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: A BCA signal reproduction method for reading a BCA signal from a disc includes detecting a peak value of the BCA signal (peak detection value); detecting a bottom value of the BCA signal using a wide tracking bandwidth (first bottom detection value); detecting a bottom value of the BCA signal using a narrow tracking bandwidth (second bottom detection value); detecting a signal indicating whether the current portion is a no-signal portion where the BCA signal is not recorded or a signal portion where the BCA signal is recorded, on the basis of the peak detection value, the first bottom detection value, and the second bottom detection value; determining a slice level for binarizing the BCA signal on the basis of the detected signal and at least the peak detection value, the first bottom detection value, and the second bottom detection value; and binarizing the BCA signal.

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 integrated circuit includes an AD converter and a self-test circuit configured to test the AD converter. The self-test circuit includes a clock generator which generates a clock for allowing the AD converter to AD-convert an external sine wave signal externally input, a sine wave generator which generates an internal sine wave signal in digital form, a subtractor which determines a differential signal between the AD-converted external sine wave signal and the internal sine wave signal, a PLL device which allows a phase-locked loop receiving the differential signal as an input to control a phase of the internal sine wave signal such that the internal sine wave signal is in phase with the external sine wave signal, and a root mean square calculator which calculates a root mean square of the differential signal to generate a diagnostic signal corresponding to the AD converter.

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: There is provided a recording apparatus which modulates record data by a predetermined modulation method and records record patterns corresponding to the record data on an optical disk, including a random data generator which generates random data as the record data, a data exchange processor which performs exchange processing on the random data so as to equalize a frequency of appearance of each of the record patterns relative to the entire record patterns on the optical disk corresponding to the respective random data, a modulator which modulates the random data subjected to the exchange processing by the predetermined modulation method, an optical head which records record patterns corresponding to the modulated random data on the optical disk, and reproduces the modulated random data from the recorded record patterns, and a record learning unit which calculates correction amounts for recorded positions of the respective record patterns based on the reproduced random data.

Abstract: According to one embodiment, in an information recording and reproducing apparatus, a record data correction unit generates correction data for correcting a record waveform generated according to record data. Further, the information recording and reproducing apparatus generates discrimination data for use in pattern discrimination performed to generate the correction data, using decoded data outputted from a PRML signal processing unit and the record data, and outputs the generated discrimination data to the record data correction unit.

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: A data processing apparatus according an aspect of this invention has a syndrome calculation unit configured to calculate the syndrome of a demodulated data sequence. The syndrome calculation unit includes a calculation unit configured to make the calculation required to realize syndrome calculation of demodulated data for each frame obtained by removing the sync code from one sync frame.

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.

Abstract: An optical disk device which decodes data recorded on an optical disk, comprises a first measuring unit which measure a cycle of a plurality of first synchronous signal regions VFO contained in a reproduction signal from an optical pickup, a cycle comparing unit which compares the measurement result of the first measuring unit with a first predetermined cycle, a second measuring unit which measures a cycle of a plurality of second synchronous signal regions SYNC which are contained in the reproduction signal from the optical pickup and have the cycle shorter than that of the plurality of first synchronous signal regions VFO, a cycle comparing unit which compares the measurement result of the second measuring unit with a second predetermined cycle, and an oscillator which generates a clock signal CKS for sampling the reproduction signal on the basis of the comparison results of the first and second cycle comparing units.

Abstract: An information reproducing apparatus according to the present invention is capable of reproducing an information storage medium storing BCA information recorded in a first area and RF information recorded in a second area on an outer side of the first area. The information reproducing apparatus includes an optical pickup to radiate laser light onto the first and second areas and detect reflected light thereof; a reproducing system unit to reproduce an RF signal and a BCA signal on the basis of the reflected light; and a focus control unit to control focusing by setting a focus position to a signal layer of the optical disc when the RF signal is to be reproduced and control defocusing by displacing the focus position from the signal layer when the BCA signal is to be reproduced, thereby equivalently suppressing a high-frequency component of the BCA signal.

Abstract: According to one embodiment, there is provided an optical disk apparatus including a detecting unit which reads a reflective light from an optical disk and outputs a read signal, a decoder which decodes the read signal from the detecting unit, an extracting unit which extracts from the read signal the first and second specification information of the same content recorded in first and second areas on the optical disk, a processor which compares the first specification information with the second specification information and processes the specification information based on the comparison result, and a controller which controls the detecting unit or the decoder, based on the specification information processed by the processor.

Abstract: According to one embodiment, a frequency detector detects a frequency error between a frequency of a reproduction signal supplied from an analog to digital converter and a frequency of a clock for conversion. A loop filter controls an oscillation frequency of a voltage control oscillator based on the frequency error and a phase error detected by a phase comparator. An adaptive equalizer equalizes a waveform of the reproduction signal supplied from the analog to digital converter to obtain a response of a predetermined PR class. A Viterbi decoder decodes the waveform equalized signal into binary data by maximum likelihood sequence estimation. A clock supply control circuit stops supply of a clock to at least the phase comparator, the adaptive equalizer and the Viterbi decoder in a case where the frequency error is larger than a designated error.

Abstract: One embodiment of the invention, a BCA signal is reproduced properly from a BCA while inhibiting influences properly from a groove contained in a reproduction signal, when a signal is reproduced from an additional writing type optical disk provided with the groove by cutting the DC component of an envelop detected from the BCA signal by an AC coupling section and then comparing with a predetermined threshold with a comparator.

Abstract: A plurality of defect management areas (DMA set groups 1 to N) are used in a ring form in such a manner that defect management information of the DMA replaces and is recorded in the next spare area while the DMA is supposed to be still sufficiently rewritable (e.g., currently used DMA sets #1-1 to #4-1 are replaced with the next DMA sets #1-2 to #4-2), and a process returns to a first defect management area again at a time when transition of the defect management information ends up to a last spare area (DMA sets #1-N to #4-N).