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. 15, 1984
Filed:
Mar. 04, 1982
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
A noise reducing apparatus consists of a compression system and an expansion system. The compression system comprises a pre-emphasis circuit for performing a pre-emphasis operation with respect to an input signal, a first variable gain control circuit for giving a level compression characteristic to an output signal of the pre-emphasis circuit, to produce an output signal to a transmission path, a first control voltage producing circuit for dividing the output signal of the first variable gain control circuit into a plurality of bands, to produce a plurality of control voltages respectively given mutually different bands, a first weighting circuit for respectively and relatively weighting the plurality of control voltages obtained from the first control voltage producing circuit, and a first adding circuit for adding the plurality of control voltages obtained from the first weighting circuit, to obtain a first control voltage and apply this first control voltage to the first variable gain control circuit. The expansion system similar to the compression system, comprises a second variable gain control circuit for giving a level expansion characteristic to the level compressed signal obtained through the above transmission path, where the level expansion characteristic is complementary to the level compression characteristic.