Abstract: A recording mark is formed on a recording medium by a predetermined recording signal, a playback signal of the recording mark formed on the recording medium is obtained, and an expected value signal of the playback signal based on the recording signal is generated. Based on an amplitude error between the playback signal and the expected value signal, and for each predetermined unit of the recording signal, a deviation amount of a mark shape of the recording mark from which the playback signal is obtained with respect to a mark shape of an ideal recording mark is calculated, and a mark shape of the recording mark formed on the recording medium is estimated. Based on the deviation amount of the mark shape of the recording mark, a correction amount is calculated for each predetermined unit of the recording signal, and a level of the recording signal is adjusted.

Abstract: A recording mark is formed on a recording medium by a predetermined recording signal, a playback signal of the recording mark formed on the recording medium is obtained, and an expected value signal of the playback signal based on the recording signal is generated. Based on an amplitude error between the playback signal and the expected value signal, and for each predetermined unit of the recording signal, a deviation amount of a mark shape of the recording mark from which the playback signal is obtained with respect to a mark shape of an ideal recording mark is calculated, and a mark shape of the recording mark formed on the recording medium is estimated. Based on the deviation amount of the mark shape of the recording mark, a correction amount is calculated for each predetermined unit of the recording signal, and a level of the recording signal is adjusted.

Abstract: A data coding device includes an error correction coder that converts user data into ECC data by error correction coding, a modulation coder that converts the ECC data into a series of modulated code data, a detector that detects a local concentration of modulation marks/modulation spaces that are shorter than or equal to a prescribed minimum run-length plus N from the series of modulated code data, a conversion determiner that judges whether to convert the series of modulated code data into another series of modulated code data, according to a concentration, detected by the detector, of the modulation marks/modulation spaces, and a modulation data converter that converts the series of modulated code data into the another series of modulated code data.

Abstract: A data coding device includes an error correction coder that converts user data into ECC data by error correction coding, a modulation coder that converts the ECC data into a series of modulated code data, a detector that detects a local concentration of modulation marks/modulation spaces that are shorter than or equal to a prescribed minimum run-length plus N from the series of modulated code data, a conversion determiner that judges whether to convert the series of modulated code data into another series of modulated code data, according to a concentration, detected by the detector, of the modulation marks/modulation spaces, and a modulation data converter that converts the series of modulated code data into the another series of modulated code data.

Abstract: An information recording method of the present disclosure is an information recording method for recording information on a write-once information recording medium, including one or more recording layers, each of the recording layers being spiral-shaped on which a land track and a groove track are alternately repeated as recording tracks, each of the recording tracks being divided into blocks, each of the blocks being a minimum unit in which recording is performed. The information recording method includes: recording the information on the information recording medium in a unit of each of the blocks; and controlling recording on the information recording medium. In the control step, switching is performed whether to perform recording in a block to be recorded in which the information is to be recorded next among the blocks based on recording conditions of the recording tracks adjacent on both sides of the block to be recorded.

Abstract: An information recording method of the present disclosure is an information recording method for recording information on a write-once information recording medium, including one or more recording layers, each of the recording layers being spiral-shaped on which a land track and a groove track are alternately repeated as recording tracks, each of the recording tracks being divided into blocks, each of the blocks being a minimum unit in which recording is performed. The information recording method includes: recording the information on the information recording medium in a unit of each of the blocks; and controlling recording on the information recording medium. In the control step, switching is performed whether to perform recording in a block to be recorded in which the information is to be recorded next among the blocks based on recording conditions of the recording tracks adjacent on both sides of the block to be recorded.

Abstract: An inspection method for a recordable optical disc includes focusing laser light on a recording layer and obtaining a data signal dependent on the laser light reflected by the recording layer. The inspection method also includes determining whether the optical disc includes a defect or not by identifying a first period every second period in the obtained data signal obtained, the first period being a period in which a signal level of the data signal is lower than a predetermined value, and each of the second periods corresponding to an ECC block, and outputting a result of the determination.

Abstract: An inspection method for a recordable optical disc includes focusing laser light on a recording layer and obtaining a data signal dependent on the laser light reflected by the recording layer. The inspection method also includes determining whether the optical disc includes a defect or not by identifying a first period every second period in the obtained data signal obtained, the first period being a period in which a signal level of the data signal is lower than a predetermined value, and each of the second periods corresponding to an ECC block, and outputting a result of the determination.

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: 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 information recording method of the present disclosure is an information recording method for recording information on a write-once information recording medium, including one or more recording layers, each of the recording layers being spiral-shaped on which a land track and a groove track are alternately repeated as recording tracks, each of the recording tracks being divided into blocks, each of the blocks being a minimum unit in which recording is performed. The information recording method includes: recording the information on the information recording medium in a unit of each of the blocks; and controlling recording on the information recording medium. In the control step, switching is performed whether to perform recording in a block to be recorded in which the information is to be recorded next among the blocks based on recording conditions of the recording tracks adjacent on both sides of the block to be recorded.

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: An information recording method of the present disclosure is an information recording method for recording information on a write-once information recording medium, including one or more recording layers, each of the recording layers being spiral-shaped on which a land track and a groove track are alternately repeated as recording tracks, each of the recording tracks being divided into blocks, each of the blocks being a minimum unit in which recording is performed. The information recording method includes: recording the information on the information recording medium in a unit of each of the blocks; and controlling recording on the information recording medium. In the control step, switching is performed whether to perform recording in a block to be recorded in which the information is to be recorded next among the blocks based on recording conditions of the recording tracks adjacent on both sides of the block to be recorded.

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: 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 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 control device inputs reliability information on the same data block a plurality of times into a reliability storage memory. A reliability generating device generates a reliability information by performing computation processing based on a stochastic computation by using reliability information generated in the previous cycle that has been saved in the reliability storage memory and reliability information generated in the present cycle, and saves the reliability information generated in the reliability storage memory when the decoding is performed by using reliability information on the data block the same as that in the previous cycle. A column processing computation device computes a column processing output value by using the reliability information generated and saved in the reliability storage memory and a row processing output value.

Abstract: A decoding device includes: an interference canceling circuit (104) which extracts, from states of 2K-number (where K is a natural number) of detected signals that are likely within a range of K bit width where an interference between bits of the digital information occurs due to predetermined frequency characteristics, most likely 2M-number (where M is a natural number) of detected signals respectively corresponding to states of 2M-number of detected signals which exist within a range of M bit width that is included in the range of K bit width; and a Viterbi decoding circuit (105) which generates a decoded signal by calculating differences between the 2M-number of detected signals extracted by the interference canceling circuit (104) and expectation signals respectively corresponding to the 2M-number of detected signals and also by selecting a transition sequence of a state of a detected signal for which the calculated difference is smallest.

Abstract: An optical disc according to the present invention includes a plurality of recording layers; a receiving section for receiving, from outside an optical disc, a switching instruction for switching a target layer to be targeted for recording or reproducing information among the plurality of the recording layers; and a switching section for switching the target layer among the plurality of recording layers, based on the switching instruction received.