JP2000164117A - Electron emitting element, electron source, image forming device, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron emitting element capable of obtaining the even electron emitting characteristic over a large area and being easily manufactured at a low cost and coping with unevenness of the element pitch per each board due to the dimensional change of the board in a heating process, and to provide an electron source having excellent evenness and productivity, to provide an image forming device, and to provide methods of manufacturing them. SOLUTION: A method of manufacturing electron emitting element has a process for forming a hydrophobic surface 7 over the whole surface of a board 1 including electrodes 2, 3, a process for forming a hydrophilic surface 6 in a part to be formed with a conductive film 4 by coating any one of acid, alkali and solvent with the ink jetting method, a process for giving the drops 9 of the solution including the conductive film forming material between the element electrodes 2, 3, a process for forming a conductive thin film 4 while heating the given solution drops for burning, and a process for forming an electron emitting part 5 in the conductive film 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, an electron source having a large number of such electron-emitting devices, and an image forming apparatus such as a display device or an exposure device using the electron source.
And their production methods.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, namely, a thermionic electron-emitting device and a cold cathode electron-emitting device. Field emission type (hereinafter, referred to as "FE")
Type ". ), Metal / insulating layer / metal type (hereinafter referred to as “MI
M type ". ) And surface conduction electron-emitting devices.

[0003] As an example of the FE type, W. P. Dyke
and W. W. Dolan, "Field Em
issue ", Advance in Elect
ron Physics, 8, 89 (1956) or C.I. A. Spindt, “Physical
Properties of thin-filmfi
eld emission cathodes wit
h molybdenum cones ", JA
ppl. Phys. , 47, 5248 (1976).
And the like are known.

As an example of the MIM type, C.I. A. Mea
d, “Operation of Tunnel-Em
issue Devices ", J. Appl.
Phys. , 32, 646 (1961).

As an example of the surface conduction electron-emitting device,
M. I. Elinson, Radio Eng.
Electron Phys. , 10, 1290 (1
965).

[0006] The surface conduction electron-emitting device utilizes a phenomenon in which electrons are emitted by passing a current through a small-area thin film formed on an insulating substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al. And a device using an Au thin film [G. Dittmer: "Thin Solid
Films ", 9, 317 (1972)], In ₂
O ₃ / SnO ₂ thin film [M. Hartwell
and C.I. G. FIG. Fonstad: "IEEE T
rans. ED Conf. ", 519 (197
5)], using a carbon thin film [Hisashi Araki et al .: Vacuum,
26, No. 1, p. 22 (1983)].

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.P. Figure 1 shows the device configuration of Hartwell
FIG. In FIG. 1, reference numeral 1 denotes a substrate. Reference numeral 4 denotes a conductive film, which is formed of a metal oxide thin film or the like formed in an H-shaped pattern. The electron emission portion 5 is formed by an energization process called energization forming described later. In the drawing, the element electrode interval L is 0.5 to 1 mm, and W ′ is 0.1 m.
m.

In these surface conduction electron-emitting devices, it is general that the electron-emitting portion 5 is formed beforehand by performing an energization process called energization forming on the conductive film 4 before electron emission. That is, the energization forming means that a voltage is applied to both ends of the conductive film 4, and the conductive film 4 is locally destroyed, deformed or deteriorated to change the structure, and the electrons in an electrically high-resistance state are formed. This is a process for forming the emission unit 5. Note that a crack is generated in a part of the conductive film 4 in the electron emitting portion 5, and electrons are emitted from the vicinity of the crack.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be arrayed over a large area because of its simple structure. Therefore, various applications for utilizing this feature are being studied. For example, a charged beam source,
Application to an image forming apparatus such as a display device is exemplified.

Conventionally, as an example in which a large number of surface conduction electron-emitting devices are arrayed, surface conduction electron-emitting devices are arranged in parallel, and both ends (both device electrodes) of each surface conduction electron-emitting device are wired. (Also referred to as a common wiring). An electron source in which rows each connected by a common line (also referred to as a ladder-type arrangement) are provided (for example, JP-A-64-31332, JP-A-1-283737, 2-257552).

In particular, in the case of a display device, a flat panel display device similar to a display device using liquid crystal can be used, and a self-luminous display device that does not require a backlight is used as a surface conduction type electron emission device. There has been proposed a display device in which an electron source in which a number of elements are arranged and a phosphor that emits visible light when irradiated with an electron beam from the electron source are combined (US Pat. No. 5,066,883).

In order to manufacture the above-mentioned surface conduction electron-emitting device, it has been manufactured by a method that makes extensive use of photolithography technology and etching technology. But,
As a simpler method and a method of manufacturing a surface conduction electron-emitting device at low cost, Japanese Patent Application Laid-Open No. 9-245625 discloses that a portion of a substrate on which a conductive film is not formed is subjected to a hydrophobic treatment, A method for manufacturing an electron-emitting device has been proposed in which a portion where a conductive film is formed is subjected to a hydrophilic treatment or both of them to stabilize a position where an element is formed and stabilize an element size. .

[0013]

In the process of forming an element on a substrate, a heat treatment process is inevitable. For example, formation of element wiring by screen printing has been attempted, and the wiring is formed by firing an Ag paste after screen printing.

However, a glass substrate generally used as a substrate has a phenomenon in which dimensions change before and after heat treatment. The amount of dimensional change can be as large as 20 μm or more per 10 inches, but the amount of dimensional change is not always constant and varies from time to time. For this reason, at the time when the device electrodes are formed, there has been a phenomenon that the device pitch differs from substrate to substrate, and the pitch is not constant depending on the location on the same substrate.

In a method using a photomask conventionally used, hydrophilic processing and element formation can always be performed only at defined positions, and the method can cope with such a change in element pitch due to such a dimensional change of the substrate. I couldn't do that. These problems have become more prominent with the increase in the area of the substrate, and a need has arisen to deal with them.

In view of the above problems, it is an object of the present invention to obtain uniform electron emission characteristics over a large area, to be easily manufactured at low cost, and to obtain an element pitch for each substrate caused by a dimensional change of the substrate in a thermal process. It is an object of the present invention to provide an electron-emitting device capable of coping with variations of the electron source, an electron source, an image forming apparatus, and a method of manufacturing the same, which are excellent in uniformity and productivity using the electron-emitting device.

[0017]

The structure of the present invention to achieve the above object is as follows.

That is, a first aspect of the present invention is a step of forming a pair of device electrodes on a substrate, a step of hydrophobizing the entire surface of the substrate including the device electrodes, and a step of forming a conductive film on the surface. Using an inkjet method, a step of performing a hydrophilic treatment by applying any of an acid, an alkali, or a solvent, and a step of applying droplets of a solution containing a conductive film forming material between element electrodes, A method for manufacturing an electron-emitting device, comprising: a step of heating and firing a droplet to form a conductive film; and a forming step of forming an electron-emitting portion in the conductive film.

According to a second aspect of the present invention, there is provided an electron-emitting device manufactured by the first method of the present invention.

A third aspect of the present invention is an electron source which emits electrons in response to an input signal, wherein a plurality of the first electron-emitting devices of the present invention are arranged on a substrate. In the electron source.

A fourth aspect of the present invention is a method of manufacturing the third electron source of the present invention, wherein a plurality of electron-emitting devices are manufactured by the second method of the present invention. In a method of manufacturing an electron source.

According to a fifth aspect of the present invention, there is provided an apparatus for forming an image based on an input signal, comprising at least the third electron source of the present invention and irradiation of an electron beam emitted from the electron source. And an image forming member for forming an image by using the image forming apparatus.

A sixth aspect of the present invention is a method for manufacturing the fifth image forming apparatus of the present invention, wherein the electron source is manufactured by the fourth method of the present invention. A method for manufacturing a forming apparatus.

According to the present invention, the solution applied in the conductive film forming step after being subjected to the surface treatment spreads on the hydrophilic surface of the substrate and repels on the hydrophobic surface.
The conductive film can be accurately formed at a predetermined position without spreading or adhering the solution to an unnecessary position. In addition, the shape and thickness of the conductive film can be easily controlled by the area of the surface-treated surface of the substrate and the amount of the applied solution, and the reproducibility and uniformity of the shape and thickness of the conductive film are improved. I do. As a result, even when a large number of electron-emitting devices are formed over a large area, uniform electron-emitting characteristics can be obtained.

Further, according to the manufacturing method of the present invention, since a large-scale film forming apparatus and the patterning of the conductive film using the photolithography technique are not required, the electron-emitting device can be manufactured easily at low cost. can do.

Further, by applying the electron-emitting device manufactured by the method of the present invention, it is possible to provide an electron source and an image forming apparatus excellent in uniformity and productivity.

Further, according to the present invention, since the hydrophilizing treatment of the portion where the conductive film is to be formed is performed by using the ink jet method, the pitch of the position can be freely adjusted in the vertical and horizontal directions. By measuring the pitch of the element electrodes formed thereon, it is possible to cope with a difference in pitch between individual substrates and a change in pitch depending on a location on the same substrate.

[0028]

Next, preferred embodiments of the present invention will be described.

FIG. 1 is a schematic view showing an example of the configuration of an electron-emitting device according to the present invention. FIG. 1 (a) is a plan view and FIG. 1 (b).
Is a sectional view. In FIG. 1, 1 is a substrate, 2 and 3 are electrodes (element electrodes), 4 is a conductive film, and 5 is an electron emitting portion.

Examples of the substrate 1 include quartz glass, glass with a reduced impurity content such as Na, blue plate glass, a laminate of blue plate glass with SiO ₂ laminated by sputtering, ceramics such as alumina, and a Si substrate. Can be used.

The materials of the opposing element electrodes 2 and 3 are as follows.
General conductor materials can be used, for example, Ni, C
metals or alloys such as r, Au, Mo, W, Pt, Ti, Al, Cu, Pd and Pd, Ag, Au, RuO ₂ , Pd
Metal or metal oxide and printed conductor composed of glass or the like, such as -ag, is appropriately selected from a semiconductor conductive materials such as transparent conductor and polysilicon or the like In ₂ O ₃ -SnO _2.

The element electrode interval L, the element electrode length W, the shape of the conductive film 4 and the like are designed in consideration of the applied form and the like. The element electrode interval L can be preferably in the range of several hundred nm to several hundred μm, and more preferably several μm to several tens μm in consideration of the voltage applied between the element electrodes.
In the range. The element electrode length W is set to several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics.
In the range. Film thickness d of device electrodes 2 and 3
Can be in the range of several tens nm to several μm.

In addition to the structure shown in FIG. 1, a structure in which a conductive film 4 and device electrodes 2 and 3 are formed on a substrate 1 in this order may be adopted. Further, depending on the manufacturing method, the entire space between the opposing element electrodes 2 and 3 may function as an electron emitting portion.

As a material constituting the conductive film 4, for example, Pd, Pt, Ru, Ag, Au, Ti, In, Cu,
Metals such as Cr, Fe, Zn, Sn, Ta, W, and Pb;
_{dO, SnO 2, In 2 O} 3, PbO, oxide conductor, such as _{Sb 2 O 3, HfB 2,} ZrB 2, LaB 6, CeB
_6, YB _4, borides such GdB4, TiC, ZrC, H
carbides such as fC, TaC, SiC, WC, TiN, Zr
Examples include nitrides such as N and HfN, semiconductors such as Si and Ge, and carbon.

As the conductive film 4, a fine particle film composed of fine particles is preferably used in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage of the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, and the like, but is usually in the range of several to several hundred nm. Preferably, it is more preferably in the range of 1 nm to 50 nm. The resistance value of Rs is 10 ² Ω / □ to 1
It is preferably a value of 0 ⁷ Ω / □. Rs is a resistance R measured in the length direction of the thin film having a width w and a length 1;
This is a value that appears when R = Rs (l / w).

In the present specification, the forming process will be described by taking an energizing process as an example. However, the forming process is not limited to this, and a process for forming a high resistance state by generating a crack in a film is described. It contains.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure in a state in which the fine particles are individually dispersed and arranged or in a state in which the fine particles are adjacent to each other or overlap each other (when some fine particles are formed). To form an island-like structure as a whole). The particle size of the fine particles is in the range of a few to a few thousand, preferably in the range of 10 to 200.

In the present specification, the term “fine particles” is frequently used, and the meaning will be described.

Small particles are called "fine particles", and smaller ones are called "ultra fine particles". It is widely practiced to call a “cluster” smaller than “ultrafine particles” and having a few hundred atoms or less. However, each boundary is not strict and changes depending on what kind of property is focused on. Also "fine particles"
And "ultrafine particles" may be collectively referred to as "fine particles", and the description in this specification is in line with this.

"Experimental Physics Course 14 Surface / Particles"
(Edited by Kinoshita Yoshio, Kyoritsu Shuppan published September 1, 1986)
Then, it is described as follows.

"In the present description, the fine particles have a diameter of about 2 to 3 μm to about 10 nm. In particular, the ultrafine particles have a diameter of about 10 nm to 2 to 3 nm.
It means up to about nm. It is not exactly strict because both are collectively written as fine particles, but it is a rough guide. When the number of atoms constituting a particle is two to several tens to several hundreds, it is called a cluster. (Pages 195, lines 22-26)

In addition, the definition of “ultrafine particles” in the “Hayashi / Ultrafine Particle Project” of the New Technology Development Corporation has the following lower limit of the particle size, and is as follows.

In the “Ultra Fine Particle Project” (1981 to 1986) of the “Creative Science and Technology Promotion System”, particles having a size (diameter) in the range of about 1 to 100 nm are referred to as “ultra fine particles” (ultra fine particles). I made it. Then one ultra fine particle is about 100 ~
It is an aggregate of about 10 ⁸ atoms. Ultra-fine particles are large to giant particles on an atomic scale. ("Ultra Fine Particles-Creative Science and Technology-" Hayashi Tax, Ryoji Ueda, Akira Tazaki
(Edited by Mita Publishing, 1988, page 2, lines 1 to 4)
"A particle that is even smaller than an ultrafine particle, that is, a single particle composed of several to several hundred atoms, is usually called a cluster." (Page 2, lines 12 to 13 of the same book)

[0044] Based on the general notation as described above,
In the present specification, “fine particles” are an aggregate of a large number of atoms and molecules, and the lower limit of the particle size is several Å to 10 Å, and the upper limit is
It refers to the degree.

The electron-emitting portion 5 is constituted by a high-resistance crack formed in a part of the conductive film 4, in which conductive fine particles having a particle size in the range of several Å to several tens nm are contained. May be present. The conductive fine particles contain some or all of the elements of the material constituting the conductive film 4. Further, the electron-emitting portion 5 and the conductive film 4 in the vicinity thereof may have carbon or a carbon compound formed by an activation step described later.

There are various methods for manufacturing the electron-emitting device of the present invention. One example will be described with reference to FIG. In FIG. 2, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

1) The substrate 1 is sufficiently washed with a detergent, pure water, an organic solvent, or the like, and a device electrode material is deposited by a vacuum deposition method, a sputtering method, or the like, and then patterned by lift-off, etching, or the like. The device electrodes 2 and 3 are formed on the substrate 1 by a method of printing and firing a paste containing an electrode material (FIG. 2A). Here, a substrate on which at least the device electrodes 2 and 3 are formed and on which the conductive film 4 is not formed is referred to as an electrode substrate 11.

2) Electrode substrate 11 provided with device electrodes 2 and 3
Is subjected to a hydrophobic treatment to form a hydrophobic surface 7 (FIG. 2B).

Hereinafter, an example of a method for treating the surface of the electrode substrate 11 will be described with reference to FIG.

Generally, the surface of clean glass, metal, or metal oxide is easily wetted by a solution such as water, and the surface of an organic material such as plastics is hardly wetted. Since the wettability of the substrate surface is derived from the surface structure, it is difficult to get wet with these solutions by introducing a highly hydrophobic hydrocarbon group or fluorocarbon group into the substrate surface and subjecting the substrate surface to hydrophobic treatment. can do.

In the present invention, an organosilicon compound having a hydrophobic group such as hydrocarbon or fluorocarbon is preferably used for the hydrophobizing treatment. The treatment may be performed by a coating method such as spin coating or spray coating or a vapor deposition method. Can be.

Examples of the organosilicon compound include trimethylmethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane,
Alkoxysilanes such as trimethylethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, triphenylmethoxysilane, diphenyldimethoxysilane, phenyltrimethoxysilane, triphenylethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, and vinyltriethoxysilane Vinylsilanes such as chlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-chloropropyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ- Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-
Aminopropylmethyldiethoxysilane, N-β (aminoethyl) -γ aminopropyltrimethoxysilane, N
Organic functional silanes such as -β (aminoethyl) -γ aminopropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, fluoroethyl Trimethoxysilane, γ-fluoropropyltrimethoxysilane, fluoroethyldimethoxyethoxysilane, fluoroethylmethyldiethoxysilane, perfluoroethyltrimethoxysilane, perfluoroethyltriethoxysilane, perfluoropropyltrimethoxysilane, perfluoropropyltri Fluoroalkylsilanes (including C4 or more) such as ethoxysilane, disilanes such as hexamethyldisilane, hexamethyldisilazane, hexamethylcyclotrisilazane, etc. Razan acids, silanols such as diphenylsilane diol, N- trimethylsilylacetamide, bis (trimethylsilyl) acetamide,
And silylamides such as N, N'-bis (trimethylsilyl) urea. In addition, a silicone resin or a fluorine resin generally used as a water repellent material may be used.

3) Next, the portion for forming the conductive film is subjected to a hydrophilic treatment. For the hydrophilization treatment, for example, an acidic solution such as hydrochloric acid or sulfuric acid, an alkaline solution such as sodium hydroxide, an organic solvent, or a mixture of these can be used. An oxidizing agent represented by a mixed solution of potassium dichromate and sulfuric acid may be used.

The solution 9 is applied to a desired position on the substrate by an ink jet device 8 such as a bubble jet or a piezo jet to perform a hydrophilic treatment, thereby forming a hydrophilic surface 6 on a portion where a conductive film is to be formed. (Figure 2
(C)).

The solution 9 removes or cuts the hydrophobic organic functional groups applied to the substrate surface,
The surface of the substrate is hydrophilized by one of the effects of -OH groups being imparted to the substrate surface, or by a plurality of these effects. Further, the selection of the type of the solution or the solvent is appropriately selected depending on the material of the substrate and the type of the hydrophobic treatment performed on the substrate.

It is desirable that the position where the solution 9 is applied is determined by measuring the state of formation of the device electrodes on the substrate immediately before. This corresponds to the fact that the substrate undergoes contraction and deformation during the thermal process, and the pitch of the device electrodes changes from the design value.

As will be described with reference to FIG. 3, reference numeral 21 denotes a designed element electrode pitch. Originally, the device electrode is formed at this position. However, it is assumed that the substrate is deformed by the thermal process and the device electrode is formed at the position 22. Microscope, XY stage,
This can be performed by an apparatus combining a CCD camera, an image processing system, and the like.
The positions of the four corner elements 4, 25 and 26 are detected, and the other elements are interpolated at equal intervals between these four elements to determine the position, and the solution is applied to those positions.

Further, as shown in FIG. 4, the positions of the elements to be detected are increased to nine elements including the center in addition to the four corners, and the positions of the other elements are interpolated between these nine elements. Thus, the position of the element can be determined with higher accuracy even for a larger-sized substrate. The number of position detections is not limited to four or nine, and the accuracy can be improved as the number of position detections increases, as long as the working time allows.

As described above, the electrode substrate 11 on which the surface of the substrate on which the conductive film 4 is to be formed is subjected to the hydrophilic treatment and the substrate surface on which the conductive film 4 is not formed is subjected to the hydrophobic treatment.

4) A solution containing a material for forming the conductive film 4 is applied to the surface-treated electrode substrate 11 (not shown). As an example of applying the solution, an example in which a droplet including a material for forming the conductive film 4 is applied using a droplet applying apparatus will be described.

As a specific example of the droplet applying device used here, any device can be used as long as it can form an arbitrary droplet, but in particular, about several tens ng to several tens μg. It is desirable to use an inkjet type apparatus which can be controlled in the range described above and can easily form a small amount of droplets of about several tens ng or more. As the inkjet system, for example, a bubble jet system can be suitably used.

The number of droplets to be applied may be singular or plural for the formation of one conductive film. In the case of a single unit, the manufacturing time can be reduced as compared with the case of a plurality. On the other hand, in the case of a plurality, the thickness of the conductive film can be controlled by the number of droplets in addition to the amount of one droplet, and the shape and pattern accuracy of the conductive film to be formed can be further improved. . Also, regardless of whether the number of droplets applied to the formation of one conductive film is singular or plural, a pair of element electrodes 2 and 3
The conductive film may be formed by applying droplets to two or more locations.

The solution to be applied as droplets contains the conductive film 4
It is desirable to use a solution or the like obtained by dispersing or dissolving a material for forming in water or a mixed solvent of water and an organic solvent. Examples of the material for forming the conductive film 4 used here include the above-described material for forming the conductive film 4 and the organometallic compound containing the material for forming the conductive film 4. The surface tension at room temperature is 20 to 90 dyne / cm, preferably 50 to 80 dy, though it depends on the surface treatment method of the substrate.
A ne / cm solution is desirable.

In this case, the applied solution is applied to the electrode substrate 1
Since the droplet spreads on the hydrophilic treatment surface 6 and is repelled on the hydrophobic treatment surface 7, the droplet does not spread irregularly on the substrate. Therefore, the shape and thickness of the conductive film 4 can be easily controlled by the area of the hydrophilized surface 6 of the substrate and the amount of liquid droplets to be applied. The performance is improved. Further, since the formation position of the conductive film 4 is determined by the processing surface of the substrate, there is no effect even if the landing position of the droplet is slightly shifted, and the conductive film 4 can be formed at a predetermined position with high accuracy.

As the solution 9 to be applied, a solution in which the material for forming the conductive film 4 is dispersed or dissolved in an organic solvent can be used in the same manner. In general, the organic solvent has a surface tension of 1%.
It is as low as 5 to 40 dyne / cm and easily wets various substrates. In this case, in the hydrophobization treatment of the substrate surface, it is preferable to perform the surface treatment using a fluorine-containing compound such as the above fluoroalkylsilane, which can form a substrate surface with lower surface energy (less wettable). .

In the present invention, the method of applying the solution containing the material for forming the conductive film 4 on the electrode substrate 11 is not limited to the method using the above-described droplet applying apparatus.
For example, a dipping method in which the surface-treated substrate is immersed in a solution containing a material for forming the conductive film 4 and then pulled up at a predetermined speed can be used. Also in this case, similarly to the above-described method, the conductive film 4 can be selectively formed according to the processing surface of the substrate.

As described above, after the solution containing the material for forming the conductive film 4 is applied, and dried if necessary, a heat treatment is performed to form the conductive film 4 (FIG. 2D). .

5) Next, an energization process called forming is performed. When an electric current is applied between the device electrodes 2 and 3, an electron-emitting portion 5 is formed at the portion of the conductive film 4 (FIG. 2E).

In the forming step, heat energy is locally concentrated on a part of the conductive film 4 instantaneously, and an electron emitting portion 5 having a changed structure is formed at that portion. In this energization process, a portion of the conductive film 4 where the structure such as destruction, deformation or alteration is locally changed is formed, and the portion constitutes the electron emission portion 5.

FIG. 5 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform.
For this purpose, the method shown in FIG. 5A for continuously applying a pulse with a constant pulse peak value and the method shown in FIG. 5B for applying a pulse while increasing the pulse peak value are used. is there.

First, the case where the pulse peak value is a constant voltage will be described with reference to FIG. T ₁ in FIG.
And T ₂ are the pulse width and the pulse interval of the voltage waveform. The peak value (peak voltage) of the triangular wave is appropriately selected according to the form of the electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens minutes. The pulse waveform is
The waveform is not limited to the triangular wave, and a desired waveform such as a rectangular wave can be adopted.

Next, a case where a voltage pulse is applied while increasing the pulse peak value will be described with reference to FIG.
T ₁ and T ₂ in FIG. 5B can be the same as those shown in FIG. 5A. The peak value (peak voltage) of the triangular wave can be increased, for example, in steps of about 0.1 V.

The end of the energization forming process can be detected by applying a voltage that does not locally destroy or deform the conductive film 4 during the pulse interval T ₂ and measuring the current. For example, a current flowing when a voltage of about 0.1 V is applied is measured, and a resistance value is obtained. When a resistance of 1 MΩ or more is indicated, the energization forming is terminated.

The electrical processing after the forming processing can be performed in a vacuum processing apparatus as shown in FIG. 6, for example. This vacuum processing device also has a function as a measurement evaluation device. In FIG. 6 as well, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as in FIG.

In FIG. 6, reference numeral 55 denotes a vacuum vessel,
Reference numeral 6 denotes an exhaust pump. An electron-emitting device is provided in the vacuum vessel 55. Reference numeral 51 denotes a power supply for applying a device voltage _Vf to the electron-emitting device, 50 denotes an ammeter for measuring a device current _If flowing between the device electrodes 2 and 3, and 54 denotes an electron-emitting portion 5 of the device. An anode electrode for capturing the emission current _Ie emitted, 53 is a high-voltage power supply for applying a voltage to the anode electrode 54, and 52 is a current for measuring the emission current _Ie emitted from the electron emission unit 5. It is total. As an example, the voltage of the anode electrode 54 is 1 kV to 1 kV.
The measurement can be performed with the range of 0 kV and the distance H between the anode electrode 54 and the electron-emitting device in the range of 2 mm to 8 mm.

The vacuum vessel 55 is provided with equipment necessary for measurement in a vacuum atmosphere, such as a vacuum gauge (not shown).
The measurement and evaluation can be performed in a desired vacuum atmosphere.

The exhaust pump 56 is composed of a normal high vacuum system such as a turbo pump and a rotary pump, and an ultra-high vacuum system such as an ion pump. The entire vacuum processing apparatus provided with the electron-emitting device substrate shown here can be heated by a heater (not shown).

6) It is preferable to perform a process called an activation step on the device after the forming. The activation step can be performed, for example, by repeatedly applying a pulse between the device electrodes 2 and 3 in an atmosphere containing an organic substance gas in the same manner as in energization forming. _f and the emission current _Ie change remarkably.

The atmosphere containing the organic substance gas in the activation step is formed by utilizing the organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump. Alternatively, it can be obtained by introducing a gas of an appropriate organic substance into a vacuum once sufficiently evacuated by an ion pump or the like that does not use oil. The preferable gas pressure of the organic substance at this time varies depending on the form of the above-described element, the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set according to the case. Suitable organic substances include aliphatic hydrocarbons of alkanes, alkenes, and alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, and organic acids such as phenols, carboxylic acids, and sulfonic acids. And specifically, C, methane, ethane, propane, etc.
saturated hydrocarbons represented by _n H _{2n + 2} , unsaturated hydrocarbons represented by a composition formula such as C _n H _2n such as ethylene and propylene,
Benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol,
Formic acid, acetic acid, propionic acid and the like can be used.

By this treatment, carbon or a carbon compound is deposited on the device from organic substances existing in the atmosphere,
The element current _If and the emission current _Ie change remarkably.

The carbon or carbon compound is, for example, graphite (including so-called HOPG, PG, GC), and HOPG has a substantially complete graphite crystal structure,
G indicates that the crystal grain is about 20 nm and the crystal structure is slightly disordered, and GC indicates that the crystal grain is about 2 nm and the disorder of the crystal structure is further increased. ), Amorphous carbon (refers to amorphous carbon and a mixture of amorphous carbon and the microcrystals of graphite);
The film thickness is preferably in the range of 50 nm or less,
More preferably, the thickness is 30 nm or less.

The termination of the activation step can be appropriately determined while measuring the device current _If and the emission current _Ie .

7) The electron-emitting device obtained through such a step is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum container. It is preferable to use a vacuum exhaust device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum exhaust device such as a sorption pump or an ion pump can be used.

The partial pressure of the organic component in the vacuum vessel is set to a partial pressure at which the carbon or carbon compound is not newly deposited.
It is preferably 3 × 10 ⁻⁶ Pa or less, more preferably 1.3 × 10 ⁻⁶ Pa.
^-8 Pa or less or particularly preferred. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. The heating conditions at this time are 80 to 2
It is desirable that the treatment be performed at 50 ° C., preferably 150 ° C. or higher, for as long as possible. However, the treatment is not particularly limited to this condition. Do. The pressure inside the vacuum vessel needs to be as low as possible, and is 1.3 × 10 ^−5.
Pa or lower is preferable, and 1.3 × 10 ⁻⁶ Pa or lower is particularly preferable.

It is preferable that the atmosphere at the time of driving after the stabilization process is performed is the same as the atmosphere at the end of the stabilization process, but the present invention is not limited to this. Even if the pressure itself increases somewhat, it is possible to maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, and as a result, the device current _If and the emission current _Ie can be suppressed.
But it stabilizes.

The basic characteristics of the electron-emitting device of the present invention obtained through the above steps will be described with reference to FIG.

FIG. 7 is a diagram schematically showing the relationship between the emission current _Ie and the device current _If measured using the vacuum processing apparatus shown in FIG. 6, and the device voltage _Vf . In FIG. 7, since the emission current _Ie is significantly smaller than the device current _If , it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is clear from FIG. 7, the electron-emitting device of the present invention has the following three characteristic characteristics with respect to the emission current _Ie .

(I) The emission current _Ie of the present device rapidly increases when a device voltage higher than a certain voltage (referred to as a threshold voltage; _{Vth in} FIG. 7) is applied. On the other hand, when the device voltage is lower than the threshold voltage _Vth , the emission current _Ie increases. _Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage V _th with respect to the emission current I _e .

(Ii) Since the emission current _Ie depends monotonically on the device voltage _Vf , the emission current _Ie can be controlled by the device voltage _Vf .

(Iii) Anode electrode 54 (see FIG. 6)
Is dependent on the time for applying the device voltage _Vf . That is, the amount of charge captured by the anode electrode 54 can be controlled by the time during which the device voltage _Vf is applied.

As understood from the above description, the electron-emitting device of the present invention can easily control the electron-emitting characteristics according to the input signal. By utilizing this property, it is possible to apply to various fields such as an electron source and an image forming apparatus having a plurality of electron-emitting devices.

[0094] In Figure 7, the device current I _f showed (MI characteristic) Example monotonically increasing with respect to the device voltage V _f,
The element current _If may exhibit a voltage-controlled negative resistance characteristic (VCNR characteristic) with respect to the element voltage _Vf (not shown).
These properties can be controlled by controlling the steps described above.

Next, application examples of the electron-emitting device to which the present invention can be applied will be described below. By arranging a plurality of electron-emitting devices to which the present invention can be applied on a substrate, for example, an electron source or an image forming apparatus can be configured.

Various arrangements of the electron-emitting devices can be adopted. As an example, each of a large number of electron-emitting devices arranged in parallel is connected at both ends, a large number of rows of electron-emitting devices are arranged (referred to as a row direction), and a direction perpendicular to the wiring (referred to as a column direction). There is a ladder-type arrangement in which electrons from the electron-emitting devices are controlled and driven by control electrodes (also referred to as grids) disposed above the electron-emitting devices. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of the electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. One example is one in which the other of the electrodes of a plurality of electron-emitting devices arranged in the same column is commonly connected to a wiring in the Y direction. This is a so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.

The electron-emitting device to which the present invention can be applied has three characteristics as described above. That is, the emission electrons from the surface conduction electron-emitting device can be controlled by the peak value and the width of the pulse-like voltage applied between the opposing device electrodes when the electrons are equal to or higher than the threshold voltage. On the other hand, below the threshold voltage, almost no emission occurs. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulse-like voltage is appropriately applied to each of the devices, a surface conduction electron-emitting device is selected according to an input signal, and the amount of electron emission is determined. Can be controlled.

Hereinafter, based on this principle, an electron source substrate obtained by arranging a plurality of electron-emitting devices of the present invention will be described with reference to FIG. 8, reference numeral 71 denotes an electron source substrate;
Reference numeral 2 denotes an X-direction wiring, and 73 denotes a Y-direction wiring. 74 is an electron-emitting device, and 75 is a connection.

The m X-direction wirings 72 are Dx1, Dx
2,..., Dxm, and can be formed of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness and width of the wiring are appropriately designed.
The Y-directional wiring 73 includes n wirings Dy1, Dy2,..., Dyn, and is formed in the same manner as the X-directional wiring 72. An interlayer insulating layer (not shown) is provided between the m X-directional wirings 72 and the n Y-directional wirings 73 to electrically separate them (m and n are both Positive integer).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 71 on which the X-directional wiring 72 is formed. The material and the production method are appropriately set. The X-direction wiring 72 and the Y-direction wiring 73 are respectively drawn out as external terminals.

A pair of device electrodes (not shown) constituting the electron-emitting device 74 are electrically connected to m X-directional wires 72 and n Y-directional wires 73 by a connection 75 made of a conductive metal or the like. It is connected.

The material forming the wiring 72 and the wiring 73, the material forming the connection 75, and the material forming the pair of element electrodes may have the same or some of the constituent elements that are the same or different from each other. Good. These materials are appropriately selected, for example, from the above-described materials for the device electrodes. When the material forming the element electrode is the same as the wiring material, the wiring connected to the element electrode can also be called an element electrode.

The X-direction wiring 72 is connected to a scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the electron-emitting devices 74 arranged in the X-direction. On the other hand, a modulation signal generating means (not shown) for modulating each column of the electron-emitting devices 74 arranged in the Y direction according to an input signal is connected to the Y-direction wiring 73. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device.

In the above configuration, individual elements can be selected and driven independently using simple matrix wiring.

An image forming apparatus constructed using such an electron source having a simple matrix arrangement will be described with reference to FIGS. 9, 10 and 11. FIG. FIG. 9 is a schematic diagram illustrating an example of a display panel of the image forming apparatus, and FIG. 10 is a schematic diagram of a fluorescent film used in the image forming apparatus of FIG. FIG.
FIG. 1 is a block diagram showing an example of a drive circuit for performing display according to an NTSC television signal.

In FIG. 9, reference numeral 71 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 81, a rear plate on which the electron source substrate 71 is fixed; 86, a fluorescent film 84 on the inner surface of a glass substrate 83;
And a face plate on which a metal back 85 and the like are formed. Reference numeral 82 denotes a support frame, and a rear plate 81 and a face plate 86 are connected to the support frame 82 using frit glass or the like. Reference numeral 88 denotes an envelope, which is sealed by firing at a temperature range of 400 to 500 ° C. for 10 minutes or more in the atmosphere or nitrogen, for example.

Reference numeral 74 denotes an electron-emitting device as shown in FIG. Reference numerals 72 and 73 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The envelope 88 includes the face plate 86, the support frame 82, and the rear plate 81, as described above. Since the rear plate 81 is provided mainly for the purpose of reinforcing the strength of the substrate 71, if the substrate 71 itself has sufficient strength, the separate rear plate 81 can be unnecessary. That is, the support frame 82 is directly sealed to the substrate 71, and the envelope 8 is formed by the face plate 86, the support frame 82 and the substrate 71.
8 may be configured. On the other hand, by providing a support (not shown) called a spacer between the face plate 86 and the rear plate 81, the envelope 88 having sufficient strength against atmospheric pressure can be configured.

FIG. 10 is a schematic diagram showing a fluorescent film. The fluorescent film 84 can be composed of only a phosphor in the case of monochrome. In the case of a color fluorescent film, it may be composed of a black conductive material 91 called a black stripe (FIG. 10A) or a black matrix (FIG. 10B) and a fluorescent material 92 depending on the arrangement of the fluorescent materials. it can. The purpose of providing the black stripes and the black matrix is to make the mixed portions inconspicuous by making the painted portions between the phosphors 92 of the necessary three primary color phosphors black in the case of color display, An object of the present invention is to suppress a decrease in contrast due to light reflection. As the material of the black conductive material 91, a material which is conductive and has little light transmission and reflection can be used in addition to a commonly used material mainly containing graphite.

The method of applying the fluorescent substance to the glass substrate 83 can employ a precipitation method or a printing method irrespective of monochrome or color. Usually, a metal back 85 is provided on the inner surface side of the fluorescent film 84. The purpose of providing a metal back is
The light emitted from the phosphor toward the inner surface is converted into a face plate 8.
Improving the brightness by specular reflection on the 6 side,
The purpose is to function as an electrode for applying an electron beam acceleration voltage, and to protect the phosphor from damage due to collision of negative ions generated in the envelope. The metal back can be manufactured by performing a smoothing process (usually called “filming”) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al using vacuum evaporation or the like.

The face plate 86 is further provided with a fluorescent film 8.
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 84 in order to increase the conductivity of the phosphor film 84.

When performing the above-described sealing, in the case of color, it is necessary to make each color phosphor correspond to the electron-emitting device, and sufficient alignment is indispensable.

The image forming apparatus shown in FIG. 9 is manufactured, for example, as follows.

While the inside of the envelope 88 is appropriately heated, the inside of the envelope 88 is exhausted through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump or a sorption pump.
After setting the atmosphere with a vacuum degree of about ^10-5 Pa and a sufficiently small amount of the organic substance, sealing is performed. In order to maintain a vacuum degree after the envelope 88 is sealed, a getter process may be performed.

This is because a getter (not shown) disposed at a predetermined position in the envelope 88 by heating using resistance heating, high-frequency heating, or the like immediately before or after the envelope 88 is sealed. ) Is heated to form a deposited film. The getter usually contains Ba or the like as a main component, and maintains a degree of vacuum of, for example, 1.3 × 10 ⁻⁵ Pa or more by the adsorption action of the deposited film. Here, steps after the forming process of the electron-emitting device can be set as appropriate.

Next, an example of a configuration of a driving circuit for performing television display based on NTSC television signals on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG. . In FIG.
101 is an image display panel, 102 is a scanning circuit, 103 is a control circuit, 104 is a shift register, 105 is a line memory, 106 is a synchronization signal separation circuit, 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 101 has terminals Dox1 through Dx
oxm, terminals Doy1 to Doyn, and a high voltage terminal 87 are connected to an external electric circuit. Terminals Dox1 to Doxm are used to sequentially drive electron sources provided in the display panel 101, that is, electron emission element groups arranged in a matrix of m rows and n columns, one row (n elements) at a time. A scanning signal is applied. To the terminals Doy1 to Doyn, a modulation signal for controlling an output electron beam of each of the electron-emitting devices in one row selected by the scanning signal is applied. The high-voltage terminal 87 is supplied with a DC voltage of, for example, 10 kV from a DC voltage source Va. This is for applying sufficient energy to the electron beam emitted from the electron-emitting device to excite the phosphor. Is the accelerating voltage.

Next, the scanning circuit 102 will be described. The circuit includes m switching elements (S1 to S
m is schematically shown). Each switching element selects either the output voltage of the DC voltage power supply Vx or 0 [V] (ground level),
It is electrically connected to terminals Dox1 to Doxm of the display panel 101. Each of the switching elements S1 to Sm operates based on a control signal _Tscan output from the control circuit 103, and can be configured by combining switching elements such as FETs, for example.

In the case of this example, the DC voltage source Vx is such that the drive voltage applied to the non-scanned element is equal to or lower than the electron emission threshold voltage based on the characteristics (electron emission threshold voltage) of the electron emission element. It is set to output a constant voltage.

The control circuit 103 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. Control circuit 103 in accordance with the synchronization signal T _sync sent from the synchronous signal separation circuit 106, T _scan, generating a respective control signal T _sft and T _mry to each unit.

The synchronizing signal separating circuit 106 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separating (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 106 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is illustrated here as a _Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. This DATA signal is input to the shift register 104.

The shift register 104 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and converts the DATA signal into a control signal _Tsft sent from the control circuit 103. (Ie, the control signal T _sft is applied to the shift register 10
4 may be rephrased as the shift clock. ).

The data for one line of the image subjected to the serial / parallel conversion (corresponding to the drive data for n electron-emitting devices) is output from the shift register 104 as n-numbered parallel signals I _{d1 to} I _dn. .

[0124] The line memory 105 is a storage device for storing only of data for one line, stores the contents of appropriate I _d1 to I _dn according to the control signal T _mry sent from the control circuit 103 I do. The stored contents are output as I _{d′ 1 to} I _{d′ n} and input to the modulation signal generator 107.

Modulation signal generator 107 outputs image data I
_d'1 to according to each of the I _d'n, a signal source for appropriately driving modulating each of the electron-emitting device, the output signal, the display panel 10 through the terminals Doy1 to Doyn
1 is applied to the electron-emitting devices.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current _Ie . That is, electron emission has a clear threshold voltage _Vth , and electron emission occurs only when a voltage equal to or higher than _Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device. From this, when a pulse-like voltage is applied to this element, for example, when a voltage lower than the electron emission threshold voltage is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold voltage is applied, electrons are not emitted. A beam is output. At this time, the pulse peak value V
By changing m, the intensity of the output electron beam can be controlled. Further, by changing the pulse width Pw, it is possible to control the total amount of charges of the output electron beam.

Therefore, as a method of modulating the electron-emitting device according to the input signal, a voltage modulation method, a pulse width modulation method, or the like can be adopted. When implementing the voltage modulation method, the modulation signal generator 107 generates a voltage pulse of a fixed length, and a voltage modulation circuit capable of appropriately modulating the peak value of the voltage pulse according to input data. Can be used. When implementing the pulse width modulation method, the modulation signal generator 107 generates a voltage pulse having a constant peak value and modulates the width of the voltage pulse appropriately according to input data. A circuit can be used.

The shift register 104 and the line memory 10
5 can be a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 106 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronization signal separation circuit 106. Just do it. In this connection, the circuit used for the modulation signal generator 107 is slightly different depending on whether the output signal of the line memory 105 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 107 includes:
For example, a D / A conversion circuit is used, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 107 includes, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. (Comparator) is used. If necessary, an amplifier for amplifying the pulse width modulated signal output from the comparator to the drive voltage of the electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, an amplification circuit using, for example, an operational amplifier or the like can be used as the modulation signal generator 107, and a level shift circuit or the like can be added as necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillator (VCO) can be employed, and an amplifier for amplifying the voltage up to the driving voltage of the electron-emitting device can be added as necessary.

In the image forming apparatus to which the present invention can be applied, which has such a configuration, by applying a voltage to each of the electron-emitting devices via the external terminals Dox1 to Doxm and Doy1 to Doyn, the electron-emitting device can emit electrons. Occurs.
A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal 87 to accelerate the electron beam.
The accelerated electrons collide with the fluorescent film 84 and emit light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. The input signal has been described in the NTSC system. However, the input signal is not limited to this. In addition to the PAL and SECAM systems,
A TV signal composed of more scanning lines than these (for example,
A high-definition TV system such as the MUSE system can also be adopted.

Next, the above-mentioned ladder-type electron source and image forming apparatus will be described with reference to FIGS.

FIG. 12 is a schematic view showing an example of the ladder-type electron source. In FIG. 12, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. 112 denotes common wirings Dx1 to Dx10 for connecting the electron-emitting devices 111.
These are drawn out as external terminals. A plurality of electron-emitting devices 111 are arranged on the substrate 110 in parallel in the X direction (this is called an element row). A plurality of the element rows are arranged to constitute an electron source. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to an element row in which an electron beam is to be emitted, and a voltage equal to or lower than the electron emission threshold is applied to an element row in which an electron beam is not desired to be emitted. The common wirings Dx2 to Dx9 located between the element rows are, for example, Dx2 and Dx3,
Dx4 and Dx5, Dx6 and Dx7, and Dx8 and Dx9 may be formed as one and the same wiring.

FIG. 13 is a schematic diagram showing an example of a panel structure in an image forming apparatus having a ladder-type electron source. Reference numeral 120 denotes a grid electrode, 121 denotes an opening through which electrons pass, Dox1 to Doxm denote external terminals, and G1 to Gn denote external terminals connected to the grid electrode 120. Reference numeral 110 denotes an electron source substrate in which the common wiring between each element row is the same wiring. In FIG. 13, the same parts as those shown in FIGS. 9 and 12 are denoted by the same reference numerals as those shown in these figures. An image forming apparatus shown here;
The major difference from the image forming apparatus having the simple matrix arrangement shown in FIG.
Between the grid electrodes 120.

In FIG. 13, a grid electrode 120 is provided between the substrate 110 and the face plate 86. The grid electrode 120 is for modulating the electron beam emitted from the electron-emitting device 111,
In order to allow an electron beam to pass through stripe-shaped electrodes provided orthogonally to the ladder-type element rows, one circular opening 121 is provided for each element. The shapes and arrangement positions of the grid electrodes are not limited to those shown in FIG. For example, a large number of passage openings can be provided in a mesh shape as openings, and a grid electrode can be provided around or near the electron-emitting device.

The external terminals Dox1 to Doxm and the external terminals G1 to Gn are electrically connected to a control circuit (not shown).

In the image forming apparatus of this embodiment, a modulation signal for one line of an image is simultaneously applied to the grid electrode rows in synchronization with sequentially driving (scanning) the element rows one by one. This makes it possible to control the irradiation of each electron beam to the phosphor and display an image one line at a time.

The image forming apparatus of the present invention described above can be used as an image forming apparatus as an optical printer constituted by using a photosensitive drum or the like, in addition to a display device for a television broadcast, a display device such as a video conference system or a computer. Etc. can also be used.

[0140]

EXAMPLES The present invention will be described below with reference to specific examples. However, the present invention is not limited to these examples, and the present invention is not limited to these examples. This includes the case where the element is replaced or the design is changed.

[Embodiment 1] The basic structure of an electron-emitting device according to this embodiment is the same as that of FIG.

The manufacturing method of the electron-emitting device in this embodiment is basically the same as that of FIG. Hereinafter, FIGS. 1 and 2
The method of manufacturing the electron-emitting device according to the present embodiment will be described step by step with reference to FIG.

Step-a A pair of device electrodes 2 and 3 made of Pt having a thickness of 500 ° were formed on a blue glass substrate 1 by a lift-off method and a sputtering method (FIG. 2A). The distance L between the device electrodes is 10 μm.

Step-b After sufficiently washing the electrode substrate on which the device electrodes 2 and 3 are formed, a 0.5% ethanol solution of octadecyltriethoxysilane is spin-coated and dried at 80 ° C. for 20 minutes. The entire surface of the electrode substrate was subjected to a hydrophobic treatment (FIG. 2B).

Step-c Next, one drop (1 dot) of a 6N sodium hydroxide solution was applied to the portion where the conductive film 4 was to be formed using an ink jet type jetting device (PJ-300S manufactured by Canon Inc.).
By applying, the surface of the portion where the conductive film 4 is formed was subjected to a hydrophilic treatment (FIG. 2C). Thereafter, the substrate was washed with pure water and dried.

As described above, an electrode substrate is obtained in which the surface of the substrate on which the conductive film 4 is formed is subjected to a hydrophilic treatment, and the surface of the substrate on which the conductive film 4 is not formed is subjected to a hydrophobic treatment.

Step-d A palladium acetate-ethanolamine complex aqueous solution was added between the device electrodes of the surface-treated electrode substrate using a bubble jet type jetting device (BJ-10V manufactured by Canon Inc.).
Drops (1 dot) were applied. The droplet applied at this time spread on the hydrophilized surface of the electrode substrate, and when it reached the hydrophobized surface, its shape was stabilized, and a droplet was formed only on the hydrophilized surface. After applying the droplets, 2 at 300 ° C
Heat treatment was performed for a time to form a conductive film 4 made of fine particles of palladium oxide (FIG. 2D).

Step-e The above-mentioned element was set in the vacuum processing apparatus shown in FIG. 6, and the inside of the vacuum vessel 55 was evacuated by the evacuation pump 56 to obtain 1.3 × 10 ^-4 P
After reaching the degree of vacuum of a, a voltage was applied between the device electrodes 2 and 3 from a power supply 51 for applying a device voltage _Vf to the device, and an energization process (forming process) was performed. Voltage waveform of the energization forming was a waveform shown in FIG. 5 (b), the pulse width 0.1msec a T _1. , 25msec the T _2. And the peak voltage was 0 to 18V.

Step-f Subsequently, the inside of the vacuum vessel 55 is evacuated to a pressure of 1.3 × 10 ^-2.
After an acetone atmosphere of Pa, 10-1
An activation process was performed by applying a pulse voltage of 6 V. The applied voltage pulse for activation was the same as the applied voltage pulse during forming.

After the electron-emitting device manufactured as described above was evacuated to a degree of vacuum of 1.3 × 10 ⁻⁵ Pa or less using the measurement system shown in FIG. 6, a drive voltage of 14 V and an anode voltage of 3 kV were applied. When the electron emission characteristics of the device were measured, the device current I _f = 1 mA and the emission current I _e = 0.8 μA
Was obtained, and good electron emission characteristics were obtained.

Example 2 Using the electron-emitting device of Example 1, a matrix-shaped electron source substrate and an image forming apparatus as shown in FIGS. 8 and 9 were manufactured.

Element electrodes 2 and 3 made of Pt having a thickness of 500 ° were formed on a blue glass substrate 71 by a lift-off method and a sputtering method. The interval L between device electrodes is 1
It was 0 μm.

An Ag paste was printed by a screen printing method and baked under heating to form an X-directional wiring 72 and a Y-directional wiring 73. Further, the X-direction wiring 72 and Y
An insulating paste (not shown) was formed by printing an insulating paste on the intersection of the directional wirings 73 by a screen printing method and heating and firing the paste.

The substrate 71 on which the device electrodes and wirings were formed was subjected to surface treatment in the same manner as in Example 1. At this time, the position for performing the hydrophilic treatment is determined by measuring the positions of the device electrodes at the four corners of the substrate in advance, and interpolating the positions of the other device electrodes between these four device electrode positions. Was done.

In the same manner as in Example 1, one drop (1 dot) of an aqueous solution of palladium acetate-ethanolamine complex was applied between the device electrodes of the substrate 71 subjected to the surface treatment.
The droplets applied at this time spread on the hydrophilically-treated surface of the substrate 71, and when reaching the hydrophobically-treated surface, their shapes were stabilized, and droplets were formed only on the hydrophilically-treated surface. Further, the uniformity of the shape between the elements was also good.

After the application of the droplets, a heat treatment was performed at 300 ° C. for 2 hours to form a conductive film 4 made of fine particles of palladium oxide.

After fixing the electron source substrate 71 thus manufactured on the rear plate 81, a face plate 86 (a fluorescent film 84 and a metal back 85 are formed on the inner surface of the glass substrate 83) 5 mm above the substrate 71. ) Was disposed via a support frame 82, and sealing was performed at 400 ° C. using frit glass. The fluorescent film has RG
B3 colors arranged in a stripe shape were used.

After the inside of the produced glass container was evacuated by a vacuum pump through an exhaust pipe, the external terminals Dox1 to Dox were used.
Through m and Doy1 to Doyn, a pulse voltage of 0 to 18 V was applied between the device electrodes of the electron-emitting device in the same manner as in Example 11, and forming was performed to form an electron-emitting portion.

Subsequently, a voltage of 10 to 16 V was applied between the device electrodes in an acetone atmosphere of about 1.3 × 10 ⁻² Pa to perform an activation process.

After the inside of the container was sufficiently evacuated and a getter treatment was performed to further maintain the degree of vacuum, the container was sealed by welding an exhaust pipe with a gas burner to produce an image forming apparatus.

In the image forming apparatus completed as described above, the external terminals Dox1 to Dox1
By applying a voltage of 15 V through oxm and Doy1 to Doyn, it was possible to obtain a light emitting spot with good uniformity on the face plate. Further, when a television display was performed based on an NTSC television signal using a driving circuit as shown in FIG. 11, a good image without luminance unevenness or display unevenness could be displayed on the entire surface. .

[Embodiment 3] Using the electron-emitting device of Embodiment 1, a ladder-shaped electron source substrate and an image forming apparatus as shown in FIGS.

The device electrodes 2 and 3 were formed on a blue glass substrate in the same manner as in Example 2, and the common wiring 112 was formed by screen printing. The surface treatment of the electrode substrate was performed in the same manner as in Example 2, and the conductive film 4 was formed.

Using the prepared electron source substrate 110, the grid electrode 1 was placed between the electron source substrate 110 and the face plate 86.
20 in the same manner as in Example 2 except that
An image forming apparatus as shown in FIG.

In the image forming apparatus completed as described above, modulation signals for one line of an image are simultaneously applied to grid electrode columns in synchronization with sequentially driving (scanning) the element rows one by one. As a result, the irradiation of each electron beam to the phosphor was controlled, and an image could be displayed line by line. When a voltage of 15 V was applied to each electron-emitting device through the external terminal of the container and a voltage of 4 kV was applied to the metal back through the high-voltage terminal, a light emission spot with good uniformity was obtained on the face plate.

Example 4 An element electrode was formed on a blue glass substrate in the same manner as in Example 1.

The surface of the prepared electrode substrate was spin-coated with a 0.5% ethanol solution of octadecyltriethoxysilane, and dried at 80 ° C. for 20 minutes to perform a hydrophobic treatment on the entire surface of the electrode substrate.

Next, an ink jet type jetting device (PJ-300 manufactured by Canon Inc.) is applied to the portion where the conductive film 4 is to be formed.
S), 1 drop of 6N sodium hydroxide solution (1
By applying dots, the surface of the portion where the conductive film 4 was formed was subjected to a hydrophilic treatment. Thereafter, the substrate was washed with pure water and dried.

After immersing the surface-treated electrode substrate in a palladium acetate-ethanolamine complex aqueous solution, the substrate was pulled up at a constant speed. At this time, the solution did not adhere to the hydrophobically treated surface, and droplets were formed only on the hydrophilically treated surface.

Next, a heat treatment was performed at 300 ° C. for 2 hours to form a conductive film made of fine particles of palladium oxide.

Next, a voltage was applied between the device electrodes in a vacuum of 1.3 × 10 ⁻⁴ Pa to carry out energization forming to form an electron-emitting portion. Voltage waveform of the energization forming was a waveform shown in FIG. 5 (b), 0.1mse pulse width T ₁
c. , 25msec pulse interval T _2. And the peak voltage was 0 to 18V.

Subsequently, a voltage of 10 to 16 V was applied between the device electrodes in an acetone atmosphere of 1.3 × 10 ⁻² Pa,
An activation process was performed. The applied voltage pulse for activation was the same as the applied voltage pulse during forming.

After the electron-emitting device manufactured as described above was evacuated to a degree of vacuum of 1.3 × 10 ⁻⁵ Pa or less using the measurement system shown in FIG. 6, a driving voltage of 15 V and an anode voltage of 3 kV were applied. When the electron emission characteristics of the device were measured, the device current _If = 1.1 mA and the emission current _Ie = 0.8.
μA was obtained, showing good electron emission characteristics.

Example 5 An electrode substrate was manufactured by forming device electrodes and wirings on a blue glass substrate in the same manner as in Example 2.

A 0.5% ethanol solution of octadecyltriethoxysilane was spin-coated on the substrate surface,
For 20 minutes, a hydrophobic treatment was performed on the entire surface of the electrode substrate.

Next, an ink jet type jetting device (PJ-300 manufactured by Canon Inc.) is applied to the portion where the conductive film is to be formed.
S), 1 drop of 6N sodium hydroxide solution (1
The surface of the portion where the conductive film is to be formed was subjected to a hydrophilic treatment by applying dots. The position for performing the hydrophilization treatment was measured in advance at four corners of the substrate, as in Example 2.
The positions of the other device electrodes were determined by interpolating between these four device electrode positions, and a hydrophilic treatment was performed. Thereafter, the substrate was washed with pure water and dried.

After the electrode substrate subjected to the surface treatment was immersed in a mixed solution of palladium acetate-triethanolamine in water / isopropyl alcohol (3/1), the substrate was pulled up at a constant speed. At this time, the solution did not adhere to the hydrophobically treated surface, and a droplet was formed on the hydrophilically treated surface.

Next, heat treatment was performed at 300 ° C. for 2 hours to form a conductive film composed of fine particles of palladium oxide.

Using the electron source substrate thus manufactured, an image forming apparatus was manufactured in the same manner as in Example 2. In the manufactured image forming apparatus, when a voltage of 15 V was applied to each electron-emitting device through a terminal outside the container and a voltage of 4 kV was applied to the metal back through a high-voltage terminal, a uniform luminescent spot could be obtained on the face plate. As a result, a uniform and good image could be displayed on the entire surface.

When a television circuit was displayed on the basis of an NTSC television signal using a drive circuit as shown in FIG. 11, a good image could be displayed on the entire surface.

[0181]

As described above, according to the present invention,
When forming a conductive film by applying a solution containing a material for forming a conductive film between device electrodes, the applied solution spreads on the hydrophilic surface of the substrate and repels on the hydrophobic surface. Therefore, the conductive film can be accurately formed at a predetermined position without spreading or adhering the solution to an unnecessary position. The shape and thickness of the conductive film can be easily controlled by the area of the surface-treated surface of the substrate and the amount of the applied solution, and the reproducibility and uniformity of the shape and thickness of the conductive film are improved. I do. As a result, even when a large number of electron-emitting devices are formed over a large area, uniform electron-emitting characteristics can be obtained.

Further, since a large-scale film forming apparatus and a patterning step of a conductive film using a photolithography technique are not required, an electron-emitting device can be manufactured easily at low cost.

Furthermore, it is possible to cope with a case where the element pitch is changed from a design value due to a substrate deformation caused by a thermal process, and a stable electron emission element can be always manufactured.

By applying the electron-emitting device manufactured by the method of the present invention, an electron source excellent in uniformity and productivity can be obtained. In an image forming apparatus using such an electron source, A high-quality image forming apparatus without uneven brightness, for example, a color flat television is realized.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an electron-emitting device according to the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing an electron-emitting device according to the present invention.

FIG. 3 is a schematic view showing an example of a method for determining a position for performing a hydrophilic treatment in the method for manufacturing an electron-emitting device of the present invention.

FIG. 4 is a schematic view showing an example of a method for determining a position for performing a hydrophilic treatment in the method for manufacturing an electron-emitting device according to the present invention.

FIG. 5 is a schematic view showing an example of a voltage waveform in an energization process that can be employed in manufacturing the electron-emitting device of the present invention.

FIG. 6 is a schematic configuration diagram showing an example of a vacuum processing apparatus (measurement evaluation apparatus) that can be used for manufacturing the electron-emitting device of the present invention.

FIG. 7 is a view showing the electron emission characteristics of the electron-emitting device of the present invention.

FIG. 8 is a schematic diagram showing an example of an electron source having a simple matrix arrangement according to the present invention.

FIG. 9 is a schematic diagram illustrating an example of a display panel of the image forming apparatus of the present invention.

FIG. 10 is a schematic diagram illustrating an example of a fluorescent film in a display panel.

FIG. 11 is a block diagram showing an example of a drive circuit for performing display in the image forming apparatus of the present invention in accordance with an NTSC television signal.

FIG. 12 is a schematic view showing an example of an electron source having a ladder-type arrangement according to the present invention.

FIG. 13 is a schematic diagram illustrating an example of a display panel of the image forming apparatus of the present invention.

FIG. 14 is a schematic view of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive film 5 Electron emission part 6 Hydrophilic surface 7 Hydrophobic surface 8 Ink-jet apparatus 9 Solution 11 Electrode substrate 21 Design element pitch 22 Actual element pitch 23,24,25,264 Device electrode located at a corner 50 Ammeter for measuring device current _If 51 Power supply for applying device voltage _Vf to electron-emitting device 52 To measure emission current _Ie emitted from electron-emitting portion 5 53 A high-voltage power supply 54 for applying a voltage to the anode electrode 54 An anode electrode for capturing electrons emitted from the electron emission section 5 55 A vacuum container 56 An exhaust pump 71 An electron source substrate 72 An X-direction wiring 73 A Y-direction Wiring 74 Electron-emitting device 75 Connection 81 Rear plate 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate G 87 High voltage terminal 88 Envelope 91 Black conductive material 92 Phosphor 101 Display panel 102 Scan circuit 103 Control circuit 104 Shift register 105 Line memory 106 Synchronous signal separation circuit 107 Modulation signal generator Vx, Va DC voltage source 110 Electron source substrate Reference Signs List 111 electron-emitting device 112 common wiring for wiring electron-emitting device 120 grid electrode 121 opening through which electrons pass

Claims (12)

[Claims] A step of forming a pair of element electrodes on a substrate; a step of hydrophobizing the entire surface of the substrate including the element electrodes; Applying a hydrophilizing treatment by applying either an alkali or a solvent, applying a droplet of a solution containing a material for forming a conductive film between the device electrodes, and heating and firing the applied droplet. A method for manufacturing an electron-emitting device, comprising: a step of forming a conductive film; and a forming step of forming an electron-emitting portion in the conductive film. 2. The method according to claim 1, wherein the droplet applying step is performed by an inkjet method. 3. The method according to claim 2, wherein the ink jet method is a bubble jet method. 4. The method according to claim 1, wherein the droplet applying step is performed by dipping. 5. An electron-emitting device manufactured by the method according to claim 1. 6. The electron-emitting device according to claim 5, wherein the electron-emitting device is a surface conduction electron-emitting device. 7. An electron source for emitting electrons in response to an input signal, wherein a plurality of the electron-emitting devices according to claim 5 are arranged on a substrate. 8. The electron source according to claim 7, wherein the plurality of electron-emitting devices are wired in a matrix. 9. The electron source according to claim 7, wherein the plurality of electron-emitting devices are wired in a ladder shape. 10. A method for manufacturing an electron source according to claim 7, wherein a plurality of electron-emitting devices are manufactured by the method according to claim 1. Description: Characteristic method of manufacturing an electron source. 11. An apparatus for forming an image based on an input signal, wherein at least the electron source according to claim 7 and an electron beam emitted from the electron source are irradiated with the image. An image forming apparatus, comprising: an image forming member to be formed. 12. A method for manufacturing the image forming apparatus according to claim 11, wherein the electron source is manufactured by the method according to claim 10.