KR20070055785A - Electron emission device and electron emission display device using the same - Google Patents

Abstract

The present invention relates to an electron emission device and an electron emission display device using the same in which the shape and arrangement of the electron emission parts are improved to increase the amount of electron emission. The electron emission device according to the present invention is formed along a direction intersecting the cathode on the cathode with the substrate, the cathode electrodes formed on the substrate, the electron emission portions formed on the cathode, and an insulating layer interposed therebetween. And gate electrodes. In this case, each of the electron emitters is formed in a triangle, and a pair of electron emitters are positioned side by side along one direction of the substrate while facing one side of each other, and the gate electrodes form triangular openings corresponding to the electron emitters.

Electron emission part, cathode electrode, gate electrode, insulating layer, focusing electrode, fluorescent layer, anode electrode, black layer

Description

ELECTRON EMISSION DEVICE AND ELECTRON EMISSION DISPLAY DEVICE USING THE SAME

1 is a partially exploded perspective view of an electron emission display device according to an exemplary embodiment of the present invention.

2 is a partial cross-sectional view of an electron emission display device according to an embodiment of the present invention.

3 is a partially enlarged plan view of the electron emitting device illustrated in FIG. 1.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission device, and more particularly, to an electron emission device having an improved shape and arrangement structure of electron emission portions in order to increase the amount of electron emission, and an electron emission display device using the same.

In general, electron emission elements may be classified into a method using a hot cathode and a cold cathode according to the type of electron source.

Here, the electron emission device using the cold cathode may be a field emitter array (FEA) type, a surface conduction emission type (SCE) type, a metal insulating layer, a metal insulating layer, or a metal insulating layer. Metal (MIM) type and Metal-Insulator-Semiconductor (MIS) type are known.

The field emission array (FEA) type electron emission device includes an electron emission portion and a driving electrode for controlling electron emission of the electron emission portion, and includes one cathode electrode and one gate electrode. The use of low or high aspect ratio materials, such as carbon nanotubes and carbon-based materials such as graphite and diamond-like carbon, takes advantage of the principle that electrons are easily released by an electric field in vacuum.

The electron emission devices are arranged in an array on the first substrate to form an electron emission device, and the electron emission device is combined with a second substrate having a light emitting unit composed of a fluorescent layer and an anode electrode to emit electrons. A display device (electron emission display device) is constituted.

A typical field emission array (FEA) type electron emission device has cathode and insulating layers and gate electrodes sequentially formed on a first substrate, and has a gate electrode and an insulating layer for each pixel where the cathode and gate electrodes cross each other. An opening is formed to expose a portion of the surface of the cathode, and the electron emission portion is formed on the cathode inside the opening.

In the above structure, as the gate electrode is positioned around the electron emission part, the electric field formed by the voltage difference between the cathode electrode and the gate electrode tends to be concentrated at the upper edge of the electron emission part closest to the gate electrode. . Therefore, electron emission occurs most at the upper edge of the electron emission region where the electric field is concentrated.

However, the conventional electron emission device has a limitation in increasing the amount of electron emission since the electron emission portion is not sufficiently considered due to the edge length of the electron emission portion and the degree of integration of the electron emission portion for each pixel. In addition, as the electron emission device is manufactured in high resolution, the size of the unit pixel decreases, and in this case, the number of electron emission units per unit pixel also decreases, thereby making it difficult to realize the target luminance.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to improve the shape and arrangement of the electron emitters, thereby increasing the degree of integration of electron emitters per unit pixel, and increasing the edge length of each electron emitter to increase the electron emission amount. To provide an electron emission device and an electron emission display device using the same that can increase the.

In order to achieve the above object, the present invention,

A substrate, cathode electrodes formed on the substrate, electron emission parts formed on the cathode, and gate electrodes formed along the direction crossing the cathode on the cathode electrodes with an insulating layer therebetween, respectively. Electron-emitting device consisting of triangles, a pair of electron-emitting devices facing each other side by side along one direction of the substrate, with the gate electrodes forming triangular openings corresponding to each electron-emitting device To provide.

The electron emitter may be formed of an isosceles triangle, and in this case, the pair of electron emitters may be positioned facing each other with the base of the isosceles triangle.

The pair of electron emission units may be positioned along the width direction of the cathode electrode. The pair of electron emission units may be disposed in a line along the length direction of the cathode electrode at each intersection area of the cathode electrodes and the gate electrodes.

The electron emitting device further includes a focusing electrode positioned above the gate electrodes and insulated from the gate electrodes, wherein the focusing electrode may form an opening for each crossing region of the cathode electrodes and the gate electrodes.

In addition, the present invention, in order to achieve the above object,

A first substrate and a second substrate disposed to face each other, cathode electrodes formed on the first substrate, electron emission portions formed on the cathode electrode, and an insulating layer interposed therebetween to the cathode electrodes; A gate electrode formed along a direction, fluorescent layers formed on one surface of the second substrate, and anode electrodes formed on one surface of the fluorescent layers, each of the electron emission parts being formed in a triangle, and a pair of electrons Provided is an electron emission display device in which the emitters are located side by side along one direction of the substrate while facing each other, and the gate electrodes form triangular openings corresponding to the respective electron emitters.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are partially exploded perspective and partial cross-sectional views of an electron emission display device according to an exemplary embodiment of the present invention, respectively, and FIG.

Referring to the drawings, the electron emission display device includes a first substrate 10 and a second substrate 12 which are disposed in parallel to each other at predetermined intervals. Sealing members (not shown) are disposed at the edges of the first substrate 10 and the second substrate 12 to bond the two substrates, and the internal space is evacuated with a vacuum of approximately 10 ⁻⁶ torr to form the first substrate 10. ), The second substrate 12 and the sealing member constitute a vacuum container.

On the opposite surface of the first substrate 10 to the second substrate 12, electron emission elements are arranged in an array to form the electron emission device 100 together with the first substrate 10, and the electron emission device ( 100 is combined with the second substrate 12 and the light emitting unit 110 provided on the second substrate 12 to form an electron emission display device.

First, the cathode electrodes 14, which are first electrodes, are formed in a stripe pattern along one direction of the first substrate 10 on the first substrate 10, and cover the cathode electrodes 14. 10) The first insulating layer 16 is formed on the whole. Gate electrodes 18, which are second electrodes, are formed on the first insulating layer 16 in a stripe pattern along a direction orthogonal to the cathode electrodes 14.

An intersection area between the cathode electrodes 14 and the gate electrodes 18 constitutes one unit pixel, and the electron emitters 20 are formed on each of the unit pixels above the cathode electrodes 14. Is formed. In addition, openings 161 and 181 (refer to FIG. 2) corresponding to the electron emission parts 20 are formed in the first insulating layer 16 and the gate electrodes 18 to form the electron emission parts 20 on the first substrate 10. To be exposed.

In the present exemplary embodiment, the planar shape of the electron emission unit 20 is a triangle, and in each unit pixel, a pair of electron emission units 20 face one side with each other and in one direction, for example, of the first substrate 10. The cathode electrode 14 is positioned at a predetermined distance along the width direction (x-axis direction in the drawing). The electron emitters 20 are positioned in one line along the other direction of the first substrate 10, for example, in the longitudinal direction (the y-axis direction in the drawing) of the cathode electrode 14, and two rows along the direction. Are arranged to form.

In particular, the electron emitter 20 may be formed of an isosceles triangle, and a pair of electron emitters 20 positioned along the width direction of the cathode electrode 14 may face the bottom surfaces of the isosceles triangle.

In this case, the openings 161 and 181 of the first insulating layer 16 and the gate electrode 18 may also have triangles corresponding to the electron emission units 20. The gate electrode 18 forms a straight portion 182 (see FIG. 3) along the longitudinal direction of the cathode electrode 14 between the openings 181 of two columns, and the straight portion 182 defines the center of the unit pixel. Can be located across.

In the structure of the electron emitter 20 and the gate electrode opening 181, the degree of integration of the electron emitters 20 per unit pixel is increased, and the edge length of each electron emitter 20 is increased to maximize the same under the same driving voltage. The amount of electron emission can be obtained.

The electron emission unit 20 may be made of materials emitting electrons when an electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. The electron emission unit 20 may include, for example, carbon nanotubes (CNT), graphite, graphite nanofibers, diamonds, diamond-like carbons (DLC), fullerenes (C ₆₀ ), silicon nanowires, and combinations thereof. As the manufacturing method, screen printing, direct growth, chemical vapor deposition (CVD), or sputtering may be applied.

The focusing electrode 22, which is a third electrode, is formed on the gate electrodes 18 and the first insulating layer 16. A second insulating layer 24 is positioned below the focusing electrode 22 to insulate the gate electrodes 18 and the focusing electrode 22, and passes the electron beam through the focusing electrode 22 and the second insulating layer 24. Openings 221 and 241 are provided. Each of the openings 221 and 241 may be formed in each unit pixel to simultaneously expose the electron emission units 20 and the gate electrode openings 181 positioned in one unit pixel.

Next, on one surface of the second substrate 12 opposite to the first substrate 10, the fluorescent layer 26, for example, the red, green, and blue fluorescent layers 26R, 26G, and 26B may be disposed on each other. It is formed at intervals, and a black layer 28 is formed between the fluorescent layers 26 to improve contrast of the screen. The fluorescent layer 26 is disposed so that the fluorescent layers 26R, 26G, and 26B of one color correspond to the unit pixels set on the first substrate 10.

An anode electrode 30 made of a metal film such as aluminum (Al) is formed on the fluorescent layer 26 and the black layer 28. The anode electrode 30 receives a high voltage necessary for accelerating the electron beam from the outside to maintain the fluorescent layer 26 in a high potential state, and is radiated toward the first substrate 10 of the visible light emitted from the fluorescent layer 26. The visible light is reflected toward the second substrate 12 to increase the brightness of the screen.

The anode electrode may be formed of a transparent conductive film such as ITO. In this case, the anode electrode is positioned on one surface of the fluorescent layer 26 and the black layer 28 facing the second substrate 12. Moreover, the structure which forms simultaneously the above-mentioned transparent conductive film and a metal film as an anode electrode is also possible.

In addition, spacers 32 (see FIG. 2) are disposed between the first substrate 10 and the second substrate 12 to support the compressive force applied to the vacuum container and to keep the distance between the two substrates constant. The spacers 32 are positioned corresponding to the black layer 28 so as not to invade the fluorescent layer 26.

The electron emission display device having the above-described configuration is driven by supplying a predetermined voltage to the cathode electrodes 14, the gate electrodes 18, the focusing electrodes 22, and the anode electrodes 30 from the outside.

For example, any one of the cathode electrodes 14 and the gate electrodes 18 receives a scan driving voltage to serve as scan electrodes, and the other electrodes receive a data driving voltage to serve as data electrodes. In addition, the focusing electrode 22 receives a voltage required for electron beam focusing, for example, 0 V or a negative DC voltage of several to several tens of volts, and the anode electrode 30 requires a voltage for accelerating the electron beam, for example, several hundred to several thousand volts. DC voltage of is applied.

As a result, an electric field is formed around the electron emission unit 20 in the unit pixels in which the voltage difference between the cathode electrode 14 and the gate electrode 18 is greater than or equal to a threshold, and electrons are emitted therefrom. The emitted electrons are focused through the opening 221 of the focusing electrode 22 to the center of the electron beam bundle, and are attracted to the fluorescent layer 26 of the corresponding unit pixel by being attracted by the high voltage applied to the anode electrode 30. It emits light.

In the above driving process, the electron emission display device of the present embodiment increases the number of electron emission units 20 per unit pixel and the edge length of the electron emission unit 20 in which electron emission is concentrated. Under these conditions, the maximum amount of electrons emitted per unit pixel can be obtained. As a result, the screen brightness and the uniformity of light emission per unit pixel are increased.

Meanwhile, electrons emitted from one side of the electron emission unit 20 facing the straight portion 182 of the gate electrode 18 among the three sides of the electron emission unit 20 are far from the focusing electrode 22. Less focusing effect.

However, with reference to FIG. 3, electrons emitted from the electron emitters 20 located in the left column and the electron emitters 20 located in the right column of the unit pixel are respectively shown in FIG. 2. Since it proceeds toward the left side, the electron beam spot reaching the fluorescent layer 26 has a constant width along the longitudinal direction of the cathode electrode 14 and does not cause other light emission.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Of course it belongs to the range of.

As described above, the electron emission display device according to the present invention can obtain the maximum electron emission amount by increasing the edge length of each electron emission unit while increasing the degree of integration of the electron emission units for each pixel. Accordingly, the electron emission display device according to the present invention can realize excellent display quality by increasing the screen brightness and the uniformity of light emission per unit pixel.

Claims (8)

A substrate; Cathode electrodes formed on the substrate; Electron emission parts formed on the cathode electrode; And A gate electrode formed along the direction intersecting the cathode electrode on the cathode electrodes with an insulating layer interposed therebetween, Each of the electron emitters is formed in a triangle, and a pair of electron emitters are positioned side by side along one direction of the substrate while facing one side of each other, And the gate electrodes form triangular openings corresponding to the respective electron emission portions. The method of claim 1, And the electron emitter is an isosceles triangle, and the pair of electron emitters is located facing each other with the base of the isosceles triangle. The method of claim 1, And the pair of electron emission portions are positioned along the width direction of the cathode electrode. The method of claim 3, And the pair of electron emission portions are arranged in a line along the longitudinal direction of the cathode electrode at each intersection region of the cathode electrodes and the gate electrodes. The method of claim 1, And a focusing electrode positioned above and insulated from the gate electrodes. The method of claim 5, And the focusing electrode forms one opening for each crossing region of the cathode and gate electrodes. The method of claim 1, And the electron emission unit comprises at least one material selected from the group consisting of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, C ₆₀ and silicon nanowires. An electron emitting device according to any one of claims 1 to 7; Another substrate disposed to face the substrate; Fluorescent layers formed on one surface of the other substrate; And An anode formed on one surface of the fluorescent layers Electron emission display device comprising a.

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