Abstract: According to one embodiment, a signal processing device includes a high spatial frequency range component evaluation unit configured to evaluate a high spatial frequency range component of each of basic colors for each of divided regions for an image picked up by an image pickup device, the divided regions being obtained by dividing an imaging surface of the image pickup device into a plurality of regions, a subject distance estimation unit configured to estimate a subject distance for each of the divided regions on the basis of the high spatial frequency range component, a filter coefficient generating unit configured to generate a filter coefficient for each of the divided regions on the basis of the subject distance, and a filter operation unit configured to perform a filter operation on the high spatial frequency range component by use of the filter coefficient.

Abstract: According to one embodiment, a signal processing device includes a high spatial frequency range component evaluation unit configured to evaluate a high spatial frequency range component of each of basic colors for each of divided regions for an image picked up by an image pickup device, the divided regions being obtained by dividing an imaging surface of the image pickup device into a plurality of regions, a subject distance estimation unit configured to estimate a subject distance for each of the divided regions on the basis of the high spatial frequency range component, a filter coefficient generating unit configured to generate a filter coefficient for each of the divided regions on the basis of the subject distance, and a filter operation unit configured to perform a filter operation on the high spatial frequency range component by use of the filter coefficient.

Abstract: According to one embodiment, a first encoder encodes main information, a second encoder encodes sub-information, a first modulator modulates a carrier based on an output of the first encoder, a duplicating module duplicates an output of the second encoder to generate encoded sub-information units, and a second modulator amplitude-modulates an output of the first modulator based on the encoded sub-information units. The second modulator amplitude-modulates with ?/(?×(2N)1/2) being 0.4 or less, wherein a noise power of a transmission path or a storage medium is ?2, a number of the encoded sub-information units is N, signal levels after amplitude modulation, which correspond to bit 1 and bit 0 of the encoded sub-information units, are A and B, and a level difference A?B is ?.

Abstract: According to one embodiment, a first encoder encodes main information, a second encoder encodes sub-information, a first modulator modulates a carrier based on an output of the first encoder, a duplicating module duplicates an output of the second encoder to generate encoded sub-information units, and a second modulator amplitude-modulates an output of the first modulator based on the encoded sub-information units. The second modulator amplitude-modulates with ?/(?×(2N)1/2) being 0.4 or less, wherein a noise power of a transmission path or a storage medium is ?2, a number of the encoded sub-information units is N, signal levels after amplitude modulation, which correspond to bit 1 and bit 0 of the encoded sub-information units, are A and B, and a level difference A?B is ?.

Abstract: According to one embodiment, a data reproducing device according to the invention includes a frequency difference detector, a phase comparator, a loop filter, an integrator, a first conversion part for converting a value of the integrator into a first conversion value, a second conversion part for converting the value of the integrator into a second conversion value, a first conversion table, a second conversion table, a first D/A converter (DAC), a second D/A converter (DAC), a voltage controlled oscillator (VCO), and a prediction table. The value of the integrator and the first conversion value are associated with each other and stored in the first conversion table in consideration of the characteristics of the VCO. Meanwhile, the value of the integrator and the second conversion value are associated with each other and stored in the second conversion table in consideration of the characteristics of the VCO.

Abstract: An optical disc reproducing device is provided which is capable of setting an optimum PR class for the comprehensive frequency characteristic of an optical disc including the recording characteristic and reproducing characteristic. An optical disc reproducing device according to the present invention relates to an optical disc reproducing device which performs reproduction from an optical disc using the PRML method. The optical disc reproducing device comprises a Viterbi decoding unit which generates binary data using maximum likelihood decoding processing based upon multi-value reproduced data obtained by sampling a reproduced signal from the optical disc. The Viterbi decoding unit generates the binary data based upon an optimum PR class determined based upon the multi-value reproduced data and the binary data in a predetermined determination period.

Abstract: A disk device includes a reading section which reads reflected light and outputs a read signal according to the read reflected light, a processing section which calculates an adjustment value from the read signal, performs predetermined processing on the read signal based on the adjustment value, and outputs a process signal, a detecting section which detects a reading defect in the reading section based on the read signal, a determining section which determines signal quality of the process signal output from the processing section, a storage section which stores the adjustment value calculated by the processing section, in a memory area, based on a result output from the determining section, and a controller which, when the detecting section detects the reading defect, performs control so that the adjustment value is read out of the storage section and is supplied to the processing section.

Abstract: According to one embodiment, An optical disc apparatus includes a decoder including branchmetric calculation section configured to calculate a branchmetric for the signal generated by executing a predetermined process on read signal obtained from a optical disc, pathmetric selection section configured to select a maximum likelihood pathmetric according to the branchmetric calculated by the branchmetric calculation section and a path memory having memory stages, each consisting of memory elements, configured to obtain a decoded signal by shifting the information to be stored in the memory to a memory of a subsequent stage according to the outcome of selection of the pathmetric selection section, and defect detection section configured to detect a defect of the optical disc according to the information possessed by the memory of the last stage or of a specific stage of the path memory.

Abstract: According to one embodiment, a phase-locked loop circuit comprises a phase difference detection unit which detects a phase error between a reproduced binary data and extracted clock and generates phase error pulse signals each having an amplitude corresponding to the phase error, a phase sifter sensitivity adjusting unit which generates a first adjustment pulse signal produced by adjusting the phase error pulse signal, and a loop filter unit which generates a pulse train signal for feedback control to generate the extracted clock from the first adjustment signal, wherein the phase shifter sensitivity adjusting unit comprises a first pulse doubler unit which generates an expanded pulse signal which doubles a time width of the phase error pulse signal, and a first amplifying unit which amplifies the amplitude of the expanded pulse signal and generates the first adjustment pulse signal.

Abstract: An optical disk drive apparatus is provided has a reading section which reads the reflection of a laser beam from a disk to produce a read signal, a filter section which filters the read signal with the use of three or more different cutoff frequencies upon receiving a control signal from a two or more bits control line, a reproducing section which playbacks the read signal filtered by the filter, and a control section which provides the filter with the control signal along the two or more bits control line so that the filtering action with the three or more different cutoff frequencies of the filter is carried out throughout three or more consecutive periods respectively.

Abstract: A recorded stream generator generates a data block stream in synchronism with the phase of a recording clock, from the input data. The recorded stream generator further generates, for each predetermined data unit constituting the data block stream, a data phase reference pulse indicative of the phase of the data unit. An inserting section inserts a VFO signal into a predetermined amount (32 sectors) of the data block stream, the VFO signal having a length of time corresponding to a difference in phase between an wobble address phase signal and a data phase reference pulse. The inserting section thus provides a data stream DST consisting of the VFO signals and the data block streams. An LD uses light beams to record the data stream on an optical disk.

Abstract: An optical disc recording and reproducing apparatus which reproduces data by the PRML scheme includes a recording waveform generating unit for generating a recording waveform, a reproducing unit for reproducing the recorded data to generate reproduction data, a defect determining unit for determining whether or not a defect is included in a reproduction signal, a reproduction state determining unit for determining whether or not the reproduction state is stable, and a recording learning unit for performing recording learning for determining a parameter of a recording waveform on the basis of the reproduction data. The recording learning unit performs the recording learning on the basis of the reproduction data acquired when the reproduction state is stable.

Abstract: An optical-disc recording/playback apparatus performs recording/playback to/from an optical-disc having a data area serving as a recordable area and a header area in which address information of the data area is pre-recorded by embossing. The apparatus includes an area determining unit for determining the data area and the header area based on a playback signal from the optical-disc, an AD converter for converting the playback signal from an analog signal to a digital signal, and a playback decoding unit for reading information of the data area and the header area from the digital signal output from the AD converter. During playback of the data area, the playback decoding unit performs first playback decoding processing. During playback of the header area, the playback decoding unit performs second playback decoding processing without making changes to a basic configuration of the playback decoding unit.

Abstract: An optical disk apparatus for recording data on and reproducing data from a recordable optical disk includes a storage unit and a control unit. The storage unit is configured to store specific useful information necessary for at least one of recording data on and reproducing data from the optical disk. The control unit is configured to record the useful information stored in the storage unit in a test write area of the optical disk, and reproduce and use the recorded useful information when the optical disk is placed in the optical disk apparatus.

Abstract: A disk apparatus has an equalizing unit which performs PR equalization for the read signal from the disk based on a plurality of tap coefficients, a decoding unit which performs a decoding process for the equalized read signal, a calculating unit which obtains an ideal signal of the decoded read signal, and compares the ideal signal with the decoded read signal, thereby calculating an error signal E, and a control unit which groups the tap coefficients into at least a first and second coefficient groups which are groups of tap coefficients at symmetrical locations each, and determines tap coefficients of the first coefficient group in a range of a first limit value K1 according to the calculated error signal, determines tap coefficients of the second coefficient group in a range of a second limit value and supplies the determined tap coefficients to the equalizing unit.

Abstract: An apparatus for reproducing digital data recorded on a recording medium by a Partial Response Maximum Likelihood method, the digital data being recorded in a code pattern in which the same code continuously appears at least two times, includes an analog-to-digital converting unit that samples an analog reproduction signal recorded on the recording medium and converts the sampled analog reproduction signal into a digital signal; a sampling rate switching unit that adaptively switches the sampling rate in the analog-to-digital converting unit from a higher rate to a lower rate; and a data demodulating unit that reproduces and demodulates the digital signal subjected to the analog-to-digital conversion in the analog-to-digital converting unit by the Partial Response Maximum Likelihood method in accordance with the switching between the higher rate and the lower rate.

Abstract: A demodulator includes a wobble signal processor configured to convert a waveform of a wobble signal, and to generate a clock and a reference value based on a converted wobble signal. A sampling circuit is configured to sample the converted wobble signal by using the clock, and to generate a sampled signal. A viterbi decoder is configured to decode an auxiliary recording signal superposed on an optical disk by using the reference value and the sampled signal.

Abstract: An information reproducing apparatus reads information recorded on a recording medium and outputs a reproduced signal, and performs, for the reproduced signal, analog offset correction of correcting offset before AD conversion, digital offset correction of correcting offset after AD conversion, and offset detection of detecting an offset control amount from a corrected reproduced signal after the digital offset correction. Further, the information reproducing apparatus divides offset data indicating the detected offset control amount into first offset data of a least significant bit unit for the AD conversion of the reproduced signal or greater and second offset data less than the least significant bit unit so as to perform the digital offset correction using the first offset data and perform the analog offset correction using the second offset data.

Abstract: An information recording-reproducing apparatus includes a recording-reproducing unit configured to record information given by encoding the data in predetermined data blocks with an error correction code, the data blocks being generated by multiplexing information indicating the positions of the defect management areas, on the information storage medium and to decode the encoded information with the error correction code and reproduce the decoded information and a complementary unit configured to complement the information indicating the positions of the defect management areas on the basis of the data in data units smaller than the data blocks, when an error can be corrected in the data units or when no error is detected even if the error correction in the data blocks cannot be performed for the information that is encoded and recorded.

Abstract: A rewritable information storage medium includes a user area for storing user data, a spare area serving as a replacement area for storing user data that was unable to be stored in the defective area, and a plurality of defect management areas. The same defect management information is stored in the plurality of defect management areas. Even when all errors of the plurality of defect management areas are uncorrectable on a predetermined data unit basis, in the case where the error of the defect management information stored in any one of the defect management areas is correctable on a data unit basis smaller than the predetermined data unit, the defect management information is compensated for on the basis of the smaller data unit.