JP2000250477A - Method and device for driving of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actualize low power consumption and high quality by driving an electron emission part so that the electron emitted by the electron emission part reaches an anode electrode through an elastic scattering process wherein the mean elastic scatter frequency on the high-potential side surface of an electron emitting element is within a specific range. SOLUTION: A thin film containing carbon on the high-potential side surface 12 of at least the electron emitting element is arranged in grating stripes on a conductive thin film and the element is driven with an element voltage Vf and an anode voltage Va so that the electron emitted 'by the electron emission part reaches the anode electrode 13 through the elastic scatter process wherein the mean elastic scatter frequency (n) on the high-potential side surface 12 of the electron emitting element is 1 to 3. The electron emitting element is characterized by that the rate of the electron reaching the anode can be made larger and larger as the scatter frequency on the high-potential side surface 12 becomes lower and lower, but the anode voltage needs to be made high and the problem of discharging, etc., is possibly generated. For the purpose, driving conditions of a mean elastic scatter frequency of >=1 are preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for driving an image forming apparatus using electron-emitting devices.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction type electron emission element.

As an example of the FE type, W. P. Dyke &
W. W. Dolan, "Fielddemissio
n ", Advance in Electron Ph
ysics, 8, 89 (1956) or C.I. A. S
pindt, "PhysicalProperties"
of thin-film field emiss
ion cathodes with mollybde
nium cones ", J. Appl. Phys.,
47, 5248 (1976).

As an example of the MIM type, C.I. A. Mead,
“Operation of Tunnel-Emis
site Devices, ”J. Apply. Phys.
s. 32, 646 (1961) and the like are known.

As an example of the surface conduction electron-emitting device,
M. I. Elinson, RadioEng. Elec
Tron Phys. , 10, 1290, (1965)
Etc.

[0006] The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using a SnO ₂ thin film by Elinson et al., And a device using an Au thin film [G. Dimmer, Thin Solid Fil
ms, 9, 317 (1972)], In ₂ O ₃ / SnO
₂ Thin film [M. Hartwell and
C. G. FIG. Fonsted, IEEE Trans. ED
Conf. , 519 (1975)], and those based on carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22, p. 22 (1983)] and the like have been reported.

As a typical configuration of these surface conduction type emission devices, the above-mentioned M.D. Figure 1 shows the device configuration of Hartwell
6 is shown. In FIG. 1, reference numeral 1 denotes an insulating substrate. Reference numeral 4 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and a linear electron emitting portion 5 is formed by an energization process called forming, which will be described later. Note that the element electrode interval L in the figure is 0.5 to 1 m.
m and W are set at 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, before the electron emission, the electron-emitting portion 5 is generally formed by applying a current to the conductive thin film 4 by a process called forming. That is, forming means applying a DC voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 4 and energizing the conductive thin film 4 to locally break, deform or alter the conductive thin film, thereby increasing the electrical resistance. This is to form the electron-emitting portion 5 in a resistance state. In the electron emitting portion 5, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface-conduction type electron-emitting device that has been subjected to the forming process is configured to apply a voltage to the conductive thin film 4 and cause a current to flow through the device, thereby causing the electron-emitting portion 5 to emit electrons.

On the other hand, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-235255, there is a case where an element which has been formed is subjected to a process called an activation process. The activation processing step means that the element current I
f, a step in which the emission current Ie changes significantly.

[0010] The activation step can be performed by applying a voltage to the element in an atmosphere containing an organic substance, similarly to the forming process. By this treatment, carbon or a carbon compound is deposited from the organic substance present in the atmosphere at the electron emission portion of the device and in the vicinity thereof, and the device current If and the emission current Ie are remarkably changed. Obtainable.

Since the above-described electron-emitting device has a simple structure, a large number of electron-emitting devices can be arranged and formed over a large area. Therefore, an image forming apparatus can be configured by using an electron source substrate on which a plurality of electron emitting elements are formed and combining it with an image forming member made of a phosphor or the like.

[0012]

However, with the rapid progress of multimedia with the advancement of information in recent years, higher performance is required for image forming apparatuses such as displays. That is, the screen size of the display device is increased, the power consumption is reduced, the definition is increased, the image quality is increased, and the space is saved.

In an image forming apparatus to which the above-described electron-emitting device is applied, in order to display a high-quality image with low power consumption, it is required to increase the efficiency of the electron-emitting device. Here, the efficiency is the ratio of the emission current Ie emitted from the electron-emitting device and reaching the anode electrode provided with the electronic image forming member to the device current If flowing through the device when a voltage is applied to the electron-emitting device. Say. In order to increase the efficiency, it is necessary to increase the ratio of the current emitted from the electron-emitting device. However, it is also important to efficiently reach the anode electrode from the electron-emitting device. ing.

[0014]

The configuration of the present invention which has been made to solve the above-mentioned problems is as follows. That is,
It has a pair of electrodes facing each other and has a pair of conductive thin films formed between the pair of electrodes, and further has an electron emitting portion by a gap between the pair of conductive thin films, and the electron emitting portion is An electron-emitting device having a pair of thin films containing carbon on a pair of conductive thin films with a gap therebetween, wherein at least the thin film containing carbon on the high potential side surface of the electron-emitting device has lattice fringes on the conductive thin film. An electron-emitting device, which is arranged in a form having, and the direction having the orientation of the lattice fringes is a direction substantially normal to the surface of the conductive thin film,
A method for driving an image forming apparatus, comprising: an electron source provided on a substrate; and an anode provided with an image forming member for forming an image by irradiation of electrons emitted from the electron emitting element. Vf, the element voltage applied to
When the anode voltage applied to the anode electrode is Va,
The element voltage Vf and the anode voltage Va, wherein the electrons emitted from the electron-emitting portion reach the anode electrode through an elastic scattering step in which the average number of elastic scattering n on the high potential side surface of the electron-emitting device is 1 or more and 3 or less. And a driving method of the image forming apparatus.

In addition, the semiconductor device has a pair of electrodes facing each other, has a pair of conductive thin films formed between the pair of electrodes, and further has an electron emitting portion formed by a gap between the pair of conductive thin films. An electron-emitting device in which the electron-emitting portion has a pair of thin films containing carbon on a pair of conductive thin films with the gap therebetween, wherein at least the thin film containing carbon on the high-potential side surface of the electron-emitting device has a conductive property. A plurality of electron-emitting devices which are arranged in a form having lattice fringes on the thin film, and in which the orientation of the lattice fringes is substantially normal to the surface of the conductive thin film, are provided on the substrate. An electron source,
An anode electrode provided with an image forming member for forming an image by irradiation of electrons emitted from the electron-emitting device; and a device voltage applied to the electron-emitting device to Vf, When the applied anode voltage is Va, electrons emitted from the electron-emitting portion are applied to the anode electrode through an elastic scattering step in which the average number of elastic scattering n on the high potential side surface of the electron-emitting device is 1 or more and 3 or less. A driving device for an image forming apparatus, wherein an element voltage Vf and an anode voltage Va are applied so as to reach the driving voltage.

In this driving method and apparatus, the element voltage Vf and the anode voltage Va may be set so as to satisfy the following equation (1).

(Equation 1) Here, F (x): the distance x from the electron emission portion when Va = 0 V
In (m), the landing point distribution function due to elastic scattering of electrons β: average elastic scattering probability of the surface on the high potential side of the electron-emitting device H: distance (m) between the electron-emitting device and the anode electrode π: pi γ: coefficient = 0.67 Further, in the driving method and the device, the carbon-containing thin film in the electron-emitting device is arranged in a form having lattice fringes on the conductive thin film, and the direction having the lattice fringe orientation. Is ± 3 from the normal direction to the conductive thin film surface.
It is better to be within 0 °.

According to the method and apparatus for driving an image forming apparatus of the present invention, it is possible to increase the ratio of electrons reaching the anode electrode to electrons emitted from the electron emission portion at a practical anode voltage. A high-luminance image forming apparatus can be provided.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. First, a basic configuration of the electron-emitting device according to the present invention will be described. FIG. 3 (a),
FIG. 3B is a plan view and a cross-sectional view showing the configuration of a basic planar electron-emitting device according to the present invention.

In FIG. 3, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, 5 is an electron emitting portion, and 6 is a deposited film containing carbon. As is apparent from FIG.
An electron emitting portion formed between the pair of electrodes 2 and 3 provided on the substrate 1 is formed as a gap between the pair of conductive thin films 4 and 4 electrically connected to the respective electrodes. One thin film 6 containing carbon is formed on the upper surface of one of the electrodes 2 and the conductive thin film 4. Similarly, the other thin film 6 containing carbon is formed over the other electrode 3 and the conductive thin film 4 on their upper surfaces. Then, a gap for forming the electron emission portion is maintained between one carbon thin film 6 and the other carbon thin film 6 forming a pair.

FIG. 4 is a cross-sectional view schematically showing the orientation of carbon of the deposited film 6 containing carbon deposited on the surface of the electron-emitting device. As the substrate 1, a quartz glass, a soda lime glass, a soda lime glass or the like formed by sputtering or the like is used.
And a ceramic substrate such as alumina.

The material of the opposing element electrodes 2 and 3 may be any material as long as it has conductivity. For example, Ni, Cr, Au, Mo, W, Pt,
Metals or alloys such as Ti, Al, Cu, Pd and Pd;
A printed conductor composed of a metal such as Ag, Au, RuO ₂ , Pd-Ag or a metal oxide and glass; ln ₂ O ₃ −
Examples include a transparent conductor of SnO ₂ and a semiconductor conductor material such as polysilicon.

The element electrode interval L, the element electrode length W, and the shape thereof are appropriately designed depending on the application form of the electron-emitting device and the like. For example, in a display device such as a television to be described later, a pixel corresponding to the screen size is used. The size is designed. In particular, a high-definition television requires a small pixel size and high definition. Therefore, in order to obtain a sufficient luminance even when the size of the electron-emitting device is limited, it is designed so that a sufficient emission current is obtained.

The element electrode interval L is from several tens nm to several hundred μm.
The photolithography technology, which is the basis of the method of manufacturing the device electrodes, that is, the performance of the exposure machine and the etching method, and is set by the voltage applied between the device electrodes,
Preferably, it is from several μm to several tens μm.

The length W of the device electrode and the device electrode 2,
3 is appropriately designed in consideration of the resistance value of the electrodes and the arrangement of a large number of electron sources. Usually, the length W of the device electrode is several μm to several hundred μm. The film thickness d of a few is from several nm to several μm.

In addition to the structure shown in FIG.
A configuration in which the conductive thin film 4 and the opposing device electrodes 2 and 3 are laminated on the above in this order can also be adopted. It is preferable to use a fine particle film composed of fine particles for the conductive thin film 4 in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage for the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, a forming condition described later, and the like.

Further, since the magnitudes of the device current If and the emission current Ie depend on the width W of the conductive thin film 4, as in the case of the shape of the device electrode, it is sufficient when the size of the electron emission device is limited. It is designed to obtain an emission current.

In general, the thermal stability of the conductive thin film 4 may dominate the life of the electron emission characteristics, and it is desirable to use a material having a higher melting point as the material of the conductive thin film 4. However, usually, as the melting point of the conductive thin film 4 is higher, larger electric power is required for energization forming described later.

Further, an applied voltage (threshold voltage) capable of emitting electrons depends on the shape of the resulting electron emitting portion.
In some cases, a problem occurs in the electron emission characteristics such as an increase in In the present invention, the material of the conductive thin film 4 is not particularly required to be a material having a high melting point, and a material / form capable of forming a good electron emission portion with a relatively low forming power can be selected.

Examples of materials satisfying the above conditions include Ni,
A conductive material such as Au, PdO, Pd, or Pt formed with a film thickness having a resistance value of Rs (sheet resistance) of 10 ² to 10 ⁷ Ω / □ is preferably used. Rs is a value that appears when a resistance R measured in the length direction of a thin film having a thickness t, a width w, and a length 1 is R = Rs (l / w). Then, Rs = ρ / t. The film thickness showing the resistance value is in the range of approximately 5 nm to 50 nm, and in this film thickness range, the thin film of each material has the form of a fine particle film.

The fine particle film described herein is a film in which a plurality of fine particles are aggregated, and has a fine structure in a state in which the fine particles are individually dispersed and arranged or in a state in which the fine particles are adjacent to each other or overlap each other (when some fine particles are mixed). To form an island-like structure as a whole).

The particle size of the fine particles is in the range of several hundred pm to several hundred nm, preferably in the range of 1 nm to 20 nm.
By the way, among the materials exemplified above, PdO is an organic P
A thin film can be easily formed by baking the d-compound in air, a relatively low electric conductivity because of the semiconductor, a wide process margin of the film thickness for obtaining the resistance value Rs in the above range, and a gap is formed in the conductive thin film. This is a preferable material because it can be easily reduced to metal Pd after performing, for example, and the film resistance can be reduced. However, the effects of the present invention are not limited to PdO, and are not limited to the materials exemplified above.

The electron-emitting portion 5 is formed of a film having carbon opposed to a gap narrower than a gap formed in the conductive thin film 4 through an activation step described later. In the activation step described later, a deposited film containing carbon is also formed on the conductive thin film 4. It is preferable that the gap width between the pair of carbon films is 50 Å or less at the maximum.

The carbon constituting the film having carbon as a deposit is, for example, graphite (so-called HO).
HOPG, which includes PG, PG and GC, has a crystal structure of almost perfect graphite, PG has a crystal grain of about 200 angstroms and has a slightly disordered crystal structure, and GC has a crystal grain of about 20 angstroms and has a disordered crystal structure. Refers to a larger one. ), And amorphous carbon (refer to amorphous carbon and a mixture of amorphous carbon and the microcrystals of graphite), and the film thickness is preferably in the range of 5 to 100 nm.

Further, the carbon constituting the film 6 having carbon deposited on the conductive thin film corresponds to the 002 plane of graphite as shown in the schematic sectional views of FIGS. 4 (a) and 4 (b). It has a structure in which lattice fringes are oriented in layers from the substrate surface upward.

FIG. 4A is a cross-sectional view schematically showing lattice fringes observed on a conductive thin film, and FIG.
FIG. 5 is an enlarged schematic cross-sectional view showing a part of FIG.
As schematically shown in FIG. 4B, the lattice fringes corresponding to the 002 plane of graphite observed in the carbon-containing film 6 of the present invention are oriented in a direction substantially normal to the substrate and the surface of the conductive thin film. It has nature.

The direction in which the lattice fringes have orientation is shown in FIG.
Are within ± 30 ° from the normal to the substrate surface and the conductive thin film surface shown in FIG. Here, the direction having the lattice fringe orientation refers to a direction in which the lattice fringes overlap (a direction perpendicular to the lattice fringes).

The lattice fringes of the carbon-deposited film 6 of the present invention shown in FIGS. 4A and 4B and the directions in which the lattice fringes have orientation are evaluated and observed as follows. Focused ion beam (FIB) as an example of the evaluation method
A cross-sectional transmission electron microscope observation (cross-sectional TEM) method is mentioned, but is not particularly limited as long as the evaluation of the orientation of the deposited film is not inconvenient.

Here, FIB was used to prepare a sample for cross-sectional TEM observation.
Since processing is used, a thickness of 1
It is possible to produce a thin section of 00 nm or less, and it is possible to evaluate the cross section of the deposited film 6 by TEM. Next, a method of evaluating the orientation of the deposited film by TEM is as follows.
There are mainly three methods described below.

(1) A high-magnification TEM image of the deposited film is taken to check the lattice fringes of the deposit. Here, the orientation direction is determined from the direction of the lattice fringes.

(2) The diffraction pattern obtained when the deposit is irradiated with the microprobe is photographed, and the intensity distribution of the diffraction ring is measured. At this time, if there is orientation, the intensity distribution of the diffraction ring becomes non-uniform, and the direction in which the intensity of the diffraction ring is strong is the orientation direction.

(3) Fourier transformation is performed on an image obtained by capturing lattice fringes of a high-magnification TEM image of the deposit to obtain a diffraction pattern, and the intensity distribution of the diffraction ring is measured. At this time, if there is orientation, the intensity distribution of the diffraction ring becomes non-uniform, and the direction in which the intensity of the diffraction ring is strong is the orientation direction.

Here, after obtaining the diffraction pattern as shown in (2) and (3), the intensity of the diffraction ring in the orientation direction and the intensity of the diffraction ring in the direction orthogonal thereto are compared (for example, an intensity ratio is obtained). By doing so, the strength of the orientation can be quantified.

By selecting appropriate conditions as an organic material used for activation and activation conditions described below, and selecting appropriate conditions as conditions for a stabilization step after the activation step described below, FIG. As shown in a) and (b),
It is considered that an element in which the direction having carbon orientation on the surface of the electron-emitting device is substantially normal to the substrate surface and the conductive thin film surface can be produced.

In order to describe the electron-emitting device of the present invention in detail, a measurement and evaluation device will be described with reference to FIG.
FIG. 5 is a schematic configuration diagram of a measurement evaluation device for measuring the electron emission characteristics of the device having the configuration shown in FIG. In FIG. 5, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, and 5 is an electron emitting portion. Reference numeral 51 denotes a power supply for applying a device voltage Vf to the device, 50 denotes an ammeter for measuring a device current If flowing through the conductive thin film 4 between the device electrodes 2 and 3, and 54 denotes an electron emission portion of the device. An anode electrode 53 for capturing the emission current Ie emitted, a high-voltage power supply 53 for applying a voltage to the anode electrode 54,
Reference numeral 2 denotes an ammeter for measuring an emission current Ie emitted from the electron emission portion 5 of the device, and 55 denotes a vacuum vessel.

In measuring the device current If and the emission current Ie of the current emitting device, the power supply 51 is connected to the device electrodes 2 and 3.
And an ammeter 50, and an anode 54 connected to a power supply 53 and an ammeter 52 is disposed above the electron-emitting device. Further, the electron-emitting device and the anode 54
Is installed in a vacuum device.

In FIG. 3, when a voltage is applied between the device electrodes 2 and 3 so that the device electrode 3 has a high potential, electrons are emitted from the electron emission portion 5 and reach the anode electrode 54. According to calculations performed by the present inventors on the orbits of electrons emitted at this time, it is known that the experimental facts can be explained by making the following assumptions (M. Okuda, "Electron Trajectory Analysis of Su
rface Conduction Electron Emitter Displays (SEDs) "
SID98).

Hereinafter, description will be made with reference to FIGS.
FIG. 1A is a diagram showing a potential distribution formed by the device voltage Vf and the anode voltage Va applied to the electron-emitting device, and FIG. 1B is a diagram showing the distribution of emitted electrons near the electron-emitting portion. The trajectory is schematically shown. In the drawing, reference numeral 11 denotes a low potential side surface (potential 0) of the electron-emitting device, 12 denotes a high potential side surface (potential Vf) of the electron-emitting device, 13 denotes an anode electrode (potential Va), and 14 denotes a singular point of the electric field. .

First, electrons are emitted from the tip of the electron emission portion on the low potential side toward the tip of the electron emission portion on the high potential side, and a part of the electrons are scattered at the tip of the electron emission portion on the high potential side and fall into a vacuum. Released. At this time, the device current I flowing through the electron-emitting device
Let β0 be the ratio of emitted electrons to f.

The electrons once emitted move in the electric field formed by the low-potential side electrode and the high-potential side electrode, and fly farther than a singular point (hereinafter referred to as a stagnation point) of the high-potential side electric field. The electrons are attracted to the anode electrode by the electric field generated by the anode voltage and reach the anode electrode.

On the other hand, electrons that do not reach the stagnation point fall on the high potential side surface of the electron-emitting device, some electrons are absorbed into the high potential side surface, and some electrons are elastically scattered here. Released again in vacuum. The ratio of the electrons scattered at this time is the elastic scattering probability β of the surface on the high potential side. The electrons that have exceeded the stagnation point by repeating this scattering reach the anode electrode.

Therefore, the efficiency of the electron-emitting device (= the ratio of the anode current Ie to the device current If) is β0 * β for one-time scattering, and can be expressed as β0 * βn for n-times scattering.

Here, for the sake of simplicity, assuming that the ratio of the electrons that have reached the anode electrode to the electrons emitted from the electron-emitting portion is the electron arrival rate 効率, (the efficiency = β0 * ζ) n is

[0053]

[Equation 2] From ζ = β ⁿ ,

[0054]

[Formula 3] It can be expressed as n = Logζ / Logβ. The electron arrival rate 到達 is

[0055]

(Equation 4) It can be expressed as. Here, F (x) is when Va = 0V,
At the distance x from the electron emitting portion, a landing point distribution function due to elastic scattering of electrons, Xs is the distance from the electron emitting portion to the stagnation point, and Xs is the distance from the electron emitting portion to the effective stagnation point. , Xs multiplied by a coefficient γ = 0.67.

In the device of the present invention, the distance Xs from the electron emitting portion to the stagnation point is

[Equation 5] Xs = D / 2 {1+ (2H · Vf / πVa · D) 2}
≒ H · Vf / π · Va.

Here, D is the width of the electron-emitting portion, H is the distance between the electron-emitting device and the anode voltage, π is the pi, Vf is the device voltage, and Va is the anode voltage.

FIG. 2 shows a landing point distribution function due to elastic scattering of electrons at a distance x from the electron emission portion when Va = 0 V.
It is the figure which showed F (x). F (x) is a graph showing a distribution of landing points after electrons emitted from the tip of the electron emission portion on the high potential side of the electron emission element at an isotropic and equal energy repeat elastic elastic scattering multiple times on the element surface. 1, which is integrated in the y-axis direction (the length direction of the electron-emitting portion).

The integration of the falling point distribution of electrons scattered isotropically and with equal energy from a certain point X0 on the electron-emitting device in the y-axis direction (length direction of the electron-emitting portion) in FIG. x (x, x0), f (x, x0) is given by
It is represented by

[0060]

(Equation 6) Here, N is a constant for normalization, and C depends on the device voltage Vf and the work function Wf of the surface on the high potential side of the electron-emitting device, and has the relationship of the following expression 7.

[0061]

Equation 7 Assuming isotropic scattering, a landing point distribution function F (x) considering multiple scattering is represented by the following equation 8 using a falling point distribution function f (x, x0) due to only one scattering and a scattering probability β. And F (x) is a function as shown in FIG.
Here, it is assumed that X0 = D / 2 (D is the width of the electron emission portion), assuming that the electrons are scattered at the tip of the electron emission portion on the high potential side and are emitted into a vacuum.

[0062]

(Equation 8) The electron arrival rate 時 when the anode voltage Va is applied can be regarded as the ratio of electrons exceeding the effective stagnation point formed by the anode voltage Va (integral value of the hatched portion in FIG. 2). The arrival rate ζ is expressed by the above equation (4). Here, F (x) dx can be approximated by Expression 9 below.

[0063]

[Equation 9] In a device having the same configuration, the width D of the electron emission portion, the elastic scattering probability β on the high potential side surface, and the work function Wf on the high potential side surface are almost constant, so that F (x) depends on the device voltage Vf. It can be obtained by calculation as a function.
(The width D of the electron-emitting portion slightly varies depending on the device voltage Vf, but it does not matter if it is assumed to be the same in the calculation.) In the electron-emitting device of the present invention, the device voltage Vf is preferably about 10 V to 30 V. It is. From Equations 3 to 5, the average number of elastic scattering times n is

[0064]

(Equation 10) It can be expressed as.

In the electron-emitting device of the present invention, the smaller the number of times of scattering on the high potential side surface of the electron-emitting device,
Although the ratio of the electrons reaching the anode can be increased, if the device voltage Vf is about 10 to 30 V, the anode voltage must be several tens to reach the anode with less than one average elastic scattering. The voltage must be increased from kV to 100 kV or more, and the possibility of occurrence of a problem such as discharge increases. Therefore, it is desirable that the driving condition is such that the average number of times of elastic scattering is 1 or more.

In the electron-emitting device of the present invention, the thin film having carbon on the high potential side surface of the electron-emitting device serving as the scattering surface is arranged in the form of lattice fringes, and has the orientation of the lattice fringes. The direction is almost normal to the substrate surface,
Or within ± 30 ° from the normal.

In such an electron-emitting device of the present invention, the elastic scattering probability at the time of irradiating low energy electrons of about 10 to 20 eV corresponding to the driving conditions of the electron-emitting device is determined by the low energy electron diffraction (LEED). As a result of the measurement, the average elastic scattering probability on the surface of the electron-emitting device of the present invention is 0.1.
It is known to be about 3. Further, in the electron-emitting device of the present invention, the device current If flowing in the electron-emitting device
, The ratio β0 of the electrons emitted into the vacuum from the tip of the electron-emitting portion depends on the shape and the like of the carbon film deposited on the electron-emitting portion in the activation step described later, but generally ranges from 3% to 7%.
% Is in good agreement with the experimental results. Therefore, when the efficiency (= β0 * β ⁿ ) is estimated, the driving condition is such that the average elastic scattering number n is 3 or less, that is,

[0068]

(Equation 1) By driving with the element voltage Vf and the anode voltage Va, a good efficiency of about 0.08% or more can be obtained.

Various methods are conceivable as a method of manufacturing the electron-emitting device. One example is shown in FIG. Less than,
The description of the manufacturing method will be described with reference to FIG. 3 and FIG.

1) After sufficiently washing the substrate 1 with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum deposition method, a sputtering method or the like, and then the device electrodes 2 and 3 are formed by a photolithography technique ( FIG. 6 (a)).

2) An organic metal film is formed between the element electrodes 2 and 3 provided on the substrate 1 by applying and drying an organic metal solution. The organic metal solution is a solution of an organic metal compound containing a metal such as Pd, Ni, Au, or Pt as a main element. Thereafter, the organic metal film is heated and baked, and is patterned by lift-off, etching, or the like to form the conductive thin film 4 (FIG. 6).
(B)). Note that, here, the description has been made by the application method of the organic metal solution. However, the present invention is not limited thereto, and is formed by a vacuum evaporation method, a sputtering method, a CVD method, a dispersion coating method, a dipping method, a spinner method, an inkjet method, or the like. In some cases.

3) Subsequently, an energizing process called forming is performed by applying a pulse voltage or a rising voltage between the element electrodes 2 and 3 by using a power supply (not shown).
A crack is formed in a part of the conductive thin film 4. (FIG. 6
(C)).

The electrical processing after the forming processing is performed in the above-described measurement and evaluation apparatus shown in FIG. Note that the measurement and evaluation apparatus shown in FIG. 5 is a vacuum apparatus, and the vacuum apparatus is provided with equipment necessary for a vacuum apparatus such as an exhaust pump (not shown) and a vacuum gauge. Can be measured and evaluated. The exhaust pump includes a high-vacuum system such as a magnetic levitation turbo pump and a dry pump that does not use oil, and an ultra-high vacuum system including an ion pump. Further, the present measuring apparatus is provided with a gas introducing device (not shown) so that a vapor of a desired organic substance can be introduced into the vacuum device at a desired pressure. Also,
The entire vacuum device and the electron-emitting device can be heated by a heater (not shown).

In the forming process, there are a case where a pulse having a constant pulse peak value is applied and a case where a voltage pulse is applied while increasing the pulse peak value. First, FIG. 7A shows a voltage waveform when a pulse having a pulse crest value of a constant voltage is applied. In FIG. 7A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec.
c to 10 msec, T2 is 10 μsec to 100 msec
It is appropriately selected in the range of c.

Next, FIG. 7B shows a voltage waveform when a voltage pulse is applied while increasing the pulse peak value. In FIG. 7B, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec to 10 ms.
ec and T2 are set to 10 μsec to 100 msec, and the applied voltage is increased by, for example, about 0.1 V steps.

The forming process ends when the conductive thin film 4 is locally destroyed during the forming pulse.
A voltage that does not deform, for example, a pulse voltage of about 0.1 V is inserted, and the element current is measured to obtain a resistance value.
When the resistance is 1 MΩ or more, the forming can be terminated.

In forming the cracks described above, the forming process is performed by applying a rectangular wave pulse between the electrodes of the element. However, the waveform applied between the electrodes of the element is not limited to a rectangular wave. Instead, a desired waveform such as a triangular wave may be used, and the peak value, pulse width, pulse interval, and the like are not limited to the above values, and an appropriate value is selected according to the resistance value of the electron-emitting device. . 4) Next, an activation process is performed on the element for which the forming has been completed. (FIG. 6D) The activation treatment is performed by introducing a gas of an organic substance into the vacuum device shown in FIG. 5 and applying a voltage between the electrodes of the element in an atmosphere containing organic molecules. . By this treatment, a film containing carbon is deposited from the organic substance present in the atmosphere on the cracks formed by the forming and on the element surface, and the element current If,
The emission current Ie changes significantly. At this time, a deteriorated portion may be formed on the substrate.

As the voltage waveform in the activation step, a bipolar voltage waveform as shown in FIG. 7C can be preferably used. The maximum voltage value is appropriately selected in the range of 10 to 20V. Since the discharge may occur when the constant voltage is applied from the beginning of the activation, it is preferable to have a step of increasing the voltage from a low voltage to a constant voltage.

