JPH11260242A - Electron-emitting element, electron source using the same, image forming device and their manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electron-emitting element as an electron beam source, which has stable and uniform electron-emitting characteristics, and by which efficiency improvement of electron emission can be aimed at and a high-quality image forming device can be realized. SOLUTION: An underlayer 6, which is composed of magnetic particles having a convex part 7 with a height in the range of 1 nm to 10 nm, is formed between electrodes 2, 3, and a conductive film 4 is formed on the underlayer 6, and afterwards an electron-emitting part 5 is formed by performing current-fed forming. Hereby, the position and the shape of the electron emissive part 5 can be controlled precisely, and the uniformity of element characteristics can be realized.

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.

[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 "F
E type ". ), Metal / insulating layer / metal type (hereinafter “M
IM 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. The interval L in the figure is set to 0.5 to 1 mm, and W 'is set to 0.1 mm.

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).

[0012]

With respect to the electron-emitting device used in the above-mentioned electron source, image forming apparatus, etc., there is a demand for more stable electron emission characteristics and improved electron emission efficiency so that a bright display image can be stably provided. Have been.

The above-mentioned electron emission efficiency means, for example, in the case of the above-mentioned surface conduction type electron-emitting device, when a voltage is applied to both ends of the conductive film, a current flowing through the electrode (hereinafter referred to as “device current”). ) And a current emitted in a vacuum (hereinafter referred to as “emission current”), and an electron-emitting device having a small device current and a large emission current is desired.

If the electron emission characteristics and efficiency which can be controlled stably are further improved, for example, in an image forming apparatus using a phosphor as an image forming member, a bright and high-quality image forming apparatus with low current can be used. For example, a flat television is realized. Further, as the current is reduced, the cost of a drive circuit and the like constituting the image forming apparatus can be reduced.

However, the above-mentioned M.P. Hartwell's electron-emitting device has the following problems,
Satisfactory stable electron emission characteristics and electron emission efficiencies have not always been obtained, and it is extremely difficult to provide an image forming apparatus with high brightness and excellent operation stability by using this. It is.

(1) That is, the local destruction, deformation or alteration of the conductive film formed by the energization forming is caused by Joule heat generated by the element current. Depending on the forming conditions, the energizing conditions of the energizing process, and the like, the positions of cracks generated in the conductive film vary, and it has been difficult to form an electron emission portion accurately at a predetermined position in the conductive film.

(2) In addition, the cracks generated in the conductive film are actually formed meandering in the width W 'direction of the conductive film, and the meandering length varies considerably for each element. Depending on the conditions for forming the conductive film or the energizing conditions of the energizing process,
Not only can the effective length of the electron-emitting portion not be designed, but also, in a plurality of electron-emitting devices, the amount of electron emission of each device varies, and it is necessary to provide an image forming apparatus with uniform and excellent operation stability. It was extremely difficult.

An object of the present invention is to solve the above-mentioned technical problems to be solved, and to provide an electron-emitting device having stable and uniform electron emission characteristics and improving electron emission efficiency. . Another object of the present invention is to provide an image forming apparatus having high luminance and excellent operation stability.

[0019]

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

That is, a first aspect of the present invention is to provide a base layer made of magnetic particles having a convex portion having a height in the range of 1 nm to 10 μm between opposing electrodes, and connecting the electrodes on the base layer. An electron-emitting device having a conductive film, wherein an electron-emitting portion is formed in a region of the conductive film corresponding to the projection.

According to a second aspect of the present invention, in a method of manufacturing an electron-emitting device having a conductive film having an electron-emitting portion between opposing electrodes, at least an underlayer made of magnetic particles is formed between the electrodes. Process and the underlayer has a height of 1 nm.
A step of forming a convex portion having a range of 10 μm to 10 μm, a step of forming a conductive film on an underlying layer having the convex portion, and a forming step of forming an electron emitting portion in the conductive film. In the manufacturing method of the electron-emitting device.

The second manufacturing method of the present invention further has a feature that "the step of forming the projections on the underlayer made of the magnetic particles involves aggregation of the magnetic particles by a static magnetic field.""The magnetic particles are particles made of a ferromagnetic material, and subsequent to the step of forming a convex portion on the underlayer made of the particles made of the ferromagnetic material, the particles are further heated and fired in an oxidizing atmosphere to sinter the particles. Including a step of forming particles made of a paramagnetic substance. "

According to a third aspect of the present invention, in the electron source in which a plurality of electron-emitting devices are arranged on a substrate, the electron-emitting device is the first electron-emitting device of the present invention. The electron source.

The third electron source of the present invention further has the following features: "the plurality of electron-emitting devices are wired in a matrix";
It is wired in the form of a ladder. "

According to a fourth aspect of the present invention, there is provided a method of manufacturing an electron source in which a plurality of electron-emitting devices are arranged on a substrate.
In the method for manufacturing an electron source, the electron-emitting device is manufactured by the second method of the present invention.

According to a fifth aspect of the present invention, there is provided an electron source having a plurality of electron-emitting devices arranged on a substrate, and an image forming member for forming an image by irradiating an electron beam emitted from the electron source. In the image forming apparatus, the electron source is the third electron source of the present invention.

Further, a sixth aspect of the present invention is to provide an electron source in which a plurality of electron-emitting devices are arranged on a substrate, and an image forming member for forming an image by irradiating an electron beam emitted from the electron source. In the method for manufacturing an image forming apparatus, the electron source is manufactured by the above-described fourth method of the present invention.

According to the present invention, by forming a convex portion between the electrodes in advance using magnetic particles, the region of the conductive film corresponding to the convex portion can be formed thinner than other regions. The resistance can be increased only in the region. For this reason, a crack can be selectively formed in the region in the forming process, and a uniform electron emission portion whose position and shape are controlled can be formed. As a result, an electron-emitting device having uniform and stable electron emission characteristics can be realized, and further, an image forming apparatus having excellent operation stability and capable of forming a good image can be realized.

[0029]

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

The electron-emitting devices to which the present invention can be applied are classified into the cold-cathode-type electron-emitting devices described above, and among them, from the viewpoint of electron-emitting characteristics and the like, particularly, surface-conduction-type electron-emitting devices. Is preferred. Therefore, a surface conduction electron-emitting device will be described below as an example.

FIG. 1 is a schematic view showing a configuration example of a surface conduction electron-emitting device according to the present invention. FIG.
FIG. 1B is a longitudinal sectional view. In FIG. 1, 1 is a substrate, 2 and 3 are electrodes (device electrodes), 4 is a conductive film, 5 is an electron-emitting portion, 6 is a base layer made of magnetic particles, and 7 is a base layer 6
The projections are formed on the substrate.

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

The material of the opposing device electrodes 2 and 3 is 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 W1, 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.
m.

The element electrode length W1 can be set in a range from several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics. The film thickness d of the device electrodes 2 and 3 can be in the range of several tens nm to several μm.

The underlayer 6 is made of magnetic particles, and the magnetic particles are desirably magnetic particles made of a ferromagnetic material having a particle size of about 10 nm to 3 μm. Can be.

The protrusions 7 formed on the underlayer 6 are made of 1n
It has a height in the range of m to 10 μm. By forming such protrusions 7 in advance, the protrusions 7 will be described in detail later.
Can be selectively formed in the region of the conductive film 4 corresponding to the above.

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;
oxides such as dO, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , Y
Borides such as B ₄ and GdB ₄ , TiC, ZrC, HfC,
Carbides such as TaC, SiC and WC, TiN, ZrN,
Examples include nitrides such as HfN, semiconductors such as Si and Ge, and carbon.

As the conductive film 4, it is preferable to use a fine particle film made of fine particles in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage to the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, a forming condition described later, and the like. The range is preferably set, and more preferably, the range is set to 1 nm to 50 nm. As for the resistance value, Rs is preferably a value of 10 ² Ω / □ to 10 ⁷ Ω / □. Note that Rs is a value when the resistance R of a thin film having a width w and a length 1 is set as R = Rs (l / w).

The fine particle film described here is a film in which a plurality of fine particles are aggregated. The fine structure of the fine particle film is not only a state in which the fine particles are individually dispersed and arranged, but also a state in which the fine particles are adjacent to each other or overlap with each other. Particles gather,
(Including the case where an island structure is formed as a whole). The particle size of the fine particles is in the range of several to several hundreds of nm, preferably in the range of 1 to 20 nm.

In this 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". Particles smaller than "ultrafine particles" and having a few hundred atoms or less are widely called "clusters".

However, each boundary is not strict and changes depending on what kind of property is focused on. Further, “fine particles” and “ultrafine particles” may be collectively referred to as “fine particles”, and the description in this specification is in line with this.

For example, in "Experimental Physics Course 14 Surface / Particles" (edited by Kinoshita Yoshio, published by Kyoritsu Shuppan, September 1, 1986), "particles in this paper have diameters of about 2-3 μm to 10 nm. And especially when it is referred to as ultrafine particles, the particle size is about 10 nm to 2-3 n.
It means up to about m. 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. (Page 195, lines 22 to 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” of the Creative Science and Technology Promotion System (1981 to 1986), a particle having a size (diameter) in the range of about 1 to 100 nm is called “ultra fine particle”. Then, one ultrafine 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 even smaller than an ultrafine particle, that is, a single particle composed of several to several hundred atoms, is usually called a cluster" (ibid., Page 2, lines 12 to 13).

[0047] 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 1 nm, and the upper limit is several μm.
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 and depends on the pattern of the convex portion 7 formed on the underlayer 6. In some cases, conductive fine particles having a particle size in the range of several 数 to several tens of nm are present inside the electron-emitting portion 5. The conductive fine particles
Some or all of the elements of the material constituting the conductive film 4 are contained. The electron emitting portion 5 and the conductive film 4 in the vicinity thereof may include carbon or a carbon compound.

There are various methods for manufacturing the surface conduction 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, and the like, and after the element electrode material is deposited by a vacuum evaporation method, a sputtering method, or the like, the substrate 1 is formed on the substrate 1 by using, for example, a photolithography technique. The device electrodes 2 and 3 are formed (FIG. 2
(A)).

2) An underlayer 6 made of magnetic particles is formed between the device electrodes 2 and 3 (FIG. 2B).

Specifically, for example, the magnetic particles are dispersed in an appropriate dispersant, and the substrate 1 is dispersed using a spray method, a doctor blade coating method, an ink jet method, a piezo jet method, a bubble jet method, or a dipping method.
It can be formed by giving it to the top. As the above dispersant, an organic solvent, a thermoplastic vinyl resin, a mixture of a urethane resin and an organic solvent, or pure water to which a surfactant is added can be used, but not limited thereto.

3) Subsequently, before the underlayer 6 applied on the substrate 1 is dried and fixed, that is, when the fluidity of the magnetic particles remains, the magnetic particles are statically applied from the outside. A magnetic field is applied to agglomerate or orient magnetic particles.
The protrusion 7 having a height in the range of nm to 10 μm is formed (FIG. 2C). By forming such protrusions 7, the electron emission portions 5 can be selectively formed in the region of the conductive film 4 corresponding to the protrusions 7 in a forming step described later. If the height of the projection 7 is lower than 1 nm, it is difficult to control the position and shape of the electron-emitting portion 5. If the height is higher than 10 μm, forming becomes difficult and a good electron-emitting portion is formed. Is difficult to do.

As a method of forming the convex portion 7 by applying a static magnetic field to the magnetic particles, for example, as shown in FIG.
There is a method using a magnetic pole 8 and a counter magnetic pole 9. In this method, the magnetic particles are desirably magnetic particles made of a ferromagnetic material having a particle size of 10 nm to 3 μm. As a specific material, for example, γ-iron oxide is suitable. The magnetic pole 8 and the opposing magnetic pole 9 are magnetically connected electromagnets, which are plate-shaped electromagnets having a width wider than the width W2 of the underlayer 6. The tip of the magnetic pole 8 on the substrate 1 side has a width t of 0.
It is processed to 1 μm to 1 μm, and the distance to the magnetic particles on the substrate 1 is kept at an appropriate value. In this state, when the electromagnets of the magnetic pole 8 and the opposing magnetic pole 9 are operated, a magnetic field generated between the magnetic pole 8 and the opposing magnetic pole 9 causes a static magnetic field to be applied to the magnetic particles with a width corresponding to the width t of the tip of the magnetic pole 8. The magnetic particles are aggregated to form the protrusions 7.

As described above, the influence of the magnetism of the magnetic particles forming the projections 7 by agglomeration can be determined by appropriately selecting the material of the magnetic particles and performing a heating and baking treatment in an oxidizing atmosphere as a subsequent step. Thus, the properties of the ferromagnetic particles can be changed to paramagnetic particles. For example, the above-mentioned γ-iron oxide is a ferromagnetic material at room temperature, but when heated and baked at 400 ° C. or more in an oxidizing atmosphere, it becomes a paramagnetic α-iron oxide.

4) Subsequently, an organic metal solution is applied between the device electrodes 2 and 3 to form an organic metal film. As the organic metal solution, a solution of an organic compound containing the metal of the material of the conductive film 4 as a main element can be used. The organic metal film is heated and baked, and patterned by lift-off, etching, or the like to form a conductive film 4 (FIG. 2D). Here, the method of applying the organometallic solution has been described, but the method of forming the conductive film 4 is not limited to this, and a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, A dipping method, a spinner method, or the like can also be used.

5) Subsequently, a forming step is performed. As an example of a method of the forming step, a method by an energization process will be described. When power is applied between the device electrodes 2 and 3 from a power supply (not shown), a crack is generated at the portion of the conductive film 4 and the electron-emitting portion 5 is formed (FIG. 2D).

In the present invention, the protrusions 7 are formed on the underlayer 6 in advance.
Is formed, in the conductive film 4 formed thereon, the region corresponding to the projection 7 is thinner than other regions. Therefore, a crack can be selectively formed in the region of the conductive film 4 corresponding to the projection 7 by the above-described energization forming, and the position and shape of the electron emission portion can be controlled.

FIG. 4 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform.
The method shown in FIG. 3A in which a pulse with a constant pulse crest value is applied continuously and the method shown in FIG. 3B in which a pulse is applied while increasing the pulse crest value are used for this purpose. is there.

First, a case where the pulse peak value is a constant voltage will be described with reference to FIG. T1 in FIG.
And T2 are the pulse width and pulse interval of the voltage waveform. The peak value of the triangular wave (peak voltage during energization forming)
It is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens minutes. The pulse waveform is not limited to a 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.
T1 and T2 in FIG. 3B can be the same as those shown in FIG. The peak value of the triangular wave (peak voltage during energization forming) can be increased, for example, by about 0.1 V steps.

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 T2, 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.

6) It is preferable to perform a process called an activation step on the device after the forming. By this activation step, the device current If and the emission current Ie can be significantly changed.

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, similarly to the energization forming. This atmosphere can be formed by using an 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, or is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum. 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 alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons, alcohols,
Aldehydes, ketones, amines, phenols, carboxyls, organic acids such as sulfonic acids, and the like,
Specifically, C _n H _{2n + 2} such as methane, ethane, and propane
C such as saturated hydrocarbon, ethylene, propylene represented by
_n H _2n unsaturated hydrocarbon expressed by a composition formula such as, 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. With this process,
Carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie
Changes significantly.

The carbon or carbon compound includes, for example, graphite (so-called HOPG, PG, GC), and HOPG has an almost perfect graphite crystal structure, P
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.
The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.

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.

In the activation step, when an oil diffusion pump or a rotary pump is used as an exhaust device and an organic gas derived from an oil component is used, it is necessary to keep the partial pressure of this component as low as possible. is there. The partial pressure of the organic component in the vacuum vessel is preferably 1 × 10 ⁻⁶ Pa or less, more preferably 1 × 10 ⁻⁸ Pa or less, at a partial pressure at which the carbon or carbon compound is not newly deposited. 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 250 ° C, preferably 150 ° C or more,
It is desirable to perform the treatment as long as possible, but the treatment is not particularly limited to this condition, and the treatment is performed under conditions appropriately selected according to various conditions such as the size and shape of the vacuum vessel and the configuration of the electron-emitting device. The pressure in the vacuum vessel needs to be as low as possible, preferably 1 × 10 ⁻⁵ Pa or less, more preferably 1 × 10 ⁻⁵ Pa.
^-6 Pa or less is particularly preferred.

The atmosphere at the time of driving after performing the stabilization step is preferably the same as the atmosphere at the end of the stabilization treatment, but is not limited to this. If the organic substance is sufficiently removed, 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
But it stabilizes.

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

FIG. 4 is a schematic view showing an example of a vacuum processing apparatus. This vacuum processing apparatus also has a function as a measurement and evaluation apparatus. 4, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

In FIG. 4, 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, an ammeter for measuring a device current If flowing through the conductive film 4 between the device electrodes 2 and 3; An anode electrode for capturing the emission current Ie emitted from the unit 5, a high-voltage power supply 53 for applying a voltage to the anode electrode 54, and a reference numeral 52 for measuring the emission current Ie emitted from the electron emission unit 5. It is an ammeter. As an example, the measurement can be performed with the voltage of the anode electrode 54 in the range of 1 KV to 10 KV and the distance H between the anode electrode 54 and the electron-emitting device in the range of 2 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 to 250 ° C. by a heater (not shown). Therefore, by using this vacuum processing apparatus, the steps after the energization forming described above can also be performed.

FIG. 5 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. 4, and the device voltage Vf. In FIG. 5, since the emission current Ie is significantly smaller than the element current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is apparent from FIG. 5, the surface conduction electron-emitting device to which the present invention can be applied has the following three characteristic characteristics regarding the emission current Ie.

First, the emission current Ie of the present element rapidly increases when an element voltage higher than a certain voltage (referred to as a threshold voltage; Vth in FIG. 5) is applied, whereas when the element voltage is lower than the threshold voltage Vth, the emission current Ie is increased. Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Second, since the emission current Ie depends monotonically on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf.

Thirdly, the amount of charge emitted by the anode electrode 54 (see FIG. 4) depends on the time during which the device voltage Vf is applied. 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 can be understood from the above description, the surface conduction electron-emitting device to which the present invention can be applied can easily control the electron emission 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.

FIG. 5 shows an example in which the device current If monotonically increases with respect to the device voltage Vf (hereinafter referred to as “MI characteristic”). It may exhibit negative resistance characteristics (VCNR characteristics) (not shown). These properties can be controlled by controlling the steps described above.

An application example of the electron-emitting device to which the present invention can be applied will be described below. By arranging a plurality of surface conduction 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 surface conduction electron-emitting device to which the present invention can be applied has three characteristics as described above. That is,
When the electron emission from the surface conduction electron-emitting device is equal to or higher than the threshold voltage, it can be controlled by the peak value and the width of the pulse voltage applied between the opposing device electrodes. 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 disposing a plurality of electron-emitting devices to which the present invention can be applied will be described with reference to FIG. In FIG. 6, reference numeral 71 denotes an electron source substrate, 72 denotes an X-direction wiring, and 73 denotes a Y-direction wiring.
74 is a surface conduction 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-direction wiring 73 is formed of n of Dy1, Dy2,.
It is formed in the same manner as the X-direction wiring 72. These m X-direction wires 72 and n Y-direction wires 7
3, an interlayer insulating layer (not shown) is provided.
Both are electrically separated (m and n are both positive integers).

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 element electrodes (not shown) constituting the surface conduction electron-emitting device 74 are connected to m X-directional wirings 72 and n Y-directional wirings 73 by a connection 75 made of a conductive metal or the like. It is electrically 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 be partially or entirely 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 surface conduction 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 surface conduction 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 configured using such an electron source having a simple matrix arrangement will be described with reference to FIGS. 7, 8 and 9. FIG. 7 is a schematic diagram illustrating an example of a display panel of the image forming apparatus, and FIG. 8 is a schematic diagram of a fluorescent film used in the image forming apparatus of FIG. FIG.
FIG. 2 is a block diagram illustrating an example of a drive circuit for performing display in accordance with a TSC television signal.

In FIG. 7, 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 is composed of 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 installing 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. 8 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. 8A) or a black matrix (FIG. 8B) and a fluorescent material 92 depending on the arrangement of the fluorescent materials. it can. The purpose of providing a black stripe and black matrix is
In the case of color display, the color separation between the phosphors 92 of the necessary three primary color phosphors is made black so that color mixing and the like become inconspicuous, and the reduction in contrast due to reflection of external light on the phosphor film 84 is suppressed. It is in. Black conductive material 91
As the material of, other than a commonly used material containing graphite as a main component, a material having conductivity and low light transmission and reflection can be used.

The method of applying the phosphor on 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 further has the 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-mentioned 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. 7 is manufactured, for example, as follows.

[0102] Within the envelope 88, similar to the aforementioned stabilization step, while being heated appropriately, ion pump, by an exhaust device not using oil, such as a sorption pump evacuated through an exhaust pipe (not shown), 10 ^- After the atmosphere of a vacuum degree of about ⁵ Pa is sufficiently low for 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 is heated by heating using resistance heating, high-frequency heating, or the like immediately before or after the envelope 88 is sealed. This is a process for forming a deposited film. The getter is usually composed mainly of Ba or the like, and for example, 1 × 10 ⁻⁵ Pa
The above degree of vacuum is maintained. Here, steps after the forming process of the surface conduction electron-emitting device can be appropriately set.

Next, an example of the configuration of a drive 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. 9, 10
1 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 synchronizing signal separation circuit, 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 101 has terminals Dx1 to Dx
m, terminals Dy1 to Dyn, and a high voltage terminal 87 are connected to an external electric circuit. Terminals Dx1 to Dxm sequentially drive electron sources provided in the display panel 101, that is, a group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns in a matrix (row by row). A scanning signal for performing the scanning is applied. The terminals Dy1 to Dyn include
A modulation signal for controlling an output electron beam of each element of one row of surface conduction electron-emitting devices selected by the scanning signal is applied. The high-voltage terminal 87 is supplied with a DC voltage of, for example, 10 K [V] from a DC voltage source Va, which is sufficient for exciting an electron beam emitted from the surface conduction electron-emitting device to excite the phosphor. It is an accelerating voltage for applying high energy.

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 Dx1 to Dxm 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 determines 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 surface conduction electron-emitting element. It is set to output such a constant voltage.

The control circuit 103 has a function of matching the operation of each unit so that an appropriate display is performed based on an externally input image signal. The control circuit 103 controls the synchronization signal Tsync sent from the synchronization signal separation circuit 106.
, Tscan, Tsft and T
mry control signals are generated.

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 shown 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 output to the shift register 10
4 is input.

The shift register 104 is for serially / parallel converting the DATA signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 103. (In other words, the control signal Tsft may be rephrased as a shift clock of the shift register 104). Data for one line of serial / parallel converted image (equivalent to drive data for n electron-emitting devices)
Are output from the shift register 104 as n parallel signals Id1 to Idn.

The line memory 105 is a storage device for storing data for one line of an image for a required time, and stores the contents of Id1 to Idn as appropriate according to a control signal Tmry sent from the control circuit 103. The stored contents are output as Id′1 to Id′n and input to the modulation signal generator 107.

The modulation signal generator 107 outputs the image data I
a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of d′ 1 to Id′n;
The output signal is applied to the surface conduction electron-emitting device in the display panel 101 through the terminals Dy1 to Dyn.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics regarding 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 voltage of the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, for example, an amplification circuit using 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 oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the drive voltage of the surface conduction 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 through terminals Dx1 to Dxm and Dy1 to Dyn outside the container, 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. 10 and 11. FIG.

FIG. 10 is a schematic view showing an example of a ladder-type electron source. In FIG. 10, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. Reference numeral 112 denotes common wirings D1 to D10 for connecting the electron-emitting devices 111, and 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. Common lines D2 to D9 located between the element rows are, for example, D2 and D3, D4 and D5,
D6 and D7, and D8 and D9 may be formed as one and the same wiring.

FIG. 11 is a schematic diagram showing an example of a panel structure in an image forming apparatus provided with a ladder-type electron source. Reference numeral 120 denotes a grid electrode, 121 denotes an opening through which electrons pass, D1 to Dm denote external terminals, and G1 to Gn denote external terminals connected to the grid electrode 120. 1
Reference numeral 10 denotes an electron source substrate in which the common wiring between the element rows is the same wiring. In FIG. 11, the same portions as those shown in FIGS. 7 and 10 are denoted by the same reference numerals as those shown in these drawings. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 7 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.

In FIG. 11, 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 surface conduction electron-emitting device 111, and allows the electron beam to pass through a stripe-shaped electrode provided orthogonal to the ladder-type element row. Therefore, one circular opening 121 is provided for each element. The shape and arrangement position of the grid electrodes are not limited to those shown in FIG. For example, a large number of passage openings may be provided in a mesh shape as openings, and a grid electrode may be provided around or near the surface conduction electron-emitting device.

The external terminals D1 to Dm 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 is a display apparatus for a television broadcast, a video conference system or a computer, or an image forming apparatus as an optical printer using a photosensitive drum or the like. Etc. can also be used.

[0126]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples, and each element within a range in which the object of the present invention is achieved. This also includes those in which substitutions or design changes have been made.

[Embodiment 1] The structure of an electron-emitting device according to this embodiment is the same as that of FIG. In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, 5 is an electron emitting portion, 6 is an underlayer made of magnetic particles, and 7 is a protrusion formed on the underlayer 6.

The method of manufacturing the electron-emitting device according to this embodiment is as follows.
Basically, it is the same as FIG. 2, and the structure and manufacturing method of the element according to the present embodiment will be sequentially described below with reference to FIGS.

(1) A quartz glass substrate was used as the substrate 1, and after sufficiently washing it with an organic solvent, device electrodes 2 and 3 made of Pt were formed on the substrate 1 (FIG. 2).
(A)). At this time, the device electrode interval L is 3 μm, the width W1 of the device electrode is 500 μm, and the film thickness d is 100 nm.
And

(2) Next, γ-iron oxide having a particle diameter of 5 nm dispersed in pure water containing a surfactant was applied between the device electrodes 2 and 3 by an ink-jet method to form a base layer 6 ( FIG. 2 (b).

(3) Next, the width 60 of the tip t of Fe-Al-Si (sendust alloy) processed to 0.3 μm is used.
The magnetic pole 8 having a width of 600 μm
The opposing magnetic pole 9 of μm was brought close to the back side of the substrate 1 and the electromagnet was actuated to aggregate the magnetic particles made of γ-iron oxide to form the projections 7 having a height of 200 nm (FIG. 2C). Subsequently, it was heated and baked at 450 ° C. in an oxidizing atmosphere. As a result, the magnetic particles made of γ-iron oxide become α-iron oxide, and the influence of magnetism in a subsequent step can be eliminated.

(4) Next, a solution containing organic palladium (ccp-4230; manufactured by Okuno Pharmaceutical Co., Ltd.) was applied onto the substrate 1 and then heated at 300 ° C. for 10 minutes to form palladium oxide (PdO). 3.) A conductive film 4 composed of fine particles (average particle size: 7 nm) was formed. Here, the conductive film 4 had a width W2 of 300 μm and was disposed substantially at the center of the device electrodes 2 and 3 (FIG. 2D). The thickness of the conductive film 4 was about 10 nm, and the resistance value Rs was about 5 × 10 ⁴ Ω / □.

Next, when a pulse voltage as shown in FIG. 3A is applied between the device electrodes 2 and 3 and an energization process (forming process) is performed, a conductive material corresponding to the protrusion 7 of the underlayer 6 is formed. The structure of the fine particle film changed from the region of the conductive film 4, and the electron emission portion 5 formed of cracks was formed in the region.
(D)). The electron emitting portion 5 was a linear and continuous crack as if the position and shape of the convex portion 7 were directly transferred, and the length was 300 μm, which was the same as the width W2 of the conductive film 4.

In this embodiment, in FIG. 3A, the pulse width T1 is 1 ms, the pulse interval T2 is 10 ms, the peak value of the triangular wave (peak voltage at the time of forming) is 5 V, and the forming process is performed. This was performed for 60 seconds in a vacuum atmosphere of about 1 × 10 ⁻⁴ Pa.

[0135] The electron-emitting portion 5 thus created
Was in a state where fine particles mainly composed of palladium element were dispersed and arranged, and the average particle diameter of the fine particles was about 3 nm.

Next, the above-mentioned element was placed in a vacuum vessel 55 of the vacuum processing apparatus shown in FIG. 4, evacuated by a rotary pump 56, and the inside of the vacuum vessel 55 was evacuated to an appropriate degree.
The activation process was performed by applying a voltage between the device electrodes 2 and 3. The voltage waveform used for the activation process is that shown in FIG.

In the activation process of this embodiment, the pulse width T1 of the voltage waveform is set to 1 ms, the pulse interval T2 is set to 10 ms,
The peak value of the triangular wave (peak voltage at the time of activation) was set to 16 V, and the operation was performed for 1 hour.

Thereafter, the evacuation pump was switched to an ultra-vacuum evacuation device using an ion pump, the degree of vacuum in the vacuum vessel 55 was set to about 1 × 10 ⁻⁴ Pa, and the electron emission characteristics were evaluated.

In this embodiment, the distance H between the anode 54 and the electron-emitting device is 5 mm, and the potential of the anode is 1K.
When the device voltage was applied between the device electrodes 2 and 3 and the device current If and emission current Ie flowing at that time were measured, the voltage-current characteristics as shown in FIG. 5 were obtained. In this device, the emission current Ie rapidly increases from the device voltage of about 8 V, and the device current If becomes 2.2 m at the device voltage of 16 V.
A, the emission current Ie becomes 1.1 μA, and the electron emission efficiency η
= Ie / If (%) was 0.05%.

The same measurement was made at the same time.
This was performed for each of the elements. When the element voltage was maintained at 16 V, the values of If and Ie were ± 0.1% for each element.
It was confirmed that it was within. Comparative Example 1 An electron-emitting device was produced in the same manner as in Example 1, except that the underlayer 6 having the convex portions 7 was not formed.

[0141] For the 500 elements produced simultaneously,
The device characteristics were evaluated in the same manner as in Example 1. As a result, the device current If when the device voltage is maintained at 16 V is 0.8 to
2.4 mA, and the emission current Ie varied widely in the range of 3 to 12 μA.

[Embodiment 2] In this embodiment, an image forming apparatus is manufactured by using an electron source in which a large number of surface conduction electron-emitting devices are arranged in a simple matrix.

FIG. 12 is a plan view of a part of a substrate on which a plurality of conductive films are arranged in a matrix. Also, A- in FIG.
FIG. 13 shows an A ′ cross-sectional view. However, the same reference numerals in FIGS. 12 and 13 indicate the same members. Here, 71 is an electron source substrate, 72 is an X-direction wiring (also referred to as a lower wiring) corresponding to Dxm in FIG. 6, and 73 is a Y corresponding to Dyn in FIG.
Direction wiring (also referred to as upper wiring), 2 and 3 are device electrodes, 4 is a conductive film, 6 is an underlayer, 7 is a convex portion, 131 is an interlayer insulating layer, and 132 is an electric connection between the device electrode 2 and the lower wiring 72. Contact hole for electrical connection.

The method of manufacturing the electron source of this embodiment is based on the lower wiring 7
2. Except for the steps of manufacturing the interlayer insulating layer 131 and the upper wiring 73,
Basically, the manufacturing pattern of the device electrodes 2 and 3, the base layer 6, the conductive film 4, and the like in the device manufacturing method of the first embodiment can be expanded, and the description is omitted here.

Next, an image forming apparatus was manufactured using the electron source substrate 71 (FIG. 12) on which the plurality of conductive films 4 were arranged in a matrix. The manufacturing procedure will be described with reference to FIGS.

First, the electron source substrate 71 (FIG. 12) on which the plurality of conductive films are arranged in a matrix is mounted on the rear plate 81.
After fixing the fluorescent film 84 on the inner surface of the glass substrate 83, the face plate 86 is placed 5 mm above the electron source substrate 71.
And a metal back 85 are formed via a support frame 82, and a face plate 86, a support frame 8
2. A frit glass was applied to the joint of the rear plate 81 and sealed by baking at 430 ° C. for 10 minutes or more in the atmosphere (FIG. 7). The fixing of the electron source substrate 71 to the rear plate 81 was also performed with frit glass.

The fluorescent film 84 is used to realize color.
A phosphor in the form of a stripe (see FIG. 8A) was formed, a black stripe was formed first, and phosphors 92 of each color were applied to the gaps by a slurry method to form a phosphor film 84. As a material for the black stripe, a material containing graphite as a main component was used.

A metal back 85 was provided on the inner surface side of the fluorescent film 84. The metal back 85 is manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 84 after the fluorescent film 84 is manufactured, and then performing vacuum deposition of Al.

The face plate 86 is further provided with a fluorescent film 8.
In some cases, a transparent electrode is provided on the outer surface side of the fluorescent film 84 in order to increase the conductivity of the metal back 8.
5 was omitted because sufficient conductivity was obtained.

The atmosphere in the envelope 88 completed as described above is exhausted by a rotary pump through an exhaust pipe (not shown), and after a sufficient degree of vacuum is reached, the external terminals Dx1 to Dxm and Dy1 to Dy1 to Dx1 to Dxm. The same pulse voltage as in Example 1 was applied between the device electrodes 2 and 3 through Dyn to perform the forming process and the activation process.

Thereafter, the envelope 8 is passed through an exhaust pipe (not shown).
8 is evacuated to a degree of vacuum of about 1 × 10 ⁻⁴ Pa, and the exhaust pipe is fused by heating with a gas burner.
Was sealed. Finally, gettering was performed by a high-frequency heating method to maintain the degree of vacuum after sealing.

The external terminals Dx1 to Dxm and Dy1 to Dyn and the high voltage terminal 87 of the display panel manufactured as described above were connected to necessary driving systems, respectively, to complete the image forming apparatus. A scanning signal and a modulation signal are applied to the respective electron-emitting devices by signal generating means (not shown) through terminals outside the container Dx1 to Dxm and Dy1 to Dyn, respectively.
5 was applied with a high voltage of several KV or more to accelerate the electron beam, collide with the fluorescent film 84, and excite and emit light to display an image.

The image forming apparatus in this embodiment was able to stably display a uniform image with high brightness.

[0154]

As described above, according to the present invention, the position and the shape of the electron-emitting portion of the electron-emitting device can be made constant among the devices, so that the device having uniform device characteristics can be obtained. Is obtained.

Further, a large number of electron-emitting devices are arranged and formed,
In an electron source that emits electrons in response to an input signal, uniformity of electron emission characteristics of each electron-emitting device is realized. In an image forming apparatus using such an electron source, luminance unevenness and
The problem of deterioration of image quality such as reduction in luminance is also solved, and a high-quality image forming apparatus, for example, a color flat television is realized.

[Brief description of the drawings]

FIG. 1 is a plan view and a longitudinal sectional view schematically showing a surface conduction electron-emitting device which is an example of the electron-emitting device of the present invention.

FIG. 2 is a diagram for explaining an example of a method for manufacturing the surface conduction electron-emitting device of FIG.

FIG. 3 is an example of a voltage waveform used for forming processing.

FIG. 4 is a schematic configuration diagram illustrating 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. 5 is a diagram showing a typical example of the relationship between the emission current Ie, the device current If, and the device voltage Vf of the surface conduction electron-emitting device suitable for the present invention.

FIG. 6 is a schematic configuration diagram of an electron source of the present invention in a simple matrix arrangement.

FIG. 7 is a schematic configuration diagram of a display panel used in the image forming apparatus of the present invention using an electron source having a simple matrix arrangement.

FIG. 8 is a diagram showing a fluorescent film in the display panel of FIG. 7;

FIG. 9 is a diagram illustrating an example of a drive circuit that drives the display panel of FIG. 7;

FIG. 10 is a schematic plan view of an electron source of the present invention in a ladder type arrangement.

FIG. 11 is a schematic configuration diagram of a display panel used in the image forming apparatus of the present invention using a ladder-type electron source.

FIG. 12 is a partial plan view of an electron source substrate having a simple matrix arrangement shown in Embodiment 2.

FIG. 13 is a partial cross-sectional view of the electron source substrate of FIG.

FIG. 14 is a plan 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 Underlayer made of magnetic particles 7 Convex part 8 Magnetic pole 9 Opposing magnetic pole 50 Ammeter 51 for measuring element current If flowing through conductive film 4 51 Electron emission A power supply 52 for applying a device voltage Vf to the device 52 An ammeter for measuring an emission current Ie emitted from the electron emission section 5 53 A high-voltage power supply for applying a voltage to the anode electrode 54 Emission from the electron emission section 5 Anode electrode 55 for capturing electrons to be emitted 55 Vacuum container 56 Exhaust pump 71 Electron source substrate 72 X-directional wiring 73 Y-directional wiring 74 Surface conduction electron-emitting device 75 Connection 81 Rear plate 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 face plate 87 high voltage terminal 88 envelope 91 black conductive material 92 phosphor 101 display panel 10 Scanning circuit 103 Control circuit 104 Shift register 105 Line memory 106 Synchronous signal separation circuit 107 Modulation signal generator 110 Electron source substrate 111 Electron emitting element 112 Common wiring for wiring electron emitting element 120 Grid electrode 121 For passing electrons Opening 131 Interlayer insulating layer 132 Contact hole

Claims (11)

[Claims] 1. A height of 1 nm to 10 μm between opposing electrodes.
an underlayer made of magnetic particles having a convex portion in a range of m, a conductive film on the underlayer that communicates between the electrodes, and electron emission in a region of the conductive film corresponding to the convex portion. An electron-emitting device, wherein a portion is formed. 2. The electron-emitting device according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device. 3. A method for manufacturing an electron-emitting device including a conductive film having an electron-emitting portion between opposing electrodes, comprising: a step of forming at least an underlayer made of magnetic particles between the electrodes; Forming a convex portion having a height in the range of 1 nm to 10 μm, forming a conductive film on an underlayer having the convex portion, and forming the electron emitting portion on the conductive film. A method for manufacturing an electron-emitting device, comprising: 4. The method for manufacturing an electron-emitting device according to claim 3, wherein the step of forming the projections on the underlayer made of magnetic particles involves aggregation of the magnetic particles by a static magnetic field. . 5. The method according to claim 1, wherein the magnetic particles are particles made of a ferromagnetic material, and after the step of forming protrusions on an underlayer made of the particles made of the ferromagnetic material, the particles are further heated and baked in an oxidizing atmosphere. 4. The method for manufacturing an electron-emitting device according to claim 3, further comprising the step of converting the particles into particles made of a paramagnetic material. 6. An electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting device is the electron-emitting device according to claim 1 or 2. 7. The electron source according to claim 6, wherein the plurality of electron-emitting devices are wired in a matrix. 8. The electron source according to claim 6, wherein the plurality of electron-emitting devices are wired in a ladder shape. 9. A method for manufacturing an electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting devices are:
A method of manufacturing an electron source, wherein the method is performed by the method according to claim 3. 10. An image forming apparatus, comprising: an electron source having a plurality of electron-emitting devices arranged on a substrate; and an image forming member that forms an image by irradiating an electron beam emitted from the electron source. An image forming apparatus, wherein the electron source is the electron source according to claim 6. 11. A method for manufacturing an image forming apparatus, comprising: an electron source having a plurality of electron-emitting devices arranged on a substrate; and an image forming member that forms an image by irradiating an electron beam emitted from the electron source. 10. The method for manufacturing an image forming apparatus according to claim 9, wherein the electron source is manufactured by the method according to claim 9.