Patents Examined by Rodney D. Bovernick
  • Optical system for use of a laser processing machine
    Patent number: 4964704
    Abstract: An improved optical system suitable for laser processing in semiconductor manufacture. The system is composed of three convex lenses. By suitably selecting the type of each of the lenses, a limited spherical aberration is obtained without compromising the numerical aperture.
    Type: Grant
    Filed: August 17, 1989
    Date of Patent: October 23, 1990
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hisato Shinohara