KR20090015623A - Electron emission display - Google Patents

Abstract

The present invention relates to an electron emission display capable of improving the adsorption performance of a getter to maintain the interior of the vacuum vessel in a high vacuum state.

An electron emission display according to the present invention is mounted to a first substrate and a second substrate, which are disposed to face each other and constitute a vacuum container, an electron emission unit provided on the first substrate, a light emitting unit provided on the second substrate, and a vacuum container. And a second getter configured to adsorb residual gas inside the vacuum vessel, and a second getter formed in the vacuum vessel and serving as a catalyst for the first getter.

Description

Electron emission display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emitting display, and more particularly, to an electron emitting display having a getter which removes harmful gases inside the electron emitting display to maintain the inside of the electron emitting display in a high vacuum.

In general, electron emission elements are classified into a method using a hot cathode and a method using 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 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 a 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, the interior of the electron emitting display is required to have a high vacuum state in order to improve the electron emission efficiency. Gas particles remaining inside the electron emission display contaminate the electron emission portion and the fluorescent layer, and a gas ionized by electrons emitted from the electron emission portion has a problem of deteriorating the electron emission display by electric discharge. Accordingly, an invention is disclosed in which a getter is mounted therein by a method of adsorbing gas particles remaining inside the electron emission display.

These getters include an evaporable getter (EG) and a non-evaporable getter (NEG). The getter is activated by induction heating or by RF or laser methods to adsorb gas particles remaining inside the electron emission display.

At this time, the gases adsorbed on the getter are inorganic gases, and the organic gas remaining in the electron emission display does not exhibit adsorption performance and thus has a limitation in maintaining the inside of the electron emission display at a high vacuum for a long time.

Accordingly, an object of the present invention is to provide an electron emission display capable of improving the adsorption performance of a getter to prevent contamination of the inside of the electron emission display by the getter material and maintaining the inside thereof in a high vacuum state.

An electron emission display according to an embodiment of the present invention comprises: a first substrate and a second substrate disposed opposite to each other to constitute a vacuum container, an electron emission unit provided on the first substrate, a light emitting unit provided on the second substrate, and a vacuum And a first getter attached to the vessel to adsorb residual gas inside the vacuum vessel, and a second getter formed in the vacuum vessel and serving as a catalyst for the first getter.

An effective region and an invalid region are formed in the first substrate, and the first getter and the second getter are formed in the invalid region.

The second getter includes at least one material selected from the group consisting of titanium oxide (TiO ₂ ), zinc oxide (ZnO), and cadmium sulfide (CdS).

The first getter consists of a non-evaporable getter or an evaporative getter.

The first getter may be any one of barium (Ba), vanadium (V), titanium (Ti), zirconium (Zr), niobium (Nb), molybdenum (Mo), tantalum (Ta), or an alloy thereof. Include.

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 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.

The electron emission display according to the embodiment of the present invention forms a getter portion capable of adsorbing or decomposing the inorganic gas and the organic gas remaining in the vacuum container, thereby improving the adsorption performance of the getter and maintaining the inside of the electron emission display in a high vacuum state. Can be.

In addition, the getter part may be easily installed inside the electron emission display through a relatively simple structure in the process, and thus the manufacturing process may be simple and the manufacturing cost may be low.

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 schematic partial cross-sectional view of an electron emission display according to an embodiment of the present invention.

Referring to FIG. 1, 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 face each other in parallel with each other at a predetermined interval. The first substrate 10 and the second substrate 12 are joined by a sealing member 14 disposed at an edge thereof to constitute a container having 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 14.

The sealing member 14 may be formed of a frit bar made by compression-molding a mixture of the glass frit and the organic compound, or may have a structure in which adhesion between the upper and lower surfaces of the glass frame is interposed therebetween. In both cases, the first substrate 10 and the second substrate 12 are integrally bonded while the surface of the frit bar is melted or the adhesive layer is melted in the firing process.

The surface of the first substrate 10 facing the second substrate 12 is provided with an electron emission unit 100 in which an array of electron emission elements is arranged, and the second substrate 12 facing the first substrate 10. The light emitting unit 110 includes a fluorescent layer, an adon electrode, and the like.

Here, the anode electrode is led out of the lead wire 341 from the light emitting unit 110 to one edge of the second substrate 12 over the inside and the outside of the sealing member 14, the lead wire 341 of the anode electrode Is connected to an external driving circuit unit (not shown), and the anode electrode receives a high voltage required for electron beam acceleration through the lead wire 341.

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.

In the above configuration, the first region 10 and the second substrate 12 are provided with the electron emission unit 100 and the light emitting unit 110, respectively, the effective area 200 for actual light emission or image display, An invalid area 210 is set which surrounds the outside of the effective area 200 and does not participate in image display.

In the present exemplary embodiment, the getter part 16 including the first getter 161 and the second getter 162 is disposed outside the effective area 200 of the first substrate 10, that is, the ineffective area 210. . Accordingly, after evacuating the vacuum container, noxious gas remaining in the vacuum container is removed to maintain the inside of the vacuum container in a high vacuum state.

The first getter 161 includes a getter container 1611 filled with getter material and a support 1612 supporting the getter container 1611. In the present embodiment, the first getter 161 may be a non-evaporable getter in a powder form or an evaporative getter.

When the first getter 161 is an evaporative getter, the getter material is mainly composed of titanium (Ti) or barium (Ba), and when these materials are heated and activated at 1000 ° C. or more, the getter material evaporates to form a wide film. And residual gas molecules inside the vacuum vessel react with it.

When the first getter 161 is a non-evaporable getter, the getter material is an alloy material of zirconium (Zr), vanadium (V) and iron (Fe) or an alloy material of zirconium and aluminum (Al). Non-evaporable getters are more preferable than evaporative getters because there is no possibility of contaminating the electron emitting unit or light emitting unit.

The first getter 161 easily adsorbs mainly inorganic gases such as hydrogen, oxygen, nitrogen, carbon dioxide, carbon monoxide and ammonia among the gas remaining in the vacuum vessel.

The second getter 162 has a getter film shape coated with a getter material, for example, titanium oxide (TiO ₂ ), and is formed in an ineffective region of the first substrate 10 and the second substrate 12. However, the getter film material forming the second getter 162 is not limited thereto, and zinc oxide (ZnO) and cadmium sulfide (CdS) may also be used.

That is, the second getter 162 is an organic gas that is easily activated by ultraviolet rays generated in the air or in a driving process and remains in the vacuum container, such as gases mixed with carbon and hydrogen such as methane, ethane, acetylene, butane, and the like. Decompose The organic gas is not easily adsorbed by the first getter 161 but is decomposed into a gas that can be adsorbed by the second getter 162. Therefore, the second getter 162 may improve the adsorption performance of the first getter 161.

The vacuum vessel of the above-described configuration is a field emission array (FEA) type, surface conduction emission (SCE) type, the vacuum vessel of the above configuration is a field emission array (FEA) type, surface conduction emission (SCE) type, metal- It can be applied to other electron emitting displays, including insulating layer-metal (MIM) type and metal-insulating layer-semiconductor (MIS) type. It demonstrates concretely.

Referring to FIG. 2, a plurality of cathode electrodes 18, which are first electrodes, are formed on the first substrate 10 with a stripe pattern along one direction of the first substrate 10.

The first insulating layer 20 is formed on the entire first substrate 10 while covering the cathode electrodes 18, and the gate electrodes 22 are formed on the first insulating layer 20 with the cathode electrodes 18. A plurality of stripe patterns are formed along the orthogonal direction (x-axis direction in FIG. 1).

As a result, an intersection region of the cathode electrode 18 and the gate electrode 22 is formed, and the intersection region may constitute one unit pixel. Electron emitters 24 are formed in each unit pixel on the cathode electrodes 18.

In addition, first and second openings 201 and 221 corresponding to each electron emission part 24 are formed in the first insulating layer 20 and the gate electrodes 22, respectively, on the first substrate 10. Allow electron emission portion 24 to be exposed. That is, the electron emission part 24 is formed on the cathode electrode 18 while being disposed in the first and second openings 201 and 221 of the first insulating layer 20 and the gate electrodes 22. In the present embodiment, the electron emitting portion 24 and the first and second openings 201 and 221 are formed in a circular shape with respect to a planar shape, but their shapes are not necessarily limited thereto.

In the present embodiment, the electron emission unit 24 is 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. That is, the electron emission unit 24 is made of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond phase carbon, fullerene (C ₆₀ ), silicon nanowires, and combinations thereof. On the other hand, the electron emission part 24 may be formed of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si).

The electron emitters 24 may be provided in plural in each unit pixel area, and the plurality of electron emitters 24 may be any one of the cathode electrode 18 and the gate electrode 22. The cathode electrodes 18 may be positioned in a line with an arbitrary distance from each other along the length direction of the cathode electrode 18. 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 26 and the focusing electrode 28 are sequentially formed on the gate electrodes 22. The second insulating layer 26 disposed below the focusing electrode 28 is formed on the front surface of the first substrate 10 so as to cover the gate electrodes 22 to form the gate electrodes 22 and the focusing electrode 28. Insulate.

In addition, the focusing electrode 28 is formed of one film having an arbitrary size on the second insulating layer 26.

In the second insulating layer 26 and the focusing electrode 28, third and four openings 261 and 281 for passing electron beams are formed, respectively.

In the present exemplary embodiment, the third opening 261 of the second insulating layer 26 and the fourth opening 281 of the focusing electrode 28 form one opening for each unit pixel to collect electrons emitted from one unit pixel. Focus comprehensively 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 30, for example, the red, green, and blue fluorescent layers 30R, 30G, and 30B may be disposed on each other. It is formed at intervals, and a black layer 32 is formed between the fluorescent layers 30R, 30G, and 30B to improve contrast of the screen. The fluorescent layer 30 may be disposed such that one fluorescent layer 30 corresponds to each unit pixel set in the first substrate 10.

An anode electrode 34 made of a metal such as aluminum (Al) is formed on the fluorescent layer 30 and the black layer 32. The anode electrode 34 receives the high voltage necessary for accelerating the electron beam from the outside to maintain the fluorescent layer 30 in a high potential state, and visible light emitted toward the first substrate 10 of the visible light emitted from the fluorescent layer 30. 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), in which case the transparent anode electrode is disposed between the second substrate and the fluorescent layer. Located. 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 36 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 36 are disposed on the focusing electrode 28 on the first substrate 10 side, and correspond to the black layer 32 on the second substrate 12 side so as not to invade the fluorescent layer 30.

Next, the above-described driving process of the electron emission display will be described with reference to the electron emission display shown in FIG.

The electron emission display is driven by supplying a predetermined voltage from outside to the cathode electrodes 18, the gate electrodes 22, the focusing electrode 28, and the anode electrode 34.

For example, any one of the cathode electrodes 18 and the gate electrodes 22 may receive a scan driving voltage to serve as scan electrodes, and the other electrodes may receive a data driving voltage to serve as data electrodes.

The focusing electrode 28 receives a voltage required for electron beam focusing, for example, a voltage of 0 volts (V) or a negative direct current voltage of several to a collection volts (V), and the anode electrode 34 has a voltage required for electron beam acceleration, for example, several hundreds. DC voltage of positive to thousands of volts (V) is applied.

Then, an electric field is formed around the electron emission unit 24 in the unit pixels in which the voltage difference between the cathode electrode 18 and the gate electrode 22 is greater than or equal to the threshold, thereby emitting electrons from the electron emission unit 24. The emitted electrons are focused to the center of the electron beam bundle while passing through the fourth opening 281 of the focusing electrode 28, and are attracted by the high voltage applied to the anode electrode 34 to impinge on the fluorescent layer 30 of the corresponding unit pixel. do. This collision causes the fluorescent layer 30 to emit light to implement an arbitrary image.

In the above driving process, the electron emission display of the present embodiment adsorbs the inorganic gas remaining in the vacuum container in the first getter, decomposes the organic gas in the second getter, and acts as a catalyst for the first getter, thereby allowing the interior of the vacuum container to be discharged. Can be maintained in a high vacuum state.

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.

1 is a cross-sectional view schematically showing the configuration of an electron emission display according to an embodiment of the present invention.

2 is a cross-sectional view showing a field emission array type electron emission display according to an embodiment of the present invention.

Claims (10)

A first substrate and a second substrate disposed opposite to each other to constitute a vacuum container; An electron emission unit provided on the first substrate; A light emitting unit provided on the second substrate; A first getter mounted to the vacuum vessel to adsorb residual gas inside the vacuum vessel; And A second getter formed in the vacuum vessel and serving as a catalyst for the first getter Electronic emission display comprising a. According to claim 1, An effective area and an invalid area are formed in the first substrate, and the first getter and the second getter are formed in the invalid area. According to claim 1, The second getter is an electron emission display made of at least one material selected from the group consisting of titanium oxide (TiO ₂ ), zinc oxide (ZnO), and cadmium sulfide (CdS). According to claim 1, And the first getter is a non-evaporable getter. According to claim 1, And the first getter is an evaporative getter. According to claim 1, The first getter includes one of barium (Ba), vanadium (V), titanium (Ti), zirconium (Zr), niobium (Nb), molybdenum (Mo), tantalum (Ta), or an alloy thereof. Electron emission display. According to claim 1, 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 An electron emission part formed on the first electrode and electrically connected to the first electrode Electronic emission display comprising a. The method of claim 7, wherein And a focusing electrode disposed on the first electrode and the second electrode, the insulation electrode being insulated from the first electrode and the second electrode. The method of claim 7, wherein The electron emission unit is at least one selected from the group consisting of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond phase carbon, fullerene (C60) and silicon nanowires. The method of claim 1, The light emitting unit, A fluorescent layer formed on the second substrate; And An anode electrode formed on the second substrate while being connected to the fluorescent layer Electronic emission display comprising a.

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