US 6,486,624 B2Granted

Cathode ray tube apparatus

AssigneeKabushiki Kaisha Toshiba

InventorsJunichi Kimiya, Shunji Ookubo

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Abstract

An electron gun structure includes a first non-axial-symmetrical lens portion which is arranged in the vicinity of an electron beam formation portion, and a second non-axial-symmetrical lens portion formed to a main lens portion, the first non-axial symmetrical lens portion has a lens action in the vertical direction that a focusing action relative to the electron beams becomes stronger as a quantity of deflection of the electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on the electron beams, and a comprehensive lens system of the second non-axial-symmetrical lens portion and the main lens portion has a lens action in the vertical direction that a divergence action relative to the electron beams becomes stronger as a quantity of deflection of the electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on the electron beams.

Claims9

Dependent claims

A cathode ray tube apparatus comprising:

an electron gun structure having an electron beam formation portion for forming electron beams and a main lens portion for focusing said electron beams onto a phosphor screen;
and
a deflection yoke for generating a deflection magnetic field f or scanning in a horizontal direction and a vertical direction on said phosphor screen by deflecting said electron beams emitted from said electron gun structure,
wherein said electron gun structure further includes a first non-axial-symmetrical lens portion whose lens action changes in accordance with a quantity of deflection of said electron beams and which is arranged in the vicinity of said electron beams formation portion, and a second non-axial-symmetrical lens portion whose lens action changes in accordance with a quantity of deflection of the electron beam and which is formed to said main lens portion;
said first non-axial-symmetrical lens portion has a lens action in the vertical direction that a focusing action relative to said electron beams becomes stronger as a quantity of deflection of said electron beams increases, and a lens act ion in the horizontal direction which substantially rarely acts on said electron beams as compared with said lens action in the vertical direction;
and
a comprehensive lens system of said second non-axial-symmetrical lens portion and said main lens portion has a lens action in the vertical direction that a divergence action with respect to said electron beams becomes stronger as a quantity of deflection of said electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on said electron beams.

4 more elements

A cathode ray tube apparatus comprising:

an electron gun structure having an electron beams formation portion forming electron beams and a main lens portion for focusing said electron beams onto a phosphor screen;
and
a deflection yoke for generating a deflection magnetic field for scanning in a horizontal direction and a vertical direction on said phosphor screen by deflecting said electron beams emitted from said electron beam gun structure,
wherein said electron gun structure includes:
an auxiliary electrode arranged between said electron beams formation portion and said main lens portion, a first dynamic focus electrode arranged between said electron beams formation portion and said auxiliary electrode, and a first focus electrode;
a second focus electrode which constitutes said main lens portion and is connected to said first focus electrode, a second dynamic focus electrode connected to said first dynamic focus electrode, at least one intermediate electrode, and an anode electrode;
and
voltage applying means which applies a first level voltage to said electron beam formation portion, applies a focus voltage on a second level which is higher than said first level to said first and second focus electrodes, applies to said first and second dynamic focus electrodes a dynamic focus voltage obtained by superposing a fluctuating voltage which fluctuates in synchronization with said deflection magnetic field on a reference voltage whose level is nearly equal to said second level, applies an anode voltage on a third level which is higher than said second level to said anode electrode, applies to said auxiliary electrode a voltage which is obtained by performing resistance division to said anode voltage through a resistor provided in the vicinity of said electron gun structure and whose level is higher than said second level and lower than said third level, and applies to said intermediate electrode a voltage which is obtained by performing resistance division to said anode voltage through said resistor and whose level is higher than said second level and lower than said third level,
a non-axial-symmetrical lens being formed between said first dynamic focus electrode and said first focus electrode.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/910,736Filed 24 Jul 2001
Priority: JP 2000-22573426 Jul 2000
Published: US 2002/0047657 A125 Apr 2002
Granted: 26 Nov 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H01J 29/488
Electron guns: schematic arrangements of the electrodes for beam forming; Place and form of the elecrodes
H01J 29/503
Two or more guns in a single vacuum space, e.g. for plural-ray tube: three or more guns, the axes of which lay in a common plane
H01J 2229/4841
Characterised by the potentials applied: dynamic potentials
H01J 2229/4865
Parallelogram: rectangle