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:
Dec. 16, 1980
Filed:
Jun. 23, 1978
Applicant:
Inventors:
Kiyoshi Fushimi, Yokohama, JP;
Keizo Shimizu, Yokohama, JP;
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ;
U.S. Cl.
CPC ...
3581931 ;
Abstract
When a receiving channel of television broadcast is selected by the frequency sweep, a video carrier and an audio carrier appear alternately at an output of an intermediate frequency (IF) stage. A channel selection system is disclosed, which distinguishes the video carrier and the audio carrier from each other by the presence or absence of a sync. separation pulse during the frequency sweep, in which a sync. pulse is distinguished from a noise pulse by the presence or absence of a horizontal flyback pulse and the video carrier is distinguished from the audio carrier in response to the presence or absence of the sync. pulse to selectively stop the sweep.