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<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a flexible LED illumination device, and more particularly to an improved flexible LED cable light. 2. Description of Related Art LED cable lights have high brightness and low power consumption so they are usually decorative lights for houses, offices, stories, etc. Furthermore, the LED cable light is flexible so the LED cable light is easy to store and decorate curved places and is even portable. To decorate large exterior walls of buildings, the LED cable light must be waterproof, low cost, cuttable or joinable, etc. To meet the forgoing requirements many types of LED cable lights have been developed. With reference to FIG. 14 , a first type of conventional LED cable light has a pair of wires ( 20 , 21 ), multiple LED chips ( 22 ) and an epoxy sheath ( 23 ). The wires ( 20 , 21 ) are connected to low power source (not shown). Each LED chips ( 22 ) is connected between the pair of wires ( 20 , 21 ), and the epoxy sheath ( 23 ) covers the pair of wires ( 20 , 21 ) and the LED chips ( 22 ). Therefore, the first type of conventional LED cable light is waterproof function but cannot be cut or joined easily. Therefore, the first type of conventional LED cable light does not completely meets the forgoing requirements. With reference to FIG. 15 , a second type of conventional LED cable light includes an insulator substrate ( 25 ), wires (not shown) and LEDs ( 26 ). The wires are on the insulator substrate ( 25 ), and the LEDs ( 26 ) are connected to the wires. The wires are usually made of aluminum, gold etc. The wires are expensive material so the second type of conventional LED cable light is not cheap. Furthermore, the second type of conventional LED cable light does not have a joinable structure or connector so the cable light does not meet the necessary requirements. With reference to FIG. 16 , a third type of conventional LED cable light has a multi-layer substrate ( 27 ), conductors ( 28 ), LEDs ( 29 ), spacers ( 50 ) and lenses ( 51 ). The multi-layer substrate ( 27 ) has two opposite sides (not numbered), and the LEDs ( 29 ) and the two conductors ( 28 ) are mounted on the multi-layer substrate ( 27 ). The LEDs are connected to the two conductors ( 28 ), and the lenses are mounted across the two opposite sides to cover the LEDs and the two conductors ( 28 ). The third type of conventional LED cable light can be cut different lengths but has a very complex structure. Consequently, the fabricating cost of the third type of conventional LED cable light is higher than the other types described. Therefore, the third type does not meet the forgoing requirements either. With reference to FIG. 17 , a fourth type of conventional LED cable light includes an insulation layer ( 52 ), conductors ( 53 ) and LEDs ( 54 ). The conductors ( 53 ) are embedded in the insulation layer ( 52 ). Each LED ( 54 ) has two contacts ( 541 ) that puncture the insulation layer ( 52 ) and connects to the conductors ( 53 ). The fourth type of conventional LED cable light has a simple structure so the cable light is easy to fabricate and the cost is cheap. However, the fourth type of conventional LED cable light is not very waterproof because the contacts ( 541 ) of the LED ( 54 ) puncture the insulation layer ( 52 ). Therefore, the fourth type of conventional LED cable light does not meet the necessary requirements. With reference to FIG. 18 , a fifth type of conventional LED cable light has a substrate strip ( 55 ), a printed circuit ( 551 ), surface mounted technology (SMT) LEDs ( 56 ) and an insulation layer ( 57 ). The printed circuit ( 551 ) is formed on the substrate strip ( 55 ). The SMT LEDs ( 56 ) are connected to the printed circuit ( 551 ), and the insulation layer ( 57 ) covers the substrate strip ( 55 ), the printed circuit ( 551 ) and LEDs ( 56 ). The LEDs ( 56 ) are connected to the printed circuit ( 551 ) so the substrate strip ( 55 ) having the printed circuit ( 551 ) must be required. Therefore, the fifth type of conventional LED cable light has complex fabricating process and has a relatively high cost. The conventional LED cable lights either are not waterproof or affordable or cannot be easily cut and joined. Therefore, the present invention provides a flexible LED cable light to achieve the aforementioned features. |
<SOH> SUMMARY OF THE INVENTION <EOH>The main objective of the invention is to provide a flexible LED cable light that is waterproof, affordable, cuttable, joinable, etc. In accordance with the present invention, an LED cable light includes an insulation body having a longitudinal slot and multiple vertical notches to respectively communicate with the longitudinal slot, at least two wires of multiple strands, a plurality of LEDs respectively mounted on circuit boards and a protective layer. The at least two wires are embedded in parallel in the insulation body, and the LEDs mounted on the circuit boards are respectively received in a corresponding one of the notches and connected to the at least two wires by conductors. The LEDs can further connect in serial to resistors received in the longitudinal slot to form multiple strings. The LEDs or strings are electrically connected in parallel to the two wires. The LEDs used in the present invention refer to the three types such as SMT LEDs, LED bare chips and sealed cube LEDs. Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. |
Solid fuel igniter |
A solid fuel igniter that provides for initial heating of solid fuel pieces to expedite reaching a self-ignition preparatory state. The igniter comprises a primary fire generating chamber, wherein heat energy is generated and transmitted upwards to an enclosing body having a top opening of wide cross section that tapers downwards to a lower end of narrower cross section. The enclosing body holds the solid fuel pieces packed therein, and a primary fire in the generating chamber heats a smaller number of the solid fuel pieces packed on the bottom of the enclosing body, which generate spontaneous and intense heat energy that propagates thermal waves uniformly upward, thereby enabling all of the solid fuel pieces to uniformly reach the self-ignition preparatory state. |
1. A solid fuel igniter that provides for initial heating of solid fuel pieces to expedite reaching a self-ignition state, comprising a primary fire generating chamber, on top of which is disposed an inverse tapered enclosing body, and a flat grill disposed between the primary fire generating chamber and the inverse tapered enclosing body. 2. The solid fuel igniter as described in claim 1 wherein air vents and assisting air inlets are defined in a top and a bottom periphery portion of the Inverse tapered enclosing body respectively. 3. The solid fuel igniter as described in claim 1, wherein at least one expanding enclosing body is additionally disposed atop a top expanded opening of the inverse tapered enclosing body. 4. The solid fuel igniter as described in claim 1, wherein a heat insulating layer is further disposed around peripheries of the enclosing body and the expanding enclosing bodies. 5. The solid fuel igniter as described in claim 1, wherein a periphery of the igniter is further configured with a protective shield, which stands upright and surrounds the igniter, and connecting members are affixed to the protective shield for joining to the igniter. 6. The solid fuel igniter as described in claim 1, wherein a far-infrared producing converter is disposed on the expanded opening of the enclosing body. 7. The solid fuel igniter as described in claim 1, wherein an oil burner or a gas burner is further configured within the generating chamber. 8. The solid fuel igniter as described in claim 1, wherein a manually operated fan device is further configured on a lower end of the generating chamber. 9. The solid fuel igniter as described in claim 1, wherein frame legs are respectively radially joined to a periphery of the igniter. 10. The solid fuel igniter as described in claim 9, wherein the frame legs are assembled by means of a pivotly connecting method. 11. The solid fuel igniter as described in claim 1, wherein a feed hole is defined in the generating chamber. 12. The solid fuel igniter as described in claim 11, wherein the feed hole is subject to relative opening and closing by a valve opening defined in a valve movably disposed on a periphery of the generating chamber, thereby achieving control of the amount of airflow. |
<SOH> BACKGROUND OF THE INVENTION <EOH>(a) Field of the Invention The present invention relates to a solid fuel igniter, and more particularly to an igniter that provides for uniform packing of solid fuel pieces, thereby enabling the fuel pieces to reach a self-ignition preparatory state. An additional fire source, using tinder, and so on, is necessary in the initial stage of heating the solid fuel to directly enkindle the solid fuel pieces packed in a bottom portion of the igniter. (b) Description of the Prior Art In recent times, it has become popular for restaurants to provide a dining method using a tabletop charcoal grill to cook, such as hot pot restaurants, charcoal grill restaurants, and so on. Such charcoal grill methods use large quantities of solid fuel. Referring to FIG. 1 , in order to prepare in advance a large quantity of fuel to produce a primary self-ignition state, a conventional solid fuel igniter uses a bucket 1 , which is partitioned by disposing a dome-shaped grill 11 at a middle portion therein. Air inlets 13 are defined in a lower portion close to a bottom opening 12 of the bucket 1 , and a handle 14 is affixed to a side of the bucket 1 to facilitate emptying out solid fuel pieces 10 that have completed self-ignition. A primary fire 2 is prepared under the bucket 1 to enkindle the solid fuel pieces 10 . Flames 20 from the primary fire 2 positioned below the bucket 1 penetrate the dome-shaped grill 11 , thereby transmitting heat energy to the lower packed solid fuel pieces 10 within the bucket 1 . However, because the flames 20 rise and concentrate along a center line, thus, fuel pieces 10 A positioned close to an inner circumference of the bucket 1 are not only unable to directly receive heat energy from the flames 20 , moreover, because of cold air drawn in by the air inlets 13 , the fuel pieces 10 A will have a lower temperature, which results in a slow speed of heat energy transmission. A catalytic self-ignition phenomenon first occurs in an upward sloping tapered space 21 formed at a center of the stacked solid fuel pieces 10 relative to center of the bucket 1 . Moreover, the fuel pieces 10 positioned in the tapered space 21 often burn excessively, whereas the fuel pieces 10 A positioned at the inner circumference are unable to reach a uniform self-ignition preparatory state. In addition, the conventional igniter is only able to provide a finite space, which fixes the number of solid fuel pieces 10 that can be packed therein for preheating. |
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention particularly provides an improved structure for a solid fuel igniter, wherein a heat source generating chamber is used to generate a primary fire, and an inverse tapered enclosing body is disposed on top of the generating chamber to provide for loading solid fuel pieces therein. A contracted bottom end of the inverse tapered enclosing body is disposed on a top end opening of the generating chamber, thus, heat energy generated by the generating chamber heats a smaller number of the fuel pieces packed at the bottom contracted opening of the inverse tapered enclosing body. The solid fuel pieces packed at the bottom contracted opening of the enclosing body are the first to be heated by the primary fire in the generating chamber, and the heat generated after the solid fuel pieces have achieved self-ignition serves as a secondary upward heating source, which subjects the fuel pieces packed in upper portions of the enclosing body to successive and uniform secondary heating. To enable a further understanding of said objectives and the technological methods of the invention herein, brief description of the drawings is provided below followed by detailed description of the preferred embodiments. |
PCR amplification reaction apparatus and method for PCR amplification reaction using apparatus |
The present invention provides a method for PCR amplification reaction that can reduce the time required for amplification reaction of nucleic acid by PCR using the target nucleotide molecule as a template, and an apparatus used for the method. The method comprises using a PCR reaction vessel in which a heater for local heating, which can thermally contact with a solution storing section with an extremely small capacity for storing a PCR reaction solution and a reaction solution stored in the solution storing section directly, is placed; feeding a pulsed current to the placed heater; and carrying out a thermal cycle of PCR reaction, so that high-speed PCR amplification reaction can be carried out. |
1. A method for PCR amplification reaction to amplify a DNA strand having a corresponding nucleotide sequence from a nucleic acid chain as template by PCR reaction, the method for PCR amplification reaction comprising: using, a reaction vessel in which a heater is placed at a position at which the heater can thermally contact the stored reaction solution as a reaction vessel for storing a PCR reaction solution containing the nucleic acid chain as a template, storing the PCR reaction solution with the designed storing capacity in a solution storing section of the reaction vessel with a heater; bringing the entire reaction vessel with the heater into contact with a medium set at a predetermined temperature to maintain the vessel at the predetermined temperature in a continuous manner; applying a predetermined pulsed voltage to the heater provided in the reaction vessel and carrying out pulsed heating corresponding to the pulse time width and the pulse voltage height to form a thermal cycle for PCR reaction; and providing a process of carrying out PCR reaction by repeating application of the pulsed voltage a plurality of times and correspondingly repeating the thermal cycle a plurality of times. 2. The method for PCR amplification reaction according to claim 1, wherein the reaction vessel has a storing capacity of the reaction solution and a shape of the solution storing section designed in order to exhibit a heat capacity in which the temperature of the reaction solution can respond to the thermal pulse generated by applying a predetermined pulsed voltage to the heater in the order of at least 0.01 second. 3. The method for PCR amplification reaction according to claim 1, wherein the process of carrying out PCR reaction repeats application of the pulsed voltage a plurality of times periodically and correspondingly repeats the thermal cycle a plurality of times. 4. A PCR reaction apparatus in which PCR reaction can be carried out in accordance with the method for PCR amplification reaction according to claim 1, the PCR reaction apparatus comprising: a reaction vessel, used as a reaction vessel for storing a PCR reaction solution, in which a heater is placed at a position at which the heater can thermally contact the stored reaction solution directly, and the storing capacity of the reaction solution and the shape of the solution storing section are designed in order to exhibit a heat capacity in which the temperature of the reaction solution can respond to the thermal pulse generated by applying a predetermined pulsed voltage to the heater in the order of at least milliseconds; a heating block that has a structure in which the reaction vessel with the heater can be held, and can maintain the entire reaction vessel at a predetermined temperature in a continuous manner through thermal conduction by bringing the reaction vessel into contact therewith; a heating block temperature control mechanism for controlling the temperature of the heating block at a predetermined temperature; a pulsed voltage generating mechanism for applying a pulsed voltage with a desired pulse time width and a desired pulse voltage height to the heater placed in the reaction vessel a desired number of times of repetition periodically; an MPU unit for managing the operation of the heating block temperature control mechanism and the pulsed voltage generating mechanism; a key input device for inputting and setting the managing conditions by the MPU unit; and a display for displaying the managing conditions by the MPU unit or the managed status information. 5. A PCR reaction vessel in which PCR reaction can be carried out in accordance with the method for PCR amplification reaction according to claim 1, wherein the reaction vessel for storing a PCR reaction solution being a reaction vessel with a heater in which a heater is placed at a position at which the heater can thermally contact the stored reaction solution directly, and the storing capacity of the reaction solution and the shape of the solution storing section are designed in order to exhibit a heat capacity in which the temperature of the reaction solution can respond to the thermal pulse generated by applying a predetermined pulsed voltage to the heater in the order of at least milliseconds. 6. A method comprising detecting a nucleic acid molecule having a specific nucleotide sequence included in a group of genetic nucleic acid molecules having a single nucleotide polymorphism or genetic polymorphism to detect a single nucleotide polymorphism or genetic polymorphism indicated by the nucleic acid molecule, the method for detecting a single nucleotide polymorphism or genetic polymorphism comprising: selecting multiple variants of nucleic acid probes having nucleotide sequences corresponding to partial nucleotide sequence which indicate a difference of nucleotide sequences with each other from the group of genetic nucleic acid molecules having a single nucleotide polymorphism or genetic polymorphism; selecting the partial nucleotide sequences from the plurality of nucleic acid probes so that at least one of nucleotides indicating a difference with each other in the single nucleotide polymorphism or genetic polymorphism is located on the 3′-end side in the nucleotide sequences of nucleic acid probes; constituting a microarray in which the multiple variants of nucleic acid probes bind to the surface of an identical carrier in an array manner via a linker connected to the 5′-end; carrying out extension of a complementary DNA strand, under conditions in which a nucleic acid molecule having a specific nucleotide sequence to be detected can selectively hybridize with the nucleotide acid probes constituting the microarray, by PCR amplification reaction using a thermal cycle with the nucleic acid molecule having a specific nucleic acid sequence to be detected as a template and the one of the multiple variants of nucleic acid probes that selectively hybridizes with the template as a primer; and specifying the one of the multiple variants of nucleic acid probes, in which a complementary DNA strand can be extended, in the microarray to detect a single nucleotide polymorphism or genetic polymorphism containing a partial nucleotide sequence corresponding to a nucleotide sequence possessed by the one of the nucleic acid probes specified. 7. The method for detecting a single nucleotide polymorphism or genetic polymorphism according to claim 6, wherein the PCR amplification reaction comprises providing a thermal cycle comprising steps of denaturing, annealing and extension, and setting the time for each of the denaturing, annealing and extension steps constituting one thermal cycle within 10 seconds or shorter. 8. A reaction vessel for detecting a single nucleotide polymorphism or genetic polymorphism in which PCR amplification reaction for detecting a single nucleotide polymorphism or genetic polymorphism can be carried out in accordance with the method for detecting a single nucleotide polymorphism or genetic polymorphism according to claim 6, wherein detection of an objective single nucleotide polymorphism or genetic polymorphism means detection of a nucleic acid molecule having a specific nucleotide sequence included in a group of genetic nucleic acid molecules having a single nucleotide polymorphism or genetic polymorphism to detect a single nucleotide polymorphism or genetic polymorphism indicated by the nucleic acid molecule; multiple variants of nucleic acid probes having nucleotide sequences corresponding to partial nucleotide sequence which indicate a difference of nucleotide sequences with each other from the group of genetic nucleic acid molecules having a single nucleotide polymorphism or genetic polymorphism are selected; the partial nucleotide sequences are selected so that at least one of nucleotides indicating a difference with each other in the single nucleotide polymorphism or genetic polymorphism is located on the 3′-end side in the nucleotide sequences of the multiple variants of nucleic acid probes; a microarray is provided so that the multiple variants of nucleic acid probes bind to the surface of an identical carrier in an array manner via a linker connected to the 5′-end, the carrier constituting the microarray is placed in the reaction vessel so that the surface of the carrier can be brought into contact with a reaction solution in the reaction vessel, and the multiple variants of nucleic acid probes constituting the microarray on the surface of the carrier can thermally contact a heat source forming a temperature change of a thermal cycle in the PCR amplification reaction via thermal conduction in the carrier; and the storing capacity of a reaction solution and the shape of a solution storing section in the reaction vessel are designed so that, in the PCR amplification reaction, the solution thickness of the reaction solution in contact with the multiple variants of nucleic acid probes is 3 mm or less in the normal direction with respect to the surface of the carrier to which the multiple variants of nucleic acid probes bind. 9. The reaction vessel for detecting a single nucleotide polymorphism or genetic polymorphism according to claim 8, wherein the material for the carrier with a surface to which the multiple variants of nucleic acid probes constituting the microarray bind is an organic material. 10. An apparatus for carrying out PCR amplification reaction, the PCR reaction apparatus comprising: a reaction vessel for storing a PCR reaction solution; a heater placed at a position at which the heater can thermally contact the stored reaction solution; a pulsed voltage generating mechanism for applying a predetermined pulsed voltage to the heater; and a block that has a structure in which the reaction vessel with the heater can be held, and can maintain the entire reaction vessel at a predetermined temperature in a continuous manner through thermal conduction by bringing the reaction vessel into contact therewith. 11. The PCR reaction apparatus according to claim 10, wherein the heater is placed at a position at which the heater can thermally contact the stored reaction solution directly. 12. The PCR reaction apparatus according to claim 10, wherein the heater is constituted as laminated on at least a part of the inner wall of the reaction vessel. 13. The PCR reaction apparatus according to claim 10, further comprising a heating block temperature control mechanism for controlling the temperature of the heating block at a predetermined temperature. 14. A PCR reaction apparatus comprising: an MPU unit for managing the operation of the heating block temperature control mechanism and the pulsed voltage generating mechanism; a key input device for inputting and setting the managing conditions by the MPU unit; and a display for indicating the managing conditions by the MPU unit or the managed status information. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a PCR amplification reaction apparatus and a method for PCR amplification reaction using the apparatus. Particularly, the present invention relates to a PCR amplification reaction apparatus that can be used for analyzing a genetic polymorphism, a single nucleotide genetic polymorphism (SNP) or the like, to a method for PCR amplification reaction using the apparatus, and to a method for detecting a genetic polymorphism, an SNP or the like to which the apparatus and/or the method are applied. 2. Related Background Art Conventionally, PCR (polymerase chain reaction) has been used as typical means for amplifying a specific region of a nucleic acid chain. PCR comprises adding a DNA polymerase enzyme and each nucleic acid as a substrate to a region to be amplified of a template nucleic acid chain, for example, a double-strand DNA using a corresponding DNA fragment called a PCR primer corresponding to the partial nucleotide sequences of both terminals of the region, and repeating a thermal cycle consisting of denaturing, annealing and extension to amplify only the DNA strand of a target region. A one-cycle process consisting of, for example, denaturing at 94° C. for 30 seconds, annealing at 55° C. for 30 seconds and extension at 72° C. for one minute as the thermal cycle for PCR reaction is repeated 30 times in total. Under these conditions, the time required for the thermal cycles as a whole is about 1.5 hours. When amplifying a nucleic acid chain in which a region to be amplified has a larger length of nucleotides, the time interval for the extension step carrying out reaction of extending a DNA strand from the 3′-end of a primer is set longer. Accordingly, it is fairly general that the total time required for the thermal cycles amounts to about 1.5 to 2.5 hours. In order to reduce as much as possible the time for such a thermal cycle process requiring a long period of time, several contrivances have been proposed. For example, Light Cycler (Roche Diagnostics), an apparatus in which amplification reaction is completed within about 20 to 30 minutes has been commercially available in recent years. However, the time reduction technique used in this commercially available apparatus is a technique of applying temperature controlled hot air to a capillary vessel simply in order to reduce the time spent for temperature change. Specifically, the technique reduces the time spent for temperature change based on the finding that use of a capillary vessel can reduce the volume of the reaction vessel and a capillary vessel has a small heat capacity. The temperature controlling technique itself is, in principle, the same as a conventional technique. In addition, air used as a heating and cooling medium in this apparatus has a small density and a small thermal conductivity and is one of the least heat conductive media. Taking these points into consideration, it cannot be said that air is not an optimal temperature controlling system. On the other hand, the greatest advantage of PCR is that the method can selectively amplify a nucleic acid chain having a specific nucleotide sequence in a sample containing various nucleic acid chains collected from the living body. In analysis of genetic polymorphisms, SNPs or the like, only the nucleic acid chain which indicates a difference of nucleotide sequences to be analyzed must be selectively amplified in a sample containing various nucleic acid chains prior to the analysis. In a process for preparing this DNA sample for analysis, PCR amplification has been widely used with the above-described selectivity against a nucleotide sequence. Conventionally, there has been no technique for analyzing gene polymorphisms, SNPs or the like that is specifically limited based on nucleotide sequences. For analysis of various genetic polymorphisms, SNPs or the like, used is an oligonucleotide fragment for a detection probe which corresponds to a partial nucleotide sequence that is known to exhibit a difference based on technological accumulation in the past. In a technology similar to a microarray technology, about 100 kinds of bead arrays of Luminex Corp. or electrode arrays of Nanogen, Inc. are used in order to achieve a hybridization reaction time remarkably shorter as compared with a conventional microarray technology. Other than the microarray technology using hybridization reaction with a detection probe, several analysis technologies have been known. An RFLP (Restriction Fragment Length polymorphism) technology comprises effecting a restriction enzyme that can cleave a partial nucleotide sequence indicating a difference oh a selectively amplified double-strand DNA, and judging whether or not the corresponding partial nucleotide sequence exists based on the difference in electrophoresis patterns among a plurality of DNA fragments produced. Direct nucleotide sequence determination comprises PCR amplifying using a Dye terminator for a DNA sequencer with a nucleic acid chain containing genetic polymorphisms, SNPs or the like as a template and directly determining the nucleotide sequence with a DNA sequencer to judge whether or not the partial nucleotide sequence indicating a difference exists. In the RFLP technology, a restriction enzyme that can cleave a partial nucleotide sequence indicating a difference between detectable genetic polymorphisms is required to be selected and used. Accordingly, the technology has a methodologically limited range of application, for example, can be applied only to a case where a difference is indicated by a partial nucleotide sequence corresponding to the site of an available restriction enzyme. On the other hand, there are no limitations, in principle, to the application range for the direct nucleotide sequence determination, because a DNA sequencer is actually used to determine the nucleotide sequence. However, when a template contains a plurality of similar sequences, it is difficult to analyze a single gene, and a problem of ambiguity found in some HLA typings occurs. In addition, the time required for pretreatment of a sample used for DNA sequencing, the running cost for a DNA sequencer apparatus, and the electrophoresis time of the technology are disadvantageous for working efficiency and economical efficiency. In particular, the number of genetic polymorphisms that can be analyzed at the same time is limited according to the number of capillaries in a DNA sequencer apparatus. On the other hand, when the number of capillaries is smaller than that of samples to be analyzed, the apparatus suffers from reduced operation efficiency. Taking these limitations into consideration, it is hard to say that direct nucleotide sequence determination is not an optimal technology. On the other hand, the technology with a microarray can analyze a plurality of probes ranging from several thousand dots to ten thousand dots in one time, advantageously. In contrast, a nucleic acid chain to be detected by each probe must be labeled such as fluorescently labeled. Such a pretreatment of a sample requires several hours as in the case of direct nucleotide sequence determination, and such a pretreatment must be carried out for each objective probe, which leads to a complicated work. Moreover, the probe hybridization reaction on a microarray is carried out as a solid phase reaction and requires several hours. Furthermore, if the length of the DNA strand of a sample is too much larger than the length of probes involved in hybridization, crossreaction with other probes may be induced. It is true that the technology with a bead array or electrode array is means for significantly improving the probe hybridization reaction time. However, it is difficult to prepare a large-scale probe array like a conventional microarray, and only about 100 kinds of probe arrays are available. For examples, regarding to HLA genetic polymorphisms, two hundred and several ten kinds of alleles have been already confirmed. The technology with a bead array or electrode array cannot be adequately applied to analysis of such many kinds. |
<SOH> SUMMARY OF THE INVENTION <EOH>As described above, conventional techniques for analyzing genetic polymorphisms, SNPs or the like can be adequately applied to individual application fields, but any of the techniques has advantages and drawbacks when the technique is to be widely applied. For use of any of the analysis techniques, it has been desired to reduce the time required for pretreatment of a sample, specifically, the time spent for PCR amplification reaction for selectively amplifying only the nucleic acid chain indicating a difference between the nucleotide sequences to be analyzed. In addition, the technology with a microarray can analyze many kinds of probes in one time, advantageously, but has been desired to allow further reduction in both the time required for pretreatment of a sample and the time required for probe hybridization reaction on a microarray, when the technology is to be widely applied. The present invention has achieved to solve these problems. A first object of the present invention is to provide a novel PCR amplification apparatus that is used for pretreatment a sample and can significantly reduce the time spent for PCR amplification reaction, and a method for PCR amplification using the apparatus. In addition, a second object of the present invention is to provide a novel method for detecting DNA in SNPs and genetic polymorphisms to which such a novel PCR amplification apparatus and such a method for PCR amplification using the apparatus can be applied and which can detect genetic polymorphisms or SNPs sensitively, simultaneously, and more conveniently in a shorter processing time with a probe fixed on a microarray. Prior to conducting investigations on means for achieving the first object, the present inventors have reviewed which step of a thermal cycle in PCR amplification reaction is a rate-determining step. In general, PCR amplification reaction employs a thermal cycle consisting of hybridization reaction of a template single-strand nucleic acid molecule with a primer, specifically, an annealing step of forming a double strand in which the single-strand nucleic acid molecule binds to the complementary strand; an extension step of effecting a DNA polymerase enzyme after the hybridization to carry out reaction of extending a DNA strand from the 3′-end of the primer constituting such a double strand; and a denaturing step of thermally dissociating the double-strand nucleic acid after the extension reaction to separate the nucleic acid into a template single-strand nucleic acid molecule and its complementary strand. The inventors have found that in this case, in the extension step of effecting a DNA polymerase enzyme after the hybridization to carry out reaction of extending a DNA strand from the 3′-end of the primer constituting such a double strand, the time for completing the extension reaction of a DNA strand by the DNA polymerase enzyme to accomplish the synthesis of the complementary strand determines the rate of the entire amplification reaction. On the other hand, the inventors have found that, by setting sufficiently high the temperature for the denaturing step of thermally dissociating the double-strand nucleic acid to separate the nucleic acid into a template single-strand nucleic acid molecule and its complementary strand, thermal dissociation of the most part of the double strand can be completed even if the heating time is several ten ms. In the hybridization reaction of a single-strand nucleic acid molecule with a primer, misfit hybridization, in which the primer hybridizes with a part other than the nucleotide sequence part complementary to the primer, may accidentally occur, usually. Misfit hybridization is avoided by selecting a temperature that does not cause misfit hybridization of a primer as the temperature for the annealing step by using the difference between the Tm value (melting temperature) of a primer that hybridizes with a full-match sequence and the Tm value of a primer that misfit hybridizes with a mismatch sequence. In this case, the temperature of the extension step is appropriately selected so that the temperature is the Tm value (melting temperature) of a primer that hybridizes with a full-match sequence or lower or the temperature for the annealing step or higher, according to the rate of DNA strand extension reaction by a DNA polymerase enzyme. The inventors have found taking the above facts into consideration that the time required for one thermal cycle can be remarkably reduced, if the thermal cycle process can comprise preheating a reaction solution as a whole to a temperature for the annealing step, heating the reaction solution to a temperature above the target denaturing temperature for several ten ms in the denaturing step, and then rapidly cooling the reaction temperature to the temperature for the annealing step. Based on this finding, the inventors have accomplished the invention of the method for PCR amplification reaction according to a first embodiment of the present invention. Specifically, the method for PCR amplification reaction according to the first embodiment of the present invention is a method for PCR amplification reaction comprising amplifying, from a nucleic acid chain as a template, a DNA strand having a corresponding nucleotide sequence by PCR reaction, the PCR amplification reaction comprising: using, as a reaction vessel for storing a PCR reaction solution containing the nucleic acid chain as a template, a reaction vessel in which a heater is placed at a position at which the heater can thermally contact the stored reaction solution; storing the PCR reaction solution of the designed storing capacity in a solution storing section of the reaction vessel with a heater; bringing the entire reaction vessel with the heater into contact with a medium set at a predetermined temperature to maintain the vessel at the predetermined temperature in a continuous manner; applying a predetermined pulsed voltage to the heater provided in the reaction vessel and carrying out pulsed heating corresponding to the pulse time width and the pulse voltage height to form a thermal cycle for PCR reaction; and providing a process of carrying out PCR reaction by repeating application of the pulsed voltage a plurality of times and correspondingly repeating the thermal cycle a plurality of times. The reaction vessel preferably has a storing capacity of the reaction solution and a shape of the solution storing section designed in order to exhibit a heat capacity in which the temperature of the reaction solution can respond to the thermal pulse generated by applying a predetermined pulsed voltage to the heater in the order of at least 0.01 second. The process of carrying out PCR reaction preferably repeats application of the pulsed voltage a plurality of times periodically and correspondingly repeats the thermal cycle a plurality of times. The present invention provides a PCR apparatus for realizing the above method. Specifically, the apparatus for carrying out PCR amplification reaction according to the present invention comprises: a reaction vessel for storing a PCR reaction solution; a heater placed at a position at which the heater can thermally contact the stored reaction-solution; a pulsed voltage generating mechanism for applying a predetermined pulsed voltage to the heater; and a block that has a structure in which the reaction vessel with the heater can be held, and can maintain the entire reaction vessel at a predetermined temperature in a continuous manner through thermal conduction by bringing the reaction vessel into contact with the reaction vessel. The heater is preferably placed at a position at which the heater can thermally contact the stored reaction solution directly. The heater is suitably constituted as laminated on at least a part of the inner wall of the reaction vessel. The apparatus preferably comprises a heating block temperature control mechanism for controlling the temperature of the heating block at a predetermined temperature. Furthermore, the apparatus suitably comprises an MPU unit for managing the operation of the heating block temperature control mechanism and the pulsed voltage generating mechanism; a key input device for inputting and setting the managing conditions by the MPU unit; and a display for displaying the managing conditions by the MPU unit or the managed status information. Next, prior to conducting investigations on means for achieving the second object, the present inventors have studied means for inhibiting progress of reaction of extending a DNA strand from the 3′-end of a primer misfit that hybridizes with a template nucleic acid molecule by a DNA polymerase enzyme in PCR amplification reaction. It is known that, even if the primer used is a sequence mismatched with a template nucleic acid molecule, when the 3′-end part of the primer is complementary, reaction of extending a DNA strand from the 3′-end by a DNA polymerase enzyme progresses. On the other hand, the inventors have found that, when the 3′-end is mismatched, reaction of extending a DNA strand from the mismatched 3′-end by a DNA polymerase is only rarely initiated. The inventors have compared the Tm value of a primer having a nucleotide sequence mismatched with a template nucleic acid molecule at the center with the Tm value of a primer having a nucleotide sequence mismatched with a template nucleic acid molecule at the 5′-end or 3′-end. As a result, the inventors have discovered that the Tm value of a primer mismatched at the center is considerably lower than the Tm value of a primer not mismatched, but the Tm value of a primer mismatched at the 5′-end or 3′-end is slightly lower than but almost the same as the Tm value of a primer not mismatched. However, the inventors have found that, with regard to the amount of a reaction product by reaction of extending a DNA strand from the 3′-end of a primer that misfit hybridizes with a template nucleic acid molecule by a DNA polymerase enzyme, a reaction product in which a DNA strand is extended can be obtained at a considerable efficiency when the primer is mismatched at the center or the 5′-end, but a reaction product in which a DNA strand is extended cannot be obtained when the primer is mismatched at the 3′-end. On the other hand, if the primer is mismatched at the center or the primer is mismatched at the 5′-end, the resulting reaction product has a 5′-end with the nucleotide sequence of the mismatched primer. Accordingly, this reaction product derived from the misfit hybridized primer can fully hybridize with a probe complementary to the nucleotide sequence of such a mismatched primer. In addition, the inventors have discovered that the reaction product derived from the primer not mismatched with a template nucleic acid molecule often misfit hybridizes with a probe complementary to the nucleotide sequence of the primer mismatched at the 5′-end or 3′-end. The inventors have conducted further investigations based on these findings and found that, by constituting a microarray in which a primer DNA mismatched at the 3′-end and a primer DNA not mismatched, bind to the surface of the same carrier in an array manner via a linker connected to the 5′-end, and then carrying out single-strand PCR amplification reaction using an objective complementary single-strand nucleic acid molecule as a template, a reaction product in which a DNA is extended only to the 3′-end of the primer DNA not mismatched can be obtained, and such a reaction product binds only to a specific spot of the microarray on the carrier surface. In addition, the inventors have also discovered that the presence of this reaction product bound to a specific spot of the microarray on the carrier surface can be easily detected by, for example, labeling the product. Further, the inventors have confirmed that, in such single-strand PCR amplification reaction, by appropriately setting conditions of a thermal cycle of the PCR reaction, so that the primer DNA not mismatched, bound to the surface of the carrier, can hybridize with the template single-strand nucleic acid molecule with high probability, and repeating the thermal cycle in a desired number of times, the amount of the target reaction product bound to a specific spot of the microarray is amplified. Based on these findings, the inventors have accomplished the invention of the method for detecting a single nucleotide polymorphism or genetic polymorphism according to a second embodiment of the present invention to which the PCR amplification reaction of the present invention is applied. Specifically, the method for detecting a single nucleotide polymorphism or genetic polymorphism according to a second embodiment of the present invention is a method comprising detecting a nucleic acid molecule having a specific nucleotide sequence included in a group of genetic nucleic acid molecules having a single nucleotide polymorphism or genetic polymorphism to detect a single nucleotide polymorphism or genetic polymorphism indicated by the nucleic acid molecule, the method for detecting a single nucleotide polymorphism or genetic polymorphism comprising: selecting multiple variants of nucleic acid probes having nucleotide sequences corresponding to partial nucleotide sequence which indicate a difference of nucleotide sequences with each other from the group of genetic nucleic acid molecules having a single nucleotide polymorphism or genetic polymorphism; selecting the partial nucleotide sequences from the multiple variants of nucleic acid probes so that at least one of nucleotides indicating a difference with each other in the single nucleotide polymorphism or genetic polymorphism is located on the 3′-end side in the nucleotide sequences of the nucleic acid probes; constituting a microarray in which the multiple variants of nucleic acid probes bind to the surface of an identical carrier in an array manner via a linker connected to the 5′-end; carrying out extension of a complementary DNA strand, under conditions in which a nucleic acid molecule having a specific nucleotide sequence to be detected can selectively hybridize with only one of the plurality of nucleotide acid probes constituting the microarray, by PCR amplification reaction using a thermal cycle with the nucleic acid molecule having a specific nucleic acid sequence to be detected as a template and the one of the multiple variants of nucleic acid probes that selectively hybridizes with the template as a primer; and specifying the one of the multiple variants of nucleic acid probes, in which a complementary DNA strand can be extended, in the microarray to detect a single nucleotide polymorphism or genetic polymorphism containing the partial nucleotide sequence corresponding to a nucleotide sequence possessed by the one of the nucleic acid probes specified. By using the method for PCR amplification reaction according to the first embodiment of the present invention, the time of the thermal cycle spent for PCR amplification reaction used for pretreatment of a sample or preparation of a complementary strand DNA extended to the 3′-end of a primer using a specific single-strand nucleic acid molecule contained in the sample as a template can be significantly reduced. The method for detecting a single nucleotide polymorphism or genetic polymorphism according to the second embodiment of the present invention can use a single-strand nucleic acid molecule to be detected contained in a sample as a template and allow a single-strand DNA, selectively extended from a primer having a nucleotide sequence complementary to the object to be detected, to bind to a spot of the primer DNA in a microarray on the surface of a carrier via a linker connected to the 5′-end of the primer DNA strand. Accordingly, in principle, the total amount of the reaction product amplified by single-strand PCR can bind to a corresponding spot to carry out detection, and a high detection sensitivity can be achieved. On the other hand, the object to be detected can significantly reduce the total reaction time required for PCR amplification reaction for pretreatment of a sample of preliminarily preparing a DNA strand having a nucleotide sequence the same as that of the template single-strand nucleic acid molecule that hybridizes with the probe while maintaining a large-scale array as in a conventional microarray technology and the subsequent probe hybridization reaction. In addition, by applying the method for PCR amplification reaction according to the first embodiment of the present invention to the process of PCR amplification reaction when carrying out the method for detecting a single nucleotide polymorphism or genetic polymorphism according to the second embodiment of the present invention, the reaction time can be further reduced. Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. |
Method and device for thermostatically regulating a fluid along a conveyance tube |
A method for thermostatically regulating a fluid along a conveyance tube, particularly a polymeric foam fluid component along a feeder tube of a dispenser, comprising supplying fluid contained in a conveyance tube with thermal energy along at least one portion of the conveyance tube varying according to a distance from one of the opposite ends of the portion, detecting the temperature of the fluid at at least one distance from the end, comparing the detected temperature with a presettable reference value, and interrupting or activating supply when the detected temperature is equal to, or lower than, the reference value. The device for thermostatically regulating a fluid along a conveyance tube comprises an electrical conductor, associable with a power supply and inserted in at least one portion of a tube for conveying fluid thermostatically regulated and with a resistance variable according to the distance from at least one of the opposite ends of the portion, and sensors for the temperature of the fluid at at least one distance from the end. |
1. A method for thermostatically regulating a fluid along a conveyance tube, comprising: supplying fluid contained in a conveyance tube with thermal energy along and between opposite ends of at least one portion of said conveyance tube that is variable according to a distance from a first one of the opposite ends of said conveyance tube portion; detecting a temperature of the fluid at at least one distance from said first end; comparing the detected temperature with a presettable reference value; and controlling thermal energy supply by interrupting and activating said supply when a detected temperature is respectively equal to, or lower than, said reference value. 2. The method of claim 1, wherein said thermal energy varies from an initial minimum value to a final maximum value in a direction of flow of said fluid in said portion. 3. The method of claim 1, wherein said thermal energy varies according to an increasing function from said minimum value to said maximum value. 4. The method of claim 1, wherein said thermal energy varies according to a stepwise discontinuous function. 5. The method of claim 1, wherein said thermal energy varies according to a continuous function. 6. The method of claim 1, wherein said thermal energy varies according to a linear function. 7. The method of claim 1, wherein the temperature of said fluid along said portion of said conveyance tube varies according to the distance from one of said opposite ends according to a function that increases from an initial minimum value to a final maximum value in a direction of flow of said fluid in said conveyance tube portion. 8. The method of claim 1, wherein the temperature of said fluid along said conveyance tube portion varies according to a continuous function. 9. The method of claim 1, wherein the temperature of said fluid along said conveyance tube portion varies according to a linear function. 10. A device for thermostatically regulating a fluid along a conveyance tube, comprising: electric power supply means; an electrical conductor, which is connected to said electric power supply means and is inserted in at least one portion of a conveyance tube for conveying a fluid to be thermostatically regulated between opposite ends thereof, said electrical conductor having a resistance that is variable according to a distance from at least a first one of said opposite ends of said conveyance tube portion; and sensing means for sensing a temperature of said fluid at at least one distance from said first end. 11. The device of claim 10, comprising that a control and monitoring unit, which is associated with said sensing means and with said power supply means, said control and monitoring unit being adapted to compare a temperature detected by said sensing means with a presettable reference value and to selectively deactivate and activate said power supply means, respectively, when a detected temperature is equal to, or lower than, said reference temperature value. 12. The device of claim 10, wherein said conductor resistance is provided so as to be variable from an initial minimum value to a final maximum value in a direction of a flow of said fluid in said conveyance tube portion. 13. The device of claim 10, wherein said conductor resistance is provided so as to be variable according to an increasing function. 14. The device of claim 10, wherein said conductor resistance is provided so as to be variable according to a discontinuous stepwise function. 15. The device of claim 10, wherein said conductor resistance is provided so as to be variable according to a continuous function. 16. The device of claim 10, wherein said conductor resistance is provided so as to be variable according to a linear function. 17. The device of claim 16, wherein said conductor comprises a cable that has a variable cross-section depending on said distance, said cross-section increasing from an initial minimum value to a final maximum value in a direction of flow of said fluid. 18. The device of claim 16, wherein said conductor comprises a cable that is wound in a spiral with turns that have a variable pitch depending on said distance. 19. The device of claim 16, wherein said cable has a substantially constant cross-section as a function of said distance. 20. The device of claim 18, wherein said cable is folded double, said spiral being double. 21. The device of claim 18, wherein said pitch varies from an initial maximum value to a final maximum value in a direction of flow of said fluid in said portion. 22. A dispenser for polymeric foams, comprising: storage means for storing component fluids that compose a polymeric foam; drawing means for drawing and sending said component fluids from said storage means to an input end of respective fluid conveyance tubes; a chamber for mixing the component fluids, which is associated with an output end of said conveyance tubes and is provided with a foam dispenser; and regulation devices for thermostatic regulation of said component fluids, which are associated with said conveyance tubes, and wherein at least one of said thermostatic regulation devices is of a type as set forth in claim 10. |
<SOH> BACKGROUND OF THE INVENTION <EOH>The need to adjust the temperature and thermostatically regulate a fluid along a conveyance tube is known in various industrial and handicraft fields. In the field of the production of polymeric foams, for example, it is known that the components of said foams, before being mixed together, must be regulated thermostatically to a preset temperature, such as to ensure their minimal reactivity, for correct growth and development of said foam, and so as to reduce their viscosity to values that facilitate their mixing. For example, in the case of polyurethane foams, the two components (isocyanate and polyol) must be regulated thermostatically to an average temperature that can vary between 40 and 65° Celsius depending on the formulation of the mixture that is used. Foam dispensers are known which are used for example to manufacture bags or padding for packaging and are essentially constituted by tanks for storing the components of said foams, from which said components are drawn by respective pumps and are sent to respective conveyance tubes, which feed them into a mixing chamber provided with a foam dispenser. In order to thermostatically regulate the components to the intended temperature, thermostatic regulation devices are known which comprise an electrical conductor that is supplied with alternating current and is inserted along their conveyance tubes; the heat generated by Joule effect warms the components conveyed by the tubes. Known devices further comprise a temperature probe, which is inserted along the component conveyance tubes at a preset distance between their opposite ends, respectively for the inflow of the (cold) components drawn from the tanks and for the outflow of the (hot) components in the mixing chamber. The electrical conductor is constituted by a coiled cable, in which the turns are distributed with a constant pitch along the entire length of the conveyance tubes; the supplied thermal energy is therefore constant along the entire length of the conveyance tubes. A control and monitoring unit activates and deactivates the supply of current and the dispensing of foam depending on the temperature values detected by the probe. When the device starts, after an initial transition and before the first dispensing of foam, all of the fluid contained along the conveyance tubes is uniformly thermostatically regulated to the intended temperature. After the first dispensing of foam and after each successive dispensing, which occur at unpredictable time intervals from each other and in variable quantities depending on the various requirements of use of the foams, the fluid contained in the conveyance tubes has a temperature that is uneven along their entire length, since it is colder along their initial portion, which is closer to their inflow ends, and warmer along their end portion, which is closer to their outflow end. When the probe detects the presence of a fluid at the temperature that is lower than the preset temperature, the control and monitoring unit deactivates the dispensing of foam and starts the supply of current until the probe detects the presence of fluid at the intended temperature. When instead the probe detects the presence of a fluid at the intended temperature, the control and actuation unit deactivates the supply of current. These known thermostatic regulators are not free from drawbacks, including the fact that they do not allow precise and constant thermostatic regulation of the fluids conveyed along the tubes, and particularly the components of foams, and the fact that they do not allow a “continuous” dispensing of said fluids at the intended temperature, in that they do not ensure the dispensing of any flow-rate of fluid that is correctly thermostatically regulated, regardless of its extent and of the moment when it is requested. It should in fact be noted that thermostatic regulation of the fluid depends on the position where the temperature probe is arranged. For example, if the probe is arranged along the initial portion of the conveyance tube, proximate to the end where the cold fluid enters, when the dispensing of a certain flow-rate of fluid is required, said probe detects the presence of the fluid in input at a temperature that is lower than the set value and accordingly the control and monitoring unit activates the supply of current; the fluid that is present along the end portion of the tube, proximate to its output end, is therefore subjected to unwanted overheating and is dispensed at a temperature that is higher than the intended value. If instead the probe is arranged along the end portion of the conveyance tube, proximate to its output end, when it detects the presence of a fluid at a temperature that is lower than the set value, the control and monitoring unit activates the supply of current and interrupts the dispensing of the fluid until the probe detects the presence of fluid at the set temperature, the length of the end portion of the conveyance tube being insufficient to ensure heating of all the fluid contained therein up to said temperature. Because of this, the possibility to dispense said fluid becomes “discontinuous”, i.e., in the time interval required to reach the set temperature it is not possible to dispense any flow-rate of fluid that might be requested by the user. The dispensing action can be interrupted also if the probe is arranged along the initial portion of the conveyance tube. |
<SOH> SUMMARY OF THE INVENTION <EOH>The aim of the present invention is to eliminate the above-mentioned drawbacks of known devices, by providing a method and a device for thermostatically regulating a fluid along a conveyance tube, particularly a fluid component of polymeric foams along a feeder tube of a dispenser of said foams, which allow to provide precision thermostatic regulation of the conveyed fluid and to ensure immediate availability and “continuous” dispensing of thermostatically-regulated fluid at a chosen temperature, regardless of the flow-rate required by the user and of the moment when it is requested. Within this aim, an object of the present invention is to provide a structure that is simple, relatively easy to provide in practice, safe in use, effective in operation, and has a relatively low cost. This aim and this object are achieved by the present method for thermostatically regulating a fluid along a conveyance tube, particularly a fluid component of polymeric foams along a feeder tube of a dispenser of said foams, characterized in that it comprises supplying the fluid contained in a conveyance tube with thermal energy along at least one portion of said conveyance tube that can vary according to the distance from one of the opposite ends of said portion, detecting the temperature of the fluid at at least one distance from said end, comparing the detected temperature with a presettable reference value, and interrupting or activating said supply when the detected temperature is respectively equal to, or lower than, said reference value. This aim and this object are also achieved by the present device for thermostatically regulating a fluid along a conveyance tube, particularly a fluid component of polymeric foams along a feeder tube of a foam dispenser, characterized in that it comprises an electrical conductor, which can be associated with means for supplying electric power and is inserted in at least one portion of a tube for conveying a fluid to be thermostatically regulated and has a resistance that can vary according to the distance from at least one of the opposite ends of said portion, and means for detecting the temperature of said fluid at at least one distance from said end. |
Intrusion detection device for spaces |
A highly versatile intrusion detection device for spaces in general and for vehicles in particular, comprising at least one intrusion detection sensor of the ultrasound type with an asymmetric emission lobe that operates in echo mode. |
1. An intrusion detection device for spaces, comprising at least one intrusion detection sensor, which is an ultrasound sensor with an asymmetric emission lobe that operates in echo mode. 2. The device of claim 1, wherein said at least one sensor is of a transceiver type. 3. The device of claim 1, further comprising a microprocessor-based control unit for controlling said at least one sensor and analyzing echoes received by said at least one sensor. 4. A method for detecting intrusion in spaces, comprising the steps of: activating at least one ultrasound sensor provided in a space, said ultrasound sensor being provided of a type with an asymmetric emission lobe that operates in echo mode; detecting an echo received by said at least one sensor and analyzing said echo in order to compare the echo with at least one reference echo, in order to check whether a difference between said detected echo and said reference echo is within a preset value range; and when said difference is out of said preset value range, issuing an alarm signal. 5. The method of claim 4, comprising an initial step that consists of an autonomous learning step, performed by said at least one sensor, of current shapes of echoes received by said at least one sensor and of considering said shapes as reference echoes. 6. The method of claim 4, further comprising a step that consists in sending to said at least one sensor, functional parameters, in order to adapt operation of said at least one sensor, to environmental variations. 7. The method of claim 4, further comprising a step that consists in reducing current consumption of said at least one sensor by spreading out verifications of the echoes on said at least one sensor. 8. The method of claim 4, wherein said echo analysis comprises analyzing of echoes received within a preset reception time. |
<SOH> BACKGROUND OF THE INVENTION <EOH>As it is known, the growing number of thefts, particularly of cars, has induced most car manufacturers to install anti-theft systems directly at the factory or, if these systems are not already installed by the manufacturer, has forced substantially all users to install an anti-theft system after purchasing the vehicle. Currently existing anti-theft systems for vehicles are divided into intrusion prevention systems, which are suitable to detect and indicate any intrusions into a controlled volume, and engine locking systems. Different types of sensor, such as microwave or ultrasound sensors, are normally used in intrusion prevention systems. Microwave sensors are complicated and expensive and also difficult to manage, since the waves are reflected by metallic objects and can cause false alarms. Microwave systems are normally used for convertible vehicles. In the case of closed vehicles, ultrasound systems are instead used which operate in an opposite mode, cannot be applied to convertible models and lose their effectiveness if the vehicle, despite being of the sedan type, has for example its windows lowered. In all these situations, known ultrasound systems are in fact unsuitable, since they can detect movements that occur outside said vehicles. |
<SOH> SUMMARY OF THE INVENTION <EOH>The aim of the present invention is to provide a highly versatile intrusion detection device for spaces and particularly for vehicles that can be used equally on convertible vehicles and on closed vehicles, since it is capable of detecting an intrusion into the region directly in the vicinity of the sensor that is used, ignoring what happens outside said region. Within this aim, an object of the present invention is to provide an intrusion detection device that allows to reduce substantially to zero false alarms caused by incorrect sensing. Another object of the present invention is to provide an intrusion detection device in which the sensors used are substantially insensitive to position variations of the internal parts of the space or vehicle cabin, such as for example adjustments of the seats or of the steering wheel. Another object of the present invention is to provide an intrusion detection device that is highly reliable, relatively simple to provide and at competitive costs. This aim and these and other objects that will become better apparent hereinafter are achieved by an intrusion detection device: for spaces, which comprises at least one intrusion detection sensor, characterized in that said at least one sensor is an ultrasound sensor with an asymmetric emission lobe that operates in echo mode. |
Velocity determination of the near-surface layers in the earth using exploration 2D or 3D seismic data |
Several methods for determining the near-surface layer velocity in the earth (can include the weathering layer velocity) from exploration seismic 2D or 3D data are presented. These velocity measurements are to be used in time-correcting seismic data during data processing in refraction statics, datum statics, elevation statics derivation and application or any other data processing scheme wherein the near-surface velocity is required. They can also be used as the near-surface velocity model for depth-migration of seismic data. The velocity of the near-surface is directly related to the character of the shot records themselves. By statistically measuring this character from the shot records in an automated fashion, a large amount of data can be processed and the character measurement numerically converted to a velocity measurement using benchmark velocities. A complete near-surface velocity field for the seismic survey can be created in this way and used to correct for false time-structure in seismic datasets used for hydrocarbon exploration or any other sub-surface exploration purposes. |
1. A method for determining the velocity of the near-surface layers in the earth by automated measurement of the character and frequency content of seismic records, for use in the calculation of statics corrections to remove false time structure from 2D and 3D seismic data. 2. A method for determining the velocity of the near-surface layers in the earth by automated measurement of the character and frequency content of seismic records for use in velocity modeling for depth or time migration of 2D or 3D seismic data. 3. A method for determining the velocity of the near-surface layers in the earth by automated measurement of the character and frequency content of seismic records for use in any 2D or 3D seismic data processing scheme wherein the near-surface velocity is required. 4. The method of claims 1, 2 and 3 wherein the method of measuring the frequency content can be by picking the frequency of maximum amplitude (dominant frequency) from a frequency spectrum chart or by picking the first major event time (trough or peak) from an estimated wavelet created from the seismic record using Fourier transforms, Hilbert transforms or Weiner filtering. 5. The method of claims 1, 2 and 3 wherein the method of measuring the frequency content is by picking the first major event time (trough, peak or zero-crossing) from an estimated wavelet created from the seismic record using auto-correlations. |
<SOH> BACKGROUND OF INVENTION <EOH>It is well-known that false time-structure (static-correction errors) can exist on most land, shallow marine (and even conventional marine) seismic 2D and 3D data. This is due to the fact that large lateral velocity variations exist in the near-surface layers of the earth which cause travel-time errors which distort the reflection-time image of the subsurface reflectors below. Refraction statics and statics created from Tomographic models can reduce the problem to some degree but both methods suffer from the lack of velocity information in this near-surface layer. Velocity information is sometimes incorporated from drilled “uphole” survey information, but this information is usually on the order of 1 or 2 kilometers spatial intervals at best which is not small enough spatial sampling to eliminate static correction errors. Depth migrated data can also suffer from an inaccurate velocity model of the near-surface layers. The false time or depth structures left in the processed 2D or 3D seismic sections can lead to misinterpretation of hydrocarbon prospects and possibly to costly errors in oil and gas well placement sometimes costing millions of dollars. For seismic data, the attenuation coefficient is related to the frequency content of seismic data and the velocity of the medium by: ∝ = ∏ f Qv where :∝ is the attenuation coefficient :f is the frequency :v is the velocity of the medium :1/Q is the specific dissipation constant It is known empirically that 1/Q is related to velocity by: 1 Q ≈ 10 6 v 2 ( Waters , 1981 ) Therefore as seismic velocity decreases, the attenuation of high frequencies increases dramatically. These axioms would be confirmed by any geophysicist who has perused many raw field seismic records. Wherever the sources and receivers are in or on top of a layer of very low velocity material (600 m/sec. silt lense for example) the records are very “boomy” with low dominant frequency. When the sources and receivers are in or on top of a relatively higher velocity layer, the dominant frequency of the records is much higher and all events are crisper. By systematically measuring the dominant frequency of the seismic traces near the source points, we can achieve a relative measurement of the near-surface velocity. By incorporating an in-situ velocity measurement from drilled uphole recording locations (preferable in both areas of fast and slow near-surface velocity) the velocity field can be calibrated to a close estimate of the actual velocity field. |
<SOH> SUMMARY OF INVENTION <EOH>Using commercially available seismic data processing software, every source record in the 2D or 3D field survey can be analyzed for frequency content or estimated wavelets and picked using an automated picker as shown in FIGS. 1 and 2 . The pick dataset can be processed through the conversion to a velocity field using a programming language or “spreadsheet” manipulations and the formulas in FIG. 3 . The associated velocity field which yields a near-surface velocity value for each source-point on the survey, ( FIG. 4 ) can be then used to create a static-time correction to a flat or floating datum which incorporates the surface elevation and near-surface velocity for each surface station. It can also be used in a refraction statics solution or depth-imaging procedure or any other seismic data processing procedure that will benefit from an accurate model of the near-surface velocity variations. detailed-description description="Detailed Description" end="lead"? |
Computer-aided design system to automate scan synthesis at register-transfer level |
A method and system to automate scan synthesis at register-transfer level (RTL). The method and system will produce scan HDL code modeled at RTL for an integrated circuit modeled at RTL. The method and system comprise computer-implemented steps of performing RTL testability analysis, clock-domain minimization, scan selection, test point selection, scan repair and test point insertion, scan replacement and scan stitching, scan extraction, interactive scan debug, interactive scan repair, and flush/random test bench generation. In addition, the present invention further comprises a method and system for hierarchical scan synthesis by performing scan synthesis module-by-module and then stitching these scanned modules together at top-level. The present invention further comprises integrating and verifying the scan HDL code with other design-for-test (DFT) HDL code, including boundary-scan and logic BIST (built-in self-test). |
1. A method of performing RTL testability analysis for checking scan rule violations in an integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising a list of scan clocks; and (c) based on said scan constraints, analyzing said design database and reporting all said scan rule violations including one or more of the following: generated set/reset signals, destructive set/reset signals, combinational gated set/reset signals, sequential gated set/reset signals, potential bus contention on tri-state busses, generated clocks, constant clocks, clocks connected to data inputs of storage elements, combinational gated clocks, sequential gated clocks, pulse generators, and potential combinational feedback loops. 2. A method of performing clock-domain minimization for generating an optimal number of scan clocks to test an integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising a list of scan clocks to be minimized; and (c) based on said scan constraints, analyzing said design database to identify which selected clock domains do not interact with each other, and when said selected clock domains do not interact with each other, selectively replacing said scan clocks controlling said selected clock domains with one or more grouped scan clocks each for testing a plurality of said selected clock domains at the same frequency concurrently. 3. The method of claim 2, further comprising selectively specifying said optimal number of scan clocks in one-hot mode, non-overlapping mode, or overlapping mode. 4. A method of performing clock-domain minimization for generating an optimal ordered sequence of scan clocks to test an integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising a list of scan clocks to be minimized and ordered; (c) based on said scan constraints, analyzing said design database to identify which selected clock domains do not interact with each other, and when said selected clock domains do not interact with each other, selectively replacing said scan clocks controlling said selected clock domains with one or more grouped scan clocks each for testing a plurality of said selected clock domains at the same frequency concurrently; and (d) based on said scan constraints and said grouped scan clocks, further analyzing said design database to search for said optimal ordered sequence of scan clocks using the least amount or near-minimal amount of computer memory when transforming said design database into an equivalent combinational circuit model. 5. The method of claim 4, wherein said using the least amount or near-minimal amount of computer memory when transforming said design database into an equivalent combinational circuit model further comprises estimating the memory usage of each said clock domain and the memory usage of each crossing clock-domain logic block within each time frame in said equivalent combinational circuit model. 6. The method of claim 4, further comprising selectively specifying said optimal ordered sequence of scan clocks in one-hot mode, non-overlapping mode, or overlapping mode. 7. A method of performing scan selection for selecting a plurality of storage elements to test an integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising a list of scan clocks and a list of modules to be included and excluded for scan selection; (c) based on said scan constraints, analyzing said design database and selecting said storage elements within each said clock domain which are directly controllable by one said scan clock; and (d) organizing all selected storage elements within all said clock domains into a plurality of scan chains. 8. The method of claim 7, wherein said storage element is a flip-flop or a latch. 9. The method of claim 7, wherein said selecting said storage elements within each said clock domain further comprises selecting said storage elements according to a selected sequential cell-depth specified in said scan constraints. 10. The method of claim 7, wherein said selecting said storage elements within each said clock domain further comprises sorting and ordering said storage elements by module names followed by instance names within each said clock domain. 11. The method of claim 7, wherein said organizing all selected storage elements within all said clock domains into a plurality of scan chains further comprises splitting said selected storage elements within a selected clock domain into two or more said scan chains according to said scan constraints. 12. The method of claim 7, wherein said organizing all selected storage elements within all said clock domains into a plurality of scan chains further comprises merging said selected storage elements within a plurality of selected clock domains into one said scan chain according to said scan constraints. 13. The method of claim 7, further comprising analyzing said design database and reporting all storage elements within each said clock domain which are not directly controllable by any said scan clock; wherein said storage elements are candidates for scan repair and scan insertion. 14. A method of performing test point selection for selecting a plurality of test points to test an integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising the number of test points to be selected; and (c) based on said scan constraints, analyzing said design database and selecting said test points. 15. The method of claim 14, wherein said selecting said test points within each said clock domain further comprises interactively guiding designers to select said test points according to testability measures or fault coverage estimates on a list of test point candidates; wherein each said test point is selectively a control point including an AND gate, an OR gate, a multiplexer or an XOR gate, an observation point including a new storage element, or an XOR gate coupled to a selected storage element or a selected primary output, or a scan point including a multiplexer coupled to a new storage element. 16. A method of performing scan repair for repairing all scan rule violations and inserting selected test points in an integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising said scan rule violations and said selected test points; (c) repairing said scan rule violations based on said scan constraints; (d) inserting said test points based on said scan constraints; and (e) generating the scan-repaired HDL code at RTL. 17. The method of claim 16, wherein said repairing said scan rule violations further comprises selectively using a test enable (TE) signal or a scan enable (SE) signal to repair selected asynchronous set/reset flip-flops or latches; wherein each said selected asynchronous set/reset flip-flop or latch is selectively generated, destructive, combinationally gated, or sequentially gated. 18. The method of claim 16, wherein said repairing said scan rule violations further comprises using a test enable (TE) signal to repair selected generated clocks, selected constant clocks, and selected clocks connected to data inputs of storage elements or primary outputs. 19. The method of claim 16, wherein said repairing said scan rule violations further comprises using a scan enable (SE) signal to repair selected combinational gated clocks and selected sequential gated clocks. 20. The method of claim 16, wherein said repairing said scan rule violations further comprises selectively using a test enable (TE) signal or a scan enable (SE) signal to repair selected transparent latches. 21. The method of claim 16, wherein said repairing said scan rule violations further comprises using a scan enable (SE) signal to repair selected bi-directional pins into a selected input or output mode. 22. The method of claim 16, wherein said repairing said scan rule violations further comprises using a test enable (TE) signal to repair selected combinational feedback loops and selected potential combinational feedback loops. 23. The method of claim 16, wherein said repairing said scan rule violations further comprises using a test enable (TE) signal to repair selected pulse generators. 24. The method of claim 16, wherein said repairing said scan rule violations further comprises using a scan enable (SE) signal to repair potential bus contention on selected tri-state busses. 25. The method of claim 16, wherein said inserting said test points further comprises selectively using a test enable (TE) signal or a scan enable (SE) signal to selectively add a selected control point, a selected observation point, or a selected scan point in each said test point; wherein said control point selectively includes an AND gate, an OR gate, a multiplexer, or an XOR gate, wherein said observation point selectively includes a new storage element, or an XOR gate coupled to a selected storage element or a selected primary output, and wherein said scan point includes a multiplexer coupled to a new storage element. 26. A method of performing scan extraction for extracting scan cells from a plurality of scan chains in a scan-based integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the scan-based HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising a scan in port and a scan out port for each said scan chain; and (c) extracting said scan cells from each said scan chain according to said scan in port and said scan out port specified in said scan constraints. 27. The method of claim 26, wherein said extracting said scan cells from each said scan chain further comprises the computer-implemented steps of: (d) setting selected scan enable (SE) signals to predetermined logic values to enable shifting of said scan chain; (e) performing topological search, simulation, or a combination of both to generate an ordered list of said scan cells from each said scan chain; and (f) reporting broken scan cells within each said broken scan chain where scan extraction fails. 28. A method of performing interactive scan debug for locating broken scan cells within each broken scan chain in a scan-based integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the scan-based HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising a scan in port and a scan out port for each said scan chain; (c) setting selected scan enable (SE) signals to predetermined logic values to enable shifting of said broken scan chain; and (d) performing simulation to locate said broken scan cells one by one within each said broken scan chain. 29. The method of claim 28, wherein said performing simulation to locate said broken scan cells one by one within each said broken scan chain further comprises interactively tracing said broken scan cells one by one by displaying their respective signal values on a computer. 30. The method of claim 28, wherein said performing simulation to locate said broken scan cells one by one within each said broken scan chain further comprises applying selected test patterns and interactively forcing logic values of O's or 1's to any internal signal to repair said broken scan cells and recording said internal signals and their forced values, called broken control points, for interactive scan repair. 31. The method of claim 28, wherein said performing simulation to locate said broken scan cells one by one within each said broken scan chain further comprises applying selected test patterns and interactively highlighting selected RTL codes and signals been traced and fixed on a schematic viewer, HDL code viewer, or a waveform viewer. 32. A method of performing interactive scan repair for repairing broken scan cells within each broken scan chain in a scan-based integrated circuit modeled at RTL (register-transfer level), the integrated circuit having a plurality of clock domains and each domain having one scan clock; said method comprising the computer-implemented steps of: (a) compiling the scan-based HDL (hardware description language) code that represents said integrated circuit at RTL into a design database; (b) receiving scan constraints from an external source, said scan constraints further comprising selected broken control points to be repaired; (c) repairing said selected broken control points within each said broken scan chain according to said scan constraints; and (d) generating the scan-repaired HDL code at RTL. 33. The method of claim 32, wherein said repairing said selected broken control points within each said broken scan chain further comprises interactively guiding designers to select said scan-repaired HDL code for repairing each said selected broken control point on said design database. 34. The method of claim 32, wherein said repairing said selected broken control points within each said broken scan chain further comprises making a plurality of interactive repair suggestions and repairing each said selected broken control point according to a selected said repair suggestion. 35. The method of claim 32, wherein said repairing said selected broken control points within each said broken scan chain further comprises interactively highlighting selected RTL codes and said selected broken control points been repaired on a schematic viewer, HDL code viewer, or a waveform viewer. 36-103. (canceled) 104. An apparatus of performing scan repair for repairing all scan rule violations and inserting selected test points in an integrated circuit modeled at RTL (register-transfer level); said apparatus comprising: (a) first hardware for selectively using a test enable (TE) signal or a scan enable (SE) signal to repair selected asynchronous set/reset flip-flops or latches; wherein each said selected asynchronous set/reset flip-flop or latch is selectively generated, destructive, combinationally gated, or sequentially gated; (b) second hardware for using a test enable (TE) signal to repair selected generated clocks, selected constant clocks, and selected clocks connected to data inputs of storage elements or primary outputs; (c) third hardware for using a scan enable (SE) signal to repair selected combinational gated clocks and selected sequential gated clocks; (d) fourth hardware for selectively using a test enable (TE) signal or a scan enable (SE) signal to repair selected transparent latches; (e) fifth hardware for using a scan enable (SE) signal to repair selected bi-directional pins into a selected input or output mode; (f) sixth hardware for using a test enable (TE) signal to repair selected combinational feedback loops or selected potential combinational feedback loops; (g) seventh hardware for using a test enable (TE) signal to repair selected pulse generators; (h) eighth hardware for using a scan enable (SE) signal to repair potential bus contention on selected tri-state busses; and (i) ninth hardware for selectively using a test enable (TE) signal or a scan enable (SE) signal to selectively add a selected control point, a selected observation point, or a selected scan point in each said test point; wherein said control point selectively includes an AND gate, an OR gate, a multiplexer, or an XOR gate, wherein said observation point selectively includes a new storage element, or an XOR gate coupled to a selected storage element or a selected primary output, and wherein said scan point includes a multiplexer coupled to a new storage element. |
<SOH> BACKGROUND <EOH>The design methodology for complex integrated circuit (IC) designs has evolved with the advancement in process technologies. Currently, hardware description languages (HDL) are widely used to describe the behavior of a circuit at different levels of abstraction. The most commonly used approach is using HDL, such as Verilog or VHDL, to describe the circuit at register-transfer level (RTL). A computer-aided design (CAD) tool, generally called logic synthesizer, is then used to transform the above HDL design description into a technology dependent gate-level netlist, taking into account user-specified constraints on timing, power, area, etc. Integrated circuits need to be tested in order to verify the correctness of their functionality. With the ever-growing complexity of integrated circuits, the testing cost has become a significant portion of the total manufacturing cost. Hence, testability issues should be taken seriously in the design process. The reason that a design with better testability usually results in lower test generation and test application costs. There are many techniques to improve the testability of a design and reduce the costs for test generation and test application. These techniques are generally referred to as DFT (design-for-test) techniques. Among various DFT techniques, the scan-based DFT technique is the most widely used. In a scan-based design, scan storage elements, called scan cells, are used to replace original storage elements (flip-flops and latches). Some additional logic may also be added to the original design. As a result, the controllability and observability of the design will be greatly enhanced. In addition, test points, both control points and observation points, can be inserted into the original design to further improve its controllability and observability. The process of repairing scan-based DFT rule violations, inserting test points, replacing original storage elements with scan cells, and stitching the scan cells together as scan chains forms the basis of a scan synthesis CAD system. Prior-art scan synthesis solutions start with a technology-dependent gate-level netlist. This means that, even though a modern IC design is often coded at RTL, it must be first synthesized into a gate-level netlist in order to conduct scan synthesis. This Scan-after-Logic-Synthesis design flow is time-consuming, inefficient, and difficult to meet design constraints. In such a design flow, when an integrated circuit design contains any DFT rule violations, they must be repaired at gate-level. In addition, replacing an original storage element with a scan cell and adding test points are also conducted on the gate-level netlist. However, the logic added to fix DFT rule violations and to improve fault coverage may violate user-specified design constraints, be it power, timing, or area. Although designers may choose to rewrite RTL codes to fix such problems, it requires re-compilation and re-synthesis, which consumes a lot of time and effort. Moreover, it has to be repeated multiple times until all DFT rule violations are fixed. The product life cycle of a modern IC design is very short. Fixing DFT problems at such a late stage in a design flow may cause the product to miss the market window and incur huge revenue losses. An alternative prior-art approach, aimed at eliminating or reducing the number of iterations in a design flow, is to perform scan synthesis during logic synthesis. Logic synthesis generally contains two major steps: generic transformation and technology mapping (including logic optimization). Generic transformation is to synthesize RTL codes into a generic technology-independent gate-level model. Technology mapping is to map the generic gate-level model into a technology dependent gate-level netlist, based on user-specified constraints and a given cell library. Scan synthesis now can be performed between generic transformation and technology mapping. This Scan-within-Logic-Synthesis is also called one-pass scan synthesis or one-pass test synthesis. In principle, this approach still works at gate-level and solely relies on designers to fix most, if not all, DFT rule violations at RTL first. The main advantage of the Scan-within-Logic-Synthesis approach over the Scan-after-Logic-Synthesis approach is that it does not need to go through the lengthy technology mapping to locate DFT rule violations, if any. The disadvantage of the Scan-within-Logic-Synthesis approach, however, is that designers must guarantee their RTL codes to be testable before one-pass scan synthesis is performed. In order to solve the problem with the current Scan-within-Logic-Synthesis approach, three prior-art solutions are available: one for test point insertion in an unmapped gate-level netlist (prior-art solution #1), one for test point insertion at RTL (prior-art solution #2), and one for scan insertion at RTL (prior-art solution #3) as summarized bellow: Prior-art solution #1 is described in U.S. Pat. No. 6,311,317 by Khoche, et al. (2001). This solution adds test points to an unmapped gate-level netlist, removing the need of adding test points to a gate-level netlist obtained after logic synthesis. This solution, however, suffers from a major disadvantage. That is, this solution does not perform any analysis on an unmapped gate-level netlist to guide designers in choosing test points. As a result, user inputs should be provided to specify test points. This is not only time-consuming but also inefficient in some cases when less-effective test points are specified. Prior-art solution #2 is described in U.S. Pat. No. 6,301,688 by Roy, et al. (2001). This solution selects test points at RTL based on a cost function derived from the controllability and observability measures. A list of candidate test points is first constructed. For each test point candidate, the solution computes a cost function that models the average number of pseudorandom patterns required to detect a fault, over the complete fault set. The candidate test point, which results in the largest reduction in the cost function, is then selected. This test point selection process is repeated until the estimated fault coverage meets the user-specified requirement, or the number of selected test points exceeds the user-specified limit. The disadvantage of this solution is that it solely relies on a computed cost function to guide test point selection, which is not always accurate. As a result, this solution may yield a less-effective set of test points since no interactive test point selection is supported. Prior-art solution #3 is described in U.S. Pat. No. 6,256,770 by Pierce, et al. (2001). This solution performs scan insertion, including scan replacement and scan stitching, at RTL. This solution, however, suffers from several disadvantages: First, this solution does not take the concept of multiple clock domains into consideration. It basically assumes that all RTL modules will be implemented on a single clock domain. This is not a practical assumption since most modern IC designs consist of multiple clock domains, operating at a signal frequency or multiple frequencies. Second, this solution does not take the concept of hierarchical scan synthesis into consideration. Given the fact that modern IC designs are growing rapidly in size and complexity, any non-scalable solution without supporting hierarchical scan synthesis will be of only limited use. Third, this solution does not support scan repair, which is indispensable in preparing a design for scan synthesis. In fact, a complex RTL design may contain many scan DFT rule violations, such as asynchronous set/reset signals, generated clocks, constant clocks, clocks connected to data inputs of storage elements, gated clocks, latches, bi-directional ports, combinational feedback loops, pulse generators, tri-state busses, etc. Such violations must be fixed before scan insertion. Fourth, this solution does not support scan extraction, which is often needed to extract scan information from a scanned RTL design. Fifth, this solution does not support interactive scan debug and interactive scan repair, which are important when scan chains do not operate as intended. In order to solve the disadvantages of prior-art solution, the present invention employs a new approach called Scan-before-Logic-Synthesis to move scan synthesis completely to the register-transfer level (RTL). The present invention will perform scan synthesis completely before logic synthesis, based on testability analysis, clock domain analysis, and user constraints. This Scan-before-Logic-Synthesis approach will allow designers to find all DFT rule violations at RTL and fix them by hand or by software. The present invention performs scan insertion and test point insertion at RTL and generate testable RTL codes for synthesis and verification. With the present invention, designers can verify scanned codes at RTL. The verified RTL codes can then be synthesized using any commercially available logic synthesis tool, based on original design constraints. The present invention can avoid costly iterations caused by scan chain insertion, test point insertion, and DFT violation repair at gate-level. In one embodiment of the present invention, the CAD system supports hierarchical RTL scan synthesis by allowing designers to conduct RTL scan synthesis module-by-module, and then stitching the scanned RTL modules hierarchically up to the top-level module. Accordingly, what is needed in this present invention is a computer-aided design (CAD) system for effectively automating RTL scan synthesis or Scan-before-Logic-Synthesis, whose advantages are listed above. The CAD system can generate flush and random test benches to verify and debug scanned RTL codes. In addition, hierarchical test benches can also be generated to verify and debug the scanned RTL design at top-level. The following table summarizes the results of analyzing different synthesis approaches: Feature/ Scan-after- Scan-within- Scan-before- Synthesis Logic Logic Logic Input Model Gate-Level RTL RTL Output Model Gate-Level Gate-Level RTL Timing Closure Difficult Medium Easy Synthesis Time Long Medium Short |
<SOH> SUMMARY <EOH>Accordingly, a primary objective of the present invention is to provide such an improved Scan-before-Logic-Synthesis system, comprising a computer-aided design (CAD) system for RTL scan synthesis. The inputs to the CAD system are RTL codes described in HDL (hardware description language) and scan constraints. The RTL codes for any integrated circuit can be in such a format as Verilog, VHDL, etc. The CAD system for RTL scan synthesis will consist of a suite of programs for performing such tasks as RTL testability analysis, clock-domain minimization, scan and test point selection, scan repair and test point insertion, scan replacement and scan stitching, scan extraction, interactive scan debug, interactive scan repair, and test bench generation. The Scan-before-Logic-Synthesis CAD system in accordance with the present invention is summarized as follows: (1) RTL Compilation Assume that an integrated circuit modeled at RTL is described in HDL, such as Verilog, VHDL, etc. RTL compilation will compile the RTL codes into a design database for all subsequent tasks. The design database captures the RTL circuit model which in essence are connections between RTL operators like adder, subtractor, multiplier, comparator, multiplexer, etc. Since not all nets in RTL nets are visible from the RTL codes, an index is given to each net in the RTL circuit. Cross probing is provided for all nets and RTL operators in the RTL circuit to the original RTL codes. The flip-flops, latches, and tri-state busses are inferred from the RTL codes. (2) Testability Analysis at RTL The present invention comprises any software that uses a CAD method to perform testability analysis on the design database to check whether the RTL codes contain any coding and DFT rule violations. In addition to reporting such violations as floating primary inputs, floating primary outputs, floating bi-directional pins, objects with floating inputs or outputs, floating nets, and transparent patches, the CAD system also reports such unique information as combinational feedback loops, potentially combinational feedback loops, generated clocks, sequentially gated clocks, combinationally gated clocks, constant clocks, connections from clocks to flip-flop or latch inputs, connections from clocks to output ports, connections to both clock and data inputs of a flip-flop or latch, generated set/reset signals, sequentially gated set/reset signals, combinationally gated set/reset signals, destructive set/reset signals, crossing clock domains, pulse generators, potential bus contentions, etc. If any such violation is found, the violation will be recorded and a summary of the violations will be reported. The testability analysis also generates clock domain analysis results that will be used in clock domain minimization. Controllability and observability measures are computed for all nets to the bit-level accuracy. These testability measures will be used as references to guide interactive test point insertion at RTL. (3) Single-Frequency Clock-Domain Minimization at RTL The present invention further comprises any software that uses a CAD method to perform clock-domain analysis based on the RTL codes of an integrated circuit in order to identify clock domains that do not interact with each other. The CAD method starts from clock input signals in the analysis process and generates a minimum set of scan clocks needed to test the integrated circuit at a reduce clock speed but concurrently. This RTL clock-domain analysis will result in less memory usage in fault simulation or test pattern generation and shorter test time. The present invention further comprises any apparatus that can merge and share scan clocks with primary data input pins. For example, consider an integrated circuit with 8 clock domains, CD 1 to CD 8 , controlled by 8 clocks, CK 1 to CK 8 , respectively. Assume that one clock frequency, which may be applied with several different clock phases, is to be used to test the integrated circuit on an ATE (automatic test equipment). Conventionally, in order to test all clock domains, 8 different set of clock waveforms need to be applied. However, if two clock domains, e.g. CD 2 and CD 4 , have no crossing clock-domain logic between them, in other words, if CD 2 and CD 4 do not interact with each other, the same set of clock waveforms can be applied to both CD 2 and CD 4 . (4) Multiple-Frequency Clock-Domain Minimization at RTL The present invention further comprises any software that uses a CAD method to perform clock-domain analysis based on the RTL codes of an integrated circuit in order to identify clock domains that do not interact with each other. The CAD method starts from clock input signals in the analysis process and generates the minimum set of scan clocks needed to test the integrated circuit at its intended clock frequency or at-speed. If used in scan-test mode, this RTL clock-domain analysis will result in less memory usage in fault simulation or test pattern generation and shorter test time. If used in self-test mode, this RTL clock-domain analysis will result in less memory usage is self-test circuitry synthesis, smaller self-test circuitry, shorter fault simulation time, and shorter test time. The present invention further comprises any apparatus that can merge and share scan clocks with primary data input pins. For example, consider an integrated circuit with 8 clock domains, CD 1 to CD 8 , controlled by 8 clocks, CK 1 to CK 8 , respectively. Assume that each clock domain is to be tested at its intended clock frequency or at-speed. Conventionally, in order to test all clock domains, 8 different set of clock waveforms need to be applied. However, if two clock domains running at the same frequency, e.g. CD 2 and CD 4 , have no crossing clock-domain logic between them, in other words, if CD 2 and CD 4 do not interact with each other, the same set of clock waveforms can be applied to both CD 2 and CD 4 . (5) Scan and Test Point Selection at RTL In order to reduce test time and test costs on an ATE (automatic test equipment), an integrated circuit is usually configured into having multiple scan chains. Scan chains are constructed based on the results of RTL testability analysis and clock domain minimization as described in (2), (3), and (4), as well as user-specified scan constraints. The CAD system will perform further analysis to decide the scan clock for each scan chain, balance the scan chain length when desired, and order the scan cells based on the clock domains when the scan chain consists of scan cells from different clock domains. Grouping and ordering of scan cells based on clock domains are useful to reduce the complication of clock skews and routing difficulties. The CAD system can select only part of storage elements as scan cells, resulting in a partial-scan design, which can reduce the area overhead, routing difficulties, and performance degradation potentially associated with a full-scan or almost full-scan design. Especially, one can choose to select only part of storage elements as scan cells in such a manner that all sequential feedback loops are virtually removed through replacing original storage elements with scan cells. The resultant partial-scan design, called a feed-forward partial-scan or a pipe-lined partial-scan design, may have several non-scanned storage elements between two stages of scan cells. This property is characterized by sequential cell-depth. For example, a partial-scan design of a sequential cell-depth of 2 means that a signal value can be propagated from one stage of scan cells to another by applying at most two clock pulses. Note that a full-scan or almost full-scan design has a sequential cell-depth of 0. The CAD system can select scan cells for a partial-scan design based on the sequential cell-depth specified in scan constraints. In addition, an integrated circuit could contain complex combinational logic blocks and large macro cells such as memories and mixed-signal blocks. In order to test the complex combinational logic blocks and the shadow logic surrounding the macro cells, it might be required to add test points, including control points, observation points, and control-observation points (called scan points). Furthermore, if an integrated circuit is to be tested with pseudorandom test patterns in self-test mode, test points may also need to be added since the circuit may contain a substantially large number of random pattern-resistant faults. The testability measures computed in RTL testability analysis can be used to guide test points insertion to improve the fault coverage of the integrated circuit. The designer can also interactively select a test point or a set of test points and let the system re-compute the estimated fault coverage for the integrated circuit. This interactive test point selection increases the flexibility and the chance of improving the circuit's fault coverage. The present invention further comprises any software using a CAD system to first identify scan cells and test points, and then build scan chains based upon the scan clocks derived as the result of single-frequency clock-domain minimization at RTL and multiple-frequency clock-domain minimization at RTL, as well as user-specified scan constraints. The order of scan cells at this stage is determined based on module names and instance names. This order may not be final as it can be easily changed at a later stage when layout information becomes available. (6) Scan Repair and Test Point Insertion at RTL The scan chains constructed as the result of (5) may not function properly and the design may suffer from low fault coverage if the design contains any unfixed DFT rule violation. The most common DFT rule violations include generated clocks, constant clocks, asynchronous set/reset signals, potential bus contentions, transparent latches, gated clocks, combinational feedback loops, etc. If any scan-based DFT rule violations are found during RTL testability analysis, the designer can either fix the violations manually on the RTL codes, or resort to the CAD system to repair the violations automatically. Two additional input signals, one being a scan enable signal SE and the other being a test enable signal TE, can be added to the RTL codes for this purpose. The two enable signals, SE and TE, will be used to control the operation of added scan logic so that the circuit can function correctly during scan operations. Depending on the type of the violation, an enable signal, SE or TE, can be used to repair the violation. The following table summarizes the circuit operation mode under different SE and TE values. TE SE Mode 0 0 normal 1 1 shift 1 0 hold and capture In addition, the CAD system will use either of the two enable signals, TE and SE, to add test points, including control points and observation points. A control point can be implemented with an AND gate, OR gate, multiplexer, or XOR gate; an observation point can be implemented with a new storage element or an XOR gate coupled to an existing storage element or primary output. The present invention further comprises any software using a CAD system to automatically repair any DFT rule violations found during RTL testability analysis, such as generated clocks, constant clocks, clocks connected to data input, asynchronous set/reset signals, potential bus contentions, transparent latches, gated clocks, combinational feedback loops, etc. In addition, it further comprises any software using a CAD system to insert the selected test points. (7) Scan Replacement and Scan Stitching at RTL The storage elements identified during scan selection should be replaced with RTL codes representing scan cells after scan selection. Scan logic is added to make latches transparent during test. Then, all scan cells should be stitched together based on the scan chain order determined in the scan and test point selection stage. The present invention further comprises any software using a CAD system to replace the storage elements identified during scan and test point selection with RTL codes representing scan cells and making latches transparent during test. In addition, the CAD system stitches all identified scan cells, either at the module level or at the top level. The scan enable signal SE is also connected in this stage to form complete scan chains. (8) Scan Extraction at RTL An integrated circuit can contain third-party scanned IP's (intellectual properties), such as CPU or DSP cores. It is important that such cores shall be tested properly. For this purpose, scan extraction is performed to extract the already existed scan chains from the circuit described in RTL codes. The present invention further comprises any software using a CAD system to extract scan chains from scanned IP cores described in RTL codes, based on user-specified scan data input and output pins. (9) Interactive Scan Debug at RTL It is possible that during scan extraction or after scan replacement and scan stitching, the scan chains are still broken. It is important that such broken scan chains and scan instances shall be identified and repaired. The present invention further comprises any software using a CAD system to allow the designer to interactively trace, either forwards or backwards, any scan chain and display signal values. Whenever any error is found, interactive commands, such as force 0 or 1, can be used to allow the designer to change internal signal values so that the designer can proceed further until all problems related to broken scan chains are identified and fixed. To aid in debugging, the present invention further comprises any software using a CAD system to display the RTL codes being traced and highlight the values on its corresponding schematics. (10) Interactive Scan Repair at RTL The present invention further comprises any software using a CAD system to allow the designer to conduct interactive scan repair. As long as any broken chains are identified and fixed during interactive scan debug, these fixes must be reflected on the RTL codes by modifying the original RTL codes by hand or by software. (11) Test Bench Generation at RTL Upon successful verification of scan chains, an integrated circuit now becomes testable. The designer can now verify the scanned integrated circuit with his/her own test benches created or use the flush and random test benches created by the CAD system. The present invention further comprises any software using a CAD system to allow a designer to generate flush or random test benches based upon the extracted scan chains on scanned RTL codes. (12) Hierarchical Scan Synthesis and Test Bench Generation at RTL A large and complex integrated circuit usually contains many large modules or IP cores. To reduce scan synthesis time, one can first do scan synthesis on a module-by-module basis, and then stitch them together at top-level. The present invention further comprises any software using a CAD system to allow the designer to do scan synthesis, comprising stages described from (1) through (12), on a module-by-module basis, stitch them together at top-level, and generate the required top-level flush or random test benches. |
Orthotic with dynamically self-adjusting stabiliser for footwear |
The orthotic is formed of a monolithic semi-rigid resilient shell for engagement inside a footwear and for conformingly fitting against the plantar portion of a patient's foot. The orthotic includes a rear heel cup portion that may have inner and outer rearwardly-extending resiliently deformable arms defining at their rear ends a rearwardly-opened notch therebetween. A number of first grooves may be made along the outer or inner flange of the heel cup portion, on the exposed top or bottom surface thereof. The orthotic further comprises a front end portion for engaging the metatarsal plantar region of the foot, having a sinuous front edge which includes five frontwardly-facing arcuate concavities each for registering wedging engagement therein by a corresponding one of the five metatarsal anterior portions of that person's foot. A number of second grooves may be made on the exposed top or bottom surface of the front end portion, and at least one of each second groove open into a corresponding arcuate concavity. The front and rear grooves provide dynamic stabilization of the patient's foot and resistance against cyclical load-induced torque during gait. No separate add-on crutch stabilizer is necessary at a raised portion of the orthotic. |
1. An orthotic device for engagement inside a footwear and for conforminglyfitting against the plantar portion of a patient's foot for compensating podiatric deficiencies, said orthotic device being formed of a monolithic semi-rigid resilient shell defining inner and outer lateral sides, a top exposed surface and a bottom surface, and having: an arched intermediate portion for complementary vertical resilient spring-back engagement against the foot arch plantar portion; a rear end portion for receiving the patient's heel; a front end portion integrally frontwardly extending from said intermediate portion and for complementary engagement near the anterior metatarsal plantar region of the foot; and reinforcement means, integral to said shell, wherein said reinforcement means provides both dynamic stabilization at said shell front end portion and resistance against cyclical load-induced torque during gait at said rear end portion thereof. 2. An orthotic device as in claim l, wherein said reinforcement means is an integral part of said front end portion of the shell. 3. An orthotic device as in claim 1, wherein said reinforcement means is an integral part of said rear end portion of the shell. 4. An orthotic device as in claim 1, wherein said reinforcement means is an integral part of both said front end portion and of said rear end portion of the shell. 5. An orthotic device as in claim 1, wherein said reinforcement means includes a number of grooves made on said top exposed surface of the shell. 6. An orthotic device as in claim 1, wherein said reinforcement means includes a number of grooves made on said bottom surface of the shell. 7. An orthotic device as in claim 1, wherein said reinforcement means includes a number of grooves made on both said top exposed surface and of said bottom surface of the shell. 8. An orthotic device as in claim 1, wherein said reinforcement means includes a number of channels made within the shell itself in embedded, at least partly concealed fashion. 9. An orthotic device as in claim 5, wherein each of said grooves is cross-sectionally U-shaped. 10. An orthotic device as in claim 5, wherein the depth of each of said grooves is at least 1.5 mm. 11. An orthotic device as in claim 3, wherein said reinforcement means includes a number of grooves made on said top exposed surface of said rear end portion of the shell, the depth of each of said grooves being at least 2 mm in depth. 12. An orthotic device as in claim 5, wherein said grooves extend generally longitudinally of the shell. 13. An orthotic device as in claim 5, wherein said grooves extend transversely and at a small acute angle relative to the longitudinal axis of said shell. 14. An orthotic device as in claim 2, wherein said reinforcement means includes a number of grooves made on said top exposed surface of said front end portion of the shell. 15. A n orthotic device as in claim 14, wherein said grooves at said front end portion of the shell extend in a forwardly diverging fan-like fashion. 16. An orthotic device as in claim 1, wherein said reinforcement means includes a number of channels made within said shell. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Footwear insoles, also called podiatric orthotic or orthotic shoe inserts, are used to support the human foot in a footwear, and have been known for quite some time in the field. These devices consist usually of a moulded blank shell formed monolithically from a resilient semi-rigid sheet material, usually a synthetic plastic material. In some orthotic shoe inserts, the orthotic rear end portion may comprise an inner and an outer rearwardly-extending resiliently deformable arms defining a rearwardly-opened notch therebetween—the so-called heel cup. This heel cup, being raised above the sole level of the footwear, requires external semi-rigid cushion pads forming a crutch-like support that engage the footwear sole, to stabilize the heel portion of the foot against load-induced rotational torque during cyclical gait movement. Orthotics are characterized by the fact that they properly adjust the orientation of a person's deficient foot during gait, for controlling its motion in view of mitigating the adverse effects of podiatric anomalies. Problems associated with these known orthotic devices include: (a) they take too much volume in the footwear, so the foot is uncomfortably compressed inside the footwear; and/or the orthotic cannot fit inside the footwear. (b) they often are undesirably allowed to accidentally shift in position inside the footwear, especially during prolonged gait. (c) they generate a second movement of the foot, to counteract the first medically deficient movement of the foot, and thus bring about instability of the orthotic under load. (d) There are problems associated both with prolonged use and with maintenance of the conventional orthotic devices. (e) Lesions can be created on the front plantar portion, under the metatarsal heads or rearwardly near them, by the front edge of the orthotic or of the insole. Indeed, the orthotics or insoles often extend short of the toes. Although the orthotic is expected to gradually frontwardly slope towards the shoe's sole so as to form therewith an almost continuous surface under the metatarsal head region, the reality is otherwise: the frontmost edge of the orthotic often repetitively raises during gait spacedly above the shoe's sole, and under repetitive contact with the foot plantar surface, is likely to cause lesions and injure the foot plantar metatarsal region. Moreover, the foot is often not allowed to recover from these lesions, since the already injured plantar foot portion continues to suffer lesions from its subtle contact with the linear front edge portion of the orthosis under continued use of the orthotic. Some orthotics include grooves made on the upper and/or exposed lower surfaces thereof, which respectively control accidental slippage movement of the foot across the orthotic, and of the orthotic relative to the footwear insole. The purpose of these grooves in such latter known orthotics is thus to control the undesirable relative movements of the orthotics. Other orthotics may have shock absorbing ribs at the rear end portion thereof, on their exposed surface. A problem with such orthotics is that they tend to create an external rotational force on the heel which causes heel supination at the tibio-fibular leg unit. These grooves operate as rotors that contribute in the rotation and the progressive shift in the position of the longitudinal axis of the orthotics. The orthotic is then used to generate a movement to counteract another movement, i.e. to generate supination to counteract pronation. Such orthotics will not limit the deviation of the segment or to correct its position, but rather will tend to control the internal rotational torque operating at the level of the tibio-femoral assembly. |
<SOH> SUMMARY OF THE INVENTION <EOH>The invention consists of an orthotic device for engagement inside a footwear and for conformingly fitting against the plantar portion of a patient's foot for compensating podiatric deficiencies, said orthotic device being formed of a monolithic semi-rigid resilient shell defining inner and outer lateral sides, a top exposed surface and a bottom surface, and having: an arched intermediate portion for complementary vertical resilient spring-back engagement against the foot arch plantar portion; a rear end portion for receiving the patient's heel; a front end portion integrally frontwardly extending from said intermediate portion and for complementary engagement near the anterior metatarsal plantar region of the foot; and reinforcement means, integral to said shell, wherein said reinforcement means provides both dynamic stabilization at said shell front end portion and resistance against cyclical load-induced torque during gait at said rear end portion thereof. In a first embodiment, said reinforcement means may be an integral part of said front end portion of the shell, or alternately in another embodiment, may be an integral part of said rear end portion of the shell, or in still another embodiment an integral part of both said front and rear portions of the shell. Said reinforcement means may include a number of grooves made on said top exposed surface of the shell, or alternately on said bottom surface thereof, or still alternately in a channel made within the shell itself in embedded, at least partly concealed fashion. Each of said grooves/channel may be cross-sectionally U-shaped. The depth of any one of each of said grooves/channels may be at least 1 mm and up to 2 mm in depth. Said stabilization of the patient's foot brought about by said reinforcement means may be of the lateral type, and/or of the medial type, depending on the medical condition of the patient's. In one embodiment, grooves/channels extend longitudinally of the shell; in alternate embodiments, grooves/channels extend transversely thereof, preferably at a small acute angle relative to the longitudinal axis of said shell. |
Image processing apparatus, image processing method, program thereof, and recording medium |
Provided herein is an image processing apparatus comprising: input means for inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; image processing parameter input means for inputting a parameter to be employed in image processing on the image data executed by a user; image processing means for performing luminance-related processing or chrominance-related processing on the image data in accordance with the image processing parameter inputted by the image processing parameter input means; and storage means for storing an intermediate result for each of the luminance-related processing and the chrominance-related processing. By virtue of storing the intermediate results, this invention contributes to not only high-speed RAW image data development processing, but also a reduced image processing load and increased processing speed. |
1. An image processing apparatus comprising: input means for inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; image processing parameter input means for inputting a parameter to be employed in image processing on the image data executed by a user; image processing means for performing luminance-related processing or chrominance-related processing on the image data in accordance with the image processing parameter inputted by said image processing parameter input means; and storage means for storing an intermediate result for each of the luminance-related processing and the chrominance-related processing. 2. The image processing apparatus according to claim 1, further comprising: image processing parameter input history storage means for storing input history information of a parameter inputted by said image processing parameter input means; and cache control means for controlling whether or not to cache the intermediate result of the image processing in said storage means in accordance with a comparison between a current image processing parameter and previous input history information stored in said image processing parameter input history storage means. 3. An image processing apparatus comprising: input means for inputting image data that is obtained by converting light from an object to an electric signal employing an image sensor, digitalizing an image signal, and performing no compression or lossless compression; image processing parameter input means for inputting a parameter to be employed in image processing on the image data executed by a user; image processing means for performing image processing on the image data in accordance with the image processing parameter inputted by said parameter input means; storage means for storing a result of image processing and an intermediate result of image processing; cache control means for caching the intermediate result of image processing in said storage means in preparation for next image processing; image processing parameter input history storage means for storing input history information of a parameter inputted by said image processing parameter input means; and cache control means for controlling whether or not to cache the intermediate result of image processing in said storage means in accordance with a comparison between a current image processing parameter and previous input history information stored in said image processing parameter input history storage means. 4. The image processing apparatus according to claim 1, wherein said cache control means invalidates as cache data an intermediate result of image processing which directly or indirectly utilizes a result of image processing corresponding to an image processing parameter having a different value from an image processing parameter employed in previous image processing. 5. The image processing apparatus according to claim 3, wherein said cache control means controls whether or not to cache an intermediate result of each image processing means based on image processing parameter input history information stored in said image processing parameter input history storage means. 6. The image processing apparatus according to claim 3, wherein said cache control means preferentially caches in said storage means a result of image processing positioned in a previous stage of image processing which is performed based on a parameter currently inputted by said image processing parameter input means. 7. The image processing apparatus according to claim 3, said image processing means including at least luminance-related processing and chrominance-related processing, and further including synthesis conversion processing means for synthesizing a result of the luminance-related processing and a result of the chrominance-related processing, wherein in a case where one of the luminance-related processing or the chrominance-related processing is performed based on a parameter currently inputted by said image processing parameter input means, said cache control means preferentially caches in said storage means an intermediate result of the other processing, which is obtained immediately before being synthesized by said synthesis conversion means. 8. The image processing apparatus according to claim 7, wherein said cache control means preferentially caches in said storage means an intermediate result of image processing, positioned in a previous stage of one of the luminance-related processing or the chrominance-related processing, performed based on a parameter currently inputted by said image processing parameter input means, and an intermediate result of the other processing which is obtained immediately before being synthesized by said synthesis conversion means. 9. An image processing method comprising: an input step of inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; an image processing parameter input step of inputting a parameter to be employed in image processing on the image data executed by a user; an image processing step of performing luminance-related processing or chrominance-related processing on the image data in accordance with the image processing parameter inputted in said image processing parameter input step; and a storage step of storing an intermediate result for each of the luminance-related processing and the chrominance-related processing. 10. The image processing method according to claim 9, further comprising: an image processing parameter input history storage step of storing input history information of a parameter inputted in said image processing parameter input step; and a cache control step of controlling whether or not to cache the intermediate result of the image processing in accordance with a comparison between a current image processing parameter and previous input history information stored in said image processing parameter input history storage step. 11. An image processing method comprising: an input step of inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; an image processing parameter input step of inputting a parameter to be employed in image processing on the image data executed by a user; an image processing step of performing image processing on the image data in accordance with the image processing parameter inputted in said parameter input step; a storage step of storing a result of image processing and an intermediate result of image processing; a cache control step of caching the intermediate result of image processing in a storage unit in preparation for next image processing; an image processing parameter input history storage step of storing input history information of a parameter inputted in said image processing parameter input step; and a cache control step of determining whether or not to cache the intermediate result of image processing in accordance with a comparison between a current image processing parameter and previous input history information stored in said image processing parameter input history storage step. 12. The image processing method according to claim 11, wherein in said cache control step, an intermediate result of image processing, which directly or indirectly utilizes a result of image processing corresponding to an image processing parameter having a different value from an image processing parameter employed in previous image processing, is invalidated as cache data. 13. The image processing method according to claim 11, wherein in said cache control step, it is determined whether or not to cache an intermediate result of each image processing means based on image processing parameter input history information stored in said image processing parameter input history storage step. 14. The image processing method according to claim 11, wherein in said cache control step, a result of image processing positioned in a previous stage of image processing which is performed based on a parameter currently inputted in said image processing parameter input step is preferentially cached. 15. The image processing method according to claim 11, said image processing step including at least luminance-related processing and chrominance-related processing, and further including a synthesis conversion processing step of synthesizing a result of the luminance-related processing and a result of the chrominance-related processing, wherein in a case where one of the luminance-related processing or the chrominance-related processing is performed based on a parameter currently inputted in said image processing parameter input step, an intermediate result of the other processing which is obtained before being synthesized in said synthesis conversion step is preferentially cached in said cache control step. 16. The image processing method according to claim 15, wherein in said cache control step, an intermediate result of image processing, positioned in a previous stage of one of the luminance-related processing or the chrominance-related processing, performed based on a parameter currently inputted in said image processing parameter input step, and an intermediate result of the other processing which is obtained immediately before being synthesized in said synthesis conversion step are preferentially cached. 17. A computer control program for causing a computer to realize the image processing method described in claim 9. 18. A computer control program for causing a computer to realize the image processing method described in claim 11. 19. A computer-readable storage medium storing-the computer control program described in claim 17. 20. A computer-readable storage medium storing the computer control program described in claim 18. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Currently it is common to view or edit images, which are sensed by a digital camera, by employing an application software installed in a personal computer (PC). Some digital cameras have a function for storing a sensed image as RAW data (data that has been subjected to photoelectric conversion by an image sensor such as a CCD or a CMOS, then subjected to A/D conversion and lossless compression at the time of image sensing by a digital camera, thus keeping sensed information intact). Hereinafter, an image stored as RAW data will be referred to as a RAW image. Further, some image processing software are capable of image processing (hereinafter referred to as RAW image development processing) based on image processing parameters (hereinafter referred to as development parameters), e.g., attribute information recorded in association with the RAW image, characteristics of the digital camera main unit, as well as resolution, sharpness, hue, and white balance set by a user. Employing such image processing software enables a user to obtain an image of which quality meets the user's preference with its parameters adjusted. Note that since image data that has been developed is generally stored in a versatile data type (JPEG, BMP, TIFF or the like), processing including storage may be referred to as development processing. For instance, according to the disclosure of Japanese Patent Application Laid-Open (KOKAI) No. 2004-080099, development processing is performed on RAW image data by applying development parameters, e.g., white balance adjustment, color-effect mode selection, contrast adjustment, color-density adjustment, sharpness adjustment and so on set by a user, and the developed result is displayed on a display device and stored in a versatile file such as JPEG. However, in RAW image development processing, the outcome of image development using the inputted development parameters is unknown until the user sees the actual result of development. Therefore, it is difficult to achieve a satisfactory processing result with one time of parameter input. Normally, a user repeats trial and error, while confirming the developed result on the display device, to determine satisfactory parameter values. Since each processing that constitutes development processing applying the user-input development parameters is performed on all pixels of RAW image data (in principle, it is the number of effective pixels of the image sensor), the processing load for the development is heavy or high. If development is performed each time the parameter value is changed in the process of trial and error to decide the development parameter values, an extremely long processing time is required. Furthermore, along with the trend toward higher resolution of a digital camera in late years, the processing load tends to become heavy. In addition, due to the user's rising interest for higher image quality, image processing on RAW image data is growing popular. |
<SOH> SUMMARY OF THE INVENTION <EOH>The object of the present invention is to solve the above-described problems of the conventional art, and to serve user's needs for image processing that has become complicated because of a high-quality trend in image processing of a sensed image, as well as to reduce a calculation load in the image processing. According to the present invention, the foregoing object is attained by providing an image processing apparatus comprising: input means for inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; image processing parameter input means for inputting a parameter to be employed in image processing on the image data executed by a user; image processing means for performing luminance-related processing or chrominance-related processing on the image data in accordance with the image processing parameter inputted by the image processing parameter input means; and storage means for storing an intermediate result for each of the luminance-related processing and the chrominance-related processing. According to another aspect of the present invention, the foregoing object is attained by providing an image processing apparatus comprising: input means for inputting image data that is obtained by converting light from an object to an electric signal employing an image sensor, digitalizing an image signal, and performing no compression or lossless compression; image processing parameter input means for inputting a parameter to be employed in image processing on the image data executed by a user; image processing means for performing image processing on the image data in accordance with the image processing parameter inputted by the parameter input means; storage means for storing a result of image processing and an intermediate result of image processing; cache control means for caching the intermediate result of image processing in the storage means in preparation for next image processing; image processing parameter input history storage means for storing input history information of a parameter inputted by the image processing parameter input means; and cache control means for controlling whether or not to cache the intermediate result of image processing in the storage means in accordance with a comparison between a current image processing parameter and previous input history information stored in the image processing parameter input history storage means. In still another aspect of the present invention, the foregoing object is attained by providing an image processing method comprising: an input step of inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; an image processing parameter input step of inputting a parameter to be employed in image processing on the image data executed by a user; an image processing step of performing luminance-related processing or chrominance-related processing on the image data in accordance with the image processing parameter inputted in the image processing parameter input step; and a storage step of storing an intermediate result for each of the luminance-related processing and the chrominance-related processing. In still another aspect of the present invention, the foregoing object is attained by providing an image processing method comprising: an input step of inputting image data, which is obtained by digitalizing an image signal that has been converted from light from an object to an electric signal by an image sensor, and performing no compression or lossless compression; an image processing parameter input step of inputting a parameter to be employed in image processing on the image data executed by a user; an image processing step of performing image processing on the image data in accordance with the image processing parameter inputted in the parameter input step; a storage step of storing a result of image processing and an intermediate result of image processing; a cache control step of caching the intermediate result of image processing in a storage unit in preparation for next image processing; an image processing parameter input history storage step of storing input history information of a parameter inputted in the image processing parameter input step; and a cache control step of determining whether or not to cache the intermediate result of image processing in accordance with a comparison between a current image processing parameter and previous input history information stored in the image processing parameter input history storage step. According to the present invention, it is possible to reduce time required for development processing and to display the processing result at high speed, thereby improving usability in development of a RAW image in accordance with user's preference. Furthermore, in RAW image data development processing, it is possible to increase the developing speed, and further to reduce the necessary memory capacity by efficiently using the memory. Other objects and advantages besides those discussed above shall be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part thereof, and which illustrate an example of the various embodiments of the invention. Such example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention. |
Optical recording medium |
An optical recording medium is provided, which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as irradiation light. The optical recording medium includes a substrate, and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of the laser light. The recording layer is substantially composed of Bi and O, and the ratio of the number of the O atoms in the recording layer is 62% or higher. |
1. An optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, the recording layer being substantially composed of Bi and O, a ratio of number of the O atoms in the recording layer being 62% or higher. 2. The optical recording medium according to claim 1, wherein the ratio of the number of the O atoms in the recording layer is 73% or lower. 3. The optical recording medium according to claim 1, wherein in the recording layer, a ratio of the number of the O atoms is 62% or higher with respect to total number of the Bi and O atoms constituting the recording layer. 4. The optical recording medium according to claim 2, wherein in the recording layer, a ratio of the number of the O atoms is 62% or higher with respect to total number of the Bi and O atoms constituting the recording layer. 5. The optical recording medium according to claim 1, wherein the recording layer comprises at least one element selected from the group consisting of Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, and Pb. 6. The optical recording medium according to claim 2, wherein the recording layer comprises at least one element selected from the group consisting of Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, and Pb. 7. The optical recording medium according to claim 3, wherein the recording layer comprises at least one element selected from the group consisting of Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, and Pb. 8. The optical recording medium according to claim 4, wherein the recording layer comprises at least one element selected from the group consisting of Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, and Pb. 9. An optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, the recording layer being substantially composed of Bi, O, and M, the M being at least one element selected from the group consisting of Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, and Pb, a ratio of total number of the Bi and O atoms to total number of the Bi, O, and M atoms being 80% or higher, a ratio of the numbers of the Bi, O, and M atoms being in the range represented by the following expression (I): {[O−(M×α/2)]/[Bi+O−(M×α/2)]}×100≧62 (I) where α is a valence of the M. 10. An optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, the recording layer being composed of Bi, O, and N, the M being at least one element except Bi and O, a ratio of number of the Bi atoms to number of the Bi and N atoms being 50% or higher, a ratio of numbers of the Bi, O, and NM atoms being in the range represented by the following expression (III): {[O−(M×α/2)]/[Bi+O−(M×α/2)]}×100≧63 (III) where α is a valence of the M. 11. The optical recording medium according to claim 9, wherein the ratio of numbers of the Bi, O, and M atoms in the recording layer being in the range represented by the following expression {[O−(M×α/2)]/[Bi+O−(M×α/2)]}×100≧73 (II). 12. The optical recording medium according to claim 10, wherein the ratio of numbers of the Bi, O, and M atoms in the recording layer being in the range represented by the following expression (II): {[O−(M×α/2)]/[Bi+O−(M×α/2)]}×100≧73 (II). 13. The optical recording medium according to claim 1, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 14. The optical recording medium according to claim 2, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 15. The optical recording medium according to claim 3, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 16. The optical recording medium according to claim 5, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 17. The optical recording medium according to claim 9, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 18. The optical recording medium according to claim 11, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 19. The optical recording medium according to claim 1, further comprising a spacer layer, and wherein a plurality of the recording layers are formed with the spacer layer therebetween. 20. The optical recording medium according to claim 2, further comprising a spacer layer, and wherein a plurality of the recording layers are formed with the spacer layer therebetween. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to an optical recording medium having a recording layer which makes an optical change for data recording when irradiated with laser light. 2. Description of Related Art Optical recording media such as a compact disc (CD) and a digital versatile disc (DVD) are widely used as information recording media. In recent years, attention is being given to optical recording media which use blue or blue violet laser light as irradiation light so that a large amount of information can be recorded at still higher densities. For the sake of specification standardization, blue violet laser light having a wavelength of approximately 405 nm has been proposed for use, and compatible optical recording media are now becoming prevalent. When the blue or blue violet laser light is used as the irradiation light, tracks on an optical recording medium are formed at track pitches within the range of 0.1 to 0.5 μm. Incidentally, a plurality of recording layers may be formed with a transparent spacer layer(s) therebetween. This multilayer recording type allows a further increase in the recording capacity. Optical recording media are broadly classified into a ROM (Read Only Memory) type in which data cannot be added or rewritten, an R (Recordable) type in which data can be added only once, and an RW (Rewritable) type in which data can be rewritten. The recording layer of R-type optical recording medium needs to make changes in optical characteristics when irradiated with laser light. Besides, it is essential that the recording layers be unsusceptible to deterioration even after a long period of storage, having excellent durability. Conventionally, organic dye has thus been used widely as a material of the recording layers of the R-type optical recording media. This conventional organic dye is a substance less likely to absorb ultraviolet rays and short-wave visible rays, such as blue and blue violet, which are prone to promote chemical reactions. It is this feature of the conventional organic dye that has contributed suppressed deterioration. Since the conventional organic dye is less likely to absorb short-wave visible rays of blue and blue violet, however, it has been impossible to obtain satisfactory change in optical characteristics for data recording when the blue or blue violet laser light is used as the irradiation light. Moreover, it has been difficult to develop an organic dye which provides satisfactory change in optical characteristics even for situations where the blue or blue violet laser light is used as the irradiation light, and is unsusceptible to deterioration for a long period of storage. In view of the foregoing, R-type optical recording media that have recording layers made of inorganic material containing Bi and O have been known(refer to, for example, Japanese Patent Laid-Open Publications Nos. 2003-48375 and Hei 10-334507). Nevertheless, even the inorganic material containing Bi and O has sometimes failed to achieve desired change in optical characteristics when the blue or blue violet laser light is used as the irradiation light. Besides, such an inorganic material containing Bi and O can vary in reflectance and in light transmittance as well, when irradiated with laser light. Consequently, if the inorganic material containing Bi and O is used to make the recording layers of an optical recording medium of multilayer recording type, the laser light to reach the lower(on the substrate side) recording layer varies in intensity between where the upper (on the cover-layer side) recording layer has been irradiated with the laser light to form recording marks and where not. There has thus been the problem that the accuracy of recording of data on the lower recording layer and the accuracy of reproduction of data from the lower recording layer are low. |
<SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing problems, various exemplary embodiments of this invention provide an optical recording medium which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as the irradiation light. Various exemplary embodiments of this invention provide an optical recording medium in which the material of its recording layer is mainly composed of Bi (bismuth) and O (oxygen), and the ratio of the number of the O atoms is 62% or higher in the material, so that data can surely be recorded/reproduced to/from the medium with blue or blue-violet laser light serving as irradiation light. The conventional inorganic material containing Bi and O is chiefly composed of Bi 2 O 3 , and thus the ratio of the number of O atoms in the recording layer is approximately 60%. Meanwhile, in the process of achieving the present invention, the inventors have made various recording layers containing Bi and O in different composition ratios, and examined them for optical characteristics. From the examination, it has been found that the ratio of the number of O atoms in the recording layer can be set at or above 62% to record and reproduce data with reliability. The reason for this is an increase in the difference between the reflectance of areas where recording marks are formed by the irradiation of blue or blue violet laser light (having a wavelength of the order of 380 to 450 nm) and the reflectance of areas where no recording mark is formed. The inventors have also found that the ratio of the number of O atoms in the recording layer can be set at or above 62% with a significant increase in light transmittance. Besides, the difference between the light transmittance of the areas where recording marks are formed and the light transmittance of the areas where no recording mark is formed becomes smaller. This material is thus suited for the recording layers of an optical recording medium of multilayer recording type. Accordingly, various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, the recording layer being substantially composed of Bi and O, a ratio of number of the O atoms in the recording layer being 62% or higher. Moreover, various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, total number of atoms of Bi and O in the recording layer is 90% or higher with respect to number of all atoms constituting the recording layer, and ratio of number of the O atoms to total number of the Bi and O atoms constituting the recording layer is 63% or higher Various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, the recording layer being substantially composed of Bi, O, and M, the M being at least one element selected from the group consisting of Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, and Pb, a ratio of total number of the Bi and O atoms to total number of the Bi, O, and M atoms being 80% or higher, a ratio of the numbers of the Bi, O, and M atoms being in the range represented by the following expression (I): in-line-formulae description="In-line Formulae" end="lead"? {[O−( M×α/ 2)]/[Bi+O−( M×α/ 2)]}×100≧62 (I) in-line-formulae description="In-line Formulae" end="tail"? where α is a valence of the M. Moreover, various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of laser light, the recording layer being composed of Bi, O, and M, the M being at least one element except Bi and O, a ratio of number of the Bi atoms to number of the Bi and M atoms being 50% or higher, a ratio of numbers of the Bi, O, and M atoms being in the range represented by the following expression (III): in-line-formulae description="In-line Formulae" end="lead"? {[O−( M×α/ 2)]/[Bi+O−( M×α/ 2)]}×100≧63 (III) in-line-formulae description="In-line Formulae" end="tail"? where α is a valence of the M. As employed herein, the phase “a recording layer is substantially made of Bi and O” shall mean that the total number of atoms of Bi and O in the recording layer is 80% or higher with respect to the number of all the atoms constituting the recording layer. In case that the recording layer is substantially made of Bi and O, it is preferable that the total number of atoms of Bi and O in the recording layer is 90% or higher with respect to the number of all the atoms constituting the recording layer. Moreover, the phase “a recording layer is substantially made of Bi, O and M” shall mean that the total number of atoms of Bi O and M in the recording layer is 80% or higher. In case that the recording layer is substantially made of Bi, O and M, it is preferable that the total number of atoms of Bi, O and M in the recording layer is 90% or higher with respect to the number of all the atoms constituting the recording layer. Moreover, Bi, O, and M in expressions (I), (II) and (III) shall represent the numbers of atoms of Bi, O, and M, respectively. The term “track pitch” shall refer to the pitch between a groove and a next groove in the case of an optical recording medium of groove type in which tracks are made of grooves. The same term shall refer to the pitch between a land and a groove next to this land in the case of an optical recording medium of land and groove type in which tracks are made of lands and grooves. |
Optical recording medium and method of recording and reproducing of optical recording medium |
An optical recording medium and a method of recording and reproducing of the optical recording medium are provided, which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as irradiation light. The optical recording medium has a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of the laser light. The recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area. |
1. An optical recording medium comprising: a substrate; and a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of laser light, the recording layer being formed on the substrate, the recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area. 2. An optical recording medium comprising: a substrate; and a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of laser light, the recording layer being formed on the substrate, the recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in a peripheral area are spaced narrower than cavities lying in an area of the center and its vicinities of the recording mark are. 3. An optical recording medium comprising: a substrate; and a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of laser light, the recording layer being formed on the substrate, the recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, the total area of the plurality of cavities in the recording mark falls within the range of 20% and 90% with respect to the area of the recording mark. 4. The optical recording medium according to claim 1, wherein the recording layer is configured so that, in the plan view taken in the direction of irradiation of the laser light, cavities lying in a peripheral area are spaced narrower than the cavities lying in an area of the center and its vicinities of the recording mark are. 5. The optical recording medium according to claim 3, wherein the recording layer is configured so that, in the plan view taken in the direction of irradiation of the laser light, cavities lying in a peripheral area are spaced narrower than the cavities lying in an area of the center and its vicinities of the recording mark are. 6. The optical recording medium according to claim 2, wherein the recording layer is configured so that, in the plan view taken in the direction of irradiation of the laser light, the total area of the plurality of cavities in the recording mark falls within the range of 20% and 90% with respect to the area of the recording mark. 7. The optical recording medium according to claim 1, wherein the recording layer is configured so that it is deformed to protrude toward the substrate in a direction of thickness and the substrate is also deformed when the recording mark is formed. 8. The optical recording medium according to claim 2, wherein the recording layer is configured so that it is deformed to protrude toward the substrate in a direction of thickness and the substrate is also deformed when the recording mark is formed. 9. The optical recording medium according to claim 3, wherein the recording layer is configured so that it is deformed to protrude toward the substrate in a direction of thickness and the substrate is also deformed when the recording mark is formed. 10. The optical recording medium according to claim 1, wherein the recording layer is configured so that the cavities are formed as enclosed in the recording layer. 11. The optical recording medium according to claim 1, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 12. The optical recording medium according to claim 2, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 13. The optical recording medium according to claim 3, wherein tracks for forming the recording mark are formed at track pitches within a range of 0.1 to 0.5 μm. 14. The optical recording medium according to claim 1, further comprising a spacer layer, and wherein a plurality of the recording layers are formed with the spacer layer therebetween. 15. A method of recording and reproducing of an optical recording medium, comprising: a recording step of irradiating an optical recording medium with laser light for recording so that a recording mark composed of a plurality of cavities is formed in a recording layer of the optical recording medium; and a reproducing step of irradiating the optical recording medium with laser light for reproduction so that information is reproduced based on a difference between a reflectance of an area of the recording mark and a reflectance of a space area around the recording mark, in the recording step, the recording mark is formed so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area. 16. A method of recording and reproducing of an optical recording medium, comprising: a recording step of irradiating an optical recording medium with laser light for recording so that a recording mark composed of a plurality of cavities is formed in a recording layer of the optical recording medium; and a reproducing step of irradiating the optical recording medium with laser light for reproduction so that information is reproduced based on a difference between a reflectance of an area of the recording mark and a reflectance of a space area around the recording mark, in the recording step, the recording mark is formed so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in a peripheral area of the recording mark are spaced narrower than cavities lying in an area of the center and its vicinities of the recording mark are. 17. The method of recording and reproducing of an optical recording medium according to claim 15, wherein in the recording step, the recording mark is formed so that, in the plan view taken in the direction of irradiation of the laser light, cavities lying in a peripheral area of the recording mark are spaced narrower than the cavities lying in an area of the center and its vicinities of the recording mark are. 18. The method of recording and reproducing of an optical recording medium according to claim 15, wherein in the recording step, the recording mark is formed so that, in the plan view taken in the direction of irradiation of the laser light, a total area of the plurality of cavities in the recording mark falls within a range of 20% to 90% with respect to an area of the recording mark. 19. The method of recording and reproducing of an optical recording medium according to claim 16, wherein in the recording step, the recording mark is formed so that, in the plan view taken in the direction of irradiation of the laser light, a total area of the plurality of cavities in the recording mark falls within a range of 20% to 90% with respect to an area of the recording mark. 20. The method of recording and reproducing of an optical recording medium according to claim 15, wherein in the recording step, the recording mark is formed in a part of the recording layer while the part is deformed to protrude toward the substrate in a direction of thickness and the substrate is also deformed. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to an optical recording medium having a recording layer which makes an optical change for data recording when irradiated with laser light, and a method of recording and reproducing of the optical recording medium. 2. Description of the Related Art Optical recording media such as a compact disc (CD) and a digital versatile disc (DVD) are widely used as information recording media. In recent years, attention is being given to optical recording media which use blue or blue violet laser light as irradiation light so that a large amount of information can be recorded at still higher densities. For the sake of specification standardization, blue violet laser light having a wavelength of approximately 405 nm has been proposed for use, and compatible optical recording media are now becoming prevalent. When the blue or blue violet laser light is used as the irradiation light, tracks on an optical recording medium are formed at track pitches within the range of 0.1 to 0.5 μm. Incidentally, a plurality of recording layers maybe formed with a transparent spacer layer(s) therebetween. This multilayer recording type allows a further increase in the recording capacity. Optical recording media are broadly classified into a ROM (Read Only Memory) type in which data cannot be added or rewritten, an R (Recordable) type in which data can be added only once, and an RW (Rewritable) type in which data can be rewritten. The recording layer of R-type optical recording medium needs to make changes in optical characteristics when irradiated with laser light. Besides, it is essential that the recording layers be unsusceptible to deterioration even after a long period of storage, having excellent durability. Conventionally, organic dye has thus been used widely as a material of the recording layers of the R-type optical recording media. This conventional organic dye is a substance less likely to absorb ultraviolet rays and short-wave visible rays, such as blue and blue violet, which are prone to promote chemical reactions. It is this feature of the conventional organic dye that has contributed suppressed deterioration. Since the conventional organic dye is less likely to absorb short-wave visible rays of blue and blue violet, however, it has been impossible to obtain satisfactory change in optical characteristics for data recording when the blue or blue violet laser light is used as the irradiation light. Moreover, it has been difficult to develop an organic dye which provides satisfactory change in optical characteristics even for situations where the blue or blue violet laser light is used as the irradiation light, and is unsusceptible to deterioration for a long period of storage. In view of the foregoing, R-type optical recording media that have recording layers made of inorganic material containing Bi and O have been disclosed, for example, in Japanese Patent Laid-Open Publications Nos. 2003-48375 and Hei 10-334507. Nevertheless, even the inorganic material containing Bi and O has sometimes failed to achieve desired change in optical characteristics when the blue or blue violet laser light is used as the irradiation light. Besides, such an inorganic material containing Bi and O can vary in reflectance and in light transmittance as well, when irradiated with laser light. Consequently, if the inorganic material containing Bi and O is used to make the recording layers of an optical recording medium of multilayer recording type, the laser light to reach the lower(on the substrate side) recording layer varies in intensity between where the upper (on the cover-layer side) recording layer has been irradiated with the laser light to form recording marks and where not. There has thus been the problem that the accuracy of recording of data on the lower recording layer and the accuracy of reproduction of data from the lower recording layer are low. |
<SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing problems, various exemplary embodiments of this invention provide an optical recording medium and a method of recording and reproducing of the optical recording medium which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as the irradiation light. According to one of the exemplary embodiments of the present invention, an optical recording medium comprises a recording layer which is configured so that a recording mark composed of a plurality of cavities is formed by irradiation of laser light. This allows reliable data recording and reproduction even when blue or blue violet laser light is used as the irradiation light. The conventional inorganic material containing Bi and O is chiefly composed of Bi 2 O 3 , and thus the ratio of the number of atoms of O to the total number of atoms of Bi and O is approximately 60%. Meanwhile, in the process of achieving the present invention, the inventors have made various recording layers containing Bi and O in different composition ratios, and examined them for optical characteristics. From the examination, it has been found that the ratio of the number of atoms of O to the total number of atoms of Bi and O can be set at or above 63% to record and reproduce data with reliability. The reason for this is an increase in the difference between the reflectance of areas where recording marks are formed by the irradiation of blue or blue violet laser light (having a wavelength of the order of 380 to 450 nm) and the reflectance of space areas where no recording mark is formed. Incidentally, in this case, the recording layers seem to contain unstable compounds such as Bi 2 O 5 and Bi 2 O 4 . The inventors have also found that the ratio of the number of atoms of O to the total number of atoms of Bi and O can be set at or above 63% with a significant increase in light transmittance. Besides, the difference between the light transmittance of the areas where recording marks are formed and the light transmittance of the space areas where no recording mark is formed becomes smaller. This material is thus suited for the recording layers of an optical recording medium of multilayer recording type. The space areas have the light transmittance equivalent to that of unrecorded areas. That is, the difference between the light transmittance of a recording layer that has been irradiated with laser light to form recording marks and spaces, and the light transmittance of an unrecorded recording layer yet to be irradiated with laser light is small. Then, the recording layer on the substrate side can be irradiated with laser light of constant intensity irrespective of the presence or absence of data recorded on the recording layer on the cover-layer side. It is therefore possible to record data on the substrate-side recording layer with reliability, and to reproduce data recorded on the substrate-side recording layer with reliability. The inventors have made intensive studies on the reason for these effects and found the following. In the recording layers where the ratio of the number of atoms of O to the total number of atoms of the inorganic materials, or Bi and O, reaches or exceeds 63%, each single recording mark formed by the irradiation of the blue or blue violet laser light is composed of a plurality of cavities. That is, it is found that in the conventional recording layers made of the organic dye or inorganic material, each recording mark is made of a single protrusion or an undeformed marking of a changed optical characteristic. In contrast, the recording layers described above are provided with recording marks of totally different structure. When such recording marks composed of a plurality of cavities are irradiated with laser light for reproduction, the laser light is diffused and refracted by the plurality of cavities. As a result, the amount of light incident on a photodetector decreases accordingly, which seems to be detected as a drop in reflectance. Moreover, it is considered that oxygen gas occurs from decomposition of Bi 2 O 5 or Bi 2 O 4 and it inflates the surrounding bismuth oxides to form the cavities in the recording marks. Since the cavities themselves cause no light absorption, they seem to have a relatively high light transmittance. While the cavities themselves have a high light transmittance, the vicinities of the interfaces of the cavities can cause diffraction and refraction with a drop in light transmittance by that much. In addition, the formed cavities thicken the recording marks other than where the cavities are. This increases the light absorptance accordingly, with a drop in light transmittance. This effect of the cavities themselves to increase the light transmittance is cancelled out by the effect of decreasing the light transmittance due to the diffraction and refraction near the interfaces of the cavities and the effect of decreasing the light transmittance at portions other than the cavities. This seems to be the reason why the entire recording marks apparently drop in reflectance as compared to the space areas, while the difference to the light transmittance of the space areas is suppressed smaller. Furthermore, in various exemplary embodiments of the invention, the recording mark is formed so that the cavities lying near the periphery are smaller than the cavities lying in the areas of the centers and their vicinities. This suppresses a deformation of the peripheral portions of the recording marks to improve recording/reproducing accuracies. Alternatively, in other various exemplary embodiments of the invention, the recording mark is formed so that the cavities formed in the areas near the peripheries are spaced narrower than those formed in the inner areas are. The peripheries of the recording mark is thus formed accordingly finely, which also improves the recording and reproducing accuracies. Accordingly, various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of laser light, the recording layer being formed on the substrate, the recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area. Alternatively, various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of laser light, the recording layer being formed on the substrate, the recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in a peripheral area are spaced narrower than cavities lying in an area of the center and its vicinities of the recording mark are. Alternatively, various exemplary embodiments of the invention provide an optical recording medium comprising: a substrate; and a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of laser light, the recording layer being formed on the substrate, the recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, the total area of the plurality of cavities in the recording mark falls within the range of 20% and 90% with respect to the area of the recording mark. Various exemplary embodiments of the invention provide a method of recording and reproducing of an optical recording medium, comprising: a recording step of irradiating an optical recording medium with laser light for recording so that a recording mark composed of a plurality of cavities is formed in a recording layer of the optical recording medium; and a reproducing step of irradiating the optical recording medium with laser light for reproduction so that information is reproduced based on a difference between a reflectance of an area of the recording mark and a reflectance of a space area around the recording mark, in the recording step, the recording mark is formed so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area. Alternatively, various exemplary embodiments of the invention provide a method of recording and reproducing of an optical recording medium, comprising: a recording step of irradiating an optical recording medium with laser light for recording so that a recording mark composed of a plurality of cavities is formed in a recording layer of the optical recording medium; and a reproducing step of irradiating the optical recording medium with laser light for reproduction so that information is reproduced based on a difference between a reflectance of an area of the recording mark and a reflectance of a space area around the recording mark, in the recording step, the recording mark is formed so that, in a plan view taken in a direction of irradiation of the laser light, the cavities lying in a peripheral area of the recording mark are spaced narrower than the cavities lying in an area of the center and its vicinities of the recording mark are. As employed herein, the phase “a recording layer is substantially made of Bi and O” shall mean that the total number of atoms of Bi and O in the recording layer reaches or exceeds 80% with respect to the number of all the atoms constituting the recording layer. Incidentally, it is preferable that the total number of atoms of Bi and O in the recording layer is 90% or higher with respect to the number of all the atoms constituting the recording layer. Moreover, Bi, O, and M in expressions (I) and (II) to be described later shall represent the numbers of atoms of Bi, O, and M, respectively. The term “track pitch” shall refer to the pitch between a groove and a next groove in the case of an optical recording medium of groove type in which tracks are made of grooves. The same term shall refer to the pitch between a land and a groove next to this land in the case of an optical recording medium of land and groove type in which tracks are made of lands and grooves. According to the exemplary embodiments of the present invention, it is possible to record and reproduce data with reliability by using blue or blue violet laser light as the irradiation light. Even with multilayer recording type, data can also be recorded and reproduced with reliability. |
Vehicle remote starting apparatus and method for executing registration process |
A vehicle remote starting apparatus includes a control device that starts an engine when the control device has set a registration flag and the control device receives an engine starting signal from an external device, which is apart from the vehicle remote starting apparatus. When the vehicle remote starting apparatus is mounted on a vehicle, the control device executes registration process for setting the registration flag, which allows the control device to start the engine when the control device receives the engine starting signal. |
1. A vehicle remote starting apparatus comprising: a control device that starts an engine when the control device has set a registration flag and the control device receives an engine starting signal from an external device, which is apart from the vehicle remote starting apparatus, wherein: when the vehicle remote starting apparatus is mounted on a vehicle, the control device executes registration process for setting the registration flag, which allows the control device to start the engine when the control device receives the engine starting signal. 2. The vehicle remote starting apparatus according to claim 1, wherein: the control device receives a signal input from the vehicle; when the control device receives the engine starting signal and confirms that the signal input from the vehicle satisfies an engine starting condition, the control device starts the engine; during the registration process, the control device checks changing of the signal input from the vehicle; when the control device determines that the signal input from the vehicle does not change during the registration process, the control device does not set the registration flag. 3. The vehicle remote starting apparatus according to claim 2, wherein during the registration process, the control device requests a user to operate the vehicle in a predetermined way, and then checks as to whether or not the signal input from the vehicle changes in response to user's operation. 4. The vehicle remote starting apparatus according to claim 2, wherein the signal input from the vehicle changes in response to a state of a switch, which is turned off when the switch is in a normal state and is turned on when the switch is operated. 5. The vehicle remote starting apparatus according to claim 2, wherein the signal input from the vehicle is a signal output from a group consisting of a door switch, a hood switch, a key sensor, an ignition switch, a brake switch, a shift position, and a gear shift position sensor. 6. The vehicle remote starting apparatus according to claim 2, further comprising: a display device, wherein: when the control device has not set the registration flag, the control device displays on the display device a message indicating that the control device is in an inhibition state. 7. The vehicle remote starting apparatus according to claim 1, wherein when the vehicle remote starting apparatus is powered down, the control device releases the registration flag. 8. The vehicle remote starting apparatus according to claim 7, wherein when the vehicle remote starting apparatus is powered down in a state where a hood of the vehicle is opened, the control device does not release the registration flag. 9. The vehicle remote starting apparatus according to claim 1, wherein when the vehicle remote starting apparatus is powered on, the control device releases the registration flag except for in a state where a hood of the vehicle is opened. 10. The vehicle remote starting apparatus according to claim 1, wherein when the engine is started with using a key, the control device checks the signal input from the vehicle and then if the signal input from the vehicle does not satisfy a predetermined condition, the control device releases the registration flag. 11. The vehicle remote starting apparatus according to claim 1, wherein: the signal input from the vehicle includes a specific signal, which should be in a predetermined state during traveling of the vehicle; and during the traveling of the vehicle, the control device checks the specific signal and then if the specific signal is not in the predetermined state, the control device releases the registration flag. 12. The vehicle remote starting apparatus according to claim 1, wherein the external device is a portable remote controller that is capable of transmitting the engine starting signal to the vehicle remote starting apparatus. 13. A vehicle remote starting system comprising: a signal transmission unit that transmits an engine starting signal; and a control device that starts an engine when the control device has set a registration flag and the control device receives the engine starting signal from the signal transmission unit, the control device being separate from the signal transmission unit wherein: when the vehicle remote starting apparatus is mounted on a vehicle, the control device executes registration process for setting the registration flag, which allows the control device to start the engine when the control device receives the engine starting signal. 14. A method for executing registration process for setting a registration flag, which allows a control device to start an engine when the control device receives an engine starting signal from an external device, the method comprising: checking changing of a signal input from a vehicle; and when the signal input from the vehicle changes, setting the registration flag. 15. The method according to claim 14, wherein the checking comprises requesting a user to operate the vehicle in a predetermined way, and then checking as to whether or not the signal input from the vehicle changes in response to user's operation. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a vehicle remote starting apparatus used for starting an engine of a vehicle placed in a place remote from a user, such as a parking area, and a method for executing a registration process. 2. Description of the Related Art In a vehicle such as an automobile, a starter motor is actuated with using a battery attached to a vehicle body as a power source and by its rotation force, cranking of an engine is performed to start the engine. A driver inserts an ignition key into a key hole of an ignition switch and rotates this key by a predetermined angle to turn on the ignition switch, thereby actuating this starter motor. However, recently, many devices for starting an engine by remote control in a state where a driver does not ride in a vehicle have been used. This is because an air conditioner or a heater is started up in summer or winter before starting moving the vehicle. A vehicle remote starting system includes a transmitter carried by a driver, a receiver attached to the vehicle and a controller. In the case that the receiver receives a starting signal from the transmitter and engine starting is controlled by the controller, only when conditions including safety condition are satisfied, the controller outputs a starting command signal and based on this starting command signal, an ignition switch constructing the starting apparatus is closed and a self starter motor is driven and the engine is started. The safety condition for outputting the starting command signal includes a condition that a door is closed and locked for theft prevention, a condition that a parking brake is activated to ensure safety so that a vehicle does not move accidentally, a condition that a gear shift is in a parking position, and further a condition that a hood is closed to prevent an accident during work in which the hood is opened. In order to check such conditions, the vehicle is provided with various switches and sensors. In some switches, control logic of an output signal changes to a high (H) level in a state where a switch is opened, that is, the switch is in a normal state. Also, the control logic changes to a low (L) level in a state where the switch is closed, that is, the switch is in an operated state. For example, a hood switch installed inside an engine room has a configuration shown in FIG. 5 . When a hood is opened, a contact point 31 of a hood switch (SW) 30 closes and when the hood is closed, the contact point 31 opens. As a result, when the hood is opened, a signal of an L level is input to a remote starting control device 40 . When the hood is closed, a signal of an H level is input to the remote starting control device 40 . The remote starting control device 40 is configured to detect as to whether or not the hood is in the opened state with using an input from this hood switch 30 . The remote starting control device 40 does not output the starting command signal unless the hood is closed. When the circuit configuration as described above is adopted, as shown in FIG. 6 , for example, in the case that wiring of the hood switch 30 is broken or the case of missing connecting the hood switch 30 , an input from the hood switch 30 shifts to an H level although the hood is opened as shown in FIG. 6 . Therefore, the remote starting control device 40 decides that the hood is closed, and the engine is started. This causes a problem in safety. As a result, when a structure in which a contact point is closed when the hood is closed is adopted as the hood switch, such a problem does not arise. However, problems that attachment accuracy of the hood switch is required or a structure of the hood switch becomes complicated and cost increases arise. JP-A-Hei. 6-137240 has disclosed a vehicle remote starting apparatus in which a resistor is connected in parallel to the contact point of the hood switch in order to recognize the open/close state of the hood reliably. Three types of signals showing a state in which the hood is closed, a state in which the hood is opened, and a state in which existence of the hood switch cannot be recognized are transmitted to the remote starting control apparatus. The state in which the existence of the hood cannot be recognized includes a case that a wiring connected to the hood switch is broken and a case that a user forgets to connect the hood switch. With this configuration, the state of the hood can be confirmed reliably. |
<SOH> SUMMARY OF THE INVENTION <EOH>For example, in the hood switch, control logic of an input signal to the remote starting control apparatus changes to an H level in a state where the switch is opened in a normal state (hood is closed) and the control logic changes to an L level in a state where the switch is closed in an operation state (hood is opened). In the case of the switch with such control logic, there arises a problem that the operation state is recognized as the normal state even when wiring of the switch part is broken or the switch is not connected as described above. The wrong recognition as described above can also be prevented by devising a switch circuit of the hood switch etc. as described above. However, this devising causes another problem that it becomes necessary to add a special circuit to the switch circuit and cost increases. Also, when a remote starting apparatus is newly attached to a vehicle, replacement of the hood switch etc. is required. As a result, much effort is taken in attachment. In view of the aforementioned circumstances, the invention provides a vehicle remote starting apparatus capable of checking that a sensor or a switch such as a hood switch is not abnormal at a time of installation of the apparatus; detecting abnormality of the switch after installation of the apparatus; and outputting an engine starting signal only when an engine remote starting condition is satisfied. According to one embodiment of the invention, a vehicle remote starting apparatus includes a control device that starts an engine when the control device has set a registration flag and the control device receives an engine starting signal from an external device, which is apart from the vehicle remote starting apparatus. When the vehicle remote starting apparatus is mounted on a vehicle, the control device executes registration process for setting the registration flag, which allows the control device to start the engine when the control device receives the engine starting signal. According to this configuration, the registration process is required at the time of mounting the remote starting apparatus on the vehicle. If the registration process is not done, the vehicle remote starting apparatus is not allowed to activate the remote engine starting function. Therefore, the safety can be ensured. According to one embodiment of the invention, the control device may receive a signal input from the vehicle. When the control device receives the engine starting signal and confirms that the signal input from the vehicle satisfies an engine starting condition, the control device may start the engine. During the registration process, the control device may check changing of the signal input from the vehicle. When the control device determines that the signal input from the vehicle does not change during the registration process, the control device may not set the registration flag. Furthermore, The signal input from the vehicle may change in response to a state of a switch, which is turned off when the switch is in a normal state and is turned on when the switch is operated. The signal input from the vehicle may be a signal output from a group consisting of a door switch, a hood switch, a key sensor, an ignition switch, a brake switch, a shift position, and a gear shift position sensor. According to this configuration, the control device confirms as to whether or not switches and sensors are normal, by checking changes of the signals input from a switch, which is turned off when the switch is in a normal state and is turned on when the switch is operated, such as a door switch, a hood switch, a key sensor, an ignition switch, a brake switch and a gear shift position sensor. If there is something wrong with any of the switches and sensors, the registration flag is not set and a function of the remote starting apparatus is inhibited. According to one embodiment of the invention, the vehicle remote starting apparatus may further include a display device. When the control device has not set the registration flag, the control device displays on the display device a message indicating that the control device is in an inhibition state. According to this configuration, when the control unit has not set the registration flag, the message indicating it is displayed. Therefore, a user can easily recognize that the remote starting function is inhibited and registration process is required. According to one embodiment of the invention, when the vehicle remote starting apparatus is powered down, the control device may release the registration flag. Also, when the vehicle remote starting apparatus is powered down in a state where a hood of the vehicle is opened, the control device may not release the registration flag. According to this configuration, when a power source of the remote starting apparatus is turned off by an operation other than normal maintenance operation, the registration flag is released, the remote starting function is inhibited. On the other hand, the control device regards a power cut in a state where the hood is opened as a normal maintenance operation, and the remote starting function of the remote starting apparatus connected is held and is validated. Therefore, the need for registration process after the normal maintenance operation can be eliminated. According to one embodiment of the invention, when the vehicle remote starting apparatus is powered on, the control device may release the registration flag except for in a state where a hood of the vehicle is opened. According to this configuration, in the case that a battery is once detached by an improper access to the battery or the case that a power source is not supplied to the remote starting apparatus, the registration flag is released if a hood is not opened when the battery is again connected and the power source is supplied to the remote starting apparatus. Therefore, the remote starting function can be inhibited at the time of unauthorized attachment. According to one embodiment of the invention, when the engine is started with using a key, the control device may check the signal input from the vehicle and then if the signal input from the vehicle does not satisfy a predetermined condition, the control device may release the registration flag. According to this configuration, an on/off state of an input signal required to perform the remote starting is checked at the time of starting the engine with using a key. When the signal input from the vehicle does not satisfy the predetermined condition, the remote starting function is inhibited. Therefore, abnormality of a switch or a sensor after the remote starting apparatus is mounted on the vehicle can be detected. According to one embodiment of the invention, the signal input from the vehicle may include a specific signal, which should be in a predetermined state during traveling of the vehicle. During the traveling of the vehicle, the control device may check the specific signal and then if the specific signal is not in the predetermined state, the control device releases the registration flag. According to this configuration, an on/off state of a predetermined input signal (specific signal) is checked during the traveling of the vehicle. When the predetermined input signal (specific signal) is not in the predetermined state, the registration flag is released and the remote starting function is inhibited. Therefore, abnormality of switches and sensors after the remote starting apparatus is mounted on the vehicle can be detected in a manner similar to the above. |
System, apparatus and method for transmitting and receiving data coded by low density parity check code having variable coding rate |
A system, an apparatus and a method for transmitting/receiving data coded by a low density parity check matrix code are provided. The apparatus for transmitting data coded by a low density parity check code includes: a low density parity check encoder for encoding input data based on the low density parity check code; and a bit puncturer for puncturing columns in an order of columns which least degrade a performance caused by puncturing in the low density check code according to a code rate of an output data. Accordingly, the low density parity check code having superior performance can be implemented to the next generation mobile communication system supporting various code rates. |
1. An apparatus for transmitting data coded by a low density parity check code, the apparatus comprising: a scrambler which scrambles input data to be transmitted; a low density parity check encoder which encodes the input data scrambled by the scrambler based on a low density parity check code; a bit puncturer for which punctures columns in the low density check code which least degrade a performance caused by puncturing; a constellation mapper which converts the punctured data to a symbol mapped to each data; and a reverse fast-fourier transformer which reverse fast-fourier transforms the symbol for orthogonal frequency division multiplexing for transmission to a receiving side. 2. The apparatus of claim 1, further comprising: a digital-to-analog converter which converts a digital output signal of the reverse fast-fourier transformer to an analog signal; and a transmitting antenna which multiplies a carrier frequency signal and the analog signal, and transmits a multiplied analog signal. 3. The apparatus of claim 2, wherein the transmitting antenna transmits the multiplied analog signal using ultra wideband frequency. 4. The apparatus of claim 1, wherein the low density parity check encoder comprises a column permuting unit which replaces columns in the low density parity check code according to an order of columns which least degrade a performance caused by puncturing. 5. The apparatus of claim 4, wherein the columns which least degrade the performance caused by puncturing are replaced with left most columns or right most columns. 6. The apparatus of claim 5, wherein the bit puncturer punctures bits according to a code rate of the output data in an order from the most left column or from the most right column of the low density parity check code. 7. The apparatus of claim 1, wherein the low density parity check encoder comprises: a parity check matrix generator which generates an M×N parity check matrix having elements of 0 and 1, wherein a number of 1's is less than a number of 0's; a column permutated matrix generator which generates a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing; a generate matrix generator which generates a generate matrix from the column permutated matrix; and an encoding calculator which encodes the input data according to the generate matrix. 8. The apparatus of claim 7, wherein the column permutated matrix generator comprises: a puncturing bit calculating unit which calculates a number of bits to be punctured according to a maximum code rate among required code rates; a punctured bit position determining unit which determines a number of columns to be permutated according to the calculated number of bits and determines the number of columns which least degrade the performance caused by puncturing as columns to be replaced; and a column replacing unit which replaces the determined columns. 9. The apparatus of claim 8, wherein the punctured bit position determining unit determines only one variable node to be punctured among a plurality of variable nodes connected to one check node on a factor graph associated with an M×N parity check matrix. 10. An apparatus for transmitting data coded by a low density parity check code, the apparatus comprising: a low density parity check encoder which encodes input data based on the low density parity check code; and a bit puncturer which punctures columns in an order of columns which least degrade a performance caused by puncturing in the low density check code according to a code rate of output data. 11. The apparatus of claim 10, wherein the low density parity check encoder includes a column permuting unit which permute columns in an order of columns which least degrade a performance caused by puncturing in the low density parity check code. 12. The apparatus of claim 11, wherein columns which least degrade a performance caused by puncturing are permuted from a right side column or from a left side column in the low density parity check code. 13. The apparatus of claim 12, wherein the bit puncturer punctures bits according to a code rate of the output data in an order from a left side column in the low density parity check code. 14. The apparatus of claim 10, wherein the low density parity check encoder comprises: a parity check matrix generator which generates an M×N parity check matrix having elements of 0 and 1, wherein a number of 1's is less than a number of 0's; a column permutated matrix generator which generates a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing; a generate matrix generator which generates a generate matrix from the column permutated matrix; and an encoding calculator which encodes input data according to the generate matrix. 15. The apparatus of claim 14, wherein the column permutated matrix generator comprises: a puncturing bit calculating unit which calculates a number of bits to be punctured according to a maximum code rate among required code rates; a punctured bit position determining unit which determines a number of columns to be permutated according to the calculated number of bits and determines the number of columns which least degrade performance caused by puncturing as columns to be replaced; and a column replacing unit which replaces the determined columns. 16. The apparatus of claim 15, wherein the punctured bit position determining unit determines a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code as the column to be punctured. 17. An apparatus for receiving data coded by a low density parity check code, the apparatus comprising: a fast fourier transformer which receives a signal transmitted from a transmitting side and fast-fourier transforms the received signal; a bit inserter which inserts intermediate values in a transformed signal output from the fast fourier transformer for bits punctured in the transmitting side; a low density parity check decoder which decodes a bit-inserted signal output from the bit inserter based on an encoding method of a low density parity check encoder in the transmitting side; and a de-scrambler which generates final output data by de-scrambling a decoded signal output by the low density parity check decoder. 18. The apparatus of claim 17, further comprising: a receiving antenna which receives the signal transmitted from the transmitting side; and an analog-to-digital converter which converts the signal received from the transmitting side to a digital signal. 19. The apparatus of claim 17, wherein the bit-inserter inserts a corresponding number of bits in columns in an order from a left side column in data which is input to the low density parity check decoder. 20. The apparatus of claim 17, wherein the low density check decoder comprises: a soft decision unit which performs a soft decision for a signal of the bit-inserted data by the bit inserter; and a decoder for decoding a soft-decided signal output by the soft decision unit based on the low density parity check code. 21. The apparatus of claim 17, wherein the low parity check decoder further comprises: a parity check matrix generator which generates an M×N parity check matrix having elements of 0 or 1, wherein a number of 1's is less than a number of 0's; and a column permutated matrix generator which generates a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing. 22. The apparatus of claim 21, wherein the column permutated matrix generator comprises: a puncturing bit calculating unit which calculates a number of bits to be punctured according to a maximum code rates among required code rates; a punctured bit position determining unit which determines number of columns to be permutated according to the calculated number of bits and determines the number of columns which least degrade performance caused by puncturing as columns to be replaced; and a column replacing unit which replace the determined columns. 23. The apparatus of claim 22, wherein the punctured bit position determining unit determines a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code as the column to be punctured. 24. An apparatus of receiving data coded by a low density parity check code, the apparatus comprising: a bit inserter which inserts bits at a corresponding punctured position as many as the number of bits punctured at a transmitting side according to a code rate of a receiving data; and a low density parity check decoder which performs a low density parity check decoding based on a low parity check code in which columns are permutated in an order of columns which least degrade a performance caused by puncturing. 25. The apparatus of claim 24, wherein the bit-inserter inserts a corresponding number of bits in columns in an order from a left side column in data which is input to the low density parity check decoder. 26. The apparatus of claim 24, wherein the low density check decoder comprises: a soft decision unit which performs a soft decision for a signal of bit-inserted data output by the bit inserter; and an LLR decoder for decoding a soft-decided signal output by the soft decision unit based on a low density parity check code. 27. The apparatus of claim 24, wherein the low parity check decoder further comprises: a parity check matrix generator which generates an M×N parity check matrix having, wherein a number of 1's is less than a number of 0's; and a column permutated matrix generator which generates a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing. 28. The apparatus of claim 24, wherein the column permutated matrix generator comprises: a puncturing bit calculating unit which calculates a number of bits to be punctured according to a maximum code rate among required code rates; a punctured bit position determining unit which determines a number of columns to be permutated according to the calculated number of bits and determining the number of columns which least degrade performance caused by puncturing as columns to be replaced; and a column replacing unit which replaces the determined columns. 29. The apparatus of claim 24, wherein the punctured bit position determining unit determines a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code as the column to be punctured. 30. A method for transmitting data coded by a low density parity check code, the method comprising: encoding input data by a low density parity check code; and puncturing the encoded input data in an order of columns which least degrade a performance caused by puncturing in the low density parity check code. 31. The method of claim 30, wherein the encoding further comprises permuting columns in the low density parity check code according to an order of columns which least degrade a performance caused by puncturing. 32. The method of claim 31, wherein in the permuting columns, columns which least degrade a performance caused by puncturing are replaced with left most columns or right most columns. 33. The method of claim 32, wherein, in the puncturing, bits are punctured according to a code rate of the output data in an order from a left side column in the low density parity check code. 34. The method of claim 30, wherein the encoding input data comprises: generating an M×N parity check matrix having elements of 0 and 1, wherein a number of 1's is less than a number of 0's; generating a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing; generating a generate matrix from the column permutated matrix; and encoding the input data according to the generate matrix. 35. The method of claim 34, wherein the generating the column permutated matrix comprises: calculating a number of bits to be punctured according to a maximum code rate among required code rates; determining a number of columns to be permutated according to the calculated number of bits and determining the number of columns which least degrade performance caused by puncturing as columns to be replaced; and replacing the determined columns. 36. The method of claim 35, wherein in the determining the number of columns, a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code is determined as the column to be punctured. 37. The method of claim 35, wherein the determining the number of columns comprises: selecting a column having a least number of 1's in a low density parity check matrix; analyzing rows of 1's in the selected column; and determining a jth column as a candidate column to be punctured if the jth column satisfies a predetermined condition in a case that the jth column is the selected column, wherein the predetermined condition is that there is at least one of the rows of I's which has non-punctured columns of non-0 elements. 38. The method of claim 37, wherein the determining the number of columns, the jth column is determined as a column to be punctured if 0th to (j-1)th columns satisfy the predetermined condition. 39. A method for receiving data coded by a low density parity check code, the method comprising: inserting bits to corresponding punctured position as many as the number of bits punctured at a transmitting side according to a code rate of a receiving data; and performing a low density parity check decoding based on a low parity check code in which columns are permutated in an order of columns which least degrade a performance caused by puncturing. 40. The method of claim 39, wherein in the inserting bits, a corresponding number of bits are inserted in columns in an order from a left side column in data which is input. 41. The method of claim 39, wherein the performing the low density parity check decoding comprises: performing a soft decision for a signal of bit-inserted data; and decoding the soft-decided signal based on the low density parity check code. 42. The method of claim 41, wherein the performing the low parity check decoding further comprises: generating an M×N parity check matrix having elements of 0 or 1, wherein a number of 1's is less than a number of 0's; and generating a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing. 43. The method of claim 42, wherein the generating the column permutated matrix comprises: calculating a number of bits to be punctured according to a maximum code rate among required code rates; determining a number of columns to be permutated according to the calculated number of bits and determining the determined number of columns which least degrade performance caused by puncturing as columns to be replaced; and replacing the determined columns. 44. The method of claim 43, wherein in the determining the number of columns, a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code is determined as the column to be punctured. 45. The method of claim 44, wherein the determining the number of columns comprises: selecting a column having least number of 1's in a low density parity check matrix; analyzing rows of 1's in the selected column; and determining a jth column as a candidate column to be punctured if the jth column satisfies a predetermined condition in a case that the jth column is the selected column, wherein the predetermined condition is that there is at least one of the rows of 1's which has non-punctured columns of non-0 elements. 46. The method of claim 45, wherein the determining the number of columns, the jth column is determined as a column to be punctured if 0th to (j-1)th columns satisfy the predetermined condition. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention Apparatuses, methods and systems consistent with the present invention relate to a transmitting/receiving data coded by a low density parity check matrix code, and more particularly, to transmitting/receiving data coded by a low density parity check matrix code for providing various code rates and superior performance. 2. Description of the Related Art A cellular mode mobile telecommunication system was introduced in the United States in the late 1970's and an advanced mobile phone service (AMPS) was provided as a voice wireless communication service in Korea in the late 1980's. The advanced mobile phone service is an analog mode of a 1 st generation mobile communication system (1G). Subsequently, a 2 nd generation mobile communication system was commercialized in the mid 1990's and a part of International Mobile Telecommunication-2000 (IMT-2000) standard was commercialized in late 1990's as a 3 rd generation mobile communication system for providing improved and high speed wireless multimedia data service. Recently, there are many studies in progress for developing the 3 rd generation mobile communication system into a 4 th generation mobile communication system (4G). The 4 th generation mobile communication system has been developed to achieve objects such as effective connection between a wired communication network and a wireless communication, and an integrated service. Therefore, various specifications of the 4 th generation mobile communication system have been standardized for developing technologies providing faster data transmission service as compared to the 3 rd mobile communication system. Meanwhile, the most fundamental problem in communication is how to transmit data effectively and reliably through a channel. The next generation mobile communication requires a high speed communication system processing various information such as voice, image and data, and transmitting the processed information at high speed. Accordingly, an effective channel coding scheme is required for improving efficiency of the communication system. Furthermore, rapid development of the mobile communication system has led to the need to develop a technology for transmitting large amounts of data in wireless networks comparable to wired networks. Therefore, increasing data transmission efficiency has become a major factor for improving a performance of the communication system. However, the mobile communication system may have difficulty transmitting large amounts of data at high speed due to unavoidable errors such as noise, interference and fading caused by channel conditions during data transmission. Accordingly, information data is often lost due to the errors. For reducing information data loss caused by the error, various error-control techniques have been introduced and widely applied according to a characteristic of a channel. The various error-control techniques have increased the reliability of the mobile communication system. Among the various error-control techniques, an error-correcting code has been commonly used. Representative error-control techniques include a turbo code and a low density parity check (LDPC). Meanwhile, the above mentioned channel coding is an essential constitutional element of a MODEM in a multiband orthogonal frequency division multiplexing (OFDM) system which is used in a wireless personal area network system. FIG. 1 is a block diagram illustrating a conventional multiband OFDM system using convolution coder. As shown in FIG. 1 , the conventional multiband OFDM system includes a transmitting unit and a receiving unit. The transmitting unit includes a scrambler 110 , a convolution encoder 111 , a puncturer 112 , a bit interleaver 113 , a constellation mapper 114 , an inverse fast fourier transform (IFFT) unit 115 , a digital-to-analog (D/A) converter 116 , a multiplier 117 and an antenna 118 . The scrambler 110 receives and scrambles input data. The convolution encoder 111 encodes the scrambled data from the scrambler 110 . The puncturer 112 punctures the encoded data from the convolution encoder 111 according to a code rate of data to be transmitted. The bit interleaver 113 interleaves a bit to the punctured data and the constellation mapper 114 converts the bit-interleaved data to corresponding symbols. The IFFT unit 115 performs IFFT of the symbols and the transformed symbols are converted to analog signal by the D/A converter 116 . The analog signal is multiplied with a carrier frequency ex(j2πf c t) by the multiplier 117 and the multiplied analog signal is transmitted to the receiving unit through the antenna 118 . The receiving unit of the multiband OFDM system includes a descrambler 120 , an decoder 121 , a de-puncturer 122 , a de-interleaver 123 , an FFT unit 124 , two A/D converters 125 a , 125 b , two multipliers 126 a , 126 b , a low noise amplifier (LNA) 127 , and an antenna 128 . The LNA 127 receives a signal transmitted from the transmitting unit through the antenna 128 and amplifies the received signal. The two multipliers 126 a and 126 b divide the received signal into an I-channel signal and a Q-channel signal and the A/D converters 125 a and 125 b convert the I-channel signal and the Q-channel signal to digital signals. The digital signal is fast-fourier transformed by the FFT unit 124 and the transformed digital signal is de-interleaved by the de-interleaver 123 . The de-puncturer 122 inserts bits for each of the punctured bits. The bit inserted digital signal is decoded by the decoder 121 i.e., a viterbi decoder. Finally, the de-scrambler 120 de-scrambles the decoded signal for generating a final output data. As mentioned above, the multiband OFDM system essentially requires an encoding operation and additional requires puncturing operation for puncturing the encoded data according to corresponding code rate in the transmitting unit. The convolution encoder has been commonly used as the encoder for supporting various code rates. However, the convolution encoder has degraded bit error rate (BER) performance as compared to the LDPC encoder. FIG. 2 is a graph showing a performance difference between a convolution coding and an LDPC coding. Referring to FIG. 2 , the graph shows packet error rates (PER) of an original signal 201 , convolution coded signals 202 , 203 , 204 and LDPC coded signals 205 , 206 and 207 . The convolution coded signals 202 , 203 , 204 are encoded and interleaved based on the convolution encoding and have a code rate of ½, ⅝ and ¾, respectively. The LDPC coded signals 205 , 206 and 207 are encoded based on the LDPC encoding and have a code rate of ½, ⅝ and ¾, respectively. According to the graph, there is aperformance difference of about 6.8 dB between the convolution coded signals and the LDPC coded signals. Therefore, the LDPC encoding has been considered as an encoding scheme for the next generation mobile communication system. However, the LDPC encoding scheme requires performing puncturing according to code rates when the LDPC encoding scheme is applied to the next generation mobile communication system supporting various code rates. If a random puncturing method is used in the LDPC encoding scheme as a method for puncturing, the performance would be degraded. Therefore, although the LDPC encoding scheme provides superior coding performance, there are difficulties in applying the LDPC encoding scheme to the mobile communication system supporting various code rates. In order to overcome the above mentioned problem, a method using a plurality of mother codes according to corresponding code rate without puncturing the LDPC code in an Infineon has been introduced as encoding scheme for supporting various code rates without degradation of performance while using the LDPC coding scheme. This method improves performance as compared to the convolution encoding scheme. However, the method results in increased complexity because additional mother codes are required according to each code rate. Therefore, there has been great demand for an encoding scheme having lower complexity and superior performance in a mobile communication system supporting various code rates. |
<SOH> SUMMARY OF THE INVENTION <EOH>Illustrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any of the problems described above. According to an aspect of the present invention, a system, an apparatus and a method are provided for transmitting/receiving data supporting various code rates by encoding data based on a low density parity check code, puncturing the encoded data and transmitting the punctured data in a mobile communication system. According to another aspect of the present invention, a system, an apparatus and a method are provided for transmitting/receiving data supporting various code data by puncturing a bit of a location which is proper to recover a signal. In accordance with an aspect of the present invention, there is provided an apparatus for transmitting data coded by a low density parity check code, including: a scrambler for scrambling input data to be transmitted; a low density parity check encoder for encoding the scrambled input data from the scrambler based on a low density parity check code; a bit puncturer for orderly puncturing columns in the low density check code which least degrade a performance caused by puncturing; a constellation mapper for converting the punctured data to a symbol mapped to each data; and a reverse fast-fourier transformer for reverse fast-fourier transforming the symbol for OFDM and transmitting the transformed data to a receiving side. The apparatus may further include: a digital-to-analog converter for converting a digital signal processed in the reverse fast-fourier transformer to an analog signal; and a transmitting antenna for multiplying a carrier frequency signal to the analog signal and transmitting the multiplied analog signal to wireless environment. The transmitting antenna may transmit data using ultra wideband frequency. The low density parity check encoder includes a column permuting unit for replacing columns in the low density parity check code according to order of columns which least degrade a performance caused by puncturing and columns which least degrade a performance caused by puncturing may be orderly replaced with one from a left side column to a right side column or one from the right side column to the left side column. The bit puncturer may puncture bits according to a code rate of the output data orderly from the most left column or from the most right column of the low density parity check code. The low density parity check encoder may include: a parity check matrix generator for generating an M×N parity check matrix having a much lesser number of 1's among elements of 0 and 1; a column permutated matrix generator for generating a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing; a generate matrix generator for generating a generate matrix from the column permutated matrix; and an encoding calculator for encoding the input data according to the generate matrix. The column permutated matrix generator may include; a puncturing bit calculating unit for calculating the number of bits to be punctured according to a maximum code rates among required code rates; a punctured bit position determining unit for determining the number of columns to be permutated according to the calculated number of bits and determining the determined number of columns degrading least performance caused by puncturing as columns to be replaced; and a column replacing unit for orderly replacing the determined columns. The punctured bit position determining unit may determine only one variable node to be punctured among a plurality of variable nodes connected to one check node on a factor graph associated with an M×N parity check matrix. In accordance with another aspect of the present invention, there is provided an apparatus for transmitting data coded by a low density parity check code, including: a low density parity check encoder for encoding input data based on the low density parity check code; and a bit puncturer for puncturing columns in an order of columns which least degrade a performance caused by puncturing in the low density check code according to a code rate of an output data. The low density parity check encoder may include a column permuting unit for permuting columns in an order of columns which least degrade a performance caused by puncturing in the low density parity check code. Columns which least degrade a performance caused by puncturing orderly may be permuted from a right side column or from a left side column in the low density parity check code. The bit puncturer may puncture bits according to a code rate of the output data orderly from a left side column in the low density parity check code. The low density parity check encoder may include: a parity check matrix generator for generating an M×N parity check matrix having a lesser number of 1's among elements of 0 and 1; a column permutated matrix generator for generating a column permutated matrix by permuting columns of the parity check matrix according to an order of column which least degrade a performance caused by puncturing; a generate matrix generator for generating a generate matrix from the column permutated matrix; and an encoding calculator for encoding the input data according to the generate matrix. The column permutated matrix generator may include; a puncturing bit calculating unit for calculating the number of bits to be punctured according to a maximum code rates among required code rates; a punctured bit position determining unit for determining the number of columns to be permutated according to the calculated number of bits and determining the determined number of columns degrading least performance caused by puncturing as columns to be replaced; and a column replacing unit for orderly replacing the determined columns. The punctured bit position determining unit may determine a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code as the column to be punctured. In accordance with still another aspect of the present invention, there is provided an apparatus for receiving data coded by a low density parity check code, including: a fast transformer for receiving a signal transmitted from a transmitting side and fast-fourier transforming the received signal; a bit inserter for inserting intermediate values in the transformed signal as many as the number of bits punctured in the transmitting side; a low density parity check decoder for decoding the bit-inserted signal based on an encoding method of a low density parity check encoder in the transmitting side; and a de-scrambler for generating final output data by de-scrambling the decoded signal. In accordance with still another aspect of the present invention, there is provided an apparatus for receiving data coded by a low density parity check code, including: a bit inserter for inserting bits to corresponding punctured position as many as the number of bits punctured at a transmitting side according to a code rate of a receiving data; and a low density parity check decoder for performing a low density parity check decoding based on a low parity check code in which columns are permutated in an order of columns which least degrade a performance caused by puncturing. The apparatus of claim may further include: a receiving antenna for receiving the signal transmitted from the transmitting side; and an analog-to-digital converter for converting the received analog signal to a digital signal. The bit-inserter may insert corresponding number of bits in columns orderly from left side column in data inputted to the low density parity check decoder. The low density check decoder may include: a soft decision unit for performing soft decision for a signal of the bit-inserted data by the bit inserter; and an LLR decoder for decoding the soft-decided signal based on a low density parity check code. The low parity check decoder may further include: a parity check matrix generator for generating an M×N parity check matrix having a lesser number of 1's among elements of 0 or 1; and a column permutated matrix generator for generating a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing. The column permutated matrix generator may include; a puncturing bit calculating unit for calculating the number of bits to be punctured according to a maximum code rates among required code rates; a punctured bit position determining unit for determining the number of columns to be permutated according to the calculated number of bits and determining the determined number of columns degrading least performance caused by puncturing as columns to be replaced; and a column replacing unit for orderly replacing the determined columns. The punctured bit position determining unit may determine a column where one variable node is punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code as the column to be punctured. In accordance with still another aspect of the present invention, there is provided a method for transmitting data coded by a low density parity check code, including: encoding input data by a low density parity check code; and puncturing the encoded data in an order of columns which least degrade a performance caused by puncturing in the low density parity check code. The encoding may further include permuting columns in the low density parity check code according to an order of columns which least degrade a performance caused by puncturing. The permuting columns, columns which least degrade a performance caused by puncturing may be orderly replaced with one from a left side column to a right side column, or one from the right side column to the left side column. The puncturing, bits may be punctured according to a code rate of the output data orderly from a left side column in the low density parity check code. The encoding input data may include: generating an M×N parity check matrix having a lesser number of 1's among elements of 0 and 1; generating a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing; generating a generate matrix from the column permutated matrix; and encoding the input data according to the generate matrix. The generating the column permutated matrix may include: calculating the number of bits to be punctured according to a maximum code rates among required code rates; determining the number of columns to be permutated according to the calculated number of bits and determining the determined number of columns degrading least performance caused by puncturing as columns to be replaced; and orderly replacing the determined columns. In the determining the number of columns, a column where one variable node may be punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code is determined as the column to be punctured. The determining the number of columns may include: selecting a column having least number of 1's in a low density parity check matrix; analyzing rows of 1's in the selected column; and determining a j th column as a candidate column to be punctured if the j th column satisfies a predetermined condition in a case that the j th column is the selected column, wherein the condition is that there is at least one of the rows of 1's having non-punctured columns of non-zero elements. In the determining the number of columns, the j th column may be determined as a column to be punctured if 0 th to (j-1) th columns satisfy with the predetermined condition. In accordance with still another aspect of the present invention, there is provided a method for receiving data coded by a low density parity check code, including: inserting bits to corresponding punctured position as many as the number of bits punctured at a transmitting side according to a code rate of a receiving data; and performing a low density parity check decoding based on a low parity check code in which columns are permutated in an order of columns which least degrade a performance caused by puncturing. In the inserting bits, corresponding number of bits may be inserted in columns orderly from left side column in data inputted to the low density parity check decoder. The performing the low density parity check decoding may include: performing soft decision for a signal of the bit-inserted data by the bit inserter; and decoding the soft-decided signal based on a low density parity check code. The performing the low parity check decoding may further include: generating an M×N parity check matrix having a lesser number of 1's among elements of 0 or 1; and generating a column permutated matrix by permuting columns of the parity check matrix according to an order of columns which least degrade a performance caused by puncturing. The generating the column permutated matrix may include: calculating the number of bits to be punctured according to a maximum code rates among required code rates; determining the number of columns to be permutated according to the calculated number of bits and determining the determined number of columns degrading least performance caused by puncturing as columns to be replaced; and orderly replacing the determined columns. In the determining the number of columns, a column where one variable node may be punctured among a plurality of variable nodes connected to one check node on a factor graph according to a characteristic of a low density parity check code is determined as the column to be punctured. The determining the number of columns may include: selecting a column having least number of 1's in a low density parity check matrix; analyzing rows of 1's in the selected column; and determining a j th column as a candidate column to be punctured if the j th column satisfies a predetermined condition in a case that the j th column is the selected column, wherein the condition is that there is at least one of the rows of 1's having non-punctured columns of non-zero elements. The determining the number of columns, the j th column may be determined as a column to be punctured if 0 th to (j-1) th columns satisfy with the predetermined condition. |
Prediction encoder/decoder, prediction encoding/decoding method, and computer readable recording medium having recorded thereon program for implementing the prediction encoding/decoding method |
A prediction encoder/decoder, a prediction encoding/decoding method, and a computer readable recording medium having a program for the prediction encoding/decoding method recorded thereon. The prediction encoder includes a prediction encoding unit that starts prediction at an origin macroblock of an area of interest of a video frame, continues prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and encodes video by performing intra-prediction using information about a macroblock that has just been coded in a square ring including a macroblock to be coded and a macroblock in a previous square ring and adjacent to the macroblock. |
1. A prediction encoder comprising: a prediction encoding unit which starts prediction at an origin macroblock of an area of interest of a video frame, predicts in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and encodes video by performing intra-prediction using information about a macroblock that has just been coded in a present square ring which includes a macroblock to be coded and a macroblock that is adjacent to the macroblock to be coded in a previous square ring which is an inner square ring adjacent to the present square ring. 2. The prediction encoder of claim 1, further comprising: an intra-prediction mode selection unit selecting a prediction mode that is most suitable for the macroblock to be coded using the information about the macroblock that has just been coded in the present square ring and the macroblock that is adjacent to the macroblock to be coded in the previous square ring; and an intra-prediction unit generating a predicted macroblock for the macroblock to be coded using the selected prediction mode. 3. The prediction encoder of claim 2, wherein the intra-prediction mode selection unit comprises: a reference macroblock search unit searching for a reference macroblock included in the present square ring and a reference macroblock that is included in the previous square ring and is adjacent to the macroblock to be coded; a reference macroblock location determining unit which determines the origin macroblock to be macroblock A if only the origin macroblock exists, determines a macroblock included in the present square ring to be the macroblock A and a macroblock included in the previous square ring to be macroblock D if such macroblocks exist, and determines a macroblock that is included in the present square ring and has just been coded to be the macroblock A, a macroblock that is in the previous square ring and adjacent to the macroblock to be coded to be macroblock B, and a macroblock that is adjacent to the macroblocks A and B and is included in the previous square ring to be the macroblock D, if a macroblock coded just before the macroblock to be coded is included in the present square ring and at least two macroblocks are included in the previous square ring; and an intra-prediction mode determining unit which calculates SADs between the predicted macroblocks obtained using the prediction modes and the macroblock to be coded and the macroblock D and determines an intra-prediction mode having the smallest SAD to be an intra-prediction mode. 4. The prediction encoder of claim 3, wherein if the macroblock A exists as a reference macroblock or the macroblocks A and D exist as reference macroblocks, the intra-prediction mode determining unit determines whichever of mode 0 and mode 1 has the smallest SAD to be an intra-prediction mode in mode 0, pixel values of a bottom-most line of the macroblock A that is adjacent to the macroblock to be coded are mapped to pixel values of the macroblock to be coded using only, and, in mode 1, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded. 5. The prediction encoder of claim 3, wherein if the macroblocks A, B, and D exist as reference macroblocks, the intra-prediction mode determining unit determines whichever of mode 2, mode 3, mode 4, and mode 5 having the smallest SAD to be an intra-prediction mode, in mode 2, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded and the bottom-most line of the macroblock B is mapped to pixel values of the macroblock to be coded, in mode 3, similarity among the macroblocks A, B, and D is measured and, if the macroblocks A and D are similar to each other, a mean of pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded or, if the macroblocks B and D are similar to each other, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded, in mode 4, similarity among the macroblocks A, B, and D is measured and, if the macroblocks A and D are similar to each other, pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be coded are mapped to the pixel values of the macroblock to be coded or, if the macroblocks B and D are similar to each other, pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded are mapped to the pixel values of the macroblock to be coded, and mode 5 is used when video characteristics of the macroblock to be coded gradually change from the macroblock A to the macroblock B. 6. The prediction encoder of claim 2, wherein the prediction encoding unit comprises: a discrete cosine transform (DCT) unit performing DCT on a difference between the intra-predicted macroblock and the macroblock to be coded; a quantization unit quantizing transformed DCT coefficients; a ripple scanning unit starting scanning from the origin macroblock of a frame composed of the quantized DCT coefficients and continuing to scan macroblocks in an outward spiral in the shape of square rings; and an entropy encoding unit entropy encoding ripple scanned data samples and intra-prediction mode information selected by the intra-prediction mode selection unit. 7. A prediction decoder comprising: a prediction decoding unit which starts prediction at an origin macroblock of an area of interest of a video frame, predicts in an outward spiral in a shape of square rings composed of macroblocks surrounding the origin macroblock, and decodes video by performing intra-prediction using information about a macroblock that has just been decoded in a present square ring which includes a macroblock to be decoded and a macroblock that is adjacent to the macroblock to be coded in a previous square ring which is an inner square ring adjacent to the present square ring. 8. The prediction decoder of claim 7, wherein the prediction decoding unit comprises: an intra-prediction mode selection unit selecting an intra-prediction mode that is most suitable for the macroblock to be decoded using the information about the macroblock that has just been decoded in the present square ring and the macroblock that is adjacent to the macroblock to be decoded in the previous square ring; and an intra-prediction unit generating a predicted macroblock for the macroblock to be decoded using the selected prediction mode. 9. The prediction decoder of claim 8, wherein the intra-prediction mode selection unit comprises: a reference macroblock search unit searching for a reference macroblock included in the present square ring and a reference macroblock that is included in the previous square ring and is adjacent to the macroblock to be decoded; a reference macroblock location determining unit which determines the origin macroblock to be macroblock A if only the origin macroblock exists, determines a macroblock included in the present square ring to be the macroblock A and a macroblock included in the previous square ring to be macroblock D if such macroblocks exist, and determines a macroblock that is included in the present square ring and has just been decoded to be the macroblock A, a macroblock that is in the previous square ring and adjacent to the macroblock to be decoded to be macroblock B, and a macroblock that is adjacent to the macroblocks A and B and is included in the previous square ring to be the macroblock D, if a macroblock coded just before the macroblock to be coded is included in the present square ring and at least two macroblocks are included in the previous square ring; and an intra-prediction mode determining unit which calculates SADs between the predicted macroblocks obtained using the prediction modes and the macroblock to be decoded and determines an intra-prediction mode having the smallest SAD to be an intra-prediction mode. 10. The prediction decoder of claim 9, wherein the intra-prediction unit maps pixel values of a bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to pixel values of the macroblock to be decoded if received intra-prediction mode information indicates mode 0. 11. The prediction decoder of claim 9, wherein the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded if received intra-prediction mode information indicates mode 1. 12. The prediction decoder of claim 9, wherein the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded and the bottom-most line of the macroblock B to pixel values of the macroblock to be decoded if received intra-prediction mode information indicates mode 2. 13. The prediction decoder of claim 9, wherein if received intra-prediction mode information indicates mode 3, the intra-prediction mode determining unit measures similarity among the macroblocks A, B, and D, and determines if the macroblocks A and D are similar to each other, or if the macroblocks B and D are similar to each other, if the macroblocks A and D are similar to each other, the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded, or if the macroblocks B and D are similar to each other, the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded. 14. The prediction decoder of claim 9, wherein if received intra-prediction mode information indicates mode 4, the intra-prediction mode determining unit measures similarity among the macroblocks A, B, and D, and determines if the macroblocks A and D are similar to each other, or if the macroblocks B and D are similar to each other, if the macroblocks A and D are similar to each other, the intra-prediction unit extrapolates pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be decoded and then maps the extrapolated pixel values to the pixel values of the macroblock to be decoded, or if the macroblocks B and D are similar to each other, the intra-prediction unit extrapolates pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded and maps the extrapolated pixel values to the pixel values of the macroblock to be decoded. 15. The prediction decoder of claim 9, wherein the intra-prediction unit performs prediction used when video characteristics of the macroblock to be coded gradually change from the macroblock A to the macroblock B if received intra-prediction mode information indicates mode 5. 16. The prediction decoder of claim 8, wherein the prediction decoding unit comprises: an entropy decoding unit which decodes bitstreams received from a prediction encoder and extracting intra-prediction mode information from the entropy decoded bitstreams; a ripple scanning unit starting scanning from the origin macroblock of a frame composed of entropy decoded data samples and continuing to scan macroblocks in an outward spiral in the shape of square rings; an inverse quantization unit inversely quantizing the ripple scanned data samples; an inverse discrete cosine transform (DCT) unit performing inverse DCT on the inversely quantized data samples; and an adder adding a macroblock composed of inversely quantized DCT coefficients and the intra-predicted macroblock. 17. A prediction encoding method comprising: starting prediction at an origin macroblock of an area of interest of a video frame, predicting in an outward spiral in a shape of square rings composed of macroblocks surrounding the origin macroblock, and encoding video by performing intra-prediction using information about a macroblock that has just been coded in a present square ring which includes a macroblock to be coded and a macroblock that is adjacent to the macroblock to be coded in a previous square ring which is an inner square ring adjacent to the present square ring. 18. The prediction encoding method of claim 17, comprising: selecting an intra-prediction mode that is most suitable for the macroblock to be coded using the information about the macroblock that has just been coded in the present square ring and the macroblock that is adjacent to the macroblock to be coded in the previous square ring; and generating a predicted macroblock for the macroblock to be coded using the selected prediction mode. 19. The prediction encoding method of claim 18, wherein the selecting of the intra-prediction mode comprises: searching for a reference macroblock included in the present square ring and a reference macroblock that is included in the previous square ring and is adjacent to the macroblock to be coded; determining the origin macroblock to be macroblock A if only the origin macroblock exists, determining a macroblock included in the present square ring to be the macroblock A and a macroblock included in the previous square ring to be macroblock D if such macroblocks exist, and determining a macroblock that is included in the present square ring and has just been coded to be the macroblock A, a macroblock that is in the previous square ring and adjacent to the macroblock to be coded to be macroblock B, and a macroblock that is adjacent to the macroblocks A and B and is included in the previous square ring to be the macroblock D, if a macroblock coded just before the macroblock to be coded is included in the present square ring and at least two macroblocks are included in the previous square ring; and calculating SADs between the predicted macroblocks obtained using the prediction modes and the macroblock to be coded and determining an intra-prediction mode having the smallest SAD to be an intra-prediction mode. 20. The prediction encoding method of claim 19, wherein, in the determining of the intra-prediction mode, if the macroblock A exists as a reference macroblock or the macroblocks A and D exist as reference macroblocks, whichever of mode 0 and mode 1 having the smallest SAD is determined to be an intra-prediction mode in mode 0, pixel values of a bottom-most line of the macroblock A that is adjacent to the macroblock to be coded are mapped to pixel values of the macroblock to be coded, and, in mode 1, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded. 21. The prediction encoding method of claim 19, wherein, in the determining of the intra-prediction mode, if the macroblocks A, B, and D exist as reference macroblocks, whichever of mode 2, mode 3, mode 4, and mode 5 having the smallest SAD is determined to be an intra-prediction mode, in mode 2, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded and the bottom-most line of the macroblock B is mapped to pixel values of the macroblock to be coded, in mode 3, similarity among the macroblocks A, B, and D is measured and, if the macroblocks A and D are similar to each other, a mean of pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded or, if the macroblocks B and D are similar to each other, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded, in mode 4, similarity among the macroblocks A, B, and D is measured and, if the macroblocks A and D are similar to each other, pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be coded are mapped to the pixel values of the macroblock to be coded or, if the macroblocks B and D are similar to each other, pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded are mapped to the pixel values of the macroblock to be coded, and mode 5 is used when video characteristics of the macroblock to be coded gradually change from the macroblock A to the macroblock B. 22. The prediction encoding method of claim 18, comprising: performing DCT on a difference between the intra-predicted macroblock and the macroblock to be coded; quantizing transformed DCT coefficients; starting scanning from the origin macroblock of a frame composed of the quantized DCT coefficients and continuing to scan macroblocks in an outward spiral in the shape of square rings; and entropy encoding ripple scanned data samples and intra-prediction mode information selected by the intra-prediction mode selection unit. 23. A prediction decoding method comprising: starting prediction at an origin macroblock of an area of interest of a video frame; predicting in an outward spiral in a shape of square rings composed of macroblocks surrounding the origin macroblock; and decoding video by performing intra-prediction using information about a macroblock that has just been decoded in a present square ring which includes a macroblock to be decoded and a macroblock that is adjacent to the macroblock to be decoded in a previous square ring which is an inner square ring adjacent to the present square ring. 24. The prediction decoding method of claim 23, further comprising: selecting an intra-prediction mode that is most suitable for the macroblock to be decoded using the information about the macroblock that has just been decoded in the present square ring and the macroblock that is adjacent to the macroblock to be decoded that is in the previous square ring; and intra-predicting by obtaining a predicted macroblock of the macroblock to be decoded according to the selected prediction mode. 25. The prediction decoding method of claim 24, wherein the selecting of the intra-prediction mode comprises: searching for a reference macroblock included in the present square ring and a reference macroblock that is included in the previous square ring and is adjacent to the macroblock to be decoded; determining the origin macroblock to be macroblock A if only the origin macroblock exists, determining a macroblock included in the present square ring to be the macroblock A and a macroblock included in the previous square ring to be macroblock D if such macroblocks exist, and determining a macroblock that is included in the present square ring and has just been decoded to be the macroblock A, a macroblock that is in the previous square ring and adjacent to the macroblock to be decoded to be macroblock B, and a macroblock that is adjacent to the macroblocks A and B and is included in the previous square ring to be the macroblock D, if a macroblock coded just before the macroblock to be coded is included in the present square ring and at least two macroblocks are included in the previous square ring; and calculating SADs between the predicted macroblocks obtained using the prediction modes and the macroblock to be decoded and determining an intra-prediction mode having the smallest SAD to be an intra-prediction mode. 26. The prediction decoding method of claim 25, wherein the intra-predicting comprises mapping pixel values of a bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to pixel values of the macroblock to be decoded if received intra-prediction mode information indicates mode 0. 27. The prediction decoding method of claim 25, wherein the intra-predicting comprises mapping a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded if received intra-prediction mode information indicates mode 1. 28. The prediction decoding method of claim 25, wherein the intra-predicting comprises mapping a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded and the bottom-most line of the macroblock B to pixel values of the macroblock to be decoded if received intra-prediction mode information indicates mode 2. 29. The prediction decoding method of claim 25, wherein, the determining the intra-prediction mode comprises measuring similarity among the macroblocks A, B, and D and determining if the macroblocks A and D are similar to each other, or if the macroblocks B and D are similar to each other, if received intra-prediction mode information indicates mode 3, and the intra-predicting comprises mapping a mean of pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded, if the macroblocks A and D are similar to each other, or mapping a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded is mapped to the pixel values of the macroblock to be decoded, if the macroblocks B and D are similar to each other. 30. The prediction decoding method of claim 25, wherein, the determining the intra-prediction mode comprises measuring similarity among the macroblocks A, B, and D and determining if the macroblocks A and D are similar to each other, or if the macroblocks B and D are similar to each other, if received intra-prediction mode information indicates mode 4, and the intra-predicting comprises, mapping pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be decoded are extrapolated and then mapped to the pixel values of the macroblock to be decoded, if the macroblocks A and D are similar to each other, or mapping pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded are extrapolated and then mapped to the pixel values of the macroblock to be decoded if the macroblocks B and D are similar to each other. 31. The prediction decoding method of claim 25, wherein, the intra-predicting comprises performing prediction used when video characteristics of the macroblock to be coded gradually change from the macroblock A to the macroblock B, if received intra-prediction mode information indicates mode 5. 32. The prediction decoding method of claim 24, comprising: entropy decoding bitstreams received from a prediction encoder and extracting intra-prediction mode information from the entropy decoded bitstreams; starting scanning from the origin macroblock of a frame composed of entropy decoded data samples and continuing to scan macroblocks in an outward spiral in the shape of square rings; inversely quantizing the ripple scanned data samples; performing inverse discrete cosine transform (DCT) on the inversely quantized data samples; and adding a macroblock composed of inversely quantized DCT coefficients and the intra-predicted macroblock. 33. A computer readable recording medium having a program for implementing a prediction encoding method recorded thereon, the prediction encoding method comprising: starting predicting at an origin macroblock of an area of interest of a video frame, predicting in an outward spiral in a shape of square rings composed of macroblocks surrounding the origin macroblock, and encoding video by performing intra-prediction using information about a macroblock that has just been coded in a present square ring which includes a macroblock to be coded and a macroblock that is adjacent to the macroblock to be coded in a previous square ring which is an inner square ring adjacent to the present square ring. 34. A computer readable recording medium having a program for implementing a prediction decoding method recorded thereon, the prediction decoding method comprising: starting predicting at an origin macroblock of an area of interest of a video frame, predicting in an outward spiral in a shape of square rings composed of macroblocks surrounding the origin macroblock, and decoding video by performing intra-prediction using information about a macroblock that has just been decoded in a present square ring which includes a macroblock to be decoded and a macroblock that is adjacent to the macroblock to be coded in a previous square ring which is an inner square ring adjacent to the present square ring. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a prediction encoder/decoder, a prediction encoding/decoding method, and a computer readable recording medium having recorded thereon a program for implementing the prediction encoding/decoding method, for coding moving pictures. 2. Description of the Related Art New standards called Motion Picture Experts Group (MPEG)-4 part 10 AVC (advanced video coding) or International Telecommunication Union Telecommunication Standardization Sector (ITU-T) H.264 emerged in 2003 in the field of video compression. Fueling the emergence was a change from conventional circuit switching to packet switching and a need for coexistence of various communication infrastructures, along with the rapid spread of new communication channels such as mobile networks. In AVC/H.264, spatial estimation encoding methods such as MPEG-1, MPEG-2, and MPEG-4 part 2 visual that differ from conventional international standards for moving picture encoding are used. In conventional moving picture encoding, coefficients transformed in a discrete cosine transform (DCT) domain are intra-predicted to improve encoding efficiency, resulting in degradation of subjective quality at low-pass band transmission bit rates. On the other hand, in AVC/H.264, spatial intra-prediction is performed in a spatial domain instead of in a transform domain. Conventional spatial intra-prediction encoding is performed in such a way that information about a block to be encoded is predicted using information about a block that has already been encoded and reproduced and only difference information indicating a difference between information about an actual block to be encoded and the predicted block is encoded and transmitted to a decoder. At this time, a parameter required for prediction may be transmitted to the decoder or prediction may be performed by synchronizing the encoder and the decoder. Information about a block to be decoded is predicted using information about an adjacent block that has already been decoded and reproduced, a sum of the predicted information and the difference information transmitted from the encoder is calculated, and desired structure information is reproduced. At this time, if a parameter required for prediction is received from the encoder, it is also decoded for use. Intra-prediction used in conventional block-based or macroblock-based video encoding uses information about blocks A, B, C, and D that are adjacent to a block E to be coded in a traditional raster scan direction, as shown in FIG. 1 . Information about blocks marked with X in FIG. 1 is to be processed after completion of encoding of the block E, and is therefore not available for encoding processing. A block marked with O can be used when a predicted value is calculated, but it is spatially far from the block E. As a result, the block marked with O does not have a high correlation with the block E and is hardly used. As such, most conventional intra-prediction uses part of the information about the blocks D, B, and C that are adjacent to the block E to be coded among blocks in a line immediately above a line including the block E and information about the block A that has been encoded just before encoding the block E. In the case of MPEG-4-part 2, a DC (Discrete Coefficient) value of the block E is predicted using differences between DC values of the blocks A, D, and B in an 8×8 DCT domain. Also, in the case of AVC/H.264, a frame is divided into 4×4 blocks or 16×16 macroblocks and pixel values in a spatial domain, instead of in a DCT domain, are predicted. Hereinafter, 16×16 spatial intra-prediction of AVC/H.264 will be briefly described. FIGS. 3A-3D show four modes of conventional 16×16 spatial intra-prediction. Macroblocks to be coded are indicated by E in FIGS. 3A-3D . Spatial intra-prediction is carried out using macroblocks A and B that are adjacent to the macroblock E. In FIGS. 3A-3D , a group of pixels used for spatial intra-prediction includes 16 pixels that are located in the right-most line of the macroblock A, which are indicated by V, and 16 pixels that are located in the bottom-most line of the macroblock B, which are indicated by H.16×16 spatial intra-prediction is performed using the four modes, each of which will now be described. A pixel value used in each mode is defined as shown in FIG. 2 . Assuming that a pixel value of the macroblock E to be intra-predicted is P[x][y](x=0 . . . 15 and y=0 . . . 15), the line H of the macroblock B can be expressed as P[x][−1] (x=0 . . . 15) and the line V of the macroblock A can be expressed as P[−1][y] (y=0 . . . 15). In FIG. 3A , a mode 0 (vertical mode) is illustrated. Referring to FIG. 3A , by using the 16 pixels in the line H of the macroblock B, spatial intra-prediction is performed by setting the values of all the pixels of a column in the macroblock E equal to the values of the pixels in the line H directly above the column. That is, in mode 0 , when P′[x][y] is defined as an intra-predicted value of the actual pixel value P[x][y] and all 16 pixels (P[x][−1], x=0 . . . 15) of the line H of the macroblock B exist, extrapolation is performed on a pixel-by-pixel basis using in-line-formulae description="In-line Formulae" end="lead"? P′[x][y]=P[x][− 1 ], x= 0 . . . 15 , y= 0 . . . 15 in-line-formulae description="In-line Formulae" end="tail"? In FIG. 3B , a mode 1 (horizontal mode) is illustrated. Referring to FIG. 3B , by using the 16 pixels in the line V of the macroblock A, spatial intra-prediction is performed by setting the values of all the pixels of a column in the macroblock E equal to the values of the pixels in the line V directly to the left of the column. Namely, in mode 1 , when P′[x][y] is defined as the intra-predicted value of the actual pixel value P[x][y] and all 16 pixels of the line V (P[−1][y], y=0 . . . 15) of the macroblock A exist, extrapolation is performed on a pixel-by-pixel basis using in-line-formulae description="In-line Formulae" end="lead"? P′[x][y]=P[− 1 ][y], x= 0 . . . 15 , y= 0 . . . 15 in-line-formulae description="In-line Formulae" end="tail"? In FIG. 3C , a mode 2 (DC mode) is illustrated. Referring to FIG. 3C , values defined by mean values (Sumx=0 . . . 15P[x][−1]+Sumy=0 . . . 15P[−1][y]+16)/32) are mapped to all of the pixel values of the macroblock E. The mean values are defined as follows. When all the 16 pixels of the line V and all the 16 pixels of the line H exist, in-line-formulae description="In-line Formulae" end="lead"? P′[x][y] =(Sum x= 0 . . . 15 P[x][− 1]+Sum y =0 . . . 15 P[− 1 ][y]+ 16)>>5 , x= 0 . . . 15 , y= 0 . . . 15 in-line-formulae description="In-line Formulae" end="tail"? When only all the 16 pixels of the line V of the macroblock A exist, in-line-formulae description="In-line Formulae" end="lead"? P′[x][y ]=(Sum x= 0 . . . 15 P[x][− 1]+8)>>4 , x= 0 . . . 15 , y= 0 . . . 15 in-line-formulae description="In-line Formulae" end="tail"? When only all the 16 pixels of the line H of the macroblock B exist, in-line-formulae description="In-line Formulae" end="lead"? P[x][y] =(Sum y= 0 . . . 15 P[− 1 ][y]+ 8)>>4 , x= 0 . . . 15 , y= 0 . . . 15 in-line-formulae description="In-line Formulae" end="tail"? Also, when neither all 16 pixels of the line V of the macroblock A nor all 16 pixels of the line H of the macroblock B exist, in-line-formulae description="In-line Formulae" end="lead"? P′[x][y]=128, x=0 . . . 15, y=0 . . . 15 in-line-formulae description="In-line Formulae" end="tail"? In FIG. 3D , a mode 3 (plane Mode) is illustrated. Referring to FIG. 3D , mode 3 only operates when both all 16 pixels of the line V of the macroblock A exist and all 16 pixels of the line H of the macroblock B exist and mapping is performed using the following Equation. in-line-formulae description="In-line Formulae" end="lead"? P′[x][y] =Clip 1 ( ( a+b. ( x− 7)+ c. ( y− 7)+16)>>5 in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? a= 16.( P[ −1][15]+ P[ 15][−1]); b =(5* H+ 32)>>6 ; c =(5* V+ 32)>>6; in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? H =Sum x =1 . . . 8( x .( P[ 7 +x][− 1 ]−P[ −1][7− y ]) ) in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? V =Sum y =1 . . . 8( y .( P[− 1][7 +y]−P[− 1][7− y ]) ) in-line-formulae description="In-line Formulae" end="tail"? Mode 3 is appropriate for prediction of pixel values of an image that slowly changes. As such, conventionally, there is a total of four modes in 16×16 macroblock spatial intra-prediction. Thus, encoding and decoding are performed using 2-bit fixed length encoding (FLC) or variable length encoding (VLC) according to probability distribution. After predicted pixel values of a block to be coded is obtained in each of the four modes, the predicted pixel values that are most similar to the actual pixel values of the block to be coded is transmitted to the decoder. At this time, to obtain a group (block) of the pixel values that are most similar to the actual pixel values, a sum of absolute differences (SAD) is calculated and a mode having the minimum SAD is selected. When P[x][y] is the actual pixel value of an image and P′[x][y] is the predicted pixel value determined in each mode, the SAD is given by in-line-formulae description="In-line Formulae" end="lead"? SADMode=Sum x= 0 . . . 15, y= 0 . . . 15 |P[x][y]−P′[x][y]| in-line-formulae description="In-line Formulae" end="tail"? Once the selected intra-prediction mode is received and decoding is completed in the intra-prediction mode, the decoder creates predicted values of a corresponding macroblock on a pixel-by-pixel basis in the same way as the encoder in the same intra-prediction mode. AVC/H.264 video encoding is designed to have high network friendliness, which is an important requirement for video encoding-related international standardization. To this end, AVC/H.264 employs slice-based independent encoding as one of its major functions. This is because data that undergoes compression encoding becomes very sensitive to transmission errors, which results in a very high probability that a part of a bit stream will be lost and such a loss has a great influence on not only a portion of the bit stream having the loss but also restoration of an image that refers to the corresponding image, resulting in a failure to obtain flawless restoration. In particular, when using packet-based transmission, which is widely used for Internet or mobile communications, if a packet error occurs during transmission, data following the damaged packet cannot be used for restoration of an image frame. Moreover, if a packet having header information is damaged, the entire data of the image frame cannot be restored, resulting in significant degradation of image quality. To solve such a problem, AVC/H.264 determines a slice that is smaller than a frame unit to be the smallest unit of data that can be independently decoded. More specifically, the slices are determined such that each slice can be perfectly decoded regardless of data corresponding to other slices that precede or follow the slice. Therefore, even when data of several slices is damaged, there is a high probability of restoration or concealment of a damaged portion of an image using image data of slices that are decoded without an error, which can minimize degradation of image quality. AVC/H.264 is designed to support not only a slice structure composed of groups of macroblocks in the raster scan direction, but also a new slice structure defined by flexible macroblock ordering (FMO). The new slice structure is adopted as an essential algorithm for a baseline profile and an extended profile. In particular, FMO mode 3 box-out scanning has modes in which scanning is performed in the clockwise direction and in the counter-clockwise direction, as shown in FIG. 4 . Scanning, such as box-out scanning, employed in AVC/H.264 is very useful for encoding a region of interest (ROI). Such scanning, as shown in FIG. 4 , begins in the center of an ROI or the center of an image and then continues outward and around the already scanned pixels, blocks, or macroblocks in the shape of square rings. In other words, scanning begins in a start region and continues such that a square ring is layered onto another square ring that is processed before the current square ring. When using ROI-oriented scanning, conventional intra-prediction designed for raster scanning cannot be used. AVC/H.264 carefully considers error resiliency and network friendliness to keep up with the rapidly changing wireless environment and Internet environment. In particular, box-out scanning is designed for ROI encoding. The box-out scanning makes it possible to improve compression efficiency based on human visual characteristics or to perform improved error protection and most preferentially perform ROI processing. However, since conventional video encoding such as AVC/H.264 employs intra-prediction encoding based on traditional raster scanning which is very different from ROI-oriented scanning, it cannot be used when a technique for improving encoding efficiency is applied to video encoding that is based on ROI-oriented scanning. |
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a prediction encoder/decoder, a prediction encoding/decoding method, and a computer-readable recording medium having recorded thereon a program for implementing the prediction encoding/decoding method, which are used for encoding/decoding an ROI. According to one aspect of the present invention, there is provided a prediction encoder comprising a prediction encoding unit. The prediction encoding unit starts prediction at an origin macroblock of an area of interest of a video frame, continues prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and encodes video by performing intra-prediction using information about a macroblock that has just been coded in a square ring including a macroblock to be coded and a macroblock in a previous square ring and adjacent to the macroblock. In an exemplary embodiment, the prediction encoder comprises an intra-prediction mode selection unit and an intra-prediction unit. The intra-prediction mode selection unit selects a prediction mode that is most suitable for the macroblock to be coded using the information about the macroblock that has just been coded in the square ring including the macroblock to be coded and the macroblock in the previous square ring and adjacent to the macroblock to be coded. The intra-prediction unit generates a predicted macroblock for the macroblock to be coded using the selected prediction mode. In an exemplary embodiment, the intra-prediction mode selection unit comprises a reference macroblock search unit, a reference macroblock location determining unit, and an intra-prediction mode determining unit. The reference macroblock search unit searches for a reference macroblock included in the square ring including the macroblock to be coded and a reference macroblock that is included in the previous square ring and adjacent to the macroblock to be coded. The reference macroblock location determining unit determines the origin macroblock to be A if only the origin macroblock exists, determines a macroblock included in the same square ring to be A and a macroblock included in the previous square ring to be D if such macroblocks exist, and determines a macroblock that is included in the same square ring and has just been coded to be A, a macroblock that is in the previous square ring and adjacent to the macroblock to be coded to be B, and a macroblock that is adjacent to the macroblocks A and B and is included in the previous square ring to be D, if a macroblock coded just before the macroblock to be coded is included in the square ring and at least two macroblocks are included in the previous square ring. The intra-prediction mode determining unit calculates SADs between the predicted macroblocks obtained using the prediction modes and the determined macroblocks A, B, and D and determines an intra-prediction mode having the smallest SAD to be an intra-prediction mode. In an exemplary embodiment, if only the macroblock A exists as a reference macroblock or only the macroblocks A and D exist as reference macroblocks, the intra-prediction mode determining unit determines whichever of mode 0 and mode 1 has the smallest SAD to be an intra-prediction mode in mode 0 , pixel values of a bottom-most line of the macroblock A that is adjacent to the macroblock to be coded are extrapolated and then mapped to pixel values of the macroblock to be coded using only using information about the macroblock A, and, in mode 1 , a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded using only the information about the macroblock A. In an exemplary embodiment, if the macroblocks A, B, and D exist as reference macroblocks, the intra-prediction mode determining unit determines whichever of mode 2 , mode 3 , mode 4 , and mode 5 having the smallest SAD to be an intra-prediction mode. In mode 2 , a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded and the bottom-most line of the macroblock B is mapped to pixel values of the macroblock to be coded. In mode 3 , similarity among the macroblocks A, B, and D is measured and, if the macroblocks A and D are similar to each other, a mean of pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded or, if the macroblocks B and D are similar to each other, a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded is mapped to the pixel values of the macroblock to be coded. In mode 4 , similarity among the macroblocks A, B, and D is measured and, if the macroblocks A and D are similar to each other, pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be coded are extrapolated and then mapped to the pixel values of the macroblock to be coded or, if the macroblocks B and D are similar to each other, pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be coded are extrapolated and then mapped to the pixel values of the macroblock to be coded. Mode 5 is used when video characteristics of the macroblock to be coded gradually change from the macroblock A to the macroblock B. In an exemplary embodiment, the prediction encoder comprises a discrete cosine transform (DCT) unit, a quantization unit, a ripple scanning unit, and an entropy encoding unit. The DCT unit performs DCT on a difference between the intra-predicted macroblock and the macroblock to be coded. The quantization unit quantizes transformed DCT coefficients. The ripple scanning unit starts scanning from the origin macroblock of a frame composed of the quantized DCT coefficients and continues to scan macroblocks in an outward spiral in the shape of square rings. The entropy encoding unit entropy encodes ripple scanned data samples and intra-prediction mode information selected by the intra-prediction mode selection unit. According to another aspect of the present invention, there is provided a prediction decoder comprising a prediction decoding unit. The prediction decoding unit starts prediction at an origin macroblock of an area of interest of a video frame, continues prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and decodes video by performing intra-prediction using information about a macroblock that has just been decoded in a square ring including a macroblock to be decoded and a macroblock in a previous square ring and adjacent to the macroblock to be decoded in a previous square ring. In an exemplary embodiment, the prediction decoder comprises an intra-prediction mode selection unit and an intra-prediction unit. The intra-prediction mode selection unit selects an intra-prediction mode that is most suitable for the macroblock to be decoded using the information about the macroblock that has just been decoded in the square ring including the macroblock to be decoded and the macroblock in the previous square ring and adjacent to the macroblock to be decoded. The intra-prediction unit generates a predicted macroblock for the macroblock to be decoded using the selected prediction mode. In an exemplary embodiment, the intra-prediction mode selection unit comprises a reference macroblock search unit, a reference macroblock location determining unit, and an intra-prediction mode determining unit. The reference macroblock search unit searches for a reference macroblock included in the square ring including the macroblock to be decoded and a reference macroblock that is included in the previous square ring and adjacent to the macroblock to be decoded. The reference macroblock location determining unit determines the origin macroblock to be A if only the origin macroblock exists, determines a macroblock included in the same square ring to be A and a macroblock included in the previous square ring to be D if such macroblocks exist, and determines a macroblock that is included in the same square ring and has just been decoded to be A, a macroblock that is in the previous square ring and adjacent to the macroblock to be decoded to be B, and a macroblock that is adjacent to the macroblocks A and B and is included in the previous square ring to be D, if a macroblock coded just before the macroblock to be coded is included in the square ring and at least two macroblocks are included in the previous square ring. The intra-prediction mode determining unit calculates SADs between the predicted macroblocks obtained using the prediction modes and the determined macroblocks A, B, and D and determines an intra-prediction mode having the smallest SAD to be an intra-prediction mode. In an exemplary embodiment, if received intra-prediction mode information indicates mode 0 , the intra-prediction unit extrapolates pixel values of a bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded and maps the extrapolated pixel values to pixel values of the macroblock to be decoded using only information about the macroblock A. In an exemplary embodiment, if received intra-prediction mode information indicates mode 1 , the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded using only the information about the macroblock A. In an exemplary embodiment, if received intra-prediction mode information indicates mode 2 , the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded and the bottom-most line of the macroblock B to pixel values of the macroblock to be decoded. In an exemplary embodiment, if received intra-prediction mode information indicates mode 3 , the intra-prediction unit measures similarity among the macroblocks A, B, and D; and if the macroblocks A and D are similar to each other, the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded; or if the macroblocks B and D are similar to each other, the intra-prediction unit maps a mean of pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded to the pixel values of the macroblock to be decoded. In an exemplary embodiment, if received intra-prediction mode information indicates mode 4 , the intra-prediction unit measures similarity among the macroblocks A, B, and D; and if the macroblocks A and D are similar to each other, the intra-prediction unit extrapolates pixel values of the bottom-most line of the macroblock B that is adjacent to the macroblock to be decoded and then maps the extrapolated pixel values to the pixel values of the macroblock to be decoded; or if the macroblocks B and D are similar to each other, the intra-prediction unit extrapolates pixel values of the bottom-most line of the macroblock A that is adjacent to the macroblock to be decoded and maps the extrapolated pixel values to the pixel values of the macroblock to be decoded. In an exemplary embodiment, if received intra-prediction mode information indicates mode 5 , the intra-prediction unit performs prediction used when video characteristics of the macroblock to be coded gradually change from the macroblock A to the macroblock B. In an exemplary embodiment, the prediction decoder comprises an entropy decoding unit, a ripple scanning unit, an inverse quantization unit, an inverse discrete cosine transform (DCT) unit, and an adder. The entropy decoding unit entropy decodes bitstreams received from a prediction encoder and extracts intra-prediction mode information from the entropy decoded bitstreams. The ripple scanning unit starts scanning from the origin macroblock of a frame composed of entropy decoded data samples and continues to scan macroblocks in an outward spiral in the shape of square rings. The inverse quantization unit inversely quantizes the ripple scanned data samples. The inverse DCT unit performs inverse DCT on the inversely quantized data samples. The adder adds a macroblock composed of inversely quantized DCT coefficients and the intra-predicted macroblock. According to yet another aspect of the present invention, there is provided a prediction encoding method. The prediction encoding method comprises starting prediction at an origin macroblock of an area of interest of a video frame, continuing prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and encoding video by performing intra-prediction using information about a macroblock that has just been coded in a square ring including a macroblock to be coded and a macroblock in a previous square ring and adjacent to the macroblock to be coded in a previous square ring. According to yet another aspect of the present invention, there is provided a prediction decoding method. The prediction decoding method comprises starting prediction at an origin macroblock of an area of interest of a video frame, continuing prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and decoding video by performing intra-prediction using information about a macroblock that has just been decoded in a square ring including a macroblock to be decoded and a macroblock in a previous square ring and adjacent to the macroblock to be decoded. According to yet another aspect of the present invention, there is provided a computer readable recording medium having a program for implementing a prediction encoding method recorded thereon, the prediction encoding method comprising starting prediction at an origin macroblock of an area of interest of a video frame, continuing prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and encoding video by performing intra-prediction using information about a macroblock that has just been coded in a square ring including a macroblock to be coded and a macroblock in a previous square ring and adjacent to the macroblock to be coded in a previous square ring. According to yet another aspect of the present invention, there is provided a computer readable recording medium having a program for implementing a prediction decoding method recorded thereon, the prediction decoding method comprising starting prediction at an origin macroblock of an area of interest of a video frame, continuing prediction in an outward spiral in the shape of square rings composed of macroblocks surrounding the origin macroblock, and decoding video by performing intra-prediction using information about a macroblock that has just been decoded in a square ring including a macroblock to be decoded and a macroblock in a previous square ring and adjacent to the macroblock to be decoded. |
Image forming apparatus and method capable of lightness adjustment of image output with color balance thereof preserved |
An apparatus for forming an image is disclosed which includes: an input device inputting image data; an image processor processing the inputted image data; an image forming device forming the image on a recording medium, based on the processed image data; a lightness setting device setting a lightness value of the image to be formed on the recording medium by the image forming device; a first corrector correcting the inputted image data according to a first correction characteristic; a first characteristic modifier modifying the first correction characteristic, in response to setting of increasing the lightness value by the lightness setting device; a second corrector correcting the processed image data according to a second correction characteristic; and a second characteristic modifier modifying the second correction characteristic, in response to setting of decreasing the lightness value by the lightness setting device. |
1. An apparatus for forming an image, comprising: an input device inputting image data; an image processor processing the inputted image data; an image forming device forming the image on a recording medium, based on the processed image data; a lightness setting device setting a lightness value of the image to be formed on the recording medium by the image forming device; a first corrector correcting the inputted image data according to a first correction characteristic; a first characteristic modifier modifying the first correction characteristic, in response to setting of increasing the lightness value by the lightness setting device; a second corrector correcting the processed image data according to a second correction characteristic; and a second characteristic modifier modifying the second correction characteristic, in response to setting of decreasing the lightness value by the lightness setting device. 2. The apparatus according to claim 1, wherein the input device includes a capturing device capturing an image of an original document to produce the image data. 3. The apparatus according to claim 1, wherein the first characteristic modifier is inhibited from modifying the first correction characteristic, in response to setting of decreasing the lightness value by the lightness setting device. 4. The apparatus according to claim 1, wherein the second characteristic modifier is inhibited from modifying the second correction characteristic, in response to setting of increasing the lightness value by the lightness setting device. 5. The apparatus according to claim 1, wherein the lightness setting device is capable of setting the lightness value in steps, wherein the first characteristic modifier modifies the first correction characteristic to achieve one of a plurality of first correction characteristic curves which corresponds to the lightness value set by the lightness setting device, and wherein the second characteristic modifier modifies the second correction characteristic to achieve one of a plurality of second correction characteristic curves which corresponds to the lightness value set by the lightness setting device. 6. The apparatus according to claim 5, wherein the first characteristic modifier modifies the first correction characteristic, based on a first basic correction-characteristic-curve which represents a basis of the first correction characteristic, and a content of setting by the lightness setting device, and wherein the second characteristic modifier modifies the second correction characteristic, based on a second basic correction-characteristic-curve which represents a basis of the second correction characteristic, and the content of the setting by the lightness setting device. 7. The apparatus according to claim 5, wherein the first characteristic modifier modifies the first correction characteristic, by selecting one of a plurality of first candidate correction-characteristic-curves which represent a plurality of candidates of the first correction characteristic, respectively, which corresponds to a content of setting by the lightness setting device, and wherein the second characteristic modifier modifies the second correction characteristic, by selecting one of a plurality of second candidate correction-characteristic-curves which represent a plurality of candidates of the second correction characteristic, respectively, which corresponds to the content of the setting by the lightness setting device. 8. The apparatus according to claim 1, wherein the first characteristic modifier modifies the first correction characteristic, based on a first basic correction-characteristic-curve which represents a basis of the first correction characteristic, and a content of setting by the lightness setting device, and wherein the second characteristic modifier modifies the second correction characteristic, based on a second basic correction-characteristic-curve which represents a basis of the second correction characteristic, and the content of the setting by the lightness setting device. 9. The apparatus according to claim 8, wherein the first characteristic modifier modifies the first correction characteristic, based on a first factor variable depending on the content of the setting by the lightness setting device, and a first function defining the first basic correction-characteristic-curve. 10. The apparatus according to claim 9, wherein the first factor is lower than one and is used for dividing a pre-selected first variable. 11. The apparatus according to claim 10, wherein the first function is defined as a function of a first input value represented by the inputted image data, wherein the first variable includes the first input value, and wherein the first characteristic modifier compensates the first input value by dividing the first input value by the first factor, and delivers the compensated first input value to the first corrector, to thereby modify the first correction characteristic. 12. The apparatus according to claim 8, wherein the second characteristic modifier modifies the second correction characteristic, based on a second factor variable depending on the content of the setting by the lightness setting device, and a second function defining the second basic correction-characteristic-curve. 13. The apparatus according to claim 12, wherein the second factor is lower than one and is used for dividing a pre-selected second variable. 14. The apparatus according to claim 13, wherein the second function is defined as a function of a second input value represented by the processed image data, wherein the second variable includes the second input value, and wherein the second characteristic modifier compensates the second input value by dividing the second input value by the second factor, and delivers the compensated second input value to the second corrector, to thereby modify the second correction characteristic. 15. The apparatus according to claim 8, wherein the first basic correction-characteristic-curve is defined by a first function of a first input value represented by the inputted image data, and wherein the first characteristic modifier compresses a range of the first input value, depending on the content of the setting by the lightness setting device, to thereby modify the first correction characteristic. 16. The apparatus according to claim 15, wherein the first characteristic modifier compresses the range of the first input value using a first factor variable depending on the content of the setting by the lightness setting device. 17. The apparatus according to claim 16, wherein the first factor is lower than one and is used for dividing the range of the first input value. 18. The apparatus according to claim 8, wherein the second basic correction-characteristic-curve is defined by a second function of a second input value represented by the processed image data, and wherein the second characteristic modifier compresses a range of the second input value, depending on the content of the setting by the lightness setting device, to thereby modify the second correction characteristic. 19. The apparatus according to claim 18, wherein the second characteristic modifier compresses the range of the second input value using a second factor variable depending on the content of the setting by the lightness setting device. 20. The apparatus according to claim 19, wherein the second factor is lower than one and is used for dividing the range of the second input value. 21. The apparatus according to claim 8, wherein the first basic correction-characteristic-curve defines a relationship between the first input value and the first output value such that a rate of change of the first output value with respect to the first input value is higher with the first input value being lower, while the rate of change is lower with the first input value being higher. 22. The apparatus according to claim 8, wherein the second basic correction-characteristic-curve defines a relationship between the second input value and the second output value such that a rate of change of the second output value with respect to the second input value is higher with the second input value being lower, while the rate of change is lower with the second input value being higher. 23. The apparatus according to claim 1, wherein the image processor comprises a converter converting the image data, inputted by the input device, indicative of R(red), B(green), and B(blue) color components, into recording data, for use in the image processor, indicative of C(cyan), M(magenta), Y(yellow), and K(black) color components, wherein the first corrector uses for the image data first individual correction-characteristic-curves on a color component basis, and wherein the second corrector uses for the recording data second individual correction-characteristic-curves on a color component basis. 24. The apparatus according to claim 23, wherein the image data represents the image on a color component basis in terms of a additive-color-based three-primary-color system, and wherein the recording data represents the image on a color component basis in terms of a subtractive-color-based three-primary-color system. 25. A method of forming an image, comprising the steps of: inputting image data; processing the inputted image data; forming the image on a recording medium, based on the processed image data; setting a lightness value of the image to be formed on the recording medium by the image forming device; correcting the inputted image data according to a first correction characteristic; modifying the first correction characteristic, in response to setting of increasing the lightness value by the step of setting; correcting the processed image data according to a second correction characteristic; and modifying the second correction characteristic, in response to setting of decreasing the lightness value by the step of setting. 26. A program executed by a computer for practicing the method according to claim 25. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to techniques of forming an image on a recording medium (e.g., a recording paper) with its lightness be adjustable, and more particularly to techniques of converting image data (e.g., data indicative of an image scanned or captured by a color scanner) of additive primary colors (e.g., three primary colors) into recording data of subtractive primary colors (e.g., a combination of three primary colors and a black color), and forming an image on the recording medium using the recording data. 2. Description of the Related Art Color copiers, and facsimile machines and digital multi-function apparatuses each having a copying function are known. Typically, such a type of an apparatus is constructed to include: a color scanner (an image reader or an image capture device); an image processor; and a color printer (an imager or an image recorder). The color scanner is adapted to capture the image of an original document, by separating the image into color components of R(red), G(green), and B(blue), which are additive three primary colors, and by producing image data indicative of the color components. The image data will be also referred to as “captured-image data.” The image processor is adapted to produce image data indicative of color components of C(cyan), M(magenta), and Y(yellow), which are subtractive three primary colors, and K(black), from the image data (captured-image data) produced by the color scanner. The image data produced by the image processor will be also referred to as “recording data.” The color printer is adapted to form an image on the recording medium, using four different colored colorants of C, M, Y, and K colors, based on the recording data of C, M, Y, and K color components produced by the image processor. Such a type of an image forming apparatus including the above-described color scanner, image processor, and color printer is operated such that an original document is captured by the color scanner to produce captured-image data (image data indicative of R, G, and B color components), the captured-image data is converted into the recording data indicative of C, M, Y, and K color components, and then, the color printer outputs a copy image of the original document, using the recording data of these four color components. Color copiers and multi-function apparatuses incorporating a copying function are typically provided with as one of standard keys a lightness-adjustment key for allowing the user to request or instruct the lightness of an image formed on a recording paper (hereinafter, referred to as “copy image output”) to be adjusted. The lightness-adjustment key is constructed as a member manipulated by the user for changing a set value of the lightness value of a copy image output, relative to a standard lightness value (e.g., a default value for the lightness), at given intervals, in multiple steps, in a selected one of a plus direction to brighten the copy image output, and a minus direction to darken the copy image output. The user is allowed to adjust in lightness a copy image output as a whole, to achieve a desired lightness, either for brightening or for darkening, depending on the user's manipulation via the lightness-adjustment key. More specifically, the aforementioned image processor is constructed to include, as illustrated in FIG. 10 , a first gamma corrector 101 ; a color converter 102 , a UCR (Under Color Removal) processor 103 ; and a second gamma corrector 104 . The first gamma corrector 101 is for use in gamma-correcting the image data of R, G, and B color components delivered from the color scanner. The color converter 102 is for use in producing from the image data of R, G, and B color components gamma-corrected by the first gamma corrector 101 , image data of C, M, and Y color components, through color conversion. The UCR processor 103 is for use in producing from the produced image data of C, M, and Y color components, image data of a K color component. The second gamma corrector 104 is for use in gamma-correcting the image data of C, M, Y, and K color components delivered from the UCR processor 103 . In the thus-constructed image processor, a gamma characteristic used in the first gamma corrector 101 is made variable depending on the set value of lightness established to the user's operation via the lightness-adjustment key, as illustrated in graph in FIG. 11 , and the captured-image data is gamma-corrected according to the gamma characteristic conforming with the set value of lightness established to the user's operation via the lightness-adjustment key, resulting in adjustment in lightness of a copy image output. More specifically, as illustrated in FIG. 11 , in the above image processor, there are stored data of a gamma characteristic curve for achieving the standard lightness value, which forms the basis of the following curves; data of a gamma characteristic curve for achieving the lightness adjustment in the minus (darkening) direction; and data of a gamma characteristic curve for achieving the lightness adjustment in the plus (brightening) direction. In the image processor, an available gamma characteristic curve is sequentially modified by selecting these curves to the user's selective action of pressing the lightness-adjustment key, resulting in adjustment in lightness of a copy image output. For darkening a copy image output, there is established through the above selective operation a gamma characteristic curve, i.e., a relationship in lightness between an input value and an output value defined such that increments of the output value with respect to the input value (i.e., the slope of the gamma curve) are lower in the region with the input value being lower, while increments of the output value with respect to the input value are higher in the region with the input value being higher. On the other hand, for brightening a copy image output, there is established through the above selective operation a gamma characteristic curve defined such that increments of the output value with respect to the input value are higher in the region with the input value being lower, while increments of the output value with respect to the input value are lower in the region with the input value being higher. The above technique, since is originated for adjusting lightness or brightness, is considered to be a technique of adjusting the lightness “L” when viewed in an L*a*b* color space. With this in mind, conventionally, the adjustment is performed at only the first gamma corrector 101 on a reading side of the instant apparatus, independent of the second gamma corrector 104 on a recording side of the instant apparatus. On the other hand, as disclosed in Japanese Patent Publications No. HEI 10-79888 and No. 2003-46779, for example, there is known in the field of an image capture device such as a digital camera and a video camera, a technique of modifying a gamma characteristic for use in a gamma correcting processing for image data of a captured image, thereby varying the density of an output image. |
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>Conventionally, color copier and multi-function apparatuses incorporating a copying function each perform adjustment in lightness of a copy image output depending on the user's operation via the lightness-adjustment key, through a gamma correction processing for image data produced by the color scanner to represent the image of an original document captured by the color scanner. As a result, these conventional apparatuses, when the lightness of a copy image output is requested to be adjusted to a set value apart from the standard lightness value in the darkening direction, fails to increase in density a darker portion of the original document while preserving the color balance thereof. These conventional apparatuses therefore suffer from a drawback that the resulting copy image output is unintendedly blacked out (darkened) due to generation of image data of a K color component, depending on the circumstances. Describing the reasons more specifically, once an input value of image data indicative of a dark image having low RGB values is converted into the corresponding output value according to the gamma characteristic curve as illustrated in FIG. 11 , the corresponding output value tends not to faithfully reflect small changes of the input value on a color-by-color basis, resulting in deterioration of color balance. In other words, as a result of the above conversion, the input value of the color converter 102 , i.e., the output value of the first gamma corrector 101 is produced as image data which is similar to so-called achromatic color data hard to represent differences between colors. For this reason, the UCR processor 103 tends to unintendedly emphasize a K color component. In an example illustrated in FIG. 12 , the UCR processor 103 produces image data of a K color component, using the minimum one of C, M, and Y color levels VC, VM, VY represented by image data of C, M, and Y color components, according to a given level conversion look-up table. The UCR processor 103 subtracts a K color level VK of the produced image data of a K color component, from the C, M, and Y color levels VC, VM, VY, respectively, thereby modifying the C, M, and Y color levels VC, VM, and VY, respectively. More specifically, in the example of FIG. 12 , the K color level VK is determined according to the given level conversion look-up table, from the C color level VK represented by image data indicative of a C color component, which is lower than the M and Y color levels VM, VY. To represent the determined K color level VK, image data of a K color component is produced. Further, the C, M, and Y color levels VC, VM, VY represented by the image data indicative of C, M, and Y color components are modified into “(VC-VK),” “(VM-VK),” and “(VY-VK),” respectively. It is added that, the ratio of the K color level VK to the referenced color level (the C color level VC, in the example of FIG. 12 ) may be determined in the designing stage, depending on the circumstances. More specifically, the K color level VK, although, in the example of FIG. 12 , is determined to be almost a half of the original C color level VC, may be determined to be approximately the same as the original C color level VC, causing the resulting C color level VC to be zeroed, for example. Referring back to FIG. 11 , as explained above, upon request from the user through operation via the lightness-adjustment key for adjusting the lightness value in a direction to darken an output image to below the standard lightness value, one of a plurality of candidate gamma characteristic curves which is assigned a darkening direction as a direction to adjust the lightness value is selected. Accordingly, the output value, outputted from the first gamma corrector 101 , and being indicative of image data of R, G, and B color components, is produced as a value lower than a value to be selected when the standard lightness value is requested, i.e., as a value representing an image darker than when the standard lightness value is requested, in the region with the input value being lower. As a result, the output value of the color converter 102 , because of C, M, and Y colors being complementary to R, G, and B colors, is produced as a value representing an image higher than a value to be selected when the standard lightness value is requested, i.e., as a value representing an image darker than when the standard lightness value is requested. The thus-produced output value of the color converter 102 , although will be eventually entered into the UCR processor 103 , has been produced as image data which is similar to so-called achromatic color data hard to represent differences between colors (R, G, and B), as described above. As a result, the output value, outputted from the color converter 103 , and represented by image data of C, M, and Y color components, has been produced as image data smaller in difference in color level between those colors, as well. Therefore, a K color component is unnecessarily emphasized at the UCR processor 103 , seemingly resulting in black-out of a full output image. FIGS. 13 ( a )- 13 ( e ) illustrate in graph examples of sets of image data indicative of C, M, Y, and K color components which are produced at the UCR processor 103 . These sets of image data are produced, after image data indicative of a darker portion of a captured image by the color scanner is gamma-corrected by the first gamma corrector 101 to achieve the standard lightness value. On the other hand, FIGS. 14 ( a )- 14 ( e ) illustrate in graph examples of sets of image data indicative of C, M, Y, and K color components which are produced at the UCR processor 103 . These sets of image data are produced, after image data indicative of the same darker portion is gamma-corrected by the first gamma corrector 101 according to a gamma characteristic curve for achieving a lightness value lower (darker) than the standard lightness value. In FIGS. 13 ( a )- 13 ( e ) and 14 ( a )- 14 ( e ), color levels of per-color image data are each represented after normalization in which a maximum level (“255” for 8-bit image data, for example)of the original image data level is scaled into “1.0.” More specifically, FIGS. 13 ( a ) and 14 ( a ) each illustrate sets of image data indicative of R, G, and B color components entered into the first gamma corrector 101 . FIGS. 13 ( b ) and 14 ( b ) each illustrate sets of image data indicative of R, G, and B color components outputted from the first gamma corrector 101 . FIGS. 13 ( c ) and 14 ( c ) each illustrate sets of image data indicative of C, M, and Y color components outputted from the color converter 102 . FIGS. 13 ( d ) and 14 ( d ) each illustrate sets of image data indicative of C, M, Y, and K color components outputted from the UCR processor 103 . FIGS. 13 ( e ) and 14 ( e ) each illustrate sets of image data indicative of C, M, Y, and K color components outputted from the second gamma corrector 104 . It is added that, a relationship between FIGS. 13 ( b ) and 13 ( c ) and a relationship between FIGS. 14 ( b ) and 14 ( c ) each reflect the characteristic of the conversion performed at the color converter 102 , for the above two cases different in desired lightness value, respectively. On the other hand, the fact that R, G, and B colors are complementary to C, M, and Y colors, respectively, originally leads to the result that the C, M, and Y color values equal the corresponding respective R, G, and B color values minus “1.” However, the color converter 102 is adapted to incorporate a look-up table “LUP” for absorbing differences in color gamut (color reproduction range) between the color scanner on a reading side and the color printer on a recording side. Therefore, those two relationships do not exhibit the thus-originally-led result. FIG. 15 illustrates in graph an example of a first gamma characteristic curve selected by the first gamma corrector 101 upon request for the standard lightness value. FIG. 16 illustrates in graph a UCR gamma characteristic curve selected by the UCR processor 103 upon request for the standard lightness value. FIG. 17 illustrates in graph an example of a second gamma characteristic curve selected by the second gamma corrector 104 upon request for the standard lightness value. In the examples of FIG. 13 , as illustrated in FIG. 13 ( c ), sets of image data indicative of C, M, and Y color components outputted from the color converter 102 are formed such that the C color level VC represented by image data of a C color component is very low, and therefore, a threshold level allowing the UCR processor 103 to generate a K color component is not reached. As a result, as illustrated in FIGS. 13 ( d ) and 16 , the UCR processor 103 does not produce a K color level VK represented by image data of a K color component, thereby preserving the color balances of an original document captured by the color scanner. In contrast, once the lightness value is requested via the lightness-adjustment key to be adjusted to a set value lower (darker) than the standard lightness value, the output value is reduced with respect to the same input value, as illustrated in FIG. 11 , the levels of image data of R, G, and B color components, upon gamma-corrected by the first gamma corrector 101 , become so low that even the maximum color level, which is represented by image data of a R color component, is not higher than “0.32,” as illustrated in FIG. 14 ( b ). As a result, the levels of image data of C, M, and Y color components, upon produced from such image data of R, G, and B color components, all become so high that even the minimum color level, which is represented by image data of a C color component, exceeds “0.5,” as illustrated in FIG. 14 ( c ). Therefore, the threshold level allowing the UCR processor 103 to generate a K color component is reached, and the level of image data of a K color component outputted from the second gamma corrector 104 also becomes very high, as illustrated in FIG. 14 ( e ). As a result, once an image is formed on a recording paper using such image data of C, M, Y, and K color components, the image seems to be blacked out due to the high-level K color component. In the examples of FIGS. 13 and 14 , when compared with respect to the color balance expressed in terms of the ratio of C: M: Y, the color balance of a copy image output undergoing the gamma correction to achieve the standard lightness value is, as illustrated in FIG. 13 ( e ): 1:6:9, while the color balance of a copy image output undergoing the gamma correction to achieve the lightness value lower (darker) than the standard lightness value is, as illustrated in FIG. 14 ( e ): 1:1.82:1.67. This comparison demonstrates that, conventionally, the adjustment of the lightness value to become darker than the standard lightness value invites a large change in color balance, leading to a change in saturation, and emphasis in blackness of the changed color. FIGS. 18 ( a )- 18 ( c ) illustrate in graph, in terms of an L*a*b* color space, a change in position of a color from position A to position B as a result of the conversion according to the first gamma characteristic curve, for the sake of easy understanding. More specifically, FIG. 18 ( a ) illustrates in perspective view the L*a*b* color space, FIG. 18 ( b ) illustrates an L*a* color plane, and FIG. 18 ( c ) illustrates an a*b* color plane. FIGS. 18 ( a )- 18 ( c ) together demonstrate that the adjustment in lightness in the darkening direction via the user's operation of the lightness-adjustment key not only reduces the lightness value “L” in the L*a*b* color space, but also performs an unintended modification to the saturation represented in the a*b* color plane. In addition, the true intent of a user who actually operates the lightness-adjustment key in the darkening direction lies, not in that the user wishes to darken the resulting copy image output, but in that, since the copy image output is too light (pale) to be visible, the user wishes the copy image output to become more clearly visible by increasing the image density. It can be recognized that such a user's operation does not truly mean a request for darkening, but a request for enhancing distinctness or definition. As a result, an added limitation is encountered with the above-described conventional apparatuses that a mere adjustment in lightness fails to such an adequate adjustment as to fulfill a user's true need correctly. More specifically, conventionally, the adjustment in lightness in the darkening direction basically means a mere adjustment in brightness. Therefore, even though a copy image output which is lighter (paler) (i.e., which lacks density differences between colors) is darkened, all that results from is the darkening of the entire copy image output, with density differences between colors not being enhanced. It is therefore an object of the present invention to provide a technique, upon request for darkening (decreasing in lightness) an image output corresponding to an original, of increasing in saturation the copy image output while preserving the lightness of the original. |
Memory elements having patterned electrodes and method of forming the same |
A memory element having a resistance variable material and methods for forming the same are provided. The method includes forming a plurality of first electrodes over a substrate and forming a blanket material stack over the first electrodes. The stack includes a plurality of layers, at least one layer of the stack includes a resistance variable material. The method also includes forming a first conductive layer on the stack and etching the conductive layer and at least one of the layers of the stack to form a first pattern of material stacks. The etched first conductive layer forming a plurality of second electrodes with a portion of the resistance variable material located between each of the first and second electrodes. |
1. A method of forming a memory element, the method comprising the acts of: forming a plurality of first electrodes over a substrate; forming a blanket material stack over the first electrodes, the stack including a plurality of layers, at least one layer of the stack comprising a resistance variable material; forming a first conductive layer on the stack; and etching the conductive layer and at least one of the layers of the stack to form a first pattern of material stacks, the etched first conductive layer forming a plurality of second electrodes with a portion of the resistance variable material located between each of the first and second electrodes. 2. The method of claim 1, wherein the act of etching comprises etching only a portion of the layers of the stack. 3. The method of claim 1, further comprising the acts of: forming an etch stop layer between first and second portions of the material stack; and forming an opening in the etch stop layer to expose the first portion, wherein the act of forming the stack comprises forming the second portion within the opening. 4. The method of claim 3, wherein the act of forming the opening comprises forming an opening over at least a portion of each of the first electrodes. 5. The method of claim 3, wherein the act of forming the opening comprises forming the opening in a second pattern. 6. The method of claim 6, wherein the first pattern is approximately a negative image of the second pattern. 7. The method of claim 1, wherein the act of forming the material stack comprises forming a layer of chalcogenide material. 8. The method of claim 7, wherein the act of forming the material stack comprises forming a metal-chalcogenide layer over the chalcogenide material layer, and forming a metal layer over the metal-chalcogenide layer. 9. The method of claim 8, wherein the act of etching comprises etching the metal layer and the metal-chalcogenide layer. 10. The method of claim 9, wherein the chalcogenide material layer is not etched during the act of etching. 11. The method of claim 1, further comprising the act of forming at least one conductive via, wherein the act of forming the conductive layer comprises forming the conductive layer in contact with the at least one conductive via. 12. A method of forming a plurality of memory elements, the method comprising the acts of: forming a first electrode over a substrate; forming a first portion of a stack over the first electrode, the first portion comprising at least one layer; forming an etch stop layer over the first portion; forming openings in the etch stop layer to the first portion, the openings being formed in a first pattern; forming a second portion of the stack over the patterned etch stop layer and within the openings, at least one layer of the stack being a resistance variable material; forming a conductive layer on the stack, the conductive layer for serving as one or more second electrodes; and etching the conductive layer and the second portion to form a second pattern. 13. The method of claim 12, wherein the first pattern is approximately a negative image of the second pattern. 14. The method of claim 13, wherein the act of forming the openings comprises forming an opening over at least a portion of the first electrode. 15. The method of claim 12, wherein the act of forming the stack comprises forming a layer of chalcogenide material. 16. The method of claim 15, wherein the act of forming the stack comprises forming a metal-chalcogenide layer over the chalcogenide material layer, and forming a metal layer over the metal-chalcogenide layer. 17. A method of forming a memory array, the method comprising the acts of: forming one or more first electrodes over a substrate; forming a chalcogenide material layer in contact with the one or more first electrodes; forming an etch stop layer over the chalcogenide material layer; forming openings in the etch stop layer to expose the chalcogenide material layer, the openings being formed in a first pattern; forming a metal-chalcogenide layer over the patterned etch stop layer and within the openings; forming a metal layer over the metal chalcogenide layer; forming a conductive layer over the metal layer, the conductive layer for serving as one or more second electrodes; etching the conductive layer, the metal layer and the metal-chalcogenide layer such that together the conductive layer, the metal layer and the metal-chalcogenide layer form a second pattern; and stopping the etching at the etch stop layer. 18. The method of claim 17, wherein the first pattern is approximately a negative image of the second pattern. 19. The method of claim 18, wherein the act of forming the openings comprises forming an opening over at least a portion of each of the one or more first electrodes. 20. The method of claim 17, wherein the act of forming the chalcogenide material layer comprises forming germanium selenide. 21. The method of claim 17, wherein the act of forming the metal-chalcogenide layer comprises forming tin-chalcogenide. 22. The method of claim 21, wherein the act of forming the metal-chalcogenide layer comprises forming tin selenide. 23. The method of claim 21, wherein the act of forming the metal-chalcogenide layer comprises forming tin telluride. 24. The method of claim 17, wherein the act of forming the metal-chalcogenide layer comprises forming silver-chalcogenide. 25. The method of claim 24, wherein the act of forming the metal-chalcogenide layer comprises forming silver selenide. 26. The method of claim 17, wherein the act of forming the metal layer comprises forming silver. 27. A memory array comprising: at least one first electrode over a substrate; at least one resistance variable material layer over the first electrode; a plurality of material stacks over the at least one resistance variable material layer, each material stack comprising at least one layer of conductive material and a second electrode. 28. The memory array of claim 27, wherein each material stack corresponds to at least one memory element, and wherein the at least one resistance variable material layer is common to each memory element. 29. The memory array of claim 27, wherein the at least one resistance variable material layer comprises a chalcogenide material. 30. The memory array of claim 29, wherein the chalcogenide material comprises chalcogenide glass. 31. The memory array of claim 30, wherein the at least one layer of conductive material comprises a metal-chalcogenide layer. 32. The memory array of claim 30, wherein the at least one layer of conductive material further comprises a metal layer. 33. The memory array of claim 31, wherein the metal-chalcogenide layer comprises tin selenide. 34. The memory array of claim 31, wherein the metal-chalcogenide layer comprises tin telluride. 35. The memory array of claim 32, wherein the metal layer comprises silver. 36. The memory array of claim 27, wherein the second electrode comprises tungsten. 37. The memory array of claim 27, wherein the at least one layer of resistance variable material is in contact with the at least one first electrode. 38. The memory array of claim 27, wherein each material stack is in contact with the resistance variable material layer. 39. The memory array of claim 27, wherein each material stack is partially offset from the at least one first electrode. 40. The memory array of claim 27, wherein each material stack is directly over a first electrode. 41. The memory array of claim 27, wherein each material stack corresponds to a single memory element. 42. A processor system comprising: a processor; and a memory device coupled to the processor, the memory device comprising: at least one first electrode over a substrate; at least one resistance variable material layer over the first electrode; a plurality of material stacks over the at least one resistance variable material layer, each material stack comprising at least one layer of conductive material and a second electrode. 43. The system of claim 42, wherein the at least one resistance variable material layer is common to each memory element. 44. The system of claim 42, wherein the at least one resistance variable material comprises a chalcogenide material. 45. The system of claim 42, wherein the at least one layer of conductive material comprises a metal-chalcogenide layer. 46. The system of claim 45, wherein the at least one layer of conductive material further comprises a metal layer. 47. The system of claim 42, wherein the at least one layer of resistance variable material is in contact with the at least one first electrode. 48. The system of claim 47, wherein each material stack is in contact with the resistance variable material layer. 49. The system of claim 42, wherein each material stack is partially offset from the at least one first electrode. 50. The system of claim 42, wherein each material stack is directly over a first electrode. 51. The system of claim 42, wherein each material stack corresponds to a single memory element. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Resistance variable memory elements, which include Programmable Conductive Random Access Memory (PCRAM) elements using chalcogenides, have been investigated for suitability as semi-volatile and non-volatile random access memory devices. A typical chalcogenide resistance variable memory element is disclosed in U.S. Pat. No. 6,348,365 to Moore and Gilton. In a typical chalcogenide resistance variable memory element, a conductive material, for example, silver, tin and copper, is incorporated into a chalcogenide glass. The resistance of the chalcogenide glass can be programmed to stable higher resistance and lower resistance states. An unprogrammed chalcogenide variable resistance element is normally in a higher resistance state. A write operation programs the element to a lower resistance state by applying a voltage potential across the chalcogenide glass and forming a conductive pathway. The element may then be read by applying a voltage pulse of a lesser magnitude than required to program it; the resistance across the memory device is then sensed as higher or lower to define two logic states. The programmed lower resistance state of a chalcogenide variable resistance element can remain intact for an indefinite period, typically ranging from hours to weeks, after the voltage potentials are removed; however, some refreshing may be useful. The element can be returned to its higher resistance state by applying a reverse voltage potential of about the same order of magnitude as used to write the device to the lower resistance state. Again, the higher resistance state is maintained in a semi- or non-volatile manner once the voltage potential is removed. In this way, such an element can function as a variable resistance memory having at least two resistance states, which can define two respective logic states, i.e., at least a bit of data. One exemplary chalcogenide resistance variable device uses a germanium selenide (i.e., Ge x Se 100-x ) chalcogenide glass as a backbone. The germanium selenide glass has, in the prior art, incorporated silver (Ag) and silver selenide (Ag 2+/−x Se) layers in the memory element. FIG. 1 depicts an example of a conventional chalcogenide variable resistance element 1 . A semiconductive substrate 10 , such as a silicon wafer, supports the memory element 1 . Over the substrate 10 is an insulating material 11 , such as silicon dioxide. A conductive material 12 , such as tungsten, is formed over insulating material 11 . Conductive material 12 functions as a first electrode for the element 1 . An insulating material, 13 such as silicon nitride, is formed over conductive material 12 . A glass material 51 , such as Ge 3 Se 7 , is formed within via 22 . A metal material 41 , such as silver, is formed over glass material 51 . An irradiation process and/or thermal process are used to cause diffusion of metal ions into the glass material 51 . A second conductive electrode 61 is formed over dielectric material 13 and residual metal material 41 . The element 1 is programmed by applying a sufficient voltage across electrodes 12 and 61 to cause the formation of a conductive path between the two electrodes 12 and 61 , by virtue of a conductor (i.e., such as silver) that is present in metal ion laced glass layer 51 . In the illustrated example, with the programming voltage applied across electrodes 12 and 61 , the conductive pathway forms from electrode 12 towards electrode 61 . It is desirable to have additional methods of forming memory elements. In particular, it is desirable to have techniques for forming memory elements in a high density. |
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>Exemplary embodiments of the invention provide memory elements having a resistance variable material and methods for forming the same. The method includes forming a plurality of first electrodes over a substrate and forming a blanket material stack over the first electrodes. The stack includes a plurality of layers, at least one layer of the stack includes a resistance variable material. The method also includes forming a first conductive layer on the stack and etching the conductive layer and at least one of the layers of the stack to form a first pattern of material stacks. The etched first conductive layer forming a plurality of second electrodes with a portion of the resistance variable material located between each of the first and second electrodes. |
APPARATUS AND METHOD FOR PROTECTING A DISK DRIVE IN A HARDCOPY DEVICE |
An apparatus and method for protecting a hard disk drive in a hardcopy device includes detecting an abnormal condition during operation of the hardcopy device, and moving a head of the hard disk drive to a safe position in response to the detection of the abnormal condition. An indication of the abnormal condition is generated after the head of the hard disk drive has been moved to the safe position. |
1. A method for protecting a hard disk drive in a hardcopy device, comprising: detecting an abnormal condition during operation of the hardcopy device; moving a head of the hard disk drive to a safe position in response to the detection of the abnormal condition; and generating an indication of the abnormal condition after the head of the hard disk drive has been moved to the safe position. 2. A method according to claim 1, wherein the abnormal condition is a paper jam. 3. A method according to claim 1, wherein the abnormal condition is a serviceman call. 4. A method according to claim 1, wherein the abnormal condition is a toner empty condition. 5. A method according to claim 1, wherein the abnormal condition is a toner waste full condition. 6. A method according to claim 1, wherein the abnormal condition is a paper empty condition. 7. A method according to claim 1, further comprising: detecting whether the abnormal condition has been resolved; and moving the head of the hard disk drive to an operational position if the resolution of the abnormal condition has been detected. 8. A method according to claim 1, wherein the generated indication of the abnormal condition is a display shown on a visual display of the hardcopy device identifying the abnormal condition. 9. A method according to claim 1, wherein the generated indication of the abnormal condition is an audible indication identifying the abnormal condition. 10. A method according to claim 1, further comprising issuing a standby command to the hard disk drive to move the head to the safe position in response to detecting the abnormal condition. 11. A method according to claim 1, wherein the safe position of the head is a position in which the head is positioned outside an outer periphery of a magnetic disk of the hard disk drive. 12. A method according to claim 1, wherein the safe position of the head is a position in which the head is positioned away from a magnetic disk of the hard disk drive such that the head cannot contact the magnetic disk in response to a vibration or shock to the hardcopy device. 13. A method according to claim 1, further comprising generating a signal when the head of the hard disk drive has reached the safe position, wherein the indication is generated in response to the signal. 14. A method for protecting a hard disk drive in a hardcopy device, comprising: detecting an abnormal condition during operation of the hardcopy device; moving a head of the hard disk drive to a safe position in response to the detection of the abnormal condition; determining whether a predetermined time has lapsed after detecting the abnormal condition; and generating an indication of the abnormal condition after the predetermined time has lapsed. 15. A method according to claim 14, wherein a time to move the head to the safe position is less than the predetermined time. 16. A method according to claim 14, further comprising: detecting whether the abnormal condition has been resolved; and moving the head of the hard disk drive to an operational position if the resolution of the abnormal condition has been detected. 17. A method according to claim 14, wherein the safe position of the head is a position in which the head is positioned outside an outer periphery of a magnetic disk of the hard disk drive. 18. A method according to claim 14, further comprising: detecting an insertion of a paper cassette in the hardcopy device; detecting if paper is present in the paper cassette inserted in the hardcopy device; and moving the head of the hard disk drive to the safe position if no paper is detected as being present in the paper cassette. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Hardcopy devices, such as a printer, a fax machine, a plotter or a multi-function peripheral (MFP), have a hard disk drive (HDD) head that is located above a magnetic disk during user operation. When an abnormal condition arises during operation of the hardcopy device, such as due to a paper jam, a serviceman call, an empty toner, a full toner bag, or an empty paper condition, the device may be subjected to vibrations or other shock as a result of a user's efforts to resolve the abnormal condition. Any vibration or shock applied to the body of the device may be translated to the HDD that is mounted in the body, causing the HDD head to strike the magnetic disk. The striking of the magnetic disk by the head can cause damage to both the magnetic disk and the head. In one conventional system, to protect the HDD from vibration or shock resulting from the recovering from the abnormal condition, a structural material is used to reduce any vibrations or shocks. In particular, a rubber or gel damper is placed between the HDD and a mounting sheet metal that fixes the HDD to a hard copy device. This system, however, may be unable to effectively reduce the vibration, as the reduction depends on the frequency of the given vibration or shock and the damping property of the rubber or gel. It also may be unable to show sufficient reduction depending on the size of the given vibration or shock. Although it is possible to use a damper that covers a wider frequency that is more effective for handling serious vibrations or shocks, such a damper is very expensive. In addition, since the quality of the damper material is soft, it can have a negative influence on recording and reproduction due to a self-excited vibration of a motor rotating inside the HDD. It would be desirable to have a more effective and less costly system for protecting the HDD when an abnormal condition is being resolved. |
<SOH> SUMMARY OF THE INVENTION <EOH>According to an aspect of the invention, an image forming apparatus and method for protecting a hard disk drive in a hardcopy device includes detecting an abnormal condition during operation of the hardcopy device, and moving a head of the hard disk drive to a safety area in response to the detection of the abnormal condition. An indication of the abnormal condition is generated after the head of the hard disk drive has been moved to the safety area. Further features, aspects and advantages of the present invention will become apparent from the detailed description of preferred embodiments that follows, when considered together with the accompanying figures of drawing. |
Airborne windshear detection and warning system |
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