are formed in the honeycomb structure based on the packed condition of each component. As a result, a honeycomb structure of high porosity can be obtained, for example, even by using no pore former in the clay. In addition, since no pore former is used, sharpening of a pore diameter distribution of the honeycomb structure can be realized with maintaining high porosity.
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7769205 | FIELD OF THE INVENTION
The present invention relates to stereo vision, particularly to a method and an apparatus for stereo and radiometric calibration, a three dimensional stereo technique and depth map calibration process to obtain accurate dense depth maps without previous knowledge of surface reflectance.
BACKGROUND
Stereo vision consists of three-dimensional data recovery of an object viewed from two or more view-points. Some fields of application for stereo vision are industrial, such as quality control of production lines, where concepts of inspection and sampling to remove defective products are required. Medicine is another important field where highly accurate models are required by specialists. Obtaining dense and accurate three-dimensional models is computationally expensive and can cause a bottleneck on production lines.
Stereo vision generally involves several stages. First, a calibration process is necessary. This process comprises both stereo and radiometric aspects. After that, a correspondence analysis is applied to the stereo images and finally the three dimensional model is obtained.
The calibration process generally consists of stereo and radiometric stages. The stereo calibration stage is solved by the geometric calibration of each camera independently and then a geometric transformation is applied to find out the geometry of the stereo setting. This geometric calibration leads to knowledge of rotation and position of the camera (commonly called the extrinsic camera parameters) and its internal characteristics (intrinsic camera parameters) such as focal length, position of the principal point, difference in scale of the image axes and so on.
There are many calibration methods that have been described for use with commercially available cameras. One such example is described in TSAI, R. Y., “An efficient and accurate camera calibration technique for 3D machine vision,” Proceedings IEEE Conference on Computer Vision and Pattern Recognition (CVPR), Miami Beach, Fla., 1986, pp. 364-374, and also in LENZ, R. K. and TSAI, R. Y., “Techniques for calibration of the scale factor and image center for high accuracy 3-D machine vision metrology,” IEEE Transactions on Pattern Analysis and Machine Intelligence, 10(5):713-720, September 1988, both of which are incorporated herein by reference.
In the articles cited above, Tsai and Lenz proposed a practical solution for off-the-shelf camera calibration. This solution estimates the relative rotation and translation by introducing a radial alignment constraint. Using these estimated values, the camera parameters can be derived by optimization. Although Tsai's model is widely used in computer vision, it produces the poorest result among other models widely used.
Another popular method is known as “Direct Linear Transformation” (DLT), and is described in ABDEL-AZIZ, Y. I. and KARARA, H. M., “Direct linear transformation into object space coordinates in close-range photogrametry,” Proceedings Symposium Close-Range Photogrametry, pp. 1-18, University of Illinois, Urbana, 1971, incorporated herein by reference. A limitation of the DLT model is that it does not take care of lens distortion, which may severely affect the measurement accuracy.
Another classical calibration techniques is known as Haralick's standard solution, and is described in HARALICK, R. and SHAPIRO, L., Computer and Robot Vision, Volume II, Chapter 13, “Perspective Projective Geometry,” pp. 43-124, AddisonWesley, Reading, Mass., 1993 and in POELZLEITNER, W. and ULM, M., “Comparative study of camera calibration algorithms with application to spacecraft navigation, “Proceedings of SPIE, vol. 2350, Videometrics III, Sabry F. El-Hakim, Editor, October 1994, pp. 187-196, both of which are incorporated herein by reference.
Haralick's standard solution uses an iterative method to find three extrinsic camera parameters (three angles for the rotation between world and pinhole coordinate system) and seven intrinsic parameters (three camera distortion factors, image center as well as scale factors in both horizontal and vertical image coordinates). One problem with Haralick's standard solution is that the non-linear equations make it impossible to get a direct solution. Thus, partial differentiation of the non-linear equation is generally used and the high order non-linear terms are omitted before iteration can be performed. This means a good guess of initial parameters must be available and it cannot be guaranteed that the iteration will get a convergent result. A similar non-linear optimization method is described in BROWN, D. C., “Close-range camera calibration,” Photogrammetric Engineering, vol. 37, no. 8, pp. 855-866, 1971, incorporated herein by reference.
Many of the disadvantages of the methods discussed above are addressed with a new calibration approach derived from the Haralick model, known as the Gintic model, and is described in JIAN, X., MALCOLM, A., and ZHONGPING, F., Camera Calibration with Micron Level Accuracy, SIMTech Technical Report (AT/01/037/PS), Singapore, 2001, incorporated herein by reference. The Gintic model simplifies the Haralick model equations and guarantees that the optimal solution is always found, and this approach finds the camera parameters which best describe the camera behavior.
The second stage of calibration is radiometric calibration. This step is necessary to recover depth information from the objects in the scene considering an arbitrary or unknown surface reflectance. The calibration of light anisotropy and the relative orientation of the anisotropy with respect to the camera are fulfilled after the radiometric calibration. Radiometric calibration is required on the assumption that camera photo-response is not linear and spatially non uniform and the lights are not isotropic. The article JANKO, Z., DRBOHLAV, O., and SARA, R., “Radiometric calibration of a Helmholtz stereo rig,” Proceedings of the 2004 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 27 Jun.-2 Jul. 2004, vol. 1, pp. 166-171, incorporated herein by reference, illustrates that radiometric calibration improves accuracy on depth data recovery.
After radiometric and geometric calibration, the next step for three-dimensional stereo recovery is the correspondence analysis which is commonly classified as either active or passive, depending on the illumination control. Active approaches adopt light scene manipulation, for example photometric stereo illumination, while passive methods do not depend on the scene illumination. The surface reflectance distribution depends on the incident illumination over the scene objects and the material of the object. Therefore, active and passive approaches both require a previous consideration of surface reflectance, which is assumed, either implicitly or explicitly.
Passive stereo approaches assume implicitly the reflectance of surfaces. That is, they assume that the reflectance of the scene objects is the same regardless the acquisition view-point. On the other hand, active stereo approaches establish a known parametric reflectance form. That is, they calculate a reflectance function from different physical models, and later they include this function in the recovery constraint. Both considerations are not valid in the real world, since reflectance depends on different aspects, such as optical characteristics of surfaces, illumination incidence angle, optical view-points positions, etc.
Other three dimensional recovery techniques refer to systems in which the scene is illuminated by a known geometrical pattern of light. These are known as structured lighting systems, and they make use of the triangulation principle to compute depth. The main disadvantage of structured lighting methods is that they require several image acquisitions (in the order of 4 to 32) under different lighting conditions in order to obtain a dense depth map, so that, these recovery techniques are computationally expensive methods, and they are not presently practical for fast 3D acquisition applications like production lines inspection or object modeling
Recently a new stereo technique has been proposed in MAGDA, S., KRIEGMAN, D., ZICKLER, T., and BELHUMEUR, P., “Beyond Lambert: Reconstructing Surfaces with Arbitrary BRDFs,” Proceedings of the International Conference on Computer Vision (ICCV), 2001, pp. 391-399, and ZICKLER, T., BELHUMEUR, P., and KRIEGMAN, D., “Helmholtz Stereopsis: Exploiting Reciprocity for Surface Reconstruction,” Proceedings of the 7th European Conference on Computer Vision (ECCV), May 2002, vol. 3, pp. 869-884, both of which are incorporated herein by reference. This new approach is proposed to achieve the recovery of depth information of scene objects considering an arbitrary or unknown surface reflectance.
This recent stereo technique takes advantage of the reflectance symmetry of surfaces. Reflectance symmetry, or reciprocity, allows an arbitrary form of surface reflectance. Thus, under a controlled illumination environment, the restrictions caused by optical properties inherent to surface materials are eliminated, and depth recovery from any kind of surfaces can be obtained.
The stereo technique based on the reflectance reciprocity has other advantages, for example, since stereo images have reciprocal irradiance, the specularities appear fixed over the surface, which is an advantage over other stereo approaches, because it is possible to match corresponding specular regions. Moreover, half-occluded regions are corresponding. That is, a half-occluded region on the left stereo image appears shadowed on the right stereo image, and vice versa. This property may enhance the quality of depth reconstruction since it allows determining depth discontinuities. Furthermore, textureless and flat surfaces cannot be recovered using either active or passive conventional stereo techniques.
A simplification of the multi-ocular stereo case is presented in ZICKLER, T., HO, J., KRIEGMAN, D., PONCE, J., and BELHUMEUR, P., “Binocular Helmholtz Stereopsis,” Proceedings of the International Conference on Computer Vision (ICCV), 2003, pp. 1411-1417, incorporated herein by reference. This article proposes a method for how a dense depth map can be retrieved from a single pair of reciprocal stereo images, considering orthographic point's projection.
Unfortunately, this article does not illustrate how such a technique can be easily integrated with the calibration process. In particular, a mechanical calibration process is assumed in which the cameras are re-positioned and detailed measurements are made. The aforementioned article also does not illustrate the steps involved in the proposed approach. Furthermore, Zickler's approach establishes a stereo analysis considering an orthographic point projection. This kind of projection geometry can be achieved if the stereo setup is far away from the scene objects. Therefore, this restriction eliminates the possibility of a practical set up which can be used on industrial tasks where space is an important constraint.
