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:
Jul. 23, 1985
Filed:
Oct. 27, 1983
Applicant:
Inventors:
Joseph M Canter, Lexington, MA (US);
William A Shelton, Cambridge, MA (US);
Assignee:
Polaroid Corporation, Cambridge, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
315151 ; 315156 ; 315157 ; 2502 / ; 354414 ; 354417 ;
Abstract
A control circuit for timing the duration of a flash of artificial illumination from an electronic flash maintains a substantially uniform amount of artificial illumination regardless of the ambient scene light intensity by detecting the ambient scene light intensity up to the instant that the flash is fired and thereafter subtracting the ambient scene light intensity so detected immediately prior to the flash being fired from the ambient and artificial scene light intensity detected during the flash of artificial illumination.