Patent application number | Description | Published |
20080205231 | Optical Disc Recording Pulse Control Method, and Control Device and Optical Disc Device Employed Therein - There are problems that recording degradation happens, and an error occurs in reproduction unless appropriate recording pulse conditions are determined. A recording pulse controlling method according to the present invention is a recording pulse controlling method for adjusting recording pulses for recording information on a writable optical disc, which includes a mark length adjustment step and a mark position adjustment step. The mark length adjustment step is a step for adjusting a recording mark length adjustment parameter, and the recording mark length adjustment parameter is adjusted to have a value for forming a recording mark having a length closest to a predetermined recording mark length. The mark position adjustment step is a step for adjusting a recording mark position adjustment parameter after the mark length adjustment step, and the recording mark position adjustment parameter is adjusted to have a value for forming a recording mark at a position closest to a predetermined recording mark position. | 08-28-2008 |
20080231332 | Clock Signal Generation Device, Semiconductor Integrated Circuit, and Data Reproduction Method - The present invention improves a lead-in time of the PLL with a phase error detector having an enlarged range of phase error detection and gain control based on the PLL synchronous state. The phase error detection range is enlarged by correcting the phase error detection point in a case where the phase error increases. A locked state of the PLL is determined based on a standard deviation of the smoothed phase error values and the gains are switched between a lead-in transient state and a stationary state. As a result, it is possible to shorten and stabilize the lead-in time of the PLL. | 09-25-2008 |
20080253251 | Position Detection Device, Position Detection Method, Position Detection Control Device, Position Detection Control Method, Position Detection Control Program, Access Authentication Device, Access Authentication Method, Access Authentication Control Device, Access Authentication Control Method, Access Authentication Control Program, Information Storage Device, and Optical Disk - A position detection device, a position detection method, a position detection control device, a position detection control method, a position detection control program, an access authentication device, an access authentication method, an access authentication control device, an access authentication control method, an access authentication control program, an information storage device, and an optical disk are provided, all of which make it possible to prevent illegal copying of the information recorded in a recording medium. | 10-16-2008 |
20090010121 | INFORMATION PROCESSING DEVICE, ACCESS DEVICE, RECORDING MEDIUM, INFORMATION PROCESSING METHOD, AND INFORMATION PROCESSING PROGRAM - An information processing device ( | 01-08-2009 |
20090028019 | RECORDING MEDIUM ACCESS DEVICE - An information reproduction device according to the present invention is a device for accessing a recording medium having first address information and second address information recorded thereon. The first address information is represented by a shape formed on the recording medium in advance; and the second address information is recorded on the recording medium together with data. The information reproduction device includes a head section for accessing the recording medium to generate a reproduction signal; a first detection section for detecting the first address information from the reproduction signal; a second detection section for detecting the second address information from the reproduction signal; and a control section for, based on a detection result of either the first detection section or the second detection section which detected the address information first, controlling an access after the detection to the recording medium. | 01-29-2009 |
20090034381 | RECORDING/REPRODUCING DEVICE, RECORDING CONDITION ADJUSTING DEVICE AND RECORDING/REPRODUCING METHOD - A calculation of a reliability value |Pa−Pb|−Pstd, representing represents a maximum likelihood decoding result on a portion which corresponds to a start or termination edge of a recording mark and has a high probability of error occurrence by a maximum likelihood decoding method, is performed on each combination of a predetermined mark length and a space length immediately before the mark and each combination of the mark length and a space length immediately after the mark. Based on the calculation result, a recording parameter is optimized, and recording reflecting the optimized recording parameter is performed. | 02-05-2009 |
20090103412 | RECORDING CONTROL APPARATUS, RECORDING AND REPRODUCTION APPARATUS, AND RECORDING CONTROL METHOD - A recording control apparatus includes a waveform rectification section for receiving a digital signal generated from an analog signal representing information reproduced from an information recording medium, and rectifying a waveform of the digital signal; a maximum likelihood decoding section for performing maximum likelihood decoding of the digital signal having the waveform thereof rectified, and generating a binary signal representing a result of the maximum likelihood decoding; a reliability calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the digital signal having the waveform thereof rectified and the binary signal; and an adjusting section for adjusting a shape of a recording signal for recording the information on the information recording medium based on the calculated reliability. | 04-23-2009 |
20090154315 | INFORMATION RECORDING MEDIUM, RECORDING METHOD, RECORDING APPARATUS AND INTEGRATED CIRCUIT - An information storage medium according to the present invention is adapted for multiple different writing speeds and stores in advance writing conditions associated with each of the multiple writing speeds. The writing conditions include: a recording-power-related parameter and a write-waveform-related parameter, which are associated with each particular writing speed to perform a write operation at the particular writing speed; and another recording-power-related parameter for performing a write operation at a different writing speed other than the particular one using the recording-power-related parameter for performing the write operation at the particular writing speed. | 06-18-2009 |
20090175151 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/REPRODUCING METHOD, AND INTEGRATED CIRCUIT - An address format for appropriately controlling the recording linear density and the number of information recording layers is provided in order to increase the recording capacity of an information recording medium such as an optical disc or the like in a range in which a necessary S/N ratio can be guaranteed. An optical disc includes an information recording layer having a concentric or spiral track, and has a format for describing a track address, which is pre-recorded on the track or is to be added to data that is to be recorded on the information recording layer. The format includes layer information regarding the information recording layer and address information regarding the track address. | 07-09-2009 |
20090175155 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/REPRODUCING METHOD, AND INTEGRATED CIRCUIT - A big pattern for a run-in area which allows data reproduction to be performed stably even when the recording density of an optical disc is increased is provided. An optical disc according to the present invention includes tracks, each of which divided into a plurality of recording blocks. Each of the plurality of blocks includes a run-in area and a data area. In the run-in area, a prescribed run-in bit pattern is recordable; and in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable. In this optical disc, at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths is higher than a cutoff frequency. The run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded. | 07-09-2009 |
20090180361 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/REPRODUCING METHOD, AND INTEGRATED CIRCUIT - In an optical disc, a track on which data is recordable is divided into a plurality of blocks, and each block includes L pieces of sub blocks. On each sub block, M-bit first digital information specifying a block address of a block including the each sub block and N-bit second digital information capable of representing a numerical value equal to or larger than L are recorded. | 07-16-2009 |
20100002556 | REPRODUCTION SIGNAL EVALUATION METHOD, REPRODUCTION SIGNAL EVALUATION UNIT, AND OPTICAL DISK DEVICE ADOPTING THE SAME - A reproduction signal evaluation method for evaluating quality of a reproduction signal reproduced from an information recording medium based on a binary signal generated from the reproduction signal using a PRML signal processing system, includes: a pattern extraction step of extracting, from the binary signal, a specific state transition pattern which has the possibility of causing a bit error; a step of computing a differential metric based on the binary signal; an extraction step of extracting the differential metric which is not greater than a predetermined signal processing threshold; a step of determining a mean value of the differential metrics which are not greater than the signal processing threshold and extracted in the extraction step; a standard deviation computing step of determining a standard deviation which corresponds to an error rate predicted from the mean value; and an evaluation step of evaluating a quality of the reproduction signal using the standard deviation. | 01-07-2010 |
20100054097 | RECORDING/REPRODUCTION APPARATUS, RECORDING/REPRODUCTION METHOD, PROGRAM, AND RECORDING POWER ADJUSTMENT APPARATUS - A recording/reproduction apparatus, comprising a first recording section for recording test information onto a medium using at least one recording power, a reproduction section for reproducing at least one test signal indicating the test information from the medium, and a second recording section for recording information onto the medium using one of the at least one recording power. The reproduction section comprises a decoding section for performing maximum likelihood decoding of the at least one test signal and generating at least one binary signal indicating a result of the maximum likelihood decoding, a calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the at least one test signal and the at least one binary signal, and an adjustment section for adjusting a recording power for recording the information onto the medium to the one recording power based on the reliability. | 03-04-2010 |
20100085851 | METHOD AND APPARATUS FOR EVALUATING INFORMATION RECORDING MEDIUM - The present invention has an object of evaluating a recording and reproduction signal quality of a high density information recording medium by providing an index representing, in a detection signal including a plurality of pieces of edge shift information, how each edge is shifted. A signal evaluation method, usable for an information recording medium having a data sequence including a mark and a space located alternately, for generating a binary signal from a signal obtained by reproducing the data sequence using a PRML signal processing method and evaluating a likelihood of the binary signal, includes a differential metric calculation step of calculating, from the binary signal, a differential metric which is a difference of a reproduction signal from a first state transition matrix having a maximum likelihood and a second state transition matrix having a second maximum likelihood; and a step of classifying the differential metric to any of a plurality of data patterns each including at least one mark and at least one space. The data pattern classification to any of the plurality of data patterns is performed using a combination of a length of a first mark included in the data sequence and a length of a first space adjacently located immediately previous or immediately subsequent to the first mark, and is further performed using a length of a second mark which is not adjacent to the first mark and located adjacent to the first space; and thus a reproduction signal quality of the information recording medium is evaluated. | 04-08-2010 |
20100097908 | REPRODUCTION SIGNAL EVALUATION METHOD, INFORMATION RECORDING MEDIUM, REPRODUCTION APPARATUS AND RECORDING APPARATUS - A reproduction signal evaluation method according to the present invention includes a step of generating a binary signal from an information recording medium on which a data sequence including marks and spaces in combination is recordable, using a PRML signal processing method from a signal obtained by reproducing the data sequence; and a differential calculation step of calculating a differential metric using a first state transition path having a maximum likelihood and a second state transition path having a second maximum likelihood, and a reproduction signal, the first state transition path and the second state transition path being obtained based on the binary signal. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark. | 04-22-2010 |
20100149940 | CLOCK SIGNAL GENERATION DEVICE - A clock signal generator according to the present invention includes: a wobble phase error detecting section for detecting a wobble phase error that is a difference in phase between a wobble signal, representing a wobbled shape of a track on an optical disk medium, and a clock signal; a data phase error detecting section for detecting a data phase error that is a difference in phase between a data signal, representing data that has been written on the optical disk medium, and the clock signal; a frequency control section for generating a frequency control signal to control the frequency of the clock signal based on the wobble phase error and the data phase error; and a clock oscillation section for generating the clock signal with its frequency controlled in accordance with the frequency control signal. | 06-17-2010 |
20100202261 | OPTICAL RECORDING MEDIUM, OPTICAL RECORDING MEDIUM MANUFACTURING METHOD, REPRODUCTION SIGNAL PROCESSING METHOD AND EVALUATION METHOD - An optical head | 08-12-2010 |
20100214895 | REPRODUCTION SIGNAL EVALUATION METHOD, REPRODUCTION SIGNAL EVALUATION UNIT, AND OPTICAL DISK DEVICE ADOPTING THE SAME - A reproduction signal evaluation unit has: a pattern detection section for extracting, from a binary signal, a specific state transition pattern which has a possibility of causing a bit error; a differential metric computing section for computing a differential metric based on the binary signal of the extracted state transition pattern; an error computing section for computing an error rate predicted based on an integration value that is integrated by an integration section, a count value that is counted by a pattern count section, an integration value that is integrated by another integration section, and a count value that is counted by another pattern count section, and a standard deviation computing section for computing a standard deviation based on the computed error rate. | 08-26-2010 |
20100302925 | REPRODUCED SIGNAL EVALUATING METHOD, INFORMATION RECORDING MEDIUM, REPRODUCING DEVICE, AND RECORDING DEVICE - A reproduction signal evaluation method according to the present invention includes a step of generating a binary signal from an information recording medium on which a data sequence including marks and spaces in combination is recordable, using a PRML signal processing method from a signal obtained by reproducing the data sequence; and a differential calculation step of calculating a differential metric using a first state transition path having a maximum likelihood and a second state transition path having a second maximum likelihood, and a reproduction signal, the first state transition path and the second state transition path being obtained based on the binary signal. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark. | 12-02-2010 |
20100329105 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/ REPRODUCING METHOD, AND INTEGRATED CIRCUIT - A big pattern for a run-in area which allows data reproduction to be performed stably even when the recording density of an optical disc is increased is provided. An optical disc according to the present invention includes tracks, each of which divided into a plurality of recording blocks. Each of the plurality of blocks includes a run-in area and a data area. In the run-in area, a prescribed run-in bit pattern is recordable; and in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable. In this optical disc, at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths is higher than a cutoff frequency. The run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded. | 12-30-2010 |
20110002201 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/REPRODUCING METHOD, AND INTEGRATED CIRCUIT - An address format for appropriately controlling the recording linear density and the number of information recording layers is provided in order to increase the recording capacity of an information recording medium such as an optical disc or the like in a range in which a necessary S/N ratio can be guaranteed. An optical disc includes an information recording layer having a concentric or spiral track, and has a format for describing a track address, which is pre-recorded on the track or is to be added to data that is to be recorded on the information recording layer. The format includes layer information regarding the information recording layer and address information regarding the track address. | 01-06-2011 |
20110026383 | REPRODUCED SIGNAL EVALUATION METHOD AND WRITE ADJUSTMENT METHOD - The present invention aims to provide a reproduced signal evaluation method and a write adjustment method for offering a Blu-ray disc having a large storage capacity with excellent media compatibility. An evaluation index L-SEAT is calculated through signed addition using a Euclidean distance difference calculated from at least one of target signals in which a focused edge is shifted to the right and left, and the quality of the reproduced signal is evaluated based on the evaluation index. Write condition adjustment using the index enables write adjustment not depending on SNR and achieving high adjustment accuracy. | 02-03-2011 |
20110032809 | INFORMATION RECORDING MEDIUM EVALUATION METHOD, INFORMATION RECORDING MEDIUM, METHOD FOR MANUFACTURING INFORMATION RECORDING MEDIUM, SIGNAL PROCESSING METHOD AND ACCESS CONTROL APPARATUS - A method for rating an information recording medium according to the present invention includes the steps of: receiving a digital read signal, which has been generated based on an analog read signal representing information that has been read from the information recording medium, and shaping the waveform of the digital read signal; subjecting the shaped digital read signal to maximum likelihood decoding, thereby generating a binarized signal showing a result of the maximum likelihood decoding; and calculating the quality of the digital read signal based on the shaped digital read signal and the binarized signal. If the quality of the read signal is calculated by a PRML method in which a number of zero-cross portions are included in a merging path of a minimum difference metric, the quality is calculated by using only a state transition pattern in which only one zero-cross portion is included in a merging path of a non-minimum difference metric. | 02-10-2011 |
20110096652 | PHASE ERROR DETECTING DEVICE, WAVEFORM SHAPING DEVICE AND OPTICAL DISC DEVICE - A waveform shaping portion receives a digital reproduced signal generated from an analog reproduced signal reproduced from an information recording medium and shapes the waveform of the digital reproduced signal. A maximum likelihood decoding portion applies maximum likelihood decoding to the digital reproduced signal in the shaped waveform and generates a binarized signal indicating the result of the maximum likelihood decoding. A phase detection portion extracts, during the maximum likelihood decoding/a phase error using state transition patterns having only a single zero cross point among differential metrics at a plurality of merging points at which a set of paths branched from a given state merges. A synchronization detection portion generates a reproduction clock signal using the phase error that has been detected and brings the digital reproduced signal into synchronization with the reproduction clock signal that has been generated. This configuration makes it possible to generate a reproduction clock signal in a stable manner. | 04-28-2011 |
20110122749 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/REPRODUCING METHOD, AND INTEGRATED CIRCUIT - An address format for appropriately controlling the recording linear density and the number of information recording layers is provided in order to increase the recording capacity of an information recording medium such as an optical disc or the like in a range in which a necessary S/N ratio can be guaranteed. An optical disc includes an information recording layer having a concentric or spiral track, and has a format for describing a track address, which is pre-recorded on the track or is to be added to data that is to be recorded on the information recording layer. The format includes layer information regarding the information recording layer and address information regarding the track address. | 05-26-2011 |
