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:
Dec. 21, 1976
Filed:
Aug. 23, 1974
Takeo Saito, Chiba, J;
Youichi Seki, Chiba, J;
Abstract
An electronic camera shutter control circuit having a reversible counter for counting a number of pulses proportional to the duration of an exposure time. When the camera shutter is opened pulses are subtracted from the memory content of the reversible counter until the counter content is zero and the exposure is terminated. The reversible counter includes a final stage which does not change state if the number of pulses applied to the counter exceeds the memory capacity of the counter. For this condition the exposure time is first controlled by the charging time of a capacitor until a voltage stored in the capacitor exceeds a certain value whereupon the memory content of the counter is subtracted until it is zero and the exposure is terminated.