JPH06342636A - Electron source and image formation device - Google Patents

Abstract

PURPOSE:To provide an image formation device of high display definition for making an image formation member to emit light at a selectively controlled brightness by selecting an optional element according to an input signal and by making the amount of discharged electron controllable. CONSTITUTION:A surface conduction type emission element connected to a wiring, to which voltage V1 is applied, is scanned by applying the voltage of V1 to a wiring selected of numeral (m) numbers of wirings in X-direction, and voltage V2 to the other wirings, by means of applying a scanning signal. The voltage wave height value Vm of a pulse is changed according to an input signal in relation to the numeral (n) number of wirings in Y-direction, by a modulation signal emitting means, and the brightness of a display image is thus modulated. The drive voltage applied to the elements not scanned is controlled so that it does not exceed the threshold ground voltage Vth of the element. An electron beam of desired intensity is output only from the scanned element, and no electron beam is output from the elements not scanned. By selecting an optional element and by making it to emit light at desired brightness, the display definition of an image is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source and an image forming apparatus such as a display device which is an application of the electron source. The present invention relates to a forming device.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitters, a thermoelectron source and a cold cathode electron source, are known.

Among the cold cathode electron sources, there are a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), a surface conduction type electron emitting device and the like.

As an example of the FE type, W. P. Dyk
e & W. W. Dolan, "Fielddemissio
n ”, Advance in Electron Ph
ysics, 8, 89 (1956) or C.I. A. S
pindt, "PHYSICAL Properties"
of thin-film field emiss
ion cathodes with mollybde
numbercones ", J. Appl. Phys., 4
7, 5248 (1976) and the like are known.

As an example of the MIM type, C.I. A. Me
ad, "The tunnel-emission a
mplifer, J.M. Appl. Phys. , 32,
646 (1961) and the like are known.

As an example of the above-mentioned surface conduction electron-emitting device, M. I. Elinson, Radio Eng. E
electron Pys. 10, (1965) and so on.

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 conduction type electron-emitting device, in addition to the one using the SnO ₂ thin film by Elinson et al., The one using an Au thin film [G. Dittmer: "Thin Sol
id Films ", 9, 317 (1972)], In
₂ O ₃ / SnO ₂ thin film [M. Hartwel
and C. G. Fonstad: "IEEE T
rans. ED Conf. "519 (197
5)], by carbon thin film [Hiraki Araki et al .: Vacuum,
Vol. 26, No. 1, p. 22 (1983)] and the like are reported.

As a typical element structure of these surface conduction electron-emitting devices, the above-mentioned M. The Hartwell device configuration is shown in FIG. In the figure, 431 is an insulating substrate, 4
Reference numeral 32 is a thin film for forming an electron emitting portion, which is composed of a metal oxide thin film or the like formed by sputtering on an H-shaped pattern,
The electron emission portion 433 is formed by an energization process called forming, which will be described later. Here, 434 is referred to as a thin film including an electron emitting portion. Note that L1 in FIG. 43 is 0.
5-1 mm and W are set to 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 433 is formed by subjecting the electron-emitting portion forming thin film 432 to an energization process called forming in advance before the electron emission. Was common. That is, the forming means that a direct current voltage or a very slow rising voltage, for example, about 1 V / min is applied to both ends of the electron emitting portion forming thin film 432,
The electron emitting portion forming thin film 432 is locally destroyed, deformed or altered to form the electron emitting portion 433 in an electrically high resistance state. The electron emission unit 433
Causes a crack to occur in a part of the electron emission portion forming thin film 432, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the forming process is one in which electrons are emitted from the electron-emitting unit 433 by applying a voltage to the thin film 434 including the above-mentioned electron-emitting unit and passing a current through the device.

However, although these conventional surface conduction electron-emitting devices have various problems in practical use, the applicants of the present invention diligently studied various improvements as will be described later, and put them into practical use. Has solved various problems.

The surface conduction electron-emitting device described above has an advantage that a large number of devices can be arrayed over a large area because it has a simple structure and is easy to manufacture. Therefore, various applications that can make full use of this feature have been studied, and examples thereof include a charged beam source and a display device.

As an example in which a large number of surface-conduction type electron-emitting devices are formed in an array, the surface-conduction type electron-emitting devices are arranged in parallel, and a large number of rows in which both ends of each element are connected by wiring are arranged in an electron array. Source (for example, Japanese Patent Application Laid-Open No. 64-31332 of the present applicant).

In particular, in image forming apparatuses such as display devices, in recent years, flat panel display devices using liquid crystal have become popular in place of CRTs, but since they are not self-luminous, they must have a backlight or the like. Therefore, development of a self-luminous display device has been desired. An image forming apparatus, which is a display apparatus in which a large number of surface conduction electron-emitting devices are arranged and a phosphor that emits visible light by the electrons emitted from the electron source, is relatively large even in a large-screen apparatus. It is a self-luminous display device that can be easily manufactured and has excellent display quality (for example, US Pat. No. 5,066,883 of the applicant).

Conventionally, an electron source configured by a large number of surface-conduction type electron-emitting devices is used to select an element for emitting electrons to cause a phosphor to emit light. Wirings arranged and connected (called a row direction wiring) and a control electrode (called a grid) installed in a space between the electron source and the phosphor in a direction orthogonal to this (called a column direction) This is based on an appropriate drive signal (for example, Japanese Patent Laid-Open No. 1-283749 of the present applicant).

However, as a matter of course, the alignment between the individual surface conduction electron-emitting devices and the grid,
It is necessary that the distance between the grid and the surface conduction electron-emitting device is uniform, which is a problem in the manufacturing method. In view of these problems, in order to solve the problems in the manufacturing method associated with these grids, a new configuration in which the grids are stacked in the vicinity of the surface conduction electron-emitting device has been proposed (for example, Japanese Patent Application Laid-Open No. Hei 10 (1999) -242242). 3-20941).

In addition to this, as an example of a surface element using a conventional surface conduction electron-emitting device, Japanese Patent Publication No. 45-31615 is available.
As shown in FIGS. 44 and 45 in the publication, a lateral current type electron emitter 442 connected in series and the electron emitter 44
Band-shaped transparent electrodes 4 arranged so as to form a lattice with 2
Glass plate 44 having a small hole 443 'between
No. 3 is arranged so that its hole 443 'is exactly at the intersection of the above-mentioned lattices, gas is enclosed in the hole 443', and a lateral current type electron emitter 442 emitting electrons and an accelerating voltage E
A display device is disclosed in which only the intersection with the transparent electrode 444 to which 2 is added emits light by gas discharge. Although there is no detailed description of the lateral current type electron emitter in this Japanese Patent Publication No. 45-31615,
Described materials (metal thin film, NES film) and neck 44
Since the structure of 2'is the same as the surface conduction electron-emitting device described above, it is considered to be included in the category of the surface conduction electron-emitting device. The name of the surface conduction electron-emitting device used by the inventors of the present application is "a thin film handbook".
It is based on the description.

[0017]

The problems that have occurred in the image display device that has been tried using the above-described conventionally known surface conduction electron-emitting device will be described below.

The display device disclosed in Japanese Patent Publication No. 45-31615 has three main problems as described below.

(1) The display device is designed to accelerate electrons emitted from a lateral current type electron emitter to collide with gas molecules to cause discharge, and the same current is applied to the lateral current type electron emitter. However, there is a problem in that the discharge light emission brightness varies from pixel to pixel, and the brightness varies even in the same pixel.
The cause is that the discharge intensity largely depends on the state of the gas, and the controllability is not good. Furthermore, the output of the lateral current type electron emitter is as described in the experimental example. It is not always stable under a pressure of about 15 mmHg.

Therefore, it is difficult for the display device to display multi-gradation, and its use is limited.

(2) In the display device, it is possible to change the emission color by changing the type of gas to be enclosed, but the wavelength of visible light obtained by discharge emission is generally limited, and it is not always in a wide range. It cannot express color. Also,
The optimum pressure for discharge light emission often varies depending on the type of gas.

Therefore, if one panel is to be colored, it is necessary to change the type and pressure of the gas to be sealed for each hole, which makes the manufacture of the panel extremely difficult. Also,
It was not practical to stack and colorize three panels filled with different gases in terms of the size, weight and cost of the device.

(3) The display device has a complicated structure because it is composed of components such as a substrate on which a lateral current type electron emitter is formed, a strip-shaped transparent electrode, and a gas-filled hole. The tolerance for positional displacement between elements is small. Further, as exemplified in the above publication, the threshold voltage for discharge light emission is as high as 35 [V], so that it is necessary to use an electric element having a high breakdown voltage in an electric circuit for driving the panel.

Therefore, it takes time and cost to manufacture the device, and it is difficult to provide the device at low cost.

For the above-mentioned three main reasons,
The display device has not been widely applied to a television receiver or the like.

On the other hand, in view of the above-mentioned problems, an electron source provided with a plurality of surface conduction electron-emitting devices proposed by the present applicant, and a phosphor disposed at a position facing the electron source. The image forming apparatus such as the display device also has the problems described above.

In the electron source, a grid is provided in the direction (column-direction wiring) orthogonal to the wiring (row-direction wiring) of the elements in which a large number of elements are arranged in parallel in order to select the element that emits electrons. In this respect, the electron source is an electron source capable of selecting an element that emits electrons and controlling the electron emission amount, but it is said that the electron source has a simple structure and can be easily manufactured. It was difficult.

Further, in the image forming apparatus using the electron source, in order to make the phosphor disposed at a position facing the electron source emit light with the brightness which is selectively controlled, it is the same as the above electron source. , A display device in which a grid is indispensable, can be manufactured easily with a simple structure, and which can control the brightness of the phosphor by selecting an element that emits electrons according to an input signal and controlling the electron emission amount It was hard to say that the image forming apparatus is the image forming apparatus.

In view of the above-mentioned conventional problems, the present invention can select any of the electron sources having a large number of surface conduction electron-emitting devices according to an input signal and control the amount of emitted electrons. An image of an electron source that has a simple structure and can be easily manufactured, is inexpensive, and has a novel structure, and an image of a display device or the like in which an image forming member such as a phosphor is arranged at a position facing the electron source using the electron source. It is an object of the present invention to provide an image forming apparatus having a novel structure, which has a high display quality that allows the image forming member to emit light with selectively controlled brightness and is easy to colorize.

A further object of the present invention is to provide an image forming apparatus having excellent gradation display characteristics in the image forming apparatus.

It is a further object of the present invention to provide an image forming apparatus having a high display quality such that the shape of the light emitting points is excellent and the crosstalk between the light emitting points is also small in the image forming apparatus.

[0032]

The present invention for achieving the above object provides an electron source that emits electrons in response to an input signal, in which the electron source is laminated on a substrate through an insulating layer. A plurality of surface-conduction type electron-emitting devices having m row-direction wirings and n column-direction wirings and a thin film including an electron-emitting portion between a pair of device electrodes. The electron-emitting devices are arranged in a matrix with the device electrodes, the row-direction wirings, and the column-direction wirings connected to each other, and the electron source is one of the plurality of surface-conduction electron-emitting devices. , A selection means for selecting an element row and a modulation means for generating a modulation signal according to the input signal and applying the modulation signal to the element row selected by the selection means. It is an electron source.

Further, the present invention is an image forming apparatus for forming an image according to an input signal, wherein the image forming apparatus has an electron source and an image forming member, the electron source is a substrate, and the substrate is provided on the substrate. M row-direction wirings and n stacked via an insulating layer
A plurality of surface-conduction electron-emitting devices having a thin film including an electron-emitting portion between a pair of device-electrodes, and the plurality of surface-conduction electron-emitting devices, The row-direction wirings and the column-direction wirings are connected to each other and arranged in a matrix corresponding to pixels forming an image, and the image forming apparatus includes a plurality of surface conduction electron-emitting devices. From the element row, and a modulation means that generates a modulation signal according to the input signal and applies the modulation signal to the element row selected by the selection means. Image forming apparatus.

Next, the present invention will be described in detail with reference to preferred embodiments.

In the following, in particular, Japanese Patent Application Laid-Open No. 2-5 by the present applicant.
The basic configuration and manufacturing method of the electron-emitting device according to the present invention, and the features thereof will be outlined below with reference to Japanese Patent No. 6822, etc. The characteristics of a new surface conduction electron-emitting device, which is the principle of, will be outlined.

The features of the structure and manufacturing method of the surface conduction electron-emitting device according to the present invention are as follows.

1) The electron emission portion forming thin film before the energization treatment called forming is formed of fine particles formed by dispersing a fine particle dispersion, or fine particles formed by heating and burning an organic metal or the like. It is basically composed of fine particles such as a thin film.

2) The thin film including the electron emitting portion after the energization process called forming is basically composed of fine particles, both the electron emitting portion and the thin film including the electron emitting portion.

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

1 (a) and 1 (b) are a plan view and a sectional view, respectively, showing the structure of a basic planar surface conduction electron-emitting device according to the present invention. The basic configuration of the device according to the present invention will be described with reference to FIG.

In FIG. 1, 1 is a substrate, 5 and 6 are device electrodes, 4 is a thin film including an electron emitting portion, and 3 is an electron emitting portion.

As the substrate 1, quartz glass, glass with a reduced content of impurities such as Na, soda lime glass, a soda lime glass substrate laminated with SiO ₂ formed by a sputtering method, or a ceramic such as alumina is used. Above all, an insulating substrate is preferably used.

The material of the element electrodes 5 and 6 facing each other may be any material as long as it has conductivity. For example, Ni, Cr, Au, M
Printing composed of metals such as o, W, Pt, Ti, Al, Cu, Pd, or alloys and metals such as Pd, Ag, Au, RuO ₂ , Pd-Ag, or metal oxides and glass Examples thereof include conductors, transparent conductors such as In ₂ O ₃ —SnO ₂ and semiconductor materials such as polysilicon.

The element electrode spacing L1 is several hundred angstroms to several hundreds of micrometers, and the photolithography technology that is the basis of the manufacturing method of the element electrodes, that is, the performance of the exposure machine and the etching method, and the application between the element electrodes are applied. It is set according to the applied voltage and the electric field strength that can emit electrons.
It is preferably several micrometers to several tens of micrometers.

The device electrode length W1 and the film thickness d of the device electrodes 5 and 6 are appropriately selected depending on the resistance value of the electrodes, the connection with the X wiring and the Y wiring described above, and the layout problem of a large number of electron-emitting devices. The device electrode length W1 which is designed is usually several micrometers to several hundreds of micrometers, and the film thickness d of the device electrodes 5 and 6 is several hundred angstroms to several micrometers.

Opposing element electrodes 5 provided on the substrate 1
And between the element electrodes 6 and on the element electrodes 5 and 6,
The thin film 4 including the electron emitting portion includes the electron emitting portion 3, but there are not only the configuration shown in FIG. 1B but also a configuration in which it is not placed on the device electrodes 5 and 6. That is, there is also a mode in which the thin film 2 for forming the electron emission portion and the opposing device electrodes 5 and 6 are laminated in this order on the substrate 1. In addition, depending on the manufacturing method, the entire space between the opposing device electrodes 5 and 6 may function as an electron emitting portion. The film thickness of the thin film 4 including the electron emitting portion is preferably several angstroms to several thousand angstroms, and particularly preferably 10 angstroms to 500 angstroms. It is appropriately set according to the resistance value between the electrodes 5 and 6, the particle size of the conductive fine particles of the electron emitting portion 3, and further the energization processing conditions described later. Further, the resistance value indicates a sheet resistance value of 10 3 to 10 7 ohm / □.

Specific examples of the material forming the thin film 4 including the electron emitting portion are Pd, Nb, Mo, Rh, and H.
f, Re, Ir, Pt, Al, Co, Ni, Cs, B
a, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, Zn, Sn, Ta, W, Pb and other metals, PdO, S
nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , BaO, M
Oxides such as gO, HfB ₂ , ZrB ₂ , LaB ₆ , Ce
Boride such as B ₆ , YB ₄ , GdB ₄ , TiC, ZrC,
Carbides such as HfC, TaC, SiC, WC, TiN, Z
It is a nitride such as rN or HfN, a semiconductor such as Si or Ge, carbon or the like, and is composed of fine particles.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state in which the fine particles are individually dispersed but also in a state in which the fine particles are adjacent to each other or overlap each other ( (Including island-shaped) film.

The electron emitting portion 3 is composed of a large number of conductive fine particles having a particle diameter of preferably several angstroms to several hundred angstroms, particularly preferably 10 angstroms to 500 angstroms, and the film thickness of the thin film 4 including the electron emitting portion. It also depends on the manufacturing method such as energization processing conditions described later and is set appropriately. The material forming the electron emitting portion 3 is a material having a part or all of the elements of the material forming the thin film 4 including the electron emitting portion.

Next, various methods can be considered as a method of manufacturing the electron-emitting device having the electron-emitting portion 3. One example thereof is shown in FIG. In FIG. 2, reference numeral 2 is a thin film for forming an electron emitting portion, and for example, a fine particle film can be mentioned.

Hereinafter, the manufacturing method will be described in order with reference to FIGS. 1 and 2.

1) After thoroughly cleaning the substrate 1 with a detergent, pure water and an organic solvent, depositing an element electrode material by a vacuum evaporation method, a sputtering method or the like, and then using a photolithography technique, the element electrode 5 on the surface of the substrate 1. , 6 are formed ((a) of FIG. 2).

2) An organometallic solution is applied on the substrate 1 between the device electrodes 5 and 6 provided on the substrate 1 and left to form an organometallic thin film. The organic metal solution means Pd, Ru, Ag, Au, Ti,
In, Cu, Cr, Fe, Zn, Sn, Ta, W, Pb
It is a solution of an organic compound whose main element is a metal such as. After that, the organic metal thin film is heat-fired and patterned by lift-off, etching, etc. to form the electron emission portion forming thin film 2 ((b) of FIG. 2). In addition, although the description has been given here using the coating method of the organic metal solution, the coating method is not limited to this.
It may be formed by a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like.

3) Next, when an energization process called forming is performed by applying a voltage between the element electrodes 5 and 6 by a power source (not shown) with a pulsed or high-speed rising voltage, the portion of the thin film 2 for forming the electron emission portion is formed. The electron-emitting portion 3 having a changed structure is formed at (3) in FIG. The electron-emitting portion forming thin film 2 is locally destroyed, deformed or altered by this energization process, and a portion whose structure is changed is called an electron-emitting portion 3. As described above, the applicants have observed that the electron emitting portion 3 is composed of conductive fine particles.

An example of the voltage waveform of the above forming process is shown in FIG.

In FIG. 4, T1 and T2 are the pulse width and the pulse interval of the voltage waveform. T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave (during forming) Peak voltage of 4-10V
The forming process was appropriately set in a vacuum atmosphere for several tens of seconds to several minutes.

When forming the electron-emitting portion described above,
Although the forming process is performed by applying the triangular wave pulse between the electrodes of the element, the waveform applied between the electrodes of the element is not limited to the triangular wave, and a desired waveform such as a rectangular wave may be used. The crest value, the pulse width, the pulse interval, etc. are not limited to the above values, and a desired value can be selected in accordance with the resistance value of the electron-emitting device so that the electron-emitting portion can be formed well. it can.

In the surface conduction electron-emitting device in which the conductive fine particles are dispersed in advance, a part of the manufacturing method may be changed.

The basic characteristics of the electron-emitting device according to the present invention, which has the above-described device structure and is manufactured by the above-described manufacturing method, will be described with reference to FIGS. 3 and 5.

FIG. 3 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring the electron emission characteristics of the device having the configuration shown in FIG.

In FIG. 3, 1 is a substrate, 5 and 6 are device electrodes, 4 is a thin film including an electron emitting portion, and 3 is an electron emitting portion. Further, 31 is a power supply for applying a device voltage Vf to the device, 30 is an ammeter for measuring a device current If flowing through the thin film 4 including the electron emitting portion between the device electrodes 5 and 6, and 34 is an ammeter.
Is an anode electrode for capturing the emission current Ie emitted from the electron emission portion of the device, 33 is a high-voltage power supply for applying a voltage to the anode electrode 34, and 32 is an emission current emitted from the electron emission portion 3 of the device It is an ammeter for measuring Ie.

When measuring the above-mentioned device current If and emission current Ie of the electron-emitting device, the power supply 31 is applied to the device electrodes 5 and 6.
And an ammeter 30 are connected to each other, and an anode electrode 34 to which a power source 33 and an ammeter 32 are connected is arranged above the electron-emitting device. Further, the electron-emitting device and the anode electrode 34 are installed in a vacuum apparatus, and the vacuum apparatus is equipped with equipment necessary for the vacuum apparatus such as an exhaust pump and a vacuum gauge (not shown). The device can be measured and evaluated. The exhaust pump is composed of a normal high vacuum device system including a turbo pump and a rotary pump, and an ultra-high vacuum device system including an ion pump. The entire vacuum apparatus and the electron source substrate can be heated up to about 200 ° C. by a heater (not shown). The voltage of the anode electrode was measured in the range of 1 kV to 10 kV, and the distance H between the anode electrode and the electron-emitting device was measured in the range of 2 mm to 8 mm.

Further, the inventors of the present invention have diligently studied the characteristics of the surface conduction electron-emitting device according to the present invention, and as a result,
The characteristic feature which is the principle of the present invention was found.

FIG. 5 shows a typical example of the relationship between the device voltage Vf and the emission current Ie and device current If measured by the measurement / evaluation apparatus shown in FIG. The emission current I is shown in FIG.
Since e is significantly smaller than the device current If, it is shown in arbitrary units. As is clear from FIG. 5, this electron-emitting device has three characteristics with respect to the emission current Ie.

First of all, in the present electron-emitting device, when a device voltage higher than a certain voltage (this is called a threshold voltage, which is shown as Vth in FIG. 5) is applied, the emission current Ie is suddenly increased.
On the other hand, on the other hand, at the threshold voltage Vth or lower, the emission current Ie
Is hardly detected. That is, this electron-emitting device is a non-linear device 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 can be controlled by the time for which the device voltage Vf is applied.

Due to the above characteristics, the electron-emitting device according to the present invention can be expected to be applied to various fields.

On the other hand, the element current If increases monotonically with respect to the element voltage Vf (shown by the solid line in FIG. 4;
And a voltage-controlled negative resistance characteristic (indicated by a broken line in FIG. 4, which is called a VCNR characteristic).
The present inventors have newly found that such characteristics of the device current If depend on the manufacturing method of the device.

That is, the VCNR characteristic of the device current If is generated when forming is performed in an ordinary vacuum apparatus system, and the characteristic is such that electrical characteristics at the time of forming, vacuum atmosphere conditions of the vacuum apparatus system, etc. Alternatively, the vacuum atmosphere conditions of the vacuum system at the time of measuring the characteristics of the electron-emitting device that has already been formed, and the electrical measurement conditions at the time of the measurement, for example,
In order to obtain the current-voltage characteristics of the electron-emitting device, the sweep speed when the voltage applied to the device is swept from a low voltage to a high voltage, or the electron-emitting device is left in the vacuum device until the measurement. It turned out that it changes greatly depending on time and the like. At this time, regarding the emission current Ie, M
I characteristic is shown.

Further, in view of the above-described matters, the present inventors moved a surface conduction electron-emitting device, in which a device current If exhibits a VCNR characteristic, to an ultrahigh vacuum system in an ordinary vacuum device, After the high temperature baking treatment (for example, left at 100 ° C. for 15 hours), the characteristics were measured, and it was newly found that both the device current If and the emission current Ie exhibit MI characteristics with respect to the voltage Vf.

Incidentally, the characteristics similar to the monotonically increasing electron current If observed conventionally are described in, for example, Japanese Patent Application Laid-Open No. 1-2 of the present applicant.
As in the element described in Japanese Patent No. 79542, it has been observed that when a voltage is applied to the element at a relatively fast sweep speed from a low voltage to a high voltage when the element is subjected to a forming process in a normal vacuum system. However, unlike the monotone increasing characteristics of Ie and If in the ultra-high vacuum system found by the present inventors, the current value is different. Therefore, it is estimated that the state of the element is obviously different from that of the conventional element.

As described above, the monotonically increasing characteristic (MI characteristic) of the device current If and the emission current Ie of the surface conduction electron-emitting device with respect to the device applied voltage Vf is further improved by the surface conduction electron-emitting device according to the present invention. Expect applications in various fields.

Next, a vertical type surface conduction electron-emitting device, which is a surface conduction electron emission device having another structure according to the present invention, will be described.

FIG. 6 is a diagram showing the structure of a basic vertical surface conduction electron-emitting device according to the present invention.

In FIG. 6, 1 is a substrate, 5 and 6 are device electrodes, 4
Is a thin film including an electron emitting portion, 3 is an electron emitting portion, and 67 is a step forming portion. Here, the substrate 1, the device electrodes 5 and 6, the thin film 4 including the electron-emitting portion, and the electron-emitting portion 3 are made of the same material as that of the above-mentioned planar type surface conduction electron-emitting device. The step forming portion 67 and the thin film 4 including the electron emitting portion which characterize the surface conduction electron-emitting device will be described in detail.

The step forming portion 67 is formed by a vacuum evaporation method, a printing method,
The step forming portion 67 is made of an insulating material such as SiO ₂ formed by a sputtering method or the like, and the thickness of the step forming portion 67 corresponds to the element electrode interval L1 of the planar surface conduction electron-emitting device described above, and is several hundreds. Tens of micrometers from Angstrom,
The thickness is set depending on the manufacturing method of the step forming portion and the voltage applied between the device electrodes and the electric field strength capable of emitting electrons, but it is preferably several thousand angstroms to several micrometers.

The thin film 4 including the electron emitting portion is the device electrode 5,
6 and the step forming portion 67 are formed and then laminated on the device electrodes 5 and 6 to be formed.
It is formed into a desired shape with an overlap for making an electrical connection with 6. Further, the film thickness of the thin film 4 including the electron emitting portion depends on the manufacturing method thereof, and the film thickness at the step portion and the film thickness of the portion laminated on the device electrodes 5 and 6 often differ, Generally, the film thickness at the step portion tends to be thin. Further, the electron emitting portion 3 is formed at any position on the thin film 4, and is not always formed at the position shown in FIG.

Although the basic structure and manufacturing method of the surface conduction electron-emitting device have been described above, according to the idea of the present invention,
As long as the surface conduction electron-emitting device has the above-mentioned three characteristics, the invention is not limited to the above-described configuration and manufacturing method, and is also applied to an electron source and an image forming apparatus such as a display device described later. it can.

Next, the electron source and the image forming apparatus which are the main objects of the present invention will be described.

The characteristics of the three basic characteristics of the surface conduction electron-emitting device according to the present invention described above are as follows. First, the present electron-emitting device is applied with a device voltage equal to or higher than the threshold voltage (Vth in FIG. 5). The emission current Ie rapidly increases, while the emission current Ie is hardly detected at the threshold voltage Vth or less. That is, this electron-emitting device is a non-linear device 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 trapped in the anode electrode 34 (FIG. 3) depend on the time for applying the device voltage Vf. That is, the amount of charges captured by the anode electrode 34 (FIG. 3) can be controlled by the time for which the device voltage Vf is applied.

According to the above, the emission device from the surface conduction electron-emitting device is controlled by the peak value and width of the pulse voltage applied between the opposing device electrodes at the threshold voltage or higher. On the other hand, below the threshold voltage, it is hardly emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged, if the pulsed voltage is appropriately applied to each surface-conduction type electron-emitting device, an arbitrary surface-conduction type electron is output according to the input signal. The effect that the electron emission amount can be controlled by selecting the emission element is exhibited.

Further, in the present invention, among the surface conduction electron-emitting devices having the above-mentioned three basic characteristics, the surface conduction electron-emitting devices which can be more preferably applied in view of the above-mentioned effects are as follows. Both the device current If and the emission current Ie are surface conduction electron-emitting devices having a monotonically increasing characteristic (MI characteristic) with respect to the voltage Vf applied to the pair of opposing element electrodes.

The configuration of the electron source substrate constructed based on this principle will be described below with reference to FIG.

In FIG. 7, 1 is a substrate, 72 is an X-direction wiring, 73 is a Y-direction wiring, 74 is a surface conduction electron-emitting device, and 75 is a connection. The surface conduction electron-emitting device 7
4 may be either the flat type or the vertical type described above.

Here, the substrate 1 is an insulating substrate such as the above-mentioned glass substrate, and the size and the thickness thereof are the same as those of the substrate 1.
The number of surface-conduction electron-emitting devices installed in the device, the design shape of each device, and the conditions for holding the container in a vacuum when configuring a part of the container when using the electron source. It is set depending on the situation.

The m X-direction wirings 72 are DX1 and DX.
, ..., DXm, which is formed on the substrate 1 by a vacuum deposition method, a printing method, a sputtering method, or the like, and is made of a conductive metal or the like having a desired pattern, and is substantially equal to many surface conduction electron-emitting devices. The material, the film thickness, and the wiring width are set so that various voltages are supplied.

In addition, the Y-direction wiring 73 includes DY1, DY2,
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,. The material, film thickness, wiring width, etc. are set so that a substantially uniform voltage is supplied to the electron-emitting device.

An interlayer insulating layer (not shown) is provided between the m X-direction wirings 72 and the n Y-direction wirings 73, and they are electrically separated to form a matrix wiring. Here, both m and n are positive integers.

The interlayer insulating layer (not shown) is SiO ₂ or the like formed by a vacuum evaporation method, a printing method, a sputtering method or the like, and X
The whole or a part of the substrate 1 on which the directional wiring 72 is formed is formed in a desired shape, and in particular, the X-directional wiring 72 and the Y-directional wiring 7 are formed.
In order to withstand the potential difference at the intersection of 3, the film thickness, material,
The manufacturing method is appropriately set, and the X-direction wiring 72 and the Y-direction wiring 73
In some cases, the wiring 75 and the X-direction wiring 72 or the Y-direction wiring 73 can be electrically connected without passing through the contact holes. The X-direction wiring 72 and the Y-direction wiring 73 are drawn out as external terminals.

Although an example in which n Y-direction wirings 73 are provided on the m X-direction wirings 72 with an interlayer insulating layer interposed therebetween has been described, m on the N Y-direction wirings 73 The X-direction wiring 72 of a book may be installed via an interlayer insulating layer. Further, the interlayer insulating layer may be a part or the whole of the material for forming the step portion of the vertical surface conduction electron-emitting device described above.

Further, in the same manner as described above, the electron electrodes (not shown) of the surface conduction electron-emitting device 74 facing each other are m number of X-direction wirings (DX1, DX2, ..., DXm) 72 and n.
Book Y direction wiring (DY1, DY2, ..., DYn) 73
And a wire 75 made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like.

Here, m X-direction wirings 72 and n Y-direction wirings are provided.
The conductive metal forming the directional wiring 73, the connection 75, and the opposing element electrode may be the same or different in some or all of their constituent elements. For example, Ni, Cr, Au, Mo, W, Pt, Ti, Al,
Metals or alloys such as Cu, Pd and Pd, Ag, Au, R
A printed conductor composed of glass or the like, such as uO ₂ , Pd-Ag or other metal or metal oxide, In ₂ O ₃ -SnO ₂
And the like, and a semiconductor material such as polysilicon and the like. The surface conduction electron-emitting device may be formed either on the substrate 1 or on an interlayer insulating layer (not shown).

As will be described later in detail, the X-direction wiring 7
2 is a surface conduction electron-emitting device 74 arranged in the X direction.
X-direction wiring 7 in order to scan the row of
A scanning signal applying means (not shown) for applying a scanning signal to 2 is electrically connected. On the other hand, in the Y-direction wiring 73, in order to modulate each row of the surface conduction electron-emitting devices 74 arranged in the Y-direction according to the input signal, there is a defect for applying a modulation signal to the Y-direction wiring 73. The modulation signal generating means shown in the drawing is electrically connected. Further, the drive voltage applied to each of the plurality of surface conduction electron-emitting devices is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

Next, an image forming apparatus using the electron source created as described above and used for display or the like will be described with reference to FIGS. 8 and 9. 8 is a basic configuration diagram of the image forming apparatus, and FIG. 9 is a diagram showing a fluorescent film.

In FIG. 8, 1 is an electron source substrate in which the electron-emitting device is manufactured as described above, 81 is a rear plate to which the electron source substrate 1 is fixed, and 86 is a fluorescent film 84 and a metal back on the inner surface of the glass substrate 83. A rear face plate 8 is formed with a face plate 85 and the like, and a support frame 82.
1. The support frame 82 and the face plate 86 are sealed by applying frit glass or the like on their joint surfaces and firing them in the atmosphere or in nitrogen at 400 to 500 ° C. for 10 minutes or more, The envelope 88 is configured. Note that FIG.
In FIG. 1, 74 corresponds to the electron emitting portion in FIG. 1, and 72 and 73 are X-direction wiring and Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device. Here, the wirings connected to these element electrodes may be referred to as element electrodes when they are made of the same material as the element electrodes.

The envelope 88 has the face plate 86, the support frame 82, and the rear plate 81 as described above.
However, since the rear plate 81 is provided mainly for the purpose of reinforcing the strength of the substrate 1, if the substrate 1 itself has sufficient strength, the separate rear plate 81 is unnecessary.
The support frame 82 is directly sealed to the substrate 1, and the face plate 8
The envelope 88 may be composed of 6, the support frame 82, and the substrate 1.

Next, FIG. 9 is a view showing a fluorescent film. The fluorescent film 84 of FIG. 8 is composed of only the phosphors in the case of monochrome, but in the case of a color fluorescent film, it depends on the arrangement of the phosphors. It is composed of a black conductive material 91 called a black stripe or a so-called black matrix and a phosphor 92.

The purpose of providing such a black stripe or black matrix is to make the color mixture of the three primary color phosphors, which is necessary in the case of color display, separate between the phosphors 92 so as to make color mixing inconspicuous. That is, the reduction in contrast due to external light reflection on the fluorescent film 84 is suppressed.

The material for the black stripe is not limited to the commonly used material containing graphite as a main component, but is also limited to this material as long as it is electrically conductive and has little light transmission and reflection. Absent.

The method of applying the phosphor to the glass substrate 83 is not limited to monochrome or color, but 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, and the purpose of the metal back is to allow the light emitted from the phosphor toward the inner surface side to face plate 86.
To improve brightness by specular reflection to the side, to act as an electrode for applying an electron beam accelerating voltage, to protect the phosphor from damage due to collision of negative ions generated in the envelope, etc. . The metal back can be manufactured by performing smoothing treatment (normally called filming) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like.

Further, the face plate 86 is further provided with
In order to enhance the conductivity of the fluorescent film 84, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 84.

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

The envelope 88 is 1 through an exhaust pipe (not shown).
A vacuum of about 0 to the 6th power of Torr is applied to the envelope 8
8 is sealed. At this time, through an exhaust pipe (not shown), a normal vacuum system such as a rotary pump or a turbo pump is used in a vacuum of about 10 <-6> torr outside the container terminal D _0. × 1
Through D ₀ × m and _{D 0 y1~D} 0 yn, a voltage is applied between the device electrodes, subjected to the forming process described above,
An electron emitting portion is formed to produce a surface conduction electron emitting device. However, in the case of a surface conduction electron-emitting device which is a particularly preferable surface conduction electron-emitting device in the present invention, when the above-mentioned device current If and emission current Ie exhibit a monotonically increasing characteristic (MI characteristic), for example, After the forming process, while performing baking at 80 ° C. to 150 ° C. for 3 to 15 hours, a process such as switching to an ultrahigh vacuum device system such as an ion pump is added.

Further, in order to maintain the degree of vacuum after the envelope 88 is sealed, a getter process may be performed. this is,
Immediately before or after sealing the envelope 88, a getter arranged at a predetermined position (not shown) in the envelope 88 is heated by a heating method such as resistance heating or high-frequency heating to form a vapor deposition film. Is a process for forming. Getter is usually Ba
Etc. are the main components, and the vacuum degree of 1 × 10 minac 5 to 1 × 10 minus 7 torr is maintained by the adsorption action of the deposited film.

In the image forming apparatus of the present invention completed as described above, each electron-emitting device has a terminal D ₀ ×
1 to D ₀ × _m, through D ₀ y1~D 0 yn, then the electron emission by applying a voltage, through the high voltage terminal Hv, the metal back 85 or a transparent electrode (not shown) applies a high voltage of several kV The image is displayed by accelerating the electron beam, causing it to collide with the fluorescent film 84, and exciting and emitting light.

The configuration described above is a schematic configuration necessary for producing a suitable image forming apparatus used for display and the like, and the detailed parts such as the material of each member are not limited to those described above. , Is appropriately selected to suit the application of the image forming apparatus.

Next, an embodiment of the driving method of the electron source and the image forming apparatus of the present invention will be described.

According to the first driving method of the present invention,
The means for applying the scanning signal (also referred to as selecting means) is
V1 [V] for the wiring arbitrarily selected from the m wirings in the X direction, and V2 [V] for the remaining wirings.
The surface conduction electron-emitting device connected to the wiring to which V1 [V] is applied is selectively scanned by applying the voltage (1) (V1 [V] and V2 [V] are different from each other). Further, the modulation signal generating means generates a pulsed voltage having a constant length with respect to the n number of Y-direction wirings.
For example, the brightness of the display image is modulated by changing the voltage peak value (called Vm [V]) of the pulse according to the brightness level of the original image signal.

More specifically, the absolute value of the drive voltage Vm-V1 [V] applied to the N electron-emitting devices being scanned uses the relationship between Vf and Ie of the electron-emitting devices described above. And is controlled so that an electron beam having a desired intensity is output according to the brightness level of the original image signal.

On the other hand, the absolute value of the drive voltage Vm [V] -V2 [V] applied to the electron emitters that are not scanned is
It is controlled so as not to exceed the absolute value of the threshold voltage Vth of the electron-emitting device described above. Therefore, the electron beam having a desired intensity is output for a certain period only from the electron emitting element which is being scanned, and the electron beam is not output from the electron emitting element which is not being scanned.

Further, according to the second driving method of the present invention, the means for applying the scanning signal is V3 for the wiring arbitrarily selected from the m wirings in the X direction.
By applying a voltage of V4 [V] to the remaining wiring [V], the surface conduction electron-emitting device connected to the wiring to which V3 [V] is applied is selectively scanned. (V3 [V] and V4 [V] are different from each other).

Further, the modulation signal generating means has a constant crest value (referred to as Vp [V]) with respect to the N wirings in the Y direction.
Is generated by changing the pulse length (referred to as Pw [S]) according to the luminance level of the original image signal corresponding to each of N pulses. The brightness of a display image is modulated.

More specifically, the absolute value of the drive voltage Vp-V3 [V] applied to the scanned N electron-emitting devices is the absolute value of the threshold voltage Vth of the electron-emitting devices described above. By individually modulating the pulse length Pw [S], it is controlled so that electrons having a desired charge amount according to the brightness level of each input signal, for example, the original image signal are output. It

On the other hand, the absolute value of the drive voltage Vp-V4 [V] applied to the unscanned electron-emitting device is controlled so as not to exceed the absolute value of the threshold voltage Vth of the electron-emitting device. Therefore, electrons having a desired charge amount are output only from the electron-emitting devices that are being scanned, and electron beams are not output from the electron-emitting devices that are not being scanned.

Further, according to the third driving method of the present invention, the means for applying the scanning signal is V5 for the wiring selected arbitrarily among the M wirings in the X direction.
By applying a voltage of V6 [V] to the remaining wiring [V], the surface conduction electron-emitting device connected to the wiring to which V5 [V] is applied is selectively scanned. (Here, between V5 [V] and V6 [V], V5-
V6 = A certain condition needs to be satisfied. ).

The modulation signal generating means is for generating a pulsed voltage for the N Y-direction wirings, and depending on the brightness level of the original image signal corresponding to each of the N wirings. The brightness of the display image is modulated by changing the pulse application timing or the voltage peak value or both (here, the pulse application timing is the pulse length or the pulse for the scanning signal). Of phase, or both.)

More specifically, the driving voltage applied to the scanning N electron-emitting devices is a voltage pulse whose pulse length and peak value are both modulated, and is emitted during the scanning period of the device. The charge integration amount of the generated electrons is controlled to be an amount according to the input signal, for example, the brightness level of the original image.

On the other hand, the drive voltage applied to the unscanned electron-emitting device is controlled so as not to exceed the threshold voltage Vth of the electron-emitting device during the scanning period of the device. Therefore, electrons having a desired charge amount are output only from the electron-emitting devices that are being scanned, and electron beams are not output from the electron-emitting devices that are not being scanned.

As described above, the basic characteristics of the surface conduction electron-emitting device, that is, the device current If and the electron emission current I
According to the electron source and the image forming apparatus of the present invention, both of which show a monotonically increasing characteristic with respect to the voltage applied to the element, in the three driving methods according to the present invention, the electron emitting element that is not scanned is Although the electron beam is not output, the electron emission current Ie shows a monotonically increasing characteristic with respect to the voltage applied to the element, but when the element current If shows the VCNR characteristic, the electron emitting element which is not scanned shows May output an electron beam. This is the drive voltage Vm [V] −V2 applied to the electron-emitting device which is not scanned.
It is estimated that the state of the surface conduction electron-emitting device changed during the application of [V] and exceeded the absolute value of the threshold voltage Vth of the electron-emitting device described above.

Next, an example of the embodiment of the division driving method of the electron source and the image forming apparatus of the present invention will be described.

As shown in FIG. 10, a plurality of electron-emitting devices A
Linear electron-emitting devices _(X 1, _{X 2,} ...) with a, in a device modulation electrodes _(Y 1, _{Y 2,} ...) and are arranged in XY matrix (matrix), a plurality of lines electronic A voltage Vf necessary for electron emission is applied to any one row of the emission elements (X ₁ , X ₂ , ...) And the one row of information signals is applied to the modulation electrode group (Y ₁ , Y ₂ , ...). A corresponding voltage is applied to form an electron beam emission pattern corresponding to the information signal for one column. Such an operation is sequentially performed for each column of the above-mentioned electron beam emitting devices, and an electron beam emitting pattern for one screen and further for multiple screens is formed. Further, by irradiating the surface of the image forming member with the electron beam having the emission pattern, an image for one screen or even for multiple screens is formed on the surface of the image forming member.

Here, in the driving method of the present invention, when a voltage is applied to the modulation electrode group (Y ₁ , Y ₂ , ...) According to the information signal, a modulation electrode (for example, Y ₂ ) to which an ON voltage is applied is applied. ) Adjacent to the modulation electrodes (Y ₁ , Y ₃
) Is applied with a cutoff voltage regardless of the information signal. As a result, the modulation electrodes Y ₁ and Y ₃ are maintained at a constant potential.

By adopting such a driving method, the electron beam flying to the image forming member due to the ON voltage is not adversely affected by the voltage applied to the adjacent modulation electrode array as described above. Also, crosstalk between electron beams is eliminated.

To give an example of the driving method of the present invention, the input of the information signal to the modulation electrode group is divided into n + 1 columns every n columns (n ≧ 1) of the modulation electrode and temporally divided. This is a driving method in which the cut-off signal is input to the modulation electrode to which the information signal has not been input.

In FIG. 10, an input signal is input into the even-numbered column and the odd-numbered column of the modulation electrode group (Y ₁ , Y ₂ , ...) In two times, and is input to the modulation electrode to which no input signal is input at each time. Is input with a cutoff signal. For example, the voltage Vf required for electron emission is applied to the X ₁ column of the line electron emission device,
Input of the information signal to the modulation electrode group (Y ₁ , Y ₂ , Y ₃ ...) is 1) First, the modulation electrodes Y ₁ , Y ₃ , Y ₅
Column information signal, the modulation electrodes _{Y 2,} Y 4, _{Y 6} columns is input cutoff signal, respectively, then, 2) modulation electrodes _{Y 2,} Y 4, information signals to _{Y 6} rows, modulation electrode Cutoff signals are input to the Y ₁ , Y ₃ , and Y ₅ columns, respectively, to form an electron beam emission pattern according to the information signal for the X ₁ column. Such an operation is sequentially performed for each line electron emission element row, and an electron beam emission pattern for one screen and further for multiple screens is formed. Further, by irradiating the surface of the image forming member with the electron beam having the emission pattern, images for one screen and for multiple screens are formed on the surface of the image forming member.

Here, in order to efficiently irradiate the surface of the image forming member with the electron beam of the emission pattern from the electron source,
An appropriate voltage is applied to the image forming member, and the magnitude of the voltage is appropriately selected depending on the magnitudes of the on-voltage and cut-off voltage and the type of electron-emitting device used.

The information signal (modulation signal) is an ON signal, that is, a voltage signal that allows the electron beam to irradiate the image forming member with a certain amount or more, and the cutoff signal, that is, the electron beam image formation. A voltage signal capable of preventing irradiation of a member, but in the case of expressing a gradation of an image, it further includes a gradation signal, that is, a voltage signal for changing the irradiation amount of the electron beam to the image forming member. The ON signal and the cutoff signal are appropriately set depending on the type of electron-emitting device used, the magnitude of the voltage applied to the image forming member, and the like.

Further, regarding the constitution of the electron source and the image forming apparatus driven by the driving method of the present invention, for example,
A color display image forming member in which red (R), green (G), and blue (B) phosphors are arranged as the image forming member may be used.

The number of divisions in the driving method of the present invention is not limited to the two divisions shown in FIG. 10, but may be set appropriately.

Although the cutoff signal is input to the modulation electrode adjacent to the modulation electrode to which the input signal is input, when the cutoff signal is not input, the time allowed per element is equal to the number of divisions. Another effect of increasing the number and sufficient electron emission can be expected.

In this case, instead of Y ₁ , Y ₂ , ..., X ₁ , X ₂ ,.

Next, the electron source and image forming apparatus of the present invention will be described below with reference to an embodiment in which a higher quality image can be obtained.

FIG. 11 shows a schematic structure and an electron beam corresponding to one pixel of the image forming apparatus shown in FIG. 8 described above, which uses an electron source in which a plurality of surface conduction electron-emitting devices are arranged in a matrix. It is a figure which shows the flight state of.

In the figure, 1 is a substrate, 5 is a high-potential side element electrode, and 6 is a low-potential side element electrode. These are formed on the substrate 1 with a narrow gap. An electron emitting portion 3 is formed from a thin film to form a surface conduction electron-emitting device, and further, an image display device is formed by a face plate 86 arranged to face the device substrate.

The face plate 86 is the glass plate 8
3, a metal back 85, and an image forming member 84 (here, a phosphor), and they are placed above the substrate 1 at a distance H.

In the above structure, when the voltage Vf is applied between the element electrodes 5 and 6 by the element driving power source 10, electrons are emitted from the electron emitting portion 3 and the electron beam accelerating power source 11 is emitted.
By the acceleration voltage Va applied to the phosphor 84 through the metal back 85 from the above, the electrons are accelerated and collide with the phosphor 84 to emit light to form the bright spot 9 on the face plate 86.

FIG. 12 is an enlarged schematic view of the bright spot 9 of the phosphor observed by the present inventors in the device as shown in FIG.

As shown in FIG. 12, it was confirmed that the entire bright spots of the phosphor had a certain spread in the direction (X direction in the drawing) of voltage application to the device electrodes and in the direction (Y direction) perpendicular thereto. Was done.

The reason why such a bright spot is formed, that is,
The reason why the electron beam reaches the image forming member with a certain spread is not clear because the electron emission mechanism of the surface conduction electron-emitting device has not been completely clarified. It is thought that from the experiment, electrons with initial velocity are emitted so as to be scattered in all directions.

Further, among the electrons emitted in all directions, the present inventors found that the electrons emitted in the direction of the high potential side element electrode (X plus direction in the figure) reach the tip portion 18 of the bright spot, The electrons having an angular distribution with respect to the substrate surface are emitted such that the electrons emitted in the direction of the low potential side element electrode (X minus direction in the drawing) reach the tail portion 19 of the bright spot. We believe that a bright spot with a wide area can be obtained. However, since the brightness of the tail portion of the bright spot was lower than that of the other portions, it is presumed that the amount of electrons emitted toward the low potential side element electrode is very small.

Further, according to the experiments by the present inventors, FIG.
Further, in FIG. 12, it was found that the bright spot 9 is displaced from the vertically upper side of the electron emitting portion 3 in the X plus direction, that is, toward the high potential side element electrode 5.

This is because the potential distribution in the space on the surface conduction electron-emitting device is such that the equipotential surface becomes parallel to the surface of the image forming member 85 in the vicinity of the electron-emitting portion 3 as shown in FIG. The inventors believe that the emitted electrons are not only accelerated by the accelerating voltage Va and fly in the Z direction in the drawing but also accelerated in the high potential side element electrode 5 because they are not emitted.

That is, it is considered that it is inevitable that the electrons are subjected to the deflection action immediately after the electrons are emitted due to the applied voltage Vf required for emitting the electrons.

Therefore, the inventors of the present invention have studied in detail the shape and size of the bright spot 9, the value of the position shift from the vertically upper side of the electron emitting portion 3 in the X direction, and the like, and have determined the shift amount to the tip of the bright spot. (Fig. 1
(ΔX1 in 1) and the amount of deviation to the bright spot tail (Δ in FIG. 11
An attempt was made to express X2) using Va, Vf, and H as parameters.

According to the equation of motion of charged particles, there is a target to which a voltage of Va (V) is applied at a distance H (Z direction) above the electron source, and when a uniform electric field exists between the electron source and the target, The electrons emitted at the initial velocity V (eV) in the X direction and at the initial velocity 0 in the Z direction reach the target in the X direction.

[0149]

[Outer 1] Only will be displaced.

In the experiment conducted by the present inventors, the electric field is curved near the electron-emitting portion as shown in FIG. 13 due to the influence of the voltage applied between the device electrodes, and the electrons are also emitted in the X direction. Although accelerated, the voltage applied to the image forming member is sufficiently higher than the voltage applied to the electron-emitting device, so that the electrons are accelerated in the X direction only near the electron-emitting portion,
After that, the velocity in the X direction is considered to be almost constant, so
It is considered that if the velocity after being accelerated in the X direction near the electron emitting portion is substituted for V in the equation (1), the shift of the electron beam in the X direction can be obtained.

Now, assuming that the velocity component in the X direction obtained after the electrons are accelerated in the X direction in the vicinity of the electron emitting portion is C (eV), C is considered to be a constant that changes depending on the value of the voltage Vf applied to the element. To be Then, C is a function of Vf and C (V
f) (unit is eV) and substituted into the equation (1),
The shift amount ΔX0 can be expressed by the following equation (2).

ΔX0 = 2H√ (C (Vf) / Va) (2) However, in the equation (2), the electrons emitted from the electron emitting portion at the initial velocity 0 in the X direction are in the element electrode near the electron emitting portion. It shows the amount of deviation when the velocity V (eV) in the X direction is reached due to the influence of the voltage Vf applied in between.

In fact, as described above, it is considered that the electrons emitted from the surface conduction electron-emitting device are emitted with an initial velocity in all directions, so the initial velocity is v0 (eV). Then, from the equation (1), the shift amount of the electron beam that is most deviated in the X direction is ΔX1 = 2H√ ((C + v0) / Va) (3) The shift amount of the electron beam that is the smallest in the X direction is It is considered that ΔX2 = 2H√ ((C−v0) / Va) (4).

Here, v0 is also considered to be a constant whose value changes depending on Vf which is the voltage energy applied to the electron emitting portion. Therefore, it can be said that both C and v0 have a relationship of Vf, so the constants K2 and K3 are set. It can be rewritten as follows: √ (C + v0) (Vf) = K2√Vf, √ (C−v0) (Vf) = K3√Vf.

When (3) and (4) are transformed using this, ΔX1 = K2 × 2H√ (Vf / Va) ... (5) ΔX2 = K3 × 2H√ (Vf / Va) ... (6) where H , Vf, Va are measurable quantities, and ΔX
1 and ΔX2 are also measurable quantities.

The present inventors have shown in FIG. 11 that H, V
By performing various experiments for measuring ΔX1 and ΔX2 while changing f and Va, the following values were obtained as the values of K2 and K3.

K2 = 1.25 ± 0.05 K3 = 0.35 ± 0.05 This holds particularly well when the intensity (Va / H) of the accelerating electric field is 1 kV / mm or more.

Based on the above knowledge, the size of the electron beam spot on the image forming member surface in the voltage application direction (X direction) to the electron-emitting device (X direction) (S1) is S1 = ΔX
It is easily obtained as 1-ΔX2.

If K1 = K2-K3 is set (5), (6)
From the formula, S1 = K1 × 2H√ (Vf / Va) (7) However, 0.8 ≦ K1 ≦ 1.0.

Next, considering the spot size in the direction perpendicular to the direction of voltage application to the electron-emitting device, as described above,
The direction perpendicular to the direction of voltage application to the electron-emitting device (Fig. 11Y
Direction), the electron beam is considered to be emitted at the initial velocity v0, but as can be seen from the figure, the electron beam is hardly accelerated in the Y direction after emission.

Therefore, the amount of displacement of the electron beam in the Y direction is
It is considered that ΔY = 2H√ (v0 / Va) (8) in both the Y plus direction and the Y minus direction.

From the expressions (3) and (4), √ ((ΔX1 ² -ΔX2 ² ) / 2) = 2H√ (v0 / Va) (9) Further, from the expressions (5) and (6), √ ( (ΔX1 ² −ΔX2 ² ) / 2) = 2H√ (Vf / Va) × √ ((K2 ² −K3 ² ) / 2) (10) Comparing equations (9) and (10), 2H√ ( v0 / Va) = 2H√ (Vf / Va) × √ ((K2 ² −K3 ² ) / 2) (11) Therefore, √ ((K2 ² −K3 ² ) / on the right side of the equation (11)
If 2) = K4 is set, the size of the electron beam spot on the image forming member surface in the Y direction (S2) can be expressed by the following equation, where the length of the electron emitting portion in the Y direction is L.

S2 = L + 2ΔY = L + 2K4 × 2H√ (Vf / Va) (12) Since H, Vf, Va, and L can be measured in the form of formula (12), S2 is experimentally measured. , Coefficient K
The value of 4 is decided, but K2 = 1.25 ± 0.05, K
From the definition of 3 = 0.35 ± 0.05 and K4, 0.08 ≦ K4 ≦ 0.09. This is in good agreement with the value obtained from the experiment for finding the spot size in the Y direction.

Further, the inventors of the present invention considered the relationship of the electron beams emitted from the plurality of electron emitting portions on the surface of the image forming member based on the relational expressions obtained above.

In the structure shown in FIG. 11, the emitted electrons are asymmetric with respect to the X axis as shown in FIG. 12 due to the curvature of the electric field near the element electrode (FIG. 13), the influence of the electrode edge, and the like. Reaches the surface of the image forming member in a uniform shape.

Distortion of the spot shape or asymmetry causes a reduction in the resolution of the image. In particular, when displaying characters, the discriminability of the characters decreases, and even in the case of a moving image, the image quality is poor and a clear image is obtained. Can't get

In this case, the shape of the bright spot is asymmetric with respect to the X axis, but it is clear from equations (5) and (6) how much the tip portion to the tail portion deviates from the vertical upper side of the electron emitting portion. If the plurality of electron emitting portions are arranged at a distance D represented by the following formula (13) in the voltage applying direction, the present inventors can obtain an image of an electron beam emitted from the plurality of electron emitting portions. It was found that a bright spot shape with good symmetry can be obtained by overlapping one on the surface of the forming member.

K2 × 2H√ (Vf / Va) ≧ D / 2 ≧ K3 × 2H√ (Vf / Va) (13) However, K2 and K3 are constants K2 = 1.25 ± 0.05 K3 = 0. 35 ± 0.05 Also in the direction (Y direction) perpendicular to the voltage application direction, from the above description, the bright spots due to the electrons emitted from the electron emitting portion having the length L in the Y direction are continuous in the Y direction. When it is necessary that the arrangement pitch P of the electron-emitting devices in the Y direction is
Should satisfy the following formula (14).

P <L + 2K5 × 2H√ (Vf / Va) (14) However, K5 = 0.80 On the contrary, the bright points due to the electrons emitted from the electron emitting portion having the length L in the Y direction are discontinuous in the Y direction. If it is necessary to set the array pitch P of the electron-emitting devices in the Y direction as follows (1
It suffices to satisfy the expression (5).

P ≧ L + 2K6 × 2H√ (Vf / Va) (15) However, K6 = 0.90 Further, according to the idea of the present invention, the image forming apparatus is not limited to a suitable image forming apparatus used for display, and it is not limited to photosensitive. The image forming apparatus described above can also be used as an alternative light source such as a light emitting diode of an optical printer including a sex drum and a light emitting diode. At this time, by appropriately selecting the above-mentioned 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.

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

[0172]

【Example】

(Embodiment 1) This embodiment relates to an electron source and an image forming apparatus of the present invention, in which a large number of plane type surface conduction electron-emitting devices are formed on an interlayer insulating layer, and device electrodes, X-direction wiring and Y-direction wiring are formed. Further, it is an example showing a case in which the material forming each of the connection lines connecting the element electrode and the wiring is the same or a part of the elements forming the material is the same.

A plan view of a part of the electron source is shown in FIG. 15 is a sectional view taken along the line AA 'in FIG. 15, and FIGS. 16 and 17 are diagrams showing the manufacturing method thereof. However, in FIG.
4, FIG. 15, and FIG. 16 that have the same symbols indicate the same things.

Here, 1 is a substrate, 72 is an X-direction wiring (also referred to as a lower wiring) corresponding to DXm in FIG. 7, and 73 is D in FIG.
Y direction wiring corresponding to Yn (also referred to as upper wiring), 4 is a thin film including an electron emitting portion, 5 and 6 are element electrodes, 111 is an interlayer insulating layer, 112 is an electrical connection between the element electrode 5 and the lower wiring 72. For contact holes.

Next, the manufacturing method will be concretely described in the order of steps with reference to FIGS.

Step-a: Cr having a thickness of 50 Å and 6000 Å having a thickness of 6000 Å was formed on a substrate 1 in which a silicon oxide film having a thickness of 0.5 μm was formed on a cleaned blue plate glass by a sputtering method by vacuum deposition. After sequentially stacking Au, a photoresist (AZ1370 Hoechst) is spin-coated by a spinner and baked, and then a photomask image is exposed and developed to form a resist pattern of the lower wiring 72, and an Au / Cr deposited film is wet. Etching is performed to form the lower wiring 72 having a desired shape ((a) of FIG. 16).

Step-b: Next, an interlayer insulating layer 111 made of a silicon oxide film having a thickness of 1.0 micron is deposited by the RF sputtering method (FIG. 16B).

Step-c: A photoresist pattern for forming the contact hole 112 is formed in the silicon oxide film deposited in the step b, and the interlayer insulating layer 111 is etched by using this as a mask to form the contact hole 112 ( FIG. 16C).

The etching was performed by RIE (Reactive Ion Etchin) using CF4 and H2 gas.
g) According to the method.

Step-d: Thereafter, the device electrodes 5 and the pattern to be the gap G between the device electrodes are formed into a photoresist (R).
D-2000N-41 (manufactured by Hitachi Chemical Co., Ltd.) and formed by vacuum vapor deposition to have a Ti of 50 Å and a thickness of 1
000 Å of Ni was sequentially deposited. The photoresist pattern was dissolved in an organic solvent, the Ni / Ti deposition film was lifted off, the device electrode spacing G was set to 3 μm, and the device electrodes 5 and 6 were formed so that the device electrode width W1 was 300 μm (FIG. 16). (D)).

Step-e: Upper wiring 7 on the device electrodes 5 and 6
After forming the photoresist pattern No. 3, Ti having a thickness of 50 Å and Au having a thickness of 5000 Å were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form the upper wiring 73 having a desired shape. ((E) of FIG. 17).

Step-f FIG. 18 shows a part of a plan view of the mask of the thin film 2 for forming the electron-emitting portion of the electron-emitting device relating to this step. A mask having an inter-element electrode gap L1 and an opening in the vicinity thereof, and a Cr film 121 having a film thickness of 1000 angstrom is deposited and patterned by vacuum vapor deposition by this mask,
Organic Pd (ccp4230 manufactured by Okuno Seiyaku Co., Ltd.) was spin-coated thereon with a spinner and heated and baked at 300 ° C. for 10 minutes ((f) in FIG. 17).

The thus-formed thin film 2 for forming an electron-emitting portion, which is composed of fine particles of Pd as a main element, has a film thickness of 100 Å and a sheet resistance value of 5 × 1.
It was 0 to the 4th power Ω / □. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated as described above, and as a fine structure thereof, not only the fine particles are individually dispersed and arranged, but also the fine particles are adjacent to each other or overlap each other. The state of the film (including an island shape) refers to the diameter of the fine particles whose particle shape is recognizable in the above state.

Step-g: The Cr film 121 and the electron emission part forming thin film 2 after firing were etched with an acid etchant to form a desired pattern ((g) of FIG. 17).

Step-h: A pattern is formed such that a resist is applied to a portion other than the contact hole 112 portion, and Ti having a thickness of 50 Å and a thickness of 50 are formed by vacuum evaporation.
00 angstroms of Au were sequentially deposited. Contact holes 112 were buried by removing unnecessary portions by lift-off (FIG. 17 (h)).

Through the above steps, the lower wiring 72, the interlayer insulating layer 111, the upper wiring 73, the element electrode 5,
6. The electron emission part forming thin film 2 was formed.

Next, an example in which a display device is configured by using the electron source created as described above will be described with reference to FIGS. 8 and 9.

After fixing the substrate 1 on which a large number of plane type surface conduction electron-emitting devices were manufactured as described above on the rear plate 81, the face plate 86 (on the inner surface of the glass substrate 83) was placed 5 mm above the substrate 1. (A fluorescent film 84 and a metal back 85 are formed) are arranged via a support frame 82, and frit glass is applied to a joint portion of the face plate 86, the support frame 82, and the rear plate 81, and the frit glass is applied in the atmosphere.
It was sealed by baking at 10 ° C. for 10 minutes (FIG. 8).

Further, the frit glass was also used to fix the substrate 1 to the rear plate 81. In FIG. 8, 74 is an electron-emitting device, and 72 and 73 are device wirings in the X and Y directions, respectively.

In the case of monochrome, the fluorescent film 84 is composed of only the fluorescent material, but in this embodiment, the fluorescent material adopts a stripe shape, a black stripe is first formed, and the fluorescent material of each color is applied to the gap. A fluorescent film 84 was produced. Here, as the material of the black stripe, a material which is often used and whose main component is graphite is used. A slurry method was used to apply the phosphor to the glass substrate 83.

Further, a metal back 85 is usually provided on the inner surface side of the fluorescent film 84. This metal back was produced by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after producing the fluorescent film, and then vacuum depositing Al.

The face plate 86 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 84 in order to further enhance the conductivity of the fluorescent film 84, but in this embodiment, a metal back is used. Since sufficient conductivity was obtained only by itself, it was omitted.

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

[0194] evacuated at above in the atmosphere in the glass container completed exhaust pipe (not shown) of the through vacuum pump, after reaching a sufficient degree of vacuum, vessel terminals Dx ₀ 1 to D
₀ xm and by applying the D ₀ y1~D ₀ through yn voltage between the device electrodes of the electron-emitting device 74, the electron emitting portion, was prepared by the thin film for electron-emitting region to energization process (forming process). FIG. 4 shows the voltage waveform of the forming process.

In FIG. 4, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this embodiment, T1 is 1 millisecond,
T2 was 10 milliseconds, the peak value of the triangular wave (peak voltage during forming) was 10 V, and the forming treatment was performed for 60 seconds in a vacuum atmosphere of about 1 × 10 −6 torr.

In the electron-emitting portion thus produced, fine particles containing palladium as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30 Å.

Next, the exhaust pipe (not shown) was heated by a gas burner at a vacuum degree of about 10 <-6> torr to weld and seal the envelope.

Finally, in order to maintain the degree of vacuum after sealing,
Getter processing was performed by the high frequency heating method.

In the image display device of the present invention completed as described above, each of the electron-emitting devices has a terminal Dx1 outside the container.
Electrons are emitted by applying a scanning signal and a modulation signal from a signal generating means (not shown) through Dxm and Dy1 to Dyn, and a high voltage of 5 kV is applied to the metal back 85 through the high voltage terminal Hv to accelerate the electron beam. Then, the image was displayed by causing it to collide with the fluorescent film 84 to excite and emit light.

Further, in order to understand the characteristics of the flat surface-conduction type electron-emitting device manufactured in the above process, at the same time, L1 and W of the flat surface-conduction type electron-emitting device shown in FIG.
A standard comparative sample in which 1, 1, W2 and the like were the same was prepared, and the electron emission characteristics of the standard comparative sample were measured using the above-described normal vacuum apparatus measurement and evaluation apparatus of FIG. The measurement conditions of the comparative sample were as follows: the distance between the anode electrode and the electron-emitting device was 4 mm, the potential of the anode electrode was 1 kV, and the degree of vacuum in the vacuum device at the time of measuring the electron-emitting characteristics was 1 × 10 −6 torr. . Further, the sweep speed of the voltage applied to the device was set to about 1 V / sec in which both the device current If and the electron emission current Ie monotonically increased.

When a device voltage was applied between the electrodes 5 and 6 of the comparative sample and the device current If and the emission current Ie flowing at that time were measured, the current-voltage characteristics as shown in FIG. 5 were obtained ( (Fig. 19). In addition, in this element, as shown in FIG.
As shown in, the emission current I rapidly increases from the device voltage of about 8V.
e increases, and the device current If is 2.2 at a device voltage of 14V.
mA, emission current Ie was 1.1 microA, and electron emission efficiency η = Ie / If × 100 (%) was 0.05%. In the embodiment, as described above, the characteristics of the element change depending on the measurement conditions, the conditions of the vacuum apparatus, etc. Therefore, these conditions were measured to be as constant as possible.

(Embodiment 2) This embodiment relates to an electron source and an image forming apparatus of the present invention, in which a large number of vertical surface conduction electron-emitting devices are formed on a substrate, and an X-direction wiring and a Y-direction wiring are formed. The interlayer insulating layer also serves as a step forming portion of the vertical surface conduction electron-emitting device, and constitutes each of the device electrode, the X-direction wiring, the Y-direction wiring, and the connection connecting the device electrode and the wiring. Is an example showing the case where the same material or some of its constituent elements are the same.

A plan view of a part of the electron source is omitted because it is roughly the same as FIG. 20 is a sectional view taken along the line AA 'in FIG. However, in FIG. 20, the same symbols as those in the above-mentioned figures indicate the same symbols. Where 1 is the substrate, 72
7 is an X-direction wiring corresponding to Dxm in FIG. 7 (also referred to as an upper wiring here), 73 is a Y-direction wiring corresponding to Dyn in FIG. 7 (also referred to as a lower wiring here), and 4 includes an electron emitting portion. Thin films, 5 and 6 are device electrodes, and 111 is an interlayer insulating layer.

Next, the manufacturing method will be concretely described with reference to FIGS.

Step-a: Pd having a thickness of 5000 angstrom was laminated on the substrate 1 made of cleaned soda lime glass by vacuum evaporation, and then a photoresist (AZ1370) was used.
(Hoechst) is spin coated with a spinner and baked, and then a photomask image is exposed and developed, and wiring in the Y direction 7
A resist pattern of No. 3 is formed and the Pd film is etched to simultaneously form the Y-direction wiring 73 and the device electrode 5 having a desired shape ((a) of FIG. 21).

Step-b: Next, the X-direction wiring 72 and the Y-direction wiring 7 are formed of a silicon oxide film having a thickness of 1.5 μm.
3 and the interlayer insulating layer 111 which also serves as the step forming portion 67 of the vertical surface conduction electron-emitting device are deposited by RF sputtering (FIG. 21B).

Step-c: A photoresist pattern for forming the step forming portion 67 and the interlayer insulating layer 111 having a desired shape is formed on the silicon oxide film deposited in the step-b,
The interlayer insulating layer 111 is etched using this as a mask to form the step forming portion 67 and the interlayer insulating layer 111 having a desired shape.
Are formed ((c) of FIG. 21).

The etching is performed by RIE (Reactive Ion Etchin) using CF ₄ and H ₂ gas.
g) According to the method.

Step-d: After that, the device electrode 6 and the connection 7
The pattern which should become 5 is photoresist (RD-2000
N-41 manufactured by Hitachi Chemical Co., Ltd.), and Pd having a thickness of 1000 angstrom was deposited by a vacuum vapor deposition method. The photoresist pattern is dissolved in an organic solvent, the Pd deposition film is lifted off, the device electrode interval corresponding to the thickness of the step forming portion 67 becomes 1.5 microns, and the device electrode 6 facing the device electrode 5 has an electrode width of 500. Micron formed (Fig. 21)
(D)).

Step-e: In the same manner as in Example 1, a Cr film having a film thickness of 1000 angstrom was deposited and patterned by vacuum evaporation in a shape having the device electrodes 5 and 6 and openings in the vicinity thereof, and Organic Pd (ccp42
30 Okuno Seiyaku Co., Ltd.) was spin-coated with a spinner and heat-baked at 300 ° C. for 10 minutes to form an electron emission portion forming thin film 2.

The main element thus formed is Pd.
The electron emission part forming thin film 2 made of fine particles has a thickness of 150 Å and a sheet resistance value of 7 × 10 4
The power was Ω / □. Then, the Cr film and the thin film 2 for forming an electron emission portion after firing were wet-etched with an acid etchant to form a desired pattern ((e) in FIG. 21).

Step-f: An Ag-Pd conductor having a thickness of about 10 μm was printed on the device electrode 6 to form an X-direction wiring 72 having a desired shape ((f) in FIG. 21).

Through the above steps, the X direction wiring 72, the interlayer insulating layer 111, the Y direction wiring 73, the device electrodes 5 and 6, the electron emitting portion forming thin film 2 and the like were formed on the insulating substrate 1.

Next, a display device was constructed in the same manner as in Example 1 using the electron source created as described above.

At the same time, in order to understand the characteristics of the vertical type surface conduction electron-emitting device manufactured in the above-mentioned step, the device electrode interval, the electrode width, etc. of the vertical type surface conduction electron emission device are made similar. A standard comparative sample as shown in FIG. 6 was prepared, and its electron emission characteristics were measured in the same manner as in Example 1 using the above-described measurement / evaluation apparatus of FIG.

When a device voltage was applied between the electrodes 5 and 6 of the comparative sample and the device current If and the emission current Ie flowing at that time were measured, the current-voltage characteristics as shown in FIG. 5 were obtained). .

In this device, the emission current Ie rapidly increases from the device voltage of about 7.5 V, and the device current If is 2.5 mA and the emission current Ie is 1.2 microA at the device voltage of 14 V.
The electron emission efficiency η = Ie / If × 100 (%) was 0.048%.

In the image forming apparatus of the present invention completed as described above, as in the first embodiment, the scanning signal and the modulation signal are not shown in the drawing through the outside-container terminals Dx1 to Dxm and Dy1 to Dyn. Each of the signal generating means causes the electrons to be emitted by applying the high voltage terminal Hv.
Through this, a high voltage of several kV or more is applied to the metal back 85 to accelerate the electron beam so that the electron beam collides with the fluorescent film 84 to excite and emit light to display an image.

(Embodiment 3) This embodiment relates to an electron source and an image forming apparatus of the present invention, in which a large number of plane type surface conduction electron-emitting devices are formed on a substrate and an X direction wiring and a Y direction wiring are formed. The interlayer insulating layer is present only at the intersection of the X and Y direction wirings, the element electrodes are connected to the X direction wirings and the Y direction wirings without connecting via contact holes, and are electrically connected. It is an example when it is directly installed on the insulating substrate.

A plan view of a part of the electron source is shown in FIG.
23 is a sectional view taken along the line AA 'in FIG. However, the same symbols in FIGS. 22 and 23 represent the same items. Here, 1 is a substrate, 72 is an X-direction wiring (also referred to as an upper wiring here) corresponding to Dxm in FIG. 7, 73
Is a Y-direction wiring corresponding to Dyn in FIG. 7 (also referred to as a lower wiring here), 4 is a thin film including an electron emitting portion, 5 and 6 are device electrodes, 75 is a connection, and 3 is an electron emitting portion.

Next, the manufacturing method will be specifically described in the order of steps with reference to FIG.

Step-a: Cr having a thickness of 50 Å and Au having a thickness of 1000 Å were laminated on the substrate 1 made of cleaned soda lime glass by vacuum deposition, and a photoresist (made by AZ1370 Hoechst) was spinnered. After spin coating and baking, the photomask image is exposed and developed to form a resist pattern of the device electrodes 5 and 6, the connection 75, and the Y direction wiring 73, and the Au / Cr film is etched to obtain a desired shape in the Y direction. Wiring 73, device electrodes 5 and 6 (electrode width; 300 microns, device electrode interval; 2
Micron) and connection 75 are formed simultaneously ((a) of FIG. 24).

Step-b: Next, a Y-direction wiring 73 and an X-direction wiring 72 made of a silicon oxide film having a thickness of 1.0 micron.
An inter-layer insulating layer 111 is deposited by RF sputtering (FIG. 24B).

Step-c: A photoresist pattern for forming an interlayer insulating layer 111 having a desired shape provided only at the intersection of the Y-direction wiring 73 and the X-direction wiring 72 is formed in the silicon oxide film deposited in the step-b, Using this as a mask, the interlayer insulating layer 111 is etched to form the interlayer insulating layer 111 (FIG. 24C).

The etching is performed by RIE (Reactive Ion Etchin) using CF4 and H2 gas.
g) According to the method.

Step-d: After that, a pattern to be the X-direction wiring 72 is formed on the photoresist (RD-2000N-4).
1 made by Hitachi Chemical Co., Ltd.), and the thickness 5
000 Å of Au was deposited. After that, the photoresist pattern was dissolved with an organic solvent, and the Au deposited film was lifted off to form the X-direction wiring 72 ((d) of FIG. 24).

Step-e: In the same manner as in Example 1, a Cr film having a film thickness of 1000 angstrom was deposited and patterned by vacuum evaporation in a shape having openings in the device electrodes 5 and 6 and in the vicinity thereof, Organic Pd (ccp4
230 of Okuno Seiyaku Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 10 minutes.

The thus-formed electron-emitting-portion-forming thin film 2 composed of fine particles having Pd as a main element has a thickness of 7
The sheet resistance was 5 Å and the sheet resistance was 1 × 10 5 ohm / □.

Then, the Cr film and the thin film 2 for forming the electron emission portion after firing were wet-etched with an acid etchant to form a desired pattern ((e) in FIG. 24).

Through the above steps, the X-direction wiring 72, the interlayer insulating layer 111, the Y-direction wiring 73, the device electrodes 5 and 6, the electron emitting portion forming thin film 2 and the like were formed on the insulating substrate 1.

Next, using the electron source created as described above, a display device was constructed in the same manner as in Example 1.

At the same time, in order to grasp the characteristics of the flat surface-conduction type electron-emitting device manufactured in the above-mentioned steps, the device-electrode spacing, the device-electrode width, etc. of the above-mentioned flat-type surface-conduction type electron-emitting device are measured. A standard comparative sample was prepared in the same manner as above, and its electron emission characteristics were measured in the same manner as in Example 1 using the above-described measurement / evaluation apparatus of FIG.

When a device voltage was applied between the device electrodes 5 and 6 of the comparative sample and the device current If and the emission current Ie flowing at that time were measured, the current-voltage characteristics as shown in FIG. 5 were obtained. .

In this device, the emission current Ie rapidly increases from the device voltage of about 7.0 V, and the device current If is 2.1 mA and the emission current Ie is 1.0 microA at the device voltage of 14 V.
The electron emission efficiency η = Ie / If × 100 (%) was 0.05%.

In the image display device of the present invention completed as described above, as in the first embodiment, the scanning signal and the modulation signal are not shown in the drawing through the external terminals Dx1 to Dxm and Dy1 to Dyn of each electron emitting device. Each of the signal generating means causes the electrons to be emitted by applying the high voltage terminal Hv.
An image was displayed by applying a high voltage of several kV or more to the metal back 85 through the through, accelerating the electron beam, causing the electron beam to collide with the fluorescent film 84, and exciting and emitting light.

(Embodiment 4) This embodiment is an image forming apparatus of the present invention, which is a partial modification of the method of manufacturing an electron source of Embodiment 1, except that the first driving method and the second method of the present invention are used. This is an example in which the driving method is applied.

The present embodiment is the same as Embodiment 1 in the configuration and manufacturing method, and the subsequent forming, sealing of the envelope including the face plate, the support frame, the rear plate and the like is also performed. Similar to Example 1.
Up to this point, two devices have been created at the same time.

Next, a vacuum system is usually used to heat the exhaust pipe (not shown) with a gas burner while vacuuming at a vacuum of about 10 −6 Torr to seal the envelope. This device is referred to as display panel A.

On the other hand, in another apparatus, the apparatus was sandwiched from the face plate and rear plate sides with a hot plate-like heat source, the entire apparatus was maintained at about 120 degrees, and baking (heat treatment) was performed for 1 hour. Then, the vacuum system was changed to an ultrahigh vacuum system ion pump system, and vacuum exhaust was performed for 10 hours while heating similarly. After that, while drawing a vacuum, an exhaust pipe (not shown) was heated by a gas burner to be welded to seal the envelope. This device is hereinafter referred to as display panel B.

Finally, in order to maintain the degree of vacuum after sealing,
Both the display panel A and the display panel B were gettered by a resistance heating method.

Next, an electric circuit configuration for performing the display operation of the display panel A and the display panel B by applying the first and second driving methods of the image forming apparatus of the present invention will be exemplified below.

FIG. 25 relates to an embodiment of the first driving method and the second driving method of the present invention, and is a schematic configuration of a driving circuit for performing television display based on an NTSC television signal. Is shown as a block. Figure 25
The display panel 1701 is manufactured as described above.
It is the display panel A or the display panel B. Further, the scanning circuit 1702 scans the display line, and the control circuit 170
3 generates an input signal or the like to be input to the scanning circuit. The shift register 1704 shifts the data for each line, and the line memory 1705 stores the shift register 170.
The data for one line from the modulation signal generator 1707
To enter. The sync signal separation circuit 1706 separates the sync signal from the input signal NTSC signal.

Vx and Va are DC voltage sources.

The function of each part of the apparatus shown in FIG. 25 will be described in detail below.

First, the display panel 1701 is connected to an external electric circuit via the terminals Dx1 to Dxm, the terminals Dy1 to Dyn, and the high voltage terminal Hv. Of these, the display panel 17 is connected to the terminals Dx1 to Dxm.
01, a scanning signal for sequentially driving the multi-electron beam source, that is, the group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns in a matrix is sequentially applied row by row (n elements). It

On the other hand, a modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting devices of one row selected by the scanning signal is applied to the terminals Dy1 to Dyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 K [V] from the DC voltage source Va, which is sufficient to excite the phosphor into the electron beam output from the surface conduction electron-emitting device. It is an accelerating voltage for applying various energies.

Next, the scanning circuit 1702 will be described.

The circuit is provided internally with m switching elements (schematically shown by S1 to Sm in the figure), and each switching element has an output voltage of the DC voltage source Vx or 0 [ V] (ground level) is selected and electrically connected to the terminals Dx1 to Dxm of the display panel 1701. S1 to Sm
Although each of the switching elements operates in accordance with the control signal Tscan output from the control circuit 1703, it can actually be easily configured by combining switching elements such as EFT.

In the case of the present embodiment, the DC voltage source Vx is set to 7 [V] so that the driving voltage applied to the non-scanned element becomes equal to or lower than the electron emission threshold Vth voltage.
Is set so as to output a constant voltage (refer to FIG. 28 again).

The control circuit 1703 has a function of matching the operations of the respective parts so that an appropriate display is performed based on the image signal input from the outside. The sync signal T sent from the sync signal separation circuit 1706 described below
Based on sync, Tscan, Tsft, and Tmry control signals are generated for each unit. still,
The timing of each control signal will be described later in detail with reference to FIG.

The synchronizing signal separation circuit 1706 is a circuit for separating a synchronizing signal component and a luminance signal component from an externally input NTSC television signal, and as is well known, frequency separation (filter). It can be easily constructed by using a circuit. Sync signal separation circuit 1706
The sync signal separated by is composed of a vertical sync signal and a horizontal sync signal as is well known, but is shown as a Tsync signal here for convenience of description. On the other hand, the luminance signal component of the image separated from the television signal is referred to as DA for convenience.
Although referred to as a TA signal, this signal is input to the shift register 1704.

The shift register 1704 is for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and is based on the control signal Tsft sent from the control circuit 1703. Works. That is, it can be said that the control signal Tsft is the shift clock of the shift register 1704.

One line of serial / parallel converted image (corresponding to driving data for n electron-emitting devices)
Data is output from the shift register 1704 as n parallel signals Id1 to Idn.

The line memory 1705 is a storage device for storing data for one line of an image for a required time, and a control signal Tmry sent from the control circuit 1703.
Accordingly, the contents of Id1 to Idn are stored as appropriate. The stored contents are output as I'd1 to I'dn and input to the modulation signal generator 1707.

The modulation signal generator 1707 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data I'd1 to I'dn.
The output signal is applied to the surface conduction electron-emitting device in the display panel 1701 through the terminals Dy1 to Dyn.

Driving Method of Display Panel As described with reference to FIG. 5 at the time of the above embodiment and at the beginning of the embodiment, the electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. is doing. That is,
As is clear from the graph of Ie in FIG. 5, there is a clear threshold voltage Vth (8 in the device of this embodiment) for electron emission.
[V]), 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 Vth, the emission current Ic also changes according to the change in voltage as shown in the graph. The value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may change by changing the material, configuration, and manufacturing method of the electron emitting device. You can say something like that.

That is, when a pulsed voltage is applied to this element, for example, as shown in FIG. 31A, basically no electron emission occurs even if a voltage below the electron emission threshold value is applied. When a voltage equal to or higher than the electron emission threshold is applied as shown in FIG. 31 (2), an electron beam is output.

In that case, firstly, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse.

Secondly, it is possible to control the total amount of charges of the electron beam output by changing the pulse length Pw.

Therefore, in order to carry out the first driving method of the display panel of the present embodiment, the modulation signal generator 1707 generates a voltage pulse of a fixed length, but it is appropriately selected according to the input data. A voltage modulation circuit that modulates the pulse peak value is used.

Further, in order to carry out the second driving method of the present invention, the modulation signal generator 1707 generates a voltage pulse having a constant peak value, but the width of the voltage pulse is appropriately set according to the input data. The circuit uses a pulse width modulation type circuit for modulation.

The functions of the respective parts shown in FIG. 25 have been described above. Before moving to the description of the overall operation, the operation of the display panel 1701 will be described in more detail with reference to FIGS. 26 to 29.

For convenience of illustration, the number of pixels of the display panel is 6 ×.
Although it is described as 6 (that is, m = n = 6), it goes without saying that the actually used display panel 1701 has a far larger number of pixels than this.

FIG. 26 shows a multi-electron beam source in which surface conduction electron-emitting devices are arranged in matrix in a matrix of 6 rows and 6 columns. For the sake of description, D (1,
1), D (1, 2) or D (6, 6), the position is indicated by (X, Y) coordinates.

When displaying an image by driving such a multi-electron beam source, a method of forming an image line-sequentially with one line of the image parallel to the X axis as a unit is adopted. To drive the electron-emitting device corresponding to one line of the image, 0 [V] is applied to the terminals of the rows corresponding to the display lines of Dx1 to Dx6, and 7 is applied to the other terminals.
[V] is applied. In synchronization with this, a modulation signal is applied to each terminal of Dy1 to Dy6 according to the image pattern of the line.

For example, a case of displaying an image pattern as shown in FIG. 27 will be described as an example. For convenience of explanation,
The brightness of the light emitting portions of the image pattern is equal, for example, 100
[Foot Lambert] It is supposed to be equivalent. In the display panel 1701, a conventionally known P-22 is used as a phosphor, an accelerating voltage is set to 10 K [V], a screen display repetition frequency is set to 60 [Hz], and a surface conduction type device having the above characteristics as an electron-emitting device is used. An emission element was used, in this case 1
To obtain a brightness of 00 [Foot Lambert], the element corresponding to the light emitting pixel has 14 [V] for 10 micro [seconds].
It was appropriate to apply the voltage of. It should be noted that this numerical value should naturally change if each parameter is changed.

Therefore, in the image of FIG. 27, for example, a period during which the third line is made to emit light will be described as an example.
FIG. 28 shows that while the third line of the image is illuminated,
Terminals Dx1 to Dx6 and terminals Dy1 to Dy
6 shows the voltage value applied to the multi-electron beam source through 6. As is clear from the figure, D (2,
3), D (3,3), D (4,3) each of the surface conduction electron-emitting devices has an electron emission threshold voltage exceeding 8 [V].
4 [V] (elements shown in black in the figure) is applied and an electron beam is output. On the other hand, other than the above 3 elements, 7 [V]
(Elements indicated by diagonal lines in the figure) or 0 [V] (elements indicated by white circles in the figure) are applied, but since these are below the threshold voltage 8 [V] for electron emission, Does not output an electron beam.

The same method is used for the other lines as shown in FIG.
The multi-electron beam source is driven in accordance with the display pattern of No. 7, and this is shown in a time chart of FIG. 29.

[0270] As shown in the figure, 1 is sequentially applied from the first line.
One screen is displayed by driving line by line, but by repeating this at a speed of 60 screens per second,
Image display without flicker is possible.

Although the above description does not mention gradation display, gradation display can be performed as follows.

In the case of performing gradation display by modulating the emission brightness of the display pattern, in order to increase (decrease) the brightness,
As a first driving method, there is a method in which the voltage peak value of the pulse of the modulation signal applied to the terminals Dy1 to Dy6 is made larger (smaller) than 14 [V], and modulation is possible by this.

For example, if the voltage peak value is changed stepwise in the unit of 0.5 [V] within the range of 7.9 [V] to 15.9 [V], the emission brightness will be 17 including zero. Stepwise modulation is possible. If you want more tones,
The range of voltage may be widened or the unit of change may be smaller.

As a second driving method, there is a method of making the pulse width longer (shorter) than 10 microseconds, and the modulation can be performed by this method as well.

For example, if the pulse width is changed in the range of 0 [second] to 15 micro [second] in units of 0.5 micro [second], the emission brightness can be modulated in 31 steps including zero. It is possible. If more gradations are desired, the range of pulse width may be widened or the unit of change may be smaller.

The driving method of the display panel 1701 has been described above by taking the 6 × 6 pixel multi-electron beam source as an example. Next, the overall operation of the apparatus of FIG. 25 will be described with reference to the time chart of FIG. To do.

FIG. 30 (1) shows the timing of the luminance signal DATA separated from the NTSC signal input from the outside by the synchronizing signal separation circuit 1706. As shown in FIG. It is output separately from the third and third lines. In synchronization with this, the control circuit 1703 sends a shift register 1704 to the shift register 1704 shown in FIG.
The shift clock Tsft as shown in (2) is output.

When one line of data is accumulated in the shift register 1704, the memory write signal Tmry is output from the control circuit 1703 to the line memory 1705 at the timing shown in FIG. Drive data for each element) is written. As a result, I'd1 to I'dn which are the output signals of the line memory 1705.
Contents 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 1702 is as shown in FIG. That is, when driving the first line,
Only the switching element S1 in the scanning circuit 1702 is 0.
At [V], the other switching elements are 7 [V], and when driving the second line, only the switching element S2 is 0 [V] and the other switching elements are 7 [V], and so on. Operation is controlled.

As a result of displaying the television using the display panels A and B by the series of operations described above,
Although the display panel B obtained a very good display image,
In the display panel A, the light emission due to the light emission of the phosphor was observed in the pixels other than the display pixel, although only slightly. Therefore, a comparative sample similar to that of Example 1 was prepared under the conditions of the display panel A and the display panel B, the device applied voltage was kept at Vth or less at the same drive frequency as the display on the television, and the electron emission current Ie, As a result of observing the device current If with the display panels A and B, the electron emission current Ie and the device current If are held constant in the display panel B, but the electron emission current I in the display panel A.
e, the device current If is not held constant, and the electron emission current I
e, it was found that the device current If was slightly increased. This is a phenomenon newly found by the present inventors, that is, the basic characteristics of the element shown in the embodiment are stable in the display panel B, the driving conditions in the display panel A, and the vacuum in the display panel. It is considered that it is derived from instability, depending on the quality.

Although not particularly mentioned in the above description,
The shift register 1704 and the line memory 1705 may be digital signal type or analog signal type, and the point is that the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed. In the case of using the digital signal type, it is necessary to convert the output signal DATA of the sync signal separation circuit 1706 into a digital signal, which is achieved by providing an A / D converter at the output section of the sync signal separation circuit 1706. It goes without saying that it is easily possible.

Further, in connection with this, the line memory 170
Depending on whether the output signal of 5 is a digital signal or an analog signal,
It goes without saying that the circuit used for the modulation signal generator 1707 is slightly different. That is, in the case of a digital signal, in the case of the first driving method, for the modulation signal generator 1707, for example, a well-known D / A conversion circuit may be used, and an amplification circuit or the like may be added if necessary.

In the case of the second driving method, the modulation signal generator 1707 is, for example, a high-speed oscillator and a counter (counter) for counting the number of waves output by the oscillator, and the output value of the counter and the output value of the memory. Those skilled in the art can easily configure the circuit by using a circuit in which a comparator for comparing the above is used.

If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator to the drive voltage of the surface conduction electron-emitting device may be added.

On the other hand, in the case of an analog signal, in the case of the first driving method, for the modulation signal generator 1707, for example, an amplifier circuit using a well-known operational amplifier may be used, and a level shift may be performed as necessary. A circuit or the like may be added.

In the case of the second driving method, for example, a well-known voltage-controlled oscillation circuit (VCO) may be used, and if necessary, voltage amplification is performed up to the driving voltage of the surface conduction electron-emitting device. An additional amplifier may be added.

Next, an apparatus relating to the third driving method of the present invention, that is, the method of driving by modulating the pulse voltage and the width will be described with reference to two fifth and sixth embodiments.
As the display panel, the display panel B used in Example 4 was used in the fifth and sixth examples.

Example 5 (Structure of Display Device) FIG. 32 shows a third example of the display device of the present invention.
3 is a block diagram of a schematic configuration of a drive circuit related to the drive method of FIG. Among the constituent elements in the figure, a display panel 1701, a scanning circuit 1702, a control circuit 1703, a shift register 1
704, line memory 1705, sync signal separation circuit 17
06, the modulation signal generator 1707, and the DC voltage source Va are the same as those described in the first driving method example of FIG. Further, Vns is a DC voltage source, and the pulse voltage generation source 2401 generates a pulse as described later.

The function of each part will be described below.
The components 01, 1704, 1705, 1706, and Va are the same as those described with reference to FIG.

The scanning circuit 1702 has therein M switching elements (schematically shown by S1 to Sm in the figure), and each switching element is the output voltage of the pulse voltage generating source 2401 or Or DC voltage source V
Select either one of the ns output voltage and display panel 1
The terminals 701 are electrically connected to the terminals Dx1 to Dxm. Each of the switching elements S1 to Sm operates based on the control signal Tscan generated by the control circuit 1703, but in practice, it can be easily configured by combining switching elements such as FETs.

Further, the control circuit 1703 has a function of matching the operations of the respective parts so that an appropriate display is performed as in the embodiment of FIG. 25. In this embodiment, in addition to the case of FIG. The control signal Tpu1 is generated for the pulse voltage generation source 2401.

The pulse voltage generation source 2401 generates a pulse voltage based on the control signal Tpu1 generated by the control circuit 1703. The timing and waveform of the generation will be described later with reference to FIG. To do. The voltage output from the DC voltage source Vns will also be described later with reference to FIG.

The modulation circuit 1707 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data I'd1 to I'dn, and its output signal waveform. This will be described later with reference to FIG.

The function of each part shown in FIG. 32 has been described above. Next, the waveform of the drive voltage applied to the surface conduction electron-emitting device in this embodiment will be described with reference to FIG.

(Driving of Display Panel) FIG. 33 (1) is a diagram for explaining the waveform of the pulse voltage generated by the pulse voltage generation source 2401. The pulse voltage generation source 2401 maintains the output voltage 7 [V] during the period in which no pulse is generated, but generates a pulse as shown in the figure at the appropriate time based on the control signal Tpu1. That is, the pulse is a rectangular pulse having a width of 30 microseconds and an output voltage of 0 [V] during the pulse application period.

Further, FIG. 33 (2) shows the DC voltage source V
It is a figure for demonstrating the output voltage of ns. Voltage source Vn
s always outputs a DC voltage of 7 [V] as shown in FIG. For the sake of convenience of explanation, the pulse voltage generation source 2401 is set to 0 [V] in order to clarify the time context.
The period during which the pulse is generated is shown in the figure.

Further, FIG. 33 (3) shows the modulation signal generator 1
It is a figure for demonstrating the waveform of the modulation signal which 707 generate | occur | produces. The modulation signal generator 1707 maintains the output voltage 7 [V] during the period in which the modulation signal is not generated, but the brightness of the image is synchronized with the pulse voltage generation source 2401 outputting the pulse of 0 [V]. A modulation signal corresponding to the data I'd1 to I'dn is generated. The modulation signal is composed of components a, b, c and d as shown by the dotted line in FIG. 3C, and the modulation signal generator 1707 generates the components a, b and c according to the luminance data of the original image.
Any combination of c and d is output.

The components a, b, c and d are 11 [V],
The pulse has a voltage of 12 [V], 13 [V], and 14 [V], and each has a length of 5 microseconds.
The pulse of FIG. 33 (1) is set to be longer than the modulated signal by about 5 microseconds. This is within the range even if the temporal relationship between the two is deviated for some reason. If there is, it is for avoiding inconvenience in operation.

Next, the drive waveform applied to the surface conduction electron-emitting device will be described with reference to these.

FIG. 33 (4) shows a drive voltage waveform of the surface conduction electron-emitting device when the output of the pulse voltage generation source 2401 is selected by the scanning circuit 1702. That is, this is equal to the difference voltage between the modulation voltage waveform of FIG. 33 (3) and the pulse waveform of FIG. 33 (1). In FIG. 33 (3), each of the components a ', b', c ', and d'indicated by dotted lines in FIG.
Corresponding to the components a, b, c, and d. If, for example, the component a ′ is applied, from the surface-conduction type electron-emitting device to which a voltage is applied, for 5 microseconds,
An electron beam of 0.27 [macro ampere (instantaneous current value)] is output. Similarly, if component b'is applied, then 0.
An electron beam having an instantaneous current of 37 [microamperes], 0.49 [microamperes] when the component c ′ was applied, and 0.66 [microamperes] when the component d ′ was applied was 5 microseconds each. ] Is output. Here, since the electron emission characteristic of the surface conduction electron-emitting device is non-linear, the differences among the four electron beam current values are not equal to each other. Therefore, for example, applying the components a ′ and b ′ does not equal the output when the component c ′ is applied, and the same applies to other combinations. Therefore, by driving the device by arbitrarily combining the components a'to d ', the total charge amount of the electron beam output during this period can be controlled in 16 ways (when no a'to d'is used). Also included in this). As a result, the emission brightness can be modulated in 16 ways.

On the other hand, FIG. 33 (5) shows the scanning circuit 1702.
The output of the DC voltage source Vns is the drive voltage waveform of the selected surface conduction electron-emitting device, that is, 33 (3)
33 and the DC voltage shown in FIG. 33 (2). In the figure, a ', b', c ', indicated by dotted lines,
Each part of d'corresponds to a, b, c, d in FIG. 33 (3), but since the electron emission threshold voltage (8 [V] in the case of the number) does not exceed in any part. , No electron beam is output.

The surface conduction electron-emitting device in the display device is driven by the method described above. Note that the overall operation of the display device of this embodiment is performed in a procedure that is generally the same as that of the embodiment of FIG. 25, so a description thereof will be omitted here.

In the above description, the modulation voltage is composed of four components a, b, c and d for convenience of illustration.
In practice it is desirable to have more parts. If the non-linear electron emission characteristic of the electron-emitting device is used, in general, n
By using this number of parts (that is, n kinds of modulation voltages), it is possible to perform gradation display in 2 n-th power.

For example, when displaying a television image, n
Is preferably 7 or more.

In the above description, the components a, b,
Each of c and d has the same pulse length and is 5 microseconds.
However, it is not always necessary to make the lengths of the respective parts equal. In addition, the components a, b, c, and d have a large voltage value in this order,
Although the voltage difference between adjacent ones is equal to 1 [V], it is not always necessary to equalize the voltage difference.

(Embodiment 6) Next, with reference to FIGS. 34 and 35, the third method for driving the display panel according to this embodiment, that is, the brightness of the image to be displayed by the voltage applied to the electron-emitting device and the pulse width. A second embodiment of the method for controlling the will be described.

(Structure of Display Device) FIG. 34 is a diagram showing a schematic structure of a drive circuit. Since there are many parts in common with those of FIG. 32 of the second embodiment, only the differences will be described. In the figure, pulse voltage generators 2601 and 2602 operate according to control signals Tpu11 and Tpu12 generated by the control circuit 1703, respectively, but the waveform of the pulse output from them differs from the pulse voltage source 2401 in FIG. Not a rectangle. Further, the modulation signal generator 1707 is
A modulation signal is generated according to the original image signals I'd1 to I'dn, but its signal waveform is different from that in the case of FIG.
These voltage waveforms will be described with reference to FIG.

FIG. 35 (1) shows a pulse voltage generator 260.
2 is a diagram for explaining the waveform of the pulse voltage generated by No. 1 of FIG. The pulse voltage generation source 2601 maintains the output voltage 7 [V] during the period in which no pulse is generated, but the control signal T
Based on pu11, a pulse as shown in the figure is generated at appropriate times. That is, the generated pulse has a width of 30 micro [seconds] and is 3 [V] when the pulse starts.
The ramp waveform linearly decreases from 0 to 0 [V].

FIG. 35 (2) is a diagram for explaining the waveform of the pulse voltage generated by the pulse voltage generation source 2602. The pulse voltage generation source 2602 maintains the output voltage 7 [V] during the period in which no pulse is generated, but it generates a pulse as shown in the figure based on the control signal Tpu12 in a timely manner. That is, the width of the pulse is 30 microseconds, and from 7 [V] to 4 with the start of the pulse.
It is a ramp waveform that linearly decreases toward [V]. Since the pulses in FIGS. 35 (1) and 35 (2) are synchronized by the control signals Tpu11 and Tpu12, there is always a potential difference of 4 [V] between them while the pulse is generated. .

Further, FIG. 35 (3) shows the modulation signal generator 1
It is a figure for demonstrating the waveform of the modulation signal which 707 generate | occur | produces. The modulation signal generator 1707 maintains the output voltage 7 [V] during the period in which no modulation signal is generated, but the brightness of the original image signal is synchronized with the pulse voltage generation sources 2601 and 2602 outputting pulses. A modulation signal corresponding to the data I'dI to I'dn is generated. The modulated signal is
The modulation signal generator 1707 outputs the components a, b, c, and d in any combination according to the luminance data of the original image. To do. The components a, b, c and d are rectangular voltage pulses each having a voltage of 14 [V] and a length of 5 microseconds,
30 microseconds shown in FIGS. 27 (1) and 27 (2)
5, 10, 15, 2 from the beginning of the pulse
It is applied after 0 microsecond.

Next, the drive waveforms applied to the surface conduction electron-emitting device will be described with reference to these.

(Driving of Display Panel) FIG. 35 (4) shows a driving voltage waveform of the surface conduction electron-emitting device when the output of the pulse voltage generating source 2601 is selected by the scanning circuit 1702. That is, this is equal to the difference voltage between the modulation voltage waveform of (3) and the pulse waveform of (1). In the figure, a ', b', c ', and d'shown by dotted lines correspond to a, b, c, and d in (3) of the figure, and all of them emit electrons. Threshold voltage (in this case 8
[V]) is exceeded. Therefore, when these waveforms are applied, an electron beam having an intensity matching the electron emission characteristic is output, but since the electron emission characteristic of the surface conduction electron-emitting device is non-linear, a ′, b ′, The charge amounts of the electron beams output from each of c'and d'are not equal to each other.

Therefore, as in the case of FIG. 33, 16 kinds of modulation are possible by arbitrarily combining the components a, b, c and d of the modulation voltage waveform.

On the other hand, FIG. 35 (5) shows the scanning circuit 1702.
6 is a drive waveform of the surface conduction electron-emitting device when the output of the pulse voltage generation source 2602 is selected by. As in the case of FIG. 25, since the threshold voltage of the electron-emitting device is not exceeded, the electron beam is hardly output.

In the above description, for convenience of illustration, as in the case of FIG. 33, the modulated signal has four components a, b, c and d.
Although it has been described that it is composed of three parts, it is needless to say that it is desirable to be composed of more parts also in this embodiment. That is, if n time-divided portions are used, it is possible to perform modulation in the 2nth power, but when displaying a television image, for example, n is preferably 7 or more.

Further, pulse voltage generation sources 2601 and 2
The pulse waveform generated by 602 is a ramp waveform that linearly decreases with time, but it is also possible to use a waveform that increases with time or a waveform that does not change linearly.

Further, in the explanation of the pulse generated by the modulation signal generator 1707, the pulse components a, b, c, d
Have the same width as the voltage, and the pulse start timings are shifted at equal intervals so as to be adjacent to each other. However, the invention is not limited to this. For example, if the voltage and length of each of a, b, c, and d are different. Alternatively, the start times of the pulses may be unequal intervals.

The embodiment relating to the third driving method of the present invention has been described above focusing on the difference from the fifth embodiment.

The first driving method or the second method described above
In the embodiment relating to the driving method of No. 3 or the third driving method, the surface conduction electron-emitting device as described at the beginning of the embodiment is used for the display panel, but the material, structure or manufacturing method of the electron-emitting device is different. In some cases, the electron emission characteristics (threshold voltage Vth and characteristic curve shape) may change slightly. Even in that case, there is no problem in applying the basic idea of the present invention, and the waveform of the pulse voltage used for scanning and modulation may be appropriately set according to the characteristics. Alternatively, there is no inconvenience even if these driving methods are applied to the surface conduction electron-emitting device as mentioned in the section of the prior art.

Further, in the embodiment, the example in which the television display is performed based on the television signal of the NTSC system is shown.
The display device to which the present invention can be applied or the application thereof is not limited to this. It can be widely used for other types of television signals or display devices directly or indirectly connected to various image signal sources such as computers, image memories, and communication networks, and particularly displays a large-capacity image. Suitable for large screen display.

Further, the present invention is not limited to the application directly to human eyes, and may be applied to the light source of a recording device for recording an optical image such as a so-called optical printer.

Alternatively, the method may be applied to a driving method of an electron beam source of an electron beam drawing apparatus that draws an image using an electron beam.

(Embodiment 7) This embodiment is an electron source in which a plurality of surface conduction electron-emitting devices having a plurality of electron-emitting portions are arranged in a matrix, or an image forming apparatus. This is an example in which a high-quality image is formed on the image forming member by superimposing electron beams from the electron emitting portion. The structure of the electron-emitting device of the present embodiment has the structure shown in FIG. 36 in which one electron is extracted from a plurality of electron-emitting devices arranged in a matrix, and is similar to the other embodiments. , An image forming apparatus was created.

The face plate arranged facing the substrate provided with the electron-emitting devices is the same as in the other embodiments.

In this example, after the insulating substrate 1 was thoroughly washed, the element wiring electrodes 373 of the high potential side element electrodes 362 were formed by vapor deposition and etching with a material containing Ni as a main component in a thickness of 1 μm and a width of 600 μm. It was made. Next, S on the entire surface of the substrate
iO ₂ was vapor-deposited to a thickness of 2 μm to form an insulating layer 372.

Thereafter, a 100 μm square hole is made in the SiO ₂ on the element wiring electrode 373 by an etching technique, and a material such as Ni is vapor-deposited in advance only on the hole portion so as to be connected to the element wiring electrode 373 through the hole. Then, a Ni material was vapor-deposited to a thickness of 0.1 μm on the entire surface.

Next, a Ni electrode is formed into a desired pattern by photolithography technology and etching technology,
High potential side element electrode 36 connected to element wiring electrode 373
2 and the low potential side element electrode 363 having an electrode gap on both sides in the width direction (X direction in the drawing) of the electrode 362 and orthogonal to the element wiring electrode 373.

As in the other embodiments, a fine particle film is formed in the gap between the device electrodes 362 and 363 to form an electron emitting portion 364, and electrons can be emitted by applying a desired voltage. is there.

In this embodiment, two electron emitting portions 36 are provided.
Width (W) in the X direction of the high-potential-side element electrode 362 sandwiched between 4
Is 400 μm, and +14 is applied to the high potential side element electrode 362.
V, 0 V was applied to the device electrode 363 on the low potential side to emit electrons, and 6 kV was applied to the phosphor on the face plate installed at a distance of 2.5 mm above. Good symmetry and almost circular bright spot shape were obtained. It was The diameter of the bright spot in this example was approximately 500 μmφ.

The electron beam from the surface conduction electron-emitting device having a single electron-emitting portion has a luminescent spot shape with poor symmetry on the surface of the image forming member, here, the phosphor surface. , If a plurality of electron emitting portions are formed with the high potential side electrode of the element electrode sandwiched in the voltage application direction with an interval W represented by a formula described later, the electron beams emitted from the plurality of electron emitting portions are By overlapping one on the image forming member surface, here the phosphor surface, a bright spot shape with good symmetry can be obtained as in the present embodiment.

K2 × 2d (Vf / Va) ^1/2 ≧ W / 2 ≧
K3 × 2d (Vf / Va) ^1/2 However, K2 and K3 are constants and K2 = 1.25 ± 0.05 K3 = 0.35 ± 0.05 Vf: Element applied voltage Va: Voltage applied to image forming member (Acceleration voltage) d: Distance between surface conduction electron-emitting device and image forming member W: Distance between electron-emitting portions

(Embodiment 8) This embodiment relates to the arrangement of a plurality of surface conduction electron-emitting devices arranged in a matrix, and FIG. 37 shows a schematic diagram of the image forming apparatus of this embodiment. .

FIG. 38 shows an enlarged perspective view of the electron-emitting device according to this embodiment, and FIG. 39 shows a sectional view taken along the X axis of the device.

In this example, a method of manufacturing an electron-emitting device on the insulating substrate 381 will be described below.

First, a method for manufacturing the image display device of this embodiment will be described.

(1) After cleaning the insulating substrate 381, the element wiring electrode 389 was formed on the substrate 381 by a vapor deposition technique and a photolithography technique to a thickness of 1 μm using a material containing Ni as a main component.

(2) Next, an insulating layer 390 made of SiO ₂ was formed to a thickness of 2 μm on the entire surface of the substrate 381.

(3) Next, after forming a hole (contact hole) at a desired position of SiO _{2 by} an etching technique, element electrodes 382 and 383 are formed by a vapor deposition technique and a photolithography technique at a thickness of 39000Å. It was made. Material is N
It was made of a material containing i as a main component.

(4) In the above process, the device electrode 382 is electrically connected to the device wiring electrode 389, the device electrodes 382 and 383 are opposed to each other with a narrow gap of 2 μm therebetween, and the narrow gap portion is provided with Pd fine particles. A film is formed and the electron emitting portion 38 is formed.
Since the process of manufacturing 4 is the same as that of the other embodiments, the description thereof will be omitted.

In this embodiment, the XY matrix is composed of the element electrodes 382 electrically connected in the Y direction and the element electrodes 383 electrically connected in the X direction, and the electron emitting portion is formed in these narrow gap portions. By having the above, the plurality of electron-emitting devices are formed in a matrix.

As shown in FIG. 38, each electron-emitting device has a voltage application direction (X direction) of the high potential side device electrode 382.
In the present embodiment, the width (W) in the X direction of the high potential side element electrode is 800 μm,
The gap width (G) between the device electrodes 382 and 383 is 2 μm.
It was made.

Further, the length (L) of the electron emitting portions in the Y direction is 140 μm, and the arrangement pitch (P) of the electron emitting elements in the Y direction.
Was 750 μm.

The arrangement pitch of the electron-emitting devices in the X direction was 1 mm in this embodiment.

A face plate 388 having an inner transparent electrode 386 and a phosphor (image forming member) 387 applied on the insulating substrate 381, on which the electron-emitting device is manufactured as described above, as in the other embodiments. Through the support frame at a distance d = 4.
Place them at a distance of 5 mm, apply frit glass to the joints of the substrate, support frame, and face plate, and apply 1 at 430 ° C.
It was adhered by baking for 0 minutes or more.

In the present image display device manufactured as described above, 5000 is added to the phosphor 387 through the transparent electrode 386.
A voltage V of 14 V is applied between the element electrodes 382 and 383 through the element wiring electrode 389 by applying an accelerating voltage Va.
Electrons were emitted by applying f.

In this embodiment, the acceleration voltage Va = 5000.
V, device voltage Vf = 14 V, device / faceplate distance d = 4.5 mm, Y-direction length L of the electron-emitting portion of the device
= 140 μ, Y-direction array pitch of electron-emitting devices P = 75
0 μ, and the high-potential side electrode width W = 800 μ. As in the case of Example 7, the electron beams emitted from the two electron emitting portions have the central axes of the bright spots substantially aligned on the image forming member,
These bright spots were just symmetrically overlaid, and one bright spot shape that was almost circular as a whole was observed. this is,
It is presumed that the condition of the present embodiment matches the formula shown in the seventh embodiment.

Further, the inventors of the present invention diligently studied the overlap of the respective bright spots in the Y direction, and as a result, it was found that the arrangement can be controlled by the arrangement regulation expressed by the following equation.

When the bright points in the Y direction are continuous and overlapped, P <L + 2K5 × 2d (Vf / Va) ^1/2 where K5 is a constant, K5 = 0.80 acceleration voltage Va, element voltage Vf, device / faceplate distance d = 4, the Y-direction length L of the electron-emitting portions of the device, the Y-direction array pitch P of the electron-emitting devices, and the high-potential-side electrode width W.

When the bright points in the Y direction do not overlap and are discontinuous P ≧ L + 2K6 × 2d (Vf / Va) ^1/2 However, K6 is a constant and K6 = 0.90 It was found that the electron emitting devices should be arranged in the Y direction under the condition of the formula. In the present example, the respective bright points in the Y direction fall within the range of the formula when they do not overlap and are discontinuous, and each bright point was observed as an independent bright point.

As described above, in the image display device of this embodiment, the optimum bright spot shape was obtained, and the discriminability and sharpness were good, and the high-luminance and high-definition display image was obtained.

(Embodiment 9) In this embodiment, a plurality of surface conduction electron-emitting devices capable of division driving are arranged in a matrix to form an image forming apparatus and a driving method.
This will be described using 1.

FIG. 40 is a perspective view showing a part of an electron source in which surface conduction electron-emitting devices are arranged in a matrix, and FIG. 41 is a view showing a driving method of this embodiment. The details will be described below.

As shown in FIG. 40, the device of this example has device electrodes 461a, 461b and wirings 462a, 46.
2b was connected. Reference numeral 462a is an X-direction wiring, and 462b is a Y-direction wiring. As shown in FIG. 41, surface conduction electron-emitting devices corresponding to red (R), green (G), and blue (B) are arranged electron sources, and are formed similarly to the fourth embodiment. Was done. The envelope was also made in the same way.

Next, the method of driving the device of this embodiment will be described with reference to FIG.

When sequentially scanning from the M = 1 column in FIG. 41, first, (1) a constant voltage is applied to the transparent electrode by the voltage applying means (not shown), and the electron emission voltage Vf is applied to the M = 1 column. Is applied.

(2) Of the information signals for one (= M) scanning columns, the information signals input to the signal wiring electrode G for green display and the signal wiring electrode B for blue display are accumulated in the memory 480. Further, the information signal input to the signal wiring electrode R for red display is directly applied as a modulation voltage (VmR) having an ON voltage, a cutoff voltage, and a gradation voltage according to the information signal through the voltage applying unit 481. It is input to the wiring electrode R. During this period, the signal wiring electrodes G and B
Irrespective of the information signal, a cutoff signal is issued from the signal switching circuit 482, and the cutoff voltage (Voff) is applied through the voltage applying means 483.

(3) Next, by the signal switching circuit 482,
Of the information signals for 1 (= M) scanning rows, the memory 4
Among the information signals stored in 80, the information signal of green display is switched so as to be input to the signal wiring electrode G, and the ON voltage, the cutoff voltage, and the gradation voltage corresponding to the information signal are changed through the voltage applying means. Modulation voltage (VmG) with
Is input to the signal wiring electrode G. During this time, the signal switching circuit 48 is applied to the signal wiring electrodes R and B regardless of the information signal.
A cutoff signal is emitted from 2, and a cutoff voltage (Voff) is applied through the voltage applying means.

(4) Next, by the signal switching circuit 482,
Of the information signals for 1 (= M) scanning rows, the memory 4
Among the information signals stored in 80, the information signal displayed in blue is switched to be input to the signal wiring electrode B, and the ON voltage, the cutoff voltage, and the gradation voltage corresponding to the information signal are changed through the voltage applying means. The modulation voltage (VmB) that it has is input to the signal wiring electrode B. During this period, a cutoff signal is issued from the signal switching circuit 482 to the signal wiring electrodes R and G regardless of the information signal, and the cutoff voltage (Voff) is applied through the voltage applying means.

The operation of inputting the information signal for one scanning column into the signal wiring electrodes by dividing the information signal for each color, that is, every two columns, into three in time is as described above. It is performed during the display timing.

The above operations (1) to (4) are sequentially repeated for each scanning row, and a full-color image for one screen or even for multiple screens is displayed on the phosphor surface.

According to the driving method of this embodiment, a plurality of bright spots (spots) forming a display image on the phosphor surface of each color are
It was possible to display a full-color image exhibiting extremely uniform and stable sizes and shapes with each other, having no crosstalk, having improved color purity of the image, and having excellent color reproducibility.

(Embodiment 10) FIG. 42 shows image information provided on a display panel using the surface conduction electron-emitting device described above as an electron beam source, for example, from various image information sources including television broadcasting. FIG. 4 is a diagram showing an example of a display device configured so that can display.
In the drawing, 500 is a display panel, 501 is a display panel drive circuit, 502 is a display controller, 503 is a multiplexer, 504 is a decoder, and 505.
Is an input / output interface circuit, 506 is a CPU, 50
7 is an image generation circuit, 508 and 509 and 510 are image memory interface circuits, 511 is an image input interface circuit, 512 and 513 are TV signal receiving circuits, and 514 is an input section (this display device is, for example, a television set). When a signal such as a signal including both video information and audio information is received, the audio is naturally reproduced at the same time as the display of the video, but the reception and separation of the audio information not directly related to the features of the present invention. , The description of circuits, speakers, etc. relating to reproduction, processing, and storage will be omitted.)

The functions of the respective parts will be described below along the flow of the image signal.

First, the TV signal receiving circuit 513 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The system of the TV signal to be received is not particularly limited, and various systems such as NTSC system, PAL system and SECAM system may be used. Further, a TV signal (for example, a so-called high-definition TV such as the MUSE system) having a larger number of scanning lines than these is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. It is a signal source. The TV signal received by the TV signal receiving circuit 513 is output to the decoder 504.

Further, the TV signal receiving circuit 512 is a circuit for receiving a TV image signal transmitted by having a wire transmission system such as a coaxial cable or an optical fiber. Similar to the TV signal receiving circuit 513, the system of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 504.

Further, the image input interface circuit 51
Reference numeral 1 denotes a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner, and the captured image signal is output to the decoder 504.

The image memory interface circuit 510 is a circuit for capturing the image signal stored in the video tape recorder (hereinafter abbreviated as VTR), and the captured image signal is output to the decoder 504.

The image memory interface circuit 509 is a circuit for fetching the image signal stored in the video disc, and the fetched image signal is output to the decoder 504.

The image memory interface circuit 508 is a circuit for fetching an image signal from a device that stores still image data, such as a so-called still image disk.
It is input to 04.

Further, the input / output interface circuit 505
Is a circuit for connecting the display device to an external computer, a computer network, or an output device such as a printer. It is of course possible to input and output image data and character / graphic information, and in some cases, input and output control signals and numerical data between the CPU 506 of the display device and the outside.

Further, the image generation circuit 507 is provided with image data, character / graphic information, or the CPU 50, which is externally input via the input / output interface circuit 505.
6 is a circuit for generating display image data based on the image data and the character / graphic information output from FIG. Inside this circuit, for example, rewritable memory for storing image data and character / graphic information, read-only memory for storing image patterns corresponding to character codes, processor for image processing, etc. And the circuits necessary for image generation are incorporated.

The display image data generated by this circuit is output to the decoder 504, but in some cases, it can be output to an external computer network or printer via the input / output interface circuit 505.

Further, the CPU 506 mainly performs operations related to operation control of the display device and generation, selection and editing of a display image.

For example, a control signal is output to the multiplexer 503 to appropriately select or combine image signals to be displayed on the display panel. At that time, a control signal is generated to the display panel controller 502 according to the image signal to be displayed, and the image display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines in one screen, etc. are displayed. The operation of the device is controlled appropriately.

Image data or character / graphic information may be directly output to the image generation circuit 507, or an external computer or memory may be accessed via the input / output interface circuit 505 to generate image data or character / character information. Enter graphic information. It should be noted that the CPU 506 may of course be involved in work for other purposes.
For example, it may be directly related to a function of generating and processing information, such as a personal computer or a word processor. Alternatively, as described above, it may be connected to an external computer network via the input / output interface circuit 505, and work such as numerical calculation may be performed in cooperation with an external device.

Also, the input unit 514 is the CPU 506.
The user inputs commands, programs, data, etc., and various input devices such as a keyboard, a mouse, a joystick, a bar code reader, and a voice recognition device can be used.

The decoder 504 converts the various image signals input from the above 507 to 513 into three primary color signals,
Alternatively, it is a circuit for inverse conversion into a luminance signal, an I signal, and a Q signal. It is desirable that the decoder 504 has an image memory therein, as indicated by a dotted line in the figure. This is to handle a television signal that requires an image memory for reverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of still images, or cooperates with the image generation circuit 507 and the CPU 506 to perform image processing and editing such as image thinning, interpolation, enlargement, reduction, and composition. This is because there is an advantage that it can be done easily.

Also, the multiplexer 503 uses the CP
The display image is appropriately selected based on the control signal input from U506. That is, the multiplexer 50
Reference numeral 3 denotes a drive circuit 501 for selecting a desired image signal from the inversely converted image signals input from the decoder 504.
Output to. In that case, by switching and selecting image signals within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen television. .

Further, the display panel controller 5
Reference numeral 02 is a circuit for controlling the operation of the drive circuit 501 based on a control signal input from the CPU 506.

First, regarding the basic operation of the display panel, for example, a signal for controlling the operation sequence of a drive power source (not shown) for the display panel is output to the drive circuit 501. Further, as a signal relating to the display panel driving method, for example, a signal for controlling the screen display frequency and the scanning method (for example, interlace or non-interlace) is output to the drive circuit 501.

In some cases, control signals relating to image quality adjustment such as brightness, contrast, color tone and sharpness of a display image may be output to the drive circuit 501.

The drive circuit 501 is a circuit for generating a drive signal to be applied to the display panel 500. The drive circuit 501 controls the image signal input from the multiplexer 503 and the control signal input from the display panel controller 502. It operates based on.

The function of each unit has been described above. With the configuration illustrated in FIG. 42, the display panel 5 displays image information input from various image information sources in this display device.
It is possible to display 00. That is, various image signals such as television broadcast are transmitted to the decoder 504.
After being inversely converted in, the signal is appropriately selected in the multiplexer 503 and input to the drive circuit 501. on the other hand,
The display controller 502 generates a control signal for controlling the operation of the drive circuit 501 according to the image signal to be displayed. The drive circuit 501 applies a drive signal to the display panel 500 based on the image signal and the control signal. As a result, the image is displayed on the display panel 500. These series of operations are performed by the CPU
It is totally controlled by 506.

Further, in this display device, the image memory built in the decoder 504 and the image generation circuit 507.
And not only displaying a selection from the information, but also enlarging, reducing,
It is also possible to perform image processing such as rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, and image editing such as composition, deletion, connection, replacement, and fitting. is there. Although not particularly mentioned in the description of this embodiment, a dedicated circuit for processing and editing audio information may be provided as in the case of the above-mentioned image processing and image editing.

Therefore, the present display device is a display device for television broadcasting, a terminal device for a video conference, an image editing device for handling still images and moving images, a computer terminal device, an office terminal device such as a word processor,
It is possible to combine the functions of a game console etc. with one unit,
It has a very wide range of applications for industrial or consumer use.

Note that FIG. 42 shows only an example of the configuration of a display device using a display panel having a surface conduction electron-emitting device as an electron beam source, and it goes without saying that it is not limited to this. Yes. For example, in FIG.
It does not matter if the circuits related to the functions that are unnecessary for the purpose of use are omitted from the constituent elements. On the contrary, the constituent elements may be added depending on the purpose of use. For example, when the display device is applied as a video telephone, it is preferable to add a television camera, a voice microphone, an illuminator, a transmission / reception circuit including a modem, and the like to the components.

In this display device, the depth of the display device can be reduced because the display panel using the surface conduction electron-emitting device as an electron beam source can be easily thinned. In addition, the display panel using surface-conduction type electron-emitting devices as the electron beam source can easily enlarge the screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display with good performance.

[0388]

As described above, the characteristics of the three basic characteristics of the surface conduction electron-emitting device according to the present invention, namely, firstly, the device has a certain voltage (called a threshold voltage,
When a device voltage equal to or higher than Vth) in FIG. 5 is applied, the emission current Ie rapidly increases, while at the threshold voltage Vth or lower, 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 can be controlled by the time for which the device voltage Vf is applied.

Further more preferably, the device current If,
Both the emission current Ie and the voltage applied to the pair of opposing element electrodes have a monotonically increasing characteristic (called MI characteristic).
Is a surface conduction electron-emitting device. According to the above
The emitted electrons from the surface conduction electron-emitting device are controlled by the peak value and width of the pulse voltage applied between the opposing device electrodes at the threshold voltage or higher. On the other hand, below the threshold voltage, it is hardly emitted.

According to this characteristic, even when a large number of surface conduction electron-emitting devices are arranged as in the present invention, a pulse having a pulse height or a pulse width or a pulse having a pulse height and a pulse width based on the input signal. Surface-conduction electron emission by combining pulse components of different wave heights with a predetermined width on the basis of the synchronizing signal, the separating means for separating the synchronizing signal included in the input signal, and the synchronizing means included in the input signal. With the configuration having the selection means for selecting the elements in order, it is possible to provide the driving method in which the surface conduction electron-emitting device is selected according to the input signal and the electron emission amount can be controlled.

Therefore, according to the novel structure and driving method of the present invention based on the characteristics of the surface conduction electron-emitting device, it is possible to reduce the number of m electrodes without grid electrodes as in the conventional case. By supplying the scanning signal and the modulation signal obtained from the input signal to the row-direction wiring and the n column-direction wiring, respectively, the electron-emitting device composed of a large number of surface conduction electron-emitting devices responds to the input signal. Is selected to provide a high-quality electron source that controls the amount of emitted electrons.

Further, a pair of device electrodes facing each other of the surface conduction electron-emitting device, and a pair of device electrodes facing each other of the surface conduction electron-emitting device are formed by the m row direction wirings and the n column direction wirings. In particular, since at least a part of the m row-direction wirings and the n column-direction wirings have the same or a part of the constituent elements,
When a high temperature is required for manufacturing the device, the problem of connecting different kinds of metals is solved, and a highly reliable, inexpensive and simple structure can be provided.

Furthermore, the insulating layer is provided only in the vicinity of the intersection of the m row-direction wirings and the n column-direction wirings, and the step forming portion of the vertical surface conduction electron-emitting device has the insulating layer. Since some or all of the layers are manufactured by the same manufacturing method, it is possible to simplify the manufacturing method such as electrical connection between the m row-directional wirings or the n column-directional wirings and the element without contact holes. It is possible to provide an electron source and an image forming apparatus that are inexpensive and have a simple structure.

Further, according to another driving method of the present invention, an input signal dividing means for dividing the input signal into a plurality of input signal groups is further provided, and the plurality of divided input signals generated by the input signal dividing means. Multiple rows (or columns) depending on
Since the surface conduction electron-emitting device of 1 is a divided drive that is selected and modulated, the time allowed for the row (or column) of the surface conduction electron-emitting device can be increased. A generous design can be made for the device.

Further, the driving method is such that the row (or column) of the adjacent electron emitting elements of the row (or column) of the selected and modulated electron emitting elements is maintained so as to be in a constant potential application state. . Therefore, there is no crosstalk between the electron beams emitted from each electron-emitting device on the electron beam irradiation surface.

Furthermore, in the electron source of the present invention, the electron beams emitted from the electron emission portions of the surface conduction electron-emitting device are superposed on each other so that the shape of the electron beam on the electron irradiation surface is It is possible to provide an electron source that can be controlled in a shape with good symmetry.

Further, by arranging the array pitch of the elements in the Y direction in a prescribed manner, it is possible to control the overlap between the electron beams emitted from the electron emitting elements on the electron beam irradiation surface.

Therefore, it is possible to provide an electron source having a simple structure and easily selecting an electron-emitting device that emits an electron and controlling the electron emission amount.

The image forming apparatus of the present invention such as a display device is an apparatus for forming an image on the basis of an input signal, and m row-direction wirings are provided on the substrate corresponding to the pixels forming the image. And n column-direction wirings laminated via an insulating layer respectively connect a pair of opposing device electrodes of a surface conduction electron-emitting device composed of at least a device electrode and a thin film including an electron-emitting portion. A plurality of surface-conduction type electron-emitting device rows of a plurality of surface-conduction type electron-emitting device rows arranged in a matrix, and an input signal including a synchronization signal and an image signal, based on the synchronization signal. A selection means for selecting an appropriate element row, and a modulation means for generating a modulation signal according to the image signal based on the synchronization signal and inputting the modulation signal to the electron-emitting device selected by the selection means. Featuring An image forming apparatus, in particular, an image forming apparatus including a phosphor that emits visible light by irradiation of an electron beam at a position facing the electron source substrate, and more preferably a surface conduction electron-emitting device. The image forming apparatus has a vacuum degree in which both the emission current and the element current exhibit a monotonically increasing characteristic (referred to as MI characteristic) with respect to the voltage applied to the pair of opposing element electrodes.

Therefore, according to the novel structure and driving method of the image forming apparatus of the present invention based on the characteristics of the surface conduction electron-emitting device, it is possible to eliminate the grid electrode without the grid electrode as in the conventional case. , M row-direction wirings and n column-direction wirings are given a scanning signal and a modulation signal obtained from the input signal, respectively, so that an electron source composed of a large number of surface conduction electron-emitting devices responds to the input signal. , The electron-emitting device can be selected, the amount of emitted electrons can be controlled, there is no crosstalk between pixels, the display brightness can be modulated with good controllability, and multi-gradation display is possible. We were able to realize a device that can display quality.

Further, since the phosphors are directly excited by the electron beam in a vacuum, the phosphors of each color, which are conventionally known in the field of CRT and the like and have excellent emission characteristics, can be used as the light emission source. Therefore, colorization is easy and a wide range of colors can be expressed. In addition, it is possible to make a color by simply coating the phosphors separately, and it is easy to manufacture the panel. Since the voltage required for scanning and modulation is small, it is easy to integrate electric circuits. Due to these advantages, the cost required for manufacturing can be reduced, and the display device can be provided at an extremely low cost.

It is possible to provide an image forming apparatus such as a display apparatus of high display quality which emits light with selectively controlled brightness.

Furthermore, by the pair of device electrodes facing each other of the surface conduction electron-emitting device, and the pair of device electrodes facing each other of the surface conduction electron-emitting device by the m row-direction wirings and the n column-direction wirings. And at least a part of the m row-direction wirings and the n column-direction wirings have the same or all of the constituent elements.

The surface conduction electron-emitting device is formed on the substrate or on the insulating layer.

The insulating layer is provided only in the vicinity of the intersection of the m row-direction wirings and the n column-direction wirings, and the step forming portion of the vertical surface conduction electron-emitting device is a part of the insulating layer. Alternatively, the configuration is such that all are the same. Since the image forming apparatus has an electron source having the above-described structure, a highly reliable and inexpensive image forming apparatus having a new structure can be provided.

Further, according to another driving method of the present invention, the image forming apparatus having the novel structure of the present invention further comprises an input signal dividing means for dividing an input signal into a plurality of input signal groups, Since the surface conduction electron-emitting devices of a plurality of rows (or columns) are selected and modulated in accordance with the plurality of divided input signals generated by the input signal dividing means, the surface conduction type electron emission devices are selected. Electron emitting device row (or column)
Since the time allowed for the driving IC and the surface conduction electron-emitting device can be increased, the design can be made with a margin.

Furthermore, the driving method is such that the row (or column) of the adjacent electron emitting elements of the row (or column) of the selected and modulated electron emitting elements is maintained so as to be in the state of constant potential application. . Therefore, there is no crosstalk between the electron beams emitted from each electron-emitting device on the image forming member.

Further, in the image forming apparatus of the present invention, a plurality of electron beams emitted from the plurality of electron emitting portions of the surface conduction electron-emitting device are superposed on the image forming member, whereby a luminescent bright spot is obtained. It is possible to provide an image forming apparatus that can be controlled to have a shape with good symmetry.

Further, by setting the arrangement pitch of the elements in the Y direction to be a prescribed arrangement, the overlap between the electron beams emitted from the respective electron-emitting elements on the image forming member can be controlled, so that it can be adjusted according to the input image. High quality images can be provided.

Furthermore, the image forming apparatus of the present invention is
An image that handles a television broadcast display device, a video conference terminal device, a still image, and a moving image because a TV signal, a signal from an image input device, a signal from an image memory, a signal from a computer, and the like can be input signals. It is possible to combine the functions of editing equipment, computer terminal equipment, office terminal equipment such as word processors, game machines, etc., and it has an extremely wide range of applications for industrial or consumer use.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a flat surface conduction electron-emitting device according to the present invention.

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

FIG. 3 is a basic measurement / evaluation apparatus diagram of a surface conduction electron-emitting device according to the present invention.

FIG. 4 is a voltage waveform of an electric conduction process of a surface conduction electron-emitting device according to the present invention.

FIG. 5 is a basic characteristic diagram of the surface conduction electron-emitting device according to the present invention.

FIG. 6 is a basic configuration diagram of a vertical surface conduction electron-emitting device according to the present invention.

FIG. 7 is a configuration diagram of an electron source of the present invention.

FIG. 8 is a diagram of an image forming apparatus of the present invention.

FIG. 9 is an explanatory diagram of a fluorescent film.

FIG. 10 is a diagram illustrating a driving method of the present invention.

FIG. 11 is a perspective view showing the configuration of one pixel of the image forming apparatus of the present invention.

FIG. 12 is a view showing a bright spot shape observed in a surface conduction electron-emitting device.

FIG. 13 is an equipotential diagram for explaining the trajectory of an electron beam of an image display device using a surface conduction electron-emitting device.

FIG. 14 is a plan view of the electron source according to the first embodiment.

FIG. 15 is a sectional view of the electron source of Example 1.

16 is an electron source manufacturing method diagram of Example 1. FIG.

FIG. 17 is an electron source manufacturing method of Example 1.

FIG. 18 is a mask diagram of the first embodiment.

FIG. 19 is a characteristic diagram of a comparative sample of Example 1.

FIG. 20 is a sectional view of the second embodiment.

FIG. 21 is an electron source manufacturing method diagram of Example 2;

FIG. 22 is a plan view of the electron source according to the third embodiment.

FIG. 23 is a sectional view of the electron source of Example 3;

FIG. 24 is an electron source manufacturing method diagram of Example 3;

FIG. 25 is an example of a schematic circuit configuration for carrying out the first and second driving methods of the present invention according to the fourth embodiment.

FIG. 26 is a partial circuit diagram of a multi-electron source in which electron-emitting devices of Example 4 are arranged in a matrix.

FIG. 27 is a diagram showing an example of an original image according to the fourth embodiment.

FIG. 28 is a diagram showing a drive voltage applied to the multi-electron source of Example 4.

FIG. 29 is a time chart in which one screen of Example 4 is sequentially displayed line by line.

FIG. 30 is a time chart for explaining the overall operation of the circuit of Example 4.

FIG. 31 is a diagram for explaining a drive voltage applied to the electron-emitting device of Example 4.

FIG. 32 is an example of the schematic circuit configuration of the first embodiment of the third driving method of the present invention of the fifth embodiment.

FIG. 33 is a diagram for explaining a drive voltage applied to the electron-emitting device of Example 5.

FIG. 34 is an example of a schematic configuration of a second embodiment of the third driving method of the present invention of the sixth embodiment.

FIG. 35 is a diagram for explaining a drive voltage applied to the electron-emitting device of Example 6.

FIG. 36 is a perspective view of an electron-emitting device of Example 7.

FIG. 37 is a perspective view of the image forming apparatus according to the eighth embodiment.

FIG. 38 is a perspective view of an electron-emitting device of Example 8.

FIG. 39 is an X-axis cross-sectional view of the electron-emitting device of Example 8.

FIG. 40 is a perspective view of an electron-emitting device of Example 9.

FIG. 41 is a partial circuit diagram showing the driving method of the present invention according to the ninth embodiment.

FIG. 42 shows an example of the display device of the present invention according to the tenth embodiment.

FIG. 43 is a plan view of a conventional surface conduction electron-emitting device.

FIG. 44 is a schematic view of a conventional image forming apparatus.

FIG. 45 is a schematic diagram of a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Electron emission part forming thin film 3 Electron emission part 4 Thin film including electron emission part 5 and 6 Element electrode 73 X direction wiring 73 Y direction wiring 74 Surface conduction type electron emission element 75 Connection

 ─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. 5-77897 (32) Priority date Hei 5 (1993) April 5 (33) Priority claim country Japan (JP) (31) Priority Claim number Japanese patent application No. 5-78165 (32) Priority date 5 (1993) April 5 (33) Priority claiming country Japan (JP) (72) Inventor Kasatoshi Kawade 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 within Canon Inc. (72) Inventor Yoshiyuki Nagata 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Toshihiko Takeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Eiji Yamaguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Asatake Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Co., Ltd. Uchi (72) Inventor Yasuyuki Gaien Higashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroaki Tojima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Seiji Isono Shimomaruko, Ota-ku, Tokyo 3-30-2 Canon Inc. (72) Inventor Naoto Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo 372-2 Canon Inc. (72) Inventor Anei Sato 3-Shimomaruko, Ota-ku, Tokyo No. 30-2 Canon Inc. (72) Shinya Sanshin 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Ichiro Nomura 3-30-2 Shimomaruko, Ota-ku, Tokyo In Canon Inc. (72) Inventor Tetsuya Kaneko 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (52)

[Claims] 1. An electron source that emits electrons in response to an input signal, wherein the electron source is a substrate, and m row-direction wirings and n column-direction wirings are stacked on the substrate via an insulating layer. And a plurality of surface conduction electron-emitting devices having a thin film including an electron emitting portion between a pair of device electrodes, the plurality of surface conduction electron-emitting devices including the device electrodes, the row-direction wirings, and The column-direction wirings are connected and arranged in a matrix, and the electron source has a selecting means for selecting a device row from the plurality of surface conduction electron-emitting devices and an input signal for the selecting means. An electron source comprising: a modulation means for generating a modulation signal in response to the element row and applying the modulation signal to the element row selected by the selection means. 2. The electron source according to claim 1, wherein the surface conduction electron-emitting device is a flat surface conduction electron-emitting device. 3. The electron source according to claim 1, wherein the surface conduction electron-emitting device is a vertical surface conduction electron-emitting device. 4. The electron source according to claim 1, wherein the surface-conduction type electron-emitting device is a surface-conduction type electron-emitting device having a device current and an electron-emission current having a monotonically increasing characteristic with respect to a device applied voltage. 5. The electron source according to claim 1, wherein the thin film including the electron emitting portion is a film composed of conductive fine particles. 6. The conductive fine particles are Pd, Nb, and M.
o, Rh, Hf, Re, Ir, Pt, Al, Co, N
i, Cs, Ba, Ru, Ag, Au, Ti, In, C
u, Cr, Fe, Zn, Sn, Ta, W, Pb, Pd
O, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , Ba
O, MgO, HfB ₂ , ZrB ₂ , LaB ₆ , CeB
₆ , YB ₄ , GdB ₄ , TiC, ZrC, HfC, Ta
C, SiC, WC, TiN, ZrN, HfN, Si, G
The electron source according to claim 5, comprising at least one material selected from e and carbon. 7. At least one set of a thin film including the electron emitting portion, the device electrode, the m row-directional wirings, the n column-directional wirings, and the connection material is a part of its constituent elements. Alternatively, the electron source according to claim 1, which is made of a material in which all the constituent elements are the same. 8. The insulating layer is provided only in the vicinity of an intersection of the m row-direction wirings and the n column-direction wirings.
The electron source described in. 9. The electron source according to claim 3, wherein the step forming portion of the vertical surface conduction electron-emitting device also serves as at least a part of the insulating layer. 10. The step forming portion of the vertical surface conduction electron-emitting device and the insulating layer are made of a material in which some or all of the constituent elements are the same.
The electron source described in. 11. The electron source according to claim 1, wherein the surface conduction electron-emitting device is formed on the surface of the substrate. 12. The electron source according to claim 1, wherein the surface conduction electron-emitting device is formed on the insulating layer. 13. The electron source according to claim 1, wherein two or more electron beams among the plurality of electron beams emitted from the plurality of surface conduction electron-emitting devices are superposed. 14. The electron source according to claim 1, wherein the modulating means is means for generating a pulse having a pulse height based on the input signal. 15. The electron source according to claim 1, wherein the modulation means is means for generating a pulse having a width based on the input signal. 16. The electron source according to claim 1, wherein the modulation means is means for generating a pulse having a wave height and a width based on the input signal. 17. A separating means for separating a synchronizing signal included in the input signal, wherein the selecting means is a means for sequentially selecting the surface conduction electron-emitting device rows based on the synchronizing signal. The electron source of claim 1, wherein 18. The electron source according to claim 1, wherein the selecting means is means for selecting a selected element row and a non-selected element row by generating pulses having different wave heights. 19. The electron source according to claim 18, wherein the modulation means is means for generating a pulse having a pulse height based on the input signal. 20. The electron source according to claim 18, wherein the modulation means is means for generating a pulse having a width based on the input signal. 21. The electron source according to claim 18, wherein the modulation means is means for generating a pulse having a wave height and a width based on the input signal. 22. Further, there is provided a means for dividing an input signal into a plurality of signal groups, and a plurality of rows or a plurality of columns of the surface conduction electron-emitting devices are provided according to a plurality of signal groups generated from the dividing means. The electron source according to claim 1, wherein is selected and modulated. 23. The electron source according to claim 22, wherein a constant potential is applied to a row or column adjacent to the row or column to be selected and modulated. 24. An image forming apparatus for forming an image according to an input signal, wherein the image forming apparatus has an electron source and an image forming member, the electron source includes a substrate and an insulating layer on the substrate. A plurality of surface-conduction electron-emitting devices having a thin film including an electron-emitting portion between a pair of device electrodes; The surface conduction electron-emitting devices are arranged in a matrix corresponding to pixels forming an image by connecting the device electrodes, the row-direction wirings and the column-direction wirings, and the image forming apparatus. Selecting means for selecting an element row from the plurality of surface conduction electron-emitting devices, and generating a modulation signal according to the input signal, and for the element row selected by the selecting means,
An image forming apparatus comprising: a modulation unit that applies the modulation signal. 25. The image forming apparatus according to claim 24, wherein the surface conduction electron-emitting device is a flat surface conduction electron-emitting device. 26. The image forming apparatus according to claim 24, wherein the surface conduction electron-emitting device is a vertical surface conduction electron-emitting device. 27. The image forming according to claim 24, wherein the surface conduction electron-emitting device is a surface conduction electron-emitting device in which the device current and the electron emission current have a monotonically increasing characteristic with respect to the device applied voltage. apparatus. 28. The image forming apparatus according to claim 24, wherein the device current and the electron emission current of the surface conduction electron-emitting device are maintained at a degree of vacuum that exhibits a monotonically increasing characteristic with respect to the applied voltage. 29. The image forming apparatus according to claim 24, wherein the thin film including the electron emitting portion is a film made of conductive fine particles. 30. The conductive fine particles are Pd, Nb, M
o, Rh, Hf, Re, Ir, Pt, Al, Co, N
i, Cs, Ba, Ru, Ag, Au, Ti, In, C
u, Cr, Fe, Zn, Sn, Ta, W, Pb, Pd
O, SnO ₂ , In ₂ O _3, PbO, Sb ₂ O ₃ , Ba
O, MgO, HfB ₂ ZrB ₂ , LaB ₆ , CeB ₆ ,
YB ₄ , GdB ₄ , TiC, ZrC, HfC, TaC,
SiC, WC, TiN, ZrN, HfN, Si, Ge,
The image forming apparatus according to claim 29, which is made of at least one material selected from carbon. 31. A thin film including the electron emitting portion, the device electrode, the m row-direction wirings, the n column-direction wirings,
25. The image forming apparatus according to claim 24, wherein at least one set of the connection materials is made of a material in which some or all of the constituent elements are the same. 32. The image forming apparatus according to claim 24, wherein the insulating layer is provided only near an intersection of the m number of row-direction wirings and the n number of column-direction wirings. 33. The image forming apparatus according to claim 26, wherein the step forming portion of the vertical surface conduction electron-emitting device also serves as at least a part of the insulating layer. 34. The step forming portion of the vertical surface conduction electron-emitting device and the insulating layer are made of a material in which some or all of the constituent elements are the same.
The image forming apparatus according to item 6. 35. The image forming apparatus according to claim 24, wherein the surface conduction electron-emitting device is formed on the surface of the substrate. 36. The image forming apparatus according to claim 24, wherein the surface conduction electron-emitting device is formed on the insulating layer. 37. The image forming apparatus according to claim 24, wherein two or more electron beams among the plurality of electron beams emitted from the plurality of surface conduction electron-emitting devices are superposed. 38. The image forming apparatus according to claim 37, wherein the plurality of electron emitting portions of the plurality of surface conduction electron-emitting devices are arranged at intervals W satisfying the following relational expression (I). K ₂ × 2H (V _f / V _a ) ^1/2 ≧ W / 2 ≧ K ₃ × 2H (V _f / V _a ) ^1/2 (I) [where K ₂ = 1.25 ± 0.05 , K ₃ = 0.35 ±
0.05, H is the distance between the surface conduction electron-emitting device and the image forming member, V _f is the voltage applied to the surface conduction electron emitting device, and V _a is the voltage applied to the image forming member]. 39. The image forming apparatus according to claim 24, wherein the array pitch P in the column direction of the plurality of surface conduction electron-emitting devices satisfies the following relational expression (II). P <L + 2K ₅ × 2H (V _f / V _a ) ^1/2 (II) [where K ₅ = 0.8, L is the length in the column direction of the surface conduction electron-emitting device, and H is the surface conduction type. The distance between the electron-emitting device and the image forming member, V _f is the voltage applied to the surface conduction electron-emitting device, and V _a is the voltage applied to the image forming member.] 40. The image forming apparatus according to claim 24, wherein the array pitch P in the column direction of the plurality of surface conduction electron-emitting devices satisfies the following relational expression (III). P ≧ L + 2K ₆ × 2H (V _f / V _a ) ^1/2 (III) [where K ₆ = 0.9, L is the length in the column direction of the surface conduction electron-emitting device, and H is the surface conduction type. The distance between the electron-emitting device and the image forming member, V _f is the voltage applied to the surface conduction electron-emitting device, and V _a is the voltage applied to the image forming member.] 41. The image forming apparatus according to claim 24, wherein the modulation means is means for generating a pulse having a wave height based on the input signal. 42. The image forming apparatus according to claim 24, wherein the modulating means is means for generating a pulse having a width based on the input signal. 43. The image forming apparatus according to claim 24, wherein the modulation means is means for generating a pulse having a wave height and a width based on the input signal. 44. A separation means for separating a synchronization signal included in the input signal is provided, and the selection means is a means for sequentially selecting the surface conduction electron-emitting device rows based on the synchronization signal. The image forming apparatus according to claim 24. 45. The image forming apparatus according to claim 24, wherein the selecting means is means for selecting a selected element row and a non-selected element row by generating pulses having different wave heights. 46. The image forming apparatus according to claim 45, wherein the modulation means is means for generating a pulse having a wave height based on the input signal. 47. The image forming apparatus according to claim 45, wherein the modulation means is means for generating a pulse having a width based on the input signal. 48. The image forming apparatus according to claim 45, wherein the modulation means is means for generating a pulse having a wave height and a width based on the input signal. 49. Further, there is provided a means for dividing an input signal into a plurality of signal groups, and a plurality of rows or a plurality of columns of the surface conduction electron-emitting devices are provided according to a plurality of signal groups generated by the dividing means. The image forming apparatus according to claim 24, wherein is selected and modulated. 50. The image forming apparatus according to claim 49, wherein a constant potential is applied to a row or a column adjacent to the selected or modulated row or the column. 51. The image forming apparatus according to claim 24, wherein the image forming member is a phosphor. 52. The image forming apparatus according to claim 24, wherein the input signal is at least one of a TV signal, a signal from an image input device, a signal from an image memory, and a signal from a computer.