JP3198210B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using an electron source, and more particularly to a large and thin image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus that excites a phosphor and emits light, such as a fluorescent display tube for performing image formation, a plasma display panel, and a display device using a field emission type and a surface conduction type electron emission element, has been known. It has the advantages of being a flat type with a short depth dimension, being bright and easy to see, and has been actively applied or expected to be applied industrially.

[0003] Two types of electron-emitting devices, a thermionic electron source and a cold cathode electron source, are known. Field emission type (hereinafter abbreviated as FE), metal / insulating layer / metal type (hereinafter abbreviated as MIM) or surface conduction electron-emitting devices (hereinafter abbreviated as SC)
E).

[0004] Examples of the FE type include WPDyke & WWDol.
an. “Field emission”, Advancein Electron Physic
s, 8,89 (1956) and CASpindt. “Physical properties
of thin-film field emission cathodes withmolyb den
um cones ". J. Appl. Phys., 47, 5248 (1976).

[0005] An example of the MIM type is CAMead.
tunnel-emission amplifier ”, J.Appl.Phys., 32,646 (1
961) is known.

An example of an SCE is EIElinson.Radio
Eng. Electron Phys, 10.1 (1965).

[0007] The SCE utilizes a phenomenon in which electrons are emitted by flowing a current in a thin film having a small area formed in a substrate shape in an equilibrium manner on the film surface.

As the SCE, those using a SnO ₂ thin film by Elinson et al. And those using an Au thin film [G. Dittmer “Thin Solid Films”, 9, 317 (1972)] In
₂ 0 ₃ / SnO ₂ by thin film [M.Hartwell and CGF
onstad: "IEEE Trans. ED conf.", 519. (1975)], and a method using a carbon thin film [Hisashi Araki: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported.

When these electron-emitting devices are used in a large-sized image forming apparatus, a large-scale manufacturing facility is required, and it is not easy to manufacture the element as a completely uniform body. There is a disadvantage that the yield is remarkably reduced as compared with the case of manufacturing, and the cost is high. In order to solve the above-mentioned drawbacks, it has been proposed to manufacture a large-sized image forming apparatus capable of displaying a large-area image by combining small-sized units that are easily manufactured (Japanese Patent Publication No. 60-1273).
4). According to the above proposal, a large-sized image forming apparatus can be manufactured without requiring large-scale manufacturing equipment, and a reduction in manufacturing yield can be improved. However, in the case of using this method, the positions of the units fixed by the adhesive during the assembling process are shifted, and as a result, the quality of the image forming apparatus may be deteriorated.

When the above-mentioned electron-emitting device is used in an image forming apparatus, the distance between the electron-emitting device and the image forming member at the opposite position must be accurately maintained, and as shown in FIG. A spacer 1 for maintaining an interval is inserted into a confidential container constituted by a face plate 2, a back plate 3, and a support frame 4 surrounding the outer periphery thereof. Conventionally, assembling and bonding of this space is performed with an adhesive in the same way as the assembling and bonding of other members. There has been a case where the quality of the device has been reduced.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in manufacturing a large-sized image forming apparatus. That is, an object of the present invention is to produce a large-sized image forming apparatus having a good yield without requiring a large-scale manufacturing facility, and to displace a device or a panel during assembly of each member. It is an object of the present invention to provide a large-sized image forming apparatus with good image quality by preventing the displacement of the spacer.

[0012]

In order to achieve the above object, the present invention provides a back plate on which an electron-emitting device is mounted, and an electron beam provided opposite to the back plate and emitted from the electron-emitting device. A front plate having an image forming member that forms an image by irradiating, and a support frame disposed between the back plate and the front plate and surrounding a periphery of the back plate and the front plate, In an image forming apparatus in which one or both of the back plate and the front plate are formed by bonding a plurality of unit plates with an adhesive, a softening temperature of an adhesive bonding the plurality of unit plates of the back plate or the front plate. the T ₁ (℃), the softening temperature of the adhesive for bonding the support frame and the rear plate or front plate when the T ₂ (℃), wherein the adhesive satisfies the following equation T _1> T ₂ Image forming characterized by the following: Intended to provide a location, that the adhesive is one that satisfies the following equation _{T 1> T 2 +10 (℃} ), said adhesive satisfies the following equation _{T 1> T 2 +20 (℃} ) The adhesive is a low-melting glass, the adhesive bonding the plurality of unit plates of the back plate or the front plate is a crystalline low-melting glass, and the back is formed by bonding a plurality of unit plates. This includes that the face plate or the front plate is formed using a large supporting substrate.

Further, the present invention has a back plate on which an electron-emitting device is mounted, and an image forming member provided opposite to the back plate and forming an image by irradiation of an electron beam emitted from the electron-emitting device. A front plate, a support frame disposed between the back plate and the front plate and surrounding the periphery of the back plate and the front plate, and a spacer disposed between the back plate and the front plate. In an image forming apparatus having one or both of the rear plate and the front plate bonded with a plurality of unit plates with an adhesive, the plurality of unit plates of the rear plate or the front plate are joined. The softening temperature of the adhesive is T ₁ (° C.), and the softening temperature of the adhesive bonding the back plate or the front plate and the support frame is T _2.
(° C.), and the adhesive satisfies the following formula T ₁ > T ₃ > T ₂ when the softening temperature of the adhesive for joining the spacer and the back plate or the front plate is T ₃ (° C.). An image forming apparatus characterized in that
The adhesive satisfies the following formula: T ₁ > T ₃ +10> T ₂ +10 (° C.), and the adhesive satisfies the following formula: T ₁ > T ₃ +20> T ₂ +20 (° C.) That the adhesive is a low-melting glass, the adhesive that bonds the plurality of unit plates of the back plate or the front plate is a crystalline low-melting glass, and that the plurality of unit plates are joined. This includes that the back plate or the front plate is formed using a large supporting substrate.

Hereinafter, the present invention will be described in detail.

According to the present invention, since one or both of the back plate and the front plate are combined as a small unit plate to increase the size, the yield can be improved without requiring large-scale manufacturing equipment. A large-sized image forming apparatus can be manufactured. Further, by changing the adhesive at the time of assembling each member, for example, the softening temperature of the low-melting glass by the member to be bonded, displacement of the member in the image forming unit is eliminated, and a large-sized image forming apparatus with good image quality is manufactured. It is possible to do. Specifically, the softening temperature of the adhesive a for joining a plurality of unit plates of the back plate or the front plate involved in image formation, and the adhesive for joining the support frame with the back plate or the front plate are set. By making the temperature higher than the softening temperature of c, the adhesive c becomes more fluid at the time of heating and joining the back plate or the front plate and the support frame, and flows between the back plate or the front plate and the support frame to adhere. . At this time, since the adhesive a joining the plurality of unit plates has a lower fluidity than the adhesive c, the adhesive is hardly displaced, and therefore, the image quality is hardly deteriorated. In order to make the displacement less likely to occur, the difference between the softening temperatures of the adhesives a and c is preferably greater than 10 ° C., and more preferably the difference between the softening temperatures is 20 ° C.
Greater, and more preferably the difference in softening temperature is 5
Greater than 0 ° C.

In the case of an image forming apparatus having a spacer between the back plate and the front plate, the softening temperature of the adhesive b for joining the spacer to the back plate or the front plate is determined by adjusting the softening temperature of the back plate or the front plate. By lowering the softening temperature of the adhesive a for bonding a plurality of unit plates and higher than the softening temperature of the adhesive c for bonding the back plate or the front plate to the support frame, image quality is improved. A plurality of unit plates of the back plate or the front plate, which exert an influence, can be joined, and furthermore, a positional shift at a joint between the spacer and the back plate or the front plate can be reduced. Also in this case, in order to prevent the occurrence of displacement and obtain good image quality, the difference between the softening temperatures of the adhesives a, b, and c is preferably greater than 10 ° C., and more preferably the difference is 20. C., and more preferably the difference is greater than 50.degree.

The adhesive used in the present invention includes:
A low-melting glass containing lead oxide, titanium oxide, boron oxide or the like is preferable in order to maintain airtightness in the image forming portion, but is not limited thereto.

In the present invention, among the low-melting glass, a crystalline low-melting glass capable of increasing the adhesive strength is used as an adhesive for bonding the plurality of unit plates of the back plate or the front plate. Is preferred.

Further, in the present invention, the joining of the plurality of unit plates of the back plate or the front plate may be reinforced by using a large supporting substrate.

[Embodiments] Embodiments of the image forming apparatus of the present invention will be described below with reference to the drawings.

The specific bonding of the components described above is as follows.
For example, as shown in FIG. 1, a back plate 3 composed of a plurality of unit plates on which electron emission portions 6 are formed is bonded onto a large-sized support substrate 7, and then the distance between the back plate 3 and the front plate 2 is reduced. The spacer 1 to be kept and the support frame 4 are bonded, and then the front plate 2
Glue. The above-mentioned bonding is performed by heating at a temperature higher than the softening temperature of the adhesive, preferably low-melting glass.

After the completion of the calcination, when the cooling is performed, the adhesive a having a high softening temperature is first fixed. Next, the adhesive b is fixed, and finally, the adhesive c is fixed. As described above, by changing the softening temperature of the adhesive, the flowability of the adhesive having a high softening temperature is controlled to prevent the members from being displaced.

It is more effective to fix the adhesive member with a fixing jig during heating and firing of the adhesive.

In the present invention, the cold cathode electron source described above can be used as the electron-emitting device.

As an example of a cold cathode electron source, a surface conduction electron-emitting device shown in FIG. FIG. 3A is a plan view, and FIG. 3B is a longitudinal sectional view. In the figure, 11 is an insulating substrate, 15 and 16 are device electrodes, 14 is a thin film including an electron emitting portion, and 13 is an electron emitting portion (see Japanese Patent Application Laid-Open No. 2-56822).

The electron emitting portion 13 of the thin film 14 including the electron emitting portion is made of conductive fine particles having a particle size of several tens of angstroms, and the thin film 14 including the electron emitting portions other than 13 is formed of a fine particle film.

The fine particle film described here is a film in which a plurality of fine particles are aggregated. The fine structure thereof is not only a state in which the fine particles are individually dispersed and arranged, but also a state in which the fine particles are adjacent to each other or overlap each other (an island). (Including the shape).

Separately, the thin film 1 including an electron emitting portion is provided.
4 may be a carbon thin film or the like in which conductive fine particles are dispersed.

Specific examples of the thin film 14 including the electron emitting portion include Pd, Ru, Ag, Au, Ti, In, Cu,
Metals such as Cr, Fe, Zn, Sn, Ta, W, and Pb;
oxides such as dO, SnO ₂ , In ₂ O, PbO, and Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , and YB
_4, GdB boride such as _{4, TiC, ZrC, HfC,} T
carbides such as aC, SiC, WC, TiN, ZrN, Hf
Nitride such as N, semiconductor such as Si and Ge, carbon, Ag
Mg, NiCu, Pb, Sn and the like.

The thin film 14 including the electron-emitting portion is formed by a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like.

As described above, as an example of the electron-emitting device used in the present invention, an image forming apparatus in which a phosphor is emitted by an electron beam emitted from a surface conduction electron-emitting device has been described. The image forming apparatus is not limited to this, and can be applied to a gas discharge display apparatus, a fluorescent display apparatus, and the like.

[0032]

Next, the present invention will be described in more detail with reference to examples.

(Embodiment 1) In Embodiment 1, the back plate is composed of four unit plates.

FIG. 2 is a cross-sectional view of an image display device according to an embodiment of the present invention. In FIG.
Is a support frame, and 7 is a support substrate for holding the back plate 3 composed of a plurality of unit plates. On the inner surface of the front plate 2 made of blue plate glass, a phosphor is formed in a layer shape as an image forming member 5 on which an image is formed by irradiation with an electron beam. Further, an inner surface of a back plate 3 made of blue sheet glass has opposed positive and negative electrodes (not shown), and a large number of electron emitting portions 6 which emit electrons when a voltage is applied between the electrodes. Is formed. The support frame 4 surrounds the outer peripheries of the front plate 2 and the back plate 3 and is made by cutting blue plate glass.

The electron-emitting device was of the type shown in FIGS. 3 (a) and 3 (b). FIG. 3A is a plan view of the present element, and FIG. 3B is a cross-sectional view.

In FIGS. 3A and 3B, reference numeral 11 denotes an insulating substrate made of soda lime glass. Reference numerals 15 and 16 denote device electrodes (Ni) for applying a voltage of the device, and 14 denotes a thin film including an electron-emitting portion, which is an organic palladium (Okuno Pharmaceutical Co., Ltd.)
After applying a solution containing ccp-4230), 300
Heat treatment at ℃ for 10 minutes, palladium oxide (PbO)
A fine particle film composed of fine particles (average particle size: 70 Å) was formed. Reference numeral 13 denotes an electron emitting portion, and the width W2 is 300 microns. L1 in the figure is the element electrode 1
5 and the device electrode 16 are 3 μm, W
1 is 500 μm in width of the device electrode, and d is 1000 Å in thickness of the device electrode.

For bonding the four unit plates of the back plate 3, a low-melting glass a having a softening point of 400.degree. C. (sealing operation temperature: 440.degree. C.) was used as an adhesive. The back plate 3 and the front plate 2 were joined to the support frame 4 using low-melting glass b having a softening point of 390 ° C. (sealing temperature: 430 ° C.) as an adhesive.

As a specific method of manufacturing the image forming apparatus,
Four back plates on which the electron emission portions are formed as described above,
It is placed on a support substrate to which low melting glass a has been previously applied, fixed using a jig, and baked at 440 ° C. for 10 minutes in a heating furnace. Next, a low-melting glass b is applied between the support frame and the back and front plates, and each member is fixed using a jig and baked at 430 ° C. for 10 minutes in a heating furnace. After the completion of the firing, when the cooling is performed, first, a low melting point glass a having a high softening temperature
Was lowered and adhered, and subsequently the low-melting glass b was adhered.

By changing the softening temperature of the low-melting glass of the adhesive used as described above, the position of the back plate having the electron-emitting portion involved in image formation during the heating of the bonding between the support frame and the back plate and the front plate. A large-sized image forming apparatus with good image quality can be manufactured by preventing the displacement.

In order to evacuate the inside of the image forming apparatus manufactured in the above process, the inside is evacuated via an exhaust pipe (not shown) provided on the support frame 4 after the bonding process. This was done by evacuating and then sealing the exhaust pipe.

(Embodiment 2) FIG. 1 is a sectional view of an image display apparatus according to a second embodiment of the present invention, wherein 2 is a front plate, 3 is a back plate, 4 is a support frame, and 7 is a unit of six units. It is a supporting substrate that holds the back plate 3 made of a plate. 1 is a front plate 2 and a back plate 3
Spacers, which are manufactured by etching photosensitive glass. A phosphor layer is formed as an image forming member 5 on which an image is formed by irradiating an electron beam on the inner surface of the front plate 2 made of blue plate glass. Further, an inner surface of a back plate 3 made of blue sheet glass has opposed positive and negative electrodes (not shown), and a large number of electron emitting portions 6 which emit electrons when a voltage is applied between the electrodes. Is formed. The support frame 4 was used to surround the outer peripheries of the front plate 2 and the rear plate 3 and to cut blue plate glass.

The number of spacers is the front plate 2, the rear plate 3
The number, interval, etc. may be changed in accordance with the size of.

The back plate 3 is composed of six unit plates and is reinforced by the support substrate 7.

As the electron-emitting device of this embodiment, the same one as in the first embodiment was used.

For bonding the plurality of unit plates of the back plate 3, a low-melting glass a having a softening point of 410 ° C. (sealing operation temperature: 450 ° C.) was used as an adhesive. The bonding of the spacer 1 was performed using a low-melting glass b having a softening point of 390 ° C. (sealing operation temperature of 430 ° C.) as an adhesive. The back plate 3 and the front plate 2 were joined to the support frame 4 using a low-melting glass b having a softening point of 369 ° C. (sealing temperature 410 ° C.) as an adhesive.

As a specific method of manufacturing an image forming apparatus,
Six back plates on which electron emission portions are formed as described above,
It was placed on a support substrate to which low-melting glass a was previously applied, fixed using a jig, and baked at 450 ° C. for 10 minutes in a heating furnace. Next, low-melting glass b is applied to a portion other than the electron-emitting portion of the back plate, and the spacer is fixed using a jig and baked at 430 ° C. for 10 minutes in a heating furnace. continue,
Low-melting glass c was applied between the support frame and the back and front plates, and between the spacer and the front plate, and each member was fixed using a jig and fired at 430 ° C. for 10 minutes in a heating furnace. After the completion of the calcination, when cooling was performed, the low-melting glass a having a high softening temperature was reduced in fluidity and fixed, the low-melting glass b was fixed, and finally the low-melting glass c was fixed.

As described above, by changing the softening temperature of the low-melting glass for bonding, displacement of members located near the image forming portion was eliminated, and a large-sized image forming apparatus having good image quality was obtained.

When the image forming apparatus manufactured in the above process was compared with the image forming apparatus manufactured in Example 1, the displacement of the bonded members was small and the image quality was excellent.

(Embodiment 3) In Embodiment 1, the back plate 3
A low-melting glass a having a softening point of 430 ° C. (sealing work temperature: 480 ° C.) is used as an adhesive for joining the plurality of unit plates, and the back plate 3 and the front plate 2 are joined to the support frame 4 by an adhesive. An image forming apparatus was manufactured in the same manner as in Example 1, except that a low-melting glass b having a softening point of 415 ° C. (sealing operation temperature: 450 ° C.) was used.

In this case, in addition to preventing displacement due to changing the softening temperature of the low-melting glass for bonding, the bonding strength of the back plate having the electron-emitting portion involved in image formation is increased, so that image quality is improved. And a large-sized image forming apparatus having excellent strength can be manufactured.

(Embodiment 4) FIG. 4 is a sectional view of a fluorescent display device according to a fourth embodiment of the present invention, wherein 2 is a front plate, 3 is a back plate, 4 is a support frame, and 7 is four units. A supporting substrate for holding a back plate 3 made of a plate; 101, a filament;
Denotes a control grid, and 103 denotes an anode pattern.

After forming a plurality of display portions on the back plate 3,
A plurality of unit plates of the back plate 3 are joined by using a low-melting glass a having a softening point of 400 ° C. (sealing operation temperature: 440 ° C.) as an adhesive. Subsequently, a low-melting glass b having a softening point of 390 ° C. (sealing work temperature: 430 ° C.) is used as an adhesive to form the back plate 3.
Then, the front plate 2 and the support frame 4 are joined.

The concrete joining of the image forming apparatus is described in Embodiment 1.
In the same manner as in the above, the bonded portion to which the low melting point glass has been applied in advance is fixed using a jig, heated to a sealing operation temperature in a heating furnace, and fired. When cooling is performed after the completion of the firing, the low-melting glass a having a high softening temperature has a low fluidity and is fixed, and then the low-melting glass b is fixed.

By changing the softening temperature of the low-melting glass for bonding as described above, displacement of the back plate having a display portion involved in image formation can be prevented when the support frame and the back plate and the front plate are heated by bonding. And a large-sized image forming apparatus having good image quality can be manufactured.

[0055]

As described above in detail, according to the present invention, a large-sized image forming apparatus having a good yield can be manufactured without requiring large-scale manufacturing equipment, and assembling of each member. It is possible to provide a large-sized image forming apparatus with good image quality by preventing the displacement of the element or the panel inside and the displacement of the spacer.

Further, a large-sized image forming apparatus having excellent strength can be manufactured without requiring a large-scale manufacturing facility.

In the embodiment, the examples of the four divisions and the six divisions have been described, but the number of divisions is not limited to these and can be arbitrarily selected.
Also, needless to say, the present invention has the same effect when the support frame is integrated with either the back plate or the front plate.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image display device showing a second embodiment of the present invention.

FIG. 2 is a cross-sectional view of the image display device according to the first embodiment of the present invention.

FIG. 3 shows an electron-emitting device used in the embodiment.
(A) is a plan view and (b) is a cross-sectional view.

FIG. 4 is a sectional view of a fluorescent display device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spacer 2 Front plate 3 Back plate 4 Support frame 5 Image forming member 6 Electron emission part 7 Support substrate 8 Low melting glass a 9 Low melting glass b 10 Low melting glass c 11 Insulating substrate 13 Electron emission part 14 Electron emission part Including thin film 15,16 device electrode

Continuation of the front page (56) References JP-A-56-167183 (JP, A) JP-A-58-71533 (JP, A) JP-A-59-178476 (JP, A) JP-A-62-40489 (JP) JP-A-2-56822 (JP, A) JP-A-2-123635 (JP, A) JP-A-3-254041 (JP, A) JP-A-4-58436 (JP, A) 4-65388 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09F 9/00-9/46 H01J 29/86 H01J 31/12

Claims (12)

(57) [Claims] A back plate on which an electron-emitting device is mounted; and a front plate provided opposite to the back plate and having an image forming member for forming an image by irradiation of an electron beam emitted from the electron-emitting device. A supporting frame disposed between the back plate and the front plate and surrounding a periphery of the back plate and the front plate, and either or both of the back plate and the front plate have a plurality of units. In an image forming apparatus configured by bonding plates with an adhesive, a softening temperature of an adhesive for joining a plurality of unit plates of the back plate or the front plate is set to T ₁ (° C.), and the softening temperature of the back plate or the front plate is supported. An image forming apparatus wherein the adhesive satisfies the following formula: T ₁ > T ₂ when the softening temperature of the adhesive for joining the frames is T ₂ (° C.). 2. The image forming apparatus according to claim 1, wherein the adhesive satisfies the following expression: T ₁ > T ₂ +10 (° C.). 3. The image forming apparatus according to claim 1, wherein the adhesive satisfies the following expression: T ₁ > T ₂ +20 (° C.). 4. The image forming apparatus according to claim 1, wherein the adhesive is a low melting point glass. 5. The image forming apparatus according to claim 1, wherein the adhesive bonding the plurality of unit plates of the back plate or the front plate is a crystalline low-melting glass. 6. The image forming apparatus according to claim 1, wherein the back plate or the front plate formed by joining a plurality of unit plates is formed using a large-sized support substrate. 7. A back plate on which an electron-emitting device is mounted, and a front plate provided opposite to the back plate and having an image forming member for forming an image by irradiating an electron beam emitted from the electron-emitting device. A support frame disposed between the back plate and the front plate, surrounding the periphery of the back plate and the front plate, and a spacer disposed between the back plate and the front plate. In an image forming apparatus in which one or both of the back plate and the front plate are formed by bonding a plurality of unit plates with an adhesive, an adhesive for bonding the plurality of unit plates of the back plate or the front plate is used. The softening temperature is T ₁ (° C.), the softening temperature of the adhesive for bonding the back plate or the front plate to the support frame is T ₂ (° C.), and the adhesive for bonding the spacer to the back plate or the front plate. The softening temperature is T ₃ ( C.), the adhesive satisfies the following formula: T ₁ > T ₃ > T ₂ . 8. The image forming apparatus according to claim 7, wherein the adhesive satisfies the following formula: T ₁ > T ₃ +10> T ₂ +10 (° C.) 9. The image forming apparatus according to claim 7, wherein the adhesive satisfies the following formula: T ₁ > T ₃ +20> T ₂ +20 (° C.). 10. The image forming apparatus according to claim 7, wherein the adhesive is a low melting point glass. 11. The image forming apparatus according to claim 7, wherein the adhesive bonding the plurality of unit plates of the back plate or the front plate is a crystalline low-melting glass. 12. The image forming apparatus according to claim 7, wherein the back plate or the front plate formed by joining a plurality of unit plates is formed using a large-sized support substrate.