Patent US4093895A successfully refreshed from Google Patents.
US4093895A
Expired / Lapsed
US
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Assymetric top-bottom pincushion correction circuit
Assignee: GTE Sylvania Inc
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Filing: 1976-05-03
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Granted: 1978-06-06
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Expires: 1996-05-03
Abstract
Abstract In a top-bottom pincushion correction circuit having a saturable reactor with a control winding coupled to a source of deflection current at a horizontal scan frequency and an output winding coupled to a source of deflection current at a vertical scan frequency, a means coupled to the control winding unbalances the waveform applied thereto from the source of deflection current at a vertical scan frequency to provide asymmetric top-bottom pincushion correction.
Inventors
- 👤 Robert P. Collette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:50
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/23; H04N3/237
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
In a cathode ray tube scanning system having a cathode ray tube with an associated deflection yoke which includes horizontal and vertical deflection windings coupled to a source of deflection current at horizontal and vertical scan frequencies and a top and bottom pincushion correction circuit having a saturable reactor with a control winding coupled to the source of deflection current at a horizontal scan frequency and an output winding coupled to a source of deflection current at a vertical scan frequency and to a shunt connected capacitor and impedance, the improvement comprising: means coupled to said output winding for unbalancing the waveform applied thereto from said source of deflection current at a vertical scan frequency to provide asymmetric top-bottom pincushion correction, said means of a form to provide a substantially constant crossover point of said waveform.
Claim 2
Dependent Claim
136 words
In a cathode ray tube scanning system having a cathode ray tube with an associated deflection yoke which includes horizontal and vertical deflection windings coupled to a source of deflection current at horizontal and vertical scan frequencies and a top and bottom pincushion correction circuit having a saturable reactor with a control winding coupled to the source of deflection current at a horizontal scan frequency and an output winding coupled to a source of deflection current at a vertical scan frequency and to a shunt connected capacitor and impedance, the improvement comprising: means coupled to said output winding for unbalancing the waveform applied thereto from said source of deflection current at a vertical scan frequency to provide asymmetric top-bottom pincushion correction, said means of a form to provide a substantially constant crossover point of said waveform.
Claim 3
Dependent Claim
34 words
The improvement of claim 1 wherein said means for unbalancing the waveform applied to said control winding is in the form of a series connected unidirectional conduction device and impedance shunting said control winding.
Claim 4
Dependent Claim
26 words
The improvement of claim 2 wherein said series connected unidirectional conduction device and impedance are in the form of a series connected diode and alterable impedance.
Claim 5
Dependent Claim
31 words
The improvement of claim 2 wherein said impedance shunting said control winding is alterable to effect control of the amount of unbalance or asymmetry between top and bottom pincushion correction waveform.
Claim 6
Dependent Claim
92 words
In a top and bottom pincushion correction circuit for a cathode ray tube scanning system wherein the correction circuit includes a saturable reactor with a control winding coupled to a source of deflection current at a horizontal scan frequency and an output winding shunted by a parallel coupled capacitor and impedance and coupled to a source of deflection current at a vertical scan frequency, the improvement comprising: a series connected unidirectional conduction device and impedance coupled to said output winding for controlling the asymmetry of a top and bottom pincushion correction waveform.
Claim 7
Dependent Claim
92 words
In a top and bottom pincushion correction circuit for a cathode ray tube scanning system wherein the correction circuit includes a saturable reactor with a control winding coupled to a source of deflection current at a horizontal scan frequency and an output winding shunted by a parallel coupled capacitor and impedance and coupled to a source of deflection current at a vertical scan frequency, the improvement comprising: a series connected unidirectional conduction device and impedance coupled to said output winding for controlling the asymmetry of a top and bottom pincushion correction waveform.
Claim 8
Dependent Claim
36 words
The improvement of claim 5 wherein said means for controlling the assymetry of a top and bottom pincushion correction waveform is in the form of a series connected diode and alterable resistor shunting said control winding.
Claim 9
Dependent Claim
24 words
The improvement of claim 6 wherein said alterable resistor provides control of the amount of asymmetry of the top to bottom pincushion correction waveform.
Claim 10
Dependent Claim
28 words
The improvement of claim 6 wherein said series connected diode and alterable resistor effect unbalance of said pincushion correction waveform with respect to a substantially constant crossover point.
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) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |