Patent US3811068A successfully refreshed from Google Patents.
US3811068A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protection circuit for cathode ray tubes
Assignee: Westinghouse Electric Corp
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Filing: 1971-12-30
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Granted: 1974-05-14
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Expires: 1991-12-30
Abstract
Abstract Described is a protective circuit for an electron beam device which gives a failure indication when the sweep signal fails and the electron beam is not properly deflected across the target. The circuit includes a bi-stable device which is set in a first output state in response to the unblank signal of the electron beam device and reset to a second output state in response to a sweep detection signal generator. The signal generator is triggered only when the sweep signal exceeds a predetermined threshold. When the signal generator is not triggered the bistable device is not reset and remains in its first output state. Output circuitry provides an output failure signal responsive to the bi-stable device when it remains in its first output state for the entire unblank portion of the unblank signal. A gate in feedback relationship to the output circuitry prevents a false failure indication.
Inventors
- 👤 R Curry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:03
CPC Classifications
G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/20
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
149 words
In combination with an electron beam device including a target, a blanking circuit for providing an unblank signal having an unblank portion followed by a blank portion, and sweep signal generating means for deflection of the electron beam, a protective circuit comprising: A. bi-stable means operable in a first and a second output state and being responsive to said unblank portion of said unblank signal for initially assuming said first output state, B. detection means responsive to said sweep signal for providing a detection signal only when said sweep signal exceeds a predetermined threshold, C. said bi-stable means being operably connected to said detection means for switching back to its second output state, in response to said sweep signal, and D. circuit means for providing an output failure signal if said bi-stable means remains in said first output state during the entire said unblank portion of said unblank signal.
Claim 2
Dependent Claim
149 words
In combination with an electron beam device including a target, a blanking circuit for providing an unblank signal having an unblank portion followed by a blank portion, and sweep signal generating means for deflection of the electron beam, a protective circuit comprising: A. bi-stable means operable in a first and a second output state and being responsive to said unblank portion of said unblank signal for initially assuming said first output state, B. detection means responsive to said sweep signal for providing a detection signal only when said sweep signal exceeds a predetermined threshold, C. said bi-stable means being operably connected to said detection means for switching back to its second output state, in response to said sweep signal, and D. circuit means for providing an output failure signal if said bi-stable means remains in said first output state during the entire said unblank portion of said unblank signal.
Claim 3
Dependent Claim
47 words
The protective circuit of claim 1 wherein said protective circuit further includes gating means operably connected in feedback relationship to said circuit means and responsive to said detection signal and said output failure signal for preventing said output failure signal during start up of said sweep signal.
Claim 4
Dependent Claim
48 words
The protective circuit of claim 2 wherein said gating means includes a NAND gate responsive to said sweep signal and said failure output signal for generating an input signal indicative of no failure of said sweep output signal to said circuit means during start-up of said sweep signal.
Claim 5
Dependent Claim
31 words
The protective circuit of claim 1 wherein said protective circuit further includes an amplifier connected to said unblank circuit for inverting said unblank signal and operably connected to said bi-stable means.
Claim 6
Dependent Claim
43 words
The protective circuit of claim 1 wherein said detection means includes pulse generating means operably connected to said bi-stable means and being responsive to said sweep signal generating means to provide a detection signal only when said sweep signal exceeds a predetermined threshold.
Claim 7
Dependent Claim
32 words
The protective circuit of claim 1 wherein said protective circuit further includes means responsive to said failure signal to render said electron beam innocuous to said target of said electron beam device.
Claim 8
Dependent Claim
18 words
The protective circuit of claim 6 wherein said means responsive to said failure signal includes said blanking circuit.
Claim 9
Dependent Claim
152 words
A protective circuit for an electron beam device including a target and a sweep signal generating means for deflection of the electron beam comprising: A. means for detecting said sweep signal only when said sweep signal exceeds a predetermined threshold and generating a detection signal in response thereto, B. control means including a blanking circuit for providing an unblank signal having an unblank portion followed by a blank portion, C. bi-stable means having a first and second output state responsive to said detection means and said control means such that said bi-stable means is initially set in said first output state by said unblank portion of said unblank signal and subsequently is reset in said second output state by said detection signal, and D. circuit means for providing an output failure signal if said bi-stable means remains in said first output state during the entire said unblank portion of said unblank signal.
Claim 10
Dependent Claim
152 words
A protective circuit for an electron beam device including a target and a sweep signal generating means for deflection of the electron beam comprising: A. means for detecting said sweep signal only when said sweep signal exceeds a predetermined threshold and generating a detection signal in response thereto, B. control means including a blanking circuit for providing an unblank signal having an unblank portion followed by a blank portion, C. bi-stable means having a first and second output state responsive to said detection means and said control means such that said bi-stable means is initially set in said first output state by said unblank portion of said unblank signal and subsequently is reset in said second output state by said detection signal, and D. circuit means for providing an output failure signal if said bi-stable means remains in said first output state during the entire said unblank portion of said unblank signal.
Claim 11
Dependent Claim
45 words
The protective circuit of claim 8 wherein said protective circuit further includes gating means connected in feedback relationship to said circuit means and responsive to said detection signal and said output failure signal for preventing said output failure signal during start-up of said sweep signal.
Claim 12
Dependent Claim
32 words
The protective circuit of claim 8 wherein said protective circuit further includes means responsive to said failure signal to render said electron beam innocuous to said target of said electron beam device.
Claim 13
Dependent Claim
47 words
The protective circuit of claim 8 wherein said means for detecting said sweep signal includes pulse generating means operably connected to said bi-stable means and being responsive to said sweep signal generating means to provide a detection signal only when said sweep signal exceeds a predetermined threshold.
Claim 14
Dependent Claim
128 words
A circuit arrangement comprising: A. an electron beam device having a target and an electron gun for generating an electron beam which impinges on said target, B. a blanking circuit operably connected to said electron beam device for providing an unblank signal having an unblank portion followed by a blank portion, C. sweep signal generating means operably connected to said electron beam device for deflection of said electron beam, D. detection means responsive to said sweep signal for providing a detection signal only when said sweep signal exceeds a predetermined threshold, and E. a protective circuit means responsive to said unblank signal and said detection signal for providing a failure output signal when said detection signal is absent during the entire said unblank portion of said unblank signal.
Claim 15
Dependent Claim
128 words
A circuit arrangement comprising: A. an electron beam device having a target and an electron gun for generating an electron beam which impinges on said target, B. a blanking circuit operably connected to said electron beam device for providing an unblank signal having an unblank portion followed by a blank portion, C. sweep signal generating means operably connected to said electron beam device for deflection of said electron beam, D. detection means responsive to said sweep signal for providing a detection signal only when said sweep signal exceeds a predetermined threshold, and E. a protective circuit means responsive to said unblank signal and said detection signal for providing a failure output signal when said detection signal is absent during the entire said unblank portion of said unblank signal.
References Cited (Backward Citations)
US3374391A
Cited
US3501670A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-13 | 1977-11-12 | 1978-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-13 | 1981-11-12 | 1982-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-13 | 1985-11-12 | 1986-05-14 | $7700.00 | Window Closed / Lapsed |