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:
Nov. 19, 1985
Filed:
May. 06, 1982
Applicant:
Inventors:
Masatake Kato, Tokyo, JP;
Shigeru Hashimoto, Kanagawa, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
350463 ; 350464 ;
Abstract
A large relative aperture objective lens having three lens groups of positive power with said three lens groups being all moved forward to effect focusing from an infinitely distant object to close objects. The three lens groups, being named from front to rear, 1st, 2nd and 3rd lens groups successively, have the amounts of forward movement of the 1st, 2nd and 3rd lens groups made progressively smaller. Accordingly, good stability of aberration correction throughout the extended focusing range is achieved.