KR20080034622A - Spacer for electron emission display and electron emission display - Google Patents

Abstract

An electron emission display device and a spacer for the same are provided to prevent a distortion of an electron beam path by decreasing a collision between the electron beam and the conducted spacer. A spacer for an electron emission display device includes a mother board(321) and a resistance layer(322). The resistance layer is formed on a side surface of the mother board. The resistance layer is made of a poly-component oxide. The resistance layer is made of a material, whose secondary electron emission coefficient is smaller than 1. The resistance layer is an oxide containing at least three materials, which are selected from the group consisting of Al, Ca, Ti, Fe, Mn, and Nb. A secondary electron emission preventive film, which is made of an amorphous structure, is formed at the side surface of the mother board.

Description

Spacer for electron emission display and Electron emission display

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

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

3 is a perspective view illustrating main parts of a spacer of an electron emission display according to an exemplary embodiment of the present invention.

4 is a graph showing the relationship between the energy of electrons impinged on the resistive layer and the secondary electron emission coefficient according to the embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission display, and more particularly, to spacers installed inside a vacuum vessel to support a compressive force applied to the vacuum vessel and an electron emission display having the spacers.

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.

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

The FEA type electron emission element includes an electron emission portion and a cathode electrode and a gate electrode as driving electrodes for controlling electron emission of the electron emission portion. Here, the electron emitting portion may be a material having a low work function or a high aspect ratio, for example, a tip structure having a sharp tip mainly made of molybdenum (Mo) or silicon (Si), or carbon nanotubes, graphite, and diamond. It can be constructed using carbon-based materials such as phase carbon, which utilize the principle of easily emitting electrons by an electric field in vacuum.

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 (electron emission display) is constructed.

In the electron-emitting display, two substrates have a sealing member such as a frit at the edge thereof, and the two substrates are bonded to each other to form a vacuum container having an internal space, wherein the vacuum container has an approximately 10 internal space. ^It is maintained at a vacuum of ^-6 Torr.

Such a vacuum container receives a strong compressive force due to the pressure difference between the inside and the outside, and the compressive force increases in proportion to the screen size.

The vacuum vessel thus comprises a plurality of spacers therein, which maintain a constant spacing between the two substrates against the atmospheric pressure applied to the vacuum vessel. In this case, the spacer is mainly made of a dielectric such as glass or ceramic so that the driving electrodes on one substrate and the anode electrode on the other substrate are not shorted through the spacer.

The spacer is exposed to the inner space of the vacuum in which the flow of electrons continuously occurs and collides with the electrons emitted from the electron emitter, which leads to charging of the spacer and distorts the path of the electron beam. As such, when the path of the electron beam is distorted, the surroundings of the spacer are prevented from accurately expressing colors, thereby causing display quality deterioration in which the spacer position of the screen is seen.

Accordingly, an object of the present invention is to provide a spacer and an electron emission display having the same, which can reduce distortion of an electron beam by suppressing charging of the spacer.

In order to achieve the above object, the electron emission display spacer according to the embodiment of the present invention is disposed between the first substrate and the second substrate constituting the vacuum container to support the compressive force applied to the vacuum container, And a resistive layer formed on the side of the mother, wherein the resistive layer is made of a multicomponent oxide.

The resistive layer is formed of a material having a secondary electron emission coefficient of substantially 1 or less, such as aluminum (Al), calcium (Ca), titanium (Ti), iron (Fe), manganese (Mn), and niobium (Nb). It consists of an oxide containing at least three materials selected from the group consisting of.

The side of the matrix further comprises a secondary electron emission prevention film made of an oxide having an amorphous structure.

The resistance layer and the secondary electron emission prevention layer are sequentially formed from the side surface of the mother body.

On the other hand, the electron emission display according to the embodiment of the present invention, the first substrate and the second substrate facing each other, the electron emission unit provided on one surface of the first substrate, the light emitting unit provided on the second substrate, and the first And a spacer for supporting the compressive force applied to the substrate and the second substrate, wherein the spacer includes a mother body and a resistance layer formed on the side surface of the mother body, and the resistance layer is formed of a multicomponent oxide.

The electron emission unit may be formed on a first electrode on a first substrate, a first electrode formed along one direction of the first substrate, a second electrode formed along a direction crossing the first electrode with an insulating layer therebetween, and a first electrode formed on the first electrode. And an electron emission unit electrically connected to the first electrode.

And a focusing electrode disposed on the first electrode and the second electrode while maintaining insulation from the first electrode and the second electrode.

The electron emission unit is made of at least one material selected from the group consisting of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond phase carbons, fullerenes (C ₆₀ ), and silicon nanowires.

The light emitting unit includes a fluorescent layer formed on the second substrate and an anode electrode formed on the second substrate while being connected to the fluorescent layer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a partially exploded perspective view of an electron emission display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

1 and 2, an electron emission display according to an exemplary embodiment of the present invention includes a first substrate 10 and a second substrate 12 disposed to be parallel to each other at predetermined intervals. The 1st board | substrate 10 and the 2nd board | substrate 12 are joined by the sealing member (not shown) arrange | positioned at the edge, and comprise the container which has an internal space. The vessel is evacuated to a vacuum of approximately 10 ⁻⁶ torr to constitute a vacuum vessel composed of the first substrate 10, the second substrate 12, and the sealing member.

On the surface of the first substrate 10 facing the second substrate 12, electron emission elements are provided in the electron emission unit 100 forming an array, and the second substrate 12 facing the first substrate 10. The light emitting unit 110 includes a fluorescent layer, an anode electrode, and the like on the surface of the substrate.

The first substrate 10 provided with the electron emission unit 100 and the second substrate 12 provided with the light emission unit 110 combine to form an electron emission display.

The vacuum vessel of the above-described configuration may include other electrons including field emission array (FEA) type, surface conduction emission (SCE) type, metal-insulating layer-metal (MIM) type, and metal-insulating layer-semiconductor (MIS) type. Applicable to an emissive display, the following is more specifically described by taking a field emission array (FEA) type electron emissive display as an example.

First, cathode electrodes 14 are formed on the first substrate 10 in a stripe pattern along one direction (y-axis direction in FIG. 1) of the first substrate 10.

The first insulating layer 16 is formed on the entire first substrate 10 while covering the cathode electrodes 14, and the gate electrodes 18 are formed on the first insulating layer 16 with the cathode electrodes 14. It is formed in a stripe pattern along the direction orthogonal (the x-axis direction in FIG. 1).

As a result, an intersection region of the cathode electrode 14 and the gate electrode 18 is formed, and the intersection region may constitute one unit pixel. Electron emitters 20 are formed in each unit pixel on the cathode electrodes 14.

In addition, first and second openings 161 and 181 corresponding to the electron emission parts 20 are formed in the first insulating layer 16 and the gate electrodes 18, respectively, on the first substrate 10. The electron emitting portion 20 is exposed. That is, the electron emission part 20 is formed on the cathode electrode 14 while being disposed in the first and second openings 161 and 181 of the first insulating layer 16 and the gate electrode 18. In the present embodiment, the electron emitting portion and the first and second openings are formed in a circular shape with respect to the planar shape, but these shapes are not necessarily limited to the illustrated example.

In the present embodiment, the electron emission unit 20 is formed of materials emitting electrons when a electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. That is, the electron emission unit 20 is composed of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbon, fullerene (C ₆₀ ), silicon nanowires, and combinations thereof. On the other hand, the electron emission unit 20 may be formed of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si).

The electron emitters 20 may be provided in plural in each unit pixel area, and the plurality of electron emitters 20 may be any one of the cathode electrode 14 and the gate electrode 18, for example, a cathode. The electrodes 14 may be positioned in a line at an arbitrary distance from each other along the longitudinal direction of the electrodes 14. Of course, the arrangement state of the electron emission units for each unit pixel is not limited to this and can be variously modified.

The second insulating layer 22 and the focusing electrode 24 are sequentially formed on the gate electrodes 18. The second insulating layer 22 disposed below the focusing electrode 24 is formed on the front surface of the first substrate 10 to cover the gate electrodes 18 to insulate the gate electrode 18 and the focusing electrode 24. Let's do it.

In addition, the focusing electrode 24 is formed of one film having an arbitrary size on the second insulating layer 22.

Third and fourth openings 221 and 241 are also formed in the second insulating layer 22 and the focusing electrode 24 to pass the electron beam.

In the present exemplary embodiment, the third opening 221 of the second insulating layer 22 and the fourth opening 241 of the focusing electrode 24 collectively focus electrons emitted from one unit pixel. However, the present invention is not limited thereto, and openings corresponding to the electron emission units may individually collect electrons emitted from each electron emission unit.

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 separated from each other. It is formed at intervals, and a black layer 28 is formed between the fluorescent layers 26R, 26G, and 26B to improve contrast of the screen. The fluorescent layer 26 may correspond to one unit pixel for each unit pixel set in the first substrate 10.

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

Meanwhile, in another embodiment of the present invention, the anode electrode may be made of a transparent conductive film such as indium tin oxide (ITO). This anode electrode is located between the second substrate and the fluorescent layer. Furthermore, in another embodiment of the present invention, the anode electrode may use the above-described transparent conductive film, and a structure in which a metal film is further formed thereon.

In addition, a plurality of spacers 32 are provided between the first substrate 10 and the second substrate 12 to maintain a constant gap between the two substrates 10 and 12 against the atmospheric pressure applied to the vacuum container. Is placed.

The spacers 32 are disposed on the focusing electrode 24 on the first substrate 10 side, and are disposed corresponding to the black layer 28 on the second substrate 12 side so as not to invade the fluorescent layer 26.

In the present embodiment, the spacer 32 includes a matrix 321 and a resistive layer 322 formed on the side surface of the matrix 321, and the resistive layer 322 is formed of a multi-component oxide.

3 is a partial perspective view of a spacer according to the present embodiment.

As shown in FIG. 3, the matrix 321 is formed in a wall shape, for example, and may be made of a material such as glass or ceramic.

A resistance layer 322 is formed on the side surface of the matrix 321 exposed to the electron beam inside the vacuum vessel. The resistive layer 322 functions to discharge the charge charged in the spacer 32 by secondary electron emission.

The resistive layer 322 is formed of an oxide containing at least three metals, and includes aluminum (Al), calcium (Ca), titanium (Ti), iron (Fe), manganese (Mn), and niobium (Nb). At least three metals selected from the group consisting of and oxygen are combined. These materials preferably have a resistance lower than that of the parent 321 in order to lower the overall resistance of the spacer 32.

The resistive layer 322 is deposited on the side of the matrix 321 using the multi-component oxide target and the metal target, and in this case, the deposition amount of the multi-component oxide target and the metal target may be adjusted to have a desired resistance value.

4 is a graph showing the relationship of the secondary electron emission coefficient according to the energy of electrons impinged on the resistance layer according to an embodiment of the present invention.

Referring to FIG. 4, when the potential difference between the electrodes is accelerated above 2000 volts (V), the electrons collide with the spacer 32 having the resistive layer 322 at an incidence angle of 90 °, thereby emitting from the spacer surface. The emission coefficient of secondary electrons to have a value of 1 or less. In addition, when electrons whose potential difference between the electrodes is accelerated at 3000 volts (V) or more impinge upon the spacer 32 on which the resistive layer 322 is formed at an angle of incidence of 45 °, secondary electrons emitted by the spacer surface are thereby released. The emission factor has a value of 1 or less.

In contrast, a spacer having a resistive layer made of a conventional chromium oxide (Cr ₂ O ₃ ) has a secondary electron emission coefficient of about 2. Accordingly, it can be seen that the spacer 32 coated with the multi-component oxide has a significantly reduced secondary electron emission coefficient compared to the spacer coated with the metal oxide.

In addition, the secondary electron emission prevention layer (not shown) may be formed by further depositing an oxide having an amorphous structure on the side of the parent 321 by changing conditions in the deposition process of forming the resistive layer 322. At this time, the resistive layer 322 and the secondary electron emission prevention film are sequentially formed from the side surface of the matrix 321.

In the present embodiment, only the matrix formed into a wall was described. The shape is not limited thereto, and may be variously modified, such as a circular columnar shape or a square columnar shape. have.

Next, the driving process of the above-described electron emission display will be described.

The electron emission display is driven by supplying a predetermined voltage from outside to the cathode electrodes 14, the gate electrodes 18, the focusing electrode 24, and the anode electrode 30.

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 volts (V) or a negative DC voltage of several to collection volts (V), and the anode electrode 30 is required for accelerating the electron beam, for example, several hundreds. DC voltage of positive to thousands of volts (V) 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 the threshold, thereby emitting electrons from the electron emission unit 20. The emitted electrons are focused to the center of the electron beam bundle while passing through the second opening 241 of the focusing electrode 24, and are attracted by the high voltage applied to the anode electrode 30 to impinge on the fluorescent layer 26 of the corresponding unit pixel. do. This collision causes the fluorescent layer 26 to emit light to produce an arbitrary image.

In the above driving process, the electron emission display of the present embodiment can reduce the secondary electron emission coefficient of the spacer to minimize the charging of the spacer.

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.

An electron emission display according to an embodiment of the present invention, a spacer exposed to a vacuum The charge on the surface of the spacer can be suppressed by forming a resistive layer made of a multicomponent oxide on the surface to reduce the secondary electron emission coefficient. Therefore, it is possible to effectively prevent the phenomenon that the electron beam path is distorted by reducing drag and collision of the electron beam with respect to the charged spacer.

Such distortion prevention of the electron beam path may provide a high-quality image by accurately emitting a fluorescent layer corresponding to the electron emission part and realizing an accurate color accordingly.

In addition, since the multi-component oxide is economical in terms of cost compared to ceramics, there is a cost reduction effect.

Claims (15)

In the spacer for an electron emission display, matrix; And Resistance layer formed on the side of the matrix Including, The resistive layer is an electron emission display spacer made of a multi-component oxide. The method of claim 1, And the resistive layer is formed of a material having a secondary electron emission coefficient of substantially 1 or less. The method according to claim 1 or 2, The resistance layer is an oxide containing at least three or more materials selected from the group consisting of aluminum (Al), calcium (Ca), titanium (Ti), iron (Fe), manganese (Mn) and niobium (Nb). Spacer for phosphorus emitting display. The method of claim 1, Electron emission spacer further comprises a secondary electron emission preventing film made of an oxide having an amorphous structure on the side of the parent. The method according to claim 1 or 4, The spacer for electron emission display in which the said resistance layer and the said secondary electron emission prevention film were formed sequentially from the side surface of the said matrix. The method of claim 1, And said matrix is wall-shaped. A first substrate and a second substrate disposed to face each other; An electron emission unit provided on one surface of the first substrate; A light emitting unit provided on one surface of a second substrate facing the first substrate; And A spacer disposed between the first substrate and the second substrate Including, The spacer, matrix; And Resistance layer formed on the side of the matrix Including, And the resistive layer is made of a multi-component oxide. The method of claim 7, wherein And the resistive layer is formed of a material having a secondary electron emission coefficient of substantially one. The method according to claim 7 or 8, The resistive layer is an oxide made of at least three materials selected from the group consisting of aluminum (Al), calcium (Ca), titanium (Ti), iron (Fe), manganese (Mn), and niobium (Nb). Electron emission display. The method of claim 7, wherein And a secondary electron emission prevention layer formed of an oxide having an amorphous structure on the side of the matrix. The method according to claim 7 or 10, And the resistance layer and the secondary electron emission prevention layer are sequentially formed from side surfaces of the mother body. The method of claim 7, wherein And said matrix is wall-shaped. The method of claim 7, wherein The electron emission unit, A first electrode formed on the first substrate along one direction of the first substrate; A second electrode formed along the direction crossing the first electrode with an insulating layer interposed therebetween; And And an electron emission unit formed on the first electrode and electrically connected to the first electrode. The method of claim 7, wherein And a focusing electrode which is insulated from the first electrode and the second electrode and positioned above the first electrode and the second electrode. The method of claim 7, wherein The light emitting unit, A fluorescent layer formed on the second substrate; And And an anode electrode connected to the fluorescent layer and formed on the second substrate.

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