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. 21, 1987
Filed:
Dec. 24, 1985
Wolfgang F Dietz, New Hope, PA (US);
Sammy S Henig, Secaucus, NJ (US);
RCA Corporation, Princeton, NJ (US);
Abstract
A phase-lock loop circuit of a television apparatus is synchronized by a horizontal synchronizing input signal. The phase-lock loop circuit includes a frequency-to-voltage converter that is responsive, during vertical trace, to the synchronizing input signal for generating a control voltage indicative of the frequency of the synchronizing input signal. During vertical trace, the control voltage varies the free running frequency of a controlled oscillator of the phase-lock loop circuit such that the free running frequency of the oscillator is directly related to the frequency of the input signal. During vertical retrace, the frequency-to-voltage converter is responsive to the oscillator output signal for generating the control signal that maintains the free running frequency of the oscillator substantially unchanged during vertical retrace. The phase of the output signal of the oscillator is controlled by a signal that is indicative of the phase difference between the oscillator output signal and the synchronizing input signal.