Patents by Inventor Kohei Nakata

Kohei Nakata has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11475918
    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.
    Type: Grant
    Filed: September 28, 2021
    Date of Patent: October 18, 2022
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Yasushi Kobayashi, Kohei Nakata, Yasumori Hino
  • Patent number: 11295779
    Abstract: 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.
    Type: Grant
    Filed: November 8, 2019
    Date of Patent: April 5, 2022
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Yasushi Kobayashi
  • Publication number: 20220020394
    Abstract: 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.
    Type: Application
    Filed: November 8, 2019
    Publication date: January 20, 2022
    Inventors: Kohei NAKATA, Yasushi KOBAYASHI
  • Publication number: 20220013144
    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.
    Type: Application
    Filed: September 28, 2021
    Publication date: January 13, 2022
    Inventors: Yasushi KOBAYASHI, Kohei NAKATA, Yasumori HINO
  • Patent number: 10783923
    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.
    Type: Grant
    Filed: March 6, 2019
    Date of Patent: September 22, 2020
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Tsuyoshi Nakasendo, Yasumori Hino, Kohei Nakata
  • Patent number: 10521297
    Abstract: 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.
    Type: Grant
    Filed: November 18, 2016
    Date of Patent: December 31, 2019
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Yuji Takagi
  • Patent number: 10453490
    Abstract: 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.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: October 22, 2019
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Tsuyoshi Nakasendo
  • Publication number: 20190279680
    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.
    Type: Application
    Filed: March 6, 2019
    Publication date: September 12, 2019
    Inventors: Tsuyoshi NAKASENDO, Yasumori HINO, Kohei NAKATA
  • Publication number: 20190189154
    Abstract: 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.
    Type: Application
    Filed: December 18, 2018
    Publication date: June 20, 2019
    Inventors: Kohei NAKATA, Tsuyoshi NAKASENDO
  • Patent number: 10223202
    Abstract: 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.
    Type: Grant
    Filed: January 8, 2018
    Date of Patent: March 5, 2019
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Yuji Takagi
  • Patent number: 10068604
    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.
    Type: Grant
    Filed: March 24, 2017
    Date of Patent: September 4, 2018
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Harumitsu Miyashita, Naohiro Kimura, Kohei Nakata
  • Patent number: 10008236
    Abstract: 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.
    Type: Grant
    Filed: July 18, 2017
    Date of Patent: June 26, 2018
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Harumitsu Miyashita
  • Patent number: 10002633
    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.
    Type: Grant
    Filed: October 5, 2016
    Date of Patent: June 19, 2018
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Harumitsu Miyashita, Naohiro Kimura
  • Publication number: 20180144772
    Abstract: 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.
    Type: Application
    Filed: October 15, 2017
    Publication date: May 24, 2018
    Inventors: Kohei NAKATA, Yoshihisa TAKAHASHI, Junichi MINAMINO
  • Patent number: 9978421
    Abstract: 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.
    Type: Grant
    Filed: October 15, 2017
    Date of Patent: May 22, 2018
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Kohei Nakata, Yoshihisa Takahashi, Junichi Minamino
  • Publication number: 20180129566
    Abstract: 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.
    Type: Application
    Filed: January 8, 2018
    Publication date: May 10, 2018
    Inventors: Kohei NAKATA, Yuji TAKAGI
  • Patent number: 9934815
    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.
    Type: Grant
    Filed: June 3, 2016
    Date of Patent: April 3, 2018
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Kohei Nakata, Yasumori Hino
  • Publication number: 20180047424
    Abstract: 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.
    Type: Application
    Filed: July 18, 2017
    Publication date: February 15, 2018
    Inventors: Kohei NAKATA, Harumitsu MIYASHITA
  • Publication number: 20170262338
    Abstract: 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.
    Type: Application
    Filed: November 18, 2016
    Publication date: September 14, 2017
    Inventors: Kohei NAKATA, Yuji TAKAGI
  • Publication number: 20170256280
    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.
    Type: Application
    Filed: October 27, 2016
    Publication date: September 7, 2017
    Inventor: Kohei NAKATA