JPH06203740A - Electron emitting element and manufacture thereof and electron beam generator and image forming device using this electron emitting element - Google Patents

Abstract

PURPOSE:To provide an electron emitting element used for an electron beam generator, image forming device, etc. CONSTITUTION:A fine grain film 5 for electrically connecting a pair of electrodes 2, 3, formed on a substrate 1, is provided. In this fine grain film, a relation between its minimum film thickness t1 and maximum film thickness t2 is set so as to obtain the relation where t2<=2t1. A forming process of an electron emitting part 4 can be stably performed in uniformity and at low voltage, thus to obtain a uniform luminescent spot of no uneven brightness.

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 used as an electron-emitting source, more specifically, a surface conduction electron-emitting device which is one of cold cathode type devices, a method for manufacturing the same, and an electron beam using the device. The present invention relates to a generator and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as a device which can emit electrons with a simple structure, for example, MI Elinson (M.
I. A cold cathode device announced by Elinson et al. Is known [Radio Engineering Electron Physics (Radio Eng.
on. Phys. ) Volume 10, pp. 1290-1296,
1965].

Such an element utilizes a phenomenon in which a small area thin film formed on a substrate causes electron emission by causing an electric current to flow in parallel in the film, and is generally called a surface conduction type emission element. Has been.

The surface conduction electron-emitting device uses the SnO ₂ (Sb) thin film developed by Elinson et al., And the Au thin film [G. Ditmer "Sin Solid Films" (G. Dittmer:
"Thin Solid Films"), 9, 31
7 (1972)], by ITO thin film [M Hartwell & Giffon Stud "IEE TRANS" Edie Conference (M.
Hartwell and C.I. G. Fonstad:
"IEEE Trans.ED Conf.") 519
P., (1975)], by carbon thin film [Haraki Araki, et al., "Vacuum", Vol. 26, No. 1, page 22, (198).
3 years)] etc. have been reported.

FIG. 11 shows a typical element structure of these surface conduction electron-emitting devices. In the figure, 2 and 3 are electrodes for obtaining electrical connection, 13 is a thin film made of an electron emitting material, 1 is a substrate, and 4 is an electron emitting portion.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 4 is formed in advance by conducting heat treatment called forming before the electron emission.
That is, by applying a voltage between the electrodes 2 and 3,
By energizing the thin film 13, the Joule heat generated thereby locally destroys, deforms or modifies the thin film 13 to form an electron emitting portion 4 in an electrically high resistance state, thereby obtaining an electron emitting function. There is.

The electrically high resistance state means the thin film 1
A discontinuous state film having a crack of 0.5 to 5 μm in a part of 3 and having a so-called island structure inside the crack. The island structure generally refers to a film in which fine particles having a diameter of several tens of μm to several μm are present on the substrate 1, and each fine particle is spatially discontinuous and electrically continuous.

Conventionally, in the surface conduction electron-emitting device, a voltage is applied to the high resistance continuous film by the electrodes 2 and 3 and a current is caused to flow on the surface of the device so that electrons are emitted from the fine particles.

However, the above-described conventional electron-emitting device manufactured by the forming process by electric heating has the following problems. That is, since it is impossible to design an island structure that serves as an electron-emitting portion, it is difficult to improve the elements, variations between elements are likely to occur, the life of the island structure is short and the stability is poor, and the elements are affected by external electromagnetic noise. Since the forming voltage, which is the minimum voltage required to make an electrically high resistance state, is large, and the Joule heat generated during the forming process is large, it is easy to break the substrate and it is difficult to make multiple substrates. The material of the island structure is limited to gold, silver, SnO ₂ , ITO and the like, and materials having a small work function cannot be used, so that a large current cannot be obtained. For this reason, the surface conduction electron-emitting device has not been positively applied industrially, although it has the advantage that the device structure is simple.

Therefore, the inventors of the present invention have disclosed in Japanese Patent Laid-Open No. 2-5682.
No. 2 proposes a novel surface conduction electron-emitting device in which a fine particle film is arranged between electrodes and an electron-emitting process is performed on the fine particle film to provide an electron-emitting portion.

The characteristics of this electron-emitting device are as follows. That is, since it is possible to reduce the amount of heat at the time of forming, it is possible to prevent film cracking and substrate cracking, and it is possible to select an island material, and by using a fine particle film as an electron-emitting material, the voltage required for the forming step is increased. (Forming voltage) can be small.

As a method for producing the above-mentioned fine particle film, a gas deposition method, a dispersion coating method, or the like is used. Among them, a dispersion liquid of fine particles of a desired material is applied to a substrate by a method such as spin coating or dipping, The dispersion coating method, in which the solvent and binder are removed by heat treatment after that, is the simplest.

[0013]

However, the above-mentioned fine particle film has a distribution in its film thickness, although the film thickness varies depending on the manufacturing method. As a result of further studies made by the present inventors on this point, in particular, in a fine particle film prepared by the above dispersion coating method which is often used as a simple method for forming a fine particle film, its central portion (relative to the peripheral portion) It was found that there are comparatively many things that have a large difference between the (concept of) and the film thickness of the peripheral portion.

FIG. 8 is a perspective view of an electron-emitting device in which the film thickness differs greatly between the central part and the peripheral part of the fine particle film as described above. FIG. 9 is a sectional view taken along line CC of FIG. It is a D sectional view. In these figures, 1 is a substrate, 5 is a substrate 1
The fine particle films 2 and 3 formed thereon are electrodes for establishing electrical connection with the fine particle film 5, and 4 is an electron emission portion formed in the fine particle film 5. In this element, as shown in FIGS. 9 and 10, the peripheral portion of the fine particle film 5 is swelled, and the film thickness is greatly different between the central portion and the peripheral portion. When a fine particle film is formed at a desired location using the dispersion coating method, a fine particle dispersion is spin-coated or a substrate is dispersed on a substrate on which a mask such as a resist or a metal used in ordinary photolithography is formed. After being dipped in the inside to apply the dispersion liquid, it is baked to form a film, and the mask is removed to form the film locally.

At this time, the dispersion liquid applied between the masks formed in a desired pattern has a dispersion liquid surface near the interface raised above that other than near the interface due to the tension at the interface with the mask material. In the case of spin coating, the dispersion moves in that direction by centrifugal force.

As a result, as in the present device, the peripheral portion of the finally obtained fine particle film is thicker than the central portion.

Such an element is used in the order of 10 ⁻⁵ to 10 ⁻⁷ Torr.
When forming is carried out in a vacuum of No. 2, there is a problem that the forming voltage becomes unstable at the central part and the peripheral part of the fine particle film, the forming becomes unstable, and the forming voltage is increased. Further, when an extraction electrode is provided above such an element in a vacuum to emit electrons, uneven brightness occurs in one element.

Further, as shown in FIG. 9, since the peripheral portion of the fine particle film 5 is raised, the device is apt to cause discharge breakdown when emitting electrons, and the anode voltage applied to the extraction electrode cannot be raised, and the emission is prevented. There is a problem that the amount of current is limited to a low level.

The present invention has been made in view of the above problems, and it is possible to perform stable forming at a lower voltage and to obtain a uniform and larger amount of emission current, and further an electron-emitting device. Aims to provide an electron beam generator and an image forming apparatus using the same.

[0020]

Means and Actions for Solving the Problems The present inventors have
In particular, as a result of an intensive study focusing on the relationship between the film thickness distribution of the fine particle film and the forming voltage, the film thickness distribution for forming the electron-emitting portion is defined by a uniform forming voltage. Using the dispersion coating method, which is a simple forming method, the inventors have earnestly studied the conditions for forming a fine particle film satisfying the above requirements, and have reached the present invention described below.

That is, according to the present invention, in an electron-emitting device having a pair of electrodes and a fine particle film electrically connecting the pair of electrodes, a minimum film thickness (t ₁ ) and a maximum film thickness (t ₂ ) of the fine particle film are provided. And a relationship of t ₂ ≦ 2t ₁ with respect to t ₂ ≦ 2t ₁ , and further manufacturing of an electron-emitting device having a pair of electrodes and a fine particle film electrically connecting the pair of electrodes. In the method, when the fine particle film is formed at a desired position by using the dispersion coating method, a mask having a film thickness of 9t ₁ or less is set, where t ₁ is the minimum film thickness of the finally obtained fine particle film. A method of manufacturing an electron-emitting device characterized by using, further, an electron source in which at least a plurality of the electron-emitting devices of the present invention are arranged, and a modulation means for modulating an electron beam emitted from the electron source. Electron beam generation characterized by comprising Furthermore, an electron source in which at least a plurality of the electron-emitting devices of the present invention are arranged, a modulation unit that modulates an electron beam emitted from the electron source, and an image that forms an image by irradiation of the electron beam. An image forming apparatus comprising: a forming member.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the electron-emitting device of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. . In these figures, 1 is an insulating substrate, 2 and 3 are electrodes, 4 is an electron emission portion, 5 is a fine particle film, t ₁ is the minimum thickness of the fine particle film 5, and t ₂ is the maximum thickness of the fine particle film 5. It is thick.

In the present invention, the above t ₁ and t ₂ are t ₂ ≤
This satisfies the relationship of 2t ₁ .

As a result, during the forming step of forming the electron emitting portion in the fine particle film, the forming voltage applied between both electrodes becomes substantially constant from the start to the end of the forming, and the electron emission formed in this manner is performed. Department is
It has almost uniform electron emission characteristics.

On the other hand, when t ₁ and t ₂ do not satisfy the above relationship, the electron emitting portions are formed by different forming voltages, and uniform electron emitting characteristics cannot be obtained.
The forming voltage increases, which is not preferable.

Materials for the fine particle film include LaB ₆ , C ₈
Borides such as B ₆ , YB ₄ , and GdB ₄ , TiC, Zr
Carbides such as C, HfC, TaC, SiC, WC, Ti
Nitride such as N, ZrN, HfN, Nb, Mo, Rh,
Hf, Ta, W, Re, Ir, Pt, Ti, Au, A
g, Cu, Cr, Al, Co, Ni, Fe, Pb, P
d, Ca, Ba and other metals, In ₂ O ₃ , SnO ₂ , S
metal oxides such as b ₂ O ₃ , semiconductors such as Si and Ge,
Carbon, AgMg, or the like can be used, but is not limited thereto.

As the electrode material, a general conductive material, A
In addition to metals such as u, Ag, and Pt, oxide conductive materials such as SnO ₂ and ITO can be used. The width of the electrode is several μm
〜Several mm is suitable. The electrode gap (L in FIGS. 1 and 2), which is the minimum distance between the electrodes, is suitably several μm to several hundred μm, and is formed so as to be electrically connected to at least the fine particle film.

As a method for forming the fine particle film, a gas deposition method or the like can be used, but in the method for producing the electron-emitting device of the present invention, the dispersion coating method, which is the simplest forming method, is used. There is.

In this dispersion coating method, a dispersion liquid of fine particles of the above-described material is applied to a substrate or the like by a method such as spin coating or dipping, and a solvent, a binder and the like are removed by heat treatment.

As the dispersion liquid, it is possible to use fine particles and an additive for promoting dispersion of the fine particles added to an organic solvent such as butyl acetate or alcohol, and the dispersion liquid of fine particles is prepared by stirring or the like.

Further, as a chemical method for dispersing and forming fine particles, there is also used a method in which a solvent of an organometallic compound is applied on a substrate, and then metal oxide of a semiconductor or fine particles of metal is formed by thermal decomposition. be able to. As an example, tin caprylate (C ₇ H ₁₅ COO) ₂ Sn, diisoacyloxyethoxyantimony C ₂ H ₅ O (C ₅ H
_By thermal decomposition of ₁₁ O) ₂ Sb, SnO ₂ and S
Examples include forming fine particles of b ₂ O ₃ and forming Pd fine particles from an organopalladium compound.

When the fine particle film is formed in this manner, the sheet resistance of the fine particle film is 5 × 10 ³ to 1 × 10 ⁷ Ω.
It is preferable that it be / □.

As a patterning method for locally forming the fine particle film 5 at a desired position, a tape, a resist used in ordinary photolithography, a mask of metal or the like is provided at a place where the fine particle film 5 is not desired to be formed. Can be formed by forming a fine particle film by using the dispersion coating method described above, and then removing the mask.

In the method of manufacturing an electron-emitting device of the present invention, a mask having a film thickness of 9t ₁ or less with respect to the minimum film thickness t ₁ of the finally obtained fine particle film is used. As a result, the fine particle film formed from the fine particle dispersion liquid applied by a method such as the spin coating or dipping described above satisfies the film thickness conditions of the fine particle film of the electron-emitting device of the present invention.

When a fine particle film is formed by a method such as spin coating or dipping, usually, as shown in FIGS. 1 and 2, the central portion of the fine particle film has a minimum thickness and the peripheral portion has a minimum thickness. However, if the formation position of the fine particle film deviates from the center of rotation, for example, in the case of spin coating,
A film thickness distribution may occur in the direction of centrifugal force.

Even in such a case, by using a mask having a film thickness satisfying the above conditions, the film thickness can be kept within a desired film thickness distribution (t ₂ ≦ 2t ₁ ).

The electron-emitting device thus formed is placed under a vacuum degree of about 1 × 10 ^-5 to 1 × 10 ^-6 Torr,
A voltage is applied between the electrodes 2 and 3 to form the electron emitting portion 4 in the fine particle film 5, but the voltage required for this forming step (forming voltage) can be made smaller than when t ₂ > 2t _1. .

That is, even when the same Pt is used as the fine particle film material, the forming voltage is 7V when t ₂ = 10t ₁ , whereas the forming voltage when t ₂ ≦ 2t ₁ is approximately 5V and is constant. It was

Also, while keeping these elements in vacuum
With a face plate on the top of the device,
V _aWhen = 1 kV is applied, their bright spot shapes are
t₂= 10t₁The element has uneven brightness as shown in FIG.
Occurred, but according to the invention t₂≤2t₁Figure 3 for the device
As shown in (b), uniform bright spots without brightness unevenness were obtained.

Further, V _aIs increased, t₂=
10t₁In the element of V _a= Where it increased to 5kV,
Discharge breakdown occurs between the element and the extraction electrode, and the element
It's broken, but t₂≤2t₁In the element of V _a= 7k
It did not break even if it increased to V.

As described above, in the electron-emitting device of the present invention,
By setting the minimum film thickness t ₁ and the maximum film thickness t ₂ of the electron-emitting material made of a fine particle film to t ₂ ≦ 2t ₁ , it is possible to perform stable forming at a low voltage and eliminate uneven brightness in one element. it can.

Furthermore, since the extraction voltage can be increased, a larger amount of emission current can be obtained.

Further, the electron beam generator and the image forming apparatus formed by using the electron source in which a plurality of electron-emitting devices of the present invention are arranged can obtain uniform brightness for the above-mentioned reason, and can obtain a brighter high-definition image. Is obtained.

[0045]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 In this example, an electron-emitting device as shown in FIGS. 1 and 2 was produced.

The method of manufacturing the device of this example is as follows.

First, the insulating substrate 1 was thoroughly washed, and Cr was deposited to a thickness of 2000 Å as a mask in a region other than the region where the fine particle film 5 is to be formed. SnO ₂ on top of this
1.0 g of fine particles and organic solvent (methyl ethyl ketone: cyclohexane = 3: 1,800 cc) were stirred with a glass bead for 24 hours on a paint shaker, and the obtained dispersion was spin-coated and baked at 250 ° C. for 10 minutes. . After that, the previously deposited Cr was etched out. This fine particle film 5 is formed by, by measurement of its thickness stylus thickness meter (manufactured by Tokyo Electron Limited, alpha-step), the the minimum film thickness at the central portion, the thickness t ₁ is 90
0 Å, the maximum film thickness is shown in the peripheral portion, and the film thickness t ₂ is 1200 Å, which satisfies t ₂ ≤2t ₁ which is the film thickness condition of the fine particle film according to the electron-emitting device of the present invention. It was

Next, the electrodes 2 and 3 were formed by the photolithography / etching technique and the vapor deposition technique which are usually used. As the material of the electrode, Al having a thickness of 2000 Å was used.

When the electron-emitting device manufactured through the above steps was placed in a vacuum and a voltage was applied between the pair of electrodes 2 and 3 to perform forming, stable forming was possible at a constant voltage of approximately 8V. It was

Further, when a face plate was provided on the device in a vacuum to emit electrons, the bright spot shape at this time showed a clean elliptical shape as shown in FIG. 3B, and uniform brightness was obtained. Was given.

The voltage V applied to the face plate
_aIs V _a= 5kV applied, the device does not break down, emission current
Ie = 2.5 μA was obtained.

For comparison, a fine particle film was formed in the same manner as described above except that Cr, which was formed as a mask before applying the fine particle film 5, was 7,000 Å, and the thickness thereof was measured by a stylus type film thickness meter. As a result of measurement, the minimum film thickness t ₁ = 900Å and the maximum film thickness t ₂ = 1900Å, which did not satisfy the film thickness conditions of the fine particle film according to the electron-emitting device of the present invention.

After that, when an electrode was formed and forming was performed in the same manner as above, the forming voltage was not stable and the final forming voltage was 10V. That is, it can be seen that the element of the present invention in which the fine particle film 5 as the electron emitting material has a uniform thickness can have a low forming voltage and can be stably manufactured with a good yield.

When a device manufactured for comparison was subjected to electron emission in the same manner as the device of the present invention, the bright spot shape was as shown in FIG. 3 (a), and uneven brightness was observed. .

Furthermore, the voltage that can be applied to the face plate
V _aIs V _a= 4kV, the device is discharged if applied more
It had been destroyed by the destruction.

It can be seen that in the device of the present invention in which the film thickness of the fine particle film 5 is uniform as described above, there is no unevenness in brightness and a larger amount of emission current can be obtained.

Further, in the present example, when the element was produced by changing the thickness of Cr deposited as a mask in various ways, it was 9 times or less of the minimum thickness t ₁ of the finally obtained fine particle film. When the mask having the film thickness was used, a device satisfying the film thickness condition of the fine particle film of the electron-emitting device of the present invention was stably manufactured.

Embodiment 2 FIG. 4 is a perspective view showing the structure of an electron-emitting device according to an embodiment of the present invention, and FIG. 5 is a sectional view taken along line BB in FIG.

In these figures, the same reference numerals as those of the elements shown in FIGS. 1 and 2 indicate the same members, and the repetitive description will be omitted.

The element of this example is the same as that of the example 1 except that the order of film formation of the fine particle film and the electrode is reversed, and is manufactured as follows.

First, the insulating substrate 1 was thoroughly washed, and electrodes 2 and 3 were formed in the same manner as in Example 1. As the electrode material, Ti50Å and Ni950Å were used as the undercoat.

Then, a fine particle dispersion liquid mixed in a molar ratio of Au: SnO ₂ = 2: 1 was applied onto a mask having a thickness of 2000 Å as in Example 1, and the fine particle film was formed in the same manner. 5 was formed.

At this time, when the film thickness of the fine particle film was measured, it showed the minimum film thickness in the central portion, and the film thickness t ₁ was 930Å
And the maximum film thickness is shown at the periphery, and t ₂ is 1200
Å, which satisfies the condition of t ₂ ≦ 2t ₁ which is the film thickness condition of the fine particle film according to the electron-emitting device of the present invention.

When the electron-emitting device manufactured through the above steps was formed in the same manner as in Example 1, it was found to be about 6
Stable forming was possible with a constant voltage of V.

Further, as a comparative example, a fine particle film was formed in the same manner as above except that the thickness of the mask formed before applying the fine particle film 5 was 7,000 Å, and the film thickness was measured. The minimum film thickness t ₁ is 930Å and the maximum film thickness t ₂
Was 1900Å, which did not satisfy the film thickness condition of the fine particle film according to the electron-emitting device of the present invention. When forming such an element, the forming voltage is not stable,
The final forming voltage was 8V.

A face plate was provided on each of these elements and the shape of the bright spots was observed. As a result, the element of the present invention showed uniform luminance, but the comparative element showed uneven luminance.

The voltage which can be applied to the face plate was up to 4.5 kV in the comparative example element, but it was not broken even up to 5 kV in the element of the present invention.

Therefore, considering together with the case of Example 1, in the element of the present invention in which the film thickness of the fine particle film 5 is made uniform, irrespective of the constitution of the fine particle film and the electrode, it was stable at a lower voltage. It can be seen that forming becomes possible and a uniform and larger amount of emission current can be obtained.

Example 3 An organic Pd complex solution was used instead of the SnO ₂ fine particles of Example 1, and a Ni electrode 1000Å instead of the Al electrode 2000Å.
A similar element was formed by using and forming was performed.

At this time, the thickness of Cr used as a mask for forming the pattern of the fine particle film was 80 Å, coating was performed by dipping, and the PdO fine particle film was formed by baking at 300 ° C. for 12 minutes. The Cr was etched out.

When the film thickness of this fine particle film was measured, the minimum film thickness was shown at the central part, the film thickness t ₁ was 70Å, and the maximum film thickness was shown at the peripheral part, and the film thickness t ₂ was 72Å. , T ₂ ≦ 2t ₁ which is the condition of the film thickness of the fine particle film according to the electron-emitting device of the present invention was satisfied.

Further, as a comparative example element, a fine particle film was formed in the same manner as described above except that the thickness of Cr used as a mask for forming the pattern of the fine particle film was 1500 Å. A device was prepared in the same manner as the device of the invention.

In the comparative element thus manufactured,
The fine particle film had a minimum film thickness t ₁ of 70 Å and a maximum film thickness t ₂ of 250 Å. When the same experiment as in Example 1 was conducted using these two types of elements, the results are shown in the table below.

[0075]

[Table 1] That is, also in the electron-emitting device of the present invention of this example, the same effect as in Example 1 was obtained.

Also in this example, similarly to the example 1, when the element was manufactured by changing the thickness of Cr deposited as a mask variously, the minimum film thickness of the finally obtained fine particle film was obtained. When a mask having a film thickness 9 times or less than t ₁ was used, a device satisfying the film thickness condition of the fine particle film of the electron-emitting device of the present invention was stably manufactured.

Embodiment 4 FIG. 6 shows a schematic structure of an electron beam generator according to this embodiment, in which a plurality of line electron emitting devices in which a plurality of electron emitting devices of the present invention are linearly arranged are provided. In the figure, 1 is a substrate, 2 and 3 are element electrodes, 5 is a fine particle film, 6 is a wiring electrode, and 7 is an electron source made of this. Further, 8 is a modulation electrode, and 9 is an electron passage hole. Whether the modulation electrode is arranged on the back surface of the electron-emitting device via an insulator or on the peripheral substrate surface of the electron-emitting device, A configuration other than the arrangement shown in FIG. 6 may be used as long as it is provided so that the emitted electron beam can be modulated according to the information signal.

The electron beam generator of this embodiment is manufactured as follows.

First, in the same manner as in Example 3, a plurality of fine particle films 5 having uniform film thickness and element electrodes 2 and 3 arranged linearly were formed. Next, the wiring electrode 6 is formed in the same manner as in the case of forming the device electrodes 2 and 3 thereon, and the electron source 7 is formed.
And Furthermore, using the normal photolithography process,
The modulation electrode 8 composed of a grid electrode was formed via an insulator (not shown).

When the electron beam generator manufactured as described above was placed in an environment of a vacuum degree of 10 ^-6 Torr and a voltage was applied between the device electrodes 2 and 3 to perform forming, stable forming was possible at 4V. .

Further, a driving voltage of 14 V is applied between the device electrodes 2 and 3.
Then, a voltage corresponding to the information signal was applied to the modulation electrode 8. That is, the electron beam can be controlled off at 0 V or less,
ON control was possible at + 30V or higher. Further, the electron amount of the electron beam could be continuously changed between 30 and 0V. As a result, an electron beam was emitted from a line electron emission element composed of a plurality of elements according to an information signal for one line. By sequentially performing the above operation on the adjacent electron beam emitting devices, electron beam emission corresponding to all information signals was obtained.

The electron beam generator of the present embodiment is capable of uniform and stable forming at low voltage during forming of each element, and further, the variation of the electron beam emitted from each element is extremely small and uniform electron beam can be obtained. There was an effect of being able to be.

Embodiment 5 FIG. 7 shows a schematic structure of an image forming apparatus in this embodiment having an electron source in which a large number of electron-emitting devices of the present invention are arranged. In the figure, 10 is an image forming plate, and 11 is a phosphor which is an image forming member, and emits light when electrons collide. 12 is the bright spot of the phosphor.

In this figure, the same reference numerals as in the electron beam generator shown in FIG. 6 indicate the same members,
The description will not be repeated.

In this image forming apparatus, an electron source 7 having a plurality of elements arranged between electrode wirings 6 and a modulation electrode 8 composed of a grid electrode.
Is a device for forming an image by driving the XY matrix in XY matrix and causing electrons to collide with the phosphors 11 on the image forming plate 10.

In the image forming apparatus of this embodiment, first, an electron beam generator was manufactured in the same manner as in Embodiment 4, placed in a vacuum container, and a voltage was applied between the element electrodes 2 and 3 to perform forming. . At this time, stable forming was possible at 4V.

Next, the image forming plate 10 having the phosphor 11 was installed vertically above the electron beam generator, and a voltage of 1 kV was applied. As a result, the bright spots 12 on the image forming body 10 were one electron-emitting device. In addition to showing an elliptical shape with uniform brightness, the brightness without variation was obtained even among a plurality of elements arranged in parallel.

Further, even when the voltage (anode voltage) V _a applied to the image forming body 10 was increased to 5 kV, the electrons were stably emitted, and the emission current amount Ie = 100 μA was obtained.

As a comparative example, the fine particle film 5 of the electron-emitting device is used.
The relationship between the minimum film thickness t ₁ and the maximum film thickness t ₂ is t ₂ = 10t
_In the device manufactured in the same manner as the above-mentioned image display device except that a large number of elements of ₁ were used, the forming voltage was not stable and was as high as 7 V, and the anode voltage V _a was only up to 4 kV. The emission current amount Ie is also 80
Only μA was obtained. In addition, the bright spots on the image forming plate were not uniform because there was uneven brightness in one electron-emitting device.

As described above, in the image forming apparatus using the electron source in which the plurality of electron-emitting devices of the present invention are arranged, the anode voltage can be increased, and not only the emission current amount Ie increases, but also Has the advantage that the beam diameter can be narrowed, and a brighter high-definition image could be obtained.

[0091]

As described above, the present invention has the following effects. By making the relationship between the minimum film thickness t ₁ and the maximum film thickness t ₂ of the fine particle film, which is the electron-emitting material, t ₂ ≦ 2t ₁ uniform, forming can be performed at a low voltage, The device can be manufactured with high yield. It is possible to obtain uniform bright spots without unevenness in brightness within the same element and without variation among a plurality of elements. Since the anode voltage is increased, a larger amount of emission current can be obtained, and the image forming apparatus using the electron-emitting device of the present invention can obtain a brighter and higher-definition image.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an electron-emitting device of the present invention.

2 is a cross-sectional view taken along the line AA of the device of FIG.

FIG. 3 is a plan view showing the shapes of bright spots of the conventional device and the device of the present invention.

FIG. 4 is a perspective view showing another example of the electron-emitting device of the present invention.

5 is a sectional view taken along line BB of the device of FIG.

FIG. 6 is a schematic configuration diagram showing an example of an electron beam generator using a plurality of electron-emitting devices of the present invention.

FIG. 7 is a schematic configuration diagram showing an example of an image forming apparatus using a plurality of electron-emitting devices of the present invention.

FIG. 8 is a perspective view of a conventional example element.

9 is a sectional view taken along line CC of the device of FIG.

10 is a cross-sectional view taken along line DD of the device of FIG.

FIG. 11 is a plan view of a conventional element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Electrode 4 Electron emission part 5 Fine particle film 6 Wiring electrode 7 Electron source 8 Modulation electrode 9 Electron passing hole 10 Image forming plate 11 Phosphor 12 Bright spot of phosphor 13 Electron emitting material

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Kawate 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuhiro Michi 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc. (72) Inventor Ichiro Nomura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. An electron-emitting device having a pair of electrodes and a fine particle film for electrically connecting the pair of electrodes, wherein a minimum film thickness (t ₁ ) and a maximum film thickness (t ₂ ) of the fine particle film are set. An electron-emitting device characterized in that the relationship is t ₂ ≦ 2t ₁ . 2. The electron-emitting device according to claim 1, wherein the fine particle film is formed by a dispersion coating method. 3. A method for manufacturing an electron-emitting device having a pair of electrodes and a fine particle film for electrically connecting the pair of electrodes, wherein the fine particle film is formed at a desired position by a dispersion coating method. A method of manufacturing an electron-emitting device, characterized in that a mask having a film thickness of 9 t ₁ or less is used, where t ₁ is a minimum film thickness of the finally obtained fine particle film. 4. An electron-emitting device manufactured by the manufacturing method according to claim 3, wherein the relationship between the minimum film thickness (t ₁ ) and the maximum film thickness (t ₂ ) of the fine particle film is t _2. An electron-emitting device characterized in that ≦ 2t ₁ . 5. An electron comprising at least an electron source in which a plurality of electron-emitting devices according to claim 1, 2 or 4 are arranged, and a modulation means for modulating an electron beam emitted from the electron source. Line generator. 6. An electron source in which a plurality of electron-emitting devices according to claim 1, 2 or 4 are arranged, a modulating means for modulating an electron beam emitted from the electron source, and an image is formed by irradiation of the electron beam. An image forming apparatus comprising: