Patent US3914650A successfully refreshed from Google Patents.
US3914650A
Expired / Lapsed
US
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Television display apparatus provided with a circuit arrangement for generating a sawtooth current through a line deflection coil
Assignee: US Philips Corp
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Filing: 1973-12-04
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Granted: 1975-10-21
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Expires: 1993-12-04
Abstract
Abstract Television display apparatus including a circuit arrangement for combined line deflection and supply voltage stabilisation with the aid of means for field frequency modulation of the line deflection current, and a circuit arrangement for use in such television display apparatus.
Inventors
- 👤 Oswald Johannes Verbeij
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:48
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/23; H04N3/233; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/62
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
200 words
Television display apparatus provided with a circuit arrangement for generating a sawtooth current through a line deflection coil forming part of a resonant network also including a trace capacitor and a retrace capacitor, switching means for applying the voltage across the trace capacitor to the deflection coil at the line frequency during the trace time of the sawtooth current, said switching means being blocked during the retrace time, a first current loop comprising a winding of an inductive element and a controllable switch for supplying energy originating from a direct voltage source to the inductive element during the conduction period of the switch and a second current loop comprising a diode and a winding of said inductive element which is connected through the diode to the resonant network and a field deflection current generator, characterized in that a modulation source controlled by the field deflection current generator is incorporated in the second current loop for modulating the amplitude of the sawtooth current, the circuit arrangement furthermore including a stabilizing circuit for maintaining the amplitude of the voltage occurring across the inductive element during the retrace time of the sawtooth current substantially constant by varying the conduction period of the switch.
Claim 2
Dependent Claim
200 words
Television display apparatus provided with a circuit arrangement for generating a sawtooth current through a line deflection coil forming part of a resonant network also including a trace capacitor and a retrace capacitor, switching means for applying the voltage across the trace capacitor to the deflection coil at the line frequency during the trace time of the sawtooth current, said switching means being blocked during the retrace time, a first current loop comprising a winding of an inductive element and a controllable switch for supplying energy originating from a direct voltage source to the inductive element during the conduction period of the switch and a second current loop comprising a diode and a winding of said inductive element which is connected through the diode to the resonant network and a field deflection current generator, characterized in that a modulation source controlled by the field deflection current generator is incorporated in the second current loop for modulating the amplitude of the sawtooth current, the circuit arrangement furthermore including a stabilizing circuit for maintaining the amplitude of the voltage occurring across the inductive element during the retrace time of the sawtooth current substantially constant by varying the conduction period of the switch.
Claim 3
Dependent Claim
39 words
Television display apparatus as claimed in claim 1, characterized in that the modulation source includes an emitter follower stage incorporated in said second current loop as well as a control device for field frequency controlling the emitter follower stage.
Claim 4
Dependent Claim
29 words
Television display apparatus as claimed in claim 1, characterized in that the modulation source supplies a line frequency voltage with line flyback pulses with a field frequency amplitude variation.
Claim 5
Dependent Claim
39 words
Television display apparatus as claimed in claim 3, characterized in that the modulation source supplies a line frequency voltage which is substantially zero at least during the part of the line trace time when the controllable switch is blocked.
Claim 6
Dependent Claim
54 words
Television display apparatus as claimed in claim 2 and characterized in that the modulation sourcE supplies a line frequency voltage with line flyback pulses with a field frequency amplitude variation and line flyback pulses originating from a winding of the inductive element control the emitter follower stage through a field frequency amplification-controlled control circuit.
Claim 7
Dependent Claim
29 words
Television display apparatus as claimed in claim 3, characterized in that the modulation source is constituted by a controllable inductor, for example, the power winding of a saturable reactor.
Claim 8
Dependent Claim
43 words
Television display apparatus as claimed in claim 1, characterized by the series arrangement of the modulation source with a winding on the inductive element and with the third diode in which a further diode is present in parallel across the said series arrangement.
Claim 9
Dependent Claim
26 words
Television display apparatus as claimed in claim 1, characterized in that the modulation source is incorporated both in the first and in the second current loop.
Claim 10
Dependent Claim
35 words
Television display apparatus as claimed in claim 1, characterized in that the switching means consist of a parallel diode and the series arrangement of a series diode and the controllable switch connected in parallel therewith.
Claim 11
Dependent Claim
194 words
A circuit arrangement for generating a sawtooth current through a line deflection coil, said circuit arrangement comprising a trace capacitor and a retrace capacitor forming a resonant circuit with said coil; switching means for applying the voltage across the trace capacitor to the deflection coil at the line frequency during the trace time of the sawtooth current, said switching means being blocked during the retrace time; a first current loop comprising a winding of an inductive element and a controllable switch means coupled to said element for supplying energy originating from a direct voltage source to the inductive element during the conduction period of the switch; a second current loop comprising, a field deflection current generator, a diode, a winding of said inductive element coupled through the diode to the resonant network and to said field deflection current generator, and a modulation source means controlled by the field deflection current generator for modulating the amplitude of the sawtooth current; and a stabilizing circuit means for maintaining the amplitude of the voltage occurring across the inductive element during the retrace time of the sawtooth current substantially constant by varying the conduction period of the switch.
Claim 12
Dependent Claim
194 words
A circuit arrangement for generating a sawtooth current through a line deflection coil, said circuit arrangement comprising a trace capacitor and a retrace capacitor forming a resonant circuit with said coil; switching means for applying the voltage across the trace capacitor to the deflection coil at the line frequency during the trace time of the sawtooth current, said switching means being blocked during the retrace time; a first current loop comprising a winding of an inductive element and a controllable switch means coupled to said element for supplying energy originating from a direct voltage source to the inductive element during the conduction period of the switch; a second current loop comprising, a field deflection current generator, a diode, a winding of said inductive element coupled through the diode to the resonant network and to said field deflection current generator, and a modulation source means controlled by the field deflection current generator for modulating the amplitude of the sawtooth current; and a stabilizing circuit means for maintaining the amplitude of the voltage occurring across the inductive element during the retrace time of the sawtooth current substantially constant by varying the conduction period of the switch.
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) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |