JPH07326309A - Electron source and image forming device - Google Patents

Abstract

PURPOSE:To provide an electron source having high generating efficiency of an electron beam and which can emit stable electron and an image forming device for showing an image of stable gradation with high generating efficiency of the electron beam. CONSTITUTION:An electron source for emitting electron based on an input signal and a plurality at surface conduction type electron emitting elements D1-D300 are connected in parallel between power supply terminals and these respective surface conduction type electron emitting elements have a pair of opposite electrodes 5, 6 which are connected to the power supply terminals respectively and an electron emitting part 3 arranged between the pair of electrodes 5, 6. A distance between the pair of electrodes 5 and 6 in the surface conduction type electron emitting element D1 adjacent to these power supply terminals is set longer than that in the other surface conduction type electron emitting element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source and its application, an image forming apparatus, and more particularly to an electron source having a large number of surface conduction electron-emitting devices and its application, for example, an image forming apparatus such as a display device. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, a thermoelectron source and a cold cathode electron source. Among these, as the cold cathode electron source, there are a field emission type (hereinafter abbreviated as FE), a metal / insulating layer / metal type (hereinafter abbreviated as MIM), a surface conduction electron emission element (hereinafter abbreviated as SCE), and the like. is there.

As an example of the FE type, WPDyke & WWDol
an, "Field emission", AdvanceinElectron Physics, 8,
89 (1956) is known.

As an example of the MIM type, CAMead, "T
he tunnel-emission amplifier, J.Appl.Phys., 32,649
(1961), CASpindt, "Physical properties of thi
n-film field emission cathodes with molybdemum con
es ", J.Appl.Phys., 47, 5248 (1976) and the like are known.

Further, as an example of the SCE type, MIElinson, R
adio Eng. Electron Pys., 10, (1965), etc.

Further, the SCE utilizes a phenomenon in which electron emission occurs when a current is passed through a thin film having a small area formed on a substrate in parallel with the film surface.

As the surface conduction electron-emitting device, one using a SnO 2 thin film by Erinson et al., One using an Au thin film [G. Dittmer: "Thin Solid Films", 9,317
(1972)], by In2O3 / SnO2 thin film [M. Hartwell
and CGFonstad: "IEEE Trans.ED Conf.", 519 (197
5)], a carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like.

As a typical device configuration of these surface conduction electron-emitting devices, the above-mentioned M. The Hartwell device configuration is shown in FIG. In the figure, 1 is an insulating substrate.
The electron emitting portion forming thin film is made of an H-shaped metal oxide thin film or the like formed by sputtering, and the electron emitting portion 3 is formed by an energization process called forming described later. 4 will be referred to as a thin film including an electron emitting portion. In addition, L in the figure
1 is set to 0.5 to 1 mm and W is set to 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, it is general that the electron-emitting portion forming thin film is formed in advance by an energization process called forming before the electron emission is performed. It was That is, the forming means that a voltage is applied to both ends of the electron emitting portion forming thin film to locally energize the electron emitting portion forming thin film to locally destroy, deform, or alter the electron emitting portion forming thin film to form an electrically high resistance electron emitting state. To form part 3.

The surface-conduction type electron-emitting device which has been subjected to the forming treatment is such that electrons are emitted from the electron-emitting region 3 by applying a voltage to the thin film 4 including the electric-emitting region and passing a current through the device surface. is there. In addition, in the electron emitting portion 3, a crack is generated in a part of the thin film for forming the electron emitting portion,
Electrons are emitted from the vicinity of the crack. Hereinafter, it is referred to as a thin film 4 including an electron emitting portion formed by forming. The surface conduction electron-emitting device that has undergone such forming processing emits electrons from the electron-emitting portion 3 by applying a voltage between the electrodes 5 and 6.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be arrayed over a large area because it has a simple structure and is easy to manufacture. Therefore, various applications that can make full use of this feature are being studied. For example,
Examples include a charged beam source and a display device. An example of arraying a large number of surface conduction electron-emitting devices is an electron source in which surface conduction electron-emitting devices are arranged in parallel and a large number of rows in which both ends of each element are connected by wiring are arranged. (For example, Japanese Patent Application Laid-Open No. 1-03133 of the present applicant.
2). On the other hand, in image forming apparatuses such as display devices, in particular, flat-panel display devices using liquid crystal have become popular in place of CRTs in recent years, but since they are not self-luminous, they must have a backlight, etc., and have a narrow viewing angle. Therefore, the development of a self-luminous display device has been desired.

Further, conventionally, as a self-luminous display device, a plurality of planar electron-emitting devices and an image-forming member (for example, a fluorescent member) that forms an image by irradiation of electron beams emitted from the electron-emitting devices. 2. Description of the Related Art There is a thin image display device in which a body, a resist material, and the like, which are members that emit light, change color, charge, and change due to the collision of electrons, face each other. As an example of such an image display device, FIGS.
FIG. 1 shows a schematic view of a conventional electron beam display device.

First, FIG. 2 shows an electron beam display apparatus having a structure in which a modulation electrode is arranged between an electron-emitting device and an image forming member which face each other.
Is a rear plate, 72 is a support, 73 is a wiring electrode, and 74
Is an electron emission part, 75 is an electron passage hole, 76 is a modulation electrode, 7
Reference numeral 7 is a glass plate, 78 is a transparent electrode, 79 is a phosphor (image forming member), 80 is a face plate, and 82 is a bright spot of the phosphor. The electron emitting portion 74 of the electron emitting element (composed of 72, 73 and 74) is formed by a thin film technique and has a hollow structure that does not contact the rear plate 71. Further, the modulation electrode 76 is arranged in the space above the electron emission portion 74 (in the electron emission direction), and therefore has a passage hole 75 for the emitted electron beam.

In this electron beam display device, a voltage is applied to the wiring electrode 73 to heat the electron emitting portion 74 having a hollow structure so as to emit thermoelectrons and modulate the electron flow according to an information signal. Electrons are taken out from the passage hole 75 by applying a voltage to 76, and the taken out electrons are accelerated to collide with the phosphor 79. Further, an XY matrix is formed by the wiring electrodes 73 and the modulation electrodes 76, and an image is displayed on the phosphor 79 which is an image forming member.

Further, as another display device, there is a horizontal address vertical electrostatic deflection type display device developed by Eiichi Miyazaki and Yasumasa Sakamoto of Kanazawa Institute of Technology. FIG. 3 is a block diagram of the device, and FIG. 4 is a principle diagram thereof.

In FIG. 3, reference numeral 91 is a substrate, 92 is a modulation electrode, 93 is a thermoelectron source, 94 is an upper deflection electrode, and 95 is a lower deflection electrode. Reference numeral 96 denotes a face plate made of a transparent electrode, a phosphor, a resist material, etc., which emits light when electrons collide with it.
An image forming member that undergoes discoloration, electrification, deterioration, etc. is provided. In FIG. 4, 97 is an electron beam and 98 is an equipotential line. This thermionic electron source is a tungsten wire coated with an electron emission material, and has an outer shape of 35 μm and an operating temperature of 70.
It is 0-850 degreeC.

A current is passed through the thermoelectron source 93 to cause electrons to be emitted, and the emitted electrons are applied with a voltage to the modulation electrode to control the ON / OFF of the electron beam. Thermionic source 93
The distance between the modulation electrode and the modulation electrode is 0.15 mm, the voltage applied to the modulation electrode 92 is cut off at -5 V, and the electron beam is extracted at 0 V. The extracted electron beam 97 is deflected by applying a voltage of −200 to 200 V to the deflection electrodes 94 and 95, and collides with the phosphor on the face plate 96 to emit light. That is, the number of vertical pixels is determined by the deflection electrodes 94 and 95, and the number of horizontal pixels is determined by the modulation electrode 92. Further, the electron beam 97 is transmitted to the face plate 9
6, an image is displayed by performing deflection and imaging with an electric field distribution determined by the potentials of the deflection electrodes 94 and 95 and the modulation electrode 92.

[0018]

However, the above-mentioned conventional image display device has the following problems. That is, (1) When the thermoelectron source that emits electrons by energization heating as shown in FIGS. 2 and 3 is used, the power consumption by heating is large and the efficiency is poor.

(2) If the components are not assembled with high precision, the displayed image will be distorted.

(3) In the structure shown in FIG. 3, since a linear thermoelectron source having a tungsten wire as a base is used,
The electron beam source thermally expands due to the energization heating, and variations or fluctuations occur in the amount of predetermined emitted electrons.

(4) Electron-optically susceptible to the influence of adjacent electrodes, and it is difficult to realize a multi-electron beam source with a fine pitch (it is difficult to achieve high definition as a display).

(5) Since the electric potential gradient is generated in the hot line cathode during heating by energization, the conditions are non-uniform electron-optically. That is, the intensity, the starting direction, or the convergence characteristic of each output electron beam tends to differ.

(6) In order to deal with the above problem, it has been attempted to stop the energization and utilize the stored heat after heating the cathode by energization heating, but the heat line cathode expands and contracts due to the heating / cooling cycle. Then, it vibrates mechanically and becomes electro-optically unstable.

Due to the above reasons, it was practically impossible to apply it to an image display device which performs a uniform display over a large area.

Further, in the image display device tried using the above-mentioned conventionally known surface conduction electron-emitting device, there is a problem that the brightness of the displayed image does not faithfully reproduce the original image.

That is, for example, in Japanese Examined Patent Publication (Kokoku) No. 45-31615, as shown in FIGS. 5 and 6, a lateral current type electron emitter 502 connected in series and a strip-shaped electron emitter 502 arranged so as to form a lattice therewith. Glass plate 503 having a small hole 503 'between transparent electrodes 504 of
3'is arranged so that it is exactly at the intersection of the above-mentioned lattices. Then, a transverse current type electron emitter 502 which emits electrons by enclosing a gas in these holes 503 'and an acceleration voltage E
A display device is disclosed in which only the intersection of the transparent electrodes 504 to which 2 is applied emits light by gas discharge.

Although there is no detailed description of the lateral current type electron emitter in this Japanese Patent Publication No. 45-31615,
Described materials (metal thin film, NES film) and neck 50
Since the structure of 2'is the same as the surface conduction electron-emitting device described in the section of the prior art, it is considered to be included in this category (referred to as the surface conduction electron-emitting device used by the inventors of the present application). The name is based on the description in the thin film handbook).

In the above display device, the electrons emitted from the lateral current type electron emitter are caused to collide with the accelerating gas molecules to cause discharge, but even if the same current is applied to the lateral current electron emitter, discharge light emission is performed. There is a problem that the brightness varies from pixel to pixel, or the brightness varies even in the same pixel. The reason for this is that the controllability is not good because the discharge intensity largely depends on the gas state, and the output of the lateral current type electron-emitting device is 15 mmHg as introduced as an experimental example.
It is not always stable under a certain pressure.

Therefore, it is difficult for such a display device to display multi-gradation, and it has not been widely applied to a television receiver or the like.

Therefore, the inventors have tried an apparatus in which a surface conduction electron-emitting device is installed instead of the electron-emitting device 74 in the display device of FIG. In this device, generally, a large number of elements are arranged on a substrate, and the elements are electrically wired by thin or thick film electrodes and used as a multi-electron source. Therefore, a phenomenon occurs in which the voltage applied to each element varies. As a result, the amount of current of the electron beam emitted from each emitting element varies, which causes a problem that density unevenness occurs in the formed image.

7 and 8 are diagrams for explaining this problem in more detail. In both figures, (a) is an equivalent circuit diagram including an electron-emitting device, wiring resistance and a power source, and (b) is each. FIG. 3 is a diagram showing the potentials of the positive electrode and the negative electrode of the electron-emitting device, and (c) is a diagram showing the voltage applied between the positive and negative electrodes of each device.

FIG. 7A shows a circuit in which N electron-emitting devices D1 to DN connected in parallel and a power source VE are connected to each other. The positive electrode of the power source and the positive electrode of the device D1 and the negative electrode of the power source are connected. Is connected to the negative electrode of the element DN. Further, the common wiring connecting the respective elements in parallel has a resistance component of r between the adjacent elements as shown in the figure (in the image forming apparatus, the pixels that are the targets of the electron beam are normally arranged at equal pitches). Therefore, the electron-emitting devices are also spatially arranged at equal intervals, and the wiring connecting them has the same resistance value between the devices unless the width and the film pressure vary in manufacturing). The electron-emitting devices D1 to DN have resistances Rd which are substantially equal to each other.

The vertical axis of FIG. 7 (c) shows the applied voltage.
Similar to (b), in order to make the tendency easy to see, the measured values are connected with a solid line for convenience.

As is clear from this figure, in the case of the circuit as shown in FIG. 7A, a larger voltage is applied to the elements (D1 and DN) at both ends, and the applied voltage is applied to the elements near the center. Becomes smaller. Therefore, in the electron source emitted from each electron-emitting device, the emission current becomes larger toward the devices at both ends. Therefore, when this is applied to the image forming apparatus, for example, the display density of the image near the both ends is high, and the image density near the center is light.

On the other hand, FIG. 8 shows the case where the positive and negative electrodes of the power source are connected only to one side (the element D1 side in this figure) of the element rows connected in parallel. In the case of such a circuit, as shown in FIG. 6B, the voltage drop due to the wiring resistance r increases as the positive electrode side and the negative electrode side are closer to D1.

In the circuit diagram of FIG. 8A, FIG. 8B shows the positive and negative electrode potentials of each element. In FIGS. 8B and 8C, the horizontal axis represents the element numbers D1 to DN and the vertical axis represents the potential. The ● mark represents the positive electrode potential of each element, and the ■ mark represents the negative electrode potential, and the ● mark (■ mark) is connected with a solid line for convenience in order to make the tendency of the potential distribution easy to see.

As is apparent from this figure, the voltage drop due to the wiring resistance r does not occur uniformly, and is steeper as it is closer to the element D1 on the positive side, and conversely closer to the element DN on the negative side. It is becoming steeper. This is on the positive side
This is because the closer the current is to D1, the larger the current flowing through the line resistance r, and on the negative electrode side, the closer to DN, the larger the current flows.

FIG. 8C is a plot of the voltage applied between the positive and negative electrodes of each element. Figure 8 (c)
In the figure, the horizontal axis represents the element numbers D1 to DN,
The voltage applied to each element is D as shown in FIG.
The closer it is to 1, the larger the size becomes, which is extremely inconvenient for application as an image forming apparatus.

The degree of variation in the applied voltage for each element as shown in the above two examples is determined by the total number N of elements connected in parallel.
Although it depends on the ratio of the element resistance Rd to the wiring resistance r (= Rd / r) or the connection position of the power source, in general, the larger N is and the smaller Rd / r is, the more remarkable the variation is. It is understood that the connection method of FIG. 8 has a larger variation in the voltage applied to the element than the connection method of FIG.

For example, in the connection method of FIG. 7, element resistance Rd = 1K
In the case of Ω and r = 10 mΩ, if N = 100, comparing the element having the largest applied voltage with the element having the smallest applied voltage,
Vmax: Vmin = 102: 100, but N = 1
000, Vmax: Vmin = 472: 100,
The rate of variation is large.

Further, N = 1000, Rd = 1 kΩ, r =
In the case of 1 mΩ, Vmax: Vmin = 127: 100, but in the case of the wiring resistance of r = 10 mΩ, Vma:
The degree of variation becomes large as x: Vmin = 472: 100.

As described above, when a plurality of electron-emitting devices having the same characteristics are connected in parallel, the voltage effectively generated in each device varies due to the voltage drop caused by the wiring resistance. Therefore, the emission amount of the electron beam becomes non-uniform, which is inconvenient when applied as an image forming apparatus.

Especially, the number of pixels is large (that is, N is large).
When trying to realize a large-capacity display device, there is a problem that the above-mentioned variation ratio becomes remarkable and uneven density of an image occurs.

The present invention has been made in view of the above conventional example, and an object of the present invention is to provide an electron source having a high electron beam generation efficiency and capable of stable electron emission.

The present invention has a high electron beam generation efficiency,
An object is to provide an image forming apparatus capable of expressing a stable gradation image.

Another object of the present invention is to provide an electron source in which variations in electron beam emission degree due to wiring resistance are prevented.

Another object of the present invention is to provide an image forming apparatus capable of obtaining a stable high-quality image by preventing variations in electron beam output due to wiring resistance.

[0048]

In order to achieve the above object, the electron source of the present invention has the following structure. That is,
An electron source that emits electrons based on an input signal, wherein a plurality of electrodes are connected in parallel between power supply terminals in a linear manner, and a pair of electrodes facing each other connected to the power supply terminals and a pair of the electrodes. A plurality of surface-conduction type electron-emitting devices having electron-emitting portions arranged between electrodes, and the distance between the pair of electrodes of the surface-conduction type electron-emitting devices in the vicinity of the power supply terminal is another surface-conduction type. It is set longer than the distance between the pair of electrodes of the electron-emitting device.

The image forming apparatus of the present invention has the following structure. That is, in an image forming apparatus in which a plurality of electron sources that emit an electron beam based on an input signal are arranged in a plane, the electron sources are linearly connected in parallel between power supply terminals, and each of the power sources is the power source. A plurality of surface conduction electron-emitting devices each having a pair of electrodes connected to the supply terminal and facing each other and an electron-emitting portion arranged between the pair of electrodes; and supplying the power based on the input signal. It has a driving means for energizing a terminal to drive the electron source, and an image forming means for forming a visible image by an electron beam emitted from the electron source.

[0050]

In the above structure, the electron source of the present invention has a pair of electrodes which are linearly connected in parallel between the power supply terminals and which are connected to the power supply terminals.
A plurality of surface-conduction type electron-emitting devices having an electron-emitting portion arranged between the pair of electrodes, and the distance between the pair of electrodes of the surface-conduction type electron-emitting devices near the power supply terminal is different Since the distance between the pair of electrodes of the surface conduction electron-emitting device is set longer, the influence of the wiring resistance is canceled by the distance between the electrodes.

[0051]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

As a typical electron emission characteristic of the surface conduction electron-emitting device, as shown in FIG. 9, electron emission starts when the device applied voltage is about 8 V, and the emission current increases in proportion to the applied voltage. Therefore, when the voltage effectively applied to the element is lowered for some reason, the emission current of the element with a low applied voltage is significantly reduced, and when applied to an image forming apparatus or the like, it appears as image unevenness. become. Particularly in a large-sized image display device in which surface conduction electron-emitting devices are spread over a large area, the emission current varies due to the voltage drop caused by the wiring resistance and the current flowing when the device is driven, and the display unevenness is remarkable. become.

Therefore, in this embodiment, the electron emission characteristics of the element are changed in advance so as to correct the voltage drop due to the wiring resistance, and the variation in the amount of emission current when the electron emission element is driven at a predetermined voltage is corrected. Therefore, the present invention aims to realize an electron source and an image forming apparatus that can obtain uniform electron emission.

Next, a means for changing the characteristics of the electron-emitting device will be described as an embodiment of the present invention. Figure 10
(A) and (b) are respectively a top view and a cross-sectional view showing the configuration of the surface conduction electron-emitting device used in this example.

In the figure, 1 is an insulating substrate, 3 is an electron emitting portion, 4 is a thin film including the electron emitting portion 3, and 5 and 6 are device electrodes. As a result of intensive studies by the inventors of the present device, it was found that the threshold voltage at which electron emission of the surface conduction electron-emitting device is started depends on the length of the device electrode interval L1. That is, the threshold voltage shifts to the higher voltage side as L1 becomes longer. FIG. 11 shows a typical difference in electron emission characteristics due to a difference in device electrode width L1. In FIG. 11, the characteristics indicated by ○ are the electrode spacing L1 = 2μ
The characteristics indicated by m and ● are for L1 = 20 μm. From the figure, in order to obtain a uniform emission current even when the effective applied voltage applied to the device is lowered for some reason, the interval L1 between the device electrodes is adjusted to an appropriate length in advance. It can be seen that an almost constant emission current can be obtained.

Among the surface conduction electron-emitting devices, the present inventors prefer the electron-emitting portion or its peripheral portion formed of a fine particle film in terms of electron-emitting characteristics or for manufacturing a large number over a large area. I'm finding a thing. Therefore, in the section of the embodiments of the present invention described below, an image display device using a surface conduction electron-emitting device formed by using a fine particle film as a multi-electron beam source is described as a preferable example of the image forming device of the present invention. To do.

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. First, the electron-emitting device according to the present embodiment will be described, and then the display device according to the present embodiment will be described. The configuration and driving method will be described.

<First Embodiment> Before explaining the display device of the present embodiment, the basic constitution, manufacturing method, and characteristics of the element relating to the present invention by the applicant of the present invention will be described below (Japanese Patent Laid-Open No. 2-56).
822 etc.) and the characteristics of the principle of the present invention found by the present inventors as a result of diligent study. The features of the structure and manufacturing method of the surface conduction electron-emitting device according to this embodiment are as follows.

(1) The thin film for forming an electron emitting portion (reference numeral 2 in FIG. 12) before energization treatment called forming is a thin film of fine particles formed by dispersing a fine particle dispersion, or an organic metal or the like is heated. Basically, it is composed of fine particles such as a thin film of fine particles formed by firing.

(2) The thin film 4 including the electron emitting portion after the energization process called forming is basically composed of the electron emitting portion 3 and the thin film 4 including the electron emitting portion 3 as fine particles.

There are two basic configurations of the surface conduction electron-emitting device according to this embodiment, that is, a planar type and a vertical type.

First, the planar surface conduction electron-emitting device will be described.

10 (a) and 10 (b) are a plan view and a sectional view, respectively, showing the structure of a basic planar surface conduction electron-emitting device according to this embodiment. The basic configuration of the element according to this embodiment will be described with reference to these drawings.

In FIG. 10, 1 is an insulating substrate, 5 and 6
Is an element electrode, 4 is a thin film including the electron emitting portion 3, and 3 is an electron emitting portion. As the insulating substrate 1, quartz glass, Na
Examples thereof include glass having a reduced content of impurities such as blue glass, soda lime glass, a glass substrate in which SiO2 formed by soaking on soda lime glass is laminated, and ceramics such as alumina.

Any material may be used as the material of the opposing element electrodes 5 and 6 as long as it has conductivity. For example, Ni, Cr, Au, No, W and P may be used.
Metals or alloys such as t, Ti, Al, Cu, Pd and P
In2O3, a printed conductor composed of a metal or metal oxide such as d, Ag, Au, RuO2, Pd-Ag and glass.
Examples thereof include transparent conductors such as SnO2 and semiconductor materials such as polysilicon. The element electrode interval L1 is several hundreds of angstroms to several hundreds of micrometers, and the photolithography technology that is the basis of the manufacturing method of the element electrodes, that is, the performance and etching method of the exposure device, the voltage applied between the element electrodes, and the like. It is set depending on the electric field strength capable of emitting electrons, etc., but is preferably 1 micrometer to 100 micrometers. Element electrode length W1, element electrode 5,
The film thickness d of 6 is properly designed in consideration of the resistance value of the electrode, the connection with the X and Y wirings described above, and the arrangement of a large number of arranged electron sources. Normally, the element electrode length W1 is several micrometer. It is several hundreds of micrometers rather than meters, and device electrodes 5, 6
The film thickness d is preferably several hundred angstroms to several micrometers.

The thin film 4 provided on the insulating substrate 1 between the device electrodes 5 and 6 facing each other and including the electron emitting portions set on the device electrodes 5 and 6 includes the electron emitting portion 3, Not only the case shown in FIG. 10 but also the case where it is not installed on the device electrodes 5 and 6. That is, this is a case where the electron emission portion forming thin film 2 and the opposing device electrodes 5 and 6 are laminated in this order on the insulating substrate 1. In addition, the opposing element electrode 5
Depending on the manufacturing method, there may be a case where everything between the device electrode 6 and the device electrode 6 functions as an electron emitting portion. The film thickness of the thin film 4 including the electron emitting portion is from several angstroms to several thousand angstroms, preferably from 10 angstroms to 20 angstroms.
0 angstrom, depending on the step coverage to the device electrodes 5 and 6, the resistance value between the electron emission part 3 and the device electrodes 5 and 6, the particle size of the conductive fine particles of the electron emission part 3, the energization processing conditions described later, etc. It is set appropriately. The resistance value indicates a sheet resistance value of 10 3 to 10 7 ohm / □.

Specific examples of the material forming the thin film 4 including the electron emitting portion are Pd, Ru, Ag, Au and T.
i, In, Cu, Cr, Fe, Zn, Sn, Ta, W,
Metals such as Pb, PdO, SnO2, In2O3, Pb
Oxides such as Sb2O3, HfB2, ZrB2, LaB
Borides such as 6, CeB6, YB4, GdB4, Tic, Zr
Carbides such as C, HfC, TaC, SiC, WC, Ti
Nitride such as N, ZrN and HfN, semiconductor such as Si and Ge, carbon, AgMg, NiCu, Pb, Sn and the like, which are fine particle films. It should be noted that the fine particle film described here is a film in which a plurality of fine particles are aggregated, and the fine structure thereof is not only a state in which the fine particles are individually dispersed and arranged but also a state in which the fine particles are adjacent to each other or overlap each other (island shape). Point

The electron emitting portion 3 is composed of a large number of conductive fine particles having a particle diameter of several angstroms to several thousand angstroms, preferably 10 angstroms to 200 angstroms. It depends on the manufacturing method such as conditions and is set appropriately. The material forming the electron emitting portion 3 is similar to some or all of the elements of the material forming the thin film 4 including the electron emitting portion.

Various methods are conceivable as a method of manufacturing the electron-emitting device having the electron-emitting portion 3, one example of which is shown in FIG. In FIG. 12, the electron emitting portion forming thin film 2 is a thin film before the electron emitting portion 3 is formed, and is, for example, a fine particle film.

The manufacturing method will be described below in sequence with reference to FIG.
And it demonstrates based on FIG.

(1) After the insulating substrate 1 is thoroughly washed with a detergent, pure water, and an organic solvent, the device electrodes 5 and 6 are formed on the surface of the insulating substrate 1 by the vacuum deposition technique and the photolithography technique ( FIG. 12A).

(2) An organic metal thin film is formed by applying an organic metal solution and leaving it on the insulating substrate 1 between the device electrodes 5 and 6 provided on the insulating substrate 1. . The organometallic solution means Pd, Ru,
Ag, Au, Ti, In, Cu, Cr, Fe, Zn, S
It is a solution of an organic compound containing a metal such as n, Ta, W, or Pb as a main element. After that, the organic metal thin film is heated and baked, patterned by lift-off, etching, etc.
The electron emission part forming thin film 2 is formed (FIG. 12B).
It should be noted that although the description has been given here by using the coating method of the organic metal solution, the electron-emitting device of the present embodiment is not limited to this, and the vacuum vapor deposition method, the sputtering method, the chemical vapor deposition method, the dispersion coating method, the dipping method. , It may be formed by the spinner method.

(3) Subsequently, an energization process called forming is performed between the element electrodes 5 and 6. This is because a pulsed voltage is applied between the electrodes 5 and 6 by a power source (not shown) to change the structure of the electron emitting portion 3 at the portion of the electron emitting portion forming thin film 2.
Are formed (FIG. 12 (c)). The electron emission portion forming thin film 2 is locally destroyed, deformed or altered by this energization process, and a portion whose structure is changed by this is called an electron emission portion 3. As described above, the electron emitting portion 3
Applicants have observed that is composed of fine metal particles.

FIG. 13 shows the voltage waveform applied to this forming process death.

In FIG. 13, each of T1 and T2 indicates the pulse width and pulse interval of the voltage waveform, and T1 is 1
Microsecond to 10 milliseconds, T2 10 microsecond to 10
The peak value of the triangular wave (peak voltage during forming) was set to about 4 V to 10 V, and the forming process was appropriately set in a vacuum atmosphere for about several tens of seconds.

When forming the electron-emitting portion 3 described above, the forming process is performed by applying the triangular wave pulse between the electrodes 5 and 6 of the element, but the waveform applied between the electrodes of the element is limited to the triangular wave. Alternatively, a predetermined waveform such as a rectangular wave may be used, and the peak value, the pulse width, the pulse interval, etc. are not limited to the above values, and any desired value may be used as long as the electron emitting portion is formed well. The value of can be selected.

The substrate characteristics of the electron-emitting device produced by the above device structure and manufacturing method will be described with reference to FIGS. 14 and 15.

(Characteristics of Electron-Emitting Element) FIG.
It is a schematic block diagram of a measuring device for measuring the electron emission characteristic of the element which has the structure shown in FIG.

In FIG. 14, the power source 31 is the element voltage Vf.
Is applied to the electron-emitting device, an ammeter 30 is an ammeter for measuring the device current If flowing through the thin film 4 including the electron-emitting portion 3 between the device electrodes 5 and 6, and the electrode 34 is an electron emission device. The anode electrode for capturing the emission current Ie emitted from the portion 3, the power source 33 is a high voltage power source for applying a voltage to the anode electrode 34, and the ammeter 32 is the emission current Ie emitted from the electron emitting portion 3 of the device. Is an ammeter for measuring.

When measuring the device current If and the emission current Ie of this electron-emitting device, the power supply 31 is applied to the device electrodes 5 and 6.
And an ammeter 30 are connected to each other, and an anode electrode 34 to which a power source 33 and an ammeter 32 are connected is arranged above the electron emitting portion 3. Further, the electron-emitting device and the anode electrode 34
Is arranged in a vacuum device 35, and the vacuum device 35 is equipped with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown), and the characteristics of this element can be measured under a desired vacuum. It is like this.

The voltage of the anode electrode 34 is 1 KV.
-10 KV, and the distance H between the anode electrode 34 and the electron-emitting device was measured in the range of 3 mm to 8 mm.

Further, as a result of earnest studies on the characteristics of the surface conduction electron-emitting device according to the above-mentioned embodiment, the inventors of the present invention found out the characteristic characteristics which are the principle of the present invention.

A typical example of the relationship between the emission current Ie and the device current If and the device voltage Vf measured by the measuring device shown in FIG. 14 is shown in FIG. As is clear from FIG. 15, this electron-emitting device has three characteristics with respect to the emission current Ie.

First, when a device voltage higher than a certain voltage Vth is applied to the electron-emitting device of this embodiment, the emission current Ie rapidly increases. On the other hand, below the voltage Vth, the emission current Ie is hardly detected. That is, this element is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie depends on the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.

Thirdly, the emitted charges captured by the anode electrode 34 depend on the time for which the device voltage Vf is applied to the device. That is, the amount of charge captured by the anode electrode 34 can be controlled by the time for which the device voltage Vf is applied.

As already described, the threshold voltage at which electron emission of the surface conduction electron-emitting device is started and the device applied voltage required to obtain a certain current value are shown in FIG.
It depends on the distance L1 between the device electrodes as shown in FIG. FIG. 16 shows the relationship between the device electrode distance L1 and the drive voltage required to obtain an emission current of 1 μA per device. Figure 1
As is clear from 6, when the distance L1 is short, the drive voltage may be low, and when the distance L1 is long, the drive voltage needs to be high. Therefore, when the effective drive voltage of the element is reduced, It is possible to make the emission current uniform by using an element with a reduced distance and using an element with an increased distance L1 when the driving voltage does not decrease. When the material of the surface conduction electron-emitting device or the film thickness is changed, the relationship between L1 and the driving voltage may not be linear as shown in FIG. 16, but in that case, L1 may be adjusted appropriately. Needless to say.

FIG. 15 shows an example of the characteristic (MI) in which the element current If monotonously increases with respect to the element voltage Vf. In addition to this, the element current If is a voltage control type with respect to the element voltage Vf. It may also exhibit negative resistance (VCNR) characteristics. Also in this case, the electron-emitting device has the above-mentioned three characteristics.

The surface conduction electron-emitting device in which the conductive particles are dispersed in advance can be constructed by partially changing the basic manufacturing method of the basic device structure.

FIG. 17 is a view showing the structure of a basic vertical surface conduction electron-emitting device according to an embodiment of the present invention.

In FIG. 17, 1 is an insulating substrate, 5 and 6
Is an element electrode, 4 is a thin film including an electron emitting portion, 3 is an electron emitting portion, and 67 is a step forming portion. The electron emitting portion 3 is a thin film 4 including the thickness and manufacturing method of the step forming portion 67 and the electron emitting portion.
The position varies depending on the thickness, manufacturing method, etc., and is not limited to the position shown in FIG.

The insulating substrate 1, the device electrodes 5 and 6, the thin film 4 including the electron emitting portion, and the electron emitting portion 3 are made of the same material as that of the above-mentioned plane type surface conduction electron emitting device. The step forming portion 67 and the thin film 4 including the electron emitting portion which characterize the vertical surface conduction electron-emitting device will be described in detail.

The step forming portion 67 is formed by a vacuum vapor deposition method, a printing method,
The step forming portion 67 is made of an insulating material such as SiO2 formed by sputtering or the like, and the thickness of the step forming portion 67 corresponds to the element electrode interval L1 of the flat surface conduction electron-emitting device described above, and is several hundred angstroms. More than tens of micrometers,
The thickness is set depending on the manufacturing method of the step forming portion 67, the voltage applied between the device electrodes 5 and 6, and the electric field strength capable of emitting electrons, but it is preferably 1000 angstroms to 10 micrometers.

The thin film 4 including the electron emitting portion 3 is laminated on the device electrodes 5 and 6 for forming after forming the device electrodes 5 and 6 and the step forming portion 67, and in some cases, the device electrodes 5 and 6 are formed. It is formed into a desired shape except for a part of the overlap that is responsible for electrical connection with. In addition, the film thickness of the thin film 4 including the electron emitting portion 3 often differs depending on the manufacturing method between the thin film at the step portion and the film thickness of the portion laminated on the device electrodes 5 and 6, Generally, the film thickness of the step portion is thin. As a result, as compared with the above-described flat surface-conduction type electron-emitting device, in many cases, the energization process is easily performed and the electron-emitting portion 3 is formed.

Next, an outline of the image forming apparatus according to the embodiment of the present invention will be described. The image forming apparatus according to the present exemplary embodiment is provided with a plurality of linear surface conduction electron-emitting device (SCE device) rows connected in parallel in a vacuum container, and arranged so as to be orthogonal to the element row. An XY matrix is formed by the modulation electrodes having the corresponding electron passage holes, and linear emission element arrays are line-sequentially driven, and an information signal is applied to the modulation electrodes, so that electrons emitted from the emission element arrays are emitted. Brightness modulation is performed according to an information signal, and the electrons are provided at a position on a phosphor substrate provided with a phosphor that emits visible light by electron beam irradiation, provided at a position where the brightness-modulated electron beam is opposed to the emitter array. A linear light emission is obtained by irradiating a line.

The operation of the image display device of this embodiment will be described in detail below.

In this device, a linear emission bright spot is formed by one line of linear electron-emitting devices connected in parallel. Therefore, for example, when one line of the electron-emitting device row is formed by 100 surface-conduction type emission devices connected in parallel, 100 modulation electrodes corresponding to the respective devices are provided orthogonal to the emission devices. Next, the electron-emitting device is driven within the allotted time corresponding to one scanning line, and a pulse voltage having an amplitude corresponding to the information signal or a pulse voltage having a length corresponding to the information signal is applied to each of the modulation electrodes corresponding to each device. Is simultaneously applied to all elements. Then,
A linear electron beam for one line whose brightness is modulated according to the information signal is generated, and the electron collides with the phosphor substrate provided with a light emitting body to obtain a linear light emission corresponding to one scanning line. Further, in order to form the next scanning line, it is possible to form the scanning line of the second row by driving the element row and the modulation electrode in the same manner as described above. By repeating the above scanning, a plurality of line-shaped images can be displayed by one electron-emitting device row.

Further, as described above, in order to perform the modulation according to the information signal, the application time of the pulse voltage applied to the modulation electrode is changed (pulse width modulation) or the amplitude of the pulse voltage is changed (amplitude modulation). Alternatively, any method such as changing the number of inputs of minute pulses having a constant amplitude and applied within the allotted time (pulse number modulation) may be used.

Next, the image display device of the present embodiment will be described in detail. For convenience of explanation, first, the manufacturing method and characteristics of the surface conduction electron-emitting device used in this embodiment will be specifically described. Then, the configuration and characteristics of the image forming apparatus produced according to this embodiment will be described.

FIG. 10 shows an electron-emitting device of this embodiment.
An electron-emitting device of the type shown in (a) and (b) was created. FIG. 10A shows a plan view of this device, and FIG. 10B shows a sectional view. In FIGS. 10A and 10B, 1 is an insulating substrate, 5 and 6 are device electrodes for applying a voltage to the device, 4 is a thin film including an electron emitting part, and 3 is an electron emitting part. . In the figure, L1 is the element electrode distance between the element electrode 5 and the element electrode 6, W1 is the element electrode width, d is the element electrode thickness, and W2 is the element width.

A method of manufacturing the electron-emitting device of this embodiment will be described with reference to FIG.

A soda lime glass is used as the insulating substrate 1,
After thoroughly washing this with an organic solvent, element electrodes 5 and 6 made of Ni were formed on the surface of the substrate 1 ((a) of FIG. 12). At this time, the element electrode interval L1 was set to 2 to 20 microns, the width W1 of the element electrode was set to 500 microns, and the thickness d thereof was set to 1000 angstroms.

Organopalladium (Okuno Pharmaceutical Co., Ltd., c
cp-4230) containing solvent, and then 1
A heat treatment for 0 minutes was performed to form a fine particle film made of palladium oxide (PdO) fine particles (average particle diameter: 70 angstrom), which was used as an electron emission portion forming thin film 2 (FIG. 12).
(B)). Here, the electron electrodes 5 and 6 are arranged substantially in the center. The film thickness of the electron emission portion forming thin film 2 is 10
0 angstrom sheet resistance is 5 × 10 4 Ω /
It was □. The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state in which the fine particles are individually dispersed and arranged but also in a state in which the fine particles are adjacent to each other or overlap each other (including an island shape ), And the particle diameter thereof means the diameter of fine particles whose particle shape can be recognized in the above state.

Next, as shown in FIG. 12C, a voltage is applied to the electron emitting portion 3 between the device electrodes 5 and 6, and the electron emitting portion forming thin film 2 is energized (forming treatment). Created by. The voltage waveform of the forming process is shown in FIG.

In FIG. 13, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this embodiment, T1 is 1 millisecond,
T2 is 10 milliseconds, the peak value of the triangular wave (peak voltage during forming) is 5 V, and the forming process is about 1
It was carried out for 60 seconds in a vacuum atmosphere of × 10 −6 [torr]. In the electron emitting portion 3 thus produced, fine particles containing palladium element as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30 angstrom.

The electron emission characteristics of the device manufactured as described above were measured. FIG. 14 shows a schematic configuration diagram of the measuring device.

Also in FIG. 14, 1 is an insulating substrate, 5 and 6 are element electrodes, 4 is a thin film including an electron emitting portion, 3 is an electron emitting portion, 31 is a power source for applying a voltage to the element, 30 is an ammeter for measuring the device current If, 34
Is an anode electrode for measuring the emission current Ie generated from the device, 33 is a high voltage power source for applying a voltage to the anode electrode 34, and 32 is an ammeter for measuring the emission current. The device current If and the emission current Ie of the electron-emitting device
In the measurement of, the power source 31 and the ammeter 30 are arranged on the element electrodes 5 and 6. Further, the present electron-emitting device and the anode electrode 34 are installed in a vacuum device, and the vacuum device is equipped with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown), and a desired vacuum is obtained. The device can be measured below. In this example,
The distance between the anode electrode and the electron-emitting device was 4 mm, the potential of the anode electrode was 1 KV, and the degree of vacuum in the vacuum apparatus at the time of specific measurement of electron emission was 1 × 10 −6 [torr].

A device voltage was applied between the electrodes 5 and 6 of the present electron-emitting device by using the above-described measuring device, and the device current If and the emission current Ie flowing at that time were measured. As shown in FIG. The current-voltage characteristics as described above were obtained.

In the above description, when the electron emitting portion is formed, the triangular wave pulse is applied between the electrodes of the element to perform the forming process, but the waveform applied between the electrodes of the element is limited to the triangular wave. Alternatively, a desired waveform such as a rectangular wave may be used, and the crest value, pulse width, pulse interval, etc. are not limited to the above values, and a desired value may be obtained as long as the electron emitting portion is well formed. You can choose.

(Structure of Display Device) Next, the structure of an image display device using the above-mentioned surface conduction electron-emitting device will be described in detail below. FIG. 18 is a schematic partial perspective view of the image display device of this embodiment.

In FIG. 18, the modulation electrodes 92 are formed in stripes corresponding to the respective emission elements so as to be orthogonal to the surface conduction electron-emitting element rows arranged in a plurality of lines. In this embodiment, since the number of emitting elements per line is 100, the stripe-shaped modulation electrode 92 also has 100 elements.
It is formed of a book, and voltage can be applied to each modulation electrode 92 independently. Therefore, by applying the brightness signal corresponding to the information signal as the modulation voltage to the modulation electrode 92 during the scanning time of one line of the emitting element array, the amount of electron emission corresponding to the information signal can be obtained.

In FIG. 18, the modulation electrode 92 is located between the surface conduction electron-emitting device 93 and the face plate 131 and has a substantially circular electron beam transmitting hole. The shape is not necessarily limited to this. The point is that the intensity of the electron beam emitted from the surface conduction type emission element 93 can be emphasized. For example, on the same plane as the surface conduction type emission element 93 on the substrate 91,
Alternatively, it may be provided below the surface conduction electron-emitting device 93.

The face plate 131 has a fluorescent film and a metal back formed on the inner surface of the glass substrate. The fluorescent film is composed of only the phosphor when it is monochrome, but when it is a color fluorescent film, it is composed of a black conductive material 1601 and a phosphor 1602 called a black stripe or block matrix depending on the arrangement of the phosphors. (FIG. 19). The purpose of providing the black stripes and the black matrix is to make the mixed colors and the like inconspicuous by blackening the coating portions between the phosphors 1602 of the three primary color phosphors necessary for color display,
This is to control the decrease in contrast due to the reflection of external light on the fluorescent film. In this embodiment, a stripe shape is adopted as the phosphor, a black stripe is first formed, and phosphors of each color are applied to the gaps to form a phosphor film. In addition, although a material containing graphite as a main component, which is usually often used as a material for the black stripe, was used,
The material is not limited to this as long as the material is electrically conductive and has little light transmission and reflection.

As a method of applying the phosphor to the glass substrate, a precipitation method or a printing method is used in the case of monochrome display, but a slurry method is used in the present embodiment for color display. Even in the case of color, an equivalent coating film can be obtained by using a printing method. A metal back is usually provided inside the fluorescent film. The purpose of this metal back is to improve the brightness by specularly reflecting the light toward the inner surface side of the light emitted from the phosphor to the face plate side, and to act as an electrode for applying an electron beam acceleration voltage. To protect the phosphor from damage due to the collision of the negative ions.

The metal back was produced by forming a fluorescent film, smoothing the inner surface of the fluorescent film (usually called filming), and then vacuum-depositing Al (aluminum).

On the face plate, a transparent electrode (not shown) is provided on the outer surface side of the fluorescent film in order to further enhance the conductivity of the fluorescent film.
May be provided, but it was omitted in this example because sufficient conductivity was obtained only by the metal back.

Further, in the case of the above-mentioned sealing, in the case of color, it is necessary to make the respective color phosphors correspond to the electron-emitting devices, so that it is necessary to perform sufficient alignment.

With the above structure and driving method, an image forming apparatus capable of expressing a good image was obtained.

The conductive metals of the electrodes may have some or all of the constituent elements that are the same or different, and Ni, Cr, Au, Mo, W, Pt, and T may be used.
Metals or alloys such as i, A1, Cu, Pd and Pd, A
In2O3-Sn, a printed conductor composed of glass or a metal or metal oxide such as g, Au, RuO2, Pd-Ag.
It is appropriately selected from a transparent conductor such as O2 and a semiconductor material such as polysilicon.

Next, the structure of the electron source portion used in this embodiment will be described in detail.

FIG. 20A is a schematic top view of the electron source portion, 3 is an electron emitting portion, 4 is a thin film including the electron emitting portion,
Reference numerals 5 and 6 are element electrodes. Further, this drawing shows the case where the drive terminals of the element arrays connected in parallel are only on one side (D1 side).

First, based on the characteristics of a typical surface conduction electron-emitting device, the voltage drop due to the wiring resistance when 300 devices (D1 to D300) were connected in parallel was estimated. = 5 mΩ, element resistance Rd is -10 kΩ
If the voltage applied to the element on the drive terminal side is Vfmax and the voltage applied to the element on the other end is Vfmin, the effective voltage applied to the element is the ratio Vfmax: Vfmin = 1.
It will be about 10: 100. This is one side of the wiring electrode (D1
It is shown that when a drive voltage of 16 V is applied from the side), the voltage of 14.5 V is effectively applied to the element (D300 side) at the other end. Therefore, in the present embodiment, in order to obtain an emission current of, for example, 1 microamperes per device, in the case of the above conditions, a portion far from the drive terminal (D30
The element on the (0 side) is 1 microampere with an applied voltage of 16V, and the element on the drive terminal side (D1 side) is an element with a characteristic that an emission current of 1 microampere is obtained with an applied voltage of 14.5V. If they are arranged, a constant emission current can be obtained from all the elements when a constant drive voltage is applied. Therefore, as is apparent from FIG. 16 described above, the electrode interval L1 of the element on the drive terminal side is 20 μm,
It suffices to set the electrode spacing of the elements far from the drive terminal to 6 microns.

Based on the above estimation, the relationship between the position of each element in the electron source portion produced in this example and the electrode spacing is shown in FIG.
It is shown in the graph of (b).

Further, in FIG. 21A, the drive terminals of the electron source are arranged on both sides, that is, for example, the drive terminal on the positive electrode side is located at the left end (D).
1 side) shows the case where the drive terminal on the negative electrode side is provided at the right end (D300 side), respectively. According to the same estimation as above, when the positive and negative drive terminals are divided into the left and right, the voltage effectively applied to the elements is Vfmax, which is the voltage applied to the elements at both ends, and When the applied voltage is Vfmin, the ratio Vfmax: Vfmin = 105: 100. This means that when a drive voltage of 16V is applied from both ends of the wiring electrode, the element in the central portion is effectively 15.2V.
It is shown that the voltage of is applied. So for example 1
1 microamp per element, 1 in the center
By arranging in parallel the elements having the characteristics such that the emission current of 1 microampere can be obtained at the applied voltage of 5.2V, the constant emission current can be obtained from all the elements when the constant drive voltage is applied. It will be. Therefore, as is apparent from FIG. 16, the electrode spacing L1 between the elements at both ends should be 20 microns, and the electrode spacing between the elements in the central portion should be 12 microns.

Based on the above estimation, the relationship between the position of each element in the electron source portion manufactured in this example and the electrode spacing is shown in FIG.
It shows in (b).

Next, a method of driving the electron source and the image forming apparatus in this embodiment will be described. FIG. 22 is a block diagram showing an electric circuit for driving the image forming apparatus manufactured in this embodiment. In the figure, 1000 is a display constituting a main part of the image forming apparatus shown in FIG. A panel, 1001 is a decoding circuit for decoding a decoded image signal input from the outside, 1002 is a serial / para conversion circuit for converting a serial signal into a parallel signal and outputting the parallel signal,
Reference numeral 1003 is a line memory, 1004 is a modulation signal generation circuit, 1005 is a timing control circuit, and 1006 is a scanning signal generation circuit. For convenience of explanation, FIG. 18 shows the case where the drive terminals Dp and Dm are taken out in different directions, that is, the electrode configuration shown in FIG.

Electrode terminals Dp1 of the image forming apparatus 1000
Dp100 and Dm1 to Dm100 are each connected to an electric circuit, a terminal EV is connected to a voltage source HV that generates an acceleration voltage of 10 [KV], and terminals G1 to G200 are connected to a modulation signal generation circuit 1004. The terminals Dp1 to Dp100 are connected to the scanning signal generating circuit 1006, and the terminals Dm1 to Dm1.
00 is connected to ground.

The function of each section will be described below. First, the decoding circuit 1001 receives an external input, for example, NTS.
In a circuit for decoding a decoded image signal such as a C television signal, a luminance signal component and a synchronization signal component are separated from the decoded image signal, the former is used as a Data signal in the serial / para conversion circuit 1002, and the latter is used as a Tsync signal. It is output to the timing control circuit 1005. That is, the decoding circuit 100
1 indicates the brightness of each RGB color component on the display panel 100.
They are arranged according to the color pixel arrangement of 0 and sequentially output to the serial / para conversion circuit 1002. Further, the vertical synchronizing signal and the horizontal synchronizing signal are extracted and output to the timing control circuit 1005. The timing control circuit 1005 generates various timing control signals for matching the operation timings of the respective parts with the synchronization signal Tsync as a reference. That is,
Tsp is used for the serial / parallel conversion circuit 1002, Tmry is used for the line memory 1003, Tmod is used for the modulation signal generation circuit 1004, and scanning signal generation circuit 100 is used.
For T6, Tscan is output.

The serial / para conversion circuit 1002 receives the luminance signal Data input from the decoding circuit 1001 and the timing signal Tsp input from the timing control circuit 1005.
Sequential sampling based on
It is output to the line memory 1003 as 1 to I100. The timing control circuit 1005 has a line memory 1003 at the time point when the data for one line of the image is serial / para-converted.
A write timing control signal Tmry is output to When the line memory 1003 receives Tmry, I1 ...
The contents of I100 are stored and output as I'1 to I'100 to the modulation signal generation circuit 1004, which is held until the next write timing control signal Tmry is input to the line memory.

The modulation signal generation circuit 1004 is a circuit for generating a modulation signal to be applied to the grid electrode of the image forming apparatus 1000 based on the brightness data for one line of the image input from the line memory 1003. Timing pass signal T generated by control circuit 1005
A modulation signal is applied simultaneously to the terminals G1 to G300 in accordance with mod. The modulation signal uses a voltage modulation method that changes the magnitude of the voltage according to the brightness data of the image, but it is also possible to use a pulse width modulation method that changes the length of the voltage pulse according to the brightness data.

The scanning signal generation circuit 1006 is a circuit for generating a voltage pulse for appropriately driving the element array of the surface conduction electron-emitting devices of the image forming apparatus 1000. The internal switching circuit is appropriately switched according to the timing control signal Tscan generated by the timing control circuit 1005, and an appropriate drive voltage VE [V] exceeding the threshold of the surface conduction electron-emitting device generated by the constant voltage source DV or ground. The level (that is, 0 [V]) is selected and applied to the terminals Dp1 to Dp100.

With the above circuit, the image forming apparatus 1000
23, a drive signal is applied at a timing shown in the time chart of FIG. Each of (a) to (d) in FIG.
A part of the signal applied from the scanning signal generation circuit 1006 to each of the terminals Dp1 to Dp100 of the display panel 1000 is shown. As is apparent from FIG. 23, the voltage pulse of the amplitude VE [V] is displayed on one line of the image. Dp1, sequentially for each hour
Dp2, Dp3, ... Are applied in this order. On the other hand, terminal Dm1
Since ~ Dm100 is always connected to the ground level (0 [V]), the element train is sequentially driven from the first train by the voltage pulse and the electron beam is output.

Further, in synchronization with this, the modulation signal generation circuit 1
From 004, the modulation signal for one line of the image is simultaneously applied to the terminals G1 to G300 at the timing shown by the dotted line in FIG. In this way, the modulation signal is sequentially switched in synchronization with the switching of the scanning signal, and an image for one screen is displayed. The television moving image is displayed by continuously and repeatedly performing this.

An excellent image can be formed by the image forming apparatus having the structure and driving method as described above.

<Second Embodiment> Next, a second embodiment of the present invention will be described.
An example will be described. For convenience of description, the electron source used in this embodiment will be described first, and then the configuration and driving method of the image forming apparatus will be described.

A perspective view of the electron source of this embodiment is the vertical type shown in FIG. In the figure, 1 is an insulating substrate, 5 and 6 are device electrodes (upper and lower parts), 4 is a thin film including an electron emitting portion, and 3 is an electron emitting portion. The step forming layer 7 is made of SiO2 in this embodiment. The electron source of this embodiment described above is manufactured as follows. In addition, L1
Indicates the thickness of the step forming layer 67.

A soda lime glass is used as the insulating substrate 1,
After thoroughly washing this with an organic solvent, Ni of 1000 angstrom was laminated on the surface of the substrate 1 by a vacuum deposition method and patterned by a photolithography and etching process to form a lower element electrode 5 made of Ni (FIG. 24 (a)). SiO2, which finally becomes the step forming layer 67, was laminated thereon by 2 μm by the CVD method (FIG. 24 (b)).

Further, a thickness of 10 is obtained by the lift-off method.
An upper difference electrode 6 (deposited by a vacuum evaporation method) made of Ni of 00 angstrom was formed as shown in FIG. After that, SiO2 is partially removed by dry etching using the upper element electrode 5 as a mask to remove SiO2.
The insulating layer end face 8 is formed to form the step forming layer 67 (see FIG. 24).
Was partially removed to form the SiO2 insulating layer end face 8 to form a step forming layer 67 (FIG. 24 (d)). The width of the device electrodes 2 and 3 described above was set to 500 μm.

Next, organic palladium (Okuno Pharmaceutical Co., Ltd.)
Co., Ltd., ccp-4230) is applied using a spin coater, and then heat treatment is performed at 300 ° C. for 10 minutes to form a fine particle film of palladium oxide (PdO) fine particles on the device electrode 5
And 6 are formed so as to cover the end face 8 of the step forming layer 67, and the thin film 2 for forming an electron emitting portion is formed (see FIG. 24).
(E)). Here, the electron emission portion forming thin film 2 has a width (element width) of 300 μm. The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state in which the fine particles are individually dispersed and arranged but also in a state in which the fine particles are adjacent to each other or overlap each other (including an island shape). ) Membrane.

Next, a voltage is applied between the device electrodes 5 and 6, and the electron-emitting portion forming thin film 2 is energized (forming) to form the electron-emitting portion 3 (FIG. 24).
(F)). The voltage waveform of the forming process is shown in FIG.

In FIG. 13, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this embodiment, T1 is 1 millisecond,
T2 was set to 10 milliseconds. Further, in this embodiment, T1 is set to 1 millisecond and T2 is set to 1 millisecond. Further, in this embodiment, the forming voltage is set to 5 V, and the forming process is performed by about 1 × 1.
It was carried out for 60 seconds in a vacuum atmosphere of 0 −6 [torr]. The electron emitting portion 3 thus formed is in a state in which fine particles containing a palladium element as a main component are dispersed and arranged.

The electron emission characteristics of the device produced as described above were measured by the measuring apparatus used in the first embodiment (see FIG. 14). However, in this example, the device was placed under a vacuum of 1 × 10 −6 [torr], the distance between the anode electrode and the electron-emitting device was 4 mm, and the potential of the anode electrode was 1.
A device voltage was applied between the device electrodes 5 and 6 so that the upper device electrode 6 had a high potential, and the device current If and the emission current Ie flowing at that time were measured. As a result, the characteristics substantially equal to the current-voltage characteristics shown in FIG. 9 are obtained,
When the device voltage is 14 V, the device current If is 2.2 mA, the emission current Ie is 1.1 μA, and the electron emission efficiency η = Ie / If.
(%) Was 0.05%.

Further, in order to change the characteristics of the electron-emitting device as in Example 1, the thickness of the step forming layer 67 was changed in the range of 1 to 20 microns in this example.
A result similar to the characteristics shown in FIG. 11 was obtained, and the vertical SC
It was confirmed that the electron emission starting voltage of E depends on the thickness of the step forming layer 67.

An image forming apparatus using the vertical type SCE was prepared in the same idea as in Example 1 and an image was formed by the same driving method, and a good image forming apparatus was obtained.

The material and structure of the SCE element according to the present embodiment, or the manufacturing method is not limited to the procedures and values described in the present embodiment.
The characteristics of the SCE element shown in FIG. 3 may be different from those of the examples. Of course, in this case, the present invention can be applied.

Although the display device of this embodiment has been described as a TV of the NTSC system, the present invention is not limited to this, and is not limited to the TV device of another system or directly to a computer, an image memory network or the like, not limited to the TV. It can also be applied to a display device connected to a joint.

Further, although the present embodiment has been described in the case of the image display device, the present invention is not limited to this.
It can be used as an electron source of a device that draws an image using an electron beam, or can be applied to a light source of a recording device that stores an optical image such as an optical printer.

FIG. 25 shows the display panel 1000 described above.
FIG. 3 is a diagram showing an example of a display device configured to be able to display image information provided from various image information sources including, for example, television broadcasting. 10 in the figure
00 is the above-mentioned display panel, 1101 is the display panel 10.
00 drive circuit, 1102 display controller, 110
3 is a multiplexer, 1104 is a decoder, 1105 is an input / output interface circuit, 1106 is a CPU, 11
Reference numeral 07 is an image generation circuit, 1108, 1109 and 1
110 is an image memory interface circuit, 1111 is an image input interface circuit, 1112 and 111.
3 is a TV signal receiving circuit, and 1114 is an input unit. (It should be noted that, in this figure, a processing circuit, a speaker, and the like relating to the audio component of each input signal such as a television are omitted.) Hereinafter, the function of each part will be described along the flow of the image signal. .

First, the TV signal receiving circuit 1113 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The system of the TV signal to be received is not particularly limited, and for example, various systems such as NTSC system, PAL system and SECAM system may be used. Further, a TV signal (for example, a so-called high-definition TV such as the MUSE method) having a larger number of scanning lines than this is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. It is a signal source. The TV signal received by the TV signal receiving circuit 1113 is output to the decoder 1114. The TV signal receiving circuit 1112 is a circuit for receiving a TV image signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. Similar to the TV signal receiving circuit 1113, the system of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 1104.

Further, the image input interface circuit 11
Reference numeral 11 denotes a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is a decoder 1104.
Is output to. The image memory interface circuit 1110 is a circuit for capturing an image signal stored in a video tape recorder (hereinafter abbreviated as VTR), and the captured image signal is output to the decoder 1104. Also, the image memory interface circuit 1109
Is a circuit for fetching the image signal stored in the video disc. The fetched image signal is the decoder 11
It is output to 04. The image memory interface circuit 1108 is a circuit for capturing an image signal from a device that stores still image data, such as a so-called still image disk, and the captured still image data is output to the decoder 1104.

Further, the input / output interface circuit 110
Reference numeral 5 is a circuit for connecting the present display device to an external computer, a computer network, or an output device such as a printer. It is of course possible to input / output image data and character / graphic information, and in some cases, input / output control signals and numerical data between the CPU 1106 of the display device and the outside.

Further, the image generation circuit 1107 is provided with image data, character / graphic information, or CPU which is externally input through the input / output interface circuit 1105.
1106 is a circuit for generating display image data based on image data and character / graphic information output from 1106. Inside this circuit, for example, a rewritable memory for accumulating image data and character / graphic information, a read-only memory in which an image pattern corresponding to a character code is stored, a processor for performing image processing, etc. And the circuits necessary for image generation are incorporated.

The display image data generated by this circuit is output to the decoder 1104, but in some cases, it may be output to an external computer network or printer via the input / output interface circuit 1105. The CPU 1106 mainly performs operations related to operation control of the display device and generation, selection, and editing of a display image. For example, a control signal is output to the multiplexer 1103 to appropriately select or combine image signals to be displayed on the display panel. At that time, a control signal is generated to the display panel controller 1102 according to the image signal to be displayed, and the display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines in one screen, etc. are displayed. The operation of the device is controlled appropriately. Further, the image data or character / graphic information is directly output to the image generation circuit 1107, or an external computer or memory is accessed through the input / output interface circuit 1105 to display the image data or character / graphic information. input.

It should be noted that the CPU 1106 may of course be involved in work for other purposes. For example,
It may be directly related to the function of generating and processing information, such as a personal computer or a word processor.

Alternatively, as described above, the input / output interface circuit 1105 may be connected to an external computer network to perform work such as numerical calculation in cooperation with an external device. Also, the input unit 1114
Is a user's command or program to the CPU 1106,
Alternatively, it is for inputting data and the like, and various input devices such as a joystick, a bar code reader, and a voice recognition device can be used in addition to a keyboard and a mouse.

Further, the decoder 1104 has the above-mentioned 1107.
Is a circuit for inversely converting various image signals input from the signals 1 to 1113 into three primary color signals or luminance signals and I signals and Q signals. It is desirable that the decoder 1104 has an image memory therein, as indicated by a dotted line in the figure. This is for handling a television signal that requires an image memory for reverse conversion, including the MUSE system. Further, the provision of the image memory facilitates the display of a still image, or facilitates image processing and editing such as image thinning, interpolation, enlargement, and synthesis in cooperation with the image generation circuit 1107 and the CPU 1106. This is because the advantage of being able to do it is born.

The multiplexer 1103 is the CPU 1
The display image is appropriately selected based on the control signal input from 106. That is, the multiplexer 1103
Selects a desired image signal from the inversely converted image signals input from the decoder 1104, and drives the drive circuit 110.
Output to 1. In that case, by switching and selecting image signals within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen television. . Further, the display panel controller 1102 has the CPU 1106.
This is a circuit for controlling the operation of the drive circuit 1101 based on a control signal input from the driver.

First, regarding the basic operation of the display panel, for example, a signal for controlling an operation sequence of a power source (not shown) for driving the display panel is output to the drive circuit 1101. In addition, the display panel 1000
A signal for controlling a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 1101 as a method related to the drive method of (1). In some cases, a control signal relating to image quality adjustment such as brightness, contrast, color tone, and sharpness of a display image may be output to the drive circuit 1101. The drive circuit 1101 is a circuit for generating a drive signal applied to the display panel 1000, and operates based on an image signal input from the multiplexer 1103 and a control signal input from the display panel controller 1102. To do.

Although the functions of the respective parts have been described above, the configuration illustrated in FIG. 25 allows the display panel 1000 to display image information input from various image information sources in the present display device. That is, various image signals such as television broadcast are inversely converted by the decoder 1104, appropriately selected by the multiplexer 1103, and input to the drive circuit 1101. on the other hand,
The display controller 1102 generates a control signal for controlling the operation of the drive circuit 1101 according to the image signal to be displayed. The drive circuit 1101 applies a drive signal to the display panel 1000 based on the image signal and the control signal. As a result, the image is displayed on the display panel 1000. A series of these operations is controlled by the CPU 1106 as a whole.

In the present display device, the image memory built in the decoder 1104 and the image generation circuit 11 are also provided.
Due to the involvement of the CPU 07 and the CPU 1106, not only is a plurality of pieces of image information that are long-lived displayed, but also image information to be displayed is enlarged, reduced, rotated, moved, edge emphasized, thinned, or the like. Interpolation, color conversion,
It is also possible to perform image processing such as image aspect ratio conversion, and image editing such as composition, deletion, connection, replacement, and fitting. Further, although not particularly mentioned in the description of the present embodiment, a dedicated circuit for processing and editing voice information may be provided as in the above-mentioned image processing and image editing.

Therefore, the present display device has functions of a display device for television broadcasting, a terminal device for a video conference, an image editing device, a computer terminal device, an office terminal device such as a word processor, and a game machine. It can be combined with a stand, and has a very wide range of applications for industrial or consumer use. Moreover, since the display panel can be easily thinned, the depth of the device can be reduced.
In addition, it is possible to display a highly realistic image with good visibility because it is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics.

As described above, according to this embodiment, it is possible to provide an electron source which is highly efficient and can stably emit electrons. Further, according to this embodiment, there is an effect that a gradation image can be expressed efficiently and stably.

<Third Embodiment> Next, a third embodiment of the present invention will be described.
Embodiments will be described in detail with reference to the drawings. The electron source portion of this embodiment is the same as that of the first embodiment, but in this embodiment, as shown in FIG. 26, the wiring electrodes on the positive electrode side and the negative electrode side of each element connected in parallel are provided at both ends. It has a connection terminal for a power source and a ground, and as shown in the figure, each wiring electrode is configured to be applied with the same voltage from two directions. When the voltage drop of each element in this element configuration is estimated in advance, the effective applied voltage to the elements near the center of the element row connected in parallel as shown in FIG. 26 is the lowest. In addition, as shown by the broken line in the figure, the effective applied voltage decreases more when driving from both ends of the positive and negative electrodes than when applying voltage from one side of each of the positive electrode side and the negative electrode side. Few.

Based on the above estimation, the electrode sense L, which is a feature of the present invention, is set to 2 μm in the vicinity of the center and 10 μm at both ends to cancel the effective drop in the applied voltage and to make uniform electron emission. The device configuration is such that The electron emission characteristics of the element manufactured as described above were measured by the measurement / evaluation apparatus used in the first example (see FIG. 14). As a result, characteristics substantially equivalent to the current-voltage characteristics shown in FIG. 9 were obtained. Was obtained, and almost the same emission current was obtained from all the devices. An image display device was produced by using the above element based on the same concept as in Examples 1 and 2, and an image was displayed. As a result, a good display image with less uneven brightness was obtained. It was also confirmed that the correction width of the electrode interval can be further reduced by driving the positive electrode side and the negative electrode side from both sides.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, the present invention can of course be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

[0165]

As described above, according to the present invention, it is possible to provide an electron source which has a high electron beam generation efficiency and can stably emit electrons.

Further, according to the present invention, it is possible to provide an image forming apparatus having a high electron beam generation efficiency and capable of expressing a stable gradation image.

Further, according to the present invention, it is possible to provide the electron source and the image forming apparatus for the electron source in which the variation of the emission degree of the electron beam due to the wiring resistance is prevented.

[0168]

[Brief description of drawings]

FIG. 1 is a top view showing a configuration example of a conventional surface conduction electron-emitting device.

FIG. 2 is a configuration diagram of an image forming apparatus using a conventional electron source.

FIG. 3 is a configuration diagram of a conventional display device.

FIG. 4 is a diagram for explaining electron trajectories in the vicinity of an electron emitting portion.

FIG. 5 is a partially enlarged view of a conventional image display device using a lateral current type electron emitter.

FIG. 6 is a configuration diagram of a conventional image display device using a lateral current type electron emitter.

FIG. 7 is a diagram showing an equivalent circuit, potentials, and applied voltages when a plurality of elements are connected in parallel.

FIG. 8 is a diagram showing an equivalent circuit, a potential, and an applied voltage when a plurality of elements are connected in parallel.

FIG. 9 is a typical characteristic diagram of a surface conduction electron-emitting device.

FIG. 10 is a schematic configuration diagram of a horizontal electron-emitting device of this embodiment.

FIG. 11 is a diagram showing changes in electron emission characteristics of this example.

FIG. 12 is a diagram showing a method for manufacturing the electron-emitting device of the example.

FIG. 13 is a voltage pulse waveform diagram at the time of forming processing performed in the manufacturing process of the electron-emitting device.

FIG. 14 is a diagram showing a configuration of an electron-emitting device measuring apparatus.

FIG. 15 is a diagram showing current-voltage characteristics of the electron-emitting device of this example.

FIG. 16 is a diagram showing a relationship between an electrode interval and a drive voltage in the electron-emitting device of this example.

FIG. 17 is a schematic configuration diagram of a vertical electron-emitting device of this example.

FIG. 18 is a perspective sectional view of the image forming apparatus of this embodiment.

FIG. 19 is an explanatory diagram of a face plate used in the image forming apparatus of this embodiment.

FIG. 20 is a diagram showing a configuration of an electron source portion when wiring is supplied with electric power from one side in the present embodiment.

FIG. 21 is a diagram showing a configuration of an electron source portion when wiring is supplied with power from both ends in the present embodiment.

FIG. 22 is a block diagram showing the configuration of the image display device of the present embodiment.

FIG. 23 is a timing chart diagram showing a driving method in the image display device of the present embodiment.

FIG. 24 is a diagram showing a manufacturing process of the vertical electron-emitting device according to the present embodiment.

FIG. 25 is a block diagram showing a schematic configuration of the image display device of the present embodiment.

FIG. 26 is a diagram illustrating a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 3 Electron emission part 4 Thin film 5,6 Element electrode 30 Ammeter 31 Power supply 67 Step forming layer 92 Modulation electrode 93 Linear electron source 131 Face plate 1000 Display panel 1002 Sili / para conversion circuit 1003 Line memory 1004 Modulation signal Generator 1005 Timing signal generator 1006 Scan signal generation circuit

Claims (9)

[Claims] 1. An electron source that emits electrons based on an input signal, wherein a plurality of electrodes are linearly connected in parallel between power supply terminals and are connected to the power supply terminals. And a plurality of surface-conduction type electron-emitting devices having an electron-emitting portion arranged between the pair of electrodes, and the distance between the pair of electrodes of the surface-conduction type electron-emitting device in the vicinity of the power supply terminal is An electron source, which is set to be longer than the distance between the pair of electrodes of another surface conduction electron-emitting device. 2. The power supply terminal is provided on one end side of the plurality of surface conduction electron-emitting devices connected in a plurality of lines, and the pair of the surface conduction electron-emitting devices near the power supply terminal are provided. The electron source according to claim 1, wherein the distance between the electrodes is longest, and the distance between the pair of electrodes becomes shorter as the distance from the power supply terminal increases. 3. The power supply terminals are provided on both sides of the plurality of surface-conduction type electron-emitting devices connected in a plurality of lines, and both ends of the plurality of surface-conduction type electron-emitting devices connected in a line. Of the plurality of surface-conduction type electron-emitting devices connected to each other in a linear manner and having the longest distance between the pair of electrodes of the surface-conduction type electron-emitting device located in the central part The electron source according to claim 1, wherein the distance between the pair of electrodes is the shortest. 4. The electron emitting unit emits an electron beam based on the input signal.
The electron source according to at least any one of 1. 5. An image forming apparatus in which a plurality of electron sources for emitting electron beams based on an input signal are arranged in a plane, wherein the electron sources are linearly connected in parallel between power supply terminals, respectively. Has a plurality of surface conduction electron-emitting devices having a pair of electrodes facing each other connected to the power supply terminal, and an electron-emitting portion arranged between the pair of electrodes, based on the input signal An image forming apparatus comprising: a driving unit that energizes the power supply terminal to drive the electron source; and an image forming unit that forms a visible image by an electron beam emitted from the electron source. 6. The device according to claim 1, further comprising a modulator that modulates the electron beam based on the input signal.
The image forming apparatus according to item 1. 7. The modulation means has a modulation electrode arranged so as to form a matrix with the electron source, and a pulse voltage of a predetermined width obtained by modulating the amplitude of the voltage based on the input signal is applied to the modulation electrode. The image forming apparatus according to claim 6, wherein the image forming apparatus is applied. 8. The modulation means has a modulation electrode arranged so as to form a matrix with the electron source, and a pulse voltage of a predetermined voltage whose pulse width is modulated based on the input signal is applied to the modulation electrode. The image forming apparatus according to claim 6, wherein the image forming apparatus is applied. 9. The image forming apparatus according to claim 5, wherein the image forming unit includes a light emitting unit that emits light when irradiated with the electron beam.