JPH11312460A - Electron emitting element, electron emitting element, electron source substrate, and method of manufacturing image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for forming a uniform surface transmission electron emission element in a large area easily at low cost. SOLUTION: This manufacturing method comprises: a step to form a pair of adjacent element electrodes 2, 3 on an insulating board 1; a step to form an insulating layer 6 having an opening 9 including the adjacent parts of the pair of adjacent element electrodes on the pair of adjacent element electrodes; a step to form a conductive thin film 4 on the opening by dropping a solution containing a conductive thin film forming material in a droplet form on the opening; and a step to form an electron emission part 5 on the conductive thin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron-emitting device, an electron-emitting device, an electron source substrate, and a method of manufacturing an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices using a thermionic electron-emitting device and a cold cathode electron-emitting device have been known. The cold cathode electron emitting device includes a field emission type (hereinafter, referred to as “FE type”), a metal / insulating layer / metal type (hereinafter, referred to as “MIM type”), a surface conduction type electron emitting device, and the like. Examples of FE type are WPDyke & WWDor
an, “Field Emission”, Advance in Electron Physics,
8,89 (1956) or CASpindt “Physical Properties
of thin-film field emission cathodes with molybden
ium cones ", J. Appl. Phys., 47, 5248 (1976).

In the MIM type, CAMead, “Operation of Tu”
nnel-Emission Devices ", J. Appl. Phys., 32, 646 (1961).

As an example of a surface conduction electron-emitting device, M.
I. Elinson, Redio Eng. Electron Phys., 10, 1290 (1965) and the like.

In a surface conduction electron-emitting device, electron emission occurs when a current flows through 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)], a thin film of In ₂ O ₃ / SnO ₂ [M.
Hartwell and CGFonstad: IEEE Trans.ED Conf., 519 (1
975)], using a carbon thin film [Hisashi Araki et al .: Vacuum,
26, No. 1, p. 22 (1983)].

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.S. Figure 12 shows the device configuration of Hartwell
Is shown schematically in FIG. In FIG. 1, reference numeral 1 denotes a substrate. Reference numeral 4 denotes a conductive thin 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.
In the drawing, the element electrode interval L is set to 0.5 to 1 mm, and W 'is set to 0.1 mm. Note that the position and shape of the electron-emitting portion 5 are schematically shown because they are uncertain.

Conventionally, in these surface-conduction electron-emitting devices, the electron-emitting portion 5 is subjected to an energization process called energization forming before the electron emission.
It was common to form That is, the energization forming means applying a DC voltage or a very slowly increasing voltage to both ends of the conductive thin film 4 and applying a current of, for example, about 1 V / min, to locally destroy, deform or modify the conductive thin film 4. The purpose is to form the electron-emitting portion 5 that has been made to have a high electrical resistance. In the electron emitting portion 5, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the energization forming process applies a voltage to the conductive thin film 4,
The electrons are emitted from the above-mentioned electron emitting portion 5 by passing a current through the element.

The above surface conduction electron-emitting device has a simple structure and is easy to manufacture, and therefore has the advantage that a large number of devices can be arranged and formed over a large area. Therefore, various applications that make use of this feature are being studied. For example, a display device such as a charged beam source and an image display device can be used.

FIG. 13 shows the structure of an electron-emitting device disclosed in Japanese Patent Application Laid-Open No. 2-56822. In the figure, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film,
Reference numeral 5 denotes an electron emitting portion. There are various methods for manufacturing the electron-emitting device. For example, the device electrodes 2 and 3 are formed on the substrate 1 by a general vacuum deposition technique or a photolithography technique. Next, the conductive thin film 4 is formed by a dispersion coating method. Thereafter, a voltage is applied to the device electrodes 2 and 3 to perform an energization process, thereby forming the electron-emitting portions 5.

[0010]

However, since the manufacturing method according to the above-mentioned conventional example is manufactured by a method mainly using a semiconductor process, it is difficult to form an electron-emitting device in a large area with the current technology. However, there is a disadvantage that a special and expensive manufacturing apparatus is required, and the production cost is high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a uniform surface conduction electron-emitting device over a large area easily at low cost, and a method for manufacturing an electron source substrate having the electron-emitting device and an image forming apparatus. To provide.

[0012]

The method of manufacturing an electron-emitting device according to the present invention, which has been accomplished to achieve the above object, has been made by intensive studies to solve the above-mentioned problems.

That is, according to the present invention, there is provided a method for manufacturing an electron emitting portion on a part of a conductive thin film communicating between a pair of device electrodes, wherein a portion where the conductive thin film is formed has a structure having an opening of an insulating layer. The method is characterized in that a conductive thin film is formed by applying a solution containing a conductive film forming material in the form of droplets in the opening. The droplet of the solution containing the conductive thin film forming material is desirably applied by an ink jet method, and it is more preferable that the ink jet method is a method of generating bubbles by applying thermal energy and discharging the liquid droplet.

The thickness of the electron-emitting portion of the electron-emitting device manufactured according to the present invention is controlled by the amount and the number of droplets when applying a droplet of the solution containing the conductive film forming material. Can be.

The electron source substrate according to the present invention is an electron source substrate in which a plurality of electron-emitting devices are arranged on an insulating substrate, and wirings between the electron-emitting devices and terminals for applying voltage to the devices are formed. Is produced by the above-described method.

