Patents by Inventor Masaharu Kaita

Masaharu Kaita 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).

  • Injection molding die apparatus for use in the production of substrate of optical disk
    Patent number: 5018962
    Abstract: An injection molding die apparatus for use in the production of an optical disk substrate has a stationary die part having a mirror-finished surface, a movable die part carrying a stamper, an outer peripheral ring slidably fitting on the outer periphery of the movable die part and contactable with the stationary die part when the movable die part has been moved close to the stationary die part, such that a die cavity to be charged with injected molten plastic is formed by the mirror surface of the stationary die part, the stamper and the outer peripheral ring.
    Type: Grant
    Filed: September 20, 1989
    Date of Patent: May 28, 1991
    Assignee: Sumitomo Heavy Industries, Ltd.
    Inventors: Takehiko Kitamura, Hirosato Amano, Masaharu Kaita