Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1984-11-27
1987-03-17
Britton, Howard W.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358171, H04N 518
Patent
active
046512136
ABSTRACT:
A feedback clamping circuit for producing a drift error free digital signal from an input analog video signal. The circuit includes a differential amplifier which receives the input analog signal and an error signal. At its output, the differential amplifier delivers a drift free analog video output. To produce the error signal, the output of the differential amplifier is digitized and supplied to a switching circuit. A reference signal is also supplied to the switching circuit. Alternatively, the switching circuit supplies the two signals it receives to a D/A and from there to first and second sample and hold circuits. A comparator compares the level of the two signals that are supplied by the switching circuit and produces the error signal from them. The video signal is sampled during its pedestal phase and the reference signal shortly thereafter. The difference amplifier adjusts its output to minimize the level of the error signal.
REFERENCES:
patent: 4124869 (1978-11-01), Heitmann
patent: 4473846 (1984-09-01), Mackereth
patent: 4562471 (1985-12-01), Eouzan et al.
Britton Howard W.
Kostak Victor R.
NEC Corporation
LandOfFree
Clamping apparatus for a video signal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Clamping apparatus for a video signal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clamping apparatus for a video signal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1791536