US4562479A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic kinescope beam current limiter
Assignee: RCA Licensing Corp
•
Filing: 1984-04-26
•
Granted: 1985-12-31
•
Expires: 2004-04-26
Abstract
Abstract In a television receiver, an automatic kinescope beam current limiter circuit includes a current path between a beam current sense point and an interating capacitor across which a control voltage is developed. A threshold conduction device causes the current path to exhibit different impedance characteristics and associated response times so that the limiter circuit has the ability to respond to average beam current values, as well as to above average r.m.s. beam current values such as may be associated with peak beam current conditions.
Inventors
- 👤 James A. McDonald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:47
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/44; H04N5/57; H04N5/59
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
202 words
In a video signal processing system including a video signal channel, and a current-conducting image display device responsive to video signals received from said video channel; control apparatus comprising: a source of signal representative of the magnitude of current conducted by said display device in response to said video signals, said representative signal being provided at a sense point; filter means; means for coupling a control voltage developed by said filter means to a control input of said video channel; and a current path including threshold conduction means for coupling said representative signal from said sense point to said filter means for causing said filter means to develop said control voltage related to the magnitude of said representative signal; said threshold conduction means exhibiting first and second conductive states as a function of the magnitude of said representative signal; wherein said threshold means when exhibiting said first conductive state causes said control apparatus to exhibit a first response time related to a first value of the impedance of said current path; and when exhibiting a second conductive state causes said control apparatus to exhibit a relatively faster second response time related to a modified, second value of impedance of said current path.
Claim 2
Dependent Claim
202 words
In a video signal processing system including a video signal channel, and a current-conducting image display device responsive to video signals received from said video channel; control apparatus comprising: a source of signal representative of the magnitude of current conducted by said display device in response to said video signals, said representative signal being provided at a sense point; filter means; means for coupling a control voltage developed by said filter means to a control input of said video channel; and a current path including threshold conduction means for coupling said representative signal from said sense point to said filter means for causing said filter means to develop said control voltage related to the magnitude of said representative signal; said threshold conduction means exhibiting first and second conductive states as a function of the magnitude of said representative signal; wherein said threshold means when exhibiting said first conductive state causes said control apparatus to exhibit a first response time related to a first value of the impedance of said current path; and when exhibiting a second conductive state causes said control apparatus to exhibit a relatively faster second response time related to a modified, second value of impedance of said current path.
Claim 3
Dependent Claim
43 words
Apparatus according to claim 1, wherein said filter means comprises an integrating capacitor; and said first and second response times are related to the value of said capacitor and respectively to said first and second values of said impedance of said current path.
Claim 4
Dependent Claim
80 words
Apparatus according to claim 2, wherein said current path includes a resistance coupled between said capacitor and said sense point; said first response time is related to the value of said capacitor and the value of said resistance when said threshold means exhibits said first conductive state; and said second response time is related to the value of said capacitor and a diminished value of resistance of said current path produced when said threshold means exhibits said second conductive state.
Claim 5
Dependent Claim
19 words
Apparatus according to claim 3, wherein said current path is DC coupled between said sense point and said capacitor.
Claim 6
Dependent Claim
28 words
Apparatus according to claim 3, wherein said capacitor develops a voltage thereacross representative of the average value of said representative signal in accordance with said first response time.
Claim 7
Dependent Claim
48 words
Apparatus according to claim 5, wherein said resistance is coupled in series between said sense point and said capacitor; said threshold means comprises a unilateral current conducting device coupled across said resistance; and said unilateral current conducting device exhibits a first, non-conductive state and a second, conductive state.
Claim 8
Dependent Claim
34 words
Apparatus according to claim 5, wherein a current source provides a resupply current for said image display device; and the magnitude of said representative signal is related to the magnitude of said resupply current.
Claim 9
Dependent Claim
159 words
In a video signal processing system including a video signal channel; a current-conducting image display device responsive to video signals received from said channel; and a source of resupply current for said image display device; apparatus comprising: means for providing a signal representative of the magnitude of said resupply current at a sense point; a filter capacitor coupled between a control point and a reference potential; means for coupling a control voltage developed by said capacitor at said control point to a control input of said video channel, for limiting the magnitude of current conducted by said display device in accordance with said control voltage; a current path including a resistor for coupling signals from said sense point to said capacitor, said capacitor developing said control voltage related to the magnitude of said representative signal; and threshold conduction means coupled across said resistor and exhibiting first and second conductive states in response to the magnitude of said representative signal.
Claim 10
Dependent Claim
159 words
In a video signal processing system including a video signal channel; a current-conducting image display device responsive to video signals received from said channel; and a source of resupply current for said image display device; apparatus comprising: means for providing a signal representative of the magnitude of said resupply current at a sense point; a filter capacitor coupled between a control point and a reference potential; means for coupling a control voltage developed by said capacitor at said control point to a control input of said video channel, for limiting the magnitude of current conducted by said display device in accordance with said control voltage; a current path including a resistor for coupling signals from said sense point to said capacitor, said capacitor developing said control voltage related to the magnitude of said representative signal; and threshold conduction means coupled across said resistor and exhibiting first and second conductive states in response to the magnitude of said representative signal.
Claim 11
Dependent Claim
17 words
Apparatus according to claim 8, wherein said current path DC couples said representative signal to said capacitor.
Claim 12
Dependent Claim
56 words
Apparatus according to claim 8, wherein said apparatus exhibits a first response time when said threshold means exhibits a first, non-conductive state, said first response time being related to the values of said capacitor and said resistor; and said apparatus exhibits a second, relatively faster response time when said threshold means exhibits a second, conductive state.
Claim 13
Dependent Claim
27 words
Apparatus according to claim 10, wherein said capacitor developes a voltage representative of the average value of said representative signal in accordance with said first response time.
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) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |