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:
Jul. 31, 1984
Filed:
Feb. 24, 1983
Tomio Kurosu, Iwatsuki, JP;
Yukio Yoshikawa, Tokyo, JP;
Copal Company Limited, Tokyo, JP;
Abstract
The electromagnetically driven programming shutter includes magnets and shutter blade driving coils provided on the respective shutter blades of the shutter and electromagnetically cooperating with the magnets and the shutter blades are actuated for opening and/or closing operation when the driving coils are energized. The present invention provides a votage compensating circuit used as the reference voltage generating circuit which is capable of varying the reference output voltage as a function of the variation in the voltage of the electric source, thereby permitting the controlled proper exposure defining output pulse to be modified so as to compensate for the variation in the actuation of the shutter blades caused by the variation in the electromagnetic force generated by the shutter blade driving coils due to the variation in the voltage of the electric source. Alternatively, a temperature detecting circuit may be provided for detecting the temperature of the shutter blade driving coils indicative of the variation in the current flowing through the driving coils and, hence, indicative of the variation in the electromagnetic force given to the shutter blades, and the temperature detecting circuit is connected to the reference voltage generating circuit. The temperature detecting circuit has such a temperature characteristics that the reference output voltage is modified by the temperature detecting circuit in response to the variation in the temperature thereby permitting the variation in the actuation of the shutter blades caused by the variation in the temperature to be compensate for in order to obtain a proper exposure of the shutter.