JP2002117789A - Flat display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat display device capable of preventing display quality from being lowered by charging of a spacer while securing sufficient strength. SOLUTION: A spacer structural body 40 disposed between a face plate 10 and a rear plate 20 is provided with an electrode plate 42, plural first spacers 48 abutting on the rear plate formed on the first main face side of the electrode plate, and plural second spacers 50 abutting on the face plate formed on the second main face side of the electrode plate. The plural second spacers are connected to one first spacer by a connecting part 52 through an opening 46 formed respectively in the electrode plate. Each first spacer is formed so as to have a smaller aspect ratio than the second spacer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display, and more particularly to a flat panel display having a spacer structure including an electrode plate between two opposing substrates.

[0002]

2. Description of the Related Art A flat display device represented by a liquid crystal display device has been widely used in various fields as a display device replacing a cathode ray tube (CRT). However,
The liquid crystal display device has some problems to be improved, for example, the display is not self-luminous, but has a display angle dependency compared to a CRT.

Under such circumstances, development of a self-luminous type flat display device such as a field emission display (FED) or a plasma display (PDP) is being promoted. In particular, FEDs or surface-conduction electron emission displays (SEDs) have been actively researched and developed because they can ensure good display characteristics comparable to CRTs.

[0004]

Normally, in an FED or SED, a face plate and a rear plate are opposed to each other with a predetermined gap therebetween, and a plurality of spacers arranged in the gap are used to face the face plate with respect to the atmospheric pressure. And the rear plate is supported to maintain the above gap.

A structure disclosed in, for example, US Pat. No. 5,846,205 is known as an FED having such a spacer. According to this FED, a grid electrode having a plurality of focusing openings is arranged between the face plate and the rear plate. The grid electrode includes an opening through which the spacer passes, is fixed to the spacer through the opening, and is supported between the two plates. With such a configuration, a spacer having a high aspect ratio and integrated with the grid electrode can be obtained.

However, since it is necessary to insert a plurality of spacers individually into the openings formed in the grid electrodes, the assembling workability is extremely complicated and impractical.

Under such circumstances, the present applicant has proposed a flat panel display device in which a spacer is integrally formed on an electrode plate. It is an object of the present invention to provide a flat display device capable of preventing a decrease in display quality due to the above.

[0008]

In order to achieve the above object, a flat panel display according to the present invention comprises a face plate and a rear plate opposed to each other at a predetermined interval; A spacer structure disposed between the face plate and the rear plate; the electrode plate being located between the face plate and the rear plate, facing the face plate and the rear plate; A plurality of first spacers formed on the surface side; a plurality of second spacers formed on the second main surface side of the electrode plate opposite to the first main surface; A connecting portion that connects the second spacer via a corresponding opening formed in the electrode plate;
It is characterized by having.

Further, another flat display device according to the present invention includes a face plate having a phosphor layer formed on an inner surface thereof;
A rear plate, which is disposed opposite to the face plate with a predetermined gap therebetween and is provided with a plurality of electron-emitting portions for exciting the phosphor layer, and a frame in which the peripheral edges of the face plate and the rear plate are joined to each other; A side wall, and a spacer structure provided between the face plate and the rear plate. The spacer structure is located between the face plate and the rear plate and faces the face plate and the rear plate. An electrode plate, a plurality of first spacers formed on the first main surface side of the electrode plate and respectively in contact with the rear plate; and a second main surface side of the electrode plate facing the first main surface. And a plurality of second spacers, each of which is in contact with the face plate. Spacers, is characterized in that it is connected by a respective connecting portion through an opening formed in the electrode plate.

According to the flat display device configured as described above, the spacer structure includes a plurality of first spacers formed on the first main surface side of the electrode plate and a plurality of first spacers formed on the second main surface side of the electrode plate. It has a plurality of second spacers formed, and a plurality of second spacers are connected to one first spacer via a connecting portion. Therefore, a sufficient structural strength of the spacer structure can be ensured, and a sufficiently large aspect ratio of the second spacer described below can be ensured.
The effect of the charging of the spacer can be reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the flat display device of the present invention is applied to an SED will be described below in detail with reference to the drawings. As shown in FIG. 1, the SED 1 has an effective display area 3 having an aspect ratio of 4: 3 and a diagonal dimension of 36 inches.
It is provided with. The SED 1 includes a rectangular face plate 10 and a rear plate 20 which are arranged to face each other. The peripheral edges of the face plate 10 and the rear plate 20 are joined to each other via a frame-shaped side wall 8 made of a glass material. And constitute a vacuum envelope. The side wall 8 is attached with a low melting point metal or alloy such as frit glass or indium. The internal space of the vacuum envelope is, for example, about 10
It is maintained at a high vacuum of ^-8 Torr.

A spacer structure (described later) having an electrode plate connected between the face plate 10 and the rear plate 12 in the effective display area 3 at a predetermined potential in order to prevent abnormal discharge between the plates. Are arranged. The face plate 10 and the rear plate 12 are supported by the spacer structure against the atmospheric pressure, and a predetermined interval between the plates is maintained at, for example, 1.6 mm.

As shown in FIGS. 1 and 2A, the face plate 10 includes an insulating substrate 11 made of non-alkali glass and a phosphor screen 12 formed on the inner surface of the insulating substrate. I have. Phosphor screen 12
Are striped phosphor layers 13 having red (R), blue (B), and green (G) emission characteristics and arranged at a pitch of 0.6 mm, and a contrast layer disposed between the phosphor layers 13. And a band-shaped light-shielding layer 14 for improving the ratio.

A conductive thin film layer 15 made of aluminum or an alloy thereof is formed on the phosphor screen 12, and a barium (B) layer is formed on the conductive thin film layer 15.
The vapor deposition getter layer 16 of a) is formed. The conductive thin film layer 15 of such a face plate 10 functions as an anode electrode. In addition, the deposition getter layer 16 is provided between the face plate 10 and the rear plate 2 in a vacuum chamber.
Prior to laminating 0, it is formed by depositing a getter material in a vacuum chamber, and a series of steps from deposition of the getter material to sealing is performed in a state of maintaining a vacuum without exposing to the atmosphere. As a result, a high-performance deposition getter layer 16 can be obtained.

As shown in FIGS. 2A and 3, the rear plate 20 is made of an insulating substrate 2 made of non-alkali glass.
And a plurality of scanning electrodes 23 and signal electrodes 2 arranged in a matrix on the inner surface of the insulating substrate 22.
4 and a gate electrode 25 and an emitter electrode 26 extending from the scanning electrode and the signal electrode, respectively, are provided near the intersection of each scanning electrode 23 and the signal electrode 24. .

The gate electrode 25 and the emitter electrode 26 are opposed to each other at a predetermined distance, for example, 50 mm. Further, although not shown, for example, a graphite film has a distance of 5 mm between these electrodes 25 and 26. The surface-conduction type electron-emitting device 27 is thus configured. Note that a protective film 28 is formed on each scanning electrode 23.

A spacer structure 40 is provided between the face plate 10 and the rear plate 20 configured as described above, and supports the face plate and the rear plate with respect to the atmospheric pressure. Hereinafter, this spacer structure 4
0 will be described in detail.

As shown in FIGS. 2A and 3, the spacer structure 40 has an electrode plate 42 arranged to prevent abnormal discharge between the face plate 10 and the rear plate 20. . This electrode plate 42 is 0.1 mm
It is formed of a thick iron-nickel alloy, and its surface is oxidized. Although the thickness of the electrode plate 42 depends on its size, if it is set to a size corresponding to an effective display area having a diagonal dimension of 20 inches or more, 0.1 to 0. Desirably, it is formed to about 25 mm.

It is conceivable that the electrode plate 42 is divided into a plurality of parts in order to secure the ease of manufacture.
It is desirable to use a large-sized electrode plate having a size corresponding to the effective display area 3 as much as possible, since the display adversely affects the display at the boundary.

The electrode plate 42 is arranged between the face plate 10 and the rear plate 20 in parallel with these plates. Each of the electrode plates 42 has a rectangular window 44 of 250 μm × 180 μm for transmitting an electron beam emitted from the surface conduction electron-emitting device 27.
A plurality of the surface conduction electron-emitting devices 27 are formed to face each other. The electrode plate 42 has first and second electrodes to be described later.
A plurality of circular openings 46 for connecting the spacers are formed.

The electrode plate 42 has a first main surface facing the rear plate 20 and a second main surface facing the face plate 10. A plurality of first spacers 48 are formed integrally with the electrode plate 42 on the first main surface side, and a plurality of second spacers 50 are formed integrally with the electrode plate 42 on the second main surface side. I have. The first spacer 48 and the second spacer 50 are connected to the opening 4 formed in the electrode plate 42.
6 are connected by a connecting portion 52 disposed therein. In the present embodiment, two second spacers 50 are connected to one first spacer 48 via connecting portions 52, respectively.

As shown in FIGS. 2 (a), 2 (b) and 3, the first spacers 48 correspond to the respective surface conduction electron-emitting devices 27, and the protective film 28 is formed on the scanning electrodes 23.
And extends along the wiring direction. Each of the first spacers 48 has an oblong cross section, and the electrode plate 4
The length L1 along the wiring direction on the second side is 0.4 mm, the length L2 along the direction perpendicular to the wiring direction is 500 μm, and the length L1 ′ along the wiring direction on the rear plate 20 side is 0.3.
5 mm, the length L2 ′ in the direction orthogonal to the wiring direction is 400
μm and a height h1 of 0.5 mm.

Further, two second spacers 50 are provided for each first spacer 48. Each second spacer 50 is formed in a columnar shape having a slight taper. The diameter φ1 at the end on the electrode plate 42 side is 320 μm, the diameter φ2 at the end on the face plate 10 side is 230 μm, and the height h2 is 1 μm. .0 mm.

That is, in this embodiment, the second spacer 50 has a sufficiently large aspect ratio (ratio between the height and the length of the end on the electrode plate 42 side in the cross-section major axis direction) with respect to the first spacer 48. Is formed. Further, the height of the first spacer 48 is formed to be approximately half the height of the second spacer 50.

Then, two adjacent second spacers 50
Are connected to one first spacer 48 via the opening 46 of the electrode plate 42, that is, via the connecting portion 52, and are integrated with the first spacer 48 and the electrode plate 42. The diameter of the connecting portion 52 and the opening 46 is smaller than the diameter φ1 of the end of the second spacer 50 on the electrode plate 42 side.

The spacer structure 40 thus configured
Is disposed in the vacuum envelope, the electrode plate 42 faces the face plate 10 and the rear plate 20 in parallel, and is connected to a predetermined potential to prevent abnormal discharge between the plates. Further, each first spacer 48 is connected to the rear plate 1 via the protective film 28 and the scan electrode 23.
0, and each of the second spacers 50 is disposed on the deposition getter layer 1.
6, the conductive thin film layer 15, and the phosphor screen 12 contact the face plate 10 so that the face plate 10 and the rear plate 2 are exposed to the atmospheric pressure.
Supports 0.

According to the SED configured as described above,
The first spacer 48 of the spacer structure 40 is disposed close to the surface conduction electron-emitting device 27; and
Since the height is as low as 0.5 mm, the charging of the first spacer 48 does not easily affect the trajectory of the electron beam despite being arranged over a sufficient area along the scanning electrode 23.

On the other hand, the second spacer 50 is
Although it has a sufficient height of 1.0 mm with respect to 8, the aspect ratio is formed sufficiently large, so that the charging of the second spacer 50 also hardly affects the trajectory of the electron beam. In addition, since the first and second spacers 48 and 50 are evenly arranged corresponding to the respective surface conduction electron-emitting devices 27, local display unevenness due to spacer charging hardly occurs.

Furthermore, since the spacer structure 40 is arranged with a sufficient contact area with each of the face plate 10 and the rear plate 20, a sufficient structural strength of the SED can be secured. Therefore, it is possible to obtain an SED that can prevent a decrease in display quality due to the charging of the spacer while securing sufficient strength.

Next, the spacer structure 4 having the above structure
0 will be described. First, as shown in FIG. 4A, an electrode plate 42 made of a 0.1-thick iron-nickel alloy and having its surface oxidized is prepared. Electrode plate 42
The surface is oxidized in order to improve the adhesion to a spacer forming material described later, and it is particularly preferable to form a spinel-type oxide film. In the electrode plate 42, a plurality of windows 44 (see FIG.
And a plurality of openings 46 for connecting the first spacer 48 and the second spacer 50 to each other. These openings 46 are formed using photoetching, laser processing, or the like.

Subsequently, as shown in FIG. 4 (b), after the molds 60, 61 are positioned above and below the electrode plate 42, they are closely attached and fixed by a not-shown clamper or the like. In the figure, a mold 60 arranged on the upper surface side of the electrode plate 42 is shown.
Are a plurality of through holes 62 for forming the second spacer 50.
have. The mold 61 arranged on the lower surface side of the electrode plate 42 has a plurality of through-holes 64 for forming the first spacer 48.

The dies 60 and 61 are made of the same type of iron-iron alloy as the electrode plate 42 and have a thickness of about 0.28 m.
It is formed by laminating four and two metal plates, respectively. This thickness is determined in consideration of a ratio of a solid content of a spacer forming material described later and a desired height of the spacer. The through holes 62 and the openings 64 are formed by laser processing, etching processing, or the like. Further, each through-hole 62 and opening 64 are provided with a mold 60,
61 is formed in a tapered shape as shown in FIG.

The surfaces of the molds 60 and 61 are treated to prevent the molds from peeling off from the spacer forming material and to prevent oxidation of the molds, such as Ni-P and Teflon (registered trademark).
Eutectoid plating of fine particles of nitride, oxide, and carbide is performed. As this oxidation resistance treatment, in addition to the above, Ni
Eutectoid plating of -Co or Ni-P with a high melting point metal such as W, Mo, Re or the like is preferably used.

After positioning the dies 60 and 61 with respect to the electrode plate 42 as described above, the squeegee 68 is used to remove the spacer forming material 66 from the through holes 6 of the die 60.
2 and the opening 64 of the mold 61 are filled. The spacer forming material 66 may be collectively filled into the through-hole 62 of the mold 60 through the opening 64 of the mold 61. In either case, care must be taken to prevent air bubbles from entering the spacer forming material 66 filled in the through hole 62 of the mold 60 and the opening 64 of the mold 61. Through-hole 62 and opening 6
Excess spacer forming material 66 leaked from 4 is wiped off with a squeegee or the like. As the spacer forming material 66, a glass paste containing at least a non-solvent type ultraviolet curable binder and a glass filler as a structural material is used.

Subsequently, as shown in FIG. 4C, the filled spacer forming material 66 is irradiated with ultraviolet (UV) rays from the outer surfaces of the dies 60 and 61 to form the spacer forming material 6.
The ultraviolet curing type binder contained in 6 is sufficiently cured.

Here, as shown in FIG.
Each of the spacers 50 is disposed so as to overlap with the corresponding first spacer 48 in plan view. In particular, the first spacer 48 is also disposed in a region between the corresponding two second spacers 50. The electrode plate 42 has an opening 46 corresponding to the second spacer 50 and having a diameter smaller than the diameter of the end of the second spacer 50 on the electrode plate side.
Therefore, as can be seen from FIG. 4C, the spacer forming material 66 filled in the through hole 62 of the mold 60 is
Despite its high aspect ratio, UV rays can be sufficiently irradiated and penetrated from the upper surface side of the mold 60 and the mold 62 side. Thus, the spacer forming material 66
In this case, a sufficient adhesion to the electrode plate 42 whose surface is oxidized is ensured, and conversely, an appropriate peeling property to the dies 60 and 61 is ensured.

Subsequently, as shown in FIG. 5A, in a state where the molds 60 and 61 are brought into close contact with the electrode plate 42, these are pre-baked in a heating furnace at 400 to 450 ° C. for one hour. This burns out the binder component in the spacer forming material 66. Further, by performing main firing at 500 ° C. for 45 minutes in a heating furnace, the connecting portion 52 formed in the opening 46 is formed.
The first and second spacers 48 and 50 integrally formed on the electrode plate 42 are formed.
The condition of the main firing depends on the size of the spacer and the like.
About 30 to 1 hour at 0 to 550 ° C is suitable.

Thereafter, after cooling to a predetermined temperature while performing strain relief annealing, the molds 60 and 61 are separated from the electrode plate 42 to complete the spacer structure 40 as shown in FIG. I do.

By forming the spacer structure 40 through the above-described steps, the second spacer 50 having a high aspect ratio and formed integrally with the electrode plate 42 can be obtained relatively easily. Productivity can be improved.

That is, according to the above-described embodiment,
By mixing and curing an ultraviolet curable binder in the spacer forming material 66, the adhesive 60 has selectivity with respect to the molds 60 and 61 and the electrode plate 42, and the spacer shape is appropriately secured accordingly. be able to. Accordingly, it is possible to perform firing with the molds 60 and 61 in close contact with the electrode plate 42. In particular, the second spacer 50 extending from the electrode plate 42 to the face plate 10 side
A high aspect ratio of 2.0 or more can be obtained. As a method for giving selectivity to adhesion, a method of mixing an ultraviolet curable binder is useful from the viewpoint of productivity, production cost, and the like, but is not limited thereto.

Further, the second spacer 50 can be sufficiently irradiated with UV rays from the side of the mold 61 for forming the first spacer 48, so that uneven curing of the spacer forming material 66 can be prevented, and the aspect ratio can be reduced. A high second spacer 50 is obtained.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, in the above embodiment, the SED has been described as an example, but the present invention can be applied to other flat display devices such as an FED and a PDP.

In the above-described embodiment, the height of each first spacer 48 is set to about half the height of the second spacer 50. However, it is preferable that the height of each first spacer 48 is smaller than the height of the second spacer 50. Less than half is preferred.

The spacer structure 40 of this embodiment includes one first spacer 48 arranged on the rear plate 20 side.
On the other hand, two second spacers 48 branched into two on the face plate 10 side are connected and arranged. However, three or more second spacers are branched from one first spacer 48. A configuration in which two spacers are connected and arranged may be adopted.
The second spacer 50 disposed on the face plate 10 side preferably has a high aspect ratio and a small overall surface area, since the charging affects the trajectory of the electron beam. Therefore, it is desirable to constitute the second spacer 50 branched into a plurality. In addition, the openings 46 corresponding to the second spacers 50 are each one opening, but may be formed of an aggregate of a plurality of openings.

Although the first spacer 48 has an elliptical cross section, it may have an L-shaped or cross-shaped cross section.

[0046]

As described in detail above, according to the present invention, it is possible to provide a flat panel display device capable of preventing a deterioration in display quality due to spacer charging while securing sufficient strength of the spacer. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an SED according to an embodiment of the present invention.

FIG. 2A is a sectional view taken along line AA in FIG. 1;
FIG. 2B is a schematic plan view of the first and second spacers viewed from the second spacer side.

FIG. 3 is a perspective view schematically showing a part of the spacer structure of the SED.

FIG. 4 is a cross-sectional view showing a step of manufacturing the spacer structure.

FIG. 5 is a cross-sectional view showing a step of manufacturing the spacer structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 8 ... Side wall 10 ... Face plate 12 ... Phosphor screen 20 ... Rear plate 23 ... Scan electrode 24 ... Signal electrode 27 ... Surface conduction electron-emitting device 40 ... Spacer structure 42 ... Electrode plate 46 ... Opening 48 ... First spacer 50 ... Second spacer 52 ... Connecting part

Continuing from the front page (72) Inventor Kumio Fukuda 1-9-2, Hara-cho, Fukaya-shi, Saitama Pref. Inside the Toshiba Fukaya Plant (72) Inventor Satoshi Ishikawa 1-9-9, Harara-cho, Fukaya-shi, Saitama F-term in Toshiba Fukaya Plant (reference) 5C032 AA07 CC10 5C036 EE14 EF01 EF03 EF06 EF08 EG02 EG31 EH01 EH04 EH21 5C094 AA21 AA55 BA21 EA10 EC03 FA01 FA02 FB12 FB20

Claims (7)

[Claims] 1. A face plate and a rear plate, which are opposed to each other at a predetermined interval, and a spacer structure disposed between the face plate and the rear plate. An electrode plate located between the face plate and the rear plate and facing the face plate and the rear plate; a plurality of first spacers formed on a first main surface side of the electrode plate; A plurality of second spacers formed on the second main surface side opposite to the main surface, and one of the first spacers and the plurality of second spacers, via corresponding openings formed in the electrode plate; A flat display device, comprising: a connected connecting portion. 2. The method according to claim 1, wherein the opening provided in the electrode plate corresponding to the first spacer and the opening provided in the electrode plate corresponding to the second spacer are connected to each other. The flat display device according to claim 1, wherein 3. The flat display device according to claim 1, wherein the size of each of the openings is smaller than the size of an end of the second spacer on the side of the electrode plate. 4. The device according to claim 1, wherein the rear plate includes a plurality of electron-emitting portions, and the electrode plate has a plurality of windows provided to face the electron-emitting portions, respectively. 4. The flat panel display according to any one of items 3. 5. The flat panel display according to claim 1, wherein the first spacer has an aspect ratio smaller than that of the second spacer. 6. The flat display device according to claim 5, wherein the height of the first spacer is less than half the height of the second spacer. 7. A face plate having a phosphor layer formed on an inner surface thereof, and a plurality of electron-emitting portions which are opposed to the face plate with a predetermined gap therebetween and excite the phosphor layer are provided. A rear plate; a frame-shaped side wall in which peripheral edges of the face plate and the rear plate are joined to each other; and a spacer structure provided between the face plate and the rear plate. An electrode plate located between the face plate and the rear plate and facing the face plate and the rear plate; a plurality of first spacers formed on the first main surface side of the electrode plate and respectively abutting on the rear plate; A plurality of second switches formed on the second main surface of the electrode plate opposite to the first main surface and in contact with the face plate, respectively. And a plurality of second spacers connected to the one first spacer by connecting portions via openings formed in the electrode plate, respectively. apparatus.