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:
Jan. 07, 1992
Filed:
Aug. 30, 1990
Applicant:
Inventors:
Yoshinobu Sato, Yokohama, JP;
Kazuhiro Matsunaga, Kawasaki, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
354435 ; 354484 ;
Abstract
This invention relates to a shutter apparatus which also serves as a diaphragm. In this invention, there are provided two drive control modes for the shutter apparatus; the first mode for controlling a control voltage to be supplied to a shutter driving motor and the second mode for controlling the duty of a voltage to be applied to the motor. These two modes are switched according to factors such as a power source voltage, whereby optimum shutter control is implemented.