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:
Feb. 12, 1980
Filed:
Dec. 20, 1977
Toshio Murakami, Yokohama, JP;
Masaru Noda, Fujisawa, JP;
Hiroaki Nabeyama, Kamakura, JP;
Takeshi Murakami, Yokohama, JP;
Hitachi, Ltd., , JP;
Abstract
A video synchronous detector apparatus for discriminating a video intermediate frequency signal, in which the video intermediate frequency signal is divided into two parts, one of which is applied to one terminal of a multiplier circuit, and the other of which is applied to the other terminal of the multiplier circuit through a picture-carrier intermediate frequency extraction circuit having a frequency selection circuit and a limiter circuit. The frequency selection circuit is provided with a trap circuit. The trap circuit has a center resonance frequency equal to a differential frequency between a picture-carrier intermediate frequency (f.sub.p) and a differential frequency between a color subcarrier intermediate frequency (f.sub.c) and a sound-carrier intermediate frequency (f.sub.s) so that a so-called sound-cross-color disturbance caused by a beat between the intermediate frequency sound signal and the intermediate frequency picture signal may be reduced.