US3697801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for producing a line-frequency sawtooth-current having a field-frequency-varying amplitude in a television display device
Assignee: US Philips Corp
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Filing: 1969-06-13
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Granted: 1972-10-10
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Expires: 1989-06-13
Abstract
Abstract A TV deflection circuit for producing a line frequency sawtooth current whose amplitude varies at the field frequency said variation being approximately parabolic to provide East - West raster correction for any pincushion distortion and approximately sawtooth shaped to provide color correction in the case of a color TV tube. The circuit includes a modulator having an electronic switch controlled by a line frequency signal. During the forward stroke of the constant amplitude sawtooth current supplied by a line deflection current generator to the line deflection coil, the switch connects a field deflection current generator to a resonant circuit including the parallel combination of a capacitor and an inductor. The inductor comprises either the line or field deflection coils, or both. The resonant circuit has a resonant period that is approximately twice the flyback time of the line frequency deflection current.
Inventors
- 👤 Hannspeter Eulenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:08
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/23; H04N3/233
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
185 words
In a television display device having a line deflection coil and a field deflection coil, a circuit arrangement for producing a line frequency sawtooth current having a field frequencyvarying amplitude comprising, a line deflection current generator and a field deflection current generator for supplying line and field frequency sawtooth deflection currents of substantially constant amplitude to said line and field-deflection coils, respectively, and a modulator controlled by the field deflection current generator for deriving the field frequency amplitude variation of the line frequency sawtooth current, said modulator comprising electronic switching means controlled by a signal of the line frequency, means including said switching means for coupling the field-deflection current generator, which provides a voltage having a field frequency variation, to a resonant circuit during the forward stroke of the line sawtooth current, said resonant circuit including the parallel combination of a capacitor and an inductor means comprising at least one deflection coil, the components of said resonant circuit being chosen so that the resonant circuit has a resonant period that is substantially equal to twice the fly-back time of the line frequency sawtooth deflection current.
Claim 2
Dependent Claim
185 words
In a television display device having a line deflection coil and a field deflection coil, a circuit arrangement for producing a line frequency sawtooth current having a field frequencyvarying amplitude comprising, a line deflection current generator and a field deflection current generator for supplying line and field frequency sawtooth deflection currents of substantially constant amplitude to said line and field-deflection coils, respectively, and a modulator controlled by the field deflection current generator for deriving the field frequency amplitude variation of the line frequency sawtooth current, said modulator comprising electronic switching means controlled by a signal of the line frequency, means including said switching means for coupling the field-deflection current generator, which provides a voltage having a field frequency variation, to a resonant circuit during the forward stroke of the line sawtooth current, said resonant circuit including the parallel combination of a capacitor and an inductor means comprising at least one deflection coil, the components of said resonant circuit being chosen so that the resonant circuit has a resonant period that is substantially equal to twice the fly-back time of the line frequency sawtooth deflection current.
Claim 3
Dependent Claim
49 words
A circuit arrangement as claimed in claim 1 wherein the line deflection coil includes two coil halves and the inductor means of the resonant circuit comprises at least four inductive components arranged in a bridge circuit, two of which comprise the two coil halves of the line deflection coil.
Claim 4
Dependent Claim
53 words
A circuit arrangement as claimed in claim 2 wherein the two coil halves of the line deflection coil in the bridge circuit are energized in parallel by the line deflection current generator, the two further inductive components of the bridge comprisIng two bifilar windings for decoupling the deflection current generator and the modulator.
Claim 5
Dependent Claim
52 words
A circuit arrangement as claimed in claim 3 wherein said bifilar windings are connected in series and form the secondary winding of a transformer, and means connecting the transformer primary winding through the electronic switching means to the field deflection current generator which supplies a substantially sawtooth-like voltage at the field frequency.
Claim 6
Dependent Claim
84 words
A circuit arrangement as claimed in claim 2 characterized in that the two coil halves of the line deflection coil arranged in said bridge circuit are energized in series by the line and field deflection generators, the further two inductive bridge components each being formed by a winding on a transformer included in the line and field deflection current generators and by a winding of a coil, the two coils being wound in bifilar fashion for decoupling the deflection current generator and the modulator.
Claim 7
Dependent Claim
55 words
A circuit arrangement as claimed in claim 5 wherein the capacitor is connected in the bridge circuit and in parallel with a secondary winding of a transformer, means connecting the transformer primary winding through the electronic switching means to the field deflection current generator which supplies a substantially sawtooth-like voltage thereto of the field frequency.
Claim 8
Dependent Claim
110 words
A circuit arrangement as claimed in claim 3 wherein the field deflection current generator, which supplies a substantially sawtooth-like voltage of field frequency, comprises a first transformer having two windings connected in series through the parallel combination of a potentiometer and a capacitor, said bifilar windings being connected in series and forming the secondary winding of a second transformer, means connecting the free ends of the windings of the first transformer through the electronic switching means to the free ends of the primary winding of said second transformer in the bridge circuit, and means connecting the arm of the potentiometer to a center tap on the second transformer primary winding.
Claim 9
Dependent Claim
50 words
A circuit arrangement as claimed in claim 1 for carrying out the East-West raster correction of the pincushion distortion on the screen of a display tube wherein the resonant circuit inductor means includes an inductive component connected in series with the line deflection current generator and the line deflection coil.
Claim 10
Dependent Claim
88 words
A circuit arrangement as claimed in claim 8 wherein the line deflection generator includes a transformer with a winding connected in series with said inductive component traversed by the line deflection current, means connecting said series combination in parallel with said capacitor, the voltage produced across said transformer winding of the series combination being equal and in an opposite sense to the voltage appearing across the inductive component produced by the flow of line deflection current therein thereby to decouple the line deflection current generator and the modulator.
Claim 11
Dependent Claim
69 words
A circuit arrangement as claimed in claim 8 wherein the field deflection generator includes means for deriving a voltage with a parabolic waveform at the field frequency, means connecting the capacitor of the resonant circuit and the electronic switching means in series with the terminals of a capacitor, one terminal of which is connected to the field deflection current generator which supplies thereto said parabolic voltage of field frequency.
Claim 12
Dependent Claim
82 words
A circuit arrangement as claimed in claim 3 wherein the resonant circuit inductor means includes an inductive component connected in series with the line deflection generator and the line deflection coil, said bridge circuit forming the inductance of a first resonant circuit including the two halves of the line deflection coil, means connecting said bridge circuit to the line deflection current generator in a series combination with said inductive component which forms a part of the inductance of a second resonant circuit.
Claim 13
Dependent Claim
100 words
A circuit arrangement as claimed in claim 5 wherein the resonant circuit inductor means includes an inductive component connected in series with the line deflection generator and the line deflection coil, the series combination of the two bifilar windings of the coil in said bridge circuit forming the inductance of a first resonant circuit including the two halves of the line deflection coil, means connecting said bifilar windings in parallel with an impedance means having a comparatively low impedance relative thereto, the impedance means including said inductive component which forms a part of the inductance of a second resonant circuit.
Claim 14
Dependent Claim
39 words
A circuit arrangement as claimed in claim 12 characterized in that said impedance means having a comparatively low impedance includes a capacitor for carrying out the S-correction connnected in series with said inductive component of the second resonant circuit.
References Cited (Backward Citations)
US3440483A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |