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:
Dec. 23, 1980
Filed:
Feb. 09, 1979
Applicant:
Inventor:
Saburo Numata, Urawa, JP;
Assignee:
Fuji Photo Optical Co., Ltd., Omiya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
315151 ; 2502 / ; 354 33 ; 356223 ;
Abstract
In an automatic electronic flash light device, a light measuring circuit includes an operational amplifier, a photosensor connected between the positive and negative inputs of the operational amplifier and a diode for log-compression connected in a feedback circuit of the operational amplifier. The output of the light measuring circuit is thus log-compressed and the log-compressed output is applied to an operational circuit which gives an output for controlling exposure.