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:
Feb. 22, 2000

Filed:

Mar. 31, 1998
Applicant:
Inventor:

Hiroaki Naganuma, Yamanashi-ken, JP;

Assignee:

Nisca Corporation, Yamanashi-ken, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
396508 ;
Abstract

A high-performance exposure adjusting device for a camera has a magnet rotor united with an aperture member capable of steadily assuming three exposing positions according to the polarity of a direct current applied to a coil surrounding the rotor. When applying no current to the coil, the aperture member takes its magnetically neutral position to form a full aperture and is magnetically stabilized by a yoke surrounding the rotor. When the direct current of one polarity is applied to the coil, the aperture member rotates in one direction to form a first reduced aperture, and when the polarity of the current applied is reversed, a second reduced aperture is formed.


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