JP4544287B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device and an electronic apparatus, and more particularly, to an electro-optical device and an electronic apparatus having a transparent protector.

  Conventionally, display devices such as liquid crystal display devices, organic luminescence display devices, and plasma display devices are known as electro-optical devices. In these display devices, a protective plate made of plastic or the like is used for preventing impact. For example, the display panel and the protective plate are bonded together with an adhesive sheet (see, for example, Patent Document 1).

JP 2006-290960 A

  Since various display devices may be used in electronic devices such as mobile phones, they are placed in various environments. Cellular phones are sometimes placed in high-temperature environments, such as cars in hot weather.

  However, when the protective plate is made of plastic or the like, the plastic or the like absorbs a gas such as air containing moisture, carbon dioxide, nitrogen, or the like, and thus the absorbed gas may be discharged at a high temperature. In that case, gas may be generated from the protective plate, and bubbles may be generated between the adhesive sheet and the protective plate.

  When bubbles are generated between the adhesive sheet and the protective plate, the bubbles appear as spots or islands when the display surface of the display panel is viewed. As a result, the appearance of the display surface of the liquid crystal display device is deteriorated. Furthermore, bubble spots may reduce the visibility of the display image on the display panel.

  In view of the above, an object of the present invention is to provide an electro-optical device that suppresses deterioration in the appearance of a display surface due to gas generated from a protective body that protects a display panel, and an electronic apparatus in which the electro-optical device is mounted.

Application Example 1 An electro-optical device according to this application example includes an electro-optical panel,
A plastic plate disposed on the viewing side of the electro-optic panel; and
A polarizing plate provided between the electro- optic panel and the plastic plate,
A first adhesive material for bonding the electro-optical panel and the polarizing plate;
A gas barrier film provided on the surface of the plastic plate opposite to the viewing side;
Bonding the gas barrier film of the plastic plate and the polarizing plate, and having a second adhesive material having a film thickness equal to or greater than the film thickness of the first adhesive material,
The gas barrier film prevents gas generated from the plastic plate material from being discharged to the side opposite to the viewing side of the plastic plate material.
According to such a configuration, it is possible to provide an electro-optical device that suppresses the deterioration of the appearance of the display surface due to the gas generated from the protector that protects the display panel.

Application Example 2 In the electro-optical device according to the application example, it is preferable that the gas barrier film is an inorganic film.
According to such a configuration, generation of bubbles can be prevented.

Application Example 3 In the electro-optical device according to the application example, it is preferable that the inorganic film includes one layer of a silicon oxide film and one layer of aluminum oxide.
According to such a structure, generation | occurrence | production of a bubble can be prevented reliably.

Application Example 4 In the electro-optical device according to the application example, it is preferable that the inorganic film includes two layers of a silicon oxide film.
According to such a structure, generation | occurrence | production of a bubble can be prevented reliably.

Application Example 5 In the electro-optical device according to the application example described above, it is preferable that the inorganic film includes three layers including two layers of silicon oxide films and one layer of aluminum oxide.
According to such a structure, generation | occurrence | production of a bubble can be prevented more reliably.

Application Example 6 In the electro-optical device according to the application example described above, one layer of the aluminum oxide is formed in contact with the transparent protective body and is provided in contact with one of the two layers of the silicon oxide film. It is desirable.
According to such a structure, generation | occurrence | production of a bubble can be prevented more reliably.

Application Example 7 In the electro-optical device according to the application example, one of the two layers of the silicon oxide film is a silicon dioxide film provided on the electro-optical panel side, and the other layer is a single layer. A silicon oxide film is desirable.
According to such a structure, generation | occurrence | production of a bubble can be prevented more reliably.

Application Example 8 In the electro-optical device according to the application example described above, a touch panel is disposed between the electro-optical panel and the transparent protector, and the touch panel is transparent through the gas barrier film and the adhesive material. It is desirable to be fixed to a protector.
According to such a configuration, even when a touch panel is provided, it is possible to provide an electro-optical device that suppresses deterioration in the appearance of the display surface due to the gas generated from the protector that protects the display panel.

Application Example 9 An electronic apparatus according to this application example includes the electro-optical device.
According to such a structure, the electronic device which suppresses the fall of the appearance of the display surface by the gas which generate | occur | produces from the transparent protector which protects a display panel can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Constitution)
First, the configuration of the electro-optical device according to the present embodiment will be described with reference to FIG. FIG. 1 is a configuration diagram showing the configuration of the liquid crystal display device according to the present embodiment. Hereinafter, the present embodiment will be described using a liquid crystal display device which is one of electro-optical devices as an example.

  In FIG. 1, a liquid crystal display device 1 includes a liquid crystal display panel 11 that is an electro-optical panel, a cover 12 that is a transparent protector, and a polarizing plate 13. A glass transparent substrate is provided on the image display surface of the display panel 11, and a polarizing plate 13 is provided on the surface of the display panel 11 via a layer of a transparent adhesive material 15. A cover 12 is provided on the surface of the polarizing plate 13 opposite to the display panel 11 side through a layer of transparent adhesive material 14. A gas barrier film 16 is provided on the surface of the cover 12 on the adhesive material 14 side. In other words, the gas barrier film 16 is provided on the back surface of the cover 12.

The display panel 11 includes a liquid crystal layer inside, and forms an image by transmitted light or reflected light by applying an electric field to the liquid crystal layer to control light transmission. Specifically, the display panel 11 has two transparent substrates, and a liquid crystal layer that is an electro-optical material is provided between the two transparent substrates, and the two substrates face each other. A plurality of electrodes are arranged on the surface to be operated. An image is displayed by forming a pixel in which the plurality of electrodes intersect with each other in a plane to form a pixel whose display mode can be controlled independently.
As shown in FIG. 1, a polarizing plate 13 is laminated on the display panel 11 with an adhesive 15, and a cover 12 is laminated on the polarizing plate 13 with an adhesive 14. The liquid crystal display device 1 is configured.

Such a liquid crystal display device 1 is disposed in the housing of the electronic device, and the user can view an image displayed on the display panel 11 from the cover 12 side, that is, the viewing side.
The cover 12, which is a protector for preventing impacts, is a plate material made of plastic. The cover 12 has a thickness of about 0.2 mm to 2 mm. The material of the cover 12 is PMMA (polymethylmethacrylate), polycarbonate, a composite material of polycarbonate and PMMA, CR39, or the like.

  Sheet-like adhesive materials 14 and 15 are bonded to the front side (viewing side) and the back side of the polarizing plate 13, respectively. The adhesive materials 14 and 15 are gel-like and transparent members, and are made of, for example, an acrylic resin, a silicone resin, an epoxy resin, or a composite layer thereof.

  The polarizing plate 13 has a thickness of 100 μm, for example. The adhesive material 14 on the cover 12 side of the polarizing plate 13 has a thickness of 25 μm to 400 μm, and the adhesive material 15 on the display panel 11 side has a thickness of 25 μm to 50 μm.

  The polarizing plate 13 has a three-layer structure, for example. The three layers are three layers having two layers of TAC (triacetyl cellulose) and one layer of PVA (polyvinyl alcohol) provided between the two layers.

  Further, a gas barrier film 16 is provided on the surface of the cover 12 on the adhesive material 14 side by being coated by vapor deposition, coating, ion beam vapor deposition, sputtering, CVD (Chemical Vapor Deposition), or the like. In the case of a silicon oxide film described later, the gas barrier film 16 has a thickness of 200 nm, for example.

  The gas barrier film 16 is for preventing generation of gas discharged from the cover 12 when the display device including the liquid crystal display device 1 is placed in a high temperature environment such as in a car. As a result, it is possible to suppress a decrease in the appearance of the display surface due to the generation of bubbles in the adhesive materials 14 and 15 due to the gas generated from the polarizing plate 13.

FIG. 2 is a configuration diagram showing the configuration of the gas barrier film.
The gas barrier film 16 in FIG. 2 is an inorganic film having a three-layer structure. For example, the gas barrier film 16 is a film composed of three layers of a silicon monoxide (SiO) layer 21, a silicon dioxide (SiO ₂ ) layer 22, and an alumina (Al ₂ O ₃ ) layer 23. In this case, the silicon dioxide (SiO ₂ ) layer 22 is disposed on the adhesive material 14 side, and the alumina (Al ₂ O ₃ ) layer 23 is disposed on the cover 12 side, and the silicon monoxide (SiO) layer 21. Is disposed between two layers, an alumina (Al ₂ O ₃ ) layer 23 and a silicon dioxide (SiO ₂ ) layer 22. That is, from the cover 12 side, an alumina (Al ₂ O ₃ ) layer 23, a silicon monoxide (SiO) layer 21, and a silicon dioxide (SiO ₂ ) layer 22 are formed in this order.

In the case of three layers, the film thicknesses of the alumina (Al ₂ O ₃ ) layer 23, the silicon monoxide (SiO) layer 21, and the silicon dioxide (SiO ₂ ) layer 22 are 25 nm to 45 nm and 15 nm, respectively. It is 45 nm or less and 100 nm or more and 150 nm or less. The optimum film thicknesses are 30 nm for the alumina (Al ₂ O ₃ ) layer 23, 30 nm for the silicon monoxide (SiO) layer 21, and 130 nm for the silicon dioxide (SiO ₂ ) layer 22.

The gas barrier film 16 may have another configuration instead of the configuration of FIG. FIG. 3 is a configuration diagram showing another configuration of the gas barrier film.
As shown in FIG. 3, the gas barrier film 16A is an inorganic film having a two-layer structure. This two-layer structure includes an alumina (Al ₂ O ₃ ) layer 23 and a silicon dioxide (SiO ₂ ) layer 22 from the cover 12 side. The two-layer structure may have the following configuration. For example, from the cover 12 side, an alumina (Al ₂ O ₃ ) layer 23 and a silicon monoxide (SiO) layer 21 are configured. Another example of the two-layer structure is a structure comprising a silicon monoxide (SiO) layer 21 and a silicon dioxide (SiO ₂ ) layer 22 from the cover 12 side.

The film thickness in the case of two layers varies depending on the composition, and there are three types as shown below.
In the case of the layer 23 of alumina (Al ₂ O ₃ ) and the layer 22 of silicon dioxide (SiO ₂ ), the film thicknesses are 25 nm or more and 45 nm or less, and 100 nm or more and 150 nm or less. These optimum film thicknesses are 30 nm for the alumina (Al ₂ O ₃ ) layer 23 and 130 nm for the silicon dioxide (SiO ₂ ) layer 22.
In the case of the layer 23 of alumina (Al ₂ O ₃ ) and the layer 21 of silicon monoxide (SiO), the film thicknesses are 25 nm or more and 45 nm or less and 15 nm or more and 45 nm or less. These optimum film thicknesses are 30 nm for the alumina (Al ₂ O ₃ ) layer 23 and 30 nm for the silicon monoxide (SiO) layer 21.
In the case of the silicon monoxide (SiO) layer 21 and the silicon dioxide (SiO ₂ ) layer 22, the film thicknesses are 45 nm to 95 nm and 100 nm to 150 nm, respectively. These optimum film thicknesses are 70 nm for the silicon monoxide (SiO) layer 21 and 130 nm for the silicon dioxide (SiO ₂ ) layer 22.

The gas barrier film 16 may be an inorganic film having a single layer structure. FIG. 4 is a configuration diagram showing another configuration of the gas barrier film.
As shown in FIG. 4, the inorganic film having a single-layer structure is a silicon monoxide (SiO) layer 21. The single-layer inorganic film may have the following configuration. For example, the composition of the inorganic film is an alumina (Al ₂ O ₃ ) layer 23 or a silicon dioxide (SiO ₂ ) layer 22.

In the case of a single layer, these film thicknesses vary depending on the respective film forming methods, and are as follows.
First, when the silicon monoxide (SiO) layer 21 is formed by vapor deposition or application, the film thickness is 45 nm or more and 95 nm or less, and is optimal at 70 nm.
Second, when the alumina (Al ₂ O ₃ ) layer 23 is formed by vapor deposition or coating, the film thickness is 25 nm or more and 45 nm or less, and is optimal at 30 nm.
Further, as the third method, when the silicon dioxide (SiO ₂ ) layer 22 is formed by ion beam evaporation, the film thickness is 150 nm or more and 250 nm or less, and is optimal at 200 nm.
Finally, in the fourth way, when the silicon dioxide (SiO ₂ ) layer 22 is formed by sputtering, the film thickness is not less than 50 nm and not more than 150 nm, and is optimal at 100 nm.

  Furthermore, the gas barrier film 16 may be an organic film. As the organic film, for example, a single layer film of epoxy resin may be used. The organic film may be, for example, a parylene-based or silicone-based film other than an epoxy resin. In the case of epoxy, it is provided on the cover 12 by application. In that case, the thickness of the gas barrier film 16 is several μm.

  Further, the design printing is performed on the surface of the gas barrier film 16.

Here, the experimental results of the gas permeability of the gas barrier films 16, 16A are shown in FIG.
FIG. 5 is a table showing the experimental data of the transmittance when two gas barrier films are provided (three layers and two layers) and when there is no gas barrier film. In this experiment, the film thickness is as follows. In the case of three layers, the thickness of the silicon monoxide (SiO) layer 21 is 30 nm, the thickness of the alumina (Al ₂ O ₃ ) layer 23 is 30 nm, and the thickness of the silicon dioxide (SiO ₂ ) layer 22 is 130 nm. It is. In the case of two layers, the film thickness of the silicon monoxide (SiO) layer 21 is 70 nm, and the film thickness of the silicon dioxide (SiO ₂ ) layer 22 is 130 nm.

The horizontal direction of the table of FIG. 5 is divided into three cases from the left: a case where no gas barrier film is provided, a case of three layers (see FIG. 2), and a case of two layers (see FIG. 3). ing. In the table, in the vertical direction, from the top, the gas permeability of carbon dioxide (CO ₂ ), nitrogen (N ₂ ), and oxygen (O ₂ ) as the kind of permeating gas, The totals are shown in order.

The permeability was measured by a differential pressure method using a gas permeation measuring device, the test pressure was about 760 mmHg, the measurement temperature was 80 ° C., and the transmission area was 38 cm ² (square centimeter). The unit of transmittance is cm ³ / m ² · 24 h · atm.

  As a result of the test, the permeability in the case of 3 layers was the lowest, and the permeability was approximately 20% (= 32.45 / 157.5) with respect to the total without gas barrier membrane (157.5). It was. In the case of two layers, the permeability was about 32% (= 50.19 / 157.5) as compared with the case where there was no gas barrier film next. In the case of one layer, the transmittance was the same as in the case of two layers.

  Although not illustrated, a combination in which the cover 12 is a composite material of PMMA and polycarbonate, the gas barrier film 16 has a three-layer structure, and the adhesive material 14 is an acrylic resin is preferable because the transmittance is low.

  Further, a combination in which the cover 12 is made of polycarbonate, the gas barrier film 16 has a two-layer structure, and the adhesive material 14 is an epoxy resin is preferable because of low transmittance.

(Production method)
FIG. 6 is a diagram for explaining a method of manufacturing the liquid crystal display device 1 of FIG.
First, the sheet-like adhesive materials 14 and 15 are bonded to the front and back surfaces of the polarizing plate 13, respectively. The polarizing plate 13 to which the adhesive materials 14 and 15 are bonded is cut into the size of one liquid crystal display device 1.

  Next, the unit 100 in which the display panel 11 and the polarizing plate 13 are bonded together so that the adhesive material 15 is in close contact with the surface of the display panel 11 is manufactured.

  On the other hand, the cover 12 is originally in the state of a large plate, and is formed by applying the gas barrier film 16 on one surface of the cover 12 of the large plate or by vapor deposition by sputtering or the like. Next, the large cover 12 provided with the gas barrier film 16 is cut, and a unit 101 having a size to be bonded to one display panel 11 is manufactured.

  The two units 100 and 101 thus manufactured are bonded together under pressure so that the gas barrier film 16 and the adhesive material 14 are in close contact with each other, whereby the liquid crystal display device 1 shown in FIG. 1 is completed. This bonding may be performed under pressure and under heating.

Note that the liquid crystal display device 1 may be completed by bonding the two units 100 and 101 under vacuum so that the gas barrier film 16 and the adhesive material 14 are in close contact with each other.
(Modification)

Next, a modified example will be described.
A liquid crystal display device may be provided with a touch panel. 7 to 9 are diagrams showing a configuration of a liquid crystal display device including a touch panel. When the liquid crystal display device includes a touch panel, a cover that is a protective material is disposed on the viewing side of the touch panel. The touch panel is, for example, a capacitive panel.
In the liquid crystal display device 1 </ b> A shown in FIG. 7, a touch panel 17 is bonded to the polarizing plate 13 via an adhesive material 15 on the display panel 11 side of the polarizing plate 13 of FIG. 1, and between the touch panel 17 and the display panel 11, A space 18 having a predetermined interval is provided.

  In the liquid crystal display device 1 </ b> B shown in FIG. 8, the touch panel 17 is bonded to the polarizing plate 13 through the adhesive material 14 on the cover 12 side of the polarizing plate 13 in FIG. Provided, the touch panel 17 is bonded to the cover 12 via the adhesive material 19. In this case, the gas barrier film 16 is disposed between the cover 12 and the adhesive material 19.

In the liquid crystal display device 1 </ b> C shown in FIG. 9, the touch panel 17 is provided on the cover 12 side of the polarizing plate 13 of FIG. 1 via a space portion 20 having a predetermined interval, and further the adhesive material 19 on the cover 12 side of the touch panel 17. Is provided, and the touch panel 17 is bonded to the cover 12 via the adhesive material 19. In this case, the gas barrier film 16 is disposed between the cover 12 and the adhesive material 19.
7 to 9 as described above, the gas barrier film 16 prevents the gas from being discharged from the cover 12.

  In addition, the electro-optical device of the present invention can be applied to various liquid crystal display devices. In addition to liquid crystal display panels, electroluminescence devices, organic electroluminescence devices, plasma display devices, electrophoretic display devices, devices using electroluminescent elements (Field Emission Display, Surface-Conduction Electron-Emission Display, etc.), etc. The present invention can be similarly applied to various electro-optical devices.

  Next, an electronic apparatus having the liquid crystal display device according to the above-described embodiment as a display device will be described. FIG. 10 is a perspective view illustrating an appearance of a mobile phone as an electronic apparatus. As shown in FIG. 10, the mobile phone 1200 includes a display unit 1100 in which the liquid crystal display device 1 as the electro-optical device described above is provided together with the earpiece 1204 and the mouthpiece 1206 in addition to the plurality of operation buttons 1202. .

Electronic devices to which the electro-optical device according to the present invention can be applied include PDAs (Personal Digital Assistants), portable personal computers, digital cameras, in-vehicle monitors, digital video cameras, and liquid crystal televisions in addition to cellular phones. , Viewfinder type or direct view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor, workstation, video phone, POS terminal, and the like.
The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

The block diagram which shows the structure of the liquid crystal display device concerning embodiment of this invention. The block diagram which shows the structure of the gas barrier film concerning embodiment of this invention. The block diagram which shows the other structure of the gas barrier film concerning embodiment of this invention. The block diagram which shows the other structure of the gas barrier film concerning embodiment of this invention. The table | surface which shows the experimental data of the permeability | transmittance at the time of providing a gas barrier film. The figure for demonstrating the manufacturing method of the liquid crystal display device concerning embodiment of this invention. The figure which shows the example of a structure of the liquid crystal display device containing a touch panel. The figure which shows the other example of a structure of the liquid crystal display device containing a touch panel. The figure which shows the further another example of a structure of the liquid crystal display device containing a touch panel. The perspective view which shows the external appearance of a mobile telephone as an electronic device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Liquid crystal display device, 11 ... Display panel, 12 ... Cover, 13 ... Polarizing plate, 14, 15 ... Adhesive material, 16 ... Gas barrier film, 17 ... Touch panel.

Claims (9)

An electro-optic panel;
A plastic plate disposed on the viewing side of the electro-optic panel; and
A polarizing plate provided between the electro- optic panel and the plastic plate,
A first adhesive material for bonding the electro-optical panel and the polarizing plate;
A gas barrier film provided on the surface of the plastic plate opposite to the viewing side;
Bonding the gas barrier film of the plastic plate and the polarizing plate, and having a second adhesive material having a film thickness equal to or greater than the film thickness of the first adhesive material,
The electro-optical device, wherein the gas barrier film prevents a gas generated from the plastic plate material from being discharged to a side opposite to the viewing side of the plastic plate material.   The electro-optical device according to claim 1, wherein the gas barrier film is an inorganic film.   The electro-optical device according to claim 2, wherein the inorganic film includes one layer of a silicon oxide film and one layer of an aluminum oxide.   The electro-optical device according to claim 2, wherein the inorganic film includes two layers of a silicon oxide film.   3. The electro-optical device according to claim 2, wherein the inorganic film includes three layers including two layers of silicon oxide films and one layer of aluminum oxide. 6. The electro-optical device according to claim 5 , wherein the one layer of aluminum oxide is formed in contact with the plastic plate and is in contact with one of the two layers of the silicon oxide film.   5. One of the two layers of the silicon oxide film is a silicon dioxide film provided on the electro-optical panel side, and the other layer is a silicon monoxide film. 6. The electro-optical device according to 5. A touch panel is disposed between the electro-optic panel and the plastic plate,
The electro-optical device according to claim 1, wherein the touch panel is fixed to the plastic plate member through the gas barrier film and the second adhesive material.   An electronic apparatus comprising the electro-optical device according to claim 1.

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