Patents by Inventor Akihiko Rokusaka

Akihiko Rokusaka 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: 5612933
    Abstract: An apparatus for reproducing recorded information reads information from the track surface of a CD-ROM disk 1, performs error detection and correction processing on the read information to reproduce recorded information and then outputs the reproduced information. This apparatus includes a control device 11, which switches a reproduction operation to the standard speed mode in response to a correction failure condition generated in the quadruple speed mode and retries standard-speed reading of the information read with an error uncorrectable in the quadruple speed mode. Reducing the signal read speed to one-fourth in the retry processing at the standard speed improves the C/N ratio of the high-frequency signal RF by 6 dB, which in turn improves the correction capability for random errors.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: March 18, 1997
    Assignees: Hitachi, Ltd., Hitachi Microcomputer System Ltd.
    Inventors: Yoshimi Iso, Toshihiko Watanabe, Kazuya Hara, Akihiko Rokusaka, Hideaki Sato