JPH0969346A - Image display device and manufacture of it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an element from being deteriorated caused by heat transfer and radiation in using of a non-evaporating type getter. SOLUTION: A plate 204 constituting an electron source composed of a front conductive electron emitting element is constituted of a thin film 204 including an electron emitting part between facing electrodes 202, 203. A getter chamber is provided on the lower part of the plate 240 constituting the electron source composed of the front conductive electron emitting element, namely, on the opposite side to a face plate 208 constituting a phosphor 210. A thin film 242 constituted of Al metal or Al alloy and having heat insulating properties is formed on the back surface of the plate 240 constituting the electron source, namely, on the getter chamber side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display apparatus using a surface conduction electron-emitting device as an electron source and a method for manufacturing the apparatus, and more specifically, to a heat insulating plate or a thin film having heat insulating property in the apparatus. Arrangement and usage of getters.

[0002]

2. Description of the Related Art Conventionally, there are roughly two types of electron-emitting devices, and those using a thermoelectron-emitting device and a cold cathode electron-emitting device are known. The cold cathode electron-emitting device includes a field emission type (hereinafter referred to as “FE type”), metal / insulating layer /
There are a metal type (hereinafter referred to as “MIM type”), a surface conduction electron-emitting device, and the like. As an example of the FE type, W. P. Dy
ke & W. W. Dolan, "Field Emi
ssion ”, Advance in Electro
n Physics, 8, 89 (1956) or C.I. A. Spindt, "PHYSICAL Prop
erties of thin-film field
emission cathodes with mo
lybdenium cones ”, J. Appl. P
hys. , 47, 5248 (1976) and the like are known.

An example of the MIM type is C.I. A. Mea
d, "Operation of Tunnel-Em
"Ission Devices", J.Apply.P
hys. , 32, 646 (1961) and the like are known.

Examples of the surface conduction electron-emitting device type include:
M. I. Elinson, Radio Eng. Ele
ctron Phys. 10, 1290 (1965)
Etc. have been disclosed.

[0005] The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al. And a device using an Au thin film [G. Dittmer: "Thin Solid Fi
lms ”, 9 317 (1972)], In ₂ O ₃ / S
nO ₂ thin film [M. Hartwell and
C. G. Fonstad: "IEEE Trans.
ED Conf. , 519 (1975)], by carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1
No., p. 22 (1983)] and the like.

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.S. Figure 10 shows the Hartwell device configuration.
Is schematically shown in. In FIG. 1, reference numeral 1 denotes an insulating substrate.
Reference numeral 2 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering on an H-shaped pattern, and the electron emission portion 3 is formed by an energization process called energization forming described later. The element electrode interval L in the figure is 0.5 to 1 m.
m and W are set to 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 3 is previously subjected to an energization process called energization forming on the conductive thin film 2 before the electron emission.
It was common to form The energization forming means that a direct current voltage or a very slow rising voltage, for example, about 1 V / min is applied to both ends of the electroconductive thin film 2 to energize the electroconductive thin film 2 so that the electroconductive thin film is locally destroyed, deformed or altered to have an electrically high resistance. This is to form the electron emission portion 3 in such a state. The electron emitting portion 3 is a crack generated in a part of the conductive thin film 2, and electrons are emitted from the vicinity of the crack.
In the surface conduction electron-emitting device that has been subjected to the energization forming process, a voltage is applied to the conductive thin film 2 and a current is caused to flow through the device so that electrons are emitted from the electron-emitting portion 3. The surface conduction electron-emitting device described above has an advantage that a large number of devices can be arrayed over a large area because it has a simple structure and is easy to manufacture. Therefore, various applications that make use of this feature are being studied.

Examples include a charged beam source and a display device. As an example in which a large number of surface-conduction type electron-emitting devices are formed in an array, as will be described later, surface-conduction type electron-emitting devices are arranged in parallel, which is called a ladder arrangement, and both ends of each device are wired (also called common wiring). There is an electron source in which a large number of connected lines are arranged. (For example, JP-A-64-0
31332, JP-A-1-283749, JP-A-2-25
7552) In particular, in image forming apparatuses such as display devices, in recent years, flat panel display devices using liquid crystal have become popular in place of CRTs, but since they are not self-luminous, they must have a backlight, etc. Therefore, the development of a self-luminous display device has been desired. As the self-luminous display device, an electron source in which a large number of surface conduction electron-emitting devices are arranged,
An image forming apparatus that is a display device in which a phosphor that emits visible light is combined with electrons emitted from an electron source can be given. (For example, USP 5066883) FIGS. 8 and 9 are a cross-sectional view and a perspective view of an image display device as an example thereof. 8 and 9, 300
Reference numeral 301 denotes an exhaust pipe for exhausting the inside of the image display device (in the figure, a state after sealing is shown), 301 is a rear plate made of soda-lime glass that constitutes an electron-emitting device, 3
02 and 303 are electrodes installed at regular intervals, 30
4 is a thin film including an electron emitting portion provided between the electrodes 302 and 303, 306 is an electron passage hole, 307 is a grid, 3
Reference numeral 08 is a face plate made of soda-lime glass on which a metal back 309 and a phosphor 310 are formed, 311 is an outer frame, and 314 is a getter material container containing a getter material. The getter material container 314 is fixed to a getter material container fixing jig 313, and an evaporation type getter material for the purpose of maintaining a vacuum inside the panel is stored inside.
The evaporation type getter material is the face plate 3 outside the image forming area.
08 or the rear plate 301 is vapor-deposited.

Now, a method of manufacturing the image display device will be described with reference to FIGS. Exhaust pipe 30 in the airtight container
After being evacuated through 0 and degassing by baking, a part of the exhaust pipe is heated to melt and sealed (sealing). Finally, the getter material container 314 installed at one end inside the airtight container is heated, and the evaporation type getter material contained therein is vapor-deposited on the face plate 308 or the rear plate 301 to complete the image display device.

In general, a getter material container is a metal tube whose part is open, in which an evaporative getter material containing Ba as a main component is housed, and there are linear and ring-shaped getter materials. The evaporation type getter material is flashed by induction heating or electric heating to adhere the getter material to the image display device, and this adsorbs gas to maintain the vacuum in the panel.

As the getter material, in addition to the above-mentioned evaporation type, there is also a non-evaporation type in which a gas adsorbing ability is developed after being activated in a vacuum at a high temperature for a certain period of time.
Alloys and Zr-V-Fe alloys are known.

In order to realize a large-screen display device using the surface conduction electron-emitting device, the applicant of the present invention has shown that the internal space of the image display device, which has been evacuated, has an image display part, a vacuum exhaust and a vacuum maintaining part. There is also proposed an image display device and the like in which the substrate is divided by a substrate material on which an electron source and the like are formed (Japanese Patent Laid-Open No. 4-1 / 1992)
32147).

[0013]

However, the large screen image display device using the surface conduction electron-emitting device has the following problems. That is, when a non-evaporable getter material is used as the getter material (including the case where the getter material is used together with the evaporative getter material), radiant heat generated when activating the getter material in a vacuum at high temperature for a certain period of time, and fixing to support the non-evaporable getter The surface conduction electron-emitting device may be deteriorated due to heat conduction through the jig.

[0014]

In order to solve the above problems, the present inventor has conducted earnest studies and arrived at the present invention. That is, according to the present invention, an electron source including a surface conduction electron-emitting device having an electron emitting portion between opposing electrodes, a phosphor screen member that emits light by irradiation of an electron beam emitted from the electron source, and an internal vacuum are maintained. An image display device having at least a getter for achieving the above is provided with a heat insulating plate or a thin film having a heat insulating property provided in a space between the electron source and the getter. .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The feature of the present invention resides in that an electron source including a surface conduction electron-emitting device having an electron emitting portion between opposing electrodes and an electron beam emitted from the electron source are irradiated. In an image display device in which at least a phosphor screen member that emits light and a getter for maintaining an internal vacuum are installed, a heat insulating plate or a thin film having a heat insulating property is installed in a space between the electron source and the getter. .

Any composition can be used as the composition of the heat insulating plate or the thin film having a heat insulating property as long as it has a high heat reflectance, little degassing in a vacuum, good corrosion resistance, and a small specific gravity (that is, light weight). Al metals or Al alloys are preferred, although they can also be used. The heat-insulating thin film is formed on the back surface of the plate forming the electron-emitting device by a sputtering method or a vapor deposition method, but the forming method is not limited thereto.

The getter referred to in the present invention, that is, the getter to which the heat insulating plate or the thin film having the heat insulating property is to be set is mainly a non-evaporable getter, and the non-evaporable getter is a Zr-Al alloy, Zr-Fe alloy, Zr
-Ni alloy, Zr-Nb-Fe alloy, Zr-Ti-Fe
Examples thereof include alloys and Zr-V-Fe alloys. These may be used alone or a plurality of them may be arranged at a plurality of locations. Further, the use of these non-evaporable getters includes the case where they are used together with the evaporative getters. These alloys are usually formed into a plate shape and used as they are or fixed to a metal plate such as Cu (by spot welding or the like).
The thickness of the plate-shaped alloy is not particularly limited, but a range of 0.1 to 5 mm is preferable.

It is also a feature of the present invention to use laser light or infrared light to activate the non-evaporable getter. In order to activate the non-evaporable getter using laser light, laser light is usually scanned from the RP side made of a quartz glass substrate or the like. Examples of the laser include a CO ₂ laser which can obtain a relatively large output, but the laser is not limited to this. Also,
Conditions such as laser output and irradiation time are largely dependent on the type of non-evaporable getter (ie, activation temperature) and plate thickness (ie, amount). Therefore, the optimal activation conditions should be determined in advance. It is necessary. As an example, Zr
The standard of activation conditions when using a -V-Fe alloy (plate thickness: 1 mm) is shown below. Laser: CO ₂ laser Output: 20 kW Spot diameter: Approximately 10 mmφ (defocus mode) Scanning speed: 500 mm / min It is desirable that the laser light be defocused before use. When infrared rays are used to activate the non-evaporable getter, a general infrared lamp can be used as a light source of the infrared rays. In this case as well, it is necessary to determine the irradiation conditions of infrared rays in advance by experiments.

Further, in the image display device in which the plate constituting the electron source is the rear plate, that is, the getter chamber is not provided under the plate, a heat insulating plate is installed in a side surface space other than the image display portion, or Another feature of the present invention is that a thin film having a heat insulating property is formed on the surface of the spacer or the getter scattering prevention plate.

A further feature of the present invention is that in the image forming apparatus having a structure in which a getter chamber is provided in the lower portion of the plate forming the electron source, that is, in the space opposite to the face plate forming the phosphor. Install a heat insulating plate in the space between the plate that composes the source and the getter, or
The heat insulating thin film is formed on the back surface of the plate that constitutes the electron source.

By installing the above-mentioned heat insulating plate or a thin film having a heat insulating property, radiant heat generated when the non-evaporable getter is activated in a vacuum at a high temperature for a certain period of time, and a fixed treatment for supporting the non-evaporable getter. It is possible to suppress heat conduction through the tool. At the same time, since the radiant heat is reflected by the heat insulating plate or the thin film having heat insulating properties, the non-evaporable getter can be efficiently activated. Further, by activating the non-evaporable getter by a direct heating method using laser light, infrared rays or the like, the radiant heat and the heat conduction can be further suppressed.

As a result, when the non-evaporable getter is activated,
Since the surface conduction electron-emitting device portion can be maintained at a relatively low temperature, device characteristics can be maintained. Further, since the non-evaporable getter is activated more efficiently, it is possible to activate the non-evaporable getter at high temperature in a short time.

The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of the configuration of the present invention.
That is, in the image display device having the structure in which the getter chamber is provided in the space below the plate that constitutes the electron source composed of the surface conduction electron-emitting device, that is, in the space opposite to the face plate that constitutes the phosphor etc. This is an example in which the thin film is formed on the back surface of the plate that constitutes the electron source, and is based on the conventional example shown in FIG.

In FIG. 1, 200 is an exhaust pipe for exhausting the inside of the image display device (in the figure, the state after sealing is shown), 201 is a rear plate, and 240 is a blue constituting an electron-emitting device. Plate made of plate glass, 2
Reference numerals 02 and 203 denote electrodes installed at a fixed interval, 20
4 is a thin film including an electron emission portion provided between the electrodes 202 and 203, 206 is an electron passage hole, 207 is a grid, 2
Reference numeral 08 denotes a face plate made of soda-lime glass on which a metal back 209 and a phosphor 210 are formed, 211 denotes an outer frame, and 214 denotes an evaporation type getter material container containing an evaporation type getter material. Evaporative getter material container 214
Is fixed to the evaporation type getter material container fixing jig 213.

A metal plate 234 supports the non-evaporable getters 235 and 236, and these are fixed to the non-evaporable getter fixing jig 233. A thin film 242 having a heat insulating property is formed on the entire back surface of the plate 240 that constitutes the electron-emitting device. Further, reference numeral 241 is a communication hole in the upper and lower spaces, and the plate 240 and the thin film 2 having a heat insulating property.
It penetrates 41.

By adopting the heat insulating thin film having such a structure, radiant heat generated when the non-evaporable getters 235 and 236 are activated in a vacuum at a high temperature for a certain period of time, and a non-evaporable getter fixing treatment. Heat conduction via the tool 233 can be suppressed. At the same time, since the radiant heat is reflected by the heat insulating thin film 242, the non-evaporable getter can be efficiently activated. In addition, the non-evaporable getter 23
By using a direct heating method of irradiating laser light, infrared rays, or the like from the outside of the rear plate 201 for activating 5,236, the radiant heat and heat conduction can be further suppressed.

The basic structure of the surface conduction electron-emitting device to which the present invention can be applied is roughly classified into a planar type and a vertical type.

First, the plane type surface conduction electron-emitting device will be described. 11A and 11B are schematic views of a planar surface conduction electron-emitting device to which the present invention can be applied, where FIG. 11A is a plan view and FIG. 11B is a sectional view. In FIG. 11, $ 1 is a substrate, $ 2 and $ 3 are element electrodes, $ 4 is a conductive thin film, and $ 5 is an electron emitting portion.

The substrate $ 1 is made of quartz glass, glass having a reduced content of impurities such as Na, soda-lime glass, a soda-lime glass substrate laminated with a SiO ₂ layer formed by sputtering or the like, and a ceramic such as alumina and a Si substrate. Etc. can be used.

As a material for the opposing element electrodes $ 2 and $ 3, a general conductor material can be used. This is, for example, Ni, Cr, Au, Mo, W, Pt, Ti, Al,
Metals or alloys such as Cu, Pd and Pd, Ag, Au, R
Select appropriately from a printed conductor composed of a metal such as uO ₂ , Pd-Ag or the like and a metal oxide and glass, a transparent conductor such as In ₂ O ₃ -SnO ₂ and a semiconductor conductor material such as polysilicon. You can

The element electrode interval L, the element electrode length W, the shape of the conductive thin film $ 4, etc. are designed in consideration of the applied form. The element electrode spacing L can be preferably in the range of several thousand angstroms to several hundreds of micrometers, and more preferably several micrometers to several tens of micrometers in consideration of the voltage applied between the device electrodes. It can be a range.

The device electrode length W can be set in the range of several micrometers to several hundred micrometers in consideration of the resistance value of the electrodes and the electron emission characteristics. Element electrode $ 2,
A film thickness d of $ 3 can range from a few hundred Angstroms to a few micrometers.

In addition to the structure shown in FIG. 11, the conductive thin film $ 4, the opposing element electrodes $ 2, $ are provided on the substrate $ 1.
It is also possible to adopt a configuration in which the layers are laminated in the order of 3.

For the conductive thin film $ 4, it is preferable to use a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage to the element electrodes $ 2 and $ 3, the resistance value between the element electrodes $ 2 and $ 3, and the forming conditions described later, but usually from several angstroms. It is preferably in the range of several thousand angstroms, more preferably in the range of 10 angstroms to 500 angstroms. The resistance value is such that R _s is 10 ² to 10 ⁷ Ω
/ □ value. Note that R _s appears when the resistance R of a thin film having a thickness t, a width w, and a length l is R = R _s (l / w). In the specification of the present application, the forming process will be described by taking an energization process as an example, but the forming process is not limited to this, and includes a process of causing a crack in a film to form a high resistance state. Is.

The material forming the conductive thin film $ 4 is Pd,
Pt, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, Zn, Sn, Ta, W, Pb and other metals, PdO, S
nO ₂ , In₂ O_Three , PbO, Sb₂ O_Three Oxides such as
HfB₂ , ZrB₂ , LaB ₆ , CeB₆ , YB_Four , G
dB_Four Boride such as TiC, ZrC, HfC, TaC,
Carbides such as SiC, WC, TiN, ZrN, HfN, etc.
Suitable from nitrides, semiconductors such as Si and Ge, carbon, etc.
Selected.

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

The term "fine particles" is frequently used in this specification, and the meaning thereof will be described. Small particles are called "fine particles" and smaller ones are called "ultra fine particles". It is widely practiced to call a “cluster” smaller than “ultrafine particles” and having a few hundred atoms or less.

However, each boundary is not strict, and changes depending on what kind of property is considered and classified. 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.

"Experimental Physics Course 14 Surface / Particles"
(Koroshio Kinoshita, Kyoritsu Shuppan, published September 1, 1986)
Then, it is described as follows. "When we say fine particles in this paper, the diameter is about 2-3 μm to 10n.
The particle size is up to about m
It means from about nm to about 2 to 3 nm. It is not exactly strict because both are collectively written as fine particles, but it is a rough guide. When the number of atoms constituting a particle is from 2 to several tens to several hundreds, it is called a cluster. (Page 195, lines 22-26) In addition, the definition of “ultrafine particles” in the “Hayashi / Ultrafine particle project” of the New Technology Development Corporation has a smaller lower limit of particle size. It was a thing. "Creative Science and Technology Promotion System" Ultrafine Particle Project "(1981-198)
In 6), the particle size (diameter) is about 1 to 100 nm.
In the range of "ultra fine particles"
participant). Then, one ultrafine particle is an aggregate of about 100 to 10 ⁸ atoms. Ultra-fine particles are large to giant particles on an atomic scale. ("Ultra Fine Particles-Creative Science and Technology-" Hayashi Chikyu, Ryoji Ueda, Akira Tazaki, ed .; Mita Publishing 1988 2
Lines 1 to 4) "Things smaller than ultrafine particles,
In other words, a single particle composed of several to several hundred atoms is usually called a cluster. "
-13th line) Based on the above general term,
In the present specification, "fine particles" are aggregates of a large number of atoms and molecules, and the lower limit of the particle size is about several angstroms to about 10 angstroms, and the upper limit is about several μm.

The electron emitting portion $ 5 is composed of a high resistance crack formed in a part of the conductive thin film $ 4, and the film thickness, film quality and material of the conductive thin film $ 4 and a method such as energization forming described later. Etc. Conductive fine particles having a particle size in the range of several angstroms to several hundred angstroms may be present inside the electron emitting portion $ 5. The conductive fine particles contain some or all of the elements of the material forming the conductive thin film $ 4.
The electron emitting portion $ 5 and the conductive thin film $ 4 in the vicinity thereof may contain carbon or a carbon compound.

Next, the vertical surface conduction electron-emitting device will be described. FIG. 12 is a schematic view showing an example of a vertical surface conduction electron-emitting device to which the surface conduction electron-emitting device of the present invention can be applied.

In FIG. 12, the same parts as those shown in FIG. 11 are designated by the same reference numerals as those shown in FIG. $ 21 is a step forming part. The substrate $ 1, the element electrodes $ 2 and $ 3, the conductive thin film $ 4, and the electron emitting portion $ 5 are
It can be made of the same material as in the case of the planar surface conduction electron-emitting device described above. The step forming portion $ 21 is made of SiO ₂ formed by a vacuum deposition method, a printing method, a sputtering method, or the like.
Can be made of an insulating material such as. Step forming section $
The film thickness of 21 corresponds to the device electrode spacing L of the flat surface conduction electron-emitting device described above, and can be in the range of several thousand angstroms to several tens of micrometers. This film thickness is set in consideration of the manufacturing method of the step forming portion and the voltage applied between the device electrodes, but is preferably in the range of several hundred angstroms to several micrometers.

The conductive thin film $ 4 includes device electrodes $ 2 and $ 3.
After the step forming portion $ 21 is formed, it is laminated on the device electrodes $ 2 and $ 3. The electron emitting portion $ 5 is formed in the step forming portion $ 21 in FIG.
The shape and position are not limited to this, depending on the forming conditions and the like.

There are various methods for manufacturing the above-mentioned surface conduction electron-emitting device, and one example thereof is schematically shown in FIG.

An example of the manufacturing method will be described below with reference to FIGS. 11 and 13. Also in FIG. 13, the same parts as those shown in FIG. 11 are designated by the same reference numerals as those shown in FIG. 11.

1) The substrate $ 1 is thoroughly washed with a detergent, pure water, an organic solvent and the like, and after the element electrode material is deposited by the vacuum deposition method, the sputtering method or the like, the substrate $ 1 is formed by using, for example, the photolithography technique. Element electrodes $ 2 and $ 3 are formed on top (FIG. 13A).

2) Substrate $ 1 provided with element electrodes $ 2 and $ 3
Then, an organometallic solution is applied to form an organometallic thin film. As the organic metal solution, a solution of an organic metal compound containing a metal of the material of the conductive film $ 4 as a main element can be used. The organometallic thin film is heated and baked, lifted off,
Patterning is performed by etching or the like to form the conductive thin film $ 4 (FIG. 13B). Here, the method of applying the organic metal solution has been described, but the method of forming the conductive thin film $ 4 is not limited to this, and a vacuum deposition method, a sputtering method,
A chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method or the like can also be used.

3) Subsequently, a forming process is performed.
As an example of a method of the forming step, a method by an energization process will be described. When electricity is applied between the device electrodes $ 2 and $ 3 by using a power source (not shown), an electron emitting portion $ 5 having a changed structure is formed in the conductive thin film $ 4 (see FIG. 1).
3 (c)). Conductive thin film $ 4 according to energization forming
Locally, a site having a structural change such as destruction, deformation or alteration is formed. This portion constitutes the electron emitting portion $ 5. FIG. 14 shows an example of the voltage waveform of the energization forming.

The voltage waveform is preferably a pulse waveform. The method shown in FIG. 14A in which a pulse with a constant pulse height is applied as a constant voltage and the method shown in FIG. 14B in which a voltage pulse is applied while increasing the pulse peak value are used for this purpose. There is.

In FIG. 14A, T1 and T2 are the pulse width and pulse interval of the voltage waveform. Normally, T1 is 1 microsecond to 10 milliseconds, and T2 is 10 microsecond to 100.
It is set in the millisecond range. The peak value of the triangular wave (peak voltage at the time of energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device. Under these conditions,
For example, the 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.

T1 and T2 in FIG. 14B can be the same as those shown in FIG. 14A. 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 break or deform the conductive thin film $ 4 during the pulse interval T2 and measure the current. For example, the device current flowing by applying a voltage of about 0.1 V is measured, the resistance value is obtained, and when the resistance is 1 MΩ or more, the energization forming is terminated.

4) It is preferable to perform a process called an activation process on the element which has finished forming. The activation process means that the device current If and the emission current Ie are
This is a process that changes significantly.

The activation step can be carried out, for example, by repeating the application of the pulse in the atmosphere containing the gas of the organic substance, similarly to the energization forming. This atmosphere can be formed by using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump, or is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum. The preferable gas pressure of the organic substance at this time varies depending on the above-described application form, the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set according to the case. Suitable organic materials include
Specific examples include alkanes, alkenes, alkynes, aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, organic acids such as phenols, carboxylic acids, and sulfonic acids. Include saturated hydrocarbons represented by C _n H _{2n + 2} such as methane, ethane and propane, unsaturated hydrocarbons represented by a composition formula such as C _n H _2n such as ethylene and propylene, benzene, toluene and methanol, Ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methyl amine,
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 are significantly changed.

The end of the activation step is determined as appropriate while measuring the device current If and the emission current Ie. The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.
(In some cases, it may be better to apply a higher voltage than during driving.) Carbon and carbon compounds are, for example, graphite (so-called HOPG, PG, GC-containing HOPG (HOP
G: High Oriented Pyrolytic
Graphite) is a crystal structure of almost perfect graphite, PG (PG: Pyrolytic Graphi)
te pyrolytic carbon) has a crystal grain of about 200 angstroms and has a slightly disordered crystal structure, GC (Glassy)
(Carbon amorphous carbon) refers to a crystal grain having a crystal grain size of about 20 angstroms and further disordered crystal structure. ), Amorphous carbon (referring to amorphous carbon and a mixture of amorphous carbon and fine crystals of graphite), and its film thickness is preferably in the range of 500 angstroms or less, and in the range of 300 angstroms or less. Is more preferable.

5) It is preferable that the electron-emitting device obtained through these steps is subjected to a stabilizing 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.

When an oil diffusion pump or a rotary pump is used as an exhaust device in the activation step and an organic gas derived from an oil component generated from this is used, the partial pressure of this component must be kept as low as possible. . The partial pressure of the organic components in the vacuum container is preferably 1 × 10 ⁻⁸ Torr or less, and more preferably 1 × 10 ⁻¹⁰ Torr or less, in terms of the partial pressure at which the carbon and carbon compound are not newly deposited. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. The heating condition at this time is preferably 80 to 200 ° C. for 5 hours or more, but is not particularly limited to this condition and may be appropriately selected depending on various conditions such as the size and shape of the vacuum container and the configuration of the electron-emitting device. To do. Considering only the desorption of the adsorbed gas, the higher the temperature is, the more preferable temperature is 80 to 200 ° C in consideration of heat damage to the electron source. However, if the heat resistance of the electron source is increased, naturally the temperature should be higher. May be.
It is necessary to make the pressure in the vacuum container as low as possible.
Not more than × 10 ^-7 Torr, more preferably 1 × 10 ^-8 T
Orr or less is particularly preferable.

It is preferable to maintain the atmosphere at the time of driving after the stabilization process is the atmosphere at the end of the stabilization process, but it is not limited to this, and if the organic substance is sufficiently removed. Even if the degree of vacuum itself is slightly lowered, it is possible to maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed, and as a result, the device current If and the emission current I
e becomes stable. Basic characteristics of the electron-emitting device to which the present invention is applicable obtained through the above steps will be described with reference to FIGS. 15 and 16.

FIG. 15 is a schematic diagram showing an example of a vacuum processing apparatus, and this vacuum processing apparatus also has a function as a measurement / evaluation apparatus. Also in FIG. 15, the same parts as those shown in FIG. 11 are designated by the same reference numerals as those shown in FIG. 11. In FIG. 15, $ 55 is a vacuum container and $ 56 is an exhaust pump. An electron emitting device is arranged in the vacuum container $ 55. That is, $ 1 is a substrate that constitutes an electron-emitting device, $ 2 and $ 3 are device electrodes,
$ 4 is a conductive thin film, and $ 5 is an electron emission part. $ 51
Is a power supply for applying the device voltage Vf to the electron-emitting device, $ 50 is an ammeter for measuring the device current If flowing through the conductive thin film $ 4 between the device electrodes $ 2 and $ 3, and $ 54 is the device Is an anode electrode for capturing the emission current Ie emitted from the electron emission part of the. $ 53 is the anode electrode $
A high voltage power source for applying a voltage to 54, and $ 52 are ammeters for measuring the emission current Ie emitted from the electron emission portion $ 5 of the device. As an example, the measurement can be performed with the voltage of the anode electrode in the range of 1 kV to 10 kV and the distance H between the anode electrode and the electron-emitting device in the range of 2 mm to 8 mm.

The vacuum container $ 55 is provided with equipment necessary for measurement in a vacuum atmosphere such as a vacuum gauge (not shown) so that measurement and evaluation can be performed in a desired vacuum atmosphere. . The exhaust pump $ 56 is composed of a normal high vacuum device system including a turbo pump and a rotary pump, and an ultra-high vacuum device system including an ion pump. The entire vacuum processing apparatus provided with the electron source substrate shown here can be heated to 200 ° C. by a heater (not shown). Therefore, by using this vacuum processing apparatus, the steps after the above-described energization forming can be performed.

FIG. 16 is a diagram schematically showing the relationship between the emission current Ie, the device current If, and the device voltage Vf measured using the vacuum processing apparatus shown in FIG. In FIG. 16, since the emission current Ie is significantly smaller than the device current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is clear from FIG. 16, the surface conduction electron-emitting device to which the present invention can be applied has three characteristic properties regarding the emission current Ie.

That is, (i) when an element voltage higher than a certain voltage (called a threshold voltage, Vth in FIG. 16) is applied to this element, the emission current Ie rapidly increases, while the threshold voltage Vth or less is applied. Emission current Ie is hardly detected in
That is, a clear threshold voltage Vt with respect to the emission current Ie
It is a non-linear element having h.

(Ii) Since the emission current Ie monotonically increases with the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.

(Iii) The emission charge captured by the anode electrode $ 54 depends on the time for applying the device voltage Vf. That is, the amount of charge captured by the anode electrode $ 54 can be controlled by the time for which the device voltage Vf is applied.

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

In FIG. 16, an example in which the element current If monotonically increases with respect to the element voltage Vf (hereinafter referred to as “MI characteristic”) is shown by a solid line. The element current If is equal to the element voltage Vf.
May exhibit a voltage control type negative resistance characteristic (hereinafter, referred to as “VCNR characteristic”) in some cases (not shown). These characteristics can be controlled by controlling the above process.

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

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

The surface conduction electron-emitting device to which the present invention can be applied has the characteristics (i) to (iii) as described above. That is, the emitted electrons from the surface conduction electron-emitting device can be controlled by the peak value and width of the pulse voltage applied between the opposing device electrodes at the threshold voltage or higher. On the other hand, when the voltage is equal to or lower than the threshold voltage, it is hardly emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulsed voltage is appropriately applied to each device,
The electron emission amount can be controlled by selecting the surface conduction electron-emitting device according to the input signal.

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 below with reference to FIG. In FIG. 17, $ 71
Is an electron source substrate, $ 72 is an X-direction wiring, and $ 73 is a Y-direction wiring. $ 74 is a surface conduction electron-emitting device, and $ 75 is a connection. The surface conduction electron-emitting device $ 74 may be either the flat type or the vertical type described above.

The m pieces of X-direction wiring $ 72 are DX1 and DX.
2,. . It is made of DXm and can be made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness, and width of the wiring are appropriately designed.
The Y-direction wiring $ 73 includes DY1, DY2 ,. . DYn n
It is composed of a book wire and is formed similarly to the X-direction wire $ 72. An interlayer insulating layer (not shown) is provided between the m X-direction wirings $ 72 and the n Y-direction wirings $ 73 to electrically separate the two (m and n are , Both positive integers).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, a board $ 7 on which the X-direction wiring $ 72 is formed
1 is formed in a desired shape on the entire surface or a part thereof, and the film thickness, material, and manufacturing method are appropriately set so as to withstand the potential difference at the intersection of the X-direction wiring $ 72 and the Y-direction wiring $ 73. . X
The direction wiring $ 72 and the Y direction wiring $ 73 are drawn out as external terminals.

A pair of electrodes (not shown) constituting the surface conduction electron-emitting device $ 74 are formed by m X-direction wirings $ 72, n Y-direction wirings $ 73, and a connection $ 75 made of a conductive metal or the like. It is electrically connected.

Materials for forming the wiring $ 72 and the wiring $ 73,
The material forming the connection $ 75 and the material forming the pair of device electrodes may be the same or different in some or all of the constituent elements. These materials are
For example, it is appropriately selected from the above-mentioned material of the device electrode. If the material forming the device electrodes and the wiring material are the same,
The wiring connected to the device electrode can also be called a device electrode.

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 is connected to the X direction wiring $ 72. On the other hand, the Y direction wiring $ 73 is connected with 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.
The driving voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

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

FIG. 18 and FIG. 19 show an image forming apparatus constructed by using an electron source having such a simple matrix arrangement.
This will be described with reference to FIG. FIG. 18 is a schematic diagram illustrating an example of a display panel of the image forming apparatus, and FIG. 19 is a schematic diagram of a fluorescent film used in the image forming apparatus of FIG. FIG. 20 is a block diagram showing an example of a drive circuit for displaying in accordance with an NTSC television signal.

In FIG. 18, $ 71 is an electron source substrate on which a plurality of electron-emitting devices are arranged, $ 81 is a rear plate to which the electron source substrate $ 71 is fixed, $ 86 is a glass substrate $ 83, and a fluorescent film $ 84 is formed on the inner surface. It is a face plate on which a metal back $ 85 or the like is formed. $ 82 is a support frame, and a rear plate $ 81 and a face plate $ 86 are connected to the support frame $ 82 by using frit glass or the like. $
Reference numeral 88 denotes an envelope, which is sealed and formed by firing in the temperature range of 400 to 500 ° C. for 10 minutes or more in the atmosphere or nitrogen.

$ 74 corresponds to the electron emitting portion in FIG. $ 72 and $ 73 are the X-direction wiring and the Y-direction wiring connected to the pair of device electrodes of the surface conduction electron-emitting device. Reference numeral 914 denotes an evaporation type getter material container containing an evaporation type getter material. The evaporation type getter material container 914 is fixed to the evaporation type getter material container fixing jig 913. A metal plate 934 supports the non-evaporable getters 935 and 936. 943 is a heat insulating plate.

The envelope $ 88 is composed of the face plate $ 86, the support frame $ 82, and the rear plate $ 81 as described above. Since the rear plate $ 81 is provided mainly for the purpose of reinforcing the strength of the substrate $ 71, if the substrate $ 71 itself has sufficient strength, the separate rear plate $ 81 can be unnecessary. That is, the support frame $ directly on the board $ 71
82 is sealed, face plate $ 86, support frame $ 82
Alternatively, the board $ 71 may form the envelope $ 88. 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 $ 8 having sufficient strength against atmospheric pressure.
8 can also be configured.

FIG. 19 is a schematic diagram showing a fluorescent film. In the case of monochrome, the fluorescent film $ 84 can be composed of only the phosphor. In the case of a color phosphor film, a black conductive material $ 91 called a black stripe or a black matrix and a phosphor $ 92 depending on the arrangement of the phosphors.
And can be composed of The purpose of providing the black stripes and the black matrix is to make the mixed colors and the like inconspicuous by blackening the coating portions between the phosphors $ 92 of the three primary color phosphors required for color display, and the phosphor film $ 84. It is to suppress the decrease in contrast due to the reflection of external light. As a material for the black stripe, other than a material mainly containing graphite which is usually used,
It is possible to use a material having conductivity and low transmission and reflection of light.

As a method of applying the phosphor to the glass substrate $ 93, a precipitation method, a printing method or the like can be adopted regardless of monochrome or color. A metal back $ 85 is usually provided on the inner surface side of the fluorescent film $ 84. The purpose of providing the metal back is to improve the brightness by specularly reflecting the light to the inner surface side of the light emission of the phosphor to the face plate $ 86 side, and to act as an electrode for applying an electron beam acceleration voltage. , Protecting the phosphor from damage caused by 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 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film $ 84 in order to further enhance the conductivity of the fluorescent film $ 84.

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

The image forming apparatus shown in FIG. 18 is manufactured, for example, as follows. The envelope $ 88 is exhausted through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump and a sorption pump, while appropriately heating, as in the above-described stabilization process, and is about 10 ^-7 Torr. After forming an atmosphere of a sufficiently small amount of an organic substance, the sealing is performed.

Here, in order to maintain the degree of vacuum after the envelope $ 88 is sealed, a getter process is usually performed. The getter includes an evaporative type and a non-evaporable type, and either one or both can be used. Note that FIG. 18 shows an example in which both the evaporation type getter and the non-evaporation type getter are arranged. The evaporation type getter process is performed by heating using resistance heating, high frequency heating, or the like immediately before or after sealing the envelope $ 88, and the getter 914 arranged at a predetermined position inside the envelope $ 88. Is a process for forming a vapor-deposited film by heating. The evaporative getter usually has Ba as a main component, and maintains the degree of vacuum by the adsorption action of the vapor deposition film.

The non-evaporable getters 935 and 936 exhibit gas adsorbing ability after being activated in a vacuum at a high temperature for a certain period of time. As the non-evaporable getter materials, Zr-Al alloy and Zr-Fe alloy are used. , Zr-Ni alloy, Zr-Nb-F
e alloy, Zr-Ti-Fe alloy, Zr-V-Fe alloy and the like. Among these, Zr-V that can be activated at relatively low temperatures
-Fe alloys are common. The heat activation of the non-evaporable getter is generally performed immediately before sealing the envelope $ 88 by resistance heating, high frequency heating, direct heating using laser light or infrared rays, or the like. Of these, activation by direct heating using laser light or infrared light is preferable.

Here, the steps after the forming treatment of the surface conduction electron-emitting device can be set appropriately.

Next, a configuration example of a drive circuit for performing television display based on an NTSC television signal on a display panel configured by using an electron source having a simple matrix arrangement will be described with reference to FIG. . In FIG. 20, $ 101 is an image display panel, $ 102 is a scanning circuit,
$ 103 is a control circuit and $ 104 is a shift register. $ 105 is a line memory, $ 106 is a sync signal separation circuit, $ 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel $ 101 is connected to an external electric circuit via the terminals Dox1 to Doxm, the terminals Doy1 to Doyn, and the high voltage terminal Hv. Terminal Do
x1 to Doxm are used to sequentially drive electron sources provided in the display panel, that is, a group of surface conduction electron-emitting devices that are matrix-wired in a matrix of M rows and N columns row by row (N elements). A scanning signal is applied.

A modulation signal for controlling the output electron beam of each element of the surface conduction type terminal emission element of one row selected by the scanning signal is applied to the terminals Dy1 to Dyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 K [V] from a DC voltage source Va, which is sufficient to excite the phosphor into an electron beam emitted from the surface conduction electron-emitting device. It is an accelerating voltage for applying energy.

The scanning circuit $ 102 will be described. This circuit includes M switching elements inside (in the drawing, S1 to Sm are schematically shown). Each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level), and is electrically connected to the terminals Dx1 to Dxm of the display panel $ 101. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit $ 103, and can be configured by combining switching elements such as FETs.

In the case of the present example, the DC voltage source Vx is a driving voltage applied to an unscanned element based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element and the electron emission threshold value. It is set to output a constant voltage that is equal to or lower than the voltage.

The control circuit $ 103 has a function of matching the operation of each part so that an appropriate display is performed based on an image signal input from the outside. The control circuit $ 103 controls the sync signal Tsyn sent from the sync signal separation circuit $ 106.
Based on c, Tscan and Tsft for each part
And Tmry control signals are generated.

The sync signal separation circuit $ 106 is a circuit for separating the sync signal component and the luminance signal component from the NTSC system television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The sync signal separated by the sync signal separating circuit $ 106 is composed of a vertical sync signal and a horizontal sync signal, but it is shown here as a Tsync signal for convenience of description. The luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience. The DATA signal is the shift register $ 104
Is input to

The shift register $ 104 is for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and the control signal Tsft sent from the control circuit $ 103. (Ie, the control signal Tsft can be said to be the shift clock of the shift register $ 104). The serial / parallel converted image data for one line (corresponding to drive data for N electron emission elements) is output from the shift register $ 104 as N parallel signals Id1 to Idn.

The line memory $ 105 is a storage device for storing data for one line of an image for a required time, and a control signal Tmry sent from the control circuit $ 103.
, The contents of Id1 to Idn are stored as appropriate. The stored contents are output as I'd1 to I'dn,
It is input to the modulation signal generator $ 107.

The modulation signal generator $ 107 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of the image data I'd1 to I'dn, and its output signal is , And is applied to the surface conduction electron-emitting devices in the display panel $ 101 through the terminals Doy1 to Doyn.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie. That is, a clear threshold voltage Vth is required for electron emission.
And electron emission occurs only when a voltage equal to or higher than Vth is applied. For voltages above 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 the element, for example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold is applied. Outputs an electron beam. At this time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. In addition, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.

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 carrying out the voltage modulation method, as the modulation signal generator $ 107, a circuit of the voltage modulation method that generates a voltage pulse of a fixed length and appropriately modulates the peak value of the pulse according to the input data is used. Can be used.

When implementing the pulse width modulation method,
As the modulation signal generator $ 107, it is possible to use a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to the input data.

Shift register $ 104 and line memory $
The digital signal 105 and the analog signal type can be adopted as 105. 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 sync signal separation circuit $ 106 into a digital signal.
A D converter may be provided. In connection with this, 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, for example, a D / A conversion circuit is used for the modulation signal generator $ 107, and an amplification circuit or the like is added if necessary. Modulation signal generator $ 10 for pulse width modulation
For example, a circuit in which a high-speed oscillator and a counter (counter) for counting the number of waves output from the oscillator and a comparator (comparator) for comparing the output value of the counter with the output value of the memory are used as the circuit 7. 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, the modulation signal generator $ 107 may be, for example, an amplifier circuit using an operational amplifier or the like, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillation circuit (VCO) can be adopted, and an amplifier for voltage amplification up to the drive voltage of the surface conduction electron-emitting device can be added if necessary.

In the image display device to which the present invention having such a structure can be applied, the electron emission element is electron-emitted by applying a voltage to each electron-emission element through the terminals Dox1 to Doxm and Doy1 to Doyn. Occurs.
A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 and emit light to form an image. The configuration of the image forming apparatus described here is an example of the image forming apparatus to which the present invention is applicable,
Various modifications are possible based on the technical idea of the present invention.
As for the input signal, the NTSC system has been mentioned, but the input signal is not limited to this, and the PAL, SECOM system, etc., and a TV signal including a larger number of scanning lines than this (for example, the MUSE system is included. High-definition TV) system can also be adopted.

Next, a ladder type electron source and an image forming apparatus will be described with reference to FIGS. 21 and 22.

FIG. 21 is a schematic view showing an example of a ladder-type electron source. In FIG. 21, $ 110 is an electron source substrate and $ 111 is an electron-emitting device. $ 112, D
x1 to Dx10 are common wirings for connecting the electron-emitting device $ 111. The electron-emitting device $ 111 is the substrate $
A plurality of them are arranged in parallel in the X direction on 110 (this is called an element row). A plurality of the element rows are arranged to constitute an electron source. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to an element row that wants to emit an electron beam, and a voltage equal to or lower than the electron emission threshold is applied to an element row that does not emit an electron beam.
The common wirings Dx2 to Dx9 between the element rows are, for example, Dx
2, Dx3 can be the same wiring.

FIG. 22 is a schematic view showing an example of a panel structure in an image forming apparatus provided with a ladder-type electron source. Note that, in FIG. 22, the evaporation type getter and / or the non-evaporation type getter and the heat insulating plate are omitted. $ 1
20 is a grid electrode, $ 121 is a hole for passing electrons, and $ 122 is Dox1, Dox2, ..., Doxm.
This is an external terminal made of a container. $ 123 is an outside-container terminal composed of G1, G2, ..., Gn connected to the grid electrode $ 120, and $ 124 is an electron source substrate in which the common wiring between each element row is the same wiring. In FIG. 22, FIG.
8, the same parts as those shown in FIG. 21 are designated by the same reference numerals as those shown in these figures. The major difference between the image forming apparatus shown here and the image forming apparatus of the simple matrix arrangement shown in FIG. 18 is whether or not the grid electrode $ 120 is provided between the electron source substrate $ 110 and the face plate $ 86. Is.

In FIG. 22, a grid electrode $ 120 is provided between the substrate $ 110 and the face plate $ 86. The grid electrode $ 120 is for modulating the electron beam emitted from the surface conduction electron-emitting device, and for passing the electron beam through the stripe-shaped electrode provided orthogonal to the ladder-shaped element rows. A circular opening $ 121 is provided for each element. The shape and installation position of the grid 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 may be provided around or near the surface conduction electron-emitting device.

The outside-container terminal $ 122 and the grid outside-container terminal $ 123 are electrically connected to a control circuit (not shown).

In the image forming apparatus of this example, the modulation signals for one image line are simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one column at a time. This makes it possible to control the irradiation of the phosphor with each electron beam and display the image line by line.

The image forming apparatus of the present invention can be used not only as a display apparatus for television broadcasting, a display apparatus such as a TV conference system or a computer, but also as an image forming apparatus as an optical printer constituted by using a photosensitive drum or the like. Can be used.

[0114]

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

Example 1 As a first example of the present invention, a getter chamber is formed in the lower part of the plate which constitutes the electron source composed of the surface conduction electron-emitting device, that is, in the space opposite to the face plate which constitutes the phosphor and the like. An example will be described in which the heat insulating thin film is formed on the back surface of the plate that constitutes the electron source in the image display device having the above structure.

FIG. 1 is a sectional view showing the structure of the first embodiment of the present invention, which is based on the conventional example shown in FIG.
In FIG. 1, 200 is an exhaust pipe for exhausting the inside of the image display device (in the figure, the state after sealing is shown), 201 is a rear plate, and 240 is a soda-lime glass constituting an electron-emitting device. Plates, 202 and 203
Is an electrode installed at a fixed interval, and 204 is an electrode 20
A thin film including an electron emitting portion provided between 2 and 203, 2
Reference numeral 06 is an electron passage hole, 207 is a grid, 208 is a face plate made of soda-lime glass on which a metal back 209 and a phosphor 210 are formed, 211 is an outer frame, and 2
Reference numeral 14 denotes an evaporation type getter material container containing an evaporation type getter material. The evaporation type getter material container 214 is fixed to the evaporation type getter material container fixing jig 213. In this embodiment, the evaporation type getter material container 214 is made of an evaporation type getter material containing Ba as a main component.

Reference numeral 234 denotes a metal plate made of Cu for supporting the non-evaporable getters 235 and 236. In this embodiment,
A Zr-V-Fe alloy (plate thickness: 1 mm) was used for the non-evaporable getters 235 and 236 (fixed by spot welding). The non-evaporable getters 235 and 236 and the metal plate 234 are fixed to the non-evaporable getter fixing jig 233.

Reference numeral 242 denotes a heat insulating thin film, which is formed on the entire back surface of the plate 240 which constitutes the electron-emitting device. In this embodiment, metal Al obtained by the sputtering method is used as the thin film 242 having a heat insulating property. Reference numeral 241 is a communication hole in the upper and lower spaces, which penetrates the plate 240 and the thin film 242 having a heat insulating property.

Next, a specific manufacturing procedure of this embodiment will be described below. First, a method of manufacturing a surface conduction electron-emitting device will be described with reference to FIGS. A quartz substrate is used as the insulating substrate 1, which is thoroughly washed with a detergent, pure water and an organic solvent (FIG. 2 (a)), and then a resist material R
D-2000N was applied at 2500 rpm for 40 seconds by a spinner and heated at 80 ° C. for 25 minutes to be pre-baked (FIG. 2).
(B)). Next, the electrode interval L1 is 2 μm and the electrode length W1
Was subjected to contact exposure using a mask corresponding to an electrode shape of 300 μm and developed with a developing solution for RD-2000N. (Figure 2
(C)). Then, it was post-baked by heating at 120 ° C. for 20 minutes.

Any material may be used as the material for the electrodes as long as it has conductivity, but nickel metal is used in this embodiment. Using a resistance heating vapor deposition machine, nickel was vapor-deposited at a rate of 3 angstroms per second until the film thickness reached 1000 angstroms (FIG. 2 (d)). Lifted off with acetone, washed with acetone, isopropyl alcohol, and then with butyl acetate, and dried (Fig. 2).
(E)).

Next, chromium was vapor-deposited on the entire surface of the substrate by 500 angstrom (FIG. 3 (f)). After that, the resist material AZ1370 was applied on the spinner at 2500 rpm for 30 seconds and heated at 90 ° C. for 30 minutes to be prebaked (FIG. 3).
(G)).

Next, exposure is carried out using a mask having a pattern for applying an electron source material (FIG. 3 (h)), and a developing solution MIF is used.
It was developed at 312 (FIG. 4 (i)). After that, 120 ℃,
It was post-baked by heating for 30 minutes.

Next, (NH ₄ ) Ce (NO ₃ ) ₆ / HC
It was immersed in a solution having a composition of 10 ₄ / H ₂ O = 17 g / 5 cc / 100 cc for 30 seconds to etch chromium (FIG. 4).
(J)). Then, the resist was peeled off by ultrasonically stirring in acetone for 10 minutes (FIG. 4 (k)).

Subsequently, it was heated at 120 ° C. for 10 minutes. Next, organic palladium (Okuno Pharmaceutical Co., Ltd., ccp-42)
30) The containing solution was spinner coated at 800 rpm for 30 seconds. Then, it is baked at 300 ° C. for 20 minutes, and palladium oxide (PdO) fine particles (particle size: 10 angstrom-
A fine particle-shaped thin film 2 for forming an electron-emitting portion having a thickness of 150 angstroms) was formed (FIG. 4 (l)).

Then, by lifting off chromium,
A thin film 2 for forming an electron-emitting portion, which partially covers the device electrodes 22 and 23, was produced (FIG. 5 (m)).

The following will be described with reference to FIG.

On the plate 240 having metal Al (film thickness: about 3000 angstroms) vapor-deposited on the back surface, the thin film including the device electrodes 202 and 203 and the electron emitting portion provided between the electrodes and the evaporation type getter material container 214 are provided. Formed. Then, the plate 240 and the rear plate 201
The non-evaporable getter fixing jig 233 was used for bonding, and then the face plate 208 and the rear plate 201 were bonded for example via the outer frame 211. For the adhesion (sealing), a low-melting glass (LS-30, manufactured by JEOL Glass Co., Ltd.) is mainly used.
81) was pressed from above by a weight and baked in the atmosphere under conditions of sealing heat treatment temperature of 410 ° C. and sealing heat treatment time of 60 minutes to form an image display device.

Next, the inside of the apparatus was evacuated from the exhaust pipe 200 by a vacuum exhaust apparatus (not shown).

Then, pre-baking for the purpose of degassing the inside of the apparatus was carried out under vacuum evacuation under the conditions of a baking temperature of 200 ° C. and a baking time of 20 minutes. In addition, this pre-baking is preferably performed in a temperature range of 150 ° C. to 300 ° C.

After that, the non-evaporable getters 235 and 236 made of a Zr-V-Fe alloy were directly heated and activated by irradiating a laser beam (not shown) through the rear plate 201 under vacuum evacuation. The laser irradiation conditions at this time are shown below. Laser: CO ₂ laser Output: 20 kW Spot diameter: Approximately 10 mmφ (defocus mode) Scanning speed: 500 mm / min Note that direct heating by infrared rays, resistance heating, high frequency heating, etc. can be used for this heating activation. However, among these, activation by direct heating with laser light or infrared rays is preferable.

Finally, by heating the exhaust pipe 200 with a gas burner at a vacuum degree of about 1 × 10 ^-7 Torr, the exhaust pipe 200 is welded to seal the envelope, and then the evaporation type getter material container 214 is attached. The image display device was completed by resistance heating and forming a vapor deposition film containing Ba as a main component. In addition to the resistance heating, high-frequency heating or the like may be used for heating the evaporation type getter material container 214. In addition, the above heating,
It may be performed immediately before the sealing of the envelope.

By adopting the heat-insulating thin film having such a structure, radiant heat generated when activating the non-evaporable getters 235 and 236 in vacuum at high temperature for a certain period of time, and non-evaporable getter fixing treatment. It was possible to suppress heat conduction through the tool 233. At the same time, since the radiant heat is reflected by the thin film 242 having a heat insulating property, the non-evaporable getter can be efficiently activated.

Further, by activating the non-evaporable getters 235 and 236 by using a direct heating method in which laser light, infrared rays, or the like is irradiated from the outside of the rear plate 201, the radiant heat and the heat conduction can be further suppressed. did it.

As a result, since the electron-emitting device portion can be maintained at a relatively low temperature when the non-evaporable getter is activated, the device characteristics can be maintained and the yield of the image display device is improved.

Example 2 As a second example of the present invention, a getter chamber is formed in the lower part of the plate which constitutes the electron source composed of the surface conduction electron-emitting device, that is, in the space opposite to the face plate which constitutes the phosphor and the like. An example will be described in which the heat insulating plate is provided between the plate that constitutes the electron source and the rear plate in the image display device having the configuration.

FIG. 6 is a sectional view showing the structure of the second embodiment of the present invention, in which the heat insulating thin film 242 in the first embodiment shown in FIG. 1 is replaced with a heat insulating plate 243. is there. Therefore, the other members are denoted by the same numbers as those shown in the first embodiment.

As the heat insulating plate 243, a plate (plate thickness: 2 mm) made of an Al alloy with a small amount of Mg and Si added was used. In addition to the above, the heat insulating plate 243 is made of metal Al,
It is possible to use an Al alloy or the like in which a trace amount of Ti, Zr, V, Mn, etc. is added.

The heat insulating plate 243 includes the plate 240,
Attach the rear plate 201 to the non-evaporable getter fixing jig 233.
At the same time, they were bonded and fixed at the same time. An image display apparatus was produced in the same manner as in Example 1 except for this. Also in this embodiment, almost the same effect as in the first embodiment was obtained.

Embodiment 3 As a third embodiment of the present invention, in a thin image display device having a structure shown in FIG. 7 using a surface conduction electron-emitting device, a heat insulating plate is provided between the electron-emitting device portion and a non-evaporating type. An example provided between the getters will be described. FIG. 7 is a sectional view showing the structure of the third embodiment of the present invention, which is based on the second embodiment shown in FIG. In FIG. 7, reference numeral 800 denotes an exhaust pipe for exhausting the inside of the image display device (in the figure, a state after sealing is shown) is shown, 801 is a rear plate, and 802 and 803 are installed with a constant interval. An electrode, 804 is a thin film including an electron emitting portion provided between the electrodes 802 and 803, 806 is an electron passage hole, 807 is a grid, 808 is a metal back 809 and a phosphor 810.
A face plate made of soda-lime glass having a glass, 8
Reference numeral 11 is an outer frame, and 814 is an evaporation type getter material container containing an evaporation type getter material. The evaporation type getter material container 814 is fixed to the evaporation type getter material container fixing jig 813. In this embodiment, the evaporation type getter material container 814 is made of an evaporation type getter material containing Ba as a main component.

Reference numeral 834 denotes a metal plate which supports the non-evaporable getters 835 and 836. In this embodiment, the non-evaporable getters 835 and 836 are made of Zr-V-Fe alloy. As the heat insulating plate 843, a plate made of an Al alloy with a small amount of Mg and Si added was used. In addition to the above, the heat insulating plate 843 may be made of metal Al, an Al alloy to which Ti, Zr, V, Mn, or the like is added in a trace amount.

The heat insulating plate 843 is the face plate 8
08 and the rear plate 801 were adhered and fixed at the same time. An image display device was produced in the same manner as in Example 2 except for this. The heat insulating plate 843 is
The image display area and the getter area are not completely separated, and may be installed in a range where the radiant heat from the non-evaporable getters 835 and 836 does not directly reach the electron-emitting device section.
Also in this embodiment, almost the same effect as in the first embodiment was obtained.

Comparative Example An example will be described in which an image display device was produced in the same manner except that the thin film 242 having a heat insulating property was removed from the structure shown in the first embodiment (FIG. 1). Also in this case, a Zr-V-Fe alloy was used for the non-evaporable getters 235 and 236, and direct activation by laser light irradiation under vacuum exhaust was used to activate the getters.

In this case, the element characteristics may be deteriorated by radiant heat or heat conduction when the non-evaporable getter is heated.

[0144]

EFFECTS OF THE INVENTION An electron source composed of a surface conduction electron-emitting device having an electron-emitting portion between opposed electrodes, a phosphor screen member emitting light by irradiation of an electron beam emitted from the electron source, and an internal vacuum are maintained. In an image display device at least containing a getter for, by installing a heat insulating plate or a thin film having a heat insulating property in the space between the electron source and the getter, when the getter is heated and activated, Radiant heat and heat conduction can be suppressed. as a result,
Since the electron emission portion is maintained at a relatively low temperature and the device characteristics can be maintained, the yield of the image display device is improved.

At the same time, since the radiant heat is reflected by the heat insulating plate or the heat insulating thin film, the non-evaporable getter can be efficiently activated.

Furthermore, for activation of the non-evaporable getter,
By using a direct heating method of irradiating laser light, infrared rays, or the like from the outside of the rear plate, it is possible to further suppress the above-mentioned radiant heat and heat conduction. Further, in an image display device in which the image display unit and the vacuum maintaining unit (getter chamber) are divided by a substrate material on which an electron source or the like is formed, by installing a heat insulating plate or a thin film having heat insulating property, Since the distance between the electron source and the getter can be made shorter than in the conventional case, the image display device itself can be made compact.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of the present invention.

FIG. 2 is a process drawing showing the process of the first part of the method of manufacturing an electron-emitting device.

FIG. 3 is a process drawing showing a process of a second part of the method for manufacturing the electron-emitting device.

FIG. 4 is a process drawing showing a process of a third part of the method of manufacturing the electron-emitting device.

FIG. 5 is a process drawing showing the process of the fourth portion of the method of manufacturing an electron-emitting device.

FIG. 6 is a sectional view showing a configuration of a second exemplary embodiment of the present invention.

FIG. 7 is a sectional view showing the configuration of a third embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a configuration of a conventional image display device using an electron-emitting device.

FIG. 9 is a perspective view showing a configuration of a conventional image display device using an electron-emitting device.

FIG. 10: M. It is a figure which shows the element structure of Hartwell typically.

FIG. 11 is a schematic view of a planar surface conduction electron-emitting device to which the present invention can be applied, where a is a plan view and b is a sectional view.

FIG. 12 is a schematic diagram showing a configuration of a surface conduction electron-emitting device to which the present invention can be applied.

FIG. 13 is a diagram schematically showing an example of a method of manufacturing a surface conduction electron-emitting device to which the present invention can be applied.

FIG. 14 is a diagram showing an example of a voltage waveform in energization forming that can be adopted when manufacturing a surface conduction electron-emitting device to which the present invention can be applied, in which a pulse having a pulse peak value as a constant voltage is continuously applied. 14b is a diagram of the technique shown in FIG. 14b and a technique of applying a voltage pulse while increasing the pulse crest value.

FIG. 15 is a schematic diagram showing an example of a vacuum processing apparatus having a measurement / evaluation function.

FIG. 16 is a graph showing the relationship between the emission current Ie, the device current If, and the device voltage Vf for the surface conduction electron-emitting device to which the present invention can be applied.

FIG. 17 is a schematic diagram showing an example of an electron source to which the present invention is applicable and which is arranged in a simple matrix.

FIG. 18 is a schematic diagram showing an example of a display panel of an image forming apparatus to which the present invention can be applied.

FIG. 19 is a schematic view showing an example of a fluorescent film.

FIG. 20 is a block diagram showing an example of a drive circuit for displaying on an image forming apparatus in accordance with an NTSC television signal.

FIG. 21 is a schematic view showing an example of a ladder-arranged electron source to which the present invention can be applied.

FIG. 22 is a schematic view showing an example of a display panel of an image forming apparatus to which the present invention can be applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Electron emission part forming thin film 3 Electron emission part 4 Thin film including an electron emission part 5, 6, 22, 23 Element electrode 24 Cr 25 Resist 200, 300, 800 Exhaust pipe 201, 301, 801 Rear plate 202 , 203, 302, 303, 802, 803
Electrodes 204, 304, 804 Electron emitting thin films 206, 306, 806 Electron passing holes 207, 307, 807 Grids 208, 308, 808 Face plates 209, 309, 809 Metal backs 210, 310, 810 Phosphors 211, 311 , 811 Outer frames 213, 313, 813, 913 Evaporative getter material container fixing jigs 214, 314, 814, 914 Evaporative getter material container 233 Non-evaporable getter fixing jigs 234, 834, 934 Metal plates 235, 236 835, 836, 935, 936
Non-evaporable getter 240 Plates 241, 244 that constitute an electron-emitting device Upper and lower space communication hole 242 Thin film having heat insulating property 243, 843, 943 Heat insulating plate $ 1 Substrate $ 2, $ 3 Element electrode $ 4 Conductive film $ 5 Electron Emitting part $ 21 Stepping emitting part $ 50 Ammeter for measuring the device current If flowing through the conductive film $ 4 between the device electrodes $ 2 and $ 3 $ 51 To add the device voltage Vf to the electron emitting device Power source $ 53 High voltage power source for applying voltage to the anode electrode $ 54 $ 54 Anode electrode $ 55 for supplementing the emission current Ie emitted from the emission portion of the element $ 55 From the electron emission portion $ 5 of the element Ammeter for measuring emitted emission current Ie $ 56 Vacuum device $ 57 Exhaust pump $ 71 Electron source substrate $ 72 X direction wiring $ 73 Y direction wiring $ 74 Surface conduction electron Emitting element $ 75 Wiring $ 81 Rear plate $ 82 Support frame $ 83 Glass substrate $ 84 Fluorescent film $ 85 Metal back $ 86 Face plate $ 87 High voltage terminal $ 88 Envelope $ 91 Black conductive material $ 92 Phosphor $ 93 Glass Substrate $ 101 Display panel $ 102 Scan circuit $ 103 Control circuit $ 104 Shift register $ 106 Line memory $ 106 Synchronous signal separation circuit $ 107 Modulation signal generator Vx and Va DC voltage source $ 110 Electron source substrate $ 111 Electron emission element $ 112 Dx1 to Dx10 are common wiring for wiring the electron-emitting device $ 120 Grit electrode $ 121 Voids through which electrons pass $ 122 Dox1, Dox2 ... Dox
m external terminal consisting of $ 123 G1 and G2 connected to grit electrode $ 120

Claims (6)

[Claims] 1. An electron source comprising a surface conduction electron-emitting device having an electron-emitting portion between opposed electrodes, a phosphor screen member emitting light by irradiation of an electron beam emitted from the electron source, and maintaining an internal vacuum. In an image display device in which at least a getter for doing so is installed, a heat insulating plate or a thin film having a heat insulating property is installed in a space between the electron source and the getter. 2. An image display device, wherein the heat insulating plate or the heat insulating thin film according to claim 1 is made of Al metal or Al alloy. 3. The getter according to claim 1 or 2, wherein the getter is Zr-
Al alloy, Zr-Fe alloy, Zr-Ni alloy, Zr-N
b-Fe alloy, Zr-Ti-Fe alloy, Zr-V-Fe
An image display device comprising one or more non-evaporable getters selected from alloys. 4. The image display device, wherein the plate constituting the electron source is a rear plate, that is, in the image display device having no getter chamber below the plate, the side space other than the image display portion is provided in a side space. An image display device, wherein the heat insulating plate according to claim 1 is installed, or the thin film having heat insulating properties according to any one of claims 1 to 3 is formed on the surface of the spacer or the getter scattering prevention plate. 5. A lower portion of a plate that constitutes the electron source,
That is, in an image display device having a structure in which a getter chamber is provided in a space on the side opposite to a face plate that constitutes a phosphor or the like, a space between the plate that constitutes the electron source and the getter may be provided. An image display device, wherein the heat insulating plate according to claim 1 is installed, or the thin film having heat insulating properties according to any one of claims 1 to 3 is formed on the back surface of the plate constituting the electron source. 6. A method of manufacturing an image display device, wherein a laser beam or an infrared ray is used to activate the non-evaporable getter according to claim 3.