Patent US3598905A successfully refreshed from Google Patents.
US3598905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
White-balance servicing circuit
Assignee: Lanteris Space LLC
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Filing: 1970-02-25
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Granted: 1971-08-10
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Expires: 1990-02-25
Abstract
Abstract A switching circuit for alternatively conditioning a color television receiver to display images on the screen of its picture tube or to permit accurate adjustment of biases controlling the white balance of the image displayed by the picture tube. The circuit comprises a double-pole single-throw switch so interconnected with sources of operating voltages for the vertical deflection output tube, the video output tube, and the picture tube, that, when the switch is thrown to its ''''service'''' position, i.e. is opened, the receiver is conditioned simultaneously in three ways: (1) plate voltage is removed from the vertical deflection output tube of the receiver, thereby cutting off that tube and preventing vertical deflection of the cathode-ray beams on the picture tube; (2) a bias voltage sufficient to cut off the video output tube is applied to a grid thereof, thereby blocking transmission of the video signal to the picture tube; and (3) a reference black level bias voltage is applied to each of the three kinescope cathodes. When the receiver is so conditioned, the white balance of the image displayed by the picture tube can be accurately set by adjusting the biases supplied to the screen grids of the picture tube. When the double-pole single-throw switch is thrown to its ''''operate'''' position, i.e. is closed, normal operating voltages are restored to the receiver, thereby enabling it to reproduce color television pictures.
Inventors
- 👤 Buran I Keprta Jr
- 👤 Sylvester Walczak Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:46
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/16; H04N9/18; H04N9/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
548 words
In an apparatus comprising: a. a cathode drive network, having first and second input terminals, for supplying signals to a plurality of cathodes of a cathode ray tube, b. first amplifying means having a control electrode and first and second electrodes, said means being responsive to i. an operating potential, when applied to said second electrode, to cause flow therethrough of an electric current, and ii. variations in a signal, when applied between said control electrode and said first electrode, to vary said electric current flowing through said second electrode, means for applying a deflection input signal between said control electrode and said first electrode, and output means, responsive to current flow through said second electrode produced in response to said deflection input signal, to generate a deflection output signal, c. second amplifying means having a control electrode and first and second electrodes, said second amplifying means being responsive to i. variations in a signal, when applied between said control electrode and said first electrode, to vary an electric current flowing through said second electrode thereof when a bias voltage of first value concurrently is applied between said control electrode and said first electrode, and ii. a bias voltage of second value, when applied between said control element and said first electrode, to cut off flow of said electric current through said second electrode thereof, video input means for applying a video signal between said control electrode and said first electrode of said second amplifying means, means connecting said second electrode of said second amplifying means to said first input terminal of said cathode drive network, first direct-current-conductive impedance means having finite resistance to the flow therethrough of constant undirectional electric current, and means directly connecting said first direct-current-conductive impedance means between said first and second input terminals of said cathode drive network, the improvement comprising: d. first and second switching means, each having a first terminal, a second terminal, and means for permitting directcurrent-conduction from said first terminal thereof to said second terminal thereof when said switching means is closed and interrupting said conduction when said switching means is open, and means connecting said first terminal of each of said two switching means to a first source of operating potential, e. first biasing means, connected between said first source of operating potential and said second terminal of said first switching means, for producing a reference voltage at said second terminal of said first switching means when said first switching means is open, f. second direct-current-conductive means connecting said second terminal of said first switching means to said second input terminal of said cathode drive network, and g. second biasing means for (i) applying between said control electrode and said first electrode of said second amplifying means a biasing voltage having said first value when said second switching means is closed and having said second value when said second switching means is open, and (ii) preventing transmission of said video signal from said video input means to said second switching means, said output means comprising third direct-current-conductive means connecting said second terminal of said second switching means to said second electrode of said first amplifying means, for supplying an operating potential to said second electrode of said first amplifying means only when said second switching means is closed.
Claim 2
Dependent Claim
548 words
In an apparatus comprising: a. a cathode drive network, having first and second input terminals, for supplying signals to a plurality of cathodes of a cathode ray tube, b. first amplifying means having a control electrode and first and second electrodes, said means being responsive to i. an operating potential, when applied to said second electrode, to cause flow therethrough of an electric current, and ii. variations in a signal, when applied between said control electrode and said first electrode, to vary said electric current flowing through said second electrode, means for applying a deflection input signal between said control electrode and said first electrode, and output means, responsive to current flow through said second electrode produced in response to said deflection input signal, to generate a deflection output signal, c. second amplifying means having a control electrode and first and second electrodes, said second amplifying means being responsive to i. variations in a signal, when applied between said control electrode and said first electrode, to vary an electric current flowing through said second electrode thereof when a bias voltage of first value concurrently is applied between said control electrode and said first electrode, and ii. a bias voltage of second value, when applied between said control element and said first electrode, to cut off flow of said electric current through said second electrode thereof, video input means for applying a video signal between said control electrode and said first electrode of said second amplifying means, means connecting said second electrode of said second amplifying means to said first input terminal of said cathode drive network, first direct-current-conductive impedance means having finite resistance to the flow therethrough of constant undirectional electric current, and means directly connecting said first direct-current-conductive impedance means between said first and second input terminals of said cathode drive network, the improvement comprising: d. first and second switching means, each having a first terminal, a second terminal, and means for permitting directcurrent-conduction from said first terminal thereof to said second terminal thereof when said switching means is closed and interrupting said conduction when said switching means is open, and means connecting said first terminal of each of said two switching means to a first source of operating potential, e. first biasing means, connected between said first source of operating potential and said second terminal of said first switching means, for producing a reference voltage at said second terminal of said first switching means when said first switching means is open, f. second direct-current-conductive means connecting said second terminal of said first switching means to said second input terminal of said cathode drive network, and g. second biasing means for (i) applying between said control electrode and said first electrode of said second amplifying means a biasing voltage having said first value when said second switching means is closed and having said second value when said second switching means is open, and (ii) preventing transmission of said video signal from said video input means to said second switching means, said output means comprising third direct-current-conductive means connecting said second terminal of said second switching means to said second electrode of said first amplifying means, for supplying an operating potential to said second electrode of said first amplifying means only when said second switching means is closed.
Claim 3
Dependent Claim
101 words
An apparatus according to claim 1 wherein said first biasing means comprises: a first voltage divider comprising resistive means and having first and second input terminals and an output terminal, means connecting said first input terminal of said first voltage divider to said first source of operating potential, means connecting said second input terminal of said first voltage divider to a point at reference potential, and, means connecting said output terminal of said first voltage divider to said second terminal of said first switching means, said reference voltage being produced at said output terminal when said first switching means is open.
Claim 4
Dependent Claim
84 words
An apparatus according to claim 2 wherein said second biasing means has: a first terminal connected to said second terminal of said second switching means, a second terminal connected to said first electrode of said second amplifying means, an output terminal, and means for applying to said control electrode of said second amplifying means the potential of said output terminal of said second biasing means while preventing transmission of said video signal from said video input to said output terminal of said biasing means.
Claim 5
Dependent Claim
53 words
An apparatus according to claim 3 wherein said first voltage divider comprises first and second resistive means connected in series between said first and second input terminals of said first voltage divider, and means connecting said output terminal of said first voltage divider to the junction of said first and second resistive means.
Claim 6
Dependent Claim
136 words
An apparatus according to claim 4, wherein said second biasing means comprises a second voltage divider and a bias network, said second voltage divider comprising third resistive means, a potentiometer having a resistance element and a variable arm, fourth resistive means, and means connecting said third resistive means, said resistance element and said fourth resistive means in series between said first terminal of said second biasing means and said point at reference potential, and means connecting said variable arm of said potentiometer to said output terminal of said second biasing means, and said bias network comprising the series combination of fifth resistive means and a second source of operating potential connected between said second terminal of said second biasing means and said point at reference potential, and capacitive means connected in shunt with said series combination.
Claim 7
Dependent Claim
43 words
An apparatus according to claim 5, wherein said cathode drive network comprises a plurality of resistive means for individually varying the amplitude of the cathode drive signal supplied to each of said cathodes when said first and second switching means are both closed.
Claim 8
Dependent Claim
116 words
An apparatus according to claim 6 wherein said video input means comprises a peaking network including resistive means and inductive means connected in shunt relationship and to said control electrode of said second amplifying means, said means for supplying to said control electrode of said second amplifying means the potential of said output terminal of said second biasing means comprises a low pass filter connected between said output terminal of said second biasing means and said peaking network, said output means for generating a deflection output signal comprises a transformer, said first direct-current-conductive impedance means comprises resistive means, said second direct-current-conductive means comprises inductive means, and said third direct-current-conductive means comprises a winding of said transformer.
Claim 9
Dependent Claim
16 words
An apparatus according to claim 7, comprising means for ganging said first and second switching means.
Claim 10
Dependent Claim
54 words
An apparatus according to claim 1 wherein each one of said first and second amplifying means comprises an electron discharge tube having a control grid, a cathode, and a plate, said control grid, said cathode, and said plate being respectively said control electrode, said first electrode, and said second electrode of said amplifying means.
Claim 11
Dependent Claim
54 words
An apparatus according to claim 3 wherein each one of said first and second amplifying means comprises an electron discharge tube having a control grid, a cathode, and a plate, said control grid, said cathode, and said plate being respectively said control electrode, said first electrode, and said second electrode of said amplifying means.
Claim 12
Dependent Claim
54 words
An apparatus according to claim 8 wherein each one of said first and second amplifying means comprises an electron discharge tube having a control grid, a cathode, and a plate, said control grid, said cathode, and said plate being respectively said control electrode, said first electrode, and said second electrode of said amplifying means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |