JP2000021338A - Image display device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image display device of a long lifetime without any unevenness in luminance while maintaining high electron emitting efficiency by preventing any outgassing, any breakage of an electron emitting element caused by electrode discharge due to the outgassing, and adhesion or adsorption of gas onto an electrode. SOLUTION: In this image display device comprising at least: an envelope consisting of a rear plate 80 having an electron emitting element thereon, a face plate 70 against which an electron emitted from the electron emitting element and a support frame 75; and a non-evaporating type getter 55 for maintaining a vacuum degree inside the envelope, the electron emitting element paired with the non-evaporating type getter 55 is disposed in a matrix fashion in each pixel, wherein the electron emitting element activates the nonevaporating type getter 55 and displays an image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a flat panel type image display device for displaying an image by emitting electrons from a large number of electron-emitting devices and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, many reports have been made on the technology of a flat panel type image display device using a large number of electron-emitting devices as a phosphor excitation source. FIG. 6 is a cross-sectional view showing one example (see JP-A-8-167394). Here, reference numeral 4 denotes a substrate made of an insulator called a rear plate, and the surface conduction electron-emitting devices 3 are arranged on the rear plate 4 in a matrix. On the other hand, a fluorescent material 13 and a metal back 14
The face plate 1 formed in the order of
, And is disposed so as to face the rear plate 4.

[0003] The rear plate 4, the face plate 1, and the support frame 2 are joined and fixed to each other with low-melting glass to form an envelope. Reference numeral 11 denotes an exhaust pipe for evacuating the inside of the envelope to a vacuum. After the rear plate 4, the face plate 1, and the support frame 2 are fixed to each other, the envelope is connected to the exhaust pipe 11. Then, the air is evacuated to a vacuum by an external exhaust device (not shown).

[0004] Reference numeral 8 denotes a non-evaporable getter for maintaining the degree of vacuum in the envelope after sealing the exhaust pipe 11, and reference numeral 5 denotes an electron-emitting device for activating the getter 8. is there. The getter activating electron-emitting device 5 applies a voltage between the positive electrode 7 and the negative electrode 6 which are opposite electrodes,
This is for emitting electrons and causing the emitted electrons to collide with the surface of the getter 8 to be activated. In addition, a positive voltage is applied to the getter 8 from a power supply (not shown) to accelerate electrons emitted from the getter activating electron-emitting device 5 to the getter 8.

[0005]

In such a conventional technique, it is necessary to provide an electron-emitting device for activating the non-evaporable getter in order to activate the non-evaporable getter. However, when the area of the image display device is increased, the gas generated from the face plate due to the electron impact is not immediately adsorbed by the getter, but diffuses in the envelope,
It is attracted to a getter provided around the image display area.

However, during this diffusion, for example, the anode electrode (metal back) or the electron-emitting device on the inner surface of the envelope is contaminated with gas, shortening the life of the electron-emitting device, or damaging the electron-emitting device due to discharge. Cause such problems.
In addition, such gas emission causes unevenness in the degree of vacuum in the envelope due to a small space between the envelopes and poor gas flowability, and causes local deterioration of the electron-emitting device. The problem is also caused.

On the other hand, if a getter is arranged in the vicinity of the electron-emitting device, the pixel size will be increased, and it will be difficult to improve the definition of an image. Further, when the non-evaporable getter is activated, the gas released from the getter adheres or adsorbs to the surface of the element electrode, changes the work function of the electrode, and lowers the electron emission efficiency.

The present invention has been made in view of such circumstances, and mainly causes a gas discharge and a damage of an electron-emitting device due to a discharge due to the gas discharge in a high-definition and large-screen image display device. It is an object of the present invention to provide a long-life image display device that maintains a high electron emission efficiency without causing gas to adhere or adsorb to the electrode surface without causing a gas to adhere to or adhere to the electrode surface, and has no luminance unevenness.

[0009]

In order to achieve the above object, according to the present invention, there is provided a rear plate provided with an electron-emitting device, a face plate and a support frame against which electrons emitted from the electron-emitting device collide. And an image display apparatus having at least a non-evaporable getter for maintaining a degree of vacuum in the envelope, wherein the electron-emitting device and the non-evaporable getter form a pair in the envelope. The electron emission elements are arranged in a matrix for each pixel, and both the activation of the non-evaporable getter and the image display are performed.

In this case, in the embodiment of the present invention, when activating the non-evaporable getter, the image display device changes the polarity of the voltage applied between the two electrodes of the electron-emitting device by changing the polarity of the image display. The electron emission element is composed of a first element electrode and a second element electrode stacked with an insulating layer interposed therebetween. A conductive thin film is formed on a surface on which the second device electrode is laminated and a surface extending in the vertical direction; a negative voltage is applied to the non-evaporable getter; While applying a positive voltage to each of the above, an inert gas is introduced into the envelope, and the introduced inert gas is ionized by electrons emitted from the surface conduction electron-emitting device. The non-evaporable getter Thereby activatable, that further, the electron-emitting device is a surface conduction electron-emitting device,
This is a preferred mode.

Further, when manufacturing the image display device having the above-described configuration, the above-described activation step of the non-evaporable getter may be performed during the heating and exhausting step of the envelope or at a later stage of the heating and exhausting step. This is also a feature of the present invention.

In such a configuration, a pair of a non-evaporable getter and an electron-emitting device are arranged in each pixel, and first, electrons emitted from the electron-emitting device are attracted by a voltage applied to the non-evaporable getter. Then, the material is activated by colliding with the material of the non-evaporable getter. Thereafter, by applying a voltage of 0 volt or less to the non-evaporable getter and a voltage of several kilovolts to the anode electrode formed on the face plate, electrons emitted from the electron-emitting device are applied to the face plate. Accelerate and display the image,
At this time, the activated non-evaporable getter quickly adsorbs gas molecules emitted by electrons colliding with the phosphor and the anode electrode during image display, thereby preventing pressure unevenness in the envelope. Therefore, the amount of getter in the non-image area can be reduced, and the non-image area can be reduced.

Further, gas molecules and a part of positive ions generated when activating the non-evaporable getter adhere and adsorb to the cathode surface of the device electrode, change the work function of the cathode surface, and increase the electron emission efficiency. When activating the non-evaporable getter, the voltage applied between the two electrodes of the electron-emitting device is made to have the opposite polarity to the polarity of the voltage applied during image display, so that the emission-emission efficiency is reduced. And an excellent image display device without luminance unevenness and lifetime unevenness can be provided.

Further, the electron-emitting device is composed of a first device electrode and a second device electrode laminated on a substrate made of an insulating material via an insulating layer. By forming a conductive thin film on the stacked surface and the surface extending in the direction perpendicular to the surface, the size of each pixel can be further reduced, and high definition is achieved, or the size of each pixel is not increased. Furthermore, it is possible to increase the amount of the non-evaporable getter that can be installed in each pixel. In addition, the voltage applied between the two device electrodes during activation of the non-evaporable getter can be reduced, and the power consumption during activation can be reduced.

In addition, an inert gas is introduced into the envelope,
The time can be shortened by ionizing the introduced inert gas by electron emission from the electron emission element and colliding the ionized inert gas with the non-evaporable getter. In the manufacture of the above-described image display device, the activation step of all the non-evaporable getters is performed during the exhaustion of the envelope, the heating step, or at a later stage of the heating step. The amount of current and the amount of inert gas introduced can be reduced, and the activation time of the non-evaporable getter can be shortened, which in turn leads to cost reduction.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to FIGS.

(First Embodiment) As a first embodiment of the present invention, a description will be given of a case where a pair of a surface conduction electron-emitting device and a non-evaporable getter are arranged in a matrix in an image display device. I do. In FIG. 1, reference numerals 51 and 52
Denotes an element wiring, and 53 denotes a surface conduction electron-emitting element. Reference numeral 55 denotes a non-evaporable getter, and the surface conduction electron-emitting device 53 and the non-evaporable getter 55 are arranged in a matrix in pairs. Reference numeral 57 denotes a wiring for applying a voltage to the non-evaporable getter 55, and all the wirings are common. Reference numeral 50 denotes a substrate made of an insulating material such as glass. The substrate 50, the element wirings 51 and 52, the surface conduction electron-emitting device 53, and the like are referred to as a rear plate 80.

Reference numeral 60 denotes a substrate made of an insulating material such as glass, 61 denotes a fluorescent material excited by electrons, and 62 denotes a metal back made of a conductive thin film for attracting electrons. The substrate 60, the fluorescent material 61, and the metal back 62 are collectively referred to as a face plate 70.

The face plate 70 and the rear plate 80 are fixed with a low-melting glass via a support frame 75 having a thickness of 4 mm to form an envelope. Support frame 75
Is for maintaining the distance between the rear plate 80 and the face plate 70 disposed opposite to the rear plate 80 even after the inside of the envelope is evacuated to a vacuum.

The surface conduction electron-emitting device used in this embodiment will be specifically described below with reference to FIG. FIG. 2 shows a configuration of a surface conduction electron-emitting device. In this example, two device electrodes 102 and 103 are arranged on a substrate 101 made of an insulator at an interval from each other. A conductive thin film 104 is provided by connecting the device electrodes 102 and 103. As the element electrode material, for example, Ni, Pd, Cr, Au, Mo, Al, or the like is used. Reference numeral 105 denotes a conductive thin film 104.
This is the electron emission portion formed on the substrate.

After all the members are fixed, the electron emission portion 1
05 is formed, and the inside of the envelope is exhausted by the exhaust pipe 79. When the inside of the envelope reaches about 10 ^-7 Torr,
A heating device (not shown) allows the entire envelope to be
Continue evacuation over about 15 hours while heating to 0 ° C.
Thereafter, when the envelope reaches room temperature, +200 volts is applied to the wiring 57 while evacuating the interior of the envelope,
In addition, between the two device electrodes of the surface conduction electron-emitting device 53, 2
By applying a rectangular voltage of 0 volts, electrons were extracted from the surface conduction electron-emitting device 53 and collided with the non-evaporable getter 55 to activate it. After the activation of the non-evaporable getter 55, the exhaust pipe 79 was sealed to complete an airtight container. Further, a drive circuit (not shown) and the like were connected to the airtight container to constitute an image display device.

After the completion of the image display device, when an external drive circuit (not shown) emits electrons, when the non-evaporable getter 55 is activated, it has a polarity opposite to the polarity applied to the element electrodes. It was driven to display an image. At this time, 4 kilovolts DC is applied to the metal back 62, and a rectangular wave is applied between both device electrodes of the surface conduction electron-emitting device.
6 volts was applied. As a result, in the above-described image display device, there is no local deterioration of the surface conduction electron-emitting device in the image display region in the image display and the unevenness in brightness, which is observed in the conventional image display device, and a favorable state. Was kept. Also,
Compared with the related art, the amount of getter in the non-image area can be reduced, and the area becomes smaller.

In the present invention, the type or material of the non-evaporable getter is not limited to the above-described embodiment. For example, metals such as Fe, Ni, V, and Zr, and metals such as these may be used. An alloy as a main component may be used.
Further, the forming method is not limited to a method such as photolithography and printing.

In this embodiment, a palladium thin film is used for the surface conduction electron-emitting device, but SnO ₂ ,
The material is not particularly limited as long as a thin film is formed by fine particles, such as Au, Pt, Ru, Ta, Ni, PdO, and In.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
1A is a partial plan view, and FIG. 2B is a partial cross-sectional view. The configuration is the first
In this embodiment, reference numeral 201 denotes a substrate, and reference numerals 202 and 203 denote device electrodes. Reference numeral 206 denotes an insulating layer made of SiO ₂ or the like.
04 is a conductive thin film, and 205 is an electron emission part.

In this embodiment, an argon gas is introduced into an envelope constituted by a face plate 170, a support frame 175, and a rear plate 180 via an exhaust pipe 179, and the surface conduction electron emission is performed. The introduced argon gas was ionized by the electrons emitted from the element 153, and the non-evaporable getter 155 was activated.

A voltage of -100 volts is applied to the non-evaporable getter 155, a voltage of +2 kilovolts is applied to the anode electrode on the face plate, argon is supplied, and the pressure in the envelope becomes 0.5 mTorr. So introduced. After activating the getter 155, while evacuating the envelope,
Baking was performed at 250 ° C. for 15 hours, the temperature was lowered to room temperature, and the exhaust pipe 179 was sealed.

In this embodiment, argon is used as the inert gas. However, the present invention is not limited to such a gas type as long as it does not chemically react with the non-evaporable getter. Further, in the image display device obtained in the present embodiment, in addition to the effects of the first embodiment, the configuration of the surface conduction electron-emitting device is as shown in FIG. In addition, the size of each pixel can be reduced without changing the number of non-evaporable getters as in the first embodiment. Further, the amount of collision of electrons to the getter 155 and the amount of current to the anode electrode can be larger than those of the surface conduction electron-emitting device shown in FIG. The power consumption was reduced and the luminance was improved.

(Third Embodiment) A third embodiment of the present invention has a configuration similar to that of the first embodiment, in which the activation of the non-evaporable getter is performed and the envelope is evacuated. This was performed during the step of heating while evacuating the tube. FIG. 5 shows the heating and exhausting process, in which the vertical axis represents temperature and the horizontal axis represents time. Here, the temperature of the heating and exhausting step of the envelope is set to 300 ° C.
The time is set to 10 hours, and the activation of the non-evaporable getter is performed in the latter half of the heating and exhausting process (9 hours after holding at 300 ° C.)
I went to.

Therefore, in the activation in the first and second embodiments, the activation of the getter material may be slightly uneven,
Insufficient activation may cause a phenomenon in which the exhaust characteristics are lower than the standard, but the activation process of the non-evaporable getter is performed during the heating and exhausting process of the envelope. Good getter characteristics without defects were obtained.

For this reason, the obtained image display device is the first
And has a longer service life than the image display device obtained in the second embodiment, and the activation time of the non-evaporable getter required in these embodiments is not required, shortening the manufacturing time, If it was, it also led to cost reduction.

[0032]

As described above, according to the present invention,
A pair of an electron-emitting device and a non-evaporable getter is arranged for each pixel, and the electron-emitting device serves both for activating the non-evaporable getter and for displaying an image. Gas is quickly adsorbed, and an image display device having a long life and a small non-image display area with less pressure unevenness in the image display device can be obtained.

Further, the polarity of the voltage applied to the electron-emitting device when activating the non-evaporable getter is set to be opposite to the polarity of the voltage applied when displaying an image, so that the device electrode of the electron-emitting device is activated. An image display device free from luminance unevenness caused by a change in work function due to gas adsorption on the surface can be obtained.

Further, the electron-emitting device has a structure in which a first device electrode and a second device electrode are laminated on an insulating substrate with an insulating layer interposed therebetween, so that the first and second device electrodes are formed.
With the structure in which the conductive thin film is formed on the surface in the direction perpendicular to the surface on which the element electrodes are stacked, the size of each pixel can be further reduced, and a high-definition image display device can be obtained. it can.

In addition, an inert gas is introduced into the envelope,
The time can be reduced by ionizing the inert gas introduced by the electron emission from the electron-emitting device and colliding it with the non-evaporable getter.

In addition, by performing the above-described activation step of all the non-evaporable getters during the exhausting of the envelope and during the heating step or at a later stage of the heating step, the amount of current required for activation and the inert gas The amount of introduction can be reduced, the activation time of the non-evaporable getter can be shortened, and the cost can be reduced.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams illustrating an image display device according to a first embodiment of the present invention in a partial plane in FIG. 1A and a partial cross section in FIG.

FIGS. 2A and 2B are diagrams showing a configuration of a surface conduction electron-emitting device used for the same, in a plan view in FIG. 2A and in a cross section in FIG.

FIGS. 3A and 3B are diagrams illustrating an image display device according to a second embodiment of the present invention in a partial plane in FIG. 3A and a partial cross section in FIG.

FIG. 4 is a cross-sectional view of a surface conduction electron-emitting device used for the same.

FIG. 5 is a diagram showing a working process in a third embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating an example of a conventional image display device.

[Explanation of symbols]

 1, 70, 170 Face plate 2, 75, 175 Support frame 4, 80, 180 Rear plate 11, 79, 179 Exhaust pipe 3 Electron source 5, 53, 153 Surface conduction electron-emitting device 51, 52, 151, 152 device Wirings 102, 103, 202, 203 Device electrodes 104, 204 Conductive thin film 105, 205 Electron emitting portions 8, 55, 155 Non-evaporable getters 57, 157 Wirings 12, 50, 60, 150, 160, 201 Substrates 4, 80 , 180 Rear plate 1, 70, 170 Face plate 13, 61, 161 Fluorescent material 14, 62, 162 Metal back 206 Insulation layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tohru Ariga 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 5C012 AA01 5C031 DD09 5C032 AA01 JJ08 5C036 EF01 EF06 EG02 EG12 EG50

Claims (6)

[Claims] 1. An enclosure comprising a rear plate provided with an electron-emitting device, a face plate and a support frame against which electrons emitted from the electron-emitting device collide, and a degree of vacuum in the envelope. An image display device having at least a non-evaporable getter to maintain, wherein the electron-emitting device and the non-evaporable getter form a pair in the envelope, are arranged in a matrix for each pixel, and
An image display device, wherein the electron-emitting device performs both activation of a non-evaporable getter and image display. 2. An electron-emitting device having an electron-emitting portion between a pair of electrodes, wherein when activating the non-evaporable getter, a voltage is applied between both electrodes of the electron-emitting device. 2. The image display device according to claim 1, wherein the polarity of the voltage is opposite to the polarity of the voltage applied during image display. 3. The device according to claim 1, wherein the electron-emitting device includes a first device electrode and a second device electrode stacked with an insulating layer interposed therebetween, and a surface on which the first and second device electrodes are stacked. The image display device according to claim 1, wherein a conductive thin film is formed on a surface extending in a vertical direction. 4. A negative voltage is applied to the non-evaporable getter, and a positive voltage is applied to an anode electrode on the face plate.
While applying each, an inert gas is introduced into the envelope. At this time, the introduced inert gas is ionized by electrons emitted from the electron-emitting device, and the non-evaporable getter is ionized by the inert gas ions. The image display device according to claim 1, wherein the image display device is activated. 5. The image display device according to claim 1, wherein said electron-emitting device is a surface-driven electron-emitting device. 6. The image display device according to claim 1, wherein the activation step of the non-evaporable getter is performed during a heating and exhausting step of the envelope or at a later stage of the heating and exhausting step. Of manufacturing an image display device.