JPH0652809A - Field emission type electron source device - Google Patents

Abstract

PURPOSE:To obtain a field emission type electron source device making it possible to realize a one-beam full-color display element capable of controlling the direction of electron emission by itself without complicating an electrode wiring. CONSTITUTION:A conical cold cathode tip 11 is formed on a substrate electrode 10. Gate electrodes 13, 14, 15 respectively insulated from each other between which an insulating layer 12 is held on the substrate electrode 10 are formed so as to surround the tip part of the cold cathode tip 11. An anode electrode 16 has a transparent electrode base board 17 in which an ITO transparent electrode film is provided on a glass substrate and a rare earth series and a zinc sulfide series R(red), G(green) and B(blue) fluorescent parts 18, 19, 20. The substrate electrode 10 and the cold cathode tip 11 are formed of a low- resistance silicon substrate, and the insulating layer 12 is formed of silicon oxide and the gate electrodes 13, 14, 15 are formed of molybdenum metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission type electron source device which is used in a display element for displaying by irradiating a fluorescent part with electrons and which operates based on the principle of field emission.

[0002]

2. Description of the Related Art In recent years, considerable progress has been made in the manufacture of field-emission electron source devices by the microfabrication technology mainly for semiconductors used in integrated circuits and the like. It has become possible to obtain an emission type electron source device. A field emission type electron source device including a cold cathode that emits electrons under the influence of a high electric field by utilizing this extremely small size is, for example, a triode type micro electron tube, or a micro electron gun or the like, which is basically Electron emission device.

The field emission type electron source device is devised as a component of a thin display device or a micro triode, for example,
The operation and the manufacturing method are particularly described in C.I. A. Stanford Research Institute by CA Spindt et al.
titute), 47th Journal of Applied Physics
Volume 12, Issue 5248-5263 (December 1976)
It is known by the research published in various magazines including. Also, H. F. US Pat. No. 4,307,507 to HF Gray et al., And US Pat.
It is also described in No. 13,308.

A conventional known type of basic field emission electron source device is shown in FIG. FIG. 6 is a schematic perspective view and shows a field emission type electron source device with a part cut away so that the structure of the electron source device can be easily understood. This field emission type electron source device has an anode electrode 68 coated with a phosphor.
And a cold cathode chip 61, 62, 63 as three electron sources corresponding to the fluorescent parts of three colors of R (red), G (green) and B (blue). ing.

The anode electrode 68 is a transparent substrate electrode 69 on which fluorescent portions 70, 71 and 72 which emit R (red), G (green) and B (blue) respectively when irradiated with electrons are formed. It is configured. In addition, the substrate electrode 6
0 is often formed of a low-resistance single crystal silicon substrate in consideration of compatibility with the fine processing technology used so far, cost reduction, and monolithicization with other electronic elements. The conical cold cathode chip 61 formed on the substrate electrode 60 is made of low-resistance single crystal silicon like the substrate electrode 60, or may have a high melting point such as molybdenum or tungsten depending on the manufacturing method. Composed of metallic material. Further, the insulating layer 64 is often composed of silicon dioxide formed by thermally oxidizing a silicon substrate electrode and having particularly excellent insulating properties.

Between the conical cold cathode chip 61 formed on the substrate electrode 60 of the electron source device and the gate electrode 65 formed by sandwiching the insulating layer 64 on the substrate electrode 60,
When a gate voltage of about 50 to 150 V is applied, a strong electric field of about 10 ⁷ V / cm is generated between the cold cathode chip 61 and the gate electrode 65, and electrons are emitted from the cold cathode chip 61 based on the principle of field emission. Is released. Here, the amount of electrons emitted from the cold cathode chip 61 can be increased or decreased by changing the gate voltage.

In addition, 2 applied to the anode electrode 68
The electrons emitted from the cold cathode chip 61 reach the anode electrode 68 by the anode voltage of 00 to 500V. The emission brightness of each of the fluorescent parts 70, 71, 72 is controlled by controlling the electron emission amount by changing the gate voltage and controlling the electron transfer energy by changing the anode voltage.

At present, a thin display device in which a large number of display elements composed of such a field emission type electron source device are manufactured in an array, or the anode electrode of such an electron source device is an anode electrode such as a metal film. The constructed field emission type micro-triode and the like have been prototyped. Furthermore, in order to further increase the density and performance of thin display devices, or to manufacture new-function electron tubes such as field emission type micro-multipole tubes and oscillation tubes, higher performance, and Development of a small-sized and highly functional field emission type electron source device is desired.

[0009]

By the way, in the above-mentioned conventional field emission type electron source device, only the amount of electron emission is variable because of its structure, and the electron emission direction cannot be changed. Therefore, as described above, when the color display element is configured by the conventional field emission type electron source device, at least 3 corresponding to the fluorescent portions 70, 71, 72 of R, G, B, respectively.
One electron source or cold cathode chip 61, 62, 63 is required. Therefore, there is a problem that it is difficult to downsize the color display element configured by the above-mentioned conventional electron source device, and it is difficult to increase the density and performance of the display device including a large number of the display elements.

However, if it is limited to a single color display element, the anode electrode 68 is replaced by the fluorescent portion 7 of each of R, G and B.
It is possible to change the emission direction of electrons from the electron source by dividing the divided portions corresponding to 0, 71, 72 and controlling the electron irradiation portion by changing the applied voltage to each divided anode electrode. Therefore, it becomes possible to selectively irradiate electrons to three different fluorescent parts from one electron source (cold cathode chip).

However, in this case, since a large current flows due to the movement of the emitted electrons between the cathode electrode and the anode electrode, the base electrode 60, the cold cathode chip 61 and the anode electrode 68, which constitute the cathode electrode, flow in the anode electrode wiring. It is practically difficult to miniaturize. Therefore, there is a problem in that the color display element configured by this electron source device, which requires miniaturization of the anode electrode wiring, is not suitable for forming an array and forming a high-density thin display device.

Further, as another electron source device capable of changing the emission direction (movement direction) of the electrons emitted from the electron source, in the above-mentioned conventional electron source device, the gate electrode 65 and the anode electrode 68 are provided. It is conceivable that a plurality of additional emission electron deflection electrodes are provided between them.

However, in the electron source device provided with the above-mentioned additional electrode, each of the electrode layer and the insulating layer has a multi-layered structure and the electrode wiring becomes complicated, so that the field emission type electron source device has a fine structure to be achieved. There is a problem that it is not suitable for high density and high density and the manufacturing process becomes complicated.

Therefore, an object of the present invention is to provide a field emission type electron source device capable of solving the above problems. That is, the electron emission direction can be controlled by itself without complicating the electrode wiring, and a one-beam full-color display element that enables full-color display with one electron source can be configured, and the movement of emitted electrons can be prevented. It is an object of the present invention to provide a field emission type electron source device capable of coping with high density and high performance of a display device without miniaturizing wirings of a cathode electrode and an anode electrode which are required to flow a large current.

[0015]

In order to achieve the above object, a field emission electron source device of the present invention comprises a cathode electrode having at least one electron emitting portion,

An electron passage region between the anode electrode and the electron emitting portion, which is irradiated with the electrons emitted from the electron emitting portion, and through which electrons pass from the electron emitting portion to the anode electrode. Is arranged so as to surround the electron passage region included in the plane, and
It is characterized by comprising a plurality of gate electrodes insulated from each other.

Further, it is preferable that the anode electrode is provided with a plurality of fluorescent portions that emit light by being irradiated with electrons in a region irradiated with the electrons emitted from the electron emitting portion.

[0018]

According to the above structure, by applying a voltage to the plurality of gate electrodes arranged so as to surround the electron passage region, electrons are emitted from the electron emitting portion. Further, by applying different voltages to the plurality of gate electrodes, the electron emission direction is controlled.

When a plurality of fluorescent portions are formed on the anode electrode, the electron emission direction from the electron emitting portion is controlled and the plurality of fluorescent portions are selectively irradiated with electrons, so that Control the emission chromaticity.

[0020]

The field emission type electron source device of the present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 is a perspective view of a display element included in the field emission type electron source device according to the first embodiment of the present invention. FIG. 2 is a top view of the display device shown in FIG. 1, showing the phosphor regions 26 to 28 through the transparent electrode substrate 17 and the electron emission region 21 of electrons emitted from the cold cathode chip 11 which is an electron source. It is the figure shown. Further, FIG. 3 is a view showing an XX cross section of the field emission type electron source device of FIG. 1 and an electron emission range from the cold cathode chip 11 which is an electron source.

In this embodiment, a cone-shaped cold cathode chip 11 is formed on a substrate electrode 10 made of a low resistance silicon substrate. The substrate electrode 10 and the cold cathode chip 11 form a cathode electrode, and the cold cathode chip 11 forms an electron emitting portion.

Since the cold cathode chip 11 is formed from a silicon substrate electrode by an etching method, the cold cathode chip height hC shown in FIG. 3 is preferably about 1.0 to 3.0 μm. In this example, hC was set to about 1.7 μm.
The radius of curvature of the tip portion of the cold cathode chip 11 is preferably 50 nm or less in order to concentrate the electric field on the tip portion, and is about 25 nm in this embodiment.

