Patents Examined by Chang K. Seo
  • Protective light filter system for image intensifier
    Patent number: 4695718
    Abstract: The photocathode of an image intensifier is protected from undue exposure to excessive incident light by a variable density filter whose density is controlled by an optical coupler. The optical coupler has an LED which conducts power supply current to the image intensifier and a phototransistor in the energization circuit of a filter driver which operates the variable density filter.
    Type: Grant
    Filed: July 9, 1986
    Date of Patent: September 22, 1987
    Assignee: EOL.sub.3 Company, Inc.
    Inventor: James M. Dill