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:
Sep. 27, 1977
Filed:
May. 15, 1975
Takeo Saito, Yotsukaido, JA;
Youichi Seki, Chiba, JA;
Seiko Koki Kabushiki Kaisha, , JA;
Abstract
An exposure time control device of an electric camera shutter includes a brightness time conversion circuit for developing a single pulse having a width representative of the brightness of a subject to be photographed and a reference pulse generating circuit for generating reference pulses at a standard rate. A reversible counter counts the reference pulses for a period of time equal to the duration of the single pulse. Upon termination of the single pulse, a reversible counter control circuit applies control signals to the reversible counter to read-out the count stored therein for controlling the shutter exposure time. A selector switch selects the input position of the reference pulses to the reversible counter in dependence upon exposure time factors other than brightness of the subject thereby enabling the selection of the exposure time in accordance with the subject brightness as well as other factors, such as film sensitivity and diaphragm setting.