公开(公告)号：US20210327465A1

公开(公告)日：2021-10-21

申请号：US17360256

申请日：2021-06-28

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Tsuyoshi NAKASENDO ,  Yoshiaki KOMMA

IPC: G11B7/1374 ,  G11B7/127 ,  G11B7/09

Abstract: An optical disk reproducing device includes a division element that divides a reflected light reflected and diffracted by an optical disk into a light flux in a central region and light fluxes in end regions; a photodetector that has a central light receiver that receives the light flux in the central region and at least two end light receivers that receive the light fluxes in the end regions, and outputs a light amount signal corresponding to a light amount of each of the received light fluxes; a non-linear processor that receives each of the light amount signals from the central light receiver and the end light receivers, and outputs linear signals and non-linear signals obtained by processing the light amount signals by linear and non-linear arithmetic operations; an equalization processor that receives the linear signals and the non-linear signals and outputs signals each amplified with a predetermined gain; an adder that adds the amplified signals and outputs an equalization signal; a reproduction signal processor that processes the equalization signal and outputs a reproduction signal and an equalization error signal; and a gain controller that receives the equalization error signal and controls an amplification gain of the non-linear signals.

公开(公告)号：US20190279680A1

公开(公告)日：2019-09-12

申请号：US16293735

申请日：2019-03-06

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Tsuyoshi NAKASENDO ,  Yasumori HINO ,  Kohei NAKATA

IPC: G11B20/18 ,  H04L1/00

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.

公开(公告)号：US20190189154A1

公开(公告)日：2019-06-20

申请号：US16223698

申请日：2018-12-18

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Kohei NAKATA ,  Tsuyoshi NAKASENDO

IPC: G11B20/10 ,  G11B7/0045

CPC classification number: G11B20/1037 ,  G11B7/0045 ,  G11B20/1833

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.