Further, the gate electrode 13, 14 is insulated from each other by sandwiching the insulating layer 12 on the substrate electrode 10.
15 is formed. The insulating layer 12 is made of silicon dioxide obtained by thermally oxidizing a silicon substrate. The gate electrodes 13 to 15 are made of molybdenum. As shown in FIGS. 1 and 3, the gate electrodes 13, 14 and 15 have a fan shape obtained by dividing a disk into three equal parts in the circumferential direction, and between the anode electrode 16 and the cold cathode chip 11, From the cold cathode chip 11 to the anode electrode 16
Is arranged so as to surround the periphery of the electron passage region included in the plane, and is insulated from each other on a plane intersecting the electron passage region. Also, the diameter of the gate electrode opening shown in FIG.
dG is about 1.0 to 2.0 μm, and gate electrode thickness tG is 0.
2 to 1.0 μm, gate electrode height hG is 0 to 0.5
.mu.m is preferable, and in the present embodiment, dG = 1.
About 3 μm, tG = about 0.5 μm, hG = about 0.1 μm.

The anode 16 is the transparent electrode substrate 1
7 and fluorescent portions 18, 19, and 20 that form respective fluorescent substance regions of R (red), G (green), and B (blue). The fluorescent portions 18, 19, 20 face the gate electrodes 13, 14, 15 respectively. The transparent electrode substrate 17 of the anode electrode 16 of this embodiment is formed by forming a transparent electrode film on a glass substrate. Here, In—Sn—O (ITO) or SnO ₂ was used for the transparent electrode film, and the film thickness was set to about 0.2 to 0.3 μm. As a film forming method, a sputtering method using an oxide film as a target or a reactive sputtering method using an In—Sn alloy or Sn metal target is used.

Further, as the fluorescent material of the fluorescent portions 18, 19 and 20 forming the respective fluorescent regions of R, G and B, R is
Fluorescent part 18 (red, peak wavelength is 626 nm)
Is rare earth type Y ₂ O ₂ S: Eu, G (green, peak wavelength is 530 nm) and B (blue, peak wavelength is 450 nm)
ZnS: Cu, Al and ZnS: Ag, Al of the zinc sulfide type were used for the fluorescent portions 19 and 20 corresponding to, respectively, and the film thickness was set to about 0.3 to 0.5 μm. Note that the phosphor material is not limited to this, and it is preferable that the phosphor material has high emission efficiency under low-speed electron beam excitation.

Further, in the fluorescent portions 18 to 20, not only the electron irradiation portion emits light, but also the peripheral portion emits light. Therefore, in order to obtain high-saturation monochromatic light emission, black paint is formed in the space between the fluorescent portions so that the light emission of the fluorescent portions 18 to 20 corresponding to R, G, and B is completely separated. However, a black matrix may be formed.

In addition, when the light emitting area of the fluorescent portion is relatively large, the fluorescent portion emitting white light and the R (red), G (green) and B (blue) color filters are combined to form the anode electrode. It is also possible.

The cold cathode chip 11 and the gate electrode 1
The gate voltage is 50 to 1 between 3, 14 and 15, respectively.
When the voltages VR, VG and VB of about 50 V are applied, 10 ⁷ V is applied between the cold cathode chip 11 and the gate electrodes 13, 14 and 15.
A strong electric field of about / cm is generated, and electrons are emitted from the cold cathode chip 11 based on the principle of field emission. Then, the emitted electrons are applied to the anode electrode 20.
The anode electrode 16 is controlled by the anode voltage of 0 to 500V.
Reach to. Since the R, G, and B phosphor regions are formed in the anode electrode 16, the anode electrode 16 emits light when irradiated with emitted electrons.

Further, in the field emission type electron source device of the above embodiment, the gate voltages VR, VG and VB applied to the gate electrodes 13, 14 and 15 are made to have a gradient,
That is, by applying different voltages to the gate electrodes 13, 14 and 15, the electron emission direction from the cold cathode chip 11 can be changed. For example, the gate voltages VR and V applied to the gate electrodes 13 and 14
By setting G to 100 V and the gate voltage VB applied to the gate electrode 15 to 105 V, the electron emission region 21
Moves in the direction of arrow 25 shown in FIG. Similarly, the electron emission region 21 can be moved in the directions of arrows 23 and 24 shown in FIG.

Next, with reference to FIG. 3, the relationship between the position of the electrode and the emitted electrons in the field emission type electron source device of this embodiment will be described.

The value of the gate voltage for field emission and the size of the emission electron region vary depending on the size of each part shown in FIG. That is, the smaller the gate electrode opening dG, the steeper the electric field distribution in the electrode opening, so that field emission is started at a low gate voltage, and the emitted electrons are improved in straightness, so that the electron emission region is improved. 21
Becomes smaller. Similarly, from the point of the electric field distribution from the tip of the cold cathode chip 11 to the inner openings of the gate electrodes 13 to 15, the larger the gate electrode thickness tG and the gate electrode height hG, the larger the electron emission region 21 becomes. It tends to become smaller. Although the gate electrode thickness tG has little effect, the field emission start voltage increases as the gate electrode height hG increases.

In the field emission type electron source device constructed as described above, by applying a gate voltage to each of the gate electrodes 13 to 15 in an inclined range of 97 to 102 V, electrons having an electron emission direction angle θe of about 5 degrees are obtained. It became possible to control the release direction.

In the display element constituted by the field emission type electron source device of the above embodiment, R contained in the anode electrode 16 is
On the fluorescent portions 18 to 20 that form the fluorescent regions of G and B,
Color display can be performed by moving the electron emission region 21 as described above. When the emitted electrons are applied to the central portion of the phosphor region, that is, the R, G, and B phosphor regions substantially evenly, the display element emits white light. In addition, the electron emission region 21 is
By moving in the direction of arrow 23, 24, or 25, the emission color changes to red, green, or blue. That is, the electron emission region 21 is indicated by the arrows 23, 2
By moving in the direction of the vector represented by 4, 25, the electron irradiation area ratio to each phosphor region changes continuously, and as a result, the chromaticity of light emission changes continuously. Further, the brightness of light emission can be changed by the amount of electrons emitted from the electron source (cold cathode chip 11) controlled by the voltage applied to the gate electrodes 13 to 15.

Therefore, according to the above embodiment, unlike the conventional example, the electron emission direction from one electron source (cold cathode chip) can be moved without complicating the electrode wiring, and a full color display can be achieved. A possible 1-beam full-color display device can be constructed, and the density and performance of the display device can be improved without making the wiring of the cathode electrode and the anode electrode, which requires a large current accompanying the movement of emitted electrons, to be fine. Can handle.

In the above embodiment, a low resistance silicon substrate is used as the substrate electrode 10 and silicon dioxide is used as the insulating layer 12. However, the substrate electrode 10 may be formed on an insulating substrate such as a glass plate in addition to the silicon substrate. A metal film may be formed, or a conductive substrate such as a metal plate may be used. In this case, the insulating layer may be formed of silicon nitride, silicon oxide, or the like by a film formation method such as a CVD method, a sputtering method, or a vacuum evaporation method, but is not limited to these as long as it has excellent insulating characteristics. Absent.

Further, in the present embodiment, the cold cathode chip is formed by the etching method from the low resistance silicon substrate which becomes the substrate electrode, but is formed by the electron beam evaporation method or the like using the refractory metal material such as molybdenum or tungsten. You may. In addition, these are the above-mentioned H. F. Gray et al., U.S. Pat. A. These methods are known in the literature of Spindt et al.

Further, in this embodiment, molybdenum is used as the gate metal material, but it is not limited to this, and electrodes such as chromium, tungsten, or gold, silver, copper, aluminum, etc. which have been conventionally used. Materials may be used. Although the gate electrode of this embodiment is divided into three, it may be divided into two or four or more, depending on the intended electron emission control direction, the wiring method of the gate electrode, and the like.

Next, a second embodiment of the field emission type electron source device of the present invention will be described with reference to FIGS.

FIG. 4 is a partial enlarged perspective view of a thin display device constructed according to the second embodiment of the present invention. In this embodiment, a large number of field emission electron sources arranged in an array, that is, cold cathode chips 41, 41 ...
And an anode electrode 47 including a large number of fluorescent parts 55, 56, 57 forming phosphor regions of R (red), G (green) and B (blue). FIG. 5 shows a part of the phosphor region indicated by F of the display device shown in FIG. 4, and shows the fluorescent portions 55 to 57 and the electron emission region 50 of electrons emitted from the electron source through the transparent electrode substrate 48. It is shown.

A large number of the cold cathode chips 41 are formed on the substrate electrode 40. The numerous cold cathode chips 41 and the substrate electrode 40 constitute a cathode electrode. further,
On the substrate electrode 40, gate electrodes 43, 44, 45, and 46 sandwiching the insulating layer 42 and insulated from each other are arranged in a grid pattern. The gate electrodes 43 to 46 are
It is arranged on a plane intersecting the electron passage area from the cold cathode chip 41 to the anode electrode 47 so as to surround the electron passage area included in the plane. In addition, the anode electrode 47 includes a transparent electrode substrate 48, and fluorescent portions 55 to 57 formed on the transparent electrode substrate 48 for forming the phosphor regions of R, G and B in a delta arrangement. , Each phosphor region forms a square region having four sides having a length equal to the pitch of the cold cathode chips 41, 41.

Here, one cold cathode chip 41 shown in FIG.
Paying attention to, the gate electrodes 43, 44, 45, 46 surrounding the cold cathode chip 41 become the gate electrodes used for controlling the electron emission and the electron emission direction.

Further, as shown in FIG. 5, reference numeral 50 denotes an electron emission region from the cold cathode chip 41, which is 55, 56, 5
7 is R (red), G (green), B (blue), respectively
Is a fluorescent portion forming a fluorescent substance region. The electron emitting region 50 has fluorescent portions 55, 56, 56 that form R, G, B fluorescent substance regions in a state where the electron emitting direction is not changed.
57 are almost evenly distributed.

Also in this embodiment, according to the same principle as the above-mentioned embodiments, electron emission is performed by the gate electrodes 43 and 44 in the directions of arrows 51 and 52, and by the gate electrodes 45 and 46 in the directions of arrows 53 and 54. It is possible to realize a thin display device in which a large number of display elements that can control the direction and can support full-color display including one cold cathode chip 41 are arranged.

Further, in the structure of the above-mentioned embodiment, since the substrate electrode 40 and the anode electrode 47 through which a large current accompanying the movement of the emitted electrons flows are each constituted by a single electrode substrate, the density of the display device can be increased. It is possible to increase the area.

In the above embodiment, the common gate electrodes 43 to 46 are used between the adjacent cold cathode chips 41, but an independent gate electrode may be arranged in each cold cathode chip 41. That is, if each of the gate electrodes 43 to 46 in FIG. 4 is composed of two electrodes, different gate voltages can be applied to the adjacent cold cathode chips 41, 41.

[0047]

As is apparent from the above description, in the field emission type electron source device of the present invention, the electron passage region included in the above-mentioned plane is provided in the plane intersecting the electron passage region from the electron emission portion to the anode electrode. By applying a gate voltage having an independent value to each of a plurality of gate electrodes that are arranged so as to be surrounded and are insulated from each other, not only the electron emission amount from the electron emission portion but also the electron emission direction is controlled. be able to.

Therefore, according to the present invention, unlike the conventional example, the electron emission direction can be controlled by itself without complicating the electrode wiring.

Therefore, when a plurality of fluorescent portions are formed on the anode electrode, the plurality of fluorescent portions can be selectively irradiated with electrons, and one-beam full-color display that enables full-color display with one electron source. Display element can be configured,
A field emission type electron source device capable of coping with high density and high performance of a display device without miniaturizing wirings of a cathode electrode and an anode electrode which need to flow a large current accompanying movement of emitted electrons. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view of a display element included in a first embodiment of a field emission type electron source device of the present invention.

FIG. 2 is a top view of a display element formed by the above-mentioned embodiment.

FIG. 3 is a diagram including a cross-sectional view taken along line XX of FIG. 1 and a schematic diagram showing an electron emission range from an electron source.

FIG. 4 is a partially enlarged perspective view of a display device configured in a second embodiment of the present invention.

FIG. 5 is a partial top view of the display device.

FIG. 6 is a perspective view of a display element included in a conventional field emission electron source device.

[Explanation of symbols]

10, 40 Substrate electrode 11, 41 Cold cathode chip 12, 42 Insulating layer 13, 14, 15, 43, 44, 45, 46 Gate electrode 16, 47 Anode electrode 17, 48 Transparent electrode substrate 18, 19, 20 Fluorescent part

Claims (2)

[Claims] 1. A cathode electrode having at least one electron-emitting portion, an anode electrode irradiated with electrons emitted from the electron-emitting portion, and the electron-emitting portion between the anode electrode and the electron-emitting portion. A plurality of gate electrodes that are arranged so as to surround the electron passage region included in the plane and that are insulated from each other in a plane that intersects the electron passage region through which electrons pass from the portion to the anode electrode. A characteristic field emission type electron source device. 2. The anode electrode has a plurality of fluorescent portions formed in a region irradiated with electrons emitted from the electron emitting portion, the fluorescent portions emitting light when the electrons are irradiated. 1. The field emission type electron source device according to 1.