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US 4,729,024 AGranted
Synchronizing pulse signal generation device
AssigneeCanon Kabushiki Kaisha
InventorsHisashi Kawai, Makoto Masunaga, Tuguhide Sakata, Masahiro Takei, Kenichi Nagasawa
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Abstract
A synchronizing pulse signal generation device separates horizontal and vertical synchronizing signals from a video signal; generates a clock signal which is phase locked relative to the phase of the horizontal synchronizing signal; and generates, by using the clock signal, a synchronizing pulse signal which is phase locked relative to the vertical and horizontal synchronizing signals.
Claims14
A synchronizing pulse signal generation device, comprising:
- (A) first means for forming a clock pulse signal which is phase locked relative to a first periodic signal, said first means including:
- (a) a phase comparator which generates a phase error signal corresponding to a phase difference between two input signals, one of said two input signals being said first periodic signal;
- (b) a variable frequency oscillator;
- and
- (c) means for controlling an oscillation frequency of said variable frequency oscillator by selectively using a level of said phase error signal and a predetermined level;
- and
- (B) second means which uses said clock pulse signal together with a second periodic signal of a longer period than said first periodic signal for generating a pulse signal phase-locked relative to both said first and second periodic signals, said second means including means for generating a first pulse signal which is of the same period as said first periodic signal by using said clock pulse signal, said first pulse signal being supplied to said phase comparator as the other input signal of said phase comparator.
4 more elements
A synchronizing pulse signal generation device, comprising:
- (A) first means for forming a clock pulse signal which is phase locked relative to a first periodic signal, said first means including:
- (a) a phase comparator which generates a phase error signal corresponding to a phase difference between two input signals, one of said two input signals being said first periodic signal;
- and
- (b) a variable frequency oscillator which has an oscillation frequency thereof controlled on the basis of said phase error signal;
- and
- (B) second means which uses said clock pulse signal together with a second periodic signal of a longer period than said first periodic signal for generating a pulse signal phase-locked relative to both said first and second periodic signals, said second means including:
- (a) means for generating a first pulse signal which is of the same period as said first periodic signal by using said clock pulse signal;
- and
- (b) means for adjusting the phase of said first pulse signal.
6 more elements
Dependencies are inferred from the claim text.