JP3217629B2 - Electron source, image forming apparatus using the electron source, method of manufacturing the electron source, and method of manufacturing the image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source having a large number of electron-emitting devices, an image forming apparatus to which the electron source is applied, and a method of manufacturing the same.

[0002]

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

As an example of the FE type, WPDyke & WWDol
an, "Field emission", Advance inElectron Physics,
8, 89 (1956) or CASpindt, "Physical Propertie
s of thin-film field emission cathodes with molbde
ninmcones ", J. Appl. phys., 47, 5248 (1976). As an example of the MIM type, CAMead," The tunne
l-emission amplifier, J. Appl. Phys., 32, 646 (1961)
Etc. are known. Examples of surface conduction electron-emitting devices include MIElinson, Radio Eng. Electron Phys., 10, (1
965).

[0004] The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al., A device using an Au thin film [G. Dittmer: “Thin Solid Films”, 9, 317 (1972)],
According to In ₂ O ₃ / SnO ₂ thin film [M. Hartwell and
CGFonstad: "IEEETrans. ED Conf.", 519 (1975)
], And those using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported.

[0005] A typical device configuration of these surface conduction electron-emitting devices is described in the aforementioned M.A. FIG. 25 shows an element configuration of the Hartwell. In the figure, reference numeral 1001 denotes a substrate.
1004 is a conductive thin film, both ends of which are element electrodes 1002,
An electron emission portion 1005 is formed by a metal oxide thin film or the like formed by sputtering in an H-shaped pattern to become 1003, and by an energization process called energization forming described later. The distance L1 between the device electrodes 1002 and 1003 in the figure is set to 0.5 to 1 mm, and the width W is set to 0.1 mm.

Heretofore, in these surface conduction electron-emitting devices, it has been general to form an electron-emitting portion 1005 on the conductive thin film 1004 in advance by an energization process called energization forming before electron emission. That is, the energization forming means applying a direct current voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 1004 and energizing the conductive thin film 1004 to locally destroy, deform or deteriorate the conductive thin film 1004. The purpose is to form the electron emitting portion 1005 in a state of being electrically high in resistance. In the electron emitting portion 1005, a crack is generated in a part of the conductive thin film 1004, and electrons are emitted from the vicinity of the crack. The surface conduction type electron-emitting device that has been subjected to the energization forming process applies a voltage to the above-described conductive thin film 1004 and causes a current to flow through the device.
It emits more electrons.

Furthermore, a step called activation is usually introduced after the completion of the energization forming step. An object of the present invention is to increase the amount of emitted electrons by continuously supplying a constant voltage to the surface conduction electron-emitting device having a high resistance by the energization forming for a predetermined time.

The above-described surface conduction electron-emitting device has an advantage that a large number of devices can be arranged and formed over a large area because the structure is simple and the production is easy. Therefore, various applications are being studied to make use of this feature. For example, a charge beam source, a display device, and the like can be given. As an example in which a large number of surface conduction electron-emitting devices are arranged and formed, a ladder-type arrangement is used, in which surface conduction electron-emitting devices are arranged in parallel, and both ends of each element are interconnected (also referred to as a common interconnect).
An electron source in which a number of connected lines are arranged in a large number of rows (for example, Japanese Patent Application Laid-Open No.
-2833749, JP-A-1-257552 and the like). In particular, in image forming apparatuses such as display apparatuses, flat panel display apparatuses using liquid crystal have recently become widespread in place of CRTs. However, they are not self-luminous and must have a backlight. Therefore, development of a self-luminous display device has been desired. Examples of the self-luminous display device include an image forming device that is a display device in which an electron source having a large number of surface conduction electron-emitting devices and a phosphor that emits visible light by electrons emitted from the electron source are combined. (Eg, US Pat. No. 5,066,883).

[0009]

As described above, an electron source having a large number of electron-emitting devices is expected to be applied to a large-area image display device or the like. However, in a situation where the resolution of an image is increasing, a high-density arrangement of electron-emitting devices is required. For that purpose, the wiring connected to each electron-emitting device must be densely wired to drive each electron-emitting device, and accordingly, the reliability of the connection between each electron-emitting device and the wiring has to be improved. Need to be further improved.

Accordingly, the present invention provides an electron source which enables high-density wiring by simplifying the wiring configuration, and at the same time, improves the reliability of electrical connection of the electron-emitting device, and an image as an application thereof. An object of the present invention is to provide a forming apparatus and a method for manufacturing the same.

[0011]

In order to achieve the above object, an electron source according to the present invention has a pair of element electrodes opposed to both ends of an electron emitting section, and a driving voltage is applied between the element electrodes. In the electron source, in which a plurality of electron-emitting devices that emit electrons from the electron-emitting portion are arranged in rows and columns on the substrate, the substrate is used as a wiring for applying a drive voltage between the device electrodes. A plurality of row direction wirings perpendicular to the element electrode facing direction and a plurality of column direction wirings parallel to the element electrode facing direction are formed so as to intersect with each other via an insulating layer extending in the column direction. direction wirings, said
The column-directional wirings are arranged below the column-directional wirings, and are arranged at positions in contact with one of the device electrodes of the electron-emitting devices arranged in the row direction. In order to electrically connect to each of the other device electrodes among the device electrodes of the emission device, the image forming member has a pattern projecting in a comb shape, in which case the image forming member is emitted from the electron emission device. It may be constituted by a phosphor film containing a phosphor that emits light when the electrons collide.

Further, each of the row direction wirings and each column direction wiring may be formed by a thick film printing method.

Further, each comb-shaped pattern of each column-direction wiring may be in contact with the other element electrode.

Further, of the row-direction wirings and the column-direction wirings, at least a wiring contacting a device electrode serving as a positive electrode of the electron-emitting device is in contact with an end of the device electrode of the electron-emitting device. It may be.

[0015] The substrate is formed with a partial wiring in contact with the other element electrode of each of the electron-emitting devices together with the row-directional wiring and the column-directional wiring. The projecting patterns may be in contact with the respective partial wirings.

Each of the partial wirings is formed by a thick-film printing method, and at least one of the partial wirings and the row-directional wirings, which is in contact with a device electrode serving as a positive electrode of the electron-emitting device, is formed of the electron-emitting device. It may be in contact with the end of the element electrode of the element.

The electron-emitting device includes a pair of opposing element electrodes and a conductive thin film that connects the pair of element electrodes and has a partially electrically high resistance state. It may be a conduction type electron-emitting device.

An image forming apparatus according to the present invention is an image forming apparatus provided with any one of the above-described electron sources, and forms an image by colliding electrons emitted from electron-emitting devices of the electron source. The image forming member to be disposed is opposed to the electron source via a support frame, and the inside of an envelope including the electron source, the support frame, and the image forming member has a vacuum atmosphere. I do.

In this case, the image forming member may be a phosphor film containing a phosphor that emits light when electrons emitted from the electron-emitting device collide.

According to the method for manufacturing an electron source of the present invention,
A plurality of pairs of element electrodes facing each other at both ends of the electron-emitting portion are arranged in a matrix, and a wiring for applying a voltage between the element electrodes and emitting electrons from the electron-emitting portion is provided. In the method for manufacturing an electron source to be formed, when a direction perpendicular to the opposing direction of the element electrodes is a row direction and a parallel direction is a column direction, the step of forming the wiring is performed for each column of the electron-emitting devices. Being arranged and extending in the row direction,
Forming a plurality of row-direction wirings in contact with one of the element electrodes arranged in the row direction; and Forming a plurality of insulating layers extending in a direction intersecting with the row direction wiring, and a comb for electrically connecting each of the element electrodes arranged in the column direction to the other element electrode on each of the insulating layers. Forming a plurality of column-directional wirings having a pattern protruding in the shape of a column.

In this case, each of the row direction wirings and each column direction wiring may be formed by a thick film printing method.

Further, each comb-shaped pattern of each column-direction wiring may be formed at a position in contact with the other element electrode.

At least one of the row direction wiring and the column direction wiring, which is in contact with a device electrode serving as a positive electrode of the electron emitting element, is formed at a position where it is in contact with an end of the device electrode of the electron emitting device. You may do it.

Prior to forming each of the column-directional wirings, a partial wiring that is in contact with the other element electrode of each of the element electrodes is formed, and each comb-shaped pattern of each of the column-directional wirings is formed by:
It may be formed at a position in contact with each of the partial wirings.

Further, each of the partial wirings is formed by a thick film printing method, and at least one of the partial wiring and each of the row direction wirings, which is in contact with a device electrode serving as a positive electrode of the electron emitting device, is formed of the electron emitting device. It may be formed at a position where it is in contact with the end of the element electrode of the element.

According to a method of manufacturing an image forming apparatus of the present invention, an electron source is manufactured by any one of the above-described methods of manufacturing an electron source, and an electron-emitting device of the electron source is provided on the electron source via a support frame. An image forming member on which an image is formed by collision of electrons emitted from the image forming member is opposed to each other to form an envelope, and then the inside of the envelope is evacuated.

[0027]

[0028]

In the electron source of the present invention configured as described above, a plurality of row-direction wirings and a plurality of columns are provided as wirings for applying a drive voltage between the device electrodes of the electron-emitting devices arranged in a matrix. In the case where the directional wirings are formed so as to intersect with each other via an insulating layer, each row directional wiring is disposed at a position in contact with one of the device electrodes of the electron-emitting devices arranged in the row direction. Are electrically connected to the device electrodes of Further, each column-direction wiring has a pattern protruding in a comb shape corresponding to the position of the other device electrode among the device electrodes of the electron-emitting devices arranged in the column direction, and this pattern is formed with the other device electrode. Electrically connected. The electrical connection of the comb-shaped protruding pattern of each column-directional wiring to the other element electrode is made directly or via a partial wiring in contact with the other element electrode. By providing a plurality of row-direction wirings and a plurality of column-direction wirings in this manner, wiring for applying a drive voltage to the element electrodes of the electron-emitting devices is achieved simply by forming each row-direction wiring and each column-direction wiring, A special structure or process for connecting the device electrode to each wiring is not required. As a result, simplification of the manufacturing process of the electron source and simplification of the wiring structure of the device electrode are achieved.
In addition, the simplification of the wiring structure improves the reliability of the connection portion between the device electrode and each wiring, and reduces the area of the portion controlled by the wiring, so that high-density wiring becomes possible. The emission elements can be arranged at a higher density.

On the other hand, as wiring for applying a drive voltage between the device electrodes of the electron-emitting devices arranged in a matrix, each of the rows of the electron-emitting devices is perpendicular to the direction in which the device electrodes face each other. When a plurality of first row-directional wirings and second row-directional wirings are formed in different directions, each row-directional wiring contacts and is electrically connected to the element electrode in a pattern protruding in a comb shape. . As a result, the first
Only the row-direction wiring and the second row-direction wiring form the wiring with the device electrode of the electron-emitting device, thereby simplifying the manufacturing process of the electron source and the wiring structure of the device electrode. In addition, since the row-directional wirings can be formed simultaneously without overlapping each other, the wiring process and the wiring structure are further simplified.

Further, in the electron source of the present invention, by forming each wiring by a thick film printing method, each wiring can be formed without the need for a photolithography step, and the process of forming each wiring can be shortened. It is planned.

Further, at least one of the wirings that contacts the element electrode serving as the positive electrode of the electron-emitting device is brought into contact with the end of the element electrode, so that the distance between the electron-emitting portion of the electron-emitting device and the wiring is reduced. Since the distance increases, the phenomenon that electrons emitted from the electron-emitting device are sucked into the wiring can be suppressed.

Particularly preferred among the electron-emitting devices used in the electron source of the present invention are surface-conduction electron-emitting devices. The surface conduction electron-emitting device has a simple structure and is simple to manufacture, and a large-area electron-emitting device can be easily manufactured. In recent years, particularly in a situation where an inexpensive image forming apparatus with a large screen is required, the electron emitting device is particularly suitable.

Since the image forming apparatus of the present invention uses the electron source of the present invention having the above-described wiring structure, the density of the wiring and the electron-emitting device can be increased, and the number of pixels per unit area can be increased. An image forming apparatus having high resolution is achieved. In particular, by using, as the image forming member, a phosphor film containing a phosphor that emits light when electrons emitted from the electron-emitting device collide, a high-resolution and large-screen image display device can be easily obtained.

[0034]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a plan view of a main part of a first embodiment of an electron source according to the present invention, in which a large number of surface conduction electron-emitting devices 9 are arranged on a substrate 1 in a matrix. The example of arrangement is shown. Each electron-emitting device 9 includes a pair of device electrodes 2 and 3 facing each other, and a pair of device electrodes 2 and 3
And a conductive thin film 4 for forming an electron-emitting portion.

On the substrate 1, the electrode extends in the Y direction (row direction) which is a direction perpendicular to the direction in which the element electrodes 2 and 3 face each other.
A plurality of first wiring layers 6 as row direction wirings and a plurality of second wirings as column direction wirings extending in the X direction (column direction) which is a direction parallel to the direction in which the element electrodes 2 and 3 face each other. The wiring layers 8 are electrically separated by the interlayer insulating layer 7 and provided in a matrix. The first wiring layer 6 is in contact with one of the device electrodes 3 of the electron-emitting devices 9 arranged in the Y direction. The second wiring layer 8 has a pattern protruding in parallel with the first wiring layer 6 at a position corresponding to the electron-emitting devices 9 arranged in the X direction. Is in contact with the element electrode 2. Thus, the electron-emitting device 9 is electrically connected between the first wiring layer 6 and the second wiring layer 8.

As will be described later in detail, a scanning signal for scanning a row of the electron-emitting devices 9 arranged in the X direction in accordance with an input signal is applied to the second wiring layer 8 (not shown). Are electrically connected to the scanning signal generating means. On the other hand, the first wiring layer 6 includes a modulation signal generating means (not shown) for applying a modulation signal for modulating each of the rows of the electron-emitting devices 9 arranged in the Y direction according to the input signal. It is electrically connected. Further, the driving voltage applied to each element of the electron-emitting device 9 is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element.

In the above configuration, individual elements can be selected and driven independently only by simple matrix wiring.

Here, a surface conduction electron-emitting device suitable for the present invention will be described.

FIGS. 6A and 6B show the structure of a basic surface conduction type electron-emitting device suitable for the present invention. FIG. 6A is a plan view and FIG. 6B is a sectional view. . Hereinafter, a basic configuration of an electron-emitting device suitable for the present invention will be described with reference to FIG.

In FIG. 6, two element electrodes 102 and 103 are arranged on a substrate 101 at an interval from each other.
By connecting each of the device electrodes 102 and 103, the electron-emitting portion 10 is connected.
5 is provided.

As the substrate 101, quartz glass, glass having a reduced content of impurities such as Na, blue plate glass, a glass substrate obtained by laminating SiO ₂ formed on blue plate glass by sputtering or the like, and ceramics such as alumina are used. Can be

As a material for the opposing device electrodes 102 and 103, a general conductor material is used.
Cr, Au, Mo, W, Pt, Ti, Al, Cu, Pd
Metal or alloy such as Pd, Ag, Au, Ru
It is appropriately selected from a printed conductor composed of a metal such as O ₂ or Pd—Ag or a metal oxide and glass, a transparent conductor such as In ₂ O ₃ / SnO _2, a semiconductor conductor material such as polysilicon, or the like.

The element electrode interval L, the element electrode length W, the shape of the conductive thin film 104, and the like are designed according to the applied form and the like. The device electrode interval L is preferably from several hundred angstroms to several hundred micrometers, and more preferably, from several micrometers to several tens of micrometers depending on the voltage applied between the device electrodes 102 and 103 and the electric field intensity capable of emitting electrons. Meters. The device electrode length W is preferably from several micrometers to several hundred micrometers depending on the resistance value and electron emission characteristics of the electrode. The film thickness of the device electrodes 102 and 103 is several hundred angstroms to several micrometers.

The structure of the substrate 1 is not limited to the structure shown in FIG.
01, the conductive thin film 104 and the opposing device electrode 10
The electrodes may be laminated in the order of 2, 103.

The conductive thin film 104 has good electron emission characteristics.
In order to obtain fine particles, a fine particle film composed of fine particles is particularly preferable.
Preferably, the thickness of the film is determined by the step on the device electrodes 102 and 103.
Up coverage, the resistance value between the device electrodes 102 and 103, and the like.
Set appropriately according to the energizing forming conditions described later
And preferably several thousand Angstroms rather than several Angstroms.
Strom, particularly preferably 10 angstroms
500 angstroms and its resistance value is 1
0^ThreeMore than 10⁷It is a sheet resistance value of Ω / □. Also,
The material forming the conductive thin film 104 is Pd, Pt, Ru,
Ag, Au, Ti, In, Cu, Cr, Fe, Zn, S
metals such as n, Ta, W, Pb, PdO, SnO_Two , In
_TwoO_Three , PbO, Sb_TwoO_Three , Such as oxide, HfB_Two,
ZrB _Two, LaB₆, CeB₆, YB_Four, GdB_FourEtc.
Boride, TiC, ZrC, HfC, TaC, SiC, W
Carbides such as C, nitrides such as TiN, ZrN, HfN, S
i, Ge and other semiconductors, carbon, and AgMg, N
iCu, PbSn and the like can be mentioned.

The fine particle film described here is a film in which a plurality of fine particles are gathered, and has a fine structure not only in a state where the fine particles are individually dispersed and arranged, but also in a state where the fine particles are adjacent to each other or overlap each other ( (Including islands), and the particle size of the fine particles is from several Angstroms to several thousand Angstroms, preferably from 10 Angstroms to 200 Angstroms.

The electron-emitting portion 105 is a crack formed in a part of the conductive thin film 104 and in a state of being in an electrically high-resistance state. And so on.
Further, the conductive fine particles may have a particle diameter of several Å to several hundred Å. The conductive fine particles are similar to some or all of the elements of the material constituting the conductive thin film 104. Further, the electron emitting portion 105 and the conductive thin film 104 in the vicinity thereof may contain carbon or a carbon compound.

Various methods are conceivable as a method for manufacturing the above-mentioned surface conduction electron-emitting device. One example is shown in FIG.

The manufacturing method will be described below in order with reference to FIGS.

(1) After sufficiently washing the substrate 101 with a detergent, pure water and an organic solvent, an element electrode material is deposited on the substrate 101 by a vacuum deposition method, a sputtering method, or the like, and then the element is deposited on the substrate 101 by a photolithography technique. Electrode 10
2 and 103 are formed (FIG. 7A).

As a method for forming the device electrodes 102 and 103, a thick film printing method may be used. As a material when the printing method is used, an organic metal paste (MO
D) and the like.

(2) An organic metal solution is applied to the substrate 101 on which the device electrodes 102 and 103 are provided and left to form an organic metal thin film. The organic metal solution is a solution of an organic metal compound containing the metal of the material of the conductive thin film 104 as a main element. Thereafter, the organic metal thin film is heated and baked, and is patterned by lift-off, etching, or the like to form a conductive thin film 104 (FIG. 7B).
Here, the method has been described by using the method of applying an organic metal solution, but the present invention is not limited to this, and it is formed by a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like. There is also.

(3) Subsequently, the device electrodes 102 and 103
In the meantime, when electricity is supplied by a power supply (not shown), the conductive thin film 10
An electron emitting portion 105 having a changed structure is formed at the portion 4 (FIG. 7C). This energization processing is called energization forming, and the conductive thin film 104 is locally destroyed, deformed or deteriorated by the energization forming, and a portion where the structure is changed is called an electron emission portion 105. FIG. 8 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform. When a pulse with a constant pulse peak value is applied continuously (FIG. 8A), a voltage pulse is applied while increasing the pulse peak value. (FIG. 8B). First, the case where the pulse peak value is a constant voltage will be described.

T1 and T2 in FIG. 8A are the pulse width and pulse interval of the voltage waveform, respectively.
1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave (peak voltage at the time of energization forming) is appropriately selected according to the above-described form of the surface conduction electron-emitting device. And a suitable degree of vacuum, for example, 1
Under a vacuum atmosphere of about 0 ^-5 Torr, the voltage is applied for several seconds to several tens minutes. Note that the waveform applied between the element electrodes 102 and 103 is not limited to a triangular wave, and a desired waveform such as a rectangular wave may be used.

T1 and T2 in FIG. 8B are the same as those in FIG. 8A, and the peak value of the triangular wave (peak voltage during energization forming) is increased by, for example, about 0.1 V steps. It is applied under a suitable vacuum atmosphere. In this case, the end of the energization forming process is as follows.
When a voltage that does not locally destroy or deform the conductive thin film 104, for example, a resistance of 1 M ohm or more is shown during the pulse interval T2, the energization forming is terminated.

(4) Next, a process referred to as an activation process is preferably performed on the element after the energization forming. The activation step means, for example, a process of repeating the application of a pulse with a pulse peak value of a constant voltage at a degree of vacuum of about 10 ^-4 to 10 ^-5 Torr, as in the energization forming, and exists in a vacuum. The element current I flowing through the conductive thin film 104 is obtained by depositing carbon and a carbon compound from an organic substance.
f, a process in which the emission current Ie emitted from the electron emission unit 105 changes significantly. Device current If and emission current Ie
, The activation step ends when the emission current Ie is saturated, for example. Further, the pulse peak value is preferably an operation drive voltage.

The carbon and the carbon compound as used herein are graphite (indicating both single and polycrystalline) and amorphous carbon (indicating a mixture of amorphous carbon and polycrystalline graphite). Is preferably 500 Å or less, more preferably 300 Å or less.

(5) The thus-produced electron-emitting device is placed in a vacuum atmosphere having a degree of vacuum higher than that in the energization forming step and the activation step, and is preferably operated and driven.
More preferably, the device is heated to 80 ° C. to 150 ° C. in a vacuum atmosphere with a higher degree of vacuum, and then driven to operate.

The vacuum atmosphere having a degree of vacuum higher than that of the energization forming step and the activation treatment is, for example, about 10
A vacuum degree having a vacuum degree of ^-6 Torr or more, more preferably an ultra-high vacuum system in which carbon or a carbon compound is not substantially newly deposited. Accordingly, this makes it possible to suppress the further deposition of carbon or carbon compound, and the device current If and the emission current I
e becomes stable.

With reference to FIGS. 9 and 10, a description will be given of the characteristic evaluation of the electron-emitting device manufactured by the above-described configuration and manufacturing method, which is suitable for the present invention.

FIG. 9 is a schematic configuration diagram of a measurement and evaluation device for measuring the electron emission characteristics of the device having the configuration shown in FIG. In FIG. 9, the same components as those in FIG.
The same reference numerals are used. Reference numeral 151 denotes a power supply for applying a device voltage Vf to the electron-emitting device; 150, an ammeter for measuring a device current If flowing through the conductive thin film 104 between the device electrodes 102 and 103; An anode electrode for capturing the emission current Ie emitted from the electron emission unit 105; 153, a high-voltage power supply for applying a voltage to the anode electrode 154; 152, an electron emission unit 1 of the device.
This is an ammeter for measuring the emission current Ie emitted from the device 05.

The electron-emitting device and the anode 1
Numeral 54 is installed in a vacuum device, and the vacuum device is provided with equipment necessary for a vacuum device such as an exhaust pump 156 and a vacuum gauge, so that measurement and evaluation of this element can be performed under a desired vacuum. I have. In addition, the exhaust pump 156 includes a normal high vacuum device system including a turbo pump and a rotary pump, and further includes an ultra-high vacuum device system including an ion pump. The entire vacuum device 155 and the substrate can be heated up to 200 ° C. by a heater (not shown). Therefore, the present measuring apparatus can also perform the steps after the energization forming described above. The voltage of the anode electrode 154 is 1 kV
-10 kV, and the distance H between the anode electrode 154 and the electron-emitting device was measured in the range of 2 mm to 8 mm.

FIG. 10 shows a typical example of the relationship between the emission current Ie, the device current If, and the device voltage Vf measured by the measurement and evaluation apparatus shown in FIG. Note that the emission current Ie is significantly smaller than the element current If, and thus is shown in arbitrary units in FIG. 10, and the vertical and horizontal axes are linear scales.

As is apparent from FIG. 10, the surface conduction electron-emitting device suitable for the present invention has three characteristic characteristics with respect to the emission current Ie.

First, the present device has a device voltage Vf equal to or higher than a certain voltage (called a threshold voltage, Vth in FIG. 10).
Is applied, the emission current Ie sharply increases, while the emission current Ie is hardly detected below the threshold voltage Vth. That is, it is a nonlinear element having a clear threshold voltage Vth with respect to the emission current Ie.

Second, since the emission current Ie depends on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf.

Third, the amount of the charges captured by the anode electrode 154 depends on the time during which the device voltage Vf is applied.
That is, the amount of charge captured by the anode electrode 154 is
It can be controlled by the time for applying the element voltage Vf.

As described above, due to the characteristic characteristics of the surface conduction electron-emitting device suitable for the present invention, according to the input signal,
The electron emission characteristics can be easily controlled even in an electron source in which a plurality of electron emission elements are arranged, an image forming apparatus, and the like.
It can be applied to various fields.

An example of a more preferable characteristic in which the element current If monotonously increases with respect to the element voltage Vf (referred to as MI characteristic) is shown by a solid line in FIG. The voltage-controlled negative resistance (VC
(Referred to as an NR characteristic). The characteristics of the device current If depend on the manufacturing method, measurement conditions at the time of measurement, and the like. In this case, also in this case, the electron-emitting device has the three characteristics described above.

Further, in the above-described evaluation apparatus, a voltage is applied between the device electrodes
When more electrons are emitted and a voltage is applied to the anode electrode 154 by the high-voltage power supply 153, the emitted electrons
The positive electrode side of the voltage applied to the element (in FIG. 9, the element electrode 102
Side). Such a radiation characteristic corresponds to the substrate 1
It is considered that the potential distribution in a plane parallel to 01 becomes asymmetric with respect to the electron-emitting portion 105.

Next, the manufacturing process of the electron source of this embodiment shown in FIG. 1 will be described.

First, as shown in FIG. 2, printing and baking are performed on the substrate 1 which has been sufficiently cleaned in advance to form device electrodes 2 and 3. Usually, since the conductive thin film 4 for forming the electron emitting portion is a film that is significantly thinner than the respective wiring layers 6 and 8, problems such as wettability and step holding properties are avoided, and the conductive thin film 4 for forming the electron emitting portion is formed. The device electrodes 2 and 3 are provided to improve the electrical connection between the conductive thin film 4 and each of the wiring layers 6 and 8. Therefore, when each of the wiring layers 6 and 8 is formed of a thin film by, for example, a sputtering method or the like, the device electrodes 2 and 3 are not necessarily provided, and may be formed simultaneously with the formation of each of the wiring layers 6 and 8 described later. It is possible.

The device electrodes 2 and 3 may be formed by a method using a vacuum system such as a vacuum deposition method, a sputtering method, or a plasma CVD method, or by printing and firing a thick film paste in which a metal component and a glass component are mixed in a solvent. There is a method of forming a thick film. In order to shorten the manufacturing process, the device electrodes 2 and 3 may be formed by a thick film printing method that does not require a photolithography process. It is desirable that the film thickness be small in the vicinity of. Therefore, when the thick film printing method is used, it is preferable to use a so-called MOD paste composed of an organometallic compound as the paste used at that time. Of course, other film forming methods may be used. The constituent materials of the device electrodes 2 and 3 are not particularly limited as long as they are electrically conductive substances.

In this embodiment, a soda lime glass substrate is used as the substrate 1 and the device electrodes 2 and 3 are formed by a thick film printing method. The paste used at this time was a MOD paste, and the metal component was Au. The printing method is a screen printing method. After printing, drying is performed at 70 ° C. for 10 minutes, and then main firing is performed. The firing temperature is 550 ° C. and the peak retention time is about 8 minutes. The size of one of the device electrodes 2 and 3 after printing and sintering is 350 × 150 μm in width × length in the facing direction of the device electrodes 2 and 3 and 0.3 μm or less in thickness. Electrode 2,
The spacing between the three was 2 micrometers.

Next, as shown in FIG.
The first wiring layer 6 is formed so as to electrically connect one of the device electrodes 2 and 3 arranged in the Y direction. The method for forming the first wiring layer 6 includes the device electrodes 2 and 3
Can be applied to the first wiring layer 6, but unlike the device electrodes 2 and 3, it is preferable that the first wiring layer 6 has a large thickness in order to reduce electric resistance. Therefore, as a method for forming the first wiring layer 6, it is preferable to use a thick film printing method. Any paste material may be used as long as it is conductive, such as Ag, Au, Pt, or Pd.
And noble metals such as Cu, Ni, Al, and Cr, or fine particles composed of a mixture thereof are dispersed in a vehicle. Further, those having high viscosity and high thixotropy are suitable for forming fine wires. Of course, thin-film wiring can be applied, but it takes more time to increase the film thickness than the thick-film printing method. In this embodiment,
Thick film screen printing was used. The paste used is A
In the g paste, the metal component is Ag. After screen printing with a desired pattern, drying is performed at 110 ° C. for 20 minutes, and baking is performed at 550 ° C. for a peak holding time of 15 minutes to form a first wiring layer 6 having a width of 100 μm and a thickness of 12 μm. I got

After forming the first wiring layer 6, an interlayer insulating layer 7 is formed as shown in FIG. As is apparent from FIG. 1, the width of the interlayer insulating layer 7 is set wider than the width of the second wiring layer 8 formed in the next step. The reason is to prevent a short circuit at the intersection of the first wiring layer 6 and the second wiring layer 8. As a constituent material of the interlayer insulating layer 7, for example, a film made of a thick film paste containing no metal component, such as a SiO ₂ thin film or a material obtained by dispersing glass fine particles or oxide fine particles in a vehicle, or the like, can maintain the insulating property. Anything that can be done is acceptable.

In this embodiment, the interlayer insulating layer 7 was formed by the thick film screen printing method. As paste, PbO
Was used as a main component, and a paste in which a glass binder was mixed was used. The firing temperature is 550 ° C and the peak retention time is about 15
Minutes. The interlayer insulating layer 7 after screen printing and firing of a desired pattern had a width of 500 micrometers and a thickness of 30 micrometers or less. In general, printing and baking are performed twice on the interlayer insulating layer 7 in order to secure insulation between the first wiring layer 6 and the second wiring layer 8. That is, after the first printing and firing, printing is performed again. This ensures insulation.

Then, as shown in FIG. 5, the interlayer insulating layer 7
A second wiring layer 8 is formed thereon. The second wiring layer 8
It has a comb-like pattern projecting in a direction parallel to the first wiring layer 6 corresponding to the position of the other element electrode 2 among the element electrodes 2 and 3 arranged in the X direction. , The second wiring layer 8 is electrically connected to the other element electrode 2. Regarding the film thickness of the second wiring layer 8, the first wiring layer 6
For the same reason as described above, a thicker one is preferable, and as a forming method, a method similar to the method of forming the first wiring layer 6 can be applied. In this embodiment, a thick film screen printing method was used. The paste used was an Ag paste, and the metal component was Ag. After screen printing with the desired pattern,
After drying for 0 minutes, baking was performed at 550 ° C. and a peak holding time of 15 minutes, and the width was 300 micrometers and the thickness was 1
A second wiring layer 8 having 0 μm and a connection pattern with the other device electrode 2 was obtained.

Thus, the matrix wiring portion is completed. Of course, the paste material, the printing method, and the like are not limited to those described above.

Finally, as shown in FIG. 1, the pair of device electrodes 2 and 3 are connected to form a conductive thin film 4 for forming an electron-emitting portion.
Is formed, and the conductive thin film 4 is subjected to an energization forming process to form an electron emission portion, thereby completing an electron source. A conventional method can be applied as it is to the method of forming the conductive thin film 4 and the energization forming process.

Specifically, organic palladium (CCP4230, manufactured by Okuno Pharmaceutical Co., Ltd.) is spin-coated by a spinner across the pair of device electrodes 2 and 3 and then heated to 300 ° C.
For 10 minutes to form a conductive thin film 4 made of Pd. The conductive thin film 4 thus formed
Is composed of fine particles containing Pd as a main element, has a thickness of 10 nm, and has a sheet resistance of 5 × 10 ⁴ Ω / □.
Met. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure not only in a state where the fine particles are individually dispersed and arranged, but also in a state where the fine particles are adjacent to each other or overlapped (including an island shape). ), And the particle diameter means the diameter of the fine particles whose particle shape can be recognized in the above state. By patterning the film containing Pd as a main element using a photolithography method, the element manufacturing process up to the energization forming process is completed.

In this embodiment, the energization forming process
As shown in FIG. 8 (a), this was performed by continuously applying a pulse having a pulse peak value at a constant voltage. The applied pulse at this time has a pulse width T1 of 1 millisecond, a pulse interval T2 of 10 milliseconds, a peak value of 14 V, and about 10 ^-6 T
This was performed for 60 seconds under a vacuum atmosphere of orr. The electron-emitting portion thus produced was in a state in which fine particles containing palladium as a main component were dispersed and arranged, and the average particle size of the fine particles was 3 nanometers.

As described above, the second wiring layer 8
By providing a pattern protruding in parallel with the first wiring layer 6, the device electrodes 2, 3 are directly connected at the same time as the formation of the respective wiring layers 6, 8 to which they are electrically connected. No special process or structure for connecting the device electrodes 2 and 3 to the respective wiring layers 6 and 8 is required. As a result, simplification of the manufacturing process of the electron source and simplification of the wiring structure of the device electrodes 2 and 3 are achieved. In addition, the simplification of the wiring structure improves the reliability of the connection portion between the element electrodes 2 and 3 and the wiring layers 6 and 8, and reduces the area of the portion controlled by the wiring, so that high-density wiring can be achieved. This makes it possible to arrange the device electrodes 2 and 3 and thus the electron-emitting devices 9 at a higher density.

Next, an example of an image forming apparatus using the electron source shown in FIG. 1 will be described with reference to FIGS. FIG. 11 is a basic configuration diagram of an example of a display panel of an image forming apparatus using the electron source shown in FIG.
FIG. 13 is a diagram showing an example of the arrangement of phosphors in the phosphor film of the display panel shown in FIG. 11. FIG. 13 shows an image forming apparatus using the electron source shown in FIG. FIG. 2 is a block diagram of a drive circuit of an example of performing display by using a display.

In FIG. 11, the rear plate 81 includes
An electron source 80 similar to that shown in FIG. 1 is fixed. The electron emitting elements 87 of the electron source 80 arranged in an m × n matrix form x wirings 88 and n each composed of m wirings, each constituting a simple matrix wiring.
It is connected to a y-wiring 89 composed of two wirings. Here, the x wiring 88 corresponds to the second wiring layer 8 shown in FIG. 1, and the y wiring 89 corresponds to the first wiring 6 shown in FIG.

The electron source 80 has a fluorescent film 84 as an image forming member and a metal back 85 on the inner surface of a glass substrate 83.
Are formed facing each other with a support frame 86 interposed therebetween. Electron source 80 and metal back 8
During the period 5, a high voltage for accelerating the electron beam emitted from the electron source 80 is applied by a power supply (not shown). The rear plate 81, the support frame 86, and the face plate 82 are air-tightly fixed (sealed) to each other, and the rear plate 81, the support frame 86, and the face plate 82 form an envelope 90. The sealing of the rear plate 81, the support frame 86 and the face plate 82 is performed by applying frit glass or the like to the fixed surfaces of each other,
It is performed by baking at 00 ° C. to 500 ° C. for 10 minutes or more. Each of the x wirings 88 has m external terminals Dx1, Dx2,..., Dx provided on the support frame 86, respectively.
m are connected, and each of the y wirings 89 has n external terminals Dy1, Dy2,... provided on the support frame 86, respectively.
Connected to Dyn.

As described above, the envelope 90 is composed of the face plate 82, the support frame 86, and the rear plate 81. Since the rear plate 81 is provided mainly for the purpose of reinforcing the strength of the electron source 80, If the electron source 80 itself has a sufficient strength, the separate rear plate 81 is not always necessary. The support frame 86 is directly sealed to the electron source 80, and the face plate 82, the support frame 86 and the electron source 8 are sealed.
0 may constitute the envelope 90. Also,
By providing a support (not shown) called a spacer between the face plate 82 and the rear plate 81, the structure of the envelope 90 having sufficient strength against the atmospheric pressure can be obtained.

In the case of monochrome, the fluorescent film 84 is made of only a phosphor which is an image forming member. In the case of color, as shown in FIG. 12, depending on the arrangement of the fluorescent material, a black stripe called a black stripe or a black matrix is used. It is composed of a conductive material 84b and a phosphor 84a. The purpose of providing the black stripes and the black matrix is to make the color mixing and the like inconspicuous by making the painted portions between the phosphors 84a of the three primary color phosphors necessary for color display less noticeable. The purpose is to suppress a decrease in contrast due to external light reflection. The material of the black stripe is not limited to a commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection. As a method of applying the phosphor onto the glass substrate 83, a precipitation method or a printing method is used regardless of monochrome or color. Further, in the case of a collar, a slurry method can be used.

A metal back 85 is usually provided on the inner surface side of the fluorescent film 84. The purpose of the metal back 85 is
Improving brightness by specularly reflecting light toward the inner surface side of the light emitted from the phosphor 84 a toward the face plate 82, acting as an electrode for applying an electron beam accelerating voltage, This is to protect the phosphor 84a from damage caused by the collision of the generated negative ions. After forming the fluorescent film 84, the metal back 85 smoothes the inner surface of the fluorescent film 84 (usually called filming).
And then depositing Al by vacuum evaporation or the like.

The face plate 82 may be provided with a transparent electrode (not shown) on the outer surface of the fluorescent film 84 in order to further enhance the conductivity of the fluorescent film 84.

When the above-mentioned sealing is performed, in the case of color, the phosphors 84b of the respective colors must correspond to the electron-emitting devices 87, so that it is necessary to perform sufficient alignment.

When the rear plate 81, the support frame 86, and the face plate 82 are sealed with each other to form the envelope 90, the envelope 90 is exhausted through an exhaust pipe (not shown).
The inside is evacuated to a degree of vacuum of about 10 ⁻⁷ Torr, and the envelope 9 is evacuated.
0 is sealed. In addition, getter processing may be performed in order to maintain the degree of vacuum after sealing the envelope 90. This is because immediately before or after sealing of the envelope 90, the envelope 9 is heated by a heating method such as resistance heating or high-frequency heating.
This is a step of heating a getter (not shown) arranged at a predetermined position within 0 to form a deposited film. The getter usually contains Ba or the like as a main component, and maintains a vacuum degree of, for example, 10 <-5> to 10 <-7> Torr by the adsorption action of the deposited film. Steps after the energization forming process of the electron-emitting device 87 are appropriately set.

Next, a schematic configuration of a driving circuit for performing a television display based on an NTSC television signal will be described.
This will be described with reference to the block diagram of FIG. Reference numeral 191 is the display panel shown in FIG. 11, 192 is a scanning circuit, 193 is a control circuit, 194 is a shift register, 19
5 is a line memory, 196 is a synchronization signal separation circuit, 197
Denotes a modulation signal generator, V _x, V _a is a DC voltage source, respectively.

[0096] Hereinafter, will be described the function of each part, the display panel 191 is first is connected to an external electric circuit through terminals Dx1 to Dxm, and Dy1 to Dyn, and a high-voltage terminal H _v. The terminals Dx1 to Dxm sequentially drive electron sources provided in the display panel 191, that is, electron emission element groups arranged in a matrix of m rows and n columns in a matrix, one row at a time (n elements). A scanning signal for moving is applied.

On the other hand, to the terminals Dy1 to Dyn, a modulation signal for controlling the output electron beam of each of the electron-emitting devices in one row selected by the scanning signal is applied. Further, the high-voltage terminal H _v, the DC voltage source V _a, for example, a DC voltage of 10kV is applied, which is sufficient energy to excite the phosphors to the electron beams output from the electron-emitting devices Is an accelerating electrode for providing

Next, the scanning circuit 192 will be described.
Scanning circuit 192, m number of switching elements in the interior as it has a (in the figure, it is shown schematically in to no S1 Sm), each switching element, the output voltage or 0V (the ground level of the DC voltage source V _x ) Is selected and electrically connected to the terminals Dx1 to Dxm of the display panel 191. Each of the switching elements S1 to Sm operates based on a control signal output from the control circuit 193.
It can be easily configured by combining the switching elements as described above.

In the case of the present embodiment, the DC voltage source Vx _supplies a drive voltage applied to an unscanned element based on the characteristics (electron emission threshold voltage) of the electron emission element. It is set so as to output a constant voltage lower than the emission threshold voltage.

The control circuit 193 receives an external input.
Components so that appropriate display is performed based on the
This has the function of matching the operations of. Next explained
The synchronization signal T sent from the synchronization signal separation circuit 196_SYNC
T for each part based on _SCANAnd T_SFTAnd T
_MRYAre generated.

The synchronizing signal separating circuit 196 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside. As is well known, a frequency separating (filter) is used. With the circuit,
It can be easily configured. Sync signal separation circuit 196
Are separated from each other by a vertical synchronizing signal and a horizontal synchronizing signal, as is well known. However, for convenience of explanation, the synchronizing signal is illustrated as a _TSYNC signal. On the other hand, the luminance signal component of the image separated from the television signal is referred to as DATA for convenience.
This signal is input to the shift register 194.

The shift register 194 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image. The shift register 194 converts the DATA signal into a control signal T _SFT sent from the control signal 193. (Ie, the control signal T _SFT may be a shift clock of the shift register 194).
The data for one line of the serial / parallel-converted image (corresponding to the drive data for n electron-emitting devices)
The shift register 194 outputs n parallel signals Id1 to Idn.

The line memory 195 is a storage device for storing data of one line of an image for a required time only, and stores the contents of Id1 to Idn as appropriate according to a control signal T _MRY sent from the control circuit 193. . The stored contents are output as I'd1 to I'dn and input to the modulation signal generator 197.

The modulation signal generator 197 is a signal source for appropriately driving and modulating each of the electron-emitting devices in accordance with each of the image data I'd1 to I'dn. Or display panel 1 through Dyn
The voltage is applied to the electron-emitting device in 91.

As described above, the electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, as described above, electron emission has a clear threshold voltage Vth, and electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes in accordance with the change in the voltage applied to the element. The value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may be changed by changing the material, configuration, and manufacturing method of the electron emission element. The same can be said.

That is, when a pulse-like voltage is applied to the device, for example, when a voltage lower than the electron emission threshold is applied, no electron emission occurs, but when a voltage higher than the electron emission threshold is applied. Outputs an electron beam. At that time, first, it is possible to control the intensity of the output electron beam by changing the peak value Vm of the pulse. Second, it is possible to control the total amount of charge of the output electron beam by changing the pulse width Pw.

Therefore, as a method of modulating the electron-emitting device in accordance with the input signal, a voltage modulation method, a pulse width modulation method, and the like can be mentioned.
As the modulation signal generator 197, a voltage modulation type circuit that generates a voltage pulse of a fixed length but appropriately modulates the peak value of the pulse according to input data is used.

In order to implement the pulse width modulation method,
As the modulation signal generator 197, a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data is used.

[0109] Through a series of operations described above, television display can be performed using the display panel 191. In addition,
Although not specifically described in the above description, the shift register 1
The digital memory 94 or the line memory 195 may be of a digital signal type or an analog signal type, as long as the serial / parallel conversion and storage of the image signal are performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 196 into a digital signal. This is provided with an A / D converter at the output of the synchronization signal separation circuit 196. Needless to say, it is easily possible. In connection with this, the line memory 1
It goes without saying that the circuit used for the modulation signal generator 197 is slightly different depending on whether the output signal of 95 is a digital signal or an analog signal. That is, in the case of a digital signal, in the case of the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 197, and an amplification circuit or the like may be added as necessary. In the case of the pulse width modulation method, the modulation signal generator 197 compares, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and an output value of the counter with an output value of the line memory 195. If a circuit combining a comparator is used, those skilled in the art can easily configure the circuit. If necessary, an amplifier for voltage-amplifying the pulse-width-modulated signal output from the comparator to the drive voltage of the electron-emitting device may be added.

On the other hand, in the case of an analog signal, in the case of the voltage modulation method, an amplifier circuit using, for example, a well-known operational amplifier may be used as the modulation signal generator 197.
If necessary, a level shift circuit or the like may be added.
In the case of the pulse width modulation method, for example, a well-known voltage controlled oscillator (VCO) may be used, and an amplifier for amplifying the voltage up to the drive voltage of the electron-emitting device may be added as necessary. Is also good.

In the image display device completed as described above, electrons are emitted by applying a voltage to each of the electron-emitting devices 87 of the electron source 80 through the terminals Dx1 to Dxm and Dy1 to Dyn, so that the high-voltage terminal H through _v
A high voltage is applied to the metal back 85 or the transparent electrode (not shown) to accelerate the electron beam and cause it to collide with the fluorescent film 84,
An image can be displayed by exciting and emitting light.
An electron source 80 having a wiring structure as shown in FIG.
Is used, the density of the wiring and the electron-emitting device 87 can be increased, so that the number of pixels per unit area is increased and an image forming apparatus having high resolution is achieved.

The configuration described above is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display or the like. For example, detailed portions such as materials of each member are not limited to the above-described contents. Is appropriately selected so as to be suitable for the use of the image forming apparatus. Also, the NTSC system has been described as an example of an input signal, but the present invention is not limited to this, and PAL, SEC
Various systems such as the AM system may be used, and a TV signal (for example, a high-definition TV including the MUSE system) including a large number of scanning lines may be used.

In this embodiment, the second wiring layer 8 (x
The example in which the comb-shaped pattern of the wiring 88) is in contact with the entire area in the direction (Y direction) perpendicular to the opposing direction of the other element electrode 2 (see FIG. 1) is shown. When the second wiring layer 8 is formed of a particularly thick film and the other element electrode 2 is on the positive electrode side, the second wiring layer 28 is connected to the other element electrode 22 as shown in FIG. It is preferable to provide a comb-shaped projecting pattern of the second wiring layer 28 so that the electrodes 22 and 23 come into contact with each other at the ends in the direction perpendicular to the facing direction.

This is because, as described above, the electrons emitted from the surface-conduction type electron-emitting device 29 have a radiation characteristic of being shifted toward the positive electrode side and fly, thereby preventing the electrons from being absorbed into the wiring. It is. That is, the second wiring layer 2
When the other element electrode 22 in contact with 8 is a positive electrode, if the second wiring layer 28, which is a thick film, is in the vicinity of the conductive thin film 24 including the electron-emitting portion, electrons emitted from the electron-emitting portion May be sucked into the second wiring layer 28 without reaching the predetermined position.
The contact position with the other element electrode 22 of the
Since the second wiring layer 28 is not positioned in the direction in which the emitted electrons slide by contacting at the end of the direction perpendicular to the facing direction of the second wiring 23, the emitted electrons are It will not be sucked into the layer 28.

On the other hand, when one of the element electrodes 23 to which the first wiring layer 26 is in contact has a positive polarity, the first wiring layer is in contact with the end of the one of the element electrodes 23 for the same reason. By arranging 26, it is possible to suppress the emitted electrons from being absorbed into the first wiring layer 26. Of course, regardless of the positive electrode and the negative electrode, the first wiring layer 26 and the second wiring layer 28 may be arranged so as to be in contact with the ends of the device electrodes 22 and 23, respectively.

(Second Embodiment) FIG. 15 is a plan view of a main part of a second embodiment of the electron source according to the present invention. In this embodiment, the other device electrode 20 of the electron-emitting device 209 is provided on the substrate 201.
2 is formed for each of the other device electrodes 202, and the second wiring layer 208 has a comb-shaped pattern that contacts each of the partial wires 210. That is, the second wiring layer 208 includes the partial wiring 2
10, the other device electrode 20 of the electron-emitting device 209
2 are electrically connected. The other configurations of the electron-emitting device 209, the first wiring layer 206, and the interlayer insulating layer 207 may be the same as those in the first embodiment, and a description thereof will not be repeated.

Next, the manufacturing process of the electron source of this embodiment will be described.

First, as shown in FIG. 16, after sufficiently cleaning the substrate 201 made of blue plate glass,
The device electrodes 202 and 2 are formed of a Pt thin film on which a Ti thin film is formed by photolithography to form an undercoat layer.
03 is formed. The size of one device electrode 202, 203 is the width of the device electrode 202, 203 in the facing direction × the width.
300 x 200 micrometers in length, 100 in thickness
The distance between the device electrodes 202 and 203 was 2 micrometers. Further, a pair of device electrodes 2
The vertical and horizontal pitches of 02 and 203 were set to 700 micrometers × 500 micrometers.

Next, as shown in FIG. 17, a first wiring layer 206 in contact with one element electrode 203 and a partial wiring 210 in contact with the other element electrode 202 are formed by a screen printing method and fired. The first
The electrical connection between the wiring layer 206 and one element electrode 203 and the electrical connection between the partial wiring 210 and the other element electrode 202 were obtained. The paste used was an Ag paste.

First wiring layer 206 and partial wiring 210
Is formed, the first wiring layer 20 is formed as shown in FIG.
An interlayer insulating layer 207 orthogonal to 6 was formed by a screen printing method and fired. The paste is a glass paste. Here, in FIG. 18, although the interlayer insulating layer 207 is formed adjacent to the partial wiring 210, the interlayer insulating layer 207 is formed.
And the partial wiring 210 may overlap each other or may be separated from each other. Then, as shown in FIG. 19, a second wiring layer 208 is formed on the interlayer insulating layer 207.
The second wiring layer 208 has a comb-shaped pattern that protrudes in a direction parallel to the first wiring layer 206 and contacts the partial wiring 210, corresponding to the position of the partial wiring 210. With the formation of the layer 208, the second wiring layer 208 is electrically connected to the other element electrode 202 through the partial electrode 210. The method for forming the second wiring layer 208 is the first method.
A method similar to the method of forming the wiring layer 206 can be applied.
Here, the second wiring layer 208 is formed by a screen printing method, and the used paste is an Ag paste.

Finally, as shown in FIG. 15, a pair of device electrodes 202 and 203 are connected to form a conductive thin film 204 for forming an electron emission portion, and the conductive thin film 204 is subjected to an energization forming process. To form an electron emission portion, and an electron source is completed. Also in this embodiment, the conductive thin film 204 is a thin film composed of fine particles of Pd, and the thin film obtained by applying and firing the organic metal solution is reverse-etched with the Cr thin film so that the thin film remains within the space between the device electrodes 202 and 203. It was formed by patterning by a method.

As described above, simultaneously with the first wiring layer 206 in contact with one of the element electrodes 203, the partial wiring 210 in contact with the other element electrode is formed, and the second wiring layer is formed through the partial wiring 210. By connecting 208 to the other element electrode 202, the tolerance for the displacement of the second wiring layer 208 can be expanded, and the alignment of the second wiring layer 208 becomes easy.

Also in this embodiment, the electron-emitting device 209 is used.
In order to prevent the electrons emitted from the substrate from being absorbed into the wiring, the contact position of the partial wiring 210 with the other element electrode 202 may be an end in a direction perpendicular to the direction in which the element electrodes 202 and 203 face each other.

(Third Embodiment) FIG. 20 is a plan view of a main part of a third embodiment of the electron source according to the present invention. In this embodiment, a large number of surface conduction electron-emitting devices 309 arranged in a matrix on the substrate 301 are each provided with a pair of device electrodes 3.
02 and 303 and a conductive thin film 304 connecting the pair of element electrodes 302 and 303 are the same as in the first embodiment, and the wiring structure of the element electrodes 302 and 303 is different from that of the first embodiment. Here is an example.

In FIG. 20, the electron source of this embodiment is basically electrically connected to a first wiring layer 306 and a second wiring layer 308 formed in parallel in the X direction. A plurality of electron-emitting devices 309 arranged in the direction are defined as one unit (this is called an element row), and a plurality of electron-emitting devices 309 are arranged in the Y direction.

First Wiring Layer 306 and Second Wiring Layer 3
Reference numeral 08 denotes comb-shaped wirings formed at intervals in the Y direction with the electron-emitting device 309 interposed therebetween, and portions corresponding to the teeth of the respective combs are alternately arranged to face each other. The wiring layer 306 is electrically connected to one element electrode 303, and the second wiring layer 308 is electrically connected to the other element electrode 302.

Next, the manufacturing process of the electron source of this embodiment will be described.

First, as shown in FIG. 21, in the same manner as in the first embodiment, element electrodes 302 and 303 are placed on a cleaned substrate 301 (here, a soda-lime glass substrate is used).
To form In this embodiment, a thick film printing method is used as a method for forming the element electrodes 302 and 303. The paste used at this time was a MOD paste, and in this embodiment, Pt was used as a metal component. The printing method is a screen printing method. After printing, drying is performed at 70 ° C. for 10 minutes, and then main firing is performed. The firing temperature is 550 ° C. and the peak retention time is about 8 minutes. The thickness of the device electrodes 302 and 303 after printing and firing was 0.25 micrometers or less.

Next, as shown in FIG. 22, a first wiring layer 306 and a second wiring layer 308 are formed. Since the first wiring layer 306 and the second wiring layer 308 are wirings each having a comb-like pattern and do not overlap each other, the first wiring layer 306 and the second wiring layer 308 must be formed at the same time. Can be. Moreover, the first wiring layer 306
By forming the second wiring layer 308, connection between one element electrode 303 and the first wiring layer 306 and connection between the other element electrode 302 and the second wiring layer 308 are made.

In this embodiment, as the method for forming the first wiring layer 306 and the second wiring layer 308, a thick film screen printing method is used. The paste used at this time was an Ag paste, and the metal component was Ag. After performing screen printing with a desired pattern and drying at 110 ° C. for 20 minutes, baking at 550 ° C. and a peak holding time of 15 minutes was performed.
A first wiring layer 306 and a second wiring layer 308 having a width of 300 micrometers and a thickness of 10 micrometers were obtained.

As described above, wiring portions to the device electrodes 302 and 303 are completed. Of course, the paste material and the printing method are not limited to those described above, as in the first embodiment. First wiring layer 306 and second wiring layer 308
Is formed, as shown in FIG.
A conductive thin film 304 that connects between the layers 2 and 303 is formed. Then, the conductive thin film 304 is subjected to an energization forming process to form an electron emission portion on the conductive thin film 304, and an electron source is completed. The method for forming the conductive thin film 304 and the energization forming process may be the same as in the first embodiment, and a description thereof will be omitted.

Based on the above configuration, by appropriately applying a drive voltage between the first wiring layer 306 and the second wiring layer 308 of each element row, the electron-emitting elements 309 are independently provided for each element row. Can be driven. That is, a voltage equal to or higher than the electron emission threshold may be applied to an element row that wants to emit electrons, and a voltage equal to or lower than the electron emission threshold may be applied to an element row that does not emit electrons.

Next, an example of an image forming apparatus using the electron source shown in FIG. 20 will be described with reference to FIG.
FIG. 23 is a basic configuration diagram of an example of a display panel of an image forming apparatus using the electron source shown in FIG.

In FIG. 23, an electron source 380 similar to that shown in FIG. 20 is fixed to a rear plate 381. Between the electron source 380 and the face plate 382, a plurality of stripe-shaped grid electrodes 3 arranged orthogonal to the element rows corresponding to the electron-emitting elements 309.
91 are provided. Each grid electrode 391 modulates the electrons emitted from the electron-emitting device 309, and has a circular opening 391 a for passing electrons corresponding to each electron-emitting device 309. The shape and arrangement of the grid electrodes 391 are not necessarily the same as those shown in FIG. For example, a large number of openings may be provided in the form of a mesh as openings, or the openings may be provided around or near the electron-emitting device 309. Each grid electrode 391 and electron source 380
These wiring layers 306 and 308 are drawn out of the envelope by external terminals (not shown). Further, each container outer terminal is electrically connected to a control circuit (not shown). The other configuration is the same as that of the first embodiment, and the description is omitted.

In the image forming apparatus of this embodiment, the number of element rows is one.
Simultaneously applying a modulation signal for one line of an image to the grid electrode rows in synchronization with the sequential driving (scanning) of each row, controls the irradiation of the phosphors with the electrons emitted from the electron-emitting devices 309. The image can be displayed line by line.

As described above, the electron source 38 of the present embodiment is used.
0, when the electron-emitting devices 309 are connected for each element row, the first wiring layer 306 and the second wiring layer 3
08 is in the form of a comb, and the electron-emitting device 30
By connecting to the nine device electrodes 302 and 303, the first wiring layer 306 and the second wiring layer 308 can be directly connected to the device electrodes 302 and 303. As a result, the wiring structure is simplified, and the reliability of the connection between the element electrodes 302 and 303 and the wiring layers 306 and 308 is improved. By simplifying the wiring structure, the area controlled by the wiring is reduced, and the device electrodes 302 and 303, and thus the electron-emitting devices 309 can be arranged at a higher density. Moreover, the first wiring layer 306 and the second wiring layer 3
08 do not overlap with each other, so that the first wiring layer 30
It is not necessary to provide an insulating structure between the first wiring layer 306 and the second wiring layer 3.
08 can be formed simultaneously, so that the number of manufacturing steps can be further reduced as compared with the first embodiment.

By using such an electron source 380 in an image forming apparatus, it is possible to easily manufacture a high-resolution image forming apparatus having a large number of pixels per unit area. In the electron source 380 of this embodiment, the first
As in the embodiment, as shown in FIG.
26 and the contact position of the second wiring layer 328 with the other device electrode 322 are:
The first wiring layer 326 and the second wiring layer 326 are formed so as to be ends of the device electrodes 322 and 323 in the direction perpendicular to the facing direction.
A pattern protruding in a comb shape may be provided on the wiring layer 328 to prevent the electrons emitted from the electron-emitting device 329 from being sucked into the wiring. In FIG. 24, both wiring layers 326,
An example is shown in which the protruding pattern 328 is provided so as to be in contact with an end in a direction perpendicular to the opposing direction of the element electrodes 322 and 323, but it is sufficient that at least the positive electrode side is in such a contact.

As is clear from the embodiments described above, the electron source according to the present invention basically uses a cold-cathode type electron-emitting device as an electron-emitting device. An electron-emitting device is used. Cold cathode type electron-emitting devices can be precisely positioned and formed on a substrate by using a manufacturing technique such as photolithography or etching. Therefore, a large number of cold-cathode electron-emitting devices can be arranged at minute intervals. In addition, as compared with a hot cathode conventionally used in a CRT or the like, the cathode itself and its peripheral portion can be driven at a relatively low temperature, so that an electron source with a finer arrangement pitch can be easily realized.

As such a cold cathode type electron-emitting device, there are a MIM type, an FE type, a surface conduction type and the like, and among them, a surface conduction type electron-emitting device is particularly preferable. That is, the thickness of the insulating layer and the upper electrode needs to be controlled relatively precisely in the MIM type electron-emitting device, and the tip shape of the needle-shaped electron-emitting portion is precisely controlled in the FE type electron-emitting device. There is a need to. For this reason, these elements have a relatively high manufacturing cost, and it is sometimes difficult to manufacture a large-area element due to limitations in the manufacturing process. On the other hand, the surface conduction type electron-emitting device has a simple structure and a simple structure, and a large-area electron-emitting device can be easily manufactured. In recent years, particularly in a situation where a large-area and inexpensive display device is required, it can be said that the cold-cathode type electron-emitting device is particularly suitable.

Further, the electron source of the present invention can be applied to a case where a member to be irradiated with emitted electrons is a member other than an image forming member, such as an electron microscope, and an electron beam which does not specify a member to be irradiated. It can also take the form of a generator.

Further, in each of the embodiments described above, an image display device for displaying an image is described as an example of an image forming device. However, according to the concept of the present invention, for example, a photosensitive drum and a light emitting diode are used. It can also be used as an alternative light source, such as a light emitting diode of a configured optical printer. In this case, the image forming member is not limited to a substance that directly emits light, such as the phosphor used in the above-described embodiment, and a member that forms a latent image by electron charging may be used. it can.

[0143]

Since the present invention is configured as described above, it has the following effects.

In the electron source and the method of manufacturing the same according to the present invention, as the wiring to the electron-emitting devices arranged in a matrix,
In the case where a plurality of row direction wirings and a plurality of column direction wirings are formed so as to cross each other via an insulating layer, each row direction wiring is directly and electrically connected to one element electrode of the electron-emitting device, and Since the directional wiring has a comb-shaped pattern that is electrically connected to the other element electrode of the electron-emitting device directly or via a partial wiring, a special structure and process for connecting the element electrode to each wiring are provided. Is no longer needed. as a result,
Simplification of the manufacturing process of the electron source and simplification of the wiring structure of the element electrode can be achieved. In addition, the simplification of the wiring structure improves the reliability of the connection portion between the device electrode and each wiring, and reduces the area of the portion controlled by the wiring, so that high-density wiring becomes possible. The emission elements can be arranged at a higher density.

On the other hand, as a wiring to the electron-emitting devices arranged in a matrix, a plurality of first rows are provided for each row of the electron-emitting devices in a direction perpendicular to the device electrode facing direction with the electron-emitting devices therebetween. In the case where the direction wiring and the second row direction wiring are formed, each row direction wiring comes into contact with the element electrode in a pattern protruding in a comb shape and is electrically connected. As a result, only the first row-direction wiring and the second row-direction wiring form wiring with the device electrode of the electron-emitting device,
Simplification of the manufacturing process of the electron source and simplification of the wiring structure of the element electrode can be achieved. In addition, since each row direction wiring can be formed at the same time, the wiring process and the wiring structure can be further simplified.

Further, in the electron source of the present invention, since each wiring is formed by a thick film printing method, each wiring can be formed without requiring a photolithography step.
The process of forming each wiring can be shortened.

Further, by contacting at least one of the wirings that contacts the element electrode serving as the positive electrode of the electron-emitting device at the end of the element electrode, electrons emitted from the electron-emitting element are sucked into the wiring. The phenomenon can be suppressed.

In particular, by using a surface conduction type electron-emitting device as the electron-emitting device used in the electron source of the present invention, the structure is simple, the production is simple, and a large-area device can be easily produced.

Since the image forming apparatus of the present invention uses the electron source of the present invention having the above-described wiring structure, the density of wirings and electron-emitting devices can be increased, and the number of pixels per unit area can be increased. An image forming apparatus having high resolution can be achieved. In particular, a high-resolution and large-screen image display device can be easily obtained by using, as the image forming member, a phosphor film containing a phosphor that emits light when electrons emitted from the electron-emitting device collide. .

In the method of manufacturing an image forming apparatus according to the present invention, the electron source is manufactured by the above-described method of manufacturing an electron source according to the present invention. An image forming apparatus can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a first embodiment of an electron source according to the present invention.

FIG. 2 is a view for explaining a manufacturing process of the electron source shown in FIG. 1 and shows a state in which device electrodes are formed.

FIG. 3 is a view for explaining a manufacturing process of the electron source shown in FIG. 1 and shows a state where a first wiring layer is formed.

FIG. 4 is a view for explaining a manufacturing process of the electron source shown in FIG. 1 and shows a state where an interlayer insulating layer is formed.

FIG. 5 is a view for explaining a manufacturing process of the electron source shown in FIG. 1 and shows a state where a second wiring layer is formed.

FIGS. 6A and 6B are diagrams showing a configuration of a basic surface conduction electron-emitting device suitable for the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a cross-sectional view.

FIG. 7 is a view for explaining an example of a manufacturing process of the surface conduction electron-emitting device shown in FIG.

FIG. 8 is a diagram showing an example of a voltage waveform applied at the time of energization forming performed when forming an electron emission portion in a surface conduction electron-emitting device.

FIG. 9 is a schematic configuration diagram of a measurement evaluation device for measuring the electron emission characteristics of the device having the configuration shown in FIG.

10 is a graph showing a typical example of a relationship between an emission current Ie, an element current If, and an element voltage Vf measured by the measurement evaluation device shown in FIG.

11 is a basic configuration diagram of an example of a display panel of an image forming apparatus using the electron source shown in FIG.

12 is a diagram showing an example of the arrangement of phosphors on the phosphor film of the display panel shown in FIG. 11;

FIG. 13 is a block diagram of a driving circuit in which an image is formed in accordance with an NTSC television signal by an image forming apparatus using the electron source shown in FIG. 1;

FIG. 14 is a main part plan view showing a modification of the wiring in the first embodiment of the electron source of the present invention.

FIG. 15 is a plan view of a main part of a second embodiment of the electron source according to the present invention.

FIG. 16 is a view for explaining the manufacturing process of the electron source shown in FIG. 15 and shows a state where element electrodes are formed.

FIG. 17 is a view for explaining the manufacturing process of the electron source shown in FIG. 15 and shows a state where a first wiring layer and a partial wiring are formed.

FIG. 18 is a view for explaining the manufacturing process of the electron source shown in FIG. 15, showing a state where an interlayer insulating layer is formed.

FIG. 19 is a view for explaining a manufacturing process of the electron source shown in FIG. 15, showing a state where a second wiring layer is formed.

FIG. 20 is a plan view of a main part of a third embodiment of the electron source according to the present invention.

FIG. 21 is a view for explaining a manufacturing process of the electron source shown in FIG. 20, showing a state where element electrodes are formed.

FIG. 22 is a diagram for explaining the manufacturing process of the electron source shown in FIG. 20, showing a state where a first wiring layer and a second wiring layer are formed.

23 is a basic configuration diagram of an example of a display panel of an image forming apparatus using the electron source shown in FIG.

FIG. 24 is a main part plan view showing a modification of the wiring in the third embodiment of the electron source of the present invention.

FIG. 25 is a view showing a typical device configuration of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

1, 201, 301 substrates 2, 3, 22, 23, 202, 203, 302, 30
3, 322, 323 Device electrode 4, 24, 204, 304 Conductive thin film 6, 26, 206, 306, 326 First wiring layer 7, 207 Interlayer insulating layer 8, 28, 208, 308, 328 Second wiring Layers 9, 29, 87, 209, 309, 329 Electron-emitting device 80, 380 Electron source 81, 381 Rear plate 82, 382 Face plate 83 Glass substrate 84 Fluorescent film 84a Phosphor 84b Black conductive material 85 Metal back 86 Support frame 88 x wiring 89 y wiring 90, 390 envelope 191 display panel 192 scanning circuit 193 control circuit 194 shift register 195 line memory 196 synchronization signal separation circuit 197 modulation signal generator 210 partial wiring 391 grid electrode 391a opening

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H01J 1/30 D (56) References JP-A-6-342636 (JP, A) JP-A-2-46636 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 31/12

Claims (17)

(57) [Claims] An electron-emitting device having a pair of device electrodes opposed to both ends of an electron-emitting portion and emitting electrons from the electron-emitting portion by applying a driving voltage between the device electrodes is arranged in a matrix on a substrate. A plurality of row-direction wirings perpendicular to a direction in which the device electrodes face each other, wherein the plurality of row-direction wires are applied to the substrate as wires for applying a drive voltage between the device electrodes; A plurality of column-directional wirings parallel to the opposing direction are formed to intersect with each other via an insulating layer extending in the column direction, and each of the row-directional wirings is arranged below the column-directional wirings,
Each of the column-direction wirings is arranged at a position in contact with one of the device electrodes of the electron-emitting devices arranged in the row direction, and the other of the device electrodes of the electron-emitting devices arranged in the column direction. An electron source having a pattern protruding in a comb shape for electrically connecting to respective electrodes. 2. The electron source according to claim 1, wherein each of said row direction wiring and each column direction wiring is formed by a thick film printing method. 3. The electron source according to claim 1, wherein each comb-shaped pattern of each column-direction wiring contacts the other element electrode. 4. The device according to claim 1, wherein at least one of the row-directional wiring and the column-directional wiring that contacts a device electrode serving as a positive electrode of the electron-emitting device is in contact with an end of the device electrode of the electron-emitting device. Item 4. The electron source according to item 3. 5. The substrate is formed with a partial wiring in contact with the other element electrode of each of the electron-emitting devices, along with each of the row-directional wirings and each of the column-directional wirings. The electron source according to claim 1, wherein the protruding patterns respectively contact the respective partial wirings. 6. The partial wiring is formed by a thick-film printing method, and among the partial wirings and the row-directional wirings,
6. The electron source according to claim 5, wherein at least a wiring contacting a device electrode serving as a positive electrode of the electron-emitting device is in contact with an end of the device electrode of the electron-emitting device. 7. The surface of the electron-emitting device includes a pair of device electrodes facing each other, and a conductive thin film that connects the pair of device electrodes and has a partially high resistance state. The electron source according to any one of claims 1 to 6 , wherein the electron source is a conduction electron-emitting device. 8. An image forming apparatus having an electron source according to any one of claims 1 to 7, the image is formed by electrons emitted from the electron-emitting devices of the electron source collide The image forming member to be disposed is opposed to the electron source via a support frame, and the inside of an envelope including the electron source, the support frame, and the image forming member has a vacuum atmosphere. Image forming apparatus. Wherein said image forming member, image forming apparatus according to claim 8 is a fluorescent film including a phosphor which emits light by electrons emitted from the electron-emitting devices collide. 10. An electron-emitting device, comprising: a plurality of pairs of device electrodes arranged in a matrix on opposite sides of an electron-emitting portion on a substrate; and applying a voltage between the device electrodes to form the electron-emitting portion. In a method of manufacturing an electron source for forming a wiring for emitting more electrons, the step of forming the wiring is performed when a direction perpendicular to a direction opposite to the element electrode is defined as a row direction and a parallel direction is defined as a column direction. Forming a plurality of row-direction wirings that are arranged for each column of the electron-emitting devices, extend in the row direction, and are in contact with one of the device electrodes arranged in the row direction; Forming a plurality of insulating layers arranged in each row of the electron-emitting devices and extending in the column direction so as to intersect with the row-direction wiring; and forming a plurality of insulating layers on the insulating layers in the column direction. The other of the device electrodes Method for producing respective electron source which comprises a step of forming a plurality of column wirings having a comb shape protruding pattern for electrically connecting. 11. The method of manufacturing an electron source according to claim 10 , wherein each of said row direction wiring and each column direction wiring is formed by a thick film printing method. 12. The method of manufacturing an electron source according to claim 10 , wherein each comb-shaped pattern of each column-direction wiring is formed at a position in contact with the other element electrode. 13. A wiring that contacts at least an element electrode serving as a positive electrode of the electron-emitting device among the row-direction wirings and the column-direction wirings, is formed at a position where it is in contact with an end of the element electrode of the electron-emitting device. The method for manufacturing an electron source according to claim 12 . 14. Before forming each of said column-direction wirings, a partial wiring which is in contact with the other device electrode of each of said device electrodes is formed, and each of said column-direction wirings is projected in a comb-like pattern. claim 1 formed at a position in contact with the respective partial wiring
12. The method for producing an electron source according to 0 or 11 . 15. Each of the partial wirings is formed by a thick film printing method, and among the partial wirings and the row wirings,
The method for manufacturing an electron source according to claim 14 , wherein at least a wiring contacting a device electrode serving as a positive electrode of the electron-emitting device is formed at a position where the wire contacts the device electrode of the electron-emitting device. 16. An electron source is manufactured by the method for manufacturing an electron source according to claim 10 , wherein the electron source is emitted from an electron-emitting device of the electron source via a support frame. An image forming member on which an image is formed by colliding electrons is formed to form an envelope, and then the inside of the envelope is evacuated. 17. The method for manufacturing an image forming apparatus according to claim 1, wherein the image forming member is formed of a phosphor film containing a phosphor that emits light when electrons emitted from the electron-emitting devices collide.