KR20070056685A - Image display device - Google Patents

Abstract

An image display device is provided to suppress the generation of cracks and reduce a baking time by reducing a temperature difference between substrates in a glass frit baking process. A vacuum receptacle(2) includes a first substrate(10), a second substrate(12) formed in the front of the first substrate to form a first region, and a reinforcing substrate(14) installed in the rear of the first substrate to form a second region. An electron emission unit(18) is formed on one side of the first substrate. A heat absorbing layer(42) is formed on the other side of the first substrate. A light emission unit(20) is formed on one side of the second substrate. One or more through holes(16) are formed in the first substrate in order to connect the first region with the second region within the vacuum receptacle.

Description

Image display {IMAGE DISPLAY DEVICE}

1 is an exploded perspective view of an image display device according to an embodiment of the present invention.

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

3 is a cross-sectional view of an image display device according to an embodiment of the present invention, showing a modification of the second substrate.

4 is a partially exploded perspective view showing a first substrate and a second substrate when the image display device according to an exemplary embodiment is applied to a field emission array type electron emission display device.

5 is a partial cross-sectional view of a first substrate and a second substrate showing a case where an image display device according to an embodiment of the present invention is applied to a field emission array type electron 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 container 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 has a basic configuration of a vacuum container including an electron emitting portion and a fluorescent layer therein, and excites a fluorescent layer with electrons emitted from the electron emitting portion to emit light or display a predetermined light. It works.

Such image display apparatuses may be classified into a method using a hot cathode and a cold cathode according to the type of electron source. Depending on the shape of the vacuum vessel, a bulb-type vessel such as a cathode ray tube (CRT) is used, and a front substrate and a rear side such as a fluorescent display tube (VFD) and a field emitter array (FEA) type electron emission display apparatus. It can be classified in such a manner as to use a flat container made of a substrate and a sealing member.

In the image display apparatus using the flat plate container, as the screen size increases and the internal vacuum degree increases, the compressive force applied to the vacuum container increases. Therefore, a structure that suppresses deformation and breakage of the vacuum container by providing a plurality of spacers inside the vacuum container has been proposed and used. In this case, the spacers are positioned corresponding to the black layers between the fluorescent layers so as not to invade the fluorescent layers.

In recent years, as the image display device becomes higher resolution, the width of the black layer on 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 only easy to manufacture, but also have difficulty in attaching thousands of micro spacers onto a front substrate or a rear substrate.

In addition, the conventional image display apparatus may not increase the initial vacuum degree due to the spacers, and a bad mounting of the spacer may occur in the exhaust process. If the image display device cannot initially secure a high vacuum, the vacuum degree gradually decreases due to the outgassing of the members provided inside the vacuum container, and thus the display characteristics are degraded, and the poorly mounted spacers block the electron beam path and degrade the screen quality. Let's do it.

Furthermore, a spacer made of a dielectric such as glass or ceramic may have the surface charged to a positive or negative potential as electrons strike the surface when the display device is acting. The charged spacer distorts the electron beam path, such as by drawing or pushing out electrons passing through the surrounding, thereby degrading display quality.

As described above, the spacer is an effective member for securing the stability of the flat plate type vacuum container, but reduces the productivity of the image display device and acts as a deterrent to improving the screen quality.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to provide an image display apparatus which can form a stable vacuum container without a built-in spacer and increase the initial vacuum degree to compensate for the deterioration of vacuum degree due to outgassing. It is.

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

A first substrate, a second substrate forming a first region together with the first substrate and positioned in front of the first substrate, and a reinforcing substrate forming a second region together with the first substrate and positioned behind the first substrate. A vacuum container, an electron emission unit provided on one surface of the first substrate, a heat absorption film formed on the other surface of the first substrate, and a light emitting unit provided on one surface of the second substrate, An image display apparatus is provided which forms at least one through hole for communicating a first region and a second region with each other in a vacuum container.

The heat absorption film may be made of a carbon-based material or made of a metal oxide film.

A support frame is positioned between the first substrate and the second substrate, and the reinforcement substrate may form a recess and a sidewall on an opposite surface to the first substrate.

The side wall may be formed to have a larger width than the support frame. The through hole of the first substrate may correspond to the side wall of the reinforcing substrate, and may form a communication groove extending from the point corresponding to the through hole to the recess.

The second substrate and the reinforcement substrate are formed to have a thickness greater than that of the first substrate.

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

1 is an exploded perspective view of an image display device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the image display device according to an embodiment of the present invention showing a cross section taken along line I-I of FIG. 1.

1 and 2, the image display device includes a first substrate 10 and a second substrate 12 disposed opposite to each other with the first region 100 interposed therebetween, and behind the first substrate 10. And a vacuum container 2 formed of a reinforcing substrate 14 disposed to form the second region 200 together with the first substrate 10. The first region 100 and the second region 200 refer to a space divided by the first substrate 10 in the vacuum container 2, and the first substrate 100 may have a first region 100 and a first region 100. Through-holes 16 are formed to allow the second region 200 to communicate with each other.

More specifically, an electron emission unit 18 for emitting electrons toward the second substrate 12 is provided on the opposite surface of the first substrate 10 to the second substrate 12, and the second substrate 12 is provided. The light emitting unit 20 that emits visible light by electrons is provided on an opposite surface of the first substrate 10. As a result, the first substrate 10 functions as a cathode substrate together with the electron emission unit 18, and the second substrate 12 functions as an anode substrate together with the light emitting unit 20.

At the edges of the first substrate 10 and the second substrate 12, a support frame for keeping the distance between the two substrates constant is positioned. In addition, the first adhesive layer 26 is positioned on the opposite surface of the support frame 24 to the first substrate 10 and the second substrate 12 so that the first substrate 10, the support frame 24, and the second substrate are positioned. (12) is integrally bonded.

As a result, a first region 100 surrounded by the first substrate 10, the second substrate 12, and the support frame 24 is formed, and according to the height of the support frame 24, the first substrate 10 and the second substrate 100 are formed. The spacing of the substrates 12 is determined. In this case, the support frame 24 may be made of the same material as the first substrate 10 and the second substrate 12 or may be made of a material having a thermal expansion coefficient similar to that of the two substrates.

On the other hand, as shown in FIG. 3, the second substrate 12 ′ may integrally form sidewalls 28 extending toward the first substrate 10 along its edge. That is, the second substrate 12 ′ may be formed of a flat plate 30 positioned in parallel with the first substrate 10 and a side wall 28 positioned at an edge of the flat plate 30. A first adhesive layer 26 is provided between the side wall 28 and the first substrate 10 to bond the first substrate 10 and the second substrate 12 'to each other.

Here, the second substrate 12 or the flat plate portion 30 of the second substrate 12 'is preferably formed to have a sufficient thickness to withstand the vacuum compression force, for example, a thickness of 10 to 30mm. On the other hand, since the vacuum compressive force is not applied to the first substrate 10 positioned across the inside of the vacuum container 2, the first substrate 10 has a thickness smaller than that of the second substrate 12, for example, 1 to 3 mm. It may be formed.

The first substrate 10 is a substrate in which various driving electrodes for controlling on / off of electron emission, electron emission amount, and electron beam path are provided together with an electron emission part, and an insulating layer for insulating between the electron emission part and the electrodes and the electrodes. The high temperature heat treatment process is performed in the process of forming the back. At this time, the first substrate 10 having a thickness of 1 to 3 mm as described above has a small thermal stress in spite of a sudden change in temperature, thereby preventing cracking and advantageously increasing the film formation characteristics of the electron emission unit 18. Works.

The reinforcing substrate 14 forming the outer shape of the vacuum container 2 in place of the first substrate 10 has a recess 32 and a sidewall 34 formed on an opposite surface with the first substrate 10 to form a first shape. A second area 200 surrounded by the substrate 10 and the reinforcement substrate 14 is provided. One surface of the sidewall 34 facing the first substrate 10 may be provided with a second adhesive layer 36 in whole or in part to form a bonding surface of the first substrate 10 and the reinforcing substrate 14.

The reinforcing substrate 14 is formed to have a thickness greater than that of the first substrate 10 in consideration of the vacuum compressive force applied to the reinforcing substrate 14. Has The reinforcing substrate 14 includes an exhaust port 38 and an exhaust pipe 40 used to exhaust the inside of the container, and a getter (not shown) for adsorbing residual gas after exhaust to increase the degree of vacuum. The exhaust port 38 and the exhaust pipe 40 may be located at the center of the reinforcing substrate 14.

The reinforcing substrate 14 described above basically provides a second region 200 in communication with the first region 100 behind the first substrate 10 while maintaining the appearance of the flat plate. Accordingly, the reinforcing substrate 14 effectively contributes to reducing the depth of the vacuum vessel 2. In addition, the reinforcing substrate 14 has the effect of reducing the vacuum stress by increasing the edge thickness due to the sidewalls 34, and reducing the weight of the reinforcing substrate 14 by reducing the thickness of the central portion due to the recesses 32.

In the present exemplary embodiment, the vacuum container 2 forms the second region 200 in communication with the first region 100 to enlarge the internal volume, so that the first substrate 100 does not have to have a spacer in the first region 100. It is possible to secure a stable structure while keeping the distance between the 10 and the second substrate 12 constant. In addition, the vacuum vessel 2 can increase the initial vacuum degree by the enlarged internal volume, and can ensure excellent product characteristics by compensating for the decrease in the vacuum degree due to outgassing.

In the present embodiment, the first substrate 10 forms the heat absorption film 42 on the whole or part of the surface facing the reinforcing substrate 14. The heat absorbing layer 42 serves to suppress crack generation due to temperature difference between the first substrate 10, the second substrate 12, and the reinforcing substrate 14 when the vacuum container 2 is sealed using the frit.

More specifically, the vacuum vessel 2 applies glass frit between the first substrate 10 and the second substrate 12 and between the first substrate 10 and the reinforcing substrate 14 to maintain vacuum tightness. Then, the glass frit is melted in a firing furnace at about 400 ° C. to 500 ° C. to seal the substrates integrally, and the interior space is evacuated and the exhaust pipe 40 is sealed.

In this case, in the case of the first substrate 10, the driving electrodes provided to the electron emission unit 18 are usually formed of a metal film such as chromium (Cr) or aluminum (Al), and the metal films serve as a heat reflecting film during glass frit firing. do. As a result, the metal films delay the temperature rise of the first substrate 10, but the heat absorbing film 42 raises the temperature of the first substrate 10 to increase the temperature of the first substrate 10 during the firing process. The substrate 12 and the reinforcing substrate 14 are matched in the same manner.

Therefore, the vacuum container 2 of the present embodiment can suppress the occurrence of cracks due to the temperature difference of the substrates during the firing process. In addition, when the heat absorbing film 42 is not provided, a firing time of 10 hours or more is required because the temperature rise and fall during firing should be maintained at about 1 ° C./min in order to suppress crack generation. In the present embodiment provided with the present invention, the amount of temperature change per minute can be greater than 1 ° C., so that the firing time can be shortened.

The heat absorption film 42 may be made of a carbon-based material such as graphite, or may be made of a metal oxide film such as chromium oxide or aluminum oxide. As the manufacturing method of the heat absorption film 42, screen printing, sputtering, spray coating, etc. can be applied.

Meanwhile, in the present exemplary embodiment, the sidewall 34 of the reinforcing substrate 14 may have a width larger than that of the support frame 24 positioned between the first substrate 10 and the second substrate 12. In consideration of the stress distribution applied to (14), it may be formed to have a maximum width at the center of the long side and the short side of which the relatively large stress is applied, and to have a minimum width at the diagonal corner where the relatively small stress is applied. This varies the application area of the second adhesive layer 36 along the edge of the reinforcing substrate 14 to reduce the stress difference applied to the reinforcing substrate 14.

In particular, the side wall 34 has a width that gradually decreases toward the diagonal corner portion at the center of the long side portion and the short side portion of the reinforcing substrate 14. Such a gentle width change serves to suppress a sudden change in strength along the edges of the first substrate 10 and the reinforcing substrate 14 to make the stress distribution of the two substrates uniform.

In addition, through holes 16 are positioned in the first substrate 10 outside the electron emission unit 18, for example, at diagonal corners of the first substrate 10. The shape of the sidewalls 34 of the substrate 14 may correspond to the sidewalls 34 rather than the recesses 32. In the present embodiment, the side wall 34 of the reinforcing substrate 14 forms a communication groove 44 extending from the point corresponding to the through hole 16 toward the recess 32, and communicates with the through hole 16. The first region 100 and the second region 200 communicate with each other through the groove 44.

The above-described vacuum vessel is an image display device using a cold cathode as an electron source, for example, a field emitter array (FEA) type or a surface-conduction emission (SCE) type electron. Suitable for emission display devices. 4 and 5, a case where the above-described image display device is applied to a field emission array (FEA) type electron emission display device will be briefly described.

4 and 5, the electron emission unit 46 provided on the first substrate 10 may include cathode electrodes 48 and gate electrodes 50, cathode electrodes 48 and gate electrodes. A first insulating layer 52 positioned between 50 to insulate the two electrodes, electron emission portions 54 electrically connected to the cathode electrodes 48, and positioned on the gate electrodes 50. The focusing electrode 56 includes a second insulating layer 58 positioned between the gate electrodes 50 and the focusing electrode 56 to insulate the two electrodes.

The first insulating layer 52 and the gate electrodes 50 form openings 521 and 501 corresponding to the electron emission portions 54 and expose the openings 521 and 501, and the second insulating layer 58 and the focusing electrode 56 are exposed. ) May form one opening 581 and 561 for each intersection region of the cathode electrode 48 and the gate electrode 50.

The electron emission unit 54 may be made of materials that emit electrons when an electric field is applied in a vacuum, such as a carbon-based material or a nanometer-sized material. The electron emission unit 54 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, C ₆₀ , silicon nanowires, and combinations thereof. 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).

The above-described heat absorbing layer 42 is positioned on the rear surface of the first substrate 10.

The light emitting unit 60 provided on the second substrate 12 is positioned between the red, green, and blue fluorescent layers 62R, 62G, and 62B, and each of the fluorescent layers 62 to increase the contrast of the screen. A layer 65 and an anode electrode 66 formed over the fluorescent layer 62 and the black layer 64 are included. The anode electrode 66 may be formed of a metal film such as aluminum, and reflects the visible light emitted toward the first substrate 10 among the visible light emitted from the fluorescent layer 62 toward the second substrate 12 to display the brightness of the screen. Increase

The image display device having the above-described configuration is driven by supplying a predetermined voltage to the cathode electrodes 48, the gate electrodes 50, the focusing electrode 56, and the anode electrode 66 from the outside.

For example, any one of the cathode electrodes 48 and the gate electrodes 50 receives a scan driving voltage to serve as scan electrodes, and the other electrodes receive a data driving voltage to serve as data electrodes. The focusing electrode 56 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 66 is required to accelerate the electron beam, for example, a quantity of several hundred to several thousand volts DC voltage of is applied.

As a result, an electric field is formed around the electron emission part 54 in the pixels in which the voltage difference between the cathode electrode 48 and the gate electrode 50 is greater than or equal to the threshold, and electrons are emitted therefrom. The emitted electrons are focused through the opening 561 of the focusing electrode 56 to the center of the electron beam bundle, and are attracted by the high voltage applied to the anode electrode 66 to impinge on the fluorescent layer 62 of the corresponding pixel to emit light. Let's do it.

In the above, the field emission array (FEA) type electron emission display device has been described as an example of the image display device. However, the present invention is not limited to the FEA type electron emission display device. It is also easily applicable to the device.

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 can secure a stable structure by keeping the distance between the first substrate and the second substrate constant without providing a spacer in the first region, and improve the initial vacuum degree to provide excellent product characteristics. It can be secured. In addition, the image display device according to the present invention can reduce the temperature difference of the substrates during the glass frit firing to suppress crack generation and shorten the firing time.

Claims (10)

A first substrate, a second substrate forming a first region together with the first substrate and positioned in front of the first substrate, and a reinforcement substrate formed behind the first substrate and forming a second region together with the first substrate A vacuum container comprising a; An electron emission unit provided on one surface of the first substrate; A heat absorption film formed on the other surface of the first substrate; And A light emitting unit provided on one surface of the second substrate, And the first substrate forms at least one through hole for communicating the first region and the second region with each other in the vacuum container. The method of claim 1, And the heat absorbing film is made of a carbon-based material. The method of claim 1, An image display device in which the heat absorption film is made of a metal oxide film. The method of claim 1, And a support frame positioned between the first substrate and the second substrate. The method of claim 4, wherein And said reinforcing substrate forming recesses and sidewalls on the opposite surface of said first substrate. The method of claim 5, And the side wall has a maximum width at the center of the long side portion and a short side of the reinforcement substrate, and has a minimum width at the diagonal corner of the reinforcement substrate. The method of claim 5, And the side wall has a width larger than that of the support frame. The method of claim 7, wherein And a through-hole of the first substrate corresponding to the sidewall of the reinforcing substrate, and forming a communication groove extending from the point corresponding to the through-hole toward the recess. The method of claim 1, And the second substrate and the reinforcement substrate have a thickness greater than that of the first substrate. The method of claim 1, And the electron emission unit includes electron emission portions made of a cold cathode electron source.

Images