JP2000251801A - Flat image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat image display device having an introducing structure which can stably apply a high voltage, and moreover has no discharge and can sufficiently stably supply high voltage to a phosphor. SOLUTION: A flat image display device is structured, such that a supporting frame 7 is held between a rear plate 1 and a face plate 2 so as to construct a vacuum envelope, and a voltage introducing terminal 10 is inserted into the flat image display device so as to introduce a voltage to an electrode 6 of the face plate 2 from the outside of the vacuum envelope. In the device, the voltage introducing terminal 10 is constructed of its center electrode 9, and an insulator 11 that is integrally formed to cover the circumference of the center electrode 9. The center electrode 9 of the voltage introducing terminal 10 is connected to the electrode 6 of the face plate 2, passing through a hole provided at the rear plate 1 or the face plate 2. The height of the insulator 11 at the inside of the vacuum is higher than an arbitrary electrode on the face plate 2 or the rear plate 1. Thereby a high pressure proof is assured and a distance along the creeping surface of the insulator 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat-panel image display device using an electron beam, and more particularly to a flat-panel image display device in which the structure of a voltage introducing terminal is devised.

[0002]

2. Description of the Related Art Conventionally, as an image display device for displaying a moving image or the like, a CRT excellent in color reproducibility, image response speed, price and the like has been widely used, particularly as a color image display device. Have been. However, the CRT has a drawback that the depth of the device is large with respect to the display area. Therefore, there has been a demand for a flat-type image display device having a short depth, and in recent years, in order to satisfy this, there has been a demand. 2. Description of the Related Art Flat-panel image display devices using liquid crystals have become widespread in place of CRTs.

However, since the image display device using the liquid crystal is not of a self-luminous type, it has a problem that it must have a backlight and has a dependency on a viewing angle. Development of a light-emitting display device has also been desired.

As such a self-luminous image display device,
Recently, a color plasma display has begun to be commercialized, but the light emission principle is different from that of a conventional CRT.
At present, it must be said that it is slightly inferior to a CRT due to the contrast of the image and the good color development.

[0005] Under these circumstances, if an image display device using an electron beam like a CRT can be expected to obtain the same image quality as a CRT, research on a flat type image display device using an electron beam has been conducted. , There is much development. In particular, most of these flat-panel image display devices using an electron beam have a source of electrons (hereinafter simply referred to as an electron source).
By arranging a plurality of hot-cathode and cold-cathode electron-emitting devices, the research and development has been conducted with the aim of reducing the electron beam deflection space required for CRTs and achieving thinner and flatter devices. I have.

[0006] In terms of image display, electrons emitted from the electron source are accelerated by a voltage and irradiated to a phosphor.
Because it tries to use the same principle as RT, CR
It is expected that the same image quality as T can be obtained. For example, Japanese Patent Application Laid-Open No. 4-163833 discloses a flat-panel image display device using an electron beam, in which a linear hot cathode and a complicated electrode structure are enclosed in a vacuum envelope.

In a flat-panel image display device using these electron beams, for example, a part of the electron beam incident on the phosphor is scattered and collides with the inner wall of the vacuum envelope to emit secondary electrons. , That part may be charged up,
In that case, the internal potential distribution is distorted, and not only the trajectory of the electron beam becomes unstable, but also there is a fear that a discharge is generated inside and the device is deteriorated or destroyed.

In order to prevent such charge-up, there is a method of forming an antistatic film on the inner wall of the vacuum envelope. For example, Japanese Patent Application Laid-Open No. 4-163833 discloses a configuration in which a conductive layer made of a high-impedance conductive material is provided on the side surface of the inner wall of a glass envelope of an image display device.

In an image display device using an electron beam, a voltage for accelerating electrons is applied between an electron source and a phosphor. For this reason, when the vacuum envelope of the image display device is made of glass containing Na, such as blue plate glass, the Na ion moves due to the electric field,
Electrolytic current occurs. As described above, the vacuum envelope using glass seals a plurality of members with frit glass,
When Na ions flow into the frit glass due to the above-described electrolytic current, PbO contained in the frit glass is reduced to precipitate Pb, and cracks are generated in the frit glass, thereby causing the frit glass to crack. There is a fear that the vacuum in the vessel cannot be maintained.

On the other hand, there is a method in which an electrode is provided at an appropriate position on the outer wall of the vacuum envelope to absorb the electrolytic current and prevent the electrolytic current from flowing through the frit glass. For example, Japanese Patent Application Laid-Open No. 4-94038 discloses a configuration in which a low-resistance conductive film is provided around the face plate and connected to the ground potential so that the electrolytic current does not flow through the frit glass. I have. Further, a configuration in which a strip-shaped electrode is provided to apply a current to the side wall of the vacuum envelope to form a potential gradient is disclosed in US Pat.
No. 357,165.

FIG. 16 shows an equivalent circuit assumed in the above case. Here, reference numeral 71 indicates a phosphor, and a voltage Va
Is applied. Reference numeral 72 denotes a joint between members of the vacuum envelope, and reference numeral 75 denotes a resistance between the phosphor 71 and the joint 72, which is formed on the inner wall of the vacuum envelope and has a high-impedance antistatic film. Is shown. Reference numeral 73 denotes a wiring for driving the electron source, which passes from inside to outside of the vacuum envelope through the joint, and reference numeral 76 denotes a resistance of the frit glass between the joint 72 and the wiring 73. . The wiring 73 is connected to a terminal 79 of a power supply for driving an electron source having a predetermined potential, and reference numeral 80 denotes a resistance of the wiring.

Further, reference numeral 77 denotes the fluorescent material 71 to the joint 7.
2 shows the resistance to the electrolytic current flowing inside the glass constituting the vacuum envelope. Reference numeral 74 indicates an electrode for capturing an electrolytic current outside the vacuum envelope, and reference numeral 78 indicates a resistance to the electrolytic current flowing inside the glass. The electrode 74 is connected to the ground via a resistance of a conductive wire connected to the electrode 74. The joint 72 is further connected to a member 82 having a specific potential via a resistor 81 such as an antistatic film. FIG. 16 illustrates one of the configurations of the conventional example, and the conventional example is not complete with the elements shown in FIG.

On the other hand, in the flat-panel image display device using the electron beam described in JP-A-4-163833, a conventional CRT is used by using a plurality of linear hot cathodes.
The electron beam deflection space that was required for this was greatly reduced.
However, this is a configuration in which a complicated electrode structure such as a horizontal deflection electrode and a vertical deflection electrode for deflecting an electron beam to a plurality of pixels (phosphors) is included in the inside of the container. However, in recent years, flat-panel image display devices using electron beams as portable information terminal devices, for example, have a thinner, so-called, The development of a device called a thin type is required.

To achieve such a flat-type image display device using an ultra-thin electron beam, the present applicant relates to a surface-conduction electron-emitting device and a flat-type image display device using the same. We have already made many proposals. For example, if the electron-emitting device described in Japanese Patent Application Laid-Open No. 7-235255 is used, the electron-emitting device here has a simple structure and can be formed in a large number in a large area. For this reason, one electron-emitting device can be formed for one pixel (phosphor).
No. 3, Japanese Patent Laid-Open Publication No. 3 (1994), discloses a flat image display device using an electron beam,
Alternatively, since a space for electron beam deflection required for a normal CRT can be omitted, a very thin flat-panel image display device can be configured.

In addition, even when a field emission type electron emitting device (hereinafter, referred to as an FE type device) is used as an electron source,
Similarly, since an ultra-thin flat-panel image display device can be configured, various developments have been continued.

By the way, a voltage for accelerating electrons is applied between the electron source and the phosphor as described above. In order to obtain light emission of a preferable color, this voltage is set as high as possible. Preferably, at least several kV
Desirably.

In an image display device using an electron beam, since the inside of the device is naturally a vacuum, the high voltage as described above must be introduced from outside the device into a vacuum device. However, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Laid-Open No. 3-280336 discloses an example of a method for introducing a high voltage corresponding to the flat-panel image display device using an electron beam described in Japanese Patent Application Laid-Open No. 3-3280. In this case, as described above, since the entire device has a certain thickness (several tens of mm), it is possible to draw out the voltage introduction terminal from the side wall of the front glass container.

On the other hand, in an ultra-thin flat panel display,
Usually, a rear plate on which an electron source is formed, and a face plate, which is disposed opposite to the rear plate and has a phosphor applied to its opposite surface, are sandwiched by a support frame or a spacer, and frit glass is used as an adhesive. Joined, and
The frit glass itself that directly bonds both plates,
Holding at intervals of 0.1 mm to several mm forms the vacuum envelope of the device. Therefore, the distance between the face plate on which the phosphor is formed and the rear plate on which the electron source is formed is extremely small, and it is difficult to draw out the voltage introduction terminal from the side wall.

For the electrical connection between the phosphor and the outside, when the phosphor voltage is relatively low, for example, a lead wire made of a conductive layer such as ITO (composite oxide of indium and tin) or a Cr film is connected to the face. A method of forming on a plate and passing through a portion to be bonded with frit glass at a side edge of the panel and pulling out the same is performed.

However, as described above, when it is desired to introduce a voltage as high as several kV or more, or when the amount of current is large, such a conductive layer cannot provide a sufficient current capacity.
In addition, the conductive layer and the frit glass portion may change with time, causing a leak that impairs airtightness, a so-called slow leak.

In order to solve such a problem, an ultra-thin flat type image display device having a high voltage introducing structure has been disclosed in
-114372. That is, in this device, the rear plate 1 in which a large number of FE-type elements are formed has a hole, and the inner end penetrates the hole to the conductive layer 6 for feeding the phosphor on the face plate 2. The structure of the electrode terminal (rod electrode) 9 which makes elastic contact is shown (see FIG. 14). In the figure, reference numeral 8 denotes a sealing layer for closing the hole. With the high voltage introduction structure of this conventional device, an ultra-thin flat-panel image display device capable of relatively stably introducing a high voltage has been realized.

[0022]

However, as described above, an electron source is provided around or near at least a voltage introducing electrode (wiring) to which a high voltage of several kV or more is applied. Since the presence of a low-voltage electrode or conductive layer, such as a wiring electrode for driving or an antistatic film for preventing charge-up in the vacuum envelope described above, cannot be avoided, the electrode 9 for introducing the high voltage is used. And their low-voltage electrodes 1
The potential difference between the two is also on the order of several kV. For this reason, if the distance is not sufficiently separated, there is a high possibility that discharge will occur directly between the two (see arrows in FIG. 14).

When a discharge occurs, an extremely large current flows instantaneously. If a part of the current flows into the wiring of the electron source, a large voltage is applied to the electron-emitting device of the electron source. If this voltage exceeds the voltage applied in normal operation, the electron emission characteristics may deteriorate,
Further, the element may be destroyed. In this case, a part of the image is not displayed, the quality of the image is reduced, and the image cannot be used as an image display device, which is a serious problem. In order to prevent discharge, if the distance between the high voltage electrode 9 and the surrounding low voltage electrode 12 is increased,
The structure of the voltage introducing section is increased, which is not preferable.

As described above, in order to obtain a sufficiently bright and well-colored image in an ultra-thin flat type electron beam image display device, it is necessary to apply a voltage as high as possible as stably as possible. Regardless, it is not sufficiently achieved to form an introduction structure capable of applying a high voltage to the phosphor with no discharge and sufficiently stable because the device is very thin. It is in the current situation.

The present invention has been made based on the above circumstances, and is capable of stably applying a high voltage, and has no discharge and is sufficiently stable to apply a high voltage to a phosphor. An object of the present invention is to provide a flat-panel image display device having an introduction structure.

[0026]

Therefore, in the present invention,
A rear plate having an electron source composed of a plurality of electron-emitting devices formed on a planar substrate; and a rear plate disposed opposite to the rear plate, and emitting light by irradiating an electron beam emitted from the electron source onto an inner surface. And a face plate on which an electrode for applying a voltage to the phosphor is formed, and a side edge of the rear plate and the face plate is sandwiched, and a vacuum is formed together with the rear plate and the face plate. A flat image display device having at least a support frame forming a part of an envelope and a voltage introduction terminal for introducing a voltage to an electrode on the inner surface of the face plate from outside the vacuum envelope. Is composed of a center electrode and an insulator integrally formed by covering the periphery of the center electrode, and the rear plate or the face plate The central electrode of the voltage introduction terminal is connected to the electrode on the inner surface of the face plate through the provided hole, and the height of the insulator portion of the voltage introduction terminal on the inner surface of the vacuum vessel is set to the rear plate. It is characterized by having a portion higher than any electrode formed on the top or on the face plate.

Further, the height of the insulator portion of the voltage introducing terminal on the inner surface of the vacuum container is d / 2 or more, where d is the distance between the face plate and the rear plate.

Further, on the insulator surface of the voltage introducing terminal,
It has irregularities at least in a vacuum vessel, and has a creepage distance of 1 kV / 1 mm or more with respect to a high voltage applied to the phosphor.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to FIGS. FIG. 1 is a perspective view showing a schematic overall configuration of a flat panel display according to the present invention, and FIG.
FIG. 2 is a schematic partial enlarged sectional view taken along line AA ′ of FIG.

Here, reference numeral 1 denotes a rear plate also serving as a substrate for forming an electron source, and 2 denotes a face plate having a phosphor 4 formed on an inner surface thereof.
Various materials are used according to design conditions, such as blue plate glass having a SiO ₂ film formed on its surface, glass with a low Na content, quartz glass, or ceramics. In addition, a substrate for forming an electron source is provided separately from the rear plate,
After the electron source is formed, the two may be joined.

Reference numerals 3-1, 3-2, and 3-3 denote wirings for driving the electron source, which are taken out of the image display device and connected to a driving circuit (not shown) for the electron source. . Reference numeral 7 denotes a support frame sandwiched between the rear plate 1 and the face plate 2, and is joined to the rear plate 1 and the face plate 2 at its edges by frit glass as an adhesive. Wiring for driving electron source 3-1, 3-2,
Reference numeral 3-3 denotes a joint between the support frame 7 and the rear plate 1.
It is pulled out to the outside while being buried in the frit glass. Reference numeral 10 denotes a voltage introducing terminal which is a feature of the present invention.

A voltage introducing terminal 10 for supplying a high voltage to the face plate has a center electrode 9 which penetrates a through hole for fitting a terminal provided in the rear plate 1 and has a metal back which will be described later. Is connected to the phosphor lead-out electrode 6 which is electrically connected to. As described above, a getter and the like are additionally arranged as necessary in the vacuum envelope formed airtightly by the plates 1 and 2 and the support frame 7.

In FIG. 2, reference numeral 2 denotes a face plate, 5 denotes an electrode made of a metal film (usually Al) called a metal back formed in contact with the phosphor, and 8 denotes frit glass. Reference numeral 12 denotes a wiring electrode for driving an electron source (or an electrode of a ground potential such as an antistatic film, or any low-voltage wiring electrode near the voltage introduction terminal 10). Here, the voltage introduction terminal 10 has an insulator structure composed of the center electrode 9 and an insulator 11 made of ceramic integrally molded so as to cover the center electrode 9. The center electrode 9 is fitted to the hole provided and adhered by frit glass 8. The tip of the center electrode 9 is electrically connected to the phosphor lead-out electrode 6, and the high voltage is applied to the phosphor 4 through the metal back 5. (Anode voltage Va). Note that the electrical connection between the center electrode 9 and the phosphor lead-out electrode 6 may be any of a connection method by elastic contact, a connection method by melting metal, and the like.

As the material of the insulator 11 covering the center electrode 9, the same material as the substrate glass can be used. However, when the substrate glass is blue plate glass or the like, forsterite porcelain or steatite porcelain is used. Even if it is used, since it has a close expansion coefficient with the substrate glass, it can be bonded with frit glass, and has a higher specific resistance than glass, is less likely to cause dielectric breakdown, and is preferable because higher insulating properties can be obtained. .

According to the voltage introduction terminal 10 of the insulator structure, the discharge path is a discharge along the surface of the insulator (surface discharge) as shown by an arrow in FIG. 15 (see FIG. 15), the discharge (see FIG. 15) occurs in the space between the center electrode 9 of the voltage introduction terminal and any low-voltage wiring electrode 12 existing in the vicinity. There is no fear of directly raising (see arrows). This is because if the distance between the face plate and the rear plate is d, and the height of the insulator inside the vacuum is d / 2 or more,
Better.

Further, as a characteristic portion of the structure of the voltage introducing terminal 10 according to the present invention, as shown in FIGS. 3 and 4, a structure which increases the creepage distance inside the vacuum envelope is used. That is. For example, in the embodiment shown in FIG. 3, the concave portion 13 is formed on the surface of the insulator 11 on the vacuum envelope side. The concave portion 13 increases the creepage distance between the high-voltage introduction electrode 9 and an arbitrary low-voltage electrode 12 in the vicinity, and increases the
It is formed so as to secure a creepage distance of at least m (see arrows in FIG. 4).

This structure not only prevents direct discharge between the high-voltage and low-voltage electrodes, but also has sufficient resistance to creeping discharge along the surface of the insulator 11. A high voltage introduction structure can be realized, and a high voltage required for stable and good image display can be supplied.

The type of the electron-emitting device constituting the electron source used in the present invention is not particularly limited as long as the characteristics such as the electron-emitting characteristics and the size of the device are suitable for the intended image forming apparatus. Not something. That is, a thermionic emission element, a field emission element, a semiconductor electron emission element,
Cold cathode devices such as an M-type electron emission device and a surface conduction electron emission device can be used.

The surface conduction type electron-emitting device shown in the embodiment described later is used as a preferred embodiment in the present invention. That is, it is similar to that described in Japanese Patent Application Laid-Open No. Hei 7-235255, which has already been filed by the present applicant, and will be briefly described below.

FIGS. 5A and 5B schematically show an example of the structure of a single surface conduction electron-emitting device (FIG. 5A is a plan view, and FIG. 5B is a plan view). It is a sectional view).
Here, reference numeral 41 is a base for forming an electron-emitting device, 42 and 43 are a pair of device electrodes, 44 is a conductive film connected to the device electrode, and an electron-emitting portion is formed in a part thereof. I have. The electron-emitting portion is a high-resistance portion formed by breaking, deforming, and altering a part of the conductive film by a forming process described later, and a crack is formed in a part of the conductive film. It is such that electrons are emitted from.

The above-mentioned forming step is performed by applying a voltage between the pair of element electrodes 42 and 43.
The voltage to be applied is preferably a pulse voltage, and a method of applying the same peak value as shown in FIG. 6A or a method of applying while gradually increasing the peak value as shown in FIG. 6B. It may be applied.

After forming the electron-emitting portion by the forming process, a process called “activation” is performed. This process is performed by repeatedly applying a pulse voltage to the device in an atmosphere in which an organic substance is present. In addition, a substance containing a carbon compound as a main component is deposited around the electron-emitting portion. By this treatment, a current flowing between the device electrodes (device current If) and a current accompanying the electron emission (emission current Ie) are reduced. Both increase.

It is preferable that the electron-emitting device obtained through the above steps is subsequently subjected to a stabilization step. This step is a step of evacuating the organic substance in the vacuum envelope. Vacuum exhaust equipment that exhausts the vacuum envelope should be designed so that oil generated from the equipment does not affect the characteristics of the element.
It is better not to use oil. Specific examples include a vacuum exhaust device such as a sorption pump and an ion pump.

The partial pressure of the organic substance in the vacuum envelope is a partial pressure at which the above-mentioned carbon and carbon compounds are not newly deposited, and is preferably about 1.3 × 10 ⁻⁶ Pa or less, particularly preferably 1.3 × 10 ⁻⁶ Pa. × 1
It is preferably 0 ^-8 Pa or less. Also, when evacuating the inside of the vacuum envelope, the entire vacuum envelope is heated and its inner walls and
It is preferable to easily exhaust the organic substance molecules adsorbed to the electron-emitting device. The heating conditions at this time are 80 to
It is desirable to perform the treatment at 250 ° C., preferably 150 ° C. or higher, for as long a time as possible. However, it is not particularly limited to this condition, and various conditions such as the size and shape of the vacuum envelope and the configuration of the electron-emitting device Depending on the temperature, time, etc.
To be elected. The pressure in the vacuum envelope needs to be as low as possible, and is preferably 1 × 10 ⁻⁵ Pa or less.
It is preferably at most 1.3 × 10 ⁻⁶ Pa.

The atmosphere at the time of driving after performing the stabilization step is preferably the same as the atmosphere at the end of the stabilization process, but is not limited to this. For example, even if the degree of vacuum itself is slightly reduced, sufficiently stable characteristics can be maintained.

By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed.
In addition, H ₂ O, O adsorbed on the inner wall of the vacuum envelope, the substrate, etc.
_{2 and the} like can be removed, and as a result, the element current If and the emission current Ie are stabilized.

The surface conduction electron-emitting device thus obtained has a relationship between the voltage Vf applied to the device, the device current If, and the emission current Ie as schematically shown in FIG. In FIG. 6, since the emission current Ie is significantly smaller than the device current If, it is shown in arbitrary units. Both the vertical and horizontal axes are linear scales.

As shown in the graph of FIG.
When an element voltage higher than a certain voltage (threshold voltage Vth) is applied, the emission current Ie sharply increases. On the other hand, when the element voltage is lower than the threshold voltage Vth, the emission current Ie is hardly detected. That is, this element is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie. By utilizing this, a matrix wiring is applied to the two-dimensionally arranged electron-emitting devices, electrons are selectively emitted from a desired device by simple matrix driving, and the electrons are irradiated on the image forming member, thereby providing a favorable image. It is possible to form an image.

Next, an example of the structure of a phosphor film composed of a phosphor and a metal back will be described. FIG. 8 is a schematic diagram showing a fluorescent film. In the case of monochrome, the phosphor film 51 can be composed of only a phosphor. In the case of a color fluorescent film, it is composed of a black conductive material 52 and a fluorescent material 53 called a black stripe or a black matrix depending on the arrangement of the fluorescent materials.

The purpose of providing the black stripes and the black matrix is to make the three-color phosphors necessary for the color display black between the phosphors 53 so as to make the color mixture less noticeable. Another object of the present invention is to suppress a decrease in contrast due to reflection of external light on the fluorescent film 51. As a material for black stripes,
In addition to the material containing graphite as a main component, a material having conductivity and low transmission and reflection of light can be used.

The method of applying the phosphor on the face plate can be a precipitation method, a printing method, or the like, irrespective of monochrome or color. Usually, a metal back is provided on the inner surface side of the fluorescent film 51. The purpose of providing the metal back is to improve the luminance by applying light to the inside of the device, out of the light emitted from the phosphor, to the face plate side (= outside of the device), and to apply an electron beam acceleration voltage. To protect the phosphor from damage caused by the collision of negative ions generated in the vacuum vessel. The metal back can be formed by performing a smoothing process (usually called “filming”) on the inner surface of the fluorescent film after forming the fluorescent film, and then depositing Al using vacuum evaporation or the like. .

The fluorescent film 51 is further provided on the face plate.
A transparent electrode may be provided on the inner surface side in order to increase the conductivity. In the case of color, it is necessary to make each color phosphor correspond to an electron-emitting device, and sufficient alignment is indispensable.

In the present invention, with the above-described configuration, the high-voltage introduction structure of the flat-panel image display device using an electron beam can prevent discharge and stably apply a required high voltage. It has become possible to improve reliability.

[0054]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be specifically described below (see FIGS. 1, 2, and 9 to 11).

Example 1 Here, a plurality of surface conduction electron-emitting devices are formed on a rear plate also serving as a substrate.
An electron source was formed by wiring in a matrix, and a flat-panel image display device was created using the electron source. Below, (A) of FIG.
The creation procedure will be described with reference to FIGS.

(Step-a) Each of the face plates has a diameter of 10
mm voltage introduction terminal passage hole 15 and vacuum evacuation hole 16
(See FIG. 10) is formed on a soda lime glass by a method such as polishing, and after sufficiently washing the soda lime glass,
A 0.5 μm SiO ₂ layer was formed by sputtering to form a rear plate 1. On this rear plate 1,
The device electrodes 21 and 22 of the surface conduction electron-emitting device are formed by using a sputtering film forming method and a photolithography method. This device electrode is composed of 5 nm of Ti and 100 nm of Ni.
Are laminated. The element electrode interval was 2 μm (see FIG. 9A).

(Step-b) Subsequently, the Ag paste is printed in a predetermined shape and baked, so that the Y-directional wiring 2 is formed.
3 was formed. The wiring 23 extends to the outside of the region where the electron source is formed, and becomes the electron source driving wiring 3-2 in FIG. This wiring has a width of 100 μm and a thickness of about 10 μm (see FIG. 9B).

(Step-c) Next, a paste containing PbO as a main component mixed with a glass binder was used.
The insulating layer 24 is formed by a printing method. This is to insulate the Y-directional wiring 23 from an X-directional wiring described later, and is formed to have a thickness of about 20 μm. A cutout is provided in the element electrode 22 to connect the X-directional wiring to the element electrode (see FIG. 9C).

(Step-d) Subsequently, the X-directional wiring 25 is formed on the insulating layer 24 (see FIG. 9D). This formation is the same as that for the Y-direction wiring, and the width of the wiring is 300
μm, and the thickness is about 10 μm. Subsequently, a conductive film 26 made of PdO fine particles is formed. This forming method
On the substrate on which the wiring was formed, C was formed by sputtering.
An r film is formed, and an opening corresponding to the shape of the conductive film 26 is formed in the Cr film by photolithography.

Subsequently, an organic Pd solution (for example, ccp
-4230: manufactured by Okuno Pharmaceutical Co., Ltd.), and baked in the air at 300 ° C. for 12 minutes to form a PdO fine particle film. Then, the Cr film is removed by wet etching, and lift-off is performed. Conductive film 26 having a predetermined shape
(See FIG. 9E).

(Step-e) The support frame 7 and the rear plate 1 are sealed using frit glass. Here, the height (thickness) of the support frame 7 is 3 mm, so that the distance between the rear plate 1 and the face plate 2, that is, the distance between the electron source and the phosphor, is set to be the flat type image display device of the present embodiment. In, about 3
mm (see FIG. 10).

(Step-f) Next, the production of the face plate 2 will be described. Note that a blue plate glass was used as the substrate. By printing using Ag, the phosphor lead-out electrode 6 is formed in a pattern that conducts (partially overlaps) with the metal back, and further, a black stripe of the phosphor film is formed, followed by a stripe-shaped phosphor. I do. Thereafter, a filming process was performed, and an Al film having a thickness of about 0.1 μm was deposited thereon by a vacuum evaporation method to form a metal back.

(Step-g) The support frame 7 joined to the rear plate 1 is joined to the face plate 2 using frit glass 8. At this time, the voltage introduction terminal 10 and the exhaust pipe 17 for evacuating the inside of the envelope are also connected at the same time.
Each is aligned with the corresponding hole 15, 16 on the rear plate 1, and joined via the frit glass 8. The voltage introducing terminal 10 has an insulator structure in which a rod made of an Fe—Ni alloy coated with Au is used as the center electrode 9 and penetrates into a ceramic insulator 11 mainly composed of steatite porcelain. The reason for using steatite porcelain is that the specific resistance is larger than that of blue sheet glass (blue sheet to 10 ¹² Ω).
respect cm, 10 ¹⁴ Ωcm or more at a temperature 20 ° C.)
This is because dielectric breakdown is unlikely to occur, and the coefficient of thermal expansion is close to that of glass, so that frit glass can be used for fixing.

Here, the overall shape of the voltage introduction terminal 10 is
FIG. 11 shows a cross section of the ceramic insulator 11. The ceramic insulator 11 has an outer diameter of 16 mm and a height (thickness) of a substantially cylindrical portion having an outer diameter of 10 mm and a height of 13 mm. 2mm
Are integrally formed. The protruding portion 18 has a flat portion 21, and the flat portion is bonded to the rear surface of the rear plate substrate by frit glass.

Then, the vacuum envelope side (indicated by reference numeral 19 in the figure) from the plane 21 of the protruding portion 18 of the insulator 11.
Is fitted into a through hole provided in the rear plate 1 and the tip 22 of the center electrode 9 is pressed against the phosphor lead-out electrode 6 on the inner surface of the face plate to elastically or melt the metal. Then, they are electrically joined by a method such as connection.

Since the voltage introducing terminal 10 of the present invention is independent of the members constituting the vacuum envelope, the voltage introducing terminal is adhered to the rear plate by another member forming the vacuum envelope. Since it is possible to carry out the process after the bonding of the parts (the face plate, the rear plate, the support frame) is completed, the method of electrical connection with the phosphor lead-out electrode 6 is appropriately determined in consideration of this point. Can be selected.

The voltage introducing terminal 10 has a rod of Fe—Ni alloy having a diameter φ of 0.8 mm to 1 mm inserted into the insulator 11 as a center electrode. The height (h in FIG. 2) of the voltage introduction terminal 10 in the vacuum vessel was 2 mm.

The straight line distance between the center electrode of the voltage introducing terminal 10 and the surrounding low-potential electrode was about 5 mm in the conventional case when the electrode was closest, but the surface of the insulator 11 was not The creepage distance (arrow in FIG. 2) was 7.5 mm, so that direct discharge could be prevented and the creepage distance could be increased.

In this embodiment, if the height of the voltage introduction terminal 10 in the vacuum vessel (h in FIG. 2) is higher than the height of any low-voltage electrode on the rear plate, the low-voltage electrode 12 is connected to the voltage. This is effective in preventing direct discharge between the introduction terminal 10 and the rod-shaped electrode 9. However, if the height is d / 2 or more as in the present embodiment, the distance between the rod-shaped electrode 9 and the phosphor extraction electrode 6 is reduced. Since the probability that the insulator 11 is interposed on the line connecting the contact portion (B in FIG. 2) and the low-voltage electrode end (A in FIG. 2) is increased, the withstand voltage between the low-voltage electrode and the rod-shaped electrode is further improved. Is preferred.

As described above, according to the voltage introducing terminal of the embodiment of the present invention, the withstand voltage and creepage distance between the center electrode (Fe—Ni rod) and any low-voltage electrode around the voltage introducing terminal can be sufficiently increased. It has a secured structure. In addition, the rear plate,
At the time of bonding with the face plate, it is necessary to carefully position each electron-emitting device of the electron source and the position of the phosphor on the face plate with care.

(Step-h) The above-mentioned flat type image display device is connected to a vacuum exhaust device via an exhaust pipe 17, and the inside of the envelope is exhausted. When the pressure in the envelope becomes 10 ⁻⁴ Pa or less, a forming process is performed. This forming was performed by applying a pulse voltage having a gradually increasing peak value as schematically shown in FIG. 6B to the X-direction wiring for each row in the X direction. The pulse interval T ₁ is 10 s
ec. , The pulse width T ₂ is 1 msec. And Although not shown in the figure, a rectangular wave pulse having a peak value of 0.1 V is inserted between the forming pulses, the current value is measured, and the resistance value of the electron-emitting device is simultaneously measured. When the resistance value per element exceeds 1 M ohm, the forming process for that row is terminated, and the process proceeds to the next row.
By repeating this, the forming process is completed for all the rows.

(Step-i) Next, an activation process is performed. Prior to this process, the image display device is evacuated by an ion pump while maintaining the temperature at 200 ° C., and the pressure is reduced to 10 ⁻⁵ Pa or less. Subsequently, acetone is introduced into the vacuum envelope.
The introduction amount was adjusted so that the pressure was 1.3 × 10 ⁻² Pa. Subsequently, a pulse voltage is applied to the X-direction wiring. The pulse waveform is a rectangular pulse having a peak value of 16 V, and the pulse width is 100 μsec. 125 μs per pulse
Pulses are applied at c intervals. Then, the X-direction wiring is switched to the next row, and a pulse is sequentially applied to each wiring in the row direction. As a result, each line has 10 msec. Pulses will be applied at intervals. As a result of this process,
A deposited film containing carbon as a main component is formed in the vicinity of the electron-emitting portion of each electron-emitting device, and the device current If increases.

(Step-j) Subsequently, the inside of the vacuum envelope is evacuated again. The evacuation was continued for 10 hours using an ion pump while maintaining the image display device at 200 ° C.
This step is for removing organic substance molecules remaining in the vacuum envelope, preventing further deposition of a deposited film containing carbon as a main component, and stabilizing electron emission characteristics.

(Step-k) After the temperature of the image display device is returned to room temperature, a pulse voltage is applied to the X-directional wiring in the same manner as in the step-h. Further, when a voltage of 4 kV is applied to the phosphor through the voltage introducing terminal 10, the phosphor emits light. Thereafter, the applied voltage was gradually increased to a voltage of 10 kV.

It is confirmed by visual observation that there is no portion that does not emit light or a very dark portion, the application of voltage to the X-direction wiring and the phosphor is stopped, and the exhaust pipe 17 is heated, welded and sealed. Subsequently, a getter (not shown) is processed by high-frequency heating to complete the flat panel display.

In the flat image display device prepared as described above, the voltage introducing terminal 10 has a conventional structure (see FIG. 15) and has the same size (outer diameter: about 10 mm). The comparison was made between the case where the applied voltage was increased to 12 kV and the discharge was measured by driving continuously for 10 hours.

As a result, in the conventional structure, a few discharges were observed. However, when the voltage introducing terminal of this embodiment was used, it was never observed, and a higher voltage could be applied more stably than in the prior art. It could be confirmed. In addition, the electron acceleration voltage (V
As a), when 10 kV is applied, a high voltage can be stably applied over a long period of time, and an image excellent in luminance and chromaticity can be displayed.

In the above embodiment, the case where the surface conduction electron-emitting device is used as the electron-emitting device constituting the electron source has been described, but the structure of the present invention is not limited to this. Therefore, the present invention can be similarly applied to a case where an electron source using an FE-type electron-emitting device, a semiconductor electron-emitting device, and other various electron-emitting devices is used. Furthermore, various members shown in the embodiments may be appropriately changed within the scope of the technical idea of the present invention.

(Embodiment 2) FIGS. 3 and 4 show a second embodiment of the voltage introduction terminal of the flat panel display according to the present invention. The configuration of the entire apparatus is the same as that of the first embodiment, and a description thereof will be omitted. In this embodiment, a portion corresponding to the cross section taken along line AA ′ of FIG. 1 is shown in FIG. 3, and an enlarged view thereof is shown in FIG.

In the present embodiment, a groove 13 having a width of 4 mm (radius from 3 mm to 7 mm from the center) and a depth of 4 mm is formed on the insulator surface of the voltage introducing terminal 10 having the same shape as in the first embodiment on the inner surface side of the vacuum vessel. It was provided concentrically. As a result, the creepage distance of 7.5 mm in Example 1 was changed to 15.5 mm.
This is particularly suitable for a flat-panel image display device that applies a high accelerating voltage. Even when a creepage distance of 1 kV / mm or more is required, a high accelerating voltage of 15 kV can be applied.

(Embodiment 3) FIG. 12 shows a third embodiment of the voltage introducing terminal of the flat panel display according to the present invention. In addition,
Since the configuration of the entire apparatus is the same as that of the first embodiment, the description of the configuration will be omitted, and the present embodiment will be described with reference to FIG.
FIG. 12 shows only the portion corresponding to the -A 'section. That is,
Here, the diameter of the fitting hole of the voltage introduction terminal 10 formed on the rear plate 1 is enlarged to 14 mm, and this is used as a terminal insertion hole, and the portion of the insulator 11 penetrating into the vacuum envelope is formed.
The diameter of the cylindrical portion was 10 mm, the size of the concave portion 13 formed on the surface was the same as in Example 1, and the outer diameter of the protrusion 18 was 20 mm. Then, the voltage introduction terminal 10 was positioned such that a gap 23 was formed between the insertion hole and the insulator inside the vacuum envelope, and was bonded with frit glass.

In the present embodiment, the creepage distance can be further increased by the gap portion 23 formed between the insulator portion 11 of the voltage introducing terminal 10 and the rear plate substrate 1, and a higher voltage can be obtained. However, it has become possible to stably supply the phosphor. In addition, this increase in creepage distance can be achieved without particularly complicated processing on the members and the rear plate.
Since this can be achieved, it is particularly suitable for a flat panel image display device to which a high acceleration voltage is applied.

(Embodiment 4) A fourth embodiment of the voltage introducing terminal of the flat panel display according to the present invention will be described with reference to FIGS. In this embodiment, the voltage introduction terminal is bonded to the fitting hole provided on the face plate side to supply the voltage from the front side of the face plate. However, since the schematic configuration of the entire apparatus is almost the same as that of the first embodiment, , Omit that description,
With respect to the position corresponding to AA ′ in FIG.
FIG. 13 shows a cross-sectional view in which the voltage introduction terminal is attached.

In this embodiment, the face plate 2
And a hole for fitting the voltage introducing terminal 10 (diameter: 10 mm)
A phosphor, a metal back, and the like are formed on a blue glass substrate provided with the same method as in step-f of Example 1 to complete the face plate 2. However, the position where the fitting hole is formed is near the end of the extraction electrode 6 of the phosphor.

The structure and size of the voltage introducing terminal 10 of the present embodiment are almost the same as those of the terminal of the first embodiment, but in the present embodiment, as shown in FIG.
The center electrode 9 is formed at the center of a hole having a diameter of 4 mm on the side surface of the vacuum envelope of the insulator 11 formed so as to be recessed from 6 to 2 mm.
Is inserted so that its height to the vacuum envelope side is substantially flush with the face plate inner surface 26, and the insulator inside the vacuum envelope is outside the hollow (4 mm to 10 mm in diameter). (A range), the central electrode 9 is formed so as to protrude so as to surround the periphery of the central electrode 9 in a wall shape.
Are formed.

The wall-like insulator 25 has a wall width (thickness) of 3 m.
m, the protruding height from the face plate surface is 2mm
(Accordingly, the height from the recess was 4 mm), and a cutout was formed in a part of the cutout at a depth and width of 2 mm.

In this embodiment, the electrical connection between the center electrode 9 of the voltage introducing terminal 10 and the phosphor lead-out electrode 6 is
Using the cutout portion, the lead electrode 6 of the phosphor and the center electrode 9 were connected by a lead wire 27, and joined using a conductive adhesive or electric welding. Therefore, in the present embodiment, first, the voltage introducing terminal 10 of the present embodiment is bonded to the face plate 2 completed with the fitting holes, and the center electrode 9 is formed.
After the electrical connection between the support frame 7 and the phosphor lead-out electrode 6, the support frame 7 and the rear plate 1 were bonded with frit glass 8, thereby completing the vacuum envelope of the apparatus.

In the flat-panel type image display device using the voltage introducing terminal 10 of this embodiment, the antistatic film 28 having a substantially ground potential for preventing the above-described charge-up in the vacuum envelope.
13, a creepage distance of 10 mm can be ensured between the electrode and the center electrode even if it is formed up to a portion in contact with the voltage introducing terminal 10.

In the case where the wall 25 is not provided on the insulator, if the distance between the center electrode and the antistatic film becomes close to each other,
Since the thickness becomes 4.5 mm, in the flat-panel image display device using the voltage introduction terminal having the structure of the present embodiment, it is possible to sufficiently prevent charging in the vacuum envelope and to apply a higher voltage to the phosphor. Is evident.

Therefore, in the case where it is desired to apply a high voltage Va for electron beam acceleration to the phosphor from the face plate side in accordance with a request for the structure of the entire device, the present embodiment stably applies a high voltage to the device. Preferred above.

[0091]

As described above, by adopting the structure of the present invention, in a thin flat-panel image display device using an electron beam, in particular, with respect to a voltage introduction structure, discharge generated in the device is prevented. A structure capable of stably applying a necessary high voltage can be achieved, and the effect of improving reliability and displaying a high-quality image with excellent luminance and color reproducibility can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic structural perspective view of a flat panel display according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a structure of a voltage introducing terminal of the flat panel display.

FIG. 3 is a cross-sectional view illustrating a voltage introduction terminal according to a second embodiment of the present invention.

FIG. 4 is also a cross-sectional view for explaining a creepage distance at a voltage introduction terminal.

FIG. 5 is a diagram illustrating a configuration of a surface conduction electron-emitting device according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a forming voltage of a surface conduction electron-emitting device.

FIG. 7 is a diagram illustrating IV characteristics of a surface conduction electron-emitting device.

FIG. 8 is a diagram illustrating a configuration of a phosphor surface.

FIG. 9 is a diagram for explaining a process of forming a rear plate (electron source substrate).

FIG. 10 is a perspective view showing main members of the flat panel display according to the first embodiment of the present invention.

FIG. 11 is an enlarged sectional view of the voltage introduction terminal.

FIG. 12 is a cross-sectional view illustrating a structure of a voltage introduction terminal portion of a flat panel display according to a third embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a voltage introducing terminal structure of a flat panel display according to a fourth embodiment of the present invention.

FIG. 14 is a partially enlarged cross-sectional view for explaining the structure of the voltage introduction terminal unit.

FIG. 15 is a cross-sectional view of a main part showing a structure for introducing a voltage from a rear plate of a conventional flat panel display.

FIG. 16 is an equivalent circuit diagram showing the resistance of the device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rear plate 2 Face plate 3 Electron source wiring 4 Phosphor 5 Metal back 6 Phosphor lead-out electrode 7 Support frame 8 Frit glass 9 Rod electrode 10 Voltage introduction terminal 11 Insulator 12 Low voltage electrode 13 Insulator concave part 15 Voltage introduction terminal fitting Hole 16 Vacuum evacuation hole 17 Exhaust pipe 18 Insulator projecting portion 19 Insulator vacuum envelope side 20 Insulator outside 21 Insulator projecting flat portion 22 Center electrode tip 23 Void portion 24 Wall-shaped insulator cutout portion 25 Wall-shaped insulator 26 Face plate inner surface 27 Lead wire 28 Antistatic film

Claims (5)

[Claims] 1. A rear plate having an electron source formed of a plurality of electron-emitting devices formed on a flat substrate, and a rear plate disposed opposite to the rear plate and having, on its inner surface, an electron beam emitted from the electron source. A face plate on which a phosphor that emits light by irradiation and displays an image, an electrode for applying a voltage to the phosphor, and a side edge of the rear plate and the face plate are sandwiched, and the rear plate is And a support frame forming a part of a vacuum envelope together with the face plate, and a voltage introduction terminal for introducing a voltage from outside the vacuum envelope to the electrode on the inner surface of the face plate. The voltage introduction terminal is composed of a center electrode and an insulator that covers the periphery of the center electrode and is integrally formed, and the rear plate or Through the holes provided in Esupureto,
The center electrode of the voltage introducing terminal is connected to the electrode on the inner surface of the face plate, and the height of the insulator portion of the voltage introducing terminal on the inner surface of the vacuum vessel is:
A flat-panel image display device having a portion higher than an arbitrary electrode formed on a rear plate or a face plate. 2. The height of the insulator portion of the voltage introducing terminal on the inner surface of the vacuum vessel is d / 2 or more, where d is the distance between the face plate and the rear plate. Item 2. The flat panel display according to item 1. 3. An insulator surface of the voltage introducing terminal has irregularities at least in a vacuum vessel, and has a creepage distance of 1 kV / 1 mm or more with respect to a high voltage applied to the phosphor. The flat panel display according to claim 1. 4. The semiconductor device according to claim 1, wherein a specific resistance of an insulator forming the voltage introducing terminal is larger than or at least equal to a specific resistance of a substrate forming a rear plate or a face plate. 4. The flat-panel image display device according to any one of 3. 5. The flat type according to claim 1, wherein an insulator portion of the voltage introducing terminal is fixed to a hole provided in the rear plate or the face plate. Image display device.