Patent US1808874A successfully refreshed from Google Patents.
US4724364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
CRT Control circuit
Assignee: Motorola Solutions Inc
•
Filing: 1985-06-06
•
Granted: 1988-02-09
•
Expires: 2005-06-06
Abstract
Abstract A circuit for controlling a CRT including a control which monitors tube parameters and adjusts the nominal cut-off level of the tube cathode current accordingly, sensing when the control is near an extreme of its range of adjustment and responsive to the sensing to change a control signal applied to a grid of the tube so as to bring the nominal cut off level control loop within its range of adjustment.
Inventors
- 👤 Anthony D. Newton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:32
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; G; G09; G09G; G09G1/00; H04N9/645
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
90 words
A circuit for controlling a cathode ray tube comprising: a nominal cut-off control loop for operatively monitoring tube parameters and adjusting the nominal cut-off level of the tube cathode current accordingly within a predetermined range of adjustment; means for sensing when the nominal cut-off level control loop is near an extreme of its range of adjustment; and means responsive to the sensing means for changing a control signal applied to a grid of the tube so as to bring the nominal cut-off level control loop within its range of adjustment.
Claim 2
Dependent Claim
90 words
A circuit for controlling a cathode ray tube comprising: a nominal cut-off control loop for operatively monitoring tube parameters and adjusting the nominal cut-off level of the tube cathode current accordingly within a predetermined range of adjustment; means for sensing when the nominal cut-off level control loop is near an extreme of its range of adjustment; and means responsive to the sensing means for changing a control signal applied to a grid of the tube so as to bring the nominal cut-off level control loop within its range of adjustment.
Claim 3
Dependent Claim
25 words
A circuit according to claim 1 wherein the changing means is arranged to change the voltage applied to the G 2 grid of the tube.
Claim 4
Dependent Claim
29 words
A circuit according to claim 1 or 2 wherein the changing means comprises a shunt feedback regulator connected in parallel with the voltage applied to the G 2 grid.
Claim 5
Dependent Claim
22 words
A circuit according to claim 3 wherein the shunt feedback regulator comprises a low voltage transistor with a cascode high voltage thyristor.
Claim 6
Dependent Claim
22 words
A circuit according to claim 3 wherein the shunt feedback regulator comprises a low voltage transistor with a cascode high voltage triac.
Claim 7
Dependent Claim
31 words
A circuit according to 1 claim wherein the changing means is so arranged as to bring the nominal cutoff level control loop to substantially an extreme of its range of adjustment.
Claim 8
Dependent Claim
88 words
An integrated circuit for controlling a cathode ray tube comprising: a cut-off control loop for operatively monitoring tube parameters and adjusting the nominal cut-off level of the tube cathode current accordingly within a predetermined range of adjustment; means for sensing when said cut-off level control loop is near an extreme of its range of adjustment; and means responsive to said sensing means for changing a control signal applied to a grid of the tube so as to bring said cut-off level control loop within its range of adjustment.
Claim 9
Dependent Claim
88 words
An integrated circuit for controlling a cathode ray tube comprising: a cut-off control loop for operatively monitoring tube parameters and adjusting the nominal cut-off level of the tube cathode current accordingly within a predetermined range of adjustment; means for sensing when said cut-off level control loop is near an extreme of its range of adjustment; and means responsive to said sensing means for changing a control signal applied to a grid of the tube so as to bring said cut-off level control loop within its range of adjustment.
References Cited (Backward Citations)
US3598913A
Cited
US3898381A
Cited
US4126884A
Cited
FR2441306A1
Cited
US4277798A
Cited
US4318034A
Cited
US4344021A
Cited
US4461983A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-08 | 1991-08-10 | 1992-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-08 | 1995-08-10 | 1996-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-08 | 1999-08-10 | 2000-02-09 | $7700.00 | Window Closed / Lapsed |