JPH0877951A - Image display device - Google Patents

Abstract

PURPOSE: To provide an image display device by which a manufacturing process is shortened by reducing the number of part items and the yield in manufacture is improved and the useless space in an image screen is also eliminated. CONSTITUTION: A getter 12 to maintain a degree of vacuum after an airtight vessel is sealed, is housed in a getter housing part 13 arranged in an outer frame 11 constituting the airtight vessel. A communicating means is formed to communicate this getter housing part 13 and the inside of the airtight vessel with each other.

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 for displaying an image by utilizing light emission generated by colliding an electron beam with a phosphor in an airtight container whose inside is kept vacuum, and a method for manufacturing the same. Regarding

[0002]

2. Description of the Related Art Image display devices include plasma displays, EL display devices, image display devices using electron beams, fluorescent display devices, and the like, and the demand for larger screens, higher definition, and higher quality is increasing. , Image display devices have been developed.

Here, an image display device using fluorescent display will be described as an example of a conventional image display device and its manufacturing method.

7A and 7B are views showing an example of a conventional fluorescent display device. FIG. 7A is a top view thereof and FIG. 7B is a sectional view thereof.

In FIG. 7, a substrate 101 is a transparent plate such as a glass plate and serves as a display surface for displaying an image. A cup-shaped lower plate 102 is hermetically bonded to the substrate 101 at the peripheral edge of the substrate 101, and the substrate 101 and the lower plate 102 form an airtight container. An anode pattern 106 is provided on the substrate 101 inside the airtight container. The surface of the anode pattern 106 is coated with a fluorescent substance that emits light by electron beam impact, and is formed of a conductive substance that allows the charge of collision electrons to flow away. Note that, as shown in FIG. 7A, here, a segment-shaped pattern dedicated to displaying numbers is used.

The filament 104 is arranged so as to face the anode pattern 106. Filament 10
Reference numeral 4 is an extremely thin line-shaped object that does not obstruct the display, and is an electron beam generation source that thermally emits electrons.

Anode pattern 106 and filament 104
Between the control grid 105 and the control grid 105, which is a mesh-shaped control grid for controlling the electron emission from the filament 104.
The filament 104, the control grid 105, and the anode pattern 106 constitute the display unit 103.

Further, a getter 107 is arranged inside the airtight container with a getter diffusion preventing plate 108 spaced apart from the display unit 103.

The getter 107 is heated and diffused to form a vapor deposition film made of a getter substance in the airtight container, and the vapor deposition film adsorbs the released gas in the airtight container, whereby the degree of vacuum in the airtight container is increased. It is a substance that has the action of maintaining.

The getter diffusion prevention plate 108 is the getter 1
This is to prevent the getter substance from adhering to the display portion 103 when diffusing 07. The getter substance is placed upright between the getter 107 and the display portion 103 and fixed to the end portion of the substrate 101 by a low melting point glass. ing. The getter diffusion prevention plate 108 is controlled so that the getter substance does not adhere to the display portion 103 when the getter is diffused.

Further, one end of the filament 104 is fixed to substantially the center of the elevation of the getter diffusion prevention plate 108, and the getter 107 is provided on the side opposite to the display portion 103 of the getter diffusion prevention plate 108. It is fixed to the elevation by means such as spot welding or brazing.

Next, a method of manufacturing the fluorescent display device will be outlined.

First, a plurality of display units 1 are provided on a substrate 101.
03, getter 107 and getter diffusion prevention plate 108
To place.

Next, the lower plate 102 and the substrate 101 are superposed on each other, and a low melting point glass or the like is applied to the superposed portion. Then, the entire apparatus is heated in the electric furnace, and the substrate 101 and the lower plate 1 are
02 is fixed to form an airtight container. Then, the space inside the airtight container is evacuated by a vacuum pump through an exhaust pipe (not shown). Subsequently, the entire apparatus is heated by a heating means such as a hot plate to degas. Finally, while the getter 107 is being diffused at appropriate times, the exhaust pipe is heated by a gas burner and welded to seal the airtight container.

The fluorescent display device is formed as described above.

The substrate 101 and the lower plate 102 constituting the airtight container have insulation properties that can withstand atmospheric pressure and maintain a vacuum atmosphere, and can withstand a high voltage applied between the filament 104 and the anode pattern 106. It is desirable to use those having

Here, since there is no particular problem in terms of strength, the case where the airtight container is composed of only the substrate 101 and the lower plate 102 is described as an example, but it is opposed to the outer frame surrounding the outer periphery so as to sandwich it. In some cases, the airtight container is configured by two plates (face plate, back plate, etc.) that are arranged in parallel.

[0018]

However, the conventional image display device as described above has the following problems.

(1) When the getter substance is diffused in the image display device, if the getter substance diffused from the getter adheres to the display portion or the like, it may deteriorate the characteristics of the display portion or cause instability. A plate to prevent diffusion is provided between the getter and the getter. However, since the number of steps for attaching the getter diffusion prevention plate increases and the number of parts increases, the work becomes complicated.

(2) The getter diffusion prevention plate is arranged between the display unit and the getter so that the getter substance does not adhere to the display unit. Since the getter diffusion prevention plate and the getter are placed at one corner of the substrate, a space for arranging the getter diffusion prevention plate and the getter is required. Therefore, the area between the getter diffusion prevention plate and the outer frame portion cannot be used as a display portion, and the effective display area is reduced. In other words,
The screen area is reduced, and the wasted space is increased.

(3) The getter diffusion prevention plate is fixed between the display section and the getter with a low melting point glass, but when the temperature of the image display device rises due to heating during degassing, the low melting point glass applied to the getter diffusion prevention plate. The viscosity of the low melting point glass may flow out to the display portion, or the getter diffusion prevention plate may be displaced. If the getter diffusion prevention plate is displaced, the getter substance diffused from the getter will adhere to the display unit or the like when the getter is diffused. These cause deterioration of the characteristics of the display portion and instability factors, leading to a reduction in manufacturing yield.

The present invention has been made in order to solve the above-mentioned problems of the conventional technique, and reduces the number of parts to shorten the manufacturing process and improve the manufacturing yield, and at the same time, the on-screen display. An object of the present invention is to provide an image display device that eliminates the wasted space.

[0023]

In order to achieve the above object, the image display device of the present invention is configured so that a back plate provided with an electron source for generating an electron beam collides with an electron beam from the electron source. A face plate that is provided with a phosphor that emits light and is arranged to face the back plate through an outer frame, and that constitutes a hermetic container whose inside is kept in a vacuum together with the back plate and the outer frame; In an image display device having a getter diffused in the airtight container to maintain the degree of vacuum of the container, the getter is housed in a getter housing portion formed inside the outer frame, and in the outer frame. Is characterized in that a communication means is formed for communicating the getter storage part and the inside of the airtight container.

At this time, the communicating means may be a slit, a notch or a hollow hole.

[0025]

In the image display device constructed and manufactured as described above, the getter is housed in the getter housing portion that communicates with the inside of the airtight container through the communicating means. Is diffused from the getter accommodating portion to a predetermined portion in the airtight container through the communication means. This eliminates the need for a getter diffusion prevention plate that controls the place where the getter substance diffuses.

Further, since the getter accommodating portion is formed inside the outer frame, it is not necessary to dispose the getter and the getter diffusion preventing plate in the airtight container, and the space can be used as the image display portion. .

Further, by disposing the getter in the getter accommodating portion formed inside the outer frame, it is not necessary to strictly control the positioning of the getter.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image display apparatus using an electron beam has an electron source for generating an electron beam in a vacuum container sandwiched between a face plate and a back plate, and the electron source emits surface conduction electron. The applicant of the present application has filed a thin image display device that uses an element to accelerate an electron beam of the element to irradiate a phosphor and emit light to display an image (Japanese Patent Application Laid-Open No. 261024/1993). Here, an example in which the present invention is applied to an image display device using the surface conduction electron-emitting device will be described.

(First Embodiment) FIG. 1 is a partially broken perspective view of a first embodiment of the image display device of the present invention. Figure 2
FIG. 3 is an enlarged view of a main part of the image display device shown in FIG. 1, and FIG. 3 is a plan view showing an example of a mask used when forming a thin film for forming an electron emission part described later.

1 and 2, a plurality of surface conduction electron-emitting devices 4 are used as electron sources for generating electron beams.
A back plate 1 on which is formed, and a face plate 7 which displays an image by acting on the electrons emitted from the electron-emitting device 4 are arranged to face each other via an outer frame 11. The back plate 1 and the outer frame 11 and the face plate 7 and the outer frame 11 are airtightly adhered (sealed) by low-melting glass, and the backplate 1, the outer frame 11 and the face plate 7 constitute an airtight container.

The electron-emitting device 4 is provided with a grid 6 via an insulating material (not shown). This grid 6
Is a modulation electrode for controlling the electrons emitted from the electron-emitting device 4, and the controlled electrons reach the face plate 7 through the electron passage holes 5 provided in the grid 6.

A phosphor 8 and a metal back 9 which is an acceleration electrode are formed on the inner surface of the face plate 7, and the phosphor 8 emits light when the electrons emitted from the electron-emitting device 4 collide. Is displayed.

On the other hand, the outer frame 11 is formed with a getter accommodating portion 13 for accommodating the getter 12, and the slitter 1 as a communicating means between the getter accommodating portion 13 and the inside of the airtight container.
It is connected by 6. The slit 16 sufficiently fills the volume necessary for the getter 12 to diffuse and degas the airtight container. Due to the relationship between the angle of the electron-emitting device 4, the getter storage portion, and the slit 16, the getter 12 is provided.
Is designed so as not to diffuse to the electron-emitting device 4 and the like even when diffused.

In the present embodiment, the getters 12 are arranged at the four corners of the outer frame 11, but the positions and the number of the getters 12 can be arranged at the necessary positions for diffusion of the getter substance described later.

In the above structure, first, a typical device structure of these surface conduction electron-emitting devices will be described with reference to FIG.

In FIG. 4, a pair of device electrodes 23, 23a are arranged on an insulating substrate 21, and electron emission made of a metal oxide thin film or the like formed by sputtering so as to straddle the device electrodes. The part forming thin film 22 is formed. An electron emitting portion 24 is formed on the electron emitting portion forming thin film 22 by an energization process called forming. Forming means the thin film 22 for forming the electron emitting portion.
A voltage is applied to both ends of the electrode to energize the thin film to form an electron emission portion forming thin film 22.
Is locally destroyed, deformed or altered to form an electron emitting portion 24 which is a region in which it is in an electrically high resistance state. In the electron emitting portion 24, a crack is generated in a part of the electron emitting portion forming thin film 22, and electrons are emitted from the vicinity of the crack.

Hereinafter, the electron emission part forming thin film 22 including the electron emission part 24 formed by forming is referred to as a thin film including an electron emission part. In the surface-conduction type electron-emitting device that has undergone the forming process, a voltage is applied to the thin film including the above-mentioned electron-emitting portion, and a current is caused to flow between the device electrodes 23 and 23a, so that electrons are emitted from the above-mentioned electron-emitting portion 24. To be done.

Of the thin film including the electron emitting portion, the electron emitting portion 24 is made of conductive fine particles having a particle diameter of several tens of angstroms, and the thin film other than the electron emitting portion 24 is made of fine particle film. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state where the fine particles are individually dispersed and arranged but also in a state where the fine particles are adjacent to each other or overlap each other (including an island shape). ) Also refers to the film.

Specific examples of the thin film including the electron emitting portion 24 will be given.
Pd, Ru, Ag, Au, Ti, In, C
Gold such as u, Cr, Fe, Zn, Sn, Ta, W, Pb
Genus, PdO, SnO₂ , In₂ O₃ , PbO, Sb₂ O
₃ Oxides such as HfB₂ , ZrB ₂ , LaB₆ , CeB
₆ , YB_Four , GdB_Four Boride, etc., TiC, ZrC, H
Carbides such as fC, TaC, SiC, WC, TiN, Zr
N, HfN, etc. nitrides, Si, Ge, etc. semiconductors, carbon
And AgMg, NiCu, Pb, Sn and the like. In addition,
Among them, SnO₂ By using a film, by an Au thin film
Thing [G.Dittmer: "Thin Solid Films", 9,317 (1972)],
In₂O₃/ SnO₃Thin film [M. Hartwell and
C.G.Fonstad: "IEEE Trans. ED Conf.", 519 (1975)],
Carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26,
No. 1, p. 22 (1983)] etc. have been reported in detail.
It

Next, an example of manufacturing an image display device using PdO as the electron-emitting device 4 will be described below.

First, the element electrode interval L1 (see FIG. 3) is 2 μm, the element electrode width W1 (see FIG. 3) is 400 μm, and the thickness is 1000 on the back plate 1 by the lift-off method.
The device electrodes 3 and 3a of Au of Angstrom are formed. Next, an organic Pd solution (CCP4230, manufactured by Okuno Chemical Industries Co., Ltd.) is applied on top of this, and heat-baked at about 300 ° C. for about 15 minutes. Then, as shown in FIG. 3, a pair of element electrodes 3 spaced apart by an element electrode interval L1
Using a mask 20 having an opening 20a extending over 3a, a resist pattern is applied and etching is performed to form a thin film for forming an electron emitting portion having a length of 280 μm and a width of 30 μm. By these steps, 600 × 400 surface conduction electron-emitting devices are manufactured on the same glass substrate. In addition, the electron emitting portion forming thin film can be formed by any of a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method and the like.

Next, after the surface conduction electron-emitting device 4 is manufactured, a 1 μm thick Au wiring is formed by a photolithography process for electrical connection with the outside.

Then, for example, a SiO ₂ film is formed as an insulating material by sputtering or the like to a thickness of about 10 μm, and a metal such as Au, Al or Cu is vapor-deposited on the insulating material, and etching is performed to obtain electron passing holes 5 and grids. 6 is produced.

The face plate 7 of the image display device
The phosphor 8 is applied to the inner surface of the above in advance, and a metal back 9 having conductivity is further formed on the surface of the phosphor 8.

Then, the low melting point glass 15 is attached to the portion where the face plate 7, the outer frame 11 having the slit 16, the back plate 1 and the getter 12 are to be attached.
(LS-3081 manufactured by Nippon Electric Glass Co., Ltd.) is applied, and the getter 12 is placed in the getter storage portion 13 in the outer frame 11.

Next, the back plate 1 and the face plate 7 are laminated so as to face each other with the outer frame 11 sandwiched therebetween, and the back plate 1 and the face plate 7 are placed in an electric furnace (not shown) equipped with a container capable of heating the entire device while fixing them with a jig or the like. , 300-650, for example
Heat in the range of ° C. After that, it is slowly cooled to room temperature and the image display device is taken out of the electric furnace.

As described above, the face plate 7, the back plate 1, and the outer frame 11 are fixed and sealed by the low-melting glass 15, so that a strong joint without vacuum leakage can be obtained. it can.

By the way, what kind of sealing material is used to seal the back plate and the outer frame and the face plate and the outer frame as long as the back plate 1 and the face plate 7 can be hermetically sealed via the outer frame? It may be composed of any material. Particularly, specific examples thereof include amorphous low melting point glass, crystalline low melting point glass, and the like.
They may be mixed with an organic solvent, or a binder such as nitrocellulose may be mixed with an organic solvent that dissolves the binder to prepare a paste. It is desirable to use a material that is sticky at least at the coating operation temperature of the sealing material.

The sealing material may be applied by any method such as a spray method or an injection method using a dispenser method, as long as a desired sealing material can be applied and formed in the sealing material storage portion.

Next, the inside of the airtight container is closed by a vacuum pump from an exhaust pipe (not shown) attached to the image display device.
-Evacuate below ⁶ Torr. After that, several V to several tens of V are applied between the device electrodes through the wiring, and the energization process called forming described above is performed to form the electron emitting portion.

Subsequently, the image display device is heated at about 130 ° C. by a hot plate or the like to degas.

Then, while the getter 12 is diffused at appropriate times, an exhaust pipe (not shown) of the image display device is heated by a gas burner and welded to seal the airtight container.

A slit-shaped gap is formed in the outer frame 11 from the getter accommodating portion 13 toward the inside of the airtight container, and a vapor deposition film made of a getter substance is formed at a predetermined portion inside the airtight container due to the diffusion of the getter. Is formed. The vapor deposition film adsorbs the released gas inside the airtight container to maintain the degree of vacuum inside the airtight container.

As described above, the getter accommodating portion 13 is formed in the outer frame 11, the getter 12 is accommodated in the getter accommodating portion 13, and the slit 16 which connects the getter accommodating portion 13 and the inside of the airtight container. By forming the getter substance, the getter substance can be diffused to a predetermined portion in the airtight container without using a getter diffusion preventing plate that regulates a place where the getter substance diffuses. As a result, the number of parts was reduced and the manufacturing process was shortened by not using the getter diffusion prevention plate. In addition, since the getter diffusion prevention plate is not used, problems due to the getter diffusion prevention plate, for example, displacement of the getter diffusion prevention plate is eliminated, and the yield is improved.

Furthermore, since the getter 12 is housed in the getter housing portion 13 of the outer frame 11, the space inside the apparatus can be effectively utilized and the image area for the entire apparatus can be increased.

Further, by providing the getter accommodating portion 13 in the outer frame 11, the getter positioning can be easily performed without strictly controlling the getter position, so that the productivity is improved.

(Second Embodiment) FIG. 5 is a perspective view of a second embodiment of the image display device of the present invention.

In this embodiment, as shown in FIG. 5, the outer frame 3
The first embodiment differs from the first embodiment in that a notch 37 is provided on the face plate side as a means for communicating the getter housing portion 33 in 1 with the inside of the airtight container. The rest of the configuration and manufacturing method are the same as in the first embodiment, so description thereof will be omitted.

In such a structure, since the outer frame 31 is partially removed, when the getter 32 is diffused, the getter substance may adhere to the electron-emitting device 34 which is an electron source. Will be even lower. Also, the strength of the outer frame is increased.

(Third Embodiment) FIGS. 6A and 6B are views showing a third embodiment of the image display device of the present invention. FIG. 6A is a perspective view thereof, and FIG. It is a figure.

In this embodiment, as shown in FIG. 6, the outer frame 4
The first embodiment is different from the first embodiment in that a hollow hole 48 is provided as a means for communicating the getter storage portion 43 in the inside 1 with the inside of the airtight container. The rest of the configuration and manufacturing method are the same as in the first embodiment, so description thereof will be omitted.

In such a structure, the hollow hole 4
8 is not limited to a cylinder as shown in FIG. 6, but the shape, orientation, size, etc. can be freely set according to the characteristics of the getter 42 and the size and shape of the airtight container, and the getter substance is attached to the electron-emitting device or the like. Since the getter substance can have the best shape and size, the getter substance is less likely to adhere to the electron-emitting device which is the electron source. In addition, hollow hole 48
Since the shape is a shape excluding a part of the outer frame, the strength of the outer frame is also increased.

In this embodiment, the getter accommodating section 43 is used.
Although one hollow hole 48 is arranged for each one, the number of hollow holes 48 is not limited to one and may be any number.

By the way, in each of the above-mentioned embodiments, the high-frequency heating ring getter is assumed as the getter, but the getter is not limited to the high-frequency heating getter, and the getter is diffused by passing an electric current with a linear getter. Any getter may be used.

Although the electric furnace is used as the method for heating the image display device, the present invention is not limited to this. In short, it is possible to heat the image display device at a desired temperature for a predetermined time. It may be something like this.

As the electron source, in addition to the surface conduction electron-emitting device, a thermoelectron source using a hot cathode and a field emission electron-emitting device (WP Dyke & WWDolan, "Field emissi") are used.
on ", Advance in Electoron Physics, 8,89 (1956) and CAS
pindt, "Physical propertiesof thin-film field emiss
ion cathodes with molybdenum cones ", J.Appl.Phys., 4
7,5248 (1976)), or metal / insulating layer / metal type electron-emitting device (CAMead, "The tunnel-emission amplifie
r, J.Appl.Phys., 32,648 (1961), etc.) are known.

The present invention is not limited to the image display device using the above-mentioned surface conduction electron-emitting device as an electron source, and the thermionic source, field emission electron-emitting device, metal / insulating layer / metal type The present invention is also effective in other display devices and recording devices in which the display unit is composed of an airtight container and whose inside is kept in a vacuum, such as an image display device using an electron-emitting device as an electron source, such as a plasma display or a fluorescent display device. .

[0068]

Since the present invention is constructed as described above, it has the following effects.

According to the present invention, the getter is stored in the getter storage part of the outer frame, and the getter storage part is provided with a communication means for connecting the getter storage part with the getter storage part. Therefore, the number of parts is reduced and the manufacturing process is shortened.

Further, since the problem caused by the getter diffusion prevention plate, for example, the position shift of the getter diffusion prevention plate is eliminated, the yield is improved.

Further, by storing the getter in the getter storage portion of the outer frame, the image area of the entire device can be increased. Also, by providing a getter storage part in the outer frame, it is not necessary to strictly control the getter position, and productivity is improved.

According to the second aspect, the getter can sufficiently fill the volume necessary for adsorbing the released gas in the airtight container and performing degassing.

According to the third aspect of the present invention, since the outer frame is formed by removing only a part thereof, when the getter is diffused, the possibility that the getter substance adheres to the electron source is further reduced. Also, the strength of the outer frame is increased.

According to the fourth aspect of the present invention, the hollow hole is not limited to a cylinder, but the shape, orientation, size, etc. can be freely set according to the characteristics of the getter and the size and shape of the airtight container, and the getter material Can have the best shape and size that does not adhere to the electron source, so that the getter substance is less likely to adhere to the electron source. Further, since the hollowed hole has a shape obtained by removing a part of the outer frame, the strength of the outer frame is also increased.

In the method according to the fifth aspect, since the step of attaching the getter diffusion prevention plate is eliminated, the manufacturing process is shortened. Further, since the getter is stored in the getter storage portion, the getter can be easily positioned and the getter diffusion preventing plate is not displaced, so that the productivity and the yield are improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a first embodiment of an image display device of the present invention.

FIG. 2 is an enlarged view of a main part of the image display device shown in FIG.

FIG. 3 is a plan view showing an example of a mask used when forming a thin film for forming an electron emitting portion.

4A and 4B are diagrams showing a typical device configuration of a surface conduction electron-emitting device, FIG. 4A being a plan view thereof and FIG. 4B being a sectional view taken along the line AA ′.

FIG. 5 is a perspective view of a second embodiment of the image display device of the present invention.

6A and 6B are views showing a third embodiment of the image display device of the invention, in which FIG. 6A is a perspective view thereof and FIG.
It is an A'line sectional view.

7A and 7B are views showing an example of a conventional image display device, FIG. 7A is a top view thereof, and FIG. 7B is a sectional view thereof.

[Explanation of symbols]

 1 Back Plate 3, 3a, 23, 23a Element Electrode 4, 34 Electron Emitting Element 5 Electron Passage Hole 6 Grid 7 Face Plate 8 Phosphor 9 Metal Back 11, 31, 41 Outer Frame 12, 32, 42 Getter 13, 33, 43 getter storage part 15 low melting point glass 16 slit 20 mask 20a opening 21 insulating substrate 22 thin film (electron emission part forming thin film) 24 electron emission part 37 notch 48 hollow hole

Claims (4)

[Claims] 1. A back plate provided with an electron source that generates an electron beam, and a phosphor that emits light when the electron beam generated by the electron source collides with the back plate. By facing each other,
An image display device having a face plate that constitutes an airtight container whose inside is kept vacuum together with the back put and the outer frame, and a getter diffused in the airtight container to maintain the degree of vacuum in the airtight container. In the above, the getter is accommodated in a getter accommodating portion formed inside the outer frame, and the outer frame is provided with a communication means for communicating the getter accommodating portion and the airtight container. Image display device. 2. The image display device according to claim 1, wherein the communication means is a slit. 3. The image display device according to claim 1, wherein the communication means is a cutout. 4. The image display device according to claim 1, wherein the communication means is a hollow hole.