JPH11339643A - Dripping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface conductive electron emitting element capable of inexpensively and easily forming an electron emitting element in the large area and excellent in uniformity, an electron source base board having it and an image forming device. SOLUTION: In a manufacturing method of an electron emitting element, the electron emitting part is formed by imparting a solution of a material for forming a conductive film between a pair of element electrode 2, 3 plural times to the same place by an ink jet system dripping means. In this case, dripping to the whole elements of plural electron emitting elements is set as a single operation unit so that the operation unit is repeated plural times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electron-emitting device and an electron source substrate, an electron source, a display panel, and a droplet applying device used for manufacturing an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter, referred to as an FE type), a metal / insulating layer / metal type (hereinafter, referred to as an MIM type), and a surface conduction type electron emission element. Examples of the FE type include “WP Dyke &
W. W. Dolan, "Field emissio
n ", Advance in Electron Ph
ysics, 889 (1956) "or" C.
A. Spindt, “Physical Proper
ties of thin-film field e
mission cathodes with mol
ybdenium "J. Appl. Phys., 475.
248 (1976) ". Examples of the MIM type are “CA Mead,“ The Tunnel ”.
-Emission amplifier ", J. Ap
pl. Phys. , 32 646 (1961) "and the like.

Examples of the surface conduction electron-emitting device include:
"MI Elinson, Radio Eng. El
electron Phys. , 10 (1965) ". The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As the surface conduction type electron-emitting device, S
One using an nO ₂ thin film, one using an Au thin film (see “G.
Dittmer: "Thin Solid Film
s ", 9 317 (1972)"), In ₂ O ₃ / Sn
O ₂ due to the thin film ( "M.Hartwell and
C. G. FIG. Fonstad: "IEEETrans.E
D Conf. ", 519 (1975)"), using a carbon thin film ("Hisashi Araki et al .: Vacuum, Vol. 26, No. 1")
No. 22, p. 22 (1983) ").

A typical device configuration of these surface conduction electron-emitting devices is described in the above-mentioned M.S. FIG. 17 shows the device configuration of the Hartwell. 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 emitting portion 5 is formed by an energization process called energization forming described later.
The element electrode interval L in the figure is 0.5 to 1 mm, W ′
Is set at 0.1 mm. Since the position and shape of the electron-emitting portion 5 are unknown, they are shown as schematic diagrams.

Conventionally, in these surface-conduction electron-emitting devices, the electron-emitting portion 5 is generally formed by subjecting the conductive thin film 4 to an energization process called energization forming before performing electron emission. It is a target. The energization forming is to apply a DC voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 4 and to energize the conductive thin film 4 to locally destroy, deform or alter the conductive thin film 4. This is to form the electron-emitting portion 5 in a resistance state. Incidentally, the electron emitting portion 5 is formed of the conductive thin film 4.
A crack is generated in a part of the substrate and electrons are emitted from the vicinity of the crack. In the surface conduction type electron-emitting device subjected to the energization forming process, a voltage is applied to the conductive thin film 4 and a current flows through the device to cause the electron-emitting portion 5 to emit electrons.

The above-mentioned surface conduction type emission element has an advantage that a large number of elements can be arranged and formed over a large area because of its simple structure and easy manufacture. Therefore, various applications that can take advantage 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, 5
Denotes an electron emission 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 and a photolithography technique. Next, a conductive thin film 4 is formed by a dispersion coating method or the like. After that, a voltage is applied to the device electrodes 2 and 3 to perform an energization process, thereby forming the electron emission portions 5.

[0008]

However, in the above-mentioned conventional manufacturing method, which is manufactured by a method mainly using a semiconductor process, it is difficult to form an electron-emitting device on a large area with the current technology. In addition, 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 surface conduction electron-emitting device capable of easily forming an electron-emitting device over a large area at low cost, and an electron source substrate and an image forming apparatus having the same. is there. Another object of the present invention is to provide a surface conduction electron-emitting device having good uniformity, an electron source substrate having the same, and an image forming apparatus.

[0010]

In order to achieve the above object, according to the present invention, a solution of a material for forming a conductive film is formed between a pair of element electrodes by an ink-jet type droplet applying means. In the method of manufacturing an electron-emitting device for forming an electron-emitting portion by applying the same portion a plurality of times in the state described above, when manufacturing a plurality of the electron-emitting devices, all of the plurality of the electron-emitting devices are used. The application of a droplet is defined as one operation unit, and the operation unit is repeated a plurality of times.

Further, a droplet applying means may be used in which the ink jet system generates bubbles by applying thermal energy and discharges droplets. Also, it is possible to manufacture an electron source substrate using the above-described manufacturing method, manufacture an electron source using the same, manufacture a display panel using the same, and further manufacture an image forming apparatus using the same. it can.

[0012]

Next, preferred embodiments of the present invention will be described. As the cold cathode electron source to which the present invention is applied, a surface conduction electron-emitting device having a simple configuration and easy to manufacture is suitable.

FIG. 4 shows a basic structure according to an embodiment of the present invention.
A schematic plan view showing the configuration of a surface conduction electron-emitting device and
FIG. In FIG. 4, 1 is a substrate, 2 and 3 are elements.
Electrodes 4, 4 are conductive thin films, and 5 is an electron-emitting portion. Substrate 1
As the low content of impurities such as quartz glass and Na
Glass, blue glass, SiO_Two Glass formed on the surface
Substrates and ceramic substrates such as alumina
You. A general conductor is used as a material for the device electrodes 2 and 3.
For example, Ni, Cr, Au, Mo, W, Pt, T
metal or alloy such as i, Al, Cu, Pd, Pd, A
g, Au, RuO _Two Or metal such as Pd-Ag
Printed conductor composed of oxide and glass, In_Two O_Three 
-SnO_Two And transparent conductors, semiconductor materials such as polysilicon
It is appropriately selected from fees and the like.

The distance L between the device electrodes 2 and 3 is preferably several hundred angstroms to several hundred micrometers. Further, it is desirable that the voltage applied between the element electrodes 2 and 3 is low, and it is required to produce the element with good reproducibility. Therefore, the preferable element electrode interval L is several micrometers to several tens of micrometers. The length W1 of the device electrodes 2 and 3 is 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 several hundred angstroms to several micrometers. Is preferred. The configuration is not limited to the configuration in FIG. 4, and a configuration in which the conductive thin film 4 and the electrodes of the device electrodes 2 and 3 are sequentially formed on the substrate 1 may be employed.

As the conductive thin film 4, a fine particle film composed of fine particles is particularly preferable in order to obtain good electron emission characteristics. It is appropriately set according to the resistance value between the electrodes and the energizing forming conditions described later, but is preferably several Angstroms to several thousand Angstroms, and particularly preferably 10 Angstroms to 500 Angstroms.
Angstrom. The sheet resistance value is 10 3
Power to 10 7 ohms / square.

The material constituting the conductive thin film 4 is P
d, Pt, Ru, Ag, Au, Ti, In, Cu, C
metals such as r, Fe, Zn, Sn, Ta, W, Pb, Pd
Oxide such as O, SnO 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,} T
carbides such as aC, SiC, WC, TiN, ZrN, Hf
Examples include nitrides such as N, 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. The fine structure thereof is not limited to a state in which the fine particles are individually dispersed and arranged, but also a state in which the fine particles are adjacent to each other or overlapped (an island). The particle size of the fine particles is from several Angstroms to several thousand Angstroms, preferably from 10 Angstroms to 200 Angstroms.

Next, a method for manufacturing the electron-emitting device shown in FIG. 4, particularly a method for forming a fine particle film constituting the conductive thin film 4, will be described in detail with reference to the drawings. 1 and 2 are views showing this manufacturing method, and FIG. 2 is a cross-sectional view showing a state when a droplet is applied.

1 and 2, 1 is a substrate, 2 and 3 are element electrodes, 6 is a droplet applying device, 7 is a droplet, and 8 is a liquid or solid state formed after applying a droplet to the substrate 1. Is a circular film (dot).

As the droplet applying device 6, any device can be used as long as it can form an arbitrary droplet. In particular, the device can be controlled in a 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. Also,
The material of the droplet may be 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, and the like.

First, device electrodes 2 and 3 are formed on a substrate 1 which has been sufficiently washed and dried with an organic solvent or the like by using a vacuum deposition technique and a photolinography technique. Next, dots 8 are provided on the substrate by the procedure shown in FIG. FIG. 1 (a)
FIGS. 1B to 1D are diagrams showing a state before dots are added, FIGS. 1B to 1D are diagrams showing a state during dot addition, and FIGS. The application was performed a plurality of times at the same location by repeating the operation unit a plurality of times, with one or more operations being performed for all the plurality of electron-emitting devices. In the figure, reference numeral 8a denotes a dot provided in one operation unit, and dots 8 are provided by repeating the operation unit a desired number of times. FIG. 1C is a diagram at the time when one operation unit ends. FIG. 1E is a diagram at the time when the operation unit ends a desired number of times and the dot application ends as a whole. In FIG. 1, the number of repetitions in the operation unit is two, but may be three or more.

Here, the diameter, film thickness and film quality of the dots 8 applied on the substrate 1 are determined by the surface condition of the substrate and the applied droplets. The droplets may change subtly, and the state of the diameter, film thickness, film quality, etc. of the dots 8 formed when the droplets are sequentially applied from one end to the other of the substrate 1 depends on the location on the substrate 1. There were different cases. However, according to the present invention, since the droplets are applied in a procedure of repeatedly applying the droplets to the entire surface of the substrate 1, it is possible to eliminate the difference in the state of the dots 8 in the substrate 1.

After the thin film is applied by the above method, a heat treatment is performed at a temperature of 300 to 600 degrees to evaporate the solvent to form a conductive thin film. The formed conductive film is uniform over each element on the substrate, like the dots before the heat treatment.

The electron-emitting device shown in FIG. 4 will be described. The electron-emitting portion 5 is a high-resistance crack formed in a part of the conductive thin film 4, and is formed by energization 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 contain carbon or a carbon compound.

In an energization process called energization forming, an energization is performed 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. Things. The site where the structure is locally changed is the electron emitting portion 5. FIG. 5 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform. When a voltage pulse having a constant pulse peak value is continuously applied (FIG. 5A), when a voltage pulse is applied while increasing the pulse peak value (FIG. 5B). First, the case where the pulse peak value is a constant voltage (FIG. 5A) will be described.

In FIG. 5A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave ( The peak voltage at the time of energization forming is appropriately selected according to the form of the surface conduction electron-emitting device, and is applied for several seconds to several tens of minutes under a vacuum atmosphere having an appropriate degree of vacuum, for example, about 10 −5 torr. . The waveform applied between the element electrodes is not limited to a triangular wave, and a desired waveform such as a rectangular wave may be used.

T1 and T2 in FIG. 5 (b) are the same as those in FIG. 5 (a), and the peak value of the triangular wave (peak voltage at the time of energization forming) is increased by, for example, about 0.1 V step and an appropriate vacuum is applied. Apply under 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. The energization forming is terminated when, for example, a resistance of 1 M ohm or more is indicated.

According to the present embodiment, since the conductive thin film 4 is uniform over each element, the energization forming process can be performed without any variation among the elements, and the formed electron-emitting portion has no variation between the elements. And even characteristics when driven as an electron-emitting device.

Next, it is desirable to perform a process called an activation process on the element after the energization forming. The activation process is, for example, a process of repeatedly applying a voltage pulse having a constant pulse peak value at a degree of vacuum of about 10 −4 to 10 −5 torr, as in the energization forming. Is deposited on the conductive thin film 4 by carbon or a carbon compound caused by an organic substance existing in the device.
f, a process for significantly changing the emission current Ie. The activation step measures the device current If and the emission current Ie,
For example, the process ends when the emission current Ie is saturated. Further, it is preferable that the applied voltage pulse be performed at an operation drive voltage.

Here, the carbon or carbon compound is
Graphite (indicating both single crystal and polycrystalline) and amorphous carbon (indicating a mixture of amorphous carbon and polycrystalline graphite). The film thickness is preferably 500 Å or less, more preferably 300 Å or less. It is.

The electron-emitting device thus prepared is preferably operated and driven in an atmosphere having a degree of vacuum higher than the degree of vacuum in the energization 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 vacuum degree higher than the vacuum degree after the forming step and the activation treatment is, for example, a vacuum degree of about 10 −6 or more, more preferably an ultra-high vacuum system, in which carbon or a carbon compound is newly formed of a conductive thin film. 4 is a degree of vacuum that hardly accumulates. This makes it possible to stabilize the element current If and the emission current Ie.

Next, the image forming apparatus will be described. An electron source substrate used in an image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on a substrate. As a method of arranging the surface-conduction electron-emitting devices, the surface-conduction electron-emitting devices are arranged in parallel, and both ends of each device are connected by wiring (hereinafter referred to as a ladder-type arrangement electron source substrate) or A simple matrix arrangement in which an X-direction wiring and a Y-direction wiring are connected to a pair of device electrodes of a surface conduction electron-emitting device, respectively (hereinafter, referred to as a matrix-type arrangement electron source substrate). Note that an image forming apparatus having a ladder-type electron source substrate requires a control electrode (grid electrode) which is an electrode for controlling the flight of electrons from the electron-emitting devices.

The structure of the electron source having the simple matrix arrangement will be described below with reference to FIG. 61 is an electron source substrate, 6
2 is an X-direction wiring, 63 is a Y-direction wiring, 64 is a surface conduction electron-emitting device, and 65 is a connection. The substrate used as the electron source substrate 61 is the above-described glass substrate or the like, and the shape is appropriately set according to the application. The m X-direction wires 62 are DX
, DXm,... DXm, and the Y-direction wiring 63 is composed of n wirings DY1, DY2,.
Further, the material, the film thickness, and the wiring width are appropriately set so that a substantially uniform voltage is supplied to many surface conduction elements 64. The m X-directional wirings 62 and the n Y-directional wirings 63 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring (m and n are both positive integers).

The interlayer insulating layer (not shown) is formed in a part of a desired region on the entire surface of the substrate 61 on which the X-directional wiring 62 is formed. The X-direction wiring 62 and the Y-direction wiring 63 are led out as external terminals. Further, the device electrodes (not shown) of the surface conduction electron-emitting device 64 are electrically connected to the m X-directional wires 62 and the n Y-directional wires 63 by connection 65. The surface conduction electron-emitting device 64 may be formed on either the substrate or an interlayer insulating layer (not shown).

As will be described in detail later, the X-direction wiring 62
Are electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for scanning a row of the surface conduction electron-emitting devices 64 arranged in the X direction according to an input signal. On the other hand, the Y-direction wiring 63 is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulating each column of the surface conduction electron-emitting devices 64 arranged in the Y direction according to an input signal. It is connected. Further, the driving voltage applied to each element of the surface conduction electron-emitting device 64 is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element. As a result, individual elements can be selected and driven independently using only simple matrix wiring.

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

In FIG. 7, reference numeral 61 denotes an electron source substrate on which an electron-emitting device 64 is formed, 71 is a rear plate on which the electron source substrate 61 is fixed, and 76 is a fluorescent film 74 and a metal back 75 on the inner surface of a glass substrate 73. A face plate 72 on which the like is formed is a support frame, and the rear plate 71, the support frame 72, and the face plate 76 are coated with frit glass or the like, and 400 to 500 in air or nitrogen.
The envelope 78 is formed by baking for 10 minutes or more at a temperature to seal. Reference numeral 5 denotes an electron-emitting portion of the electron-emitting device 64;
Reference numeral 3 denotes an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of each surface conduction electron-emitting device 64.

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 electron source substrate 61, if the electron source substrate 61 itself has sufficient strength, the separate rear plate 71 is unnecessary, and The support frame 72 may be directly sealed, and the envelope 78 may be constituted by the face plate 76, the support frame 72, and the electron source substrate 61. Further, by providing 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 obtained.

In FIG. 8, reference numeral 82 denotes a phosphor constituting the phosphor film 74. The phosphor 82 is composed of only the phosphor in the case of monochrome, but is composed of the black conductive material 81 called a black stripe or a black matrix depending on the arrangement of the phosphor in the case of a color phosphor film. The purpose of providing a black stripe and a black matrix is to provide each of the three primary color phosphors 82 required for color display.
The purpose of this is to make the color mixture or the like inconspicuous by making the inter-colored portions black, and to suppress a decrease in contrast due to reflection of external light on the fluorescent film 74. The material of the black stripe is not limited to a commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection.

As a method of applying a fluorescent substance to the glass substrate 73, a precipitation method or a printing method is used regardless of monochrome or color. A metal back 75 (FIG. 7) is usually provided on the inner surface side of the fluorescent film 74 (FIG. 7). The metal back 75 improves the brightness by reflecting the light toward the inner surface side of the light emitted from the phosphor to the face plate 76 side to improve the brightness, acts as an electrode for applying an electron beam acceleration voltage, and It has a role of protecting the phosphor from damage due to collision of negative ions generated in the vessel.
The metal back 75 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 74 after manufacturing the fluorescent film 74 and then depositing Al by vacuum evaporation or the like.

The face plate 76 further includes a fluorescent film 7.
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 74 in order to increase the conductivity of the fluorescent film 74. When performing the above-mentioned sealing, in the case of color, the phosphors of each color must correspond to the electron-emitting devices, and it is necessary to perform sufficient alignment.

The envelope 78 passes through an exhaust pipe (not shown) and
^The degree of vacuum is set to about ^-7 torr, and sealing is performed. In some cases, getter processing is performed to maintain the degree of vacuum of the envelope 78 after sealing. This is performed at a predetermined position (not shown) in the envelope 78 by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 78 is sealed.
This is a process of heating the getter arranged in the above to form a deposited film. The getter is usually composed mainly of Ba or the like, and maintains a degree of vacuum of, for example, 1 × 10 ⁻⁵ torr to 1 × 10 ⁻⁷ torr by the adsorption action of the deposited film.
Steps after the energization forming of the surface conduction electron-emitting device are appropriately set.

Next, this display panel constituted by using an electron source having a simple matrix arrangement type substrate is driven and NT
A schematic configuration of a driving circuit for performing television display based on an SC television signal will be described with reference to FIG. 9
1 is the display panel, 92 is a scanning circuit, 93 is a control circuit, 94 is 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 is connected to the terminals Dox1 to Doxm and the terminal Dx1.
It is connected to an external electric circuit via oy1 to Doyn and the high voltage terminal Hv. Of these terminals, the terminals Dox1 to Doxm sequentially drive electron sources provided in the display panel 91, that is, a group of surface conduction electron-emitting devices arranged in a matrix of M rows and N columns, one row at a time (N elements). A scanning signal for moving is applied. On the other hand, terminal D
To oy1 to Doyn, a modulation signal for controlling the output electron beam of each element of the one row of surface conduction electron-emitting devices selected by the scanning signal is applied. Further, for example, 10K [V] is applied to the high voltage terminal Hv from the DC voltage source Va.
This is an accelerating voltage for applying sufficient energy to the electron beam output from the surface conduction electron-emitting device to excite the phosphor.

Next, the scanning circuit 92 will be described. This circuit has M switching elements inside (in the figure, S1 to Sm are schematically shown), and each switching element is provided with an output voltage of a DC voltage source Vx or 0V.
[V] (ground level) is selected and electrically connected to the terminals Dox1 to Doxm of the display panel 91. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 93, but can be actually configured by combining switching elements such as FETs. The DC voltage source Vx is a characteristic (electron emission threshold voltage) of the surface conduction electron-emitting device.
Is set so as to output a constant voltage such that the drive voltage applied to the element not scanned is equal to or lower than the electron emission threshold voltage.

The control circuit 93 has a function of matching the operations of the respective units so that an appropriate display is performed based on an externally input image signal. Based on the synchronization signal Tsync sent from the synchronization signal separation circuit 96 described below, Tscan, Tsft, and Tm
ry control signals are generated.

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, and can be formed by using a frequency separating (filter) circuit. It is.
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 Tsync signal for convenience of explanation. On the other hand, a luminance signal component of an image separated from the television signal is referred to as a DATA signal for convenience, and the signal is input to a 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 operates based on a control signal Tsft sent from the control circuit 93. I do. That is, the control signal Tsft is
May be rephrased as the shift clock. One line of serial / parallel converted image (electron emitting element N
(Corresponding to the drive data for the elements) is output from the shift register 94 as N parallel signals Id1 to Idn.

The line memory 95 is a storage device for storing data for 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 Tmry 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 Id
A signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of 1 to Idn, and an output signal thereof is sent to the surface conduction electron-emitting device in the display panel 91 through terminals Doy1 to Doyn. Applied.

As described above, the electron-emitting device 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 clear 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. Note that the value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may be changed by changing the material, configuration, and manufacturing method of the electron emission element. I can say that.

That is, when a pulse-like voltage is applied to the device, for example, when a voltage lower than the electron emission threshold is applied, no electron emission occurs but a voltage higher than the electron emission threshold is applied. Outputs an electron beam. that time,
First, it is possible to control the intensity of the output electron beam by changing the pulse peak value Vm. Second, 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 in accordance with the input signal, there are a voltage modulation method, a pulse width modulation method, and the like. A voltage modulation circuit is used which generates a voltage pulse having a length of, but modulates the peak value of the pulse appropriately according to input data. In order to implement the pulse width modulation method, the modulation signal generator 97 generates a voltage pulse having a constant peak value, but the pulse width is such that the width of the voltage pulse is appropriately modulated according to input data. A modulation type circuit is used.

By the above-described series of operations, the image display device can display a television using the display panel 91. Although not specifically 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 are performed at a predetermined speed. It should be done in.

When using a digital signal type,
It is necessary to convert the output signal DATA of the synchronization signal separation circuit 96 into a digital signal. This can be achieved by providing an A / D converter at the output of the synchronization signal separation circuit 96. 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 for counting the number of waves output by the oscillator,
And a circuit combining a comparator (comparator) for comparing the output value of the counter with the output value of the line memory 95. 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 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 method, for example, a well-known voltage-controlled oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device may be added as necessary. You may.

In the image display device having the above-described configuration, the electron-emitting devices of the display panel 91 are provided with external terminals Dox1 to Doxm, Doy1 to Doyn.
Through the high voltage terminal Hv to apply a high voltage to the metal back 75 or a transparent electrode (not shown) to accelerate the electron beam, collide with the fluorescent film 84, and excite An image can be displayed by emitting light.

The structure described above is a schematic structure necessary for producing a suitable image forming apparatus used for display and 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. Also, the NTSC system has been described as an example of the input signal, but 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 composed of a larger number of scanning lines (for example, a high-definition TV including the MUSE system) may be used.

Next, the above-mentioned ladder-type arrangement electron source substrate and an image display device using the same will be described with reference to FIGS. 10, reference numeral 101 denotes an electron source substrate, 102 denotes an electron-emitting device, and 103 denotes Dx1 to Dx10.
Is a common wiring connected to the electron-emitting device 110. A plurality of electron-emitting devices 101 are arranged on the substrate 101 in parallel in the X direction. This is called an element row. A plurality of such element rows are arranged on a substrate to form a ladder-type electron source substrate. By appropriately 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 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, the common wirings Dx2 to Dx9 between the element rows, for example, Dx2 and Dx3 may be the same wiring.

FIG. 11 shows the structure of an image forming apparatus having such a ladder-type electron source. 111 is a grid electrode, 112 is a hole for passing electrons, 113 is
Dox1, Dox2 ... Doxm outer terminals, 114 are G1, G connected to the grid electrode 111
.., Gn, the external terminal 115 is an electron source substrate in which the common wiring between the element rows is the same as described above. 7 and 10 indicate the same members. Image forming apparatus with simple matrix arrangement described above (FIG. 7)
The difference is that the electron source substrate 115 and the face plate 76
Is provided with the grid electrode 111 therebetween.

The grid electrode 111 is capable of modulating the electron beam emitted from the surface conduction electron-emitting device, and passes the electron beam to a stripe-shaped electrode provided orthogonal to the ladder-shaped device row. For this purpose, one circular opening 112 is provided for each element 102. The shape and the installation position of the grid need not always be as shown in FIG. 11, and a large number of openings may be provided in the form of a mesh as openings. For example, the openings may be provided around or near the surface conduction electron-emitting device 102. Good. The terminal 113 outside the container and the terminal 114 outside the grid container are electrically connected to a control circuit (not shown).

In the present image forming apparatus, the modulation signals for one line of an image are simultaneously applied to the grid electrode rows in synchronization with the sequential driving (scanning) of the element rows one by one.
By controlling the irradiation of each electron beam to the phosphor, an image can be displayed line by line.

According to this, it is possible to provide an image forming apparatus suitable for a display device such as a television conference system and a computer as well as a display device for a television broadcast. Further, it can be used as an image forming apparatus as an optical printer including a photosensitive drum or the like.

The image forming apparatus can be applied not only to a surface conduction electron-emitting device but also to a cold cathode electron source using an MIM-type electron-emitting device, a field-emission-type electron-emitting device, or the like. . Further, the present invention can be applied to an image display device using a thermoelectron source.

[0068]

[Example 1] Through the following steps (1) to (3), device electrodes were formed in a substrate shape, and droplets were applied by the method shown in FIG. 1 to produce a surface conduction electron-emitting device. did. FIG. 3 is a diagram showing the manufacturing method.

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

Next, device electrodes 2 and 3 made of Ni were formed on the substrate 1 by using a general vacuum film forming technique and a photo lithography technique. The distance L between the device electrodes was 2 μm, the width W of the device electrode was 600 μm, and the thickness thereof was 1000 °.

Next, an ink jet ejecting apparatus using a piezoelectric element was used as a droplet applying apparatus, and the liquid droplet applying apparatus shown in FIG.
As shown in (1), an organic palladium-containing solution (palladium acetate-ethanolamine complex aqueous solution (2 wt%)) was applied to form dots. The application of the droplet was performed twice for each element electrode pair arranged on the substrate. At that time, first, the application of the droplet was performed once to all the element electrode pairs. The droplets were applied to all the device electrode pairs one more time. The formed dots were uniform without variation among the elements.

Next, a heat treatment was performed at 300 ° C. for 10 minutes to form a fine particle film made of fine particles of palladium oxide (PdO), thereby forming a thin film 4.

Next, a voltage is applied between the electrodes 2 and 3 and the thin film 4 is subjected to an energizing process (forming process).
An electron emitting portion 5 was formed.

In the electron source substrate manufactured by the above-described method, the thin film 4 and the electron emitting portion 5 do not vary from element to element.
The uniformity of the device characteristics of the electron-emitting device was good. Using the electron source substrate manufactured in this way, a peripheral device was formed with the above-described face plate, support frame, and rear plate, sealing was performed, and a display panel was manufactured. Since the patterning of No. 4 can be omitted, the cost can be suppressed.

[Example 2] A surface conduction electron-emitting device was manufactured using the substrate which was wired in a matrix and had device electrodes formed by the method described above through the following steps (1) to (4). FIG. 12 is a schematic diagram for explaining the manufacturing method according to the second embodiment of the present invention.

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

Next, the device electrodes 2 and 3 made of Ni were formed on the substrate 1 by using a general vacuum film forming technique and a photo lithography technique. The distance between the device electrodes was 2 μm, the width of the electrodes was 600 μm, and the thickness thereof was 1000 °.

Next, a lower wiring 122 made of Al, an insulating layer 126 made of SiO ₂ , and an upper wiring made of Al are formed on the substrate on which the device electrodes are formed by using a general vacuum film forming technique and a photolithography technique. 123 were sequentially formed. FIG. 12A is a schematic diagram showing a state in which the upper wiring is formed on the substrate.

Next, as a droplet applying device, an ink jet device using a method of generating bubbles by applying thermal energy and discharging droplets is used, and an organic palladium-containing solution (palladium acetate solution) is applied between the device electrodes 2 and 3. An aqueous solution of an ethanolamine complex (2 wt%) was applied to form dots.When applying droplets, first, the droplets were applied once to all the device electrode pairs, and then all the device electrodes were applied. Droplets were applied one more time to the pair.
The dots formed on each element were uniform without variation among the elements. FIG. 12B is a schematic diagram showing a state where the first droplet application is performed, and FIG. 12C is a schematic diagram showing a state where the second droplet application is performed.

Next, a heat treatment was performed at 300 ° C. for 10 minutes to form a fine particle film composed of fine particles of palladium oxide (PdO), thereby forming a thin film 4.

Next, a voltage is applied between the electrodes 2 and 3 and the thin film 4 is subjected to an energizing process (forming process),
The electron-emitting device section 5 was formed.

Using the electron source substrate thus manufactured,
The above-described face plate, support frame, and rear plate formed an outer package, sealed, and produced a display panel, and further an image forming apparatus having a drive circuit for performing television display. Since there were few defects and the patterning of the thin film 4 could be omitted, the cost could be reduced.

[0083] [Example 3] the device electrode width W ₁ 600 [mu]
m, the device electrode spacing L ₁ 2 [mu] m, the thickness of the device electrodes 10
A surface conduction electron-emitting device was manufactured in the same manner as in Example 2 using a substrate having device electrodes wired in a ladder shape and formed as 00 °. Using the obtained electron source substrate, an envelope is formed with a face plate, a support frame, and a rear plate in the same manner as in Example 2, sealing is performed, and a display panel and a television signal of an NTSC system are further formed. Based on the above, an image forming apparatus having a driving circuit for performing television display was manufactured. As a result, the same effect as in Example 2 was obtained.

[Embodiment 4] FIG. 14 is a schematic diagram for explaining a manufacturing method according to a fourth embodiment of the present invention. In this embodiment, first, a substrate on which element electrodes and matrix wirings were formed was manufactured in the same manner as in the first embodiment.

As a droplet applying device, an ink jet device using a method of generating bubbles by applying thermal energy and discharging droplets is used, and an organic palladium-containing solution (palladium acetate-ethanolamine complex) is applied between the device electrodes 2 and 3. An aqueous solution (2 wt%) was applied to form dots.
In applying the droplet, first, the droplet was applied once to all the device electrode pairs, and then the droplet was applied another time to all the device electrode pairs.

At this time, the first application is performed along the arrow (a) in FIG. 14A, and the second application is performed according to FIG.
The droplets were continuously applied through the first and second times. In this embodiment, since the application of the droplet is continuously performed at a certain cycle or less, the application of the droplet can be performed more stably. The dots formed on each element were uniform without variation among the elements.

Next, a heat treatment was carried out at 300 ° C. for 10 minutes to form a fine particle film composed of fine particles of palladium oxide (PdO), thereby obtaining a thin film 4.

Next, a voltage is applied between the electrodes 2 and 3 and the thin film 4 is subjected to an energizing process (forming process).
An electron emitting portion 5 was formed.

Using the electron source substrate thus manufactured,
The above-described face plate, support frame, and rear plate formed an outer package, sealed, and produced a display panel, and further an image forming apparatus having a drive circuit for performing television display. Since there were few defects and the patterning of the thin film 4 could be omitted, the cost could be reduced.

[Embodiment 5] FIG. 15 is a schematic diagram for explaining a manufacturing method according to a fifth embodiment of the present invention. In the present embodiment, first, a substrate on which device electrodes and matrix wirings were formed was manufactured in the same manner as in the second embodiment.

Next, as a droplet applying device, an ink jet device using a method of generating bubbles by applying thermal energy to discharge droplets is used, and an organic palladium-containing solution (palladium acetate-ethanol) is applied between the device electrodes 2 and 3. Amine complex aqueous solution (2 wt%)) was applied as droplets to form dots. When applying the droplet, first, the droplet is applied once to all the device electrode pairs, and then,
Droplets were applied once more to all the device electrode pairs.

At this time, the first application is performed from the peripheral portion to the center along the arrow (a) in FIG. 15A, and the second application is performed as indicated by the arrow (b) in FIG. Along the first and second times, the application of droplets was performed continuously through the first and second times. In the present example, the droplet application was performed continuously at a certain cycle or less, so that the droplet application could be performed more stably. The dots formed on each element were uniform without variation among the elements.

Next, a heat treatment was performed at 300 ° C. for 10 minutes to form a fine particle film made of fine particles of palladium oxide (PdO), thereby forming a thin film 4.

Next, a voltage is applied between the electrodes 2 and 3 and the thin film 4 is subjected to an energizing process (forming process),
An electron emitting portion 5 was formed.

Using the thus prepared electron source substrate,
The above-described face plate, support frame, and rear plate formed an outer package, sealed, and produced a display panel, and further an image forming apparatus having a drive circuit for performing television display. Since there were few defects and the patterning of the thin film 4 could be omitted, the cost could be reduced.

[Embodiment 6] FIG. 16 is a schematic diagram for explaining a manufacturing method according to a sixth embodiment of the present invention. In this embodiment, first, a substrate on which element electrodes and matrix wirings are formed in the same manner as in the second embodiment is used.

Next, as a droplet applying device, an ink jet device using a method of generating bubbles by applying thermal energy and ejecting droplets is used, and an organic palladium-containing solution (palladium acetate-ethanolamine) is applied between the device electrodes 2 and 3. The aqueous solution of the complex (2% by weight) was applied as droplets to form dots.When applying the droplets, first, applying the droplets twice to all the device electrode pairs was repeated three times. Drops were applied to the element six times in total.
FIG. 16A is a schematic diagram showing a state after the first repetition operation is completed, and FIG. 16B is a schematic diagram showing a state after the repetition operation is performed three times and droplets are applied to each element a total of six times. FIG. The dots formed on each element were uniform without variation among the elements.

Next, a heat treatment was performed at 300 ° C. for 10 minutes to form a fine particle film made of palladium oxide (PdO) fine particles, thereby forming a thin film 4.

Next, a voltage is applied between the electrodes 2 and 3, and the thin film 4 is subjected to an energizing process (forming process).
An electron emitting portion 5 was formed.

Using the thus prepared electron source substrate,
The above-described face plate, support frame, and rear plate formed an outer package, sealed, and produced a display panel, and further an image forming apparatus having a drive circuit for performing television display. Since there were few defects and the patterning of the thin film 4 could be omitted, the cost could be reduced.

[Embodiment 7] In the seventh embodiment of the present invention,
When applying the droplet, the substrate is divided into two blocks,
A device similar to the second example was prepared except that a droplet was applied to each region. In this embodiment, substantially the same effects as in the second embodiment could be obtained.

[0102]

As described above, according to the present invention,
Since the application of the droplet by the ink jet method is performed once or plural times for all the plurality of electron-emitting devices as one operation unit, the operation unit is repeated a plurality of times, so that uniformity is excellent. An electron-emitting device, an electron source substrate, and an electron source can be manufactured, and a low-cost display panel image forming apparatus with less luminance unevenness and defects can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for manufacturing a basic surface conduction electron-emitting device according to an embodiment of the present invention.

FIG. 2 is a view showing a method of manufacturing a basic surface conduction electron-emitting device according to an embodiment of the present invention.

FIG. 3 is a view illustrating a method of manufacturing a basic surface conduction electron-emitting device according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a basic surface conduction electron-emitting device according to an embodiment of the present invention.

FIG. 5 is a diagram showing a voltage waveform of energization forming applicable to the present invention.

FIG. 6 is a diagram showing an electron source having a simple matrix arrangement to which the present invention can be applied.

FIG. 7 is a schematic configuration diagram of a display panel of an image forming apparatus to which the present invention can be applied.

FIG. 8 is a diagram illustrating a phosphor film of the display panel of FIG. 7;

9 is a block diagram of a driving circuit for performing display on the display panel of FIG. 7 in response to an NTSC television signal, and an image display device having the driving circuit.

FIG. 10 is a diagram showing an electron source having a ladder arrangement to which the present invention can be applied.

FIG. 11 is a schematic configuration diagram of a display panel of another image forming apparatus to which the present invention can be applied.

FIG. 12 is a view illustrating a manufacturing method according to a second embodiment of the present invention.

FIG. 13 is a view showing a substrate having ladder-like wiring and element electrodes applicable to the manufacturing method according to the third embodiment of the present invention.

FIG. 14 is a diagram illustrating a manufacturing method according to a fourth embodiment of the present invention.

FIG. 15 is a view illustrating a manufacturing method according to a fifth embodiment of the present invention.

FIG. 16 is a view illustrating a manufacturing method according to a sixth embodiment of the present invention;

FIG. 17 is a view showing a conventional electron-emitting device.

FIG. 18 is a configuration diagram of another conventional electron-emitting device.

[Explanation of symbols]

1: substrate, 2: 3: device electrode, 4: conductive thin film, 5: electron emitting portion, 6: droplet applying device, 7: droplet, 8: dot,
61: electron source substrate, 62: X direction wiring, 63: Y direction wiring, 64: surface conduction electron-emitting device, 65: connection, 7
1: rear plate, 72: support frame, 73: glass substrate,
74: fluorescent film, 75: metal back, 76: face plate, 77: high voltage terminal, 78: envelope, 81: black conductive material, 82: phosphor, 83: glass substrate, 91: display panel, 92: scanning Circuit, 93: control circuit, 94: shift register, 95: line memory, 96: synchronization signal separation circuit, 97: modulation signal generator, Vx and Va: DC voltage source, 101: electron source substrate, 102: electron emission element , 10
3: Dx1 to Dx10 are common wirings for wiring the electron-emitting devices, 111: grid electrodes, 112: holes for passing electrons, 113: Dox1, Dox2,.
..External container terminal composed of Doxm, 114: external terminal composed of G1, G2,... Gn connected to grid electrode # 120, 115: electron source substrate, 122: lower wiring, 1
23: upper wiring, 126: insulating layer, 132: wiring.

Claims (8)

[Claims] 1. An element electrode substrate comprising: a plurality of electrode pairs each comprising a pair of element electrodes arranged with a gap arranged on the substrate along a plurality of rows and a plurality of columns; An ink jet system having a nozzle for discharging droplets composed of a material solution, and a droplet applying means for repeating a single operation of discharging droplets from the nozzle a plurality of times sequentially toward each gap of the plurality of electrode pairs. Droplet applying device. 2. The method according to claim 1, wherein the substrate is glass, and the droplet applying device is a unit that applies a solution of the material in a liquid state directly to a glass surface between the pair of element electrodes. The application device according to claim 1. 3. An element electrode substrate in which a plurality of electrode pairs consisting of a pair of element electrodes arranged with gaps are arranged on a substrate along a plurality of rows and a plurality of columns, and a conductive film is formed. Having a nozzle for discharging droplets composed of a material solution, toward the respective gaps of the plurality of electrode pairs, sequentially, odd-numbered rows and even-numbered rows of the plurality of rows in the reverse order,
And performing a first operation of discharging the liquid droplets from the nozzles in the order of the plurality of columns in one direction, and performing a first operation of discharging the liquid droplets from the nozzles in an order reverse to the order of the rows and columns of the first operation. 2. An ink-jet type droplet applying apparatus having means for performing two operations. 4. The apparatus according to claim 1, wherein the substrate is glass, and the droplet applying apparatus is an apparatus for directly applying a solution of the material in the form of droplets to a glass surface between the pair of element electrodes. The applicator according to claim 3. 5. The order of the first operation or the second operation is a continuous order starting from an electrode pair in an upper row of the plurality of electrode pairs and ending with an electrode pair in a lower row. 3. The applying device according to 3. 6. An element electrode substrate in which a plurality of electrode pairs consisting of a pair of element electrodes arranged with gaps are arranged on a substrate along a plurality of rows and a plurality of columns, and a conductive film is formed. A nozzle for discharging droplets composed of a material solution, and toward each gap of the plurality of electrode pairs, sequentially, in the reverse order of the upper row and the lower row of the plurality of rows,
And performing a first operation of discharging the droplets from the nozzles in the reverse order of the right and left columns of the plurality of columns, and in a reverse order to the order of the rows and columns of the first operation. And an ink jet type droplet applying apparatus having means for performing a second operation of discharging a droplet from a nozzle. 7. The apparatus according to claim 1, wherein the substrate is glass, and the droplet applying apparatus is an apparatus for applying a solution of the material in a liquid state directly to a glass surface between the pair of element electrodes. The applicator according to claim 6. 8. The order of the first operation or the second operation is started from an electrode pair on an outer row among the electrode pairs on the plurality of rows, and ends with an electrode pair on an inner row among the electrode pairs on the plurality of rows. 7. The continuous order starting from the outer electrode pair of the plurality of electrode pairs and ending with the inner electrode pair of the plurality of electrode pairs. Device.