JP2000208074A - Image display device and cathode tube - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When bonding a glass face plate and a transparent front plate having mutually different coefficients of thermal expansion to each other, the glass face plate and the transparent front plate can be specified to prevent deformation and destruction of an image display panel and destruction of an adhesive layer due to temperature change. An image display device in which a front plate is adhered using the adhesive layer provided. SOLUTION: In an image display device having a structure in which a transparent front plate is bonded to a glass face plate, the thermal expansion coefficient β _a [K ⁻¹ ] of the adhesive layer is determined by the thermal expansion coefficient β _g [K ^{− 1} ] and the thermal expansion coefficient β _{p of the} front plate
[K ^-1 ].

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 such as a plasma display panel (PDP), a field emission display (FEP), a cathode ray tube (CRT), a liquid crystal display (LCD), and a cathode tube.

[0002]

2. Description of the Related Art Image display devices having various image display face plates, such as CRTs, are required to be further enlarged and research is being actively conducted. Also,
With the increase in size, reduction in thickness, weight, and cost of the device have become important issues. Then, the inventors have studied a surface conduction electron-emitting device and an image display device using the surface conduction electron-emitting device as an image display device that can solve the above-described problem.

[0003] The inventors, for example, have shown in FIG.
The application of a multi-electron beam source by an electrical wiring method as shown in FIG. That is, it is a multi-electron beam source in which a large number of surface conduction emission devices are two-dimensionally arranged and these devices are wired in a simple matrix as shown in the figure.

[0004] In the figure, reference numeral 4001 schematically shows a surface conduction electron-emitting device, 4002 is a wiring in a row direction, and 4003 is a wiring in a column direction. For convenience of illustration, the matrix is shown as a 6 × 6 matrix, but the size of the matrix is, of course, not limited to this, and the elements are arranged and wired enough to display a desired image. It is.

FIG. 7 shows the structure of a cathode ray tube using this multi-electron beam source. Here, an outer container bottom 4005 having a multi-electron beam source 4004, an outer container frame 4007, and a phosphor Layer 4008 and metal back 4
And a face plate 4006 provided with 009. A high voltage is applied to the metal back 4009 of the face plate 4006 by a high voltage power supply 4010 through a high voltage introduction terminal 4011.

[0006] In a multi-electron beam source in which surface conduction electron-emitting devices are arranged in a simple matrix, an appropriate electric signal is applied to a row direction wiring 4002 and a column direction wiring 4003 in order to output a desired electron beam. For example, to drive the surface-conduction emission element of an arbitrary row in the matrix, the selection voltage Vs is applied to the row-directional wiring 4002 of the selected row, and at the same time, the row-directional wiring 40 of the non-selected row is applied.
02, a non-selection voltage Vns is applied. In sync with this,
A driving voltage Ve for outputting an electron beam is applied to the column direction wiring 4003.

According to this method, a voltage of Ve-Vs is applied to the surface conduction electron-emitting device of the selected row.
A voltage of Ve-Vns is applied to the surface conduction type emission elements in the non-selected rows. If Ve, Vs, and Vns are set to voltages of appropriate magnitudes, an electron beam with a desired intensity is output only from the surface conduction electron-emitting device in the selected row, and a different drive voltage Ve is applied to each of the column-directional wirings. If applied, electron beams of different intensities are output from each of the elements in the selected row. In addition, since the response speed of the surface conduction electron-emitting device is high, if the length of time during which the drive voltage Ve is applied is changed, the length of time during which the electron beam is output can be changed.

[0008] The electron beam output from the multi-electron beam source 4004 by the voltage application as described above is applied to the metal back 4009 to which a high voltage is applied, and excites a target phosphor to emit light. Therefore, for example, if a voltage signal corresponding to image information is appropriately applied, an image display device can be obtained.

In the above image display device, a multi-electron beam source, a phosphor layer, and the like are formed in a glass vacuum vessel. In other image display devices, a glass member is used for a portion for displaying a screen. Is the majority. For this reason, the image display sections of these image display devices are damaged,
Scattering of dangerous glass shards may put the observer at serious danger, but this danger increases with the size of the device.

