JP2010181462A - Electrophoretic display device and electronic apparatus - Google Patents

Abstract

To provide an electrophoretic display device and an electronic apparatus having excellent impact resistance.
An electrophoretic display panel having an element substrate and an electrophoretic layer disposed on the element substrate is provided to be spaced from the electrophoretic display panel. A frame member surrounding the side portion, and an impact relaxation member provided to fill the gap between the electrophoretic display panel and the frame member, and the impact relaxation member contacts at least a corner portion of the element substrate. And a low elastic modulus portion formed so as to have a lower elastic modulus than other portions of the impact relaxation member and the element substrate.
[Selection] Figure 1

Description

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

  In recent years, electrophoretic display devices have been used as display units for electronic paper and the like. The electrophoretic display device has an electrophoretic dispersion liquid in which a plurality of electrophoretic particles are dispersed in a liquid phase dispersion medium, and the electrophoretic dispersion is changed by changing the distribution state of the electrophoretic particles by applying an electric field. This is a device that utilizes the change in the optical characteristics of the liquid for display. As a specific configuration of the electrophoretic display device, a configuration in which an electrophoretic sheet is attached to a display area of an element substrate and a protective substrate is attached to the electrophoretic sheet is known.

  The element substrate has a configuration in which a plurality of pixel electrodes and elements are formed in a display area on a substrate made of, for example, glass. The electrophoresis sheet has a configuration in which an electrophoresis layer and an adhesive layer are formed on a transparent sheet on which a common electrode made of ITO or the like is deposited. The transparent sheet is often composed of, for example, polyethylene terephthalate (PET). Examples of the electro-optic layer include a configuration in which microcapsules in which electrophoretic particles and a liquid layer dispersion medium for dispersing the electrophoretic particles are enclosed are spread over the entire surface of the sheet.

  As described above, since most of the materials constituting each part of the electrophoretic display device are formed of organic materials, the strength of the material itself is insufficient when pursuing thinness and lightness, and it is weak against external impact. As a result, there is a problem that it cannot be used as a product. For this reason, it is effective to avoid destruction of the display device by applying a material having an impact mitigating function used in a flat display device such as a plasma display. For example, the impact disclosed in Patent Document 1 is effective. A structure for mitigating shock to an element substrate has been proposed by a structure comprising a layer and a shock absorbing layer.

JP 2006-150755 A

  For example, a rectangular glass substrate is often used as the element substrate. In general, the corner portion of the element substrate is more easily damaged than the side portion, and thus it is necessary to ensure the shock resistance more reliably.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an electrophoretic display device and an electronic apparatus having excellent impact resistance.

  An electrophoretic display device according to the present invention is provided so as to leave an interval between an electrophoretic display panel having an element substrate and an electrophoretic layer disposed on the element substrate, and the electrophoretic display panel. A frame member surrounding a side portion of the electrophoretic display panel; and an impact mitigating member provided to fill the gap between the electrophoretic display panel and the frame member, wherein the impact mitigating member includes at least the element It has a low elastic modulus portion provided at a position in contact with a corner portion of the substrate and formed so as to have a lower elastic modulus than other portions of the impact relaxation member and the element substrate.

  According to the present invention, the impact relaxation member provided so as to fill the gap between the electrophoretic display panel and the frame member is located at a position in contact with the corner of the element substrate from the other portion of the element substrate and the impact relaxation material. Since the low elastic modulus portion is formed so as to have a low elastic modulus, the corner portion of the element substrate can be deformed against an impact. Due to this deformation, the impact can be released to the other part of the impact mitigating member, so that the impact resistance of the corner portion of the element substrate, which is more likely to be damaged, can be improved.

In the electrophoretic display device, the low elastic modulus portion is formed from a position in contact with a corner portion of the element substrate to a position in contact with the frame member.
According to the present invention, since the low elastic modulus portion is formed from the position in contact with the corner portion of the element substrate to the position in contact with the frame member, the shock transmitted from the frame portion to the corner portion of the element substrate is also reduced. It can escape to other parts of the member. Thereby, the impact to the corner | angular part of an element substrate can be reduced more reliably.

The electrophoretic display device is characterized in that the low elastic modulus portion is formed so as to be in contact with the entire thickness direction of the element substrate among corner portions of the element substrate.
According to the present invention, since the low elastic modulus portion is formed so as to be in contact with the whole of the corner portion of the element substrate in the thickness direction, the impact resistance of the corner portion of the element substrate can be further reliably improved. .

The electrophoretic display device is characterized in that the low elastic modulus portion is formed of air.
According to the present invention, since the low elastic modulus portion is formed of air, the corner portion of the element substrate can be flexibly deformed.

  An electrophoretic display device according to the present invention is provided so as to leave an interval between an electrophoretic display panel having an element substrate and an electrophoretic layer disposed on the element substrate, and the electrophoretic display panel. A frame member that encloses the side portion of the electrophoretic display panel, and the space between the electrophoretic display panel and the frame member is provided so as to fill a region excluding a position in contact with a corner portion of the element substrate. And an impact relaxation member.

  According to the present invention, since the impact relaxation member is provided so as to fill the region excluding the position in contact with the corner portion of the element substrate, the impact relaxation member is provided with a position in contact with the corner portion of the element substrate. It becomes composition. Even in such a configuration, the impact can be released to the other portion of the impact mitigating member, so that the impact resistance of the corner portion of the element substrate, which is more likely to be damaged, can be improved.

In the electrophoretic display device, a surface protection member that protects the electrophoretic display panel is provided on at least one of the panel front surface and the panel back surface of the electrophoretic display panel, and the impact relaxation member includes: It is provided to be in contact with the surface protection member.
According to the present invention, since the impact relaxation member is provided so as to contact the surface protection member, a part of the impact transmitted to the impact relaxation member can be released to the surface protection member side. Thereby, the impact resistance of the corner | angular part of an element substrate can be improved.

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 excellent in impact resistance is mounted, a highly durable electronic device 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. Process drawing which shows the process of welding a frame member. The figure which shows the structure of the electronic device which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the drawings. The following drawings are for explaining the configuration of the embodiment of the present invention, and the size, thickness, dimensions, etc. of each part shown in the drawings are different from the dimensional relationship of an actual electrophoretic display device. There is.

[First Embodiment]
FIG. 1 is a plan view schematically showing an electrophoretic display device according to a first embodiment of the present invention. 2 is a schematic cross-sectional view taken along the line AA shown in FIG.

  As shown in FIGS. 1 and 2, the electrophoretic display device EPD includes an electrophoretic display panel PL, a frame member FL, and an impact relaxation member BF. In the electrophoretic display device EPD, a frame member FL is disposed so as to surround the side of the panel with a space between the electrophoretic display panel PL, and an impact reducing member is disposed between the electrophoretic display panel PL and the frame member FL. The BF is arranged.

The electrophoretic display panel PL includes an element substrate 2 and an electrophoretic sheet 3.
The element substrate 2 has a configuration in which pixel electrodes, elements, wiring, terminals, and the like are formed on the inner surface of the plate-like member 20. The pixel electrodes are formed in a matrix at the center of the plate-like member 20 in plan view. The region where the pixel electrode is formed is a display region 5 on which an image such as a still image or a moving image is displayed. The outside of the display area 5 is a non-display area 6 where no image is displayed. The plate-like member 20 has a plurality of terminals (not shown) formed along one side (lower side in the figure) of the four sides, and is connected to the drive substrate DS via the terminals.

  The plate-like member 20 is provided in a rectangular shape in plan view. As a material constituting the plate member 20, for example, an inorganic substrate such as a glass substrate, quartz substrate, silicon substrate, gallium arsenide substrate, polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA). A plastic substrate (resin substrate) composed of polycarbonate (PC), polyethersulfone (PES), aromatic polyester (liquid crystal polymer), or the like can be used.

The electrophoretic sheet 3 has a transparent substrate 30, an electrophoretic layer 31, and an adhesive layer 33.
The transparent substrate 30 is a substrate that holds the electrophoretic layer 31, and is a rectangular substrate made of a material having high light transmittance, such as polyethylene terephthalate (PET), polyethersulfone (PES), polycarbonate (PC), and the like. The surface side of the transparent substrate 30 is the display surface side of the electrophoretic display device 1. A common electrode (not shown) is formed on the inner surface of the transparent substrate 30 over substantially the entire surface. The common electrode is made of a conductive material having high light transmission, such as ITO, and is connected to the element substrate 2 by a vertical conductive material (not shown).

  The electrophoretic layer 31 has a plurality of microcapsules 32. The microcapsule 32 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 32 include compounds such as a gum arabic / gelatin composite film, urethane resin, urea resin, and urea resin. The electrophoretic dispersion liquid enclosed in the microcapsule 32 includes a plurality of electrophoretic particles and a liquid layer dispersion medium for dispersing the electrophoretic particles.

  Examples of the liquid layer dispersion medium 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 32, 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, one of which is negatively charged and the other of which 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 adhesive layer 33 is a thermosetting adhesive that also serves as a binder. The adhesive layer 33 is preferably an adhesive having good affinity for the capsule wall film of the microcapsule 32, excellent adhesion to the common electrode and the pixel electrode, and good insulation. Further, the periphery of the electrophoretic sheet 3 is in a state of being sealed with, for example, a sealing material 9.

  In the electrophoretic display panel PL, the surface protection member 50 is disposed on the upper surface of the electrophoretic sheet 3, and the surface protection member 60 is disposed on the lower surface of the element substrate 2. The surface protection members 50 and 60 include, for example, a protective substrate that protects the surface of the electrophoretic display panel PL on the side of the electrophoretic sheet 3 and the surface on the side of the element substrate 2, and an impact mitigating film that alleviates the impact on the electrophoretic display panel PL. It has the composition which has. The surface protection members 50 and 60 have a configuration in which, for example, the impact relaxation film side is bonded to the electrophoretic display panel PL. Further, for example, an impact relaxation layer (not shown) may be arranged between the surface protection members 50 and 60 and the electrophoretic display panel PL.

  The frame member FL has the same thickness as the electrophoretic display panel PL in a cross-sectional view. The surface protection members 50 and 60 are formed so as to cover the frame member FL. The surface protection members 50 and 60 are joined to the upper and lower surfaces of the frame member FL having the same thickness as the electrophoretic display panel PL by, for example, welding.

  The impact relaxation member BF is disposed so as to fill a portion surrounded by the electrophoretic display panel PL, the frame member FL, and the surface protection members 50 and 60. As shown in FIG. 1, the impact relaxation member BF has a low elastic modulus portion 70 and a high elastic modulus portion 80.

  The low elastic modulus portion 70 is provided at a position in contact with the corner portion of the element substrate 2 and is a portion formed with a lower elastic modulus than the other portion (high elastic modulus portion 80) of the impact relaxation member BF. The low elastic modulus portion 70 is formed so as to contact the corner portion of the element substrate 2 in plan view and also contact the frame member FL. Thus, since the frame member FL and the corner portion of the element substrate 2 are connected by the low elastic modulus portion 70, the impact applied to the frame member FL is more reliably mitigated. Yes. In addition, as shown in FIG. 2, the low elastic modulus portion 70 is formed so as to be in contact with the entire element substrate 2 in the thickness direction of the element substrate 2 in a cross-sectional view. As described above, the low elastic modulus portion 70 is in contact with the entire corner portion of the element substrate 2, so that the entire corner portion of the element substrate 2 is reliably protected.

As an example of the elastic modulus of the low elastic modulus portion 70, the storage elastic modulus is 1.54 × 10 ⁵ Pa, the loss elastic modulus is 0.69 × 10 ⁵ Pa, and the loss coefficient (= loss elastic modulus / storage elasticity). Ratio) can be set to 0.450. Further, regarding the elastic modulus of the other part of the impact relaxation member BF, the storage elastic modulus is 4.56 × 10 ⁵ Pa, the loss elastic modulus is 1.38 × 10 ⁵ Pa, and the loss coefficient is 0.303. Can be set to be

  About the elastic modulus of the high elastic modulus part 80 of the impact relaxation member BF, both the storage elastic modulus and the loss elastic modulus are values that exceed the respective values of the impact relaxation member BF. Examples of the material of the impact relaxation member BF that satisfies such an elastic modulus include a resin material. In this case, the low elastic modulus portion 70 may be an air layer, for example.

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 32 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 32 by the Coulomb force. As a result, white electrophoretic particles gather on the transparent substrate 30 side in the microcapsule 32, 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, black electrophoretic particles gather on the transparent substrate 30 side in the microcapsule 32, 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.

