KR20070046511A - Electron emission display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission display device for correcting a difference in luminous efficiency and luminance that may occur according to the color of a fluorescent layer. The electron emission display device according to an embodiment of the present invention is disposed to face each other. And cathode electrodes formed on the first substrate, the line electrodes forming an opening therein, an isolation electrode disposed spaced apart from the line electrode inside the opening, and a resistance layer connecting the line electrode and the isolation electrode; And red (R) and green (G) formed on one surface facing the first substrate among the electron emission parts connected to the isolation electrode, the gate electrodes positioned while being insulated from the cathode electrodes, and the second substrate. And a blue (B) fluorescent layer. Here, the length of each resistive layer corresponding to each of the red, green, and blue fluorescent layers, and formed along the line electrode and the isolation electrode, is formed in inverse proportion to the luminous efficiency of the red, green, and blue fluorescent layers. .

Electron emission, luminous efficiency, luminance, fluorescent layer, cathode electrode, resistive layer

Description

Electron Emission Display Device {ELECTRON EMISSION DISPLAY DEVICE}

1 is a partial perspective view of an electron emission display device according to an 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 partial plan view of an electron emission display device according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission display device, and more particularly to a drive electrode for controlling the emission of electrons that emit red, green and blue fluorescent layers.

In general, an electron emission element 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.

Among them, the FEA type electron emission device includes an electron emission unit and driving electrodes for controlling electron emission of the electron emission unit, and includes one cathode electrode and one gate electrode, and has a low work function as a material of the electron emission unit. Or a high aspect ratio material, such as molybdenum (Mo) or silicon (Si), with a sharp tip structure, or an electric field in vacuum using carbon-based materials such as carbon nanotubes and graphite and diamond-like carbon. By using the principle that the electron is easily emitted by.

On the other hand, the electron emission elements are formed in an array on one substrate to form an electron emission device, and the electron emission device is combined with another 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.

That is, the conventional electron emitting device includes a plurality of driving electrodes that function as scan electrodes and data electrodes in addition to the electron emitting part, so that the electron emission amount and the electron emission amount per pixel are controlled by the action of the electron emitting part and the driving electrodes. To control. The electron emission display device excites the fluorescent layer with the electrons emitted from the electron emission unit to perform a predetermined light emission or display function.

The electron emission display device displays the color required for the designated pixel by adjusting the amount of emission of each of the red, green, and blue fluorescent layers existing in each pixel region. The amount of light emitted from the red, green, and blue fluorescent layers is controlled by the amount of emitted electrons emitted from the electron emission unit.

On the other hand, the red, green, and blue fluorescent layers show different luminous efficiency and luminance even when they collide with the same amount of electrons due to the properties of the constituent materials. For example, in order to display white color on one pixel, the red, green, and blue phosphor layers emit light at the same ratio. To this end, when the same amount of electrons collide with each phosphor, the light emission efficiency and luminance difference according to the color are different. There is a problem that white is not displayed on a pixel that is set to display white.

This causes the screen display quality of the electron emission display device to deteriorate. To this end, a method of controlling the amount of electron emission for each phosphor in terms of a driving circuit in order to correct a difference in luminous efficiency and luminance of phosphors for each color is conventionally used. Is being presented. However, this causes a problem of complicating the driving circuit.

Accordingly, an object of the present invention is to provide an electron emission display device capable of correcting a difference in luminous efficiency and luminance according to a color of a fluorescent layer.

In order to achieve the above object, an electron emission display device according to an exemplary embodiment of the present invention includes a first substrate and a second substrate disposed to face each other, a line electrode formed on the first substrate, and having an opening therein; Cathode electrodes comprising an isolation electrode positioned apart from the line electrode and a resistance layer connecting the line electrode and the isolation electrode inside the opening, electron emission parts connected to the isolation electrode, and insulated from the cathode electrodes. And red (R), green (G), and blue (B) fluorescent layers formed on one surface of the gate electrodes and the second substrate facing the first substrate. Here, the length of each resistive layer corresponding to each of the red, green, and blue fluorescent layers, and formed along the line electrode and the isolation electrode, is formed in inverse proportion to the luminous efficiency of the red, green, and blue fluorescent layers. .

In addition, the luminous efficiency of each of the red, green, and blue fluorescent layers is denoted by E _R , E _G , and E _B , and each length of the resistive layer positioned corresponding to each of the red, green, and blue fluorescent layers is represented by L _R,. When L _G and L _B , the electron emission display device simultaneously meets the following conditions.

E _G > E _B > E _R ... (1)

L _R > L _B > L _G ... (2)

In addition, the E _R , E _G , E _B , L _R , L _G and L _B may satisfy the following conditions.

E _R × L _R = E _G × L _G = E _B × L _B

The red fluorescent layer may be formed of an oxide compound, and the green and blue fluorescent layers may be formed of a sulfide compound. In this case, L _R , L _G and L _B may satisfy 2: 1: 1.2.

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

1 is a partial perspective view of an electron emission display device according to an embodiment of the present invention, FIG. 2 is a partial cross-sectional view of an electron emission display device according to an embodiment of the present invention, and FIG. 3 is an electron emission display according to an embodiment of the present invention. A partial plan view of a display device.

Referring to FIGS. 1 and 2, the electron emission display device includes a first substrate 2 and a second substrate 4 that are disposed to face each other in parallel at predetermined intervals. Sealing members (not shown) are disposed at the edges of the first substrate 2 and the second substrate 4 to bond the two substrates, and the internal space is evacuated with a vacuum of approximately 10 ⁻⁶ torr to allow the first substrate 2 to be bonded. ), The second substrate 4 and the sealing member constitute a vacuum container.

On the opposite surface of the first substrate 2 to the second substrate 4, electron emission elements are arranged in an array to form an electron emission device together with the first substrate 2, and the electron emission device is a second substrate. (4) and the light emitting unit provided on the second substrate 4 to form an electron emission display device.

First, cathode electrodes 6 are formed on the first substrate 2 in a stripe pattern along one direction (y-axis direction in FIG. 1) of the first substrate 2, and cover the cathode electrodes 6. The first insulating layer 8 is formed on the entire first substrate 2. Gate electrodes 10 are formed on the first insulating layer 8 in a stripe pattern along a direction orthogonal to the cathode electrode 6 (the x-axis direction in FIG. 1).

In the present exemplary embodiment, when the intersection region of the cathode electrode 6 and the gate electrode 10 is defined as a pixel region, each cathode electrode 6 forms a plurality of openings therein for each pixel region. And an isolation layer 66 spaced apart from the line electrode 64 inside the opening 62, and a resistance layer 68 formed therebetween to electrically connect the line electrode 64 and the isolation electrode 66. )

The line electrode 64 may be made of a transparent conductive film such as indium tin oxide (ITO), and the resistance layer 68 may be made of amorphous silicon.

An electron emission portion 12 is formed on each isolation electrode 66. The electron emission unit 12 may be made of materials emitting electrons, for example, carbon-based materials or nanometer-sized materials, when an electric field is applied in a vacuum. Preferred materials for use as the electron emitter 12 include carbon nanotubes, graphite, graphite nanofibers, diamond, diamond-like carbon, fullerene (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).

Openings 82 and 102 corresponding to the electron emission portions 12 are formed in the first insulating layer 8 and the gate electrode 10, so that the electron emission portions 12 are formed on the first substrate 2. To be exposed.

The focusing electrode 14 is formed on the first insulating layer 8 and the gate electrodes 10. A second insulating layer 16 is positioned below the focusing electrode 14 to insulate the gate electrodes 10 and the focusing electrode 14, and passes the electron beam through the focusing electrode 14 and the second insulating layer 16. Openings 142 and 162 are provided. The openings 142 and 162 may be formed, for example, for each pixel area.

Next, on one surface of the second substrate 4 opposite to the first substrate 2, the fluorescent layer 18, for example, the red, green, and blue fluorescent layers 18R, 18G, and 18B may be randomly selected from each other. It is formed at intervals, and a black layer 20 for improving contrast of the screen is formed between each fluorescent layer 18. The fluorescent layer 18 is disposed so that a fluorescent layer of one color corresponds to the pixel region set on the first substrate 2.

An anode electrode 22 made of a metal film such as aluminum (Al) is formed on the fluorescent layer 18 and the black layer 20. The anode 22 receives the high voltage necessary for accelerating the electron beam from the outside to maintain the fluorescent layer 18 in a high potential state, and visible light emitted toward the first substrate 2 of the visible light emitted from the fluorescent layer 18. Is reflected to the second substrate 4 side 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 disposed on one surface of the fluorescent layer 18 and the black layer 20 facing the second substrate 4. The anode electrode may also have a structure in which the above-mentioned transparent conductive film and a metal film are simultaneously formed.

The spacers 24 are disposed between the first substrate 2 and the second substrate 4 to support the compressive force applied to the vacuum container, and to space the space between the first substrate 2 and the second substrate 4. Keep it constant. The spacers 24 are positioned corresponding to the black layer 20 so as not to invade the fluorescent layer 18.

In the electron emission display device having the above structure, the present invention is located in correspondence with the red, green, and blue fluorescent layers 18R, 18G, and 18B, respectively, along the line electrode 64 and the isolation electrode 66; Each length of the resistance layer 68 to be formed is formed differently.

Referring to FIG. 3, the present invention provides a resistance layer formed between the line electrode 64R and the isolation electrode 66R while corresponding to the red phosphor layer 18R to correct a difference in luminous efficiency according to the color of the phosphor layer. The length L _G of the resistance layer 68G formed between the line electrode 64G and the isolation electrode 66G while corresponding to the length L _R of the 68R and the green fluorescent layer 18G, and the blue fluorescent layer ( Corresponding to 18B, the length L _B of the resistance layer 68B formed between the line electrode 64B and the isolation electrode 66B is formed in inverse proportion to the luminous efficiency of each fluorescent layer.

Although the luminous efficiency of the fluorescent layer 18 varies depending on the constituent material, when the red fluorescent layer is formed of an oxide compound and the green and blue fluorescent layers are formed of a sulfide compound, a green fluorescent layer The light emission efficiency E _G of 18G is the highest, followed by the high light emission efficiency E _B of the blue fluorescent layer 18B, and the lowest light emission efficiency E _R of the red fluorescent layer 18R. (E _G > E _B > E _R )

The fluorescent layer with high luminous efficiency emits more visible light and shows higher luminance even when collided with the same amount of electrons, compared to the fluorescent layer with low luminous efficiency. Therefore, the electron emitting portion for emitting the fluorescent layer with high luminous efficiency should emit less electrons than the electron emitting portion for emitting the fluorescent layer with low luminous efficiency.

In the same structure as in the present embodiment, the electron emission amount is adjusted by changing the resistance value of the resistive layer 68 by changing the length of the resistive layer 68 formed between the line electrode 64 and the isolation electrode 66. That is, where the amount of electron emission is necessary, the length of the resistance layer 68 formed between the line electrode 64 and the isolation electrode 66 is increased to lower the resistance value of the resistance layer 68 and to reduce the amount of electron emission. Where is necessary, the resistance value of the resistance layer 68 is increased by reducing the length of the resistance layer 68 formed between the line electrode 64 and the isolation electrode 66.

This is because the length of the resistive layer 68 formed between the line electrode 64 and the isolation electrode 66 is proportional to the cross-sectional area of the resistive layer 68 through which current passes, and the cross-sectional area of the resistive layer 68 is the resistive layer ( The principle is inversely proportional to the resistance value of 68).