Accordingly, there is a need for a method and apparatus for three-dimensional depth recovery utilizing the concept of reflectance reciprocity that does not have the limitations stated above. In particular, there is a need for a complete system, that is, a practical method and apparatus, which tackles all the stages of a highly accurate three-dimensional recovery process, from camera calibration to a final grid adjustment process, including some specific tasks related with the reciprocal reflectance property. Moreover, a complete system should fulfill the real-time requirements of applications such as industrial inspection.
BRIEF SUMMARY OF THE INVENTION
The invention provides a method and an apparatus for acquiring stereo images which fulfill the reciprocity reflectance property to recover depth information of an object placed into the field of view of a single or multi stereo cameras array. This particular property of surface reflectance allows three dimensional modeling of objects regardless their reflectance distribution, that is, the system can handle textureless and specular surfaces while conventional and photometric stereo techniques fail. In a preferred embodiment, the present invention utilizes an extended binocular approach which does not have any restriction related with the projection geometry or the camera setup configuration.
The system uses a stereo and radiometric calibration process prior to the capture of object images. The stereo calibration process requires two stereo pairs of a calibration pattern for modeling the intrinsic and extrinsic parameters of a single or multiple stereo camera arrays. The radiometric calibration needs a single stereo pair of reciprocal images of a white calibration pattern to apply an isotropic light distribution to the stereo images. Finally, a stereo rectification process is applied in order to fulfill the epipolar constraint and recover depth information of the object in the scene.
A dense three dimensional model is obtained, according to the invention, by stereo and radiometric calibration procedures. After this, a stereo rectification process is applied to fulfill the epipolar constraint. Then, an algorithm for three dimensional recovery is applied over complementary epipolar lines in order to obtain dense depth data from the object in the scene. Finally a depth map calibration process is applied for obtaining highly accurate 3D point cloud.
The system has a stereo head with an interior illumination control which includes a beam-splitter in order to align the optical axis with the beam of light. Alternatively, an exterior illumination distribution can be utilized, which consists of placing the light source near of the optical center. The apparatus is designed considering an acquisition process which allows the automatic commutation of the stereo light sources to fulfill the reciprocity property of the images.
The system is fully automatic, easy to use, has a simple setup and calibration process. The system is unique in that it requires only two object images for highly accurate three dimensional modeling of objects regardless their reflectance distribution. Therefore, it is potentially faster than other 3D scanners or 3D recovery systems, such that, the system may be used in a wide range of applications as metrology, quality control, medical, dynamic three dimensional modeling and so on.
The system of the present invention simplifies the light control to obtain stereo images with symmetrical intensity curves. Unlike others photometric stereo techniques, this approach obtains the depth measures of the object in the scene directly, avoiding the normal field integration which means an important reduction of the computational cost.
Additionally, an embodiment of the imaging apparatus allows a stereo camera configuration with a parallel and convergent optical axis. This option could also be applied to an extended multi-view camera system.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: FIELD OF THE INVENTION
The present invention relates to stereo vision, particularly to a method and an apparatus for stereo and radiometric calibration, a three dimensional stereo technique and depth map calibration process to obtain accurate dense depth maps without previous knowledge of surface reflectance.
BACKGROUND
Stereo vision consists of three-dimensional data recovery of an object viewed from two or more view-points. Some fields of application for stereo vision are industrial, such as quality control of production lines, where concepts of inspection and sampling to remove defective products are required. Medicine is another important field where highly accurate models are required by specialists. Obtaining dense and accurate three-dimensional models is computationally expensive and can cause a bottleneck on production lines.
Stereo vision generally involves several stages. First, a calibration process is necessary. This process comprises both stereo and radiometric aspects. After that, a correspondence analysis is applied to the stereo images and finally the three dimensional model is obtained.
The calibration process generally consists of stereo and radiometric stages. The stereo calibration stage is solved by the geometric calibration of each camera independently and then a geometric transformation is applied to find out the geometry of the stereo setting. This geometric calibration leads to knowledge of rotation and position of the camera (commonly called the extrinsic camera parameters) and its internal characteristics (intrinsic camera parameters) such as focal length, position of the principal point, difference in scale of the image axes and so on.
There are many calibration methods that have been described for use with commercially available cameras. One such example is described in TSAI, R. Y., “An efficient and accurate camera calibration technique for 3D machine vision,” Proceedings IEEE Conference on Computer Vision and Pattern Recognition (CVPR), Miami Beach, Fla., 1986, pp. 364-374, and also in LENZ, R. K. and TSAI, R. Y., “Techniques for calibration of the scale factor and image center for high accuracy 3-D machine vision metrology,” IEEE Transactions on Pattern Analysis and Machine Intelligence, 10(5):713-720, September 1988, both of which are incorporated herein by reference.
In the articles cited above, Tsai and Lenz proposed a practical solution for off-the-shelf camera calibration. This solution estimates the relative rotation and translation by introducing a radial alignment constraint. Using these estimated values, the camera parameters can be derived by optimization. Although Tsai's model is widely used in computer vision, it produces the poorest result among other models widely used.
Another popular method is known as “Direct Linear Transformation” (DLT), and is described in ABDEL-AZIZ, Y. I. and KARARA, H. M., “Direct linear transformation into object space coordinates in close-range photogrametry,” Proceedings Symposium Close-Range Photogrametry, pp. 1-18, University of Illinois, Urbana, 1971, incorporated herein by reference. A limitation of the DLT model is that it does not take care of lens distortion, which may severely affect the measurement accuracy.
Another classical calibration techniques is known as Haralick's standard solution, and is described in HARALICK, R. and SHAPIRO, L., Computer and Robot Vision, Volume II, Chapter 13, “Perspective Projective Geometry,” pp. 43-124, AddisonWesley, Reading, Mass., 1993 and in POELZLEITNER, W. and ULM, M., “Comparative study of camera calibration algorithms with application to spacecraft navigation, “Proceedings of SPIE, vol. 2350, Videometrics III, Sabry F. El-Hakim, Editor, October 1994, pp. 187-196, both of which are incorporated herein by reference.
Haralick's standard solution uses an iterative method to find three extrinsic camera parameters (three angles for the rotation between world and pinhole coordinate system) and seven intrinsic parameters (three camera distortion factors, image center as well as scale factors in both horizontal and vertical image coordinates). One problem with Haralick's standard solution is that the non-linear equations make it impossible to get a direct solution. Thus, partial differentiation of the non-linear equation is generally used and the high order non-linear terms are omitted before iteration can be performed. This means a good guess of initial parameters must be available and it cannot be guaranteed that the iteration will get a convergent result. A similar non-linear optimization method is described in BROWN, D. C., “Close-range camera calibration,” Photogrammetric Engineering, vol. 37, no. 8, pp. 855-866, 1971, incorporated herein by reference.
Many of the disadvantages of the methods discussed above are addressed with a new calibration approach derived from the Haralick model, known as the Gintic model, and is described in JIAN, X., MALCOLM, A., and ZHONGPING, F., Camera Calibration with Micron Level Accuracy, SIMTech Technical Report (AT/01/037/PS), Singapore, 2001, incorporated herein by reference. The Gintic model simplifies the Haralick model equations and guarantees that the optimal solution is always found, and this approach finds the camera parameters which best describe the camera behavior.
The second stage of calibration is radiometric calibration. This step is necessary to recover depth information from the objects in the scene considering an arbitrary or unknown surface reflectance. The calibration of light anisotropy and the relative orientation of the anisotropy with respect to the camera are fulfilled after the radiometric calibration. Radiometric calibration is required on the assumption that camera photo-response is not linear and spatially non uniform and the lights are not isotropic. The article JANKO, Z., DRBOHLAV, O., and SARA, R., “Radiometric calibration of a Helmholtz stereo rig,” Proceedings of the 2004 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 27 Jun.-2 Jul. 2004, vol. 1, pp. 166-171, incorporated herein by reference, illustrates that radiometric calibration improves accuracy on depth data recovery.
After radiometric and geometric calibration, the next step for three-dimensional stereo recovery is the correspondence analysis which is commonly classified as either active or passive, depending on the illumination control. Active approaches adopt light scene manipulation, for example photometric stereo illumination, while passive methods do not depend on the scene illumination. The surface reflectance distribution depends on the incident illumination over the scene objects and the material of the object. Therefore, active and passive approaches both require a previous consideration of surface reflectance, which is assumed, either implicitly or explicitly.
Passive stereo approaches assume implicitly the reflectance of surfaces. That is, they assume that the reflectance of the scene objects is the same regardless the acquisition view-point. On the other hand, active stereo approaches establish a known parametric reflectance form. That is, they calculate a reflectance function from different physical models, and later they include this function in the recovery constraint. Both considerations are not valid in the real world, since reflectance depends on different aspects, such as optical characteristics of surfaces, illumination incidence angle, optical view-points positions, etc.
Other three dimensional recovery techniques refer to systems in which the scene is illuminated by a known geometrical pattern of light. These are known as structured lighting systems, and they make use of the triangulation principle to compute depth. The main disadvantage of structured lighting methods is that they require several image acquisitions (in the order of 4 to 32) under different lighting conditions in order to obtain a dense depth map, so that, these recovery techniques are computationally expensive methods, and they are not presently practical for fast 3D acquisition applications like production lines inspection or object modeling
Recently a new stereo technique has been proposed in MAGDA, S., KRIEGMAN, D., ZICKLER, T., and BELHUMEUR, P., “Beyond Lambert: Reconstructing Surfaces with Arbitrary BRDFs,” Proceedings of the International Conference on Computer Vision (ICCV), 2001, pp. 391-399, and ZICKLER, T., BELHUMEUR, P., and KRIEGMAN, D., “Helmholtz Stereopsis: Exploiting Reciprocity for Surface Reconstruction,” Proceedings of the 7th European Conference on Computer Vision (ECCV), May 2002, vol. 3, pp. 869-884, both of which are incorporated herein by reference. This new approach is proposed to achieve the recovery of depth information of scene objects considering an arbitrary or unknown surface reflectance.
This recent stereo technique takes advantage of the reflectance symmetry of surfaces. Reflectance symmetry, or reciprocity, allows an arbitrary form of surface reflectance. Thus, under a controlled illumination environment, the restrictions caused by optical properties inherent to surface materials are eliminated, and depth recovery from any kind of surfaces can be obtained.
The stereo technique based on the reflectance reciprocity has other advantages, for example, since stereo images have reciprocal irradiance, the specularities appear fixed over the surface, which is an advantage over other stereo approaches, because it is possible to match corresponding specular regions. Moreover, half-occluded regions are corresponding. That is, a half-occluded region on the left stereo image appears shadowed on the right stereo image, and vice versa. This property may enhance the quality of depth reconstruction since it allows determining depth discontinuities. Furthermore, textureless and flat surfaces cannot be recovered using either active or passive conventional stereo techniques.
A simplification of the multi-ocular stereo case is presented in ZICKLER, T., HO, J., KRIEGMAN, D., PONCE, J., and BELHUMEUR, P., “Binocular Helmholtz Stereopsis,” Proceedings of the International Conference on Computer Vision (ICCV), 2003, pp. 1411-1417, incorporated herein by reference. This article proposes a method for how a dense depth map can be retrieved from a single pair of reciprocal stereo images, considering orthographic point's projection.
Unfortunately, this article does not illustrate how such a technique can be easily integrated with the calibration process. In particular, a mechanical calibration process is assumed in which the cameras are re-positioned and detailed measurements are made. The aforementioned article also does not illustrate the steps involved in the proposed approach. Furthermore, Zickler's approach establishes a stereo analysis considering an orthographic point projection. This kind of projection geometry can be achieved if the stereo setup is far away from the scene objects. Therefore, this restriction eliminates the possibility of a practical set up which can be used on industrial tasks where space is an important constraint.
Accordingly, there is a need for a method and apparatus for three-dimensional depth recovery utilizing the concept of reflectance reciprocity that does not have the limitations stated above. In particular, there is a need for a complete system, that is, a practical method and apparatus, which tackles all the stages of a highly accurate three-dimensional recovery process, from camera calibration to a final grid adjustment process, including some specific tasks related with the reciprocal reflectance property. Moreover, a complete system should fulfill the real-time requirements of applications such as industrial inspection.
BRIEF SUMMARY OF THE INVENTION
The invention provides a method and an apparatus for acquiring stereo images which fulfill the reciprocity reflectance property to recover depth information of an object placed into the field of view of a single or multi stereo cameras array. This particular property of surface reflectance allows three dimensional modeling of objects regardless their reflectance distribution, that is, the system can handle textureless and specular surfaces while conventional and photometric stereo techniques fail. In a preferred embodiment, the present invention utilizes an extended binocular approach which does not have any restriction related with the projection geometry or the camera setup configuration.
The system uses a stereo and radiometric calibration process prior to the capture of object images. The stereo calibration process requires two stereo pairs of a calibration pattern for modeling the intrinsic and extrinsic parameters of a single or multiple stereo camera arrays. The radiometric calibration needs a single stereo pair of reciprocal images of a white calibration pattern to apply an isotropic light distribution to the stereo images. Finally, a stereo rectification process is applied in order to fulfill the epipolar constraint and recover depth information of the object in the scene.
A dense three dimensional model is obtained, according to the invention, by stereo and radiometric calibration procedures. After this, a stereo rectification process is applied to fulfill the epipolar constraint. Then, an algorithm for three dimensional recovery is applied over complementary epipolar lines in order to obtain dense depth data from the object in the scene. Finally a depth map calibration process is applied for obtaining highly accurate 3D point cloud.
The system has a stereo head with an interior illumination control which includes a beam-splitter in order to align the optical axis with the beam of light. Alternatively, an exterior illumination distribution can be utilized, which consists of placing the light source near of the optical center. The apparatus is designed considering an acquisition process which allows the automatic commutation of the stereo light sources to fulfill the reciprocity property of the images.
The system is fully automatic, easy to use, has a simple setup and calibration process. The system is unique in that it requires only two object images for highly accurate three dimensional modeling of objects regardless their reflectance distribution. Therefore, it is potentially faster than other 3D scanners or 3D recovery systems, such that, the system may be used in a wide range of applications as metrology, quality control, medical, dynamic three dimensional modeling and so on.
The system of the present invention simplifies the light control to obtain stereo images with symmetrical intensity curves. Unlike others photometric stereo techniques, this approach obtains the depth measures of the object in the scene directly, avoiding the normal field integration which means an important reduction of the computational cost.
Additionally, an embodiment of the imaging apparatus allows a stereo camera configuration with a parallel and convergent optical axis. This option could also be applied to an extended multi-view camera system.
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7676743 | FIELD OF THE INVENTION
The present disclosure relates to a method and apparatus for grouping multiple text frames in a page layout application and for uniformly applying type fitting across the grouped text frames.
BACKGROUND OF THE INVENTION
A number of page layout applications are known in the art, such as Adobe InDesign®, Adobe PageMaker®, and QuarkXPress®. When using a page layout application, text can be input into a plurality of text frames, which are simply regions or boxes in the page layout. Typically, the text frames have borders in which the text is contained and can be moved or otherwise manipulated in the application. Often, the user must modify attributes of the text in the text frames so that the text sufficiently fits within the text frame, such as point (font) size, leading (i.e., the spacing between lines of text), tracking (i.e., spacing between letter and words), kerning, spacing between paragraphs, spacing before and after text, vertical and/or horizontal scaling, etc. Modifying text attributes to fit the text in a text frame is often referred to as “type fitting” or “copy fitting,” and current page layout applications offer various utilities to aid in type fitting. With these utilities, users must specify attributes of the text and preferred parameters of the attributes to be used when type fitting the text.
A commercial example of a prior art type-fitting system for a page layout application is the CopyFit™ XTensions module used in DesignMerge™. Referring toFIG. 1, an interface100is illustrated that is similar to the prior art CopyFit™ XTensions module, which may be used to type fit text within a text frame of a given size in a QuarkXPress™ page layout application. The interface100is used to fit and fix “overflow” or “underflow” of text within a text frame, i.e., conditions respectively where the text is too large to fit in the text frame (“overset”) or where the text is too small and does not adequately fill up the text frame (“underset”).
Non-optimized text fitting, and the manner in which interface100can be used to fix such problems, is shown first by reference to the exemplary text frames200,210, and220ofFIG. 2A. As shown, text frame200is overset, while text frames210and220are underset. An overflow of text may occur when the text is imported or manually input into a text frame such that it is longer than the space allotted in the text frame, rendering some of the text non-visible within the frame (200). Likewise, an underflow of text may occur when the text as imported or input is shorter than the space allotted in the text frame (210,220), in which case empty space follows the text within the frame. The user in these circumstances can make the text fit within the text frames200,210, and220by modifying the sizes of the text frames, but this may not be desirable or possible in all circumstances. For example, a page layout (e.g., for a brochure or newspaper) may have several text frames carefully laid out on one or more pages and interspersed among pictures, drawings, logos, or other graphics, such that changing the sizes of text frames would not be practical as this would tend to alter the interrelations of the graphical elements and hence the entirety of the page layout.
Because the user may not wish to change the size of a text frame or frames, the user can access the interface100ofFIG. 1to change attributes of the text so that the text can be made to fit the text frame(s). In this regard, interface100includes a set of attributes110for type fitting text in a text frame, such as those discussed earlier. Each attribute110is defined with minimum and maximum values for the parameters112,114by which the attribute110can be automatically adjusted in accordance with an algorithm implemented by the interface100. Each attribute110is also defined by a step value116to set the gradations by which the attribute110may be changed. Also present is a priority118which the algorithm uses to preferentially adjust the parameters. For example, as shown inFIG. 1, in the case of an non-optimized fit, the algorithm would first adjust the tracking to see if a proper fit can be achieved within its prescribed parameters; if not, the horizontal scaling would similarly be adjusted; followed by the point size, etc. The parameters112,114, steps116, and priorities118are user-definable, and may be typed into the interface100or loaded in as a pre-stored template of parameters using drop down menu102. As one skilled in the art will recognize, the algorithm can be iterative in nature to find a most optimal fit even when priorities are specified, and can be achieved in any number of ways.
To type fit text, the user selects the text frame in the page layout application and then brings up (in any number of ways) the interface100. The selected frame to be fitted is then displayed in interface100as entry101, and thereafter the user enters or loads (102) the parameters112,114, step116, and priority118for the type-fitting attributes110to be used on the selected frame. Thereafter, the user can engage the algorithm to apply the parameters to the text frame to fit the text by selecting the “fit frame” button120. The user can also “tag” the selected text frame104with a particular parameter set102without applying the same via the button120. This is useful when the user knows a certain frame needs a particular set of attributes and parameters for type fitting the text, but it is not yet useful to actual fit the text of the frame, for example, because the sizes or locations of the text frames are still being altered in the page layout application. Such “tagging” can also be removed (108) or read (106) to understand or perhaps modify the parameters associated with the frame101.
FIG. 2Bshows the text frames200-220after each has been subject to the type fitting attributes, parameters, steps, and priorities shown inFIG. 1(i.e., “Set 1” from box102inFIG. 1). Thus, in accordance with the type fitting algorithm, it can be seen that the text in text frame200has been type fit by changing the font size of the text from 12.0 to 9.5 (a 20.8% decrease); text frame210has been type fit by changing the font size from 12.0 to 13.0 (a 8.3% increase); and text frame220has been type fit by changing the font size from 16.0 to 18.6 (a 16.3% increase). Thus, the independently type-fit text frames200,210, and220ofFIG. 2B, although they have each been type fit, are not scaled uniformly by the algorithm, which is not surprising as the algorithm does nothing to take the attributes and parameters of another text frame not currently being set into account. Of course, other type fitting attributes (e.g., tracking) may also have been changed in a non-uniform manner, but this is not shown in theFIG. 2for clarity.
Non-uniform scaling can be troubling to the user. For example, suppose that text frame220represents the title of a story, text frame200represents a subtitle of the story, and that frame210contains the actual text of the story (which may or may not continue in a different column on a subsequent page in the page layout). The user might have determined while entering the text that the title, subtitle, and story text as put in the frames looked pleasing in relation to one another: i.e., the subtitle and the story text look sensible when written in the same font size, while the title is sensibly a little bigger than both. However, applying the same type fitting attributes and parameters (i.e., “Set 1” in box102) to each frame independently produces the non-scaled changes in font size discussed above (and perhaps other attributes) between the text frames200-220. Thus, the subtitle in frame200is now considerably smaller than the story text in frame210, a potentially odd-looking result.
Because of this problem, the user may be relegated to a frustrating and complicated iterative process where the user has to modify the type fitting attributes and parameters manually for each frame (perhaps using another user interface (not shown) which displays the actual value for the attributes of the text, as opposed to potential parameters or ranges of the attributes as in interface100). Of course, as attribute parameters for one (first) frame are manually changed, another (second) frame may need to be similarly changed if uniform or near-uniform scaling is desired. However, such a change may not be permissible in the second frame (e.g., it might result in an overset condition), thus requiring the user to go back to the first frame to investigate whether modifying different attribute parameters can be changed in both the first and second frames, hoping that such a modification will be acceptable in some other related (third) frame, etc. When dealing with multiple frames and multiple attributes, such manual “tweaking” can be a very complex task, especially when there are multiple font sizes or other attributes present in a single frame, or across multiple frames. As a result, much of the benefit of the interface100, and the algorithm it promotes, are lost.
The subject matter of the present disclosure is directed to addressing these and other problems.
SUMMARY OF THE DISCLOSURE
Methods are disclosed for type-fitting text in multiple text frames of a page layout application. The text frames are associated with a group, and permissible variances of parameters of type fitting attributes are assigned to the group using a graphical user interface. In one embodiment, to type-fit the text, a best-individual-fit setting for the text of each text frame is first individually assessed to determine parameters of the attributes that would result in the text substantially fitting within its associated text frame. Thereafter, one best-group-fit setting for all frames in the group is determined by sorting through the best-individual-fit settings for each of the frames to determine a setting for the fitting group that, when applied to all of the frames of the fitting group, will achieve uniform type fitting of the group. More specifically, the now-optimized frames are compared to determine which frame's best-individual-fit parameters result in the highest degree of text shrinkage or the least degree of text expansion, with such best-individual-fit parameters being selected as the best-group-fit setting for all frames in the group. In accordance with this embodiment, the frames, when fitted, will be uniformly scaled in accordance with a scaling factor. In an additional embodiment, the values for the parameters for the now-grouped and now-fitted frames can be changed in one frame, with such changes rippling through the other frames to modify that value in a scaled fashion.
The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.
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SUMMARY: FIELD OF THE INVENTION
The present disclosure relates to a method and apparatus for grouping multiple text frames in a page layout application and for uniformly applying type fitting across the grouped text frames.
BACKGROUND OF THE INVENTION
A number of page layout applications are known in the art, such as Adobe InDesign®, Adobe PageMaker®, and QuarkXPress®. When using a page layout application, text can be input into a plurality of text frames, which are simply regions or boxes in the page layout. Typically, the text frames have borders in which the text is contained and can be moved or otherwise manipulated in the application. Often, the user must modify attributes of the text in the text frames so that the text sufficiently fits within the text frame, such as point (font) size, leading (i.e., the spacing between lines of text), tracking (i.e., spacing between letter and words), kerning, spacing between paragraphs, spacing before and after text, vertical and/or horizontal scaling, etc. Modifying text attributes to fit the text in a text frame is often referred to as “type fitting” or “copy fitting,” and current page layout applications offer various utilities to aid in type fitting. With these utilities, users must specify attributes of the text and preferred parameters of the attributes to be used when type fitting the text.
A commercial example of a prior art type-fitting system for a page layout application is the CopyFit™ XTensions module used in DesignMerge™. Referring toFIG. 1, an interface100is illustrated that is similar to the prior art CopyFit™ XTensions module, which may be used to type fit text within a text frame of a given size in a QuarkXPress™ page layout application. The interface100is used to fit and fix “overflow” or “underflow” of text within a text frame, i.e., conditions respectively where the text is too large to fit in the text frame (“overset”) or where the text is too small and does not adequately fill up the text frame (“underset”).
Non-optimized text fitting, and the manner in which interface100can be used to fix such problems, is shown first by reference to the exemplary text frames200,210, and220ofFIG. 2A. As shown, text frame200is overset, while text frames210and220are underset. An overflow of text may occur when the text is imported or manually input into a text frame such that it is longer than the space allotted in the text frame, rendering some of the text non-visible within the frame (200). Likewise, an underflow of text may occur when the text as imported or input is shorter than the space allotted in the text frame (210,220), in which case empty space follows the text within the frame. The user in these circumstances can make the text fit within the text frames200,210, and220by modifying the sizes of the text frames, but this may not be desirable or possible in all circumstances. For example, a page layout (e.g., for a brochure or newspaper) may have several text frames carefully laid out on one or more pages and interspersed among pictures, drawings, logos, or other graphics, such that changing the sizes of text frames would not be practical as this would tend to alter the interrelations of the graphical elements and hence the entirety of the page layout.
Because the user may not wish to change the size of a text frame or frames, the user can access the interface100ofFIG. 1to change attributes of the text so that the text can be made to fit the text frame(s). In this regard, interface100includes a set of attributes110for type fitting text in a text frame, such as those discussed earlier. Each attribute110is defined with minimum and maximum values for the parameters112,114by which the attribute110can be automatically adjusted in accordance with an algorithm implemented by the interface100. Each attribute110is also defined by a step value116to set the gradations by which the attribute110may be changed. Also present is a priority118which the algorithm uses to preferentially adjust the parameters. For example, as shown inFIG. 1, in the case of an non-optimized fit, the algorithm would first adjust the tracking to see if a proper fit can be achieved within its prescribed parameters; if not, the horizontal scaling would similarly be adjusted; followed by the point size, etc. The parameters112,114, steps116, and priorities118are user-definable, and may be typed into the interface100or loaded in as a pre-stored template of parameters using drop down menu102. As one skilled in the art will recognize, the algorithm can be iterative in nature to find a most optimal fit even when priorities are specified, and can be achieved in any number of ways.
To type fit text, the user selects the text frame in the page layout application and then brings up (in any number of ways) the interface100. The selected frame to be fitted is then displayed in interface100as entry101, and thereafter the user enters or loads (102) the parameters112,114, step116, and priority118for the type-fitting attributes110to be used on the selected frame. Thereafter, the user can engage the algorithm to apply the parameters to the text frame to fit the text by selecting the “fit frame” button120. The user can also “tag” the selected text frame104with a particular parameter set102without applying the same via the button120. This is useful when the user knows a certain frame needs a particular set of attributes and parameters for type fitting the text, but it is not yet useful to actual fit the text of the frame, for example, because the sizes or locations of the text frames are still being altered in the page layout application. Such “tagging” can also be removed (108) or read (106) to understand or perhaps modify the parameters associated with the frame101.
FIG. 2Bshows the text frames200-220after each has been subject to the type fitting attributes, parameters, steps, and priorities shown inFIG. 1(i.e., “Set 1” from box102inFIG. 1). Thus, in accordance with the type fitting algorithm, it can be seen that the text in text frame200has been type fit by changing the font size of the text from 12.0 to 9.5 (a 20.8% decrease); text frame210has been type fit by changing the font size from 12.0 to 13.0 (a 8.3% increase); and text frame220has been type fit by changing the font size from 16.0 to 18.6 (a 16.3% increase). Thus, the independently type-fit text frames200,210, and220ofFIG. 2B, although they have each been type fit, are not scaled uniformly by the algorithm, which is not surprising as the algorithm does nothing to take the attributes and parameters of another text frame not currently being set into account. Of course, other type fitting attributes (e.g., tracking) may also have been changed in a non-uniform manner, but this is not shown in theFIG. 2for clarity.
Non-uniform scaling can be troubling to the user. For example, suppose that text frame220represents the title of a story, text frame200represents a subtitle of the story, and that frame210contains the actual text of the story (which may or may not continue in a different column on a subsequent page in the page layout). The user might have determined while entering the text that the title, subtitle, and story text as put in the frames looked pleasing in relation to one another: i.e., the subtitle and the story text look sensible when written in the same font size, while the title is sensibly a little bigger than both. However, applying the same type fitting attributes and parameters (i.e., “Set 1” in box102) to each frame independently produces the non-scaled changes in font size discussed above (and perhaps other attributes) between the text frames200-220. Thus, the subtitle in frame200is now considerably smaller than the story text in frame210, a potentially odd-looking result.
Because of this problem, the user may be relegated to a frustrating and complicated iterative process where the user has to modify the type fitting attributes and parameters manually for each frame (perhaps using another user interface (not shown) which displays the actual value for the attributes of the text, as opposed to potential parameters or ranges of the attributes as in interface100). Of course, as attribute parameters for one (first) frame are manually changed, another (second) frame may need to be similarly changed if uniform or near-uniform scaling is desired. However, such a change may not be permissible in the second frame (e.g., it might result in an overset condition), thus requiring the user to go back to the first frame to investigate whether modifying different attribute parameters can be changed in both the first and second frames, hoping that such a modification will be acceptable in some other related (third) frame, etc. When dealing with multiple frames and multiple attributes, such manual “tweaking” can be a very complex task, especially when there are multiple font sizes or other attributes present in a single frame, or across multiple frames. As a result, much of the benefit of the interface100, and the algorithm it promotes, are lost.
The subject matter of the present disclosure is directed to addressing these and other problems.
SUMMARY OF THE DISCLOSURE
Methods are disclosed for type-fitting text in multiple text frames of a page layout application. The text frames are associated with a group, and permissible variances of parameters of type fitting attributes are assigned to the group using a graphical user interface. In one embodiment, to type-fit the text, a best-individual-fit setting for the text of each text frame is first individually assessed to determine parameters of the attributes that would result in the text substantially fitting within its associated text frame. Thereafter, one best-group-fit setting for all frames in the group is determined by sorting through the best-individual-fit settings for each of the frames to determine a setting for the fitting group that, when applied to all of the frames of the fitting group, will achieve uniform type fitting of the group. More specifically, the now-optimized frames are compared to determine which frame's best-individual-fit parameters result in the highest degree of text shrinkage or the least degree of text expansion, with such best-individual-fit parameters being selected as the best-group-fit setting for all frames in the group. In accordance with this embodiment, the frames, when fitted, will be uniformly scaled in accordance with a scaling factor. In an additional embodiment, the values for the parameters for the now-grouped and now-fitted frames can be changed in one frame, with such changes rippling through the other frames to modify that value in a scaled fashion.
The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.
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7649480 | This application relates to image signal processing and in particular to black level calibration circuitry and methods.
An imaging sensor, for example a charge coupled device (CCD), comprises a plurality of optical sensing elements, for example photo-diodes, that each represents a pixel. Each sensing element provides pixel data, for example a voltage, representing the intensity of light falling on it. The pixel data is output from the sensor via one or more output terminals.
The pixel data from the sensor is typically sensitive to environmental conditions such as temperature. For example, in a photo-diode, carriers are generated optically and thermally: the thermally generated carriers are indistinguishable from the optically generated carriers and add a component, or an offset, to the desired optical component of the photodiode's output signal. Not only are the output values of the sensor temperature-dependent, they are also sensitive to manufacturing conditions, and so each sensor varies from one another. However, the plurality of sensing elements on a given sensor are manufactured together and will be subject to the same manufacturing conditions and operating temperature, so the effects of manufacturing and temperature are manifested as a substantially equal shift, for example, an equal d.c. offset voltage in the output of each sensing element.
This d.c. offset uses up part of the input signal range of the circuitry, for example an analogue-to-digital-converter (ADC), that receives the output of the sensor, which results in a reduction in the useful dynamic range of the system output signal.
FIG. 1illustrates the concept of “black pixels” and “image pixels”. Contained in a sensor are a plurality of “black level sensing elements”100, each one of which represents a “black pixel”, that are optically shielded from any light, optical shielding being one method of generating a “black level” reference. It is these black level sensing elements100that are used to track variations in the sensor output. The remaining sensing elements110in the sensor120shall be referred to as “image level sensing elements” as they each provide an output, i.e. “image pixels”, (for example a current, a voltage or a charge) that represents the light falling on part of an image being sensed.
Should the image level sensing elements110and black level sensing elements100be manufactured together and operated under the same environmental conditions (for example, at the same temperature) each of the black level sensing elements100will provide the same output signal as each of the image level sensing elements110that are not exposed to any light. Black level calibration circuitry is provided so as to subtract a signal equal to, or representative of, the black level sensing element100output signals that are output from the sensor during the calibration period (A) (that is, the “black pixel” period) from each image pixel sensing element110output signal during the operational period (B) (that is, the “image pixel” period). This removes the unpredictable and environmentally sensitive component, the d.c. offset voltage for example, from the image pixel sensing element output signals. The subtraction of the black level sensing element output signal (the “black level offset”) that has been determined during the calibration period (A) allows subsequent circuitry to be used across a fuller signal range, or even its full signal range, and the output level corresponding to the colour black to be more predictable.
These black level sensing elements100and image level sensing elements110can be used as part of linear or array type image sensor120.
The black level calibration circuitry may be formed on either the same single integrated circuit (IC) as the sensing elements100,110and associated output circuitry or as one of more separate ICs, as may any subsequent processing circuitry such as an ADC or circuitry for subsequent digital processing. In the case of an IC, the optical shielding of the black level sensing elements is typically achieved using one or more metal layers.
Other methods of generating a “black level” reference include those in which the imaging sensor senses: a “black calibration strip” i.e. a strip of black tape or paint; or an unexposed image that is hidden, such as by a camera shutter for example. Therefore, there are a number of different methods whereby the black level calibration circuitry can possibly generate a “black level” depending upon the system in which the black level calibration circuitry is being used.
The circuitry following the sensor may contain a gain stage amplifier to amplify, or possibly attenuate, the sensor output signal so as to match the sensor output signal range to the input signal range of the circuitry following the sensor, for example, to span a greater range or even the full input range of an ADC.
It is known for there to be provided a black level correction loop to provide an offset to be applied to the inputted signal prior to this amplification by having a feedback loop around the gain stage amplifier. For accurate offset cancellation, this loop must have a high closed-loop gain and in order to settle accurately during the limited number of available black pixels before the image pixel signal arrives, the loop must have a certain bandwidth and not be excessively under- or over-damped. For a given application and amplifier gain, there will be some optimum or nominal response.
However, the gain stage amplifier is usually configured to allow its gain to be varied, either manually or automatically, to maintain a wide output signal swing. This is despite reductions in the general or maximum brightness of the image being sensed, or to compensate for general variation in the optical sensitivity of the sensor elements, for example. But variation of this amplifier gain will cause a corresponding gain change to be applied to the open-loop gain response. A high amplifier gain will increase the gain-bandwidth causing the loop to be under-damped, or even oscillate when closed. A low amplifier gain may give insufficient open-loop gain or a low bandwidth, leading to an excessive settling time. As the feedback loop incorporates the gain stage amplifier, a known solution is to simply introduce a further amplifier, or attenuator, with a gain value the inverse of this amplifier, so that the overall loop response becomes independent of the amplifier gain setting.
The inverse amplifier may be of similar complexity, power consumption, and area to the gain stage amplifier, including a similar number of gain elements (for example resistors, switches and/or variable switched-capacitor arrays) to provide a gain-independent open-loop gain. Having such a complex inverse amplifier is a drawback, especially in a system that is integrated on a monolithic structure, such as an IC for example. Furthermore, a complex inverse amplifier leads to increased chip area, and also involves additional overheads in the accurate production test of gain for all the settings.
It would be desirable therefore to provide for a black level offset loop without the above drawbacks.
In a first aspect of the invention there is provided a circuit for obtaining a calibrated output signal from an input signal, the circuit comprising: an analogue gain amplifier for applying a gain to said input signal; an analogue to digital converter for converting said input signal to digital form after amplification by said gain amplifier; a correction circuit for receiving a signal derived from the output of the analogue to digital converter and outputting a digital offset signal; and a digital to analogue converter for receiving said digital offset signal and feeding a corresponding analogue offset signal back to the input of said gain amplifier, such that said correction circuit and said digital to analogue converter form a feedback loop applying an offset to said input signal, wherein said correction circuit includes an inverse gain circuit for applying an inverse gain to a signal within said correction circuit prior to said digital to analogue converter.
Said inverse gain may be applied so as to establish a combined gain response applied around said feedback loop within predetermined bounds.
The gain of said gain amplifier may be variable, the circuit further comprising a controller for controlling said inverse gain circuit so as to vary the inverse gain automatically so as to maintain the loop gain factor within said predetermined bounds as the gain of the gain amplifier varies. Said controller may be arranged to vary the gain of the inverse gain circuit more coarsely than the gain of the gain amplifier. Said variation of the loop gain factor around the circuit's feedback loop may be restricted within said pre-determined bounds, wherein said pre-determined bounds enable the feedback loop to maintain stability. The variation of the loop gain factor around said feedback loop may be restricted within 50% of a nominal value to said pre-determined bounds. Said nominal value may be the midpoint of the feedback loop's stability range. In one embodiment, the midpoint of the feedback loop's stability range may be unity and said variation of the loop gain factor around said feedback loop may be restricted within the bounds 0.5 and 1.5.
The number of possible gain values said inverse gain circuit can apply may be a power of two.
Said gain amplifier may be a programmable gain amplifier, the gain being dependent on an input coefficient applied to a control input of the calibration circuit. The number of possible gain values that said inverse gain circuit can apply may be less than the total number of possible input coefficients for said programmable gain amplifier. Said controller may be arranged to use a look up table in order to select the inverse gain to be applied by reference to the coefficient controlling said gain amplifier. Said look up table may be divided into regions, with a single inverse gain factor being selected for all the coefficient values in each region. Said single inverse gain factor for each region may be calculated from the mean coefficient value in that region.
Said inverse gain circuit may be a multiplier. Said multiplier may be a shift-add multiplier.
Said calibrated output signal may be dependent on a target calibration level. Said target calibration level may be settable by a user. Said correction circuit may further comprise a digital adder, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter such that said offset applied to said input signal may be dependent on said target calibration level. Alternatively, a digital adder may be comprised in an output signal path of said circuit, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter, to obtain said calibrated output signal.
Said circuit may be arranged to take a number of iterations, if necessary, in order to perform said calibration wherein a pre-determined delay may be introduced between successive iterations to allow for latency in the calibration circuit. Said latency may be as a result of the delay between the adjustment of the digital to analogue converter and its effect being seen on the output of the analogue to digital converter or to delays in the circuit elements.
The circuit may be specifically designed for setting a black level offset for image processing. Said calibration may be arranged to be performed while specifically designated black pixels are being scanned. Said black-pixels may be arranged to be low-pass filtered in the feedback path.
There may be further provided a manual calibration override for applying an offset directly onto the input signal.
Said correction circuit may further comprise a holding circuit for holding the signal level in the calibration circuit prior to conversion by said digital to analogue converter. Said holding circuit may have a control input for controlling when said signal level should be held. Said holding circuit may comprise a digital accumulator or an integrator.
In a further aspect of the invention there is provided a method for obtaining a calibrated output signal from an input signal prior to amplification by a gain amplifier comprising:converting the amplified signal to a digital signal;applying an inverse gain factor to a signal derived from said digital signal to obtain a digital offset signal;converting said digital offset signal to an analogue offset signal; and using said analogue offset signal to apply an offset to said input signal, thereby to define a feedback loop.
Said inverse gain factor may be applied such that the loop gain factor around said feedback loop stays within predetermined bounds. The gain of said gain amplifier may be variable, and further including controlling said inverse gain factor so as to vary the inverse gain automatically so as to maintain the loop gain factor within said predetermined bounds as the gain of the gain amplifier varies. The gain of the inverse gain factor may be varied more coarsely than the gain of the gain amplifier. Said variation of the loop gain factor around the circuit's feedback loop may be restricted within said pre-determined bounds, wherein said pre-determined bounds enable the feedback loop to maintain stability. The variation of the loop gain factor around said feedback loop may be restricted within 50% of a nominal value to said pre-determined bounds. In one embodiment the midpoint of the feedback loop's stability range may be unity and variation of the loop gain factor around said feedback loop may be restricted within the bounds 0.5 and 1.5.
Said gain amplifier may be a programmable gain amplifier, the gain being dependent on an input coefficient. When applying the inverse gain factor, the number of possible gain values that can be applied may be a power of two and/or may be less than the total number of possible input coefficients for said programmable gain amplifier. A look up table may be used in order to select the inverse gain factor to be applied, depending on the value of said input coefficient of the programmable gain amplifier. Said look up table may be divided into regions, with a single inverse gain factor being selected for all the coefficients in each region. Said single inverse gain factor for each region may be calculated from the mean coefficient in that region.
Said inverse gain factor may be applied using a multiplier. Said multiplier may be a shift-add multiplier.
Said calibrated output signal may be dependent on a target calibration level. Said target calibration level may be settable by a user. Said target calibration level may be set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter such that said offset applied to said input signal may be dependent on said target calibration level. Alternatively, Said target calibration level may be set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter, to obtain said calibrated output signal.
A number of iterations may be taken, if necessary, in order to perform said calibration and a pre-determined delay may be introduced between successive iterations to allow for latency in the calibration circuit.
Said method may be specifically performed to set a black level offset for image processing. Said calibration may be performed while specifically designated black pixels are being scanned. Said black-pixels may be low-pass filtered, prior to amplification by the inverse amplifier.
The offset applied to said input signal may be a manually calibrated input signal.
The signal level may be held prior to conversion by said digital to analogue converter.
In a further aspect of the invention there is provided an image capturing system comprising an imaging sensor, a signal conditioning circuit which comprises an analogue gain amplifier for applying a gain to said input signal, a signal conversion circuit which comprises an analogue to digital converter for converting said input signal to digital form after amplification by said gain amplifier, wherein said signal conversion circuit generates, at an output, a calibrated digital signal representing an analogue input signal received from said imaging sensor via said signal conversion circuit, wherein said image capturing system further comprises calibration circuitry for calibrating said input signal, said calibration circuitry comprising: a correction circuit for receiving a signal derived from the output of the analogue to digital converter and outputting a digital offset signal; and a digital to analogue converter for receiving said digital offset signal and feeding a corresponding analogue offset signal back to the input of said gain amplifier, such that said correction circuit and said digital to analogue converter form a feedback loop applying an offset to said input signal, wherein said correction circuit includes an inverse gain circuit for applying an inverse gain to a signal within said correction circuit prior to said digital to analogue converter.
Said inverse gain may be applied so as to establish a combined gain response applied around said feedback loop within predetermined bounds.
The gain of said gain amplifier may be variable, the circuit further comprising a controller for controlling said inverse gain circuit so as to vary the inverse gain automatically so as to maintain the loop gain factor within said predetermined bounds as the gain of the gain amplifier varies. Said controller may be arranged to vary the gain of the inverse gain circuit more coarsely than the gain of the gain amplifier. Said variation of the loop gain factor around the circuit's feedback loop may be restricted within said pre-determined bounds, wherein said pre-determined bounds enable the feedback loop to maintain stability. The variation of the loop gain factor around said feedback loop may be restricted within 50% of a nominal value to said pre-determined bounds. Said nominal value may be the midpoint of the feedback loop's stability range. In one embodiment, the midpoint of the feedback loop's stability range may be unity and said variation of the loop gain factor around said feedback loop may be restricted within the bounds 0.5 and 1.5.
The number of possible gain values said inverse gain circuit can apply may be a power of two.
Said gain amplifier may be a programmable gain amplifier, the gain being dependent on an input coefficient applied to a control input of the calibration circuit. The number of possible gain values that said inverse gain circuit can apply may be less than the total number of possible input coefficients for said programmable gain amplifier. Said controller may be arranged to use a look up table in order to select the inverse gain to be applied by reference to the coefficient controlling said gain amplifier. Said look up table may be divided into regions, with a single inverse gain factor being selected for all the coefficient values in each region. Said single inverse gain factor for each region may be calculated from the mean coefficient value in that region.
Said inverse gain circuit may be a multiplier. Said multiplier may be a shift-add multiplier.
Said calibrated output signal may be dependent on a target calibration level. Said target calibration level may be settable by a user. Said correction circuit may further comprise a digital adder, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter such that said offset applied to said input signal may be dependent on said target calibration level. Alternatively, a digital adder may be comprised in an output signal path of said circuit, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter, to obtain said calibrated output signal.
Said circuit may be arranged to take a number of iterations, if necessary, in order to perform said calibration wherein a pre-determined delay may be introduced between successive iterations to allow for latency in the calibration circuit. Said latency may be as a result of the delay between the adjustment of the digital to analogue converter and its effect being seen on the output of the analogue to digital converter or to delays in the circuit elements.
The circuit may be specifically designed for setting a black level offset for image processing. Said calibration may be arranged to be performed while specifically designated black pixels are being scanned. Said black-pixels may be arranged to be low-pass filtered in the feedback path.
There may be further provided a manual calibration override for applying an offset directly onto the input signal.
Said correction circuit may further comprise a holding circuit for holding the signal level in the calibration circuit prior to conversion by said digital to analogue converter. Said holding circuit may have a control input for controlling when said signal level should be held. Said holding circuit may comprise a digital accumulator or an integrator.
Said system may further comprise an output device.
Said system may form part of a scanner, part of a photocopier, or part of a multi-functional device capable of copying, scanning, storing, transmitting and printing images.
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SUMMARY: This application relates to image signal processing and in particular to black level calibration circuitry and methods.
An imaging sensor, for example a charge coupled device (CCD), comprises a plurality of optical sensing elements, for example photo-diodes, that each represents a pixel. Each sensing element provides pixel data, for example a voltage, representing the intensity of light falling on it. The pixel data is output from the sensor via one or more output terminals.
The pixel data from the sensor is typically sensitive to environmental conditions such as temperature. For example, in a photo-diode, carriers are generated optically and thermally: the thermally generated carriers are indistinguishable from the optically generated carriers and add a component, or an offset, to the desired optical component of the photodiode's output signal. Not only are the output values of the sensor temperature-dependent, they are also sensitive to manufacturing conditions, and so each sensor varies from one another. However, the plurality of sensing elements on a given sensor are manufactured together and will be subject to the same manufacturing conditions and operating temperature, so the effects of manufacturing and temperature are manifested as a substantially equal shift, for example, an equal d.c. offset voltage in the output of each sensing element.
This d.c. offset uses up part of the input signal range of the circuitry, for example an analogue-to-digital-converter (ADC), that receives the output of the sensor, which results in a reduction in the useful dynamic range of the system output signal.
FIG. 1illustrates the concept of “black pixels” and “image pixels”. Contained in a sensor are a plurality of “black level sensing elements”100, each one of which represents a “black pixel”, that are optically shielded from any light, optical shielding being one method of generating a “black level” reference. It is these black level sensing elements100that are used to track variations in the sensor output. The remaining sensing elements110in the sensor120shall be referred to as “image level sensing elements” as they each provide an output, i.e. “image pixels”, (for example a current, a voltage or a charge) that represents the light falling on part of an image being sensed.
Should the image level sensing elements110and black level sensing elements100be manufactured together and operated under the same environmental conditions (for example, at the same temperature) each of the black level sensing elements100will provide the same output signal as each of the image level sensing elements110that are not exposed to any light. Black level calibration circuitry is provided so as to subtract a signal equal to, or representative of, the black level sensing element100output signals that are output from the sensor during the calibration period (A) (that is, the “black pixel” period) from each image pixel sensing element110output signal during the operational period (B) (that is, the “image pixel” period). This removes the unpredictable and environmentally sensitive component, the d.c. offset voltage for example, from the image pixel sensing element output signals. The subtraction of the black level sensing element output signal (the “black level offset”) that has been determined during the calibration period (A) allows subsequent circuitry to be used across a fuller signal range, or even its full signal range, and the output level corresponding to the colour black to be more predictable.
These black level sensing elements100and image level sensing elements110can be used as part of linear or array type image sensor120.
The black level calibration circuitry may be formed on either the same single integrated circuit (IC) as the sensing elements100,110and associated output circuitry or as one of more separate ICs, as may any subsequent processing circuitry such as an ADC or circuitry for subsequent digital processing. In the case of an IC, the optical shielding of the black level sensing elements is typically achieved using one or more metal layers.
Other methods of generating a “black level” reference include those in which the imaging sensor senses: a “black calibration strip” i.e. a strip of black tape or paint; or an unexposed image that is hidden, such as by a camera shutter for example. Therefore, there are a number of different methods whereby the black level calibration circuitry can possibly generate a “black level” depending upon the system in which the black level calibration circuitry is being used.
The circuitry following the sensor may contain a gain stage amplifier to amplify, or possibly attenuate, the sensor output signal so as to match the sensor output signal range to the input signal range of the circuitry following the sensor, for example, to span a greater range or even the full input range of an ADC.
It is known for there to be provided a black level correction loop to provide an offset to be applied to the inputted signal prior to this amplification by having a feedback loop around the gain stage amplifier. For accurate offset cancellation, this loop must have a high closed-loop gain and in order to settle accurately during the limited number of available black pixels before the image pixel signal arrives, the loop must have a certain bandwidth and not be excessively under- or over-damped. For a given application and amplifier gain, there will be some optimum or nominal response.
However, the gain stage amplifier is usually configured to allow its gain to be varied, either manually or automatically, to maintain a wide output signal swing. This is despite reductions in the general or maximum brightness of the image being sensed, or to compensate for general variation in the optical sensitivity of the sensor elements, for example. But variation of this amplifier gain will cause a corresponding gain change to be applied to the open-loop gain response. A high amplifier gain will increase the gain-bandwidth causing the loop to be under-damped, or even oscillate when closed. A low amplifier gain may give insufficient open-loop gain or a low bandwidth, leading to an excessive settling time. As the feedback loop incorporates the gain stage amplifier, a known solution is to simply introduce a further amplifier, or attenuator, with a gain value the inverse of this amplifier, so that the overall loop response becomes independent of the amplifier gain setting.
The inverse amplifier may be of similar complexity, power consumption, and area to the gain stage amplifier, including a similar number of gain elements (for example resistors, switches and/or variable switched-capacitor arrays) to provide a gain-independent open-loop gain. Having such a complex inverse amplifier is a drawback, especially in a system that is integrated on a monolithic structure, such as an IC for example. Furthermore, a complex inverse amplifier leads to increased chip area, and also involves additional overheads in the accurate production test of gain for all the settings.
It would be desirable therefore to provide for a black level offset loop without the above drawbacks.
In a first aspect of the invention there is provided a circuit for obtaining a calibrated output signal from an input signal, the circuit comprising: an analogue gain amplifier for applying a gain to said input signal; an analogue to digital converter for converting said input signal to digital form after amplification by said gain amplifier; a correction circuit for receiving a signal derived from the output of the analogue to digital converter and outputting a digital offset signal; and a digital to analogue converter for receiving said digital offset signal and feeding a corresponding analogue offset signal back to the input of said gain amplifier, such that said correction circuit and said digital to analogue converter form a feedback loop applying an offset to said input signal, wherein said correction circuit includes an inverse gain circuit for applying an inverse gain to a signal within said correction circuit prior to said digital to analogue converter.
Said inverse gain may be applied so as to establish a combined gain response applied around said feedback loop within predetermined bounds.
The gain of said gain amplifier may be variable, the circuit further comprising a controller for controlling said inverse gain circuit so as to vary the inverse gain automatically so as to maintain the loop gain factor within said predetermined bounds as the gain of the gain amplifier varies. Said controller may be arranged to vary the gain of the inverse gain circuit more coarsely than the gain of the gain amplifier. Said variation of the loop gain factor around the circuit's feedback loop may be restricted within said pre-determined bounds, wherein said pre-determined bounds enable the feedback loop to maintain stability. The variation of the loop gain factor around said feedback loop may be restricted within 50% of a nominal value to said pre-determined bounds. Said nominal value may be the midpoint of the feedback loop's stability range. In one embodiment, the midpoint of the feedback loop's stability range may be unity and said variation of the loop gain factor around said feedback loop may be restricted within the bounds 0.5 and 1.5.
The number of possible gain values said inverse gain circuit can apply may be a power of two.
Said gain amplifier may be a programmable gain amplifier, the gain being dependent on an input coefficient applied to a control input of the calibration circuit. The number of possible gain values that said inverse gain circuit can apply may be less than the total number of possible input coefficients for said programmable gain amplifier. Said controller may be arranged to use a look up table in order to select the inverse gain to be applied by reference to the coefficient controlling said gain amplifier. Said look up table may be divided into regions, with a single inverse gain factor being selected for all the coefficient values in each region. Said single inverse gain factor for each region may be calculated from the mean coefficient value in that region.
Said inverse gain circuit may be a multiplier. Said multiplier may be a shift-add multiplier.
Said calibrated output signal may be dependent on a target calibration level. Said target calibration level may be settable by a user. Said correction circuit may further comprise a digital adder, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter such that said offset applied to said input signal may be dependent on said target calibration level. Alternatively, a digital adder may be comprised in an output signal path of said circuit, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter, to obtain said calibrated output signal.
Said circuit may be arranged to take a number of iterations, if necessary, in order to perform said calibration wherein a pre-determined delay may be introduced between successive iterations to allow for latency in the calibration circuit. Said latency may be as a result of the delay between the adjustment of the digital to analogue converter and its effect being seen on the output of the analogue to digital converter or to delays in the circuit elements.
The circuit may be specifically designed for setting a black level offset for image processing. Said calibration may be arranged to be performed while specifically designated black pixels are being scanned. Said black-pixels may be arranged to be low-pass filtered in the feedback path.
There may be further provided a manual calibration override for applying an offset directly onto the input signal.
Said correction circuit may further comprise a holding circuit for holding the signal level in the calibration circuit prior to conversion by said digital to analogue converter. Said holding circuit may have a control input for controlling when said signal level should be held. Said holding circuit may comprise a digital accumulator or an integrator.
In a further aspect of the invention there is provided a method for obtaining a calibrated output signal from an input signal prior to amplification by a gain amplifier comprising:converting the amplified signal to a digital signal;applying an inverse gain factor to a signal derived from said digital signal to obtain a digital offset signal;converting said digital offset signal to an analogue offset signal; and using said analogue offset signal to apply an offset to said input signal, thereby to define a feedback loop.
Said inverse gain factor may be applied such that the loop gain factor around said feedback loop stays within predetermined bounds. The gain of said gain amplifier may be variable, and further including controlling said inverse gain factor so as to vary the inverse gain automatically so as to maintain the loop gain factor within said predetermined bounds as the gain of the gain amplifier varies. The gain of the inverse gain factor may be varied more coarsely than the gain of the gain amplifier. Said variation of the loop gain factor around the circuit's feedback loop may be restricted within said pre-determined bounds, wherein said pre-determined bounds enable the feedback loop to maintain stability. The variation of the loop gain factor around said feedback loop may be restricted within 50% of a nominal value to said pre-determined bounds. In one embodiment the midpoint of the feedback loop's stability range may be unity and variation of the loop gain factor around said feedback loop may be restricted within the bounds 0.5 and 1.5.
Said gain amplifier may be a programmable gain amplifier, the gain being dependent on an input coefficient. When applying the inverse gain factor, the number of possible gain values that can be applied may be a power of two and/or may be less than the total number of possible input coefficients for said programmable gain amplifier. A look up table may be used in order to select the inverse gain factor to be applied, depending on the value of said input coefficient of the programmable gain amplifier. Said look up table may be divided into regions, with a single inverse gain factor being selected for all the coefficients in each region. Said single inverse gain factor for each region may be calculated from the mean coefficient in that region.
Said inverse gain factor may be applied using a multiplier. Said multiplier may be a shift-add multiplier.
Said calibrated output signal may be dependent on a target calibration level. Said target calibration level may be settable by a user. Said target calibration level may be set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter such that said offset applied to said input signal may be dependent on said target calibration level. Alternatively, Said target calibration level may be set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter, to obtain said calibrated output signal.
A number of iterations may be taken, if necessary, in order to perform said calibration and a pre-determined delay may be introduced between successive iterations to allow for latency in the calibration circuit.
Said method may be specifically performed to set a black level offset for image processing. Said calibration may be performed while specifically designated black pixels are being scanned. Said black-pixels may be low-pass filtered, prior to amplification by the inverse amplifier.
The offset applied to said input signal may be a manually calibrated input signal.
The signal level may be held prior to conversion by said digital to analogue converter.
In a further aspect of the invention there is provided an image capturing system comprising an imaging sensor, a signal conditioning circuit which comprises an analogue gain amplifier for applying a gain to said input signal, a signal conversion circuit which comprises an analogue to digital converter for converting said input signal to digital form after amplification by said gain amplifier, wherein said signal conversion circuit generates, at an output, a calibrated digital signal representing an analogue input signal received from said imaging sensor via said signal conversion circuit, wherein said image capturing system further comprises calibration circuitry for calibrating said input signal, said calibration circuitry comprising: a correction circuit for receiving a signal derived from the output of the analogue to digital converter and outputting a digital offset signal; and a digital to analogue converter for receiving said digital offset signal and feeding a corresponding analogue offset signal back to the input of said gain amplifier, such that said correction circuit and said digital to analogue converter form a feedback loop applying an offset to said input signal, wherein said correction circuit includes an inverse gain circuit for applying an inverse gain to a signal within said correction circuit prior to said digital to analogue converter.
Said inverse gain may be applied so as to establish a combined gain response applied around said feedback loop within predetermined bounds.
The gain of said gain amplifier may be variable, the circuit further comprising a controller for controlling said inverse gain circuit so as to vary the inverse gain automatically so as to maintain the loop gain factor within said predetermined bounds as the gain of the gain amplifier varies. Said controller may be arranged to vary the gain of the inverse gain circuit more coarsely than the gain of the gain amplifier. Said variation of the loop gain factor around the circuit's feedback loop may be restricted within said pre-determined bounds, wherein said pre-determined bounds enable the feedback loop to maintain stability. The variation of the loop gain factor around said feedback loop may be restricted within 50% of a nominal value to said pre-determined bounds. Said nominal value may be the midpoint of the feedback loop's stability range. In one embodiment, the midpoint of the feedback loop's stability range may be unity and said variation of the loop gain factor around said feedback loop may be restricted within the bounds 0.5 and 1.5.
The number of possible gain values said inverse gain circuit can apply may be a power of two.
Said gain amplifier may be a programmable gain amplifier, the gain being dependent on an input coefficient applied to a control input of the calibration circuit. The number of possible gain values that said inverse gain circuit can apply may be less than the total number of possible input coefficients for said programmable gain amplifier. Said controller may be arranged to use a look up table in order to select the inverse gain to be applied by reference to the coefficient controlling said gain amplifier. Said look up table may be divided into regions, with a single inverse gain factor being selected for all the coefficient values in each region. Said single inverse gain factor for each region may be calculated from the mean coefficient value in that region.
Said inverse gain circuit may be a multiplier. Said multiplier may be a shift-add multiplier.
Said calibrated output signal may be dependent on a target calibration level. Said target calibration level may be settable by a user. Said correction circuit may further comprise a digital adder, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter such that said offset applied to said input signal may be dependent on said target calibration level. Alternatively, a digital adder may be comprised in an output signal path of said circuit, said target calibration level being set by addition of a target calibration signal to said signal derived from the output of the analogue to digital converter, to obtain said calibrated output signal.
Said circuit may be arranged to take a number of iterations, if necessary, in order to perform said calibration wherein a pre-determined delay may be introduced between successive iterations to allow for latency in the calibration circuit. Said latency may be as a result of the delay between the adjustment of the digital to analogue converter and its effect being seen on the output of the analogue to digital converter or to delays in the circuit elements.
The circuit may be specifically designed for setting a black level offset for image processing. Said calibration may be arranged to be performed while specifically designated black pixels are being scanned. Said black-pixels may be arranged to be low-pass filtered in the feedback path.
There may be further provided a manual calibration override for applying an offset directly onto the input signal.
Said correction circuit may further comprise a holding circuit for holding the signal level in the calibration circuit prior to conversion by said digital to analogue converter. Said holding circuit may have a control input for controlling when said signal level should be held. Said holding circuit may comprise a digital accumulator or an integrator.
Said system may further comprise an output device.
Said system may form part of a scanner, part of a photocopier, or part of a multi-functional device capable of copying, scanning, storing, transmitting and printing images.
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7760659 | TECHNICAL FIELD
This invention relates to data communication for multi-party video conferencing and, in particular, to transmission optimization for application-level multicast.
BACKGROUND
The Internet has become an essential part of our daily life and is increasingly utilized as an electronic form of communication via emails, instant messenger services, and similar text-based communication technologies. Additionally, there are increasing demands for real-time, multi-party voice and video conferencing, such as for long-distance education courses, telemedicine, other global business needs, and similar multicast video conferencing applications.
In contrast to a one-to-many content distribution system, small-scale video conferencing applications are implemented with a few-to-few semantic which typically includes ten or fewer participants. Membership in these video conferences can change suddenly where any member may join or leave the video conference, or a member may invite others to conference at any time. Each participant in a multicast video conference is a data source of video and audio data, and each participant is a data recipient of the video and audio data from the other participants.
Each participant in a video conference generates at least video and audio media streams, both of which are highly bandwidth intensive. However, most Internet users have a limited bandwidth connection by which to communicate and receive the video and audio data. Additionally, participants of a video conference may have diverse Internet connections, such as dial-up, DSL, cable modem, and LAN connections. There is an on-going need to optimally serve all of the participants of a real-time, multicast video conference, particularly when many of the participants have different bandwidth capabilities and varying end-to-end communication latencies.
SUMMARY
Transmission optimization for application-level multicast is described herein.
In an implementation, a multicast tree is generated for each member of a video conference. A multicast tree represents a data communication configuration of a data source and other members of a video conference which are data recipients that receive video and audio data from the data source. An end-to-end transmission delay between any two members of the video conference is determined, and the available bandwidth between any two members of the video conference is determined. One or more of the multicast trees, each corresponding to a data source, are refined according to the end-to-end transmission delay and available bandwidth for a particular data source to optimize the data communication configuration of the data source in the video conference.
| 0 | You are a knowledgeable patent classifier specializing in environmental technology. Examine the following summary of a patent and determine if it relates to green technology.
SUMMARY: TECHNICAL FIELD
This invention relates to data communication for multi-party video conferencing and, in particular, to transmission optimization for application-level multicast.
BACKGROUND
The Internet has become an essential part of our daily life and is increasingly utilized as an electronic form of communication via emails, instant messenger services, and similar text-based communication technologies. Additionally, there are increasing demands for real-time, multi-party voice and video conferencing, such as for long-distance education courses, telemedicine, other global business needs, and similar multicast video conferencing applications.
In contrast to a one-to-many content distribution system, small-scale video conferencing applications are implemented with a few-to-few semantic which typically includes ten or fewer participants. Membership in these video conferences can change suddenly where any member may join or leave the video conference, or a member may invite others to conference at any time. Each participant in a multicast video conference is a data source of video and audio data, and each participant is a data recipient of the video and audio data from the other participants.
Each participant in a video conference generates at least video and audio media streams, both of which are highly bandwidth intensive. However, most Internet users have a limited bandwidth connection by which to communicate and receive the video and audio data. Additionally, participants of a video conference may have diverse Internet connections, such as dial-up, DSL, cable modem, and LAN connections. There is an on-going need to optimally serve all of the participants of a real-time, multicast video conference, particularly when many of the participants have different bandwidth capabilities and varying end-to-end communication latencies.
SUMMARY
Transmission optimization for application-level multicast is described herein.
In an implementation, a multicast tree is generated for each member of a video conference. A multicast tree represents a data communication configuration of a data source and other members of a video conference which are data recipients that receive video and audio data from the data source. An end-to-end transmission delay between any two members of the video conference is determined, and the available bandwidth between any two members of the video conference is determined. One or more of the multicast trees, each corresponding to a data source, are refined according to the end-to-end transmission delay and available bandwidth for a particular data source to optimize the data communication configuration of the data source in the video conference.
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