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:
Mar. 22, 1994

Filed:

Mar. 30, 1993
Applicant:
Inventor:

Masaaki Morizumi, Omiya, JP;

Assignees:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359700 ; 359698 ; 354402 ; 348345 ;
Abstract

A compensator lens is driven by a second driving means such that the rear end of the focal depth of an object image at infinity coincides with a surface of image-formation irrespective of the movement of a variable lens when the object image is photographed. With this arrangement, the whole range of the focal depth can be effectively utilized, so that the range of photographing can be enlarged without focussing immediately after the power source is turned on as compared with the conventional zoom lens system. That is, even an object disposed at a close distance can be photographed without focussing as compared with the conventional zoom lens system which can utilize only the substantially half length of the focal depth. Furthermore, even when the object disposed at the closest distance is photographed, focussing can be made in a short period of time as compared with the conventional zoom lens system.


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