Patents by Inventor Sachio Kumagai

Sachio Kumagai 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).

  • Information recording medium and method for reproducing the same
    Patent number: 4748611
    Abstract: In an optical disk, one turn of a recording track is divided into a number of sectors. Each of these sectors is composed of a servo field, which is stored in advance with servo information for tracking, and a data recording area which is to be written with data. A predetermined number of these sectors are joined together to form a plurality of blocks. Each of these blocks is recorded at the data recording areas of its predetermined sectors with identification information for identifying the blocks and phase synchronization loop pull-in information for read out clocks.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: May 31, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Toshiaki Tsuyoshi, Masatoshi Otake, Sachio Kumagai, Kazuo Ichino, Wasao Takasugi, Seiji Yonezawa