JPH11317168A - Image forming device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote desoprtion of the residual gas molecules and to reduce the gas release by electron collision by emitting electrons from an electron emitting part while applying a negative voltage to an anode part formed on a substrate during exhausting of an image display device. SOLUTION: The residual gas in a vessel is discharged through an exhaust pipe 109 while heating the envelop of an image forming device. A getter also degasses by external induction heating. To the ground voltage corresponding to a driving XY matrix wiring within a rear plate 100, a minus voltage is applied to an anode part 104 while evacuating an airtight vessel. A pulse voltage is also added to the element electrode of a surface electron emitting element 102 to drive it. A gas molecule 132 adsorbed near the element is repelled by an electron 135, partially forming a plasma ion 131, which is then accelerated by the minus voltage applied to the anode part 104 and collided to a phosphor 105 and the anode part 104. Further, the residual adsorbed gas is descerped from the collision part, and the pressure in the image forming device is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device using electrons as a phosphor excitation source, and more particularly to a flat plate type image display device and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, CRTs have been widely used as image forming apparatuses for displaying images using electron beams.

In recent years, flat-panel display devices using liquid crystal have been widely used in place of CRTs. However, since they are not self-luminous, they have problems such as having to have a backlight. The development of a display device has been desired. As a self-luminous display device, a plasma display has recently been commercialized. However, the principle of light emission is different from that of a conventional CRT, and it is slightly inferior to a CRT due to the contrast of an image and the characteristics of coloring. It is. on the other hand,
If a plurality of electron-emitting devices are arranged and used in a flat panel image forming apparatus, it is expected that an image of the same quality as a CRT can be obtained, and much research and development has been carried out. For example, Japanese Patent Application Laid-Open No. 4-163833 discloses a flat-plate electron beam image forming apparatus (flat panel display) in which a linear hot cathode and a complicated electrode structure are enclosed in a vacuum vessel.

In an image forming apparatus using an electron source,
For example, a part of the electron beam incident on the image forming member may be scattered, collide with the inner wall of the vacuum vessel, discharge secondary electrons, and charge up to increase the potential of the part. This not only distorts the potential distribution inside the vacuum vessel and makes the trajectory of the electron beam unstable, but also causes a discharge inside, which may cause the device to be deteriorated or destroyed. Is being developed. This is because the charged portion has a higher potential and attracts electrons, so that the charge-up further proceeds and a discharge is generated along the inner wall of the vacuum vessel. As a method of preventing charge-up of the inner wall of the vacuum vessel which causes such discharge, a method of forming an antistatic film having an appropriate impedance on the inner wall of the vacuum vessel and removing the charge generated as described above is used. Can be applied. An example to which such a method is applied is disclosed in
Japanese Patent No. 163833 discloses a configuration in which a conductive layer made of a high-impedance conductive material is provided on a side surface of an inner wall of a glass container of an image forming apparatus.

Conventionally, a number of flat panel displays using surface conduction electron-emitting devices have been filed by the present applicant, and FIG. 3 is a partial cross-sectional view showing an example of a configuration of a conventional flat panel display. It will be described according to.

In FIG. 3, reference numeral 301 denotes a glass substrate made of an insulating material such as blue plate glass or soda glass; 302, a surface conduction electron-emitting device; and 303, which accelerates electrons emitted from the surface conduction electron-emitting device. Is a face plate 300 having a phosphor 305 covered with an anode portion (metal back) 304 on the inner surface of an airtight container and having a glass substrate of an insulating material such as soda glass. Glass substrate 301 and surface conduction electron-emitting device 30 formed on glass substrate 301
2. The term “rear plate” includes wiring (not shown) and the like. An outer frame 307 made of an insulating material such as glass is provided between the face plate 303 and the rear plate 300.
Are joined to the face plate 303 and the rear plate 300 to form an airtight container.

[0007] A low melting point glass, an ultrasonic solder, an ultraviolet curable resin, or the like is used for a joint between the face plate 303 and the rear plate 300 and the outer frame 307. 309 is an exhaust pipe for exhausting the inside of the envelope. 330 is a residual gas molecule, 331 is a residual gas ion, 332 is a residual adsorbed molecule,
335 is an electron. Although the inside of the hermetic container is exhausted through the exhaust pipe 9, it is difficult to completely dispose of the hermetic container.
1. Residual adsorbed molecules 332 and electrons 335 remain, but are reduced to such an extent that image display is not affected.

FIG. 4 shows a rear plate 3 as an image display device.
The outline of the surface conduction electron-emitting device formed at 00 is shown.
In FIG. 4, reference numeral 301 denotes a substrate, 352 and 353 denote device electrodes, which are 0.1 μm-thick electrodes made of platinum.
Reference numeral 357 denotes a conductive thin film, which is an organic metal solution of organic Pd.
(Palladium / ccP4230; manufactured by Okuno Pharmaceutical Co., Ltd.) This is a fine particle thin film containing PdO (palladium oxide) as a main component, which is formed by applying a solution and then performing a heat treatment. 35
Reference numeral 5 denotes an electron emitting portion.

Next, a method for manufacturing the image display device will be described. First, an element wiring (not shown) and a surface conduction electron-emitting device 302 are formed on a blue glass substrate 301.
Next, a low melting point glass (LS-30) is connected to the upper and lower end surfaces of the outer frame 307, the exhaust pipe 309, the getter support material and the like (not shown).
81; Nippon Electric Glass Co., Ltd.) dissolved in an organic binder is preliminarily applied and calcined. Next, each is combined and subjected to main firing in an electric furnace to complete the envelope. The exhaust pipe 309 is connected to a vacuum pump, and the inside of the container is approximately 2 ×
After evacuating to 10 ⁻⁵ Pa, the device wiring and device electrode 35 were exhausted.
A voltage of more than ten volts is applied through the electrodes 2 and 353 to form the electron emission portions 355 of the surface conduction electron-emitting device 302. After forming the electron emitting portion 355, the inside of the hermetic container of the envelope is heated to 300 ° C. while evacuating, and the residual gas in the container is removed. After performing this heat treatment in a vacuum for 10 hours, it is cooled to room temperature. When the degree of vacuum in the envelope reaches 1 × 10 ⁻⁶ Pa or less, the exhaust pipe 309 is heated with a gas burner, sealed, and an airtight container is obtained.

Thereafter, a getter (not shown) is heated by a high frequency from outside the hermetic container and activated to complete the hermetic container. The getter is a metal that has the function of maintaining and improving the vacuum in the hermetic container by activating it. There is. Finally, the anode part 30
4, a high-voltage power supply (not shown) is connected to the element wiring, and a drive circuit (not shown) is connected to complete the image display device.

The electron emitting portion 355 is formed by a known method disclosed in Japanese Patent Application Laid-Open No. 7-235255.

The operation of the image display device will be described below. The surface conduction electron-emitting device 302 is driven by an external driving circuit to emit electrons 335. The emitted electrons 335 are attracted to the face plate 303 by the high voltage (several to several tens of kV) applied to the metal back 304 from an external power supply, and collide with the metal back 304 and the phosphor 305, thereby causing the phosphor 305 to move. Excite and emit visible light.

[0013]

However, in the above-described image display device and the method of manufacturing the same, high energy (ten to several keV) emitted from the electron emission portion despite the heat degassing treatment is performed. Electron with a phosphor,
When the anode portion formed on the substrate having the phosphor and the secondary electrons and the like collide with the electron emission portion itself, the residual adsorbed gas is desorbed and ionized from the collision portion and the vicinity thereof, and the inside of the image display device is removed. This causes problems such as pressure rise, destruction of the electrode due to ion bombardment, discharge, and deterioration of the electron emission portion. In particular, a flat-panel type image display device is thin, and therefore has not only a high electric field strength but also a very small volume and a large pressure rise caused by electron impact desorption, which is an important subject.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, in which a phosphor after heat treatment, an anode formed on a substrate having the phosphor, and residual adsorbed gas due to electron bombardment from the electron emitting portion itself. Pressure increase due to desorption and ionization,
It is an object of the present invention to provide an image display device free from destruction of electrodes, discharge, and deterioration of an electron emission portion due to ion bombardment.

[0015]

In order to achieve the above object, an image display device and a method of manufacturing the same according to the present invention are as follows.

An airtight container comprising two substrates made of a flat insulating material arranged opposite to each other and an outer frame provided between the two substrates, wherein the airtight container is an airtight container. At least an exhaust pipe for exhausting, a phosphor, an anode portion, and an electron emission portion, the electrons emitted from the electron emission portion are accelerated by a voltage applied to an anode portion formed on a substrate having the phosphor, and the fluorescence is accelerated. In a flat-panel type image display device that collides with a body to display an image, an electron emission portion emits electrons while applying a negative voltage to an anode portion formed on a substrate having a phosphor while exhausting the image display device. Is released to ionize gas molecules present in the image display device, and cause the ionized gas to collide with the phosphor and the anode formed on the substrate having the phosphor.

Further, argon or nitrogen gas is introduced into the image display device, and the introduced gas is introduced so that the pressure in the image display device is in the range of 5 Pa to 50 Pa.

Further, the above process is performed when the temperature of the image display device is high at the latter stage of the vacuum heat treatment process.

In addition, the electron emission portion is a surface conduction electron emission device, and the polarity of the device electrode is switched during driving.

[Operation] The operation and the manufacturing method of each means will be described below.

During the evacuation of the image display device according to the present invention, electrons are emitted from the electron emitting portion while applying a negative voltage to the anode portion formed on the substrate having the phosphor, so that the vicinity of the electron emitting portion is reduced. The gas molecules adsorbed on the surface are excited by the collision of electrons, and a part of the gas molecules become positive ions and desorb from the adsorption point. Then, by the negative voltage applied to the anode disposed opposite to the substrate having the electron-emitting portion, the detached positive ions are attracted to the anode and the phosphor,
Collide with the former. The collision of the desorbed positive ions with the phosphor and the anode promotes desorption of residual gas molecules attached to the phosphor and the anode. Further, the desorption process is accelerated by ions desorbed from the phosphor and the anode. On the other hand, neutral gas molecules desorbed by ions or electrons are exhausted by an exhaust pipe. This cycle of ionization of the adsorbed molecules, collision, desorption, and evacuation of neutral gas molecules reduces the amount of gas released in the image display device.

Further, according to the present invention, by introducing argon or nitrogen gas, even when the amount of ions generated from the electron emission portion after the heat treatment is small, the ionization of the introduced gas by the desorbed gas in the vicinity of the element is possible. In addition, the introduced gas is ionized by electrons from the electron emission section, causing a collision phenomenon of the introduced gas ions to the phosphor and the anode section, and removing residual gas molecules attached to the phosphor and the anode section. Separation is promoted.

This manufacturing method leads to a reduction in the time required for the manufacturing process, in addition to the reduction in the outgassing of the present invention.

Further, according to the present invention, by performing the process at a later stage of the vacuum heat treatment process when the temperature of the image display device is high, it is possible to reduce outgassing and prevent remaining of introduced gas without newly spending time. Further, there is an advantage that the image display device can be uniformly heated by the propagation of heat by gas molecules.

Further, according to the present invention, since the electron emission portion is a surface conduction type electron emission device, electrons can be emitted from both electrodes of the surface conduction type electron emission device. Desorption of residual gas molecules is also promoted.

[0026]

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

(First Embodiment) FIG. 1 is a conceptual view showing a degassing step in a method of manufacturing a flat panel display according to a first embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes a blue glass substrate in a rear plate, on which surface conduction electron-emitting devices 102 are formed in a matrix (hereinafter, the substrate 101 and the device 102 are combined together). , Rear plate 100
). Reference numeral 106 denotes a phosphor 10 covered with an anode (metal back) 104 on a substrate 103 made of an insulator.
Reference numeral 107 denotes an outer frame for keeping the rear plate 100 and the face plate 106 at a predetermined distance (7 mm in this embodiment). The face plate 106, the rear plate 100, and the outer frame 107 are joined at an end face of the outer frame 107 to form an envelope of the airtight container.

Reference numeral 109 denotes an exhaust pipe for exhausting the inside of the envelope, which is provided in a part of the outer frame 107. In this embodiment, soda lime glass having an outer diameter of 4 mm and an inner diameter of 2 mm is used. . A high voltage is applied to the anode (metal back) 104 by an external high voltage power supply (not shown).

Reference numeral 130 denotes residual gas molecules, 131 denotes residual gas ions, 132 denotes residual adsorbed molecules, and 135 denotes electrons. Although the inside of the hermetic container is exhausted through the exhaust pipe 109, the residual gas molecules 130, the residual gas ions 131, the residual adsorbed molecules 132, and the electrons 135 may remain in the hermetic container, so that the image display is not affected. , The life can be extended. For this reason, the processing described later is performed.

Hereinafter, a method of manufacturing the above-described image display device will be described. First, the substrate 1 of the rear plate 100
In step 01, the surface conduction electron-emitting device 102 is formed in advance. Next, the rear plate 100 and the face plate 10
6. A solution in which low-melting glass (LS-3081; manufactured by Nippon Electric Glass Co., Ltd.) is melted with a binder is applied to the joint between the outer frame 107 and the exhaust pipe 109, and each is calcined.
At this time, though not shown, at the same time, a pressure-resistant supporting member (spacer) fixed to either the rear plate 100 or the face plate 106 in the envelope is coated with the frit glass for bonding and pre-baked. Keep it. After that, align each position, fix them in an electric furnace at 410 ° C, 15
The main baking was performed in minutes, and an envelope was obtained.

After all the members have been fixed, the exhaust pipe 109 is connected to an exhaust device (a turbo molecular pump and a rotary pump), and the residual gas in the container is exhausted while the envelope is heated at 300 ° C. At this time, the getter also emits gas from the outside of the envelope by induction heating. In the present embodiment, Ba-Al
Was used as the main component.

After the heat treatment, the pressure in the envelope becomes about 1 × 10
When the pressure becomes lower than ⁻⁶ Pa, the air-tight container is evacuated and the anode (metal back) 1 is raised against the ground potential corresponding to the driving XY matrix wiring in the rear plate 100.
40, a voltage of −0.5 kV is applied to the device electrodes of the surface conduction electron-emitting device 102 (353, 353 in FIG. 4).
353), a pulse voltage of 16 V is applied to drive for 1 hour. By driving the surface conduction electron-emitting device 102, the pressure in the image display device increases to 1 × 10 ⁻⁵ Pa or more. This is because gas molecules 132 adsorbed in the vicinity of the element, such as hydrocarbons and water, are repelled by the electrons 135, and a part thereof becomes positive ions 131, and is accelerated by a negative voltage applied to the anode 104. (Having an energy of 1 keV), phosphor 1
The reason for this is that it collides with the positive electrode part 05 and the anode part 104, and the residual adsorbed gas is desorbed from the collision part.

Again, the pressure in the airtight container is about 1 × 10 ^-6
When the pressure reaches Pa or less, the exhaust pipe 109 is burned with a burner and hermetically sealed. After sealing the exhaust pipe, the getter is heated again by induction heating from the outside of the airtight container and activated to complete the airtight container. After completion of the airtight container, the electron-emitting device 10
2, an external drive circuit (not shown) and the like are connected to complete the image display device.

In this embodiment, the anode part (metal back)
Although the element drive voltage during application of a negative voltage was 16 V and the voltage applied to the metal back was −1 kV, the invention is not limited to this. However, the anode part (metal back)
It is desirable that the voltage applied to the device be in the range of minus 50 V to minus several kV, and that the device drive voltage be 15 V or more.

Gas emission during driving in the image display device manufactured as described above is reduced as compared with a conventional product which is only subjected to heat treatment in a vacuum at 300 ° C. for 10 hours, and the life of the surface conduction electron-emitting device is extended. Was. After the airtight container is completed, the exhaust pipe 1
After exhausting the interior from 09 and applying a negative voltage to the above-described anode section, the exhaust pipe is sealed, so that the adsorbed gas molecules 132 near the electron-emitting device, the phosphor and the residual adsorbed molecules 132 in the anode section are removed. It is considered that the device can be desorbed and evacuated to the outside of the hermetic container, thereby preventing element defects and extending the life.

(Second Embodiment) FIG. 2 is a conceptual diagram showing a degassing step in a method of manufacturing a flat panel display according to a second embodiment of the present invention.

This embodiment has the same configuration as the above-described first embodiment. A face plate 206 on which a transparent glass substrate 203, a phosphor 205, and an anode 204 as a metal back are formed; and a rear plate 200 on which a substrate 201 and a surface conduction electron-emitting device 202 on the substrate 201 are formed. , And the exhaust pipe 209 at their respective peripheral joints were sealed to the outer frame 207 with low-melting glass to form an envelope of an airtight container.

After forming the envelope, the exhaust pipe 209 was connected to an exhaust device, and the envelope was heated to 300 ° C. while evacuating the envelope.
After 7 hours while maintaining the temperature at 300 ° C., argon 250 was introduced from the exhaust pipe 209 so that the pressure in the envelope became about 10 Pa, and a voltage of −1 kV was applied to the anode section 204 and the surface conduction was performed. A rectangular pulse voltage of ± 18 V is applied to the device electrodes (device electrodes 352 and 353 in FIG. 4) of the electron-emitting device 202. By applying a voltage to the device electrode, a palladium thin film (thin film 3 in FIG. 4)
Electrons 235 are directly emitted from the cathode side to the anode side in 57). The emitted electrons 235 collide with the argon 250 introduced into the envelope and the residual gas molecules 232 adsorbed on the surface conduction electron-emitting device 202 to generate argon ions 251 and residual gas ions 231. I do. These ions 231 are accelerated by the anode unit 204, collide with the anode unit 204 and the phosphor 203, and desorb and ionize the residual adsorbed molecules 232.

The argon ions 250 and the residual gas ions 231 collide with other argon ions 250 and the residual gas molecules 230 before reaching the anode 204,
Ionize your opponent. Thus, the residual adsorbed gas 230
To be removed. After 1 hour, the supply of argon ions 250 is stopped, and the residual gas molecules (including argon) are continuously removed for 2 hours while keeping the envelope at 300 ° C. When the envelope reaches room temperature, the exhaust pipe 209 is sealed, a getter (not shown) is activated, and the hermetic container is completed.

In this embodiment, a rectangular pulse voltage of plus or minus 18 V is applied to the element electrode. However, the present invention is not limited to this. A triangular pulse or a sine pulse may be used.

In this embodiment, argon is used as the introduced gas. However, similar results were obtained when nitrogen was used.

The flat panel display manufactured as described above has the above-described effects of the first embodiment. Particularly, it exerted a remarkable effect on hydrocarbon, CO, CO ₂ and water.

[0044]

The present invention has the following effects by using the above-described structure.

According to the present invention, the electron emission section emits electrons while applying a negative voltage to the anode section formed on the substrate having the phosphor during the exhaust of the image display apparatus, so that the vacuum chamber is kept in a vacuum. This can promote desorption of residual gas molecules adhering to the phosphor, the anode portion, and the electron emission portion after the heat treatment, and can reduce gas emission in the image display device due to electron collision.

Further, according to the present invention, even when the amount of ions generated from the electron emitting portion after the heat treatment is small, gas emission from the phosphor and the anode portion can be reduced, and the effect is large. Therefore, it leads to shortening of the process time.

Further, according to the present invention, since the above-described step itself is performed during the heating step, the time required for the step is the same as or less than that of the conventional method, and the heating temperature in the image display device by the introduced gas is reduced. The uniformity is improved.

Further, when the electron emitting portion of the present invention is a surface conduction type electron emitting device, the polarity of the electrode of the electron emitting portion can be switched during the above process, and a further degassing effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an image display device and a method of manufacturing the same according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating an image display device and a method of manufacturing the same according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of factors of a conventional image display device.

FIG. 4 is a perspective view of a surface conduction electron-emitting device.

[Explanation of symbols]

 101, 201, 301 Substrate 102, 202, 302 Surface conduction electron-emitting device 103, 203, 303 Face plate 104, 204, 304 Anode 105, 205, 305 Phosphor 107, 207, 307 Outer frame 109, 209, 309 Exhaust pipe 130, 230, 330 Residual gas molecule 131, 231, 331 Residual gas ion 132, 232, 332 Residual adsorbed molecule 250 Argon 251 Argon ion 352, 353 Device electrode 355 Electron emission part 357 Palladium thin film

Claims (10)

[Claims] 1. An airtight container comprising two substrates made of a flat insulating material arranged opposite to each other and an outer frame provided between the two substrates, wherein the airtight container includes It has at least an exhaust pipe for exhausting the inside of the airtight container, a phosphor, an anode portion, and an electron emission portion, and electrons emitted from the electron emission portion are accelerated by a voltage applied to the anode portion formed on the substrate. In the image display device for colliding with the phosphor and displaying an image, while exhausting the inside of the hermetic container, while applying a negative voltage to the anode portion, electrons are emitted from the electron emitting portion, and the hermetic sealing is performed. An image display device comprising an airtight container processing means for ionizing gas molecules present in a container and causing ionized gas to collide with the phosphor and an anode formed on a substrate having the phosphor. 2. The image display device according to claim 1, wherein
2. The image display device according to claim 1, wherein argon or nitrogen gas is introduced into the airtight container. 3. The image display device according to claim 2, wherein
The pressure of the introduced gas is 5 Pa in the hermetic container.
An image display device characterized by being introduced so as to fall within a range of from 50 Pa to 50 Pa. 4. The image display device according to claim 1, wherein the step of processing the hermetic container is performed when the temperature of the hermetic container is high in a later stage of the vacuum heating process. apparatus. 5. The image display device according to claim 1, wherein the electron-emitting portion is a surface-conduction electron-emitting device, and switches the polarity of the device electrode during driving. . 6. An airtight container comprising two substrates made of a flat insulating material arranged to face each other and an outer frame provided between the two substrates, wherein the airtight container includes It has at least an exhaust pipe for exhausting the inside of the airtight container, a phosphor, an anode portion, and an electron emission portion, and electrons emitted from the electron emission portion are accelerated by a voltage applied to the anode portion formed on the substrate. In the image display device, which collides with the phosphor and displays an image, while applying a negative voltage to the anode while discharging the inside of the hermetic container, the electron emitting portion emits electrons from the electron emitting portion; A method for manufacturing an image display device, comprising a step of ionizing gas molecules present in a container and causing an ionized gas to collide with the phosphor and the anode formed on the substrate having the phosphor. 7. The method for manufacturing an image display device according to claim 1, wherein argon or nitrogen gas is introduced into the hermetic container. 8. The method for manufacturing an image display device according to claim 7, wherein the introduced gas is introduced such that the pressure in the hermetic container is in a range of 5 Pa to 50 Pa. Production method. 9. The method for manufacturing an image display device according to claim 6, wherein the step of processing the airtight container is performed when the temperature of the airtight container is high in a later stage of the vacuum heating process. Of manufacturing an image display device. 10. The image display device according to claim 6, wherein the electron-emitting portion is a surface-conduction electron-emitting device, and switches the polarity of the device electrode during driving. Manufacturing method.