In this electron source substrate, for example, column-directional wirings and row-directional wirings are arranged in a matrix with an insulating layer interposed therebetween, and at the intersection, one of the pair of element electrodes is continuously provided on the insulating substrate. Connected to form a column-directional wiring, the insulating layer has an opening only at a portion where a conductive thin film that connects between the pair of device electrodes is formed and a connection portion of one of the device electrodes connected to the row-directional wiring, A droplet of a solution containing a conductive film forming material is continuously applied to an opening of a portion where the conductive thin film is formed, thereby forming an electron emitting portion.

An image forming apparatus according to the present invention includes an electron-emitting device as an electron source, voltage applying means for the device, a luminous element which receives electrons emitted from the device and emits light, and And a drive circuit for controlling a voltage applied to the device, wherein the electron-emitting device is manufactured by the above-described method.

According to the present invention, a conductive thin film can be formed by the above-mentioned method without using a photolithography process, so that a large-area electron-emitting device can be easily manufactured at low cost. In addition, a conductive film pattern for forming an electron-emitting portion can be formed in a self-aligned manner by injecting a droplet into an opening of a portion where a conductive thin film of a pair of device electrodes is formed, so that alignment accuracy is high. It is not necessary, and the yield can be improved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

The flat surface conduction electron-emitting device will be described.

FIG. 1 is a schematic plan view showing a basic structure of a plane type surface conduction electron-emitting device according to an embodiment of the present invention, and a sectional view taken along the line AA '.

In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, 5 is an electron emitting portion, 6 is an insulating film, 9
Is an opening for forming a conductive thin film.

As the substrate 1, quartz glass, glass with a reduced content of impurities such as Na, blue plate glass, a glass substrate on which SiO ₂ is deposited by sputtering or the like, a ceramic substrate such as alumina, or the like can be used. .

As the material of the device electrodes 2 and 3 facing each other, a general conductive material is used.
metals or alloys such as r, Au, Mo, W, Pt, Ti, Al, Cu, Pd, Pd, As, Ag, Au, RuO
Can be selected from _2, Pd-Ag or the like metal or metal oxide and printed conductor composed of glass or the like, an In ₂ O ₃ -SnO transparent conductor ₂ and the like and a semiconductor conductive material such as polysilicon .

The distance L between the device electrodes 2 and 3 is preferably several hundred angstroms to one hundred micrometers. Further, it is desirable that the voltage applied between the device electrodes 2 and 3 is low, and it is necessary to produce the device with good reproducibility. Therefore, a particularly preferable device electrode interval L is several micrometers to several tens of micrometers. The length W1 of the device electrodes 2 and 3 is from several micrometers to several hundred micrometers from the resistance value and electron emission characteristics of the electrodes, and the film thickness d of the device electrodes 2 and 3 is from several hundred angstroms to several micrometers. Is preferred.

The conductive thin film 4 which is a portion including an electron emitting portion
Is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics.
It is set appropriately according to 3 and the energizing forming conditions to be described later, but is preferably several angstroms to several thousand angstroms, and particularly preferably 10 angstroms to 500 angstroms. The sheet resistance is 10 ³ to 10 ⁷ Ω / □. The sheet resistance value is defined as a resistance value in terms of unit thickness (mm unit) of a conductor having the same length and width.

The material constituting the conductive thin film 4 is Pd, P
t, Ru, Ag, Au, Ti, In, Cu, Cr, F
metals such as e, Zn, Sn, Ta, W, Pb, PdO, S
oxides such as nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB
_4, GdB boride such as _4, TiC, ZrC, HfC,
Carbides such as TaC, SiC, WC, TiZ, ZrN, H
Examples include nitrides such as fN, semiconductors such as Si and Ge, and carbon.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure not only in a state where the fine particles are individually dispersed but also in a state where the fine particles are adjacent to each other.
Alternatively, it refers to a film in an overlapped state (including an island shape), and the particle diameter of the fine particles is from several angstroms to thousands of angstroms, preferably from 10 angstroms to 200 angstroms.

FIG. 2 shows a manufacturing method according to an embodiment of the present invention,
FIG. 3 is a view showing an example of a surface conduction electron-emitting device manufactured by the manufacturing method according to the embodiment of the present invention.

2 and 3, reference numeral 1 denotes a substrate;
Is an element electrode, 4 is a conductive thin film, 5 is an electron emitting portion, 6 is an insulating film, 7 is a droplet applying device, 8 is a droplet, and 9 is an opening for forming the conductive thin film 4.

As the droplet applying device 7, any device can be used as long as it can form an arbitrary droplet. In particular, the device can be controlled in the range of about several tens to several tens of ng. An ink jet type apparatus which can easily form a small amount of droplets of about 10 ng or more is preferable. The material of the droplet may be in any state as long as the droplet can be formed, and examples thereof include a solution in which the above-described metal or the like is dispersed and dissolved in water, a solvent, or the like, an organic metal solution, or the like. .

First, the insulating substrate 1 is sufficiently washed with an organic solvent and dried, and then the device electrodes 2 and 3 (FIG. 2) are formed on the substrate 1 by using a vacuum deposition technique and a photolithography technique.
(A)), a column direction wiring 1 connected to one element electrode 2
0 (FIG. 2B), an insulating film 6 having a part of the other element electrode 3 and an opening 9 for forming a conductive thin film (FIG. 2B).
(C)) and a row-direction wiring 11 (FIG. 2D) connected to the element electrode 3 are sequentially formed.

Next, a droplet 8 of a material solution for forming the conductive thin film 4 is injected and applied to the opening 9 of the substrate by using a droplet applying device 7, and then heated at a temperature of 300 ° C. to 600 ° C. The conductive thin film 4 is formed by treating and evaporating the solvent.
(E)).

