US3814854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of synchronizing television compatible signal generating equipment to composite synchronization signals
Assignee: Datavision Inc
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Filing: 1971-10-04
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Granted: 1974-06-04
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Expires: 1991-10-04
Abstract
Abstract To synchronize vertical and horizontal sync pulses produced by an auxiliary television generator, external reference sync pulses received via standard transmission are inverted and applied to the input of an AND gate along with the uninverted internallygenerated sync pulses. The output of the AND gate is inverted and applied to start and stop a fixed-frequency oscillator providing the time base for internal sync pulse generation. The oscillator is turned off intermittently by the inverted AND gate output to delay the internal sync pulse signal sufficiently to correct for its overall phase difference relative to the reference sync pulse signal. Individual sync pulses are also delayed to correct for frequency mismatch so long as the internal sync signal frequency is from zero to 8 percent higher than the external signal frequency.
Inventors
- 👤 P Edwards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:02
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/06; H04N5/067; H04N5/073
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
215 words
A TV synchronizing system for directly superimposing an auxiliary TV picture on a standard TV picture, comprising means for receiving an external standard TV composite sync pulse signal in binary form, internal timing means for generating an internal TV sync pulse signal in binary form having a format identical to that of the external sync signal, independently fixed frequency oscillator means for producing a time-base output of independent frequency to said internal timing means such that said internal signal has an independently fixed nominal frequency higher than the corresponding nominal frequency of the external sync signal, logic means connected to said oscillator means for operatively receiving both the external and internal sync signals for producing a control output to stop said oscillator means on the occurrence of the predetermined coincidence of one state in said internal sync signal and the other state in the external sync signal and to start said oscillator means on the termination of said predetermined coincidence so as to alter pulsewidths within said internal sync signal to accommodate the frequency difference between said internal and external sync signals and to synchronize the phase of said external and internal signals, and video-generator means connected to said internal timing means for producing a picture output timed in accordance with said internal sync signal.
Claim 2
Dependent Claim
215 words
A TV synchronizing system for directly superimposing an auxiliary TV picture on a standard TV picture, comprising means for receiving an external standard TV composite sync pulse signal in binary form, internal timing means for generating an internal TV sync pulse signal in binary form having a format identical to that of the external sync signal, independently fixed frequency oscillator means for producing a time-base output of independent frequency to said internal timing means such that said internal signal has an independently fixed nominal frequency higher than the corresponding nominal frequency of the external sync signal, logic means connected to said oscillator means for operatively receiving both the external and internal sync signals for producing a control output to stop said oscillator means on the occurrence of the predetermined coincidence of one state in said internal sync signal and the other state in the external sync signal and to start said oscillator means on the termination of said predetermined coincidence so as to alter pulsewidths within said internal sync signal to accommodate the frequency difference between said internal and external sync signals and to synchronize the phase of said external and internal signals, and video-generator means connected to said internal timing means for producing a picture output timed in accordance with said internal sync signal.
Claim 3
Dependent Claim
28 words
The system of claim 1, wherein said frequency of said internal sync signal is up to 8 percent higher than the corresponding frequency of said external sync signal.
Claim 4
Dependent Claim
24 words
The system of claim 2 further comprises high frequency modulation means for superimposing said picture output on a carrier frequency for standard television reception.
Claim 5
Dependent Claim
64 words
The system of claim 2 wherein said logic means includes inverter means connected to receive and invert the external sync signal, AND gate means operatively receiving the internal sync signal and the inverted external sync signal for producing an output indicative of said predetermined coincidence, said oscillator means being responsive to said AND gate means output for starting and stopping oscillation in accordance therewith.
Claim 6
Dependent Claim
24 words
The system of claim 4, wherein said logic means includes another inverter means connected between said oscillator means and said AND gate means output.
Claim 7
Independent Claim
172 words
A system for synchronizing auxiliary signal-generating equipment with an external precoded composite binary pulse timing signal, comprising internal timing means for generating an internal binary pulse timing signal having a format identical to that of said external binary timing signal, independently fixed frequency oscillator means for producing a time-base output of independent frequency to said internal timing means such that said internal signal has an independently fixed nominal frequency higher than the corresponding nominal frequency of the external signal, logic means connected to said oscillator means and operatively receiving both said external and internal signals for producing a control output to stop said oscillator means on the occurrence of the predetermined coincidence of one state in said internal signal and the other state in said external signal and to start said oscillator means on the termination of said predetermined coincidence so as to alter pulsewidths within said internal signal to accommodate the frequency difference between said internal and external signals and to synchronize the phase of said internal and said external signals.
Claim 8
Independent Claim
172 words
A system for synchronizing auxiliary signal-generating equipment with an external precoded composite binary pulse timing signal, comprising internal timing means for generating an internal binary pulse timing signal having a format identical to that of said external binary timing signal, independently fixed frequency oscillator means for producing a time-base output of independent frequency to said internal timing means such that said internal signal has an independently fixed nominal frequency higher than the corresponding nominal frequency of the external signal, logic means connected to said oscillator means and operatively receiving both said external and internal signals for producing a control output to stop said oscillator means on the occurrence of the predetermined coincidence of one state in said internal signal and the other state in said external signal and to start said oscillator means on the termination of said predetermined coincidence so as to alter pulsewidths within said internal signal to accommodate the frequency difference between said internal and external signals and to synchronize the phase of said internal and said external signals.
Claim 9
Dependent Claim
28 words
The system of claim 6, wherein said frequency of said internal timing signal is up to 8 percent higher than the corresponding frequency of the external timing signal.
Claim 10
Dependent Claim
21 words
The system of claim 7 further comprising information signal generating means connected to receive the internal timing signal and controlled thereby.
Claim 11
Dependent Claim
65 words
The system of claim 8 wherein said logic means includes inverter means connected to receive and invert the external timing signal, AND gate means operatively receiving the internal timing signal and the inverted external timing signal for producing an output indicative of said predetermined coincidence, said oscillator being responsive to the output of said AND gate means for starting and stopping oscillation in accordance therewith.
Claim 12
Dependent Claim
24 words
The system of claim 9, wherein said logic means includes another inverter means connected between said oscillator means and said AND gate means output.
References Cited (Backward Citations)
US2752424A
Cited
US3069504A
Cited
US3187261A
Cited
US3518374A
Cited
US3532806A
Cited
US3639838A
Cited
US3562415A
Cited
US3567861A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |