JPH11149860A - Electron-emitting device, electron source, image forming apparatus, and manufacturing method thereof - Google Patents

Abstract

(57) Abstract: In an electron-emitting device, a conductive film 4 is formed of a metal oxide, and an electron-emitting portion 5 is formed with a high yield by low-voltage forming. A forming process is performed by applying a voltage between element electrodes (2, 3) to an electrically conductive film (4) made of a metal oxide in an atmosphere containing a substance that promotes reduction of the metal oxide. When the value was measured and a forming failure occurred, the conductive film 4 was exposed to an oxidizing atmosphere while being kept at a high temperature, subjected to an oxidizing treatment, the forming conditions were changed, and a reforming treatment was performed. An emission part 5 is formed.

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 using a plurality of the devices, an image forming apparatus such as a display device and an exposure device using the same, and a method of manufacturing these devices.

[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), surface electron-emitting devices, and the like.

[0003] As an example of the FE type, W.P.Dyck and W.W.
Dyke and W.S. W. Dolan) "Field Emission",
Advance in Electron Physics (Ad
vance in Electron Physic
s), 8, 89 (1956) or CA Spindt, "Physical Properties of Thin-Film Field Emissions Cassors with Molybdenum Cornes (Ph.
ysical Properties of thin
-Film field emission cath
odes with molebdenum cone
s) ", J.M. Appl. Phys. , 47,5248
(1976).

[0004] As an example of the MIM type, C.A. Mead (CA Mead), "Operation of Tunnel-Emission Devices (Opera)"
Tion of Tunnel-Emission D
devices) ", J.M. Appl. Phys. , 32,
646 (1961) and the like are known.

[0005] As an example of a surface conduction electron-emitting device, MI Elinson, R.
adio Eng. Electron Phys. ,
10, 1290 (1965).

[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].
"Shin Solid Films
Films) ", 9, 317 (1972)], In ₂
O ₃ / SnO ₂ thin film [M. Hartwell
And Shii Ji Fonstad (M. Hartw
ell and C.I. G. FIG. Fonstad), "IEEE
Trans. 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. Hartwell device configuration is schematically shown in 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, and 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 set to 0.5 to 1 mm, and W 'is set to 0.1 mm.

In these surface conduction electron-emitting devices, the electron-emitting portion 5 is generally formed by subjecting the conductive film 4 to an energization process called energization forming before performing electron emission. That is, energization forming is
A voltage is applied to both ends of the conductive film 4 and a current is applied.
Is a process of locally breaking, deforming, or altering the structure to change the structure, thereby forming the electron-emitting portion 5 in an electrically high-resistance state. In the electron emitting portion 5, a crack is generated in a part of the conductive film 4, and the electron is emitted from the vicinity of the crack.

The above-described surface conduction electron-emitting device has an advantage that a large number of devices can be arranged and formed over a large area because of its simple structure. Therefore, various applications for making use of 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. (Common wiring), an electron source in which a number of rows connected to each other are arranged (ladder-like arrangement) (for example, JP-A-64-31332, JP-A-1-283).
749, and 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]

In the forming step of forming an electron-emitting portion in the conductive film of the electron-emitting device, it is better to reduce the voltage applied to the conductive film as much as possible to obtain an electron-emitting device having better characteristics. Easy to get. As a method of reducing the applied voltage in the forming step, a conductive film is formed of a metal oxide, preferably fine particles, and when a voltage is applied in an atmosphere that promotes the reduction of the metal oxide, the conductive film is formed with the reduction. It has been found that the aggregation occurs in a part of the conductive film, so that the electron emission portion is formed even at a low applied voltage. In this method as well, it is desirable that the applied voltage be as low as possible within a range in which the forming process can be performed. However, if the voltage is erroneously set too low, the conductive film is reduced before the electron emission portion is formed. Progresses, the resistance of the conductive film becomes very small, and normal forming processing can no longer be performed even if the voltage is increased a little at that time.

In the case of manufacturing an electron source having a plurality of electron-emitting devices, a plurality of devices (for example, devices connected to the same wiring and belonging to one device row) may be formed simultaneously. However, if the resistance of the conductive film of a certain element is low, the other elements connected to the same wiring do not receive a sufficient voltage, and most of the elements in the element row emit electrons. The part may be left unformed. In this case, after the completion of the forming process, the conductive film having the forming defect has already been reduced and the resistance value has been reduced, so that the forming process cannot be performed normally again, and a defective portion remains in the electron source. .

As described above, the forming process in a reducing atmosphere is a preferable method for reducing the applied voltage, but the manufacturing yield may be reduced due to the variation in the resistance value of the conductive film. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide an electron-emitting device having excellent electron-emitting characteristics by a forming step of applying a low voltage, and a method of forming an electron source using a plurality of the electron-emitting devices with a high yield. To provide an inexpensive method for manufacturing an image forming apparatus having good display characteristics.

[0016]

According to the present invention, first, a pair of device electrodes formed on a substrate, a conductive film electrically connected to each of the device electrodes, and one of the conductive films are provided. A method for manufacturing an electron-emitting device having an electron-emitting portion formed in a portion, connecting a pair of device electrodes formed on a substrate,
Forming a conductive film made of a metal oxide, and forming an electron emitting portion by applying a pulse voltage between the device electrodes in an atmosphere containing a substance that promotes reduction of the metal oxide. Measuring the resistance between the device electrodes and detecting the quality of the formation of the electron-emitting portion, and oxidizing the conductive film of the device in which the formation of the electron-emitting portion is determined to be defective in the detection process. And forming the electron-emitting portion by applying a pulse voltage between the device electrodes in an atmosphere containing a substance that promotes reduction of the metal oxide constituting the oxidized conductive film. And a method for manufacturing an electron-emitting device.

According to the manufacturing method of the present invention, it is determined whether the formation of the electron-emitting portion is completed or not (defective forming) by measuring the resistance between the device electrodes of each device after the forming process. However, in the case of a forming failure, a favorable electron-emitting portion can be formed by oxidizing the conductive film of the element and reforming it under appropriate conditions. That is, a forming defect in a forming step in a reducing atmosphere is repaired to reduce the occurrence of defective products.

The present invention also provides an electron-emitting device manufactured by the above manufacturing method.

Further, the present invention provides an electron source using a plurality of the above-mentioned electron-emitting devices. First, an element row formed by arranging and connecting a plurality of the above-mentioned electron-emitting devices in parallel is provided. It is characterized by having at least one row and wirings for driving each element are arranged in a ladder shape.
A second feature is that the device has at least one element row in which a plurality of the electron-emitting devices are arranged, and wirings for driving the elements are arranged in a matrix.

Still further, according to the present invention, there is provided an image forming apparatus comprising the above-mentioned electron source, an image forming member, and a control electrode for controlling an electron beam emitted from each element by an information signal. An image forming apparatus comprising an electron source and an image forming member is provided.

According to the present invention, there is provided a method of manufacturing an electron source, wherein a plurality of electron-emitting devices are formed on the same substrate by the above-described method of manufacturing an electron-emitting device, and an electron obtained by the method. A source is combined with a control electrode for controlling an electron beam emitted from the electron source and an image forming member for forming an image by irradiation of the electron beam from the electron source, or an electron source obtained by the manufacturing method. And an image forming member for forming an image by irradiation of an electron beam from the electron source.

[0022]

Next, the present invention will be described in detail by taking a surface conduction electron-emitting device as a preferred embodiment of the present invention. .

The basic structure of a surface conduction electron-emitting device is roughly classified into a planar type and a vertical type.

First, a plane type surface conduction electron-emitting device will be described.

FIG. 1 is a schematic view showing an example of the configuration of a planar surface conduction electron-emitting device. FIG. 1A is a plan view, and FIG. 1B is a longitudinal sectional view. In FIG. 1, 1 is a substrate,
Reference numerals 2 and 3 denote device electrodes, 4 denotes a conductive film, and 5 denotes an electron-emitting portion.

Examples of the substrate 1 include quartz glass, glass having a reduced content of impurities 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 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 , P
It is appropriately selected from a printed conductor composed of a metal such as d-Ag or a metal oxide and glass, a transparent conductor such as In ₂ O ₃ —SnO ₂ , and a semiconductor conductor material such as polysilicon.

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 device electrode interval L is preferably several hundred nm to several hundred μ.
m, and more preferably in the range of several μm to several tens μm in consideration of the voltage applied between the device electrodes.

The element electrode length W is preferably in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics, and the film thickness d of the element electrodes 2 and 3 is preferably several tens. The range is from nm to several μm.

In addition to the configuration shown in FIG.
A configuration in which the conductive film 4 and the opposing element electrodes 2 and 3 are laminated on the above in this order may be adopted.

The material constituting the conductive film 4 is Pd
Metal oxides such as O, SnO ₂ , In ₂ O ₃ , PbO, and Sb ₂ O ₃ are mentioned.

As the conductive film 4, it is preferable to use a fine particle film composed 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 between the device electrodes 2 and 3, and the like. Preferably, it is more preferably in the range of 1 nm to 50 nm. Its resistance, R _s is 1 × 10 ³ ~1 × 1
0 is a ^{7 Ω} / □ of value. Note that R _s has a width w and a length l.
R = R _s (l /
w).

The fine particle film described here is a film in which a plurality of fine particles are aggregated. The fine structure thereof 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 overlapped (some). (Including the case where the fine particles aggregate to form an island-like structure 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 the present specification, the term “fine particles” is frequently used, and the meaning will be described.

Generally, small particles are called “fine particles”.
Those smaller than this are called "ultrafine particles". It is widely practiced to call a “cluster” a particle that is smaller than “ultrafine particles” and has a few hundred atoms or less.

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, "Experimental Physics Course 14 Surface /
Particles ”(edited by Yoshio Kinoshita, Kyoritsu Shuppan, September 1, 1986)
(Published on the same day), "When we say fine particles in this paper, the diameter is about 2-3 μm to about 10 nm,
Especially when it is referred to as ultrafine particles, the particle size is from about 10 nm to 2 to
It means up to about 3 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. (Page 195, lines 22 to 26).

In addition, in the definition of "ultra fine particles" in the "Hayashi / Ultra Fine Particle Project" of the New Technology Development Corporation, the lower limit of the particle size was even smaller, as follows.

In the “Ultrafine 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 “ultrafine 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
Ed., Mita Shuppan, 1988, page 2, lines 1 to 4) / "Even smaller than ultrafine particles, that is, several atoms to
One particle composed of several hundred particles is usually called a cluster ”(p. 2, p. 12 to 13).

[0040] Based on the general notation as described above,
In this specification, the term “ultrafine particles” refers to an aggregate of a large number of atoms and molecules, and the lower limit of the particle size is about several Å to 1 nm, and the upper limit is about several μm.

The electron-emitting portion 5 is constituted by a crack region formed in a part of the conductive film 4 and depends on a crack formation method described later. A few 放出
In some cases, conductive fine particles having a particle size in the range of ｎｍ10 nm to several tens nm are present. The conductive fine particles contain some or all of the elements of the material constituting the conductive film 4. The electron emitting portion 5 and the conductive film 4 in the vicinity thereof may include carbon or a carbon compound.

Next, a vertical type surface conduction electron-emitting device will be described.

FIG. 2 is a schematic view showing an example of the structure of a vertical surface conduction electron-emitting device. The same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG. ing.
21 is a step forming part. Substrate 1, device electrodes 2 and 3,
The conductive film 4 and the electron-emitting portion 5 can be made of the same material as in the case of the above-mentioned flat surface conduction electron-emitting device. The step forming portion 21 is made of an insulating material such as SiO ₂ formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The film thickness of the step forming portion 21 corresponds to the device electrode interval L of the flat surface conduction electron-emitting device described above, and is preferably in the range of several hundred nm to several tens μm. This film thickness is set in consideration of the manufacturing method of the step forming portion 21 and the voltage applied between the device electrodes 2 and 3, and is preferably in the range of several tens nm to several μm.

Since the conductive film 4 is usually formed after the device electrodes 2 and 3 are formed, the conductive film 4 is laminated on the device electrodes 2 and 3. Made,
The device electrodes 2 and 3 can be stacked on the conductive film 4. Further, as described in the description of the planar surface conduction type electron-emitting device, the formation of the electron-emitting portion 5 depends on the manufacturing method such as the film thickness, film quality, material, and forming conditions of the conductive film 4 described later. However, the position and shape are not limited to the position and shape as shown in FIG.

Next, as a manufacturing method of the present invention, the manufacturing method of the surface conduction electron-emitting device shown in FIG.
This will be described with reference to FIG. In FIG. 3, 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 washed, sufficiently washed with pure water and an organic solvent, etc., 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. 3
(A)).

2) On the substrate 1 on which the device electrodes 2 and 3 are provided,
An organometallic solution is applied to form an organometallic film. The organic metal solution is a solution of an organic compound containing the metal of the material of the conductive film 4 as a main element. The organic metal film is heated and baked, and patterned by lift-off, etching, or the like to form a conductive film 4 made of a metal oxide (FIG. 3B). 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, an inkjet method, or the like can be used.

When the ink jet method is used, 10
Fine droplets of about ng to several tens of ng can be generated with good reproducibility and applied to the substrate, and patterning by photolithography and a vacuum process are unnecessary, which is preferable in terms of productivity. As a device of the ink jet method, a bubble jet type using an electrothermal converter as an energy generating element, a piezo jet type using a piezoelectric element, or the like can be used. As the means for firing the droplets, means for irradiating electromagnetic waves, means for irradiating heated air, and means for heating the entire substrate are used. As the electromagnetic wave irradiation means, for example, an infrared lamp, an argon ion laser, a semiconductor laser, or the like can be used.

3) Subsequently, a forming step is performed.
When a current is supplied from a power supply (not shown) between the device electrodes 2 and 3 in an atmosphere containing a substance that promotes reduction of the metal oxide constituting the conductive film 4, a high-resistance crack is formed in the conductive film 4. As a result, an electron emission portion 5 is formed (FIG. 3C). By this forming process, the conductive film 4 is locally destroyed, deformed or deteriorated, and a portion having a changed structure is formed. A part of the portion is the electron emission portion 5.

Examples of the substance that promotes the reduction of the metal oxide include methane, ethane, ethylene, and the like in addition to H ₂ and CO.
Gases of organic substances such as propylene, benzene, toluene, methanol, ethanol, and acetone are also effective.

Next, an example of a forming voltage waveform is shown in FIG.
Shown in

The voltage waveform is particularly preferably a pulse waveform.
For this, a method shown in FIG. 4A in which a pulse with a constant pulse peak value is applied continuously and a method shown in FIG. 4B in which a pulse is applied while increasing the pulse peak value are applied. There is.

First, the case where the pulse crest value is a constant voltage will be described with reference to FIG. T in FIG. 4 (a)
₁ and T ₂ are the pulse width and pulse interval of the voltage waveform,
Normally, T ₁ is 1μsec~10msec, T ₂ is 10μ
It is set in a range from sec to several hundred msec. The peak value of the triangular wave (peak voltage during energization forming) 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 of seconds. The pulse waveform is not limited to a triangle wave,
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. 4 (b) is the same as T _1, T ₂ shown in Figure 4 (a). The peak value of the triangular wave is increased, for example, by about 0.1V.

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 by applying a voltage of about 0.1 V is measured, and a resistance value is obtained. When the resistance value indicates 1 MΩ or more, the energization forming is terminated.

In the above, the case where the forming process has been successfully performed has been described. However, in actual execution of the forming process, an electron-emitting portion is formed depending on the forming process conditions (for example, it is considered that the forming power is insufficient such as a small peak value of the applied voltage or a narrow pulse width). Previously, the metal oxide constituting the conductive film 4 is reduced to metal, and the resistance value of the conductive film 4 may be reduced, so that a favorable electron emitting portion may not be formed.

4) In the present invention, a repair process is performed for the case where the conductive film 4 is reduced without forming the above-described electron-emitting portion.

FIG. 15 is a flowchart showing a forming defective element detecting and repairing step after the forming step.

First, after the forming process is performed by the above-described method, the resistance of each element is measured. Thereafter, if the measured resistance value is equal to or more than a desired value R _f , for example, 1 MΩ or more, it is determined that an electron emitting portion has been formed, and the forming step is completed. If the element resistance is low, it is determined that the conductive film 4 has been reduced and a good electron-emitting portion has not been formed, and the next oxidation treatment step is performed.

Various methods can be employed for the oxidation treatment step of returning the conductive film reduced to the metal to the oxide again, but the simplest method is to expose the conductive film 4 to an oxidizing gas atmosphere while keeping the conductive film 4 at a high temperature. The conductive film 4
Can be oxidized. At this time, the higher the temperature of the conductive film 4 is, the more easily the oxidation reaction proceeds, but it is desirable to set the temperature so as not to change the shape of the conductive film 4 and to affect other members (substrate, element electrode, etc.). . In addition, oxygen is generally used as the oxidizing gas, but is not limited thereto, and may be appropriately selected according to the material of the conductive film 4.

As a method of keeping the periphery of the element in an oxidizing gas atmosphere, a method of placing the element in a vacuum vessel and introducing the oxidizing gas into the vessel, a method of blowing the oxidizing gas around a defective forming element, Alternatively, the simplest method is to keep the element at a high temperature in the atmosphere. The oxidation process has been described above. However, the method is not limited to the above method as long as the conductive film according to the present invention can be returned to a metal oxide film.

5) The conductive film 4 which has returned to the metal oxide film in the above-mentioned oxidation treatment step is subjected to a re-forming treatment. Regarding the reforming processing method, basically, the above 3)
However, it is effective to increase the forming power applied between the element electrodes in order to prevent the occurrence of the forming failure in the re-forming step. Specifically, the peak value of the applied pulse voltage is increased, or the pulse width is increased,
For example, the pulse interval may be narrowed. by this,
At the time of reforming, it is possible to prevent the occurrence of a defect in the formation of the electron emission portion due to the reduction of the conductive film 4.

After the reforming process, the element resistance is measured again. If the resistance of the element is sufficiently large, it is determined that a good electron-emitting portion has been formed, and the reforming step is terminated. If the element resistance is small, it is determined that the forming is defective, and the above step 4) is repeated again until the element resistance becomes large.

6) It is preferable to perform a process called an activation step on the element in which the electron-emitting portion 5 is formed on the conductive film 4. By this activation step, the device current I _f and the emission current I _f
e can be changed significantly.

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. This atmosphere can be formed by using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated by using, for example, a combination of an oil diffusion pump and a rotary pump. It can also be obtained by introducing a gas of an appropriate organic substance into the evacuated vacuum. The preferable gas pressure of the organic substance at this time varies depending on the form of the above-mentioned element electrode, the shape of the vacuum vessel, the type of the organic substance, and the like. Suitable organic substances include alkane, alkene, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, carboxylic acids, and organic acids such as sulfonic acids. can be mentioned, specifically, methane, ethane, saturated hydrocarbons represented by C _n H _{2n + 2} such as propane, ethylene, propylene C _n H _2n such
Unsaturated hydrocarbon represented 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 or the like can be used. By this treatment, 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 are significantly changed.

The carbon and the carbon compound include, for example, graphite (so-called HOPG, PG, and GC, and HOPG has a substantially complete graphite crystal structure, PG
Are those with crystal grains of about 20 nm and a slightly disordered crystal structure,
GC refers to those in which the crystal grains are about 2 nm and the disorder of the crystal structure is further increased), and amorphous carbon (refers to amorphous carbon and a mixture of amorphous carbon and the fine crystals of graphite). The thickness is preferably 50 nm or less, and more preferably 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 . Note that the pulse width, pulse interval, pulse peak 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, an ultra-high vacuum exhaust device such as a combination of a sorption pump and an ion pump can be used.

When a combination of an oil diffusion pump and a rotary pump is used as an exhaust device in the activation step and an organic gas derived from an oil component generated from the combination 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 hardly newly deposited.
Further, when the inside of the vacuum vessel is evacuated, it is preferable to heat the entire vacuum vessel so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device can be easily evacuated. The heating conditions at this time are preferably at least 80 ° C., and more preferably at least 150 ° C., for as long a time as possible. However, the present invention is not limited to this condition. It is performed under conditions appropriately selected according to various conditions such as the above. 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 stabilizing step is preferably the same as the atmosphere at the end of the stabilizing process. However, the present invention is not limited to this, as long as the organic substance is sufficiently removed. However, even if the pressure itself slightly increases, sufficiently stable characteristics can be maintained. By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed, and as a result, the device current I _f and the emission current I _f
e stabilizes.

The basic characteristics of the electron-emitting device of the present invention will be described with reference to FIGS. 5 and 6, taking the above-mentioned flat surface conduction electron-emitting device as an example.

FIG. 5 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. Also in FIG. 5, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

In FIG. 5, 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. That is, 1 is a substrate constituting an electron-emitting device, 2 and 3 are device electrodes, 4 is a conductive film, and 5 is an electron-emitting portion. 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 I _e emitted from the electron emission section 5, a high-voltage power supply 53 for applying a voltage to the anode electrode 54, and a reference numeral 52 for the emission current I _e emitted from the electron emission section 2. It is an ammeter for measuring. As an example, the measurement is 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 pressure gauge (not shown).
The measurement and evaluation can be performed in a desired vacuum atmosphere.

The entire vacuum processing apparatus provided with the electron-emitting device substrate shown here can be heated by a heater (not shown). Therefore, when this vacuum processing apparatus is used, the steps after the above-described energization forming can also be performed.

FIG. 6 is a diagram schematically showing the relationship between the emission current I _e and the device current _If measured using the vacuum processing apparatus shown in FIG. 5, and the device voltage _Vf . In FIG. 6, 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. 6, the electron-emitting device of the present invention has the following three characteristic properties with respect to the emission current _Ie .

First, when an element voltage higher than a certain voltage (referred to as a threshold voltage; V _{th in} FIG. 6) is applied to the present element, the emission current _Ie rapidly increases, while the threshold voltage V Below _th , the emission current _Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage V _th for the emission current I _e .

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 .

Third, the emission charge trapped by the anode electrode 54 (see FIG. 5) 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 will be 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.

[0082] In Figure 6, monotonically increases with respect to the device current I _f also the device voltage V _f to (hereinafter, referred to as "MI characteristic") has shown an example, device current I _f of the element voltage V _f In some cases, the voltage control type negative resistance characteristic (hereinafter, referred to as “VCNR characteristic”) may be exhibited (not shown). These properties can be controlled by controlling the steps described above.

Due to the characteristic characteristics of the electron-emitting device of the present invention as described above, an electron source having a plurality of electron-emitting devices can easily control the amount of emitted electrons according to an input signal even in an image forming apparatus or the like. It can be applied to various fields.

An application example of the electron-emitting device of the present invention will be described below. By arranging a plurality of electron-emitting devices of the present invention on a substrate, for example, an electron source and further 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 (row direction), and the electron emission devices are arranged in a direction perpendicular to the wiring (column direction). There is a ladder-like arrangement in which electrons from the electron-emitting device are controlled and driven by a control electrode (grid electrode) disposed above the device. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X direction and the Y direction, 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, and the same. One example is one in which the other of the electrodes of the plurality of electron-emitting devices arranged in a row is commonly connected to a wiring in the Y direction. Such an arrangement is a so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.

The electron-emitting device of the present invention has three characteristics as described above. In other words, the electrons emitted from the 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 threshold voltage is exceeded. On the other hand, below the threshold voltage, almost no electrons are emitted. 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, the electron-emitting device can be selected and the amount of electron emission can be controlled in accordance with an input signal. .

Hereinafter, based on this principle, an electron source substrate obtained by disposing a plurality of surface conduction electron-emitting devices, which is one embodiment of the electron-emitting device of the present invention, will be described with reference to FIG. In FIG. 7, 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. Note that the electron-emitting device 74
May be a flat type or a vertical type.

The m X-directional wirings 72 have D _x1 , D _x2,.
.., D _xm , and can be made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness and width of the wiring are appropriately designed. Y-direction wiring _{73, D y1, D y2, ......} , it consists n wirings of D _yn, is formed in the same manner as the X-direction 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, the film 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 production method is 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-direction wires 72 and n Y-direction wires 73 by a connection 75 made of a conductive metal or the like. It is connected.

The material forming the X-direction wiring 72 and the Y-direction wiring 73, the material forming the connection 75, and the material forming the pair of element electrodes are the same even if some or all of the constituent elements are the same. , And may be different from each other. These materials are appropriately selected, for example, from the above-described materials for the device electrodes. When the material forming the element electrode and the wiring material are the same, it can be said that the wiring connected to the element electrode is the 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.

In the present invention, in the manufacturing process of the electron source having the plurality of electron-emitting devices provided on the same substrate,
Preferably, a pulse voltage is used for the forming process,
A forming step is performed by applying a pulse voltage for each element row, one pulse at a time, switching the element rows to be applied for each pulse, and repeatedly scanning a plurality of element rows. According to this method, a pulse voltage is applied to one element row, and then a pulse is immediately applied to another element row. The time for the forming process can be shortened.

The above-described forming step will be described specifically. FIG. 16 shows a forming device of an electron source. In the drawing, 161 is a forming voltage source for generating a forming voltage pulse, 162 is a line selector for applying a voltage pulse generated by the forming voltage source 161 to a required line, 163 is an ammeter for monitoring the total current value of the device current flowing through the electron-emitting devices arranged on each line,
Reference numeral 164 denotes a control unit for controlling the forming voltage source 161 and the line selection unit 162 based on the element current value of one line detected by the ammeter 163, and 165 denotes a plurality of electron emission elements for forming the m rows. × n columns of electron source substrates arranged in a simple matrix. Here, the electron source substrate 165 is disposed in a vacuum device (not shown), and can be heated or a reducing / aggregating gas or an oxidizing gas can be introduced as necessary. The X-direction wirings D _{x1 to} D _xm of the electron source substrate 165 are connected to S _{x1 to} S _xm of the forming apparatus.

First, the first forming process will be described. In FIG. 16, D _{y1 to} D _yn are electrically shared and connected to the ground. At the time of forming, a voltage is supplied from the X-direction wiring of the electron source substrate 165, and the forming voltage is applied to n elements arranged on the X-direction wiring at the same time, and the forming process is performed. Here, the voltage output from the forming voltage source 161 is sequentially scanned one line at a time from D _{x1 to} D _xn via the line selection unit 162 controlled by the control unit 164, so that the forming process is simultaneously performed on all the elements. Has been given. In addition, since the ammeter 163 also measures the current at the time of the forming process, the combined resistance of the m elements arranged on the wiring can be immediately detected. Therefore, the resistance measurement after the forming process is also performed here. Can be.

After the first forming process, the combined resistance value of the elements in each line is measured to determine whether the resistance is low.
A line including an element that is not sufficiently high, that is, the conductive film is reduced and the electron emission portion is not formed is detected. When the line is detected, a process similar to the above-described oxidation process of the electron-emitting device is performed.

Next, the control section 164 and the line selection section 16
According to 2, a pulse voltage is applied only to the line where the forming failure has occurred while introducing the reducing gas,
A re-forming process is performed. After the processing, if the combined resistance value of the line is high as in the other lines, the re-forming step is ended there. If the combined resistance value has become low again, the above-described oxidation process and re-forming process are repeated. In any case, in the re-forming process, it is desirable to change conditions such as increasing the peak value or increasing the pulse width or narrowing the pulse interval compared to the first forming process.

FIGS. 8, 9A, 9B, 9C, 9D, and 9E show an image forming apparatus constructed using the electron sources having the simple matrix arrangement as described above.
This will be described with reference to FIG. FIG. 8 is a schematic view showing an example of a display panel of the image forming apparatus, and FIG. 9 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG. 10 is a block diagram showing an example of a driving circuit for performing display in accordance with an NTSC television signal. The same parts as those shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. Note that the conductive film 4 is omitted for convenience.

In FIG. 8, reference numeral 81 denotes a rear plate to which the electron source substrate 71 is fixed, and 86 denotes a face plate in which a fluorescent film 84 and a metal back 85 are formed on the inner surface of a glass substrate 83. 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 in a temperature range of 400 to 500 ° C. for 10 minutes or more in the atmosphere or nitrogen, for example.

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 electron source substrate 71, if the substrate 71 itself has sufficient strength, the separate rear plate 81 is unnecessary.
That is, the support frame 82 may be directly sealed to the substrate 71, and the envelope 88 may be configured by the face plate 86, the support frame 82, and the substrate 71. 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. 9 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, the fluorescent film is composed of a black conductive material 91 called a black stripe (FIG. 9A) or a black matrix (FIG. 9B) or the like depending on the arrangement of the fluorescent materials. Can be. The purpose of providing a black stripe and black matrix is
In the case of a color display, the purpose is to make the mixed portions between the three primary color phosphors 92 necessary black to make color mixing less noticeable, and to suppress a decrease in contrast due to reflection of external light on the fluorescent film 84. 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, a printing method, or the like 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
Improving the brightness by mirror-reflecting light toward the inner surface side of the phosphor emission toward the glass substrate 83 side, acting as an electrode for applying an electron beam accelerating voltage, generated in the envelope. The purpose is to protect the phosphor from damage caused by the collision of negative ions. The metal back is
After the formation of the fluorescent film, a smoothing treatment (usually called “filming”) of the inner surface of the fluorescent film is performed, and then A
1 can be produced by depositing using vacuum evaporation or the like.

The face plate 86 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 84 in order to further enhance the conductivity of the fluorescent 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. 8 is manufactured, for example, as follows.

The interior of the envelope 88 is evacuated through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump and a sorption pump, while appropriately heating, as in the stabilization process described above. Sealing is performed after setting the atmosphere of a vacuum degree of about ^-5 Pa to a sufficiently low level of an organic substance.
In order to maintain the degree of vacuum after sealing the envelope 88, getter processing may be performed. This is because a getter (not shown) arranged 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 ⁻³ to 1
The vacuum degree of ^10-5 Pa 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. . 10, 101 is an image display panel, 102 is a scanning circuit, 10
3 control circuit, 104 a shift register, a line memory 105, the 106 sync signal separation circuit, 107 a modulation signal generator, the V _x and V _a is a DC voltage source.

The display panel 101 is connected to an external electric circuit via terminals D _{x1 to} D _xm , terminals D _{y1 to} D _yn and a high voltage terminal 87. The display panel 101 is connected to the terminals D _{x1 to} D _xm.
A scanning signal for sequentially driving the electron sources provided therein, that is, electron emission element groups arranged in a matrix of m rows and n columns in a matrix is applied one row at a time (n elements). Terminals D _{y1 to} D
A modulation signal for controlling the output electron beam of each of the electron-emitting devices in one row selected by the scanning signal is applied to _yn . The high-voltage terminal 87, the DC voltage source V _a, for example, a DC voltage of 10kV is applied, which the electron beams emitted from the electron-emitting device, to impart sufficient energy to excite the phosphor Voltage for acceleration.

Next, the scanning circuit 102 will be described. This circuit includes m switching elements (S in FIG. 10).
_{1 to} S _m ). Each switching element is an output voltage or 0 of the DC voltage source V _x
[V] (ground level) is selected and electrically connected to terminals D _{x1 to} D _xm of the display panel 101. Each of the switching elements S _{1 to} S _m is connected to the control circuit 103.
_Operates based on the control signal _Tscan output from the switching element, and can be configured by combining switching elements such as FETs, for example.

[0111] DC voltage source V _x is based on characteristics of the electron-emitting device (electron emission threshold voltage), the drive voltage applied to devices that are not scanned such that the less the electron emission threshold voltage constant It is set to output 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
Based on 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 separation 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 separation (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 referred to 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 104
Shift clock). The data of one line of the serial / parallel-converted image (corresponding to the driving data of n electron-emitting devices) are I _{d1 to} I _dn.
Are output from the shift register 104 as n parallel signals.

The line memory 105 is a storage device for storing data for one line of an image for a required time only, and stores the contents of I _{d1 to} I _dn as appropriate according to a control signal T _mry sent from the control circuit 103. I do. The stored contents are output as I _d'1 ~I _d'n, the modulation signal generator 1
07.

Modulation signal generator 107 outputs image data I
Depending on each of _d'1 ~I _d'n, a signal source for appropriately driving modulating each of the electron-emitting device, the output signal, the electronic display panel 101 through the terminals D _y1 to D _yn Applied to the emitting element.

As described above, the electron-emitting device of the present invention has the following basic characteristics with respect to the emission current _Ie . That is, electron emission has a clear threshold voltage V _th , and V _th
Electron emission occurs only when the above voltage 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. For this reason, when a pulse-like voltage is applied to the present element, for example, even if a voltage lower than the electron emission threshold voltage is applied, no electron emission occurs, but a voltage higher than the electron emission threshold voltage is applied. In this case, an electron beam is output. At this time, by varying the peak value V _m of pulse, it is possible to control the intensity of the output electron beam. Further, by changing the width P _w of pulse, it is possible to control the total amount of the outputted electron beam charge.

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, 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 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 of the present invention which can take such a configuration, each of the electron-emitting devices is provided with a terminal D _x1 outside the container.
To D _xm, by applying a voltage via the D _y1 to D _yn, electron emission occurs. At the same time, a high voltage is applied to the metal back 85 or the 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 the image forming apparatus of the present invention, and various modifications can be made based on the technical idea of the present invention. N for input signal
Although the TSC system has been described, the input signal is not limited to this, and may be a PAL, SECAM system or the like, or a television signal (for example, M
A high-definition TV) system including the USE system can also be adopted.

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

FIG. 11 is a schematic view showing an example of a ladder-shaped electron source. In FIG. 11, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. 112 is a common wiring D ₁ to D ₁₀ 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 these element rows are arranged to form 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 wiring D ₂ to D ₉ located at each element rows, for example, a D ₂ and D ₃ may be an integral of the same wiring.

FIG. 12 is a schematic diagram showing an example of a panel structure in an image forming apparatus having a ladder-like arrangement of electron sources. 120 grid electrodes, 121 an opening for electrons to pass through, D ₁ to D _m is the vessel terminals, G ₁ ~G _n is vessel terminals connected to the grid electrode 120. 110
Is an electron source substrate in which the common wiring between each element row is the same wiring. 12, the same parts as those shown in FIGS. 8 and 11 are denoted by the same reference numerals. Note that the conductive film 4 is omitted for convenience. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 8 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.

Also in the ladder-shaped electron source, a pulse voltage is applied to the forming process, and a pulse voltage is applied for each element row. It is preferable to repeat the process of sequentially scanning all the element rows by switching the element rows to be applied every time. In this case, among the wirings in FIG. 11, for example, odd-numbered wirings D ₁ , D ₃ ,... Are connected to the line selection unit 162 in FIG. 16 via an ammeter 163, and even-numbered wirings D ₂ , D ₄ ,... May all be connected to ground. Other procedures are the same as those in the case of the matrix wiring.

In FIG. 12, 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-shaped element rows, one circular opening 121 is provided for each element. The shape and arrangement 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 outer terminals D _{1 to} D _m and G _{1 to} G _n are connected to a control circuit (not shown). Then, in synchronization with sequentially driving (scanning) the element rows one by one, a modulation signal for one image line is simultaneously applied to the grid electrode columns. 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 display apparatus such as a video conference system or a computer, and an image forming apparatus as an optical printer using a photosensitive drum or the like. Etc. can also be used.

FIG. 14 is a diagram showing an example in which the image forming apparatus of the present invention is configured to be able to display image information provided from various image information sources such as a television broadcast.

In the figure, 1700 is a display panel, 1
701 is a display panel driving circuit, 1702 is a display controller, 1703 is a multiplexer,
1704 is a decoder, 1705 is an input / output interface circuit, 1706 is a CPU, 1707 is an image generation circuit,
Reference numerals 708 to 1710 denote image memory interface circuits,
711 is an image input interface circuit, 1712 and 1713 are TV signal receiving circuits, and 1714 is an input unit.

When the present image forming apparatus receives a signal containing both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the present invention are omitted.

Hereinafter, the function of each unit will be described along the flow of the image signal.

First, the TV signal receiving circuit 1713 is a circuit for receiving a TV signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The type of the TV signal to be received is not particularly limited.
Any system such as the TSC system, the PAL system, and the SECAM system may be used. Further, a TV signal including a larger number of scanning lines than these, for example, a so-called high-definition TV signal such as a MUSE system is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. Signal source.

The TV signal received by the TV signal receiving circuit 1713 is output to a decoder 1704.

The TV signal receiving circuit 1712 is a circuit for receiving a TV signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber.
Like the TV signal receiving circuit 1713, the TV
The signal system is not particularly limited, and the TV signal received by this circuit is also output to the decoder 1704.

Image input interface circuit 1711
Is a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is output to the decoder 1704.

Image memory interface circuit 1710
Stands for Video Tape Recorder (hereinafter referred to as "VTR")
Is a circuit for taking in the image signal stored in the decoder 1704, and the taken-in image signal is output to the decoder 1704.

Image memory interface circuit 1709
Is a circuit for taking in an image signal stored in the video disk.
04 is output.

Image memory interface circuit 1708
Is a circuit for taking in an image signal from a device storing still image data, such as a still image disk, and the taken still image data is input to the decoder 1704.

The input / output interface circuit 1705 is
This is a circuit for connecting the present image display device to an output device such as an external computer, computer network or printer. Input / output of image data and character / graphic information, and in some cases, CP
It is also possible to input and output control signals and numerical data between the U1706 and the outside.

The image generation circuit 1707 is provided with image data and character / graphic information input from the outside via the input / output interface circuit 1705, or the CPU 1706.
Based on image data and character / graphic information output from
This is a circuit for generating display image data. Inside this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory storing an image pattern corresponding to a character code, a processor for performing image processing, and the like And other circuits necessary for generating an image.

The display image data generated by this circuit is output to the decoder 1704, but may be output to an external computer network or printer via the input / output interface circuit 1705 in some cases.

The CPU 1706 mainly performs operations related to operation control of the image display apparatus, generation, selection, and editing of a display image.

For example, a control signal is output to the multiplexer 1703, and image signals to be displayed on the display panel are appropriately selected or combined. In that case, the display panel controller 1
A control signal is generated for the display device 702 to appropriately control the operation of the display device such as the screen display frequency, the scanning method (for example, interlaced or non-interlaced), and the number of scanning lines on one screen. In addition, image data, character / graphic information is directly output to the image generation circuit 1707, or an external computer or memory is accessed via the input / output interface circuit 1705 to access image data, character / graphic information, or the like.
Enter graphic information.

It should be noted that the CPU 1706 may be involved in work for other purposes. For example, it may directly relate to a function of generating and processing information, such as a personal computer or a word processor. Alternatively, as described above, the input / output interface circuit 1705
The computer may be connected to an external computer network via a computer, and work such as numerical calculation may be jointly performed as an external device.

The input unit 1714 is for the user to input commands, programs, data, and the like to the CPU 1706. For example, in addition to a keyboard and a mouse,
Various input devices such as a joystick, a barcode reader, and a voice recognition device can be used.

The decoder 1704 is provided by
This is a circuit for inversely converting various image signals input from 13 into three primary color signals or a luminance signal and an I signal and a Q signal. As shown by the dotted line in FIG.
Preferably has an image memory inside. This is for handling a television signal that requires an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of a still image. Alternatively, the image generation circuit 17
07 and the CPU 1706, there is obtained an advantage that image processing and editing including thinning, complementing, enlarging, reducing, and synthesizing images are facilitated.

The multiplexer 1703 is connected to the CPU 1
A display image is appropriately selected based on a control signal input from 706. That is, the multiplexer 1703
Selects a desired image signal from the inversely converted image signals input from the decoder 1704 and selects a driving circuit 1701
Output to In that case, by switching and selecting an image signal within one screen display time, it is also possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. .

Display panel controller 1702
Is a circuit for controlling the operation of the drive circuit 1701 based on a control signal input from the CPU 1706.

As a signal related to the basic operation of the display panel, for example, a signal for controlling an operation sequence of a drive power source (not shown) for the display panel is output to the drive circuit 1701. As a method related to the display panel driving method, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlaced or non-interlaced) is output to the driving circuit 1701. In some cases, a control signal related to image quality adjustment such as luminance, contrast, color tone, and sharpness of a display image may be output to the driving circuit 1701.

A drive circuit 1701 is a circuit for generating a drive signal to be applied to the display panel 1700, and is based on an image signal input from the multiplexer 1703 and a control signal input from the display panel controller 1702. It works.

The function of each section has been described above. With the configuration illustrated in FIG. 14, in the present image forming apparatus, image information input from various image information sources can be displayed on the display panel 1700. is there. That is, various image signals such as television broadcasts are inversely converted by the decoder 1704 and then converted by the multiplexer 1.
At 703, it is appropriately selected and input to the driving circuit 1701. On the other hand, the display controller 1702
A control signal for controlling operation of the driving circuit 1701 is generated in accordance with an image signal to be displayed. Drive circuit 1701
Applies a drive signal to the display panel 1700 based on the image signal and the control signal. Thus, an image is displayed on display panel 1700. These series of operations are totally controlled by the CPU 1706.

In the present image forming apparatus, an image memory built in the decoder 1704 and an image generation circuit 170
7 and information selected from the information, as well as image information to be displayed, such as enlargement, reduction, rotation, movement, edge enhancement, thinning, complementing, color conversion, image aspect ratio conversion, etc. Initial image processing, compositing, erasing,
It is also possible to perform image editing including connection, replacement, fitting, and the like. As with the image processing and image editing, a dedicated circuit for processing and editing audio information may be provided.

Therefore, the present image forming apparatus can be used as a television broadcast display device, a video conference terminal device, an image editing device that handles still images and moving images, a computer terminal device,
It can be equipped with the functions of a word processor and other office terminal equipment, game consoles, and the like, and has a very wide range of applications for industrial or consumer use.

FIG. 14 shows only an example of the configuration of an image forming apparatus using a display panel in which an electron-emitting device is used as an electron beam source. It goes without saying that it is not limited.

For example, of the components shown in FIG. 14, circuits relating to functions that are unnecessary for the purpose of use may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present image display device is applied as a videophone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present image forming apparatus, since the electron-emitting device is used as the electron source, the display panel can be easily made thin, so that the depth of the image forming apparatus can be reduced. In addition, a display panel using an electron-emitting device as an electron beam source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics, so that the image forming apparatus is capable of realizing a realistic and powerful image. It is possible to display with good visibility. Further, by using an electron source that realizes stable and highly efficient electron emission characteristics, a long-life, bright, high-quality color flat television can be realized.

[0160]

[Example 1] As a first example of the present invention, a flat surface conduction electron-emitting device shown in FIG. 1 was manufactured by the following steps.

(1) A quartz substrate was used as the substrate 1, and after sufficiently washing the substrate with an organic solvent, device electrodes 2 and 3 made of Ni were formed by a general vacuum film forming technique and a photolithography technique. The distance L between these device electrodes
Is 10 μm, the length W is 600 μm, and the thickness d is 100 nm.
And

(2) A Cr film was formed to a thickness of 50 nm by a vacuum evaporation method.
And an opening corresponding to the pattern of the conductive film 4 is formed by a photolithography technique, and an organic palladium-containing solution (“ccp-423” manufactured by Okuno Pharmaceutical Co., Ltd.)
0 ") was applied by a spinner and subjected to a heat treatment at 300 ° C. for 10 minutes to form a fine particle film composed of fine particles of palladium oxide (PdO). The Cr film was wet-etched and lifted off to form a conductive film 4 having a desired pattern.

[0163] (3) After the device schematically placed in a vacuum chamber 55 in shown in FIG. 5, to evacuate the vessel below 1.3 × 10 ^-3 Pa, the pulse width between the device electrodes T ₁ = 1mse
c, a triangular wave having a pulse interval T ₂ = 10 msec, a voltage having a peak value of 4 V is applied, a mixed gas of N ₂ : 98%, H ₂ : 2% is introduced, and a pulse voltage is applied for 10 minutes, and the conductive film is applied. 4 was performed.

(4) When the element resistance after the above-mentioned forming treatment was measured, it showed 12 Ω which was smaller by one digit or more than that before the forming (850 Ω), and the conductive film 4 was reduced to metal to form an electron emitting portion. No forming failure was found.

(5) Oxygen gas was introduced into the vacuum chamber, and the forming failure element was heated to 350 ° C. and held for 10 minutes to perform an oxidation treatment. By this processing, the element resistance becomes 880Ω, and PdO before forming processing is performed.
It was confirmed that the state had returned to.

(6) Reforming was performed in exactly the same manner as in (3) except that the peak value was changed to 6V.

(7) The element resistance was measured and found to be 1 MΩ
From the above, it was confirmed that the forming was successfully performed.

(8) Next, an activation treatment was performed. After the inside of the vacuum vessel is once evacuated to 1 × 10 ⁻⁵ Pa, benzonitrile vapor is introduced, the pressure is set to 1 × 10 ⁻⁴ Pa,
Peak value 15V, pulse width 1msec, pulse interval 10m
A voltage of sec was applied between the device electrodes. Pulse application 3
After 0 minutes, the pulse application was stopped to terminate the activation process.

Next, while the inside of the vacuum vessel was evacuated, the vacuum vessel and the electron-emitting device were kept at 200 ° C. for 10 hours, and then returned to room temperature. As a result, the pressure became about 1.3 × 10 ⁻⁶ P. . This processing completed the stabilization processing.

The characteristics of the electron-emitting device obtained by the above manufacturing process were evaluated using the apparatus shown in FIG.
Emission current _Ie = 2.0 μA, device current _If = 1.0 mA
And it was confirmed that good electron emission characteristics were exhibited.

[Comparative Example 1] (1) to (1) of Example 1 above
After performing the same process as in (3), the same activation process and stabilization process as in Example 1 were performed, and the electron emission characteristics of the obtained device were measured. However, it was confirmed that a defect occurred due to a forming defect.

Reference Example 1 The steps (1) to (3) were carried out in the same manner as in the step (3) of the above-mentioned embodiment 1, except that the peak value of the pulse voltage was changed to 6 V.
The same activation processing and stabilization processing as described above were performed. When the electron emission characteristics of the obtained device were measured, the same characteristics as those of the device of Example 1 were obtained.

From the results of Example 1, Comparative Example 1, and Reference Example 1, by repairing and reforming the conductive film by the oxidizing process according to the present invention, the same good electron emission characteristics as usual can be obtained. It turned out that the element shown was obtained.

[Embodiment 2] After performing the same steps as in (1) to (5) of the embodiment 1 to oxidize the element in which the forming defect was confirmed, the step (6) was repeated until the peak value was 5. 5V,
Pulse width T ₁ = ₂ msec, pulse interval T ₂ = 5 msec
c. After that, since the element resistance became 1 MΩ or more, the re-forming step was terminated, and the same activation and stabilization as in Example 1 were performed. When the electron emission characteristics of the obtained device were evaluated, the emission current _Ie = 2.0 μm
A, showing a device current _If = 1.0 mA, it was confirmed that good electron emission characteristics were exhibited.

[Embodiment 3] In this embodiment, an electron source (m = 100, n = 300) as shown in FIG. 7 in which a large number of planar surface conduction electron-emitting devices of FIG. 1 are arranged in a simple matrix. And an image forming apparatus.

The forming process of the electron source according to this embodiment will be described. The forming process is performed as shown in FIG.
The measurement was performed using the apparatus shown in FIG. The specific forming conditions include a pulse width T ₁ as a waveform applied to each line.
= 1 msec, pulse interval T ₂ = 300 msec, peak value = 7 V, and a forming process is performed by introducing a mixed gas of N ₂ : 98% and H ₂ : 2% while applying a forming voltage to each line. Was done.

When the combined resistance of the elements in each line after the forming was measured, it was confirmed that the combined resistance was larger than the initial combined resistance in most of the lines, and that good forming was performed. It was confirmed that the resistance value of only two lines was lower by about one digit than the initial value, and almost no electron-emitting portions were formed in the elements in that line, and a forming failure line occurred. This is because, in the line, there was an element having a low initial resistance, so that a sufficient voltage was not applied to the entire line, and the element was reduced without forming an electron emitting portion in the conductive film of most elements in the line. It seems to be.

Since a forming failure line has occurred,
The electron source substrate was heated to 300 ° C., oxygen was introduced, the mixture was allowed to stand for 1 hour, the temperature was again lowered to room temperature, and the resistance of the forming failure line was measured in vacuum. That is, it was confirmed that the oxidation treatment was successfully performed.

Next, while applying a rectangular wave having a pulse width of 1 msec, a pulse interval of 10 msec and a peak value of 8 V only to the above-mentioned forming failure line, N ₂ : 98%, H
₂ : Reforming was performed by introducing a 2% mixed gas. As a result, the resistance of the line became sufficiently large, and it was confirmed that the electron emission portion was formed.

The same activation and stabilization treatments as in Example 1 were performed on the electron source substrate, and the electron emission characteristics of each device were evaluated. It turned out to be obtained. As described in the above embodiment, the same effects can be obtained even after the above-described forming step in a state where the envelope is formed, and a good image forming apparatus can be manufactured.

[0181]

As described above, according to the present invention,
Since a defective element generated in the forming step can be easily repaired, the yield in the forming step can be improved, and an electron source including a plurality of the electron-emitting devices and an image forming apparatus including the electron source as a constituent member Also in the apparatus, it can be provided at low cost by improving the production yield.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a planar type surface conduction electron-emitting device which is an embodiment of the electron-emitting device of the present invention.

FIG. 2 is a schematic configuration diagram showing a vertical surface conduction electron-emitting device which is an embodiment of the electron-emitting device of the present invention.

FIG. 3 is a diagram showing a method of manufacturing the electron-emitting device shown in FIG.

FIG. 4 is a diagram illustrating an example of a forming waveform.

FIG. 5 is a schematic configuration diagram illustrating an example of a vacuum processing apparatus according to the present invention.

FIG. 6 is a graph showing emission current-device voltage characteristics (IV characteristics) of the electron-emitting device of the present invention.

FIG. 7 is a schematic configuration diagram showing an electron source having a simple matrix arrangement according to an embodiment of the electron source of the present invention.

FIG. 8 is a schematic configuration diagram of a display panel used in an embodiment of the image forming apparatus of the present invention using an electron source having a simple matrix arrangement.

FIG. 9 is a diagram showing a fluorescent film in the display panel shown in FIG.

FIG. 10 is a diagram showing an example of a drive circuit for driving the display panel shown in FIG.

FIG. 11 is a schematic configuration diagram showing a ladder-shaped electron source according to an embodiment of the electron source of the present invention.

FIG. 12 is a schematic configuration diagram of a display panel used in an embodiment of an image forming apparatus of the present invention using a ladder-shaped electron source.

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

FIG. 14 is a schematic configuration diagram illustrating a conventional planar surface conduction electron-emitting device.

FIG. 15 is a flowchart of an oxidation treatment step and a reforming step according to the present invention.

FIG. 16 is a schematic view of a forming apparatus in the method for manufacturing an electron source according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive film 5 Electron emission part 21 Step formation part 50 Ammeter 51 Power supply 52 Ammeter 53 High voltage power supply 54 Anode electrode 55 Vacuum container 56 Exhaust pump 71 Electron source board 72 X direction wiring 73 Y direction Wiring 74 Surface conduction electron-emitting device 75 Connection 81 Rear plate 82 Support frame 83 Glass substrate 84 Phosphor film 85 Metal back 86 Face plate 87 High voltage terminal 88 Enclosure 91 Black conductive material 92 Phosphor 101 Image display panel 102 Scanning circuit 103 Control Circuit 104 Shift Register 105 Line Memory 106 Synchronization Signal Separation Circuit 107 Modulation Signal Generator 110 Electron Source Board 111 Electron Emitting Element 112 Common Wiring 120 Grid Electrode 121 Opening 161 Forming Voltage Source 162 Line Selector 163 Ammeter 164 Control unit 165 Electron source board 1700 Display panel 1701 Drive circuit 1702 Display controller 1703 Multiplexer 1704 Decoder 1705 Input / output interface circuit 1706 CPU 1707 Image generation circuit 1708-1710 Image memory interface circuit 1711 Image input interface circuit 1712, 1713 TV signal receiving circuit 1714 Input section

Claims (17)

[Claims] A pair of device electrodes formed on a substrate; a conductive film electrically connected to each of the device electrodes;
A method for manufacturing an electron-emitting device having an electron-emitting portion formed on a part of the conductive film, wherein a conductive film made of a metal oxide is formed to connect a pair of device electrodes formed on a substrate. Forming an electron emitting portion by applying a voltage between the device electrodes in an atmosphere containing a substance that promotes reduction of the metal oxide, and measuring a resistance between the device electrodes. A step of detecting whether or not the formation of the electron-emitting portion is good or bad; a step of oxidizing a conductive film of the element whose formation of the electron-emitting portion is determined to be defective in the detecting step; and a step of oxidizing the conductive film. A reforming step of applying a voltage between the device electrodes to form an electron-emitting portion in an atmosphere containing a substance that promotes reduction of the metal oxide constituting the electrode. Method of manufacturing the emission device. 2. The method according to claim 1, wherein the oxidizing step is a step of exposing the conductive film to an oxidizing atmosphere while maintaining the temperature at a high temperature.
A method for manufacturing the electron-emitting device according to the above. 3. The pulse voltage applied between the device electrodes in the first forming step and the re-forming step is a pulse voltage, and the conditions of the applied pulse voltage are different in the first forming step and the re-forming step. A method for manufacturing the electron-emitting device according to the above. 4. The method of manufacturing an electron-emitting device according to claim 3, wherein the peak value of the pulse voltage applied in the re-forming step is larger than the peak value of the pulse voltage in the first forming step. 5. The method for manufacturing an electron-emitting device according to claim 3, wherein the pulse width of the pulse voltage applied in the re-forming step is wider than the pulse width of the pulse voltage in the first forming step. 6. A pair of device electrodes formed on a substrate, a conductive film electrically connected to each of the device electrodes,
An electron-emitting device having an electron-emitting portion formed on a part of the conductive film, and manufactured by the manufacturing method according to claim 1. 7. The electron-emitting device according to claim 6, wherein said device electrodes are planar devices arranged on the same plane. 8. The electron-emitting device according to claim 6, wherein said device electrode is a vertical device in which a conductive film is provided on a side surface of said insulating layer, said device electrode being located vertically above and below an insulating layer. 9. The electron-emitting device according to claim 6, wherein said electron-emitting device is a surface conduction electron-emitting device. 10. A device having at least one element row in which a plurality of the electron-emitting devices according to claim 6 are arranged in parallel and connected, and a wiring for driving each element is in a ladder shape. An electron source characterized by being arranged. 11. A device having at least one element row in which a plurality of the electron-emitting devices according to claim 6 are arranged, and wirings for driving the elements are arranged in a matrix. An electron source characterized by the following. 12. An image forming apparatus comprising: the electron source according to claim 10; an image forming member; and a control electrode for controlling an electron beam emitted from each element according to an information signal. 13. An image forming apparatus, comprising: the electron source according to claim 11; and an image forming member. 14. A method for manufacturing an electron source, comprising: forming a plurality of electron-emitting devices on the same substrate by the method according to claim 1. 15. The electron source has a plurality of element rows in which a plurality of elements are arranged in one row, and a pulse voltage is applied in the forming step by one pulse for each element row. 15. The method for manufacturing an electron source according to claim 14, wherein the forming process is simultaneously performed on all target element rows by repeating a step of sequentially scanning a plurality of element rows by switching element rows to be applied for each pulse. 16. An electron source obtained by the method according to claim 14 or 15, wherein a control electrode for controlling an electron beam emitted from the electron source, and an image formed by irradiation of the electron beam from the electron source. A method for manufacturing an image forming apparatus, wherein the method is combined with an image forming member to be formed. 17. An image forming apparatus comprising: an electron source obtained by the method according to claim 14; and an image forming member that forms an image by irradiating an electron beam from the electron source. Production method.