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:
Jan. 04, 1977
Filed:
Mar. 10, 1975
Yukio Sugimoto, Katano, JA;
Matsushita Electric Industrial Co., Ltd., Osaka, JA;
Abstract
A compatible discrete four-channel (CD-4) stereophonic reproducing system which comprises a detecting circuit for detecting a sub-channel signal. A control means detects an over-deviation of the sub-channel signal and deactivates a noise elimination switching circuit connected in a stage following the detecting circuit when the over-deviation signal appears, thereby preventing an output from being transmitted from the detecting circuit to succeeding stages. A distortion reducing circuit is also provided. This circuit is responsive to an output of said control means for attenuating at least a high frequency band of an output of the switching circuit for a predetermined time period, this period being longer than the period for which the over-deviation signal appears. Consequently, the noise produced by various causes can be effectively eliminated.