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. 02, 1999
Filed:
Feb. 20, 1996
Jurgen H Geerlings, Tadley, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A device for deriving a clock signal having a specific frequency, from an electrical signal, for example, a video signal, the device including an input terminal (1) for receiving the synchronizing signal; a phase comparator (5) having a first input coupled to the input terminal, a second input and an output; a voltage controlled oscillator (15) having an input coupled to the output of the phase comparator, and an output; a counter (23) having a first input coupled to the output of the voltage controlled oscillator, a second input for receiving a preset control signal, and an output coupled to the second input of the phase comparator; a preset control signal generator (30) having an input coupled to the input terminal, and an output coupled to the second input of the counter, the counter being adapted to set its count value to a preset value in response to the preset control signal applied to its preset control signal input. The preset control signal generator includes a window signal generator (48) for determining a window signal in response to a specified count value in the counter; and a detector (34, 36) for detecting whether at least one edge in the synchronizing signal falls outside a time interval defined by the window signal, and for generating the preset control signal in response to this detection, the detector having an input coupled to the input of the preset control signal generator and an output coupled to the output of the preset control signal generator.