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. 13, 1977
Filed:
Feb. 18, 1975
Takeo Saito, Yotsukaido, JA;
Youichi Seki, Chiba, JA;
Seiko Koki Kabushiki Kaisha, , JA;
Abstract
An exposure time control device of an electric shutter includes a brightness-time conversion circuit for developing a single pulse having a width representative of the brightness of a scene to be photographed and a standard pulse generating circuit for generating pulses at a standard rate. A reversible counter counts the standard 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 delay circuit develops a trigger pulse upon opening of the shutter. The trigger pulse is applied to the reversible counter control circuit, and if it is applied prior to the termination of the single pulse, read-out of the count stored in the reversible counter is initiated prior to termination of the single pulse.