  Next, when manufacturing the electrophoretic display device EPD configured as described above, an electrophoretic display panel PL is first created, a frame member FL is disposed around the electrophoretic display panel PL, The surface protection member 60 is disposed on one of the upper and lower surfaces (here, the lower surface) of the electrophoretic display panel PL and the frame member FL.

  Next, the impact relaxation member BF is filled in a portion surrounded by the electrophoretic display panel PL, the frame member FL, and the surface protection member 60. When filling the impact relaxation member BF, the low elastic modulus portion 70 is formed at the corner portion of the element substrate 2. When the low elastic modulus portion 70 is made of a resin material, the low elastic modulus portion 70 is formed first with the resin material, and after the low elastic modulus portion 70 is formed, the high elastic modulus portion 80 is formed using another material. To do.

  After the impact relaxation member BF is filled, the surface protection member 50 is disposed, and the surface protection members 50 and 60 and the frame member FL are welded. Hereinafter, a method of thermally welding (fusion) materials together by heating with laser light will be described. FIG. 3 is a schematic diagram showing a process of melting materials by heating with a laser beam.

  In this thermal welding method using a laser, first, as shown in FIG. 3A, an irradiated object 100 configured by laminating a light-absorbing resin 102 and a light-transmitting resin 103 on a metal substrate 101. In contrast, the laser beam L is irradiated from the side of the light transmissive resin 103 opposite to the metal substrate 101.

  Since the light-transmitting resin 103 does not absorb the laser light L, the laser light L is light-absorbing resin 102 that is an interface between the light-transmitting resin 103 and the light-absorbing resin 102 as shown in FIG. Is absorbed by the surface 102a. For this reason, the light-absorbing resin 102 is heated by the laser light L, and a portion near the surface 102a is melted to generate a melted portion M.

  When the laser beam L is subsequently irradiated, the surface 103a of the light-transmitting resin 103, which is the interface between the light-transmitting resin 103 and the light-absorbing resin 102, is caused by the heat of the melting portion M as shown in FIG. It melts and becomes a part of the melting part M.

  Next, as shown in FIG. 3D, when the irradiation of the laser beam L is stopped after the melting portion M is sufficiently formed, the temperature of the melting portion M is lowered and the molten resin is cured. In FIG. 3 (d), the boundary line of the melted part M is shown, but actually there is no boundary line between the light absorbing resin 102 and the light transmitting resin 103. In this way, the materials can be welded and integrated by heating with laser light.

  In the case where the low elastic modulus portion 70 is constituted by an air layer, for example, the surface protective member 50 is disposed instead of the surface protective member 60, and the high elastic modulus portion 80 is filled by filling the resin material from the electrophoretic sheet 3 side. Is formed first. At this time, the resin material is prevented from contacting the element substrate 2. By disposing the surface protection member 50 on the element substrate 2 side in this state, the low elastic modulus portion 70 is formed as an air layer. Then, the process of welding between the surface protection members 50 and 60 and the frame member FL is the same as the above.

  As described above, according to the present embodiment, the shock absorbing member BF provided so as to fill the space between the electrophoretic display panel PL and the frame member FL is located at a position where the shock absorbing member BF is in contact with the corner of the element substrate 2. 2 and the low elastic modulus portion 70 formed so as to have a lower elastic modulus than other portions of the impact relaxation member BF, the corner portion of the element substrate 2 can be deformed against an impact. it can. By this deformation, the impact can be released to the other part (high elastic modulus part 80) of the impact relaxation member BF, so that the impact resistance of the corner part of the element substrate 2 having a higher possibility of breakage is higher than the others. Can do.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the present embodiment, a case where the electrophoretic display device 100 of the above embodiment is applied to an electronic device will be described.

  FIG. 4A is a perspective view illustrating a configuration of the electronic paper 1100. The electronic paper 1100 includes the electrophoretic display device EPD of the above embodiment in the display area 1101. The electronic paper 1100 is flexible and includes a main body 1102 made of a rewritable sheet having the same texture and flexibility as conventional paper.

  FIG. 4B is a perspective view showing the configuration of the electronic notebook 1200. An electronic notebook 1200 is obtained by bundling a plurality of the electronic papers 1100 and sandwiching them between covers 1201. The cover 1201 includes display data input means (not shown) for inputting display data sent from an external device, for example. Thereby, according to the display data, the display content can be changed or updated while the electronic paper is bundled.

  According to the electronic paper 1100 and the electronic notebook 1200 described above, since the electrophoretic display device EPD according to the present invention is employed, an electronic apparatus including a display unit having excellent image retention characteristics and excellent display quality is obtained.

  In addition, said electronic device illustrates the electronic device which concerns on this invention, Comprising: The technical scope of this invention is not limited. For example, the electrophoretic display device according to the present invention can also be suitably used for display units of other electronic devices such as mobile phones and portable audio devices.

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 above-described embodiment, the buffer film is arranged on both sides of the surface protection members 50 and 60. However, the present invention is not limited to this, and the structure is arranged on one of the surface protection members 50 and 60. It doesn't matter. Moreover, in the said embodiment, although it was set as the structure which arrange | positions both the surface protection members 50 and 60 in the electrophoretic display panel PL, the structure which arrange | positions only any one may be sufficient.

  Moreover, in the said embodiment, although it was set as the structure formed so that the low elastic modulus part 70 might contact | connect the whole thickness direction among the corner | angular parts of the element substrate 2, it is not restricted to this, For example, an element substrate The low elastic modulus portion 70 may be formed so as to be in contact with only a part of the two corners in the thickness direction.

  In the above embodiment, the low elastic modulus portion 70 is formed so as to connect the corner portion of the element substrate 2 and the frame member FL. However, the present invention is not limited to this. For example, the element substrate 2 It may be configured to contact only the corners. Even with this configuration, the impact on the corners of the element substrate 2 can be sufficiently released to the high elastic modulus portion 80 side.

  In the above-described embodiment, the impact relaxation member BF is configured to be disposed so as to fill the portion surrounded by the electrophoretic display panel PL, the frame member FL, and the surface protection members 50, 60. The BF may be configured to be provided in at least a part of a portion surrounded by the electrophoretic display panel PL, the frame member FL, and the surface protection members 50 and 60. In this case, the impact relaxation member BF is provided at least at a portion connecting the corner portion of the element substrate 2 and the frame member FL. Further, it is preferable that the impact relaxation member BF is provided at each side of the electrophoretic display panel PL so as to have a portion connecting the side and the frame member FL.

  EPD ... electrophoretic display device PL ... electrophoretic display panel FL ... frame member BF ... impact mitigating member 2 ... element substrate 3 ... electrophoresis sheet 30 ... transparent substrate 31 ... electrophoresis layer 33 ... adhesive layer 70 ... low elastic modulus portion 80 ... High modulus part (other parts)

Claims (7)

An electrophoretic display panel having an element substrate and an electrophoretic layer disposed on the element substrate;
A frame member provided so as to be spaced from the electrophoretic display panel, and surrounding a side portion of the electrophoretic display panel;
An impact mitigating member provided to fill the gap between the electrophoretic display panel and the frame member;
The impact relaxation member is
An electrical device comprising: a low elastic modulus portion provided at least at a position in contact with a corner portion of the element substrate, and formed so as to have a lower elastic modulus than the other portion of the impact relaxation member and the element substrate. Electrophoretic display device. The electrophoretic display device according to claim 1, wherein the low elastic modulus portion is formed from a position in contact with a corner portion of the element substrate to a position in contact with the frame member. The electrophoretic display according to claim 1, wherein the low elastic modulus portion is formed so as to be in contact with the entire thickness direction of the element substrate among corner portions of the element substrate. apparatus. The electrophoretic display device according to any one of claims 1 to 3, wherein the low elastic modulus portion is formed of air. An electrophoretic display panel having an element substrate and an electrophoretic layer disposed on the element substrate;
A frame member provided so as to be spaced from the electrophoretic display panel, and surrounding a side portion of the electrophoretic display panel;
An electrophoretic display comprising: an impact mitigating member provided so as to fill a region excluding a position in contact with a corner portion of the element substrate in the interval between the electrophoretic display panel and the frame member. apparatus. At least one of the surface of the electrophoretic display panel and the back surface of the panel is provided with a surface protection member for protecting the electrophoretic display panel,
The electrophoretic display device according to claim 1, wherein the impact relaxation member is provided in contact with the surface protection member.   An electronic apparatus comprising the electrophoretic display device according to any one of claims 1 to 6.

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