JP5387749B2 - Electrophoretic display device and electronic apparatus - Google Patents

Description

  The present invention relates to an electrophoretic display device and an electronic apparatus.

  There is known an electrophoretic display device in which an electrophoretic layer is sandwiched between an element substrate and a counter substrate.

  FIG. 7 is a plan view showing the configuration of the electrophoretic display device 201, and FIG. 8 is a diagram showing the configuration along the section CC in FIG. As shown in FIGS. 7 and 8, the electrophoretic display device 201 is configured so that the counter substrate 203 covers the display region 205 of the element substrate 202, and is disposed in a region outside the display region 205 of the element substrate 202. Drive circuits 222 and 223, wirings, and the like are formed.

  The counter substrate 203 side of the electrophoretic display device 201 is the display surface side. In order to protect this display surface, a protective substrate 207 is provided on the surface 203 a of the counter substrate 203. The counter substrate 203 and the protective substrate 207 are fixed with a transparent adhesive 208b. Further, the peripheral edge portion of the counter substrate 203 between the protective substrate 207 and the element substrate 202 is sealed with a sealing material 208a made of a resin material or the like. As shown in FIGS. 7 and 8, the sealing material 208 was formed not only on the peripheral portions of the element substrate 202 and the protective substrate 207, but also on the region where the drive circuits 222, 223, wirings, and the like were disposed. .

JP 2005-114822 A

  However, since the linear expansion coefficient of the resin material constituting the sealing member 208 is usually higher than the linear expansion coefficient of the material constituting the element substrate 202 and the protective substrate 207, for example, a thermal shock test of −20 ° C. to 85 ° C. In this case, local stress is generated between the element substrate 202 and the sealing material 208 due to the difference in the linear expansion coefficient, which affects the components formed on the element substrate such as the drive circuit and the wiring. There was a case where it gave it. In particular, when the stress is large, the characteristics of the drive circuit may be changed, or in some cases, local peeling may occur between the element substrate 202 and the sealing material 208, and the drive circuit may be destroyed. there were.

  In view of the above circumstances, it is an object of the present invention to provide an electrophoretic display device and an electronic device that are excellent in reliability.

  To achieve the above object, an electrophoretic display device according to the present invention is an electrophoretic display device in which an electrophoretic layer is sandwiched between an element substrate and a counter substrate, and is driven to a region other than the display region of the element substrate. A circuit is provided, and the counter substrate overlaps at least a part of the element substrate in which the driver circuit is provided and the display region.

  According to the present invention, the drive circuit is provided in a region other than the display region of the element substrate, and the counter substrate overlaps at least a part of the region of the element substrate where the drive circuit is provided and the display region. Therefore, at least a part of the region where the drive circuit is provided is protected by the counter substrate. For this reason, even when it is necessary to form a layer having a high thermal expansion coefficient at a position overlapping the drive circuit in plan view, the layer is formed on the counter substrate, and the thermal expansion coefficient is formed on the drive circuit. It is possible to prevent a high layer from being directly formed. For this reason, even when a thermal shock is applied and a stress is generated between the element substrate and the layer, the influence of the stress does not reach the components on the element substrate. Thereby, an electrophoretic display device excellent in reliability can be obtained.

The electrophoretic display device is characterized in that the counter substrate overlaps a region occupying approximately two-thirds or more of the driving circuit in a plan view.
According to the present invention, since the counter substrate overlaps with an area occupying approximately two-thirds or more of the drive circuit in plan view, the drive circuit can be more reliably protected.

The electrophoretic display device is characterized in that the counter substrate overlaps the entire driving circuit in plan view.
According to the present invention, since the counter substrate overlaps the entire drive circuit in plan view, the entire drive circuit can be reliably protected. Thereby, it is possible to reliably prevent the components of the element substrate from being affected.

In the electrophoretic display device, a protective substrate for protecting the surface is provided on the surface of the counter substrate, and a sealing material is provided between the element substrate and the protective substrate. And
According to the present invention, the surface of the counter substrate is provided with the protective substrate for protecting the surface, and the sealing material is provided between the element substrate and the protective substrate. Even when the sealing material is disposed at a position overlapping in plan view, the sealing material is provided on the counter substrate overlapping the driving circuit. For this reason, even if it is a case where a sealing material expand | swells with a heat | fever, it can prevent reliably affecting a drive circuit.

  An electrophoretic display device according to the present invention is an electrophoretic display device in which an electrophoretic layer is sandwiched between an element substrate and a counter substrate, and the driving circuit provided in a region other than the display region of the element substrate; And a protective layer provided so as to overlap at least part of a region of the element substrate where the driving circuit is provided.

  According to the present invention, a drive circuit provided in a region other than the display region of the element substrate and a protective layer provided so as to overlap at least part of the region of the element substrate provided with the drive circuit are provided. As a result, at least a part of the drive circuit is protected by the protective layer. For this reason, even when it is necessary to form a layer having a high thermal expansion coefficient at a position overlapping the drive circuit in plan view, the layer is formed on the protective layer, and the thermal expansion coefficient is formed on the drive circuit. It is possible to prevent a high layer from being directly formed. For this reason, even when a thermal shock is applied and a stress is generated between the element substrate and the layer, the influence of the stress does not reach the components on the element substrate. Thereby, an electrophoretic display device excellent in reliability can be obtained. In addition, according to the present invention, since it is possible to prevent the components of the element substrate from being affected without increasing the size of the counter substrate, an area outside the display area (frame area) is expanded. Can be avoided.

The electrophoretic display device is characterized in that a plurality of the protective layers are provided.
According to the present invention, since a plurality of protective layers are provided, it is possible to more reliably prevent the constituent elements of the element substrate from being affected.

In the electrophoretic display device, a protective substrate for protecting the surface is provided on the surface of the counter substrate, and a sealing material is provided between the element substrate and the protective substrate. And
In the electrophoretic display device, the sealing material is provided between the protective layer and the protective substrate.

The electrophoretic display device is characterized in that the linear expansion coefficient of the protective layer gradually decreases from the counter substrate side to the element substrate side.
According to the present invention, since the linear expansion coefficient of the protective layer gradually decreases from the counter substrate side to the element substrate side, the influence of thermal expansion decreases as the distance from the element substrate approaches. Thereby, it is possible to suppress the influence of thermal expansion on the element substrate. When the protective layer is a single layer, the linear expansion coefficient can be gradually reduced in the protective layer. When there are a plurality of protective layers, the linear expansion coefficient may be configured to decrease stepwise for each layer, or the linear expansion coefficient may be continuously decreased over a plurality of layers from the upper layer side to the lower layer side. May be. When changing the linear expansion coefficient, for example, the linear expansion coefficient can be reduced by mixing an inorganic filler such as silica or an organic filler such as rubber in the protective layer.

An electronic apparatus according to the present invention includes the above-described electrophoretic display device.
According to the present invention, since the electrophoretic display device capable of reliably preventing the damage to the constituent elements of the element substrate is mounted, an electronic device having excellent durability can be obtained.

1 is a plan view showing a configuration of an electrophoretic display device according to a first embodiment of the present invention. FIG. 3 is a cross-sectional view showing the configuration of the electrophoretic display device according to the embodiment. The top view which shows the structure of the electrophoretic display device which concerns on 2nd Embodiment of this invention. FIG. 3 is a cross-sectional view showing the configuration of the electrophoretic display device according to the embodiment. Sectional drawing which shows the other structure of the electrophoretic display apparatus which concerns on this invention. The top view which shows the structure of the conventional electrophoretic display apparatus. Sectional drawing which shows the structure of the conventional electrophoretic display apparatus. The perspective view which shows the structure of the electronic device which concerns on 3rd Embodiment of this invention.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a schematic configuration of an electrophoretic display device 1 according to the present embodiment. FIG. 2 is a diagram showing a configuration along the section AA in FIG.

  As shown in FIGS. 1 and 2, the electrophoretic display device 1 includes an element substrate 2, a counter substrate 3, and an electrophoretic layer 4, and the electrophoretic layer 4 is sandwiched between the element substrate 2 and the counter substrate 3. It has a configuration. The electrophoretic display device 1 is provided with a display area 5 for displaying images such as still images and moving images. A plurality of pixels are provided in the display area 5, and these pixels are arranged in a matrix. In the display area 5, display is performed for each pixel. A region 6 around the display region 5 is a non-display region where no image is displayed. The non-display area 6 is not provided with pixels, but is provided with a drive circuit, wiring, and the like.

  A protective substrate 7 for protecting the outer surface 3a is provided on the outer surface 3a side of the counter substrate 3, and the protective substrate 7 and the element substrate 2 are sealed with a sealing material 8a. As the protective substrate 7, glass having high light transmittance, excellent flatness, and being hardly scratched is suitable. Specifically, inorganic glass or crystal glass can be used. Further, sapphire glass or acrylic glass may be used. The protective substrate 7 and the counter substrate 3 are fixed with a transparent adhesive 8b.

  Examples of the material constituting the sealing material 8a include epoxy-based, acrylic-based, and silicon-based resins. The element substrate 2 is larger in dimensions in the left-right direction in the drawing than the counter substrate 3, and is provided with a region (projected region) 2 a that projects from the counter substrate 3. The overhang region 2a is provided with a flexible substrate P for electrical connection to an external circuit or the like.

  In addition, the electrophoretic layer 4 is sandwiched between the element substrate 2 and the counter substrate 3 and is covered with the protective substrate 7, and the peripheral portion is sealed with a sealing material 8 a. Since the electrophoretic layer 4 that dislikes moisture is covered in this way, it is possible to reliably prevent moisture from entering.

  The element substrate 2 includes a rectangular substrate 20 on which electrodes, elements, wirings, and the like for driving the electrophoretic display device 1 are provided. The substrate 20 is, for example, a glass substrate, a quartz substrate, a silicon substrate, a gallium arsenide substrate, polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethersulfone ( There are plastic substrates (resin substrates) composed of PES), aromatic polyester (liquid crystal polymer) and the like. In the region corresponding to the display region 5 in the substrate 20, a driving layer 21 having pixel electrodes and switching elements provided for each pixel, data lines and scanning lines connected to the switching elements, and the like is formed. A driver circuit 23 connected to the data line, a driver circuit 22 connected to the scanning line, and the like are formed in an area corresponding to the non-display area 6 in the substrate 20.

  The counter substrate 3 is a substrate for holding the electrophoretic layer 4 with the element substrate 2, and the outer surface 3 a side of the counter substrate 3 is the display surface side of the electrophoretic display device 1. The counter substrate 3 includes a rectangular substrate 30 made of a material having a high light transmittance such as polyethylene terephthalate (PET), polyethersulfone (PES), polycarbonate (PC), and the like. A common electrode is formed on almost the entire surface. The common electrode is made of a conductive material having high light transmittance such as ITO. The counter substrate 3 is provided so as to overlap in a plan view over a region corresponding to the display region 5 of the element substrate 2 and a region including the driver circuit 22 and the driver circuit 23 in the non-display region 6 of the element substrate 2. It has been. The common electrode of the counter substrate 3 is connected to the element substrate 2 by a vertical conductive material 9.

  The electrophoretic layer 4 is a layer sandwiched between the pixel electrode of the element substrate 2 and the common electrode of the counter substrate 3, and includes a plurality of microcapsules 40 and a binder 41. The electrophoretic layer 4 is disposed over substantially the entire surface of the region where the counter substrate 3 is provided in plan view, and is also disposed on the region including the driver circuit 22 and the driver circuit 23 of the element substrate 2. The microcapsule 40 is a substantially spherical capsule in which an electrophoretic dispersion is enclosed, and the diameter of each capsule is substantially the same (50 μm to 100 μm). Examples of the material for forming the capsule wall film of the microcapsule 40 include compounds such as gum arabic / gelatin composite film, urethane resin, urea resin, and urea resin. The electrophoretic dispersion liquid enclosed in the microcapsule 40 includes electrophoretic particles and a liquid layer dispersion medium in which the electrophoretic particles are dispersed.

  Examples of liquid dispersion media include water, alcohol solvents, various esters, ketones, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, carboxylates, and other various oils. These can be used alone, or a mixture of these with a surfactant or the like.

  As the electrophoretic particles, organic or inorganic particles (polymer or colloid) having a property of moving by electrophoresis due to a potential difference in a liquid phase dispersion medium can be used. Specifically, black pigments such as carbon black and aniline black, white pigments such as titanium dioxide, monoazo azo pigments, yellow pigments such as isoindolinone, monoazo azo pigments, red pigments such as quinacridone red, phthalocyanine One or more of blue pigments such as blue and green pigments such as phthalocyanine green can be used. These pigments include electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, charge control agents composed of particles such as compounds, titanium-based coupling agents, aluminum-based coupling agents, silanes as necessary. A dispersant such as a system coupling agent, a lubricant, a stabilizer, and the like can be added.

  In the microcapsule 40, for example, two types of electrophoretic particles of titanium dioxide which is a white pigment and carbon black which is a black pigment are encapsulated, and one is negatively charged and the other is positively charged. Of course, other electrophoretic particles may be used, or only one type of electrophoretic particle may be used, and the electrophoretic particles may be moved to the common electrode side or the pixel electrode side so that display can be performed.

  The binder 41 is a fixing member that fixes the plurality of microcapsules 40 to the counter substrate 3 in particular. As the binder 41, it is preferable to use a material having good affinity for the capsule wall film of the microcapsule 40, excellent adhesion to the common electrode, and insulating properties.

Next, the operation of the electrophoretic display device 1 configured as described above will be briefly described.
When a voltage is applied between the pixel electrode and the common electrode so that the voltage of the common electrode becomes relatively high, the positively charged black electrophoretic particles are moved to the pixel electrode side in the microcapsule 40 by the Coulomb force. Gravitate. On the other hand, the negatively charged white electrophoretic particles are attracted to the common electrode side in the microcapsule 40 by the Coulomb force. As a result, white electrophoretic particles gather on the counter substrate 3 side in the microcapsule 40, and the color (white) of the white electrophoretic particles is displayed in the display area 5 of the electrophoretic display device 1. The Rukoto.

  Conversely, when a voltage is applied between the pixel electrode and the common electrode so that the potential of the pixel electrode is relatively high, the negatively charged white electrophoretic particles are attracted to the pixel electrode side by Coulomb force. On the other hand, the positively charged black electrophoretic particles are attracted to the common electrode side by the Coulomb force. As a result, the black electrophoretic particles gather on the counter substrate 3 side in the microcapsule 40, and the color (black) of the black electrophoretic particles is displayed in the display area 5 of the electrophoretic display device 1. It will be.

  According to the present embodiment, the driver circuit 22 and the driver circuit 23 formed in the non-display area 6 are connected to the counter substrate 3 even when the electrophoretic display device 1 is exposed to an environment where the use temperature changes rapidly. With the configuration of covering, it is possible to prevent the driver circuit and the sealing material 8a from coming into direct contact. Thereby, even when a thermal shock is applied and a stress is generated between the element substrate 2 and the sealing material 8a, the influence of the stress does not reach the driver circuit 23, and high reliability is ensured. can do. This configuration is particularly effective when the element substrate 2 is made of glass having a large difference in thermal expansion coefficient from the sealing material 8a.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 3 is a plan view showing the configuration of the electrophoretic display device 101 according to the present embodiment, and corresponds to FIG. 1 of the first embodiment. FIG. 4 is a diagram showing a configuration along the BB cross section in FIG. 3, and corresponds to FIG. 2 of the first embodiment. In the present embodiment, the configuration of the element substrate 102 is different from that of the first embodiment.

  Specifically, the counter substrate 103 is provided so as to substantially overlap the display region 105 of the element substrate 102, and a protective layer 124 is provided on the region of the element substrate 102 where the driver circuit 122 and the driver circuit 123 are formed. Is provided. The protective layer 124 is made of, for example, a material having a linear expansion coefficient that is a value between the linear expansion coefficient of the element substrate 102 and the linear expansion coefficient of the sealing material 108a. Examples of such a material include a resin material having a high filler content. The protective layer 124 is provided in close contact with the side portion of the counter substrate 103 and the side portion of the electrophoretic layer 104, and the electrophoretic layer 104 is sealed by the protective layer 124 and the sealing material 108 a. ing.

  According to the present embodiment, since the protective layer 124 is provided so as to overlap the region of the element substrate 102 where the driver circuit 122 and the driver circuit 123 are provided, the driver circuit 122 and the driver circuit 123 are protected from the protective layer 124. Will be protected by. For this reason, the sealing material 108a is formed on the protective layer 124, and it is possible to prevent the driver circuit 122 and the driver circuit 123 from directly contacting the sealing material 108a having a high thermal expansion coefficient. As a result, even when a thermal shock is applied and a stress is generated between the element substrate 102 and the sealing material 108a, the influence of the stress does not reach the driver circuit 123, and high reliability is ensured. can do. In addition, according to the present embodiment, since it is possible to prevent damage to the components of the element substrate 102 without increasing the size of the counter substrate 103, an area outside the display area 105 (the frame) of the counter substrate 103. (Area) can be prevented from spreading. This configuration is particularly effective when the element substrate is made of glass having a large difference in thermal expansion coefficient from that of the sealing material. Note that the sealing material 108 a may be provided between the protective layer 124 and the protective substrate 107. Even if it is the said structure, there will exist said effect.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
FIG. 5 is a perspective view showing the configuration of the electronic paper. The electronic paper 1000 includes the electrophoretic display devices 1 and 101 as a display unit. The electronic paper 1000 has a configuration in which a display unit 200 including electrophoretic display devices 1 and 101 is provided on the surface of a main body 1001 including a sheet having the same texture and flexibility as conventional paper. Since the electronic paper 1000 according to the present embodiment includes the display unit 200 that includes the above-described electrophoretic display device, the electronic paper 1000 itself is also highly reliable with stable display characteristics.

  In addition to the examples described above, other examples include liquid crystal televisions, viewfinder type and monitor direct view type video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, watches And a device equipped with a touch panel. The electrophoretic display device 200 according to the present invention can also be applied as a display unit of such an electronic device.

The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention.
For example, in the second embodiment, the protective layer 124 is composed of one layer. However, the present invention is not limited to this. For example, as shown in FIG. 6, the protective layer 124 may be composed of a plurality of layers. Absent. FIG. 6 is a view showing a cross-sectional configuration of the electrophoretic display device 101 (a cross-sectional view taken along the line BB in FIG. 3), and corresponds to FIG. 4 of the second embodiment. In FIG. 6, for example, the protective layer 124 has a three-layer structure of a lower layer 124a, a middle layer 124b, and an upper layer 124c, but it may be two layers or four or more layers.

  In FIG. 6, the material of each layer may be selected so that the linear expansion coefficient gradually decreases from the upper layer 124 c to the lower layer 124 a in the protective layer 124. For example, each layer can be formed so that the linear expansion coefficient of each of the upper layer 124c, the middle layer 124b, and the lower layer 124a shown in FIG. Thereby, since the linear expansion coefficient becomes smaller as the element substrate 102 is approached, the influence of thermal expansion can be minimized. The linear expansion coefficient may not be reduced stepwise for each layer, but the linear expansion coefficient may be continuously reduced over a plurality of layers. When the linear expansion coefficient is changed, the linear expansion coefficient can be reduced by mixing each protective layer 124 with an inorganic filler such as silica or an organic filler such as rubber. This configuration is particularly effective when the element substrate 103 is made of glass or the like having a large difference in thermal expansion coefficient from the sealing material 108a. Note that the sealing material 108 a may be provided between the protective layer 124 and the protective substrate 107. Even if it is the said structure, there will exist said effect.

  In the first embodiment, the counter substrate 3 is provided so as to overlap the entire area of the driver circuit 22 and the driver circuit 23. However, the counter substrate 3 overlaps only part of the driver circuit 22 and the driver circuit 23. It does not matter. In this case, the driver circuit 22 and the driver circuit 23 are preferably provided so as to overlap two or more regions of the driver circuit 22 and the driver circuit 23. Thereby, the driver circuit 22 and the driver circuit 23 can be more reliably protected.

  DESCRIPTION OF SYMBOLS 1,101 ... Electrophoretic display device 2,102 ... Element board | substrate 3,103 ... Opposite board | substrate 4,104 ... Electrophoresis layer 5,105 ... Display area 6,106 ... Non-display area 7,107 ... Protective substrate 8,108 ... Sealing material 22, 122 ... driver circuit 23, 123 ... driver circuit 124 ... protective layer 124a ... lower layer 124b ... middle layer 124c ... upper layer 1000 ... electronic paper

Claims (4)

An electrophoretic display device sandwiching an electrophoretic layer between an element substrate and a counter substrate,
A drive circuit provided in a region other than the display region of the element substrate;
A protective layer provided so as to overlap at least a part of a region of the element substrate where the drive circuit is provided ,
A protective substrate for protecting the surface is provided on the surface of the counter substrate,
A sealing material is provided between the element substrate and the protective substrate,
The sealing material is provided between the protective layer and the protective substrate,
The electrophoretic display device , wherein the protective layer is made of a material having a linear expansion coefficient that is a value between the linear expansion coefficient of the element substrate and the linear expansion coefficient of the sealing material . The electrophoretic display device according to claim 1, wherein a plurality of the protective layers are provided. The electrophoretic display device according to claim 1, wherein a linear expansion coefficient of the protective layer gradually decreases from the counter substrate side to the element substrate side. An electronic apparatus comprising the electrophoretic display device according to any one of claims 1 to 3 .

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