20110122750 | OPTICAL DISC, OPTICAL DISC DRIVE, OPTICAL DISC RECORDING/REPRODUCING METHOD, AND INTEGRATED CIRCUIT - A big pattern for a run-in area which allows data reproduction to be performed stably even when the recording density of an optical disc is increased is provided. An optical disc according to the present invention includes tracks, each of which divided into a plurality of recording blocks. Each of the plurality of blocks includes a run-in area and a data area. In the run-in area, a prescribed run-in bit pattern is recordable; and in the data area, bit patterns having a plurality of bit lengths obtained by modulating data as a recording target in accordance with a prescribed modulation rule are recordable. In this optical disc, at least one of spatial frequencies corresponding to the bit patterns having the plurality of bit lengths is higher than a cutoff frequency. The run-in bit pattern recordable in the run-in area includes the bit patterns having the plurality of bit lengths, from which the bit pattern corresponding to the frequency higher than the OTF cutoff frequency has been excluded. | 05-26-2011 |
20110149704 | SIGNAL EVALUATION METHOD AND SIGNAL EVALUATION APPARATUS - A signal evaluation method according to the present invention is a method for evaluating a read signal, retrieved from an information recording medium, based on a binarized signal generated from the read signal by a PRML method. The method includes the steps of: detecting the patterns of multiple paths associated with the binarized signal and merging into the same state; getting the ideal value of a correct pattern associated with the binarized signal and that of an erroneous pattern that is similar to, but different from, the correct pattern; calculating the difference between a distance from the ideal value of the correct pattern to the read signal and a distance from that of the erroneous pattern to the read signal; calculating, based on the difference, an expected error rate for each predetermined group of patterns by the PRML method; and calculating a standard deviation that is associated with a total error rate, which is obtained by adding together the error rates of the predetermined groups of patterns, and that is used for evaluating the read signal. | 06-23-2011 |
20110292780 | INFORMATION RECORDING MEDIUM EVALUATION METHOD, INFORMATION RECORDING MEDIUM, METHOD FOR MANUFACTURING INFORMATION RECORDING MEDIUM, SIGNAL PROCESSING METHOD AND ACCESS CONTROL APPARATUS - A method for rating an information recording medium according to the present invention includes the steps of: receiving a digital read signal, which has been generated based on an analog read signal representing information that has been read from the information recording medium, and shaping the waveform of the digital read signal; subjecting the shaped digital read signal to maximum likelihood decoding, thereby generating a binarized signal showing a result of the maximum likelihood decoding; and calculating the quality of the digital read signal based on the shaped digital read signal and the binarized signal. If the quality of the read signal is calculated by a PRML method in which a number of zero-cross portions are included in a merging path of a minimum difference metric, the quality is calculated by using only a state transition pattern in which only one zero-cross portion is included in a merging path of a non-minimum difference metric. | 12-01-2011 |
20120092974 | INFORMATION REPRODUCTION METHOD, INFORMATION RECORDING METHOD, AND INFORMATION RECORDING MEDIUM - According to the present invention, a first error pattern caused by a shift of a bit relating to a recording mark or a space of a shortest length and a second error pattern caused by an edge shift of the recording mark are used. For each of a plurality of error patterns, a pattern shift obtained by normalizing a difference between a square of a Euclidean distance between the error pattern and a reproduction signal and a square of a Euclidean distance between a correct pattern and the reproduction signal, using a square of a Euclidean distance between the correct pattern and the error pattern is detected. Length and phase errors are calculated by a sum of, or a difference between, a first pattern shift amount obtained by normalization performed using the first error pattern and a second pattern shift amount obtained by normalization performed using the second error pattern. | 04-19-2012 |
20120201112 | REPRODUCTION SIGNAL EVALUATION METHOD, REPRODUCTION SIGNAL EVALUATION UNIT, AND OPTICAL DISK DEVICE ADOPTING THE SAME - A reproduction signal evaluation method evaluates the quality of a reproduction signal reproduced from an information recording medium based on a binary signal generated from the reproduction signal using a PRML signal processing system. A pattern extraction step extracts, from the binary signal, a specific state transition pattern which has the possibility of causing a bit error; a step computes a differential metric based on the binary signal; an extraction step extracts the differential metric which is not greater than a predetermined signal processing threshold; a step determines a mean value of the differential metrics which are not greater than the signal processing threshold and extracted in the extraction step; a standard deviation computing step determines a standard deviation which corresponds to an error rate predicted from the mean value; and an evaluation step evaluates a quality of the reproduction signal using the standard deviation. | 08-09-2012 |
20130308434 | OPTICAL READ/WRITE APPARATUS - This optical read/write apparatus has first and second optical heads | 11-21-2013 |
20140003211 | OPTICAL READ/WRITE APPARATUS | 01-02-2014 |
20140341006 | INFORMATION REPRODUCING APPPARATUS AND INFORMATION REPRODUCING METHOD - An information reproducing apparatus includes a photodetector ( | 11-20-2014 |