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:
Apr. 21, 1981
Filed:
Oct. 29, 1979
Sony Corporation, Tokyo, JP;
Abstract
An automatic fine tuning (AFT) circuit includes a frequency discriminator for discriminating an intermediate frequency signal, a capacitor supplied with the discriminated intermediate frequency signal to produce an AFT voltage thereacross, a comparator circuit for comparing the AFT voltage with a reference voltage, a first switching transistor controlled by the comparator circuit and which supplies and charges the capacitor with the reference voltage during a channel selection operation when the AFT voltage is less than the reference voltage, a second switching transistor controlled by the comparator circuit and which connects the capacitor to ground to discharge the same during a channel selection operation when the AFT voltage is greater than the reference voltage, and a third switching transistor for rendering the comparator circuit operative during a channel selection operation and inoperative during an AFT operation.