JP3302298B2 - Image forming device and image display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus in which a spacer in a vacuum vessel is covered with a high-resistance film and an image display apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a hot cathode device and a cold cathode device, are known. Among these, among the cold cathode devices, for example, a surface conduction type emission device, a field emission type device (hereinafter referred to as FE type), a metal / insulating layer / metal type emission device (hereinafter referred to as MIM type), and the like are known. I have.

[0003] As a surface conduction type emission element, for example,
MIElinson, Radio Eng. ElectronPhys., 10, 1290, (196
5) and other examples described later are known. The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, in addition to the use of a thin film of SnO ₂ according to the Ellingson, etc., by an Au thin film [G.Dittmer: "Thin Solid Fi
lms ", 9,317 (1972)] and, In ₂ O ₃ / SnO ₂ by thin film [M.Hartwell and CGFonstad:" IEEE Trans.ED
Conf. ", 519 (1975)] and those using carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, 22 (198)
3)] has been reported.

FIG. 15 shows a plan view of a device by M. Hartwell et al. As a typical example of the device configuration of these surface conduction electron-emitting devices. In the figure, reference numeral 3001 denotes a substrate, and reference numeral 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. The conductive thin film 3
An electron emission portion 3005 is formed by performing an energization process called energization forming described below on 004. The interval L in the figure is 0.5 to 1 [mm], and W is 0.1 [m].
m]. In addition, for convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is a schematic one, and the position and shape of the actual electron emitting portion are faithfully represented. Not necessarily.

In the above-described surface conduction electron-emitting devices, such as the device by M. Hartwell et al., The conductive thin film 3004 is subjected to an energization process called energization forming before the electron emission, so that the electron emission is performed. Forming part 3005 was common. That is, the energization forming means that a constant DC voltage is applied to both ends of the conductive thin film 3004, or a DC voltage which is boosted at a very slow rate of, for example, about 1 V / min, and current is applied. Electron-emitting portion 3005 in which the electrically conductive thin film 3004 is locally destroyed, deformed, or deteriorated, and is in an electrically high-resistance state.
Is to form Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. After the energization forming, the conductive thin film 30
When an appropriate voltage is applied to the element 04, electrons are emitted in the vicinity of the crack.

An example of the FE type is, for example, WPDyke
& W.W.Dolan, "Field emission", Advance in Electron
Physics, 8, 89 (1956) or CASpindt, "Phys
icalproperties of thin-film field emission catho
des with molybdenium cones ", J. Appl. Phys., 47, 524
8 (1976).

FIG. 16 is a cross-sectional view of an element according to CASpindt et al. As a typical example of the FE element structure. In the figure, reference numeral 3010 denotes a substrate; 3011, an emitter wiring made of a conductive material; and 3012, an emitter core.
Reference numeral 3013 denotes an insulating layer, and 3014 denotes a gate electrode.
This device comprises an emitter cone 3012 and a gate electrode 301.
By applying an appropriate voltage during the period 4, field emission is caused from the tip of the emitter cone 3012. Further, as another element configuration of the FE type, there is an example in which an emitter and a gate electrode are arranged on a substrate almost in parallel with the substrate plane, instead of the laminated structure as shown in FIG.

As an example of the MIM type, for example,
CAMead, "Operation of tunnel-emission Devices, J.
Appl. Phys., 32, 646 (1961) and the like are known. MIM
FIG. 17 shows a typical example of the element configuration of the mold. The figure is a sectional view, in which 3020 is a substrate, 3021 is a lower electrode made of metal, 3022 is a thin insulating layer having a thickness of about 100 Å, and 3023 is a thickness of 80 to 300.
The upper electrode is made of a metal of about Angstrom. M
In the IM type, by applying an appropriate voltage between the upper electrode 3023 and the lower electrode 3021, the upper electrode 3023
Causes electron emission from the surface of the substrate.

Since the above-mentioned cold cathode device can obtain electron emission at a lower temperature than the hot cathode device, the heating cathode
No need for tar. Therefore, the structure is simpler than that of the hot cathode element, and a fine element can be produced. Also,
Even if a large number of elements are arranged on a substrate at a high density, problems such as thermal melting of the substrate hardly occur. Also, unlike the hot cathode element, which operates by heating the heater, which has a low response speed, the cold cathode element has the advantage of a high response speed.

For this reason, research for applying the cold cathode device has been actively conducted.

For example, the surface conduction electron-emitting device has the advantage of being able to form a large number of devices over a large area because it has a particularly simple structure and is easy to manufacture among the cold cathode devices. Therefore, as disclosed in, for example, JP-A-64-31332, a method for arranging and driving a large number of elements has been studied.

As for the application of the surface conduction electron-emitting device, for example, an image forming apparatus such as an image display device and an image recording device, a charged beam source, and the like have been studied. In particular, as an application to an image display device, for example, USP 5,06
6,883 and JP-A-2-257551 and JP-A-4-24-2
As disclosed in Japanese Patent Application Publication No. 8137, an image display device using a combination of a surface conduction electron-emitting device and a phosphor that emits light when irradiated with an electron beam has been studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image display devices. For example, compared to a liquid crystal display device that has become widespread in recent years, it can be said that it is superior in that it does not require a backlight because it is a self-luminous type and that it has a wide viewing angle.

A method of driving a large number of FE types in a row is disclosed, for example, in US Pat. No. 4,904,895 by the present applicant. As an example of applying the FE type to an image display device, for example, R. Meyer et al. [R. Meyer: "Recent D
evelopment on Microtips Display at LETI ", Tech.Dige
st of 4th Int.Vacuum Microelectronics Conf., Nagah
ama, pp. 6-9 (1991)] is known.

An example in which a number of MIM types are arranged and applied to an image display device is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-55738.

[0015] Among the image forming apparatuses using the above-mentioned electron-emitting devices, a flat display device having a small depth has attracted attention as a replacement for a cathode-ray tube display device because of its space saving and light weight. .

FIG. 18 is a perspective view showing an example of a display panel portion forming a flat-panel image display device, in which a part of the panel is cut away to show the internal structure.

In the figure, 3115 is a rear plate, 3116
Denotes a side wall, 3117 denotes a face plate, and a rear plate 3115, a side wall 3116, and a fuse plate 3
117 forms an envelope (airtight container) for maintaining the inside of the display panel in a vacuum.

A substrate 3111 is fixed to the rear plate 3115, and nxm cold cathode elements 3112 are formed on the substrate 3111. (N and m are positive integers of 2 or more and are appropriately set according to the target number of display pixels.) Further, the n × m cold cathode elements 311 are provided.
2 are m row-directional wirings 3113 as shown in FIG.
And n column-directional wirings 3114. These substrate 3111, cold cathode element 3112, row direction wiring 3
The portion constituted by the 113 and the column direction wiring 3114 is called a multi-electron beam source. Also, the row direction wiring 31
An insulating layer (not shown) is formed between at least the portion where the column 13 and the column-directional wiring 3114 intersect, so that electrical insulation is maintained.

On the lower surface of the face plate 3117, a phosphor film 3118 made of a phosphor is formed, and phosphors (not shown) of three primary colors of red (R), green (G), and growth (B) are applied. Divided. A black body (not shown) is provided between the phosphors of the respective colors constituting the fluorescent film 3118, and a metal back 3119 made of Al or the like is formed on the surface of the fluorescent film 3118 on the rear plate 3115 side. ing.

Further, Dx1 to Dxm and Dy1 to Dy
n and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel and an electric circuit (not shown). Dx1 to Dxm are electrically connected to the row wiring 3113 of the multi-electron beam source, Dy1 to Dyn are connected to the column wiring 3114 of the multi-electron beam source, and Hv is electrically connected to the metal back 3119 supplying a high voltage.

The inside of the airtight container is 10 ^-6 Torr.
r, and as the display area of the image display device increases, means for preventing deformation or destruction of the rear plate 3115 and the face plate 3117 due to a pressure difference between the inside and the outside of the airtight container is required. . Rear plate 3115 and face plate 31
The method of increasing the thickness of not only increases the weight of the image display device, but also causes image distortion and parallax when viewed from an oblique direction. On the other hand, in FIG. 18, a structural support (called a spacer or a rib) 312 made of a relatively thin glass plate and supporting the atmospheric pressure is used.
0 is provided. In this way, the distance between the substrate 3111 on which the multi-beam electron source is formed and the face plate 3116 on which the fluorescent film 3118 is formed is usually kept at a sub-millimeter to several millimeters, and the inside of the airtight container is kept at a high vacuum as described above. ing.

In the image display apparatus using the above-described display panel, when a voltage is applied to each cold cathode element 3112 through the external terminals Dx1 to Dxm and Dy1 to Dyn, electrons are emitted from each cold cathode element 3112. At the same time, a high voltage of several hundred [V] to several tens [kV] is applied to the metal back 3119 through the external terminal Hv to accelerate the emitted electrons, and the face plate 3117
Collision with the inside. As a result, the phosphors of each color forming the fluorescent film 3118 are excited and emit light, and an image is displayed.

[0023]

The display panel of the image display device described above has the following problems.

First, there is a possibility that a part of the electrons emitted from the vicinity of the spacer 3120 hit the spacer 3120 or the action of the emitted electrons may cause the spacer to be charged. The electrons emitted from the cold cathode element 3112 due to the charging of the spacer are bent in their trajectories, reach a position different from the normal position on the phosphor, and the image near the spacer is distorted and displayed.

Second, in order to accelerate electrons emitted from the cold cathode device 3112, a high voltage of several hundred volts or more (ie, 1 k) is applied between the multi-beam electron and the face plate 3117.
V / mm or more), the spacer 3
There is a concern about creeping discharge on the surface of the H.120. In particular, when the spacer is charged as described above, discharge may be induced.

In order to solve this problem, it has been proposed to remove the charge by making a small current flow through the spacer (Japanese Patent Application Laid-Open Nos. 57-118355 and 57-118).
1-124031). There, a high-resistance thin film is formed on the surface of an insulating spacer so that a minute current flows on the surface of the spacer. The antistatic film used here is tin oxide or a mixed crystal thin film of tin oxide and indium oxide or a metal film.

The semiconductor type thin film such as tin oxide used in the above proposal is sensitive to a gas such as oxygen so that it is applied to a gas sensor, so that its resistance value easily changes in an atmosphere. In addition, since these materials or metal films have low specific resistance, it is necessary to form them in an island shape or to make them extremely thin in order to increase the resistance. That is, the conventional high-resistance film has drawbacks in that the reproducibility of film formation is difficult, and the resistance value is easily changed in a heating process such as frit sealing or baking in a display manufacturing process.

The amount of secondary electrons emitted when part of the electrons emitted from the vicinity of the spacer 3120 hits the high-resistance film depends on the state and thickness of the high-resistance film. When the film is formed in an island shape or as a very thin film, there is a disadvantage that the charged state varies in the plane of the high resistance film.

The present invention overcomes the drawbacks of the above-mentioned conventional spacers, and provides a highly stable antistatic film for a spacer and an image image forming apparatus using the same.

[0030]

The object of the present invention is achieved by an electron beam apparatus having the following configuration. That is,
The present invention provides an envelope that maintains a vacuum atmosphere, an electron source for emitting electrons, an image forming member having a phosphor that emits light by collision of electrons, and an object for accelerating electrons toward the image forming member. In an image forming apparatus having an accelerating electrode and a spacer as a pressure-resistant structure, the spacer is covered with a high-resistance film , and the high-resistance film of the spacer has a maximum temperature equal to or higher than a maximum temperature in an assembly process of the present apparatus. It is characterized by being heat-treated at a temperature.

Further, in the above-mentioned image forming apparatus, the heat treatment of the spacer is performed in the same atmosphere as the step at the highest temperature in the assembling step of the present apparatus. Further, the high-resistance film covering the spacer is made of at least one material selected from nickel oxide, iron oxide, zinc oxide, and chromium oxide. Further, the thickness of the high-resistance film covering the spacer is 20 nm.
It is characterized by the above. Further, the power consumption per spacer is 1 W or less.
Further, the spacer is made of glass containing Na,
A silicon nitride film is provided between the spacer and the high resistance film. In addition, the high resistance film is electrically connected to the driving wiring of the electron source and the acceleration electrode. Further, the high resistance film is electrically connected to the driving wiring of the electron source and the acceleration electrode via a low resistance film.

In the above-mentioned image forming apparatus, the electron source is a plurality of surface conduction electron-emitting devices. In the above image forming apparatus, the spacer is covered with a high-resistance film, and the high-resistance film is formed of NiO.
In the case of a film, the film thickness is 20 to 50 nm, and Fe ₂ O ₃
In the case of a film, its thickness is 50 to 300 nm, and ZnO
In the case of a film, the film thickness is 10 to 20 nm, and Cr ₂ O ₃
In the case of a film, its thickness is 50 to 300 nm. Further, the image display device according to the present invention applies the signal according to the image signal to the electron-emitting devices formed at the matrix cross points, so that the image can be visually recognized on the face plate. It is characterized by using a forming device.

[Operation] Next, the spacer which is an important component in the image forming apparatus of the present invention will be described in detail with reference to FIG.

(Material of Spacer 1020) The spacer 1020 has an insulating property enough to withstand a high voltage of about 1 KV to 30 KV applied between the electron source row wiring 1014 and the metal back 1019, and has the atmospheric pressure or the like. Any material can be used as long as it can prevent the envelope from being broken by an unexpected impact and does not break in the sealing process.

Examples of the insulating substrate 1 of the spacer 1020 include quartz glass, blue plate glass, and ceramic members such as alumina. It is preferable that the coefficient of thermal expansion is close to the members forming the insulating substrate of the envelope and the electron source.

(Regarding High Resistance Film 2) The high resistance film 2 has an antistatic effect and needs to have a small leak current even when a high voltage is applied to both ends of the spacer 1020. Considering these, the surface resistance is preferably in the range of 10 ⁵ to 10 ¹² (ohm / □).

As this material, if a single material is used to obtain a predetermined surface resistance, for example, semiconductors such as silicon, germanium and gallium arsenide, and oxide semiconductors such as tin oxide, nickel oxide and zinc oxide are used. Can be used.

However, actually, the surface resistance value is 10 ⁵
The material in the range of 10 to 10 ¹² (ohm / square) is close to a dielectric material, and it is a fact that a preferable material cannot be obtained unless the film thickness, film formation conditions, and the like are sufficiently examined.

As will be described in detail in the embodiments, since the image forming apparatus is processed at a high temperature of 400 to 500 ° C. when assembled, it is necessary to use a material which does not undergo oxidation or decomposition reaction at the assembly temperature. is there. Although it is desirable to use a material that does not change the surface resistance,
Materials and combination ratios must be designed so that a predetermined surface resistance value is obtained after a high temperature treatment at 400 to 500 ° C.

The high resistance film 2 is further required to have some characteristics. One is that the temperature change of the surface resistance value is small. In general, as the temperature of a semiconductor film increases, the number of carriers that carry charges increases, and the resistance value decreases. However, when a high voltage is applied to the spacer 1020, the spacer 1020 is heated by a leak current, and when the resistance value further decreases, a thermal runaway occurs in which a current flows more and more.

Therefore, the surface resistance of the high resistance film 2 is 10
It is necessary to select a material so that even if the temperature rises to 0 ° C., it does not decrease to (1/10) or less.

Another is that the change in the surface resistance of the high-resistance film 2 is small even after the image forming apparatus has been operated for a long time.

As described above, the electrons emitted from the electron source collide with the phosphor, the spacer, and the residual gas molecules to generate various ions. These ions and residual gas molecules are gradually deposited on the high-resistance film 2. Therefore, a material whose resistance value largely changes by surface adsorption (usually, the resistance value decreases by adsorption) is not preferable. According to the results of the experiment, when the thickness of the high-resistance film 2 is 20 nm or less, the surface resistance changes greatly with time.

