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:
Feb. 26, 1980
Filed:
Dec. 09, 1977
Applicant:
Inventors:
Yasuo Ishiguro, Tokyo, JP;
Kenji Wakazono, Tokyo, JP;
Assignee:
Copal Company Limited, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
354234 ; 354267 ;
Abstract
A shutter driving circuit including a voltage judging circuit and indicating circuit in order to always properly make shutter opening and closing operations, whereby an electric current is prevented from flowing to driving coils and such state can be indicated by the indicating circuit when the voltage of a current source for feeding a current to a pair of driving coils to be made to make opening and closing motions of the shutter by the voltage judging circuit is below a predetermined value.