JPH02250245A - Image display device - Google Patents

Abstract

PURPOSE:To facilitate locational coordination of an electron source with a modulating electrode and have an image with no unevenness in display, by furnishing the modulating electrode on a base board in the lower part of a hot electron source of hollow structure. CONSTITUTION:In an image display device, a hot electron emitting element is provided in a hollow structure, and a modulating electrode 12 is located in the lower part of an electron emitting part 4 in a single piece construction on or within a base board 1. Impression of a voltage on a wiring electrode 3 actuates heat emission from the electron emitting part 4 to cause emission of electrons. These emitted electrons are accumulated in the space around the electron emitting part 4, and the stream of the emitted electrons is modulated with the voltage of the modulating electrode 12. On the base board 1, the electron emitting part 4 and modulating electrode 12 are formed in a single piece construction, so that alignment can be taken easily, and a uniform image with not unevenness in the brightness can be created.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image display device comprising an element that emits electrons in a vacuum and a face plate coated with a phosphor.

[Prior Art] Currently, a number of quizzes have been proposed for flat display devices. Representative methods include electroluminescence method, plasma method, and liquid crystal method. However, when trying to apply these types of flat display devices to applications that require high-speed scanning and high-density images, such as color televisions, there are problems with luminous efficiency, and they are not suitable for large screens. is not practical. For this reason, an electron beam acceleration type flat display device, which reproduces images by accelerating electrons emitted from an electron source in a vacuum with high voltage and colliding with a phosphor to reproduce an image, has therefore become a promising candidate for televisions and other applications. ing.

This electron beam display has a flat plate shape, so when considering atmospheric pressure resistance, one method suitable for this is a multi-electron source structure in which each pixel corresponds to an electron source on a one-to-one basis. Regarding the electron source, it has also been proposed to realize an electron source using a thin film. An example of these is JP-A-58-195.
No. 6, JP-A No. 60-225342, etc. These electron beam display devices have the following structure.

FIG. 1 shows an outline of a conventional display device. 1 is a glass substrate, 2 is a support body, 3 is a wiring electrode, 4 is an electron emission part, 5 is an electron passage hole, 6 is a modulation electrode, 7 is a glass plate, 8 is a transparent electrode, 9 is a phosphor, a resist material, etc. The image forming member emits light, changes color, is charged, changes in quality, etc. by collision with electrons, 10 is a face plate, and 11 is a bright spot of phosphor. The electron emitting section 4 is created by thin film technology and has a hollow structure that does not come into contact with the glass substrate 1. The wiring electrode 3 may be formed using the same material as the electron emitting member, or may be formed using a different material (generally, a material with a high melting point and low electrical resistance is used. The support 2 may be formed of an insulating material or a conductive material. made of material.

These electron beam display devices apply a voltage to a wiring electrode 3 to emit electrons from an electron emitting portion having a hollow structure, and extract the electrons by a modulating electrode 6 that modulates the electron flow according to an information signal. is accelerated to collide with the image forming member (phosphor) 9. Further, an XY matrix electrode is formed by the wiring electrode and the modulation electrode, and an image is displayed on the image forming member.

This electron beam display usually has an IX 10-7 to I
In order to operate in a vacuum state of X 10-'torr, the display device must be manufactured by vacuum-sealing the entire system.

[Problems to be Solved by the Invention] However, the above conventional example has the following problems.

1. Because it is difficult to align the image forming member (phosphor) 9, the modulation electrode 6, and the electron emission section 4, it is impossible to create a large-screen, high-definition display.

2. Since the distance between the modulation electrode 6 and the electron emission section 4 varies depending on the location, unevenness occurs in the displayed image. This is a common problem in displays using thermionic sources. Electron emission part 4
It is necessary to manufacture it accurately so that the distance between the modulating electrode 6 and the modulating electrode 6 does not change depending on the location.

In view of 3.1.2, manufacturing a large-screen, high-definition display requires a large amount of capital investment, and the price of the display becomes very high.

[Means and effects for solving the problems] The present invention solves the above-mentioned problems by providing a modulation electrode under the electron emission part, that is, on or in the substrate on which the electron source is formed. .

Next, the present invention will be explained in detail with reference to Examples.

[Embodiment] Figure 2 shows the electron source and modulation electrode 12 of this embodiment.

This embodiment is a conventional example in which the modulation electrode between the electron emitting part and the phosphor is placed on a glass substrate.

FIG. 3 shows a method for creating an image display device according to an embodiment.
It is a cross section taken along line A-'A' in FIG.

a. The glass substrate 1 is thoroughly cleaned, and a group of 12 line-shaped modulation electrodes is formed using the vapor deposition technique and photolithography technique used. The substrate may be made of an insulator such as alumina ceramics other than glass. The modulation electrode may be made of a conductive material such as gold, nickel, or tungsten, but a material with a high melting point and little thermal damage is preferable, and tungsten, a tungsten alloy, tantalum, or the like is preferable.

51 Next, the support 2, the wiring electrode 3, and the electron emitting part 4 were sequentially formed into films using a vapor deposition technique. Although glass is used as the support 2, it is not limited to this as long as it is an insulator that is less susceptible to thermal deterioration. In this example, the wiring electrode 3 and the electron emission part 4 were made of tungsten. Here, it is desirable that the electron emitting portion 4 be formed of a low work function material, and that the wiring electrode 3 be formed of a low resistivity material that is less subject to thermal deterioration.

C0 Next, a desired shape of the electron emitting section 4 is created by photolithography and etching techniques.

61 Next, by using etching technology, the glass below the electron emitting part 4 is removed to form an electron source with a hollow structure and the modulation electrode 1.
Create 2. Electron emission part 4 made of tungsten material
is 0.8~2.0pm thick, 5~30pm wide, and 50mm long.
Although it is desirable to make the film with a thickness of ~500 gm, it is not limited to this value. In this example, the thickness is 1.0 μm and the width is 1.0 μm.
It was made with a diameter of 5 lumen and a length of 200 μm. The width of the modulating electrode 12 was 800 μm, and the pitch of the electron emission parts was 1 mm. Further, the thickness of the glass support is preferably 5 to 1100 μm, and in this example, the thickness was 10 μm. The distance between the modulation electrode 12 and the electron emission section 4 is determined by the thickness of the support 2.
The accuracy is higher than that of the conventional example.

On the plate having the electron source and modulation electrode described above, the face plate lO described in the conventional example was installed to create an image display device (not shown).Next, the driving method of this example will be outlined.

When a voltage is applied to the wiring electrode 3, the electron emitting section 4 is heated and electrons are emitted. The emitted electrons are spatially accumulated around the electron emitting part 4, and the voltage of the modulation electrode 12 modulates the electron flow of the emitted electrons. The voltage applied to the modulation electrode 12 is the voltage of the phosphor and the voltage applied to the electron emission part 4 and the modulation electrode 1.
2 and the distance between the electron emitting part and the modulation electrode. In this example, when a voltage of +IOV is applied to the modulation electrode 12, the electron flow can be drawn out to the phosphor side, and -
When a voltage of 30 V was applied, no electron current could be extracted. Furthermore, the amount of emitted current could be changed by applying a voltage between -30v and IOV.

The position of the face plate is 1 to 10 mm from the electron emission part.
The voltage of the transparent electrode 8 set at the position is 100 to 10.0 OO
Although V is preferable, it is not limited to this.

An XY matrix electrode is formed by the wiring electrode 3 and the modulation electrode, and electrons are emitted by scanning the wiring electrode 3 line-sequentially, and a voltage is applied to the modulation electrode 12 according to the information signal to cause an electron flow from the electron source. The electron flow is accelerated and collided with the phosphor to display an image.

In this example, the electron emission part and the modulation electrode are integrally formed on the substrate, so alignment is easy, and since it is manufactured using thin film manufacturing technology, it is possible to obtain a large-screen, high-definition display. did it. Furthermore, since the distance between the electron emitting part and the modulation electrode can be created with extremely high precision, it is possible to form an extremely uniform image with uniform brightness.

FIG. 4 shows the electron source and modulation electrode section of the image display device of the second embodiment.

Here, in contrast to Example 1, an insulator film 13 was provided above the modulation electrode 12.

The material of the insulating film 13 is preferably an insulating film such as glass or ceramics that is difficult to change due to heat, and its thickness is 1 to 15 gm.
degree is preferred. The modulation electrode 12 is preferably made of a conductive material such as gold, nickel, aluminum, or tungsten.

Example 1 was prepared and evaluated in the same manner as in Example 1.
The same modulation effect was obtained. Furthermore, since the modulating electrode 12 is located between the insulating film 13 and the substrate 1, it was found that the influence of radiant heat from the electron emitting section 4 is small, and deterioration is small. Therefore, the modulating electrode material can be applied to materials with low melting points.

1. In this example, the support body 2 in Example 2 shown in FIG. 4 is formed of a metal material. The electron emitting portion 4 and the insulating film 13 were created in the same manner as in Example 2. Further, the wiring electrode 3 in this embodiment is formed from tungsten, which is an electron emitting member, and the support 2 that supports the tungsten.

The support 2 in this example was made of copper material and had a thickness of 10 pn+.

This example not only obtains the same effect as Example 1, but also
Since the resistance of the wiring electrode 3 can be significantly lowered, this is particularly effective for large-screen, high-definition display devices.

[Effects of the Invention] As explained above, by providing the modulating electrode on the substrate below the thermionic source having a hollow structure, it becomes easy to align the electron source and the modulating electrode, and furthermore, it is possible to obtain an image without display unevenness. is effective. Furthermore, by manufacturing the thermionic source and modulation electrode using thin film manufacturing technology, a large-screen, high-definition image display device can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional electron beam display. FIG. 2 is a diagram showing the electron source and modulation electrode section of the electron beam display in Example 1. FIG. 3 is a diagram showing a manufacturing method of an electron source and a modulation electrode section of an electron beam display in Example 1. FIG. 4 is a diagram showing an electron source, a modulation electrode, and an insulating film of an electron beam display in Examples 2 and 3.

Claims (2)

[Claims] (1) An image is formed by the collision of the electron stream with a thermionic source group in which a plurality of thermionic beam sources each having a plurality of thermionic emission elements arranged in parallel, and a modulation electrode group that modulates the electron flow from the thermionic source. In an image display device equipped with an image forming member, the thermionic emission element has a hollow structure, the modulation electrode is located below the electron emission part, and is integrally formed on or in the substrate. Characteristic image display device. (2) The image display device according to claim 1, wherein the electron source and the modulation electrode group perform matrix driving to form an image.