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:
Nov. 16, 1976
Filed:
Jul. 02, 1975
Applicant:
Inventor:
John S Wirtz, Henrietta, NY (US);
Assignee:
Itek Corporation, Lexington, MA (US);
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
355 68 ; 354 / ; 354 31 ; 354 50 ; 354 / ;
Abstract
A system is disclosed for measuring the background density of an object to be photographed wherein a count is inserted into a counter proportional to the measured density. The intensity of illumination of the object is thereafter measured and the count within the counter is counted down at a rate proportional to the measured illumination intensity until the count reaches zero; the beginning of the exposure interval being defined by the start of the countdown step and the end of the interval being defined by the count in the counter reaching a predetermined value.