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:
May. 04, 1976
Filed:
Apr. 02, 1974
Takayoshi Sato, Tokyo, JA;
Kunio Ando, Warabi, JA;
Fuji Photo Optical Co., Ltd., Omiya, JA;
Abstract
An exposure control circuit connected with an electrically operated exposure control element such as an electric shutter or an electrically controlled diaphragm includes a bridge circuit. The bridge circuit has four arms and is provided in one arm thereof with a photodetector to receive light from the object to be photographed. A resistor is connected in series with the photodetector to convert the current flowing through the photodetector into a voltage. A transistor is connected with the photodetector to amplify the photocurrent thereof. Another resistor is connected with the transistor to convert the current obtained by amplification of the photocurrent of the photodetector by use of the transistor to a voltage. These two resistors are provided in one arm of the bridge circuit so as to be independently varied of their resistance.