KR20070078904A - Electron emission device and electron emission display device using the same - Google Patents

Abstract

An electron emission device and an electron emission display device using the same are provided to emit smoothly electrons therefrom and to enhance luminance thereof by enhancing functional characteristics of a resistive layer. A plurality of cathode electrodes(14) are formed on an upper surface of a substrate. A plurality of gate electrodes(18) are isolated from the plurality of cathode electrodes. A plurality of electron emission units(22) are electrically connected with the cathode electrodes. Each of the cathode electrodes includes a main electrode(141), a plurality of isolation electrodes(142), and a resistive layer(143). The main electrode includes an opening formed at each of unit pixels. The isolation electrodes are positioned apart from the main electrode within the opening. An electron emission unit is positioned on one side of each of the isolation electrodes. The resistive layer is formed to connect electrically the main electrode with each of the isolation electrodes at one side of the isolations electrode.

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 cathode electrode illustrated in FIG. 1.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emitting device, and more particularly, to an electron emitting device having a resistive layer for uniformly controlling the emission characteristics of the electron emitting units and an electron emitting 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 elements are arranged in an array on one substrate to form an electron emission device, and the electron emission device is combined with another substrate provided with a light emitting unit composed of a fluorescent layer and an anode electrode, and the electron emission display device. (electron emission display device) is configured.

When the electron emission device is in operation, an unstable driving voltage is applied to an electrode (hereinafter, referred to as a 'first electrode' for convenience) that is electrically connected to the electron emission unit and supplies a current required for electron emission, or a voltage drop of the first electrode This may cause a difference in the voltage applied to the electron emission parts. In this case, the emission characteristics of the electron emission parts become nonuniform, leading to a decrease in the uniformity of emission for each pixel.

In order to solve the above problem, an opening is formed in each unit pixel in the first electrode, the isolation electrodes are disposed in the opening, an electron emission portion is formed over each isolation electrode, and the first electrode is disposed on both sides of the isolation electrodes. A technique of forming a resistive layer between the isolation electrodes to equalize the emission characteristics of the electron emitting portions by the resistive layer has been proposed and used.

In the above-described structure, the resistance layer must be in close contact with the first electrode and the isolation electrodes to make a smooth contact, thereby fulfilling the role of the resistance layer electrically connecting the first electrode and the isolation electrodes.

However, the conventional resistive layer has a weak contact force with the first electrode and the isolation electrode has a disadvantage that the contact surface is easily lifted. As a result, the emission characteristics of the electron emission portions are deteriorated, and a product defect in which electron emission does not occur in the electron emission portion occurs with respect to the resistance layer in which a poor contact with the first electrode and the isolation electrodes occurs.

Therefore, the present invention is to solve the above problems, an object of the present invention is to strengthen the contact force of the resistive layer to the first electrode and the isolation electrode to increase the functionality of the resistive layer and the electron emission device using the same It is to provide a display device.

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

A substrate, cathode electrodes formed on the substrate, gate electrodes insulated from the cathode electrodes, and electron emission portions electrically connected to the cathode electrodes, each cathode electrode having an opening for each unit pixel on the substrate. A plurality of isolation electrodes which are spaced apart from the main electrode inside the opening, the electron emitters being positioned on one surface thereof, and electrically connecting the main electrode and the isolation electrodes on at least one side of the isolation electrodes. Provided is an electron emitting device comprising a resistive layer having a concave-convex shape.

The isolation electrodes may be positioned in a line along the length direction of the main electrode, and the resistance layer may be disposed covering both the top surface of the main electrode and a part of the top surface of the isolation electrodes on both sides of the isolation electrodes.

The edge of the resistive layer may be formed of any one of a wave shape, a triangular saw tooth and a square saw tooth shape.

The electron emitting device may further include a focusing electrode which is insulated from the cathode electrodes and the gate electrodes and positioned above the cathode electrodes and the gate electrodes.

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

First and second substrates disposed opposite to each other, cathode electrodes formed on the first substrate, gate electrodes positioned to be insulated from the cathode electrodes, electron emission parts electrically connected to the cathode electrodes, and 2, a phosphor electrode formed on one surface of the substrate, an anode disposed on one surface of the phosphor layers, each cathode electrode having a main electrode forming an opening for each unit pixel on the first substrate, and a main electrode inside the opening. An electron emission display including a plurality of isolation electrodes positioned apart from each other and having an electron emission portion disposed on one surface thereof, and a resistance layer electrically connected between the main electrode and the isolation electrodes on at least one side of the isolation electrodes and having an uneven edge; Provide a device.

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, and FIG. 3 is a partial plan view of the cathode electrode shown in FIG. 1.

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 in a stripe pattern on the first insulating layer 16 in a direction orthogonal to the cathode electrodes 14. An intersection area between the cathode electrode 14 and the gate electrode 18 constitutes one unit pixel.

In the present exemplary embodiment, each of the cathode electrodes 14 is positioned to be spaced apart from the main electrode 141 forming an opening 20 therein corresponding to each unit pixel, and the main electrode 141 inside the opening 20. The plurality of isolation electrodes 142 and the main electrode 141 and the isolation electrodes 142 are electrically connected at both sides of the isolation electrodes 142, and the resistance layer 143 is formed in an uneven shape. Include.

The isolation electrodes 142 may be positioned in a line along one direction of the first substrate 10, for example, the length direction (y-axis direction of the drawing) of the main electrode 141, and Resistive layers 143 are disposed on both left and right sides of the isolation electrodes 142 along the width direction (the x-axis direction of the drawing).

The resistance layer 143 has a predetermined width and is formed to cover a portion of the upper surface of the main electrode 141 and the isolation electrodes 142 to reduce contact resistance between the main electrode 141 and the isolation electrodes 142. The edge thereof is formed into a concave-convex shape to enhance the contact force between the main electrode 141 and the isolation electrodes 142. As a result, the resistance layer 143 is in smooth contact with the electrodes without contact between the main electrode 141 and the isolation electrodes 142.

The edge of the resistive layer 143 may be formed in various irregularities such as wavy or triangular saw tooth or square saw tooth shape. FIG. 1 and 3 illustrate wavy irregularities as an example.

The resistive layer 143 is a material having a specific resistance value of approximately 10,000 to 100,000 Ωcm, and has a larger resistance than a conventional conductive material forming the main electrode 141 and the isolation electrode 142. For example, p-type or n-type doping Amorphous silicon.

An electron emission part 22 is formed on each isolation electrode 142. The electron emission unit 22 may be formed of materials emitting electrons when a electric field is applied in a vacuum, such as a carbon-based material or a nanometer-sized material. The electron emission unit 22 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, fullerenes (C ₆₀ ), silicon nanowires, and combinations thereof.

On the other hand, the electron emission unit may be formed of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si).

In the above-described structure, the main electrode 141 is connected to an external circuit (not shown) to receive a driving voltage therefrom, and the resistor layer 143 electrically connects the main electrode 141 and the isolation electrodes 142. In connection with each other, a driving voltage having the same condition is applied to the electron emission parts 22.

Openings 161 and 181 corresponding to the electron emission parts 22 are formed in the first insulating layer 16 and the gate electrodes 18 to expose the electron emission parts 22 on the first substrate 10. . In the drawing, the case where the electron emitters 22 and the openings 161 and 181 are circular is illustrated, but the planar shape of the electron emitters 22 and the openings 161 and 181 is not limited to the illustrated example.

The focusing electrode 24, which is a third electrode, is formed on the gate electrodes 18 and the first insulating layer 16. A second insulating layer 26 is disposed under the focusing electrode 24 to insulate the gate electrodes 18 and the focusing electrode 24, and also passes the electron beam through the focusing electrode 24 and the second insulating layer 26. Openings 241 and 261 are provided.

The focusing electrode 24 forms an opening corresponding to each of the electron emission units 22 to individually collect electrons emitted from each electron emission unit 22, or forms one opening 241 for each unit pixel. The electrons emitted from the unit pixels of may be comprehensively focused. 1 shows the second case.

Next, on one surface of the second substrate 12 opposite to the first substrate 10, the fluorescent layer 28, for example, the red, green, and blue fluorescent layers 28R, 28G, and 28B may be randomly selected from each other. It is formed at intervals, and a black layer 30 is formed between the fluorescent layers 28 to improve the contrast of the screen. The fluorescent layer 26 is disposed so that the fluorescent layers 28R, 28G, and 28B of one color correspond to the unit pixels set on the first substrate 10.

An anode electrode 32 made of a metal film such as aluminum (Al) is formed on the fluorescent layer 28 and the black layer 30. The anode electrode 32 receives the high voltage necessary for accelerating the electron beam from the outside to maintain the fluorescent layer 28 in a high potential state, and visible light emitted toward the first substrate 10 of the visible light emitted from the fluorescent layer 28. 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 indium tin oxide (ITO). In this case, the anode electrode is positioned on one surface of the fluorescent layer 28 and the black layer 30 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 34 (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 34 are positioned corresponding to the black layer 30 so as not to invade the fluorescent layer 28.

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 electrode 24, and the anode electrode 32 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 24 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 32 requires a voltage for accelerating the electron beam, for example, several hundred to several thousand volts. DC voltage of is applied.

Then, an electric field is formed around the electron emission part 22 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 the threshold, and electrons are emitted therefrom. The emitted electrons are focused to the center of the electron beam bundle while passing through the opening 241 of the focusing electrode 24, and are attracted to the fluorescent layer 28 of the corresponding unit pixel by being attracted by the high voltage applied to the anode electrode 32. It emits light.

In the above-described driving process, the electron emission display device of the present embodiment has the main electrode 141, the resistive layer 143, the isolation electrodes 142, and the resistive layer 143 due to the irregularities of the edges of the resistive layer 143. As the contact force between) is enhanced, the resistance layer 143 may fulfill its role more faithfully.

Therefore, in the electron emission display device of the present embodiment, the electron emission is smoothly emitted from all the electron emission parts 22 to realize a high brightness screen, and the resistive layer 143 uniformly controls the emission currents of the electron emission parts 22. The luminance uniformity of each pixel can be increased.

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. Naturally, it belongs to the range of.

As described above, the electron emission display device according to the present invention increases the functionality of the resistive layer by the above-described resistive layer shape, so that the electron emission is smoothly emitted from all the electron emission parts, thereby increasing the brightness of the screen, and the resistive layer is By uniformly controlling the emission current of the emitters, there is an effect of increasing the uniformity of light emission per unit pixel.

Claims (7)

A substrate; Cathode electrodes formed on the substrate; Gate electrodes positioned to be insulated from the cathode electrodes; And And electron emission parts electrically connected to the cathode electrode, Each of the cathode electrodes, A main electrode forming an opening for each unit pixel on the substrate; A plurality of isolation electrodes within the opening spaced apart from the main electrode and having the electron emission part disposed on one surface thereof; And At least one side of the isolation electrode electrically connects the main electrode and the isolation electrode and has a resistive layer having an irregular shape. Electron emitting device comprising a. The method of claim 1, And the isolation electrodes are positioned in a line along the longitudinal direction of the main electrode. The method of claim 2, And the resistance layer is located on both sides of the isolation electrodes to cover the top surface of the main electrode and a portion of the top surface of the isolation electrodes. The method of claim 1, And the edge of the resistive layer is formed of any one of a wave shape and a triangular saw tooth and a square saw tooth shape. The method of claim 1, And a focusing electrode overlying the cathode and gate electrodes and insulated from 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, fullerenes (C ₆₀ ) and silicon nanowires. An electron emitting device according to any one of claims 1 to 6; 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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