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:
May. 27, 1986

Filed:

Nov. 30, 1982
Applicant:
Inventors:

Hisashi Tokumaru, Osaka, JP;

Shuji Ogino, Osaka, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
350427 ; 350426 ;
Abstract

A zoom lens system of a relatively high zoom ratio about 2.5 to 3.5 ranging to a wide field angle such as 76 degrees is disclosed. The zoom lens system comprises, from the object to the image side, a first movable negative lens group, a second movable positive lens group, a third stationary negative lens group and a fourth movable positive lens group with a first to third variable air spaces formed therebetween, respectively. And, the zoom lens system functions as an inverted telephoto type lens system in the shorter focal length range of the whole lens system by means of a combination of only the first lens group as a front negative group and the whole of the second to fourth lens groups as a rear positive group, while the zoom lens system functions as a telephoto type lens system in the longer focal length range of the whole lens system by means of a combination of the whole of the first and second lens groups as a front positive group and the whole of the third and fourth lens groups as a rear negative group. The first lens group includes a negative front lens, and the lens system fulfills the following condition:


Find Patent Forward Citations

Tokumaru, Hisashi. (1986). Zoom lens system (U.S. Patent No. 4591235). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4591235

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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