US3628159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Locking of television synchronism generators
Assignee: Pye Electronic Products Ltd
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Filing: 1969-10-08
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Granted: 1971-12-14
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Expires: 1989-10-08
Abstract
Abstract A circuit for synchronizing a local television synchronizing oscillator with a remote one has a second phase discriminator coupled to receive the local and remote synchronizing signals. It generates an output voltage that is applied to a varicap of an integrating circuit that receives the local sync signal so that the time constant varies with phase difference of the signals. A first phase discriminator receives the remote sync signal and the integrated local sync signal and applies a control voltage to the local oscillator for synchronizing it with the remote oscillator.
Inventors
- 👤 Richard John Godwin Ellis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:18
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/10; H04; H04N; H04N5/00; H04N5/04; H04N5/06; H04N5/067; H04N5/073
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A circuit comprising an oscillator; means for deriving a signal from said oscillator; integrating means coupled to said deriving means and having a variable time constant; a first phase discriminator having a first input coupled to said integrating means, a second input coupled to receive a remote synchronization signal, and an output coupled to said oscillator for frequency and phase control thereof; and a second phase discriminator having a first input coupled to receive said remote synchronization signal, a second input coupled to said deriving means, and an output coupled to said integrating means for controlling the time constant thereof as a function of the phase difference between the input signals of said second discriminator.
Claim 2
Dependent Claim
115 words
A circuit comprising an oscillator; means for deriving a signal from said oscillator; integrating means coupled to said deriving means and having a variable time constant; a first phase discriminator having a first input coupled to said integrating means, a second input coupled to receive a remote synchronization signal, and an output coupled to said oscillator for frequency and phase control thereof; and a second phase discriminator having a first input coupled to receive said remote synchronization signal, a second input coupled to said deriving means, and an output coupled to said integrating means for controlling the time constant thereof as a function of the phase difference between the input signals of said second discriminator.
Claim 3
Dependent Claim
43 words
A circuit as claimed in claim 1 wherein said deriving means comprises means for producing a square wave and said integrating means produces a ramp waveform having a steeper slope when said time constant is short as compared to when it is long.
Claim 4
Dependent Claim
44 words
A circuit as claimed in claim 1 wherein said integrating means comprises a resistor and a voltage-variable capacitor coupled to said resistor; and said second discriminator output is coupled to said capacitor and produces a variable voltage that controls the capacity of said capacitor.
Claim 5
Dependent Claim
16 words
A circuit as claimed in claim 1 wherein said deriving means comprises a bistable trigger circuit.
Claim 6
Dependent Claim
65 words
A circuit as claimed in claim 4 whErein said trigger circuit comprises a set input, a reset input, and an output coupled to said second discriminator second input and said integrating means; and said deriving means further comprises a first synchronization separator having a field signal output coupled to both of said trigger circuit inputs, and a frame signal output coupled to said reset input.
Claim 7
Dependent Claim
54 words
A circuit as claimed in claim 1 further comprising a pulse generator having an input coupled to receive said remote synchronization signal and an output means coupled to said first discriminator second input for generating pulses having a shorter duration than that of said remote synchronization signal applied to said second discriminator first input.
Claim 8
Dependent Claim
45 words
A circuit as claimed in claim 6 further comprising a second synchronization separator having an input coupled to receive a remote video signal and an output means coupled to said pulse generator input and said second discriminator first input for producing said remote synchronization signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |