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.

Date of Patent:
Aug. 05, 1997

Filed:

Nov. 13, 1995
Applicant:
Inventor:

Hironori Shibata, Hachioji, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359692 ; 359714 ;
Abstract

A compact yet high-performance zoom lens system which is well corrected in terms of aberrations, includes reduced number of lens elements and has a reduced total lens thickness. The system has a first lens group G1 including, in order from the object side, a lens having a meniscus shape convex on the object side and negative refracting power (first lens), a lens of weak refracting power (second lens) and a lens having positive refracting power together with at least one aspheric surface (third lens). The first lens group has a positive refracting power in its entirety. The system further has a second lens group G2, the focal length of the overall system being variable by varying an axial separation between the first and second lens groups G1 and G2, and conforms to the following condition: (1) relation to the refracting power range of the lens of weak refracting power and the following condition (2) relating to the axial position of the lens of weak refracting power:


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