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, 1981
Filed:
Dec. 14, 1979
Kiyonori Tominaga, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A phase-tracking loop circuit which can be used, for example, as an FM detector or as a frequency-tracking control circuit to control the index signal of a beam-index cathode ray tube (CRT), includes an adder receiving an input signal of fluctuating frequency, a tracking filter coupled to the output of the adder and whose passband center frequency is shiftable, in response to a control voltage, to follow changes in the frequency of the input signal, an attenuator feeding an attenuated version of the output from the tracking filter back to the adder for combining in the latter with the input, and a phase comparator comparing the phase of the output of the adder with the output of the tracking filter to provide a corresponding control voltage to the tracking filter. If used as an FM detector, the control voltage can also constitute a demodulated signal. If used to control color switching in a beam index CRT, a controlled signal tracking the phase of the index signal can be derived from a phase-locked loop circuit which provides one of the inputs to the phase comparator in response to the output of the tracking filter.