JPH01220340A - Image display device - Google Patents

Abstract

PURPOSE:To reduce the discontinuity of a screen in the vertical direction by arranging small circular phosphors illuminated by electron beam radiation in dots at random and inserting black layers between them. CONSTITUTION:Small circular dot phosphors 20' with the diameter of about 30-4mum are arranged on a screen 21 in an in-line shape of three primary colors R, G, R macroscopically and at random microscopically, gaps between phosphors are buried by black 23. Phosphors 20' are scan-radiated and illuminated by an electron beam deflected in both the horizontal and vertical directions. Even if the vertical landing position of the electron beam differs from the solid line X to the broken line Y in the figure, for example, no change occurs on the screen 21 by this layout of phosphors. The ununiformity due to the vertical landing is practically reduced, and the image quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an image display device in which a phosphor is coated in a vacuum container, emitted by an electron beam, and a television image is displayed using deflection, focusing, and signal modulation means. Regarding.

Conventional technology Conventionally, cathode ray tubes have been mainly used as display elements for displaying color television images, but conventional cathode ray tubes have a much longer depth than the screen, making it difficult to manufacture thin television receivers. It was impossible to do so.

In addition, although EL display elements, plasma display devices, liquid crystal display elements, etc. have recently been developed as flat display elements, all of them are insufficient in terms of performance such as brightness, contrast, and color reproducibility of color display. , it has not yet been put into practical use. Therefore, we aimed to achieve a device that can display color television images on a flat display device using electron beams, and we divided the screen on the screen vertically into multiple sections. The electron beam is deflected vertically for each line to display multiple lines, and is further divided horizontally into multiple sections to display R, G,
The phosphors such as B are made to emit light sequentially, and the R and G phosphors are made to emit light sequentially.

There is a device that displays a television silane image as a whole by controlling the amount of electron beam irradiation on a phosphor such as B using a color video signal (Japanese Patent Laid-Open No. 457-13559).
(See Publication No. 0). FIG. 2 shows its basic configuration.

In FIG. 2, from the back to the front, the back electrode 1, the line cathode 2 as an electron beam source, and the vertical focusing electrode 3a.
, 3b, a vertical deflection electrode 4, an electron beam flow control electrode 6, horizontal focusing electrodes 6a and 6b, a horizontal deflection electrode 7, an electron beam acceleration electrode 8 and a glass container 59.22 are arranged 9,
The components are placed in the glass container and evacuated.

The operation of the image display device configured as described above will be described below. First, a line cathode 2 serving as an electron beam source is stretched horizontally so as to generate an electron beam distributed linearly in the horizontal direction. Here 2-2
(Only four pieces are shown). In this embodiment, it is assumed that 15 pieces are provided, and 2I to 2Y are provided.

These wire cathodes 2 are constructed by applying an oxide cathode material to the surface of a tungsten wire having a diameter of 10 to 20 μm, for example. Then, as will be described later, the electron beams are controlled to be emitted sequentially from the upper line cathode 2a for a fixed period of time. The back electrode 1 suppresses the generation of electron beams from line cathodes 2 other than the line cathode 2 that is controlled to emit electron beams for a certain period of time, which will be described later, and directs the generated electron beams only in the forward direction. It has the effect of pushing out toward the target. The back electrode 1 may be formed by a coating film of a conductive material adhered to the inner surface of the rear wall of the glass pulp. Further, instead of the back chamber electrode 1 and the line cathode 2, a planar electron beam emitting cathode may be used.

The vertical focusing electrode 3a is a conductive plate 11 having a horizontally long slit 10 facing each of the line cathodes 2i to 2yo, and takes out the electron beam emitted from the line cathode 2 through the slit 1o, and vertically focus in a direction. The sleeve) 10 may be provided with crosspieces at appropriate intervals in the middle, or may be a row of through holes provided horizontally at small intervals (the intervals are such that they almost touch each other). It may also be designed substantially as a slit. The vertical focusing electrode 3b is also similar.

A plurality of vertical deflection electrodes 4 are arranged horizontally in the middle of each of the above-mentioned sleeves 10, and conductors 13a and 13b are provided on the upper and lower surfaces of the insulating substrate 12, respectively.
It consists of a set of Then, a vertical deflection voltage is applied between the opposing conductors 13a and 13b to deflect the electron beam in the vertical direction. In this configuration example, one wire cathode 2 is formed by a pair of conductors 13a and 13b.
The electron beam is deflected vertically to a position corresponding to 16 lines. Then, 16 vertical deflection electrodes 4
Sixteen conductor pairs corresponding to each of the book line cathodes 2 are constructed, and the electron beam is ultimately deflected to draw 240 horizontal lines on the screen 21.

Next, the electron beam flow control electrodes 6 are composed of conductive plates 16 each having a vertically long slit 14, and a plurality of the electron beam flow control electrodes 6 are arranged in parallel in the horizontal direction at predetermined intervals.

In this configuration example, 320 control electrode conductive plates 15a to 1
5n are provided (only 10 are shown in the figure)
. Each of the electron beam flow control electrodes 6 separates and extracts the electron beam into one picture element in the horizontal direction, and controls the amount of electron beam passing therethrough in accordance with a video signal for displaying each picture element. Therefore, the electron beam flow control electrode 5
If 32,020 pixels are provided, 320 picture elements can be displayed per horizontal line. Also, in order to display images in color, each picture element is R and G.

Display is performed using phosphors of three colors, B, and R, G, and B video signals are sequentially applied to each electron beam flow control electrode 6. Nine, 320 pairs of video signals for one line are simultaneously applied to the 320 electron beam flow control electrodes 6, and one
Video for each line is displayed at once.

The horizontal focusing electrode 6a is composed of a conductive plate 17 having a plurality of vertically long slits 16 (320 slits 16) facing the slits 14 of the electron beam flow control electrode 5, and each picture element divided in the horizontal direction. Each electron beam is focused horizontally into a fine electron beam.

The horizontal deflection electrode 7 is composed of a plurality of conductive plates 18 arranged vertically in the middle of each of the slits 16, and a horizontal thickness unevenness voltage is applied between each conductive plate 18, so that each picture element Each electron beam is deflected in the horizontal direction, and the R, G, and B phosphors are sequentially irradiated on the screen 21 to cause them to emit light. In this embodiment, the deflection range is the width of one picture element for each electron beam. The electron beam accelerating electrode 8 is composed of a plurality of conductive wires 19 provided horizontally at the same position as the vertical deflection electrode 4, and accelerates the electron beam so that it collides with the screen 21 with sufficient energy. .

The screen 21 is constructed by coating the back surface of a glass container 9 with a phosphor 2o that emits light when irradiated with an electron beam, and adding a metal back layer (not shown).

A pair of phosphors 20 of three colors R, G, and H is provided for each slit 14 of the electron beam flow control electrode 5, that is, for each horizontally divided electron beam. It is applied in stripes in the vertical direction.

In FIG. 2, the broken lines drawn on the screen 21 indicate divisions in the vertical direction corresponding to the plurality of line cathodes 2, and the two-dot chain lines indicate the plurality of electron beam flow control electrodes 6.
Shows the horizontal divisions displayed corresponding to each.

As shown in the enlarged view in Fig. 3, one section partitioned by these two has R, G, and B phosphors 20 for one pixel in the horizontal direction, and 16 lines in the vertical direction. It has a width.

Note that in the figure, A is one section in the vertical direction, and B is one section in the horizontal direction. The size of one section is, for example, 11+III mm in the horizontal direction and 16 mm in the vertical direction. Note that in FIG. 2, the length in the horizontal direction is greatly expanded relative to the length in the vertical direction for clarity.

Further, in this embodiment, one electron beam flow control electrode 5, that is, R and G for one electron beam.

Although only one pair of B phosphors 20 is provided for one picture element, it is of course possible to provide two or more picture elements, and in that case, the electron beam flow control electrode 6 has two or more picture elements. R, G, and B video signals are sequentially applied to the image, and horizontal deflection is performed in synchronization with the R, G, and B video signals.

The above is the general principle of the N-image display device.

Among these, the pattern of the phosphors 2° on the screen 21 is an inline pattern of R, G, and B in the vertical direction, as shown in FIG. 4, and is divided by blacks 23. Note that 24 in the figure is a line indicating a boundary in the vertical direction.

Problems to be Solved by the Invention However, with such a configuration, there is a problem in that discontinuities occur at each boundary 24 that divides the screen 21 in the vertical direction, and the quality of the entire image is significantly degraded.

In view of the above-mentioned problems, the present invention aims to reduce image quality deterioration due to discontinuities at boundaries.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention forms the phosphors of the conventional in-line phosphor array into a small circular dot-like pattern, and injects black light between them as before. It is equipped with a filling structure.

Function: By configuring the phosphor pattern on the screen as described above, the present invention can reduce the negative effects even if the vertical landing position, which is a major factor in beam spot discontinuity, is uneven to some extent. ]
This helps improve the uniformity of the image over the entire @ surface.

Embodiment FIG. 1A shows an embodiment of the present invention, in which small circular dot phosphors 20' with a diameter of about 30 to 40 μm are randomly placed in the conventional R, G, and H inline positions. It is set up. As shown in FIG. 1B, although the vertical landing position of the electron beam changes between the solid line X and the broken line Y, the effect of this configuration is clearly understood by observing that no change occurs on the screen 21.

As is clear from FIG. 1B, the non-uniformity due to vertical landing on the screen 21 is substantially reduced, and image quality deterioration due to non-uniformity of the beam position in the vertical direction can be greatly reduced. Especially the vertical division boundary 2
The effect is large in the vicinity of 4. Furthermore, the area ratio of black increases, which has a great effect on improving contrast.

Effects of the Invention As described above, according to the present invention, the R, G, and B phosphors are macroscopically inline, and microscopically, they are inline and have small circular phosphors. By configuring them to be randomly scattered, it is possible to greatly reduce image quality deterioration due to non-uniformity of the beam position at the vertical boundary, and the area ratio of black between the phosphors increases, which improves the contrast. This greatly contributes to improvement.

[Brief explanation of the drawing]

1A and 1B are a front view and an enlarged front view of essential parts of an image display device according to an embodiment of the present invention, FIG. 2 is a perspective view showing the basic configuration of the image display device, and FIG. FIG. 4 is an enlarged front view of a part of a conventional screen. 20'...phosphor, 21...screen, 23...black. Figure 3 Figure 4

Claims (1)

[Claims] A screen coated with a phosphor that emits light when irradiated with an electron beam is provided, and a plurality of electrodes for focusing, deflecting, and signal modulating the electron beam are provided, and the pattern of the phosphor on the screen is set to R, G. , B are macroscopically arranged in-line, and microscopically R, G, and B phosphors are randomly scattered as small circular phosphors within the in-line. An image display device with a black layer coated in between.