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. 21, 1982
Filed:
Jan. 22, 1981
Minoru Ogita, Hamamatsu, JP;
Shigenobu Kimura, Hamamatsu, JP;
Nippon Gakki Seizo Kabushiki Kaisha, Shizuoka, JP;
Abstract
A radio receiver comprises a phase locked loop and an automatic frequency control loop which are selectively coupled with a voltage-controlled local oscillator to control a local oscillator frequency. The phase locked loop and the automatic frequency control loop have a common loop filter which supplies the voltage-controlled oscillator with a control voltage. The loop filter is arranged so that its time constant may be switched from a small value to a great value in response to switching of the operation mode of the voltage-controlled oscillator from a phase locked loop control mode for the selection of broadcasting station to an automatic frequency control loop control mode for the maintenance of the local oscillator frequency after tuning of the radio receiver. The radio receiver can be arranged so that the local oscillator frequency may be maintained by the phase locked loop after the tuning of the receiver to a weak broadcast signal when muting control is rendered ineffective by a muting switch.