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. 06, 1982
Filed:
Oct. 06, 1980
Michael D Flasza, Schaumburg, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
A phasing circuit is described for automatically controlling the phase of an oscillator input to a synchronous detector which demodulates a video signal in a television receiver. A conventional phase locked loop develops an oscillator signal whose phase tracks with variations in the phase of a video intermediate frequency (I.F.) signal applied to the loop. The automatic phasing circuit includes a phase adjustment network for coupling the video I.F. signal to the phase locked loop and for varying the phase of the latter signal input to the loop in response to a phase correction signal. The phase correction signal is preferably developed by a multiplier which senses the video I.F. signal and the input to the phase locked loop and controls the phase adjustment network such that the latter network varies the phase of the video I.F. input to the phase locked loop until the phase of the oscillator signal has a selected phase relationship to the video I.F. signal input to the synchronous detector.