Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Kohei Nakata

Harumitsu Miyashita

Yasumori Hino

Junichi Minamino

Naohiro Kimura

Yuji Takagi

Tsuyoshi Nakasendo

Hiroshi Ueda

Takashi Ishida

Mamoru Shoji

Makoto Usui

Toyoji Gushima

Yoshikazu Yamamoto

Yoshihisa Takahashi

Yasushi Kobayashi

Kazuya Ohshima

Hiromichi Ishibashi

Takeshi Nakajima

Isao Kobayashi

Hironori Deguchi

Youichi Ogura

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.

Recording state evaluation method, recording compensation method, and information recording/playback device

The present disclosure provides an optical disk device capable of reproducing data recorded on a high linear density optical disk stably. The optical disk device according to the disclosure is characterized by being equipped with a recording expected waveform generation circuit which generates, at the time of recording, an expected waveform that is expected to be obtained at the time of decoding; and a recording pulse generation circuit which generates a recording pulse for driving a laser with power and a time width suitable for an amplitude value of the recording expected waveform for each sampling point of the recording expected waveform.

Optical disk device

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.

Data coding method and data coding device

In an optical disc apparatus that records and reproduces data onto and from an optical disc in units of predetermined block, an information divider divides the data so as to reduce an amount of the data included in each of blocks when a recording state of the optical disc does not satisfy a predetermined criterion, and reproduces recording data in units of the block by adding sub-information including a value indicating the amount of the data included in each of the blocks. An error-correction encoder circuit encodes the recording data in a first error-correction code format, and a recorder converts encoded recording data into a recording signal, and records the recording signal onto the optical disc. A quality evaluator circuit produces an evaluation value indicating a recording quality based on a result of reproducing the recording signal recorded on the optical disc.

Optical disc apparatus and optical disc in which user data is recorded in a first space in units of a first length and management information is recorded in a second space in units of a second length different from the first length

An optical disc device includes a first error correction coding circuit that codes the recording data according to a first error correction coding format, a second error correction coding circuit that codes the recording data according to a second error correction coding format, and a recorder that converts the recording data into a recording signal and records it on an optical disc. The second error correction coding format is different in an arrangement of the recording data from the first error correction coding format. The second error correction coding format is configured to generate a second parity code with a higher degree of redundancy. The recorder records the recording data coded by the first error correction coding circuit and only the second parity code in the recording data coded by the second error correction coding circuit.

Optical disc device

Optical disc apparatus for recording and reproducing data onto and from an optical disc based on an evaluation value

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.

Information recording device and data erasing method

An optical disk includes a disk management information area in which predetermined information is recorded in advance, and a recording system area in which information for identifying a recording system of the optical disk recorded in a predetermined position within a non-data area included in a recordable area is recorded. A method for accessing the optical disk is decided based on disk management information and the information for identifying a recording system.

Optical disk, optical disk recording device, and optical disk playback device

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.

Optical disk, optical disk recording method, optical disk recording device, and integrated circuit

The optical disk device performs recording/reproducing of data by a predetermined recording block on the track of an optical disk. The device has a recording unit, an optical-head, and a failure detection unit. The recording unit generates a recording signal by modulating the data. The optical-head records data on the track by optical beam emission to the track according to the recording signal, and detects light reflected off the track and then generates a detection signal based on the reflected light. The failure detection unit detects an abnormal condition based on the detection signal changed from a normal condition. If the sum of duration of an abnormal condition in the recording block is equal to or greater than a first time-length, the failure detection unit determines that the recording block has a flaw.

Optical disk device and large-scale optical disk device

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.

Optical disc apparatus and optical disc reproduction method

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.

Optical disc apparatus controlling irradiation position based on cross-correlation value between reproduction signal and decoded signal

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.

Optical disk recording method, optical disk apparatus, and optical disk medium

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.

Optical device and optical disc recording or reproducing method for optical disc including BCA having zone format identifier

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.

Growing community of inventors

Nara, Japan

Kohei Nakata