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:
Apr. 09, 1985
Filed:
Dec. 14, 1982
Kenzo Tanabe, Katano, JP;
Keiichiro Shimizu, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An electronically controlled variable semiconductor resistor having a three layer construction of either an NPN-type or a PNP-type which is similar to that of a bipolar transistor and basically using the base region and collector region of the transistor as a variable resistor having its resistance value controlled by varying its emitter current. The conductivity of the base region adjoining the emitter region and that of the collector region opposite the emitter region across the base region are modulated largely by minority carriers injected into the base region from the emitter. The carrier density at each emitter, base or collector region is reasonably controlled so as to thereby make it possible to obtain a variable resistor whose resistance value changes about in an inverse proportion to the emitter current and the electrode of proper construction is designed to allow the control signal component for controlling the emitter current not to appear at both ends of the resistor electrode at the resistor.