Television – Synchronization – Automatic phase or frequency control
Patent
1997-01-29
1998-07-21
Grant, Chris
Television
Synchronization
Automatic phase or frequency control
348529, H04N 508
Patent
active
057841217
ABSTRACT:
A vertical synchronization signal detector for detecting a vertical synchronization signal in a composite video signal. The detector comprises an input (1) for receiving the composite video signal, a first detector (4,16,22) for detecting equalization pulses occurring in the composite video signal and for generating a first detection signal upon detection of an equalization pulse, a second detector (4,16,20) for detecting horizontal sync pulses occurring in the composite video signal and for generating a second detection signal upon detection of an horizontal sync pulse, a third detector (4,12) for detecting negative going pulses occurring in the composite video signal that have a longer duration than the horizontal sync pulses and for generating a third detection pulse upon detection of such a pulse, a first signal combination unit (FF1) for generating a fourth detection signal (VBI) in response to at least one first and second detection signal generated by the first and second detector respectively, a first counter (58) for counting, when being enabled, the number of occurrences of second detection signals generated by the second detector and for generating a first control signal upon the detection of n occurrences of such second detection signals, where n is a constant integer larger than 1. Further, a second signal combination unit (AND) is provided for combining the third and fourth detection signals so as to obtain a second control signal. A third signal combination unit (FF2) receives the first control signal generated by the first counter and the second control signal from the second signal combination unit and generates in response thereto an output signal which is indicative of the occurrence of the vertical synchronization signal. The first counter is in an enabled state upon the presence of the output signal of the third signal combination unit (FF2).
REFERENCES:
patent: 4459612 (1984-07-01), Shinkai et al.
patent: 4684988 (1987-08-01), Johannes
patent: 5189515 (1993-02-01), Chen
Patent Abstacts of Japan, vol. 18, No. 470, E-1600, abstract of JP, A, 6-153023 (Sony Corp), 31 May 1994 (May 31, 1994).
Goodman Edward W.
Grant Chris
U.S. Philips Corporation
LandOfFree
Vertical synchronisation signal detector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vertical synchronisation signal detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vertical synchronisation signal detector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1651450