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:
Nov. 28, 1978
Filed:
Dec. 20, 1976
Takao Mogi, Tokyo, JP;
Hisao Okada, Yokohama, JP;
Sony Corporation, Tokyo, JP;
Abstract
A tuning system for digitally controlled electronically tuned tuner with automatic fine tuning (AFT) constantly operable to hold the tuner at a predetermined optimum frequency setting, especially a television channel. A reversible counter provides the digital signal to control the tuning of the tuner and is, itself, deliberately shifted from one setting to another by pulses from a source, such pulses being applied to the UP input terminal of the counter as the up-tuning pulses to shift the tuner frequency higher. Pulses from the same source are also used as down-tuning pulses when applied to the DOWN input terminal of the tuning pulses to a lower frequency supplied to two AFT AND circuits. One output logic up-tuning instruction signal E.sub.U of the AFT circuit enables the up-tuning AFT AND circuit only in a certain sub-range below the desired frequency. The other output logic down-tuning instruction signal E.sub.D of the AFT circuit enables the other AFT AND circuit only in a certain sub-range above the desired frequency. Consequently, deliberate application of up-or-down-tuning pulses to the UP or DOWN terminals changes the count as desired, being only partially counteracted by the lower frequency, AFT-controlled pulses to the opposite counter terminal.