By the above principle, the resistive layer 68 corresponding to each fluorescent layer has a length L _R of the resistive layer 68R corresponding to the red fluorescent layer 18R in inverse proportion to the luminous efficiency of the fluorescent layer 18. And the length L _B of the resistance layer 68B corresponding to the blue fluorescent layer 18B, and the length L _G of the resistance layer 68G corresponding to the green fluorescent layer 18G. _R> L _B> L _G) in FIG. 3 was only shown for convenience in one side length _{(L R / 4, L G} / 4 L B / 4) of each resistive layer. At this time, the width W of each of the resistive layers 68R, 68G, and 68B may be the same.

In the drawing, the resistance layer 68 is formed while filling all the spaces formed between the line electrode 64 and the isolation electrode 66, but may be formed only in part. In addition, although the resistance layer is formed in a rectangular ring shape in the drawing, its shape may be variously modified.

In addition, the present invention can ensure that the luminous efficiency of each fluorescent layer and the length of the resistive layer corresponding thereto satisfy the following conditions.

E _R × L _R = E _G × L _G = E _B × L _B

That is, the product is formed such that the product of the luminous efficiency of the fluorescent layer corresponding to each color and the length of the resistive layer corresponding thereto are constant. For example, E _R : E _G : E _B is 0.5 : 1: 0.83, L _R : L _G : L _B is 2 : 1: 1.2. Here, E _R × L _R , E _G × L _G and E _B × L _B all have the same value as 2.

Up to now, in the embodiment of the present invention, the cathode electrode 6 has been described only for the structure as shown in Figs. 1 and 2, but the present invention is not limited to this, and the first electrode and the first electrode spaced at a predetermined interval Any electron emission display device can be applied as long as it has an electrode structure composed of two electrodes and a resistance layer connecting the electrodes.

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, according to the present invention, by adjusting the length of the resistive layer formed on the cathode, the light emission efficiency and luminance difference that may appear according to the color of the fluorescent layer may be corrected to improve the display quality of the screen, and the driving circuit There is no need to correct this in terms of simplification of the drive circuit.

Claims (9)

A first substrate and a second substrate disposed to face each other; Cathode electrodes formed on the first substrate, the line electrodes forming an opening therein, an isolation electrode spaced apart from the line electrode inside the opening, and a resistance layer connecting the line electrode and the isolation electrode; Electron emission parts connected to the isolation electrode; Gate electrodes positioned to be insulated from the cathode electrodes; And A red (R), green (G), and blue (B) fluorescent layer formed on one surface of the second substrate facing the first substrate, Electron emission corresponding to the red, green, and blue fluorescent layers, respectively, and having a length of each resistive layer formed between the line electrode and the isolation electrode in inverse proportion to the luminous efficiency of the red, green, and blue fluorescent layers Display device. The method of claim 1, The luminous efficiency of the red, green, and blue fluorescent layers is denoted by E _R , E _G , and E _B , and the respective lengths of the resistive layers positioned corresponding to the red, green, and blue fluorescent layers, respectively, are represented by L _R , L _G. And L _B , an electron emission display device satisfying the following conditions simultaneously. E _G > E _B > E _R ... (1) L _R > L _B > L _G ... (2) The method of claim 2, An electron emission display device wherein E _R , E _G , E _B , L _R , L _G and L _B satisfy the following conditions. E _R × L _R = E _G × L _G = E _B × L _B The method of claim 3, And the red phosphor layer is formed of an oxide compound, and the green and blue phosphor layers are made of a sulfide compound. The method of claim 4, wherein Emission display devices that satisfy 1.2: wherein the _R L, _G L and _B L 2: 1. The method of claim 3, And the resistance layer is formed around the isolation electrode while filling between the line electrode and the isolation electrode. The method of claim 6, And the resistive layer comprises amorphous silicon. The method of claim 1, And the isolation electrode is formed of a transparent conductive film. 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.

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