Therefore, in order to ensure safety in front of the face plate of the image display device, a transparent resin plate or a tempered glass front plate is provided on the observer side of the face plate with a gap from the face plate. It has been proposed.

However, if a transparent resin plate is provided as a front plate with a gap between the face plate and the face plate, the rigidity of the resin plate is insufficient when the screen is enlarged, and the resin plate is bent. It is a problem that they come into contact with each other. In addition, if the tempered glass is provided as a front plate with a gap between the face plate and the face plate, a sufficient strength is obtained and the weight becomes considerable. Moreover, when the front plate is provided with a gap, external light is reflected on both the front and rear surfaces of the front plate and the front side of the face plate. Becomes large, so that there is a problem that an image becomes extremely difficult to see. The reflection of external light can be reduced by an antireflection film, but generally, there is a problem in that the production of the antireflection film requires a large cost.

In order to solve these problems, a structure is considered in which a transparent resin plate is bonded to a face plate using a transparent adhesive. With this configuration, because the front plate is a resin plate, it is lighter than using tempered glass, and since the refractive index of the glass, the adhesive layer, and the front plate are not so different, the reflection of external light is It only occurs on the front side of the front panel.

[0013]

The following problems occur when the transparent front plate is bonded to the glass face plate. That is, when a transparent front plate such as a resin plate or a tempered glass is bonded to the glass face plate of the image display device, the glass of the face plate and the transparent front plate have different coefficients of thermal expansion. Changes in the thermal expansion. For this reason, stress is generated at the interface between the adhesive layers and there is a fear that the image display panel may be deformed or broken or the adhesive layer may be broken.

An object of the present invention has been made based on the above circumstances, and an object of the present invention is to provide a method for bonding an image by a temperature change when a glass face plate and a transparent front plate having different thermal expansion coefficients are bonded to each other. It is an object of the present invention to provide an image display device in which a front plate is adhered using a specified adhesive layer which can prevent deformation and destruction of a display panel and destruction of an adhesive layer.

[0015]

Therefore, in the present invention,
In an image display device having a structure in which a transparent front plate is bonded to a glass face plate, a thermal expansion coefficient β _a [K
^-1 ] is the thermal expansion coefficient β _g of the glass face plate
It is a value between [K ^-1 ] and the thermal expansion coefficient β _p [K ^-1 ] of the front plate.

[0016] In this case, as an embodiment of the present invention, the thermal expansion coefficient beta _a of the adhesive layer, as viewed in the thickness direction from the glass surface β _g ≦ β _a ≦ β _p or β _p ≦ β _a ≦ β _g That the adhesive layer is divided into n layers of an integer of 2 or more, and the coefficient of thermal expansion of each layer changes stepwise from β _a1 to β _an . In the adhesive layer, fine particles are preferably dispersed in order to adjust the coefficient of thermal expansion, and the fine particles are preferably SiO ₂ fine particles. Further, it is effective that the average particle diameter of the SiO ₂ fine particles dispersed in the adhesive layer is 100 nm to 1 μm, and that the front plate is a resin plate.

[0017] The volume ratio I on adhesion layer of SiO ₂ particles dispersed in the adhesive layer, the thermal expansion coefficient of the SiO ₂ particles and β _SiO2 [K ^-1], also the thermal expansion coefficient of the adhesive As β _adh [K ⁻¹ ], (β _p −β _adh ) / (β _SiO2 −β _adh ) ≦ I <0.7
(However, β _p <β _adh ) 0 ≦ I <0.7 (However, (10β _g− 7β _SiO2 ) / 3
≦ β _adh ≦ β _p ) 0 ≦ I ≦ (β _g −β _adh ) / (β _SiO2 −β _adh ) (where,
It is preferable that the present invention satisfies β _adh <(10β _g- 7β _{SiO 2} ) / 3).
In this case, the front plate preferably has a transmittance limiting function.

Further, by using the face plate provided with the front plate having the above-described structure, a preferable cathode ray tube can be formed. In this case, the cathode ray tube preferably uses a surface conduction electron-emitting device.

According to such a configuration of the present invention, the thermal expansion coefficient of the adhesive layer for bonding the face plate and the transparent front plate to each other is viewed from the thermal expansion coefficient of the face plate in the thickness direction. By changing to the coefficient of thermal expansion, the occurrence of thermal stress caused by the difference in thermal expansion between the face plate and the front plate caused by the temperature change of the image display device can be reduced by the thermal expansion of the adhesive layer, Deformation and destruction of the panel and destruction of the adhesive layer can be prevented.
Further, by dividing the thermal expansion coefficient of the adhesive layer into n layers and changing the thermal expansion coefficient in a stepwise manner, the bonding step becomes easier than in the case where the thermal expansion coefficient is continuously changed in one layer.

Further, fine particles such as SiO ₂ are used for the adhesive layer.
Preferably, by dispersing the particles having an average particle diameter of 100 nm to 1 μm, the deterioration of the image such as blurred or distorted image can be prevented and the coefficient of thermal expansion of the adhesive layer can be adjusted.

Further, the volume ratio of the SiO ₂ fine particles to the adhesive layer is expressed as (β _p −β _adh ) / (β _SiO2 −β _adh ) ≦ I <0.7
(However, β _p <β _adh ) 0 ≦ I <0.7 (However, (10β _g− 7β _SiO2 ) / 3
≦ β _adh ≦ β _p ) 0 ≦ I ≦ (β _g −β _adh ) / (β _SiO2 −β _adh ) (where,
β _adh <(10β _g− 7β _SiO2 ) / 3) An adhesive layer having a desired coefficient of thermal expansion using an adhesive having a different coefficient of thermal expansion from that of the glass face plate or front plate by dispersing under conditions that satisfy the condition. Can be created.

Further, in the image display device of the present invention, by providing the front plate with the function of limiting the transmittance, the amount of external light reflected on the phosphor surface can be reduced and the contrast can be improved.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Next, FIG.
The configuration of the face plate and the transparent front plate of the image display device which is the subject of the present invention will be described with reference to FIG. Here, a phosphor layer 1008 having a thickness of about 20 μm is formed on the inner surface of a face plate 1007 made of soda lime glass and having a thickness of 3 mm, and an aluminum metal back layer 1009 having a thickness of about 1000 Å is provided so as to cover the phosphor layer. Is formed. Also, the high voltage introduction terminal 10
Reference numeral 21 is connected to an aluminum metal back 1009 and connected to a high-voltage power supply 1020 so that a high-voltage potential, for example, 10 k
V is applied.

A front plate 1012 is adhered to the outside of the face plate 1007 using an adhesive layer 1013. In this embodiment, the face plate 10
07 is 800 × 600 mm, front plate 1012 is 700 ×
The size was 400 mm. Here, a 1 mm thick polycarbonate plate was used as the transparent front plate in consideration of insulation, flame retardancy, and light transmittance.
It is not limited to this, and is approximately 0.5m thick
The object of the present invention is achieved by a transparent resin plate of m or more, such as polycarbonate or acrylic.

As the adhesive layer 1013 for bonding the face plate and the front plate, a photocurable adhesive LCR0631 manufactured by Toagosei Chemical Co., Ltd. was used. The adhesive is colorless and transparent, and the image is not deteriorated by the adhesive layer.
Since it is photocurable, productivity is high. The adhesive layer 10
Reference numeral 13 denotes a first layer 1014 for reducing a stress generated due to a difference in thermal expansion between the face plate (thermal expansion coefficient β _g ) and the front plate (thermal expansion coefficient β _p ) when the temperature of the image display panel changes. (Coefficient of thermal expansion β _a1 ), second layer 1015 (coefficient of thermal expansion β _a2 ), and third layer 1016 (coefficient of thermal expansion β _a3 ), and the coefficients of thermal expansion are β _g <β _a1 <β _a2 <β _a3. <was created to meet the β _p.

The coefficient of thermal expansion of the glass face plate used in this embodiment is β _g = 8.5 × 10
⁻⁶ [K ⁻¹ ], and the coefficient of thermal expansion of the polycarbonate used as the front plate is β _p = 7.0 × 10 ⁻⁵ [K ⁻¹ ]. Here, the adhesive layer is divided into three layers, 1014 to 1016, and the thermal expansion coefficient is changed. However, the present invention is not limited to this, and the adhesive layer is divided into two or more layers, and the thermal expansion coefficient is inclined. If so, the object of the present invention is achieved.

The adhesive layers 1014 to 1016 have an average particle size of 100 to 200 n in order to adjust the coefficient of thermal expansion.
m of SiO ₂ fine particles are dispersed. Here, in the adhesive layer, the fine particles having the above-mentioned particle size were used so that the fine particles did not adversely affect the image quality. However, the present invention is not limited to this, and the average particle size may be 100 nm.
1 μm transparent fine particles having a refractive index of 1.4 to 1.6 and having a value close to that of a face plate, a front plate, or an adhesive, and mixing the fine particles to form an adhesive layer. Any material can be used as long as it has a desired coefficient of thermal expansion.

The thermal expansion of the adhesive used in this embodiment
The tension coefficient is 1.1 × 10^-Five[K^-1] And polycarbonate
Larger than the thermal expansion coefficient of the heat sink. Also, do not disperse the fine particles.
If the thermal expansion coefficient of the adhesive layer is
It does not have an intermediate value of the thermal expansion coefficient of the face plate. Glue heat
Expansion coefficient β_adhIs (β_p−β_adh) / (Β_SiO2−β_adh) For adhesives satisfying ≧ 0.7, the coefficient of thermal expansion is smaller than that of the front plate.
In order to make the_Two Volume ratio of fine particles
0.7 or more, but SiO _Two Particulate
Since it is impossible to make the particle size uniform from a structural point of view,
An adhesive satisfying the above conditions cannot be used. So
When using polycarbonate for the front plate,
The thermal expansion coefficient of the agent is approximately 2.3 × 10^-Five[K^-1]
Must be below.

In this embodiment, the dispersed SiO ₂
The volume ratio of the fine particles to the adhesive layer was 0.65 for the first layer 1014, 0.6 for the second layer 1015, and 0.55 for the third layer.
And At that time, each coefficient of thermal expansion is the first layer 1
014, the thermal expansion coefficient β _a1 = 3.8 × 10 ⁻⁵ , the second layer 10
Coefficient of thermal expansion β _a2 = 4.4 × 10 ⁻⁵ , third layer 101
The thermal expansion coefficient β _a3 = 5.5 × 10 ⁻⁵ . Here, the thickness of each of the adhesive layers 1014 to 1016 is set to approximately 0.2 mm, but is not limited to this, and can be made uniform when applying the adhesive. If the thickness is appropriate, the object of the present invention is achieved.

The adhesive layer was prepared as follows.
First, SiO ₂ fine particles were respectively dispersed in the adhesive used for the adhesive layers 1014 to 1016 at the above volume ratio. Using these adhesives, the adhesive layer 1014 was applied to the glass face plate and the adhesive layer 1016 was applied to the front plate, and was cured. Next, an adhesive was applied to the face plate or the front plate to form an adhesive layer 1015, and these were adhered.

Here, the adhesive layers 1014 and 1016 are cured and formed on both the face plate and the front plate, and then they are adhered.
After the layers 14 and 1015 are sequentially formed, or after the adhesive layers 1016 and 1015 are sequentially formed on the front plate, both may be bonded.

As a result of conducting a temperature environment test at -20.degree. C. to 70.degree. C. for 100 cycles on the thus formed image display panel, peeling of the adhesive layer 1013 and deformation / destruction of the image display panel were confirmed. Did not. In addition, no image deterioration such as distortion or blurring of the image was observed.

As described above, by dispersing the fine particles in the adhesive layer, the thermal expansion coefficient of the adhesive layer can be distributed, and the stress generated due to the difference in thermal expansion can be absorbed. Peeling can be prevented.

Next, the structure and manufacturing method of the display panel of the image display device to which the present invention is applied will be described with reference to specific examples. FIG. 4 is a perspective view of the display panel used in the example, and a part of the panel is cut away to show the internal structure. In the drawing, reference numeral 1005 denotes an outer container bottom (sometimes referred to as a rear plate), 1006 denotes a side wall, and 1007 denotes a face plate. These components 1005 to 1007 maintain the inside of the display panel in a vacuum. To form an airtight container.

When assembling the airtight container, it is necessary to seal the joints of the members so as to maintain sufficient strength and airtightness. 400 degrees Celsius in nitrogen atmosphere
The sealing was achieved by baking at 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container will be described later.

The rear plate 1005 has a substrate 1001
Are fixed, but N × M surface-conduction emission devices 1002 are formed on the substrate (NM is a positive integer of 2 or more, and is appropriately set according to the target number of display pixels. Here, N = 3360 and M = 630). The N × M surface conduction electron-emitting devices are arranged in a simple matrix by M row-directional wirings 1003 and N column-directional wirings 1004. The constituent member 10
01 to 1004 are called multi-electron beam sources.

In this embodiment, the substrate 1001 of the multi-electron beam source is fixed to the rear plate 1005 of the airtight container. However, the substrate 1001 of the multi-electron beam source has a sufficient strength. In this case, the substrate 1001 of the multi-electron beam source may be used as the rear plate of the hermetic container.

On the lower surface of the face plate 1007, a fluorescent film 1008 is formed. Here, since the image display device is a color display device, the fluorescent film 100
Part 8 is red, green, blue, used in the field of CRT.
The three primary color phosphors are separately applied. The phosphor of each color is, for example, separately applied in a stripe shape as shown in FIG. 5A, and a black conductor 1010 is provided between the phosphor stripes.

The purpose of providing the black conductor 1010 is to prevent the display color from being shifted even if the electron beam irradiation position is slightly shifted, and to prevent the reflection of external light to improve the display contrast. It is necessary to prevent the phosphor film from being lowered and prevent the fluorescent film from being charged up by the electron beam. Although graphite is used as the main component for the black conductor 1010, any other material may be used as long as it is suitable for the above purpose.

The method of applying the three primary color phosphors is not limited to the stripe arrangement shown in FIG. 5A, but may be, for example, a delta arrangement as shown in FIG. 5B. It may be an array or another array. When a monochrome display panel is manufactured, a single-color phosphor material may be used for the fluorescent film 1008, and a black conductive material is not necessarily used.

A metal back 1009 known in the CRT field is provided on the surface of the fluorescent film 1008 on the rear plate side.
Is provided. The purpose of providing the metal back 1009 is
A part of the light emitted from the fluorescent film 1008 is specularly reflected to improve the light utilization rate, and the fluorescent film 1008 is protected from the collision of negative ions.
Protection of the electron beam 8, functioning as an electrode for applying an electron beam acceleration voltage, and functioning the fluorescent film 1008 as a conductive path of excited electrons. The metal back 1009 was formed by forming a fluorescent film 1008 on the face plate substrate 1007, smoothing the surface of the fluorescent film, and vacuum-depositing aluminum thereon. Note that when a fluorescent material for low voltage is used for the fluorescent film 1008, the metal back 1009 is not used.

Although not used here, a transparent electrode made of, for example, ITO is provided between the face plate substrate 1007 and the fluorescent film 1008 for the purpose of applying an acceleration voltage and improving the conductivity of the fluorescent film. May be provided. Also, Dx1 to Dxm and Dy1 to Dyn and Hv
Is a terminal for electric connection of an airtight structure provided for electrically connecting the display panel to an electric circuit (not shown). Dx1 to Dxm are electrically connected to the row wiring 1003 of the multi-electron beam source, Dy1 to Dyn are connected to the column wiring 1004 of the multi-electron beam source, and Hv is electrically connected to the metal back 1009 of the face plate.

In order to evacuate the inside of the airtight container, after the airtight container is assembled, an exhaust pipe and a vacuum pump (both not shown) are connected, and the inside of the airtight container is raised to the power of 10 −7 [ Torr]. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. The getter film is, for example, a film formed by heating and evaporating a getter material containing Ba as a main component by a heater or high-frequency heating. 5th power or 1 × 1
The degree of vacuum is maintained at 0-7 (Torr). The basic configuration and manufacturing method of the display panel according to the embodiment of the present invention have been described above.

Next, the multi-electron beam source used for the display panel of the above embodiment will be described. The material, shape, and manufacturing method of the surface conduction electron-emitting device are not limited as long as the multi-electron beam source used in the image display device of the present invention is an electron source in which surface conduction electron-emitting devices are arranged in a simple matrix. However, the present inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed from a fine particle film have excellent electron-emitting characteristics and can be easily manufactured. . Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-luminance, large-screen image display device.

Therefore, in this embodiment, a surface conduction electron-emitting device formed of a fine particle film in the electron-emitting portion or its peripheral portion is used for the display panel.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. Here, a phosphor layer 10 having a thickness of about 20 μm is formed on the inner surface of a face plate 1007 made of soda lime glass and having a thickness of 3 mm.
08 is formed, and further, about 1
Aluminum metal back layer 100 with a thickness of 000 Å
9 are formed.

The high-voltage introduction terminal 1021 is connected to the aluminum metal back 1009, is connected to the high-voltage power supply 1020, and is applied with a high-voltage potential, for example, 10 kV. The same electron source as that used in the first embodiment was used.

A front plate 1012 is adhered to the outside of the face plate 1007 using an adhesive layer 1013. Here, the face plate 1007 is 800 × 6
The front plate 1012 had a size of 700 × 400 mm. Further, in this embodiment, in consideration of insulation, flame retardancy, and light transmittance, a transparent front plate is used.
Although a polycarbonate plate having a thickness of mm was used, of course, the present invention is not limited to this, and a transparent resin plate such as polycarbonate or acrylic having a thickness of 0.5 mm or more can achieve the object of the present invention. .

Here, Epotech 305 manufactured by Rikei Co., Ltd. was used for the adhesive layer 1013 for bonding the face plate and the front plate. The adhesive is colorless and transparent, and the image is not deteriorated by the adhesive layer. The adhesive is a two-part adhesive, and is cured by heating after mixing. Further, since the above-mentioned adhesive has a relatively long pot life, workability in bonding a large-sized one is improved.

The adhesive layer 1013 serves as a face plate (thermal expansion coefficient β _g ) when the temperature of the image display panel changes.
A front plate in order to relieve the stress generated by the difference in thermal expansion (thermal expansion coefficient beta _p), the first layer 1014 (thermal expansion coefficient beta _a1) · second layer 1015 (thermal expansion coefficient beta _a2) · No. Three layers 1
016 (thermal expansion coefficient β _a3 ), and the thermal expansion coefficient was prepared so as to satisfy β _g <β _a1 <β _a2 <β _a3 <β _p .
The thermal expansion coefficient of the glass face plate used here is β
_g = 8.5 × 10 ^-6 "K ^-1 ", and the coefficient of thermal expansion of the polycarbonate used as the front plate was β _p = 7.0 × 10
^-5 "K ^-1 ".

In this embodiment, the adhesive layer is made 10
Although the thermal expansion coefficient was changed by dividing the thermal expansion coefficient into three layers of 14 to 1016, it is needless to say that the present invention is not limited to this. Is done. Further, in the adhesive layers 1014 to 1016, SiO ₂ fine particles having an average particle diameter of 100 to 200 nm similar to those of the first embodiment are dispersed in order to adjust the thermal expansion coefficient. The thermal expansion coefficient of the adhesive used here is 6.5 × 10 ⁻⁵ “K ⁻¹ ”, which is smaller than the thermal expansion coefficient of polycarbonate, and the thermal expansion coefficient of the adhesive layer is the thermal expansion coefficient of the face plate and the front plate. This is an intermediate value between the coefficients.

An adhesive whose thermal expansion coefficient β _adh satisfies β _adh <(10β _g− 7β _{SiO 2} ) / 3 (here, the thermal expansion coefficient β _{adh of the} adhesive)
<2.7 × 10 ^-5 "K ^- In ^1] adhesive meet), the volume ratio of the SiO ₂ particles to the adhesive layer to 0.7,
Since the coefficient of thermal expansion of the adhesive layer is smaller than the coefficient of thermal expansion of the faceplate, the volume ratio must be such that the coefficient of thermal expansion of the adhesive layer is greater than the coefficient of thermal expansion of the faceplate. Therefore, the adhesive used here is
Since the coefficient of thermal expansion does not satisfy the above condition, it can be dispersed to the maximum volume ratio of 0.7, which can be dispersed as much as possible when the particle diameter of the SiO ₂ fine particles is uniform.

The volume ratio of the dispersed SiO ₂ fine particles to the adhesive layer was 0.5 for the first layer 1014 and 0.5 for the second layer.
015 was set to 0.3 and the third layer was set to 0.0. The respective thermal expansion coefficients at that time are the thermal expansion coefficient β of the first layer 1014.
_a1 = 2.6 × 10 ⁻⁵ , thermal expansion coefficient β _a2 of the second layer 1015
= 4.6 × 10 ^-5 , thermal expansion coefficient β _a3 of third layer 1016 =
It becomes 6.5 × 10 ^-5 . In addition, the adhesive layers 1014 to 101
6, the thickness of each was approximately 0.2 mm,
Of course, the present invention is not limited to this, and the object of the present invention can be achieved as long as the thickness can be made uniform when the adhesive is applied.

The adhesive layer was prepared as follows.
First, SiO ₂ fine particles were dispersed in the adhesive used for the adhesive layers 1014 and 1015 at the above volume ratio.
Using these adhesives, the adhesive layer 1014 was applied to the glass face plate and the adhesive layer 1016 was applied to the front plate, and was cured. Next, an adhesive was applied to the face plate or the front plate to form an adhesive layer 1015, and these were adhered.

In this embodiment, after the adhesive layers 1014 and 1016 are cured and formed on both the face plate and the front plate, the two are bonded. However, the adhesive layers 1014 and 1015 are sequentially formed on the face plate. After that, or after the adhesive layers 1016 and 1015 are sequentially formed on the front plate, they may be bonded to each other.

As a result of performing a temperature environment test of -20 ° C. to 70 ° C. for 100 cycles on the image display panel thus produced, no peeling of the adhesive layer 1013 and no deformation or destruction of the image display panel were confirmed. Was. In addition, no image deterioration such as distortion or blurring of the image was observed.

As described above, by dispersing the fine particles in the adhesive layer, the thermal expansion coefficient of the adhesive layer can be distributed, and the stress generated due to the difference in thermal expansion can be absorbed. Peeling can be prevented.

In these embodiments, the front plate 1
Although polycarbonate was used as 012, it is needless to say that the invention is not limited to this, and a transparent resin plate such as acryl, polypropylene (PP), polyethylene terephthalate (PET), or tempered glass may be used. In addition, the front plate 1012 may have a transmittance limiting function to reduce the reflectance of external light reaching the phosphor surface, thereby improving the contrast.

In this case, the face plate 100
7, an image display device using a surface conduction electron-emitting device including a front plate 1012 and an adhesive layer 1013 was prepared, but is not limited to this, and is not limited to this. Glass such as a cathode ray tube or a plasma display panel is used. An image display device in which a transparent front plate is bonded to a face plate can also be produced. Also, here, as an adhesive,
The photocurable adhesive LCR0631 manufactured by Toagosei Chemical Co., Ltd. and the Epotech 305 manufactured by Rikei Co., Ltd. were used. Of course, the present invention is not limited to this, and the desired thermal expansion coefficient can be obtained without adversely affecting the image. Then, the object of the present invention is achieved.

[0060]

As described above, according to the present invention, in the image display device, the glass face plate and the transparent front plate having different thermal expansion coefficients have different thermal expansion coefficients in the thickness direction. The adhesive layer adheres, so it can absorb the stress generated due to the difference in thermal expansion, preventing deformation and destruction of the image display panel and peeling of the adhesive layer, and high reliability against temperature changes Sex can be obtained.

Further, by dispersing SiO ₂ fine particles in the adhesive layer, the thermal expansion coefficient of the adhesive layer can be changed without deteriorating the image quality.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing a face plate, an adhesive layer, and a front plate of an image display panel according to the first and second embodiments of the present invention.

FIG. 3 is a diagram showing an image display area (a) when the image display device is viewed from the front, and a line of sight (b) of the image display device and the observer viewed from above.

FIG. 4 is a perspective view showing the image display device with a part of a display panel cut away.

FIG. 5 is a plan view showing a phosphor array of a face plate of the display panel.

FIG. 6 is a diagram in which a conventional surface conduction electron-emitting device is connected to a matrix wiring.

FIG. 7 is a perspective view of a display panel of a conventional image display device with a part thereof cut away.

[Explanation of symbols]

 1001 Rear plate 1002 Electron beam source 1007 Face plate 1008 Phosphor film 1009 Metal back 1012 Front plate 1013 Adhesive layer 1014 Adhesive layer first layer 1015 Adhesive layer second layer 1016 Adhesive layer third layer 1020 High voltage power supply 1021 High voltage lead 4001 Rear Plate 4006 Face plate 4008 Phosphor film 4009 Metal back 4010 High voltage power supply 4011 High voltage lead wire

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 31/12 H01J 31/12 C

Claims (11)

[Claims] 1. An image display device having a structure in which a transparent front plate is bonded to a glass face plate, wherein a thermal expansion coefficient β _a [K ⁻¹ ] of the adhesive layer is a thermal expansion coefficient β _g [K ^-1 ] and the thermal expansion coefficient β _{p of the} front plate
An image display device characterized by being a value between [K ^-1 ]. 2. The thermal expansion coefficient β _a of the adhesive layer is β _g ≦ β _a ≦ β _p or β _p ≦ β _a when viewed from the glass surface in the thickness direction.
Claim 1, characterized in that it is inclined at a range of ≦ beta _g
An image display device according to claim 1. 3. The adhesive layer according to claim 2, wherein the adhesive layer is divided into n layers each having an integer of 2 or more, and the coefficient of thermal expansion of each layer changes stepwise from β _a1 to β _an . 3. The image display device according to 2. 4. The image display device according to claim 3, wherein the adhesive layer has fine particles dispersed in order to adjust a coefficient of thermal expansion. 5. The image display device according to claim 4, wherein said fine particles are SiO ₂ fine particles. 6. The image display device according to claim 5, wherein the average particle size of the SiO ₂ fine particles dispersed in the adhesive layer is 100 nm to 1 μm. 7. The image display device according to claim 1, wherein the front plate is a resin plate. 8. the SiO ₂ particles dispersed in the adhesive layer, a volume ratio I for adhesive layer, the thermal expansion coefficient of the SiO ₂ particles β _SiO2 [K ^-1], the thermal expansion coefficient of the adhesive beta
_adh [K ^-1 ], (β _p −β _adh ) / (β _SiO2 −β _adh ) ≦ I <0.7
(However, β _p <β _adh ) 0 ≦ I <0.7 (However, (10β _g− 7β _SiO2 ) / 3
≦ β _adh ≦ β _p ) 0 ≦ I ≦ (β _g −β _adh ) / (β _SiO2 −β _adh ) (where,
_{β adh <(10β g -7β SiO2} ) / 3) The image display apparatus according to claim 7, characterized in that meet. 9. The image display device according to claim 1, wherein said front plate has a function of limiting transmittance. 10. A cathode ray tube using the face plate provided with the front plate according to claim 1. Description: 11. The cathode ray tube according to claim 10, wherein the cathode ray tube uses a surface conduction electron-emitting device.