KR20060060470A - Image display device - Google Patents

Abstract

The present invention relates to an image display apparatus capable of forming a stable vacuum structure without embedding a spacer,

An image display device according to the present invention includes a first substrate on which an electron emission portion is formed, a second substrate on which a fluorescent layer is formed, and disposed in front of the first substrate to form a first region together with the first substrate, and a first substrate. And a vacuum structure having a reinforcing member disposed behind the first substrate to form a second region with the first substrate. At this time, the first substrate forms at least one through hole for communicating the first region and the second region with each other in the vacuum structure, and the second region has a larger volume than the first region.

Substrate, electron emitting part, fluorescent layer, exhaust pipe, reinforcing member, side wall, vacuum structure

Description

Image display {IMAGE DISPLAY DEVICE}

1 is a cross-sectional view of an image display device according to a first embodiment of the present invention.

2 is a rear perspective view of the image display device according to the first embodiment of the present invention.

3 is a perspective view of the side wall shown in FIG.

4 is a cross-sectional view of an image display device according to a second embodiment of the present invention.

5 is a cross-sectional view of an image display device according to a third embodiment of the present invention.

6 is a partially exploded perspective view showing a case where the image display device according to the present invention is applied to a field emission display device.

7 is a partial cross-sectional view showing the case where the image display device according to the present invention is applied to a field emission display device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly, to an image display device having a vacuum structure capable of maintaining an area where an electron emission portion is located at a uniform interval without embedding a spacer.

An image display apparatus using electrons for emitting a fluorescent layer typically has a basic structure of a vacuum structure having an electron emitting portion and a fluorescent layer therein, and excites a fluorescent layer with electrons emitted from the electron emitting portion to display a predetermined display. It works.

Such image display apparatuses can be classified into a method using a hot cathode and a method using a cold cathode according to the type of electron source. In addition, depending on the shape of the vacuum structure, a bulb-type structure such as a cathode ray tube is used, and an inner space is formed after the front substrate and the rear substrate are bonded at random intervals, such as a fluorescent display tube and a field emission display device. It can be classified in a manner using an exhausted plate-like structure.

In the image display apparatus using the flat panel structure as described above, as the screen size increases and the internal vacuum degree increases, the compressive force applied to the vacuum structure increases. Therefore, in the conventional image display apparatus, a large number of spacers are provided inside the vacuum structure to prevent deformation or breakage of the vacuum structure due to the compressive force while maintaining the front substrate and the rear substrate at regular intervals.

In order to fabricate a vacuum structure with a built-in spacer, ① process the glass or ceramic to make a spacer, ② attach the spacer on the front substrate or the rear substrate, and ③ assemble the front substrate and the rear substrate with the spacer in between. Next, a process of joining the edges of the two substrates and exhausting the internal space through the exhaust pipe is required.

However, in recent years, as the image display device becomes higher resolution, the width of the non-light emitting area in which the spacer is to be located becomes narrower. Accordingly, a spacer having a fine size and a high aspect ratio is required. However, spacers satisfying this condition are not easy to manufacture, and there are many difficulties in the process when attaching thousands of micro spacers onto the front substrate or the rear substrate.

In addition, the conventional image display apparatus may not increase the initial vacuum degree due to the spacers in the process of exhausting the inside of the structure through the exhaust pipe, and a bad mounting of the spacer may occur in the exhaust process. If the image display device does not initially secure high vacuum, the degree of vacuum is gradually lowered due to outgassing of members provided inside the vacuum structure, thereby degrading device characteristics. In addition, spacers in which mounting failure occurs may damage the fluorescent layer or block the electron beam path, thereby degrading the screen quality.

Furthermore, in the field emission display device, a spacer made of a dielectric material may be charged while the electron beam is hit when the display device is driven. The charged spacers distort the electron beam path around the spacers to prevent accurate color implementation, and the potential of the anode electrode for maintaining the fluorescent layer in a high potential state may be induced toward the electron emission side through the spacers to cause an arc discharge.

In addition, the gap between the front substrate and the rear substrate, which is determined by the height of the spacer, has a certain limit in increasing its size due to the manufacturing limitation of the spacer. This is a limit to increase the anode voltage in consideration of the above-described arc discharge or the influence of the anode electric field on the electron emission portion. In general, the anode voltage and the screen brightness have a proportional relationship, and for the above-described reasons, the conventional image display device has difficulty in implementing high brightness.                         

As described above, the spacer is an effective member for securing the stability of the flat plate vacuum structure, but is a major cause of lowering the productivity of the image display device, and serves as a detrimental factor in improving the screen quality.

Therefore, the present invention is to solve the above problems, an object of the present invention is to form a stable vacuum structure without the built-in spacer to facilitate the manufacturing, to increase the initial vacuum degree to compensate for the deterioration of the vacuum degree by the outgassing, An object of the present invention is to provide an image display device capable of increasing screen quality by enlarging a gap between a substrate and a rear substrate.

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

A plurality of regions including a vacuum structure in which an electron emitting portion and a fluorescent layer emitting light by electrons emitted from the electron emitting portion are embedded, and a substrate disposed in the vacuum structure to divide the interior of the vacuum structure into a plurality of regions. Provides an image display device in communication with each other, the volume of which is formed differently.

The substrate may be divided into a first region in which the electron emission unit and the fluorescent layer are positioned, and a second region having a volume larger than the first region. At this time, the volume of the second region is preferably at least twice the volume of the first region.

The image display device may further include a getter positioned in the second area and an exhaust pipe connected to the second area.

At least one through hole may be formed in the substrate to communicate the plurality of regions with each other.

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

A first substrate on which an electron emission portion is formed, a second substrate on which a fluorescent layer is formed, and disposed in front of the first substrate to form a first region together with the first substrate, and a first substrate disposed behind the first substrate And a vacuum structure having a reinforcing member defining a second region, wherein the first substrate forms at least one through hole for communicating the first region and the second region with each other in the vacuum structure, and the second structure includes: An image display apparatus is provided in which an area has a volume larger than that of the first area.

The second substrate and the reinforcing member may be formed to have a thickness greater than that of the first substrate.

The reinforcing member may include a central portion forming a partial spherical surface convex toward the first substrate, and a body portion connecting the central portion and the first substrate with a concave curvature toward the first substrate.

The electron emitter may be formed as a cold cathode electron source.

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

1 and 2 are cross-sectional and rear perspective views, respectively, of an image display device according to a first embodiment of the present invention.

Referring to the drawings, the image display apparatus is attached to the first substrate 2 and the second substrate 4 disposed opposite to each other with the first region 100 interposed therebetween, and is attached to the rear of the first substrate 2 and the first substrate. It is provided with a vacuum structure (8) consisting of a reinforcing member (6) forming a second region (200) together with a substrate (2). The first region 100 and the second region 200 refer to a space divided by the first substrate 2 in the vacuum structure 8, and may be formed on the first substrate 2 inside the vacuum structure 8. The through hole 2a is formed to allow the first region 100 and the second region 200 to communicate with each other.

More specifically, the first substrate 2 is provided with a configuration for emitting electrons, that is, an electron emitting means 10 so that the first substrate 2 functions as a cathode substrate, and the second substrate 4 is provided with electrons. A configuration for emitting any visible light to perform any light emission or display, that is, a light emitting means 12 is provided so that the second substrate 4 functions as an anode substrate.

The first substrate 2 and the second substrate 4 may be integrally bonded in a state where the rectangular frame-shaped sidewall 14 shown in FIG. 3 is positioned at an edge portion between the two substrates 2 and 4. have. As a result, a first region 100 surrounded by the first substrate 2, the second substrate 4, and the sidewall 14 is formed, and the first substrate 2 and the second substrate (according to the height of the sidewall 14) are formed. The interval of 4) is determined.

The side wall 14 may be attached to the first substrate 2 and the second substrate 4 by frit, which is a low melting glass, and in the drawing, reference numeral 16 denotes the two substrates 2 and 4 and the side wall 14. ) Is a first frit layer to be bonded.

Here, the second substrate 4 is preferably formed to a sufficient thickness to withstand the vacuum compression force, for example, a thickness of 10 mm or more. On the other hand, the first substrate 2 is preferably formed to a thickness smaller than the second substrate 4, for example, 5 mm or less.

Since the first substrate 2 is a substrate having various driving electrodes for emitting electrons from the electron emitting portion in addition to the electron emitting portion, the first substrate 2 forms an insulating layer for insulating between the electron emitting portion and the driving electrodes and the electrodes. The process undergoes several high temperature heat treatments. Accordingly, the thickness of the first substrate 2 is preferably 5 mm or less in order to reduce thermal stress of the first substrate 2 due to temperature change, thereby preventing cracking of the first substrate 2, and to increase film formation characteristics.

A reinforcing member forming the outer shape of the vacuum structure 8 is attached to the rear surface of the first substrate 2, and the second region surrounded by the first substrate 2 and the reinforcing member 6 is attached. 200 is formed. In this case, the second region 200 is connected to the first region 100 through the through hole 2a, and the volume of the second region 200 is larger than that of the first region 100. The reinforcing member 6 providing the second region 200 may be provided with an exhaust pipe 18 used to exhaust the inside of the structure and a getter 20 for adsorbing and removing residual gas after the exhaust.

The reinforcing member 6 may be attached to the first substrate 2 by frit, in which the reference numeral 22 denotes a second frit layer joining the first substrate 2 and the reinforcing member 6. It is preferable that the minimum thickness of the reinforcing member 6 is greater than the thickness of the first substrate 2 in consideration of the strength characteristic.

As described above, the vacuum structure 8 forms the second region 200 which is connected to the first region 100 behind the first substrate 2 by the reinforcing member 6, thereby expanding the internal volume. The gap between the first substrate 2 and the second substrate 4 can be kept constant without providing a spacer in the 100, and a stable structure can be ensured.

In addition, the vacuum structure 8 of the present embodiment has an enlarged internal volume to increase the initial vacuum degree to about 10 ⁻⁶ Torr or more. If the initial vacuum degree is increased, even if the gas is released from the materials constituting the electron emitting means 10 or the light emitting means 12 when the product is used, the high initial vacuum degree compensates for this even if the vacuum degree is lowered, thereby preventing deterioration of the vacuum degree and consequent deterioration of device characteristics. Can be.

In consideration of the decrease in the degree of vacuum due to the gas discharge, the volume of the second region 200 is preferably at least twice the volume of the first region 100. The volume expansion ratio of the second region 200 with respect to the first region 100 is inversely related to the amount of vacuum decrease due to gas discharge. That is, if the volume of the second region 200 is three times the volume of the first region 100, the decrease in vacuum degree due to the gas discharge may be reduced compared to the case where the vacuum structure 8 includes only the first region 100. It is 1/3 level. As a result, the vacuum structure 8 of the present embodiment can effectively reduce the vacuum degree deterioration by reducing the vacuum degree decrease due to the gas discharge.

Furthermore, as the first substrate 2 is positioned across the interior of the vacuum structure 8 between the first region 100 and the second region 200 in communication with each other, the image display device of the present embodiment is driven by a vacuum compression force. Shape deformation of the first substrate 2 can be minimized.

1 and 2 illustrate a case in which the reinforcing member 6 is formed by combining two or more opposite surfaces, that is, a concave surface concave toward the first substrate 2 and a convex surface toward the first substrate 2.

In this embodiment, the reinforcing member 6 has a central portion 6a which forms a partial spherical surface convex toward the first substrate 2, and a central portion 6a and the first having a concave curvature toward the first substrate 2. It consists of a body part 6b connecting the substrate 2. This reinforcing member 6 is formed by the concave curvature of the body portion 6b facing the first substrate 2 while maintaining a sufficient volume of the second region 200 while maintaining the volume of the central portion 6a facing the first substrate 2. Due to the convex curvature, there is an effect of preventing an increase in the depth of the vacuum structure 8.

The reinforcing member 6 of the above-described shape is effective in dispersing the stress by the vacuum compression force, and helps to form a stable vacuum structure 8. At this time, the exhaust pipe 18 may be located at the center of the central portion 6a to minimize the overall length of the vacuum structure 8, the getter 20 is to be installed inside the body portion 6b of the reinforcing member 6 Can be.

4 is a cross-sectional view of an image display device according to a second embodiment of the present invention.

Referring to the drawings, in the present embodiment, the reinforcing member 24 includes a third substrate 26, a first substrate 2, and a third substrate 26 disposed parallel to the rear surface of the first substrate 2 at a predetermined distance. It is composed of sidewalls 28 disposed at edge portions between the substrates 26 to form the second region 200 with the two substrates 2, 26.

For convenience of explanation, the sidewalls 14 disposed between the first and second substrates 2 and 4 are called first sidewalls, and the sidewalls 28 positioned between the first and third substrates 2 and 26. Is called the second sidewall. The second sidewall 28 may be attached to the first substrate 2 and the third substrate 26 by frits, and the reference numeral 30 in the drawing denotes the first and third substrates 2, 26 and the second sidewall ( 28 shows a second frit layer to be bonded.

In this case, the second sidewall 28 is formed to have a height greater than that of the first sidewall 14 so that the second region 200 may have a volume larger than that of the first region 100. The second region 200 is formed at a height capable of having a volume twice or more than that of the first region 100. In addition, the thickness of the third substrate 26 may be greater than the thickness of the first substrate 2.

5 is a cross-sectional view of an image display device according to a third embodiment of the present invention.

Referring to the drawings, in this embodiment, the reinforcing member 32 is disposed at a predetermined distance from and parallel to the rear surface of the first substrate 2 and the first portion 32a and the first portion from the edge of the opposite portion 32a. The skirt portion 32b extends vertically toward the substrate 2 to form the second region 200 therein with the opposing portion 32a.

The reinforcing member 32 of the present embodiment may also be attached to the rear surface of the first substrate 2 by frits, and in the drawing, reference numeral 34 denotes a second frit layer bonding the first substrate 2 and the reinforcing member 32 to each other. Indicates.

At this time, the skirt portion 32b has a height greater than that of the sidewall 14 positioned between the first and second substrates 2 and 4 so that the second region 200 has a larger volume than the first region 100. Preferably, the skirt portion 32b is formed to a height such that the second region 200 can have a volume twice or more than that of the first region 100.

The above-described vacuum structure 8 is an image display device using a cold cathode as an electron source, for example, a field emission display (FED), a surface conduction emission display (FED). ; SED) and metal / insulating layer / metal (IMM) type electron emission display devices.

A case in which the above-described image display device is applied to the field emission display device will be described with reference to FIGS. 6 and 7.                     

Referring to the drawings, the cathode electrodes 36 are formed in a stripe pattern along one direction (y direction of the drawing) on the first substrate 2, and cover the cathode electrodes 36 to cover the entire first substrate 2. An insulating layer 38 is formed on the substrate. Gate electrodes 40 are formed in a sprite pattern on the insulating layer 38 in a direction orthogonal to the cathode electrode 36 (x direction in the drawing).

Openings 40a and 38a are formed in the gate electrode 40 and the insulating layer 38 at each intersection of the cathode electrode 36 and the gate electrode 40 to expose a part of the surface of the cathode electrode 36. An electron emission portion 42 is formed over the cathode electrode 36.

The electron emission part 42 is formed of materials emitting electrons when an electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. Preferred materials for use as the electron emitter 42 include any one or a combination of carbon nanotubes, graphite, graphite nanofibers, diamond, diamond-like carbon, C ₆₀ and silicon nanowires, and the electron emitter 42 ), Screen printing, chemical vapor deposition, sputtering or direct growth of carbon nanotubes may be applied.

On the other hand, although not shown, the electron emitting portion may be made of a composite of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si). In the above, the case where the gate electrode 40 is positioned above the cathode electrode 36 with the insulating layer 38 interposed therebetween has been described. However, the case where the gate electrode is positioned below the cathode electrode with the insulating layer interposed therebetween. It is possible.                     

On one surface of the second substrate 4 facing the first substrate 2, a fluorescent layer 44, for example, a red, green, and blue fluorescent layer is formed at random intervals, and the fluorescent layer 44 The black layer 46 may be formed to improve contrast of the screen. An anode electrode 48 made of a metal film (for example, an aluminum film) by vapor deposition is formed on the fluorescent layer 44 and the black layer 46. The anode 48 receives a voltage necessary for accelerating the electron beam, and increases the brightness of the screen.

When a predetermined driving voltage is applied to the above-described cathode electrode 36 and the gate electrode 40, an electric field is formed around the electron emission part 42 due to the potential difference between the two electrodes, and electrons are emitted therefrom. The electrons are attracted by the high voltage applied to the anode electrode 48 to the second substrate 4 and collide with the fluorescent layer 44 of the corresponding pixel to emit light.

At this time, the vacuum structure is made of a structure that sufficiently withstands the vacuum compression force without providing a support structure therein, it is possible to increase the distance between the first substrate 2 and the second substrate 4 to 5mm or more. As a result, a high voltage of 7 kV or more can be applied to the anode electrode 48, thereby improving screen brightness and color reproduction.

In the above, the field emission display device has been described as an example of the image display device. However, the present invention is not limited thereto and can be applied to other image 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 image display device according to the present invention provides a stable vacuum structure that withstands the vacuum compression force without embedding a spacer. Therefore, the image display device according to the present invention is easy to manufacture, and is advantageous for ensuring high vacuum, thereby preventing the deterioration of characteristics caused by the decrease in the degree of vacuum. In addition, when the image display device according to the present invention is applied to a field emission display device, a high voltage can be applied to the anode electrode by increasing the distance between the first substrate and the second substrate, and as a result, the brightness and color reproduction of the screen are increased. It has a big effect on improving screen quality.

Claims (16)

A vacuum structure including an electron emitting portion and a fluorescent layer emitting light by electrons emitted from the electron emitting portion; And A substrate disposed in the vacuum structure to divide the interior of the vacuum structure into a plurality of regions, And the plurality of areas communicate with each other and have different volumes. The method of claim 1, And the substrate divides the interior of the vacuum structure into a first region in which the electron emission portion and a fluorescent layer are located, and a second region having a volume larger than the first region. The method of claim 2, And the volume of the second area is greater than or equal to twice the volume of the first area. The method of claim 2, And a getter positioned in the second area, and an exhaust pipe connected to the second area. The method of claim 1, And the substrate forms at least one through hole for communicating the plurality of regions with each other. A first substrate on which an electron emission portion is formed, a second substrate on which a fluorescent layer is formed, and disposed in front of the first substrate to form a first region together with the first substrate, and a first substrate disposed behind the first substrate And a vacuum structure having a reinforcing member forming a second region therewith, The first substrate forms at least one through hole for communicating the first region and the second region with each other in the vacuum structure, And the second region has a volume larger than that of the first region. The method of claim 6, And a side wall bonded to the substrates at an edge portion between the first substrate and the second substrate. The method of claim 6, And the second substrate and the reinforcing member have a thickness greater than that of the first substrate. The method of claim 6, And the reinforcing member comprises a central portion forming a partial spherical surface convex toward the first substrate, and a body portion connecting the central portion and the first substrate with a convex curvature toward the first substrate. The method of claim 9, And an exhaust pipe disposed at the center of the central portion of the reinforcing member. The method of claim 7, wherein And a third substrate on which the reinforcing member is disposed in parallel with a rear surface of the first substrate, and another sidewall bonded to the substrates at an edge portion between the first substrate and the third substrate. The method of claim 11, And a sidewall positioned between the first substrate and the second substrate has a height greater than that of the sidewall positioned between the first substrate and the second substrate. The method of claim 7, wherein And an opposing portion in which the reinforcing member is disposed in parallel with a rear surface of the first substrate, and a skirt portion extending from an edge of the opposing portion toward the first substrate. The method of claim 13, And the skirt portion has a height greater than a sidewall positioned between the first substrate and the second substrate. The method of claim 6, And the volume of the second area is greater than or equal to twice the volume of the first area. The method according to claim 1 or 6, And the electron emitter is formed of a cold cathode electron source.

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