Video signal clamping circuit operating in the digital domain fo

Details Video signal clamping circuit operating in the digital domain fo Video signal clamping circuit operating in the digital domain fo

1990-01-31

1991-10-15

Peng, John K.

Facsimile and static presentation processing

Facsimile

Specific signal processing circuitry

358172, 358170, H04N 516, H04N 518, H04N 514

Patent

active

050579207

ABSTRACT:
In a video signal clamping circuit, a FIFO register stores a sequence of digital samples of an input video signal taken during a portion of a horizontal blanking interval of the signal during which the signal is at a black level. A black level error PROM generates a digital error signal representing any deviation between a digital sample from the FIFO register and a reference black level. An accumulator accumulates digital error signals supplied thereto by the PROM to produce an accumulated digital error signal which is converted to analog form by a digital-to-analog converter. A clock controls the supply of the stores samples in sequence from the FIFO register to the PROM such that the samples are supplied, during a line-active period that follows the horizontal blanking interval, at a clock frequency which is less than the sampling frequency. The analog error signal is combined with the input video signal in an operational amplifier to cause the black level of the input video signal to approach the reference black level.

REFERENCES:
patent: 3207998 (1965-09-01), Corney et al.
patent: 3670100 (1972-06-01), Briggs et al.
patent: 4110790 (1978-08-01), Wheeler
patent: 4403253 (1983-09-01), Morris et al.
patent: 4562471 (1985-12-01), Eouzan et al.
patent: 4651213 (1987-03-01), Takimoto
patent: 4663666 (1987-05-01), Bloom
patent: 4742392 (1988-05-01), Hashimoto
patent: 4811087 (1989-03-01), Engel et al.
patent: 4811101 (1989-03-01), Yagi

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