Patents Examined by Herbert Kernes
  • Patent number: 5530518
    Abstract: A projection exposure apparatus includes illuminating optical means for illuminating a projection negative, and projection optical means for projection-exposing the projection negative illuminated by the illuminating optical means onto a substrate, the illuminating optical means including light source means for supplying exposure light, annular light source forming means for forming an annular secondary light source by the light from the light source means, and condenser means for condensing the light beam from the annular light source forming means on the projection negative, and is designed to satisfy the following condition:1/3.ltoreq.d.sub.1 /d.sub.2 .ltoreq.2/3,where d.sub.1 is the inner diameter of the annular secondary light source, and d.sub.2 is the outer diameter of the annular secondary light source.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: June 25, 1996
    Assignee: Nikon Corporation
    Inventors: Kazuo Ushida, Masaomi Kameyama