KR20060060478A - Image display device - Google Patents

Abstract

The present invention relates to an image display apparatus which improves the shape of the exhaust port and can maintain the region where the electron emission portion and the fluorescent layer are located at uniform intervals without embedding a spacer, and the image display apparatus according to the present invention provides electron emission. An additionally provided first substrate, a second substrate provided with a fluorescent layer and disposed in front of the first substrate to form a first region with the first substrate, and a rear substrate disposed behind the first substrate, together with the first substrate And a vacuum structure having a reinforcing member forming a second region in communication with the first region. At this time, an exhaust port is formed in the reinforcing member in which at least two portions having different diameters are continuous, and the exhaust pipe is fitted into the exhaust port and joined to the reinforcing member.

Vacuum structure, exhaust port, exhaust pipe, electron emitting part, fluorescent layer, frit, side wall, reinforcing member, reinforcing board

Description

Image display {IMAGE DISPLAY DEVICE}

1 is a partially enlarged cross-sectional view of a vacuum structure in an image display apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of the vacuum structure part shown in FIG. 1. FIG.

3 is a partially enlarged cross-sectional view of a vacuum structure showing a modification of the exhaust port.

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

FIG. 5 is a perspective view of the image display device shown in FIG. 4 viewed from the rear. FIG.

6 is a cross-sectional view of an image display device showing a modification of the reinforcing member.

7 is a sectional view of an image display device showing a modification of the vacuum structure.

8 is a partially enlarged perspective view of the reinforcing substrate shown in FIG. 7.

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 apparatus, and more particularly, to an image display apparatus capable of improving the shape of an exhaust port and maintaining an area where an electron emitting portion and a fluorescent layer are located at uniform intervals without having a built-in 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. An exhaust port is formed in the vacuum structure, and an exhaust pipe is joined to the outer surface of the structure so as to be connected to the exhaust port, and the inside is exhausted through the exhaust pipe to form a vacuum.

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, the conventional exhaust port is mainly cylindrical, and it is not easy to align the position with the exhaust port when attaching the exhaust pipe. As a result, the conventional image display apparatus may have misalignment such as misalignment of the exhaust port and the center of the exhaust pipe, and it is difficult to accurately control the thickness and coating amount of the frit to which the exhaust pipe is attached. .

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, in the conventional image display apparatus, the initial vacuum degree cannot be increased due to the spacers in the process of exhausting the inside of the structure, and the mounting failure 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 luminance 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.

Therefore, the present invention is to solve the above problems, an object of the present invention is to increase the position alignment of the exhaust port and exhaust pipe and the bonding strength of the exhaust pipe, to form a stable vacuum structure without the built-in spacers to facilitate the manufacture, It is an object of the present invention to provide an image display device capable of compensating for vacuum deterioration due to gas discharge by increasing vacuum degree.

The image display device of the present invention for achieving the above object includes a vacuum structure provided with an electron emitting portion and a fluorescent layer therein. At this time, the vacuum structure includes an exhaust port in which at least two portions having different diameters are continuous, and is fitted with the exhaust port and connected to the vacuum structure.

The vacuum structure includes a first substrate provided with an electron emission unit, a second substrate provided with a fluorescent layer and disposed in front of the first substrate to form a first region together with the first substrate, and disposed behind the first substrate. And a reinforcing member which, together with the first substrate, forms a second region in communication with the first region, wherein the exhaust port is provided.

On the other hand, the vacuum structure includes a first substrate provided with an electron emitting portion, a second substrate having a thickness greater than that of the first substrate and disposed in front of the first substrate and provided with a fluorescent layer, and a thickness greater than the first substrate. And a reinforcing substrate attached to the rear surface of the first substrate, wherein the exhaust port is provided in the first substrate and the reinforcing substrate.

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

1 is a partially enlarged cross-sectional view of a vacuum structure in an image display apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of a portion of the vacuum structure shown in FIG. 1.

1 and 2, the vacuum structure 2 forms an exhaust port 4 in which two portions having different diameters, that is, a small diameter portion 4a and a large diameter portion 4b are continuous. The small-diameter portion 4a of the exhaust port 4 is located toward the inside of the vacuum structure 2, and the large-diameter portion 4b is located toward the outside of the vacuum structure 2. And the exhaust pipe 6 is fitted in the large diameter part 4b of the exhaust port 4, and is joined to the vacuum structure 2 by the frit 8 which is low melting glass.

In this way, the exhaust port 4 is provided with a portion at which the exhaust pipe 6 is fitted to fix its position, that is, a large-diameter portion 4b, to improve the positional alignment of the exhaust port 4 and the exhaust pipe 6. The exhaust port 4 of the above-described shape also facilitates the application of the frit 8 so that the frit 8 has an optimum thickness along the circumference of the exhaust pipe 6, and consequently the exhaust pipe 4 for the vacuum structure 2. Increase the bonding strength of 6).

In addition, the exhaust port 4 may be formed with a protrusion 10 protruding toward the outside of the vacuum structure 2 ′ surrounding the small diameter portion 4a as shown in FIG. 3. The protrusion 10 engages with the inner side of the exhaust pipe 6 and serves to more securely fix the position of the exhaust pipe 6.                     

1 to 3 illustrate the case where the exhaust port 4 is composed of two parts having different diameters, the exhaust port 4 may be composed of two or more parts having different diameters. In addition, although the planar shape of the exhaust port 4 is circular in the figure, the planar shape of the exhaust port 4 is not limited to a circular shape, It can be variously modified.

Next, a detailed shape of the above-described vacuum structure will be described with reference to FIGS. 4 to 8. The shape of the vacuum structure provided with the above-described exhaust port is not limited to the examples below.

4 is a cross-sectional view of an image display device according to an embodiment of the present invention, and FIG. 5 is a perspective view of the image display device shown in FIG.

4 and 5, the image display device includes a first substrate 14 and a second substrate 16 arranged to face each other with the sidewall 12 interposed therebetween to form the first region 100. It is provided with a vacuum structure 2 made of a reinforcing member 18 attached to the rear of the first substrate 14 to form the second region 200 together with the first substrate 14.

The first region 100 and the second region 200 refer to a space divided by the first substrate 14 inside the vacuum structure 2, and may be formed on the first substrate 14 inside the vacuum structure 2. A through hole 14a is formed to allow the first region 100 and the second region 200 to communicate with each other.

More specifically, the first substrate 14 is provided with a configuration for electron emission, that is, electron emission means 20. The second substrate 16 is provided with a configuration for performing any light emission or display that emits visible light by electrons, that is, light emitting means 22.

The first substrate 14 and the second substrate 16 are integrally bonded in a state where the rectangular frame-shaped sidewall 12 is positioned at the edge portion between the two substrates. As a result, a first region 100 surrounded by the first substrate 14, the second substrate 16, and the sidewalls 12 is formed, and the first substrate 14 and the second substrate (according to the height of the sidewall 12) are formed. 16) is determined. The side wall 12 is bonded to the first substrate 14 and the second substrate 16 by a frit, and the reference numeral 24 in the drawing joins the side wall 12 to the first substrate 14 and the second substrate 16. The first frit layer to be shown is shown.

Here, the second substrate 16 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 14 is preferably formed to a thickness smaller than the second substrate 16, for example, 5 mm or less.

Since the first substrate 14 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 14 is preferably 5 mm or less in order to reduce thermal stress of the first substrate 14 due to temperature change to prevent cracking of the first substrate 14 and to increase film formation characteristics.

The reinforcing member 18 forming the outline of the vacuum structure 2 is attached to the rear surface of the first substrate 14 and surrounded by the first substrate 14 and the reinforcing member 18. 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 18 is attached to the first substrate 14 by a frit, and in the figure, reference numeral 26 denotes a second frit layer bonding the first substrate 14 and the reinforcing member 18.                     

It is preferable that the minimum thickness of the reinforcing member 18 is greater than the thickness of the first substrate 14 in consideration of strength characteristics. The exhaust port 4 of the shape mentioned above is formed in this reinforcement member 18, and the exhaust pipe 6 is fitted in the exhaust port 4, and is joined to the reinforcement member 18. As shown in FIG. In addition, a getter 28 may be provided inside the reinforcing member 18 for adsorbing and removing residual gas after exhausting.

As described above, the vacuum structure 2 forms the second region 200 communicating with the first region 100 behind the first substrate 14 by the reinforcing member 18, thereby expanding the internal volume. The gap between the first substrate 14 and the second substrate 16 can be kept constant without having a spacer in the region 100, and a stable structure can be secured.

In addition, the vacuum structure 2 of the present embodiment can enlarge the internal volume to increase the initial vacuum degree to approximately 10 ⁻⁶ Torr or more. If the initial vacuum degree is increased, even if gas is released from the materials constituting the electron emitting means 20 or the light emitting means 22 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 14 is positioned across the inside of the vacuum structure 2 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 14 can be minimized.

4 and 5 illustrate a case in which the reinforcing member 18 is a combination of two or more opposite surfaces, that is, a concave surface concave toward the first substrate 14 and a convex surface toward the first substrate 14.

In this embodiment, the reinforcing member 18 has a central portion 18a that forms a partial spherical surface convex toward the first substrate 14, and a central portion 18a and the first having a concave curvature toward the first substrate 14. It consists of a body portion 18b connecting the substrate 14. This reinforcing member 18 is formed by the concave curvature of the body portion 18b facing the first substrate 14, while ensuring the volume of the second region 200 sufficiently while maintaining the volume of the central portion 18a facing the first substrate 14. Due to the convex curvature, there is an effect of preventing an increase in the depth of the vacuum structure 2.

The reinforcing member 18 of the above-described shape is effective in dispersing the stress by the vacuum compression force, and helps to form a stable vacuum structure. At this time, the exhaust port 4 and the exhaust pipe 6 is located at the center of the central portion 18a so as to minimize the total length of the vacuum structure 2.

The reinforcing member 18 may be formed in the shape shown in FIG. 6 in addition to the shape described above. Referring to FIG. 6, the reinforcing member 30 has an opposite portion 30a disposed parallel to the rear surface of the first substrate 14 at a predetermined distance and the first substrate 14 from an edge of the opposite portion 30a. It is made of a skirt portion (30b) is extended toward the first substrate 14 is attached to the back. In this case, the skirt portion may be formed to have a height greater than that of the side wall 12 so that the second region 200 has a larger volume than the first region 100. The exhaust port 4 and the exhaust pipe 6 of the shape mentioned above are located in the opposing part 30a of the reinforcing member 30.

Meanwhile, a reinforcing substrate may be provided on the rear surface of the first substrate 14 instead of the reinforcing members 18 and 30 described above. Referring to FIG. 7, a reinforcing substrate 32 is attached to the rear surface of the first substrate 14 to form a vacuum structure 2 ′ together with the first substrate 14 and the second substrate 16. The reinforcing substrate 32 is formed to have a thickness greater than that of the first substrate 14, and after all the film forming processes are completed on the first substrate 14, the reinforcing substrate 32 is attached to the outside of the first substrate 14.

The first substrate 14 and the reinforcement substrate 32 have a total thickness of at least 10 mm, preferably at least 15 mm. The reinforcing substrate 32 is bonded to the back surface of the first substrate 14 by frits, and in the drawing, reference numeral 34 denotes a second frit layer for bonding the first substrate 14 and the reinforcing substrate 32.

As shown in FIGS. 7 and 8, the reinforcing substrate 32 may be formed in a shape having a lattice-shaped protrusion 32b by forming a plurality of recesses 32a having a square pattern on the outer surface thereof. On the other hand, although not shown, the reinforcing substrate may be formed of a flat plate having a constant thickness. The lattice-shaped reinforcement board 32 exhibits strength characteristics similar to those of a flat plate reinforcement board, thereby reducing the weight of the reinforcing board 32 to reduce the weight of the image display device.

The reinforcement substrate 32 may be formed of glass or engineering plastic. Engineering plastics are polymer resins having molecular weights of hundreds of thousands to millions, and are excellent in strength, elasticity, impact resistance, wear resistance, heat resistance, cold resistance, chemical resistance, and electrical insulation. Among various kinds of engineering plastics, thermoplastic polyamide resin can be used as the reinforcing substrate 32.

The vacuum structure 2 ′ is also provided with an exhaust port for exhausting the internal space. For example, as illustrated in FIG. 7, an exhaust port 4 communicating with the first substrate 14 and the reinforcing substrate 32 is provided. Can be formed. The exhaust port 4 is located in a region where the electron emission means 20 is not provided, that is, an ineffective region, and the exhaust pipe 6 is fitted to the exhaust port 4 and bonded to the reinforcing substrate 32.

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, cathode electrodes 36 are formed on the first substrate 14 in a stripe pattern along one direction (y-axis direction of the drawing) of the first substrate 14, and cover the cathode electrodes 36. In addition, the insulating layer 38 is formed on the entire first substrate 14. Gate electrodes 40 are formed in a sprite pattern on the insulating layer 38 in a direction orthogonal to the cathode electrode 36 (x-axis 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 addition, 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 gate electrode 40 has the cathode layer with the insulating layer 38 interposed therebetween. (36) It is also possible to locate below.

On one surface of the second substrate 16 facing the first substrate 14, a fluorescent layer 44, for example, red, green, and blue fluorescent layers are formed at random intervals, and the fluorescent layer 44 A black layer 46 is formed to improve the 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 cathode electrode 36 and the gate electrode 40, an electric field is formed around the electron emission part 42 due to the voltage difference between the two electrodes, and electrons are emitted therefrom, and the emitted electrons are emitted. They are attracted by the high voltage applied to the anode electrode 48 to the second substrate 16 and collide with the fluorescent layer 44 of the corresponding pixel to emit light.

At this time, since the vacuum structure is formed to sufficiently endure the vacuum compressive force without providing a supporting structure therein, the distance between the first substrate 14 and the second substrate 16 can be increased to 5 mm 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. Further, the image display device according to the present invention can increase the positional alignment of the exhaust port and the exhaust pipe and the bonding strength of the exhaust pipe by the above-described exhaust port shape.

Claims (14)

It includes a vacuum structure provided with an electron emission portion and a fluorescent layer therein, And the vacuum structure includes an exhaust pipe in which at least two portions having different diameters are continuous, and which is fitted into the exhaust port and joined to the vacuum structure. The method of claim 1, And an exhaust pipe having a small diameter portion positioned toward the inside of the vacuum structure and a large diameter portion positioned toward the outside of the vacuum structure, wherein the exhaust pipe is fitted into the large diameter portion. The method of claim 2, And the projection further enclosing the small diameter portion and protruding toward the outside of the vacuum structure. The method according to any one of claims 1 to 3, The vacuum structure includes a first substrate provided with the electron emission unit, a second substrate provided with the fluorescent layer and disposed in front of the first substrate to form a first region together with the first substrate, and a rear side of the first substrate. And a reinforcing member disposed in the second substrate to form a second region in communication with the first region, wherein the exhaust port is provided in the reinforcing member. The method of claim 4, wherein 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 4, wherein And the second substrate and the reinforcing member have a thickness greater than that of the first substrate. The method of claim 4, wherein And the volume of the second area is greater than or equal to twice the volume of the first area. The method of claim 4, wherein 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 8, And an exhaust port is formed at the center of the center portion. The method of claim 4, wherein And an opposing portion in which the reinforcing member is disposed parallel to the rear surface of the first substrate at a predetermined distance, and a skirt portion extending from the edge of the opposing portion toward the first substrate. The method according to any one of claims 1 to 3, The vacuum structure has a first substrate provided with the electron emitting portion, a second substrate having a thickness greater than that of the first substrate and disposed in front of the first substrate, and provided with the fluorescent layer, and having a thickness greater than that of the first substrate. And a reinforcing substrate attached to a rear surface of the first substrate, wherein the exhaust port is provided to the first substrate and the reinforcing substrate. The method of claim 11, And the reinforcing substrate forms a lattice projection on its outer surface. The method of claim 11, And the reinforcing substrate is formed of any one of glass and engineering plastic. The method of claim 1, An image display device, wherein the electron emission portion is a cold cathode electron source.

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