KR20060060113A - Image display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display apparatus which maintains an area where electron emission portions and a fluorescent layer are located at uniform intervals without embedding a spacer, and improves the bonding strength of the vacuum structure. An image display device according to the present invention includes a first substrate on which an electron emission portion is formed, and a second substrate on which a fluorescent layer is formed and disposed in front of the first substrate with sidewalls interposed therebetween to form a first region together with the first substrate. And a reinforcing member disposed behind the first substrate and having a reinforcing member formed together with the first substrate to form a second region in communication with the first region. At this time, the side wall is joined to the first substrate and the second substrate by a frit, and forms a recess in at least one of the bonding surfaces of the bonding surface with the first substrate and the bonding substrate with the second substrate.

Vacuum structure, side wall, frit, recess, electron emitting part, fluorescent layer, anode electrode, reinforcing member, reinforcing board

Description

Image display {IMAGE DISPLAY DEVICE}

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

FIG. 2 is a perspective view of the image display device shown in FIG. 1 viewed from the rear. FIG.

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

4 is a cross-sectional view taken along line II of FIG. 3.

5 is a partially enlarged cross-sectional view of the sidewall and the second substrate illustrating a bonding process of the sidewall and the second substrate.

6 and 7 are partial cross-sectional views of sidewalls showing another embodiment of the recess.

8 is a sectional view of an image display device showing another embodiment of the reinforcing member.

9 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.

10 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. More particularly, the present invention relates to an image display device in which an area where electron emission portions and a fluorescent layer are located at uniform intervals is provided without embedding spacers, thereby improving bonding strength of a vacuum structure. It is about.

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.

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.

Moreover, 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 limitations of the spacer. In the case of the field emission display device, this causes display defects such as electrons being emitted under the influence of the anode electric field in the electron emission portion of the pixel to be turned off. In general, the anode voltage and the screen brightness have a proportional relationship, and for the aforementioned reasons, the conventional field emission display 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.

On the other hand, since the image display device bonds the front substrate and the rear substrate using frit, which is a low melting point glass, and exhausts the internal space to form a vacuum structure, the frit layer has a uniform width between the two substrates after bonding. The bonding strength of the vacuum structure is improved when having a height of and. Accordingly, there is a demand for structural improvement for improving the bonding strength of vacuum structures.

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 manufacture, to increase the initial vacuum degree to compensate for the deterioration of the vacuum degree due to the gas discharge, vacuum structure It is an object of the present invention to provide an image display device capable of increasing the bonding strength of the same.

The image display device of the present invention for achieving the above object, the first substrate with the electron emission portion is formed, the fluorescent layer is formed and disposed in front of the first substrate with the sidewalls interposed therebetween the first substrate And a second substrate forming a region, and a reinforcing member disposed behind the first substrate, the reinforcing member forming a second region in communication with the first region together with the first substrate. At this time, the side wall is joined to the first substrate and the second substrate by a frit, and forms a recess in at least one of the bonding surfaces of the bonding surface with the first substrate and the bonding substrate with the second substrate.

When the side wall forms a recess in both of the joining surfaces with the first substrate and the second substrate, the recesses provided in each joining surface are formed at different positions along the thickness direction of the side walls. The recess is formed to have a cross-sectional shape of any one of a V shape and a U shape.

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

1 is a cross-sectional view of an image display device according to an embodiment of the present invention, and FIG. 2 is a perspective view of the image display device shown in FIG.

1 and 2, an image display device includes a first substrate 2 and a second substrate 4 arranged to face each other with the sidewall 6 interposed therebetween to form a first region 100, and a second substrate 4. It is provided with a vacuum structure 10 made of a reinforcing member 8 attached to the rear of the first substrate 2 and forming the second region 200 together with the first 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 10. The first region 100 and the second region 200 may be formed in the first substrate 2 in the vacuum structure 10. 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 electron emission, that is, electron emission means 12. The second substrate 4 is provided with a structure that emits visible light by electrons to perform any light emission or display, that is, light emitting means 14.

The first substrate 2 and the second substrate 4 are integrally bonded in a state where the square frame-shaped side wall 6 shown in FIG. 3 is positioned at the edge portion between the two substrates. As a result, a first region 100 surrounded by the first substrate 2, the second substrate 4, and the sidewall 6 is formed, and the first substrate 2 and the second substrate (according to the height of the sidewall 6) are formed. The interval of 4) is determined.

The side wall 6 is bonded 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 designates the side wall 6 to the first substrate 2 and the first substrate 2. The 1st frit layer bonded to the 2 board | substrates 4 is shown.

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 provided with driving electrodes for emitting electrons from the electron emitting portion together with the electron emitting portion, a process of forming an insulating layer for insulating between the electron emitting portion, the driving electrodes, and the driving electrodes is performed. Is subjected to several high temperature heat treatment processes. 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.

The reinforcing member 8 forming the outline of the vacuum structure 10 is attached to the rear surface of the first substrate 2, and is surrounded by the first substrate 2 and the reinforcing member 8. The second region 200 is formed. The second region 200 is formed to have a volume larger than that of the first region 100, preferably two times or more. The reinforcing member 8 is attached to the first substrate 2 by a frit, in which the reference numeral 18 denotes a second frit layer for joining the first substrate 2 and the reinforcing member 8.

It is preferable that the minimum thickness of the reinforcing member 8 is greater than the thickness of the first substrate 2 in consideration of strength characteristics. This reinforcing member 8 may be provided with an exhaust pipe 20 used to exhaust the inside of the structure and a getter 22 for adsorbing and removing residual gas after the exhaust.

As described above, the vacuum structure 10 forms the second region 200 communicating with the first region 100 behind the first substrate 2 by the reinforcing member 8, thereby expanding the internal volume. The gap between the first substrate 2 and the second substrate 4 can be kept constant without having a spacer in the region 100, and a stable structure can be secured.

In addition, the vacuum structure 10 of the present embodiment can increase the initial volume of approximately 10 ^-6 Torr or more by increasing the internal volume. If the initial vacuum degree is increased, even if the gas is released from the materials constituting the electron emitting means 12 or the light emitting means 14 when the product is used, a 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.

Furthermore, as the first substrate 2 is positioned across the inside of the vacuum structure 10 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 8 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 8 has a central portion 8a which forms a partial spherical surface convex toward the first substrate 2, and a central portion 8a and the first having a concave curvature toward the first substrate 2. It consists of a body part 8b connecting the substrate 2. This reinforcing member 8 is formed by the concave curvature of the body portion 8b facing the first substrate 2 and thus the center portion 8a facing the first substrate 2 while sufficiently securing the volume of the second region 200. The convex curvature has an effect of preventing an increase in the depth of the vacuum structure 10.

The reinforcing member 8 of the above-described shape is effective in dispersing the stress by the vacuum compression force, and helps to form a stable vacuum structure 10. At this time, the exhaust pipe 20 is located at the center of the central portion 8a to minimize the total length of the vacuum structure 10.

In addition, in the present embodiment, the side wall 6 has a concave portion to be described later, and the first frit layer 16 has a substantially uniform width and a uniform thickness in the process of assembling and bonding the vacuum structure 10. To form. 4 is a cross-sectional view taken along line II of FIG. 3.

3 and 4, the sidewall 6 forms a recess 24 in the joint surface 6a of the second substrate to provide a free space for the frit to be filled into the sidewall 6. The recessed portion 24 is formed in an annular shape along the planar shape of the side wall 6, so that the frit is not overexposed to the outside of the side wall 6, that is to the outside of the vacuum structure 10. May be disposed towards the edge.

As a result, as shown in FIG. 5, the frit is applied to the upper surface of the side wall 6, and softened at a high temperature to bond the side wall 6 to the second substrate 4 so that the frit excessively overflows out of the side wall 6. The first frit layer 16 is formed with a substantially uniform width and thickness between the side wall 6 and the second substrate 4 without work.

On the other hand, as shown in FIG. 6, the side walls 6 ′ may form recesses 24 and 24 ′ in both the bonding surface 6b of the first substrate and the bonding surface 6a of the second substrate. have. At this time, in consideration of the strength characteristics of the side wall 6, the recess 24 'provided on the bonding surface 6b with the first substrate and the recess 24 provided on the bonding surface 6a with the second substrate are removed. It is preferable not to form in the same position along the thickness direction of the side wall 6.

4 and 6 show that one concave is formed in each joint surface of the side walls 6 and 6 ', but at least one, preferably five or less concave portions are formed in each joint surface of the side walls 6 and 6'. Can be provided. The concave portion has a V-shaped or U-shaped cross-sectional shape, and FIG. 7 shows a sidewall 6 'in which the concave portions 26 and 26' have a U-shaped cross-sectional shape. . The cross-sectional shape of the recess is not limited to the illustrated example and can be variously modified.

As such, the first frit layer 16 has a substantially uniform width between the sidewall 6 and the first substrate 2 and between the sidewall 6 and the second substrate 4 by the recess 24. It has a thickness, and as a result, the joining precision and joining strength of the vacuum structure 10 are improved. Furthermore, since the frit is not excessively exposed out of the vacuum structure 10 by the recess 24, the frit and the frit when the explosion-proof band (not shown) is fastened along the outer circumference of the second substrate 4 and the side wall 6. The interference between the explosion-proof bands can be effectively prevented.

The reinforcing member 8 may be formed in the shape shown in FIG. 8 in addition to the above-described shape. Referring to FIG. 8, the reinforcing member 28 includes an opposing portion 28a disposed at a predetermined distance from the rear surface of the first substrate 2 and arranged in parallel therewith, and the first substrate 2 from an edge of the opposing portion 28a. And a skirt portion 28b extending toward the back surface and attached to the rear surface of the first substrate 2. At this time, it is preferable that the skirt portion 28b is formed to have a height greater than that of the side wall 6 so that the second region 200 has a larger volume than the first region 100.

The above-described vacuum structure 10, 10 '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 (Surface) Suitable for conduction emission display (SED) and metal / insulation layer / metal (IMM) type electron emission display.

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. 9 and 10.

Referring to the drawings, the cathode electrodes 30 are formed in a stripe pattern along one direction (y-axis direction of the drawing) on the first substrate 2, and cover the cathode electrodes 30 with the first substrate 2. The insulating layer 32 is formed in the whole. Gate electrodes 34 are formed in a sprite pattern on the insulating layer 32 in a direction orthogonal to the cathode electrode 30 (the x-axis direction of the drawing).

Openings 34a and 32a are formed in the gate electrode 34 and the insulating layer 32 at each intersection of the cathode electrode 30 and the gate electrode 34 to expose a part of the surface of the cathode electrode 30. The electron emission part 36 is formed on the cathode electrode 30.

The electron emission unit 36 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 36 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 36 ), 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 addition, although the case where the gate electrode 34 is positioned above the cathode electrode 30 with the insulating layer 32 interposed therebetween has been described, 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 38, for example, a red, green, and blue fluorescent layer is formed at random intervals, and the fluorescent layer 38 is formed. The black layer 40 is formed to improve the contrast of the screen. An anode electrode 42 made of a metal film (for example, an aluminum film) by vapor deposition is formed on the fluorescent layer 38 and the black layer 40. The anode electrode 42 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 cathode electrode 30 and the gate electrode 34 described above, an electric field is formed around the electron emission part 36 due to the voltage difference between the two electrodes, and electrons are emitted from the electron. The electrons are attracted by the high voltage applied to the anode electrode 42 to the second substrate 4 and collide with the fluorescent layer 38 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 higher can be applied to the anode electrode 42, so that screen brightness and color reproduction rate can be increased.

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, while the preferred embodiment of the present invention has been described above, the present invention is not limited thereto, and various modifications 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, the image display device according to the present invention has the effect that the bonding accuracy and bonding strength of the vacuum structure is improved as the first frit layer is formed to have a uniform thickness and a uniform width.

Claims (9)

A first substrate having an electron emission portion formed thereon, a second substrate having a fluorescent layer formed thereon, and having a sidewall interposed therebetween to form a first region together with the first substrate; A vacuum structure having a reinforcement member disposed to form a second region with the first substrate and in communication with the first region, And the side wall is joined to the first substrate and the second substrate by a frit, and forms a recess in at least one of the bonding surfaces of the first substrate and the second substrate. The method of claim 1, And the side wall forms a recess in both of the bonding surfaces of the first substrate and the second substrate, and the recesses provided in each of the bonding surfaces are formed at different positions along the thickness direction of the side walls. The method according to claim 1 or 2, And the concave portion has a cross-sectional shape of any one of a V shape and a U shape. The method of claim 1, And the first substrate forms at least one through hole for allowing the first region and the second region to communicate with each other in the vacuum structure. The method of claim 1, And the second substrate and the reinforcing member have a thickness greater than that of the first substrate. The method of claim 1, And the volume of the second area is greater than or equal to twice the volume of the first area. The method of claim 1, And a central portion forming the 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 method of claim 1, And an opposing portion disposed in parallel with the rear surface of the first substrate at a predetermined interval, and a skirt portion extending from an edge of the opposing portion toward the first substrate. The method of claim 1, An image display device, wherein the electron emission portion is a cold cathode electron source.

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