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:
Mar. 25, 2003
Filed:
Nov. 16, 2001
Katsumi Motomura, Saitama, JP;
Kiyoshi Ichikawa, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
In a photometry device, a pair of transistors having the same properties. The first transistor is connected at its base to the CdS photo sensor, and at its collector to a resistor. The second transistor is connected at its base to the resistor, and at its collector to the photoconductive element. When a subject brightness is below a reference level that is defined by a resistance of the resistor, the CdS photo sensor has a smaller resistance than the resistance of the resistor, so a smaller current flows into a base of the first transistor than a current flowing into a base of the second transistor. Consequently, the first transistor is turned off, and the second transistor is turned on, conducting current through a solenoid. Thereby, a stop blade is switched over to change the stop size.