US3737564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control circuit for varying and for color and black-and-white gradations in color and monochrome television
Assignee: US Philips Corp
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Filing: 1971-03-17
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Granted: 1973-06-05
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Expires: 1991-03-17
Abstract
Abstract A control circuit for varying colors and for colors and blackand-white gradations in color and monochrome television, particularly for color television in which in a reproduction of the picked-up scene having certain colored parts or regions, differently colored regions may be adjusted optionally. When a chrominance signal exceeds a threshold level, clamping pulses are derived from each of the three channels, The clamping pulses of each channel are applied to all three video channels for black level introduction. Subsequently, a plurality of gated level control circuits follow in each video channel which circuits are divided into groups of three in these channels. Each group of gated level control circuits divided in the three channels is activated in cooperation with the clamping pulses which are derived from one or more video channels so as to introduce optionally color information.
Inventors
- 👤 A Bruinsma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:24
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/74; H04N5/00; H04N5/222; H04N5/262
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
137 words
A circuit for varying the information content of at least two video channels, said circuit comprising at least one adjustable threshold circuit means coupled to one of said channels for supplying an output signal when a signal in said one channel exceeds a selectable level; a common clamp circuit means coupled to said threshold circuit and to each of said channels for clamping said channels to a black reference level when at least said one signal exceeds said threshold level, and at least two adjustable gated level control circuit means coupled to said channels respectively following said clamp circuit and to said clamp circuit for setting the amplitude of the signals in said channels to respective values upon an output from said clamp circuit; whereby said information content of the video signals in said channels is varied.
Claim 2
Dependent Claim
137 words
A circuit for varying the information content of at least two video channels, said circuit comprising at least one adjustable threshold circuit means coupled to one of said channels for supplying an output signal when a signal in said one channel exceeds a selectable level; a common clamp circuit means coupled to said threshold circuit and to each of said channels for clamping said channels to a black reference level when at least said one signal exceeds said threshold level, and at least two adjustable gated level control circuit means coupled to said channels respectively following said clamp circuit and to said clamp circuit for setting the amplitude of the signals in said channels to respective values upon an output from said clamp circuit; whereby said information content of the video signals in said channels is varied.
Claim 3
Dependent Claim
37 words
A circuit as claimed in claim 1 wherein each of said channels comprises a threshold circuit, all of said threshold circuits being coupled to said clamp circuit and individually coupled tO said gated level control circuits respectively.
Claim 4
Dependent Claim
35 words
A circuit as claimed in claim 2 wherein each of said channels further comprises a coincidence passing gate having inputs coupled to said threshold circuits and an output coupled to the respective level control circuit.
Claim 5
Dependent Claim
38 words
A circuit as claimed in claim 3 further comprising a coincidence blocking gate having inputs coupled to said passing gate output and to one of said threshold circuits respectively and an output coupled to said level control circuits.
Claim 6
Dependent Claim
44 words
A circuit as claimed in claim 3 further comprising coincidence blocking and a further passing gate, each having an input coupled to outputs of said first recited passing gates respectively, said first recited passing gates outputs being coupled to said level control circuits respectively.
Claim 7
Dependent Claim
81 words
A circuit as claimed in claim 1 wherein said channels comprise first, second and third channels and are adapted to receive respective color television signals, said first, second and third channels comprising first, second and third threshold circuits respectively, each of said channels comprising first, second and third gated level control circuits coupled in said channels after said respective threshold circuits, each of said first, second and third control circuits being coupled to said first, second and third threshold circuits respectively.
Claim 8
Dependent Claim
43 words
A circuit as claimed in claim 1 wherein said channels comprise a single input adapted to receive a monochrome signal and three outputs adapted to be coupled to a color monitor, each of said channels comprising at least one gated level control circuit.
Claim 9
Dependent Claim
47 words
A circuit as claimed in claim 1 further comprising a gate having a first input coupled to said threshold circuit, a second input, and an output coupled to said level control circuit; and a control signal generator means coupled to said second input for enabling said gate.
Claim 10
Dependent Claim
33 words
A circuit as claimed in claim 8 wherein said gate comprises a third input, and further comprising a source of blocking potential and a switch coupled between said third input and said source.
Claim 11
Dependent Claim
40 words
A circuit as claimed in claim 1 further comprising means coupled to said level control circuits for effecting a mutual coupling therebetween wherein the control exercised by any one control circuit effects the amplitude settings of the other control circuits.
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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |