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. 15, 1977
Filed:
Aug. 04, 1975
Yoshiaki Sakauchi, Tenri, JA;
Kazufumi Ushijima, Hirakati, JA;
Hajime Suzuki, Higashiosaka, JA;
Shigeru Wakamoto, Daito, JA;
Sanyo Electric Co., Ltd., Moriguchi, JA;
Abstract
An automatic tuning apparatus comprising a tuner having a tank circuit employing a voltage controlled variable capacitance diode as a circuit element, which diode is reverse biased with a scanning control voltage from a solid state potential memory device, which control voltage is varied under the control of a scanning voltage control circuit to scan the frequencies in the frequency band by the tuner and is set by a scan stop signal obtained from the tuner as a result of tuning of the tuner to a certain frequency, said scan stop signal being withdrawn by way of a logical product of the level detected output of the IF signal and the level detected output of the ratio detected output of the IF signal, a manual switch for starting the scanning, an automatic frequency control responsive to said level detected output of said ratio detected output for charging or discharging said potential memory device, said automatic frequency control being disabled in response to the absence of the level detected output of the IF signal, and a pseudo IF signal generating circuit responsive to turning on of the power source for providing a pseudo IF signal for a predetermined period of time, whereby the automatic frequency control is performed irrespective of a possible change in the IF signal after the power source is turned off until it is turned on again.