The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 1990
Filed:
Aug. 26, 1988
Tetsuo Kikuchi, Tokyo, JP;
Masahiro Nakagawa, Kanagawa, JP;
Koichi Matsumoto, Tokyo, JP;
Haruo Ozawa, Tokyo, JP;
Hiroshi Shirasu, Kanagawa, JP;
Yuji Kudoh, Kanagawa, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An illumination optical apparatus includes secondary light source forming means for forming a plurality of light source images from collimated light beams emitted from a light source, tertiary light source forming means arranged midway along an optical path from the secondary light source forming means, and a condenser lens arranged midway along an optical path from the tertiary light source forming means. The secondary light source forming means includes an optical integrator having entrance and exit surface. A plurality lens surface having a larger focal length than a distance between the entrance and exit surfaces are formed on the entrance sarfaces. Thus, a plurality of secondary light source images are formed by the secondary light source forming means in a space behind the exit surface of the optical integrator.