Abstract: In an optical disc apparatus for reproducing information recorded on a track of an optical disc, an optical head irradiates a light beam onto the track, detects a reflected light reflected by the track, and generates a reproduction signal based on the reflected light. A decoder circuit decodes the reproduction signal, and generates a decoded signal including information recorded on the track. A correlation detector circuit calculates a cross-correlation value between the reproduction signal and the decoded signal. A servo circuit detects a deviation amount of an irradiation position of the light beam onto the track, from the reproduction signal, and controls the irradiation position of the optical head based on the cross-correlation value and the deviation amount.

Abstract: A track of an optical disk is formed by wobbling and divided into zones, a clock ratio of a recording clock to a wobble clock is preset for each zone, a wobble signal is detected from the optical disk, the wobble clock is generated from the wobble signal, a present position is identified by reproducing ADIP indicating a position of the track from the wobble signal and the wobble clock, the recording clock is generated with respect to the wobble clock, a data address present position is identified from the present position, a start end position of the ADIP in a recording target zone, a start end position of the data address in the recording target zone, and the clock ratio, a recording start position is identified based on the data address present position; and the data is recorded from the recording start position of the recording target zone.

Abstract: Upon receiving an erase command for data recorded in a write-once optical disc, an information recording device corrupts data in an information area (synchronization signal in Run-in, frame synchronization signal, address information and the like), in an erased area on the optical disc, in which information necessary for synchronization of reproducing data by overwriting the data in the information area with an erasing pattern. The erased area is specified by an erase starting position and a size of data to be erased. In this way, the information recording device erases the data in the erased area.

Abstract: According to an optical disc, a track, where data is recorded in predetermined block units, is formed by wobbling at a spatial period in accordance with a radial position, and the track is divided into zones in a radial direction. Data is recorded in each of the zones at a predetermined line density based on a ratio n/m of the number of bits of a bit pattern of recording data to one wavelength of wobbling. The optical disc includes a first area having one of the zones, a second area having one of the zones different from the one of the zones in the first area, and a line density of data different from a line density of data in the first area, and a BCA where a zone format identifier specifying a zone table defining a boundary position of each of the zones and the ratio n/m is recorded.

Abstract: A phase error detector includes an N counter configured to frequency-divide a first clock by N, and output a signal at predetermined timing, an M counter configured to frequency-divide a second clock by M, and output a signal at predetermined timing, a comparator configured to perform phase comparison between a phase when a value of the N counter is 0 and a phase when a value of the M counter is 0, and perform phase comparison between a phase when a value of the N counter is equal to a value obtained by dividing N into a substantially predetermined value and a phase when a value of the M counter is equal to a value obtained by dividing M into a substantially predetermined value and a synthetic circuit configured to generate a phase error, based on comparison results of the comparator.

Abstract: There are provided an optical disk and an optical disk recording method which are capable of stable data reading in a case where a recording linear density is increased. According to an optical disk of the present disclosure, a run-in pattern recorded in a groove track and a run-in pattern recorded in a land track are made different patterns so that no great change is caused in the amplitude of an acquired signal due to interference between adjacent recording patterns, and thus, data may be stably read.

Abstract: An information recording and reproducing apparatus including: a reproducing unit which generates a digital signal from an analog signal; a recording compensation unit which generates an expectation signal from the digital signal, detects a signal difference between the digital signal and the expectation signal, and adjusts a recording condition for recording the information; and a recording unit configured to record the information based on the recording condition. First recording compensation is performed for adjusting the recording condition using first recording where lengths of a preceding space and a succeeding space of a first recording mark and lengths of a preceding space and a succeeding space of a second recording mark are not in intersymbol interference; and second recording compensation is performed for adjusting the recording condition for the first recording mark using second recording data for changing a length of the second recording mark.

Abstract: 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).

Abstract: An optical disc medium includes a land and a groove at which information can be recorded. A predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium. The address information unit of the land includes three or more address recording areas capable of recording address information. The address information is recorded on one area selected from among the three or more address recording areas. The address information unit of the land has address information which is recorded, in the same modulation, on the side of the inner adjacent groove and on the side of the outer adjacent groove. The one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction.

Abstract: A phase error detector includes a sine wave generation circuit that generates a sine wave signal, based on a first input signal of a first period, a cosine wave generation circuit that generates a cosine wave signal, based on the first input signal, a first calculator that calculates a phase difference between the sine wave signal and a second input signal of a second period, a second calculator that calculates a phase difference between the cosine wave signal and the second input signal, and a first selection unit that outputs the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is within a predetermined range, and outputs a predetermined value having a same sign as a sign of the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is out of the predetermined range.

Abstract: A track of an optical disk is formed by wobbling and divided into zones, a clock ratio of a recording clock to a wobble clock is preset for each zone, a wobble signal is detected from the optical disk, the wobble clock is generated from the wobble signal, a present position is identified by reproducing ADIP indicating a position of the track from the wobble signal and the wobble clock, the recording clock is generated with respect to the wobble clock, a data address present position is identified from the present position, a start end position of the ADIP in a recording target zone, a start end position of the data address in the recording target zone, and the clock ratio, a recording start position is identified based on the data address present position; and the data is recorded from the recording start position of the recording target zone.

Abstract: An optical disc apparatus includes a synchronizer that generates a reproduction clock signal synchronized with a reproduction signal of information recorded in an optical disc medium, and generates a digital reproduction signal synchronized with the reproduction clock signal, an adaptive equalizer that generates a post-adaptive-equalization digital reproduction signal, and a maximum likelihood decoder that performs maximum likelihood decoding of the post-adaptive-equalization digital reproduction signal to generate a binary signal. The apparatus also includes an expected waveform generator that generates an expected waveform from the binary signal, a phase-advance waveform generator that generates a phase-advance waveform, a phase-delay waveform generator that generates a phase-delay waveform, and a metric detector that detects a phase error. In the optical disc apparatus, the synchronizer controls the phase of the digital reproduction signal using the phase error.

Abstract: An optical disc medium includes a land and a groove at which information can be recorded. A predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium. The address information unit of the land includes three or more address recording areas capable of recording address information. The address information is recorded on one area selected from among the three or more address recording areas. The address information unit of the land has address information which is recorded, in the same modulation, on the side of the inner adjacent groove and on the side of the outer adjacent groove. The one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction.

Abstract: An information recording and reproducing apparatus including: a reproducing unit which generates a digital signal from an analog signal; a recording compensation unit which generates an expectation signal from the digital signal, detects a signal difference between the digital signal and the expectation signal, and adjusts a recording condition for recording the information; and a recording unit configured to record the information based on the recording condition. First recording compensation is performed for adjusting the recording condition using first recording where lengths of a preceding space and a succeeding space of a first recording mark and lengths of a preceding space and a succeeding space of a second recording mark are not in intersymbol interference; and second recording compensation is performed for adjusting the recording condition for the first recording mark using second recording data for changing a length of the second recording mark.

Abstract: According to an optical disc, a track, where data is recorded in predetermined block units, is formed by wobbling at a spatial period in accordance with a radial position, and the track is divided into zones in a radial direction. Data is recorded in each of the zones at a predetermined line density based on a ratio n/m of the number of bits of a bit pattern of recording data to one wavelength of wobbling. The optical disc includes a first area having one of the zones, a second area having one of the zones different from the one of the zones in the first area, and a line density of data different from a line density of data in the first area, and a BCA where a zone format identifier specifying a zone table defining a boundary position of each of the zones and the ratio n/m is recorded.

Abstract: An optical disc medium includes a land and a groove at which information can be recorded. A predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium. The address information unit of the land includes three or more address recording areas capable of recording address information. The address information is recorded on one area selected from among the three or more address recording areas. The address information unit of the land has address information which is recorded, in the same modulation, on the side of the inner adjacent groove and on the side of the outer adjacent groove. The one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction.

Abstract: A phase error detector includes a sine wave generation circuit that generates a sine wave signal, based on a first input signal of a first period, a cosine wave generation circuit that generates a cosine wave signal, based on the first input signal, a first calculator that calculates a phase difference between the sine wave signal and a second input signal of a second period, a second calculator that calculates a phase difference between the cosine wave signal and the second input signal, and a first selection unit that outputs the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is within a predetermined range, and outputs a predetermined value having a same sign as a sign of the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is out of the predetermined range.

Abstract: A phase error detector includes an N counter configured to frequency-divide a first clock by N, and output a signal at predetermined timing, an M counter configured to frequency-divide a second clock by M, and output a signal at predetermined timing, a comparator configured to perform phase comparison between a phase when a value of the N counter is 0 and a phase when a value of the M counter is 0, and perform phase comparison between a phase when a value of the N counter is equal to a value obtained by dividing N into a substantially predetermined value and a phase when a value of the M counter is equal to a value obtained by dividing M into a substantially predetermined value and a synthetic circuit configured to generate a phase error, based on comparison results of the comparator.

Abstract: An optical disc medium includes a land and a groove at which information can be recorded. A predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium. The address information unit of the land includes three or more address recording areas capable of recording address information. The address information is recorded on one area selected from among the three or more address recording areas. The address information unit of the land has address information which is recorded, in the same modulation, on the side of the inner adjacent groove and on the side of the outer adjacent groove. The one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction.

Abstract: An optical disc medium includes a land and a groove at which information can be recorded. A predetermined number of address information units which record address information of the land or groove are provided in a circumferential direction of the optical disc medium. The address information unit of the land includes three or more address recording areas capable of recording address information. The address information is recorded on one area selected from among the three or more address recording areas. The address information unit of the land has address information which is recorded, in the same modulation, on the side of the inner adjacent groove and on the side of the outer adjacent groove. The one area to be selected from among the three or more address recording areas for recording the address information of the land is different among three address information units adjacently arranged in a radial direction.