In the present invention, it is necessary to form the carbon-containing film deposited on the surface of the electron-emitting device by the activation process into the shape shown in FIG. 4 with good control. The shape of the film containing carbon, which is a deposit, depends on the voltage waveform applied to the element, the pressure of the introduced organic substance, the diffusion mobility on the element surface, the average residence time on the element surface, and the like. It is also important to have easy handling such as easy introduction into a vacuum device and easy exhaustion after activation. From the above viewpoints, as a result of examining various organic substances, it was found that a nitrile compound was effective, and particularly when tolunitrile (toluene cyanide), benzonitrile or acrylonitrile was used, it had good controllability. Although the reason why these organic substances are preferably used is not strictly understood, it is considered that the state of adsorption to the element surface via the nitrile group (-C−N) conforms to the above conditions. .

The activation of the element is performed in a vacuum device in which the pressure in the vacuum device is once reduced to a pressure of the order of 10 ⁻⁶ Pa, and then a gas of an organic substance is introduced. Here, a case where tolunitrile is used as an organic substance will be described as an example. The preferable pressure of the tolunitrile to be introduced is slightly affected by the shape of the vacuum device, the members used for the vacuum device, and the like.
It is about × 10 ⁻⁵ Pa to 1 × 10 ⁻³ Pa. 1 × 10 ^-5
At a pressure of Pa or less, the progress of the activation becomes extremely slow,
Activation may not proceed sufficiently depending on the composition and partial pressure of the remaining gas. On the other hand, at a pressure of 1 × 10 ⁻³ Pa or more, the progress of activation becomes extremely fast, and it becomes difficult to form a desired deposit shape with good reproducibility. The preferred range of the introduced partial pressure depends on the saturated vapor pressure of the organic substance at that temperature, and in the case of benzonitrile, 1 ×
It is about 10 ⁻⁵ Pa to 1 × 10 ⁻³ Pa, and in the case of acrylonitrile, it is about 1 × 10 ⁻³ Pa to ¹ × 10 ⁻¹ Pa.

The carbon of the carbon-containing deposit in the present invention contains graphite-like carbon. The graphite-like carbon in the present invention means a carbon having a complete graphite crystal structure (a so-called HOPG), and a crystal grain having 2 crystal grains.
A crystal structure slightly disturbed at about 0 nm (PG); a crystal grain disordered at about 2 nm to further disturb the crystal structure (GC); and amorphous carbon (amorphous carbon and a mixture of the amorphous carbon and the graphite). Refers to a mixture of microcrystals). That is, it can be preferably used even if there is a layer disorder such as a grain boundary between graphite particles.

6) The electron-emitting device thus manufactured is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum vessel. Although it is desirable to eliminate the organic substance in the vacuum vessel as much as possible, the partial pressure of the organic substance is preferably 1 to 3 × 10 ⁻⁸ Pa or less. The pressure including other gases is preferably 1 to 3 × 10 ⁻⁶ Pa or less, more preferably 1 × 10 ⁻⁷ Pa or less. As the vacuum exhaust device for exhausting the vacuum container, a device that does not use oil is used so that oil generated from the device does not affect the characteristics of the element. Specifically, a sorption pump,
A vacuum exhaust device such as an ion pump can be used.
Further, when the inside of the vacuum vessel is evacuated, the entire vacuum vessel is heated so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device are easily evacuated. The heating condition at this time is desirably as long as possible at 150 to 350 ° C., preferably 200 ° C. or more, for as long as possible. However, the heating condition is not particularly limited thereto. This is performed under conditions appropriately selected according to various conditions.

At this time, the electron-emitting device is set at 200 ° C. to 3 ° C.
The organic components adsorbed on the surface of the electron-emitting device are removed by heating to 50C, more preferably 300C to 350C.
Thus, it is considered that a low-molecular organic compound, which is a factor for reducing the probability of elastic scattering of electrons on the surface of the electron-emitting device, can be removed, and the probability of elastic scattering of electrons on the surface of the electron-emitting device can be increased.

The atmosphere at the time of driving after performing the stabilization step is preferably the same as the atmosphere at the end of the stabilization treatment, but is not limited to this. If the organic substance is sufficiently removed, Even if the pressure itself increases somewhat, it is possible to maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, so that the shape of the film having carbon of the present invention is maintained, and as a result, the device current If and the emission current Ie are stabilized. Further, by removing the organic component adsorbed on the surface of the electron-emitting device, the probability of elastic scattering of electrons on the surface of the electron-emitting device can be increased.

The basic characteristics of the electron-emitting device manufactured by the above-described manufacturing method to which the present invention can be applied will be described with reference to FIGS. The emission current Ie of the device after the stabilization process measured by the measurement and evaluation device shown in FIG.
FIG. 8 shows a typical example of the element current If and the element voltage Vf. In FIG. 8, since the emission current Ie is significantly smaller than the element current If, the emission current Ie is shown in an arbitrary unit, and each is a linear scale. As is clear from FIG. 8, the electron-emitting device has three properties with respect to the emission current Ie.

First, when an element voltage higher than a certain voltage (referred to as a threshold voltage, Vth in FIG. 8) is applied to the present element, the emission current Ie sharply increases.
Below th, the emission current Ie is hardly detected. That is, a clear threshold voltage Vt for the emission current Ie
h is a non-linear element.

Second, since the emission current Ie depends on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf. Third, the emission charge captured by the anode electrode 54 depends on the time during which the device voltage Vf is applied. That is,
The amount of charge captured by the anode electrode 54 is equal to the device voltage Vf
Can be controlled by the application time.

By using the characteristics of the electron-emitting device as described above, the electron-emitting characteristics can be easily controlled according to the input signal. Furthermore, since the electron-emitting device according to the present invention has stable and high-luminance electron-emitting characteristics, it can be expected to be applied to various fields. An application example of an electron-emitting device to which the present invention can be applied will be described below.

By arranging a plurality of electron-emitting devices according to the present invention on a substrate, for example, an electron source or an image forming apparatus can be constructed. Regarding the arrangement of elements on the substrate, for example, a large number of electron-emitting elements are arranged in parallel, and both ends of each element are connected by wiring, and a large number of rows of electron-emitting elements are arranged (referred to as a row direction). An array configuration (called a ladder type) in which electrons are controlled and driven by control electrodes (called a grid) installed in a space above the electron source in a direction orthogonal to the wiring (called a column direction), and On the m X-directional wirings described, n Y-directional wirings were provided via an interlayer insulating layer, and the X-directional wiring and the Y-directional wiring were connected to a pair of device electrodes of the surface conduction electron-emitting device, respectively. An arrangement form is exemplified.
Hereinafter, this is referred to as a simple matrix arrangement.

Next, the simple matrix arrangement will be described in detail. According to the characteristics of the above-mentioned three basic characteristics of the electron-emitting device according to the present invention, when the electron emitted from the electron-emitting device is equal to or higher than the threshold voltage, the pulse-like voltage applied between the opposing device electrodes is reduced. It can be controlled by high price and width. On the other hand, when the voltage is equal to or lower than the threshold voltage, it is hardly emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged,
If the pulse voltage is appropriately applied to each element, a surface conduction electron-emitting device can be selected according to an input signal, and the amount of electron emission can be controlled.

Hereinafter, the structure of the electron source substrate formed based on this principle will be described with reference to FIG. The m X-directional wirings 102 are made up of DX1, DX2,.
It is formed on the substrate 1 by a vacuum evaporation method, a printing method, a sputtering method, or the like, and is made of a conductive metal or the like having a desired pattern, so that a substantially uniform voltage is supplied to many electron-emitting devices.
Material, film thickness, wiring width, etc. are designed. An interlayer insulating layer (not shown) is provided between the m X-directional wirings 102 and the n Y-directional wirings 103, and is electrically separated to form a matrix wiring. Positive integer).

The interlayer insulating layer (not shown) is made of SiO 2 or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like, and has a desired shape on the entire surface or a part of the substrate 101 on which the X-directional wiring 102 is formed. In particular, the film thickness and the thickness are set so as to withstand the potential difference at the intersection of the X-direction wiring 102 and the Y-direction wiring 103.
The material and manufacturing method are appropriately set. X direction wiring 102 and Y
The direction wiring 103 is drawn out as an external terminal.

Further, in the same manner as described above, opposing electrodes (not shown) of the electron-emitting device 104 are composed of m X-directional wirings 102 (DX1, DX2,..., DXm) and n Y-directional wirings 103 ( DY1, DY2,..., DYn) are electrically connected by a connection 105 made of a conductive metal or the like.

Here, the conductive metal of the element electrode opposed to the m X-directional wirings 102, the n Y-directional wirings 103, and the connection 105 has the same structure as that of the conductive metal even if some or all of the constituent elements are the same. Moreover, each may be different. These materials are appropriately selected, for example, from the above-described materials for the device electrodes.

As will be described later in detail, the X-direction wiring 102 is not provided with a scanning signal for applying a scanning signal for scanning a row of the electron-emitting devices 104 arranged in the X direction in accordance with an input signal. The scanning signal applying means shown in the drawing is electrically connected. On the other hand, in the Y-direction wiring 103, each column of the surface conduction type emission elements 104 arranged in the Y direction is set in accordance with an input signal.
It is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulation.

Further, the driving voltage applied to each element of the electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element. Next, an example of an electron source using the electron source substrate manufactured as described above and an image forming apparatus used for display and the like will be described with reference to FIGS. FIG. 10 is a basic configuration diagram of the image forming apparatus, and FIG. 11 is a fluorescent film.

10, reference numeral 101 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 111, a rear plate on which the electron source substrate 101 is fixed; 116, a fluorescent film 114 and a metal back 115 formed on the inner surface of a glass substrate 113; This is the finished face plate. Reference numeral 112 denotes a support frame, and the rear plate 111, the support frame 112, and the face plate 1
16 is coated with frit glass and baked in air or nitrogen at 400 to 500 ° C. for 10 minutes or more to be sealed to form an envelope 118. In FIG. 10, reference numeral 104 corresponds to the electron-emitting device shown in FIGS. Reference numerals 102 and 103 are an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device. In addition, the wiring to these device electrodes may be called a device electrode when the material of the device electrode and the wiring material are the same. The xzz envelope 118 includes the face-plate 116, the support frame 112, and the rear plate 111 as described above.
However, since the rear plate 111 is provided mainly for the purpose of reinforcing the strength of the substrate 101, if the substrate 101 itself has sufficient strength, the separate rear plate 111 is unnecessary, and the rear plate 111 is directly attached to the substrate 101. Sealing the support frame 112,
The envelope 118 may be constituted by the face plate 116, the support frame 112, and the substrate 101.

On the other hand, by installing a support (not shown) called a spacer between the face plate 116 and the rear plate 111, an envelope 118 having sufficient strength against atmospheric pressure can be formed. .

FIG. 11 shows a fluorescent film. Phosphor film 114
Is composed of only a phosphor in the case of a monochrome, but is composed of a black conductive material 121 called a black stripe or a black matrix and a phosphor 122 depending on the arrangement of the phosphor in the case of a color phosphor film. The purpose of providing the black stripe and black matrix is
Each phosphor of three primary color phosphors required for color display 1
The purpose is to make the color mixture and the like inconspicuous by making the painted portion between 22 black, and to suppress a decrease in contrast due to reflection of external light on the fluorescent film 114. The material of the black stripe is not limited to the commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection.

The method of applying the phosphor on the glass substrate 113 uses a precipitation method, a printing method, etc. irrespective of monochrome or color. A metal back 115 is usually provided on the inner surface side of the fluorescent film 114. The purpose of the metal back is to improve the brightness by mirror-reflecting the light emitted from the phosphor toward the inner surface side to the face plate 116 side, to act as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from damage due to collision of negative ions generated in the enclosure. After the fluorescent film is formed, the metal back is subjected to a smoothing process (usually called filming) on the inner surface of the fluorescent film, and then to the Al film.
Is deposited by using vacuum evaporation or the like.

The face plate 116 may be provided with a transparent electrode (not shown) on the outer surface of the fluorescent film 114 in order to further increase the conductivity of the fluorescent film 114. When performing the above-mentioned sealing, in the case of a color, it is necessary to correspond to each color phosphor and the electron-emitting device, so it is necessary to perform sufficient alignment.

The envelope 118 passes through an exhaust pipe (not shown).
After the degree of vacuum is set to about 1 × 10 ⁻⁷ Pa, sealing is performed. In addition, getter processing may be performed in order to maintain the degree of vacuum of the envelope 118 after sealing. This is because the getter disposed at a predetermined position (not shown) in the envelope 118 is heated by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 118 is sealed. This is a process for forming a deposited film. Getter is usually Ba
Are the main components, and maintain a degree of vacuum of, for example, about 1 × 10 ⁻⁵ or 1 × 10 ⁻⁷ Pa by the adsorption action of the deposited film.

In the image display device of the present invention completed as described above, a voltage is applied to each electron-emitting device through the external terminals Dox1 to Doxm and Doy1 to Doyn, thereby emitting electrons. Metal back 115 or transparent electrode (not shown)
A high voltage of several kV or more is applied to accelerate the electron beam, collide it with the fluorescent film 114, and excite and emit light to display an image.

The above-described configuration is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display and the like, and detailed portions such as materials of each member are limited to the above-described contents. Instead, it is appropriately selected so as to be suitable for the use of the image forming apparatus. Next, a configuration example of a driving circuit for performing television display based on an NTSC television signal on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG.

FIG. 12 is a block diagram showing an example of a driving circuit for performing display according to an NTSC television signal. In FIG. 12, reference numeral 131 denotes a display panel, 132 denotes a scanning signal generation circuit, and 133 denotes a timing. The control circuit 134 is a shift register. 135 is a line memory, 136
Is a synchronization signal separation circuit, 137 is a modulation signal generation circuit, Vx
And Va are DC voltage sources.

The display panel 131 has terminals Dox1 to Dox1
oxm, terminals Doy1 to Doyn, and high voltage terminal Hv
Connected to an external electric circuit via Terminal Dox1
Scan signals for sequentially driving electron sources provided in the display panel, that is, electron emission element groups arranged in a matrix of m rows and n columns, one row at a time (n elements) are applied to Doxm. Is done. The terminals Doy1 to Doyn include:
A modulation signal for controlling an output electron beam of one row of electron-emitting devices selected by the scanning signal is applied. A DC voltage is supplied to the high voltage terminal Hv from a DC voltage source Va, which is an accelerating voltage for applying sufficient energy to an electron beam emitted from the electron-emitting device to excite the phosphor. .

The scanning signal generating circuit 132 has m switching elements therein (S1 to S1 in the figure).
m). Each switching element selects either the output voltage of the DC voltage source Vx or 0 V (ground level) and is electrically connected to the terminals Dox1 to Doxm of the display panel 131. S
Each of the switching elements 1 to Sm operates based on the control signal Tscan output from the control circuit 133, and can be configured by combining switching elements such as FETs, for example.

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

The timing control circuit 133 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. The timing control circuit 133 sends Tscan to each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 136.
And Tsft and Tmry control signals.

The synchronizing signal separation circuit 136 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 136 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience. The DATA signal is input to the shift register 134.

The shift register 134 is for serially / parallel converting the DATA signal input serially in time series for each line of an image, and is a control signal Tsft sent from the timing control circuit 133.
(Ie, the control signal Tsft can be said to be a shift clock of the shift register 134). The data for one line of the image that has been subjected to the serial / parallel conversion (corresponding to drive data for N electron-emitting devices) is output from the shift register 134 as N parallel signals Id1 to Idn.

The line memory 135 is a storage device for storing data for one line of an image for a necessary time only, and a control signal T sent from the timing control circuit 133.
The contents of Id1 to Idn are stored as appropriate according to mry. The stored contents are output as I'd1 to I'dn and input to the modulation signal generator 107.

Modulation signal generator 137 outputs image data I '.
The signal source is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of d1 to I'dn, and its output signal is supplied to the surface conduction electron-emitting device in the display panel 131 through terminals Doy1 to Doyn. Applied to the emitting element.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie. That is, a clear threshold voltage Vth is required for electron emission.
And electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device. From this, when applying a pulsed voltage to this element,
For example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold is applied, an electron beam is output. At that time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. In addition, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw. Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method of modulating the electron-emitting device according to the input signal.

In implementing the voltage modulation method, the modulation signal generator 137 generates a voltage pulse of a fixed length, and modulates the peak value of the pulse appropriately according to input data. A circuit can be used.

When implementing the pulse width modulation method,
As the modulation signal generator 137, a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data can be used.

The shift register 134 and the line memory 13
5 can be either a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separation circuit 136 into a digital signal. For this purpose, an A / D converter may be provided at the output section of the signal generator 136. In connection with this, the line memory 13
Depending on whether the output signal of 5 is a digital signal or an analog signal,
The circuit used for the modulation signal generator 137 is slightly different. That is, in the case of the voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 137, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 137 includes, for example, a high-speed oscillator, a counter (counter) for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. (Comparator) is used. If necessary, an amplifier for amplifying the pulse width modulated signal output from the comparator to the drive voltage of the electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, the modulation signal generator 137 can employ, for example, an amplifier circuit using an operational amplifier or the like, and can add a level shift circuit or the like as necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the drive voltage of the electron-emitting device can be added as necessary.

In the image display apparatus to which the present invention can be applied, which has such a configuration, by applying a voltage to each of the electron-emitting devices via the external terminals Dox1 to Doxm and Doy1 to Doyn, the electron-emitting device can emit electrons. Occurs.
A high voltage is applied to the metal back 115 or a transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 114 and emit light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. As for the input signal, the NTSC system has been described, but the input signal is not limited to this, and the PAL, SECAM system, etc.
A TV signal composed of a large number of scanning lines (for example,
A high-definition TV system such as the MUSE system can also be adopted.

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

[0123]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 The basic structure of an electron-emitting device according to this example is the same as the plan view and cross-sectional view of FIGS. 3A and 3B.

The method for manufacturing the surface conduction electron-emitting device according to this embodiment is basically the same as that shown in FIG. Hereinafter, a basic configuration and a manufacturing method of the element according to the present embodiment will be described. Step-a First, on a substrate 1 in which a 0.5 mm-thick silicon oxide film is formed on a cleaned blue sheet glass by a sputtering method, a pattern to be a gap L between the device electrodes 2 and 3 and a desired device electrode is formed. With photoresist (RD-2000N-4)
1 made by Hitachi Chemical Co., Ltd.), and 5 nm thick Ti and 30 nm thick Pt were sequentially deposited by electron beam evaporation. Dissolve the photoresist pattern with an organic solvent and add Pt
/ Ti deposited film is off, the device electrode interval L is 3 μm, and the device electrode 2 has a device electrode width W of 500 μm.
No. 3 was formed (FIG. 6A).

Step-b: A Cr film having a thickness of 100 nm is deposited by vacuum evaporation, patterned so as to have an opening corresponding to the shape of a conductive thin film described later, and an organic palladium compound solution (c
cp4230 manufactured by Okuno Pharmaceutical Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 12 minutes. The conductive thin film 4 composed of fine particles of Pd as the main element thus formed had a thickness of 10 nm and a sheet resistance Rs of 2 × 10 4 Ω / port. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated as described above.

Step-c The Cr film and the baked conductive thin film 4 are etched with an acid etchant so that the width W ′ of the conductive thin film 4 is 30 or less.
A conductive thin film 4 having a desired pattern was formed so as to have a thickness of 0 μm (FIG. 6B).

Through the above steps, the device electrodes 2, 3 and the conductive thin film 4 were formed on the substrate 1. Step-d Next, the device is set in the measurement and evaluation apparatus of FIG. 5, evacuated by a vacuum pump, and after reaching a degree of vacuum of 1 × 10 ⁻⁵ Pa, a power source 51 for applying an element voltage Vf to the element. A voltage is applied between the device electrodes 2 and 3 of the device to perform a forming process;
A crack was formed in the conductive thin film. The voltage waveform of the forming process is shown in FIG. 7B (FIG. 6).
(C)).

In FIG. 7B, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this embodiment, T1 is 0.1 msec, T2 is 16.7 msec, and the peak value of the rectangular wave is 0. The voltage was increased in steps of .1 V, and a forming process was performed. During the forming process,
At a voltage of 0.1 V, a resistance measurement pulse was inserted between the forming pulses, and the resistance was measured. The forming process was terminated when the value measured by the resistance measurement pulse became about 1 MΩ or more, and at the same time, the application of the voltage to the element was terminated. The maximum voltage applied during forming is about 5V.
Met.

Step-e Subsequently, the chamber was evacuated until the pressure in the vacuum vessel reached the order of 10 ^-6 Pa, and to perform the activation step, tolunitrile was introduced into the vacuum apparatus through a slow leak valve. 0
× 10 ⁻⁴ Pa was maintained. Next, a bipolar pulse voltage shown in FIG. 7C was applied to the formed element via the element electrodes 2 and 3 to activate the element. (Figure 6
(D)) The voltage was increased at a rate of 0.1 V / sec from 10 V to 16 V, and then maintained at 16 V for 50 minutes. Further, the pulse width T1 was 1 msec, and the pulse interval T2 was 20 msec. After stopping the energization, the slow leak valve was closed, and the activation process was terminated.

Step-f Subsequently, a stabilizing step was performed. While the vacuum device and the electron-emitting device were heated by a heater and maintained at about 300 ° C., the evacuation of the vacuum device was continued. After 20 hours, when the heating by the heater was stopped and the temperature was returned to room temperature, the pressure in the vacuum apparatus reached about 1 × 10 ⁻⁸ Pa.

The deposit formed on the conductive thin film of the device of this example was subjected to electron probe microanalysis (EPM).
Elemental analysis was performed by A), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy, and it was confirmed that the deposit mainly contained carbon.

Further, for the device of this example manufactured in the above process, the cross section of the device was observed by FIB-cross section TEM method. Here, observation was performed by digital recording using an imaging plate. First, when observed at a low magnification, the deposited film 6 containing carbon has a thickness of about 10 nm or more not only in the vicinity of the electron emission portion 5 formed in the conductive thin film 4 of FIG. Was formed.

Next, when the deposited film was observed at a higher magnification, there was a wide area where lattice fringes oriented in a substantially normal direction (<± 30 °) were observed on the substrate surface and the conductive thin film surface. Was.

Further, when a diffraction pattern was obtained by performing a Fourier transform on an observed image of the deposited film having carbon on the conductive thin film, the diffraction pattern was obtained in a direction substantially normal to the substrate surface and the conductive thin film surface (<± 30 °). There was a wide range where the diffraction ring having the maximum intensity was measured. In addition, the ratio of the intensity of the diffraction ring in a direction having a maximum intensity divided by the intensity of the diffraction ring in a direction orthogonal thereto was measured to be 2.5 or more.

Further, when the device of this example was subjected to low energy electron diffraction (LEED) to measure the elastic scattering probability on the device surface when irradiated with an electron beam from 14 eV to 16 eV, the elastic scattering probability was 0%. .28 to 0.31.

Next, the electron emission characteristics of the electron-emitting device manufactured by the same manufacturing method were measured in the vacuum apparatus shown in FIG. The distance H between the anode electrode 54 and the electron-emitting device was set to 5 mm, and a rectangular pulse voltage was applied between the device electrodes 2 and 3 to drive the device. Also, the high voltage power supply 53
To apply a voltage to the anode electrode 54.

The anode voltage Va was set so that the number of times of scattering on the surface of the electron-emitting device was as shown in Table 1 below.
At this time, the average elastic scattering probability β on the surface of the electron-emitting device
= 0.3, the work function Wf of the surface of the electron-emitting device is 5 eV, which is the work function of carbon, the width D of the electron-emitting portion is 3 nm, and the device voltages Vf = 14.0 V and 14.5 V are calculated. Was done. Under each driving condition, the element current If and the emission current Ie are measured by the ammeter 50 and the ammeter 5.
2 and the efficiency was determined. Table 1 below shows the results.
Shown in

[0139]

[Table 1] As a result, good electron emission efficiency was obtained by driving under the driving condition in which the average elastic scattering number n was 3 or less.

When the anode voltage Va at which the average number of times of elastic scattering n is less than 1 is obtained by calculation, Va is 100 kV
As described above, the voltage applied to the anode was an inappropriate value that was too high.

(Example 2) In this example, the same steps as in Example 1 were performed up to step-d.

Step-e Subsequently, in order to perform an activation step, benzonitrile was introduced into the vacuum apparatus through a slow leak valve,
× 10 ⁻⁴ Pa was maintained. Next, a voltage as shown in FIG. 7C was applied to the formed element through the element electrodes 2 and 3 to activate the element. Voltage from 10V to 1
Boost at 6V at 0.1V / sec, then 45V at 16V
Maintained for minutes. The pulse width T1 was 1 msec, and the pulse interval T2 was 20 msec. After stopping the energization, the slow leak valve was closed, and the activation process was terminated.

Step-f Subsequently, a stabilizing step was performed. While the vacuum device and the electron-emitting device were heated by a heater and maintained at about 300 ° C., the evacuation of the vacuum device was continued. After 20 hours, when the heating by the heater was stopped and the temperature was returned to room temperature, the pressure in the vacuum apparatus reached about 1 × 10 ⁻⁸ Pa.

The deposit formed on the conductive thin film of the device of this example was subjected to electron probe microanalysis (EPM).
Elemental analysis was performed by A), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy, and it was confirmed that the deposit mainly contained carbon.

Further, for the device of this example manufactured in the above process, the cross section of the device was observed by FIB-cross section TEM method. Here, observation was performed by digital recording using an imaging plate. First, when observed at a low magnification, the deposited film 6 containing carbon has a thickness of about 10 nm or more not only in the vicinity of the electron emission portion 5 formed in the conductive thin film 4 of FIG. Was formed.

Next, when the deposited film was observed at a higher magnification, there was a wide area where lattice fringes oriented in a substantially normal direction (<± 30 °) were observed on the substrate surface and the conductive thin film surface. Was.

Further, when a diffraction pattern was obtained by performing a Fourier transform on an observed image of the deposited film having carbon on the conductive thin film, a substantially normal direction (<± 30 °) to the substrate surface and the conductive thin film surface was obtained. There was a wide range where the diffraction ring having the maximum intensity was measured. In addition, the ratio of the intensity of the diffraction ring in a direction having a maximum intensity divided by the intensity of the diffraction ring in a direction orthogonal thereto was measured to be 2.5 or more.

Further, the device of this example was subjected to low energy electron diffraction (LEED) to measure the elastic scattering probability on the device surface when irradiated with an electron beam of 14 eV to 16 eV. 28-0.31.

Next, the electron emission characteristics of the electron-emitting device manufactured by the same manufacturing method were measured in the vacuum apparatus shown in FIG. The distance H between the anode electrode 54 and the electron-emitting device was 5 mm. A rectangular pulse voltage having a peak value of 15.5 V was applied between the device electrodes 2 and 3 to drive the device. Further, a voltage was applied to the anode electrode 54 by the high voltage power supply 53. The anode voltage Va was set so that the number of times of scattering on the surface of the electron-emitting device was as shown in Table 1 below.
At this time, the average elastic scattering probability β on the surface of the electron-emitting device
= 0.3, the work function Wf on the surface of the electron-emitting device is 5 eV, which is the work function of carbon, the width D of the electron-emitting portion is 3 nm, and the device voltages Vf = 14.0 V and 15.0 V are calculated. Was done. Under each driving condition, the element current If and the emission current Ie are measured by the ammeter 50 and the ammeter 5.
2 and the efficiency was determined. Table 2 below shows the results.
Shown in

[0150]

[Table 2] As a result, good electron emission efficiency was obtained by driving under the driving condition in which the average elastic scattering number n was 3 or less.

When the anode voltage Va at which the average number of elastic scattering n is less than 1 is obtained by calculation, Va is 100 kV
As described above, the voltage applied to the anode was an inappropriate value that was too high.

(Embodiment 3) This embodiment is an example of an image forming apparatus using an electron source in which a large number of electron-emitting devices similar to those of Embodiment 1 are arranged on a substrate in a simple matrix.

FIG. 13 is a plan view of a part of the electron source. FIG. 14 is a sectional view taken along the line AA ′ in the figure. However, FIG.
3. In FIG. 14, the same symbols indicate the same components. Here, 101 is a substrate, 102 is an X-direction wiring (also referred to as a lower wiring) corresponding to DXm in FIG. 9, and 103 is a D in FIG.
Y direction wiring corresponding to Yn (also referred to as upper wiring), 4 is a conductive thin film, 2, 3 is an element electrode, 171 is an interlayer insulating layer,
Reference numeral 72 denotes a contact hole for electrical connection between the element electrode 2 and the lower wiring 102.

Next, the manufacturing method will be specifically described with reference to FIGS. Step-a Cr of 5 nm in thickness and Au of 0.6 mm in thickness were sequentially laminated by vacuum evaporation on a substrate 1 in which a 0.5 mm thick silicon oxide film was formed on a cleaned blue plate glass by a sputtering method. Thereafter, a photoresist (manufactured by Hoechst AZ1370) is spin-coated with a spinner and baked, and then a photomask image is exposed and developed to form a resist pattern of the lower wiring 102, and the Au / Cr deposited film is wet-etched. The lower wiring 102 having the shape shown in FIG.
(A)).

Step-b Next, an interlayer insulating layer 171 made of a silicon oxide film having a thickness of 1.0 μm is deposited by an RF sputtering method (FIG. 1).
5 (b)). Step-c A photoresist pattern for forming a contact hole 172 is formed in the interlayer insulating layer 171 deposited in the step-b, and the interlayer insulating layer 171 is etched using the photoresist pattern as a mask to form a contact hole 172 (FIG. c)).

Step-d Thereafter, a pattern to be a gap L between the device electrode 2 and the device electrode is formed by a photoresist (RD-2000N-41 manufactured by Hitachi Chemical Co., Ltd.), and the thickness is 5 nm by a sputtering method.
Ti and 30 nm thick Pt were sequentially deposited. The photoresist pattern was dissolved with an organic solvent, the Pt / Ti deposited film was lifted off, the device electrode interval L = 3 μm, and the device electrode width W
= 500 μm was formed (FIG. 1).
5 (d)).

Step-e After forming a photoresist pattern of the upper wiring 103 on the device electrodes 2 and 3, Ti having a thickness of 5 nm and a thickness of 0.5 mm
Are sequentially deposited by vacuum evaporation, and unnecessary portions are removed by lift-off to form an upper wiring 103 having a desired shape (FIG. 15E).

Step-f A Cr film (not shown) having a thickness of 0.1 mm is deposited and patterned by vacuum evaporation, and an organic palladium compound solution (ccp4230 manufactured by Okuno Pharmaceutical Co., Ltd.) is spin-coated thereon by a spinner. A heating and baking treatment was performed at 300 ° C. for 10 minutes. The conductive thin film 4 formed of fine particles of Pd as the main element thus formed had a thickness of 10 nm and a sheet resistance of 2 × 10 4 Ω / port.

Next, the Cr film and the fired conductive thin film 4
Was etched off with an acid etchant and lifted off to form a conductive thin film 4 having a desired pattern.
5 (f)). Step-g A pattern was formed such that a resist was applied to portions other than the contact hole 172, and 5 nm thick Ti and 0.5 mm thick Au were sequentially deposited by vacuum evaporation. Unnecessary portions were removed by lift-off to bury the contact holes 172 (FIG. 15 (g)).

Through the above steps, the lower wiring 102, the interlayer insulating layer 171, the upper wiring 103, the device electrodes 2 and 3, and the conductive thin film 4 were formed on the insulating substrate 1. Next, an example in which an electron source and a display device are configured using the electron source substrate manufactured as described above will be described with reference to FIGS.

After fixing the substrate 1 on which the element was fabricated as described above on the rear plate 111, a face plate 116 (a fluorescent film 114 and a metal back 115 were formed on the inner surface of the glass substrate 113) 5 mm above the substrate 1. Is arranged via a support frame 112, frit glass is applied to the joint between the face plate 116, the support frame 112, and the rear plate 111, and 10 f at 400 ° C. in the air.
It was sealed by baking for a minute. The fixing of the substrate 101 to the rear plate 111 was also performed using frit glass.

In this embodiment, reference numeral 104 in FIG. 10 denotes an electron-emitting device before forming an electron-emitting portion, and reference numerals 102 and 103 denote device wirings in the X and Y directions, respectively. Fluorescent film 11
Reference numeral 4 denotes only a phosphor in the case of monochrome, but in this embodiment, the phosphor has a stripe shape. First, a black stripe was formed, and a phosphor of each color was applied to the gap, thereby forming a phosphor film 114. As the material for the black stripe, a material mainly containing graphite, which is generally used, was used. A slurry method was used as a method of applying the phosphor on the glass substrate 113.

A metal back 115 is usually provided on the inner side of the fluorescent film 114. The metal back was manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after the fluorescent film was manufactured, and then vacuum-depositing Al. The face plate 116 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 114 in order to further enhance the conductivity of the fluorescent film 114.
In the present example, a sufficient conductivity was obtained only with the metal back, and thus the description was omitted.

At the time of the above-mentioned sealing, in the case of color, since the phosphors of each color must correspond to the electron-emitting devices, sufficient alignment was performed. The atmosphere in the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, the external terminals Doxl to Doxm and Doyl to Doy.
A voltage was applied between the electrodes 2 and 3 of the electron-emitting device 104 through n to form the conductive thin film 4. The voltage waveform of the forming process is the same as that shown in FIG. The maximum voltage applied during the forming was about 5V.

In this embodiment, T1 is 0.1 msec, T2
Was set to 10 msec and performed in a vacuum atmosphere of about 1.3 × 10 ⁻³ Pa. Next, after evacuation was continued until the pressure in the panel reached a level of 10 ⁻⁶ Pa, tolunitrile was introduced into the panel from the exhaust pipe of the panel so that the total pressure was 1.3 × 10 ⁻⁴ Pa. , Maintained. Outer container terminal Doxl to D
electron emitting device 1 through oxm and Doyl or Doyn
Activation was performed by applying the same bipolar pulse voltage as in FIG. 7C between the electrodes 2 and 3 of 04. For voltage application, the Y-direction wiring was shared and connected to Gnd, and the X-direction wiring was sequentially selected to apply a voltage. The voltage ranges from 10V to 17V.
The pressure was increased at 1 V / sec, and then maintained at 17 V for 50 minutes. Also, pulse width T1 = 1 msec, pulse interval T2 = 20 m
sec. After energizing all the elements, the slow leak valve was closed, and the activation process was completed.

Next, the entire panel was evacuated while being heated to 300 ° C., the temperature was lowered to room temperature, and the inside was set to a pressure of about 10 ⁻⁷ Pa. Then, an exhaust pipe (not shown) was welded by heating with a gas burner. The envelope was sealed.

Finally, in order to maintain the pressure after sealing, a getter process was performed by a high-frequency heating method. In the image display device of the present invention completed as described above, a scanning signal and a modulation signal are applied to the respective electron-emitting devices from signal generating means (not shown) through the external terminals Doxl to Doxm and Doyl to Doyn. As a result, an anode voltage is applied to the metal back 115 or the transparent electrode (not shown) through the high-voltage terminal 117, and the electron beam is accelerated so as to collide with the fluorescent film 114 to excite and emit light. displayed.

At this time, a rectangular pulse voltage of device voltage Vf = 14.0 V and Vf = 14.5 V was applied to each electron-emitting device in the same manner as in Example 1, and the same anode voltage Va as the condition in Table 1 was applied. Driven.

Under each driving condition, the element current I
f and emission current Ie were measured and the efficiency was obtained.
By reproducing the result of Example 1 and driving under the driving condition in which the average elastic scattering number n was 3 or less, good electron emission efficiency was obtained. By driving under the above conditions,
In the image display device according to the present embodiment, a good image with high luminance could be displayed.

Next, the produced image forming apparatus is disassembled, and the electron-emitting device of this embodiment is used in the same manner as in the first embodiment.
A cross section of the device was observed using a B-cross section TEM method. First, when observed at a low magnification, as in Example 1, the deposited film 6 containing carbon is not only in the vicinity of the electron-emitting portion 5 formed in the conductive thin film 4 but also on the conductive thin film around the same. It was found that the film was formed with the above thickness.

Next, when the deposited film was observed at a higher magnification, a large area where lattice fringes oriented in a substantially normal direction (<± 30 °) were observed on the substrate surface. Furthermore, when a diffraction pattern was obtained by performing a Fourier transform of the observed image of the deposited film having carbon on the conductive thin film, a diffraction ring having a maximum intensity in a substantially normal direction (<± 30 °) with respect to the substrate surface was obtained. There were a wide range of locations to be measured. In addition, the ratio of the intensity of the diffraction ring in a direction having a maximum intensity divided by the intensity of the diffraction ring in a direction orthogonal thereto was measured to be 2.5 or more.

The probability of elastic scattering on the surface of the device when the device of this example was irradiated with an electron beam of 14 eV to 16 eV was measured by low energy electron diffraction (LEED). It was confirmed that it was 28-0.31.

Embodiment 4 This embodiment is an example of an image forming apparatus using an electron source in which a large number of electron-emitting devices similar to those in Embodiment 2 are arranged on a substrate in a simple matrix.

In the same manner as in Example 3, an electron source substrate on which a large number of electron-emitting devices were arranged was prepared. In the same manner as in Example 3, the electron source substrate and the face plate were sealed to form a panel.

Next, a forming step was performed in the same manner as in Example 3. Next, after exhausting was continued until the pressure in the panel reached the level of 10 ⁻⁶ Pa, benzonitrile was introduced into the panel from the exhaust pipe of the panel such that the total pressure was 1.3 × 10 ⁻⁴ Pa. And maintained. Outer container terminal Doxl to D
electron emitting device 1 through oxm and Doyl or Doyn
Activation was performed by applying the same bipolar pulse voltage as in FIG. 7C between the electrodes 2 and 3 of 04. Voltage application is Y
The direction wiring was shared and connected to Gnd, and the X direction wiring was sequentially selected and a voltage was applied. The voltage was increased from 10 V to 17 V at 0.1 V / sec, and then maintained at 17 V for 45 minutes. Further, the pulse width T1 = 1 msec and the pulse interval T2 = 2
It was set to 0 msec. After energizing all the elements, the slow leak valve was closed, and the activation process was completed.

Next, the entire panel was evacuated while being heated to 300 ° C., the temperature was lowered to room temperature, and the inside was set at a pressure of about 10 ⁻⁷ Pa. Then, an exhaust pipe (not shown) was welded by heating with a gas burner. The envelope was sealed.

Finally, in order to maintain the pressure after sealing, gettering was performed by a high-frequency heating method. In the image display device of the present invention completed as described above, by applying a modulation signal to each electron-emitting device from a signal generation means (not shown), electrons are emitted, and the metal back 115 is passed through the high-voltage terminal 117. Alternatively, an anode voltage was applied to a transparent electrode (not shown), and the electron beam was accelerated to collide with the fluorescent film 114 to excite and emit light, thereby displaying an image. At this time, a rectangular pulse voltage of device voltage Vf = 14.0 V and Vf = 15.0 V was applied to each electron-emitting device in the same manner as in the second embodiment, and the anode voltage Va was the same as the condition in Table 2 of the second embodiment. Driven. Under each driving condition,
When the device current If and the emission current Ie were measured and the efficiency was obtained, the result of Example 2 was reproduced. By driving the device under the driving condition in which the average number of elastic scattering n was 3 or less, good electron emission efficiency was obtained. Obtained. Further, by driving under the above conditions, the image display device of the present example was able to display a high-luminance and good image.

Next, the produced image forming apparatus is disassembled, and the electron-emitting device of this embodiment is used in the same manner as in the second embodiment.
A cross section of the device was observed using a B-cross section TEM method. First, when observed at a low magnification, the deposited film 6 containing carbon not only near the electron emitting portion 5 formed on the conductive thin film 4 but also on the conductive thin film around the same as in Example 2.
Was formed with a thickness of about 10 nm or more.

Next, when the deposited film was observed at a higher magnification, there was a wide area where lattice fringes oriented in a substantially normal direction (<± 30 °) were observed on the substrate surface and the conductive thin film surface. Was.

Further, when a diffraction pattern was obtained by performing a Fourier transform on the observed image of the deposited film having carbon on the conductive thin film, a substantially normal direction (<± 30 °) with respect to the substrate surface and the conductive thin film surface was obtained. There was a wide range where the diffraction ring having the maximum intensity was measured. In addition, the ratio of the intensity of the diffraction ring in a direction having a maximum intensity divided by the intensity of the diffraction ring in a direction orthogonal thereto was measured to be 2.5 or more.

Further, the device of this example was subjected to low energy electron diffraction (LEED) to measure the elastic scattering probability of the device surface when irradiated with an electron beam of 14 eV to 16 eV. It was confirmed that it was 28-0.31.

(Embodiment 5) In this embodiment, an example of a display device configured to display image information provided from various image information sources such as television broadcasting will be described. Display was performed on the image forming apparatus shown in FIG. 10 using the driving circuit shown in FIG. 12 according to an NTSC television signal.

In the present display device, in particular, it is easy to make the display panel thin using a surface conduction electron-emitting device as an electron beam source, so that the depth of the display device can be reduced. In addition, the display panel using the display conduction type electron-emitting device as the electron beam source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display with good visibility.

Also in the present display device, by using the driving method of the present invention, a television image corresponding to an NTSC television signal was successfully displayed.

[0185]

As described above, according to the method and the apparatus for driving an image forming apparatus of the present invention, the electrons reaching the anode electrode with respect to the electrons emitted from the electron emission portion at a practical anode voltage. , It is possible to provide a high-luminance image forming apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a potential distribution and electron trajectories of an electron-emitting device of the present invention.

FIG. 2 is a diagram showing a landing point distribution function of emitted electrons when an anode voltage is set to 0 V in the electron-emitting device of the present invention.

FIG. 3 is a schematic view of an electron-emitting device according to the present invention.

FIG. 4 is a schematic view of an electron-emitting device according to the present invention.

FIG. 5 is a schematic diagram illustrating an example of a vacuum processing apparatus having a measurement evaluation function.

FIG. 6 is a schematic view showing a part of the manufacturing process of the electron-emitting device of the present invention.

FIG. 7 is a schematic diagram showing an example of a voltage waveform that can be used in a manufacturing process of the electron-emitting device of the present invention.

FIG. 8 is a schematic diagram showing the relationship between the emission current Ie, the device current If, and the device voltage Vf of the electron-emitting device of the present invention.

FIG. 9 is a schematic diagram showing an example in which the electron-emitting device of the present invention is applied to an electron source in which a simple matrix is arranged.

FIG. 10 is a schematic diagram illustrating an example in which the electron-emitting device of the present invention is applied to an image forming apparatus.

FIG. 11 is a schematic diagram illustrating an example of a fluorescent film.

FIG. 12 is a block diagram of a driving circuit for performing display according to an NTSC television signal when the electron-emitting device of the present invention is applied to an image forming apparatus.

FIG. 13 is a schematic diagram showing an example in which the electron-emitting device of the present invention is applied to an electron source in which a simple matrix is arranged.

FIG. 14 is a schematic partial cross-sectional view taken along line AA ′ of FIG.

FIG. 15 is a schematic diagram for explaining a part of the manufacturing process of the electron source according to the embodiment of the present invention.

FIG. 16 is a schematic view showing a configuration of a conventional electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive thin film 5 Electron emission part 6 Deposited film containing carbon 11 Low potential side surface of electron emission element 12 High potential side surface of electron emission element 13 Anode electrode 14 It is a singular point of an electric field. 50 Ammeter for measuring device current If flowing through conductive thin film 4 between device electrodes 2 and 3 51 Power supply for applying device voltage Vf to electron-emitting device 52 Emission current Ie emitted from electron-emitting device Ammeter 53 for measurement 53 Voltage power supply for applying voltage to anode electrode 54 Anode electrode 55 for accelerating and supplementing electrons emitted from electron-emitting device 55 Vacuum container 101 Electron source substrate 102 X-direction wiring 103 Y Direction wiring 104 Electron emitting element 105 Connection 111 Rear plate 112 Support frame 113 Glass substrate 114 Phosphor film 115 Metal back 116 Face plate 117 High voltage terminal 118 Enclosure 121 Black member 122 Phosphor 131 Display panel 132 Scan circuit 133 Control circuit 134 Shift Register 135 line memory 136 Synchronization signal separation circuit 137 Modulation signal generator Vx and Va DC power supply 171 Interlayer insulating layer 172 Contact hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuhiro Hamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 5C036 EE01 EE19 EF06 EF09 EF16 EG12 EG48 EH26 5C080 AA18 BB05 CC03 DD26 DD30 EE01 EE17 EE19 EE29 EE30 FF03 FF12 GG08 GG12 JJ01 JJ02 JJ04 JJ05 JJ06

Claims (6)

[Claims] A pair of opposing electrodes, a pair of conductive thin films formed between the pair of electrodes, and an electron emission portion formed by a gap between the pair of conductive thin films. An electron-emitting device in which the electron-emitting portion has a pair of thin films containing carbon on a pair of conductive thin films with the gap therebetween, wherein at least the thin film containing carbon on the high-potential side surface of the electron-emitting device has a conductive property. A plurality of electron-emitting devices which are arranged in a form having lattice fringes on the thin film, and in which the orientation of the lattice fringes is substantially normal to the surface of the conductive thin film, are provided on the substrate. An electron source, and an anode electrode provided with an image forming member for forming an image by irradiating electrons emitted from the electron-emitting device. In a method for driving an image forming apparatus, the device voltage applied to the electron-emitting device is Vf , When the anode voltage applied to the node electrode is Va, the electrons emitted from the electron-emitting portion pass through an elastic scattering step in which the average number of elastic scattering n on the high potential side surface of the electron-emitting device is 1 or more and 3 or less. A method for driving an image forming apparatus, comprising: driving at an element voltage Vf and an anode voltage Va reaching an anode electrode. 2. The method according to claim 1, wherein the element voltage Vf and the anode voltage Va are set so as to satisfy the following equation (1). (Equation 1) Here, F (x): the distance x from the electron emission portion when Va = 0 V
In (m), the landing point distribution function due to elastic scattering of electrons β: average elastic scattering probability of the surface on the high potential side of the electron-emitting device H: distance (m) between the electron-emitting device and the anode electrode π: pi γ: coefficient = 0.67 3. The thin film containing carbon in the electron-emitting device is arranged on the conductive thin film in a form having lattice fringes, and the direction of the orientation of the lattice fringes is normal to the surface of the conductive thin film. The method according to claim 1, wherein the driving direction is within ± 30 ° from the direction. And a pair of opposing electrodes, a pair of conductive thin films formed between the pair of electrodes, and an electron-emitting portion formed by a gap between the pair of conductive thin films. An electron-emitting device in which the electron-emitting portion has a pair of thin films containing carbon on a pair of conductive thin films with the gap therebetween, wherein at least the thin film containing carbon on the high-potential side surface of the electron-emitting device has a conductive property. A plurality of electron-emitting devices which are arranged in a form having lattice fringes on the thin film, and in which the orientation of the lattice fringes is substantially normal to the surface of the conductive thin film, are provided on the substrate. An image forming apparatus comprising: an electron source; an anode electrode having an image forming member for forming an image by irradiation of electrons emitted from the electron emitting element; and a device voltage applied to the electron emitting element being Vf , When the anode voltage applied to the node electrode is Va, the electrons emitted from the electron-emitting portion pass through an elastic scattering step in which the average number of elastic scattering n on the high potential side surface of the electron-emitting device is 1 or more and 3 or less. A device for driving an image forming apparatus, wherein an element voltage Vf and an anode voltage Va are applied so as to reach an anode electrode. 5. The driving device for an image forming apparatus according to claim 4, wherein the element voltage Vf and the anode voltage Va are set so as to satisfy the following equation 1. (Equation 1) Here, F (x): the distance x from the electron emission portion when Va = 0 V
In (m), the landing point distribution function due to elastic scattering of electrons β: average elastic scattering probability of the surface on the high potential side of the electron-emitting device H: distance (m) between the electron-emitting device and the anode electrode π: pi γ: coefficient = 0.67 6. The carbon-containing thin film in the electron-emitting device is arranged in a form having lattice fringes on a conductive thin film, and the direction of the orientation of the lattice fringes is normal to the surface of the conductive thin film. The driving device for an image forming apparatus according to claim 4, wherein the driving direction is within ± 30 ° from the direction.