Patent US4754330A successfully refreshed from Google Patents.
US4754330A
Expired / Lapsed
US
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Display deflection control loop
Assignee: BAE Systems Aerospace Inc
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Filing: 1987-07-22
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Granted: 1988-06-28
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Expires: 2007-07-22
Abstract
Abstract A system for synchronizing a succession of horizontal deflection coil currents of a CRT display with a succession of synchronization signals includes a variable delay which is strobed by a synchronization signal and triggers the generation of a deflection current after a specified delay. The delay is automatically controlled by a feedback loop in which the present delay is measured by a set-reset flip-flop, the flip-flop providing an output pulse having a duration equal to the delay. An integrator averages a train of output pulses from the flip-flop, and combines a reference signal with the average value to provide the control signal for the delay. The system operates with minimal bandwidth and with dynamics which are free of acquisition constraints so as to provide minimal sensitity to noise.
Inventors
- 👤 Robert H. Spieth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:27
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
127 words
A display deflection synchronization circuit for synchronizing the occurrence of a succession of display deflection signals with the occurrence of a succession of synchronization signals, the circuit comprising: means for detecting a difference in phase between the deflection signals and the synchronization signals, said detecting means providing an output signal indicating a magnitude of said difference; means coupled to said detecting means for integrating said output signal to provide an average value thereof; deflection means providing said deflection signals; and trigger means driven by said synchronization signals for strobing said deflection means to provide said deflection signals, said trigger means consisting of a monostable multivibrator for strobing relative to a synchronization signal, said vibrator being operative in response to said average value provided by said integrating means.
Claim 2
Dependent Claim
127 words
A display deflection synchronization circuit for synchronizing the occurrence of a succession of display deflection signals with the occurrence of a succession of synchronization signals, the circuit comprising: means for detecting a difference in phase between the deflection signals and the synchronization signals, said detecting means providing an output signal indicating a magnitude of said difference; means coupled to said detecting means for integrating said output signal to provide an average value thereof; deflection means providing said deflection signals; and trigger means driven by said synchronization signals for strobing said deflection means to provide said deflection signals, said trigger means consisting of a monostable multivibrator for strobing relative to a synchronization signal, said vibrator being operative in response to said average value provided by said integrating means.
Claim 3
Dependent Claim
43 words
A circuit according to claim 1 wherein said integrating means includes means for combining said average value with a reference signal, the resulting average value representing a shift in said phase from a desired value of said phase designated by said reference signal.
Claim 4
Dependent Claim
43 words
A circuit according to claim 2 wherein phase detecting means comprises a flip-flop set by said synchronization signals and reset by said deflection signals, the duration of pulses of said output signal being a measure of time delay between synchronization and deflection signals.
Claim 5
Dependent Claim
28 words
A circuit according to claim 3 wherein said deflection means includes a coil and a coil driver, said deflection signal being a sample of a current flyback signal.
Claim 6
Independent Claim
112 words
A system for synchronizing a succession of deflection coil currents of a CRT display with a succession of synchronization signals comprising: means for generating a signal sample characteristic of a deflection coil current; means for measuring delay between each of the succession of deflection signal samples and corresponding signals of said succession of synchronization signals to provide a measure thereof; and trigger means coupled to said measuring means and driven by said synchronization signals for triggering the generation of a deflection coil current, said trigger means consisting of a monostable multivibrator for delaying a strobing signal relative to a synchronization signal, said vibrator being operative in response to said measure of delay.
Claim 7
Independent Claim
112 words
A system for synchronizing a succession of deflection coil currents of a CRT display with a succession of synchronization signals comprising: means for generating a signal sample characteristic of a deflection coil current; means for measuring delay between each of the succession of deflection signal samples and corresponding signals of said succession of synchronization signals to provide a measure thereof; and trigger means coupled to said measuring means and driven by said synchronization signals for triggering the generation of a deflection coil current, said trigger means consisting of a monostable multivibrator for delaying a strobing signal relative to a synchronization signal, said vibrator being operative in response to said measure of delay.
Claim 8
Dependent Claim
36 words
A system according to claim 5 wherein said measuring means includes means for integrating said delay measure to provide an average value thereof, said average value of said delay measure being applied to said trigger means.
Claim 9
Dependent Claim
38 words
A system according to claim 6 wherein said integrating means includes means for combining said average value with a reference signal, the resulting average value representing a shift in said delay from a desired value of said delay.
Claim 10
Dependent Claim
39 words
A system according to claim 7 wherein said measuring means comprises a flip-flop set by said synchronizing signals and reset by said deflection signal samples, the duration of an output signal of said flip-flop constituting said measure of delay.
Claim 11
Dependent Claim
33 words
A system according to claim 8 wherein said deflection signal sample is obtained from a flyback of said coil current upon termination of the current at the end of a horizontal line scan.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |