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:
Dec. 07, 1993
Filed:
Jan. 28, 1993
Applicant:
Inventors:
Manami Saka, Kyoto, JP;
Katsuhiro Takamoto, Nagaokakyo, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359690 ; 359716 ;
Abstract
A variable lens system has three lens unit whose refractive powers are positive, negative and positive from an object side to the image side. Each lens unit consists of at least two lens elements. The central lens unit and the image side lens unit are shifted along an optical axis during a zooming operation. The lens system fulfills the conditions: ##EQU1## wherein fS, Z, and Y' represent the shortest focal length, a zoom ratio and an image height, respectively, of the lens system. .phi.1 and .phi.2 represent refractive powers of the object side and central lens units.