JP3860460B2 - Filter-integrated image display device - Google Patents

Description

【００３６】
表１の結果から明らかなとおり、各実施例のものは、耐衝撃性に優れ、また、気泡の発生もなく、視認性に優れたものであった。
【００３７】
【発明の効果】
以上説明したように、本発明のフィルター一体型画像表示装置によれば、画像表示装置のコストダウンや薄型化が規制されるという従来技術の問題点を解消することができることに加えて、電磁波シールド材と光学フィルターとの間に設けられた透明粘着材によって、画像表示装置に加わる外力に対する緩衝機能が奏され、優れた耐衝撃性が発揮される。また、透明粘着材が電磁波シールド材の表面によく馴染み、気泡の発生のない、視認性、外観に優れた画像表示装置が提供される。電磁波シールド材の導電性メッシュの微細凹凸に対しても気泡や剥離を発生せずに密着する。
また、電磁波シールド材の、電極が設けられる周縁部を残して、電磁波シールド材面と光学フィルターとを透明粘着材を用いて密着一体化することにより、電磁波シールド材に接続する電極の取り出し部を確保し、電磁波シールド材の機能を有効に発揮させることができる。
【図面の簡単な説明】
【図１】 画像表示パネル１の構造を示すもので、（ａ）は縦断面図、（ｂ）は正面図である。
【図２】 本発明に係る画像表示装置に用いられる積層板の断面図である。
【図３】 本発明に係る画像表示装置に用いられる透明粘着シートの断面図である。
【図４】 実施例における耐衝撃試験方法の説明図である。
【符号の説明】
１ 画像表示パネル
２ 表示面基板
３ 電磁波シールド材
４ 透明粘着材
５ 光学フィルター
４０ 離型フィルム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image display device that is excellent in visibility and impact resistance and has an integrated filter function.
[0002]
[Prior art]
A protective panel is combined so that when an impact is applied to the surface of an image display device such as a plasma light emitting display (PDP), the impact is transmitted to the image display panel and the display panel is not damaged. This protective panel has an anti-reflection layer, color tone correction layer, electromagnetic wave shield layer, and near infrared cut layer to improve image visibility, hue adjustment, electromagnetic wave cut, and remote control malfunction, and is also called a filter. .
[0003]
Conventionally, an air layer having a constant thickness is formed between the display panel and the protective panel, and a shock is dispersed and absorbed by the protective panel and the air layer to prevent the display panel from being damaged. Furthermore, the use of a tempered glass plate, a polycarbonate (PC) plate or an acrylic plate with higher impact resistance for the protective panel prevents damage to the protective panel itself and improves the durability of the image display device.
[0004]
However, in the configuration in which the air layer is formed between the display panel and the protective panel as described above, the reflection of light due to the refractive index difference between the air layer and the protective panel is large, resulting in double image and a decrease in contrast. Therefore, in order to obtain good visibility, a plurality of antireflection layers are required. In addition, since an air layer having a certain thickness for preventing the display panel from being damaged is required, there is a problem in that cost reduction and thinning of the image display device are restricted.
[0005]
In view of these points, a method of injecting a liquid resin between the display panel and the protective panel and then curing at room temperature, or a method of heat-melting with a hot-melt adhesive and a bonding process has been proposed.
However, there is a problem that the room temperature curable liquid resin tends to cause distortion of the display panel due to air bubbles and curing shrinkage, and the hot melt adhesive tends to cause a decrease in function of the display panel due to heating. In addition, when combining electromagnetic shielding materials, commercially available hard adhesive sheets are expensive due to the formation of bubbles due to surface irregularities of the conductive mesh of the electromagnetic shielding material, resulting in poor visibility or insufficient impact resistance. There was a problem that the display panel was damaged.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems, and an object thereof is to provide a filter-integrated image display device having excellent visibility and impact resistance.
[0007]
[Means for Solving the Problems]
As a result of various studies to obtain a filter-integrated image display device excellent in visibility and impact resistance, the present inventor has used a display surface substrate of an image display panel, an electromagnetic wave shielding material, an optical filter, and a transparent adhesive material. By integrating, the present invention has been reached. Moreover, the suitable arrangement | positioning for ensuring the taking-out part of the electrode of an electromagnetic wave shielding material was discovered.
[0008]
(1) The present invention provides an electromagnetic wave shielding material in which a conductive mesh is formed on the surface of a transparent film on the display surface substrate of the image display panel, and the adhesive film is applied to the back surface of the transparent film. An optical filter using a transparent adhesive material having the following requirements (a) and (b) for dynamic viscoelastic properties and elastic modulus on the surface side of the conductive mesh. an image display device being characterized in that closely integrated.
(A) The relationship between the thickness of the transparent adhesive material and the dynamic viscoelastic property measured by frequency dispersion is in the range of the following formula.
K = d × 2πf × √ (ρ / 3G ′) ≧ 0.5
d: thickness of transparent adhesive material (m)
f: frequency of tan δ peak value (Hz)
ρ: Density of transparent adhesive (kg / m ³ )
G ′: tan δ peak storage elastic modulus (Pa)
(B) The transparent adhesive material is in the elastic modulus range of the following (a) and (b).
(A) Storage elastic modulus G ′ (1 Hz) at a measurement temperature of 20 ° C. and a frequency of 1 Hz is 5 × 10 ^3. ~ 5 × 10 ⁵ Pa.
(B) Storage elastic modulus G ′ (10 ⁻⁷ Hz) at a reference temperature of 20 ° C. and a frequency of 10 ⁻⁷ Hz is 5 × 10 ^1. ~ 5 × 10 ³ Pa.
[0009]
(2) Preferably, the electromagnetic wave shielding material surface and the optical filter are closely integrated with each other using a transparent adhesive material, leaving a peripheral portion of the electromagnetic wave shielding material where the electrode is provided.
[0010]
(3) The transparent adhesive material is preferably in the form of a sheet made of any of acrylic resin, epoxy resin, urethane resin, silicone resin, and rubber resin.
(4) The optical filter preferably has one or more functions of antireflection, near infrared cut, color tone correction, and surface hardness improvement.
(5) The optical filter has a thickness of 0.1 mm to 5 mm using at least one transparent substrate of polyester resin, acrylic resin, polycarbonate resin, alicyclic polyolefin resin, and glass. Some are preferred.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a longitudinal sectional view schematically showing the structure of an image display panel 1 in an image display device in which the present invention is configured as a plasma light emitting display device (PDP), and FIG. 1B is a front view.
[0013]
An electromagnetic wave shielding material 3 is laminated on the display surface substrate 2 of the image display panel 1. The optical filter 5 is tightly integrated with the transparent adhesive material 4 while leaving the periphery (four sides) of the electromagnetic wave shielding material 3 in a frame shape. An electrode 6 is provided at the periphery of the electromagnetic wave shielding material 3, which is a region where the transparent adhesive material 4 and the optical filter 5 are not formed. The surface of the display surface substrate 2 is usually formed of a glass plate, but is not particularly limited.
[0014]
As the electromagnetic shielding material 3 , a material in which a conductive mesh is formed on the surface of a transparent film and the back surface thereof is subjected to adhesive processing is used. The transparent adhesive material 4 may be formed of one layer or may be formed of a plurality of layers.
The optical filter 5 has an optical action, and for example, an optical filter having one or more functions of antireflection, near infrared cut, color tone correction, and surface hardness improvement is used. As the optical filter, those having a thickness of 0.1 mm to 5 mm using at least one transparent substrate of polyester resin, acrylic resin, polycarbonate resin, alicyclic polyolefin resin and glass are preferably used. It may have a plurality of layers. A function such as a gas barrier may be added.
The shape and material of the electrode 6 are not particularly limited, but it is preferably formed in a frame shape on the surface along the periphery of the electromagnetic wave shielding material 3 which is a region where the transparent adhesive material 4 and the optical filter 5 are not formed.
[0015]
The transparent adhesive material 4 is made of a relatively soft material having viscoelasticity. The relationship between the thickness of the transparent adhesive material 4 and the dynamic viscoelastic property measured by frequency dispersion is in the range of the following formula .
[0016]
K = d × 2πf × √ (ρ / 3G ′) ≧ 0.5
d: thickness of transparent adhesive material (m)
f: frequency of tan δ peak value (Hz)
ρ: Density of transparent adhesive (kg / m ³ )
G ′: tan δ peak storage elastic modulus (Pa)
[0017]
Said tan-delta was read from the master curve obtained by measuring with the viscoelasticity measuring apparatus mentioned later. An image display device having excellent impact resistance can be obtained by configuring the present invention using the transparent adhesive material 4 having a K value obtained by the above formula of ≧ 0.5.
[0018]
Moreover, the transparent adhesive material 4 exists in the range of the elastic modulus of the following (a) and (b) .
(A) Storage elastic modulus G ′ (1 Hz) at a measurement temperature of 20 ° C. and a frequency of 1 Hz is 5 × 10 ^{3 to} 5 × 10 ⁵ Pa.
(B) Storage elastic modulus G ′ (10 ⁻⁷ Hz) at a reference temperature of 20 ° C. and a frequency of 10 ⁻⁷ Hz is 5 × 10 ^{1 to} 5 × 10 ³ Pa.
[0019]
The elastic modulus is measured under the following conditions using a rheometrics dynamic analyzer RDAII manufactured by Rheometrics.
・ Temperature: 20 ~ 150 ℃
Angular frequency: ω = 0.005 to 500 rad / sec
・ Parallel plate: 25mmφ
・ Distortion amount: 3%
[0020]
A temperature-time converted master curve is created using the above RDAII with a reference temperature of 20 ° C., and the frequency f value is calculated by f (Hz) = ω / 2π, and storage elastic modulus G ′, loss elastic modulus G ″ and Read G ″ / G ′ = tan δ.
[0021]
In the case of (a), if the storage elastic modulus G ′ (1 Hz) at a frequency of 1 Hz is less than 5 × 10 ³ Pa, it may be difficult to maintain the shape after the transparent adhesive material is subjected to a close-contact treatment. ^If it exceeds ⁵ Pa, the wettability of the interface is inferior and sufficient adhesive strength may not be ensured.
[0022]
Further, for the above (b), the storage modulus G at the frequency ^{10 -7 Hz '(10 -7 Hz} ) is less than 5 × 10 ¹ Pa, after adhesion treatment too flow, the transparent adhesive If it exceeds 5 × 10 ³ Pa, bubbles may be generated in the recess due to the unevenness of the slight thickness of the transparent adhesive material that is too hard during the adhesion treatment. May occur. The range for reasons such as those described above (a) (b).
[0023]
The transparent adhesive material 4 can be selected from, for example, any of acrylic resins, epoxy resins, urethane resins, silicone resins, and rubber resins. It is preferable to use an acrylic resin having good weather resistance and transparency. As the acrylic resin, there is an ionomer resin obtained by adding a metal compound or the like to a (meth) acrylic acid ester copolymer containing ethylene and an α, β unsaturated carboxylic acid to crosslink the metal ions. As the metal compound, an acetylacetone metal complex having a zinc ion, a sodium ion or the like, a metal oxide, a fatty acid metal salt, or the like is used. An ionomer resin that has already been ionically crosslinked may be used, but it is preferable to ionically crosslink a copolymer by adding a metal compound during production. Moreover, the transparent adhesive material 4 is preferable from the point etc. which are easy to manufacture the pressure-sensitive thing which is a sheet form.
[0024]
FIG. 2 shows a configuration example of a laminated plate used in the image display device according to the present invention. This laminated sheet for an image display device is used for the above-described image display device, and one surface of the transparent adhesive material 4 in the form of a sheet is pressure-bonded and laminated on the optical filter 5. A release film 40 having a release function such as polyethylene terephthalate is attached to the other surface of the transparent adhesive material 4. The release film 40 is peeled off, and the surface thereof can be applied to an image display device by pressure bonding to an electromagnetic shielding material, various panels, or a film used in the image display device.
[0025]
FIG. 3 shows a transparent adhesive sheet used in the image display device according to the present invention. The transparent adhesive material 4 is sandwiched between the release films 40 and formed integrally, and the release films 40 are formed on both surfaces of the transparent adhesive material 4. By peeling off the release film 40 on each surface, the film can be used by interposing between the electromagnetic wave shielding material 3 and the optical filter 5 so as to be closely integrated.
[0026]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and additions are possible within the scope of the present invention. Although an example in which the image display device is configured as a plasma light emitting display device (PDP) has been shown and described, the present invention can also be configured as a liquid crystal display device (LCD), an organic electroluminescence (EL), or other image display device. .
[0027]
【Example】
Example 1
As a substitute for an optical filter, a 2.0 mm thick acrylic transparent adhesive sheet obtained by crosslinking a acrylate ester copolymer with a metal compound on a 2.0 mm thick plate (90 mm × 90 mm) made of polycarbonate (PC). Roll-bonded. As a substitute for an image display panel (display surface substrate), a commercially available electromagnetic shielding film with an adhesive material subjected to conductive mesh processing was roll-bonded to a 3.0 mm thick float glass panel (100 mm × 100 mm) surface. An image display device (sample) was obtained by pressure-bonding the electromagnetic shielding film on the surface of the mesh having a peripheral edge of 5 mm as an electrode portion in such a direction as to contact the acrylic transparent adhesive sheet.
[0028]
The acrylic ester copolymer is obtained by copolymerizing n-butyl acrylate: 78.4% by weight, 2-ethylhexyl acrylate: 19.6% by weight and acrylic acid: 2.0% by weight. The molecular weight and molecular weight distribution of the acid ester copolymer measured by GPC (gel permeation chromatography) are: weight average molecular weight (MW): 2.27 × 10 ⁶ , weight average molecular weight (MW) / number average molecular weight (MN) : 3.6.
[0029]
The acrylic transparent pressure-sensitive adhesive sheet is a sheet having a predetermined thickness between release films after melting and stirring 0.7 parts by weight of acetylacetone aluminum salt as a metal compound with respect to 100 parts by weight of an acrylic ester copolymer. What was obtained by molding into a shape was used.
[0030]
(Example 2)
As a substitute for the optical filter substrate, a transparent acrylic adhesive having a thickness of 1.0 mm obtained by crosslinking a acrylate copolymer with a metal compound on a 2.0 mm thick plate (90 mm × 90 mm) made of polycarbonate (PC). The sheet was roll pressed. As a substitute for the image display panel, a commercially available electromagnetic shielding film with an adhesive material subjected to conductive mesh processing was roll-bonded to a surface of a float glass panel (100 mm × 100 mm) having a thickness of 3.0 mm. An image display device (sample) was obtained by pressure-bonding the electromagnetic shielding film on the surface of the mesh having a peripheral edge of 5 mm as an electrode portion in such a direction as to contact the acrylic transparent adhesive sheet.
The acrylic transparent adhesive sheet was produced by the same method as in Example 1.
[0031]
Example 3
As a substitute for the optical filter base material, a transparent acrylic film having a thickness of 2.0 mm obtained by crosslinking an acrylic acid ester copolymer with a metal compound on a 0.2 mm thick film (90 mm × 90 mm) made of polyethylene terephthalate (PET). The pressure-sensitive adhesive sheet was roll-bonded. As a substitute for an image display panel, a commercially available electromagnetic shielding film with an adhesive material having a conductive mesh processed on a float glass panel (100 mm × 100 mm) having a thickness of 3.0 mm was roll-bonded. An image display device (sample) was obtained by pressure-bonding the electromagnetic shielding film on the surface of the mesh having a peripheral edge of 5 mm as an electrode portion in such a direction as to contact the acrylic transparent adhesive sheet.
The acrylic transparent adhesive sheet was produced by the same method as in Example 1.
[0032]
The following tests were performed using the image display devices (samples) obtained by the above-described examples. Moreover, it observed and evaluated with the following evaluation method. The results are shown in Table 1. In each example, the K value defined by the present invention and the elastic moduli of (a) and (b) defined by the present invention are also shown in Table 1.
[0033]
[Impact resistance test method (see FIG. 4)]: Place a glass stand (thickness 3 mm × 100 mm square) as shown in FIG. 4 on a fixed cylindrical metal support (outer diameter 60 mm / inner diameter 50 mm / height 40 mm). On top of that, # 1200 sandpaper (100mm square) and each image display device (sample) were placed with the PC plate facing up, and a 95g steel ball was dropped freely from a height of 0.53m. It was. At this time, the impact value (0.5 J) was used to observe whether or not the image display panel substitute float glass panel was broken. The ones that were not destroyed were marked with ○.
[0034]
[Adhesion Appearance Evaluation Method]: The in-plane of the image display device (sample) obtained in each example was observed, and the conductive mesh with no bubbles on the irregularities was rated as ◯.
[0035]
[Table 1]

[0036]
As is clear from the results in Table 1, each example had excellent impact resistance, no bubbles, and excellent visibility.
[0037]
【The invention's effect】
As described above, according to the filter-integrated image display device of the present invention, in addition to solving the problems of the prior art that the cost reduction and thinning of the image display device are regulated, the electromagnetic wave shield The transparent adhesive material provided between the material and the optical filter provides a buffering function against an external force applied to the image display device, and exhibits excellent impact resistance. In addition, an image display device is provided in which the transparent adhesive material is well adapted to the surface of the electromagnetic wave shielding material, has no air bubbles, and is excellent in visibility and appearance. It adheres to the fine irregularities of the conductive mesh of the electromagnetic shielding material without generating bubbles or peeling.
In addition, the electromagnetic wave shielding material is provided with an electrode shielding portion by attaching the surface of the electromagnetic wave shielding material and the optical filter tightly using a transparent adhesive material, leaving a peripheral edge where the electrode is provided. And the function of the electromagnetic wave shielding material can be effectively exhibited.
[Brief description of the drawings]
1A and 1B show a structure of an image display panel 1, wherein FIG. 1A is a longitudinal sectional view and FIG. 1B is a front view.
FIG. 2 is a cross-sectional view of a laminate used in the image display device according to the present invention.
FIG. 3 is a cross-sectional view of a transparent adhesive sheet used in the image display device according to the present invention.
FIG. 4 is an explanatory diagram of an impact resistance test method in an example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image display panel 2 Display surface board 3 Electromagnetic wave shielding material 4 Transparent adhesive material 5 Optical filter 40 Release film

Claims (5)

On the display surface substrate of the image display panel, an electromagnetic shielding material in which a conductive mesh is formed on the surface of the transparent film and adhesive processing is performed on the back surface of the transparent film is laminated with the surface subjected to the adhesive processing facing the surface. The optical filter is closely integrated on the surface side of the conductive mesh using a transparent adhesive material having the following requirements (a) and (b) for dynamic viscoelastic properties and elastic modulus. A characteristic image display device.
(A) The relationship between the thickness of the transparent adhesive material and the dynamic viscoelastic property measured by frequency dispersion is in the range of the following formula.
K = d × 2πf × √ (ρ / 3G ′) ≧ 0.5
d: thickness of transparent adhesive material (m)
f: frequency of tan δ peak value (Hz)
ρ: Density of transparent adhesive material (kg / m ³ )
G ′: storage elastic modulus (Pa) of tan δ peak value
(B) The transparent adhesive material is in the elastic modulus range of the following (a) and (b).
(A) Storage elastic modulus G ′ (1 Hz) at a measurement temperature of 20 ° C. and a frequency of 1 Hz is 5 × 10 ^{3 to} 5 × 10 ⁵ Pa.
(B) Storage elastic modulus G ′ (10 ⁻⁷ Hz) at a reference temperature of 20 ° C. and a frequency of 10 ⁻⁷ Hz is 5 × 10 ^{1 to} 5 × 10 ³ Pa.   2. The image display device according to claim 1, wherein the electromagnetic shielding material surface and the optical filter are closely integrated using a transparent adhesive material, leaving a peripheral portion of the electromagnetic shielding material where the electrode is provided.   The image according to claim 1, wherein the transparent adhesive material is in the form of a sheet made of any one of an acrylic resin, an epoxy resin, a urethane resin, a silicone resin, and a rubber resin. Display device.   The image display device according to claim 1, wherein the optical filter has one or more of functions of antireflection, near infrared cut, color tone correction, and surface hardness improvement.   The optical filter has a thickness of 0.1 mm to 5 mm using at least one transparent substrate of polyester resin, acrylic resin, polycarbonate resin, alicyclic polyolefin resin, and glass. The image display apparatus in any one of 1-4.

Images