Patents by Inventor Soichi Toorisawa

Soichi Toorisawa 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).

  • Patent number: 4148065
    Abstract: A pair of chromium masks of similar pattern are optically read out to generate video signals corresponding to the patterns thereon. Comparison of the pair of masks is carried out in binary signals converted from the video signals using different recognition thresholds, thereby discriminating defects in the masks. Defect information is recorded in a recording medium and used for identifying and positioning the defects in the correction process.
    Type: Grant
    Filed: January 25, 1977
    Date of Patent: April 3, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoshi Nakagawa, Soichi Toorisawa, Hiroyuki Ibe, Shigeaki Nakashima, Yasuhiko Hara