KR20070055784A - Spacer and electron emission display device having the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer capable of reducing the effective area of a spacer with which an electron beam collides, thereby minimizing spacer charging and thus electron beam distortion, and an electron emission display device having the spacer. The spacer according to the present invention is installed inside the vacuum vessel to support the compressive force applied to the vacuum vessel, has a first end and a second end in contact with the vacuum vessel, and has a rectangular spring shape having a predetermined elasticity along the height direction The first end and the second end are formed to have a size covering at least one unit pixel.

Spacer, vacuum vessel, driving electrode, cathode electrode, gate electrode, focusing electrode, fluorescent layer, anode electrode

Description

SPACER AND ELECTRON EMISSION DISPLAY DEVICE WITH THE SAME}

1 is a perspective view of a spacer according to an embodiment of the present invention.

2 is a plan view of a spacer according to an embodiment of the present invention.

3 and 4 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.

5 is a partial plan view illustrating a positional relationship between a spacer and a fluorescent layer in an electron emission display device according to an exemplary 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 an electron emission display device having spacers mounted inside a vacuum container to support a compressive force applied to the vacuum container.

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-emitting device using the cold cathode is a field emitter array (FEA) type, a surface conduction emission type (SCE) type, a metal-insulation layer-metal Metal (MIM) type and Metal-Insulator-Semiconductor (MIS) type are known.

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.

The electron emission device has a plurality of driving electrodes for controlling the amount of emission current of the electron emission portions per unit pixel in addition to the electron emission portion, and the electron emission display device excites a fluorescent layer with electrons emitted from the electron emission portion to It will emit light or display.

In the electron emission display device, the first substrate and the second substrate are integrally bonded to each other by a sealing member, and then the inner space is evacuated to a vacuum of approximately 10 ⁻⁶ torr to form a vacuum container together with the sealing member. The vacuum container is applied with a strong compressive force by the pressure difference between the inside and the outside, and the compressive force increases in proportion to the screen size.

Accordingly, in the conventional electron emission display device, spacers are installed inside the vacuum container to support a compressive force applied to the vacuum container, and maintain a constant distance between the first substrate and the second substrate.

The spacer is mainly made of a dielectric such as glass or ceramic so that the driving electrodes of the first substrate and the anode electrode of the second substrate are not short-circuited through the spacer, and are positioned corresponding to the black layer so as not to invade the fluorescent layer. The spacer is mainly formed in a wall shape in consideration of supporting force and ease of installation, and is positioned between a plurality of unit pixels along one direction of the first substrate.

However, in the conventional electron emission display device, since electrons emitted from the electron emission portion tend to spread with a predetermined divergence angle toward the second substrate, electrons spread on the spacer surface due to electron beam spreading, and electrons The spacer that has collided with is charged with a positive or negative potential on its surface depending on the material properties (dielectric constant, secondary electron emission coefficient, etc.).

In particular, since the wall-shaped spacer forms a kind of blocking wall between the plurality of unit pixels, the effective area where the electron beam collides is considerably wide, and the surface thereof is easily charged.

Charged spacers distort the electron beam path by changing the electric field around the spacers. In other words, the spacer charged at the positive potential attracts the electron beam, and the spacer charged at the negative potential pushes the electron beam. Such electron beam path distortion hinders accurate color implementation around the spacers and causes display quality deterioration in which the spacers are seen on the screen.

Accordingly, the present invention is to solve the above problems, an object of the present invention is to reduce the effective area of the spacer collided with the electron beam to suppress the spacer charging, and to minimize the electron beam distortion due to the spacer charging and this An electron emission display device having a spacer is provided.

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

A spacer installed inside the vacuum vessel to support a compressive force applied to the vacuum vessel and having a first end and a second end in contact with the vacuum vessel, the spacer having a predetermined spring shape with a predetermined elasticity along the height direction, and A spacer having a first end portion and a second end portion having a size covering at least one unit pixel is provided.

The first end portion and the second end portion may have a size covering three unit pixels constituting one pixel.

The spacer may further include an insulation coating layer surrounding at least the first end and the second end.

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

A first substrate and a second substrate disposed to face each other, electron emission portions provided on the first substrate, driving electrodes provided on the first substrate to control the amount of emission current of the electron emission portions per unit pixel, and the second substrate Between the first substrate and the second substrate, having fluorescent layers formed on one surface of the anode, an anode located on one surface of the fluorescent layers, and a first end facing the first substrate and a second end facing the second substrate. And spacers positioned, each spacer having a rectangular spring shape having a predetermined elasticity along the thickness direction of the substrates, and having a first end and a second end surrounded by at least one unit pixel. Provide a display device.

The driving electrodes may include cathode electrodes and gate electrodes formed in a direction crossing each other with an insulating layer interposed therebetween, wherein the electron emission part may be electrically connected to the cathode electrodes.

The electron emission display 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.

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

1 and 2 are a perspective view and a plan view of a spacer according to an embodiment of the present invention, respectively.

Referring to the drawings, the spacer 2 according to the present embodiment has a rectangular spring shape having a predetermined elasticity along its height direction, and includes a first end portion 4 and a first contact portion which are in contact with the structure of the first substrate in the vacuum container. 2 The second end 6 in contact with the structure of the substrate is formed in a rectangle.

The spacer 2 may be made of a nonconductor in its entirety, or may be made of a base made of a conductor and an insulating coating layer located on a part or the entire surface of the base. In the second case, an insulating coating layer can optionally be formed at the first end 4 and the second end 6. As a result, the spacer 2 prevents the driving electrodes of the first substrate and the anode electrode of the second substrate from being shorted through the spacer.

The first end 4 and the second end 6 of the spacer 2 are formed to have a size covering at least one sub-pixel. For example, three unit pixels constituting one pixel may be formed. It may be formed in a comprehensive size and may be disposed outside the unit pixels while surrounding the three unit pixels.

The spacer 2 described above has an effect of effectively reducing the effective area in which electrons collide compared with conventional wall-shaped spacers to suppress charging due to electron collisions.

3 and 4 are partially exploded perspective views and partial cross-sectional views of an electron emission display device according to an embodiment of the present invention, each including the above-described spacer, and show, for example, a field emission array (FEA) type electron emission display device. .

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 electron emission parts 20 are formed in each unit pixel above the cathode electrode 14. In addition, openings 161 and 181 corresponding to the electron emission parts 20 are formed in the first insulating layer 16 and the gate electrodes 18 to expose the electron emission parts 20 on the first substrate 10. .

The electron emission unit 20 may be formed of materials that emit 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. have. 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 drawing, the circular electron emitters 20 are arranged in a line along the longitudinal direction of the cathode electrode 14, but the shape of the electron emitter 20, the number and arrangement per pixel area, etc. are illustrated. It is not limited to the example and can be variously modified.

In addition, the structure in which the gate electrodes 18 are positioned on the cathode electrodes 14 with the first insulating layer 16 interposed therebetween, but the gate electrodes 18 with the first insulating layer interposed therebetween. A structure located below the cathode electrodes is also possible. In this case, the electron emission part may be formed on the side of the cathode electrode on the first insulating layer.

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. The openings 221 and 241 may be formed in each electron emission unit 20 or one in each unit pixel, and the second case is illustrated in the drawing.

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 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.

The anode electrode may be formed of a transparent conductive film such as ITO, in which 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 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 2 are positioned corresponding to the black layer 28 so as not to invade the fluorescent layer 26.

In the present embodiment, the spacer 2 has a rectangular spring shape as described above having a predetermined elasticity along the thickness direction (the z-axis direction of the drawing) of the first substrate 10 and the second substrate 12. The first end 4 facing the first substrate 10 and the second end 6 facing the second substrate 12 are formed to have a size covering three unit pixels.

Thus, the first end 4 surrounds three unit pixels on the focusing electrode 22, and the second end 6 covers the red, green, and blue fluorescent layers 26R, 26G, and 26B on the anode electrode 30. Position it to surround. 5 illustrates the positional relationship between the second end 6 of the spacer and the fluorescent layers 26R, 26G, and 26B.

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 electrons may diverge when they pass toward the second substrate 12 after passing through the focusing electrode 22 to impinge on the spacer 2. However, in the spacer 2 of the present embodiment, the effective area in which electrons collide by the spring shape is reduced, so that charging by electron collision does not occur easily.

In addition, even when the surface of the spacer 2 is charged by an electron collision, the electric field distortion caused by the charging occurs evenly along the circumference of the spacer 2, thereby minimizing the electron beam distortion caused by pushing or pulling the electron beam in a specific direction. Can be.

In the above, the field emission array (FEA) type electron emission display device which emits electrons from the electron emission portion by using an electric field has been described. However, the present invention is not limited to this type of FEA, but other types of electron emission having a spacer It is applicable to display devices, for example, surface conduction emission (SCE) type, metal-insulating layer-metal (MIM) type, and metal-insulating layer-semiconductor (MIS) type electron emission display devices.

In addition, although the preferred embodiment of the present invention has 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 is within the scope of the present invention.

As described above, the electron emission display device according to the present invention effectively reduces the effective area in which electrons collide by installing a spring-shaped spacer, thereby minimizing spacer charging due to electron collision and thus electron beam distortion. Therefore, the electron emission display device according to the present invention can perform accurate color display around the spacers, and improve the display quality by making the spacers invisible on the screen.

Claims (8)

In the spacer provided inside the vacuum vessel to support the compression force applied to the vacuum vessel, and having a first end and a second end in contact with the vacuum vessel, The spacer is formed in the shape of a square spring having a predetermined elasticity along the height direction, wherein the first end and the second end is formed to a size covering at least one unit pixel. The method of claim 1, And a first end portion and a second end portion having a size covering three unit pixels constituting one pixel. The method of claim 1, The spacer further comprises an insulating coating layer surrounding the at least first and second ends. A first substrate and a second substrate disposed to face each other; Electron emission parts provided on the first substrate; Driving electrodes provided on the first substrate to control the amount of emission current of the electron emission units for each unit pixel; Fluorescent layers formed on one surface of the second substrate; An anode located on one surface of the fluorescent layers; And Spacers positioned between the first substrate and the second substrate, the spacers having a first end facing the first substrate and a second end facing the second substrate, And each of the spacers has a rectangular spring shape having a predetermined elasticity along a thickness direction of the substrates, and the first and second ends surround at least one unit pixel. The method of claim 4, wherein And a first end portion and a second end portion surrounding three unit pixels forming one pixel. The method of claim 4, wherein And an insulating coating layer on which the spacer surrounds at least the first end and the second end. The method of claim 4, wherein The driving electrodes include cathode electrodes and gate electrodes formed along a direction crossing each other with an insulating layer interposed therebetween, And an electron emission portion electrically connected to the cathode electrodes. The method of claim 7, wherein And a focusing electrode which is insulated from the cathode and gate electrodes and positioned above the cathode and gate electrodes.

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