JP2000100356A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reproducibility of films and prevent their resistance value from being varied in a thermal process such as frit sealing in display making processes, by giving conductivity to a spacer and applying a heat-resisting organic polymer film to its surface. SOLUTION: A spacer 10 is made up by forming an Na block layer 10b on the surface of an insulating base material 10, and forming thereon an antistatic film 10e having two layers, a semiconducting film 10c made of an alloy nitride film of a typical element of the group III or the group IV and a transition metal, and an insulating film 10d made of a heat-resisting polymer. The Na block layer 10b is provided as necessary, and the spacer 10 is provided so that an enclosure 8 is not broken or deformed by the atmospheric pressure, when the enclosure 8 is evacuated. The combination of typical elements, such as Al, Si, or B, and a transition metal, Cr or W, is used for the semiconducting film 10c, and for the insulating film 10d, for example, polyimide or polybenzoimidazole is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electron-emitting device.

[0002]

2. Description of the Related Art A flat display having a small depth is attracting attention as a replacement for a cathode ray tube display because of its space saving and light weight. At present, there are flat type displays using a liquid crystal type, a plasma emission type, and a multi-electron source. Above all, the plasma emission type and the multi-electron source display have a large viewing angle and the image quality is comparable to that of a cathode ray tube, so that a high-quality image can be displayed.

Such an image forming apparatus includes a back plate on which an electron source having a large number of minute electron-emitting devices is disposed, a front plate on which phosphors are disposed, and a vacuum container together with the back plate and the front plate. And a spacer for maintaining a gap between the back plate and the front plate. As the electron-emitting device, a cold-cathode device, such as a field-emission electron-emitting device or a surface-conduction-type electron-emitting device that can emit electrons from a conical or needle-like tip in a high density, has been developed. ing.

[0004] As the display area of the display increases, the back plate and the front plate must be made thicker in order to suppress deformation of the vacuum vessel due to the difference between the internal vacuum and the external atmospheric pressure. This not only increases the weight of the display, but also results in distorted images when viewed at an angle.
Therefore, in order to construct a vacuum vessel that can withstand atmospheric pressure using relatively thin members, a structural support called a spacer or a rib is arranged between the back plate and the front plate. Further, the distance between the back plate on which the electron source is disposed and the front plate on which the phosphor is disposed is usually kept at a sub-millimeter to several millimeters, and as described above, the inside is kept at a high vacuum. In order to accelerate the electrons emitted from the electron source, a high voltage of several hundred volts or more is applied between the electron source and the phosphor. That is, since a strong electric field exceeding 1 kV / mm in electric field intensity is applied between the phosphor and the electron source, there is a concern about discharge at the structural support such as the spacer.

[0005] Further, the spacer is exposed to electrons emitted from an electron source or a part of reflected electrons from the phosphor side, or due to the attachment of positive ions ionized by the emitted electrons to the spacer. Causes charging. Due to the charging of the spacers, the electrons emitted from the electron source bend their trajectories and reach different locations on the phosphor from their normal positions.When the display image is viewed through the front glass, the image near the spacers Is distorted.

In order to solve this problem, it has been proposed to remove a charge by making a small current flow through the spacer (for example, Japanese Patent Laid-Open No. 57-118355,
JP-A-61-124031). In this technique, a minute current flows on the surface of the spacer by forming a semiconductive film on the surface of the insulating 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.

[0007]

The semiconductor type thin film such as tin oxide used in the above conventional example is so sensitive to gas such as oxygen as to be applied to a gas sensor, and therefore its resistance value is liable to change in an atmosphere. In addition, since these materials and metal films have low specific resistance, in order to make them semiconductive, it is necessary to form them in an island shape or to make them extremely thin. That is, in the conventional antistatic film, the reproducibility of film formation is difficult, and the resistance value tends to change in a heat process such as frit sealing or baking in a display manufacturing process.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of forming a higher quality image.

Another object of the present invention is to provide an image forming apparatus for forming a high-quality image by minimizing the effect of spacers arranged in the image forming apparatus on image formation. .

In order to achieve the above object, the present invention provides a container provided with a first substrate and a second substrate arranged at a distance as constituent members, and an electron source arranged in the container. And an image forming member that forms an image by irradiation of electrons from the electron source, and a spacer that maintains a distance between the first substrate and the second substrate,
The image forming apparatus is characterized in that the spacer has conductivity and has a heat-resistant organic polymer film on its surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an image forming apparatus, an antistatic film forms a conductive material on the surface of an insulating member in a container containing an electron source and an image forming member for forming an image by irradiation of electrons from the electron source. By covering with a film, the electric charge accumulated on the surface of the insulating member is removed. Usually, the surface resistance (sheet resistance Rs) of the antistatic film is preferably 10 ¹² Ω or less. Further, in order to obtain a sufficient antistatic effect, it is desirable to have a lower resistance value, and it is particularly preferable that the sheet resistance Rs is 10 ¹¹ Ω or less. If the resistance is lower, the charge eliminating effect is improved.

When the antistatic film is applied particularly to a spacer of an image forming apparatus, the surface resistance Rs of the spacer is set in a desirable range from the viewpoint of antistatic and power consumption. The lower limit of the sheet resistance is limited by the power consumption of the spacer. The lower the resistance, the quicker the charge accumulated in the spacer can be removed, but the more power is consumed by the spacer. The antistatic film used for the spacer is preferably a film made of a semiconductive material, rather than a metal film having a small specific resistance.
The reason is that when a film made of a metal material having a small specific resistance is used as an antistatic film, the thickness of the antistatic film must be extremely thin in order to make the surface resistance Rs a desired value. Depending on the surface energy of the material constituting the antistatic film, the adhesion to the substrate, and the substrate temperature, if the antistatic film is too thin, the thin film becomes island-shaped, and the resistance is unstable, and the film is reproduced. Sex becomes poor.

Therefore, it is preferable to use semiconductive materials having a specific resistance value larger than that of a metal conductor and smaller than that of an insulator. However, these materials often have a negative temperature coefficient of resistance. If the temperature coefficient of resistance is negative, the resistance value decreases due to the temperature rise due to the power consumed on the spacer surface, and the temperature continues to rise due to heat generation, causing an excessive current to flow, so-called thermal runaway. However, thermal runaway does not occur in a situation where the calorific value, that is, power consumption and heat radiation are balanced.
If the absolute value of the temperature coefficient of resistance TCR of the antistatic film material is small, it is difficult to cause thermal runaway.

[0014] In conditions TCR was used -1% of the antistatic film, the power consumption per spacer 1 cm ² is about 0.1
Experiments have shown that when W exceeds W, the current flowing through the spacer continues to increase, resulting in a thermal runaway state.
This depends, of course, on the spacer shape, the voltage Va [V] applied between the spacers, and the temperature coefficient of resistance of the antistatic film. From the above conditions, the power consumption is 1 cm ^2.
The value of Rs not exceeding 0.1 W per unit is 10 × Va ² Ω /
□ or more. That is, the sheet resistance Rs of the antistatic film formed on the spacer is 10 × Va ² Ω / □ to 10 ¹¹
It is preferable to set in the range of Ω / □.

As described above, the thickness t of the antistatic film formed on the insulating spacer substrate is desirably 10 nm or more. On the other hand, when the film thickness t is 1 μm or less, the risk of film peeling due to film stress is extremely small, and the film formation time is shortened and productivity is increased. Therefore, the film thickness is 10 nm to 1 μm.
m, preferably in the range of 20 to 500 n
m is particularly preferable.

The specific resistance ρ is a product of the sheet resistance Rs and the film thickness t. From the preferable range of Rs and t described above, the specific resistance ρ of the antistatic film is 10 ⁻⁵ × Va ² to 10 ⁷ Ωcm. Ρ is preferably 2 × 10 ⁻⁵ Va ² in order to realize a more preferable range of the sheet resistance and the film thickness.
It is preferable to set it to 5 × 10 ⁶ Ωcm.

The acceleration voltage Va of electrons in the image forming apparatus is preferably 100 V or more, and more preferably 1 kV in order to obtain sufficient luminance.
Under the condition of Va = 1 kV, the specific resistance of the antistatic film is preferably in the range of 10 to 10 ⁷ Ωcm.

As a result of the inventor's intensive study on the antistatic film realizing the above-mentioned characteristics, the antistatic film obtained by further coating a heat-resistant organic polymer film on the conductive film having the above specific resistance is extremely excellent. Was found.

Hereinafter, the antistatic film according to the present invention will be described in detail.

First, the material of the conductive film is a resistance value
Can be adjusted to the preferable range for the spacer described above, and
Are preferred, especially oxides and nitrides.
However, it is preferable to select from. Among them, transition metals
Ceramics composite (cermet), Cr-SiO, C
r-SiO_Two, Cr-Al_TwoO_Three, In_TwoO_Three-Al _Two
O_ThreeEtc. and transition metals and high resistance nitrides (aluminum nitride,
Composites such as boron nitride and aluminum silicon nitride)
Easy adjustment of resistance value and during image forming device manufacturing process
It is a preferable material having a stable resistance value.

The transition metals are Ti, V, Cr, Mn, F
e, Co, Ni, Cu, Zr, Nb, Mo, Hf, T
a, W, and the like, and these may be used alone, or two or more transition metals may be used in combination. Transition metal nitrides are good metallic conductors, and nitrides of Group III or IV typical elements are insulators. An alloy nitride film of a group III or group IV typical element and a transition metal is adjusted by adjusting the transition metal composition.
The resistivity can be controlled in a wide range from a good conductor to an insulator. That is, the above-described specific resistance value desired as the spacer antistatic film can be realized by changing the composition. Further, it has been found that the material is relatively stable with little change in resistance value in a process of manufacturing an image forming apparatus described later. The material has a negative temperature coefficient of resistance but an absolute value of less than 1% and is unlikely to cause thermal runaway.

Further, as for the heat-resistant organic polymer covering the conductive film, it is preferable to use a material having a small secondary electron emission coefficient in order to suppress the generation of charge.

For organic polymers or various metals and inorganic insulators, the maximum secondary electron emission efficiency δ, δ _m , δ _m
The energy E _0m [value in keV] of the incident electron when taking is empirically δ _m = 9.5E _0m , E _0m = (K / 1
2.09) It is known to be given as ^0.580 .
(EA Burke, IEEE Trans.on
Nuclear Sci. , NS- 27 , 1760 (1
980). Here, K is a constant determined by the substance. In general, the K value decreases with the structural complexity of the repeating unit in the organic polymer, and the number of valence electrons of the monomer N (N = 1, H, C, N, and O, respectively)
The ratio (N / M) of (3, 4, 5) to the monomer molecular weight M is quantitatively expressed as K = 10.64 (N / M) -3.15. For example, Teflon is K = 1.55 ((N / M)
= 0.44), and Kapton (polyimide) has K =
0.68 ((N / M) = 0.360), and K = 0.72 ((N / M) for cerazole (polybenzimidazole).
M) = 0.364).

Therefore, as the heat-resistant organic polymer film for covering the alloy nitride film, one having a ratio (N / M) of the number of valence electrons N to the molecular weight M of the monomer (N / M) as small as possible is preferable. 4 is a suitable range.

Further, with respect to heat-resistant organic polymer films such as polyimide and polybenzimidazole, the thickness of the surface charging layer by secondary electron emission is 400 to 1000 °. In the present invention, the preferable range of the film thickness is 10 to 500 ° from the viewpoint of suppressing the charge amount and further ensuring the conductivity.

In the present invention, the conductive film is formed by a sputtering method,
It can be formed on an insulating member by a thin film forming means such as a reactive sputtering method, an electron beam evaporation method, an ion plating method, an ion assisted evaporation method, a CVD method, and an alkoxide method.

As the conductive film, it is preferable to use a material which is thermally stable and whose resistance does not depend on the atmosphere. However, since the spacer in the present invention is covered with a heat-resistant organic polymer film, the above-mentioned conductive film is covered. In addition, it is less likely to be directly affected by the atmosphere in the manufacturing process of the image forming apparatus. Therefore, it is possible to select materials not only in terms of physical properties but also in terms of material costs and advantages in the production method.

The heat-resistant organic polymer film of the present invention comprises:
Sputtering method, dipping method, spin coating method, Langmuir project method, organic molecular beam epitaxy (OM
It can be formed on the alloy nitride film by a thin film forming means such as a BE) method and a vapor deposition polymerization method.

The antistatic film of the spacer of the image forming apparatus has been described above. However, since the antistatic film in which the conductive film is coated with the heat-resistant organic polymer film has a very excellent antistatic ability, the image forming apparatus It is a very useful material for applications other than spacers.

The image forming apparatus of the present invention will be further described with reference to preferred embodiments.

FIG. 1 is a sectional view schematically showing a portion centering on a spacer 10 of the image forming apparatus according to the present embodiment. In FIG. 1, reference numeral 1 denotes a number of minute electron-emitting devices, 13 denotes an electron source substrate, 2 denotes a rear plate, and 3 denotes a side wall. Reference numeral 4 denotes a glass substrate on which the fluorescent film 5 is formed, and 6 denotes a metal back, which constitutes a face plate 7. The rear plate 2, the side walls 3, and the face plate 7 form an airtight container (enclosure 8) for maintaining the inside of the display panel at a vacuum.

As the electron-emitting device, a cold cathode such as a field-emission device that emits electrons from a conical or needle-like tip capable of increasing the density or a surface conduction electron-emitting device may be used. 9 is an X-direction wiring, and 10 is a spacer. In FIG. 1, wiring for driving the electron source is omitted.

The spacer 10 has a Na block layer 10b on the surface of an insulating base material 10a,
It is constituted by forming an antistatic film 10e having two layers of a semiconductive film 10c made of an alloy nitride film of a group I or IV typical element and a transition metal and an insulating film 10d made of a heat-resistant organic polymer. I have. In this embodiment, the Na block layer 10b is provided as needed, and the spacer 10 receives atmospheric pressure by evacuating the envelope 8 to prevent the envelope 8 from being damaged or deformed. Provided to avoid. The material, shape, arrangement, and number of the spacers 10 are determined in consideration of the shape of the envelope 8, the coefficient of thermal expansion, the atmospheric pressure, heat, and the like that the envelope receives. The shape of the spacer includes a flat plate type, a cross type, an L-shaped type, and the like. The effect of using the spacer 10 becomes remarkable as the size of the image forming apparatus increases.

Since the insulating substrate 10a needs to support the atmospheric pressure applied to the face plate 7 and the rear plate 2, a material having high mechanical strength and high heat resistance, such as glass and ceramics, is suitable. When glass is used as the material of the face plate and the rear plate, in order to suppress thermal stress during the manufacturing process of the image forming apparatus, the insulating base material 10a is made of the same material as these materials as much as possible or has the same thermal expansion coefficient. Desirably, it is a material.

When glass containing alkali ions such as soda glass is used for the insulating base material 10a, for example, Na
There is a possibility that the conductivity of the antistatic film 10e is changed by ions. By forming a Na block layer 10b of silicon nitride, aluminum oxide or the like as needed between the insulating base material and the antistatic film, it is possible to prevent alkali ions such as Na from entering the antistatic film.

The semiconductive film made of an alloy nitride film 10c of a group III or group IV typical element and a transition metal is made of, for example, A
A combination of a typical element such as l, Si or B and Cr or W as a transition metal was used.

An insulating film 10d made of a heat-resistant organic polymer
For example, polyimide and polybenzimidazole were used.

The spacer 10 is formed of a metal back 6 and X
By electrically connecting to the directional wiring 9, its potential is defined, and a voltage substantially equal to the acceleration voltage Va is applied to both ends of the spacer 10. In this embodiment, the spacer is connected to the X-direction wiring 9, but may be connected to an electrode formed separately to regulate the potential. Further, in a configuration in which an intermediate electrode plate (grid electrode or the like) is provided between the face plate 7 and the rear plate 2 for the purpose of shaping an electron beam or preventing electrification of a substrate insulating portion, the spacer penetrates the intermediate electrode plate or the like. Alternatively, the spacer and the intermediate electrode may be insulated, or may be connected to a separate potential regulating means via an intermediate electrode plate or the like.

When electrodes 11 of good conductivity such as Al and Au are formed at both ends of the spacer, the effect of improving the electrical connection between the antistatic film and the electrodes on the face plate and the electrodes on the rear plate is improved. is there.

Next, an image forming apparatus using the above-described spacer will be described. FIG. 2 is a perspective view of a display panel used in an embodiment described later, in which a part of the panel is cut away to show an internal structure.

In the drawing, reference numeral 2 denotes a rear plate, 3 denotes a side wall,
Reference numeral 7 denotes a face plate, which forms an airtight container (enclosure 8) for maintaining the inside of the display panel at a vacuum by using 2, 3, and 7. In assembling the airtight container, it is necessary to seal the joint of each member to maintain sufficient strength and airtightness, for example, apply frit glass to the joint, and in the air or nitrogen atmosphere, Seal by baking at 400 to 500 degrees Celsius for 10 minutes or more. A method of evacuating the inside of the airtight container to a vacuum will be described later.

A substrate 13 is fixed to the rear plate 2, and N × M cold cathode elements 1 are formed on the substrate (N and M are positive integers of 2 or more, For example, in an image forming apparatus for displaying a high-definition television, it is desirable to set N = 3000 and M = 1000 or more). The N × M cold cathode elements are M
A simple matrix wiring is formed by the X-directional wirings 9 and the N Y-directional wirings 12. The portion constituted by 1, 9, 12, and 13 is an electron source. The manufacturing method and structure of the electron source will be described later in detail.

In this embodiment, the substrate 13 of the electron source is fixed to the rear plate 2 of the airtight container.
If the electron source substrate 13 has a sufficient strength, the electron source substrate 13 itself may be used as the rear plate 2 of the airtight container.

On the lower surface of the face plate 7, an image forming member composed of the fluorescent film 5 and the metal back 6 is arranged. Since the present embodiment is a color image forming apparatus, phosphors of three primary colors of red, green, and blue used in the field of CRT are separately applied to a portion of the fluorescent film 5. The phosphors of the respective colors are separately applied in stripes as shown in FIG. 3A, for example, and black conductors 5b are provided between the stripes of the phosphors. Black conductor 5
The purpose of providing b is to prevent the display color from being shifted even if the irradiation position of the electron beam is slightly shifted,
This includes preventing the reflection of external light to prevent the display contrast from lowering, and preventing the fluorescent film 5 from being charged up by an electron beam. Although graphite is used as a main component for the black conductor 5b, any other material may be used as long as it is suitable for the above purpose.

The method of applying the three primary color phosphors is shown in FIG.
The arrangement is not limited to the stripe arrangement shown in FIG. 3A, but may be a delta arrangement as shown in FIG. 3B or another arrangement.

When a monochrome display panel is produced, a monochromatic phosphor material may be used for the phosphor film 5, and a black conductive material is not necessarily used.

On the surface of the fluorescent film 5 on the rear plate side, a metal back 6 known in the field of CRT is provided. The purpose of providing the metal back 6 is to improve the light utilization rate by mirror-reflecting a part of the light emitted from the fluorescent film 5,
Examples include protecting the fluorescent film 5 from collision with negative ions, acting as an electrode for applying an electron beam acceleration voltage, and acting as a conductive path for excited electrons of the fluorescent film 5. The metal back 6 was formed by forming the fluorescent film 5 on the face plate substrate 4, then smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon. When a fluorescent material for low voltage is used for the fluorescent film 5, the metal back 6 is not used as an image forming member.

Although not used in this embodiment, for the purpose of applying an acceleration voltage and improving the conductivity of the fluorescent film, for example, an IT
A transparent electrode made of O may be provided.

Codes Dx1 to Dxm and Dyl 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 the X-direction wiring of the electron source and Dx1 to Dxm.
y1 to Dyn are electrically connected to the Y-direction wiring of the electron source, and Hv is electrically connected to the metal back 6 of the face plate 7.

In order to evacuate the inside of the hermetic container, after the hermetic container is assembled, 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. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. 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 10 ⁻⁵ to 10 ⁻⁷ Torr by the adsorbing action of the getter film. Is maintained at a vacuum degree.

As described above, an example of the basic configuration of the image forming apparatus of the present invention has been described with reference to the preferred embodiments.

Next, a method of manufacturing an electron source used in the image forming apparatus of the above embodiment will be described. The electron source used in the image forming apparatus of the embodiment is not limited as long as it is an electron source in which the cold cathode devices are individually arranged in a matrix, and the material, shape and manufacturing method of the cold cathode devices are not limited. 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, in a situation where an inexpensive image forming apparatus having a large display 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 film and the upper electrode thin and uniform, which is also a disadvantageous factor in achieving an increase in area and a reduction in manufacturing cost.

On the other hand, since the surface conduction electron-emitting device is relatively simple to manufacture, it is easy to increase the area and reduce the manufacturing cost. Next, the basic configuration, manufacturing method, and characteristics of a suitable surface conduction electron-emitting device will be described, and then, the structure of an electron source in which a large number of devices have simple matrix wiring will be described.

(Preferable Device Configuration and Manufacturing Method of Surface Conduction Emission Device) Typical configurations of the surface conduction type emission device include two types, a planar type and a vertical type.

(Flat-type surface conduction electron-emitting device) First, the structure and manufacturing method of a flat-surface conduction electron-emitting device will be described.

FIGS. 4A and 4B are a plan view and a sectional view, respectively, for explaining the structure of a planar type surface conduction electron-emitting device. In the figure, 13 is a substrate, 14 and 15 are device electrodes, 16 is a conductive thin film, 17 is an electron-emitting portion formed by an energization forming process, and 18 is a thin film formed by an energization activation process.

As the substrate 13, for example, various glass substrates such as quartz glass and blue plate glass, various ceramics substrates such as alumina, or an insulating layer made of, for example, SiO ₂ is laminated on the various substrates described above. A substrate or the like can be used.

The device electrodes 14 and 15 provided on the substrate 13 in parallel with the substrate surface are formed of a conductive material. For example, Ni, Cr, A
Metals such as u, Mo, W, Pt, Ti, Cu, Pd, Ag and the like, alloys of these metals, metal oxides such as In ₂ O ₃ -SnO ₂ , and semiconductors such as polysilicon The material may be appropriately selected and used from among these. 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, other methods (eg, printing technique)
It can be formed by using the same.

The shapes of the device electrodes 14 and 15 are appropriately designed according to the application purpose of the electron-emitting device. Generally, the electrode interval L is usually designed by selecting an appropriate numerical value from the range of several tens of nm to several tens of μm. Range. As for the thickness d of the device electrode, an appropriate numerical value is usually selected from the range of several tens nm to several μm.

Further, a fine particle film is used for the portion of the conductive thin film 16. The fine particle film described here refers to a film including a large number of fine particles as constituent elements (including an island-shaped aggregate). When the fine particle film is examined microscopically, 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 usually observed.

The particle size of the fine particles used for the fine particle film is in the range of several tenths to several hundreds of nm.
Among them, those having a range of 1 nm to 20 nm are preferable. The thickness of the fine particle film is appropriately set in consideration of the following conditions. That is, the device electrode 14
Alternatively, conditions necessary for good electrical connection to 15, conditions necessary for good energization forming described later, conditions necessary for setting the electrical resistance of the fine particle film itself to an appropriate value described later, and the like. It is. Specifically, it is set within a sufficient range of several nanometers to several hundred nanometers, and particularly preferably, it is between 1 nm and 50 nm.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T
a, W, Pb and other metals, PdO, S
oxides such as n, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , La
Borides such as B ₆ , CeB ₆ , YB ₄ , GdB ₄ , TiC, ZrC, HfC, TaC, Si
Carbides such as C and WC, TiN, Zr
Nitrides such as N and HfN, semiconductors such as Si and Ge, carbon, and the like;
It is appropriately selected from these.

As described above, the conductive thin film 16 is formed of a fine particle film.
^{3 ~10 7 Ω} / □ of so as to be included in the scope has been set.

Since the conductive thin film 16 and the device electrodes 14 and 15 are desirably electrically connected to each other, they have a structure in which a part of each of them overlaps.
In the example of FIG. 4, the overlapping method is as follows.
Although the device electrode and the conductive thin film are laminated in this order, the substrate, the conductive thin film and the device electrode may be laminated in this order from the bottom in some cases.

The electron emitting portion 17 is formed of a conductive thin film 16
Is a crack-like portion formed in a part of the conductive film, and has a property of being electrically higher in resistance than the surrounding conductive film. The cracks are formed by performing a later-described energization forming process on the conductive thin film 16. In some cases, fine particles having a sufficient particle size of several nm to several tens of nm are 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 18 is a thin film made of carbon or a carbon compound, and covers the electron emitting portion 17 and its vicinity. The thin film 18 is formed by performing an energization activation process described later after the energization forming process.

The thin film 18 is made of any one of single-crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 50 nm or less.
More preferably, it is 0 nm or less.

Since it is difficult to accurately show the actual position and shape of the thin film 18, it is schematically shown in FIG. Further, in the plan view (a), an element in which a part of the thin film 18 is removed is shown.

While the basic structure of the preferred device has been described above, the following device was used in the examples.

That is, blue glass was used for the substrate 13 and Pt thin films were used for the device electrodes 14 and 15. The thickness d of the device electrode was 100 nm, and the electrode interval L was 2 μm.
Using Pd or PdO as the main material of the fine particle film,
The thickness of the fine particle film was about 10 nm, and the width W was 10 nm.

Next, a method of manufacturing a preferred flat surface conduction electron-emitting device will be described.

FIGS. 5A to 5D 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 of FIG.

1) First, device electrodes 14 and 15 are formed on a substrate 13 as shown in FIG.

When forming, the substrate 1
After sufficiently cleaning 3 with a detergent, pure water and an organic solvent, the material of the device electrode is deposited. (As a deposition method, for example, a vacuum film forming technique such as a vapor deposition method or a sputtering method may be used.) Thereafter, patterning is performed using the deposited electrode material or photolithography / etching technique.
A pair of device electrodes 14 and 15 shown in FIG.

2) Next, a conductive thin film 16 is formed as shown in FIG.

In the formation, 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 was used as a main element in this example.
In this example, a dipping method was used as a coating method.
Other than that, for example, a spinner method or a spray method may be used).

As a method of 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 this example, such as a vacuum evaporation method, a sputtering method, or a chemical vapor deposition method In some cases, such as is used.

3) Next, as shown in FIG. 7C, an appropriate voltage is applied between the element electrodes 14 and 15 from the forming power supply 19, and an energization forming process is performed.
An electron emitting portion 17 is formed.

The energization forming treatment is to energize the conductive thin film 16 made of a fine particle film and to appropriately break, deform, or alter the part, thereby changing the structure to a structure suitable for emitting electrons. This is the process that causes In a portion of the conductive thin film made of the fine particle film that has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 17), an appropriate crack is formed in the thin film. It should be noted that the electrical resistance measured between the device electrodes 14 and 15 is significantly increased after the formation, as compared to before the electron emission portion 17 is formed.

FIG. 6 shows an example of an appropriate voltage waveform applied from the forming power supply 19 in order to explain the energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulsed voltage is preferable,
In the case of this example, as shown in the figure, a triangular wave pulse having a pulse width T1 was continuously applied at a pulse interval T2. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. In addition, monitor pulses Pm for monitoring the state of formation of the electron-emitting portions 17 were inserted between triangular-wave pulses at appropriate intervals, and the current flowing at that time was measured by the ammeter 20.

In this example, for example, 10 ^-5 Torr
Under a vacuum atmosphere of a degree, for example, the pulse width T1 is 1 ms, the pulse interval T2 is 10 ms, and the peak value Vpf
Was increased by 0.1 V for each pulse. Then, the monitor pulse Pm was inserted at a rate of one every time five triangular waves were applied. The monitor pulse voltage Vpf was set to 0.1 V so as not to adversely affect the forming process. Then, the device electrodes 14 and 15
At the time when the electric resistance becomes 1 × 10 ⁶ Ω, that is, when the current measured by the ammeter 20 when the monitor pulse is applied becomes 1 × 10 ^-7 Å or less, the energization related to the forming process is terminated. did.

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

4) Next, as shown in FIG. 5D, an appropriate voltage is applied between the element electrodes 14 and 15 from the activating power supply 21 to carry out an energization activating process, so that electron emission is performed. Improve characteristics.

The energization activation process is a process of energizing the electron-emitting portion 17 formed by the energization forming process under appropriate conditions to deposit carbon or a carbon compound in the vicinity thereof. (In the figure, a deposit made of carbon or a carbon compound is schematically shown as the member 18.) By performing the energization activation process, the emission current at the same applied voltage as compared with before the activation is typically obtained. Can be increased 100 times or more.

Specifically, 10 ^-4 to 10 ^-5 Torr
By applying a voltage pulse periodically in a vacuum atmosphere within the range of above, carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 18 is made of single crystal graphite, polycrystal graphite,
It is either amorphous carbon or a mixture thereof, and has a thickness of 50 nm or less, more preferably 30 nm or less.

FIG. 7A shows an example of an appropriate voltage waveform applied from the activation power supply 21 in order to describe the energization method in more detail. In this example, the energization activation process was performed by periodically applying a rectangular wave having a constant voltage. Specifically, the voltage Vac of the rectangular wave was 14 V, the pulse width T3 was 1 ms, and the pulse interval T4 was 10 ms. And Note that the above-mentioned 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 preferable to appropriately change the conditions accordingly.

Reference numeral 22 shown in FIG. 5D denotes an anode electrode for capturing an emission current Ie emitted from the surface conduction electron-emitting device, to which a DC high voltage power supply 23 and an ammeter 24 are connected. (If the activation process is performed after incorporating the substrate 13 into the display panel, the phosphor screen of the display panel is used as the anode electrode 22.) While the voltage is applied from the activation power supply 21, the ammeter is used. At 24, the emission current Ie is measured to monitor the progress of the energization activation process, and the operation of the activation power supply 21 is controlled. FIG. 7B shows an example of the emission current Ie measured by the ammeter 24. When the pulse voltage is started to be applied from the activation power supply 21, the emission current Ie increases with the passage of time, but eventually saturates. . As described above, when the emission current Ie is substantially saturated, the application of the voltage from the activation power supply 21 is stopped, and the energization activation process ends.

The above-mentioned 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 appropriately change the conditions accordingly.

As described above, the planar surface conduction electron-emitting device shown in FIG. 5E was manufactured.

(Vertical Type Surface Conduction Emission Element) FIG. 8 shows another typical configuration 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. Element. FIG. 8 is a schematic cross-sectional view for explaining the basic structure of the vertical type. In the figure, 25 is a substrate, 26 and 27 are device electrodes, 28 is a step forming member, and 29 is a conductive film using a fine particle film. Reference numeral 30 denotes an electron emitting portion formed by an energization forming process, and 31 denotes a thin film formed by an energization activation process.

The difference between the vertical type and the flat type described above is that one (26) of the device electrodes is formed with a step forming member 28.
The conductive thin film 29 is provided on the step forming member 2.
8 is covered. Therefore, the element electrode interval L in the planar type shown in FIG. 4 is set as the step height Ls of the step forming member 28 in the vertical type. For the substrate 25, the device electrodes 26 and 27, and the conductive thin film 29 using the fine particle film, the materials listed in the description of the flat type can be used in the same manner. Also,
An electrically insulating material such as SiO ₂ is used for the step forming member 28.

(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. 9 shows the elements used in the image forming apparatus.
Typical examples of (emission current Ie) versus (device applied voltage Vf) characteristics and (device current If) versus (device 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
When a voltage of the above magnitude is applied to the element, the emission current Ie sharply increases. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current Ie is hardly detected.

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 depends on 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 during which the voltage Vf is applied. 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 an image forming apparatus provided with a large number of elements 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 under driving according to the desired light emission luminance, and a voltage lower than the threshold voltage Vth is applied to the element in the non-selected state. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

Further, since the emission luminance can be controlled by utilizing the second characteristic or the third characteristic, gradation display can be performed.

(Structure of Electron Source in Which Many Devices are Wiring in Simple Matrix) Next, the structure of an electron source in which a plurality of the above-described surface conduction emission devices are arranged on a substrate and wired in a simple matrix will be described.

FIG. 10 is a plan view of an electron source in which a plurality of the surface conduction electron-emitting devices shown in FIG. On the substrate 13, surface conduction type emission elements similar to those shown in FIG. 4 are arranged, and these elements are wired in a simple matrix by the X-direction wiring 9 and the Y-direction wiring 12. An insulating layer (not shown) is formed between the X-directional wirings 9 and the Y-directional wirings 12 at the intersections of the wirings, so that electrical insulation is maintained.

FIG. 11 is a sectional view taken along the line AA ′ in FIG.
Shown in

The electron source having such a structure includes an X-directional wiring 9, a Y-directional wiring 12, an inter-electrode insulating layer (not shown), and device electrodes 14 and 15 of a surface conduction electron-emitting device. After the conductive thin film 16 was formed, each element was subjected to an energization forming process and an energization activation process via the X-direction wiring 9 and the Y-direction wiring 12 to manufacture the device.

[0106]

Next, examples of the present invention will be described.

Example 1 In this example, the above-described image forming apparatus shown in FIGS. 1 and 2 having a plurality of surface conduction electron-emitting devices as an electron source was manufactured. First, as shown in FIG. 12, a pair of device electrodes 14 and 15 and a conductive film 16 for forming a surface conduction electron-emitting device on a substrate 13 made of cleaned blue glass are arranged in a matrix.
A plurality of 0 × 720 wirings and a plurality of X direction (row direction) wirings 9 and a plurality of Y direction (column direction) wirings 12 for matrix wiring of the plurality of surface conduction electron-emitting devices to be formed were formed. Here, the element electrodes 14 and 15 are Pt films formed by a sputtering method, and the X-directional wiring 9 and the Y-directional wiring 12
Is an Ag wiring formed by a screen printing method. The conductive film 16 is a PdO fine particle film formed by applying and firing a Pd amine complex solution. FIG. 13 is a cross-sectional view taken along the line AA ′ of FIG.

Next, the fluorescent film 5 shown in FIG. 1 and FIG.
As shown in FIG. 14, each of the color phosphors 5a adopts a stripe shape extending in the Y direction, and the black conductive material 5b separates not only between the color phosphors 5a but also between the pixels in the Y direction and will be described later. A shape including a portion for installing a spacer was used. First, a black conductive material 5b was formed, and a phosphor 5a of each color was applied to a gap portion between the black conductive material 5b to form a fluorescent film 5. As a material for the black stripe, a material mainly containing graphite, which is generally used, was used. A slurry method was used for applying each color phosphor 5a on a glass substrate.

As shown in FIGS. 1 and 2, a metal back 6 is provided on the inner surface side of the fluorescent film 5, and the metal back 6 is formed on the inner surface of the fluorescent film 5 after the fluorescent film 5 is formed. (Usually called filming), and then Al was vacuum-deposited.

The spacer 10 shown in FIG. 1 and FIG. 2 is an insulating substrate 10a (3.8 mm in height, 200 μm in thickness, 20 μm in length) made of cleaned soda lime glass.
mm), a 0.5 μm-thick silicon nitride film is formed as the Na block layer 10b, and a film containing each element of W, Al, and N is formed thereon as the semiconductive film 10c by vacuum film formation. Then, a heat-resistant organic polymer insulating film 10d made of polyimide was formed thereon by vacuum film formation.

The semiconductive film 10c containing each element of W, Al and N used in this embodiment is formed by simultaneously sputtering W and Al targets in a mixed atmosphere of argon and nitrogen using a sputtering apparatus. Filmed. The composition was adjusted by changing the power applied to each target, and an optimum resistance value was obtained. The substrate is connected to ground at room temperature. The manufactured semiconductive film 10c containing each element of W, Al and N has a thickness of t = 200n.
m and the specific resistance was ρ = 2.8 × 10 ⁵ Ωcm.

The insulating film 10d of the heat-resistant organic polymer made of polyimide used in this embodiment is formed by first preparing a polyimide sputtering target, and performing RF sputtering of this target in an argon atmosphere by a sputtering apparatus. did. The polyimide target was coated and dried five times on a φ5 inch Na-free glass substrate by applying a varnish of a polyimide (Bayer ML: manufactured by IST Co., Ltd.) using a spinner at 1500 rpm for 30 s. Thereafter, curing was performed at 350 ° C. to perform imidization, thereby producing the film. After curing, Na
The polyimide film thickness formed on the free glass substrate is 50
μm.

The polyimide target was Ar0.5
By RF sputtering under the conditions of Torr and 200 W, a heat-resistant organic polymer insulating film 10d made of polyimide was formed to a thickness of 150 ° on the above-mentioned semiconductive film 10c.

As shown in FIG. 1, the spacer 10 is provided with electrodes 11 made of Al at both connection portions to ensure the connection with the X-direction wiring 9 and the connection with the metal back 6. The electrodes 11 completely covered the four surfaces of the spacer 10 exposed in the envelope 8 within a range of 50 μm from the upper surface of the X-direction wiring toward the face plate 7 and 300 μm from the metal back surface toward the rear plate 2.

The spacers 10 having the heat-resistant organic polymer insulating film 10d made of polyimide formed on the semiconductive film 10c containing each element of W, Al, and N formed as described above are arranged at regular intervals. It was fixed on the directional wiring 9.

Then, the face plate 7 is arranged via the support frame 3 as shown in FIGS. 1 and 2 so that the face plate 7 is arranged 3.8 mm above the electron-emitting device 1, and the rear plate 2 and the face Plate 7, support frame 3
And the joint part of the spacer 10 was fixed.

The joint between the rear plate 2 and the support frame 3 and the joint between the face plate 7 and the support frame 3 were sealed by applying frit glass and firing at 430 ° C. for 10 minutes or more in the atmosphere. The spacer 10 is fixed on the black conductive material 5b (line width 300 μm) on the face plate 7 side by using a conductive frit glass 40 containing silica spheres coated with Au. The continuity with the back 6 was secured.

The atmosphere in the envelope 8 completed as described above is exhausted by a vacuum pump through an exhaust pipe, and after reaching a sufficient degree of vacuum, the external terminals Dx1 to Dx shown in FIG.
m, Dy1 to Dyn, X direction wiring 9 and Y direction wiring 1
12, a voltage is applied between the plurality of pairs of device electrodes 14 and 15 on the substrate 13 shown in FIG. An electron emission portion was formed on the film 16. The forming process was performed by applying a voltage having a waveform shown in FIG.

Next, acetone was passed through the exhaust pipe for 1 mTorr.
r into the envelope 8 and the container outer terminal Dx1
An activation process for depositing carbon or a carbon compound on each conductive film 16 was performed by periodically applying a voltage pulse to Dxm and Dy1 to Dyn. The activation process was performed by applying a voltage having a waveform as shown in FIG. As described above, an electron source having a plurality of surface conduction electron-emitting devices arranged in a matrix as shown in FIG. 10 was manufactured.

Next, the entire envelope 8 was heated to 200 ° C.
After evacuating for 10 hours ^-6True about Torr
At the air temperature, the exhaust pipe is welded by heating with a gas burner.
The enclosure 8 was sealed.

Finally, gettering was performed to maintain the degree of vacuum after sealing.

In the image forming apparatus shown in FIGS. 1 and 2 completed as described above, each electron-emitting device 1
Electrons are emitted by applying a scanning signal and a modulation signal from signal generation means (not shown) through terminals Dx1 to Dxm and Dy1 to Dyn outside the container, respectively.
The high-voltage terminal Hv applies a high voltage to accelerate the emitted electron beam, causing electrons to collide with the fluorescent film 5,
An image was displayed by exciting and emitting the phosphor. The applied voltage Va to the high voltage terminal Hv is 1 kV to 5 kV,
The applied voltage Vf between the device electrodes 14 and 15 was 14V.

For the spacer 10, the resistance value of the antistatic film 10e is measured before assembling and after sealing to the face plate.
After the sealing to the rear plate, after evacuation, after the device electrode energization treatment, and the like, measurement was made in each step, and almost no change in the resistance value was observed throughout all the steps.

In addition, a light emitting spot caused by electrons emitted from the electron emitting element 1 located near the spacer 10 is also included.
Emitting spot rows were formed at equal intervals on two dimensions, and a clear and good color reproducible color image could be displayed. This indicates that even if the spacer 10 is provided, no disturbance of the electric field which affects the electron trajectory occurs, and the charging of the spacer 10 is negligible. The temperature coefficient of resistance of the material was -0.5%, and no thermal runaway was observed even at Va = 5 kV.

(Embodiment 2) This embodiment is different from Embodiment 1 in that a film containing each element of W, B and N is used as the semiconductive film 10c of the spacer 10 shown in FIG. The other points are the same as in the first embodiment.
And the image forming apparatus shown in FIG.

The semiconductive film 10c containing each element of W, B and N used in this embodiment is formed by simultaneously sputtering W and B targets in a mixed atmosphere of argon and nitrogen using a sputtering apparatus. Filmed. The composition was adjusted by changing the power applied to each target, and an optimal resistive film was obtained. The substrate is at room temperature and grounded. The prepared semiconductive film 10c containing each element of W, B and N had a thickness t = 200 nm and a specific resistance ρ = 2.7 × 10 ⁵ Ωcm.

Further, a heat-resistant organic polymer insulating film 10d made of polyimide was formed thereon in the same manner as in Example 1 to produce the spacer 10 of this example.

Regarding the spacer 10 in this embodiment,
The resistance value of the antistatic film 10e was measured in each step before assembling, after sealing to the face plate, after sealing to the rear plate, after evacuation, and after energization of the device electrode. No fluctuation was observed.

In addition, a light emitting spot due to electrons emitted from the electron emitting element 1 located near the spacer 10 is also included.
Emitting spot rows were formed at equal intervals on two dimensions, and a clear and good color reproducible color image could be displayed. This indicates that even if the spacer 10 is provided, no disturbance of the electric field which affects the electron trajectory occurs, and the charging of the spacer 10 is negligible. The temperature coefficient of resistance of the material was -0.5%, and no thermal runaway was observed even at Va = 5 kV.

Embodiment 3 This embodiment is different from Embodiment 1 in that the heat-resistant organic polymer insulating film 10d of the spacer 10 shown in FIG. 1 is made of polyimide (PIX-L110
SX: manufactured by Hitachi Chemical Co., Ltd.) and FIGS.
Was manufactured.

The semiconductive film 10c containing W, Al and N elements manufactured by the same method as in the first embodiment.
Means that the film thickness is t = 200 nm and the specific resistance is ρ = 2.8 × 10
It was ⁵ Ωcm.

The insulating film 10d of a heat-resistant organic polymer made of polyimide used in this embodiment is formed by first preparing a polyimide sputtering target and performing RF sputtering of this target in an argon atmosphere by a sputtering apparatus. did. The polyimide target was a varnish of polyimide (PIX-L110SX: manufactured by Hitachi Chemical Co., Ltd.) on a φ5 inch Na-free glass substrate by a spinner at 1500 rpm.
The coating and drying were performed 5 times under the conditions of m and 30 s, and then 35
It was prepared by curing at 0 ° C. and imidization. After curing, the thickness of the polyimide formed on the Na-free glass substrate was 50 μm.

The polyimide target was Ar0.5
By RF sputtering under the conditions of Torr and 200 W, a heat-resistant organic polymer insulating film 10d made of polyimide was formed to a thickness of 150 ° on the above-mentioned semiconductive film 10c.

Regarding the spacer 10 in this embodiment,
The resistance value of the antistatic film 10e was measured in each step before assembling, after sealing to the face plate, after sealing to the rear plate, after evacuation, and after energization of the device electrode. No fluctuation was observed.

In addition, a light emitting spot due to electrons emitted from the electron emitting element 1 located near the spacer 10 is also included.
Emitting spot rows were formed at equal intervals on two dimensions, and a clear and good color reproducible color image could be displayed. This indicates that even if the spacer 10 is provided, no disturbance of the electric field which affects the electron trajectory occurs, and the charging of the spacer 10 is negligible. The temperature coefficient of resistance of the material was -0.5%, and no thermal runaway was observed even at Va = 5 kV.

(Embodiment 4) This embodiment is different from Embodiment 3 in that a film containing each element of W, B and N is used as the semiconductive film 10c of the spacer 10 shown in FIG. The image forming apparatus shown in FIGS. 1 and 2 was manufactured in the same manner as in Example 3.

The W.R. The semiconductive film 10c containing each element of B and N was formed by simultaneously sputtering W and B targets in a mixed atmosphere of argon and nitrogen using a sputtering apparatus. The composition was adjusted by changing the power applied to each target, and an optimum resistance value was obtained. The substrate is at room temperature and grounded. The prepared semiconductive film 10c containing each element of W, B and N had a thickness t = 200 nm and a specific resistance ρ = 2.7 × 10 ⁵ Ωcm.

Further, a heat-resistant organic polymer insulating film 10d made of polyimide was formed thereon in the same manner as in Example 3 to manufacture the spacer 10 of this example.

Regarding the spacer 10 in this embodiment,
The resistance value of the antistatic film 10e was measured in each step before assembling, after sealing to the face plate, after sealing to the rear plate, after evacuation, and after energization of the device electrode. No fluctuation was observed.

In addition, a light emitting spot caused by electrons emitted from the electron emitting element 1 located near the spacer 10 is also included.
Emitting spot rows were formed at equal intervals on two dimensions, and a clear and good color reproducible color image could be displayed. This indicates that even if the spacer 10 is provided, no disturbance of the electric field which affects the electron trajectory occurs, and the charging of the spacer 10 is negligible. The temperature coefficient of resistance of the material was -0.5%, and no thermal runaway was observed even at Va = 5 kV.

(Embodiment 5) This embodiment is different from Embodiment 1 in that the heat-resistant organic polymer insulating film 10d of the spacer 10 shown in FIG. 1 is made of polybenzimidazole (P
BI) (Cerazole: manufactured by Hoechst Industry Co., Ltd.), and the image forming apparatus shown in FIGS. 1 and 2 was manufactured in the same manner as in Example 1 except for the above.

The semiconductive film 10c containing each element of W, Al and N manufactured by the same method as in the first embodiment.
Means that the film thickness is t = 200 nm and the specific resistance is ρ = 2.8 × 10
It was ⁵ Ωcm.

The insulating film 10d of the heat-resistant organic polymer made of polybenzimidazole (PBI) used in this embodiment.
Was performed first from the production of a PBI sputtering target, and a film was formed by RF sputtering the target in an argon atmosphere using a sputtering apparatus. PBI target is φ5 inch Na-free.
Polybenzimidazole (Cerazo) on a glass substrate
le: manufactured by Hoechst Industry Co., Ltd.) using a spinner at 1000 rpm for 30 seconds.
Drying was performed five times, and then heat treatment was performed at 300 ° C. After the heat treatment, the PBI film formed on the Na-free glass substrate had a thickness of 60 μm.

This PBI target is Ar0.5To
By performing RF sputtering under the conditions of rr and 200 W,
A heat-resistant organic polymer insulating film 10d made of polybenzimidazole is formed on the aforementioned semiconductive film 10c to a thickness of 150 °.
Was formed.

Regarding the spacer 10 in this embodiment,
The resistance value of the antistatic film 10e was measured in each step before assembling, after sealing to the face plate, after sealing to the rear plate, after evacuation, and after energization of the device electrode. No fluctuation was observed.

[0146] In addition, a light emitting spot due to electrons emitted from the electron emitting element 1 located near the spacer 10 is also included.
Emitting spot rows were formed at equal intervals on two dimensions, and a clear and good color reproducible color image could be displayed. This indicates that even if the spacer 10 is provided, no disturbance of the electric field which affects the electron trajectory occurs, and the charging of the spacer 10 is negligible. The temperature coefficient of resistance of the material was -0.5%, and no thermal runaway was observed even at Va = 5 kV.

(Embodiment 6) This embodiment is different from Embodiment 5 in that a film containing each element of W, B and N is used as the semiconductive film 10c of the spacer 10 shown in FIG. The other points are the same as in the fifth embodiment.
And the image forming apparatus shown in FIG.

The semiconductive film 10c containing each element of W, B and N used in this embodiment is formed by simultaneously sputtering W and B targets in a mixed atmosphere of argon and nitrogen by using a sputtering apparatus. Filmed. The composition was adjusted by changing the power applied to each target, and an optimum resistance value was obtained. The substrate is at room temperature and grounded. The prepared semiconductive film 10c containing each element of W, B and N had a thickness t = 200 nm and a specific resistance ρ = 2.7 × 10 ⁵ Ωcm.

Further, a heat-resistant organic polymer insulating film 10d made of polybenzimidazole was formed thereon in the same manner as in Example 5 to produce the spacer 10 of this example.

With respect to the spacer 10 in this embodiment,
The resistance value of the antistatic film 10e was measured in each step before assembling, after sealing to the face plate, after sealing to the rear plate, after evacuation, and after energization of the device electrode. No fluctuation was observed.

In addition, a row of light-emitting spots are formed two-dimensionally at equal intervals, including light-emitting spots generated by the electrons emitted from the electron-emitting devices 1 located close to the spacer 10, and a clear color image with good color reproducibility can be obtained. did it. This indicates that even if the spacer 10 is provided, the electric field does not disturb the electron activation, and the charging of the spacer 10 is negligible. The temperature coefficient of resistance of the material was -0.5%, and no thermal runaway was observed even at Va = 5 kV.

(Embodiment 7) This embodiment is different from Embodiment 1 in the step of forming the envelope 8 shown in FIGS. 1 and 2, and the other steps are the same as in Embodiment 1. The image forming apparatus shown in FIGS. 1 and 2 was manufactured. In forming the envelope 8, in Example 1, the frit glass and the conductive frit glass were applied to predetermined positions in the envelope 8 and sealed by firing at 430 ° C. in the atmosphere for 10 minutes or more. . On the other hand, the following steps were used in this example.

(A) Frit glass is applied to the joint between the rear plate 2 and the support frame 3 and the joint between the face plate 7 and the support frame 3 and dried at 120 ° C. to evaporate the solvent to remove the binder. For this purpose, firing was performed at 380 ° C. in the air.

(B) Spacer 1 on face plate 7
A conductive frit glass containing silica spheres coated with Au is applied to the position where the O is bonded, dried at 120 ° C. to evaporate the solvent, and at 380 ° C. in air to remove the binder. Fired.

(C) After the rear plate 2, the support frame 3, the face plate 7, and the spacer 10 are aligned with each other with desired accuracy, the rear plate 2, the support frame 3, the face plate 7, and the spacer 10 are placed in a nitrogen atmosphere at 430 ° C.
The envelope 8 was sealed by heating for more than one minute.

With respect to the spacer 10 before and after the above steps, the resistance value of the antistatic film 10e was measured.
No remarkable fluctuation of the resistance value was observed.

(Embodiment 8) The present embodiment is different from Embodiment 1 in that the conditions of heating in a vacuum performed at 200 ° C.
The difference is that the temperature was changed to 300 ° C. for 10 hours.

With respect to the spacer 10 before and after the above steps, the resistance value of the antistatic film 10e was measured.
No remarkable fluctuation of the resistance value was observed.

(Embodiment 9) This embodiment differs from Embodiment 1 in that tin oxide (SnO ₂ ) is used as the semiconductive film 10c of the spacer 10 shown in FIG.
Other than that, the image forming apparatus shown in FIGS. 1 and 2 was produced in the same manner as in Example 1. In this embodiment, several tens of SnO ₂ were formed by a vacuum film formation method, and a polyimide film was formed thereon in the same manner as in the first embodiment. Compared to a comparative example described later,
The change in resistance in the display manufacturing process was small.

As described above, even for the island-shaped semiconductive film, the process stability could be improved by coating with the heat-resistant polymer.

In the case where the heating step in the reducing atmosphere shown in Embodiment 7 is performed, the oxide semiconductor Sn
The resistance fluctuation of the semiconductive film made of O ₂ was reduced by coating with a heat-resistant polymer.

In each of the embodiments described above, the spacer 10 was manufactured by the following method instead of forming the heat-resistant organic polymer film by RF sputtering. However, the same effect as described in each of the above embodiments was obtained. Obtained.

That is, the polyimide films in Examples 1 to 4 and 7 to 9 were made of a polyimide solution manufactured by Hitachi Chemical
A solution obtained by diluting IX-1500 with an N-2-methyl-pyrrolidone solution so as to have a 100-fold volume is applied on a substrate heated to a substrate temperature of 80 ° C. by spray coating,
After confirming the drying of the surface, baking was performed at 350 ° C. for 30 minutes in an oven. The thickness of the formed polyimide film, which is a heat-resistant organic polymer film, was 1
It was 0 nm.

The polybenzimidazole films in the above Examples 5 and 6 were prepared by spray coating a polybenzimidazole solution manufactured by Hoechst Industries Co., Ltd., which was prepared by diluting Cerazole with N, N-dimethylacetamide. Apply on the heated substrate and confirm drying of the surface.
The firing was performed for 30 minutes. The thickness of the formed polybenzimidazole film, which is a heat-resistant organic polymer film, is SEM.
As a result, it was 10 nm.

The image forming apparatuses of the above-described embodiments and examples have the following effects. First, a high-quality image can be formed. Further, the influence of the spacer on the image formation can be reduced as much as possible. Further, the charging of the spacer can be suppressed. Further, it is possible to suppress a change in the electrical characteristics of the spacer due to heat during the manufacturing process or the driving process of the device. Further, in the driving process of the apparatus, the influence of the gas released from the spacer on the image formation can be reduced as much as possible.

(Comparative Example) As a comparative example, when SnO ₂ alone was used as an antistatic film, the resistance value varied greatly in each assembly process. After passing through all the assembly processes, the specific resistance is 9.2 Ωcm, the resistance value is 1.8 × 10 ⁶ Ω, and Va
Could not be applied up to 1 kV. That is,
Since the resistance greatly changes in the display manufacturing process and the amount of the change is not constant, the resistance variation after the process is large and the controllability is poor. In addition, the specific resistance value of SnO ₂ must be extremely thin, that is, 1 nm or less, and it is difficult to control the resistance.

[0167]

According to the present invention, an image forming apparatus for forming a high-quality image can be provided.

Further, according to the present invention, it is possible to reduce as much as possible the effect of spacers arranged in the image forming apparatus on image formation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a part of an image forming apparatus of the present invention.

FIG. 2 is a perspective view of the image forming apparatus of the present invention in which a part of a display panel is cut away.

3A and 3B illustrate a phosphor array of a face plate of a display panel, wherein FIG. 3A is a plan view and FIG. 3B is an enlarged plan view of a part thereof.

FIGS. 4A and 4B schematically show a configuration of a planar surface conduction electron-emitting device, wherein FIG. 4A is a plan view and FIG.

FIG. 5 is a process chart showing a process of forming a planar surface conduction electron-emitting device.

FIG. 6 is a pulse waveform of a forming application pulse of an electron beam source.

FIGS. 7A and 7B are graphs showing waveforms of applied pulses in an energization activation step, wherein FIG. 7A is a graph showing an activation power supply output voltage, and FIG.

FIG. 8 is a sectional view of a vertical surface conduction electron-emitting device.

FIG. 9 is a graph showing the relationship between the device voltage, the device current, and the emission current of the surface conduction electron-emitting device.

FIG. 10 is a plan view showing a configuration of an electron source arranged in a simple matrix.

FIG. 11 is a sectional view taken along the line AA ′ in FIG. 10;

FIG. 12 is a plan view for explaining a method of manufacturing an electron source arranged in a simple matrix.

FIG. 13 is a sectional view taken along line AA ′ of FIG. 12;

FIG. 14 is a diagram showing another example of a phosphor array.

[Explanation of symbols]

 Reference Signs List 4 glass substrate 5 fluorescent film 8 envelope 10 spacer 10a insulating base material 10b Na block layer 10c semiconductive film 10d insulating film 10e antistatic film 13 electron source substrate

Claims (10)

[Claims] 1. A container provided with a first substrate and a second substrate arranged at an interval as constituent members, an electron source disposed in the container, and irradiation of electrons from the electron source. An image forming apparatus comprising: an image forming member that forms an image; and a spacer that maintains a distance between the first substrate and the second substrate, wherein the spacer has conductivity, and
An image forming apparatus having a heat-resistant organic polymer film on its surface. 2. A container provided with a first substrate and a second substrate arranged at an interval as constituent members, an electron source disposed in the container, and irradiation of electrons from the electron source. An image forming apparatus, comprising: an image forming member for forming an image; and a spacer for maintaining a distance between the first substrate and the second substrate, wherein the spacer comprises: an insulating base; An image forming apparatus comprising: a conductive film on a material; and a heat-resistant organic polymer film on the conductive film. 3. The image forming apparatus according to claim 1, wherein the electron source is disposed on the first substrate, and the image forming member is disposed on the second substrate. . 4. The electron source includes a plurality of electron-emitting devices and wiring for connecting the plurality of electron-emitting devices, the image forming member includes a fluorescent film and a metal back, and the spacer includes: The image forming apparatus according to claim 3, wherein the image forming apparatus is in contact with the wiring and the metal back. 5. The film of an organic polymer having heat resistance of 10
The image forming apparatus according to claim 1, wherein the image forming apparatus has a film thickness in a range of {500}. 6. The heat-resistant organic polymer film, wherein the ratio of the valence number N of the monomer to the molecular weight M is (N / M) ≦ 0.4.
The image forming apparatus according to any one of claims 1 to 5, comprising an organic polymer. 7. The image forming apparatus according to claim 1, wherein the heat-resistant organic polymer film is a film made of polyimide. 8. The image forming apparatus according to claim 1, wherein the heat-resistant organic polymer film is a film made of polybenzimidazole. 9. The conductive film has a thickness of 100 ° to 1000 °.
The image forming apparatus according to claim 2, wherein the image forming apparatus has a thickness in the range of: 10. The image forming apparatus according to claim 1, wherein said electron source includes a plurality of surface conduction electron-emitting devices.