Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1992-09-11
1994-01-18
Powell, Mark R.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358172, 358 34, 358153, H04N 516, H04N 518, H04N 972, H04N 508
Patent
active
052803562
ABSTRACT:
The clamp circuit of the present invention includes a comparator 10, a pulse signal generating circuit 10, an integrating circuit 17 and a subtractor 17. The comparator compares a composite video signal with a threshold potential and detects a composite synchronizing signal. The pulse signal generating circuit generates pulse signals indicative of which of the detected composite synchronizing signal and a reference time period is larger. The integrating circuit corrects a threshold potential in response to the pulse signals and such that the pulse width of the horizontal synchronizing signal of the composite video signal corresponds to the reference time period t. The subtractor subtracts the threshold potential from the composite video signal, so as to fix the DC level of the composite video signal at a prescribed potential. Since a threshold potential which makes constant the pulse width of the synchronizing pulse signals is generated and the video signal is clamped by using this threshold potential, the video signal including the synchronizing signal is made less susceptible to the influence of noise and the like, and clamping operation of the video signal can be done more accurately.
REFERENCES:
patent: 4064541 (1977-12-01), Schneider et al.
patent: 4369466 (1983-01-01), Matsuzaki et al.
patent: 4403251 (1983-09-01), Okada et al.
patent: 4707741 (1987-11-01), Stratton
patent: 4860099 (1989-08-01), Kuwajima
patent: 5057920 (1991-10-01), Wilkinson
patent: 5105272 (1992-04-01), Kanai
patent: 5105276 (1992-04-01), Schrock
patent: 5140421 (1992-08-01), Sumiyoshi
patent: 5142354 (1992-08-01), Suzuki et al.
English translation of Abstr. of Japanese Appln. No. 63-210480.
English translation of Abstr. of Japanese Appln. No. 63-305675.
English translation of Abstract of Japan Application No. 2-22966.
Hiramatsu Yonejiro
Sakatsuji Osamu
Miller John W.
Powell Mark R.
Sharp Kabushiki Kaisha
LandOfFree
Clamp circuit for clamping video signal including synchronizing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Clamp circuit for clamping video signal including synchronizing , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clamp circuit for clamping video signal including synchronizing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1139817