The electron-emitting portion 5 is a high-resistance crack formed in a part of the conductive thin film 4 and is formed by current forming or the like. The crack may have conductive fine particles having a particle size of several Angstroms to several hundred Angstroms. The conductive fine particles contain at least some of the elements constituting the conductive thin film 4. Further, the electron-emitting portion 5 and the conductive thin film 4 in the vicinity thereof may include carbon or a carbon compound.

In the energization forming, an electric current is applied between the element electrodes 2 and 3 from a power source (not shown) to locally destroy, deform or alter the conductive thin film 4, thereby forming a portion having a changed structure. The site where the structure is locally changed is referred to as an electron emitting portion 5 (FIG. 2F). FIG. 4 shows an example of the voltage waveform of the energization forming.

The voltage waveform is preferably a pulse waveform. When a voltage pulse having a constant pulse peak value is continuously applied (FIG. 4A), when a voltage pulse is applied while increasing the pulse peak value (FIG. 4B) will be described.

In FIG. 4A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, respectively. T1 is 1 to 10 ms, T2 is 10 to 100 ms, and the peak value of the triangular wave is (Peak voltage at the time of energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device, and a voltage is applied for several seconds to several tens of minutes in a vacuum atmosphere having an appropriate degree of vacuum, for example, about 10 ^-5 torr. . Note that the waveform applied between the element electrodes is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted.

T1 and T2 in FIG.
As in (a), the peak value of the triangular wave (peak voltage at the time of energization forming) is increased, for example, by about 0.1 V step and applied under an appropriate vacuum atmosphere.

In the energization forming process in this case, the element current is measured at a voltage that does not locally destroy or deform the conductive thin film 4 during the pulse interval T2, for example, a voltage of about 0.1 V, and the resistance value is measured. And the resistance value is, for example, 1M
The energization forming is terminated when a resistance equal to or higher than ohms is indicated.

Next, it is desirable to perform a process called an activation process on the device after the energization forming. The activation step is performed at a degree of vacuum of, for example, about 10 ⁻⁴ to 10 ⁻⁵ torr,
Similar to the energization forming, this is a process of repeatedly applying a voltage pulse having a constant pulse peak value, and depositing carbon or a carbon compound caused by an organic substance existing in a vacuum on a conductive thin film, thereby causing an element current If and a discharge. This is a process for significantly changing the current Ie. The activation process is performed with the device current I
f, while measuring the emission current Ie, for example, the emission current Ie
It ends when is saturated. Further, it is preferable that the applied voltage pulse be performed at an operation drive voltage (voltage at which the completed electron-emitting device is operated).

Here, the carbon or carbon compound is graphite (indicating both single and polycrystalline) and amorphous carbon (indicating a mixture of amorphous carbon and polycrystalline graphite). The thickness is preferably Å or less, more preferably 300 Å or less.

It is preferable to operate and drive the electron-emitting device thus prepared in an atmosphere having a higher vacuum degree than the forming step and the activation step. Further, it is desirable to drive the device after heating at 80 ° C. to 150 ° C. in an atmosphere with a higher degree of vacuum.

The degree of vacuum higher than the degree of vacuum in the forming step and the activation processing step is, for example, 10 ^−6.
The degree of vacuum is not less than torr, more preferably an ultrahigh vacuum system, and a degree of vacuum in which carbon or a carbon compound is hardly newly deposited on the conductive thin film. This makes it possible to stabilize the element current If and the emission current Ie.

Next, a method for manufacturing the image forming apparatus of the present invention will be described.

The electron source substrate used in the image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on the substrate.

As a method of arranging the surface-conduction electron-emitting devices, a surface-conduction electron-emitting device is arranged in parallel, and both ends of each element are connected by wiring. And a simple matrix arrangement in which an X-direction wiring and a Y-direction wiring are respectively connected to a pair of device electrodes of a surface conduction electron-emitting device (hereinafter, referred to as a "matrix-type arrangement electron source substrate"). . Note that an image forming apparatus having a ladder-type arranged electron source substrate requires a control electrode (grid electrode) that is an electrode for controlling the flight of electrons from the electron-emitting devices. FIG. 5 is a plan view showing an example of a matrix-type arranged electron source substrate using the surface conduction electron-emitting device of FIG. 1 and a cross-sectional view taken along the line CC ′.

Hereinafter, the configuration of the electron source substrate of the present invention will be described with reference to FIG. In FIG. 6, reference numeral 61 denotes an electron source substrate, 62 denotes an X-direction wiring, and 63 denotes a Y-direction wiring.
64 is a surface conduction electron-emitting device, and 65 is a connection.

In the figure, the substrate used as the electron source substrate 61 is the above-mentioned glass substrate or the like, and the shape is appropriately set according to the application. The X-direction wiring 62 is DX1, DX2,
.., DXm, and the Y direction wiring 63 is DY
1, DY2,..., DYn. The wiring can be made of a conductive metal or the like formed by using a vacuum evaporation method, a printing method, a sputtering method, or the like, and a voltage is supplied to a large number of surface conduction electron-emitting devices with a substantially uniform voltage. The material, thickness and width of the wiring are appropriately designed. The m X-directional wirings 62 and the n Y-directional wirings 63 are electrically separated by an interlayer insulating film (not shown) to form a matrix wiring (m and n are both positive integers).

The interlayer insulating film (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 substrate 61 on which an X-direction wiring 62 is formed
The film thickness, material, and manufacturing method are set so as to be able to withstand the potential difference at the intersection of the X-direction wiring 62 and the Y-direction wiring 63, particularly on the entire surface or a part thereof. The X-direction wiring 62 and the Y-direction wiring 63 are led out as external terminals.

Further, the surface conduction electron-emitting device 64 is electrically connected to the m X-directional wires 62, the n Y-directional wires 63, and the connection 65.

The surface conduction electron-emitting device 64 may be formed on either the substrate or the interlayer insulating layer (not shown).

As will be described in detail later, the X-direction wiring 62 includes surface conduction type emission elements 64 arranged in the X-direction.
Are electrically connected to a scanning signal applying unit (not shown) for scanning the row according to an input signal.

On the other hand, each column of the surface conduction electron-emitting devices 64 arranged in the Y direction is arranged in the Y direction wiring 63 in accordance with an input signal.
It is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulation.

The driving voltage applied to each element of the surface conduction electron-emitting device 64 is supplied as a difference voltage between the scanning signal and the modulation signal applied to the element.

In the above configuration, individual surface conduction electron-emitting devices 64 can be selected and driven independently only by simple matrix wiring.

Next, an image forming apparatus using an electron source substrate having a simple matrix arrangement prepared as described above will be described with reference to FIGS. 7, 8 and 9. FIG. FIG. 7 is a basic configuration diagram of a display panel of the image forming apparatus, and FIG. 8 is a schematic diagram of a fluorescent film used in the image forming apparatus of FIG.
FIG. 9 is a block diagram of a driving circuit for performing display according to a television signal of the NTSC method, and shows an image forming apparatus including the driving circuit.

In FIG. 7, reference numeral 61 denotes an electron source substrate on which a plurality of surface conduction electron-emitting devices are arranged; 71, a rear plate on which the electron source substrate 61 is fixed; and 76, a fluorescent film 74 and a metal back 75 on the inner surface of a glass substrate 73. And the like are formed on the face plate. Reference numeral 72 denotes a support frame, and the rear plate 7
1. The support frame 72 and the face plate 76 are coated with frit glass or the like, and 400 to 50 in air or nitrogen.
The envelope 78 is formed by baking at 0 degree for 10 minutes or more to seal.

In FIG. 7, reference numeral 5 corresponds to the electron emitting portion 5 in FIG. Reference numerals 62 and 63 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The envelope 78 includes the face plate 76, the support frame 72, and the rear plate 71 as described above.
Since the rear plate 71 is provided mainly for the purpose of reinforcing the strength of the power supply substrate 61, if the electron source substrate 61 itself has sufficient strength, the separate rear plate 71 is unnecessary,
The support frame 72 may be directly sealed to the electron source substrate 61, and the envelope 78 may be configured by the face plate 76, the support frame 72, and the electron source substrate 61. Furthermore, by installing an anti-atmospheric pressure support member called a spacer between the face plate 76 and the rear plate 71, the envelope 78 having sufficient strength against atmospheric pressure can be formed.

In FIG. 8, reference numeral 82 denotes a phosphor. Fluorescent film 74
(FIG. 7) can be composed of only the phosphor 82 in the case of monochrome. In the case of a color fluorescent film, it is composed of a black conductive material 81 called a black stripe or a black matrix and a fluorescent material 82 depending on the arrangement of the fluorescent materials. The purpose of providing the black stripes and the black matrix is to make the color separation between the phosphors 82 of the necessary three primary color phosphors black in the case of color display so as to make color mixing less noticeable, The purpose is to suppress a decrease in contrast due to reflection.
The material of the black stripe is not limited to a material that mainly uses graphite, which is generally used, as long as the material has little light transmission and reflection.
As a method of applying a phosphor on the glass substrate 73, a precipitation method, a printing method, or the like is used regardless of monochrome or color.

A metal back 75 is usually provided on the inner surface side of the fluorescent film 74 (FIG. 7). The purpose of providing the metal back is to improve the luminance by reflecting the light toward the inner surface side of the phosphor emission toward the face plate 76 in a specular manner, to function as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from damage due to collision of negative ions generated in the enclosure. The metal back can be manufactured by performing a smoothing treatment (usually called “filming”) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al using a vacuum evaporation method or the like. The face plate 76 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 74 to further increase the conductivity of the fluorescent film 74. When the above-mentioned sealing is performed, in the case of color, the phosphors of each color and the surface conduction electron-emitting devices must correspond to each other, and it is necessary to perform sufficient alignment.

The envelope 78 is connected to an exhaust pipe (not shown) through
^The degree of vacuum is set to about ^-7 torr, and sealing is performed.

Further, the degree of vacuum after sealing the envelope 78 is maintained.
In some cases, a getter process is performed for this purpose. This is the perimeter
Resistance heating immediately before or after sealing of vessel 78
Or by using a heating method using high-frequency heating or the like,
Heats the getter located at a predetermined position (not shown)
This is a process for forming a deposited film. Getter is usually Ba
Are the main components, and by the adsorption action of the deposited film, for example,
1 × 10^-Five~ 1 × 10 ^-7Maintain torr vacuum
Things. Note that the surface conduction electron-emitting device
The steps after the ringing are appropriately set.

Next, a schematic configuration of a driving circuit for performing a television display based on an NTSC television signal in an image forming apparatus using an electron source having a simple matrix arrangement type substrate is shown in a block diagram of FIG. This will be described with reference to FIG. In FIG. 9, reference numeral 91 denotes an image display panel (enclosure 78).
, 92 denotes a scanning circuit, 93 denotes a control circuit, and 94 denotes a shift register. 95 is a line memory, 96 is a synchronizing signal separation circuit, 97 is a modulation signal generator, and Vx and Va are DC voltage sources.

The function of each section will be described below. First, the display panel 91 includes terminals Dox1 to Doxm and a terminal Doy.
It is connected to an external electric circuit via 1 to Doyn and the high voltage terminal Hv. Terminals Dox1 to Doxm
The electron source substrate 61 provided in the display panel
A scanning signal is applied to sequentially drive a group of the surface conduction electron-emitting devices 64 arranged in a matrix of m rows and n columns in a row (n elements).

On the other hand, to the terminals Dy1 to Dyn, a modulation signal for controlling the output electron beam of each element 64 of the surface conduction electron-emitting elements in one row selected by the scanning signal is applied. From the DC voltage source Va, the high voltage terminal Hv
For example, a DC voltage of 10 K [V] is supplied, which is an accelerating voltage for applying sufficient energy to an electron beam emitted from the surface conduction electron-emitting device 64 to excite the phosphor 82. .

Next, the scanning circuit 92 will be described. This circuit includes m switching elements inside (in the figure, S1 to Sm are schematically shown). Each switching element selects one of the output voltage of the DC voltage source Vx and 0 [V] (ground level) and electrically connects it to the terminals Dx1 to Dxm of the display panel 91. Each of the switching elements S1 to Sm operates based on the control signal T _SCAN output from the control circuit 93, and can be actually configured by combining switching elements such as FETs.

It should be noted that the DC voltage source Vx is such that the drive voltage applied to an element that is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting device 64 is equal to or lower than the electron emission threshold voltage. It is set to output a constant voltage such that

The control circuit 93 has a function of coordinating the operation of each unit so that appropriate display is performed based on an image signal input from the outside. Based on the synchronizing signal T _SYNC sent from the synchronizing signal separating circuit 96 described below, each control signal of T _SCAN , T _SFT and T _MRY is generated for each unit.

The synchronizing signal separating circuit 96 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside. As is well known, the synchronization signal separated by the synchronization signal separation circuit 96 is composed of a vertical synchronization signal and a horizontal synchronization signal, but is shown here as a T _SYNC signal for convenience of explanation. On the other hand, the luminance signal component of the image separated from the television signal is referred to as DAT for convenience.
This signal is referred to as an A signal, and is input to the shift register 94.

The shift register 94 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 T _SFT sent from the control circuit 93. It operates (that is, the control signal T _SFT can be said to be a shift clock of the shift register 94). The data of one line of the serial / parallel converted image (corresponding to the drive data of the surface conduction electron-emitting device 64 of n elements)
The shift register 94 outputs n parallel signals Id1 to Idn.

The line memory 95 is a recording device for storing data of one line of an image for a required time only.
The contents of Id1 to Idn are stored as appropriate according to the control signal T _MRY sent from the control circuit 93. The stored contents are output as Id1 to Idn and input to the modulation signal generator 97.

The modulation signal generator 97 outputs the image data I
The signal source is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of d1 to Idn, and its output signal is supplied to the surface conduction electron-emitting device 64 in the display panel 91 through terminals Doy1 to Doyn. Is applied to

As described above, the surface conduction electron-emitting device 64 according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, as described above, electron emission has a definite threshold voltage Vth, and electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes in accordance with the change in the voltage applied to the device. The electron emission threshold V can be changed by changing the material, configuration, and manufacturing method of the electron emission element.
In some cases, the degree of change of the emission current with respect to the value of th or the applied voltage changes, but in any case, the following can be said.

When a pulsed voltage is applied to this 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, an electron beam is output. At that time, first, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Second, the pulse width P
By changing w, it is possible to control the total amount of charges of the output electron beam. Therefore, as a method of modulating the surface conduction electron-emitting device 64 according to an input signal, a voltage modulation method, a pulse width modulation method, and the like can be mentioned. A voltage modulation circuit that generates a voltage pulse of a fixed length and modulates the peak value of the pulse appropriately according to input data is used.

In order to implement the pulse width modulation method,
As the modulation signal generator 97, 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 input data is used.

By the series of operations described above, the image display device of the present invention can display a television using the display panel 91. Although not particularly described in the above description, the shift register 94 and the line memory 95 may be of a digital signal type or an analog signal type. In short, serial / parallel conversion and storage of image signals can be performed at a predetermined speed. It should be done.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separating circuit 96 into a digital signal. This can be achieved by providing an A / D converter at the output of the synchronizing signal separating circuit 96. It is possible. In connection with this, the circuit used for the modulation signal generator 97 differs slightly depending on whether the output signal of the line memory 95 is a digital signal or an analog signal.

First, the case of a digital signal will be described. In the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 97, and an amplification circuit or the like may be added as necessary. In the case of the pulse width modulation method, the modulation signal generator 97 includes, for example, a high-speed oscillator, a counter that counts the number of waves output from the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. (Comparator) can be used. If necessary, an amplifier for amplifying the pulse width modulated signal output from the comparator to the drive voltage of the surface-conduction electron-emitting device 64 may be added.

Next, the case of an analog signal will be described.
In the voltage modulation method, for example, an amplification circuit using a well-known operational amplifier or the like may be used as the modulation signal generator 97, and a level shift circuit or the like may be added as necessary. In the case of the pulse width modulation system, for example, a well-known voltage controlled oscillator (VCO) may be used, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device 64 may be added as necessary. You may.

In the image display apparatus according to the present invention which can have such a configuration, electrons are emitted by applying a voltage to the respective surface conduction electron-emitting devices through the external terminals Dox1 to Doxm and Doy1 to Doyn. An image can be displayed by applying a high voltage to the metal back 75 or a transparent electrode (not shown) through the terminal Hv, accelerating the electron beam, colliding with the fluorescent film 74, and exciting and emitting light.

The configuration described above is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display or the like. For example, detailed portions such as materials of each member are not limited to the above-described contents. Is appropriately selected so as to be suitable for the use of the image forming apparatus. Although the NTSC system has been described as an example of the input signal, the present invention is not limited to this, and PAL, SECA
Various systems such as the M system may be used, and a TV signal (for example, high-definition TV) system including a larger number of scanning lines may be used.

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

FIG. 10 is a schematic view showing an example of an electron source substrate having a ladder-type arrangement. In FIG. 10, 101 is an electron source substrate, 64 is a surface conduction electron-emitting device, and 103 is Dx.
1 to Dx10 are common wirings connected to the surface conduction electron-emitting device 64. Surface conduction electron-emitting device 64
Are arranged in parallel in the X direction on the substrate 101 (this is called an element row). A ladder-type electron source substrate is provided with a plurality of the element rows. By appropriately applying a drive voltage between the common lines of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold may be applied to an element row that emits an electron beam, and a voltage equal to or lower than the electron emission threshold may be applied to an element row that does not emit an electron beam. Further, among the common wirings Dx2 to Dx9 between the element rows, adjacent wirings such as Dx2 and Dx3 and Dx5 and Dx5 may be connected together to form the same wiring.

FIG. 11 is a view showing the structure of an image forming apparatus provided with a ladder-type electron source substrate. 111 is a grid electrode, 112 is a hole through which electrons pass, 113
Are external terminals made of Dox1, Dox2,..., Doxm. Reference numeral 114 denotes an external terminal composed of G1, G2,..., And Gn connected to the grid electrode 111, and 101 denotes an electron source substrate in which the common wiring between the element rows is the same as described above. 11, the same reference numerals as those in FIGS. 7 and 10 indicate the same members. An image forming apparatus incorporating a ladder-type electron source substrate is different from the above-described image forming apparatus having a simple matrix arrangement (FIG. 7) in that a grid electrode 111 is provided between the electron source substrate 101 and the face plate 76. .

The grid electrode 111 is for modulating the electron beam emitted from the surface conduction electron-emitting device 64. The grid electrode 111 applies the electron beam to a stripe-shaped electrode provided orthogonal to the ladder-shaped element row. In order to allow the light to pass, one circular opening 112 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.

The external terminal 113 and the external container terminal 114 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 the sequential driving (scanning) of 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.

Example 1 An electron source substrate having a large number of surface conduction electron-emitting devices 64 was manufactured using a substrate on which wirings and device electrodes were formed in a matrix in the manner described above. FIG. 2 is a diagram showing the manufacturing method. FIG.
5A is a plan view of an electron source substrate manufactured according to the present embodiment, and FIG. 5B is a cross-sectional view taken along the line CC ′ of FIG. 5A.

(1) A quartz substrate is used as the insulating substrate 1,
This was sufficiently washed with an organic solvent or the like, and then dried at 120 ° C.

(2) The device electrodes 2 and 3 (FIG. 2A) made of Ni and the X-directional wiring 10 (FIG. 2B) are formed on the insulating substrate 1 by using a vacuum film forming technique and a photolithographic technique.
Was formed. At this time, the gap interval between the device electrodes 2 and 3 was 20 μm, the width of the electrodes was 500 μm, the thickness was 500 Å, the pitch between the devices was 1 mm, the width of the X-direction wiring 10 was 300 μm, and the thickness was 500 Å. Further, an insulating film 6 is formed by using a vacuum film forming technique, and an opening 9 for forming a conductive thin film connecting the gap between the device electrodes 2 and 3 is formed by using a photolithographic technique and an etching technique. , Y direction wiring 11
An opening was formed at the connection with one of the element electrodes 3 connected to the substrate (FIG. 2C). The opening 9 was 100 μm on a side, and the thickness of the insulating film 6 was 5000 Å. Then, a Y-directional wiring 11 made of Au connected to one of the device electrodes 3 was formed by using a vacuum film forming technique and a photolithography technique (FIG. 2D). The width of the wiring was 200 angstroms and the thickness was 5000 angstroms.

(3) Next, the substrate 1 contains organic palladium.
A solution (Okuno Pharmaceutical Co., Ltd. ccp-4230) with droplets
Inkjet device using a piezoelectric element as the feeding device 7
Over the device electrodes 2 and 3 in each opening 9
And heat-treated at 300 ° C for 10 minutes.
Go to the fine particles of palladium oxide (PdO) fine particles
A conductive film was formed to form a conductive thin film 4 (FIG. 2E). 1
One drop volume is 60 μm ^Three Was controlled.

(4) Next, a voltage is applied between the device electrodes 2 and 3 to energize the conductive thin film 4 (energization forming).
As a result, the electron emission portion 5 was formed (FIG. 2).
(F)).

Using the thus prepared electron source substrate,
As shown in FIG. 7, the face plate 76, the support frame 72,
An enclosure 78 is formed by the rear plate 71 and sealed, and a display panel is formed. Further, an image forming apparatus having a driving circuit for performing television display based on an NTSC television signal as shown in FIG. Was prepared.

The electron-emitting device manufactured as described above according to the manufacturing method of this embodiment not only exhibited good characteristics without any problem, but also provided droplets and formed the conductive thin film 4. And the droplets were injected into the openings 9 in a self-aligned manner, so that they could be easily formed without the need for high-precision alignment.

Example 2 In the same manner as in Example 1, the device electrode width (W1) was 600 μm and the device electrode pair spacing (L1).
A surface conduction electron-emitting device 64 having a thickness of 2 μm, a thickness of the element electrode section of 500 Å, and a pitch between the elements of 500 μm is formed in a ladder shape, and is the same as that of the first embodiment using the wired electron source substrate 101 (FIG. 10). In the method, the envelope 78 is formed by the face plate 76, the support frame 72, and the rear plate 71.
Was formed and sealed to produce a display panel, and an image forming apparatus having a drive circuit for performing television display based on NTSC television signals as shown in FIG. As a result, a good image forming apparatus similar to that of Example 1 was obtained.

(Embodiment 3) In the same manner as in Embodiment 1, using a substrate (FIG. 5) wired in a matrix, an ink jet apparatus of a type in which bubbles are generated by applying thermal energy and droplets are ejected. To produce a surface conduction electron-emitting device 64 in the same manner as in Example 1 to obtain an electron source substrate 61. Using the obtained electron source substrate 61, an envelope 78 is formed by the face plate 76, the support frame 72, and the rear plate 71 in the same manner as in Example 1, and the display panel is further sealed by performing sealing. An image forming apparatus having a driving circuit for performing television display based on an NTSC television signal as shown in FIG. 9 was manufactured. As a result, Example 1
As a result, a good image forming apparatus was obtained.

(Embodiment 4) A method in which a device electrode is formed in a ladder shape as shown in FIG. 10 and wired, and bubbles are generated by applying thermal droplet energy in the same manner as in Embodiment 3 to discharge bubbles. Example 3 using the inkjet device of
In the same manner as described above, a surface conduction electron-emitting device 64 was manufactured to obtain an electron source substrate 101 (FIG. 10). Obtained electron source substrate 10
10, an envelope 1088 is formed by the face plate 1086, the support frame 1082, and the rear plate 1081 in the same manner as in the first embodiment, and sealing is performed to display the display panel, as shown in FIG. An image forming apparatus having a driving circuit for performing television display based on NTSC television signals was manufactured. As a result, a good image forming apparatus similar to that of Example 1 was obtained.

Example 5 A substrate (FIG. 3) wired in a matrix was used, and the opening 9 was circular and had a diameter of 100.
Other than that, a surface conduction electron-emitting device was manufactured in the same manner as in Example 1 to obtain an electron source substrate 61. Using the obtained electron source substrate 61, a face plate 1086, a support frame 1082, a rear plate 1081 are formed in the same manner as in the first embodiment.
Then, an envelope 1088 was formed, sealing was performed, and a display panel, and further, an image forming apparatus having a driving circuit for performing television display based on an NTSC television signal as shown in FIG. 10 was manufactured. . As a result, a good image forming apparatus similar to that of Example 1 was obtained.

(Embodiment 6) In this embodiment, a substrate (FIG. 3) wired in a matrix is formed by a screen printing method.
Was prepared to obtain an electron source substrate 61. Using the obtained electron source substrate 61, an envelope 78 is formed by the face plate 76, the support frame 72, and the rear plate 71 in the same manner as in the first embodiment.
Was formed and sealed to produce a display panel, and an image forming apparatus having a drive circuit for performing television display based on NTSC television signals as shown in FIG. As a result, a good image forming apparatus similar to that of Example 1 was obtained.

In this embodiment, since the image forming apparatus is manufactured by a manufacturing method that does not use the photolithography technique for forming the wirings and elements as described above, the cost is lower than the thin film process, and the manufacturing yield is lower. Greatly improved.

(Embodiment 7) The electron source substrate of the present embodiment was prepared by dissolving Pd acetate in water as a material solution for forming a conductive thin film.
Except that a solution containing 5 wt% was used, it was produced in the same manner as in the example.

Using the obtained electron source substrate 61, the face plate 76, the support frame 72,
An enclosure 78 is formed by the rear plate 71 and sealed, and a display panel is formed. Further, an image forming apparatus having a driving circuit for performing television display based on an NTSC television signal as shown in FIG. Was prepared. As a result, an excellent image forming apparatus similar to that of Example 1 could be obtained despite the difference in the components contained in the material solution.

Example 8 The electron source substrate of this example was manufactured in the same manner as in Example 1 except that the droplet amount was 30 μm ³ and two droplets (2 dots) were applied.

Using the obtained electron source substrate 61, the face plate 76, the support frame 72,
An enclosure 78 is formed by the rear plate 71 and sealed, and a display panel is formed. Further, an image forming apparatus having a driving circuit for performing television display based on an NTSC television signal as shown in FIG. Was prepared. As a result, a good image forming apparatus similar to that of Example 1 was obtained. That is, it has been found that a desired thin film can be obtained by giving a desired number of droplets according to the production method of the present invention.

Example 9 The electron source substrate of this example was manufactured in the same manner as in Example 1 except that the droplet amount was 200 μm ³ .

Using the obtained electron source substrate 61, the face plate 76, the support frame 72,
An enclosure 78 is formed by the rear plate 71 and sealed, and a display panel is formed. Further, an image forming apparatus having a driving circuit for performing television display based on an NTSC television signal as shown in FIG. Was prepared. Further, in the present embodiment, although the liquid overflowed from the opening 9 (not shown), it was found that there was no problem in the electron emission characteristics of the electron emission element 64. As a result, a good image forming apparatus similar to that of Example 1 was obtained.

[0108]

As described above, according to the present invention,
Since the solution containing the material of the fine particle film having the electron-emitting portion in the opening is applied in the form of a droplet, a desired amount can be applied to a predetermined position by self-alignment, and high-precision alignment is not required. The yield can be improved.

In the case of applying droplets by the ink-jet method, there is an effect that a small amount of droplets of about several tens ng or more controlled in the range of about ten and several ng to several μg can be applied.

Further, since no photolithography technology is used for the element, there is an effect that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic plan view and a cross-sectional view illustrating a basic configuration of a planar surface conduction electron-emitting device according to an embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view illustrating a manufacturing method according to the embodiment of the present invention.

FIG. 3 is a schematic diagram showing a part of an electron source substrate in a matrix arrangement in which the surface conduction electron-emitting devices of FIG. 1 are arranged.

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

5A and 5B are a plan view and a cross-sectional view illustrating an example of a matrix-type electron source substrate according to the embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating an electron source substrate having a simple matrix arrangement according to an embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an image forming apparatus using an electron source substrate having a simple matrix arrangement according to an embodiment of the present invention.

8 is a pattern diagram of the fluorescent film 74 of FIG.

FIG. 9 is a block diagram showing an example of a drive circuit for performing display in accordance with a television signal of the NTSC method in the image forming apparatus according to the present invention.

FIG. 10 is a schematic diagram showing a ladder-type arrangement of electron source substrates according to an embodiment of the present invention.

FIG. 11 is a schematic configuration diagram of an image forming apparatus using a ladder-type arrangement of electron source substrates according to an embodiment of the present invention.

FIG. 12 is a schematic plan view showing a conventional electron-emitting device.

FIG. 13 is a schematic perspective view showing another conventional electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive thin film 5 Electron emission part 6 Insulating film 7 Droplet applying device 8 Droplet 9 Opening for forming conductive thin film 10, 62 X direction wiring (column direction wiring) 11, 63 Y Direction wiring (row direction wiring) 61 Electron source substrate 64 Surface conduction electron-emitting device 65 Connection 71 Rear plate 72 Support frame 73 Glass substrate 74 Fluorescent film 75 Metal back 76 Face plate 77 High voltage terminal 78 Enclosure 81 Black member 82 Fluorescence Body 91 Display panel 92 Scanning circuit 93 Control circuit 94 Shift register 95 Line memory 96 Synchronous signal separation circuit 97 Modulation signal generator Vx, Va: DC voltage source 101 Electron source substrate 103 (Dx1 to Dx10) Wiring the electron emitting elements Wiring 111 Grid electrode 112 Hole 113 for passing electrons (Dox) 1, Dox2,..., Doxm) Outer terminal 114 (G1, G2,..., Gn) Grid electrode 111
Outer container terminal connected to

Claims (11)

[Claims] Forming a pair of adjacent device electrodes on an insulating substrate; and forming an insulating layer having an opening including an adjacent portion of the pair of adjacent device electrodes on the pair of adjacent device electrodes. Forming a conductive thin film in the opening by dropping a solution containing a conductive thin film forming material into the opening in the form of droplets; and forming an electron emitting portion in the conductive thin film. A method for manufacturing an electron-emitting device, comprising: 2. The method according to claim 1, wherein a thickness of the conductive thin film is controlled by an amount and / or a number of the droplets. 3. The method for manufacturing an electron-emitting device according to claim 1, wherein the droplet applying device for applying the droplet is an ink jet system. 4. The method according to claim 3, wherein the ink jet method is a method in which bubbles are formed in the solution by thermal energy and the solution is discharged as droplets. 5. A method for manufacturing an electron source substrate in which a plurality of electron-emitting devices are arranged on an insulating substrate and a wiring between the electron-emitting devices and a terminal for applying a voltage to the devices are formed. A method for manufacturing an electron source substrate, wherein the element is manufactured by the method according to claim 1. 6. A step of forming a plurality of electrode pairs arranged in a matrix on an insulating substrate; and a step of forming a plurality of column-directional wirings connecting one side of the electrode pairs in the same column on the insulating substrate. Forming an insulating layer on the substrate, leaving a first opening including an opposing portion of the electrode pair and a second opening including a connection portion between the other side of the electrode pair and a row wiring. Forming a plurality of row-directional wirings on the insulating layer that connect the other side of the electrode pair in the same row via the second opening; and forming a conductive thin film in the first opening. Forming a conductive thin film in the opening by dropping a solution containing a forming material in the form of droplets; and forming an electron emitting portion in the conductive thin film. Source substrate manufacturing method. 7. The method according to claim 6, wherein the thickness of the conductive thin film is controlled by the amount and / or the number of the droplets. 8. The method for manufacturing an electron source substrate according to claim 6, wherein the liquid droplet applying device for applying the liquid droplet is an ink jet method. 9. The method of manufacturing an electron source substrate according to claim 8, wherein the ink jet method is a method in which bubbles are formed in the solution by thermal energy and the solution is discharged as droplets. 10. An electron-emitting device as an electron source, means for applying a voltage to the device, a luminous body that emits light by receiving electrons emitted from the device, and a voltage applied to the device based on an external signal. 10. A method for manufacturing an image forming apparatus, comprising: a driving circuit for controlling an image forming apparatus, wherein the electron source substrate is manufactured by the method according to claim 5. Method. 11. An insulating layer having an insulating substrate, a pair of element electrodes formed on the insulating substrate, and an opening formed in a gap between the pair of element electrodes and including a part of the pair of element electrodes. And a conductive film formed in the opening to electrically connect the pair of device electrodes, and an electron emitting portion formed in the conductive film.