US4705992A
Expired / Lapsed
US
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System for stabilizing cathode emissions with an in-line gun cathode ray tube
Assignee: CONRAC TECHNOLOGY Corp
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Filing: 1985-11-21
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Granted: 1987-11-10
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Expires: 2005-11-21
Abstract
Abstract A system for stabilizing the cathode emissions of an in-line gun cathode ray tube includes subsystems functionally identical to one another linked to each of the cathodes of an in-line gun cathode ray tube. During the time that the CRT beam is retracing vertically, each subsystem imposes a fixed, predetermined voltage on a cathode in the cathode ray tube, samples the current flowing to the cathode, compares the sampled current to a predetermined, desired reference current for the cathode, develops a differential signal representing the difference, if any, between the sampled current and the reference current, and then drives the current flowing to the cathode from its actual value to its predetermined, reference value so as to maintain a predetermined, desired ratio of the currents flowing to each of the cathodes.
Inventors
- 👤 Dan N. Ciocan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:58
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/135; H04; H04N; H04N9/00; H04N9/64; H04N9/645
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
167 words
A system for stabilizing cathode emissions in a cathode ray tube comprising at least one video signal amplifier; means linked in series between the output of said at least one video signal amplifier and at least one cathode of said tube for interrupting the flow of a video signal to said tube during a test period; means for impressing a test signal of predetermined value on at least one of the cathodes of said tube; means for sampling the actual current of the test signal flowing to said at least one cathode in said tube, said sampling means being linked in parallel to said interrupting means; means for developing a differential signal representing the difference between the actual current flowing to said at least one cathode during a test period and a predetermined current to be flowing to said at least one cathode; and means for utilizing said differential signal to drive the actual current flowing to said at least one cathode to said predetermined desired value.
Claim 2
Independent Claim
167 words
A system for stabilizing cathode emissions in a cathode ray tube comprising at least one video signal amplifier; means linked in series between the output of said at least one video signal amplifier and at least one cathode of said tube for interrupting the flow of a video signal to said tube during a test period; means for impressing a test signal of predetermined value on at least one of the cathodes of said tube; means for sampling the actual current of the test signal flowing to said at least one cathode in said tube, said sampling means being linked in parallel to said interrupting means; means for developing a differential signal representing the difference between the actual current flowing to said at least one cathode during a test period and a predetermined current to be flowing to said at least one cathode; and means for utilizing said differential signal to drive the actual current flowing to said at least one cathode to said predetermined desired value.
Claim 3
Dependent Claim
15 words
The system of claim 1 wherein said tube is an in-line gun cathode ray tube.
Claim 4
Dependent Claim
15 words
The system of claim 1 wherein said tube is a delta gun cathode ray tube.
Claim 5
Dependent Claim
58 words
The system of claim 1 further comprising switch means for effecting said interrupting, said switch means comprising an optocoupler linked to a pair of transistors, said pair of transistors being adapted to conduct said video signal when activated by a signal from said optocoupler, and to block said video signal when deactivated by a signal from said optocoupler.
Claim 6
Dependent Claim
15 words
The system of claim 4 wherein said tube is an in-line gun cathode ray tube.
Claim 7
Dependent Claim
45 words
The system of claim 4 further comprising means for sampling the actual current flowing to said at least one cathode when said switch means is open and means for developing a signal representing the difference, if any, between said test signal and said actual current.
Claim 8
Independent Claim
141 words
A system for stabilizing cathode emissions in a cathode ray tube comprising at least one video signal amplifier; means linked in series between the output of said at least one video signal amplifier and at least one cathode of said tube for interrupting the flow of a video signal to said tube; means for impressing a test signal of predetermined value on at least one of the cathodes of said tube; means for sampling the actual current of the test signal flowing to said at least one cathode in said tube, said sampling means being linked in parallel to said interrupting means; and means for developing a differential signal representing the difference between the actual current flowing to said at least one cathode during a test period and a desired, predetermined current to be flowing to said at least one cathode.
Claim 9
Independent Claim
141 words
A system for stabilizing cathode emissions in a cathode ray tube comprising at least one video signal amplifier; means linked in series between the output of said at least one video signal amplifier and at least one cathode of said tube for interrupting the flow of a video signal to said tube; means for impressing a test signal of predetermined value on at least one of the cathodes of said tube; means for sampling the actual current of the test signal flowing to said at least one cathode in said tube, said sampling means being linked in parallel to said interrupting means; and means for developing a differential signal representing the difference between the actual current flowing to said at least one cathode during a test period and a desired, predetermined current to be flowing to said at least one cathode.
Claim 10
Dependent Claim
15 words
The system of claim 7 wherein said tube is an in-line gun cathode ray tube.
Claim 11
Dependent Claim
15 words
The system of claim 7 wherein said tube is a delta gun cathode ray tube.
Claim 12
Dependent Claim
58 words
The system of claim 7 further comprising switch means for effecting said interrupting, said switch means comprising an optocoupler linked to a pair of transistors, said pair of transistors being adapted to conduct said video signal when activated by a signal from said optocoupler, and to block said video signal when deactivated by a signal from said optocoupler.
Claim 13
Dependent Claim
15 words
The system of claim 10 wherein said tube is an in-line gun cathode ray tube.
Claim 14
Dependent Claim
45 words
The system of claim 10 further comprising means for sampling the actual current flowing to said at least one cathode when said switch means is open and means for developing a signal representing the difference, if any, between said test signal and said actual current.
Claim 15
Independent Claim
79 words
A system comprising switch means adapted to be linked in series between the output of at least one video signal amplifier and at least one cathode of a cathode ray tube, including means for opening and closing said switch means, and means for charging and discharging the capacitance of a load, and, alternatively, for interrupting said charging and discharging; and means for sampling current flowing to said load, said sampling means being linked in parallel to said switch means.
Claim 16
Independent Claim
79 words
A system comprising switch means adapted to be linked in series between the output of at least one video signal amplifier and at least one cathode of a cathode ray tube, including means for opening and closing said switch means, and means for charging and discharging the capacitance of a load, and, alternatively, for interrupting said charging and discharging; and means for sampling current flowing to said load, said sampling means being linked in parallel to said switch means.
Claim 17
Dependent Claim
66 words
The switch means of claim 13 wherein said opening and closing means comprises an optocoupler, and said charging and discharging means comprises a pair of bipolar transistors linked emitter-to-collector, means for connecting said transistors in series between at least one gun of a cathode ray tube, and the output of a video signal amplifier, and means for connecting said transistors in parallel to current sampling means.
Claim 18
Dependent Claim
41 words
The system of claim 1 further comprising switch means for effecting said interrupting, said switch means comprising transistor means adapted to conduct said video signal when said transistors are activated, and to block said video signal when said transistors are deactivated.
Claim 19
Dependent Claim
18 words
The system of claim 15 further comprising means for delivering activation and deactivation signals to said transistor means.
Claim 20
Dependent Claim
14 words
The system of claim 16 wherein said signal delivering means comprises an optocoupler means.
Claim 21
Dependent Claim
41 words
The system of claim 7 further comprising switch means for effecting said interrupting, said switch means comprising transistor means adapted to conduct said video signal when said transistors are activated, and to block said video signal when said transistors are deactivated.
Claim 22
Dependent Claim
18 words
The system of claim 7 further comprising means for delivering activation and deactivation signals to said transistor means.
Claim 23
Dependent Claim
14 words
The system of claim 19 wherein said signal delivering means comprises an optocoupler means.
Claim 24
Independent Claim
145 words
A system for stabilizing cathode emissions in a cathode ray tube comprising at least one video signal amplifier; means linked in series between the output of said at least one video signal amplifier and at least one cathode of said tube for interrupting the flow of a video signal to said tube during a test period; means for impressing a test signal of predetermined value on at least one of the cathodes of said tube; means for sampling the actual current of the test signal flowing to said at least one cathode in said tube, said sampling means being linked in parallel to said interrupting means; and means for utilizing the sampled actual current and a predetermined, desired current to be flowing to said at least one cathode to drive the actual current flowing to said at least one cathode to said predetermined, desired value.
Claim 25
Independent Claim
145 words
A system for stabilizing cathode emissions in a cathode ray tube comprising at least one video signal amplifier; means linked in series between the output of said at least one video signal amplifier and at least one cathode of said tube for interrupting the flow of a video signal to said tube during a test period; means for impressing a test signal of predetermined value on at least one of the cathodes of said tube; means for sampling the actual current of the test signal flowing to said at least one cathode in said tube, said sampling means being linked in parallel to said interrupting means; and means for utilizing the sampled actual current and a predetermined, desired current to be flowing to said at least one cathode to drive the actual current flowing to said at least one cathode to said predetermined, desired value.
Claim 26
Dependent Claim
41 words
The system of claim 21 further comprising switch means for effecting said interrupting, said switch means comprising transistor means adapted to conduct said video signal when said transistors are activated, and to block said video signal when said transistors are deactivated.
Claim 27
Dependent Claim
18 words
The system of claim 22 further comprising means for delivering activation and deactivation signals to said transistor means.
Claim 28
Dependent Claim
14 words
The system of claim 23 wherein said signal delivering means comprises an optocoupler means.
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) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |