Patents by Inventor Tamotu Iida

Tamotu Iida 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).

  • Optical information recording medium utilizing pits having a sharp front face and method of manufacturing the same
    Patent number: 4896313
    Abstract: An optical information recording medium having a sharp front face of an optical information recording pit to thereby reduce jitter of a reproduced optical signal. The front and back end portions of a pit are made to have a sharp edge and a wider portion. In a cutting operation for an original medium used for mass production of medium, the light exposure amount to a photoresist on the original medium is controlled to increase it at the front and back edge portions of a pit.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: January 23, 1990
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Atsuki Hirose, Tamotu Iida