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:
Mar. 15, 1988
Filed:
Sep. 05, 1984
Applicant:
Inventors:
Yoshio Amemiya, Yokosuka, JP;
Masanori Oguino, Yokohama, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ;
U.S. Cl.
CPC ...
380 15 ; 358176 ;
Abstract
An AGC circuit used in a subscriber's receiver of a CATV system in which the television signal is scramble-modulated so that only subscribers are allowed to view toll programs, wherein the detected video signal is conducted through a low-pass filter to extract the vertical sync signal, a keying pulse is produced in response to the vertical sync signal, and the AGC operation is performed by the keying pulse in accordance with the magnitude of the vertical sync signal.