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. 25, 1977
Filed:
Feb. 15, 1974
Kunio Ando, Warabi, JA;
Fuji Photo Optical Co., Ltd., Omiya, JA;
Abstract
A diaphragm of a camera is controlled by a servomotor which is actuated with an output of an amplifier. A bridge circuit including a photodetector which receives light from the object to be photographed is connected with the amplifier so that the imbalance output of the bridge circuit may be amplified by the amplifier and transmitted to the servomotor to actuate the motor in accordance with the imbalance of the bridge circuit. The output of the photodetector is differentiated by a differentiation circuit connected between the photodetector and the amplifier so that the output of the amplifier may be controlled by the differentiated output which represents the rate of variation in the quantity of light received by the photodetector.