Video signal data and composite synchronization extraction circu

Television – Synchronization – Automatic phase or frequency control

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

348545, 348536, 348464, H04N 708

Patent

active

055963722

ABSTRACT:
A composite synchronization extraction circuit is particularly suited for receiving composite video signals containing closed captioning data in raster scan line 21 by means of a signal CMOS integrated circuit device. A dual mode voltage clamp is realized in CMOS technology. The clamp includes temperature compensated current sources in the form of complementary current mirrors through which a clamped composite synchronization node of is charged and discharged, the output of which controls a transistor for charging the composite synchronization node. Detected pulse amplitude is set by slicing the incoming pulse at the back porch level and then doubling the amplitude with an amplifier and comparing that level with the back porch level as derived from a sample-and-hold device. The slice voltage level is maintained without an off-chip capacitor by an analog-digital-analog conversion process. Frequency and phase synchronization is accomplished by a combination of frequency lock loop and phase lock loop working in concert to generate a control voltage for a voltage controlled oscillator in a flywheel mode. The voltage controlled oscillator is not subject to noise in the incoming signal and provides a clean source of timing information for the circuit. The effects of impulse noise in the detection of the vertical retrace pulse are eliminated by the use of digital counting circuits to count the requisite number of horizontal synchronization pulses which occur between valid retrace pulses and to block pulses which appear at other times.

REFERENCES:
patent: 3781695 (1973-12-01), Jackson
patent: 4310854 (1982-01-01), Baer
patent: 4430742 (1984-02-01), Milleker et al.
patent: 4449145 (1984-05-01), Ciciora
patent: 4554584 (1985-11-01), Elam et al.
patent: 4595952 (1986-01-01), Filliman
patent: 4595953 (1986-06-01), Willis
patent: 4620227 (1986-10-01), Levis
patent: 4633297 (1986-12-01), Skerlos et al.
patent: 4647974 (1987-03-01), Butler et al.
patent: 4667235 (1987-05-01), Nozoe et al.
patent: 4698677 (1987-10-01), Kinghorn et al.
patent: 4701794 (1987-10-01), Froling et al.
patent: 4719510 (1988-01-01), Kinghorn
patent: 4725886 (1988-02-01), Galumbeck et al.
patent: 4731587 (1988-03-01), Jensen
patent: 4739402 (1988-04-01), Maeda et al.
patent: 4803680 (1989-02-01), Rokugo et al.
patent: 4829569 (1989-05-01), Seth-Smith et al.
patent: 4837620 (1989-06-01), Harvey
patent: 4845662 (1989-07-01), Tokumitsu
patent: 4849818 (1989-07-01), Hartmann et al.
patent: 4857999 (1989-08-01), Welsh
patent: 4890321 (1989-12-01), Seth-Smith et al.
patent: 4894714 (1990-01-01), Christis
patent: 4894789 (1990-01-01), Yee
patent: 4908706 (1990-03-01), Bugg
patent: 4908707 (1990-03-01), Kinghorn
patent: 4910595 (1990-03-01), Bugg et al.
patent: 4912555 (1990-03-01), Van Gestel
patent: 4931870 (1990-06-01), den Hollander
patent: 4933764 (1990-06-01), Kinghorn
patent: 4933959 (1990-06-01), Knechtel
patent: 4954882 (1990-09-01), Kamemoto
patent: 4977455 (1990-12-01), Young
patent: 4991017 (1991-02-01), Raaijmakers
patent: 4991018 (1991-02-01), Davies
patent: 4992871 (1991-02-01), Bensch et al.
patent: 4999706 (1991-03-01), Kinghorn
patent: 5003390 (1991-03-01), Helgert et al.
patent: 5008750 (1991-04-01), Gomikawa
patent: 5010499 (1991-04-01), Yee
patent: 5012338 (1991-04-01), Davis
patent: 5019907 (1991-05-01), Murakoshi et al.
patent: 5023721 (1991-06-01), Moon-Hwan
patent: 5038212 (1991-08-01), Van Den Hombergh et al.
patent: 5045941 (1991-09-01), Davies
patent: 5052031 (1991-09-01), Molloy

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Video signal data and composite synchronization extraction circu does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Video signal data and composite synchronization extraction circu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Video signal data and composite synchronization extraction circu will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2327922

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.