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. 07, 1982
Filed:
Jul. 14, 1980
Toshinori Murata, Yokohama, JP;
Shigeo Matsuura, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a channel selection apparatus for a television receiver or FM radio receiver having an electronic tuner, a local oscillation signal of the electronic tuner having a local oscillator which is swept by a voltage sweeping circuit is passed through a comb-shape filter having a SAW element. Peak outputs from the comb-shape filter are counted by a presettable counter. When the count reaches a preset count, the sweeping operation of the voltage sweeping circuit is stopped to select a desired channel. A portion of the peaks of the comb-shape filter characteristic is attenuated and a gap appearing at the attenuated portion is detected by the frequency sweep of the local oscillation signal with a change in time interval. The detection signal is compared to discriminate the first pulse necessary for the channel selection.