In the case of a spacer substrate containing a large amount of an alkali component such as soda lime glass, sodium element or the like precipitates on the substrate surface when a high temperature is applied during assembly and sealing as an image display or when a high voltage is applied. Or to form. Due to this effect, the connection between the spacer and the upper and lower plates becomes defective, or a region having low resistance is formed.

When the resistance value of the spacer changes depending on the place (height direction), the formed image is disturbed as follows. (1) Face plate 1017 with phosphor 1018
When the surface resistance of the spacer 1020 increases in the vicinity of, the electric field concentrates on the face plate 1017 side, and the electron beam bends away from the spacer 1020. Even when the electrical connection between the spacer 1020 and the face plate 1017 is poor, the electron beam is similarly bent. (2) When the surface resistance of the spacer increases near the rear plate side where the electron source substrate is located, the electric field concentrates on the rear plate side, and the electron beam bends toward the spacer. Even when the electrical connection between the spacer 1020 and the electron source wiring is defective, the electron beam is similarly bent.

As a result of the inventor's diligent studies, it has been found that the surface resistance of the spacer 1020 does not cause unevenness in location.
That is, it has been found that in order to stabilize the resistance value of the spacer 1020, it is effective to perform a heat treatment at a temperature equal to or higher than the maximum temperature at which a high resistance value is received in the assembly process of the image forming apparatus. Further, it was also found that heat treatment in the same atmosphere as in the step of assembling the image forming apparatus at the highest temperature is effective in stabilizing the resistance value of the spacer 1020 during the assembling step.

As a high-resistance film material satisfying the resistance value range of the spacer 1020, nickel oxide, iron oxide, zinc oxide, and chromium oxide are suitable. These materials are used as spacers 10
As a method of coating on 20, a vacuum evaporation method, a sputtering method,
A vacuum film forming method such as a chemical vapor deposition method, or a method in which an organic solvent or a dispersion solution method is applied by dipping or spin coating, followed by baking is applicable, and is appropriately selected according to a target material. .

Further, in order to suppress the influence of the substrate, an undercoating layer 61 shown in FIG. 6 having an effect of blocking the diffusion of the alkali element into the high resistance film 2 is provided between the spacer substrate 1 and the high resistance film 2. Can also be provided.

The undercoat layer 61 is preferably made of a material capable of forming a dense film.
A great effect can be obtained by providing a thickness of 0 nm or more, preferably 200 nm or more.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION

[Configuration and Manufacturing Method of Display Panel of Image Forming Apparatus] Next, the configuration and manufacturing method of the display panel of the image forming apparatus to which the present invention is applied will be described with reference to specific examples.

FIG. 1 is a perspective view of a display panel used in the embodiment, in which a part of the panel is cut away to show the internal structure.

In the figure, 1015 is a rear plate, 1016
Is a side wall, 1017 is a face plate, and 1015
An airtight container for maintaining the inside of the display panel at a vacuum is formed by 1017 to 1017. When assembling an airtight container, it is necessary to seal the joints of each material to maintain sufficient strength and airtightness.For example, apply frit glass to the joints, Sealing was achieved by baking at 400 to 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container to a vacuum will be described later. The inside of the airtight container is 1
Since the vacuum is maintained at about 0 ^-6 [Torr], the spacer 1020 is provided as an atmospheric pressure resistant structure by a method for preventing the hermetic container from being broken by the atmospheric pressure or an unexpected impact.

The rear plate 1015 has a substrate 1011
Is fixed, but the cold cathode element 1012 is provided on the substrate.
Are formed n × m. Here, n and m are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. For example, in an image forming apparatus for displaying high-definition television, n = 3000, m =
It is desirable to set the number to 1000 or more. The nx
The m cold cathode devices are arranged in a simple matrix by m row wirings 1013 and n column wirings 1014. The portion constituted by 1011 to 1014 is called a multi-electron beam source.

[Configuration of Multi-Electron Beam Source] The multi-electron beam source used in the image forming apparatus of the present invention is limited to the material, shape, or manufacturing method of the cold cathode element as long as the cold cathode elements are arranged in a simple matrix wiring. There is no. Therefore,
For example, a surface conduction type emission element, FE type, or MIM
A cold cathode device such as a mold can be used.

Next, the structure of a multi-electron beam source in which a surface conduction electron-emitting device (described later) as a cold cathode device is arranged on a substrate and wired in a simple matrix will be described.

FIG. 2 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate 1011, surface conduction type emission devices similar to those shown in FIG. 102 to be described later are arranged.
03 and the column direction wiring electrodes 1004 are wired in a simple matrix. An insulating layer (not shown) is formed between the electrodes at the intersections of the row wiring electrodes 1003 and the column wiring electrodes 1004, so that electrical insulation is maintained.

FIG. 3 shows a section taken along the line BB 'of FIG.

The multi-electron source having such a structure is as follows.
After previously forming a row direction electrode 1003, a column direction wiring electrode 1004, an interelectrode insulating layer (not shown), a device electrode of a surface conduction electron-emitting device and a conductive thin film on a substrate, the row direction electrode 1003 and the column direction are formed. The device was manufactured by supplying power to each element via the wiring electrode 1004 and performing an energization forming process (described later) and an energization activation process (described below).

In the present embodiment, the substrate 1011 of the multi-electron beam source is fixed to the rear plate 1015 of the airtight container.
When 11 has a sufficient strength, the substrate 10 of the multi-electron beam source is used as a rear plate of the hermetic container.
11 itself may be used.

A fluorescent film 1018 is formed on the lower surface of the face plate 1017. In the present embodiment, a color display device is used.
Phosphors of three primary colors of red, green and blue used in the field of RT are separately applied. The phosphors of the respective colors are separately applied in stripes as shown in FIG. 4A, for example, and black conductors 1010 are provided between the stripes of the phosphors. The purpose of providing the black conductor 1010 is to prevent the display color from shifting even if the electron beam irradiation position is slightly shifted, and to prevent the reflection of external light to prevent the display contrast from lowering. And preventing charge-up of the fluorescent film by the electron beam. Although graphite is used as a main component for the black conductor 1010, any other material may be used as long as it is suitable for the above purpose.

The method of applying the phosphors of the three primary colors is not limited to the stripe arrangement shown in FIG. 4A, but may be, for example, a delta arrangement as shown in FIG. Other arrangements may be used.

When a monochrome display panel is manufactured, a monochromatic phosphor material may be used for the phosphor film 1018, and a black conductive material is not necessarily used.

Further, as shown in FIG.
A metal back 1019 known in the field of CRT is provided on the surface on the rear plate side. Metal back 101
The purpose of providing 9 is to improve the light utilization rate by mirror-reflecting a part of the light emitted from the fluorescent film 1018, to protect the fluorescent film 1018 from the collision of negative ions, and to apply an electron beam accelerating voltage. Function as an electrode for the fluorescent film 1
018 acts as a conductive path for the excited electrons. The metal back 1019 was formed by forming the fluorescent film 1018 on the face plate substrate 1017, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon. Note that when a fluorescent material for low voltage is used for the fluorescent film 1018, the metal back 1019 is not used.

Although not used in the present embodiment, for the purpose of applying an acceleration voltage and improving the conductivity of the fluorescent film, a transparent material made of, for example, ITO is used between the face plate substrate 1017 and the fluorescent film 1018. Electrodes may be provided.

FIG. 5 is a schematic cross-sectional view taken along the line AA 'of FIG. 1, and the numbers of the respective parts correspond to those of FIG. Spacer 102
Numeral 0 indicates that a high-resistance film 2 for preventing static electricity is formed on the surface of the insulating member 1, and is arranged as many as necessary and at necessary intervals to support the atmosphere. And is fixed to the surface of the substrate 1011 by a bonding material 1040. The high resistance film 2 is formed on at least the surface of the insulating member 1 that is exposed to the vacuum in the hermetic container, and the low resistance film 62 on the spacer 1020 is formed.
And the face plate 10 via the bonding material 1041.
17 (metal back 1019 etc.) and substrate 101
1 (row direction wiring 1013 or column direction wiring 101)
4) is electrically connected. In the embodiment described here, the spacer 1020 has a thin plate shape, is arranged in parallel with the row wiring 1013, and is electrically connected to the row wiring 1013.

As the spacer 1020, the substrate 1011
Has insulating properties enough to withstand high voltage applied between the upper row direction wiring 1013 and column direction wiring 1014 and the metal back 1019 on the inner surface of the face plate 1017;
In addition, it is necessary to have conductivity enough to prevent the surface of the spacer 1020 from being charged. This is as described above.

Examples of the insulating member 1 of the spacer 1020 include quartz glass, glass with a reduced impurity content such as Na, soda lime glass, and ceramic members such as alumina. Note that the insulating member preferably has a coefficient of thermal expansion close to that of the member forming the airtight container and the substrate 1011.

As described above, the surface resistance Rs of the high-resistance film 2 is 10 ⁵ [Ω / cm] in consideration of maintaining the antistatic effect and suppressing power consumption due to leakage current.
[□] to 10 ¹² [Ω / □], and the various materials described above are used as the material.

As shown in FIG. 6, the low-resistance film 62
What is necessary is just to select a resistance value sufficiently lower than that of the high-resistance film 2,
Ni, Cr, Au, Mo, W, Pt, Ti, Al, C
metals or alloys such as u, Pd, and Pd, Ag, A
u, RuO ₂ , Pd-Ag or other metal or metal oxide and a printed conductor made of glass or the like, or In ₂ O ₃ —S
It is appropriately selected from a transparent conductor such as nO ₂ and a semiconductor material such as polysilicon.

The bonding material 1041 needs to have conductivity so that the spacer 1020 is electrically connected to the row wiring 1013 and the metal back 1019. That is, frit glass to which a conductive adhesive, metal particles, or a conductive filler is added is preferable.

Further, Dx1 to Dxm and Dy1 to Dyn
And Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel to an electric circuit (not shown). Dx1 to Dxm are electrically connected to the row wiring 1013 of the multi-electron beam source, Dy1 to Dyn are electrically connected to the column wiring 1014 of the multi-electron beam source, and Hv is electrically connected to the metal back 1019 of the face plate.

In order to evacuate the inside of the hermetic container to a vacuum, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is evacuated to a degree of vacuum of about 10 ^-7 [Torr]. Exhaust until After that, the exhaust pipe is sealed,
In order to maintain the degree of vacuum in the airtight container, a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after sealing. The getter film is, for example, a film formed by heating and depositing a getter material containing Ba as a main component by a heater or high-frequency heating, and the inside of the hermetic container is 1 × 10 ⁻⁵ or 1 × due to the adsorbing action of the getter film. 1
The degree of vacuum is maintained at 0 ^-7 [Torr].

In the image forming apparatus using the display panel described above, when a voltage is applied to each cold cathode element 1012 through the external terminals Dx1 to Dxm and Dy1 to Dyn, electrons are emitted from each cold cathode element 1012. At the same time, a high voltage of several hundred [V] to several tens [kV] is applied to the metal back 1019 through the external terminal Hv to accelerate the emitted electrons, and the face plate 1017
Collision with the inside. As a result, the phosphor of each color forming the fluorescent film 1018 is excited and emits light, and an image is displayed.

Normally, the voltage applied to 1012 to the surface conduction electron-emitting device of the present invention, which is a cold cathode device, is 12 to 16
[V], metal back 1019 and cold cathode element 101
The distance d between the metal back 1019 and the cold cathode element 1012 is between 0.1 [mm] and 8 [mm].
It is about 1 [kV] to about 10 [kV].

The basic configuration and manufacturing method of the display panel according to the embodiment of the present invention and the outline of the image forming apparatus have been described above.

[Method of Manufacturing Multi-Electron Beam Source]
A method for manufacturing the multi-electron beam source used for the display panel of the embodiment will be described. The material, shape, and manufacturing method of the cold cathode device are not limited as long as the multi-electron beam source used in the image forming apparatus of the present invention is an electron source in which cold cathode devices are arranged in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction type emission device, an FE type, or an MIM type can be used.

However, under the circumstances where an inexpensive forming apparatus having a large surface screen is required, among these cold cathode devices, a surface conduction type emission device is particularly preferable. That is, in the FE type, since the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics, extremely high-precision manufacturing technology is required, but this achieves a large area and a reduction in manufacturing cost. Is a disadvantageous factor. In the case of the MIM type, it is necessary to make the thicknesses of the insulating layer and the upper electrode thin and uniform, which is also a disadvantageous factor in achieving a large area and a reduction in manufacturing cost. On the other hand, since the surface conduction electron-emitting device has a relatively simple manufacturing method, it is easy to increase the area and reduce the manufacturing cost. In addition, the inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have particularly excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-luminance, large-screen image forming apparatus. Therefore, in the display panel of the above embodiment, a surface conduction electron-emitting device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is used. Therefore, the basic configuration, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron beam source in which many devices are arranged in a simple matrix will be described.

A typical configuration of a surface conduction electron-emitting device in which an electron-emitting portion or its peripheral portion is formed from a fine particle film includes:
There are two types, a flat type and a vertical type. (Flat-type surface conduction electron-emitting device) First, an element configuration and a manufacturing method of a flat-type surface conduction electron-emitting device will be described. FIG. 7 is a plan view (a) and a cross-sectional view (b) for describing the configuration of a planar surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1103 are device electrodes, 1104 is a conductive thin film, 1105 is an electron-emitting portion formed by energization forming, and 1113 is a thin film formed by energization activation.

As the substrate 1101, for example, various glass substrates such as quartz glass and blue plate glass, various ceramic substrates such as alumina, or an insulating layer made of, for example, SiO ₂ is formed on the various substrates described above. A laminated substrate or the like can be used.

The device electrodes 1102 and 1103 provided on the substrate 1101 so as to be parallel to the substrate surface are formed of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
A material such as Ag or the like, an alloy of these metals, a metal oxide such as In ₂ O ₃ —SnO ₂ , or a semiconductor such as polysilicon may be appropriately selected and used. . An electrode can be easily formed by using a combination of a film forming technique such as vacuum evaporation and a patterning technique such as photolithography and etching. However, the electrode can be formed by other methods (for example, printing technique). I can't wait.

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
Generally, the electrode spacing L is usually designed by selecting an appropriate value from the range of several hundreds of angstroms to several hundreds of micrometers. It is in the range of ten micrometers. Further, regarding the thickness d of the device electrode,
Usually, an appropriate numerical value is selected from the range of several hundred angstroms to several micrometers.

A fine particle film is used for the conductive thin film 1104. The fine particle film mentioned here is a film containing a large number of fine particles (including an island-shaped aggregate)
I mean If you examine the microparticle film microscopically, usually
A structure in which the individual fine particles are spaced apart, a structure in which the fine particles are adjacent to each other, or a structure in which the fine particles overlap each other is observed.

The particle size of the fine particles used in the fine particle film is in the range of several Angstroms to several thousand Angstroms, and preferably in the range of 10 Angstroms to 200 Angstroms. Further, the thickness of the fine particle film is appropriately set in consideration of various conditions described below. That is, the device electrode 11
02, or 1103, conditions necessary for satisfactorily performing energization forming described later, conditions necessary for setting the electric resistance of the fine particle film itself to an appropriate value described later. , And so on. In particular,
The setting is made in the range of several Angstroms to several thousand Angstroms, and a preferable value is between 10 Angstroms and 500 Angstroms.

Also, it can be used to form a fine particle film.
Materials such as Pd, Pt, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Ta,
Metals such as W, Pb, etc., PdO, AnO
_Two , In_Two O_Three , PbO, Sb _Two O_Three , Etc.
Oxide or HfB_Two , ZrB_Two , LaB₆ , CeB
₆ , YB_Four , GdB_Four , And other borides,
TiC, ZrC, HfC, TaC, SiC, WC, etc.
And TiN, ZrN, HfN,
Such as nitride, Si, Ge, etc.
Semiconductors, carbon, etc.
Is selected as appropriate.

As described above, the conductive thin film 1104 is formed of a fine particle film.
It was set to be included from 10 ³ to a range of 10 ⁷ ohms / sq].

The conductive thin film 1104 and the device electrode 11
Since it is desirable that the wires 02 and 1103 be electrically connected well, they have a structure in which a part of each overlaps with the other. In the example of FIG. 7, the overlapping manner is such that the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, but in some cases, the substrate, the conductive thin film, and the device electrode are stacked in this order from the bottom. I can't wait.

The electron emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has an electrically higher resistance than the surrounding conductive thin film. The crack is formed by performing a later-described energization forming process on the conductive thin film 1104. Fine particles having a particle size of several Angstroms to several hundred Angstroms may be arranged in the crack. Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion, they are schematically shown in FIG.

The thin film 1113 is a thin film made of carbon or a carbon compound, and covers the electron emitting portion 1105 and its vicinity. The thin film 1113 is formed by performing an energization activation process described later after the energization forming process.

The thin film 1113 is made of any one of single crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 [Å] or less, but 300 [Å] or less. Is more preferred. The actual thin film 1113
Since it is difficult to precisely illustrate the position and the shape of, they are schematically shown in FIG. In addition, in the plan view (a), an element in which a part of the thin film 1113 is removed is illustrated.

The basic structure of the preferred element has been described above. In the embodiment, the following element is used.

That is, blue glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrode was 1000 [angstrom], and the electrode interval L was 2 [micrometer].

Pd or P as the main material of the fine particle film
Using dO, the thickness of the fine particle film was set to about 100 [angstrom], and the width W was set to 100 [micrometer].

(Manufacturing Method of Planar Surface Conduction Emission Device) Next, a preferred method of manufacturing a flat surface conduction electron-emitting device will be described. FIGS. 8A to 8D are cross-sectional views for explaining a manufacturing process of the surface conduction electron-emitting device. The notation of each member is the same as that in FIG.

(1) First, as shown in FIG. 8A, device electrodes 1102 and 1103 are formed on a substrate 1101.

Before forming, the substrate 1
After sufficiently washing 101 with a detergent, pure water and an organic solvent,
The material for the device electrode is deposited (as a deposition method,
For example, a vacuum film forming technique such as an evaporation method or a sputtering method may be used. ). Thereafter, the deposited electrode material is patterned by using a photolithography / etching technique, and a pair of device electrodes (1102 and 1102) shown in FIG.
Form 3).

(2) Next, as shown in FIG. 8B, a conductive thin film 1104 is formed.

In forming, first, an organic metal solution is applied to the substrate (a), dried, heated and baked to form a fine particle film, and then patterned into a predetermined shape by photolithography and etching. . here,
The organic metal solution is a solution of an organic metal compound whose main element is a material of fine particles used for the conductive thin film (specifically, Pd is used as a main element in the present embodiment. In the embodiment, coating is performed. As the method, a dipping method was used, but a spinner method or a spray method may be used.

As a method for forming a conductive thin film made of a fine particle film, a method other than the method of applying an organic metal solution used in the present embodiment, for example, a vacuum evaporation method, a sputtering method, or a chemical vapor deposition method Method may be used.

(3) Next, as shown in FIG. 8C, the forming electrodes 1110 and 1112 are supplied from the forming power supply 1110.
The electron emitting portion 1105 is formed by applying an appropriate voltage during the period 03 and performing the energization forming process.

The energization forming treatment is to energize the conductive film thin film 1104 made of a fine particle film and to appropriately break, deform, or alter a part of the conductive film thin film 1104 to change into a structure suitable for emitting electrons. This is the process that causes A portion of the conductive thin film made of a fine particle film that has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 110
In 5), an appropriate crack is formed in the thin film.
Note that the electrical resistance measured between the device electrodes 1102 and 1103 is significantly increased after the formation of the electron emission portions 1105 as compared to before the formation.

FIG. 9 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 in order to explain the energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulse-like voltage is preferable. In the case of this embodiment, a triangular wave pulse having a pulse width T1 is continuously generated at a pulse interval T2 as shown in FIG. Was applied. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. Also, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 are inserted at appropriate intervals between the triangular-wave pulses, and the current flowing at that time is measured by an ammeter 11.
11 was measured.

In the embodiment, for example, 10 ⁻⁵ [t
orr], for example, the pulse width T1 is 1 [millisecond], the pulse interval T2 is 10 [millisecond], and the peak value Vpf is 0.1 [V] for each pulse.
The pressure was increased. Then, the monitor pulse Pm was inserted at a rate of one every time five triangular waves were applied. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. The electric resistance between the device electrodes 1102 and 1103 is 1
When the current reaches × 10 ⁶ [Ohm], that is, the current measured by the ammeter 1111 when the monitor pulse is applied is 1 × 1
At the stage when the value became 0 ^-7 [A] or less, the energization related to the forming process was terminated.

The above method is a preferable method for the surface conduction electron-emitting device of the present embodiment. For example, the design of the surface conduction electron-emitting device such as the material and film thickness of the fine particle film or the element electrode interval L is changed. In such a case, it is desirable to appropriately change the energization conditions accordingly.

(4) Next, as shown in FIG.
The device electrodes 1102 and 1103 are supplied from the activation power source 1112.
During the energization activation process, apply an appropriate voltage during
Improve electron emission characteristics.

The energization activation process is a process of energizing the electron-emitting portion 1105 formed by the energization forming process under appropriate conditions and depositing carbon or a carbon compound in the vicinity thereof (in the figure). Shows a deposit made of carbon or a carbon compound as a member 1113.) Note that by performing the energization activation process, the emission current at the same applied voltage can be typically increased by 100 times or more as compared with before the energization activation process.

Specifically, 10 ⁻⁴ to 10 ⁻⁵ [tor
r], a voltage pulse is periodically applied in a vacuum atmosphere to deposit carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere.
The deposit 1113 is one of single-crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 Å or less, and more preferably 300 Å or less.

FIG. 10A shows an example of an appropriate voltage waveform applied from the activation power supply 1112 in order to explain the energization method in more detail. In the present embodiment, the energization activation process is performed by periodically applying a rectangular wave of a constant voltage. Specifically, the rectangular wave voltage Vac is 14
[V], pulse width T3 is 1 [millisecond], pulse interval T4
Was set to 10 [milliseconds]. The above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed,
It is desirable to change the conditions accordingly.

An anode electrode 1114 shown in FIG. 8D is used to capture an emission current Ie emitted from the surface conduction electron-emitting device. The anode electrode 1114 is connected to a DC high voltage power supply 1115 and an ammeter 1116 (FIG. 8D). Note that the substrate 1101 is
When the activation process is performed after being incorporated in the display panel, the phosphor screen of the display panel is used as the anode electrode 1114. ). While a voltage is applied from the activation power supply 1112, the emission current Ie is measured by the ammeter 1116 to monitor the progress of the energization activation process, and the activation power supply 111
2 is controlled. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG.
When the pulse voltage starts to be applied from 112, the emission current Ie increases with time, but eventually saturates and hardly increases. As described above, when the emission current Ie is substantially saturated, the application of the voltage from the activation power supply 1112 is stopped, and the energization activation process ends.

The above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, the conditions should be changed accordingly. desirable.

As described above, the flat surface conduction electron-emitting device shown in FIG. 8E was manufactured.

(Vertical Type Surface Conduction Emission Element) Next, another typical structure of a surface conduction type emission element in which an electron emission portion or its periphery is formed of a fine particle film, that is, a vertical type surface conduction emission device. The configuration of the element will be described.

FIG. 11 is a schematic cross-sectional view for explaining the basic structure of a vertical type. In FIG.
202 and 1203 are device electrodes, 1206 is a step forming member, 1204 is a conductive thin film using a fine particle film, 1205
Are electron-emitting portions formed by an energization forming process;
213 is a thin film formed by activation of current.

The difference between the vertical type and the planar type described above is that one of the device electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 is provided on the side surface of the step forming member 1206. It is in the point of coating. Therefore, the element electrode interval L in the planar type shown in FIG.
Is the step height L of the step forming member 1206 in the vertical type.
s. In addition, the substrate 1201, the element electrode 1
202 and 1203, conductive thin film 1 using fine particle film
204, the materials listed in the description of the planar type can be used in the same manner. For the step forming member 1206, an electrically insulating material such as SiO ₂ is used.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 12A to 12F are cross-sectional views for explaining a manufacturing process.
Same as 1.

(1) First, as shown in FIG.
An element electrode 1203 is formed over a substrate 1201.

(2) Next, as shown in FIG.
An insulating layer for forming the step forming member is laminated. The insulating layer may be formed by stacking, for example, SiO ₂ by a sputtering method, but another film forming method such as a vacuum evaporation method or a printing method may be used.

(3) Next, as shown in FIG.
An element electrode 1202 is formed over the insulating layer.

(4) Next, as shown in FIG.
A part of the insulating layer is removed by using, for example, an etching method, so that the element electrode 1203 is exposed.

(5) In order, as shown in FIG.
A conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the flat type, a film forming technique such as a coating method may be used.

(6) Next, as in the case of the flat type,
An energization forming process is performed to form an electron emission portion.
(The same process as the planar type energization forming process described with reference to FIG. 8C may be performed.) (7) Next, as in the case of the planar type, the energization activation process is performed, and electron emission is performed. Carbon or a carbon compound is deposited near the part (FIG. 8
What is necessary is just to perform the same process as the planar type energization activation process described using (d). ).

As described above, the vertical type surface conduction electron-emitting device shown in FIG.

(Characteristics of Surface Conduction Emission Device Used in Image Forming Apparatus) The element structure and manufacturing method of the planar and vertical surface conduction electron emitting elements have been described above. The characteristics of will be described.

FIG. 13 shows an example of the elements using the image forming apparatus.
Typical examples of (discharge current Ie) versus (element applied voltage Vf) characteristics and (element current If) versus (element applied voltage Vf) characteristics are shown. Note that the emission current Ie is significantly smaller than the element current If, and it is difficult to show them on the same scale. In addition, these characteristics are changed by changing design parameters such as the size and shape of the element. Therefore, 2
The graphs in the book are shown in arbitrary units.

The element used in the image forming apparatus has an emission current I
e has three characteristics described below.

First, a certain voltage (this is referred to as a threshold voltage Vth
The emission current Ie sharply increases when a voltage having the above magnitude is applied to the element, but the emission current Ie is hardly detected at a voltage lower than the threshold voltage Vth.

That is, the non-linear element has a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie changes depending on the voltage Vf applied to the element, the emission current Ie varies with the voltage Vf.
The magnitude of e can be controlled.

Third, since the response speed of the current Ie emitted from the element is faster with respect to the voltage Vf applied to the element, the amount of charge of the electrons emitted from the element depends on the length of time for applying the voltage Vf. Can control.

Because of the above characteristics, the surface conduction electron-emitting device could be suitably used in an image forming apparatus. For example, in a display device in which a large number of elements are provided corresponding to pixels of a display screen, if the first characteristic is used, display can be performed by sequentially scanning the display screen. That is, a voltage equal to or higher than the threshold voltage Vth is appropriately applied to the element being driven, and a voltage lower than the threshold voltage Vth is applied to the element in a non-selected state. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

Further, by using the second characteristic or the third characteristic, the light emission luminance can be controlled, so that gradation display can be performed.

(Structure of a multi-electron beam source in which a large number of elements are arranged in a simple matrix) Next, the structure of a multi-electron beam source in which the above-mentioned surface conduction electron-emitting devices are arranged on a substrate and arranged in a simple matrix will be described.

FIG. 2 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate, surface conduction type emission elements similar to those shown in the above-mentioned figures are arranged, and these elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. Row direction wiring electrode 1003 and column direction wiring electrode 1
At the intersection of 004, an insulating layer (not shown) is provided between the electrodes.
Are formed, and electrical insulation is maintained.

FIG. 3 shows a cross section taken along the line BB 'in FIG. The multi-electron source having such a structure is provided in advance by using the row-direction wiring electrode 1003 and the column-direction wiring electrode 1 on the substrate.
004, after forming an interelectrode insulating layer (not shown), a device electrode of a surface conduction electron-emitting device, and a conductive thin film, power is supplied to each device via a row direction wiring electrode 1003 and a column direction wiring electrode 1004 to energize the device. It was manufactured by performing a forming process and a current activation process.

[0134]

【Example】

Embodiment 1 The flat plate spacer 1020 of this embodiment has a height of 3 mm, a thickness of 200 μm, and a length of 40 mm, and is made of an insulating substrate 1 of soda lime glass. A 0.5 μm thick silicon nitride film is formed thereon as an Na block layer 61.
A high-resistance film 2 made of nickel oxide was formed thereon.

The silicon nitride film and the nickel oxide film used in this example were formed using a sputtering apparatus. For the silicon nitride film, the silicon target was set at a partial pressure ratio of argon and nitrogen of 1: 1 and the sputtering pressure was set at 0.6 Pa.
A high-frequency power of 00 W was applied for 40 minutes to form a film.

As for the nickel oxide film, the NiO target was formed by setting the partial pressure ratio of argon and oxygen to 4: 1, and the sputtering pressure to 0.6 Pa.
, And a high-frequency power of 500 W is applied for 20 minutes.
A film was formed to a thickness of 50 nm. At this time, the surface resistance of the nickel oxide film was 3.5 × 10 ⁸ (Ω / □), and the resistance per spacer was 1.2 × 10 ⁷ Ω.

The spacer 10 of the first embodiment created here
Sample No. 20 was subjected to a heat treatment for 1 hour in an electric furnace in a clean atmosphere at a maximum temperature of 430 ° C. which is heated in a display device assembling step described below. The reason will be described later.

Next, the spacer 1020 is further provided with a low resistance film 62 in a 100 μm band shape in parallel with the connection portion between the face plate and the rear plate.
An Au film having a thickness of μm was formed.

Next, the spacer is connected to the metal back on the X-direction wiring and the face plate using conductive frit glass. The conductive frit glass used was a mixture of frit glass and conductive fine particles, and was electrically connected to the antistatic (high resistance 2) film on the spacer surface and the X-directional wiring or face plate.

Frit glass is a low-melting glass containing a large amount of lead. The sealing temperature (for fusing the insulating substrate 1 and the X-direction wiring or the face plate and the frit glass) is usually 300 ° C. to 500 ° C.

More specifically, a frit glass paste is previously printed on the X-direction wiring to which the frit glass powder paste dispersed in the solvent is to be connected and on the metal back portion on the face plate.

Next, for example, the rear plate is placed on a hot plate, and the insulating base material 1 is fixed at a predetermined position on the X-direction wiring to be connected by using an auxiliary jig made of quartz glass.

Next, heating is performed to a temperature at which the frit glass is sufficiently melted: for example, 430 ° C. After holding for about 30 minutes, the substrate was cooled and the insulating substrate 1 was set upright on the rear plate wiring.

Next, the support frame in which the paste powder frit glass is applied in advance to the rear plate and the face plate in which the paste powder frit glass is applied in advance to a predetermined metal back portion are fixed at predetermined positions. Temperature for sufficiently melting: In this example, heating was performed to 430 ° C. Similarly, after holding for about 30 minutes,
After cooling, the airtight container was assembled.

If there is a concern about the surface oxidation of the members used,
For example, it is preferable to assemble under a non-oxidizing atmosphere gas such as nitrogen. In view of the ease of the assembling process, it is preferable that the sealing is performed at a temperature as low as possible.

However, as for the sealing temperature, if the temperature does not reach a temperature at which the frit glass is sufficiently melted, connection cannot be performed with sufficient strength.

If the oxygen partial pressure is, for example, about 10%,
As oxidation proceeds in the same way as in air, under non-oxidizing atmosphere gas,
Assembling under conditions without surface oxidation is also difficult with a simple device configuration (eg, all assembly is automated).

The electron source formed on the rear plate is
One line of the X-direction wiring has 480 electron-emitting devices, and 240 lines in the Y-direction. Further, red, green, and blue phosphors are formed on the face plate so as to face the electron-emitting devices, respectively.

Thereafter, in order to form an electron emitting portion, an energization format process and an energization activation process were performed at room temperature.

To evacuate the inside of the airtight container completed as described above, after assembling the airtight container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the airtight container is evacuated to 10 ⁻⁷ T.
Evacuate to a degree of vacuum of about orr. In order to maintain the degree of vacuum in the airtight container, heating (up to about 300 ° C.) deaeration is performed within a range where the characteristics of the cold cathode element substrate are not deteriorated,
The exhaust pipe was fused and sealed with a gas burner. Finally, a getter process was performed to maintain the degree of vacuum after sealing.

The assembly of the image forming apparatus is completed by the above steps.
Approximately 1 hour from 420 ° C to 420 ° C, 200 ° C when degassing by heating
To about 300 ° C. for about 10 hours.

For this reason, if the material used for the high resistance film 2 changes in the film structure, composition, etc. in the heating step, the original surface resistance value may not be obtained.

The X-direction wiring and the Y-direction wiring of the image forming apparatus prepared by the above-described steps are connected to an image signal circuit (not shown) to display a television image, and image distortion (beam orbit bending) is performed by the following method. ) Was measured.

[Evaluation of Beam Orbit Deflection] In the above-described image evaluation apparatus, 5 kV was applied as the electron acceleration voltage Va, and a driving voltage of 20 V was applied to the electron-emitting devices, so that all the devices emitted light.

At this time, the row direction wiring (including 180 elements)
The current flowing in one line was 510 mA. The beam trajectory bends, for each element of the X-direction light emitting line closest to the spacer 1020, whether the trajectory does not bend as designed or approaches the spacer 1020: no beam suction occurs, or the spacer 1020
Leave: Checked for beam rebound.

As a result, in Example 1, the orbit was not bent in the spacer.

Next, a method for measuring the “spacer surface resistance distribution” will be described.

In the image evaluation apparatus assembling step, after sealing the spacer to the face plate, a DC voltage of 100 V is applied to both ends of the spacer electrode between the metal back 1019 and the wiring electrode 1014 as a simple method.

Here, the low resistance film on the rear plate side of the spacer 1020 is grounded.

Next, one end of the voltmeter probe is grounded, and the other probe electrode is shifted from the rear plate side to the face plate side while the spacer 102 is moved.
The potential distribution of a voltage of 100 V applied to 0 was measured.

If the resistance value of the spacer 1020 does not change in the height direction, the potential appearing at the probe electrode varies from the ground potential 0 at the rear plate contact to the potential 100 V at the face plate contact in proportion to the distance from the rear plate. Should increase linearly.

However, for example, when the connection between the plate and the spacer electrode portion is defective, the corresponding portion becomes high in resistance and the potential change becomes large. Further, for example, when the resistance near the face plate becomes small due to the influence of the adsorbed substance, the potential change becomes small at the corresponding portion.

In the first embodiment, 1.2 mm from the rear plate
mm, and 2.5 mm and 3.8 mm at the center, the measured values were 24 V, 51 V, and 77 V, respectively. If the linearity was obtained, the voltage would be 24 V, 50 V, and 76 V, respectively, and it was confirmed that Example 1 was a film having almost no deviation and having no favorable potential distribution.

[Durability Test Method with Image Evaluation Apparatus] Next, the method and the result of the durability test with the image evaluation apparatus will be described.

Using the image evaluation device, the electron acceleration voltage Va
, And a voltage pulse of 20 V, a pulse width of 50 μsec, and 60 Hz was applied to the electron-emitting device, and a durability test was performed continuously for 1000 hours.

Thereafter, the beam orbit bending was evaluated under the same conditions as described above.

At this time, the leak current flowing per spacer was 30 μA. In addition, since 20 spacers were arranged in one image evaluation device, the total leakage power was 3 W.

When the emission line was observed in the same manner, it was found that each element in each X-direction line adjacent to the spacer glowed without orbital bending as designed.

As described above, even after the lapse of 1000 hours, the light emission luminance slightly decreased and the leak current of the spacer increased, but it was at a level that could be used.

After disassembling the image evaluation apparatus having been operated for 1000 hours, the surface resistance distribution of the spacer of Example 1 was measured and evaluated by the same method as described above.

The results were measured at three places of 1.2 mm from the rear plate, 2.5 mm at the center, and 3.8 mm at the center, and were 25 V, 52 V, and 78 V, respectively. The film had no good potential distribution even after the durability test. It was confirmed that there was.

[Comparative Example 1] A high-resistance film 2 was prepared in the same manner as in Example 1 except that only the soda-lime glass insulating substrate 1 was used for the substrate 1 of the spacer 1020.
Comparative Example 1 having no spacer was produced.

Evaluation was performed in the same manner as in Example 1, and Table 1 shows the results.

When the beam trajectory is measured, the electron beam is attracted to the line close to the spacer 1020. The electrons that have been attracted and collided with the spacer surface are scattered and collide with the phosphor.
The outline of 020 looks whitish. If an RGB color phosphor screen is used, the outline will be colored (it turned green in the experiment). This phenomenon is called color unevenness.

Comparative Example 2-5 Example 1 was repeated except that the heat treatment temperature was changed before assembling the spacer 1020.
A spacer 1020 was prepared and measured and evaluated in exactly the same manner as described above.

The pretreatment temperature was 200 ° C. for Comparative Example 2, 300 ° C. for Comparative Example 3, 500 ° C. for Comparative Example 4, and 60 ° C. for Comparative Example 5.
0 ° C.

Comparing the results in Table 1, the spacer resistance values of Comparative Examples 2 and 3 which were heat-treated at a temperature lower than the temperature of the assembling process did not change much as compared with Example 1. However, when the resistance distribution was measured, the surface resistance increased near the rear plate. As a result, the beam trajectory showed a tendency to rebound. Also, the beam in the vicinity of the spacer 1020 had a large difference in the tendency of repulsion depending on the location (in some locations,
The behavior of beam suction was shown. ).

The reason for this is that the structure of the NiO film changes during the thermal process, but during assembly, for example, volatiles from the phosphor in the face plate, volatiles from the element substrate (specifically, sulfur, carbon, etc.) , Hydrocarbons, etc.) are adsorbed on the surface and incorporated into the film, and as a result, the film structure after the thermal process is considered to be different from that heat-treated under conditions free of these effects.

If the surface adsorption is not uniform, it is considered that the film after the heat treatment also has non-uniform characteristics.

The spacer resistance values of Comparative Examples 4 and 5 heat-treated at a temperature higher than the temperature of the assembling process tended to be smaller than that of Example 1.

It is considered that this is mainly because the alkali element such as Na in the insulating substrate 1 (soda glass) diffused through the SiN film to the NiO film to reduce the resistance value of the film.

In particular, in Comparative Example 5 which was heat-treated at 600 ° C., the resistance value of the high resistance film 2 (NiO) was too low, so that a high voltage could not be applied.

In order to prevent the film characteristics from changing during the assembling process, it is important to perform a heat treatment in advance at a temperature close to the highest temperature in the process. In addition, as long as an insulating substrate containing an element that changes the resistance value of the high-resistance film 2 at the temperature of the assembling process is used, it is not preferable to perform the heat treatment at a temperature much higher than the maximum temperature.

This is not limited to the NiO film, but generally applies to a material whose film structure changes at a temperature of about 500 ° C. and a material whose specific resistance value changes due to mixing of an alkali element.

[Example 2-5] In the same manner as in Example 1,
The spacer 1020 was manufactured by changing only the thickness of the high resistance film 2 (NiO), and the same evaluation was performed.

As shown in Table 1, when the thickness of the NiO film is 10 nm (Example 2), beam suction cannot be suppressed yet.

When the film thickness is 100 nm (Example 5), the resistance is too low to apply a high voltage. Therefore, the optimal thickness of the NiO film is 20 nm to 50 nm.

[Embodiment 6-11] As in Embodiment 1, as Embodiment 6-11, a high-resistance film 2 (Fe ₂ O ₃ )
The spacer 1020 was manufactured by changing only the film thickness of, and the same evaluation was performed.

As shown in Table 1, it can be seen from the results that the suction of the electron beam was suppressed. In Example 11 in which the film thickness of Fe ₂ O ₃ was 600 nm, the leakage current increased after the durability test, and a high voltage could not be applied, so that it could not be used. When the surface resistance distribution of the spacer was examined after an endurance test using an image evaluation apparatus, it was found that high resistance portions were formed on the face plate side in Examples 6 and 7 having a film thickness of 10 nm and 20 nm.
The beam should be repelled by the resistance distribution, but the film properties are somewhat beam-absorbing and seem to be exactly balanced. However, as shown in the above comparative example, uneven spots were observed,
Not preferred. Therefore, in the case of the Fe ₂ O ₃ film, 3
00 nm is the optimum film thickness.

Example 12-16 As in Example 1, as Example 12-16, a spacer 1020 was fabricated by changing only the thickness of the high-resistance film 2 (ZnO), and the same evaluation was performed. Was.

As shown in Table 1, beam absorption was observed at a film thickness of 5 nm (Example 12), and at a film thickness of 50 nm and 100 nm (Examples 15 and 16), the film had low resistance and a high voltage was applied. I can no longer do it. Therefore, 10 nm to 20 nm is the optimum film thickness.

[Embodiment 17-22] In the same manner as in Embodiment 1, as Embodiment 17-22, a high-resistance film 2 (Cr
_The spacer 1020 was manufactured by changing only the film thickness of ₂ O ₃ ), and the same evaluation was performed.

As shown in Table 1, when the film thickness was 10 nm (Example-17), beam suction was observed. At a film thickness of 600 nm (Example-22), large beam repulsion was observed after the durability test. This is because a high resistance portion was formed on the face plate side. Therefore, in the case of the Cr ₂ O ₃ film, 50
nm to 300 nm is the optimum film thickness.

[Comparative Examples 6-9] Comparative Examples 6 and 7 correspond to Sn
O ₂ and Comparative Examples 8 and 9 are examples using an Au material. Table 1
As can be seen from the graph, particularly, in both cases, the effect of suppressing the beam suction as in the embodiment is small.

SnO ₂ has high secondary electron emission efficiency.
This is probably because the surface is easily positively charged. It is considered that Au still has an island structure in a state where the film thickness is reduced to increase the surface resistance value, and the SiN film having high secondary electron emission efficiency is also exposed on the surface.

[0196]

[Table 1]

[0197]

In the image forming apparatus using a multi-electron source, a semiconductive film is provided on the surface of an insulating member such as a spacer, which is a constituent element, under the following conditions so that the deviation of the arrival position of electrons can be reduced with a simple structure. Thus, a highly reliable image forming apparatus can be provided.

When a single semiconductive material is used, the material is selected so that the film thickness is 20 nm or more and the leak power per spacer is 1 W or less.

[Brief description of the drawings]

FIG. 1 is a perspective view of an image forming apparatus according to an embodiment of the present invention, in which a part of a display panel is cut away.

FIG. 2 is a plan view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 3 is a partial cross-sectional view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 4 is a plan view illustrating a phosphor array of a face plate of the display panel.

FIG. 5 is a sectional view taken along line AA ′ of the display panel according to the embodiment of the present invention.

FIG. 6 is a sectional view of a spacer of the image forming apparatus of the present invention.

FIGS. 7A and 7B are a plan view and a cross-sectional view, respectively, of a planar surface conduction electron-emitting device used in an example.

FIG. 8 is a cross-sectional view showing a manufacturing process of the planar type surface conduction electron-emitting device.

FIG. 9 shows an applied voltage waveform in the energization forming process.

FIG. 10 shows an applied voltage waveform (a) in the energization activation process;
It is a change (b) of the emission current Ie.

FIG. 11 is a sectional view of a vertical surface conduction electron-emitting device used in an example.

FIG. 12 is a sectional view showing a manufacturing process of the vertical surface conduction electron-emitting device.

FIG. 13 is a graph showing typical characteristics of the surface conduction electron-emitting device used in the example.

FIG. 14 is a diagram for explaining another configuration example of the phosphor.

FIG. 15 is a schematic view of an example of a conventionally known surface conduction electron-emitting device.

FIG. 16 is a schematic view of an example of a conventionally known FE element.

FIG. 17 is a schematic view of an example of a conventionally known MIM element.

FIG. 18 is a schematic sectional view of a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spacer base 2 High resistance film 61 Undercoat layer 62 Low resistance film 1001, 1011 Base material 1003, 1004 Wiring electrode 1010, 3118 Phosphor film 1012, 3112 Electron emission element 1013 Row wiring electrode 1014 Column wiring electrode 1015, 3115 Rear plate 1016 , 3116 Side wall 1017, 3117 Face plate 1018, 3118 Phosphor film 1019, 3119 Metal back 1020, 3120 Spacer 1102, 1103, 3004 Device electrode 1104, 3005 Conductor thin film 1105 Electron emission part 1113 Deposit 1114 High voltage electrode

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Kuroda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Takagi 3- 30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-2-299131 (JP, A) JP-A 8-7811 (JP, A) JP-A 8-180821 (JP, A) Properties of glass and glass ceramic, Corning General Business Division Co., Ltd. (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01J 29/87 H01J 31/12

Claims (11)

(57) [Claims] An image forming member having an envelope for maintaining a vacuum atmosphere, an electron source for emitting electrons, a phosphor emitting light by collision of electrons, and accelerating the electrons toward the image forming member. Image forming apparatus having an acceleration electrode and a spacer as a pressure-resistant structure, the spacer is covered with a high-resistance film , and the high-resistance film of the spacer is used in advance in an assembly process of the apparatus. An image forming apparatus which is heat-treated at a temperature equal to or higher than the maximum temperature. 2. The image forming apparatus according to claim 1, wherein the heat treatment of the spacer is performed in the same atmosphere as the process at the highest temperature in the assembling process of the present device. 3. The high-resistance film covering the spacer is made of at least one material selected from nickel oxide, iron oxide, zinc oxide, and chromium oxide.
Or the image forming apparatus according to 2. 4. The high-resistance film covering the spacer has a thickness of 20 nm or more.
The image forming apparatus according to claim 1. 5. The power consumption per spacer is 1
The image forming apparatus according to any one of claims 1 to 4, wherein W is equal to or less than W. 6. The image according to claim 1, wherein the spacer is made of a glass containing Na, and has a silicon nitride film between the spacer and a high-resistance film. Forming equipment. 7. The high-resistance film is electrically connected to a drive wiring of the electron source and the acceleration electrode.
To an image forming apparatus according to any one of 6. 8. The image forming apparatus according to claim 1, wherein the high resistance film is electrically connected to a driving wiring of the electron source and the acceleration electrode via a low resistance film. apparatus. 9. The image forming apparatus according to claim 1, wherein said electron source is a plurality of surface conduction electron-emitting devices. 10. A <br/> image forming apparatus according to any one of claims 1 to 9, wherein the spacer is coated with a high resistance film, if the high-resistance film is NiO film the membrane The thickness is 20 to 50 nm, the thickness of the Fe ₂ O ₃ film is 50 to 300 nm, the thickness of the ZnO film is 10 to 20 nm, and the thickness of the Cr ₂ O ₃ film is An image forming apparatus having a thickness of 50 to 300 nm. 11. The method according to claim 1, wherein :
An image display device characterized by using the image forming apparatus of the placement.