Synchronous video detector circuit using phase-locked loop

Details Synchronous video detector circuit using phase-locked loop Synchronous video detector circuit using phase-locked loop

1982-11-02

1985-06-18

Chin, Tommy P.

Facsimile and static presentation processing

Facsimile

Specific signal processing circuitry

358167, 358197, 455202, H04N 544, H04B 168

Patent

active

045243891

ABSTRACT:
In a synchronous video detector circuit using a phase-locked loop, the synchronous detection of a video IF signal is effected with a synchronous carrier signal reproduced by the PLL including a voltage-controlled oscillator. Each of a phase comparator of the PLL and a synchronous video detector has its input terminal connected to an output terminal of a video IF amplifier by untuned coupling, and arranged on the output side of the synchronous video detector is a phase-locked mode detector for detecting that the PLL is in its phase-locked mode. The phase-locked mode detector is adapted to control the band width of a low-pass filter of the PLL in either a narrow band mode or a wide band mode and the low-pass filter is controlled to operate in the narrow band mode only when the PLL is in the phase-locked mode of operation. The black and white noise included in the output signal of the synchronous video detector are both cancelled by a noise cancellation circuit including a black noise detector for pulse noise cancellation purposes.

REFERENCES:
patent: 4336616 (1982-06-01), Carson et al.

Affiliated with

Also associated with

Rating

Synchronous video detector circuit using phase-locked loop does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Synchronous video detector circuit using phase-locked loop, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synchronous video detector circuit using phase-locked loop will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-982975