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. 18, 1978
Filed:
Dec. 02, 1976
Eiji Aoyama, Tokyo, JP;
Nihon Beru-Haueru Kabushiki Kaisha, Higashimurayama, JP;
Abstract
A sensitivity control circuit is described for use with a sound movie camera having an automatic sound level control circuit. In one embodiment, the automatic sound level control circuit includes a pair of cascaded amplifiers whose overall gain is controlled by the conduction of an active control element. The active control element has an input terminal which receives a control signal representative of the amplitude of the signal output of the cascaded amplifiers. To desensitize the automatic sound level control circuit to background noise, a voltage source and a variable impedance element are serially coupled to the control terminal of the active control element to provide a control current for selectably varying the conduction of the active control element. The gain of the cascaded amplifiers is thereby selectively controlled and the sensitivity of the automatic sound level control circuit is reduced.