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:
May. 22, 1984
Filed:
Feb. 26, 1982
Kenji Fujibayashi, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An automatic signal level control device has a variable impedance element whose impedance varies with the level of a control signal; a variable gain circuit whose gain varies with the impedance of the variable impedance element; and a detector for generating the control signal upon receipt of an output signal from the variable gain circuit. The detector includes a transistor whose base is supplied with a first signal corresponding to the output signal from the variable gain circuit and from whose emitter there is drawn out a second signal having a potential corresponding to that of the first signal; a feedback element which is connected between the base and emitter of the transistor; and a capacitor which is connected between the emitter of the transistor and a circuit having substantially no AC potential to store a charge corresponding to the second signal. A feedback signal corresponding to the charged potential of the capacitor is supplied to the base of the transistor through the feedback element, and the second signal is used as the control signal.