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. 11, 2000
Filed:
Apr. 02, 1998
Applicant:
Inventor:
Shintaro Kudo, Kawasaki, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
359754 ; 359649 ;
Abstract
A projection optical system including a first lens group G1 having positive power; a second lens group G2 having negative power; and a third lens group G3 having positive power wherein the lens elements in each of the lens groups are composed of glass materials selected from the group consisting of fluorite and quartz. Also, the projection optical system satisfies the following condition: