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:
Aug. 29, 1989
Filed:
Mar. 11, 1987
Applicant:
Inventors:
Takeo Sato, Sagamihara, JP;
Nobuhiro Araki, Yokohama, JP;
Koichi Kawata, Tama, JP;
Noboru Nomura, Kyoto, JP;
Atushi Ueno, Hirakata, JP;
Shotaro Yoshida, Sendai, JP;
Assignee:
Matsushita Electric Industrial Co., Inc., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
350505 ; 350443 ; 350620 ; 350174 ;
Abstract
A projection optical system for use in a precise copy which uses a pair of catadioptric optical systems consisting of convex mirrors, concave mirrors, and phase correction members is shown. Two catadioptric optical systems commonly use an entrance pupil on a coaxis and are coupled so as to respectively face the phase correction members. Each of the concave mirrors has an opening at the center. Each of the convex mirrors has no opening in one embodiment but has an opening portion at the center in another embodiment.