Patents Examined by F. Shami
  • Method and apparatus for detecting patterns
    Patent number: 5153444
    Abstract: A method and apparatus for detecting a defect in a circuit pattern by detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another, and detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern.
    Type: Grant
    Filed: January 14, 1991
    Date of Patent: October 6, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Shunji Maeda, Takashi Hiroi, Hitoshi Kubota, Hiroshi Makihira, Fumiaki Endo