Patents by Inventor Ryuichi Kemi

Ryuichi Kemi 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).

  • Projection exposure apparatus
    Patent number: 4825247
    Abstract: An exposure apparatus particularly suitable usable for the manufacture of semiconductor microcircuit is disclosed. The apparatus includes a specific arrangement that allows accurate and precise detection of any change in the imaging magnification and/or the image surface position of a projection optical system included in the projection exposure apparatus. Thus, with the present invention, a pattern can be projected upon a workpiece with improved accuracy.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: April 25, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryuichi Kemi, Kazuo Takahashi, Itaru Fujita