JPH1055745A - Electron emission element and electron source provided therewith, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an electron emission part to be configured three- dimensionally and increase an electron emission area and an emission current without an element area by laminating an element electrode via each insulation layer on the element electrode and forming a pair of the electrodes. SOLUTION: Element electrodes 2 and 3 and element electrodes 7 and 8 laminated on the element electrodes 2 and 3 via each insulation layer 6 form a pair of electrodes. Electron emission parts 5a to 5c are formed respectively between the element electrodes 2 and 3, between the element electrodes 2 and 7, and between the element electrodes 3 and 8. When a driving method for simultaneous electron emission from the electron emission parts 5a to 5c is employed, the element electrodes 2 and 7 and the element electrodes 3 and 8 are connected and driven respectively to common wires. When it is applied to a color display, electron emission parts with their different luminescence efficiency of three colors of R, G, and B are employed. Thus, an electron emission area is increased without increasing the element area by forming the electron emission part three-dimensionally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Heretofore, two types of electron-emitting devices, a thermionic electron-emitting device and a cold cathode electron-emitting device, are known. Field emission devices (hereinafter, referred to as cold cathode electron emission devices)
It is called "FE type". ), Metal / insulating layer / metal type (hereinafter, referred to as
It is called "MIM type". ) And surface conduction electron-emitting devices.

[0003] As an example of the FE type, W. P. Dyke
and W. W. Dolan, "Field Emis
zone ", Advance in Electron
Physics, 8, 89 (1956) or C.I.
A. Spindt, "Physical Proper
ties of thin-filmfield em
issue cathodes withmollyb
denum cones ", J. Appl. Phys.
s. , 47, 5248 (1976).

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

As an example of the surface conduction electron-emitting device,
M. I. Elinson, RadioEng. Elec
Tron 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 a SnO ₂ thin film by Elinson et al., And a device using an Au thin film [G. Dittmer: "ThinSolid
Films ", 9,317 (1972)] , In 2 O 3
/ SnO ₂ thin film [M. Hartwell a
nd C.I. G. FIG. Fonstad: “IEEE Tran
s. ED Conf. , 519 (1975)], and those based on carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported.

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

As a surface conduction electron-emitting device, apart from the above-mentioned structure, the present applicant has disclosed, for example, Japanese Patent Application Laid-Open No. Hei 7-2352.
As disclosed in Japanese Unexamined Patent Publication No. 55-55, there is a report of a configuration in which a conductive film including an electron emitting portion is formed of an appropriate material different from an element electrode for supplying a current to the conductive film. Among them, as a preferred example of a method for forming a conductive film, a method is disclosed in which an organic metal compound is applied, dried, heated and baked to thermally decompose and remove an organic component, thereby forming a metal or metal oxide. .

FIG. 16 schematically shows an example of the structure of the above element. FIG. 16A is a plan view, and FIG. 16B is a cross-sectional view. Reference numerals 2 and 3 in the drawing denote a pair of device electrodes formed separately from the conductive film 4.

Heretofore, in these surface conduction electron-emitting devices, it has been general that the electron-emitting portion 5 is formed on the conductive film 4 in advance by an energization process called energization forming before electron emission. That is, the energization forming means that a DC voltage or a very slowly increasing voltage (for example, about 1 V / min) is applied to both ends of the conductive film 4 (between the two element electrodes 2 and 3 in the case of having the element electrodes). This is a process in which the current is applied and the conductive film 4 is locally destroyed, deformed or deteriorated to change the structure, thereby forming the electron-emitting portion 5 in an electrically high-resistance state. Note that a crack is generated in a part of the conductive film 4 in the electron emitting portion 5, and electrons are emitted from the vicinity of the crack. The surface conduction type electron-emitting device that has been subjected to the energization forming process is configured to apply a voltage to the above-described conductive film 4 and cause a current to flow through the device, thereby causing the above-described electron-emitting portion 5 to emit electrons.

The above-described surface conduction electron-emitting device has a feature that its structure is simple and its manufacture is easy.
There is an advantage that a large number of elements can be arranged and formed over a large area.
Therefore, various applications for utilizing this feature are being studied. For example, it can be used for an image forming apparatus such as a charged beam source and a display device.

Conventionally, as an example in which a large number of surface conduction electron-emitting devices are arranged and arranged, surface conduction electron-emitting devices are arranged in parallel, and both ends of each surface conduction electron-emitting device are interconnected (also referred to as common interconnection). ) Are arranged in a large number of rows (also referred to as a ladder type 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).

[0014]

The electron-emitting devices used in the above-mentioned electron sources and image forming apparatuses have a large electron emission current so as to provide a bright and clear image.
It is desirable that the electron emission efficiency is high. Here, the electron emission current (Ie) refers to, for example, in the case of the above-mentioned surface conduction electron-emitting device, a current emitted into a vacuum when a voltage is applied to both ends of the conductive film. The ratio of the electron emission current (Ie) to the device current (If) flowing through the film is called electron emission efficiency.

However, in the conventional surface conduction electron-emitting device, satisfactory electron emission characteristics are not always obtained, and a means for obtaining a larger electron emission current and a higher electron emission efficiency are required. It has been desired to develop a means to obtain it. Further, in the conventional surface conduction electron-emitting device, a part of the electrons emitted from the electron-emitting portion are trapped on the high potential side of the conductive film and cannot reach the anode electrode, and the electron emission current and the electron emission efficiency Was one of the causes of the decline. Also, the trajectory of the emitted electrons is displaced and does not hit the correct position of the phosphor, which may cause a decrease in luminance or color mixing.

An object of the present invention is to provide an electron-emitting device capable of improving the electron emission current and the electron emission efficiency and correcting the trajectory of the emitted electrons. Another object of the present invention is to provide an image forming apparatus that can realize a bright and clear display image by using a plurality of such electron-emitting devices.

[0017]

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

That is, a first aspect of the present invention is that a first electrode and a second electrode formed on a base are opposed to each other, and a first electrode and a second electrode are laminated on each other with an insulating layer interposed therebetween. Having a third electrode and a fourth electrode, between the first electrode and the second electrode, between the first electrode and the third electrode, and between the second electrode and the fourth electrode. An electron-emitting device is characterized in that an electron-emitting portion is formed between them.

The first electron-emitting device of the present invention further has a feature that "the first electrode and the fourth electrode, and the second electrode and the third electrode are supplied with the same potential, respectively. And "the first to fourth electrodes are each given an independent potential".

A second aspect of the present invention is that a first electrode and a second electrode formed on a substrate are opposed to each other, and a first electrode and a second electrode are laminated on each other with an insulating layer interposed therebetween. A third electrode and a fourth electrode, wherein an electron emission portion is formed between the first electrode and the second electrode, and between the first electrode and the third electrode, An electron-emitting device is characterized in that the second electrode and the fourth electrode are insulated from each other.

The second electron-emitting device according to the second aspect of the present invention is further characterized in that the fourth electrode is an electric field correction electrode to which a potential independent of the first to third electrodes is applied. "The fourth electrode is given a higher potential than the potentials given to the first to third electrodes", and "The second electrode and the third electrode are given the same potential. "The second electrode and the third electrode include:
A higher potential than the potential applied to the first electrode is applied. "

According to a third aspect of the present invention, there is provided an electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting device is the electron-emitting device according to the first or second invention. An electron source characterized by the following.

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

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

The fourth image forming apparatus of the present invention further has a feature that "in the electron source used in the image forming apparatus, two to three electrodes formed by the first to fourth electrodes are used. A part of the set of electron emitting units is set as a normal electron emitting unit, and the other is set as a spare electron emitting unit. The normal electron emitting unit is set to a spare driving circuit by a normal driving circuit. And a control device that operates the spare driving circuit so that the corresponding spare electron emitting unit emits electrons when the normal electron emitting unit does not normally emit electrons ''. Is also included.

According to the first electron-emitting device of the present invention, the device electrode is further formed on the conventional device electrode via the insulating layer, and the electron-emitting portion is also formed in the three-dimensional direction.
The electron emission area can be increased without increasing the element area (pixel pitch in an image forming apparatus to which the present invention is applied), and a larger electron emission current can be obtained.

According to the second electron-emitting device of the present invention, in addition to the above-mentioned effects, by applying an appropriate voltage to the fourth electrode, the electron-emitting efficiency can be improved, and the electrons can be emitted by the fluorescent light. It is also possible to modify the trajectory of the electrons so as to irradiate the correct position on the body, thereby preventing a decrease in luminance and color mixing.

[0028]

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

The electron-emitting device of the present invention is a surface conduction electron-emitting device classified as a cold cathode type electron-emitting device as described above.

FIG. 1 is a schematic view showing an example of the first surface conduction electron-emitting device of the present invention. FIG. 1 (a) is a longitudinal sectional view and FIG. 1 (b) is a plan view. In FIG. 1, reference numeral 1 denotes a base, 4 denotes a conductive film, 5a to 5c denote electron emitting portions, and 6 denotes an insulating layer. 2, 3, 7, and 8 are device electrodes, and the device electrodes 7, 8 are stacked on the device electrodes 2, 3 with an insulating layer 6 interposed therebetween. 2 is the first electrode, 3 is the second electrode, 7 is the third electrode
Electrode 8 corresponds to the fourth electrode.

In FIG. 1, the device electrodes 7 and 8 form a pair of electrodes with the device electrodes 2 and 3, respectively, and are provided between the device electrodes 2 and 3, the device electrodes 2 and 7, and the device electrodes 3 and 8. Electron emitting portions 5a to 5c are formed respectively.

In the surface conduction electron-emitting device shown in FIG.
When the driving method of simultaneously emitting electrons from the electron emitting portions 5a to 5c is adopted, the device electrodes 2 and 7 and the device electrodes 3 and 8 can be connected to a common wiring and driven, respectively, and the wiring is newly added. No need to provide. In the case of application to a color display or the like, the number of electron emitting portions of the three electron emitting portions 5a to 5c for emitting electrons is adjusted so as to compensate for the difference in luminous efficiency between the phosphors of the three colors R, G, and B. In the case where the electron emission amount is controlled by changing the number of electrons, each element electrode can be connected to a different wiring.

FIG. 2 is a schematic view showing another example of the surface conduction electron-emitting device of the present invention. In FIG. 2, the same components as those shown in FIG. 1 are the same. Reference numeral 8 ′ denotes a correction electrode, and the correction electrode 8 ′ is stacked on the element electrode 3 via the insulating layer 6. The correction electrode 8 'corresponds to a fourth electrode.

In FIG. 2, the device electrode 7 forms the device electrode 2 and a pair of electrodes, and the device electrodes 2 and 3 and the device electrode 2 are formed.
The electron emitting portions 5a and 5b are formed between the first and second portions, respectively. The correction electrode 8 'and the element electrode 3 are insulated.

In the surface conduction electron-emitting device shown in FIG. 2, the electron emission efficiency can be improved by applying an appropriate voltage to the correction electrode 8 '. In particular, it is preferable that the potential of the correction electrode 8 ′ is higher than the potentials of the element electrodes 3 and 7. The optimum value of the potential of the correction electrode 8 'is selected according to the distance between the electron-emitting portions 5a and 5b and the correction electrode 8', the distance between the electron-emitting portions 5a and 5b and the anode electrode, the potential of the anode electrode, and the like. Preferably, the potential is higher than the potential of the device electrodes 3 and 7 by about ten to several hundreds of volts. This makes it possible to pull electrons that have been absorbed into the element electrode up to the anode electrode, thereby improving electron emission efficiency.

When the potentials of the device electrodes 3 and 7 are higher than the potential of the device electrode 2 (the device electrodes 3 and 7 are used as anodes and the device electrode 2 is used as cathode), emitted electrons are emitted. Is more susceptible to the effect of the correction electrode 8 ', so that a greater effect can be obtained by improving the electron emission efficiency.

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

Device electrodes 2, 3, 7, 8 and correction electrode 8 '
As the material of the above, a general conductor material can be used, for example, Ni, Cr, Au, Mo, W, Pt, Ti,
Metals or alloys such as Al, Cu, Pd and Pd, Ag, A
u, RuO _2, Pd-Ag or the like metal or metal oxide and printed conductor composed of glass or the like, In ₂ O ₃ -SnO ₂
And the like and a semiconductor conductor material such as polysilicon.

As a material of the insulating layer 6, a general insulating material can be used, for example, SiO ₂ , SiN, PS
G or the like can be used. Element electrode intervals L1, L2,
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. Here, the element electrode interval L2 is equal to the film thickness of the insulating layer 6. Element electrode interval L
1, L2 can be preferably in the range of several hundred nm to several hundred μm, and more preferably in the range of several μm to several tens μm in consideration of the voltage applied between the device electrodes. Can be.

The length W of the device electrode can be in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics. Device electrodes 2, 3, 7, 8 and correction electrode 8 '
Can be in the range of several tens nm to several μm.

As a material for forming the conductive film 4, for example, Pd, Pt, Ru, Ag, Au, Ti, In, Cu,
Metals such as Cr, Fe, Zn, Sn, Ta, W, and Pb;
oxides such as dO, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , Y
Borides such as B ₄ and GdB ₄ , TiC, ZrC, HfC,
Carbides such as TaC, SiC and WC, TiN, ZrN,
Examples include nitrides such as HfN, semiconductors such as Si and Ge, and carbon.

As the conductive film 4, it is preferable to use a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The film thickness is determined by the step coverage of the device electrodes 2, 3, 7, 8 and the correction electrode 8 ', and the device electrodes 2, 3 and 2,
The resistance is set as appropriate in consideration of the resistance value between 7, 3 and 8, and the forming conditions described later.
And more preferably 10 ° to 5 °.
It is better to be within the range of 00 °. The resistance value is such that Rs is 1
The value is from 0 ² Ω / □ to 10 ⁷ Ω / □. Note that Rs is
Resistance R measured in the length direction of a thin film having a width w and a length 1
Is set as R = Rs (l / w). In the specification of the present application, the forming process will be described by taking an energizing process as an example, but the forming process is not limited to this, and includes a process of forming a crack in a film to form a high resistance state. It is.

The fine particle film described here is a film in which a plurality of fine particles are aggregated. The fine structure thereof is not limited to 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). Particles gather,
(Including the case where an island structure is formed as a whole). The particle size of the fine particles is in the range of several to several hundred nm, preferably in the range of 10 to 200.

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

Small particles are called "fine particles", and smaller ones are called "ultra fine particles". Particles smaller than "ultrafine particles" and having a few hundred atoms or less are widely called "clusters".

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

For example, in "Experimental Physics Course 14 Surface / Particles" (edited by Yoshio Kinoshita, published by Kyoritsu Shuppan, September 1, 1986), "when referred to as particles in this paper, the diameter is about 2-3 μm to 10 nm. And especially when it is referred to as ultrafine particles, the particle size is about 10 nm to 2-3 n.
It means up to about m. It is not exactly strict because both are collectively written as fine particles, but it is a rough guide. When the number of atoms constituting a particle is two to several tens to several hundreds, it is called a cluster. (Page 195, lines 22 to 26).

In addition, the definition of "ultra-fine particles" in the "Hayashi / Ultra-fine Particle Project" of the New Technology Development Corporation has the following lower limit of the particle size, and is as follows.

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

[0050] Based on the general notation as described above,
In the present specification, “fine particles” are an aggregate of a large number of atoms and molecules, and the lower limit of the particle size is several Å to 10 Å, and the upper limit is several μm.
It refers to the degree.

The electron-emitting portions 5a to 5c are constituted by high-resistance cracks formed in a part of the conductive film 4, and depend on the film thickness, film quality and material of the conductive film 4, and energization forming described later. It will be. In some cases, conductive fine particles having a particle size ranging from several Å to several hundreds of 存在 are present inside the electron-emitting portions 5 a to 5 c. The conductive fine particles contain some or all of the elements of the material constituting the conductive film 4. The electron emitting portions 5a to 5c and the conductive film 4 in the vicinity thereof may include carbon and a carbon compound.

Next, each method of manufacturing the electron-emitting device of the present invention will be described with reference to the device configuration diagram of FIG. 1 and the manufacturing process diagram of FIG. In FIG. 3, the same parts as those shown in FIG. 1 are denoted by the same reference numerals.

1) A conductive material and an insulating material are formed on the substrate 1 by a vacuum deposition method, a sputtering method, a printing method, or the like, and are formed by laminating a conductive layer 10 / an insulating layer 6 / a conductive layer 11 ( FIG. 3 (a).

2) An opening 12 is formed by removing a part of the conductive layer 10 / insulating layer 6 / conductive layer 11 by etching or lift-off (FIG. 3B).

3) The conductive film 4 is formed in the opening 12 (FIG. 3C). The conductive film 4 is formed by a method of forming a film by a vacuum evaporation method, a sputtering method, a chemical vapor deposition method, or a method of applying a solution containing an organometallic compound by a spin coating method, a dipping method, an inkjet method, or the like. It can be performed by such as.

As described above, the device electrodes 2 and 3
An insulating layer 6, element electrodes 7 and 8, and a conductive film 4 are formed.

4) Next, the electron emitting portions 5a to 5c are formed by forming (FIG. 3D). As an example of the method of the forming step, a method by an energization process will be described.
When a current is supplied from a power supply (not shown) between the device electrodes 2 and 3, the device electrodes 2 and 7, and the device electrodes 3 and 8, a portion of the conductive film 4 having a changed structure is formed. This portion constitutes the electron emission portions 5a to 5c. FIG. 4 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform.
For this purpose, the method shown in FIG. 4A for continuously applying a pulse with a constant pulse peak value and the method shown in FIG. 4B for applying a pulse while increasing the pulse peak value are used. is there.

First, the case where the pulse peak value is a constant voltage will be described with reference to FIG. T1 in FIG.
And T2 are the pulse width and pulse interval of the voltage waveform. Usually, T1 is 1 μsec to 10 msec, and T2 is 10 μsec to 100 msec.
It is set in the range of m seconds. The peak value (peak voltage) of the triangular wave is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens minutes. The pulse waveform is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted.

Next, a case where a voltage pulse is applied while increasing the pulse peak value will be described with reference to FIG.
T1 and T2 in FIG. 4B can be the same as those shown in FIG. 4A. The peak value of the triangular wave (peak voltage during energization forming) can be increased, for example, by about 0.1 V steps.

The end of the energization forming process can be detected by applying a voltage that does not locally destroy or deform the conductive film 4 during the pulse interval T2, and measuring the current. For example, a current flowing when a voltage of about 0.1 V is applied is measured, a resistance value is obtained, and when a resistance of 1 MΩ or more is indicated, the energization forming can be terminated.

When the surface conduction electron-emitting device shown in FIG. 2 is manufactured, the electron-emitting portions 5a and 5b are formed by forming between the device electrodes 2 and 3 and the device electrodes 2 and 7 in the forming step. Is formed, and a voltage higher than the forming voltage is applied between the element electrode 3 and the correction electrode 8 ′ to form a wide crack in the conductive film 4 to insulate the element electrode 3 and the correction electrode 8 ′. Let it.

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

The activation step can be performed, for example, by repeatedly applying a pulse in an atmosphere containing an organic substance gas in the same manner as in the energization forming. This atmosphere can be formed by using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump, or is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum. The preferred gas pressure of the organic substance at this time is different depending on the form of the above-described element, the shape of the vacuum vessel, the type of the organic substance, and the like.
It is set appropriately according to the case. Suitable organic materials include
Alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, carboxyls, organic acids such as sulfonic acids and the like can be mentioned. Is methane,
Saturated hydrocarbons represented by C _n H _{2n + 2} such as ethane and propane, unsaturated hydrocarbons represented by a composition formula such as C _n H _2n such as ethylene and propylene, benzene, toluene, methanol, ethanol, formaldehyde and acetaldehyde , Acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used. By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie change significantly.

The carbon and the carbon compound include, for example, graphite (so-called HOPG, PG, 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 a crystal having a crystal grain of about 2 nm and further disorder in the crystal structure. ), Amorphous carbon (refers to amorphous carbon and a mixture of amorphous carbon and the above-mentioned graphite microcrystals), and the film thickness is preferably within a range of 500 ° or less.
こ と が It is more preferable to set the following range.

The termination of the activation step can be appropriately determined while measuring the device current If and the emission current Ie during the activation process. The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.

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

In the activation step, when an oil diffusion pump or a rotary pump is used as an exhaust device and an organic gas derived from an oil component generated from the oil diffusion pump or the rotary pump 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 1.3 × 10 ⁻⁶ Pa or less, more preferably 1.3 × 10 ⁻⁸ Pa or less, at a partial pressure at which the carbon or carbon compound is not newly deposited. preferable. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. At this time, it is desirable to perform the treatment at a temperature as high as possible for as long as possible. The pressure inside the vacuum vessel needs to be as low as possible, and is 1.3 × 10 ^−5.
Pa or lower is preferable, and 1.3 × 10 ⁻⁶ Pa or lower is particularly preferable.

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

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

FIG. 5 is a schematic diagram 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. Also, 51 is a power supply for applying a device voltage Vf to the electron-emitting device, 50 is an ammeter for measuring a device current If flowing through the conductive film 4 between the device electrodes,
54, an anode electrode for capturing an emission current Ie emitted from the electron emission portion of the device; 53, an anode electrode 54;
Is a high-voltage power supply for applying a voltage, and 52 is an ammeter for measuring an emission current Ie emitted from the electron emission section. As an example, the voltage of the anode electrode 54 is 1 kV to 1 kV.
The measurement can be performed with the range of 0 kV and the distance H between the anode electrode 54 and the electron-emitting device in the range of 2 mm to 8 mm.

The vacuum vessel 55 is further provided with equipment necessary for measurement in a vacuum atmosphere, such as a vacuum gauge (not shown), so that measurement and evaluation in a desired vacuum atmosphere can be performed. . The exhaust pump 56 is composed of a normal high vacuum device system including a turbo pump and a dry pump, and an ultra high vacuum device system including an ion pump and the like.
The entire vacuum processing apparatus provided with the electron-emitting device base 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 Ie 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 element current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is apparent from FIG. 6, the surface conduction electron-emitting device of the present invention has the following three characteristic characteristics with respect to the emission current Ie.

First, the emission current Ie of the present device rapidly increases when a device voltage higher than a certain voltage (referred to as a threshold voltage; Vth in FIG. 6) is applied. On the other hand, when the device voltage is lower than the threshold voltage Vth, the emission current Ie is increased. Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

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

Thirdly, the amount of charge discharged to 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 surface conduction electron-emitting device of the present invention can easily control the electron emission characteristics according to the input signal. Using this property, an electron source composed of a plurality of electron-emitting devices,
It can be applied to various fields such as an image forming apparatus.

FIG. 6 shows an example in which the device current If monotonically increases with respect to the device voltage Vf (MI characteristic).
The element current If may exhibit a voltage-controlled negative resistance characteristic (VCNR characteristic) with respect to the element voltage Vf (not shown).
These properties can be controlled by controlling the steps described above.

An application example of the electron-emitting device of the present invention will be described below. By arranging a plurality of surface conduction electron-emitting devices of the present invention on a substrate, for example, an electron source or an image forming apparatus can be constructed.

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

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

Hereinafter, based on this principle, an electron source substrate obtained by arranging a plurality of electron-emitting devices to which the present invention can be applied will be described.

FIG. 7 is a schematic view of an electron source substrate using the surface conduction electron-emitting device shown in FIG.
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;
6, 77, 78 are connection lines.

The device electrodes constituting the surface conduction electron-emitting device 74 include m X-directional wires 72 and n Y-directional wires 7.
3. Connections 75, 76, 77, 7 made of conductive metal or the like
8 are electrically connected. The element electrode 2 is connected to a wiring 73 by a connection 75, the element electrode 3 is connected to a wiring 72 by a connection 76, and the element electrode 7 is connected to a wiring 72 by a connection 77.
In addition, the element electrode 8 is connected to a wiring 73 by a connection 78. In this configuration, the device electrodes 2 and 8 and the device electrodes 3 and 7 can share the wirings 72 and 73, respectively.

FIG. 8 is a schematic view of an electron source substrate using the surface conduction electron-emitting device shown in FIG. 2, and the same reference numerals as those shown in FIG. 7 are the same. 79 is a wiring for a correction electrode. The element electrode 2 is connected to the wiring 73 by a connection 75, the element electrode 3 is connected to the wiring 72 by a connection 76, the element electrode 7 is connected to the wiring 72 by a connection 77, and the correction electrode 8 ′ is connected to the correction electrode wiring 79 by a connection 79. I have.

The m X-direction wires 72 are Dx1, Dx2,
.., Dxm, and can be made of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness and width of the wiring are appropriately designed. .., Dyn, and the correction electrode wiring 79 is Dh1, Dh2,.
.., Dhn, which are formed in the same manner as the X-direction wiring 72. These m X-direction wirings 72
And an n-direction wiring 73 and a correction electrode wiring 79, an interlayer insulating layer (not shown) is provided between them to electrically separate them (m and n are both positive. Integer).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, it is formed in a desired shape on the entire surface or a part of the base 71 on which the X-directional wiring 72 is formed. In particular, the potential difference at the intersection of the X-directional wiring 72 and the Y-directional wiring 73 and the correction electrode wiring 79 is reduced. The film thickness, material, and manufacturing method are appropriately set so as to withstand. The X-direction wiring 72, the Y-direction wiring 73, and the correction electrode wiring 79 are led out as external terminals.

The materials forming the wirings 72, 73, and 79, the materials forming the connections 75, 76, 77, 78, and the materials forming the element electrodes have some or all of the same constituent elements. May also be different. These materials are appropriately selected, for example, from the above-described materials for the device electrodes. When the material forming the element electrode is the same as the wiring material, the wiring connected to the element electrode can also be called an element electrode.

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

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

An image forming apparatus constructed using such an electron source having a simple matrix arrangement will be described with reference to FIGS. 9, 10 and 11. FIG. 9 is a schematic diagram illustrating an example of a display panel of an image forming apparatus using the electron source of FIG. 7, and FIG. 10 is a schematic diagram of a fluorescent film used in the image forming apparatus of FIG. FIG. 11 is a block diagram illustrating an example of a drive circuit for performing display in accordance with an NTSC television signal.

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

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

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

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

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

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

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

The inside 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 above-described stabilization step. After setting the atmosphere with a vacuum degree of about 3 × 10 ⁻⁵ Pa and a sufficiently small amount of the organic substance, sealing is performed. In order to maintain the degree of vacuum after sealing the envelope 88,
Getter processing can also be performed. This is the envelope 88
Immediately before or after sealing, a getter (not shown) disposed at a predetermined position in the envelope 88 is heated by heating using resistance heating, high-frequency heating, or the like, to form a deposited film. Processing. The getter is usually composed mainly of Ba or the like.
It maintains a degree of vacuum of 10 ^{−3 to} 1.3 × 10 ⁻⁵ Pa or more. 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 driving circuit for performing television display based on NTSC television signals on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG. . In FIG.
101 is an image display panel, 102 is a scanning circuit, 103 is a control circuit, 104 is a shift register, 105 is a line memory, 106 is a synchronizing signal separation circuit, 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

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

The scanning circuit 102 will be described. The circuit includes m switching elements (S1 to S
m is schematically shown). Each switching element selects either the output voltage of the DC voltage power supply Vx or 0 [V] (ground level),
It is electrically connected to terminals Dx1 to Dxm of the display panel 101. Each of the switching elements S1 to Sm operates based on a control signal Tscan output from the control circuit 103, and can be configured by combining switching elements such as FETs, for example.

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

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

The synchronizing signal separating circuit 106 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separating (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 106 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. This DATA signal is output to the shift register 10
4 is input.

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

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

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

As described above, the electron-emitting device 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 Vth, and Vth
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. From this, when a pulse-like voltage is applied to this element, for example, when a voltage lower than the electron emission threshold voltage is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold voltage is applied, electrons are not emitted. A beam is output. At that time, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Further, by changing the pulse width Pw, it is possible to control the total amount of charges of the output electron beam.

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

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

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

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

In the image forming apparatus of the present invention which can take such a configuration, each of the electron-emitting devices is provided with an external terminal Dx.
By applying a voltage via 1 to Dxm and Dy1 to Dyn, electron emission occurs. A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal 87 to accelerate the electron beam. The accelerated electrons are
The light collides with the fluorescent film 84 and emits 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 are possible 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 a PAL, SECAM system, or other TV signal including a larger number of scanning lines (eg, a high-quality TV including the MUSE system). A method can also be adopted.

Next, the ladder type electron source of the present invention will be described.

FIG. 12 is a schematic view of an electron source substrate using the surface conduction electron-emitting device shown in FIG. In FIG. 12, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. Reference numeral 112 denotes common wirings D1 to D10 for connecting the electron-emitting devices 111, and these are drawn out as external terminals. 113, 114, 115, and 116 are connections.

Of the device electrodes constituting the surface conduction electron-emitting device 111, the device electrode 2 is connected to odd-numbered wires 112 (D 1, D 3,..., D (m−1)) by connection 113.
The element electrode 3 is connected to the even-numbered wiring 112 by the connection 114.
(D2, D4,... Dm), the element electrode 7 is connected to the even-numbered wiring 112 by the connection 115, and the element electrode 8 is connected to the connection 11
6 is connected to the odd-numbered wiring 112. In this configuration, the device electrodes 2 and 8 and the device electrodes 3 and 7 can share the wiring 112, respectively.

FIG. 13 is a schematic view of an electron source substrate using the surface conduction electron-emitting device shown in FIG. In FIG. 13, the same components as those shown in FIG. 12 are the same. 1
Reference numeral 17 denotes a wiring for a correction electrode. The element electrode 2 is connected 113
, D1, D3,..., D
(M-1), the element electrode 3 is connected to the even-numbered wiring 112 by the connection 114, the element electrode 7 is connected to the even-numbered wiring 112 (D2, D4,..., Dm) by the connection 115, and the correction electrode 8 'is The wiring 116 for the correction electrode is formed by the connection 116.
It is connected to the.

The electron-emitting device 111 is provided on the base 110.
A plurality are arranged in parallel in the X direction (this is called an element row). A plurality of the element rows are arranged to constitute an electron source. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to the element rows where the electron beam is to be emitted, and a voltage equal to or lower than the electron emission threshold is applied to the element rows where the electron beam is not desired to be emitted. The common wirings D2 to D (m-1) located between the element rows are, for example, D2 and D3, D4 and D5,..., D (m-2) and D (m-
1) and 1) may be formed as one and the same wiring.

FIG. 14 is a schematic view showing an example of a panel structure in an image forming apparatus provided with the ladder type electron source shown in FIG. 120 is a grid electrode, 121 is an opening for passing electrons, D1 to Dm are terminals outside the container,
G1 to Gn are external terminals connected to the grid electrode 120. Reference numeral 110 denotes an electron source substrate in which the common wiring between each element row is the same wiring. In FIG. 14, the same portions as those shown in FIGS. 9 and 12 are denoted by the same reference numerals as those shown in these drawings. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 9 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.

In FIG. 14, a grid electrode 120 is provided between the base 110 and the face plate 86. The grid electrode 120 is for modulating the electron beam emitted from the surface conduction electron-emitting device 111, and allows the electron beam to pass through a stripe-shaped electrode provided orthogonal to the ladder-type element row. Therefore, one circular opening 121 is provided for each element. The shape and arrangement position of the grid electrode are not limited to those shown in FIG. For example, a large number of passage openings may be provided in a mesh shape as openings, and a grid electrode may be provided around or near the surface conduction electron-emitting device.

The external terminals D1 to Dm and the external terminals G1 to Gn are electrically connected to a control circuit (not shown).

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

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

[0128]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to specific examples, but the present invention is not limited to these examples, and each element within a range in which the object of the present invention is achieved. And those in which the design has been replaced or changed.

Example 1 An electron-emitting device as shown in FIG. 1 was manufactured. Hereinafter, the manufacturing method in this embodiment will be described with reference to FIG.

A photoresist pattern for lift-off was formed on the blue plate glass substrate 1. Next, a Pt / Ti film having a thickness of 500 ° / 50 ° is formed by a sputtering method, and a 4 μm-thick Si film is formed thereon by a sputtering method.
After forming the O ₂ layer, a 500 ° / 50 ° thick P
A film of t / Ti was formed (FIG. 3A).

By removing the photoresist using an organic solvent to form the openings 12, the device electrodes 2, 3,
7, 8 and the insulating layer 6 were formed (FIG. 3B). The distance L1 between the device electrodes was 4 μm.

Organic palladium complex solution (CCP4230)
/ Okuno Pharmaceutical Co., Ltd.) by spin coating,
A conductive film composed of fine particles of palladium oxide is formed by performing a heat treatment at 0 ° C. for 20 minutes, and is patterned into a predetermined shape by dry etching using Ar gas.
Was formed (FIG. 3C).

Next, in a vacuum of 1.3 × 10 ⁻⁴ Pa, a voltage is simultaneously applied between the device electrodes 2 and 3, 2, 7, 3 and 8 to form an energization. , 2 and 7,
Electron emitting portions 5a to 5c were formed between 3 and 8, respectively (FIG. 3).
(D)). The voltage waveform of the energization forming is the waveform shown in FIG. 4B, the pulse width T1 is 0.1 msec, the pulse interval T2 is 25 msec, and the peak voltage is 0 to 15 V.
And

Subsequently, 10 to 10 element electrodes 2, 3, 2, 7, 3 and 8 were placed in an acetone atmosphere of 1.3 × 10 ⁻² Pa.
An activation process was performed by applying a voltage of 16V. The applied voltage pulse for activation was the same as the applied voltage pulse during forming.

After the electron-emitting device manufactured as described above was evacuated to a pressure of 1.3 × 10 ⁻⁵ Pa or less using the measurement system shown in FIG. 5, a driving voltage of 14 V and an anode voltage of 3
When the electron emission characteristics of the device were measured by applying kV,
Device current If = 2.6 mA, emission current Ie = 3.2 μA
And good electron emission characteristics were obtained. In forming, activating, and driving, the potentials of the device electrodes 2 and 8 were set to 0 V (ground level), and a predetermined voltage was applied to the device electrodes 3 and 7, respectively.

Example 2 Using the electron-emitting device of Example 1, an electron source substrate having matrix wiring and an image forming apparatus as shown in FIGS. 7 and 9 were manufactured.

A Pt paste was printed on a blue plate glass substrate by an offset printing method and baked under heating to form device electrodes 2 and 3 having a thickness of 500 °. Device electrode 2,
The distance L1 between the electrodes 3 was 30 μm.

The Ag paste was printed by a screen printing method and baked by heating to form the X-directional wiring 72, the connection 75, and the connection 76. Next, the device electrodes 2, 3
An insulating paste was printed on the upper portion and at the intersection of the X-directional wiring 72 and the Y-directional wiring 73 by a screen printing method, followed by heating and baking to form an insulating layer 6 having a thickness of 30 μm. The Pt paste is printed by the offset printing method, and is heated and baked, so that the device electrodes 7 and 8 having a thickness of 500
Was formed. The Ag paste was printed by a screen printing method and baked by heating to form the Y-direction wiring 73, the connection 77, and the connection 78. Further, the connection 75 and the Y-direction wiring 73 were connected.

A bubble jet type injector (BJ-10V manufactured by Canon Inc.) is used for the opening 12 (see FIG. 3).
An aqueous solution of a palladium acetate-ethanolamine complex was added dropwise, and a heat treatment was performed at 300 ° C. for 1 hour.
A conductive film 4 made of fine particles of palladium oxide was formed between 2, 7, 3 and 8.

After the electron source substrate 71 thus manufactured is fixed on the rear plate 81, a face plate 86 (a fluorescent film and a metal back are formed on the inner surface of a glass substrate) is formed 5 mm above the substrate 71. ) To support frame 82
And sealing was performed at 400 ° C. using frit glass. Note that a phosphor film in which three colors of RGB were arranged in a stripe shape was used.

After the inside of the produced glass container was evacuated by a vacuum pump through an exhaust pipe, a voltage of 0 to 17 V was applied between the device electrodes of the electron-emitting device through an external terminal of the container to perform forming, thereby forming an electron-emitting portion 5a. ~ 5c was formed.

Subsequently, a voltage of 10 to 18 V was applied in an acetone atmosphere of 1.3 × 10 ⁻² Pa to perform an activation treatment.

After the inside of the container was sufficiently evacuated and a getter treatment was performed to further maintain the degree of vacuum, the exhaust pipe was welded with a gas burner to seal the container, thereby producing an image forming apparatus.

In the image forming apparatus completed as described above, each electron-emitting device is connected to a terminal outside the container through a terminal.
When a voltage of V was applied and a voltage of 5 kV was applied to the metal back through the high voltage terminal 87, a high-luminance luminescent spot could be obtained on the face plate. When a television display was performed based on an NTSC television signal using a driving circuit as shown in FIG.
A bright and good image could be displayed on the entire surface. In forming, activating, and driving, the potentials of the device electrodes 2 and 8 are set to 0 through terminals outside the container.
V (ground level), a predetermined voltage was applied to each of the device electrodes 3 and 7.

Example 3 An electron-emitting device as shown in FIG. 2 was manufactured by the following steps.

In the same manner as in Example 1, the soda-lime glass substrate 1
A lift-off photoresist pattern was formed thereon. Next, using a sputtering method, a thickness of 500
A Pt / Ti film having a thickness of 0 ° was formed thereon, and a 5 μm-thick SiO ₂ layer was formed thereon by a sputtering method. Then, a Pt / Ti film having a thickness of 500 ° / 50 ° was formed in the same manner. By removing the photoresist using an organic solvent to form the opening 12, the element electrodes 2, 3, and 7, the correction electrode 8 ', and the insulating layer 6 were formed. The distance L1 between the device electrodes was 5 μm. Next, the conductive film 4 is formed in the same manner as in the first embodiment.
Was formed.

In a vacuum of 1.3 × 10 ⁻⁴ Pa, a voltage is simultaneously applied between the device electrodes 2, 3, 2, and 7 to perform energization forming, and electrons are applied between the device electrodes 2, 3, 2, and 7. Emission unit 5
Was formed. The voltage waveform of the energization forming is shown in FIG.
The pulse width T1 is 0.1 msec, the pulse interval T2 is 25 msec, and the peak voltage is 0 to 15
V. Further, a voltage of 20 V is applied between the device electrode 3 and the correction electrode 8 ′ to destroy the conductive film 4 between the device electrode 3 and the correction electrode 8 ′, thereby causing a gap between the device electrode 3 and the correction electrode 8 ′. Was insulated.

Subsequently, a voltage of 10 to 16 V was applied between the device electrodes 2, 3, 2, and 7 in an acetone atmosphere of 1.3 × 10 ^-2 Pa to perform an activation process. The applied voltage pulse for activation was the same as the applied voltage pulse during forming. In forming and activating, the device electrode 3
And 7 are set to 0V (ground level),
, A predetermined voltage was applied.

The electron-emitting device manufactured as described above was set in a measurement system similar to that shown in FIG. 5, and was evacuated to a vacuum of 1.3 × 10 ⁻⁵ Pa or less. The device was driven by applying 0 V to the device electrodes 3 and 7 and 14 V to the device electrode 2, and the electron emission characteristics of the device were measured at an anode voltage of 3 kV. When 100 V was applied to the correction electrode 8 ', the device current If = 1.
7A and an emission current Ie = 4.5 μA are obtained, and the electron emission efficiency is 2 compared to the case where no voltage is applied to the correction electrode 8 ′.
More than doubled.

Example 4 The same device as in Example 3 was installed in the same measurement system as in FIG. 5, and the pressure was evacuated to 1.3 × 10 ⁻⁵ Pa or less. The device is driven by applying 0 V to the device electrodes 3 and 7 and -14 V to the device electrode 2, and setting the anode voltage to 3 k
As V, the electron emission characteristics of the device were measured. Correction electrode 8 '
When 100 V is applied to the device, the device current If = 1.7
A, emission current Ie = 5.1 μA was obtained, and good electron emission efficiency was obtained.

(Embodiment 5) FIGS. 8 and 9 using the electron-emitting device of Embodiment 3 (however, the wiring for the correction electrode is not shown)
The electron source substrate and the image forming apparatus shown in FIG.

A Pt paste was printed on a blue plate glass substrate by an offset printing method, and heated and fired to form device electrodes 2 and 3 having a thickness of 500 °. Device electrode 2,
The distance L1 between the electrodes 3 was 30 μm.

The Ag paste was printed by a screen printing method and baked under heating to form the X-directional wiring 72, the connection 75, and the connection 76. Next, the device electrodes 2, 3
An insulating paste is printed by a screen printing method on an intersection of the X-direction wiring 72 and the Y-direction wiring 73 and an intersection of the X-direction wiring 72 and the correction electrode wiring 79, and is heated and baked to have a thickness of 30 μm. Layer 6 was formed. The Pt paste was printed by the offset printing method, and was heated and baked to form the device electrode 7 and the correction electrode 8 ′ each having a thickness of 500 ° on the insulating layer 6. The Ag paste is printed by a screen printing method and baked by heating, so that the Y-direction wiring 73, the correction electrode wiring 79, the connection 77, and the connection 78
Was formed, and the connection 75 and the Y-direction wiring 73 were connected.

A bubble jet type injector (BJ-10V manufactured by Canon Inc.) is used for the opening 12 (see FIG. 3).
In the same manner as in Example 2, a conductive film 4 made of fine particles of palladium oxide was formed.

After fixing the electron source substrate 71 thus manufactured on the rear plate 81, a face plate 86 (formed by forming a fluorescent film and a metal back on the inner surface of a glass substrate) 5 mm above the substrate. Was placed via a support frame 82, and sealing was performed at 400 ° C. using frit glass. Note that a phosphor film in which three colors of RGB were arranged in a stripe shape was used.

After the inside of the produced glass container was evacuated by a vacuum pump through an exhaust pipe, the glass container of Example 4 was passed through a terminal outside the container.
In the same manner as described above, 0 is applied between the device electrodes 2 and 3 and between the device electrodes 2 and 7.
Forming is performed by applying a voltage of ~ 17 V, and the electron emission portions 5a, 5a,
5b was formed. A voltage of 23 V is applied between the device electrode 3 and the correction electrode 8 ′ to break the conductive film 4 between the device electrode 3 and the correction electrode 8 ′ to insulate the device electrode 3 from the correction electrode 8 ′. Was.

Subsequently, a voltage of 10 to 18 V was applied between the device electrodes 2 and 3 and between the device electrodes 2 and 7 in an acetone atmosphere of 1.3 × 10 ⁻² Pa to perform an activation process.

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

In the image forming apparatus completed as described above, the device electrodes 3 and 7 are connected to the device electrodes 3 and 7 through terminals outside the container.
V, 0 V was applied to the element electrode 2 to drive the element, and 150 V was applied to the correction electrode 8 '. When a voltage of 4 kV was applied to the metal back through the high voltage terminal, a high-luminance luminescent spot was obtained on the face plate.
Further, using a driving circuit as shown in FIG.
When television display was performed based on the television signal of the system, a bright and good image could be displayed on the entire surface.

(Embodiment 6) This embodiment is directed to an electron source in which a large number of electron-emitting devices having the same structure as in Embodiment 1 are arranged.
The same matrix wiring as in Example 5 was connected to each electron-emitting device (however, the electrode 8 is not a correction electrode, but is used as the same device electrode as the other electrodes).
When the electron-emitting portions 5a and 5b formed between the electrodes 2 and 7 function normally, the electron-emitting portion 5c between the electrodes 3 and 8 does not emit electrons. When an abnormality occurs in the emission section 5a or 5b, the electron emission section 5c
The function is supplemented by emitting electrons from the.

The structure and manufacturing method of the electron source are the same as those described in the first and fifth embodiments. However,
In the fifth embodiment, the conductive film between the electrode 8 and the electrode 3 is destroyed, but this process is not performed, and the process of forming the electron-emitting portion 5c is performed as in the first embodiment.

The configuration of an image forming apparatus using this is shown in FIG.
1 is substantially the same as that shown in FIG. 1, but is partially modified in order to perform the driving described above. The changed part will be described with reference to FIG.

The display panel 101, the scanning circuit 102, and the modulation signal generator 107 are the same as those in FIG. The modulation signal generator 107 is connected to Y-direction wirings Dy1 to Dym in FIG. 8 via external terminals Doy1 to Doym.
Reference numeral 131 denotes a preliminary modulation signal generator, which is Dh1 to Dhn in FIG.
(However, in this embodiment, the wiring is not the correction electrode wiring, but the second Y-directional wiring), and the external terminals D'oy to D'oy are used.
n. 132 is a preliminary modulation signal control device.

The driving method is, for example, the X-direction wirings Dx1 to Dx1.
To the Dxm, a potential of +7.5 V is applied to the wiring of the selected row by the scanning circuit, and 0 V is applied to the other wirings. Y
In the direction wiring, a modulation signal generator 107
A pulse falling to 7.5 V is applied to each wiring with an appropriate pulse width according to the signal. Normally, 0 is applied to the second Y-direction wiring by the preliminary modulation signal generator 131.
A potential of V is applied. However, when the electron emission portion at the corresponding position is abnormal and sufficient electron emission cannot be obtained, the same voltage pulse as applied to the corresponding Y-direction wiring is applied by the preliminary modulation signal generator 131. You.
This is controlled by the preliminary modulation signal control device 132,
The pre-modulation signal generator 131 is driven so as to emit electrons from the corresponding electron emitting section 5c only when necessary based on the inspection performed in advance.

When a large-area, high-definition flat panel display is formed using an electron source as in the present invention, if any of a large number of electron-emitting devices has a defective element, the pixel in that portion is not considered. Is lost, and the quality of an image is remarkably deteriorated. Therefore, it is difficult to obtain an electron source that does not include a defective element, and the production yield is significantly reduced. Therefore, as in this embodiment, by providing a spare element for each pixel and compensating for any defective element,
The production yield is greatly improved. Further, in this embodiment,
As described above, since the electron-emitting devices are three-dimensionally arranged, even if the spare devices are arranged as described above, the electron-emitting devices can be arranged while maintaining a sufficiently small pitch, and high definition can be achieved. Can satisfy the requirements for

This effect can be obtained by using the electrode 8 as a correction electrode in the same manner as in the fifth embodiment and, for example, using the electron emission portion 5a as a normal electron emission portion and 5b as a spare electron emission portion. It can also be obtained by a driving method depending on the driving method.

[0167]

As described above, according to the present invention, the following effects can be obtained.

(1) According to the first electron-emitting device of the present invention, the device electrode is further formed on the conventional device electrode via the insulating layer, and the electron-emitting portion is also formed in the three-dimensional direction. The electron emission area can be increased without increasing the element area (pixel pitch in an image forming apparatus to which the present invention is applied), and a larger electron emission current can be obtained.

(2) In the case of employing a driving method in which electrons are simultaneously emitted from the electron emitting portions 5a to 5c, the first electrode and the fourth electrode, and the second electrode and the third electrode are commonly used. Driving can be performed by connecting to a wiring, and there is no need to newly provide a wiring.

(3) By connecting each element electrode to a different wiring, it is possible to change the number of electron-emitting portions for emitting electrons among the three electron-emitting portions 5a to 5c.
Therefore, when applied to a color display or the like, an image forming apparatus that can control the amount of electron emission so as to compensate for the difference in luminous efficiency between the phosphors of R, G, and B colors and has excellent luminance characteristics. Is realized.

(4) According to the second electron-emitting device of the present invention, in addition to the above-mentioned effect (1), by applying an appropriate voltage to the fourth electrode (electric field correction electrode), The current and the electron emission efficiency can be improved, and the trajectory of the electrons can be corrected so that the electrons are irradiated to the correct position of the phosphor. This can prevent a decrease in luminance and color mixing.

(5) In particular, by setting the potential of the fourth electrode to be higher than the potentials of the second electrode and the third electrode, more electrons that have been absorbed into the element electrode in the related art reach the anode electrode. Can be done. Further, the potentials of the second electrode and the third electrode are made higher than the potential of the first electrode (the second electrode and the third electrode are used as anodes, and the first electrode is used as a cathode). By setting the potential of the first electrode to be higher than the potentials of the second electrode and the third electrode, a greater effect can be obtained by improving the electron emission efficiency.

(6) Therefore, in an electron source / image forming apparatus constituted by using a plurality of electron-emitting devices of the present invention, a bright and clear display image can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view and a plan view schematically showing an example of a first electron-emitting device of the present invention.

FIG. 2 is a cross-sectional view schematically showing one example of the second electron-emitting device of the present invention.

FIG. 3 is a schematic view for explaining a method for manufacturing the electron-emitting device of FIG.

FIG. 4 is a schematic diagram showing an example of a voltage waveform in a current forming process that can be employed in manufacturing the electron-emitting device of the present invention.

FIG. 5 is a schematic diagram showing a measurement evaluation system for evaluating the electron emission characteristics of the electron-emitting device of the present invention.

FIG. 6 is a diagram showing the electron emission characteristics of the electron-emitting device of the present invention.

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

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

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

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

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

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

FIG. 13 is a schematic view showing another example of the ladder-type electron source of the present invention.

FIG. 14 is a schematic diagram illustrating an example of a display panel of the image forming apparatus of the present invention.

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

FIG. 16 is a schematic diagram showing another example of a conventional surface conduction electron-emitting device.

FIG. 17 is a block diagram illustrating a configuration of an image forming apparatus according to a sixth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base | substrate 2 1st electrode 3 2nd electrode 4 Conductive film 5, 5a-5c Electron emission part 6 Insulating layer 7 3rd electrode 8 4th electrode 8 'Electric field correction electrode 10, 11 Conductive layer 12 Opening 50 ammeter for measuring the device current If 51 power supply for applying the device voltage Vf to the electron-emitting device 52 ammeter for measuring the emission current Ie emitted from the electron-emitting portion 53 applying a voltage to the anode electrode A high-voltage power supply 54 Anode electrode 55 for capturing electrons emitted from the electron emission unit 55 Vacuum container 56 Exhaust pump 71 Electron source substrate 72 X-direction wiring 73 Y-direction wiring 74 Electron emission elements 75, 76, 77, 78 Connection 79 Wiring for correction electrode 81 Rear plate 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate 87 High voltage terminal 88 Outside Enclosure 91 Black conductive material 92 Phosphor 101 Display panel 102 Scanning circuit 103 Control circuit 104 Shift register 105 Line memory 106 Synchronous signal separation circuit 107 Modulation signal generator Vx, Va DC voltage source 110 Electron source substrate 111 Electron emitting element 112 Electron Common wiring for wiring emission elements 113, 114, 115, 116 Connection 117 Wiring for correction electrode 120 Grid electrode 121 Opening for electrons 131 Preliminary modulation signal generator 132 Preliminary modulation signal control device

Claims (13)

[Claims] A first electrode and a second electrode formed on the substrate facing each other, and a third electrode laminated on the first and second electrodes with an insulating layer interposed therebetween. A fourth electrode, wherein an electron emission portion is provided between the first electrode and the second electrode, between the first electrode and the third electrode, and between the second electrode and the fourth electrode. An electron-emitting device characterized by being formed. 2. The electron-emitting device according to claim 1, wherein the same potential is applied to each of the first and fourth electrodes and the second and third electrodes. . 3. The electron-emitting device according to claim 1, wherein an independent potential is applied to each of the first to fourth electrodes. 4. A first electrode and a second electrode formed on a substrate facing each other, and a third electrode laminated on the first electrode and the second electrode with an insulating layer interposed therebetween. A fourth electrode, wherein an electron emission portion is formed between the first electrode and the second electrode and between the first electrode and the third electrode; Wherein the electrodes are insulated from each other. 5. The electron-emitting device according to claim 4, wherein the fourth electrode is an electric field correction electrode to which a potential independent of the first to third electrodes is applied. 6. The electron-emitting device according to claim 5, wherein a potential higher than a potential applied to the first to third electrodes is applied to the fourth electrode. 7. The electron-emitting device according to claim 4, wherein the same potential is applied to the second electrode and the third electrode. 8. The method according to claim 4, wherein a potential higher than a potential applied to the first electrode is applied to the second electrode and the third electrode. Electron-emitting device. 9. An electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting devices are arranged in a plurality of groups.
9. An electron source, which is the electron-emitting device according to any one of 8. 10. The electron source according to claim 9, wherein the plurality of electron-emitting devices are wired in a matrix. 11. The electron source according to claim 9, wherein the plurality of electron-emitting devices are wired in a ladder shape. 12. An image forming apparatus comprising: an electron source in which a plurality of electron-emitting devices are arranged on a substrate; and an image forming member that forms an image by irradiating an electron beam emitted from the electron source. An image forming apparatus, wherein the source is the electron source according to claim 9. 13. An electron source used in the image forming apparatus, wherein a part of a set of two or three electron emitting portions formed by the first to fourth electrodes is used as a normal electron emitting portion. None, the rest as spare electron emitters, normal electron emitters are driven by normal drive circuits, spare electron emitters are driven by spare drive circuits, and normal electron emitters emit electrons normally. 13. The image forming apparatus according to claim 12, further comprising a control device that operates the spare driving circuit so that the corresponding spare electron emitting unit emits electrons when there is no electron emission unit.