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US 6,608,435 B1Granted
Cathode ray tube apparatus with electron beam forming structure
AssigneeKabushiki Kaisha Toshiba
InventorsJunichi Kimiya, Syunji Ookubo
Life of this patent
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Abstract
In a cathode ray tube apparatus, an electron beam generating section for generating electron beams is composed of a cathode and a plurality of electrodes. Two electrodes of the plurality of electrodes are connected to each other via a resistor. A constant voltage is supplied from the outside of the tube to the one electrode, and a voltage dynamically changed in synchronism with a deflection magnetic field is supplied to an electrode adjacent to the other electrode. Therefore, the shape of a beam spot can be improved, and the resolution of the entire screen can be improved without requiring extensive provision of a lead wire of a stem.
Claims42
A cathode ray tube apparatus having a screen, comprising:
- an electron gun assembly provided with electron beam forming means for generating and emitting at least one electron beam, said electron beam forming means including a cathode and a plurality of electrodes disposed along an electron beam traveling direction, and a main focus lens for focusing the electron beam from the cathode on the screen;
- and
- a deflection yoke for generating a deflection magnetic field deflecting the electron beam in horizontal and vertical directions to scan the screen with the deflected electron beam,
- wherein the main focus lens of the electron gun assembly is formed by focus electrodes and an anode electrode, focus voltages having intermediate voltage levels being applied to the focus electrodes from an outside of the electron gun assembly and an anode voltage having a high voltage level being applied to the anode electrode, the focus electrodes including at least one focus electrode to which a constant focus voltage is applied from the outside of a tube, and at least one dynamic focus electrode to which a dynamic focus voltage varied in synchronism with the deflection magnetic field generated from the deflection yoke is applied, and
- a resistor being connected to at least two electrodes which constitutes the electron beam forming means, a fixed voltage being applied from an outside of the tube to the one of the electrodes connected to the resistor, the another one of the electrodes connected to the resistor is so arranged to face the dynamic focus electrode to which the dynamic focus voltage varied in synchronism with the deflection magnetic field generated from the deflection yoke is applied to form the main lens, and axially asymmetrical lens forming means for forming an axially asymmetrical lens being formed between the at least two electrodes connected to the resistor.
2 more elements
A cathode ray tube apparatus having a screen, comprising:
- an electron gun assembly including,
- electron beam forming means for generating and emitting at least one electron beam, said electron beam forming means including a cathode and at least first, second, and third electrodes disposed along an electron beam traveling direction,
- a resistor connecting said first and second electrodes to each other, an axially asymmetrical lens being formed between said first electrode and the second electrode adjacent to the first electrode, and
- a main focusing lens for focusing the electron beam from the electron beam forming means on the screen, the main focusing lens including at least fourth and fifth electrodes and an anode electrode, the second and third electrodes facing each other;
- a deflection yoke for deflecting the electron beam emitted from the electron gun assembly in horizontal and vertical directions and generating deflection magnetic field for scanning the screen with the deflected electron beam;
- and
- first applying means for applying a constant voltage to said first electrode and second electrode via said resistor, and for applying to the third electrode a dynamic voltage that changes in synchronism with the deflection magnetic field generated from said deflection yoke.
4 more elements
A cathode ray tube apparatus having a screen, comprising:
- an electron gun assembly including,
- electron beam forming means for generating and emitting at least one electron beam, said electron beam forming means including a cathode and at least first, second, and third electrodes disposed along the electron beam traveling direction from the cathode,
- a resistor connecting the first and second electrodes to each other, an axially asymmetrical lens being formed between said first electrode and the second electrode adjacent to the first electrode, and
- a main focusing lens for focusing the electron beams from the electron beam forming means on the screen, the main focusing lens including at least fourth and fifth electrodes and an anode electrode, the second and third electrodes facing each other and the second and fourth electrodes being connected to each other;
- a deflection yoke for deflecting the electron beam emitted from the electron gun assembly in horizontal and vertical directions, the deflection yoke generating a deflection magnetic field for scanning the screen with the deflected beam;
- and
- first applying means for applying a constant voltage to said first, second and fourth electrodes via said resistor, and for applying to the third and fifth electrodes a dynamic voltage that changes in synchronism with the deflection magnetic field generated from the deflection yoke.
4 more elements
A cathode ray tube apparatus having a screen, comprising:
- an electron gun assembly provided with an electron beam generator configured to generate and emit at least one electron beam, said electron beam generator including a cathode and a plurality of electrodes disposed along an electron beam traveling direction, and a main focus lens configured to focus the electron beam from the cathode on the screen;
- and
- a deflection yoke configured to generate a deflection magnetic field deflecting the electron beam in horizontal and vertical directions to scan the screen with the deflected electron beam,
- wherein the main focus lens of the electron gun assembly is formed by focus electrodes and an anode electrode, focus voltages having intermediate voltage levels being applied to the focus electrodes from an outside of the electron gun assembly and an anode voltage having a high voltage level being applied to the anode electrode, the focus electrodes including at least one focus electrode to which a constant focus voltage is applied from the outside of a tube, and at least one dynamic focus electrode to which a dynamic focus voltage varied in synchronism with the deflection magnetic field generated from the deflection yoke is applied, and
- a resistor being connected to at least two electrodes forming the electron beam generator, a fixed voltage being applied from an outside of the tube to the one of the electrodes connected to the resistor, the another one of the electrodes connected to the resistor is so arranged to face the dynamic focus electrode to which the dynamic focus voltage varied in synchronism with the deflection magnetic field generated from the deflection yoke is applied to form the main lens, and an axially asymmetrical lens formed between the at least two electrodes connected to the resistor.
2 more elements
A cathode ray tube apparatus having a screen, comprising:
- an electron gun assembly including,
- an electron beam generator configured to generate and emit at least one electron beam, said electron beam generator including a cathode and at least first, second, and third electrodes disposed along an electron beam traveling direction,
- a resistor connecting said first and second electrodes to each other, and an axially asymmetrical lens formed between said first electrode and the second electrode adjacent to the first electrode, and
- a main focusing lens configured to focus the electron beam from the electron beam generator on the screen, the main focusing lens including at least fourth and fifth electrodes and an anode electrode, the second and third electrodes facing each other;
- a deflection yoke configured to deflect the electron beam emitted from the electron gun assembly in horizontal and vertical directions and generating deflection magnetic field for scanning the screen with the deflected electron beam;
- and
- a first applying circuit configured to apply a constant voltage to said first electrode and second electrode via said resistor, and to apply to the third electrode a dynamic voltage that changes in synchronism with the deflection magnetic field generated from said deflection yoke.
4 more elements
A cathode ray tube apparatus having a screen, comprising:
- an electron gun assembly including,
- an electron beam generator configured to generate and emit at least one electron beam, said electron beam generator including a cathode and at least first, second, and third electrodes disposed along the electron beam traveling direction from the cathode,
- a resistor connecting the first and second electrodes to each other, and an axially asymmetrical lens formed between said first electrode and the second electrode adjacent to the first electrode, and
- a main focusing lens configured to focus the electron beams from the electron beam generator on the screen, the main focusing lens including at least fourth and fifth electrodes and an anode electrode, the second and third electrodes facing each other and the second and fourth electrodes being connected to each other;
- a deflection yoke configured to deflect the electron beam emitted from the electron gun assembly in horizontal and vertical directions, the deflection yoke generating a deflection magnetic field for scanning the screen with the deflected beam;
- and
- a first applying circuit configured to apply a constant voltage to said first, second and fourth electrodes via said resistor, and to apply to the third and fifth electrodes a dynamic voltage that changes in synchronism with the deflection magnetic field generated from the deflection yoke.
4 more elements
Dependencies are inferred from the claim text.