Patent US3567861A successfully refreshed from Google Patents.
US3567861A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video/sync processor
Assignee: National Aeronautics and Space Administration
•
Filing: 1968-12-11
•
Granted: 1971-03-02
•
Expires: 1988-12-11
Abstract
Abstract A video sync processor which includes a phase locked loop which compares the horizontal sync of an incoming video signal to the horizontal sync of a local sync generator and thereby locks a voltage control oscillator of the processor to a master oscillator carried in the remote transmitting station. In this manner all local processing equipment is referenced to the remote master oscillator. Frequently, when signals are received from remote stations, such as spacecrafts, there is a low signal-tonoise ratio and the quality of the signal is poor. In order to improve the stability of the composite signal the sync and blanking portion are stripped from the incoming video signals and a clean sync and blanking signal from the local sync generator is inserted therein. Therefore, as long as horizontal phase-lock is maintained all ground recording and monitoring equipment are presented with video and clean sync regardless of the signal-tonoise ratio of the signal received.
Inventors
- 👤 Darrow L Webb
- 👤 Francis Byrne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:46
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/06; H04N5/067
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
429 words
A system for removing the vertical and horizontal sync signal portions from a composite video signal received from a remote station such as a space vehicle and reconstructing the signal with a new clean sync signal portion comprising: A. a sync separator; B. means for supplying said remote composite signal to said sync separator for separating the horizontal and vertical sync signal portions from said composite signal; C. a local sync generator producing local sync and blanking signals; D. a voltage controlled oscillator coupled to the input of said local sync generator for providing an input signal thereto: E. a phase detector coupled to said output of said sync separator for receiving the horizontal sync portion of said remote composite video signal; F. means for supplying said local sync signal to said phase detector to be compared with said horizontal sync portion of said remote composite video signal; G. said phase detector generating an output signal indicating the frequency difference between said local sync signal and said horizontal sync portion of said remote signal; H. means for coupling said signal indicating the frequency difference to said voltage controlled oscillator for changing the frequency of said voltage controlled oscillator which makes the local sync generator come back in phase with said remote horizontal sync signal; I. means for including a loop filter for maintaining the frequency of said voltage controlled oscillator near its normal operating value when said remote signal is temporarily lost; J. a video switcher having an input means for receiving blanking pulses and sync signals; K. input means for coupling said remote composIte signal to said video switcher; L. means for coupling said local sync and blanking signals from said sync generator to said video switcher for removing said sync signals from said remote composite video signal and combining said local sync with the video portion of said remote composite video signal; M. a vertical integrator; N. a vertical phase comparator coupled to the input of said integrator; O. means for coupling said remote vertical sync signal portion from said sync separator to said vertical phase comparator through said integrator; P. means for supplying a local vertical signal from said sync generator to said vertical phase comparator to be compared with said remote vertical sync signal portion; and Q. means for coupling the output of said vertical phase comparator to said sync generator for resetting said sync generator when said local vertical signal is out of phase with said remote vertical sync signal portion to synchronize said local sync signal with said remote vertical sync signal portion.
Claim 2
Independent Claim
429 words
A system for removing the vertical and horizontal sync signal portions from a composite video signal received from a remote station such as a space vehicle and reconstructing the signal with a new clean sync signal portion comprising: A. a sync separator; B. means for supplying said remote composite signal to said sync separator for separating the horizontal and vertical sync signal portions from said composite signal; C. a local sync generator producing local sync and blanking signals; D. a voltage controlled oscillator coupled to the input of said local sync generator for providing an input signal thereto: E. a phase detector coupled to said output of said sync separator for receiving the horizontal sync portion of said remote composite video signal; F. means for supplying said local sync signal to said phase detector to be compared with said horizontal sync portion of said remote composite video signal; G. said phase detector generating an output signal indicating the frequency difference between said local sync signal and said horizontal sync portion of said remote signal; H. means for coupling said signal indicating the frequency difference to said voltage controlled oscillator for changing the frequency of said voltage controlled oscillator which makes the local sync generator come back in phase with said remote horizontal sync signal; I. means for including a loop filter for maintaining the frequency of said voltage controlled oscillator near its normal operating value when said remote signal is temporarily lost; J. a video switcher having an input means for receiving blanking pulses and sync signals; K. input means for coupling said remote composIte signal to said video switcher; L. means for coupling said local sync and blanking signals from said sync generator to said video switcher for removing said sync signals from said remote composite video signal and combining said local sync with the video portion of said remote composite video signal; M. a vertical integrator; N. a vertical phase comparator coupled to the input of said integrator; O. means for coupling said remote vertical sync signal portion from said sync separator to said vertical phase comparator through said integrator; P. means for supplying a local vertical signal from said sync generator to said vertical phase comparator to be compared with said remote vertical sync signal portion; and Q. means for coupling the output of said vertical phase comparator to said sync generator for resetting said sync generator when said local vertical signal is out of phase with said remote vertical sync signal portion to synchronize said local sync signal with said remote vertical sync signal portion.
Claim 3
Dependent Claim
111 words
The system as set forth in claim 1 wherein said remote video signal is a commutated signal and further comprising: A. a plurality of combined video switchers and decommutators; B. means for supplying said commutated signal to said combined video switchers and decommutators; C. means for supplying a switching signal to said combined video switchers and decommutators for causing said remote video signal to be decommutated; and D. means for coupling said local sync and blanking signals from said sync generator to said combined video switchers and decommutators for cancelling said signals from said remote composite video signal and combining said local sync with the video portion of said decommutated signals.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |