US3715463A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tracking control circuits using a common potentiometer
Assignee: Thomas International Corp
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Filing: 1971-03-18
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Granted: 1973-02-06
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Expires: 1991-03-18
Abstract
Abstract Simultaneously tracking chroma and contrast controls in a color television receiver use a common potentiometer having a wiper connected to a source of reference potential. One end of the potentiometer resistor is AC coupled to a luminance amplifier, and the other end is directly coupled to a DC bias circuit for a chroma amplifier. As the wiper is adjusted, the contrast of the luminance signal and the chroma level change in corresponding directions.
Inventors
- 👤 L Matzek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:36
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/73
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
137 words
In a television receiver including first signal translating means for developing a first signal having an adjustable level and second signal translating means for developing a second signal having an adjustable level, circuit means for causing the adjustable levels to track, comprising: a potentiometer having a wiper contact movable across a resistance element connected between a pair of end contacts; a source of reference potential; means DC coupling one of said contacts to said reference potential source; first tracking means connecting another of said contacts to said first signal translating means for varying the level of said first signal in response to movement of said wiper; and second tracking means connecting the remaining of said contacts to said second signal translating means for varying the level of said second signal in response to movement of said wiper.
Claim 2
Dependent Claim
137 words
In a television receiver including first signal translating means for developing a first signal having an adjustable level and second signal translating means for developing a second signal having an adjustable level, circuit means for causing the adjustable levels to track, comprising: a potentiometer having a wiper contact movable across a resistance element connected between a pair of end contacts; a source of reference potential; means DC coupling one of said contacts to said reference potential source; first tracking means connecting another of said contacts to said first signal translating means for varying the level of said first signal in response to movement of said wiper; and second tracking means connecting the remaining of said contacts to said second signal translating means for varying the level of said second signal in response to movement of said wiper.
Claim 3
Dependent Claim
137 words
In a television receiver including first signal translating means for developing a first signal having an adjustable level and second signal translating means for developing a second signal having an adjustable level, circuit means for causing the adjustable levels to track, comprising: a potentiometer having a wiper contact movable across a resistance element connected between a pair of end contacts; a source of reference potential; means DC coupling one of said contacts to said reference potential source; first tracking means connecting another of said contacts to said first signal translating means for varying the level of said first signal in response to movement of said wiper; and second tracking means connecting the remaining of said contacts to said second signal translating means for varying the level of said second signal in response to movement of said wiper.
Claim 4
Dependent Claim
137 words
In a television receiver including first signal translating means for developing a first signal having an adjustable level and second signal translating means for developing a second signal having an adjustable level, circuit means for causing the adjustable levels to track, comprising: a potentiometer having a wiper contact movable across a resistance element connected between a pair of end contacts; a source of reference potential; means DC coupling one of said contacts to said reference potential source; first tracking means connecting another of said contacts to said first signal translating means for varying the level of said first signal in response to movement of said wiper; and second tracking means connecting the remaining of said contacts to said second signal translating means for varying the level of said second signal in response to movement of said wiper.
Claim 5
Dependent Claim
62 words
The circuit means of claim 1 wherein said reference potential source is common to both said first and second signal translating means and the adjustable levels of said first and second signals both vary with respect to said reference potential, said DC coupling means connecting said wiper contact to said reference potential source to electrically separate said resistance element into two portions.
Claim 6
Dependent Claim
40 words
The circuit means of claim 2 wherein said first and second signal translating means each comprise transistor amplifiers which are to track in corresponding directions, bias means for biasing one of said transistor amplifiers in its forward gain control region.
Claim 7
Dependent Claim
57 words
The circuit means of claim 3 wherein the AC level of the other of said transistor amplifiers is to be varied, and the tracking means of said other transistor amplifier includes a capacitor in series between the potentiometer contact and said transistor amplifier to cause said potentiometer to vary the AC degeneration of said other transistor amplifier.
Claim 8
Dependent Claim
74 words
The circuit means of claim 1 wherein the AC level of said first signal is to be varied and the DC level of said second signal is to be varied, said first tracking means includes a capacitor in series between said another contact and said first signal translating means to cause the portion of said resistance element between said another contact and said wiper to control the AC impedance of said first tracking means.
Claim 9
Dependent Claim
116 words
In a color television receiver including a luminance amplifying means for developing a luminance signal level and a chroma amplifying means for developing a chroma signal level, circuit means for causing the luminance and chroma signal levels to track, comprising: a potentiometer having a single wiper contact movable across a resistance element between a pair of end contacts; contrast means AC coupling said potentiometer to said luminance amplifying means for varying the AC degeneration of said luminance amplifying means in response to movement of said single wiper; and chroma means DC coupling said potentiometer to said chroma amplifying means for varying the gain of said chroma amplifying means in response to movement of said single wiper.
Claim 10
Dependent Claim
116 words
In a color television receiver including a luminance amplifying means for developing a luminance signal level and a chroma amplifying means for developing a chroma signal level, circuit means for causing the luminance and chroma signal levels to track, comprising: a potentiometer having a single wiper contact movable across a resistance element between a pair of end contacts; contrast means AC coupling said potentiometer to said luminance amplifying means for varying the AC degeneration of said luminance amplifying means in response to movement of said single wiper; and chroma means DC coupling said potentiometer to said chroma amplifying means for varying the gain of said chroma amplifying means in response to movement of said single wiper.
Claim 11
Dependent Claim
61 words
The circuit means of claim 6 wherein said contrast means AC couples one of said potentiometer contacts to said luminance amplifying means, said chroma means DC couples another of said potentiometer contacts to said chroma amplifying means, and reference means coupling the remaining of said potentiometer contacts to a circuit common to said luminance amplifying means and said chroma amplifying means.
Claim 12
Dependent Claim
39 words
The circuit means of claim 7 wherein said reference means DC couples said remaining contact to said common circuit, whereby said potentiometer controls the AC gain of said luminance amplifying means and the gain of said chroma amplifying means.
References Cited (Backward Citations)
US3374310A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |