JPH08212943A - Image forming device and electron beam generating source - Google Patents

Abstract

PURPOSE: To provide an electron beam source wherein white balance can be easily taken and to provide an image forming device of performing an image display with good color reproducibility by using this electron beam source. CONSTITUTION: Three surface conduction type electron emitting elements having a different width W of an electron emitting part 3 are prepared, and the element having the electron emitting part 3 of standard width W22 corresponds to a green phosphor serving as the reference in the case of taking white balance. For instance, by making the element of width W23 (<W22) correspond to the electron emitting element corresponding to a blue phosphor, an emission current Ie is decreased to make this luminous intensity curve agree with a reference characteristic curve in the case of taking white balance. By making the element of width W21 (>W22) correspond to the electron emitting element corresponding to a red phosphor, the emission current Ie is increased to conform this luminous intensity curve to the reference characteristic curve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an electron beam generator, and more particularly to an image forming apparatus using an electron beam generator in which a plurality of cold cathode electron sources are two-dimensionally arranged.

[0002]

2. Description of the Related Art There are two types of electron-emitting devices, a hot cathode device and a cold cathode device. Among these, the cold cathode element, for example,
Field emission device (hereinafter referred to as "FE type"), metal / insulating layer /
There are metal-type electron-emitting devices (hereinafter referred to as "MIM type") and surface-conduction electron-emitting devices.

As an example of the FE type, for example, WP Dyke &
WWDolan, "Field emission", Advance in Electron P
hysics, 8, 89 (1956) or CASpindt, "Phys
icalproperties of thin-film field emission cathode
s with molybdenium cones ", J.Appl.Phys., 47, 5248 (1
976) and so on.

As an example of the MIM type, for example, CAM
ead, "Operation of Tunnel-emission Devices", J.App
l.Phys., 32, 646 (1961), etc.

Further, as the surface conduction electron-emitting device,
For example, MIElinson, Radio Eng. Electron Phys., 10,
1290 (1965) and other examples described later.

The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is passed through a thin film having a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, in addition to the SnO2 thin film by Elinson, etc., the Au thin film is used.
[G.Dittmer: "Thin Solid Films", 9, 317 (1972)], In2
O3 / SnO2 thin film [M. Hartwell and CGFonstad:
"IEEE Trans. ED Conf.", 519 (1975)] and carbon thin films [Haraki Araki et al .: Vacuum, Vol. 26, No. 1, 22 (198)
3)] etc. have been reported.

As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG. 1 shows a plan view of the device according to the above-mentioned Hartwell. In the figure, 3001 is a substrate, 30
Reference numeral 04 is a conductive thin film made of metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped plane shape as shown in the figure. An electron-emitting portion 3005 is formed by performing an energization process called energization forming described later on this conductive thin film 3004. The distance L in the figure is
0.5 to 1 mm, W is set to 0.1 mm. Note that, for convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape in the center of the conductive thin film 3004, but this is a schematic one and faithfully represents the actual position and shape of the electron emitting portion. It doesn't mean that.

Starting with devices such as Hartwell,
In the above-mentioned surface conduction electron-emitting device, it is general that the electron-emitting portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming before emitting electrons. That is, the energization forming means that a constant DC voltage is applied to both ends of the conductive thin film 3004, or a DC voltage that is boosted at a very slow rate of, for example, about 1 V / min is applied to conduct current, and the conductive thin film 3004 is locally That is, the electron emission portion 3005 is formed in a state of being electrically high in resistance by being destroyed, deformed or altered. Note that a crack is generated in a part of the conductive thin film 3004 which is locally broken, deformed or altered. When an appropriate voltage is applied to the conductive thin film 3004 after this energization forming, electrons are emitted near the crack.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area because it has a simple structure and is easy to manufacture. Therefore, as disclosed in, for example, Japanese Patent Laid-Open No. 64-31332 by the present applicant, a method for arranging and driving a large number of elements has been studied.

Regarding the application of the surface conduction electron-emitting device, for example, an image forming apparatus such as an image display device and an image recording device, and a charged beam source have been studied. Particularly as an application to an image display device, for example, as disclosed in USP 5,066,883 by the present applicant and Japanese Patent Application Laid-Open No. 2-257551, a combination of a display conduction type emission element and a phosphor that emits light by irradiation of an electron beam is combined. The image display device used for the above is being studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image display devices. For example, it can be said that it is superior in that it does not require a backlight and has a wide viewing angle because it is a self-luminous type, as compared with a liquid crystal display device that has become widespread in recent years.

[0011]

DISCLOSURE OF THE INVENTION The inventors of the present invention have described various materials and manufacturing methods, including those described in the above-mentioned conventional examples.
A surface conduction electron-emitting device having a structure has been tried. further,
We have conducted research on a multi-electron beam source in which a large number of surface conduction electron-emitting devices are arranged, and an image display device to which this multi-electron beam source is applied.

The inventors have tried, for example, a multi-electron beam source by the electronic wiring method shown in FIG. That is, it is a multi-electron beam source in which a large number of surface conduction electron-emitting devices are two-dimensionally arranged and these devices are arranged in a matrix as shown in the figure.

In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 is a row direction wiring, and 4003 is a column direction wiring. The row wiring 4002 and the column wiring 4003 actually have finite electric resistance, but they are shown as wiring resistances 4004 and 4005 in the drawing. Such a wiring method is called “simple matrix wiring”. Although a 6 × 6 matrix is shown for convenience of illustration, the scale of the matrix is not limited to this, for example, in the case of a multi-electron beam source for an image display device, desired image display is performed. The necessary elements are arranged and wired.

In the multi-electron beam source in which the surface conduction electron-emitting devices are wired in a simple matrix, appropriate electric signals are applied to the row-direction wiring 4002 and the column-direction wiring 4003 in order to output a desired electron beam. For example, in order to drive the surface conduction electron-emitting device of any one row in the matrix, the selection voltage Vs is applied to the row direction wiring 4002 of the selected row, and at the same time, the row direction wiring 4002 of the non-selected row is applied. Is applied with a non-selection voltage Vns. In synchronization with this, column direction wiring 400
A drive voltage Ve for outputting an electron beam is applied to 3.

According to this method, the wiring resistances 4004 and 40
Ignoring the voltage drop due to 05, the voltage Ve-Vs is applied to the surface conduction electron-emitting devices in the selected row, and the voltage Ve-Vns is applied to the surface conduction electron-emitting devices in the unselected row. . If Ve, Vs, and Vns are set to appropriate voltages, an electron beam with a desired intensity should be output only from the surface conduction electron-emitting devices of the selected row, and the column-direction wiring 40
If different drive voltages Ve are applied to the respective 03, electron beams of different intensities should be output from the elements of the selected row. Further, since the response speed of the surface conduction electron-emitting device is high, if the length of time for applying the driving voltage Ve is changed, the length of time for which the electron beam is output should be changed.

Therefore, the multi-electron beam source in which the surface conduction electron-emitting devices are wired in a simple matrix has various potential applications. For example, if an electric signal according to image information is appropriately applied, it can be used for an image display device. It can be suitably used as an electron source. However, the image forming apparatus using the multi-electron beam source in which the surface-powered electron-emitting devices are wired has the following problems.

That is, since the phosphors of the three primary colors of red, green, and blue have different emission characteristics, as will be described later, when an electron beam is made incident on the phosphors of each color with a predetermined intensity, white light is emitted. There is a problem that it cannot be balanced.

FIG. 3A is a diagram showing typical emission characteristics of phosphors. As shown in FIG. 3, the emission characteristics of phosphors are not the same due to the difference in emission color, and the characteristic curves are non-linear. Hold. The emission characteristics of this phosphor are defined depending on the total amount of charges that have reached a phosphor surface of a certain unit area per unit time. Of course, the degree of nonlinearity also differs depending on the type of phosphor.

By the way, regarding the non-linearity of the phosphor, it is possible to obtain a substantially linear characteristic by introducing a gamma correction circuit which has been conventionally introduced in a CRT or the like for each color. However, the slope of the characteristic curve is
It will be different for each color, as shown in 3B. If this difference in inclination is different from the intensity ratio with which white balance can be obtained, the color reproducibility will be poor.

The present invention is intended to solve the above-mentioned problems, and an electron beam generator capable of easily achieving white balance and an image forming apparatus capable of displaying an image with good color reproducibility using the electron beam generator. The purpose is to provide.

[0021]

[Means for Solving the Problems] and

The present invention has the following structure as one means for achieving the above object.

The image forming apparatus according to the present invention is an electron beam in which at least a plurality of surface conduction electron-emitting devices are two-dimensionally arranged on a substrate and each device is connected in a matrix by row-direction wiring and column-direction wiring. A source, a phosphor of three colors that emits light by irradiation of an electron beam generated by the electron beam generator, and a modulator that modulates the electron beam with which the phosphor is irradiated based on an input image signal. And the electron emission characteristic of the surface conduction electron-emitting device arranged in the electron beam generation source is changed according to the emission characteristic of each color of the phosphor.

Further, in the electron beam generating source according to the present invention, at least surface conduction electron-emitting device groups having different electron emission characteristics are two-dimensionally arranged on the substrate, and each device is formed by row-direction wiring and column-direction wiring. Are connected in a matrix form.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to the present invention basically forms an image by irradiating an electron beam with a multi-electron beam source in which a large number of cold cathode elements are arranged on a substrate in a thin vacuum container. An image forming member is provided so as to face the image forming member. Since the cold cathode elements can be precisely positioned and formed on the substrate by using a manufacturing technique such as photolithography / etching, a large number of cold cathode elements can be arranged at minute intervals. Moreover, as compared with the hot cathode conventionally used in CRTs and the like, the cathode itself and the peripheral portion can be driven at a relatively low temperature, so that a multi-electron beam source with a finer array pitch can be easily realized. .

The present invention relates to an image forming apparatus using the cold cathode device described above as a multi-electron beam source.

Among the cold cathode devices, the surface conduction electron-emitting device is particularly preferable. That is, the MIM type element needs to precisely control the thickness of the insulating layer and the upper electrode, and the FE type element needs to precisely control the tip shape of the needle-shaped electron emitting portion. Therefore, the manufacturing cost of these devices is high, and it is difficult to manufacture a large area device due to the limitation of the manufacturing process. On the other hand, the surface conduction electron-emitting device has a simple structure and is easy to manufacture, and a large-area one can be easily manufactured. In recent years, it can be said that the cold cathode device is particularly suitable particularly in a situation where a large-screen and inexpensive display device is required.

Further, the inventor of the present application has found that among the surface conduction electron-emitting devices, the one in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is preferable in view of characteristics or a large screen. There is. Therefore, in the embodiments of the present invention described below, an image display apparatus using a surface conduction electron-emitting device formed by using a fine particle film as a multi-electron beam source will be described as a preferable example of the image forming apparatus of the present invention. .

The basic structure and manufacturing method of the element according to the present embodiment, the characteristics thereof, and the characteristics which are the principle of the present invention found as a result of intensive studies by the inventors will be described below. The features of the structure and manufacturing method of the surface conduction electron-emitting device according to this embodiment are as follows.

(1) The thin film for forming an electron emitting portion before energization processing called forming is composed of a thin film of fine particles formed by dispersing a fine particle dispersion, or fine particles formed by heating and baking an organic metal or the like. Basically, it is composed of fine particles such as a thin film. (2) A thin film including an electron emission part after energization processing called forming, is basically composed of fine particles together with the electron emission part and the thin film including the electron emission part. Next, the basic structure of the surface conduction electron-emitting device according to this embodiment will be described. 4A and 4B respectively,
It is the top view and sectional drawing which show the composition of the basic surface conduction type electron-emitting device concerning a present Example. In the figure, 1
Is an insulating substrate, 5 and 6 are device electrodes, 4 is a thin film including an electron emitting portion, and 3 is an electron emitting portion.

The insulating substrate 1 is made of quartz glass, glass having a reduced content of impurities such as Na, soda-lime glass, a soda glass substrate laminated with SiO2 formed on the soda-lime glass by a sputtering method, and ceramics such as alumina. Etc. can be used. The material of the device electrodes 5 and 6 facing each other may be any as long as it has conductivity, for example, Ni, Cr, Au, Mo, W, Pt, T
Metals or alloys such as i, Al, Cu, Pd, Pd, Ag, Au, R
Metals such as uO2 and Pd-Ag, printed conductors composed of metal oxides and glass, transparent conductors such as In2O3-SnO2, and semiconductor materials such as polysilicon.

The distance L1 between the device electrodes 5 and 6 is in the range of several hundred Å to several hundred μm. Specifically, the photolithography technique that is the basis of the manufacturing method of the device electrodes 5 and 6, that is, the exposure device It is set depending on the performance and the etching method, the voltage applied between the device electrodes, the electric field strength capable of emitting electrons, etc., but is preferably several μm to several tens μm. The length W1 and the film thickness d of the device electrodes 5 and 6 are appropriately designed in consideration of the resistance value of the electrodes, the connection with the wiring in the X and Y directions described above, and the placement problem of a large number of arranged electron sources. The thickness W1 is several μm to several hundred μm, and the film thickness d is preferably several hundred Å to several hundred μm.

The thin film 4 including the electron emission portion 3 provided between the opposing device electrodes 5 and 6 provided on the insulating substrate 1 and on the device electrodes 5 and 6 is provided only in the case shown in FIG. 1B. Alternatively, it may not be formed on the device electrodes 5 and 6. That is, this is the case where the electron emission portion forming thin film and the opposing device electrodes 5 and 6 are laminated in this order on the insulating substrate 1. Further, the entire space between the opposing device electrodes 5 and 6 may function as the electron emitting portion 3 depending on the manufacturing method. The film thickness of the thin film 4 including the electron emitting portion 3 is several Å to several thousand Å, preferably several tens of Å to several hundred Å, the step coverage to the device electrodes 5 and 6, the electron emitting part 3 and the device electrode. It is appropriately set depending on the resistance value between 5 and 6, the particle size of the conductive fine particles of the electron emitting portion 3, the energization processing conditions described later, and the like. The resistance value is a sheet resistance value of 10 ^ 3 to 10 ^ 7Ω / cm ^ 2 (a ^ b represents a to the power b).

Specific examples of the material forming the thin film 4 including the electron emitting portion 3 include Pd, Ru, Ag, Au, Ti, In, Cu,
Cr, Fe, Zn, Sn, Ta, W, Pb and other metals, PdO, SnO2, In
Oxides such as 2O3, PbO, Sb2O3, HfB2, ZrB2, LaB6, CeB
6, boride such as YB4, GdB4, TiC, ZrC, HfC, TaC, SiC,
Carbides such as WC, nitrides such as TiN, ZrN, HfN, Si, Ge
It is a semiconductor such as, carbon, AgMg, NiCu, Pb, Sn, etc., and is composed of a fine particle film. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated, and not only a state in which fine particles are individually dispersed and arranged as a fine structure but also a state in which fine particles are adjacent to each other or overlap each other (including island shape) Means the membrane of.

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

Various methods are conceivable as a method of manufacturing an electron-emitting device having the electron-emitting portion 3, and FIGS. 5A to 5C are diagrams showing an example thereof. In the figure, reference numeral 2 is a thin film for forming an electron emitting portion, which is, for example, a fine particle film. Less than,
The manufacturing method will be described in order based on FIGS. 4A and 4B and FIGS. 5A to 5C.

Step 1: After thoroughly cleaning the insulating substrate 1 with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum vapor deposition method, a sputtering method or the like, and the insulating substrate 1 is subjected to photolithography. Element electrodes 5 and 6 are formed on the surface (FIG. 5A).

Step 2: Element electrodes formed on the insulating substrate 1
Insulating substrate between 5 and 6 and element electrodes 5 and 6 formed
By applying the organometallic solution on 1 and leaving it
An organometallic thin film is formed. The organometallic solution is the above-mentioned Pd, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T.
It is a solution of an organic compound whose element is a metal such as a, W, or Pb. After that, the organic metal thin film is heated and baked, and is patterned by lift-off, etching, etc. to form the electron emission part forming thin film 2 (FIG. 5B). Although the method of applying the organic metal solution has been described here, the method is not limited to this, and the vacuum vapor deposition method, the sputtering method, the chemical vapor deposition method, or the like.
It can also be formed by (CVD), a dispersion coating method, a dipping method, a spinner method, or the like.

Step 3: Subsequently, an energization process called forming, that is, a voltage is applied between the device electrodes 5 and 6 by a power source (not shown) at a pulse rate or at a high boost rate, electron emission is performed. An electron emitting portion 3 having a changed structure is formed at a predetermined portion of the portion forming thin film 2 (FIG. 5).
C). In other words, this energization process locally destroys, deforms, or modifies the electron-emitting-portion-forming thin film 2, and the portion whose structure has changed is called an electron-emitting portion 3. In addition,
As described above, the present applicants have observed that the electron emitting portion 3 is composed of conductive fine particles. Figure 6 is a diagram showing the voltage waveform of the forming process. T1 and T2 are the pulse width and interval of the voltage waveform.
T2 is set to 10 μs to 100 ms, the peak value of the triangular wave (peak voltage during forming) is set to about 4 V to 10 V, and the forming process is appropriately set to about several tens of seconds under a substantial vacuum.

In forming the electron-emitting portion 3 as described above, an example of applying a triangular wave pulse between the electrodes of the element to perform the forming process has been described, but the waveform applied between the electrodes of the element is limited to the triangular wave. Alternatively, other waveforms such as a rectangular wave may be used, and the crest value, pulse width, pulse interval, etc. are not limited to the above values. That is,
A waveform or a value with which the electron emitting portion 3 is favorably formed may be selected and set.

Next, the basic characteristics of the electron-emitting device manufactured by the above device structure and manufacturing method will be described.

FIG. 7 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring the electron emission characteristics of the device having the configuration shown in FIGS. 4A and 4B, 31 is a power supply for applying the device voltage Vf to the device,
30 is an ammeter for measuring the device current If flowing in the thin film 4 including the electron emitting portion 3 between the device electrodes 5 and 6, and 34 is for capturing the emission current Ie emitted from the electron emitting portion 3 of the device. Is an anode electrode, 33 is a high-voltage power supply for applying a voltage to the anode electrode 34, and 32 is an ammeter for measuring the emission current Ie emitted from the electron emission portion 3 of the device.

In measuring the device current If and the emission current Ie of the electron-emitting device, a power source 31 and an ammeter 30 are connected to the device electrodes 5 and 6, and a high-voltage power supply 33 and an ammeter are provided above the electron-emitting device. An anode electrode 34 connected to 32 is arranged. In addition, the electron-emitting device and the anode electrode 34 are installed in a vacuum device 235, and the vacuum device 235 is provided with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge, which are not shown in the drawing. The measurement and evaluation of this device can be performed. The voltage of the anode electrode 34 is set to 1 kV to 10 kV, and the distance H between the anode electrode 34 and the electron-emitting device is set to a range of 3 mm to 8 mm for measurement.

FIG. 8 is a diagram showing a typical example of the relationship between the emission current Ie and the device current If and the device voltage Vf measured by the measurement / evaluation apparatus shown in FIG. The magnitudes of If and Ie are significantly different (emission current Ie is approximately 1 / 2,00 of device current If).
Therefore, they are shown in arbitrary units in FIG.
As is clear from FIG. 8, the electron-emitting device of this example has three characteristics with respect to the emission current Ie.

First, the present electron-emitting device has a certain voltage.
When a device voltage Vf higher than Vth (called “threshold voltage”) is applied, the emission current Ie rapidly increases, while the threshold voltage Vth
In the following, the emission current Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

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

Thirdly, the emitted charges captured by the anode electrode 34 depend on the time for which the device voltage Vf is applied. That is, the amount of charge captured by the anode electrode 34 is equal to the device voltage Vf.
Can be controlled by the time of application. Since the electron-emitting device has the above characteristics, it can be expected to be applied to various fields.

The characteristic of the element current If shown in FIG. 8 may show a negative characteristic with respect to the element voltage Vf, that is, a voltage control type negative resistance (called “VCNR characteristic”) characteristic. In addition,
In this case as well, the present electron-emitting device has the three characteristic features described above.

The method of manufacturing the present electron-emitting device is not limited to the basic manufacturing method described above, and a part of the basic manufacturing method of the basic device structure may be modified.

[0049]

[First Embodiment] Next, an electron source and an image forming apparatus according to a first embodiment of the present invention will be described.

According to the three characteristics of the basic characteristics of the surface-conduction type electron-emitting device according to the present invention, the emitted electrons from the surface-conduction type electron-emitting device are equal to or more than the threshold voltage Vth.
The crest value and width of the pulsed voltage applied between the opposing element electrodes are controlled. On the other hand, it is not released below the threshold voltage Vth. According to this characteristic, even when a large number of electron-emitting devices are arranged, if the pulsed voltage is appropriately applied to each device, an arbitrary surface conduction electron-emitting device is selected and its electron emission amount is controlled. You can do it. The configuration of the electron source substrate constructed based on this principle will be described below.

FIG. 9 is a diagram showing a configuration example of an electron beam source substrate, 71 is an insulating substrate, 72 is X-direction wiring, 73 is Y-direction wiring,
74 is a surface conduction electron-emitting device, and 75 is a wire connection.

In the figure, the insulating substrate 71 is the above-mentioned glass substrate or the like, and the size and the thickness thereof are the number of surface conduction electron-emitting devices 74 installed on the insulating substrate 71 and the individual devices. When the electron source is used to form a part of the container, it is appropriately set depending on the conditions for holding the container in a vacuum.

The X-direction wiring 72 is composed of m wirings of Dx1, Dx2, ..., Dxm, and is formed on the insulating substrate 1 by a vacuum vapor deposition method, a printing method, a sputtering method or the like to form a desired pattern. The material, the film thickness, and the wiring width are set so that a large number of surface conduction electron-emitting devices 74 are made of a conductive metal or the like and are supplied with a substantially uniform voltage. Y direction wiring 73 is Dy1, Dy2,
…, Dyn's n wires, like the X-direction wire 72,
It is made of a conductive metal or the like that is formed by a vacuum deposition method, a printing method, a sputtering method, or the like and has a desired pattern, and a material or film is formed so that a voltage as uniform as possible is supplied to a large number of surface conduction electron-emitting devices 74. Thickness, wiring width, etc. are set.
Note that both m and n are positive integers.

These m X-direction wirings 72 and n Y-direction wirings
An interlayer insulating layer (not shown) is provided between 73 and electrically separated to form a matrix wiring. The interlayer insulating layer for electrically separating the wiring is SiO2 or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like, and is desired on the entire surface or a part of the insulating substrate 71 on which the X-direction wiring 72 is formed. The film thickness, the material, and the manufacturing method are appropriately set so as to withstand the potential difference at the intersection of the X-direction wiring 72 and the Y-direction wiring 73, in particular. In addition, it may be installed only at the intersection of the X-direction wiring 72 and the Y-direction wiring 73. At this time, the electrical connection between the connection 75 and the X-direction wiring 72 or the Y-direction wiring 73 does not go through a contact hole. , Can be done directly. Also, X
The directional wiring 72 and the Y-directional wiring 73 are led out to external terminals, respectively.

In the above, n Y wires are arranged on m X direction wirings 62.
Although the example in which the directional wiring 73 is installed via the interlayer insulating layer has been described, there may be a case where m X-directional wires 72 are installed on the n Y-directional wires 73 via the interlayer insulating layer. Furthermore, the opposing electrodes of the surface conduction electron-emitting device 74 and m X-direction wirings
The 72 and the n Y-direction wirings 73 are connections 55 made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like.
Are electrically connected by.

In addition, m X-direction wirings 72 and n Y-direction wirings
73, the connection 5 and the conductive metal of the opposing device electrode, part or all of the constituent elements may be the same or different, Ni, Cr, Au, Mo, W, Pt,
Metals or alloys such as Ti, Ai, Cu, Pd and Pd, Ag,
It is appropriately selected from a printed conductor composed of a metal such as Au, RuO2, Pd-Ag or a metal oxide and glass, a transparent conductor such as In2O3-SnO2 and a semiconductor conductor material such as polysilicon. The surface conduction electron-emitting device 74 may be formed either on the insulating substrate 71 or on an interlayer insulating layer (not shown). Further, a scanning signal generating means (not shown) for applying a scanning signal for arbitrarily scanning a row of the surface conduction electron-emitting devices 74 arranged in the X direction is electrically connected to the X-direction wiring 72. There is. On the other hand, the Y direction wiring 73 is electrically provided with a modulation signal generating means (not shown) for applying a modulation signal for arbitrarily modulating each row of the surface conduction electron-emitting devices 74 arranged in the Y direction. It is connected. Further, the drive voltage applied to each element of the surface conduction electron-emitting device 74 is supplied as a difference voltage between the scanning signal applied to the element and the modulation signal.

Next, an image forming apparatus for displaying images using the electron source created as described above will be described.

FIG. 10 is a basic block diagram of the image forming apparatus.
Is an electron source for which an electron-emitting device is created as described above,
Is a rear plate for fixing the electron source 100, and 86 is a glass substrate 8
A face plate having a fluorescent film 84 and a metal back 85 formed on the inner surface of 3. Reference numeral 82 denotes a support frame, which seals the rear plate 81 and the face plate 86 with frit glass or the like to form an envelope 88. As described above, the envelope 88 includes the face plate 86, the support frame 82, and the rear plate 81. Since the rear plate 81 is provided mainly for the purpose of supplementing the strength of the substrate 100, the substrate 100 itself. If the rear plate 81 is unnecessary, the support frame 82 is directly sealed to the substrate 100, and the face plate 86, the support frame 82, and the substrate 100 constitute the envelope 88. Good.

11A and 11B show an example of the fluorescent film 84, which is a phosphor 92.
And a black conductive material 91 called a black stripe or a black matrix depending on the arrangement method of the phosphors 92. The purpose of providing the black stripes or the black matrix is to make the mixed colors and the like inconspicuous by blackening the separately-applied portions between the phosphors 92 of the three primary color phosphors, which are required for color display. This is to suppress the decrease in contrast due to the reflection of external light at 84. As the material of the black stripe or the black matrix, a material containing graphite as a main component is often used, but the material is not limited to this and may be a material having conductivity and little light transmission and reflection. Good.

As a method for applying the phosphor 92 to the glass substrate 83, a precipitation method or a printing method is used. Further, a metal back 85 is usually provided on the inner surface side of the fluorescent film 84. The purpose of the metal back 85 is to improve the brightness by specularly reflecting the light toward the inner surface side of the light emission of the phosphor to the face plate 86 side, and to act as an electrode for applying an electron beam acceleration voltage, For example, protecting the phosphor 92 from damage due to collision of negative ions generated in the envelope 88. The metal back 85 is created by performing a smoothing process (usually called “filming”) on the inner surface of the created fluorescent film 84, and then depositing Al (aluminum) by vacuum evaporation or the like. On the face plate 86, a fluorescent film 84
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 84 in order to improve the conductivity of the fluorescent film 84.

When performing the above-mentioned sealing, phosphors of each color are used.
Since the 92 and the electron-emitting device need to correspond to each other, it is necessary to perform sufficient alignment. After the pressure inside the envelope 88 is reduced to a vacuum degree of about 10 ^ (-6) Torr through an exhaust pipe (not shown), the envelope 88 is sealed. In addition, terminals outside the container Dx1 to D
A voltage is applied between the device electrodes 5 and 6 through xm and Dy1 to Dyn to perform the above-described forming process, and the electron emitting portion 3
To form an electron-emitting device. Further, a getter process may be performed in order to maintain the vacuum degree of the envelope 88 after sealing. This is to heat the getter (not shown) arranged at a predetermined position in the envelope 88 by a heating method such as resistance heating or high frequency heating immediately before or after the envelope 88 is sealed, This is a process of forming a vapor deposition film. The getter usually has Ba as a main component, and maintains the vacuum degree of, for example, 10 ^ (-5) to 10 ^ (-7) Torr due to the adsorption action of the deposited film.

In the image display device of this embodiment manufactured as described above, each electron-emitting device has terminals Dx1 to Dxm outside the container.
Electrons are emitted by applying a voltage from Dy1 and Dyn, and a high voltage of several kV or more is applied to the metal back 85 or the transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam and collide with the fluorescent film 84. The image is displayed by exciting and emitting light.

The above-mentioned structure is a schematic structure required for manufacturing an image forming apparatus suitable for use in display,
For example, the detailed parts such as the material of each member are not limited to those described above, and may be appropriately selected to suit the application of the image forming apparatus. Further, according to the idea of the present invention, its application is not limited to the image forming apparatus used for display, and it is described above as an alternative light emitting source of the light emitting diode of the optical printer including the photosensitive drum and the light emitting diode. An image forming apparatus can also be used. At that time,
By appropriately selecting m row-direction wirings and n column-direction wirings, it can be applied not only as a line-shaped light emitting source but also as a two-dimensional light emitting source.

Next, a method of achieving white balance in the image forming apparatus of this embodiment will be described.

As already described, the fluorescent film shown in FIG.
Since the electron-emitting devices are arranged corresponding to the respective red, green, and blue phosphors of 84, assuming that the emission characteristics of the electron-emitting devices are uniform, the emission brightness for each color with respect to the irradiation current Je is shown in FIG. 3B. The characteristics are as shown. Shown in solid line in Figure 12
The RGB characteristic curve is the same as the characteristic curve in FIG. 3B. In the same figure, the characteristic curves R'and B'shown by broken lines show that when the irradiation current densities Je from the electron-emitting devices are the same, as a result of color mixing due to the emission of the red, green and blue phosphors, the green emission luminance is used as a reference This is a plot of the red and green emission luminances with which white balance can be obtained. Therefore, depending on the emission characteristics of the phosphors used, there will be a deviation between the reference emission luminance curve R ′ of red and the actual emission luminance curve R with which white balance can be obtained, as shown in FIG. The same applies to the blue reference emission luminance curve B ′ and the actual emission luminance curve B. Therefore, changing the emission characteristics of the electron-emitting device,
The irradiation current density Je corresponding to the above deviation can be corrected.

FIG. 13 is a diagram for explaining a specific method of changing the electron emission characteristic, and the basic structure of the device is the same as that of FIGS. 4A and 4B. In the three devices shown in FIG. 13, the width W (the length in the direction orthogonal to the device current If) of the electron emitting portion 3 becomes narrower in the order of (a), (b), and (c). The width W of the electron emission portion 3 of the device of FIG. 11B is a standard length, and corresponds to the emission luminance characteristic curve G of the green phosphor that serves as a reference for white balance in FIG.
That is, if the length of the electron emitting portion 3 in the direction parallel to the device current If is constant, the area of the electron emitting portion 3 (electron emitting area) increases in proportion to the width W, and FIG. Assuming that the characteristics of the emission current Ie with respect to the device voltage Vf are uniform in the electron emission portion 3, the emission current Ie is proportional to the width W.
Will increase. Therefore, as shown in FIG.
The electron emission current characteristic curves (a) (b) (c) corresponding to the widths W21, W22, W23 of the electron emitting portion 13 of 13 are obtained.

Therefore, when the phosphors of the respective colors exhibit the characteristics shown in FIG. 12, the electron-emitting device corresponding to the blue phosphor is shown in FIG.
By making the element of (c) correspond, the emission current Ie can be reduced and the emission luminance curve B can be made to coincide with the reference characteristic curve B ′. Similarly, by making the device of FIG. 13 (a) correspond to the electron emitting device corresponding to the red phosphor, the emission current I
By increasing e, the emission luminance curve R can be matched with the reference characteristic curve R ′.

The inventors of the present invention described the above-mentioned device, in which the device electrode interval L1 is about 10 μm, the electron emission portion width W21 is about 300 μm, and W22.
Of about 200 μm and W23 of about 100 μm were prepared, and their characteristics were measured. As a result, it was confirmed that the characteristics shown in FIG. 14, that is, a desired electron emission amount corresponding to the width W of each electron emission portion 3 was obtained.

As described above, the emission current characteristic can be changed by changing the width W of the electron emitting portion 3 of the electron emitting element according to the emission luminance characteristic of the phosphor, and white balance can be easily achieved. it can.

The structure of the electric circuit for performing the display operation in the image forming apparatus created as described above will be described below.

FIG. 15 is a block diagram showing a schematic configuration of a drive circuit for performing television display based on an NTSC television signal.

In the figure, 101 is a display panel comprising the image forming apparatus of this embodiment, 102 is a scanning circuit, 103 is a control circuit, 104 is a shift register, 105 is a line memory, 106 is a sync signal separation circuit, and 107 is Modulation signal generator, Vx and Va
Is a DC voltage source. The function of each unit will be described below.

The display panel 101 is connected to an external electric circuit via terminals Dx1 to Dxm, terminals Dy1 to Dyn, and a high voltage terminal Hv. Of these, terminals Dx1 to Dxm
A scanning signal for sequentially driving a multi-electron beam source provided in the display panel 101, that is, a group of surface conduction electron-emitting devices arranged in a matrix of M rows and N columns by one row (N elements) is applied. On the other hand, from terminals Dy1 to Dyn,
A modulation signal for controlling the electron beam output from each element in one row selected by the scanning signal is applied. Further, the high voltage terminal Hv is supplied with a direct current voltage of, for example, 10 kV from a direct current voltage source Va, which is an electron beam output from the surface conduction electron-emitting device and has sufficient energy to excite the phosphor. Is an accelerating voltage for imparting.

Next, the scanning circuit 102 will be described. The circuit has M switching elements inside (S1 to Sm are shown in the figure), and each switching element is either the output voltage of the DC voltage source Vx or 0V (ground level). Is selected and electrically connected to the terminals Dx1 to Dxm of the display panel 101. Each switching element from S1 to Sm has a control signal Tsc output from the control circuit 103.
It works based on an, but in reality
The scanning circuit 102 can be easily configured by combining switching elements such as T.
In this embodiment, the DC voltage source Vx is set to output a constant voltage of about 7V based on the characteristics of the surface conduction electron-emitting device. Further, the control circuit 103 has a function of matching the operation of each unit so that an appropriate display is performed based on the image signal input from the outside.
Then, based on the synchronization signal Tsync sent from the synchronization signal separation circuit 106 described below, the control signals Tscan, Tsft, and Tmry are generated for each unit. The timing of each control signal will be described later in detail.

The sync signal separation circuit 106 is a circuit for separating a sync signal component and a luminance signal component from an NTSC television signal input from the outside, and is easily constructed by using a frequency separation (filter) circuit. It is possible. The sync signal separated by the sync signal separation circuit 106 is composed of a vertical sync signal and a horizontal sync signal, but is illustrated here as a Tsync signal for convenience of description. On the other hand, the luminance signal component of the image separated from the television signal (referred to as a DATA signal for convenience) is sequentially input to the shift register 104. Here, the shift register 104 is for performing serial-parallel conversion for each line of the image, and the control circuit 103
It operates based on the control signal Tsft sent from the computer. That is, the control signal Tsft is the shift clock of the shift register 104.

The image data corresponding to the drive data for one line, which is serial-parallel converted, that is, for the N elements of the electron-emitting device, is represented by N parallel signals Id1 to Idn.
It is output from the shift register 104. Line memory 105
Is a storage device for storing image data for one line for a predetermined time, and a control signal Tmr sent from the control circuit 103.
The contents of Id1 to Idn are stored as appropriate according to y. The stored contents are output from I'd1 as I'dn, and the modulated signal generator
Input to 107. The modulation signal generator 107 outputs the image data I ′
It is a signal source for appropriately driving and modulating each electron-emitting device according to each of d1 to I'dn, and its output signal is applied to the electron-emitting device in the display panel 101 through terminals Dy1 to Dyn.

As described above, this electron-emitting device has three basic characteristics with respect to the emission current Ie. For this reason,
For example, electron emission does not occur when a voltage below the electron emission threshold (for example, 8 V) as shown in FIG. 16A is applied, but when a voltage above the electron emission threshold as shown in FIG. 16B is applied,
The output electron beam can be controlled by changing the pulse width Pw or the pulse peak value Vm.
Therefore, the modulation signal generator 107 is of a pulse width modulation type that generates a pulse of a constant voltage by appropriately modulating the pulse width Pw according to the input data, or the peak value thereof according to the input data. It is also possible to use a voltage modulation system that generates a voltage pulse of a constant width by modulating Vm. In other words, the brightness (luminance) perceived by human vision
Is the result of time integration of light emission.

The function of each part of the drive circuit for performing the television display based on the NTSC system television signal has been described above.
The operation of 1 will be described in more detail. For convenience,
Although the number of pixels of the display panel will be described as 6 × 6, that is, M = N = 6, it goes without saying that the actually used display panel 101 has a much larger number of pixels than this.

FIG. 17 is a diagram showing an example of a multi-electron beam source in which surface conduction electron-emitting devices are wired in a 6 × 6 matrix. For the sake of explanation, the position of each device is D (1,1), D (1 , 2),…, D (6,
It shall be indicated by (X, Y) coordinates as in 6).

When displaying an image by driving such a multi-electron beam source, the image is formed in line order with one line of the image parallel to the X axis as a unit. To drive the electron-emitting device corresponding to one line of the image, the terminals Dx1 to Dx1
0V is applied to the terminals of the row corresponding to the display line of x6, and about 7V is applied to the other terminals. In synchronization with this, a modulation signal is applied to each terminal of Dy1 to Dy6 according to the image pattern of the line.

FIG. 18 is an example of an image pattern, and the case of displaying this will be described below as an example. However, for the sake of convenience, it is assumed that the luminances of the light emitting portions of the image pattern are the same, for example, 100 foot lanes. In the display panel 101, using a known P-22 for the phosphor 92, the acceleration voltage is about 10 kV,
The image display repeating frequency was about 60 Hz, and the surface conduction electron-emitting device having the above-mentioned characteristics was used as the electron-emitting device. In this case, it was appropriate to apply a voltage of about 14V. It should be noted that this numerical value should naturally change if each parameter is changed.

Here, the period during which the third line of the image pattern shown in FIG. 18 is made to emit light will be described as an example. Figure 19
Is the terminal during the period when the third line of the image pattern is illuminated.
FIG. 6 is a diagram showing voltage values applied to a multi-electron beam source through Dx1 to Dx6 and terminals Dy1 to Dy6. As is clear from the figure, a voltage of about 14 V is applied to each of the surface conduction electron-emitting devices D (2,3), D (3,3), D (4,3) to output an electron beam. To be done. On the other hand, in addition to the above three elements, about 7V (elements shown with diagonal lines) or 0V (elements shown with outlines in the figure)
Is applied, but since this is below the threshold voltage for electron emission, no electron beam is output from these elements.
Similarly for other lines, the multi-electron beam source is driven according to the display pattern of FIG.

FIG. 20 is a timing chart showing how the multi-electron beam source is driven. As shown in the figure,
By driving one line at a time from the first line,
Image display without flicker is possible. To change the brightness of the display pattern, to increase (or decrease) the brightness, make the pulse width of the modulation signal applied to terminals Dy1 to Dy6 longer (or shorter) than 10 μs, or change the pulse width of the pulse. It is possible by making the voltage peak value larger (or smaller) than 14V.

The driving method of the display panel 101 has been described above by taking the 6 × 6 multi-electron beam source as an example.
The overall operation of the device shown in FIG. 15 will be described.

FIG. 21 is an example of a timing chart of the entire apparatus shown in FIG. 15. FIG. 21A shows the luminance signal DATA separated by the synchronizing signal separation circuit 106 from the NTSC signal input from the outside. At the timing, as shown in the figure, the first line, the second line, the third line, ... Are sent in this order.
Also, in synchronization with this, the control circuit 103 sends a shift clock to the shift register 104 as shown in FIG.
Tsft is output. When the data DATA for one line is accumulated in the shift register 104, the memory write signal Tmry is output from the control circuit 103 to the line memory 105 at the timing shown in FIG. The drive data is stored and held. As a result, the contents of I'd1 to I'dn, which are the output signals of the line memory 105, change at the timing shown in FIG.

On the other hand, the content of the control signal Tscan for controlling the operation of the scanning circuit 102 is as shown in FIG. 21 (5).
That is, when driving the first line, the scanning circuit 102
Only the switching element S1 inside is 0V and the other switching elements are about 7V, and when driving the second line, only the switching element S2 is 0V and the other switching elements are about 7V,
The operation is controlled as follows. Further, in synchronization with this, the modulation signal generator 107 outputs the modulation signal to the display panel 101 at the timing shown in FIG.

Although not particularly described in the above description, the functional block composed of the shift register 104 and the line memory 105 may be of a digital signal type or an analog signal type. It suffices if serial / parallel conversion and storage of the image signal can be performed at a predetermined speed and timing. In the case of using the digital signal system, it is necessary to convert the output signal DATA of the sync signal separation circuit 106 into a digital signal, but this is easy if an A / D converter is provided at the output section of the sync signal separation circuit 106. It goes without saying that it can be realized.

By the operation described above, the display panel 10
It becomes possible to display a television using 1.

[0089]

[Second Embodiment] An image forming apparatus according to a second embodiment of the present invention will be described below. It should be noted that in the second embodiment, substantially the same configurations as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Next, as a second embodiment according to the present invention,
Another method of changing the electron emission characteristics of the electron emitting device will be described.

FIG. 22 is a diagram for explaining another method for changing the electron emission characteristic of the surface conduction electron-emitting device, and FIG. 23 is a diagram showing its electron emission characteristic curve. The structure of the element is shown in Figure 4A.
And 4B is the same.

In the three elements shown in FIG. 22, the element electrode spacing L becomes longer in the order of (a) (b) (c). The device electrode spacing L of the device of FIG. 23B has a standard length, and the characteristics of its emission current Ie are as shown in FIG. 23B, which is the device voltage shown in FIG.
This corresponds to the characteristic of the emission current Ie with respect to Vf. Therefore, FIG.
The characteristics of the element in (b) correspond to the emission luminance characteristic curve G of the green phosphor that serves as a reference for white balance in FIG.

The electron emission characteristics can be changed depending on the length of the device electrode interval L. The region of the device electrode interval L excluding the electron emitting portion 3 is a wiring having a finite resistance value.
In other words, it can be regarded as a series resistance. Therefore, as the device electrode interval L becomes longer, the series resistance value becomes larger, the voltage drop due to it becomes larger, and the voltage applied to the electron emitting portion 3 becomes smaller. As a result, as shown in FIG. 23, corresponding to the device electrode intervals L11, L12, L13 of FIG. 22, the electron emission current characteristic curve (a) (b) (the threshold voltage Vth at which electron emission is started is shifted. c) will be obtained.

Therefore, when the phosphors of the respective colors exhibit the characteristics as shown in FIG. 12, the emission current Ie can be obtained by associating the element of FIG. 22 (c) with the electron emission element corresponding to the blue phosphor.
Can be reduced to match the emission luminance curve B with the reference characteristic curve B ′. Similarly, by making the element of FIG. 22 (a) correspond to the electron emitting element corresponding to the red phosphor, the emission current Ie is increased and the emission luminance curve R is set to the reference characteristic curve.
Can match R '.

The inventors of the present invention produced the above-mentioned device having an electron emission portion width W2 of about 200 μm, a device electrode spacing L11 of about 2 μm, L12 of about 10 μm, and L13 of about 30 μm, and measuring the characteristics. did. As a result, it was confirmed that the characteristics shown in FIG. 23, that is, the desired electron emission amount corresponding to each element electrode interval L was obtained.

As described above, the emission current characteristic can be changed by changing the element electrode interval L of the electron emitting element according to the emission luminance characteristic of the phosphor, and the white balance can be easily taken.

[0097]

As described above, according to the present invention, it is possible to provide an electron beam generating source that can easily achieve white balance and an image forming apparatus that uses the electron beam generating source to display an image with good color reproducibility. .

[Brief description of drawings]

FIG. 1 is a plan view showing a typical example of a device configuration of a surface conduction electron-emitting device,

FIG. 2 is a diagram showing an example of a multi-electron beam source by an electronic wiring method,

FIG. 3A is a diagram showing typical emission characteristics of a phosphor,

FIG. 3B is a diagram showing typical emission characteristics of a phosphor,

FIG. 4A is a plan view showing the configuration of a basic surface conduction electron-emitting device according to the present invention,

4B is a cross-sectional view showing the configuration of the element shown in FIG. 4A,

FIG. 5A is a diagram showing an example of a method for manufacturing an electron-emitting device having an electron-emitting portion,

FIG. 5B is a diagram showing an example of a method of manufacturing an electron-emitting device having an electron-emitting portion,

FIG. 5C is a diagram showing an example of a method for manufacturing an electron-emitting device having an electron-emitting portion,

FIG. 6 is a diagram showing a voltage waveform of a forming process,

FIG. 7 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring electron emission characteristics of an element having the configuration shown in FIGS. 4A and 4B.

8 is a diagram showing a typical example of the relationship between the emission current Ie and the device current If and the device voltage Vf measured by the measurement / evaluation apparatus shown in FIG.

FIG. 9 is a diagram showing a configuration example of an electron beam source substrate,

FIG. 10 is a basic configuration diagram of an image forming apparatus according to an embodiment of the invention,

FIG. 11A is a diagram showing an example of a fluorescent film,

FIG. 11B is a view showing an example of a fluorescent film,

FIG. 12 is a diagram showing an example of a light emission luminance characteristic curve for explaining a problem in taking white balance;

FIG. 13 is a diagram illustrating a specific method for changing the electron emission characteristics of the surface conduction electron-emitting device,

14 is a diagram showing an example of electron emission characteristics of each element shown in FIG.

FIG. 15 is a block diagram showing a schematic configuration of a drive circuit for performing television display based on an NTSC television signal.

16A is a diagram illustrating a method of controlling an output electron beam of a surface conduction electron-emitting device, FIG.

FIG. 16B is a diagram illustrating a method of controlling an output electron beam of a surface conduction electron-emitting device,

FIG. 17 is a diagram showing an example of a multi-electron beam source in which surface conduction electron-emitting devices are wired in a 6 × 6 matrix.

FIG. 18 is an example of an image pattern,

19 is a diagram showing a voltage value applied when the third line of the multi-electron beam source shown in FIG. 17 is caused to emit light,

20 is a timing chart showing how the multi-electron beam source shown in FIG. 17 is driven,

21 is a timing chart example of the entire apparatus shown in FIG.

FIG. 22 is a view for explaining a method of changing the electron emission characteristics of the surface conduction electron-emitting device of the second embodiment according to the present invention,

FIG. 23 is a diagram showing an example of electron emission characteristics of each element shown in FIG. 22.

[Explanation of symbols]

 1 Insulating substrate 2 Thin film for forming electron emission part 3 Electron emission part 4 Thin film including electron emission part 5,6 Device electrode 34 Anode electrode 67 Step forming part 72 X direction wiring 73 Y direction wiring 74 Surface conduction electron emitting device 75 Wiring 81 Rear plate that fixes the electron source 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate 88 Envelope 91 Black conductive material 92 Fluorescent substance 101 Display panel 102 Scanning circuit 103 Control circuit 104 Shift register 105 lines Memory 106 Sync signal separation circuit 107 Modulation signal generator

Claims (11)

[Claims] 1. An electron beam generating source in which a plurality of surface conduction electron-emitting devices are two-dimensionally arranged on a substrate, and the devices are connected in a matrix by row-direction wiring and column-direction wiring, and the electron beam. An electron beam generated by a source, emitting three-color phosphors that emit light; and a modulator that modulates the electron beam that irradiates the phosphors based on an input image signal. An image forming apparatus, characterized in that the electron emission characteristics of the surface conduction electron-emitting device arranged in the light source are changed according to the emission characteristics of the phosphor for each color. 2. The image forming apparatus according to claim 1, wherein the electron emission characteristic is changed by changing an element shape of the surface conduction electron-emitting device. 3. The image forming apparatus according to claim 1, wherein the electron emission characteristic is changed by changing a width of an electron emission portion of the surface conduction electron-emitting device. 4. The image forming apparatus according to claim 1, wherein the electron emission characteristic is changed by changing an interval between device electrodes of the surface conduction electron-emitting device. 5. The image forming apparatus according to claim 1, wherein the electron emission characteristic is changed by changing an area of an electron emission portion of the surface conduction electron-emitting device. 6. A surface conduction electron-emitting device group having at least different electron emission characteristics is two-dimensionally arranged on a substrate, and each device is connected in a matrix by row-direction wiring and column-direction wiring. A source of electron beam generation. 7. The electron beam generating source according to claim 6, wherein the surface conduction electron-emitting device groups having different electron emission characteristics are periodically arranged. 8. The electron beam generating source according to claim 6, wherein the electron emission characteristic is changed by changing an element shape of the surface conduction electron-emitting device. 9. The electron beam generating source according to claim 6, wherein the electron emission characteristic is changed by changing a width of an electron emitting portion of the surface conduction electron-emitting device. 10. The electron beam generating source according to claim 6, wherein the electron emission characteristic is changed by changing a distance between device electrodes of the surface conduction electron-emitting device. 11. The electron beam generating source according to claim 6, wherein the electron emission characteristic is changed by changing an area of an electron emission portion of the surface conduction electron-emitting device.