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:
Mar. 27, 1979
Filed:
Nov. 01, 1977
Applicant:
Inventor:
Mitsuo Isobe, Moriguchi, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03B / ; H03D / ; H04N / ;
U.S. Cl.
CPC ...
329 50 ; 325419 ; 329122 ; 331-4 ; 331 23 ; 358 25 ; 358195 ;
Abstract
An RF-IF signal receiving circuit of a television receiver controls a tuner which receives an amplitude modulated RF signal and converts it to an IF signal and an IF signal carrier generator for demodulating the amplitude modulated signal from the IF signal by synchronous detection, using a phase synchronous loop. A sweep voltage generator of a voltage-controlled oscillator in the phase synchronous loop comprises an envelope detector which is DC-coupled to an output of an amplitude synchronous detector and a low pass filter in order to enhance the pull-in range of the phase synchronous loop.