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. 06, 2003

Filed:

May. 21, 2001
Applicant:
Inventors:

Toshio Takahashi, Hachioji, JP;

Akiyoshi Tochigi, Hachioji, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 1/308 ;
U.S. Cl.
CPC ...
G02B 1/308 ;
Abstract

A real image type view finder comprising an objective optical system which has positive refractive power and forms an intermediate image, an image erecting optical system which erects the intermediate image and an eyepiece optical system which leads the intermediate image to an observer's eye, in which the objective optical system comprises a first positive lens unit, a second negative lens unit, a third negative lens unit and a fourth positive lens unit, moves the second lens unit and the third lens unit for a magnification change, has a vari-focal ratio on the order of 4, and has favorable optical performance over an entire zooming region.


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