US3706847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slicing synchronizing pulse separator circuit
Assignee: US Philips Corp
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Filing: 1970-12-17
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Granted: 1972-12-19
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Expires: 1990-12-17
Abstract
Abstract A synchronizing pulse separator circuit with which slicing of the separated synchronizing pulse relative to a fixed level between the peak level and black level is obtained by combining the reference level for the separator, preferably by averaging, from an optionally corrected level obtained by both peak level detection and by porch level detection.
Inventors
- 👤 Wouter Smeulers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:23
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
157 words
A circuit for separating the synchronizing signal from a composite video signal having luminance and synchronization components, said circuit comprising means adapted to receive said video signal for detecting the peak value of said synchronization signal; means adapted to receive said video signal for detecting the porch level of said synchronization signal, said porch level detector having a selection signal input; means coupled to said peak and porch detecting means for combining the peak and porch level signals and for producing a reference signal having a value between said signals; and a first amplitude selection means having an input means adapted for receiving said video signal, a reference input means coupled to receive said reference signal for determining the threshold thereof, and an output means for producing an output signal during the occurrence of said synchronizing signal; and second amplitude selection means coupled to receive said video signal for applying a signal to said selection signal input.
Claim 2
Dependent Claim
157 words
A circuit for separating the synchronizing signal from a composite video signal having luminance and synchronization components, said circuit comprising means adapted to receive said video signal for detecting the peak value of said synchronization signal; means adapted to receive said video signal for detecting the porch level of said synchronization signal, said porch level detector having a selection signal input; means coupled to said peak and porch detecting means for combining the peak and porch level signals and for producing a reference signal having a value between said signals; and a first amplitude selection means having an input means adapted for receiving said video signal, a reference input means coupled to receive said reference signal for determining the threshold thereof, and an output means for producing an output signal during the occurrence of said synchronizing signal; and second amplitude selection means coupled to receive said video signal for applying a signal to said selection signal input.
Claim 3
Dependent Claim
37 words
A circuit as claimed in claim 1 wherein said porch detector comprises a detection element, and a first detection capacitor having a first end coupled to said element and a second end coupled to said peak detector.
Claim 4
Dependent Claim
40 words
A circuit as claimed in claim 1 wherein said peak level detector comprises a second detection capacitor and a detection resistor having a first end coupled to said second detection capacitor and a second end coupled to said porch detector.
Claim 5
Dependent Claim
25 words
A circuit as claimed in claim 3 wherein said combining means comprises said detection resistor, said resistor having a tap coupled to said reference input.
Claim 6
Dependent Claim
42 words
A circuit as claimed in claim 1 wherein said peak detector and said second amplitude selector comprise a transistor having emitter, base, and collector electrodes, the base-emitter junction comprising a peak detector element; said collector being coupled to said selection signal input.
Claim 7
Dependent Claim
24 words
A circuit as claimed in claim 1 wherein said porch detector has a time constant greater than one field period of said video signal.
Claim 8
Dependent Claim
39 words
A circuit as claimed in claim 1 further comprising a switching circuit having a first input coupled to one of said detectors, an output coupled to said combining means, and a second input adapted to receive an interference signal.
Claim 9
Dependent Claim
17 words
A circuit as claimed in claim 7 wherein said first input is coupled to said porch detector.
Claim 10
Dependent Claim
34 words
A circuit as claimed in claim 1 wherein each of said detectors comprises a direct current restorer circuit and said reference signal input means comprises said input means adapted for receiving said video 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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |