Patent US3626089A successfully refreshed from Google Patents.
US3626089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chroma signal processing circuit for a color television receiver
Assignee: Motorola Solutions Inc
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Filing: 1969-11-26
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Granted: 1971-12-07
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Expires: 1989-11-26
Abstract
Abstract A color television receiver has an integrated circuit chroma amplifier and burst-separating circuit using a pair of differential current-steering gates as the output and separating stage thereof with switching of the steering gates being utilized to gate the chroma signals to a chroma output during the scan portions of the cycle of operation of the receiver, and to gate the burst signals to an output coupled to a reference oscillator, with a substitution of a corresponding DC operating level being provided at each of these outputs when the signal is being switched to the other output. In addition, the chroma amplifier DC operating point is determined by a constant current source which is immune to variations in the DC level of the signals caused by variations in the ACC gain control signal.
Inventors
- 👤 Gildo Cecchin
- 👤 Francis H Hilbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:09
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/68
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
301 words
In a color television receiver for utilizing composite signals comprising at least a subcarrier component, modulated in phase and amplitude to represent hue and saturation of the color image, and a color reference burst signal component, a signalprocessing circuit including in combination: first differential current gate means having an input and first and second outputs; second differential current gate means having an input and first and second outputs; means for coupling together the first outputs of the first and second differential current gates; means for coupling together the second outputs of the first and second differential current gates; input amplifier means for supplying at least the subcarrier component and the burst signal component to the input of the first differential current gate means; means for establishing a DC operating current for the input amplifier means, the operating current being substantially independent of the DC level of the signal present on the input of the input amplifier means; means for supplying a DC signal having a current level bearing a predetermined relationship with said DC operating current to the input of the second differential current gate means; switch means having at least two states of operation coupled to the first and second differential current gate means for controlling the operation of the first and second differential current gate means To cause the first output of the first differential current gate means and the second output of the second differential current gate means to appear when the switch means is in one state of operation, and causing the second output of the first differential current gate means and the first output of the second differential current gate means to appear with the switch means in a second state of operation; and control means for controlling the state of operation of the switch means.
Claim 2
Dependent Claim
301 words
In a color television receiver for utilizing composite signals comprising at least a subcarrier component, modulated in phase and amplitude to represent hue and saturation of the color image, and a color reference burst signal component, a signalprocessing circuit including in combination: first differential current gate means having an input and first and second outputs; second differential current gate means having an input and first and second outputs; means for coupling together the first outputs of the first and second differential current gates; means for coupling together the second outputs of the first and second differential current gates; input amplifier means for supplying at least the subcarrier component and the burst signal component to the input of the first differential current gate means; means for establishing a DC operating current for the input amplifier means, the operating current being substantially independent of the DC level of the signal present on the input of the input amplifier means; means for supplying a DC signal having a current level bearing a predetermined relationship with said DC operating current to the input of the second differential current gate means; switch means having at least two states of operation coupled to the first and second differential current gate means for controlling the operation of the first and second differential current gate means To cause the first output of the first differential current gate means and the second output of the second differential current gate means to appear when the switch means is in one state of operation, and causing the second output of the first differential current gate means and the first output of the second differential current gate means to appear with the switch means in a second state of operation; and control means for controlling the state of operation of the switch means.
Claim 3
Dependent Claim
65 words
The combination according to claim 1 wherein the means for supplying said DC signal to the input of the second differential current gate means includes a constant current source; and wherein the means for establishing the DC operating current for the input amplifier means includes a second constant current source, with means for causing the second constant current source to appear as an AC ground.
Claim 4
Dependent Claim
274 words
In a color television receiver for utilizing composite signals comprising at least a subcarrier component, modulated in phase and amplitude to represent hue and saturation of the color image, and a color reference burst signal component, a signal processing circuit including in combination: first differential current gate means having an input and first and second outputs; second differential current gate means having an input and first and second outputs; means for coupling together the first outputs of the first and second differential current gate means; means for coupling together the second outputs of the first and second differential current gate means; means for supplying at least the subcarrier component and the burst signal component at a predetermined DC current level to the input of the first differential current gate means; means for supplying a DC current at a level which is substantially the same as said predetermined DC current level to the input of the second differential current gate means; switch means having at least two states of operation coupled to the first and second differential current gate means for controlling the operation of the first and second differential current gate means to cause the first output of the first differential current gate means and the second output of the second differential current gate means to appear with the switch means in one state of operation and causing the second output of the first differential current gate means and the first output of the second differential current gate means to appear with the switch means in a second state of operation; and control means for controlling the state of operation of the switch means.
Claim 5
Dependent Claim
274 words
In a color television receiver for utilizing composite signals comprising at least a subcarrier component, modulated in phase and amplitude to represent hue and saturation of the color image, and a color reference burst signal component, a signal processing circuit including in combination: first differential current gate means having an input and first and second outputs; second differential current gate means having an input and first and second outputs; means for coupling together the first outputs of the first and second differential current gate means; means for coupling together the second outputs of the first and second differential current gate means; means for supplying at least the subcarrier component and the burst signal component at a predetermined DC current level to the input of the first differential current gate means; means for supplying a DC current at a level which is substantially the same as said predetermined DC current level to the input of the second differential current gate means; switch means having at least two states of operation coupled to the first and second differential current gate means for controlling the operation of the first and second differential current gate means to cause the first output of the first differential current gate means and the second output of the second differential current gate means to appear with the switch means in one state of operation and causing the second output of the first differential current gate means and the first output of the second differential current gate means to appear with the switch means in a second state of operation; and control means for controlling the state of operation of the switch means.
Claim 6
Dependent Claim
64 words
The combination according to claim 3 wherein the composite signals also include synchronizing components and wherein the control means includes means responsive to said synchronizing components to cause the switch means to be in said one state of operation when said subcarrier component is present and to be in said second state of operation when said burst component is present in said composite signal.
Claim 7
Dependent Claim
198 words
The combination according to claim 4 wherein the first and second differential current gate means each include first and second transistors, the transistors each having first, second and control electrodes, with the second electrodes of the first and second transistors of the first current gate means being coupled together as the input of the first differential current gate means, the second electrodes of the first and second transistors of the second differential current gate means being coupled together as the input of the second differential current gate means, the switch means being coupled to the control electrodes and rendering the first transistor of the first differential current gate means and the second transistor of the second differential current gate means conductive in said one state of operation and rendering the second transistor of the first differential current gate means and the first transistor of the second differential current gate mEans conductive in said second state of operation with the first electrodes of the first transistors in each of the differential current gate means comprising said first outputs and with the first electrodes of the second transistors in each of the differential current gate means comprising said second outputs.
Claim 8
Dependent Claim
110 words
The combination according to claim 5 wherein the second electrodes are emitter electrodes, the first electrodes are collector electrodes, and the control electrodes are base electrodes of the first and second transistors of the first and second differential current gate means, with the second transistor of the first differential current gate means and the first transistor of the second differential current gate means being nonconductive with the switch means in said one state of operation and with the first transistor of the first differential current gate means and the second transistor of the second differential current gate means being nonconductive with the switch means in said second state of operation.
Claim 9
Dependent Claim
29 words
The combination according to claim 5 wherein the means for supplying the DC current to the transistors of the second differential current gate means includes a constant current source.
Claim 10
Dependent Claim
151 words
The combination according to claim 5 wherein the switch means includes a third differential current gate means having first and second switching transistors therein, each having first, second, and control electrodes, with the control electrodes of the first switching transistor being coupled to a point of reference potential, and wherein the control means includes means for applying switching pulses to the control electrode of the second switching transistor when said burst component is present in the composite signal, the first electrode of the first switching transistor being coupled to the control electrodes of the first transistor of the first differential current gate means and the second transistor of the second differential current gate means, and the first electrode of the second switching transistor being coupled to the control electrodes of the second transistor of the first differential current gate means and the first transistor of the second differential current gate means.
Claim 11
Dependent Claim
64 words
The combination according to claim 8 wherein the second switching transistor of the third differential current gate means is normally conductive and the first switching transistor is normally nonconductive for said one state of operation of the switch means, said switching pulses rendering the first switching transistor conductive and the second switching transistor nonconductive for said second state of operation of the switch means.
Claim 12
Dependent Claim
224 words
In a color television receiver for utilizing composite signals comprising at least a subcarrier component, modulated in phase and amplitude to represent hue and saturation of a color image, and a color reference burst signal component, said receiver including means responsive to the burst signal component to develop a DC control voltage varying in amplitude with amplitude variations of the burst signal component, an amplifier circuit including in combination: differential current modulator means including first and second amplifier devices each having first, second and control electrodes, the first electrodes each connected with a source of operating potential; means for connecting a reference bias potential to the control electrode of one of the amplifier devices; means for applying the DC control voltage to the control electrode of the other of the amplifier devices to vary the relative conductivities of the first and second amplifier devices with respect to one another; means for applying said composite input signal to the differential current modulator means; output amplifier means having an input; means for DC coupling the first electrode of the first amplifier device to the input of the output amplifier means; and means for establishing a constant DC operating current for the output amplifier means, the operating current being independent of the DC level of the signal present on the first electrode of the first amplifying device.
Claim 13
Dependent Claim
224 words
In a color television receiver for utilizing composite signals comprising at least a subcarrier component, modulated in phase and amplitude to represent hue and saturation of a color image, and a color reference burst signal component, said receiver including means responsive to the burst signal component to develop a DC control voltage varying in amplitude with amplitude variations of the burst signal component, an amplifier circuit including in combination: differential current modulator means including first and second amplifier devices each having first, second and control electrodes, the first electrodes each connected with a source of operating potential; means for connecting a reference bias potential to the control electrode of one of the amplifier devices; means for applying the DC control voltage to the control electrode of the other of the amplifier devices to vary the relative conductivities of the first and second amplifier devices with respect to one another; means for applying said composite input signal to the differential current modulator means; output amplifier means having an input; means for DC coupling the first electrode of the first amplifier device to the input of the output amplifier means; and means for establishing a constant DC operating current for the output amplifier means, the operating current being independent of the DC level of the signal present on the first electrode of the first amplifying device.
Claim 14
Dependent Claim
56 words
The combination according to claim 10 wherein the first and second amplifier devices are first and second transistors having collector, emitter and base electrodes corresponding to the first, second, and control electrodes, respectively, and wherein the DC control voltage varies the amount of signal current which is passed through the collector-emitter path of the first transistor.
Claim 15
Dependent Claim
74 words
The combination according to claim 11 wherein the output amplifier means includes a third transistor having collector, emitter and base electrodes, with the output signals appearing on the collector electrode of the first transistor being coupled with the base electrode of the third transistor, and with the emitter of the third transistor being coupled to a constant current source comprising said means for establishing said independent DC operating current for the output amplifier transistor.
Claim 16
Dependent Claim
81 words
The combination according to claim 12 wherein the constant current source is an additional transistor having base, collector, and emitter electrodes, with means for coupling the base electrode to a stabilized biasing potential and with the collector-emitter path of said additional transistor being connected in circuit between the emitter of the third transistor and a point of reference potential, said combination further including alternating current bypass means coupled between the emitter of the third transistor and the point of reference potential.
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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |