US4494137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated interface circuit between the RGB matrix and the video output stages of color-television sets
Assignee: ITT Inc
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Filing: 1982-06-16
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Granted: 1985-01-15
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Expires: 2002-06-16
Abstract
Abstract The interface circuit contains a single operational amplifier (OR, OG, OB) per chrominance channel, with a resistance network (WR, WG, WB) for white-level adjustment connected between the inverting input and the output of this amplifier. The output resistances of the matrix output amplifiers (MR, MG, MB) must be low, and a low-value resistor (RR, RG, RB) is connected between the output of each output amplifier and the noninverting input of each operational amplifier (OR, OG, OB). Video-signal, brightness-, blanking, and external-signal-control currents (ISR, ISG, ISB; IHR, IHG, IHB; IBR, IBG, IBB; IER, IEG, IEB) are applied to the non-inverting input of the respective operational amplifier. The control currents permit the white-level adjustment and the blanking-voltage adjustment to be made independently of each other and eliminate any interaction between brightness adjustment, blanking, and external-signal gating. Compared with prior art arrangements, a simpler circuit is obtained.
Inventors
- 👤 Laurin C. Freyberger
- 👤 Bernd Novotny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:16
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/641
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
214 words
In a color television or the like, the combination comprising: an RGB matrix having a plurality of output amplifiers, each of said output amplifiers being associated with one of the plurality of chrominance channels and providing a video signal circuit at its output; each having a low output impedance; a plurality of video output stages for driving a picture tube or the like; a plurality of interface circuits, each of said interface circuits coupling the output of one of said plurality of output amplifiers to an input of a corresponding one of said plurality of video output stages, each of said plurality of interface circuits comprising: an operational amplifier having first and second complementary inputs and an output, said output being coupled to said input of said corresponding one of said plurality of video output stages; a low-value resistor coupled between the output of said one of said plurality of output amplifiers and said first input; an adjustable resistance network coupled between said second input and said operational amplifier output for white level adjustment; blanking voltage adjustment means for supplying a blanking voltage control current to said second input; brightness means for coupling a brightness control current to said first input; and blanking means for coupling a blanking control current to said first input.
Claim 2
Dependent Claim
214 words
In a color television or the like, the combination comprising: an RGB matrix having a plurality of output amplifiers, each of said output amplifiers being associated with one of the plurality of chrominance channels and providing a video signal circuit at its output; each having a low output impedance; a plurality of video output stages for driving a picture tube or the like; a plurality of interface circuits, each of said interface circuits coupling the output of one of said plurality of output amplifiers to an input of a corresponding one of said plurality of video output stages, each of said plurality of interface circuits comprising: an operational amplifier having first and second complementary inputs and an output, said output being coupled to said input of said corresponding one of said plurality of video output stages; a low-value resistor coupled between the output of said one of said plurality of output amplifiers and said first input; an adjustable resistance network coupled between said second input and said operational amplifier output for white level adjustment; blanking voltage adjustment means for supplying a blanking voltage control current to said second input; brightness means for coupling a brightness control current to said first input; and blanking means for coupling a blanking control current to said first input.
Claim 3
Dependent Claim
21 words
The combination in accordance with claim 1 further comprising: gating means for coupling a gating control current to said first input.
Claim 4
Dependent Claim
35 words
The combination in accordance with claim 1 wherein: said blanking voltage adjustment means comprises a first digital to analog current converter responsive to digital blanking voltage adjustment signals for generating said blanking voltage control current.
Claim 5
Dependent Claim
30 words
The combination in accordance with claim 1 wherein: said brightness means comprises a second digital to analog converter for generating said brightness control current in response to brightness control signals.
Claim 6
Dependent Claim
28 words
The combination in accordance with claim 2 wherein: said gating means comprises an analog voltage to current converter responsive to analog signals for generating said gating control current.
Claim 7
Dependent Claim
35 words
The combination in accordance with claim 2 wherein: said blanking voltage adjustment means comprises a first digital to analog current converter responsive to digital blanking voltage adjustment signals for generating said blanking voltage control current.
Claim 8
Dependent Claim
30 words
The combination in accordance with claim 2 wherein: said brightness means comprises a second digital to analog converter for generating said brightness control current in response to brightness control signals.
Claim 9
Dependent Claim
28 words
The combination in accordance with claim 6 wherein: said gating means comprises an analog voltage to current converter responsive to analog signals for generating said gating control current.
Claim 10
Dependent Claim
28 words
The combination in accordance with claim 7 wherein: said gating means comprises an analog voltage to current converter responsive to analog signals for generating said gating control current.
Claim 11
Dependent Claim
21 words
A combination in accordance with claim 1 wherein: said adjustable resistance network is adjustable in response to a digital control signal.
Claim 12
Dependent Claim
21 words
A combination in accordance with claim 2 wherein: said adjustable resistance network is adjustable in response to a digital control signal.
Claim 13
Dependent Claim
21 words
A combination in accordance with claim 3 wherein: said adjustable resistance network is adjustable in response to a digital control signal.
Claim 14
Dependent Claim
21 words
A combination in accordance with claim 4 wherein: said adjustable resistance network is adjustable in response to a digital control signal.
Claim 15
Dependent Claim
21 words
A combination in accordance with claim 5 wherein: said adjustable resistance network is adjustable in response to a digital control signal.
Claim 16
Dependent Claim
90 words
A combination in accordance with claim 1 wherein: said RGB matrix has first, second and third inputs; and comprising: a third digital to analog converter having an analog output coupled to said RGB matrix first input and controlled with a digital R-Y signal; a fourth digital to analog converter having an analog output coupled to said RGB matrix second input and controlled with a B-Y signal; and a fifth digital to analog converter having an analog output coupled to said RGB matrix third input and controlled with a Y signal.
Claim 17
Dependent Claim
90 words
A combination in accordance with claim 2 wherein: said RGB matrix has first, second and third inputs; and comprising: a third digital to analog converter having an analog output coupled to said RGB matrix first input and controlled with a digital R-Y signal; a fourth digital to analog converter having an analog output coupled to said RGB matrix second input and controlled with a B-Y signal; and a fifth digital to analog converter having an analog output coupled to said RGB matrix third input and controlled with a Y signal.
Claim 18
Dependent Claim
90 words
A combination in accordance with claim 3 wherein: said RGB matrix has first, second and third inputs; and comprising: a third digital to analog converter having an analog output coupled to said RGB matrix first input and controlled with a digital R-Y signal; a fourth digital to analog converter having an analog output coupled to said RGB matrix second input and controlled with a B-Y signal; and a fifth digital to analog converter having an analog output coupled to said RGB matrix third input and controlled with a Y signal.
Claim 19
Dependent Claim
90 words
A combination in accordance with claim 4 wherein: said RGB matrix has first, second and third inputs; and comprising: a third digital to analog converter having an analog output coupled to said RGB matrix first input and controlled with a digital R-Y signal; a fourth digital to analog converter having an analog output coupled to said RGB matrix second input and controlled with a B-Y signal; and a fifth digital to analog converter having an analog output coupled to said RGB matrix third input and controlled with a Y signal.
Claim 20
Dependent Claim
90 words
A combination in accordance with claim 5 wherein: said RGB matrix has first, second and third inputs; and comprising: a third digital to analog converter having an analog output coupled to said RGB matrix first input and controlled with a digital R-Y signal; a fourth digital to analog converter having an analog output coupled to said RGB matrix second input and controlled with a B-Y signal; and a fifth digital to analog converter having an analog output coupled to said RGB matrix third input and controlled with a Y signal.
Claim 21
Dependent Claim
90 words
A combination in accordance with claim 10 wherein: said RGB matrix has first, second and third inputs; and comprising: a third digital to analog converter having an analog output coupled to said RGB matrix first input and controlled with a digital R-Y signal; a fourth digital to analog converter having an analog output coupled to said RGB matrix second input and controlled with a B-Y signal; and a fifth digital to analog converter having an analog output coupled to said RGB matrix third input and controlled with a Y 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) | 1988-01-15 | 1988-07-16 | 1989-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-15 | 1992-07-16 | 1993-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-15 | 1996-07-16 | 1997-01-15 | $7700.00 | Window Closed / Lapsed |