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:
Sep. 07, 1999
Filed:
Oct. 03, 1997
Applicant:
Inventors:
Akira Sato, Shiga-ken, JP;
Katsuhiro Takamoto, Sakai, JP;
Assignee:
Minolta Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
353 70 ; 353 69 ;
Abstract
A projection optical apparatus has a projection optical system for projecting from a primary image an enlarged or reduced secondary image. A line connecting a center of an aperture diaphragm of the projection optical system to a center of an enlargement-side image plane forms a predetermined angle with respect to a normal to the enlargement-side image plane. The enlargement-side image plane and a reduction-side image plane are approximately parallel to each other. The projection optical system provides, on its enlargement side, curvature of field that is convex toward the projection optical system.