Patent application number | Description | Published |
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 |
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 |
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 |
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 |
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 |
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 |
20110164487 | INFORMATION RECORDING/REPRODUCING DEVICE AND INFORMATION RECORDING/ REPRODUCING METHOD - A writing condition adjusting apparatus according to the present invention adjusts a writing condition using first and second recording patterns. The first recording pattern is used to adjust a writing condition for recording marks and spaces, of which the lengths are equal to or longer than a predetermined recording length, while the second recording pattern is used to adjust a writing condition for recording marks and spaces, of which the lengths are shorter than the predetermined recording length by one recording unit length. If it has been decided that the writing condition that has once been determined by making the write adjustment on such marks that are shorter by one recording unit length needs to be adjusted again, a signal index value that has been defined based on the first recording pattern is set to be a target value. The writing condition for recording marks, which are shorter by one recording unit length, is adjusted again so that a signal index value associated with those marks that are shorter by one recording unit length becomes as close to the target value as possible. | 07-07-2011 |
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 |
20140053044 | DECODING DEVICE AND DECODING METHOD - A decoding device ( | 02-20-2014 |
20140056116 | DECODING METHOD AND DECODING DEVICE - A discrete Fourier transform circuit ( | 02-27-2014 |
20140126657 | DECODING SYSTEM AND DECODING METHOD - A decoding system includes: a modulator which modulates user data by using a modulation rule which converts the user data into a modulation pattern; a regenerator which generates a regenerative signal from a signal obtained by transmitting the user data after modulation through a transmission path; a transmission path decoder which generates signals as generation signals corresponding to the modulation pattern, and calculates k (k is a positive integer) distances between the regenerative signal and the k generation signals in an interval having a length fixedly or dynamically determined; and a demodulator which calculates reliability information for each bit of the user data, and estimates each bit of the user data based on the calculated reliability information. The demodulator calculates likelihood that each bit of the user data is 1 and each bit of the user data is 0 by Formula (A), and calculates the reliability information by Formula (B). | 05-08-2014 |
20140160908 | OPTICAL DISK RECORDING MEDIUM, OPTICAL DISK DEVICE, AND RECORDING METHOD - An integral multiple of a period of wobbling in a portion other than address information of groove tracks ( | 06-12-2014 |
20140334282 | DECODING DEVICE AND DECODING METHOD - A decoding device includes: an interference canceling circuit ( | 11-13-2014 |
20140341006 | INFORMATION REPRODUCING APPPARATUS AND INFORMATION REPRODUCING METHOD - An information reproducing apparatus includes a photodetector ( | 11-20-2014 |