JP2630989B2 - Electron-emitting device, electron-emitting device and light-emitting device using the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, an electron-emitting device and a light-emitting device using the same, and more particularly to controlling the shape of an electron beam emitted from the electron-emitting device, One-dimensional (line)
Alternatively, the present invention relates to an electron-emitting device and a light-emitting device that emit two-dimensional (plane) electrons.

[Prior art] Conventionally, as a device capable of emitting electrons with a simple structure, for example, MIElinson
And the like are known. [Radio Eng. Electron Phys., Vol. 10, pp. 1290-1296, 19
65 years] This utilizes the phenomenon that electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel with the film surface, and is generally called a surface conduction electron-emitting device. ing.

As the surface conduction electron-emitting device, a device using a SnO ₂ (Sb) thin film developed by Elinson et al.
By thin film [G. Dittmer: “Thin Solid Films”),
9, 317, (1972)], using ITO thin film [M.
Hartwell and C.G.Fonstad “I.E.E.E.Trans.E.D.D.
Conf. ”(M. Hartwell and CGFonstad:“ IEEE Trans.
ED Conf. ") P. 519, (1975)], using a carbon thin film [Hisashi Araki et al .:" Vacuum ", Vol. 26, No. 1, p. 22, (198)
3 years)].

FIG. 7 shows a typical device configuration of these surface conduction electron-emitting devices. In FIG. 7, reference numerals 1 and 2 denote electrodes for obtaining electrical connection, 3 a thin film formed of an electron emitting material, 4 a substrate, and 5 an electron emitting portion.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 5 is formed by an energization process called forming before electron emission. That is, by applying a voltage between the electrode 1 and the electrode 2, the thin film 3 is energized, and the thin film 3 is locally broken, deformed or deteriorated by the Joule heat generated by the application of the voltage, and has a high electrical resistance. An electron emission function is obtained by forming the electron emission portion 5 in the state.

In FIGS. 7 and 8, reference numeral 6 denotes a phosphor coated with a phosphor on an electron beam irradiation surface of a transparent substrate so that the spread area of the electron beam emitted from the surface conduction electron-emitting device can be measured visually. The substrate 7 is a light emitting unit that emits light by the emitted electron beam.

The emission characteristics of the conventional surface conduction electron-emitting device are as follows. A phosphor substrate 6 is placed in a space about several mm away from the surface conduction electron-emitting device, and a voltage of several hundred V to several thousand V is applied. When a driving voltage is applied between the electrode and the electrode 2, the light emitting portion 7 that emits light on the phosphor substrate 6 has a three-month shape as shown in FIG. This radiation characteristic is a characteristic inherent to the conventional surface conduction electron-emitting device.

Further, when the surface conduction electron-emitting devices are arranged in a line in a multitude, as shown in FIG.
Constitutes a highly deformed line electron source that is lined up.

[Problems to be Solved by the Invention] As described above, the conventional surface conduction electron-emitting device flies while spreading the emitted electron beam three months,
It has the following disadvantages.

(1) To reduce the electron beam emitted from the surface conduction electron-emitting device to an arbitrary shape, an extremely complicated electron optical system is required.

(2) When a plurality of surface conduction electron-emitting devices are regularly arranged in a multi-line manner, uniform electron emission cannot be obtained in a line shape.

Due to the above-described problems, the conventional surface conduction electron-emitting device has a simple structure, and it is easy to arrange two or more devices in a line. At present, it has not been applied positively.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the related art, and it is intended to make it possible to easily control the shape of an electron beam and to obtain a well-aligned line-shaped electron emission. With the goal.

[Means for Solving the Problems] Means taken in the present invention to achieve the above object will be described with reference to FIG. 1 corresponding to one embodiment of the present invention. In an electron-emitting device having an electron-emitting portion 5 formed between a rectangular electrode 1 and a rectangular electrode 2 whose tip sides are opposed to each other by applying an electric current or dispersing fine particles, the electrodes 1 and 2 forming the electrode gap 8 are formed. In this case, means for making the lengths of the tip sides different from each other are taken.

The shape of the electrodes 1 and 2 in the present invention is the shape of the electrode in the vicinity of the tip side opposed to each other, and is a rectangular shape in the present invention.
In addition, the present invention combines an electrode 1 having a short distal end and an electrode 2 having a long distal end. In the following description, for the sake of convenience, “the length of the tip side”
Is described as “width”.

In the present invention, either the wide electrode 2 or the narrow electrode 1 may be used as a positive electrode or a negative electrode. However, it is preferable that the narrow electrode 1 be a positive electrode and the wide electrode 2 be a negative electrode. Here, the positive electrode refers to an electrode to which a positive potential is applied, and the negative electrode refers to an electrode to which a negative potential is applied.

Since the above-described electron-emitting devices according to the present invention can easily obtain an electron beam having a well-shaped shape, it is necessary to arrange the devices linearly in a line to form an electron-emitting device that emits one-dimensional electrons. Are suitable. In addition, by arranging the elements in a plurality of rows, it is possible to obtain an electron emission device that emits two-dimensional electrons and can uniformly irradiate the entire target region with an electron beam.

Further, by combining the above-described electron emitting device of the present invention with the phosphor substrate 6 as shown in FIG. 5, a light emitting device forming a one-dimensional or two-dimensional light emitting portion can be obtained.

To further explain the present invention, the electron-emitting device of the present invention is formed on a substrate 4 in the same manner as in the prior art, and the substrate 4 is made of an insulating material such as glass or quartz.

The electrodes 1 and 2 can be formed by a commonly used method such as a vacuum deposition process and a photolithography process. The material of the electrodes 1 and 2 is a general conductive material such as a metal such as Ni, Al, Cu, Au, Pt, and Ag, and a metal oxide such as SnO ₃ and ITO.

The interval between the electrodes 1 and 2, that is, the electrode gap 8 may be 0.1 μm to several μm, but is not limited thereto. The width W ₁ of the narrow electrode 1 may be any size, but typically formed of several tens of microns to several millimeters in size. The width W ₂ of the wide electrode 2 is equal to the width W _{1 of the} electrode ₁
It must be larger. Even if the difference between the widths of the two electrodes 1 and 2 is slight, a desired effect can be obtained to some extent, but in general, it is preferable that one of them is several times as large as the other, and ideally, It is desirable to increase the width of one of them so as to be negligible (tens of times or more).

Formation of the electron-emitting region 5 between the electrodes 1 and 2, in a conventional manner for example _{In 2 O 3, SuO 2,} PbO metal oxide such as Ag, Pt, Al, C
The thin film 3 can be formed by forming a thin film 3 by vacuum evaporation or the like using an electron emitting material such as a metal such as u or Au, carbon, and various other semiconductors, and performing a forming process.

Another method for forming the electron-emitting portion 5 is to apply a dispersion liquid in which fine particles of the electron-emitting material are dispersed in a dispersion medium to the substrate 4 by, for example, dipping or spin coating, and then bake. Is mentioned. The dispersion medium in this case may be any medium that can disperse the fine particles without deteriorating the particles, and examples thereof include butyl acetate, alcohols, methyl ethyl ketone, cyclohexane, and a mixture thereof. The fine particles are several tens to several μm.
Those having a particle size of m are preferred.

In the present invention, as shown in FIG. 2, each end of a pair of electrodes 1 and 2 is located at the upper end of a step portion of a step forming layer 10 provided on a substrate 4, and the electrodes 1 and 2 An electrode gap 8 is opposed to the stepped portion, and an electron emission portion 5 is formed on an end surface on the side of the stepped portion which is the electrode gap 8.
The same effect can be obtained in the structure of the electron-emitting device characterized in that electrons are emitted from the electron-emitting portion 5 by applying a voltage between 1 and 2.

As the step forming layer 10, an insulating material is generally used. For example, it may be SiO ₂ , MgO, TiO ₂ , Ta ₂ O ₅ , Al ₂ O _3, etc. and a laminate thereof or a mixture thereof. The electrode gap 8 is determined by the thickness of the step forming layer 10 and the thicknesses of the electrodes 1 and 2, and is preferably several tens to several μs. For other components, the same materials and configurations as those described above can be used.

[Operation] The reason why the shape of the electron beam can be controlled by the present invention is not necessarily clear, but the present inventors have proposed that the electrodes 1, 2
It is speculated that the formation of a three-dimensional electron optical lens is a major cause of the above-mentioned shape. According to the present invention, since the electron beam can be formed into a well-shaped shape, when the electron-emitting devices are linearly arranged in a line, a uniform continuous electron-emitting state is easily obtained. It is.

In the present invention, if the narrow electrode 1 is used as a positive electrode and the wide electrode 2 is used as a negative electrode, the spread of the electron beam can be suppressed, and if the polarity is reversed, the electron beam can be spread and emitted. it can.

Example 1 Example 1 FIG. 1 is a schematic explanatory view for explaining the present example.

A pair of electrodes 1 and 2 were formed on a quartz substrate 4 by a vacuum film forming technique and a patterning technique that are commonly used. The electrode gap 8 (electrode interval) was 2 μm, and the widths W ₁ and W ₂ of the electrodes 1 and ₂ were 0.5 mm and 10 mm, respectively.

After the electrodes 1 and 2 are formed, organic palladium (CCP-4230, Okuno Pharmaceutical Co., Ltd.) is applied between the electrodes 1 and 2 by a spinner coating method. After that, it was baked for 1 hour at a temperature of 250 ° C.
Fine palladium particles were formed in between.

Next, a voltage was applied to the device by the power supply 9 so that the electrode 1 side became positive, and electrons were emitted. The environment in which electrons are emitted may be any as long as it has a degree of vacuum at which an electron beam can fly. Generally, however, a degree of vacuum of 1 × 10 ⁻⁴ torr or more is desirable.

The phosphor substrate 6 was separated from the quartz substrate 4 by 10 mm, and the flight direction of the electron beam was observed. Here, the voltage Va applied to the phosphor substrate 6 was set at plus 1000 volts from the device potential.

Further, as an example of a conventional element, an element having the same electrode widths W ₁ and W ₂ was formed and compared with the effect of the present embodiment. All the conventional elements were formed in the same manner as in this embodiment except for the electrode width, and W ₁
= W ₂ = 0.5 mm.

Table 1 shows the results. In addition, as a parameter of the spread of the electron beam, the comparison was made with the width L of the luminescent spot on the phosphor substrate 6.

As is clear from the results, the present invention provides an electron-emitting device having a smaller spread of the electron beam than the conventional device.

In this embodiment, when the voltage applied to the device was reversed, the width L of the bright spot on the phosphor substrate 6 was increased to 5.2 mm.

As described above, the widths of the electrodes 1 and 2 of the electron-emitting device are formed to be different from each other, and the respective electrodes 1 and 2 are formed.
By changing the polarity of the voltage applied to the electron beam, the flight direction of the electron beam was changed, and the spread of the beam could be improved.

Embodiment 2 FIG. 2 is a schematic explanatory view for explaining the present embodiment. FIG. 3 is a schematic sectional view for explaining the electron-emitting portion 5.

A liquid coating material of SiO ₂ (CCD manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied as a step forming layer 10 on the quartz substrate 4 and dried to form a 3000 mm thick SiO ₂ layer. Next, the step forming layer 10 was pattern-etched with an HF etchant so that the electron emitting section 5 had a planar shape, thereby providing a step. Further, a 500-nm thick Ni film was formed on the step portion by a mask vacuum evaporation method, and electrodes 1 and 2 were formed in the same shape as in Example 1. At this time, Ni was not deposited on the electrode gap 8 by deteriorating the step coverage during film formation. Thereafter, fine particles were formed in the same manner as in the above-described embodiment, and the electron-emitting portion 5 was disposed in the electrode gap 8.

The widths W ₁ and W ₂ of the electrodes 1 and ₂ were 0.5 mm and 10 mm, respectively.

A voltage was applied to the element so that the electrode 1 side had a positive potential, and the same evaluation as in Example 1 was performed. As a result, a similar effect was obtained.

Embodiment 3 FIG. 4 is a schematic explanatory view for explaining the present embodiment. In this embodiment, the elements of the first embodiment are regularly arranged in a multi-line manner in a line shape.

The electrodes 1 and 2 and the electron emitting portion 5 were formed in the same manner as in Example 1. The width W of the electrode 1 is 0.5 mm,
The element pitch P was made 1.2 mm.

When the bright spot on the phosphor substrate 6 was observed in the same manner as in Example 1, the conventional problem was solved, and a very uniform linear bright line was obtained.

As described above, in this embodiment, a linear electron emission source is formed without using a complicated electron optical lens.

[Effects of the Invention] As described above, the following effects are obtained by changing the widths of the two electrodes in the electron-emitting portion of the electron-emitting device.

1. It can change the flight direction of the electron beam (change the spread of the electron beam).

2. By making the narrower electrode width a positive potential and the wider electrode width a negative potential to emit electrons, the spread of the electron beam can be improved.

3. By arranging the elements linearly in multiples, it is effective to obtain a uniform linear electron source and a light emitting device.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view for explaining Embodiment 1, FIG.
FIG. 3 is a schematic explanatory view for explaining Example 2, FIG. 3 is a schematic sectional view for explaining an electron-emitting portion thereof, FIG. 4 is a schematic explanatory view for explaining Example 3; FIG. 5 and FIG. 6 are explanatory diagrams of the prior art. 1.2: electrode, 8: electrode gap

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshihiko Takeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tetsuya Kaneko 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Seishiro Yoshioka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hidetoshi Suzuki 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. ( 56) References JP-A-51-40860 (JP, A) JP-A-56-167456 (JP, U) JP-B-46-20944 (JP, B1) JP-B-46-20949 (JP, B1)

Claims (6)

(57) [Claims] 1. An electron-emitting device having an electron-emitting portion formed by energizing or dispersing fine particles between rectangular electrodes whose leading edges oppose each other with an electrode gap therebetween, wherein said electrode gap is formed. An electron-emitting device, wherein the lengths of the tip sides of the electrodes are different from each other. 2. The electron-emitting device according to claim 1, wherein an electrode having a long tip side is a load, and an electrode having a short tip side is a positive electrode. 3. The electron-emitting device according to claim 1, wherein the tip sides of the electrodes face each other on the same plane. 4. The electron-emitting device according to claim 1, wherein the tips of the electrodes face each other across the step. 5. An electron-emitting device according to claim 1, wherein the electron-emitting devices according to any one of claims 1 to 4 are arranged in a regular multiple manner with the electron-emitting portions of each device positioned linearly. 6. A light emitting device, comprising: the electron emitting device according to claim 5; and a phosphor substrate which emits light when irradiated with an electron beam emitted from the electron emitting device.