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.
Patent No.:
Date of Patent:
Mar. 23, 1982
Filed:
Nov. 18, 1980
Applicant:
Inventors:
Assignees:
Canon Kabushiki Kaisha, Tokyo, JP;
Canon Denshi Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
354235 ; 354246 ;
Abstract
In the shutter disclosed, a conductor and a permanent magnet, movable relative to each other, form a driver to drive at least one shutter blade across an optical path for photographic light and the force of the driver is supplemented by an auxiliary spring arrangement that exerts zero force at the start of movement of the shutter blade and gradually increases toward termination of movement of the blade.