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:
Nov. 18, 2003

Filed:

Oct. 06, 2000
Applicant:
Inventors:

Hajime Oda, Narashino, JP;

Yoichi Seki, Narashino, JP;

Assignee:

Seiko Precision Inc., Chiba-ken, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B 1/318 ; G03B 7/26 ;
U.S. Cl.
CPC ...
G03B 1/318 ; G03B 7/26 ;
Abstract

To prevent temporary reduction of battery voltage when driving a shutter, an exposure control drive apparatus is provided with a boosting circuit for boosting a voltage of the battery and outputting a boosted voltage. A capacitor is charged by the boosted voltage for driving an actuator of an exposure control mechanism. A detecting circuit detects a current flowing in the boosting circuit and a control circuit controls operation of the boosting circuit in accordance with a magnitude of the detected value so that the boosting circuit is prevented from boosting the battery voltage when the detected current exceeds a predetermined level and is permitted to boost the battery voltage when the detected current is below the predetermined level. In this manner, the current flowing from the battery is prevented from exceeding a maximum level.


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