JPS5816740B2 - display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention displays an image by controlling the electron beam emitted from a planar electron source by a pair of MAI-IJ sock electron beam control electrodes, accelerating it and colliding it onto a phosphor surface. The present invention relates to a flat display device that performs.

The electron beam emitted from the flat electron source is passed through a pair of matrices.
Attempts have been made to construct a flat display device that displays characters or images and is controlled by IJ Lux electron beam control electrodes.

FIG. 1 shows an example of a main part configuration diagram of this type of display device.

1 is a flat electron source, and a hot cathode, a field emission cold cathode, etc. are used.

2 is a grid-like electrode plate with a large number of through holes 6, and the cathode 1
A positive voltage is applied to the electron beam, and an electron beam is extracted.

A part of the electron beam passes through the through holes of the grid electrode plate 2,
The electron beam reaches the surface of the electron beam control electrode plate 3.

A large number of through holes 6a and 6b are regularly drilled in the control plates 3 and 4, vertically and horizontally, and strip-shaped electrodes 7 and 8 are provided in each row and each column, and are arranged in appropriate positions so as to be perpendicular to each other. Through-holes 5a are provided in both electrode plates at each orthogonal intersection point with a certain distance maintained between them.

6b are arranged so that they match.

The beam current of the electron beam that has reached the surface of the electron beam control electrode plate 3 is modulated in accordance with the signal voltage applied to each strip-shaped electrode 7, and passes through the through hole 6a to reach the surface of the electron beam control electrode plate 4. reach

Regarding the electrode plate 4, the electron beam is modulated by the same mechanism as the electrode plate 3 and passes through the through hole 6b.

The electron beam passing through the through hole 6b is accelerated by a positive high voltage applied to the accelerating electrode plate 9, collides with the phosphor film 11 coated on the surface of the accelerating electrode 9, and emits light.

Generally, a focusing electrode plate 5 is provided between the electron beam control plate 4 and the accelerating electrode plate 9 to focus or collimate the electron beam and to prevent the potentials of the control electrodes 3 and 4 from being affected by the high voltage for acceleration. insert.

In the display device configured in this manner, characters or images can be displayed by sequentially applying signal voltages to each electrode of the electron beam control electrode plates 3 and 4.

10 is a transparent glass substrate. Conventionally, the focusing electrode plate 5 has been provided with through holes 12 corresponding to the positions of the through holes 6a and 6b provided in the electron beam control electrode plates 3 and 4, or a mesh electrode plate has been used.

FIG. 2 shows the focused state of the electron beam when the focusing electrode plate 5 having the through holes 12 is used.

Since a high voltage of 10 to 20 KV is applied between the focusing electrode plate 5 and the accelerating electrode 11, a strong electric field distortion occurs near the through hole 12 provided in the focusing electrode plate 5, and as shown in 13. A potential surface is formed.

The concave electric field distortion near the through hole 12 has the effect of focusing the electron beam.

The degree of the focusing effect varies depending on the diameter of the through hole 12, the applied voltage, and the parallelism or divergence angle of the electron beam. Generally, the larger the diameter of the through hole 12 and the higher the accelerating voltage, the stronger the focusing effect.

For example, when an accelerating voltage of 10 KV is applied, if the diameter of the through hole is 0.3 mm or more, the focusing effect is strong, so the trajectory 14 of the electron beam forms a cross point 15 and spreads again on the surface of the accelerating electrode 9. It becomes impossible to obtain a fine electron beam.

On the other hand, in order to allow as many electron beams as possible to pass through the through-hole 12, it is necessary to increase the diameter of the through-hole 12. Therefore, increasing the electron beam current passing through the through-hole and obtaining a fine electron beam are mutually important. They have a contradictory relationship.

In addition, when using grid-like mesh electrodes with a pitch of 0.3 mm or less, the electron beam may not be focused sufficiently or the electron beam that passes through multiple holes in the mesh electrode will become an electron beam corresponding to each hole. As a whole, there is a drawback that only an electron beam larger than the diameter of the through hole 12 provided in the electron beam control electrode 4 can be obtained, rather than a fine electron beam focused on one point.

The present invention provides an electrode structure that can eliminate the above-mentioned drawbacks, by making the electric field distortion near the through hole of the focusing electrode plate into a constant shape, and always on the accelerating electrode or phosphor surface as shown in FIG. The cross point of the electron beam shown in the figure is formed.

The present invention will be described below with reference to drawings and actual cases.

FIGS. 3a and 3b and FIGS. 4a and 4b show an embodiment of the present invention.

The focusing electrodes 20 shown in FIGS. 3a and 3b are spaced at 0.8 mm intervals by 0.6 mm9! The mesh-like through holes 21 of f are arranged in a grid pattern,
It is formed on a metal plate with a thickness of 0.1 mm by photo-etching technology, and has a radius of curvature of 12 mm as shown in the cross-sectional view in Figure 3a.
A concave surface of m7IL is formed for each through hole 21.

In addition, the focusing electrode shown in FIGS. 4a and 4b is similar to the focusing electrode 20 shown in FIG. , 1 y
It is constructed by overlapping a metal plate 23 with a thickness of 0.2 mm and a metal plate 24 with a thickness of 0.2 mm provided with through holes of 0.6 mrn9!5 at the same interval.

In the two embodiments, the focusing electrode 20 and the accelerating electrode 9
4. mm, and when an accelerating voltage of 10 KV was applied, the electron beam diameter was focused to 0.1 to 0.2 mm.

When the electrode structures shown in the examples are used, in both cases, as shown in FIGS. 3a and 4a, the electric field near the focusing electrode causes a constant shape distortion that is not as severe as that of the conventional one.
An equipotential surface 22 as shown in the figure is obtained, which gives a focusing effect to the electron beam.

Although the mesh-like through-holes 21 are formed at a pitch of 0.15 in this embodiment, there is no significant change in the focusing effect up to a pitch of about 0.3, and it is also possible to form the through-holes in a square shape.

The beam diameter depends on the voltage applied between both electrodes, the concave curvature of the mesh-like through hole 2' in the case of Figures 3a and b, and the concave curvature of the mesh-like through hole 2' in Figures 4a and 4.
In case b, it is determined by the thickness of the electrode 24 and is not affected much by the distance between the two electrodes.

Therefore, the radius of curvature or plate thickness should be determined depending on the accelerating voltage and the required beam diameter.

As explained above, in the present invention, since the plurality of through-hole groups formed in the through-hole of the focusing electrode are formed in a concave shape, if the accelerating voltage and the radius of curvature of the concave shape are determined, an electron beam of an arbitrary beam diameter can be obtained. can be obtained on a fluorescent surface, and the beam diameter can be made finer to improve resolution.

Further, by using a mesh-like electric plate, leakage electric fields caused by application of high voltage will not have an adverse effect on the electron beam control electrode in the previous stage.

[Brief Description of the Drawings] Fig. 1 is a diagram showing the main configuration of a conventional flat panel display device, Fig. 2 is a diagram showing the state of electric field distortion near the through-hole of a conventional focusing electrode having a through-hole, and Fig. 3 FIGS. 4A and 4B are an enlarged sectional view and a plan view of each actual case of the display device of the present invention. 1... Electron source, 2... Electrode means, 3,
4... Control electrode, 20, 23, 24...
・Focusing electrode, 21...Through hole group, 22...
... Equipotential surface, 11 ... Light emitting surface, 9 ...
・Acceleration electrode.

Claims (1)

[Claims] 1. A flat electron source, an electrode means for extracting electrons from the electron source and emitting an electron beam, a control means for controlling selective passage of the electron beam, and a concentrating electrode for focusing the electron beam. and a display device comprising an acceleration means for accelerating the electron beam, and a light emitting plate that emits light upon collision of the electron beam, wherein the focusing electrode is located at a position corresponding to the electron beam emitted from the electrode means. It is characterized by comprising a through hole provided and a plurality of through hole groups formed in the through hole, and further characterized in that the through hole group is formed in a concave shape with respect to the direction of the accelerating means. Display device.