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. 09, 1976
Filed:
Jul. 25, 1974
Robert J Anderson, Villa Park, CA (US);
Beckman Instruments, Inc., Fullerton, CA (US);
Abstract
A densitometer for providing an output which is a function of the density of a film badge in a photodosimeter system. The light passing through the film badge is received by a photodiode which generates a current signal which is directly proportional to the intensity of the received light. The current signal is converted to a voltage signal, the converting means being biased so that the voltage signal is zero when no light is received by the photodiode. The voltage signal is applied, together with a reference voltage, to a log-ratio circuit which generates an output signal proportional to the log of the ratio of the reference voltage to the voltage signal, the output of the log-ratio circuit being displayed. A circuit is operative, when the film badge is removed from the light path, to adjust the reference voltage until the output of the log-ratio circuit is zero.