JP2000182543A - Planar display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the strength of spacers and dispose them in a self-supporting manner, stabilize a displayed picture and improve the quality of picture without being affected by the spacers, in the case of a planar display device. SOLUTION: In this planar display device 25, first and second substrates 1, 2 confront each other leaving a required space between them by means of spacers 23, peripheral parts of the first and second substrates 1, 2 are airtightly sealed up to form an airtight flat space between the first and second substrates 1, 2, an electron emitting part is disposed on the side of the first substrate 1, a fluorescent screen is formed on the side of the second substrate 2, and electrons taken out from the electron emitting part are accelerated and irradiated to the fluorescent screen, thereby exciting the fluorescent screen to emit light for display. The spacers 23 are each formed of at least two crossing sheet- like surfaces, and the resistance of the surfaces of the spacer is 109 to 1012 Ω/square.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat panel display utilizing a field electron emission phenomenon.

[0002]

2. Description of the Related Art A conventional flat display device 15 utilizing the field electron emission phenomenon has, for example, first and second glass substrates as shown in a perspective view of FIG. The second substrates 1 and 2 are opposed to each other via a reinforcing spacer 3 with a required interval therebetween,
The peripheral portions of these opposing substrates 1 and 2 are hermetically sealed with, for example, a glass frit via an insulating peripheral frame 14 made of ceramic or the like, so that an airtight flat space is formed between the substrates 1 and 2. The electron emission portion 4 is arranged on the first substrate 1 side, and the phosphor screen 5 is formed on the second substrate 2 side.

On the first substrate 1, a plurality of stripe-shaped first and second electrodes 11 and 12, for example, are respectively arranged in parallel in the direction in which they cross each other. Formed electrically insulated.

[0004] For example, an electron emitting portion 4 is formed corresponding to the intersection of the first and second electrodes 11 and 12, respectively. These electron emitting portions 4 have a cold cathode configuration, and first and second electrodes are provided as shown in FIGS. At the intersection of 11 and 12, a through hole 8 penetrating through the insulating layer 7 and the upper second electrode 12 is formed. In these through holes 8, a conical shape is formed on the lower first electrode 11, for example. The so-called Spindt-type field emission cathode 9 is arranged. In this case, a plurality of cathodes 9 are arranged for one pixel.

A metal back layer 6 of a thin film conductive layer is formed on the fluorescent screen 5 on the second substrate 2 side, and a high accelerating voltage of, for example, 5 KV is supplied to the metal back layer 6.

Then, the first and second electrodes 11 and 12
When a required voltage is applied between the selected electrodes, electrons are taken out from each cathode 9 of the electron-emitting portion 4 disposed at the intersection, and the electrons are accelerated by the above-described acceleration voltage to thereby increase the metal back layer. 6, the fluorescent screen 5 is impacted, and this portion is excited to emit light, thereby performing a desired light emission display, for example, an image display.

In such a flat display device 15, the airtight flat space formed between the first and second substrates 1 and 2 is maintained at a high degree of vacuum. A substantially atmospheric pressure is applied to the first and second substrates 1 and 2. In order to allow the substrates 1 and 2 to withstand the pressure against the atmospheric pressure, for example, a rectangular or circular cross-sectional shape, that is, a thin plate or a columnar reinforcing spacer is interposed, or FIG. As shown, a plurality of reinforcing spacers 3 each made of a long rectangular thin plate are interposed in parallel so that the plate surface direction is orthogonal to the plate surface direction of the substrates 1 and 2.

[0008]

In the above-mentioned flat display device 15, when the spacer 3 is formed of a thin plate or a column, the forming method is simplified, but the spacer 3 is not disposed between the substrates 1 and 2. In addition, it is difficult to stand and stand, and it is difficult to manufacture and assemble a flat display device, for example, it buckles when a load is applied, and cannot obtain strength.

Further, when a long thin plate-like spacer 3 as shown in FIG. 10 is used, it appears as a black line on the screen, and the image quality deteriorates. Long thin plate spacer 3
When this is disposed between the first and second substrates 1 and 2, it is disposed by applying a required tension in the longitudinal direction, but unless the expansion coefficient is equivalent to that of the substrates 1 and 2, During the firing step performed before evacuation, there are problems such as thermal expansion and damage such as cutting, or contact with the fluorescent screen or the like to damage the fluorescent screen or the like. In addition, since the inside of the flat display device is separated by the long thin plate-shaped spacer 3, a slight difference occurs in the degree of vacuum inside the flat display device, resulting in a difference in vertical luminance on the screen.

On the other hand, if the reinforcing spacers 3 are made of an insulator, for example, a ceramic such as alumina for insulation between the electrodes disposed on the substrates 1 and 2, respectively, the reinforcing spacers 3 are radiated from the electron emitting portion 4, Some of the accelerated electrons having high energy collide with the spacers 3 and emit secondary electrons, so that the surface of the spacers 3 is positively and unstablely charged, so that the surface of the spacers 3 should be directed toward the phosphor screen 5. An unstable electric field is applied to the electron path, thereby affecting the electron trajectory, particularly the electron trajectory near the spacer, causing image shift and color shift, resulting in a decrease in image quality.

The present invention has been made in view of the above circumstances, and provides a flat-panel display device which enhances the strength of a spacer, enables self-sustaining, and improves image quality without being affected by the spacer. .

[0012]

In a flat panel display according to the present invention, a first and a second substrate are opposed to each other with a required distance therebetween via a spacer. The periphery of the opposing portion is hermetically sealed to form an airtight flat space between the first and second substrates, the electron emission portion is arranged on the first substrate side, and the second substrate side has an electron emission portion. A flat display device in which a phosphor screen is formed and electrons taken out of the electron emission section are accelerated and irradiated on the phosphor screen, and the phosphor screen is excited to emit light to perform display, wherein the spacer is It is configured to have at least two intersecting thin plate surfaces.

In the configuration of the present invention, since the spacer is formed to have at least two thin plate-like surfaces that intersect,
The strength of the spacer itself is increased, and the spacer can be arranged independently on the substrate.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

FIG. 1 is a perspective view showing a part of a main part of a flat-panel display device utilizing the field electron emission phenomenon according to the present embodiment, and FIG. 2 is a cross-sectional view of the main part. .

The flat display device 25 according to the present embodiment.
The first and second substrates 1 and 2 each formed of, for example, a glass substrate are opposed to each other at a required interval via a reinforcing spacer 23 having a required height. The peripheral portions of the substrates 1 and 2 facing each other are hermetically sealed with, for example, a glass frit (not shown) via an insulating peripheral frame 14 made of ceramic or the like, so that the substrates 1 and 2 are airtightly flat. A space is formed, the electron emission section 4 is arranged on the first substrate 1 side, and the fluorescent screen 5 is formed on the second substrate 2 side.

On the first substrate 1, a plurality of stripe-shaped first and second electrodes 11 and 12, for example, are respectively arranged in parallel in a direction crossing each other. It is formed electrically insulated. The second electrode 12 serves as a so-called electron extraction electrode.

For example, an electron emitting portion 4 having a cold cathode configuration is formed corresponding to each intersection of the first and second electrodes 11 and 12. These electron emitting portions 4
Is composed of, for example, well-known electron-emitting devices. For example, a surface conduction electron-emitting device structure formed by energizing a conductive thin film, or the above-described FIG.
A so-called Spindt-type field emission element (that is, a cathode 9) having a sharp conical shape described in 1A and 1B, or a so-called MIM-type electron emission element having a metal / insulating layer / metal structure. can do. In addition, as shown in FIG.
A plurality of electron-emitting devices (cathodes) 9 can be arranged.

The fluorescent screen 5 on the side of the second substrate 2 has a predetermined arrangement of, for example, red, green and blue phosphors R, G and B when forming a flat display device by color display, for example. The phosphors R, G, B are formed in order.
So-called black matrix 10 having a light absorbing layer between
Is formed.

As shown in FIG. 3, for example, as shown in FIG. 3, a plurality of sets of phosphors (R, G, B) are arranged in a matrix on the color phosphor screen 5 with one set of rectangular phosphors R, G, and B. The black matrix 10 is formed between each set and each color phosphor R, G, B. On the phosphor screen 5, a metal back layer 6 made of a thin film conductive layer having the function of an accelerating electrode is formed, and a high accelerating voltage, for example, 5 KV, is supplied to the metal back layer 6 through an accelerating power supply 26.

Then, with the space between the first and second substrates 1 and 2 kept at a predetermined distance between the first and second substrates 1 and 2, the airtight space between the two substrates 1 and 2 is subjected to an external pressure ( A plurality of reinforcing spacers 23 that are held against atmospheric pressure) are erected at required intervals.

The spacer 23 has at least two intersecting thin plate surfaces. That is, the spacer 23
For example, as shown in FIG. 4, four thin plates are formed in a structure in which the cross sections are orthogonal to each other and form a cross shape (a structure having so-called four thin plate-shaped surfaces). As shown in FIG.
Can be arranged so that the plate surface of the first and second substrates 1 and 2 is orthogonal to the plate surfaces of the first and second substrates 1 and 2.

These cross-shaped spacers 23 have a cross shape.
As shown in FIG. 3, the light-emitting device can stand alone, and is disposed so as to overlap with a non-light emitting portion between the phosphors R, G, and B of the phosphor screen 5, that is, the black matrix 10. This allows
Does not interfere with light emission. Further, the spacers 23 can be arranged at required intervals, for example, at 5 mm intervals.

The spacer 23 having a cross-shaped cross section can be formed of an insulating material. For example, it can be formed using a photo-etchable photosensitive glass. Specifically, a necessary cross-shaped cross-sectional shape is prepared by preparing a required thick plate-shaped photosensitive glass, forming a fine cross-shaped mask pattern on the surface of the photosensitive glass, exposing, and etching. Is obtained. Others
The spacer 13 can be formed by a physical method such as injection molding of a polymer material or bead blasting.

The photosensitive glass is a composition in which the glass itself is easily crystallized to some extent, and a colloid of a metal, for example, lithium is used as a starting point for crystal growth. Microcrystals can be precipitated, and the dissolution rate of this portion in dilute hydrofluoric acid is about 60 times as large as that of a transparent glass portion. Utilizing this property, it becomes possible to form cuts, holes, grooves, and the like in a glass plate by photoetching, which are difficult to machine by machining. The ratio of the plate thickness to the minimum processing hole diameter is 10
It is said to reach as many as 20. This photosensitive glass is a photosensitive glass having a so-called positive type property. Furthermore, when this photosensitive glass is exposed to light over the entire surface and heated at a temperature higher than the temperature at which lithium monosilicate crystals precipitate,
Fine crystals of lithium disilicate precipitate throughout the glass,
It is three times stronger than glass. Further, if the glass sheets are stacked and heated, they can be fused simultaneously with crystallization (so-called self-fusion), so that a tunnel having a complicated shape or a multilayer structure can be formed (Reference: Glass Arroyo / HOYA).
(Ed./Toyo Keizai Shimpo).

The spacer 23 can be configured so that its surface has a resistance of 10 ⁹ Ω / □ to 10 ¹² Ω / □. For example, as shown in FIG. 2, the spacer 23 has a resistance value of 10 ⁹ to 1 on the surface of the insulating spacer body 231.
A structure in which a high resistance coating 232 of 0 ¹² Ω / □ is formed can be employed. The method of forming the high resistance film 232 is to form a metal or metal oxide film by a method such as sputtering, and then oxidize the film in a furnace or the like. Examples of the metal used include Ni, Cr, and Ti. In addition, the high resistance film 232 can be formed by, for example, a wet coating.

The spacer 23 is formed as shown in FIG.
As shown in FIG.⁹-10 ¹²Ω / □
Alternatively, it can itself be formed of a high resistance material.

A conductive film 22 of, for example, Al or Cr is formed on both end surfaces of the spacer 23. With the spacer 23 sandwiched between the substrates 1 and 2, these conductive films 22 are formed. For example, it is electrically connected to the metal back layer 6 and the second electrode 12 constituting the electron emission section 4.

The conductive film 22 can be formed by, for example, a method such as sputtering or a wet coating method.

The shape of the spacer 23 can be any of various shapes that can be self-supporting, except that the cross section of FIG. 4 has a cross shape. That is, as the spacer 23, for example, as shown in FIG. 7, an L-shaped structure (a structure having two thin plate-like surfaces) whose cross sections are orthogonal to each other can be formed. As shown in the figure, it is also possible to form an H-shaped structure (a so-called thin plate-like structure having three surfaces) whose cross sections are orthogonal to each other.

In the same manner as described above, the spacer 23 having an L-shaped cross section shown in FIG. 7 is formed by exposing and etching using photosensitive glass, a physical method such as injection molding of a polymer material, and bead blasting. Alternatively, it can be formed by heating and bending a thin glass plate. Similarly, the spacer 23 having an H-shaped cross section in FIG. 8 is formed by a physical method such as exposure and etching using photosensitive glass, injection molding of a polymer material, and bead blasting, similarly to the above. be able to.

Other configurations and arrangements of the spacer 23 shown in FIGS. 7 and 8 are the same as those of the spacer 23 shown in FIGS.

Each of the spacers 23 in the above example has a configuration in which the thin plate-shaped surfaces are orthogonal to each other, but may alternatively have a configuration in which the spacers intersect at a required angle.

Also in the flat display device 25 according to the present embodiment, a predetermined voltage is applied between selected ones of the first and second electrodes 11 and 12 so as to be arranged at the intersection. Electrons from the electron-emitting portion 4
This is accelerated by the above-mentioned accelerating voltage, penetrates through the metal back layer 6 and impacts the phosphor screen 5 to excite this portion to emit light, thereby performing a desired light emission display, for example, an image display.

The control circuit 27 is connected to the second electrode 12.
And a control voltage is supplied through the
About 0 V is supplied. A cathode voltage is supplied to the first electrode 11 through the scanning circuit 28, and for example, 0 V is supplied at the time of selection.

According to the flat display device 25 according to the present embodiment, the spacer 23 is formed in a structure having at least two thin plate-shaped cross sections such as a cross, an L or an H, for example. By doing so, it becomes possible to stand alone. Accordingly, in the manufacturing and assembling steps, by arranging the spacer 23 independently between the first and second substrates, even if the spacer 23 and the substrates 1 and 2 have different coefficients of thermal expansion, the vacuum evacuation is performed. Spacer 23 during previous firing
However, there is no problem such as damage due to a difference in thermal expansion or damage to the fluorescent screen 5. The spacer 23 itself does not easily buckle even when a load is applied, and has sufficient strength. Further, workability in the assembly process of the spacer 23 is also improved.

The required high resistance (10
By imparting a conductivity of ⁹ to 10 ¹² Ω / square), electrons are bombarded by the spacers 23 to prevent secondary electrons from being charged. Also,
By forming a conductive film 22 on both end surfaces of the spacer 23 and electrically connecting the conductive film 22 to the metal back layer 6 and the second electrode 12 constituting the electron-emitting portion 4,
Potential non-uniformity in the airtight flat space can be suppressed.

Therefore, the accelerated electrons are irradiated to a desired position on the phosphor screen 5 without affecting the trajectory of the electrons by the spacers 23, and a screen free from image shift and color shift is obtained. Can be stabilized and the image quality can be improved.

Since the spacers 23 are fine, they can be arranged on the black matrix 10 regardless of the expansion coefficient.

[0040]

According to the flat display device of the present invention,
By forming the spacer to have at least two thin plate-like surfaces that intersect, the spacer can stand alone and can have sufficient strength without buckling even when subjected to a load.

Therefore, in the manufacturing and assembling steps of the flat panel display device, even if the expansion coefficients of the spacer and the first and second substrates are different, the spacer may be damaged by thermal expansion during firing, or the fluorescent screen or the like may be damaged. Can be prevented from being injured by contact with the substrate, thereby improving manufacturing workability and manufacturing yield.

The resistance of the surface of the spacer is 10 ⁹ -10 ¹² Ω
In the case of / □, it is possible to prevent electrification due to impact of electrons on the spacer and generation of secondary electrons, so that disturbance of the electric field due to this electrification can be avoided, and the electron orbit near the spacer can be prevented. And the display screen can be stabilized and the image quality can be improved.

Further, when a conductive film is formed on the surface of the contact portion between the spacer and the accelerating electrode and the electron emitting portion, potential non-uniformity in the airtight flat space is hardly generated, that is, from the electron emitting portion. A so-called uniform electric field in which the potential changes uniformly toward the accelerating electrode can be obtained, and the display screen can be stabilized and the image quality can be improved without affecting the electron trajectory.

[Brief description of the drawings]

FIG. 1 is a perspective view, partially in section, of a main part showing an embodiment of a flat panel display according to the present invention.

FIG. 2 is a sectional view of a main part of an embodiment of the flat panel display according to the present invention.

FIG. 3 is a plan view of a main part showing an arrangement relationship between a phosphor screen and spacers in one embodiment of the flat panel display according to the present invention.

FIG. 4 is a configuration diagram showing an embodiment of a spacer according to the present invention.

FIG. 5 is a perspective view showing an arrangement of spacers in one embodiment of the flat panel display according to the present invention.

FIG. 6 is a sectional view of a main part of another embodiment of the flat panel display according to the present invention.

FIG. 7 is a configuration diagram showing another embodiment of the spacer according to the present invention.

FIG. 8 is a configuration diagram showing another embodiment of the spacer according to the present invention.

FIG. 9 is a perspective view in which a part of a main part of a conventional flat display device is sectioned.

FIG. 10 is a perspective view showing a spacer arrangement of a conventional flat panel display device.

FIG. 11 is a perspective view showing an electron emission unit of the flat panel display device. B It is sectional drawing of the principal part.

[Explanation of symbols]

1,2 substrate, 3,23 spacer, 4 electron emitting part, 5 phosphor screen, 6 metal back layer, 11 layer
First electrode, 12 {second electrode, 15, 25} flat display device, 231 {insulating spacer body, 232}
{High resistance film, 22} Conductive film

Claims (7)

[Claims] The first and second substrates are opposed to each other via a spacer with a required space therebetween, and the periphery of the opposed portion of the first and second substrates is hermetically sealed. An airtight flat space is formed between the first and second substrates, an electron emission portion is arranged on the first substrate side, a phosphor screen is formed on the second substrate side, and A flat display device in which the extracted electrons are accelerated and irradiated on the phosphor screen to excite the phosphor screen to emit light, thereby performing display, wherein the two thin plate-like surfaces intersecting at least the spacers are formed. A flat display device characterized by being formed to have. 2. The flat display device according to claim 1, wherein the spacer is formed of an insulating material. 3. The flat display device according to claim 1, wherein the spacer is formed of photo-etched photosensitive glass. 4. The resistance of the surface of the spacer is 10 ⁹ -1.
2. The flat display device according to claim 1, wherein the value is set to 0 ¹² Ω / □. 5. The method according to claim 5, wherein the spacer has a structure in which a high resistance film is formed on the surface of the insulating spacer body, and the surface of the high resistance film has a resistance of 10 ⁹ Ω / □ to 10 ¹² Ω / □. The flat panel display according to claim 1. 6. A conductive film is formed on a surface of a contact portion of the spacer with an acceleration electrode for applying an acceleration potential to the electron-emitting portion and the phosphor screen. 13. The flat display device according to claim 1. 7. A conductive film is formed on a surface of a contact portion of the spacer with an acceleration electrode for applying an acceleration potential to the electron-emitting portion and the fluorescent screen. 13. The flat display device according to claim 1.