Back to results
US 6,664,746 B2Granted
Dynamic focusing circuit, picture display device and method of generating a dynamic focusing voltage
AssigneeKoninklijke Philips Electronics N.V.
InventorAlbertus Aemilius Seyno Sluyterman
Life of this patent
Estimating the term…
Abstract
A dynamic focusing circuit includes a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current. An integrator, coupled to the secondary winding, generates a line-frequency focusing voltage from the transformed deflection current. A waveform generator coupled to the secondary winding generates an additional line-frequency focusing voltage and superimposes the additional line-frequency focusing voltage on the line-frequency focusing voltage.
Claims12
A dynamic focusing circuit comprising:
- a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current;
- and
- an integrator coupled to the secondary winding, for generating a line-frequency focusing voltage from the transformed deflection current,
- wherein a waveform generator coupled to the secondary winding is provided to generate an additional line-frequency focusing voltage and to superimpose the additional line-frequency voltage on the line-frequency focusing voltage;
- and
- wherein the line-frequency focusing voltage has an amplitude of at least 1500 volts after the additional line-frequency focusing voltage has been superimposed on the line-frequency focusing voltage.
3 more elements
A dynamic focusing circuit comprising:
- a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current;
- and
- an integrator coupled to the secondary winding, for generating a line-frequency focusing voltage from the transformed deflection current,
- wherein a waveform generator coupled to the secondary winding is provided to generate an additional line-frequency focusing voltage and to superimpose the additional line-frequency voltage on the line-frequency focusing voltage;
- and
- wherein the additional line-frequency focusing voltage has substantially fourth-order and higher order line-frequency harmonic components.
3 more elements
A dynamic focusing circuit comprising:
- a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current;
- and
- an integrator coupled to the secondary winding, for generating a line-frequency focusing voltage from the transformed deflection current,
- wherein a waveform generator coupled to the secondary winding is provided to generate an additional line-frequency focusing voltage and to superimpose the additional line-frequency voltage on the line-frequency focusing voltage;
- wherein the waveform generator comprises a waveform-generating circuit for generating the additional line-frequency focusing voltage (VI2), and also an amplifier, coupled to the waveform-generating circuit for amplifying the generated additional line frequency focusing voltage.
2 more elements
A dynamic focusing circuit comprising:
- a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current;
- and
- an integrator coupled to the secondary winding, for generating a line-frequency focusing voltage from the transformed deflection current,
- wherein a waveform generator coupled to the secondary winding is provided to generate an additional line-frequency focusing voltage and to superimpose the additional line-frequency voltage on the line-frequency focusing voltage;
- wherein the additional line-frequency focusing voltage has an amplitude of between 0.5 and 2 times the amplitude of the line-frequency voltage.
2 more elements
A picture tube display device comprising:
- a cathode ray tube for displaying a video signal;
- deflection means (L1, Lf) for deflecting an electron beam (201) in the cathode ray tube;
- an electron gun in the cathode ray tube for generating the electron beam, comprising a DAF section for dynamically adapting a focusing and an astigmatism of the electron beam in dependence upon the deflection of the electron beam,
- a deflection circuit, coupled to the deflection means for generating a line-frequency deflection current and a field-frequency deflection current, synchronized with the video signal, and
- a dynamic focusing circuit supplying line-frequency voltage to the DAF section,
- wherein the dynamic focusing circuit generates a line-frequency focusing voltage and an additional line-frequency focusing voltage that is added on said line-frequency voltage so that an amplitude of the line-frequency focusing voltage after the addition of said additional line-frequency focusing voltage is at least 1500 Volts.
3 more elements
A method of generating a line-frequency focusing voltage in a picture display device, the method comprising the steps of:
- transforming a line-frequency deflection current to a transformed deflection current;
- and
- integrating the transformed deflection current to a line-frequency focusing voltage,
- comprising the steps of
- generating an additional line-frequency focusing voltage and
- superimposing the additional line-frequency focusing voltage on the line-frequency focusing voltage;
- wherein the line-frequency voltage has an amplitude of at least 1500 volts after the superimposing of the additional line-frequency focusing voltage.
4 more elements
Dependencies are inferred from the claim text.