Patents by Inventor Toshihilo Nakata

Toshihilo Nakata 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: 5098191
    Abstract: Method of inspecting reticles and an apparatus therefor, where means for holding and transferring an inspected reticle and a standard reticle respectively, means for illuminating light with spatial coherency adjusted onto both reticles respectively, and an objective lens for collecting transmitted light or reflected light from the illuminated body produced by the illuminating, are installed on respective Fourier transformation surfaces of both reticle surfaces, and a light blocking plate for blocking light corresponding to the adjusted spatial coherency is installed, and electric signals obtained are compared thereby a defect or a foreign substance existing on the inspected reticle can be detected.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: March 24, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Minori Noguchi, Hiroaki Shishido, Mitsuyoshi Koizumi, Nobuyuki Akiyama, Toshihilo Nakata