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. 12, 1992

Filed:

Jul. 06, 1990
Applicant:
Inventors:

Atsushi Nagata, Tokyo, JP;

Atsushi Misawa, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ; H04N / ;
U.S. Cl.
CPC ...
354402 ; 3541951 ; 358227 ;
Abstract

A zoom lens system in which an angle of view is automatically varied according to camera-to-subject distances so as to be able to provide on a photographing screen a subject which is always constant in size. In the zoom lens system, a focus lens is stopped at a given position and, in this condition, a magnification varying lens and a compensator lens are driven to thereby achieve a focusing operation. In this operation, the angle of view is automatically varied according to the camera-to-subject distances, so that the size of the subject can be always constant with respect to the photographing screen regardless of the camera-to-subject distances. As a result of this, according to the invention, there is eliminated the need for provision of a data table memory for performing an automatic zooming operation, and exclusive and complicated control device and position detection device.


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