US4081833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronizing signal separating circuit for television video signal processing
Assignee: NEC Corp
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Filing: 1976-02-13
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Granted: 1978-03-28
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Expires: 1996-02-13
Abstract
Abstract A synchronizing pulse separating circuit provides synchronizing pulser from an incoming composite television signal wave including such a wave formed of switched plural individual television signals of differing array D.C. level. The pulse separating circuit employs keyed clamping circuitry to clamp the peak synchronizing levels of the incoming wave to a reference level, and clipping circuitry directly coupled to the clamping circuitry to provide output synchronizing pulses responsive to the clamped incoming, such pulses. The output synchronizing pulse train is also employed to key on the clamp circuit.
Inventors
- 👤 Hideo Akiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:36
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
93 words
In combination in television wave synchronizing pulse separating apparatus, a source of reference potential, keyed clamping means for clamping synchronizing pulse peaks of the television wave to said reference potential responsive to an applied keying pulse, clipping means responsive to said clamped television wave synchronizing pulser for producing an output synchronizing pulse train, direct current feedback means for coupling said output synchronizing pulse train to said keyed clamping means to serve as said keying pulser, and D.C. coupling means coupling the output of said clamping means and the input of said clipping means.
Claim 2
Dependent Claim
93 words
In combination in television wave synchronizing pulse separating apparatus, a source of reference potential, keyed clamping means for clamping synchronizing pulse peaks of the television wave to said reference potential responsive to an applied keying pulse, clipping means responsive to said clamped television wave synchronizing pulser for producing an output synchronizing pulse train, direct current feedback means for coupling said output synchronizing pulse train to said keyed clamping means to serve as said keying pulser, and D.C. coupling means coupling the output of said clamping means and the input of said clipping means.
Claim 3
Dependent Claim
45 words
A combination as in claim 1 wherein said keyed clamping means includes a series coupling capacitor, a controlled switch connecting said capacitor to said source of reference potential and controlled by said output synchronizing pulse train, and resistance means in parallel with said controlled switch.
Claim 4
Dependent Claim
30 words
A combination as in claim 2 wherein the time constant defined by said capacitor and the conduction impedance of said controlled switch is substantially shorter than an horizontal scanning period.
Claim 5
Dependent Claim
24 words
A combination as in claim 3 wherein the time constant defined by said capacitor and said shunt resistance means exceeds an horizontal scanning period.
Claim 6
Dependent Claim
16 words
A combination as in claim 4 wherein said D.C. coupling means includes a buffer D.C. amplifier.
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) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |