KR20060060479A - Image display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device having a vacuum structure for maintaining an electron emission portion and a region in which a fluorescent layer is located at even intervals without embedding a spacer, wherein the image display apparatus according to the present invention is provided with an electron emission portion. A first substrate, 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 a first region disposed behind the first substrate and together with the first substrate And a vacuum structure having a reinforcing member forming a second region in communication with each other. In this case, the second substrate integrally forms a sidewall extending toward the first substrate along the edge of the surface opposite to the first substrate.

Vacuum structure, substrate, sidewalls, electron emitting portion, fluorescent layer, anode electrode, reinforcing member, reinforcing substrate

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.

FIG. 2 is a bottom view of the second substrate shown in FIG. 1.

3 is a perspective view of the image display device illustrated in FIG. 1 as viewed from the rear.

4 is a right side view of the second substrate illustrated in FIG. 3.

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

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

7 is a sectional view of an image display device according to a fourth embodiment of the present invention.

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 device, and more particularly, to an image display device having a vacuum structure that maintains an area where an electron emission portion and a fluorescent layer are located at uniform intervals 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.

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, the conventional plate-like structure is arranged sidewalls at the edge portion between the front substrate and the rear substrate. This sidewall is bonded to the two substrates by frits, which are low melting glass. However, the structure has a disadvantage in that the manufacturing process is complicated because the process of manufacturing the sidewalls by a separate process from the two substrates, applying a frit to the upper and lower surfaces of the sidewalls, and then softening them to bond the two substrates and the sidewalls. In addition, since two frit layers exist between the front substrate and the rear substrate, even a small thickness change of the frit layer during the bonding process causes non-uniformity of the gap between the two substrates, which leads to display quality degradation.

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 manufacture, to increase the initial vacuum degree to compensate for the deterioration of the vacuum degree by the gas discharge, vacuum It is to provide an image display device that can secure the uniformity of the distance between the front substrate and the rear substrate while simplifying the structure and assembly of the structure.

The image display device of the present invention for achieving the above object is a second substrate provided with an electron emitting portion, and a fluorescent layer is provided and disposed in front of the first substrate to form a first region together with the first substrate And a vacuum structure having a substrate and a reinforcing member disposed behind the first substrate to form a second region with the first substrate to communicate with the first region. In this case, the second substrate integrally forms a sidewall extending toward the first substrate along the edge of the surface opposite to the first substrate.

In addition, the image display device of the present invention for achieving the above object is a first substrate provided with an electron emitting portion, and 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 reinforcing substrate having a thickness greater than that of the first substrate and attached to a rear surface of the first substrate and forming a vacuum structure together with the first substrate and the second substrate. In this case, the second substrate integrally forms a sidewall extending toward the first substrate along the edge of the surface opposite to the first substrate.

The second substrate includes a terminal region extending outside the sidewall and an anode pad portion provided in the terminal region. At least one opening is formed in the side wall contacting the terminal region, and an anode pad portion is formed through the opening. The second substrate may also form a recess for assembly with the upper cabinet along the outer surface edge.

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 a first embodiment of the present invention, and FIG. 2 is a perspective view of the image display device shown in FIG.

Referring to FIGS. 1 and 2, the image display apparatus is disposed to face each other, and includes a first substrate 2 and a second substrate 4 forming a first region 100 therebetween, and a first substrate 2. It is provided with a vacuum structure (8) made of a reinforcing member (6) attached to the rear of the and forming a second region (200) together with the first substrate (2).

The first region 100 and the second region 200 mean a space divided by the first substrate 2 in the vacuum structure 8, and the first substrate 2 in the vacuum structure 8. The through hole 2a is formed in 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 10. The second substrate 4 is provided with a configuration, that is, a fluorescent screen 12, which emits visible light by electrons to perform any light emission or display.                     

The second substrate 4 integrally forms a side wall 4a extending toward the first substrate 2 along the edge of the surface opposite to the first substrate 2. The side wall 4a is bonded to the first substrate 2 by frit, which is low melting glass, and in the drawing, reference numeral 14 denotes a first frit layer for bonding the first substrate 2 and the side wall 4a. . As a result, the distance between the second substrate 4 and the first substrate 2 is determined according to the height of the sidewall 4a, and the second substrate 4 is bonded to the first substrate 2 in one bonding process.

The integrated structure of the second substrate 4 and the side wall 4a is easy to manufacture since the process of separately manufacturing the second substrate 4 and the side wall 4a and bonding them is easy, and the two substrates 2 and 4 It is possible to maintain a substantially uniform interval between the () to ensure a stable display quality.

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 6 forming the outline of the vacuum structure 8 is attached to the back of the first substrate 2 in place of the first substrate 2, and is surrounded by the first substrate 2 and the reinforcing member 6. 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 6 may be attached to the first substrate 2 by a frit, in which the reference numeral 16 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. The reinforcing member 6 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.

As described above, the vacuum structure 8 forms the second region 200 communicating with 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 having a spacer in the region 100, and a stable structure can be ensured.

And the vacuum structure 8 of the present embodiment can increase 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 the gas is released from the materials constituting the electron emitting means 10 or the fluorescent screen 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.

1 and 2 illustrate a case in which the reinforcing member 6 is composed of two or more opposite surfaces, that is, a concave curved surface concave toward the first substrate 2 and a convex curved 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 total length of the vacuum structure (8).

In the present embodiment, the fluorescent screen 12 is a fluorescent layer, for example, red, green, and blue fluorescent layers 22R, 22G, 22B positioned at arbitrary distances from each other, and each of the fluorescent layers 22R, 22G, 22B) to the black layer 24 which increases the contrast of the screen, and to the anode electrode 26 of the metal (for example, aluminum) formed on the fluorescent layers 22R, 22G, 22B and the black layer 24. Is done.

The anode electrode 26 is made of a metal film by deposition, not a transparent electrode layer such as indium tin oxide (ITO). The anode electrode 26 is applied with a high voltage of several tens of kV so that the electrons emitted from the electron emission means 10 are well accelerated toward the fluorescent layers 22R, 22G and 22B, and the fluorescent layers 22R, 22G and 22B. ) Reflects the visible light emitted toward the anode electrode 26 toward the second substrate 4 to increase the brightness of the screen.

3 is a bottom view of the second substrate shown in FIG. 2, and FIG. 4 is a right side view of the second substrate shown in FIG. 3.

3 and 4, the second substrate 4 extends the terminal region 4b to the outside of the side wall 4a and forms an anode pad portion 28 in the terminal region 4b. The anode pad portion 28 penetrates through the opening 4c provided in the side wall 4a and is formed inside and outside the vacuum structure 8, and one end inside the vacuum structure 8 contacts the anode electrode 26. One end of the outer side of the vacuum structure 8 contacts an external circuit device (not shown), receives an anode voltage therefrom, and transmits the anode voltage to the anode electrode 26.

In this case, at least one opening 4c corresponding to the number of the anode pads 28 is provided at a portion of the side wall 4a that is in contact with the terminal region 4b, and a frit is applied to the opening 4c to seal it. In the figure, reference numeral 30 denotes a third frit layer that seals the opening 3c.

As shown in Fig. 5, the second substrate 4 forms a recess 4d along the outer surface edge. The front cabinet 32 is engaged with the recessed portion 4d, and the front cabinet 32 forms an outer surface parallel to the outer surface of the second substrate 4 so as not to protrude forward of the second substrate 4. The image display device having the concave portion 4d and the front cabinet 32 has the advantage of further increasing the flatness of the screen by forming the vacuum structure 8 'and the front cabinet 32 in a completely planar structure.

Meanwhile, the reinforcing member 6 may be formed in the shape shown in FIG. 6 in addition to the shape described above. Referring to FIG. 6, the reinforcing member 34 includes an opposing portion 34a disposed at a predetermined distance from the rear surface of the first substrate 2 and arranged in parallel thereto, and the first substrate 2 from an edge of the opposing portion 34a. It is made of a skirt portion 34b extending toward the back and attached to the rear surface of the first substrate (2). In this case, it is preferable that the skirt portion 34b is formed to have a height greater than that of the side wall 4a so that the second region 200 has a larger volume than the first region 100.

In addition, a reinforcement substrate may be provided on the rear surface of the first substrate 2 instead of the reinforcement members 6 and 34 described above. Referring to FIG. 7, a reinforcement substrate 36 is attached to the rear surface of the first substrate 2 to form a vacuum structure 8 ″ together with the first substrate 2 and the second substrate 4. 36 is formed to have a thickness greater than that of the first substrate 2, and after all the film forming processes are completed on the first substrate 2, it is attached to the outside of the first substrate 2.

The first substrate 2 and the reinforcement substrate 36 have an overall thickness of at least 10 mm, preferably at least 15 mm. The reinforcing substrate 36 is bonded to the back surface of the first substrate 2 by frits, and in the drawing, reference numeral 38 denotes a second frit layer for bonding the first substrate 2 and the reinforcing substrate 36.

As shown in FIGS. 7 and 8, the reinforcing substrate 36 may be formed in a shape having a lattice-shaped protrusion 36b by forming a plurality of recesses 36a having a rectangular 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 substrate 36 exhibits a similar strength characteristic to that of the flat reinforcement substrate, thereby reducing the weight of the reinforcement substrate 36 to reduce the weight of the image display device.

The reinforcement substrate 36 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, abrasion resistance, heat resistance, cold resistance, chemical resistance, and electrical insulation. Among various kinds of engineering plastics, thermoplastic polyamide resin may be used as the reinforcing substrate 36.

The vacuum structure 8 ″ is provided with an exhaust port for exhausting an internal space. For example, as illustrated in FIG. 7, exhaust ports 2b and 36c may be formed in the first substrate 2 and the reinforcement substrate 36. In this case, the exhaust port 2b is located on the first substrate 2 in a region where the electron emission means 10 is not provided, that is, an ineffective region, and 40 denotes an exhaust pipe in the drawing.

Next, 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 42 are formed on the first substrate 2 in a stripe pattern along one direction (y-axis direction of the drawing) of the first substrate 2, and cover the cathode electrodes 42. In addition, the insulating layer 44 is formed on the entire first substrate 2. Gate electrodes 46 are formed in a sprite pattern on the insulating layer 44 in a direction orthogonal to the cathode electrode 42 (the x-axis direction in the drawing).

At least one openings 46a and 44a are formed in the gate electrode 46 and the insulating layer 44 at each intersection region of the cathode electrode 42 and the gate electrode 46 to expose a part of the surface of the cathode electrode 42. The electron emission part 48 is formed on the exposed cathode electrode 42.

The electron emission unit 48 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 48 include any one of carbon nanotubes, graphite, graphite nanofibers, diamond, diamond-like carbon, C ₆₀ and silicon nanowires, or a combination thereof, and electron emitter 48 ), 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 46 is positioned above the cathode electrode 42 with the insulating layer 44 interposed therebetween is also described. However, the case where the gate electrode is positioned below the cathode electrode with the insulating layer interposed therebetween. It is possible.

The fluorescent screen 12 having the above-described configuration is formed on one surface of the second substrate 4 facing the first substrate 2.

When a predetermined driving voltage is applied to the cathode electrode 42 and the gate electrode 46, an electric field is formed around the electron emission part 48 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 26 to the second substrate 4 and collide with the fluorescent layers 22R, 22G and 22B of the 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 26, so that screen brightness and color reproducibility 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, 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, the image display device according to the present invention increases the dimensional accuracy of the vacuum structure by the integral structure of the second substrate and the side wall, and further enhances the flatness of the screen by preventing the front cabinet from protruding toward the front of the second substrate.

Claims (13)

A first substrate provided with an electron emitting portion, 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 a first substrate disposed behind the first substrate And a vacuum structure having a reinforcing member forming a second region in communication with the first region. And the second substrate integrally forms a sidewall extending toward the first substrate along an edge of the surface opposite to the first substrate. A first substrate provided with an electron emission section; 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 reinforcing substrate having a thickness greater than that of the first substrate and attached to a rear surface of the first substrate and forming a vacuum structure together with the first substrate and the second substrate, And the second substrate integrally forms a sidewall extending toward the first substrate along an edge of the surface opposite to the first substrate. The method according to claim 1 or 2, And a terminal region in which the second substrate extends outside the sidewall, and an anode pad portion provided in the terminal region. The method of claim 3, At least one opening is formed in a sidewall contacting the terminal region, and the anode pad portion is formed through the opening. The method according to claim 1 or 2, And the second substrate forms a recess for assembly with the upper cabinet along the outer surface edge. 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 of the reinforcing member forming a partial spherical surface convex toward the first substrate, and a body portion connecting the first substrate with a concave curvature toward the first substrate. The method of claim 1, And an opposing portion in which the reinforcing member is disposed parallel to the rear surface of the first substrate at an arbitrary distance, and a skirt portion extending from the edge of the opposing portion toward the first substrate. The method of claim 2, And the reinforcing substrate forms a lattice projection on its outer surface. The method of claim 2, And the reinforcing substrate is formed of any one of glass and engineering plastic. The method according to claim 1 or 2, An image display device, wherein the electron emission portion is a cold cathode electron source.

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