Patents by Inventor Tetuji Takamizawa

Tetuji Takamizawa 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).

  • Polishing of the rear surface of a stamper for optical disk reproduction
    Patent number: 5209027
    Abstract: The rear surface of a stamper for use in the manufacture of optical disks should be polished to precision. A length of abrasive tape is fed across the stamper in pressure contact with the rear surface of the stamper through a pressure roller having a rubber sleeve with a hardness of up to 80 degrees as measured according to ASTM D 2240 type A while the stamper is rotating.
    Type: Grant
    Filed: January 10, 1992
    Date of Patent: May 11, 1993
    Assignee: TDK Corporation
    Inventors: Toshihiko Ishida, Tetuji Takamizawa, Hiroyuki Arioka