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. 29, 1985
Filed:
Feb. 22, 1982
Junji Sakamoto, Gunma, JP;
Hiroyasu Kishi, Gunma, JP;
Sanyo Electric Co., Ltd., both of, JP;
Tokyo Sanyo Electric Co., Ltd., both of, JP;
Abstract
A noise detecting circuit in a television receiver, which comprises a horizontal synchronizing signal separating circuit (17) for separating a horizontal synchronizing signal from a detected composite video signal, a differential circuit (101) for extracting a noise component included in the horizontal synchronizing signal period of the composite video signal as a function of the separated horizontal synchronizing signal, and a rectifying circuit (102) for rectifying the extracted noise component for providing a direct current voltage associated with the magnitude of the noise component in the composite video signal. The noise detected output is applied to an automatic frequency control circuit (26) for the purpose of controlling the sensitivity of an automatic frequency control operation thereof. The noise detected output is also applied to the automatic frequency control circuit (26) for the purpose of controlling the impedance of a filter thereof. Synchronization of a horizontal output signal with the horizontal synchronizing signal is also detected and the control of the automatic frequency control circuit (26) responsive to the noise detected output is disabled responsive to a non-synchronization detected output and the sensitivity of the automatic frequency control circuit (26) and the impedance of the filter thereof are also controlled responsive to the non-synchronization detected output.