JP2909706B2 - Electron emitting element, electron source, image forming apparatus, and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface conduction electron-emitting device, an electron source using a plurality of such devices, an image forming apparatus such as a display device and an exposure device using the same, and a method of manufacturing these devices.

[0002]

2. Description of the Related Art A surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted by passing a current through a conductive thin film formed on an insulating substrate in parallel with the film surface.

As a typical configuration example of a surface conduction electron-emitting device, a conductive thin film such as a metal oxide which connects a pair of device electrodes provided on an insulating substrate is referred to as forming in advance. One in which an electron-emitting portion is formed by an energization process is exemplified. Forming is usually performed by applying a voltage to both ends of the conductive thin film and conducting electricity.The conductive thin film is locally destroyed, deformed or altered to change its structure, and the electron-emitting portion is in an electrically high-resistance state. Is a process of forming The electron emission is performed from the vicinity of a crack generated in the electron emission portion by applying a voltage to the conductive thin film on which the electron emission portion is formed and causing a current to flow.

[0004] The above-mentioned electron-emitting device has an advantage that it can be formed in a large number over a large area because of its simple structure and easy manufacture. Therefore, various applications for utilizing this feature are being studied. For example, it can be used for an image forming apparatus such as a display device.

Conventionally, as an example of arranging a large number of surface conduction electron-emitting devices, the electron-emitting devices are arranged in parallel, and both ends (both device electrodes) of each electron-emitting device are interconnected (also referred to as a common interconnect). ), An electron source in which rows connected to each other in a row are arranged (also referred to as a trapezoidal arrangement) (JP-A-1-31332, JP-A-1-283749, and JP-A-1-257552). In particular, in the case of a display device, a flat panel display device similar to a display device using liquid crystal can be used, and a large number of surface conduction electron-emitting devices are used as self-luminous display devices that do not require a backlight. A display device has been proposed in which an arranged electron source is combined with a phosphor that emits visible light when irradiated with an electron beam from the electron source (US Pat. No. 5,066,883).

In a display device using the above-mentioned surface conduction electron-emitting device, in order to obtain a high-quality and high-definition image on a large screen, the number of rows and columns of the electron-emitting device is several hundred to several thousand, respectively. It is necessary to arrange a very large number of electron-emitting devices. Therefore, it is desired that the electrical characteristics of each electron-emitting device be uniform and easy to control.

[0007]

In the above-described forming, by applying a voltage to the conductive thin film, usually continuous cracks are formed and the resistance is increased. However, depending on the conditions of the material and the like, when there is variation in the thickness of the conductive thin film, the contact resistance with the device electrode, and the like, the width of the crack to be formed may vary greatly depending on the location.
If the width of the crack becomes larger than a certain extent, electron emission cannot be performed, and as a result, the characteristics of the device will be much lower than the characteristics that should be originally obtained. Such variation in the width of the crack is likely to occur when a simple process is used without performing special control during forming. Therefore, ideally, electrical control should be performed in response to subtle variations in the thickness of the conductive thin film for each element during forming, or a conductive thin film should be formed so as to form a uniform, narrow width crack. It is necessary to use a film forming method in which variations in thickness and contact resistance with an element electrode are strictly suppressed. However, the former is difficult to implement as an actual production process, and the latter may increase production costs.

When a conductive thin film is formed using a high melting point material, the durability and the like of the element are improved. However, when the conductive thin film made of a high melting point material is thick, the forming step is completed. The value of the forming current, which is the maximum value of the element current necessary for the formation, becomes large, which causes a problem in the manufacturing method in an electron source having a plurality of elements.

Further, when forming processing is performed for one line at a time in an electron source composed of a large number of elements, for example, an XY matrix, when the number of elements in one line increases, the wiring resistance becomes smaller than the resistance of each element before forming. There is a risk that the voltage applied to each element differs depending on the position of the element due to the voltage drop due to the wiring resistance, and the characteristics of the element at a specific position may be lower than those of the other elements.

[0010] Also, due to the parasitic resistance of the conductive thin film,
There are problems such as a difference in the amount of emitted electrons depending on the distance from the power supply.

As described above, in a surface conduction electron-emitting device, an electron source using a plurality of such devices, and an image forming apparatus, an inexpensive device is used without using special electric control means.
There has been a demand for a method capable of forming a uniform electron-emitting portion on a conductive thin film, and a method of forming a large number of elements so as to have uniform characteristics without being affected by wiring resistance.

According to a first aspect of the present invention, there is provided an electron emission device comprising: a pair of device electrodes provided on an insulating substrate so as to face each other; and a conductive thin film having an electron emission portion provided between the device electrodes. An element, wherein the conductive thin film has at least two
Made of a thin film of a layer, a thin film of the first layer in between the device electrodes
A second layer of thin film is formed of a material having a higher melting point than that of the first layer (excluding carbon) and on the first layer of thin film and in the first layer of thin film ; In addition, a crack of the second layer thin film is formed inside the crack of the first layer to form an electron emission portion.

[0013] Claims 5 and 6 are electron sources formed with a plurality of the electron emission portions, and claims 7 and 8 are image forming apparatuses using the electron sources.

Further, claims 9 to 12 are inventions of these production methods.

Hereinafter, the present invention will be described in detail.

The surface conduction electron-emitting device of the present invention includes a planar type and a vertical type, and any of the electron-emitting devices can be used in the present invention. First, a basic configuration of the flat-type electron-emitting device will be described.

FIGS. 1A and 1B are views showing the basic structure of a flat surface conduction electron-emitting device.

In FIG. 1, 1 is a substrate, 2 is an electron-emitting portion,
3 is a conductive thin film, and 4 and 5 are device electrodes.

As the substrate 1, for example, quartz glass, Na
And glass having reduced impurity content such as glass, blue plate glass, a laminate obtained by laminating SiO ₂ on a blue plate glass by a sputtering method or the like, and ceramics such as alumina.

Materials for the opposing device electrodes 4 and 5 include:
Common conductor materials are used, such as Ni, Cr, Au,
Metals or alloys such as Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag, Au, RuO ₂ , Pd-Ag
Printed conductors composed of metals or metal oxides and glass and the like, transparent conductors such as In ₂ O ₃ —SnO ₂ , and semiconductor conductor materials such as polysilicon are appropriately selected.

The element electrode interval L, the element electrode length W, the shape of the conductive thin film 3 and the like are designed depending on the form to be applied.

The distance L between the device electrodes is preferably several hundred μm to several hundred μm, and more preferably several μm to several hundred μm depending on the voltage applied between the device electrodes 4 and 5 and the intensity of the electric field capable of emitting electrons. 10 μm.

The element electrode length W is preferably several μm to several hundred μm in consideration of the resistance value and electron emission characteristics of the electrode, and the element electrode thickness d is several hundred μm to several μm.

In the present invention, the conductive thin film 3 comprises at least two layers of a first layer 3a and a second layer 3b formed of different materials. In order to obtain good electron emission characteristics for both the first layer 3a and the second layer 3b, it is particularly preferable to use a fine particle film composed of fine particles. Coverage, device electrodes 4 and 5
The resistance value is appropriately selected depending on the resistance value between them and the forming conditions to be described later, and is preferably several to several thousand degrees, particularly preferably 10 to 500 degrees, and the resistance value is 10 ³ to 1
It is 0 ⁷ Ω / □ sheet resistance value of. The film thickness of the second layer 3b is smaller than the film thickness of the first layer, and is appropriately set according to forming conditions and the like described later, preferably several to several hundreds of degrees, particularly preferably 10 to 50 degrees, and the resistance value. Has a sheet resistance value of 10 ³ to 10 ⁷ Ω / □ as in the case of the first layer 3a.

Examples of the material constituting the conductive thin film 3 include Pd, Pt, Ru, Ag, Au, Ti, In, and C.
metals such as u, Cr, Fe, Zn, Sn, Ta, W, Pd, PdO, SnO ₂ , In ₂ O ₃ , PdO, Sb ₂ O
Oxides such as ₃ , HfB ₂ , ZrB ₂ LaB ₆ , CeB
₆ , borides such as YB ₄ and GdB ₄ , TiC, ZrC, H
carbides such as fC, TaC, SiC, TiN, ZrN, H
nitrides such as fN Si, include a semiconductor such as Ge.

In the present invention, the constituent materials of the second layer 3b are each selected from the above materials so as to have a higher melting point than the first layer. For example, the first layer 3a is made of Pd, and Pt, Ru, W or the like having a higher melting point is selected as the material of the second layer 3b. The melting point of a thin film, particularly, a fine particle film is lower than the general melting point of a material.

The fine particle film is a film in which a plurality of fine particles are aggregated, and has a fine structure not only in a state in which the fine particles are individually dispersed and arranged, but also in a state in which the fine particles are adjacent to each other or overlap each other (island shape). ). In the case of a fine particle film, the particle size of the fine particles is preferably several to several thousand, and particularly preferably 10 to 200.

The electron emitting portion 2 is a conductive thin film 3 composed of two layers.
Is a high resistance crack formed in a part of the first layer 3
After forming a and forming a high-resistance crack, the second layer 3b is laminated by an appropriate method, and a high-resistance crack is formed in the second layer 3b. Therefore, the vicinity of the final high-resistance crack is mainly made of the material of the second layer, and the crack is formed depending on the manufacturing method such as the film thickness, film quality, material, and forming conditions of the conductive thin film 3 described later. . The crack may have conductive fine particles having a particle size of several to several hundreds of mm. The conductive fine particles are similar to some or all of the elements of the material constituting the conductive thin film 3. Further, the electron emitting portion 2 including the crack and the conductive thin film 3 in the vicinity thereof may include carbon and a carbon compound.

Next, the basic structure of the vertical surface conduction electron-emitting device will be described.

FIG. 2 is a view showing a basic structure of a vertical electron-emitting device. In FIG. 2, reference numeral 21 denotes a step forming member.
The same reference numerals indicate the same members.

The substrate 1, the electron-emitting portion 2, the conductive thin film 3, and the device electrodes 4 and 5 are made of the same material as that of the above-mentioned flat-type electron-emitting device.

The step forming member 21 is formed, for example, by a vacuum evaporation method,
It is made of an insulating material such as SiO ₂ provided by a printing method, a sputtering method or the like. The film thickness of the step forming member 21 corresponds to the device electrode interval L (see FIG. 1) of the flat-type electron-emitting device described above. It is set depending on the applied voltage and the electric field intensity capable of emitting electrons, but is preferably several hundred
It is several tens μm, particularly preferably several hundreds of μm to several μm.

In the following description, a plane type electron emitting device will be described as an example of the above-mentioned flat type electron emitting device and vertical type electron emitting device. Is also good.

Various methods are conceivable as a method for manufacturing the surface conduction electron-emitting device. One example will be described with reference to FIG. In FIG. 3, the same reference numerals as those in FIG. 1 indicate the same members.

1) After sufficiently cleaning the substrate 1 with a detergent, pure water and an organic solvent, depositing an element electrode material by a vacuum evaporation method, a sputtering method, or the like, and then depositing the element on the surface of the substrate 1 by a photolithography technique. Electrodes 4 and 5 are formed (FIG. 3A).

2) On the substrate 1 provided with the device electrodes 4 and 5,
By applying the organometallic solution of the first layer and leaving it to stand,
An organic metal thin film is formed by connecting between the device electrode 4 and the device electrode 5. The organic metal solution is a solution of an organic compound containing a metal as a constituent element of the conductive thin film 3 as a main element. Thereafter, the organic metal thin film is heated and baked to form a first layer 3a of a conductive thin film patterned by lift-off, etching, or the like (FIG. 3B). Here, the description has been given of the method of applying the organic metal solution. However, the present invention is not limited thereto. For example, the organic metal solution may be 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. A film can also be formed.

3) Subsequently, an energization process called forming is performed. When a power supply (not shown) is applied between the device electrodes 4 and 5, a crack 31 is formed in the first layer 3a.
(C)).

FIG. 4 shows an example of a forming voltage waveform.

The voltage waveform is particularly preferably a pulse waveform.
There are a case where a voltage pulse with a constant pulse peak value is continuously applied (FIG. 4A) and a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 4B).

First, the case where the pulse peak value is a constant voltage will be described with reference to FIG.

In FIG. 4A, T ₁ and T ₂ are the pulse width and pulse interval of the voltage waveform, for example, T ₁ is 1 μm.
sec~10msec, the T ₂ 10μsec~100m
The peak value (peak voltage at the time of forming) is appropriately selected in accordance with the form of the above-described electron-emitting device, and a few seconds to several tens of minutes under an appropriate vacuum degree, for example, a vacuum atmosphere of about 10 ⁻⁵ torr. Apply. Note that the voltage waveform to be applied is not limited to the illustrated triangular wave, and a desired waveform such as a rectangular wave can be used.

Next, a case where a voltage pulse is applied while increasing the pulse peak value will be described with reference to FIG.

T ₁ and T ₂ in FIG.
As in (a), the peak value (peak voltage at the time of forming) is increased by, for example, about 0.1 V steps,
The voltage is applied in an appropriate vacuum atmosphere similar to that described with reference to FIG.

[0044] Incidentally, the end of the forming process in this case, during the pulse interval T _2, locally destroying the first layer 3a,
A voltage that does not cause deformation or deterioration, for example, 0.1 V
The resistance is obtained by measuring the element current at a voltage of the order of magnitude, and the forming is terminated when the resistance shows, for example, 1 MΩ or more.

4) A second layer of an organometallic solution is applied on the device electrodes 4 and 5, the first layer 3 a provided with the cracks 31, and the substrate 1, heated and baked, and patterned to obtain the same as the first layer 3 a. Then, a second layer 3b is formed (FIG. 3D). Here, the method of forming the second layer 3b is not limited to the coating method as in the case of the first layer 3a. If the resistance of the second layer is sufficiently large, patterning by lift-off, etching, or the like may be omitted.

5) A forming process is performed on the second layer 3b in the same manner as in the step 3) to form a crack similar to the first layer 3a, thereby forming the electron-emitting portion 2 (FIG. 3E).

6) Next, it is preferable to perform an activation step on the device after the forming step.

The activation step is, for example, 10 ⁻⁴ to 10 ⁻⁵ t
Similar to the description of the forming process, a process of repeating application of a pulse with a pulse peak value of a constant voltage at a degree of vacuum of about orr, and converts carbon and carbon compounds from organic substances existing in a vacuum atmosphere into electrons. This is a step in which the state of the device current and the emission current can be significantly improved by depositing the light on the emission portion 2 (see FIGS. 1 and 2). This activation step is preferably performed while measuring, for example, the device current and the emission current, and is completed when, for example, the emission current is saturated, since it is effective and is preferable. The pulse peak value in the activation step is preferably the peak value of the drive voltage.

The above-mentioned carbon and carbon compound are graphite (indicating both single crystal and polycrystal) and amorphous carbon (indicating amorphous carbon and a mixture thereof with polycrystalline graphite). Further, the deposited film thickness is preferably 500 ° or less, more preferably 300 ° or less.

7) More preferably, the thus-produced electron-emitting device is operated and driven in a vacuum atmosphere having a degree of vacuum higher than the degree of vacuum in the forming step and the activation step. Further, more preferably, after the heating at 80 ° C. to 150 ° C. in the vacuum atmosphere with the higher degree of vacuum, the operation is driven.

The vacuum atmosphere having a degree of vacuum higher than that of the forming step and the activation treatment is, for example, about 10 ^−6.
It is a degree of vacuum having a degree of vacuum of torr or more, more preferably an ultrahigh vacuum system, and a degree of vacuum in which carbon and carbon compounds are not newly deposited.

By the step 7), further deposition of carbon and carbon compounds is suppressed, and the device current and emission current are stabilized.

The basic characteristics of the surface conduction electron-emitting device thus obtained will be described below.

FIG. 5 is a schematic configuration diagram showing an example of a measurement evaluation system for measuring the electron emission characteristics of the surface conduction electron-emitting device. First, this measurement evaluation system will be described.

In FIG. 5, the same reference numerals as those in FIG. 1 denote the same members. Reference numeral 51 denotes a power supply for applying a device voltage _Vf to the device, 50 denotes an ammeter for measuring a device current _If flowing through the conductive thin film 3 between the device electrodes 4 and 5, and 54 denotes an electron emitting portion. An anode electrode for capturing the emission current _Ie emitted, 53 is a high-voltage power supply for applying a voltage to the anode electrode 54, 52 is an ammeter for measuring the emission current _Ie , 55 is a vacuum device, 56 Is an exhaust pump.

The electron-emitting device, the anode electrode 54, and the like are installed in a vacuum device 55. The vacuum device 55 includes necessary equipment such as a vacuum system (not shown). Can be measured and evaluated.

The exhaust pump 56 is composed of a normal high vacuum system such as a turbo pump and a rotary pump, and an ultrahigh vacuum system such as an ion pump.
The entire vacuum device 55 and the substrate 1 of the electron-emitting device are
The heater can heat up to about 200 ° C. In this measurement evaluation system, at the stage of assembling a display panel (see 201 in FIG. 8) described later, the display panel and the inside thereof are configured as the vacuum device 55 and the inside, so that the above-described forming step, activation It can be applied to the measurement evaluation and processing in the chemical conversion step and the subsequent steps described later.

The basic characteristics of the surface conduction type electron-emitting device described below were measured by setting the voltage of the anode electrode 54 of the above-mentioned measurement and evaluation system to 1 kV to 10 kV and setting the distance H between the anode electrode 54 and the electron-emitting device to 2 to 8 mm. It is based on measurements.

First, the emission current _Ie and the device current _If ,
FIG. 6 shows a typical example of the relationship with the element voltage _Vf . still,
In FIG. 6, since the emission current _Ie is significantly smaller than the device current _If , it is shown in arbitrary units. In addition, the vertical axis,
Both horizontal axes are linear scales.

As apparent from FIG. 6, the electron-emitting device has the following three characteristic characteristics with respect to the emission current _Ie .

First, the device voltage V _f of the electron-emitting device is higher than a certain voltage (called a threshold voltage: V _{th in} FIG. 6).
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 non-linear element having a clear threshold voltage V _th with respect to the emission current I _e .

Second, since the emission current _Ie has a characteristic that monotonously increases with respect to the device voltage _Vf (referred to as MI characteristic), the emission current _Ie can be controlled by the device voltage _Vf .

Thirdly, the amount of charge emitted by the anode electrode 54 (see FIG. 5) depends on the time during which the device voltage _Vf is applied. That is, the amount of charge captured by the anode electrode 54 can be controlled by the time during which the device voltage _Vf is applied.

The emission current _Ie is equal to MI with respect to the device voltage _Vf .
At the same time having a characteristic, it may have a MI characteristic with respect to the device current I _f also the device voltage V _f. An example of the characteristics of such a surface conduction electron-emitting device is a characteristic indicated by a solid line in FIG. On the other hand, as shown by the broken line in FIG. 6, the device current _If is different from the device voltage _Vf by the voltage-controlled negative resistance characteristic (VCN).
R characteristic). Which characteristic is exhibited depends on the manufacturing method of the electron-emitting device, the measurement conditions at the time of measurement, and the like. However, in FIG. 6, the characteristics shown by the solid line and the broken line are shown on scales different from each other both in the vertical and horizontal axes. Also, the device current _If is higher than the device voltage _Vf by VCN.
Even in the electron-emitting device having the R characteristic, the emission current _Ie has the MI characteristic with respect to the device voltage _Vf .

When the form of the crack in the conventional surface conduction electron-emitting device is observed with a scanning electron microscope, the crack has a narrow portion and a wide portion. It is considered that the local electron emission amount and current amount change variously depending on the width of the crack, and it is considered that the narrow portion of the crack probably contributes to electron emission. The cause of such a crack width distribution is considered to be as follows.

The supplied current is distributed according to the thickness of the conductive thin film, and cracks start to occur when the temperature rise due to Joule heat exceeds a certain threshold value. Once cracks begin to form, power concentration occurs at the ends and wide cracks are formed at a stretch, but when progressing to a certain extent, the cracks gradually reach a large thickness and the current density falls below the threshold, so the cracks are narrow And stop. When the voltage is increased, the next process starts again, and this repetition alternates between wide and narrow cracks.

In the surface conduction electron-emitting device according to the present invention, current is not concentrated in places where cracks in the conductive thin film of the first layer are wide because the resistance of the second layer is increased due to current application. . Rather, the current concentrates on the first layer where the crack is small, and the crack starts to progress from here. Further, in the present invention, since a material having a higher melting point than that of the first layer is used for the second layer, the crack of the formed second layer is narrower than the crack width of the first layer. The portion formed inside and contributing to electron emission increases, and the electron emission characteristics are improved.

Next, the arrangement of the surface conduction electron-emitting devices in the electron source of the present invention will be described.

The arrangement of the surface conduction electron-emitting devices in the electron source according to the present invention is not limited to a ladder arrangement as described in the section of the prior art, but also to the arrangement of n Y-direction wirings on m X-direction wirings. There is an arrangement method in which directional wiring is provided via an interlayer insulating layer, and an X-directional wiring and a Y-directional wiring are connected to a pair of device electrodes of the electron-emitting device, respectively. This is hereinafter referred to as a simple matrix arrangement. First, the simple matrix arrangement will be described in detail.

According to the above-described basic characteristics of the surface conduction electron-emitting device, the emitted electrons in the electron-emitting devices arranged in a simple matrix are not affected by the voltage exceeding the threshold voltage.
It can be controlled by the peak value and pulse width of the pulse voltage applied between the opposing element electrodes. On the other hand, below the threshold voltage, almost no electrons are emitted. Therefore, even when a large number of electron-emitting devices are arranged, if the pulse-like voltage is appropriately applied to each of the devices, the electron-emitting device can be selected according to the input signal, and the amount of electron emission can be controlled. Individual electron-emitting devices can be selected and driven independently only by the matrix wiring.

The simple matrix arrangement is based on such a principle, and the configuration of the electron source having the simple matrix arrangement, which is an example of the electron source of the present invention, will be further described with reference to FIG.

In FIG. 7, the substrate 1 is a glass plate or the like as described above, and the number and shape of the surface conduction electron-emitting devices 104 arranged on the substrate 1 are appropriately set according to the application. is there.

The m X-directional wirings 102 have external terminals D _x1 , D _x2 ,..., D _xm , respectively.
The conductive metal is formed by a vacuum deposition method, a printing method, a sputtering method, or the like. Further, the material, the film thickness, and the wiring width are set so that the voltage is supplied to the many electron-emitting devices 104 almost uniformly.

The n number of Y direction wirings 103 have external terminals D _y1 , D _y2 ,..., D _yn , respectively.
02 is created in the same way as the above.

These m X-directional wirings 102 and n Y wires
An interlayer insulating layer (not shown) is provided between the direction wirings 103, and is electrically separated to form a matrix wiring. Note that both m and n are positive integers.

The interlayer insulating layer (not shown) is, for example, SiO ₂ formed by a vacuum deposition method, a printing method, a sputtering method, or the like, and has a desired shape on the entire surface or a part of the substrate 1 on which the X-directional wiring 102 is formed. In particular, the film thickness, material, and manufacturing method are appropriately set so as to withstand the potential difference at the intersection of the X-direction wiring 102 and the Y-direction wiring 103.

Further, device electrodes (not shown) opposed to the electron-emitting devices 104 are formed by m X-directional wirings 102, n Y-directional wirings 103, a vacuum deposition method, a printing method, a sputtering method and the like. Electrically connected by a connection 105 made of a conductive metal or the like.

Here, the m X-directional wires 102, the n Y-directional wires 103, the connection 105, and the opposing device electrodes may have the same or a part of the constituent elements, Further, they may be different from each other, and are appropriately selected from the above-described materials of the device electrodes and the like. The wires to these device electrodes may be collectively referred to as device electrodes when the material is the same as the device electrodes. The electron-emitting device 104 is provided on the substrate 1
Alternatively, it may be formed on an interlayer insulating layer (not shown).

As will be described later in detail, the X-direction wiring 102 has electron-emitting devices 104 arranged in the X-direction.
A scanning signal applying unit (not shown) for applying a scanning signal is electrically connected to scan the row according to the input signal.

On the other hand, a modulation signal generating means (not shown) for applying a modulation signal in order to modulate each column of the electron emission elements 104 arranged in the Y direction according to an input signal is provided on the Y direction wiring 103. Are electrically connected. Further, the drive voltage applied to each electron-emitting device 104 is supplied as a difference voltage between a scanning signal and a modulation signal applied to the electron-emitting device 104.

Next, an example of the image forming apparatus of the present invention using the electron source of the present invention having a simple matrix arrangement as described above will be described with reference to FIGS. 8 is a diagram showing the basic configuration of the display panel 201, FIG. 9 is a diagram showing the fluorescent film 114, and FIG. 10 is a diagram showing the display panel 201 of FIG.
FIG. 2 is a block diagram illustrating an example of a driving circuit for performing television display in accordance with a TSC television signal.

In FIG. 8, reference numeral 1 denotes a substrate of an electron source on which the surface conduction electron-emitting devices are arranged as described above, 111 denotes a rear plate to which the substrate 1 is fixed, and 116 denotes a glass substrate.
13 is a face plate in which a fluorescent film 114 and a metal back 115 are formed on the inner surface. Reference numeral 112 denotes a support frame, and frit glass or the like is applied to the rear plate 111, the support frame 112, and the face plate 116, and is applied in the air or in nitrogen. Then, the envelope 118 is formed by baking at 400 to 500 ° C. for 10 minutes or more for sealing.

In FIG. 8, reference numeral 2 corresponds to the electron-emitting portion in FIG. 102 and 103 are electron-emitting devices 104
X-direction wiring connected to the pair of device electrodes 4 and 5 and Y
In the direction wirings, respectively external terminals D _x1 to D _xm, and a D _y1 to D _yn.

The envelope 118 includes the face-plate 116, the support frame 112, and the rear plate 111, as described above. However, the rear plate 111 is provided mainly for the purpose of reinforcing the strength of the substrate 1. If the substrate 1 itself has sufficient strength, the separate rear plate 111 is unnecessary, and the support frame is directly attached to the substrate 1. Seal 112,
The envelope 118 may be constituted by the face plate 116, the support frame 112, and the substrate 1. Further, by further providing a support (not shown) called a spacer between the face plate 116 and the rear plate 111, the envelope 118 having sufficient strength against atmospheric pressure can be obtained.

The fluorescent film 114 is composed of only the phosphor 122 in the case of monochrome, but in the case of the color fluorescent film 114, depending on the arrangement of the phosphor 122, a black stripe (FIG. 9A) or a black matrix (FIG. 9
(B)) a black conductive material 121 and a phosphor 122 called
It is composed of The purpose of providing the black stripes and the black matrix is to make the mixed portions between the phosphors 122 of the three primary colors necessary for color display black so that mixed colors and the like are not noticeable, and to reflect external light on the fluorescent film 114. Is to suppress a decrease in contrast due to As a material of the black conductive material 121, not only a material mainly containing graphite, which is often used, but also a material having conductivity and low light transmission and reflection may be used. it can.

As a method of applying the phosphor 122 to the glass substrate 113, a precipitation method or a printing method is used regardless of monochrome or color.

Further, as shown in FIG.
A metal back 115 is usually provided on the inner surface side of 4.
The purpose of the metal back 115 is to improve the brightness by mirror-reflecting light toward the inner surface side of the light emitted from the phosphor 122 (see FIG. 9) toward the glass substrate 113, and to apply an electron beam acceleration voltage. Acting as an electrode,
For example, protection of the phosphor 122 from damage due to collision of negative ions generated in the envelope 118 is performed. Metal back 1
15 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 114 after the fluorescent film 114 is manufactured, and then depositing Al by vacuum evaporation or the like.

The face plate 116 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 114 in order to further increase the conductivity of the fluorescent film 114.

When the above-mentioned sealing is performed, in the case of color, the phosphors 122 of each color must correspond to the electron-emitting devices 104, so that it is necessary to perform sufficient alignment.

The inside of the envelope 118 is evacuated to a degree of vacuum of about 1 × 10 ⁻⁷ torr through an exhaust pipe (not shown) and sealed. Also, a getter process may be performed immediately before or after sealing the envelope 118. This is a process of heating a getter (not shown) arranged at a predetermined position in the envelope 118 to form a deposited film. The getter is usually composed mainly of Ba or the like, and is used to maintain a degree of vacuum of, for example, 1 × 10 ⁻⁵ to 1 × 10 ⁻⁷ torr by the adsorption action of the deposited film.

The above-described forming and subsequent manufacturing steps of the electron-emitting device are usually performed immediately before or after sealing of the envelope 118, and the contents thereof are as described above.

The display panel 201 described above is, for example, as shown in FIG.
Can be driven by a driving circuit as shown in FIG.
In FIG. 10, 201 is a display panel, 202 is a scanning circuit, 203 is a control circuit, 204 is a shift register,
205 is a line memory, 206 is a synchronization signal separation circuit, 2
07 the modulation signal generator, V _x and V _a are DC voltage sources.

As shown in FIG. 10, the display panel 20
1 is connected to an external electric circuit through the external terminals D _x1 to D _xm, external terminals D _y1 to D _yn and a high-voltage terminal Hv.
Of these, the external terminals D _{x1 to} D _xm are connected to the display panel 201.
A scanning signal is applied to sequentially drive the electron-emitting devices provided therein, that is, electron-emitting device groups arranged in a matrix of m rows and n columns, one row at a time (n devices).

On the other hand, to the external terminals D _{y1 to} D _yn , a modulation signal for controlling the output electron beam of each electron-emitting device in one row selected by the scanning signal is applied. Also,
The high-voltage terminal Hv, the DC voltage source V _a, for example, 10k
V DC voltage is supplied. This is an accelerating voltage for applying sufficient energy to the electron beam output from the electron-emitting device to excite the phosphor.

The scanning circuit 202 includes m switching elements (schematically indicated by S _{1 to} S _m in FIG. 10). Each of the switching elements S _{1 to} S _m includes a DC voltage power supply V _x. , Or 0 V (ground level), and is electrically connected to the external terminals D _{x1 to} D _{xm of} the display panel 201. Each of the switching elements S _{1 to} S _m operates based on a control signal T _scan output from the control circuit 203, and is actually easily configured by combining elements having a switching function such as an FET, for example. It is possible.

[0096] The DC voltage source V _x in this example, based on said characteristics of the surface conduction electron-emitting device (the threshold voltage), scanned non electron-emitting devices of the driving voltage applied thereto threshold voltage It is set to output a constant voltage as follows.

The control circuit 203 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. Based on the synchronization signal T _sync next fed from the synchronizing signal separation circuit 206 to be described, T _scan, generating a respective control signal T _sft and T _mry to each unit.

The synchronizing signal separating circuit 206 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 206
The sync signal separated by is composed of a vertical sync signal and a horizontal sync signal, as is well known. here,
It is illustrated as T _sync for convenience of explanation. On the other hand, the luminance signal component of the image separated from the television signal is referred to as DAT for convenience.
This is shown as an A signal. This DATA signal is input to the shift register 204.

The shift register 204 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and is based on a control signal _Tsft sent from the control circuit 203. Work. This control signal _Tsft may be rephrased as a shift clock of the shift register 204. The data of one line of the serial-parallel-converted image (corresponding to the drive data of n electron-emitting devices) is represented by I
Examples n parallel signals _d1 ~I _dn shift register 2
04.

The line memory 205 is a storage device for storing data for one line of an image for a required time.
Stores the contents of the appropriate I _d1 ~I _dn according to the control signal T _mry sent from the control circuit 203. The stored content is I
It is output as _d'1 ~I _d'n, is input to the modulation signal generator 207.

The modulation signal generator 207 is a signal source for appropriately driving and modulating each of the electron-emitting devices in accordance with each of the image data I _{d′ 1 to} I _{d′ n} .
The voltage is applied to the electron-emitting devices in the display panel 201 through the terminals D _{y1 to} D _yn .

As described above, the electron-emitting device has a clear threshold voltage for electron emission, and electron emission occurs only when a voltage exceeding the threshold voltage is applied. For a voltage exceeding the threshold voltage, the emission current also changes in accordance with the change in the voltage applied to the electron-emitting device.
By changing the material, configuration, and manufacturing method of the electron-emitting device, the value of the threshold voltage or the degree of change of the emission current with respect to the applied voltage may change, but in any case, the following can be said.

That is, when a pulse-like voltage is applied to the electron-emitting device, for example, when a voltage lower than the threshold voltage is applied, no electron emission occurs, but when a voltage exceeding the threshold voltage is applied. Causes electron emission. At that time, first, it is possible to control the intensity of the output electron beam by changing the peak value of the voltage pulse. Second
By changing the width of the voltage pulse, it is possible to control the total amount of charges of the output electron beam.

Therefore, as a method of modulating the electron-emitting device in accordance with the input signal, there are a voltage modulation method and a pulse width modulation method. In the case of performing the voltage modulation method, the modulation signal generator 207 generates a voltage pulse having a fixed length, and uses a voltage modulation circuit capable of appropriately modulating the pulse peak value according to input data. In the case of performing the pulse width modulation method, the modulation signal generator 207 generates a voltage pulse having a constant peak value, but a pulse width modulation method circuit capable of appropriately modulating the pulse width according to input data. Used.

The shift register 204 and the line memory 20
Reference numeral 5 may be a digital signal type or an analog signal type, as long as it can perform serial / parallel conversion and storage of an image signal 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 206 into a digital signal. This can be achieved by providing an A / D converter at the output of the synchronization signal separation circuit 206.

In connection with this, the line memory 20
Depending on whether the output signal of 5 is a digital signal or an analog signal,
The circuit provided in modulation signal generator 207 is slightly different.

That is, in the case of a voltage modulation method using a digital signal, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 207, and an amplification circuit or the like may be added as necessary. In the case of a pulse width modulation method using a digital signal, the modulation signal generator 207 includes, for example, a high-speed oscillator, a counter (counter) for counting the number of waves output from the oscillator, and an output value of the counter and an output value of the memory. It can be easily configured by using a circuit in which comparators for comparison are combined. Further, if necessary, an amplifier for 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 a voltage modulation method using an analog signal, for example, a well-known amplifier circuit using an operational amplifier or the like may be used as the modulation signal generator 207, and a level shift circuit or the like may be added as necessary. You may. In the case of a pulse width modulation method using an analog signal, for example, a well-known voltage controlled oscillator (VCO) may be used. If necessary, an amplifier for amplifying the voltage up to the driving voltage of the electron-emitting device may be used. May be added.

The image forming apparatus of the present invention having the display panel 201 and the driving circuit as described above can apply the voltage from the terminals D _{x1 to} D _xm and D _{y1 to} D _yn to change the necessary electron emitting elements from the necessary elements. Is excited by applying a high voltage to the metal back 115 or the transparent electrode (not shown) through the high-voltage terminal Hv to accelerate the electron beam and causing the accelerated electron beam to collide with the fluorescent film 114. -By light emission, television display can be performed according to an NTSC television signal.

The configuration described above is a schematic configuration necessary for obtaining the image forming apparatus of the present invention used for display and the like. For example, detailed portions such as materials of each member are limited to the above-described contents. Instead, it is appropriately selected so as to be suitable for the use of the image forming apparatus. Although the NTSC system has been described as an input signal, the image forming apparatus according to the present invention is not limited to this, and may employ another system such as a PAL or SECAM system. For example, a high-definition TV system such as a MUSE system may be used.

Next, an example of the above-described trapezoidal electron source and an image forming apparatus of the present invention using the same will be described with reference to FIGS. 11 and 12. FIG.

In FIG. 11, reference numeral 1 denotes a substrate; 104, a surface conduction electron-emitting device; 304, ten common wirings for connecting the electron-emitting devices 104, each of which has external terminals D _{1 to} D ₁₀ . ing.

A plurality of electron-emitting devices 104 are arranged on the substrate 1 in parallel. This is called an element row. These element rows are arranged in a plurality of rows to constitute an electron source.

By applying an appropriate drive voltage between the common wiring 304 of each element row (for example, the common wiring 304 of the external terminals D ₁ and D ₂ ), each element row can be driven independently. That is, a voltage exceeding the threshold voltage may be applied to an element row where electron beams are to be emitted, and a voltage lower than the threshold voltage may be applied to an element row where electron beams are not desired to be emitted. Application of the driving voltage, the common wiring D ₂ to D ₉ located at each element rows, the external terminals D ₂ and D ₃ adjacent common wiring 304, i.e. each phase adjacent each phase, D ₄ and D ₅ it can also be performed as an integrated same wire common wiring 304 of D ₆ and D _7, D ₈ and D _9.

FIG. 11 is a view showing the structure of a display panel 301 provided with the above-mentioned trapezoidal arrangement of electron sources, which is another example of the electron source of the present invention.

In FIG. 11, reference numeral 302 denotes a grid electrode; 303, an opening through which electrons pass; D _{1 to} D _m , external terminals for applying a voltage to each electron-emitting device; and G _{1 to} G _n , grid electrodes 302 External terminal connected to the Further, the common wiring 304 between each element row is formed on the substrate 1 as an integral same wiring.

In FIG. 12, the same reference numerals as in FIG. 8 denote the same members, and the main difference between the display panel 201 using the electron sources in the simple matrix arrangement shown in FIG. The point is that a grid electrode 302 is provided between the electrodes 116.

The grid electrode 302 is provided between the substrate 1 and the face plate 116 as described above. The grid electrode 302 is capable of modulating the electron beam emitted from the electron-emitting device 104. The grid electrode 302 allows the electron beam to pass through a stripe-shaped electrode provided perpendicular to the ladder-shaped element row. In addition, one circular opening 303 is provided for each electron-emitting device 104.

The shape and arrangement position of the grid electrode 302
12, the openings 303 may be provided in a large number in a mesh shape, and the grid electrode 302 may be provided around or near the electron-emitting device 104, for example.

The external terminals D _{1 to} D _m and G _{1 to} G _n are connected to a drive circuit (not shown). Then, by applying a modulation signal for one image line to the column of the grid electrode 302 in synchronization with sequentially driving (scanning) the element rows one by one, each electron beam is irradiated on the fluorescent film 114. And images can be displayed line by line.

As described above, the image forming apparatus of the present invention
It can be obtained by using any of the electron sources of the present invention in a simple matrix arrangement or a trapezoidal arrangement, and is suitable not only for the above-described television broadcast display device, but also as a video conference system and a display device such as a computer. A device is obtained. Furthermore, the present invention can be used as an exposure device of an optical printer including a photosensitive drum.

[0123]

【Example】

Example 1 and Comparative Examples 1 and 2 As a first example of the present invention, the surface conduction electron-emitting device shown in FIG. 1 was manufactured according to the manufacturing process of FIG. The steps will be described below.

Step-a A thin film of T was formed on an insulating substrate 1 made of quartz as an element electrode thin film.
i50 ° and Pt250 ° were formed. This was spin-coated with a resist, exposed and developed using an electrode pattern mask to form a resist electrode pattern.
After removing an unnecessary thin film by etching, the resist was removed to obtain device electrodes 4 and 5 (FIG. 3A).

Step-b: A Cr film was formed on the entire surface by a sputtering method, a resist was spinner-coated thereon, and a pattern for forming a first layer described later was exposed using a photomask. This was developed to remove unnecessary resist, an unnecessary Cr film was removed by etching to form an opening, and the remaining resist was removed. An organic Pd complex solution (Okuno Pharmaceutical Co., Ltd.)
Manufactured by CCP4230) at 300 ° C
A heat treatment was performed for 12 minutes to form a PdO film. This coating and baking process was repeated seven times, and the Cr film and the unnecessary PdO film were removed by lift-off to form the first layer 3a (FIG. 3).
(B)).

Step-c A pulse voltage was applied between the device electrodes 4 and 5 to form a crack 31 in a part of the first layer 3a. The applied voltage is pulse width 1
The pulse was a triangular wave pulse having a pulse interval of 10 msec and a pulse height of 5 V / min from 0 V to 14 V (FIG. 3C).

Step-d After forming the opening of the Cr film in the same manner as in the above-described step-b,
A W film was formed by a sputtering method, and a second layer 3b was formed by lift-off (FIG. 3D).

Step-e In the same manner as in Step-c, a crack was formed in the second layer 3b to obtain an electron-emitting portion 2 (FIG. 3E).

As Comparative Example 1, the process-a of Example 1 was performed.
After forming a PdO film such that the total film thickness becomes the same as the conductive thin film 3 of Example 1 in the same manner as
The electron-emitting portion was formed by performing the energization treatment of c. The voltage of the forming process is the same as in the first embodiment.

Further, as Comparative Example 2, after device electrodes 4 and 5 were formed in the same manner as in Example 1, PdO was
A W film was formed instead of the film, and a Pt film was formed by omitting step-c to form a conductive thin film. The same forming process as in Example 1 was performed to form an electron-emitting portion.

As described above, Example 1 and Comparative Example 1,
2 were manufactured, and _Ie and _{If of} each element were manufactured.
Was measured by the measurement system shown in FIG. The applied voltage is a 14 V rectangular wave pulse with a pulse interval of 10 msec.
The pulse width is 0.1 msec. In addition, the anode electrode 5
The distance H between 4 and the element is 2 mm, and the extraction voltage is 1 kV.

The values of I _e and _If are slightly different for each element, but Example 1 showed about 6 times larger value of I _e and about 2 times larger value of _If than the comparative example 1. That improvement of I _e exceeds the improvement of I _f is that able to design the electron-emitting device of sufficient performance with low power consumption, highly desirable results.

Next, when _Ie and _If were compared between Example 1 and Comparative Example 2, although each value was slightly different for each element,
The values were almost equivalent. However, the forming current, which is the maximum value of the current required for crack formation, was 5 times as large as the forming current of the second layer of the device of Example 1 in the device of Comparative Example 2.

When the forming current value is large, there is no problem if forming is performed for each element. However, when forming is performed by arranging a plurality of elements and connecting them with wiring electrodes, an excessive current flows through the wiring electrodes. However, there are problems such as heat generation and, in severe cases, cracking of the substrate. Therefore, it is desirable from a manufacturing viewpoint that the forming current can be suppressed to a small value.

The device of Example 1 was able to form a crack with a small forming current value and had a large electron emission amount, which was a very desirable result. Further, when each element was operated in a vacuum, the element of Example 1 had a smaller amount of deterioration in emission current as compared with Comparative Example 1, and favorable results were obtained. Although the melting point of the thin film is unknown, the melting point of bulk metal is 1555 ° C. for Pd and 3655 ° C. for W.

[Embodiment 2] As in Embodiment 1, FIG.
The surface conduction electron-emitting device shown in FIG. However, as the conductive thin film, the first layer was an Au film, and the second layer was an Ir film. The melting points of Au are 1063 ° C. and Ir are 2454 ° C., respectively. This device was measured and evaluated in the same manner as in Example 1.
The same effect as in Example 1 was obtained.

Example 3 and Comparative Example 3 As a third example of the present invention, an electron source having a simple matrix shown in FIG. 7 was manufactured. FIG. 13 is a plan view of a part of the electron source. FIG. 14 is a cross-sectional view taken along the line AA ′ in FIG. 14, and FIGS. 13 to 16 indicate the same components. Here, 141 is an interlayer insulating layer, and 142 is a contact hole. Hereinafter, the manufacturing process will be described in detail with reference to FIGS.

Step-a A 50-mm-thick Cr film on a cleaned blue sheet glass,
000Å of Au is sequentially laminated, and a photoresist (AZ1
370, manufactured by Hoechst) by spinner,
After baking, the photomask image is exposed and developed to form a resist pattern for the lower wiring 102, and the Au / Cr deposited film is wet-etched to form the lower wiring 102 having a desired shape.
Was formed.

Step-b Next, an interlayer insulating layer 141 made of a silicon oxide film having a thickness of 1000 ° was deposited by a high frequency sputtering method.

Step-c A photoresist pattern for forming the contact hole 142 was formed in the silicon oxide film deposited in the step-b, and the interlayer insulating layer 141 was etched using the photoresist pattern as a mask to form the contact hole 142. Etching is performed by RIE (Reactive) using CF ₄ and H ₂ gas.
Ion Etching) method.

Step-d A photoresist (RD2000N-41, manufactured by Hitachi Chemical Co., Ltd.) having a pattern to be a gap between device electrodes is formed.
50 mm thick Ti, 1000 mm N by vacuum evaporation
i were sequentially laminated, and the photoresist was dissolved with an organic solvent to lift off the excess Pt film, thereby forming device electrodes 4 and 5. The device electrode gap L was 2 μm.

Step-e After forming a photoresist pattern of the upper wiring 103 on the device electrodes 4 and 5, a Ti film having a thickness of 50.degree.
Au was sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form an upper wiring 103 having a desired shape.

Step-f A resist film is formed so as to cover portions other than the contact hole 142, and a 50 ° thick Ti, 5
Au of 000Å was sequentially laminated. Unnecessary portions were removed by lift-off to bury the contact holes 142.

Step-g After depositing and patterning a Cr film in the same manner as in Example 1, a Pd film was formed by a sputtering method.
It was baked in an air atmosphere at 0 ° C. for 15 minutes to obtain a PdO film.
Subsequently, unnecessary PdO was removed together with a Cr mask by lift-off, and a first-layer conductive thin film 3a was formed.

As shown in FIG. 18, the X-direction wiring (lower wiring) 1 is connected to the Y-direction wiring (upper wiring) 103 as a common connection.
The element connected to 02 was subjected to an energization treatment line by line to form a crack 31 in the first layer. In the drawing, reference numeral 102 denotes a lower wiring which is a wiring in the X direction, and reference numeral 103 denotes an upper wiring which is a wiring in the Y direction, which is grounded via a common electrode 181. One electron-emitting device 104 of the present invention is arranged at each intersection of the upper wiring and the lower wiring. 18
Reference numeral 2 denotes a pulse generator, the positive electrode of which is connected to one of the lower wirings 102, and the negative electrode of which is grounded via a shunt resistor 183. 184 is an oscilloscope for monitoring the pulse current. The pulses to be applied are the same as those described in the first embodiment.

Step-h In the same manner as in step-g, after forming a pattern, an Ir film was formed by a sputtering method, and a current was applied to form an electron-emitting portion 2.

Through the above steps, the lower wiring 102, the interlayer insulating layer 141, the upper wiring 103, the device electrodes 4 and 5, and the conductive thin film 3 were formed on the insulating substrate 1.

Next, as Comparative Example 3, in the same manner as in Example 3 described above, only the Ir film was deposited so as to have the same total thickness of the PdO film and the Ir film of Example 3, and forming was performed. Done. As a result, in Comparative Example 3, in order to form a crack in the conductive thin film, a current five times the forming current value, which is the maximum value of the current necessary for forming the crack in the first layer in Example 3, was required. .

The electron source of Example 3 and Comparative Example 3 was
As shown in FIG. 9, the extraction electrode 198 and the fluorescent plate were attached, and all the elements were scanned and driven in time sequence. A surface conduction electron-emitting device applies a driving pulse to the X-direction wiring during driving, utilizing the non-linear characteristic that almost no current flows and no electron emission occurs when the applied voltage is below a certain threshold. By setting the Y-direction wiring connected to the element to be turned on to the ground level and setting the other Y-direction wiring to the ground level and halfway between the maximum voltage of the pulse (half-selection voltage), only the element at the desired position can be set. Electrons can be emitted.

The measurement system shown in FIG. 19 will be described. Reference numeral 191 denotes a vacuum chamber, which is 5 × 10 ⁻⁷ torr by an exhaust system (not shown).
Exhausted below. 192 is a window, 1 is an element substrate, 1
Reference numeral 94 denotes an element main body composed of an electron-emitting portion, electrodes, wiring, and the like. Reference numerals 195 and 196 denote driving wirings for X and Y direction lines, respectively. A driver 197 applies an appropriate pulse to the wiring. Reference numeral 198 denotes an extraction electrode, which is formed by fitting glass on which an ITO thin film of a transparent electrode is formed in an aluminum frame, and applying a phosphor on the lower surface thereof.

The device has a driving voltage of 14 V and a half-selection voltage of 7 V
A rectangular pulse was applied by a driver so that The extraction voltage was 5 kV.

When the light emission of the phosphor due to the electron emission was visually observed through the window 192, the electron source of Example 3
Brightness equivalent to that of the electron source of Comparative Example 3 was observed.

A display panel shown in FIG. 8 was constructed by using each of the above electron sources to form an image display device of the present invention.

After fixing the unformed electron source substrate 1 produced in the above steps to the rear plate 111, the electron source 1
5 mm above, a face plate 116 (having a fluorescent film 114 and a metal back 116 formed on the inner surface of a glass substrate 113) is sufficiently aligned via a support frame 112 and arranged. Frame 11
2. A frit glass was applied to the joint of the rear plate 111 and sealed by baking at 400 ° C. to 500 ° C. in the air for 10 minutes or more. The fixing of the electron source substrate 1 to the rear plate 111 was also performed using frit glass.

In this embodiment, the phosphor has a stripe shape (see FIG. 9A), and the material of the black stripe is a material mainly composed of graphite.
A slurry method was used as a method of applying the phosphor to No. 3.

The metal back 115 provided on the inner surface side of the fluorescent film 114 is subjected to a smoothing process (filming) on the inner surface of the fluorescent film after the fluorescent film is formed.
1 was produced by vacuum evaporation. Face plate 1
In 16, in order to further increase the conductivity of the fluorescent film 114, a transparent electrode may be provided on the outer surface side of the fluorescent film 114. However, in this embodiment, since the metal back 115 alone provided sufficient conductivity, Omitted.

The atmosphere in the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, the external terminals D _{x1 to} D _xm to D _y1. A voltage was applied between the device electrodes through _Dyn to perform a forming process to form an electron-emitting portion. At this time, the voltage waveform of the forming process was the same as that of the first embodiment, and the forming process was performed in a vacuum atmosphere of about 1 × 10 ⁻⁵ torr.

Next, in a vacuum atmosphere having a degree of vacuum of 10 ⁻⁵ torr, a voltage pulse of 20 V was repeatedly applied for 30 minutes to deposit a compound mainly composed of carbon at 80 °.

At a degree of vacuum of about 1 × 10 ^−6.5 torr,
The exhaust pipe (not shown) is fused by heating with a gas burner,
The envelope 118 was sealed.

Finally, in order to maintain the degree of vacuum after sealing, a getter process was performed by a high-frequency heating method.

The external terminals D _{x1 to} D _xm to D _{y1 to} D _yn and the high-voltage terminal H of the display panel manufactured as described above.
v were connected to necessary drive systems, respectively, to complete the image forming apparatus. External terminals D _{x1 to} D _xm to D _y1 to
Electrons are emitted by applying a scanning signal and a modulation signal through signal generation means (not shown) through D _yn , respectively, and several k are applied to the metal back 115 through the high voltage terminal Hv.
A high voltage of V or more is applied to accelerate the electron beam, and the fluorescent film 1
A good image was displayed by colliding with 14 to excite and emit light.

[Embodiment 4] FIG. 17 shows an example of a display device in which the image forming apparatus of Embodiment 3 is configured to be able to display image information provided from various image information sources such as television broadcasting. FIG. 2 in the figure
80 is a display panel, 261 is a display panel drive circuit, 262 is a display controller, 2
63 is a multiplexer, 264 is a decoder, 265 is an input / output interface circuit, 266 is a CPU, 267 is an image generation circuit, 268, 269 and 270 are image memory interface circuits, 271 is an image input interface circuit, and 272 and 273 receive TV signals. Circuit, 27
Reference numeral 4 denotes an input unit. When the present display device receives a signal containing both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the above are omitted.

Hereinafter, each part will be described along the flow of the image signal.

First, the TV signal receiving circuit 273 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The format of the received TV signal is not particularly limited, and may be, for example, various systems such as the NTSC system, the PAL system, and the SECAM system. Further, a TV signal (for example, a so-called high-definition TV including the MUSE system) composed of a larger number of scanning lines than the above is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. Signal source. TV received by the TV signal receiving circuit 273
The signal is output to the decoder 264.

The image TV signal receiving circuit 272 is a circuit for receiving a TV image signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. As with the TV signal receiving circuit 273, the type of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 264.

The image input interface circuit 27
Reference numeral 1 denotes a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is output to a decoder 264.

The image memory interface circuit 2
70 is a video tape recorder (hereinafter abbreviated as VTR)
Is a circuit for receiving the image signal stored in the decoder 264. The captured image signal is output to the decoder 264.

The image memory interface circuit 2
Reference numeral 69 denotes a circuit for capturing an image signal stored in the video disk. The captured image signal is output to the decoder 264.

An image memory-interface circuit 268 is a circuit for taking in an image signal from a device storing still image data, such as a so-called still image disk.
4 is output.

The input / output interface circuit 265
Is a circuit for connecting the present display device to an output device such as an external computer, a computer network, or a printer. In addition to inputting and outputting image data and character / graphic information, control signals and numerical data can be input and output between the CPU 266 of the display device and the outside in some cases.

The image generation circuit 267 is provided with image data, character / graphic information input from the outside via the input / output interface circuit 265, or the CPU 266.
This is a circuit for generating display image data based on the image data and character / graphic information output from the display unit. Inside this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory storing an image pattern corresponding to a character code,
A circuit necessary for generating an image such as a processor for performing image processing is incorporated therein.

The display image data generated by this circuit is output to the decoder 264, but may be output to an external computer network or printer via the input / output interface circuit 265 in some cases.

The CPU 266 mainly performs operations related to operation control of the display device and generation, selection, and editing of a display image.

For example, a control signal is output to the multiplexer 263, and image signals to be displayed on the display panel 280 are appropriately selected or combined. At that time, a control signal is generated for the display panel controller 262 in accordance with the image signal to be displayed, and the display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines on one screen, and the like are displayed. The operation of the device is appropriately controlled.

Further, image data, character / graphic information is directly output to the image generation circuit 267, or an external computer or memory is accessed through the input / output interface circuit 265 to access the image data, character / graphic information, etc.
Enter graphic information.

The CPU 266 may, of course, be involved in operations for other purposes. For example, like a personal computer or word processor,
It may be directly related to the function of generating and processing information.

Alternatively, the computer may be connected to an external computer network via the input / output interface circuit 265 as described above, and operations such as numerical calculations may be performed in cooperation with external devices.

The input section 274 is connected to the CPU 266.
The user inputs commands, programs, data, or the like, and various input devices such as a joystick, a barcode reader, and a voice recognition device can be used, for example, in addition to a keyboard and a mouse.

The decoder 264 converts various image signals input from the above 267 to 273 into three primary color signals,
Alternatively, it is a circuit for inversely converting a luminance signal into an I signal and a Q signal. As shown by a dotted line in FIG.
64 preferably has an image memory inside. This is for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of a still image, or the image generation circuit 26
7 and the CPU 266 in cooperation with the image processing, such as image thinning, interpolation, enlargement, reduction, and synthesis, and the advantage that editing can be easily performed.

The multiplexer 263 is connected to the CPU
A display image is appropriately selected based on a control signal input from the 266. That is, the multiplexer 263 selects a desired image signal from the inversely converted image signals input from the decoder 264 and outputs the selected image signal to the drive circuit 261. In that case, by switching and selecting an image signal within one screen display time, it is also possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. .

The display panel controller 2
Reference numeral 62 denotes a circuit for controlling the operation of the drive circuit 261 based on the control signal input from the CPU 266.

First, for example, a signal for controlling an operation sequence of a drive power supply (not shown) for the display panel is output to the drive circuit 261 as one related to the basic operation of the display panel.

As a signal relating to the display panel driving method, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 261.

In some cases, a control signal relating to image quality adjustment such as luminance, contrast, color tone, and sharpness of a display image may be output to the drive circuit 261.

The driving circuit 261 is a circuit for generating a driving signal to be applied to the display panel 280. The driving circuit 261 converts the image signal input from the multiplexer 263 and the control signal input from the display panel controller 262. It operates on the basis of:

The function of each unit has been described above. With the configuration illustrated in FIG. 17, in this display device, image information input from various image information sources is displayed on the display panel 2.
70 can be displayed. That is, various image signals including television broadcasts are inversely converted by the decoder 264, appropriately selected by the multiplexer 263, and input to the drive circuit 261. On the other hand, the display controller 262 generates a control signal for controlling the operation of the drive circuit 261 according to the image signal to be displayed. The drive circuit 261 applies a drive signal to the display panel 280 based on the image signal and the control signal. Thus, an image is displayed on display panel 280. These series of operations are performed by the CPU 2
66 is controlled collectively.

In the present display device, an image memory built in the decoder 264 and an image generation circuit 267 are provided.
And the involvement of the CPU 266 not only displays the selected one of the plurality of pieces of image information but also displays, for example, enlargement, reduction, rotation, movement, edge emphasis, thinning, interpolation, It is also possible to perform image processing such as color conversion and image aspect ratio conversion, and image editing such as combining, erasing, connecting, exchanging, and fitting. In the description of the present embodiment,
Although not particularly mentioned, a dedicated circuit for processing and editing audio information may be provided as in the above-described image processing and image editing.

Therefore, the present display device is a television broadcast display device, a video conference terminal device, an image editing device that handles still and moving images, a computer terminal device, an office terminal device including a word processor, a game terminal, and the like. It is possible to combine the functions of a single machine, etc., and has a very wide range of applications for industrial or consumer use.

FIG. 17 is merely an example of the image forming apparatus of the present invention, and it goes without saying that the present invention is not limited to this. For example, among the components shown in FIG. 17, circuits relating to functions that are not necessary for the purpose of use may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present display device is applied to a videophone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present display device, in particular, it is easy to reduce the thickness of a display panel using a surface conduction electron-emitting device as an electron source, so that the depth of the display device can be reduced. In addition, display panels that use surface-conduction electron-emitting devices as electron sources are easy to enlarge and have high brightness and excellent viewing angle characteristics. It is possible to display well.

Further, since the electron source of the present invention has uniform electron emission characteristics between the respective surface conduction electron-emitting devices, the quality of the formed image is high, and a high-definition image can be displayed. .

[0192]

As described above, according to the present invention,
A surface conduction electron-emitting device having uniform and improved electron emission characteristics can be obtained without taking complicated electric control means, so that an electron source without unevenness can be obtained for each device and high display quality can be obtained. An image forming apparatus is provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a surface conduction electron-emitting device of the present invention.

FIG. 2 is a sectional view showing another embodiment of the surface conduction electron-emitting device of the present invention.

FIG. 3 is a diagram showing an example of a manufacturing process of the surface conduction electron-emitting device of the present invention.

FIG. 4 is a diagram showing a voltage waveform of an energization process for manufacturing the surface conduction electron-emitting device of the present invention.

FIG. 5 is a diagram showing a measurement evaluation system for evaluating the electron emission characteristics of the surface conduction electron-emitting device of the present invention.

FIG. 6 is a view showing electron emission characteristics of the surface conduction electron-emitting device of the present invention.

FIG. 7 is a schematic diagram of a simple matrix electron source of the present invention.

FIG. 8 is a diagram showing one embodiment of a display panel of the image forming apparatus of the present invention.

FIG. 9 is a diagram showing a fluorescent film used in the image forming apparatus of the present invention.

FIG. 10 is a block diagram of an embodiment of the image forming apparatus of the present invention.

FIG. 11 is a schematic view of a ladder-type electron source according to the present invention.

FIG. 12 is a diagram showing a display panel of the image forming apparatus of the present invention using a ladder-type electron source.

FIG. 13 is a diagram illustrating an electron source according to a third embodiment of the present invention.

FIG. 14 is a partial sectional view of an electron source according to a third embodiment of the present invention.

FIG. 15 is a manufacturing process diagram of the electron source according to the third embodiment.

FIG. 16 is a manufacturing process diagram of the electron source according to the third embodiment.

FIG. 17 is a block diagram of an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 18 is a diagram illustrating a connection configuration at the time of forming of an electron source according to a third embodiment of the present invention.

FIG. 19 is a diagram illustrating a measurement system of an electron source according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Electron emission part 3 Conductive thin film 3a 1st layer 3b 2nd layer 4,5 element electrode 21 Step forming member 31 Crack 50 Ammeter 51 Power supply 52 Ammeter 53 High voltage power supply 54 Anode electrode 55 Vacuum device 56 Exhaust Pump 102 X-directional wiring 103 Y-directional wiring 104 Surface conduction electron-emitting device 105 Connection 111 Rear plate 112 Support frame 113 Glass substrate 114 Fluorescent film 115 Metal back 116 Face plate 118 Enclosure 121 Black conductive material 122 Phosphor 141 Interlayer Insulating layer 142 Contact hole 181 Common electrode 182 Pulse generator 183 Shunt resistor 184 Oscilloscope 191 Vacuum chamber 192 Window 194 Element body 195 X-direction drive wiring 196 Y-direction drive wiring 197 Driver 198 Leader electrode 199 Source 201 Display panel 202 Scanning circuit 203 Control circuit 204 Shift register 205 Line memory 206 Synchronous signal separation circuit 207 Modulation signal generator 261 Drive circuit 262 Display panel controller 263 Multiplexer 264 Decoder 265 Input / output interface 266 CPU 267 Image generation circuit 268 Image memory Interface 269 Image memory interface 270 Image memory interface 271 Image input memory interface 272 TV signal receiving circuit 273 TV signal receiving circuit 274 Input section 280 Display panel 301 Display panel 302 Grid electrode 303 Opening 304 Common wiring

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 1/30 H01J 9/02 H01J 31/12

Claims (12)

(57) [Claims] 1. An electron-emitting device comprising: a pair of device electrodes provided on an insulating substrate so as to face each other; and a conductive thin film having an electron-emitting portion provided between the device electrodes. The conductive thin film is composed of at least two upper and lower thin films , the first thin film has a crack in the middle between the device electrodes,
The thin film of the layer is made of a material having a higher melting point than that of the first layer (excluding carbon).
In step (c) , an electron emission portion is formed by forming a crack in the second layer thin film on the first layer thin film and in the crack in the first layer thin film , and forming a crack in the second layer thin film inside the first layer crack. An electron-emitting device, comprising: Wherein the electron-emitting device according to claim 1, wherein the element electrodes are planar elements formed on the same surface. 3. An insulator provided adjacent to one of the device electrodes.
2. The electron-emitting device according to claim 1 , wherein the other device electrode is located on the edge layer, and a vertical device in which a conductive thin film is formed on a side surface of the insulating layer. 4. The electron-emitting device according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device
4. The electronic device according to claim 1, wherein
Element. 5. A device according to claim 1, wherein a plurality of electron-emitting devices according to any one of claims 1 to 4 are arranged in parallel and connected to each other, and at least one device line is provided, and a wiring for driving each device has a ladder shape. An electron source, which is arranged. 6. An electron-emitting device according to claim 1, wherein :
At least one element row composed of a plurality of
And wires for driving the element are arranged in a matrix.
An electron source characterized in that: An electron source according to claim 7 claim 5, the image forming member,及
Control the electron beam emitted from each element by the information signal
An image forming apparatus comprising a control electrode . 8. An electron source comprising the electron source according to claim 6 and an image forming member.
An image forming apparatus. 9. The electron-emitting device according to claim 1, wherein :
Comprising the steps of:
Next, a thin film of the first layer is formed, and the thin film is
After the step of forming a fissure, a second layer of thin film is formed and energized.
Repeat once or more times a step of forming a Crack and
A method for manufacturing an electron-emitting device . 10. The method according to claim 9, wherein a plurality of copies are formed on the same substrate.
A method for manufacturing an electron source , comprising forming a number of electron-emitting devices . 11. An electron source is manufactured by the manufacturing method according to claim 10 , and the obtained electron source is used as an electron beam emitted from the electron source.
And an image forming member for forming an image by irradiation of an electron beam from the electron source . 12. An electron source is manufactured by the manufacturing method according to claim 10.
And the obtained electron source is irradiated with an electron beam from the electron source.
Combining with image forming members to form more images
A method for manufacturing an image forming apparatus characterized by the above-mentioned.