JP2000243222A - Electron emitting element, electron source, image forming device and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the forming power and at the same time to improve the heat resisting stability of the electron discharging characteristic by comprising an electron emissive portion on a conductive thin film over a part of elemental electrodes, forming two layers in a conductive thin film, and forming the lower layer by a thin film having aggregation energy lower than that of an upper layer. SOLUTION: A flat surface conductive-type electron discharge element is formed by a base 1, an electron emissive portion 2, a conductive thin-film upper layer 3, a conductive thin-film lower layer 6, and the element electrodes 4, 5. A conductive thin-film 7 is totally formed by two different layers, the film of the conductive thin-film lower layer 6 is composed of a material having the aggregation energy smaller than that of a film of the conductive thin-film upper layer 3. The aggregation energy of metal is obtained mainly of metallic bond, and in the case of transition metal, since the mutual action of d-orbit electrons contributes to the bond, the aggregation energy is variable corresponding to a value of a shell. Particularly, corresponding Cu, Ag, Au have low aggregation energy in a transition metal in a state in which the electron of 3d, 5d orbits are filled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art An electron-emitting device, for example, a surface conduction electron-emitting device, comprises a conductive thin film formed on an insulating substrate.
This utilizes the phenomenon that electron emission occurs when a current is passed in parallel to 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 performed on both ends of the conductive thin film.
This is a process that is usually performed by applying a voltage and energizing, and locally destroying, deforming, or altering the conductive thin film to change the structure, thereby forming an electron emission portion in an electrically high-resistance state. 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.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of arrays can be formed over a large area because of its simple structure and easy manufacture. Therefore, various applications for making use of this feature are being studied. For example, it can be used for an image forming apparatus such as a charged beam source and a display device.

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 self-luminous display device that does not require a backlight is used.
A display device has been proposed in which an electron source in which a number of surface conduction electron-emitting devices are arranged and a phosphor that emits visible light by irradiating an electron beam from the electron source are combined (US Pat. No. 5,066,883). ).

Further, with respect to forming when an electron source and an image forming apparatus are provided by arranging a plurality of the elements, the conductive thin film is made of a metal oxide film and hydrogen is introduced while energizing to form a plurality of elements on the same wiring. A hydrogen-assisted forming method has been proposed in which elements can be formed simultaneously and uniformly (JP-A-06-12997).

[0007]

In the case of a surface conduction electron-emitting device in which an electron-emitting portion is formed on a part of a conductive thin film by the above-described forming process, the power required for the forming and the power of the electron-emitting portion are reduced. Properties and the like greatly depend on the film quality of the conductive thin film.

Regarding the forming power, especially in the case of an electron source in which a large number of surface conduction electron-emitting devices are arranged and arranged, if a large current is required for forming per element, a large number of surface conduction electron-emitting devices are simultaneously energized. In addition, it is difficult to carry out forming, and it requires a large amount of electric power, so that an expensive forming apparatus is required. At the same time, in order to increase the current capacity of the wiring, use of expensive wiring material having high electrical conductivity is required. Is required.

Furthermore, when a display device is manufactured by combining an electron source having a large number of surface conduction electron-emitting devices arranged as described above and an image forming member, etc., in particular, a display device using glass is used. It is indispensable to go through a high temperature heating process. Through such a high-temperature heating step, the electrical properties of the conductive thin film may change, making it impossible to apply a desired voltage to the electron-emitting portion.

More specifically, the change in morphology in the above-described high-temperature heating step and the change in crack shape due to current concentration on an electron-emitting portion formed by forming are suppressed by using a conductive thin film having a high melting point. However, when a metal having a high melting point is used, as described above, a large amount of power is required at the time of forming. On the other hand, if a metal oxide film is used to increase the melting point, the above-described change can be suppressed, but the electric resistance that is several orders of magnitude higher than in the case of using a metal causes a current that effectively flows to the electron-emitting portion to be increased. There was a problem of becoming smaller.

SUMMARY OF THE INVENTION In view of the above circumstances, it is a main object of the present invention to reduce the forming power and at the same time improve the heat stability of electron emission characteristics. At the same time, the present invention provides a water-soluble ink for forming a conductive thin film which reduces the forming power and improves the heat stability of the electron emission characteristics in view of the above circumstances, and provides an electron emission element, an electron source and an image display. The main purpose of the apparatus is to provide a manufacturing method.

[0012]

According to a first aspect of the present invention, there is provided an electron emitting device according to the present invention, wherein the electron emitting portion is provided on a conductive thin film extending between a pair of device electrodes. The conductive thin film is composed of two layers, and the lower layer is composed of a film having lower cohesive energy than the upper layer.

Further, an electron source according to the present invention is characterized in that a plurality of the above-mentioned electron-emitting devices are provided on a substrate.

Further, an image forming apparatus according to the present invention includes the above-mentioned electron source and an image forming member for forming an image by irradiating an electron beam from the electron source.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention relates to an electron-emitting device, an electron source using the electron-emitting device, and an image forming apparatus using the electron source. The operation will be further described below.

The basic configuration of the surface conduction electron-emitting device according to the present invention will be described. The basic configuration of the surface conduction electron-emitting device is as shown in FIG.
Among them, 1 is a substrate, 2 is an electron emitting portion, 3 is a conductive thin film upper layer including the electron emitting portion 2, 6 is a conductive thin film lower layer, 7 is a combination of the conductive thin film upper and lower layers, and 4 and 5 are device electrodes. It is.

As the substrate 1, for example, quartz glass, Na
Glass, blue sheet glass, a laminated body obtained by laminating SiO ₂ on a blue sheet glass by a sputtering method or the like, ceramics such as alumina, etc. are preferably used.

Materials for the opposing device electrodes 4 and 5 include:
A general conductor material is used, for example, Ni, Cr, A
u, Mo, W, Pt, Ti, Al, metals or alloys such as Cu, Pd, Ag, Au, printed conductors composed of RuO _2, metal or metal oxide such as Pd-Ag and glass, an In ₂ It is appropriately selected from a transparent conductor such as O ₃ —SnO ₂ and a semiconductor conductor material such as polysilicon.

The distance L between the device electrodes, the length W1 of the device electrode, the shape of the conductive thin film 7, and the like are appropriately designed depending on the form to be applied. The distance L between the device electrodes is several hundreds to several hundred μm.
And more preferably, the device electrode 4,
It is several μm to several hundred μm depending on the voltage applied between the five.

The element electrode length W1 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.

The conductive thin film 7 is composed of two different layers, and the lower film is made of a substance having a smaller cohesive energy than the upper film. First, the material of the conductive thin film 7 has a high melting point in which the morphology of the film does not easily change even after a high-temperature heating step and the crack shape after forming does not easily change due to local current concentration due to application of a driving voltage. It is preferably a metal material. Second, in order to sufficiently secure a voltage locally applied to the electron-emitting portion, it is preferable that both the upper layer and the lower layer are films having low electric resistivity, that is, metal films. Third, at least the upper layer film is preferably a metal suitable for performing hydrogen-assisted forming to reduce the forming power, that is, a metal that is easily oxidized in the air and easily reduced in hydrogen. Fourth, it is preferable to form a stable complex ion for forming an ink solution in order to form a conductive thin film that does not require a photolithography step by an ink-jet method described later.

More specifically, as the material satisfying the first and second conditions, a high-melting metal material such as a noble metal or a transition metal can be used for both the upper layer and the lower layer. That is, noble metals (platinum group (Ru, Rh, Pd, Os, Ir, Pt)
And gold (Au), silver (Ag), or noble metal, W,
Transition metals such as Ta, Mo, and Cr are exemplified. As a material that satisfies the third condition, at least the upper layer is a film that is easily redox-reduced in order to reduce forming power during energization forming by hydrogen assist. Mg, Ca, B
a, La, Y, Ti, Zr, W, Ni and the like.
In addition, Pd is an additional active metal element among the above-mentioned noble metals. Of course, as described above, if the forming power can be reduced by hydrogen assist during the forming, the effect of reducing the forming power can be obtained by the hydrogen assist forming as described above. This is not the case for metals that are easy to work with. Even if the metal is not generally considered to be easily oxidized, if it is oxidized in a thin film state due to a local temperature rise of the film when forming is conducted, it is considered that the above third condition is satisfied. Similarly, even metals that are not generally said to be easily reduced, for example, at 200 ° C.
When the resistance is decreased by exposure to a reducing gas such as hydrogen or carbon monoxide with a certain degree of heating, it is considered that the above third condition is satisfied.

Generally, the cohesive energy of a metal is mainly composed of a metal bond. In particular, in the case of the above-mentioned transition metals, the interaction of d-orbital electrons contributes to the bonding, and therefore, the aggregation energy varies depending on the valence of the d-shell. Especially 3d,
It is known that Cu, Ag, and Au, which correspond to the state where electrons of the 4d and 5d orbits are filled, respectively, have low cohesive energy especially in the above-mentioned transition metals.

Further, in order to satisfy the above fourth condition, the above-mentioned metal material is used as a stable complex ion for forming a solution for a simple device film forming process using an ink jet method. Preferred are mentioned. That is, it is well known that the platinum group elements have many oxidation numbers, do not form simple cations, and exist as complexes in addition to several aqua ions.

The thickness of the conductive thin film 7 is appropriately set according to the electric resistance between the device electrodes 4 and 5 and the forming conditions described later. The thickness of the conductive thin film 7 is preferably 10 ° to 1000 °, particularly preferably 100 ° to 1000 °.
It is 300Å.

In particular, it is desirable that the conductive thin film lower layer 6 substantially covers the substrate 1 under the conductive thin film upper layer 3. On the other hand, as described above, the conductive thin film lower layer 6 is made of a metal having a small cohesive energy. In the case where the oxidation in the film firing step and the reduction during hydrogen assist are not performed, the electric resistance of the conductive thin film 7 is low due to the large film thickness and the forming power is increased. Is set.

The electron emitting portion 2 contains a crack, and the electron emission is performed from the vicinity of the crack. The electron-emitting portion 2 including the crack and the crack itself are formed depending on the thickness, the film quality, the material of the conductive thin film 7 and the manufacturing method such as forming conditions described later. Therefore, the position and shape of the electron-emitting portion 2 are not limited to the position and shape as shown in FIG.

An example of a method of manufacturing a surface conduction electron-emitting device according to the present invention will be described with reference to a manufacturing process diagram of FIG. 2 using the surface conduction electron-emitting device having the structure shown in FIG. 1 as an example. 1) The substrate 1 is sufficiently washed with a detergent, pure water, and an organic solvent, and an element electrode material is deposited by a vacuum deposition method, a sputtering method, or the like. Then, the substrate 1 is coated on the surface of the substrate 1 by a photolithography technique or a printing method. The device electrodes 4 and 5 are formed (FIG. 2A).

2) On the substrate 1 provided with the device electrodes 4 and 5,
Sputtering method, CVD method, electron beam heating evaporation method,
Alternatively, the conductive thin film 7 is formed by using a method of applying an organic metal compound and heating and baking. Next, the conductive thin film lower layer 6 and the conductive thin film upper layer 3 having a desired pattern are sequentially formed by patterning by lift-off, etching, or the like (FIG. 2B). Alternatively, a baking step is provided after the conductive thin film lower layer 6 is formed, and then a suitable manufacturing step such as forming the conductive thin film upper layer 3 is used. Here, the organic metal solution is a solution of an organic compound containing the metal constituting the conductive thin film 7 as a metal complex, and the viscosity of which is adjusted with a solvent to obtain a desired film thickness is used. Further, by performing the above-described patterning step of the conductive thin film lower layer 6 and the conductive thin film upper layer 3 by an ink jet method, the step of photolithography technology can be extremely simplified. First, the conductive thin film lower layer 6 is formed by a method of applying a dot film between the element electrodes 4 and 5 by droplet ejection by an ink jet method and then heating and baking. Further, a conductive thin film upper layer 3 is provided thereon with a dot film, and then heated and baked, thereby sequentially forming two conductive thin films. The ink referred to here is an organic metal solution containing the above-described metal complex ions, and is used whose viscosity is adjusted with a solvent so as to obtain a desired film thickness and dot diameter by inkjet.

3) Subsequently, an energization process called forming is performed. When power is supplied between the device electrodes 4 and 5 by a power supply (not shown), the electron-emitting portion 2 having a changed structure is formed at the conductive thin film 7. By this energization process, the conductive thin film 7
Is locally destroyed, deformed or altered, and the portion where the structure is changed is the electron emission portion 2 (FIG. 2C). Further, in the case of an electron source in which a plurality of electron-emitting devices are arranged or an image display device, it is necessary to form a plurality of electron-emitting devices on a wiring at the same time. In such a case, a reducing atmosphere ( In particular, it is preferable to perform the energization treatment in a hydrogen atmosphere). The effect of suppressing the forming power by the hydrogen assist is at least when the conductive film upper layer 3 is subjected to the energizing process under the hydrogen assist and when the energizing process is performed without the hydrogen assist.
It is effective in principle when a voltage difference occurs.

When the conductive thin film 7 is made of two kinds of metal elements as described above, and at least one of the metals can reduce the forming power by hydrogen assist during the energization treatment, hydrogen assist forming is preferably used. A case where hydrogen assist forming is preferably used will be described. FIG. 3 shows the relationship between the mixed composition of the two types of metal elements A and B (the thickness ratio between the upper conductive layer 3 and the lower conductive layer 6) and the forming voltage. An element in which the conductive thin film 7 is formed by changing the mixed composition of the metal elements A and B is prepared. The element is placed in a vacuum device as described later, evacuated, and then the voltage Vf is applied between the element electrodes 4 and 5. Is applied, Vf is gradually increased, and Vf1 at the time when the device current If flowing through the conductive thin film falls is obtained. Another element having the same configuration is prepared, placed in a vacuum device as described below, evacuated, then introduced with a reducing gas (eg, 2% hydrogen 98% nitrogen), reduced for a sufficient time, and then reduced again. The reducing gas is exhausted, and a voltage Vf is applied between the device electrodes 4 and 5 to gradually reduce the Vf.
Is increased, and Vf2 at the time when the element current If flowing through the conductive thin film falls is obtained (FIG. 3A). Metal elements A and B
When there is a difference between Vf1 and Vf2 in the mixed composition of the above, forming by hydrogen assist is effective in principle (FIG. 3B).

FIG. 4 shows an example of the voltage waveform of the above-mentioned forming. The voltage waveform is particularly preferably a pulse waveform. When a voltage pulse with a constant pulse peak value is applied continuously (FIG. 4A), or when 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. T1 and T2 in FIG. 4A are the pulse width and pulse interval of the voltage waveform. For example, T1 is 1 μs to 10 ms, T2 is 10 μs to 100 ms,
The peak value (peak voltage at the time of forming) is appropriately selected according to the form of the surface conduction electron-emitting device described above, and is applied for several seconds to several tens of minutes in a vacuum atmosphere having an appropriate degree of vacuum.
The applied voltage waveform may be a rectangular wave other than the illustrated triangular wave. Next, a case where a voltage pulse is applied while increasing the pulse peak value will be described. T1 and T2 in FIG. 4B correspond to FIG.
Same as above, peak value (peak voltage during forming)
Is increased by, for example, about 0.1 V step, and FIG.
The application is performed under an appropriate vacuum atmosphere as described in (a).

It is more preferable that the resistance of the conductive thin film 7 after the forming is sufficiently reduced uniformly by exposing it to a hydrogen atmosphere after completion of the forming or by performing thermal reduction by heating the substrate.

4) The surface conduction electron-emitting device according to the present invention is preferably further subjected to an activation step. The activation step refers to a process of repeating application of a pulse with a pulse peak value of a constant voltage at a degree of vacuum of, for example, about 10 ⁻⁴ to 10 ⁻⁷ Torr, as described in the forming step. By depositing carbon and a carbon compound from the organic substance existing in the atmosphere on the electron-emitting portion 2 (see FIG. 1), the state of the device current and the emission current can be significantly improved. This activation step is preferably performed while measuring, for example, the device current and the emission current, and is completed when the emission current is saturated. In addition, the pulse peak value in the activation step is preferably a peak value of a driving voltage applied when driving the element.

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.

The basic characteristics of the surface conduction electron-emitting device according to the present invention thus obtained will be described below. FIG.
Is a schematic configuration diagram showing an example of a measurement evaluation system for measuring the electron emission characteristics of a surface conduction electron-emitting device. First, this measurement evaluation system will be described. 5, the same reference numerals as those in FIG. 1 indicate the same members. Reference numeral 51 denotes a power supply for applying an element voltage Vf to the element, 50 denotes an ammeter for measuring an element current If flowing through the conductive thin film 7 between the element electrodes 4 and 5, 5
Reference numeral 4 denotes an anode electrode for capturing an emission current Ie emitted from the electron emission unit 2, 53 denotes a high-voltage power supply for applying a voltage to the anode electrode 54, and 52 denotes an emission current Ie emitted from the electron emission unit 2. An ammeter for measurement, 55 is a vacuum device, and 56 is an exhaust pump.

The surface conduction electron-emitting device, the anode electrode 54 and the like are installed in a vacuum device 55.
Is equipped with necessary equipment such as a vacuum gauge (not shown),
Measurement and evaluation of the surface conduction electron-emitting device can be performed under a desired vacuum.

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.
Further, the entire vacuum device 55 and the substrate 1 of the surface conduction electron-emitting device can be heated to about 300 ° C. by a heater. In this measurement evaluation system, the display panel and the inside thereof are connected to a vacuum device 5 at the stage of assembling the display panel (see 201 in FIG.
5 and the inside thereof can be applied to measurement evaluation and processing in the above-described forming step and activation step.

The basic characteristics of the surface conduction electron-emitting device described below are as follows: the voltage of the anode electrode 54 in the above-mentioned measurement and evaluation system is 1 kV to 10 kV, and the distance H between the anode electrode 54 and the surface conduction electron-emitting device is 2 mm to 8 mm. The measurement is usually performed as follows.

First, the emission current Ie and the device current If,
FIG. 6 (a solid line in the figure) shows a typical example of the relationship between the element voltages Vf.
Shown in In FIG. 6, since the emission current Ie is significantly smaller than the element current If, it is shown in arbitrary units.

As apparent from FIG. 6, the surface conduction electron-emitting device has the following three characteristic characteristics with respect to the emission current Ie. First, when the surface conduction electron-emitting device is applied with a device voltage Vf higher than a certain voltage (Vth in FIG. 6, hereinafter referred to as "threshold voltage"), the emission current I sharply increases.
e increases, while the emission current Ie is hardly detected below the threshold voltage Vth. That is, the emission current I
It is a non-linear element having a clear threshold voltage Vth for e. Secondly, since the emission current Ie has a characteristic that monotonically increases with respect to the element voltage Vf (referred to as MI characteristic),
The emission current Ie can be controlled by the device voltage Vf.

Thirdly, the amount of charge discharged to 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 for applying the device electrode Vf.

The characteristic shown by the solid line in FIG.
Has the MI characteristic with respect to the element voltage Vf, and the element current If also has the MI characteristic with respect to the element voltage Vf. However, as shown by a broken line in FIG. On the other hand, a voltage control type negative resistance characteristic (referred to as VCNR characteristic) may be exhibited. Which property is shown
It depends on the manufacturing method of the element and the measurement conditions at the time of measurement. However,
Even if the device current If has a VCNR characteristic with respect to the device voltage Vf, the emission current Ie is M with respect to the device voltage Vf.
It has an I characteristic.

Due to the characteristic characteristics of the surface conduction electron-emitting device according to the present invention as described above, even in an electron source or an image forming apparatus in which a plurality of devices are arranged, the amount of emitted electrons can be easily changed according to an input signal. Can be controlled, and can be applied to various fields.

Next, the arrangement of the surface conduction electron-emitting devices in the electron source of the present invention will be described. As the arrangement system of the surface conduction electron-emitting devices in the electron source of the present invention,
In addition to the trapezoidal arrangement, n Y-directional wirings are placed on m X-directional wirings via an interlayer insulating layer, and the X-directional wiring and the Y-direction An arrangement method in which wiring is connected may be used. This is hereinafter referred to as a simple matrix arrangement.

According to the above-mentioned basic characteristics of the surface conduction electron-emitting device, when the applied device voltage Vf exceeds the threshold voltage Vth, the electron is expressed by the peak value and pulse width of the applied pulse voltage. The amount of release can be controlled. On the other hand, below the threshold voltage Vth, almost no electrons are emitted. Therefore, even when a large number of surface conduction electron-emitting devices are arranged, it becomes possible to apply a pulse-like voltage controlled in accordance with an input signal with only a simple matrix wiring and to select individual devices to be driven independently. .

The simple matrix arrangement is based on the above principle, and the configuration of an electron source having a 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.

Each of the m X-directional wirings 102 has external terminals Dx1, Dx2,... Dxm, and is a conductive metal film formed on the substrate 1 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 a voltage is supplied to a large number of the surface conduction electron-emitting devices 104 almost uniformly. n Y-direction wirings 103
Have external terminals Dy1, Dy2,... Dyn, and are formed in the same manner as the X-direction wiring 102. These m
An interlayer insulating layer (not shown) is provided between the X-directional wirings 102 and the n Y-directional wirings 103, and is electrically separated to form a matrix wiring. Note that m and n
Are both 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-direction wiring 102 is formed. The thickness, material, and manufacturing method are appropriately set so as to be able to withstand the potential difference at the intersection of the X-direction wiring 102 and the Y-direction wiring 103, in particular.

Further, device electrodes (not shown) opposed to the surface conduction electron-emitting device 104 are provided with m X-directional wirings 10.
2, and the n number of Y-direction wirings 103 are electrically connected by a connection 105 made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like.

Here, the m X-directional wires 102, the n Y-directional wires 103, the connection 105, and the opposing element 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 surface conduction electron-emitting device 104 may be formed on either the substrate 1 or an interlayer insulating layer (not shown).

As will be described in detail later, a scanning signal is applied to the X-direction wiring 102 in order to scan a row of the surface conduction electron-emitting devices 104 arranged in the X-direction in accordance with an input signal. A scanning signal applying unit (not shown) is electrically connected. On the other hand, a modulation signal applying means (not shown) for applying a modulation signal in order to modulate each of the rows of the surface conduction electron-emitting devices 104 arranged in the Y direction according to an input signal. Are electrically connected. The driving voltage applied to each surface conduction electron-emitting device 104 is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device.

Next, an example of the image forming apparatus of the present invention using the electron source of the present invention having the above-described simple matrix arrangement will be described with reference to FIGS. 8 shows the basic configuration of the display panel 201, FIG. 9 shows the fluorescent film 114, and FIG. 10 shows the display panel 201 of FIG.
It is a block diagram which shows an example of the drive circuit for performing television display according to the television signal of SC system.

In FIG. 8, reference numeral 1 denotes an electron source substrate on which the surface conduction electron-emitting devices 104 are arranged as described above.
Reference numeral 11 denotes a rear plate to which the substrate 1 is fixed, 116 denotes a face plate in which a fluorescent film 114 serving as an image forming member and a metal back 115 are formed on the inner surface of a glass substrate 113, and 112 denotes a support frame. Rear plate 111,
The support frame 112 and the face plate 116 are sealed by applying frit glass or the like to these joints and baking them at 400 ° C. to 500 ° C. for 10 minutes or more in the air or in a nitrogen or argon atmosphere. The container 118 is constituted.

In FIG. 8, reference numeral 2 corresponds to the electron-emitting portion in FIG. Reference numerals 102 and 103 denote X-direction wiring and Y-direction wiring connected to a pair of device electrodes 4 and 5 (see FIG. 1) of the surface conduction electron-emitting device 104.
To Dxm and Dy1 to Dyn.

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 rear plate 1
11 is unnecessary, and the support frame 112 may be directly sealed to the substrate 1, and the envelope 118 may be configured by the face plate 116, the support frame 112, and the substrate 1. Further, by further installing a support (not shown) called a spacer between the face plates 111, the envelope 118 having sufficient strength against atmospheric pressure can be obtained.

The fluorescent film 114 is composed of only the phosphor 112 in the case of monochrome, but is composed of the phosphor 1 in the case of color.
Black stripes (FIG. 9A)
Alternatively, it is composed of a black conductive material 121 called a black matrix (FIG. 9B) and the like and a phosphor 122.
The purpose of providing the black stripes and the black matrix is to make the phosphors 122 of the three primary colors necessary for color display.
The purpose of this is to make the color mixture and the like inconspicuous by making the painted portions black, and to suppress a decrease in contrast due to reflection of external light on the fluorescent film 114. Black conductive material 121
In addition to the commonly used material mainly composed of graphite, any other material can be used as long as it is conductive and has little light transmission and reflection. 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.
4 is usually provided with a metal back 115. The purpose of the metal back 115 is to use the phosphor 122 (FIG. 9).
Of the light emitted toward the inner side of the face plate 1
16 to improve the brightness by specular reflection, function as an electrode for applying an electron beam acceleration voltage from the high voltage terminal Hv, and emit fluorescence from damage caused by the collision of negative ions generated in the envelope 118. Protection of the body 122 and the like. The metal back 115 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. Face plate 1
16 may be further provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 114.

When the above-mentioned sealing is performed, in the case of a color, each color phosphor 122 must correspond to the surface conduction electron-emitting device, so that it is necessary to perform sufficient alignment. The inside of the envelope 118 passes through an exhaust pipe (not shown),
The degree of vacuum is set to about 0 ^-7 Torr, and sealing is performed. 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) disposed at a predetermined position in the envelope 118 by a heating method such as resistance heating or high-frequency heating to form a deposition film. A getter typically contains Ba as a principal component, the adsorption effect of the vapor deposition film, for example, 10 ^-5
This is for maintaining a degree of vacuum of about 10 ⁻⁹ Torr.

The subsequent steps of manufacturing the surface conduction electron-emitting device, such as the above-described forming and activation, are performed by the envelope 118.
Is carried out immediately before or after sealing. In order to uniformly introduce and exhaust gas into and out of the envelope 118 (introducing and exhausting hydrogen during forming, and introduce and exhaust organic compound gas during activation), and to derive wiring from outside the envelope. In order to suppress the defective cost, it is desirable that the subsequent manufacturing steps such as the above-described forming and activation be performed before sealing. The conductive thin film 7 in the present invention comprises:
For example, the resistivity of the film does not change remarkably even through a high-temperature heating step such as 350 ° C. to 450 ° C., which is considered to be necessary for the sealing step, for several minutes to several tens of minutes. By sealing the enclosure 118, it is possible to reduce the cost of the lost item, which is preferable.

The display panel 201 described above is, for example, shown in FIG.
Can be driven by a driving circuit as shown in FIG. In FIG. 10, reference numeral 201 denotes the 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, 207 is a modulation signal generator, and Vx and Va are DC voltage sources.

As shown in FIG. 10, the display panel 20
1 is connected to an external electric circuit via external terminals Dx1 to Dxm, external terminals Dy1 to Dyn, and a high voltage terminal Hv. Of these, the external terminals Dx1 to Dx1
In xm, a surface conduction electron-emitting device provided in the display panel 201, that is, an element group arranged in a matrix of m rows and n columns is sequentially driven one row (n element) at a time. Are applied.

On the other hand, the external terminals Dy1 to Dyn
A modulation signal for controlling an output electron beam of each element in one row selected by the scanning signal is applied. Also,
The high-voltage terminal Hv is connected to a DC voltage source Va by, for example, 10
A DC voltage of kV is supplied. This is an accelerating voltage for applying sufficient energy to the electron beam output from the surface conduction electron-emitting device to excite the phosphor.

The scanning circuit 202 has m switching elements therein (schematically indicated by S1 to Sm in FIG. 10).
Each of the switching elements S1 to Sm selects either the output voltage of the DC voltage source Vx or 0 V (ground level) and is electrically connected to the external terminals Dx1 to Dxm of the display panel 201. Things. Each of the switching elements S1 to Sm includes a control circuit 203
Operates on the basis of the control signal Tscan output by the device, and in fact, it can be easily configured by combining elements having a switching function such as an FET, for example.

In the DC voltage source Vx according to the present invention, a driving voltage applied to a surface-conduction electron-emitting device that is not scanned is a threshold based on the characteristics (threshold voltage) of the surface-conduction electron-emitting device. It is set to output a constant voltage that is equal to or lower than the value voltage.

The control circuit 203 has a function of coordinating the operation of each unit so that an appropriate display is performed based on an image signal input from the outside. The synchronization signal Ts sent by the synchronization signal separation circuit 206 described next
Tscan, Tsft for each part based on the sync
And Tmry control signals.

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. ) If a circuit is used, it can be easily configured. Synchronous signal separation circuit 2
The sync signal separated by 06 comprises a vertical sync signal and a horizontal sync signal, as is also well known. Here, it is illustrated as Tsync for convenience of explanation. On the other hand, a luminance signal component of an image separated from the television signal is illustrated as a DATA signal for convenience. 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. Operate. This control signal Tsft is supplied to the shift register 20
4 may be rephrased as the shift clock. Also,
One line of serial / parallel converted image (equivalent to drive data for n elements of surface conduction electron-emitting device)
Are output from the shift register 204 as n parallel signals of Id1 to Idn. The line memory 205 is a storage device for storing data for one line of an image for a required time, and appropriately stores Id1 to Id according to a control signal Tmry sent from the control circuit 203.
Store the contents of n. The stored contents are output as Id′1 to Id′n and input to the modulation signal generator 207.

The modulation signal generator 207 is a signal line for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of the image data Id'1 to Id'n. Are applied to the surface conduction electron-emitting devices in the display panel 201 through the external terminals Dy1 to Dyn.

As described above, the surface conduction electron-emitting device has a distinct threshold voltage for electron emission, and electron emission occurs only when a voltage exceeding the threshold voltage is applied. For voltages exceeding the threshold voltage,
The emission current also changes according to the change in the voltage applied to the surface conduction electron-emitting device. By changing the material, configuration, and manufacturing method of the surface conduction electron-emitting device, the value of the threshold voltage and the degree of change of the emission current with respect to the applied voltage may be changed. I can say that.

That is, when a pulse-like voltage is applied to the surface conduction electron-emitting device, electron emission does not occur even if a voltage lower than the threshold voltage is applied, but a voltage exceeding the threshold voltage is applied. In this case, electron emission occurs. 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.

Accordingly, as a method of modulating the surface conduction electron-emitting device in accordance with an input signal, there are a voltage modulation method and a pulse modulation method. In the case of performing the voltage modulation method, the modulation signal generator 207 generates a voltage pulse of a fixed length, and uses a voltage modulation method circuit that can appropriately modulate the peak value of the pulse according to input data. When the pulse width modulation method is performed, 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 separating 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) that calculates the number of waves output from the oscillator, 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 a drive voltage of the surface conduction electron-emitting device may be added.

On the other hand, in the case of a voltage modulation method using an analog signal, for example, an amplification circuit using a well-known 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 oscillation circuit (VCO) may be used, and a voltage is amplified to a drive voltage of a surface conduction electron-emitting device as necessary. May be added.

The image forming apparatus of the present invention having the display panel 201 and the driving circuit as described above has the external terminals Dx1 to Dx1.
By applying a voltage from Dxm and Dy1 to Dyn, electrons can be emitted from any surface conduction electron-emitting device 104, and a high voltage is applied to the metal back 115 or the transparent electrode (not shown) through the high voltage terminal Hv. To accelerate the electron beam and apply the accelerated electron beam to the fluorescent film 1
14 by the excitation and emission generated by the collision with
A television display can be performed according to a TSC 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 of the present invention is not limited to this, and may employ another system such as a PAL or SECAM system, or a TV having a larger number of scanning lines. A signal, for example, a high-definition TV system such as the MUSE system may be used. Also, in the above description, a simple matrix method has been described as an image display device using the most preferable simple driving method and driving wiring.
Even if a ladder arrangement is used, television display can be performed in the same manner,
An image forming apparatus suitable as a display device for a television conference system, a computer, or the like as well as the above-described display device for a television broadcast can be obtained. Further, the present invention can be used as an exposure device of an optical printer including a photosensitive drum and the like.

[0081]

The present invention will be further described below with reference to examples and comparative examples. [Embodiment 1] In this embodiment, an example of manufacturing a surface conduction electron-emitting device having the structure shown in FIG. 1 will be described. FIG. 1 (a)
1 is a plan view of a surface conduction electron-emitting device, and FIG. 1B is a cross-sectional view. In the drawing, L represents the interval between the device electrodes 4 and 5, W1 represents the width of the device electrode, and W2 represents the width of the conductive thin film 3.

Next, a method for manufacturing the surface conduction electron-emitting device of this embodiment will be described with reference to FIG. 1) A quartz substrate is used as the substrate 1, and after sufficiently washing the substrate with an organic solvent, device electrodes 4 and 5 made of Pt are formed on the substrate 1 by a general vacuum forming technique and a photolithography technique. The distance L between device electrodes is 10μ
m, length W1 is 600 μm, and thickness d is 1000 °.

2) Next, an aqueous solution was prepared so that ammonium dicyanoaurate (I) was 10 mmol / l and IPA was 15 wt%, and a droplet jetting device of a bubble jet type was used as a droplet applying device. It was applied once or twice between the device electrodes in the state, and the film thickness was approximately 40 °. It was baked in an oven at 300 ° C. for 20 minutes. Next, after the substrate was sufficiently cooled, 14 mmol / l of palladium (II) acetate monoethanolamine complex and 15 wt% of IPA were used.
The aqueous solution is adjusted so as to be, using a bubble jet type ink jet ejecting device as a droplet applying device, in a state of a liquid droplet so as to overlap the dot film formed earlier between the element electrodes 4 and 5 a plurality of times, It was applied as shown in FIG. The film thickness was about 120 ° for the laminate.

3) A heat treatment was performed at 350 ° C. for 30 minutes, and the upper layer was palladium oxide (PdO) and the lower layer was gold (A
u) to form a conductive thin film 7. At this time, the fine particles of palladium oxide and gold were not particularly formed separately, but were formed as a substantially uniform fine particle film.

4) Next, the substrate 1 on which the device electrodes 4 and 5 and the conductive thin film 7 are formed is set in a vacuum apparatus 55 of the measurement and evaluation system shown in FIG. The inside of the vacuum device 55 was set at about 10 ^-5 Torr. Thereafter, the power supply 51 for applying the device voltage Vf causes the device electrodes 4, 5 to be applied.
Immediately after the voltage is applied, hydrogen 2%, nitrogen 98%
Forming is performed while gradually introducing gas. The voltage waveform at the time of forming was a rectangular wave of 1 ms / 10 ms. Note that the device of this embodiment has a voltage of 10 when forming.
Forming was completed in about 10 minutes with V.

5) Next, an activation process is performed on the element subjected to the forming process. After the forming is completed, the inside of the vacuum device 55 is evacuated again, and the inside of the vacuum device 55 is 10 ⁻⁷ To.
The degree of vacuum was rr. Benzonitrile was used as the organic compound to be activated, and the benzonitrile was introduced by gradually opening a variable leak valve (not shown), and the inside of the vacuum device 55 was evacuated to 10 ^-6 Torr. After the degree of vacuum after the introduction of benzonitrile became sufficiently constant, a voltage was applied between the device electrodes 4 and 5. 1 ms /
A bipolar rectangular wave of 10 ms and 15 V was used. The activation process was performed for one hour, and the process was performed until the activation current did not increase and the device current If became substantially constant.

The measurement of the electron emission characteristics of the surface conduction electron-emitting device of this example was performed using the above-described measurement and evaluation system. The measurement conditions were as follows: the distance H between the anode electrode 54 and the surface conduction electron-emitting device was 4 mm, and the potential of the anode electrode 54 was 1
kV, the degree of vacuum in the vacuum device 55 at the time of measuring the electron emission characteristics was set to about 1 × 10 ⁻⁸ Torr.

As a result, the device according to the present invention obtained current-voltage characteristics as shown by the solid line in FIG. A typical element characteristic is an element voltage Vf
= 15 V, the device current If = 1.0 mA, the emission current Ie = 1 μA, and the variation among a plurality of devices was extremely small.

Comparative Example 1 Further, the conductive thin film 7 was
d (II) monoethanolamine complex 14 mmol / l
A device made in the same manner as in Example 1 except that the device was made of a single-layer film of only Pd was subjected to current-voltage characteristics as shown by a solid line in FIG. Was obtained, but not only the same element characteristics as in Example 1 were obtained, but also the element current If sometimes decreased. In particular, when an element in which the element current If was not sufficiently obtained was observed in detail using an electron microscope or the like, it was found that Example 1
Unlike this, a state was observed in which the morphology of the conductive thin film 7 was sparse especially in a region relatively close to the electron-emitting portion 2. Thus, it can be easily inferred that a voltage required for electron emission is less likely to be locally applied to the electron emission unit 2.

[Embodiment 2] In this embodiment, an electron source as shown in FIG. 7 in which many surface conduction electron-emitting devices as shown in FIG. 1 are arranged in a simple matrix is used. An example in which the above-described image forming apparatus is manufactured will be described.

The electron source is manufactured by expanding each pattern of the device electrodes 4 and 5 and the conductive thin film 3 described in the first embodiment, simultaneously forming a large number of surface conduction electron-emitting devices, and simultaneously performing X-direction wiring. (Also called lower wiring) 102 and Y
This was performed by forming a direction wiring (also referred to as an upper wiring) 103.

An example in which an image forming apparatus is formed using the unformed electron source substrate manufactured as described above will be described with reference to FIGS. First, the substrate 1 of the unformed electron source was placed in a vacuum device 55 and evacuated by a vacuum pump 56, and the inside of the vacuum device was set to 10 ^-5 Torr.
Next, through the external terminals Dx1 to Dxm and Dy1 to Dyn, the device electrodes 4 and 5 of each surface conduction electron-emitting device 104 are connected.
A voltage is applied between the device electrodes 4 and 5 by the power supply 51 for applying the device voltage Vf, as in the first embodiment. Immediately after the voltage is applied, hydrogen 2% nitrogen 98% gas is applied. Was formed while gradually introducing, and an electron emission portion 2 was produced.

Thereafter, the substrate 1 of the formed electron source
Is fixed to the rear plate 111, and a face plate 116 (formed by forming a fluorescent film 114 which is an image forming member and a metal back 115 on the inner surface of the glass substrate 113) is formed 4 mm above the substrate 1. Support frame 112
, The face plate 116, the support frame 11
2. A frit glass was applied to the joint of the rear plate 111 and sealed by baking in argon at 420 ° C. for 10 minutes or more (see FIG. 8). The fixing of the substrate 1 to the rear plate 111 was also performed using frit glass.

The fluorescent film 114 serving as an image forming member
Is made of only a phosphor in the case of monochrome, but in the present embodiment, the phosphor has a stripe shape (see FIG. 9A), and a black stripe is first formed with the black conductive material 121. The phosphors 12 of each color are formed in the spaces by the slurry method.
2 was applied to form a fluorescent film 114. Black conductive material 12
As 1, a commonly used material mainly composed of graphite was used.

Further, a metal back 115 was provided on the inner side of the fluorescent film 114. The metal back 115 is a phosphor 1
After the fabrication of 14, the inner surface of the fluorescent film 114 is subjected to a smoothing treatment (generally called filming).
It was produced by vacuum deposition of Al. The face plate 116 may be provided with a transparent electrode on the outer surface side of the fluorescent film 114 in some cases. However, in the present embodiment, the metal back 115 alone has been omitted because sufficient conductivity was obtained.

At the time of performing the above-described sealing, in the case of color, the phosphors 122 of each color must correspond to the surface conduction electron-emitting device 104, so that sufficient alignment was performed.

The atmosphere in the envelope 118 completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, an organic compound for performing an activation process is obtained. Introduce benzonitrile and use external terminal Dx
1 to Dxm and Dy1 to Dyn, a voltage is applied between the device electrodes 4 and 5 of each surface conduction electron-emitting device 104,
Forming was performed in the same manner as in Example 1, and the electron emission section 2 was activated. The activation step was performed in the same manner as in Example 1, and was terminated when the rise of the device current If substantially stopped.

Thereafter, the envelope 1 is passed through an exhaust pipe (not shown).
The inside of the envelope 18 was sealed by evacuating the exhaust pipe to a degree of vacuum of about 10 ^-7 Torr by heating the exhaust pipe with a burner. Finally, to maintain the vacuum after sealing,
Getter treatment was performed by a high-frequency heating method. Getter is B
a was the main component.

In the display panel 201 (see FIG. 8) configured using the electron sources in the simple matrix arrangement as described above, the external terminals Dx1 to Dxm and Dy1 to Dy1
yn, the scanning signal and the modulation signal are applied to each of the surface conduction electron-emitting devices 104 by a signal generating means (not shown) to emit electrons.
By applying a high voltage of several kV or more to the metal back 115 through v, the electron beam was accelerated, collided with the phosphor 114, and excited and emitted to display an image. As a result, the surface-conduction electron-emitting device used in this example had electron emission characteristics substantially similar to those of the device in the vacuum apparatus in Example 1. In addition, there was little variation in elements, and a high-brightness, high-definition image could be stably displayed over a long period of time without luminance reduction.

Comparative Example 2 On the other hand, the conductive thin film 3
The conductive thin film 3 in this example was prepared by using Pd (II) acetate monoethanolamine complex 14 mmol / l as Pd.
The same forming process as in Example 2 was performed using an electron source substrate prepared in exactly the same manner as in Example 2 except that the electron source substrate was formed only from Example 2, and then sealing was performed in the same manner. When the activation step was performed in the same manner as in Example 2, a plurality of devices with poor activation were generated, and even if the device current If was increased by the activation, the device was not necessarily equivalent to the electron emission characteristic of the device of Example 2. Was not always obtained. In particular, when the morphology of the film of the conductive thin film 3 after the sealing step was observed in detail using an electron microscope or the like, a large number of regions were observed in which the film was highly agglomerated and the fine particle film was in a sparse state. There were areas where the continuity of the film was almost lost (that is, the particles were strongly agglomerated and the metal grains were independent of each other). In Example 2, such a violent aggregation region was not observed in the conductive thin film 7 after the sealing step, and it is presumed that a sufficient voltage was applied to the electron-emitting portion 2 during the subsequent activation step and further during driving. You.

Example 3 When an NTSC signal was input to the image forming apparatus manufactured by the manufacturing method shown in Example 2 as described above, a good television image could be obtained.

[0102]

As described above, the electron-emitting device of the present invention can easily perform forming with very low power, and at the same time, perform a forming process and / or a forming process for forming an electron-emitting portion. Even if a sealing step is performed after the activation process, voltage application to the electron-emitting portion can be effectively performed sufficiently thereafter, thereby greatly reducing the cost of defective products. In addition, by suppressing the aggregation of the conductive thin film 7, the electrical change of the conductive thin film 7 through the sealing step is small, so that the energizing step after sealing a plurality of elements, Variations are reduced, and the uniformity of the electron source substrate and the image display device is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a planar surface conduction electron-emitting device according to one embodiment of the present invention.

FIG. 2 is a diagram for explaining an example of a method of manufacturing the surface conduction electron-emitting device of FIG.

FIG. 3 is a schematic diagram showing the dependency of the forming voltage on the composition of the conductive thin film of the surface conduction electron-emitting device according to the present invention.

FIG. 4 is a diagram showing an example of a voltage waveform used for forming processing.

FIG. 5 is a schematic view of a measurement evaluation system for measuring the electron emission characteristics of the surface conduction electron-emitting device.

FIG. 6 is a diagram showing a typical example of the relationship between the emission current Ie and the device current If and the device voltage Vf of the surface conduction electron-emitting device according to the present invention.

FIG. 7 is a schematic diagram of an electron source in a simple matrix arrangement.

FIG. 8 is a partially cutaway perspective view showing a schematic configuration of a display panel including an electron source in a simple matrix arrangement.

FIG. 9 is a diagram illustrating a configuration example of a fluorescent film used for a display panel.

FIG. 10 is a block diagram illustrating an example of a drive circuit of an image forming apparatus that performs image display according to an NTSC television signal.

[Explanation of symbols]

1: substrate, 2: electron emission portion, 3: upper layer of conductive thin film, 4,
5: device electrode, 6: conductive thin film lower layer, 7: whole conductive thin film, 50: ammeter for measuring device current If flowing through conductive thin film 3, 51: device voltage Vf to surface conduction type electron-emitting device , 52: an ammeter for measuring the emission current Ie emitted from the electron emission section 2, 5
3: a high-voltage power supply for applying a voltage to the anode electrode 54, 54: an anode electrode for capturing electrons emitted from the electron emission unit 2, 55: a vacuum device, 56: an exhaust pump, 102: X-direction wiring, 103: Y direction wiring, 10
4: 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, Hv: high voltage terminal, 118: envelope, 12
1: black conductive material, 122: phosphor, 201: display panel, 202: scanning circuit, 203: control circuit, 204: shift register, 205: line memory, 206: synchronization signal separation circuit, 207: modulation signal generator , Va: DC voltage source, Vx: DC voltage source, 301: display panel, 302:
Grid electrode 303: opening for passing electrons, 3
04: Common wiring for wiring the surface conduction electron-emitting device 104.

Claims (10)

[Claims] 1. An electron-emitting device in which an electron-emitting portion is provided on a conductive thin film extending between a pair of device electrodes, wherein the conductive thin film is composed of two layers and the lower layer has a smaller cohesive energy than the upper layer. An electron-emitting device comprising: 2. The electron-emitting device according to claim 1, wherein each of the two layers of the conductive thin film is made of a transition metal, and a lower metal has less outermost electrons than an upper metal. 3. The electron-emitting device according to claim 2, wherein each of the two layers of the conductive thin film is made of a transition metal, and the metal of the lower layer is one of gold, silver, and copper. 4. The electron-emitting device according to claim 2, wherein each of the two layers of the conductive thin film is made of a transition metal, the upper metal is palladium, and the lower metal is gold. 5. The method for manufacturing an electron-emitting device according to claim 1, wherein the two layers of the conductive thin film are each coated with a solution containing an element constituting the conductive thin film,
A method for manufacturing an electron-emitting device, characterized by being formed by firing. 6. The method for manufacturing an electron-emitting device according to claim 5, wherein both of the two layers of the conductive thin film are formed by applying the solution by an ink-jet method. 7. The method for manufacturing an electron-emitting device according to claim 5, wherein an electron-emitting portion is formed in the conductive thin film by applying a current to the conductive thin film in a reducing atmosphere. 8. An electron source comprising a plurality of the electron-emitting devices according to claim 1 on a substrate. 9. The electron source has at least one element row in which a plurality of electron-emitting devices are arranged, and wirings for driving each electron-emitting element are arranged in a matrix. Item 10. The electron source according to Item 8. 10. An image forming apparatus comprising: the electron source according to claim 8; and an image forming member that forms an image by irradiating an electron beam from the electron source.