Patents by Inventor Masatoshi Ishiwata

Masatoshi Ishiwata 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 controlling the quantity of light of a copying apparatus
    Patent number: 5057864
    Abstract: The present invention relates to an apparatus for controlling the quantity of light of a copying apparatus, and more particularly, to an apparatus for controlling the quantity of light to uniformalize the quantity of central light and the quantity of marginal light in a variable power type copying apparatus. The apparatus for controlling the quantity of light of a variable power type copying apparatus has a douser i.e. a light interrupting plate for controlling the quantity of marginal light can be automatically inserted into the projection optical system interlocking with the variable power operation.
    Type: Grant
    Filed: December 14, 1990
    Date of Patent: October 15, 1991
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Hiromitsu Kijima, Susumu Usami, Masatoshi Ishiwata