Patents by Inventor Toshiki Shojima

Toshiki Shojima 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).

  • Apparatus for manufacturing an optical disk substrate by injection molding
    Patent number: 5156860
    Abstract: An apparatus for manufacturing an optical disk substrate having a foreign-substances index of not more than 1.times.10.sup.5 .mu.m.sup.2 /g, an optical information-storage medium wherein the substrate has an information-recording layer, includes a cylinder with a liner and a screw coated with TiC and TiN.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: October 20, 1992
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventors: Kotaro Kojima, Yasumasa Shibata, Toshiki Shojima
  • Optical disk substrate, optical information-storage medium, and process and apparatus for manufacturing the optical disk substrate
    Patent number: 5059461
    Abstract: An optical disk substrate having a foreign-substances index of not more than 1.times.10.sup.5 .mu.m.sup.2 /g, an optical information-storage medium wherein the substrate has an information-recording layer, and a propocess and an apparatus for manufacturing the optical disk substrate.
    Type: Grant
    Filed: January 17, 1990
    Date of Patent: October 22, 1991
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventors: Kotaro Kojima, Yasumasa Shibata, Toshiki Shojima