JP5435233B2 - Electrophoretic display device, clock, electronic device - Google Patents

Description

  The present invention relates to an electrophoretic display device, a timepiece, and an electronic device.

  Conventionally, a display device including an electrophoretic display panel having an electrophoretic layer is known (for example, Patent Document 1). In such a display device, in order to protect the electrophoretic layer from a moist environment, the electrophoretic layer is sealed with a sealing material provided at a peripheral portion of the electrophoretic layer.

JP 2009-115686 A

  However, since the sealing material provided on the periphery of the electrophoretic layer is made of resin, when a load is applied to the sealing material due to impact or the like, the sealing material is peeled off from the boundary surface by shear stress, and the electrophoretic layer There is a risk that moisture (humidity) may enter from the outside.

  The present invention has been made in view of such problems. According to some embodiments of the present invention, it is possible to provide an electrophoretic display device having impact resistance, a watch including the same, and an electronic apparatus.

  (1) The present invention includes a transparent substrate, a common electrode layer on which a common electrode is formed, an electrophoretic display layer, a drive electrode layer on which a drive electrode for driving the electrophoretic display layer is formed, and a back surface An electrophoretic display device comprising an electrophoretic display panel having a substrate laminated from the surface side, and a panel frame of the electrophoretic display panel, wherein the electrophoretic display layer is a peripheral edge of the electrophoretic display layer The panel is sealed between the transparent substrate and the back substrate by a sealing portion provided in a region including the portion, and the panel frame is formed so as to contact the electrophoretic display panel while avoiding the sealing portion. It is characterized by that.

  According to the present invention, since the panel frame does not come into contact with the sealing portion even when subjected to an impact, it is possible to prevent the sealing portion from being peeled off due to the impact, and to prevent moisture from entering the electrophoretic display layer. Can be suppressed.

  (2) Moreover, in this invention, the said panel frame may be formed so that the said sealing part may be avoided and it may contact with the said back substrate.

  According to the present invention, even if an impact is received, the panel frame comes into contact with the back substrate and does not come into contact with the sealing portion, so that the sealing portion can be prevented from peeling off due to the impact.

  (3) Moreover, in this invention, you may make it provide the protrusion which contacts the said back substrate avoiding the said sealing part in the said panel frame.

  According to the present invention, even if an impact is received, the projection provided on the panel frame comes into contact with the back substrate and does not come into contact with the sealing portion, so that the sealing portion can be prevented from peeling off due to the impact. .

  (4) Moreover, in this invention, you may make it provide the groove | channel for avoiding a contact with the said sealing part in the said panel frame.

  According to the present invention, even if an impact is received, the panel frame does not come into contact with the sealing portion due to the groove provided in the panel frame, so that the sealing portion can be prevented from peeling off due to the impact.

  (5) Moreover, the timepiece of the present invention includes the electrophoretic display device according to the present invention.

  According to the present invention, since the panel frame does not come into contact with the sealing portion even when subjected to an impact, it is possible to prevent the sealing portion from being peeled off due to the impact, and to prevent moisture from entering the electrophoretic display layer. A timepiece that can be suppressed can be provided.

  (6) Further, an electronic apparatus according to the present invention includes the electrophoretic display device according to the present invention.

  According to the present invention, since the panel frame does not come into contact with the sealing portion even when subjected to an impact, it is possible to prevent the sealing portion from being peeled off due to the impact, and to prevent moisture from entering the electrophoretic display layer. An electronic device that can be suppressed can be provided.

The front view of the wristwatch provided with the electrophoretic display device concerning this embodiment. A-A 'cross-sectional schematic diagram of FIG. The back surface schematic diagram of an electrophoretic display panel and a panel frame. Cross-sectional schematic diagram schematically showing the configuration of the electrophoretic display panel and panel frame

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of a wristwatch 1 provided with an electrophoretic display device according to the present embodiment.

  As shown in the figure, the wristwatch 1 is mainly composed of a watch case 2 (exterior case) and a pair of bands (not shown) connected to the watch case 2. The watch case 2 is made of a metal such as stainless steel or a resin such as a plastic resin. A display unit 50 and a solar cell 3 (solar panel) are provided on the front surface of the watch case 2. An operation button 10 is provided on the side surface of the watch case 2, and three operation buttons 11 are also provided on the lower front portion of the watch case 2.

  FIG. 2 is a schematic cross-sectional view taken along the line A-A ′ of FIG. 1.

  As shown in the figure, inside the watch case 2, a circuit board 42, a secondary battery (not shown), an antenna 44, a display unit 50, and the solar battery 3 are accommodated. The circuit mounted on the circuit board 42, the secondary battery, and the antenna 44 are accommodated in the circuit case 4 attached to the circuit board 42.

  On the circuit board 42, a clock circuit including an oscillation circuit and a frequency dividing circuit, a drive circuit for driving the electrophoretic display panel 5, a control IC, a capacitor, and the like are mounted.

  The display unit 50 is configured by, for example, an active matrix driving electrophoretic display panel 5, arranged on the clock front side of the circuit board 42, and held by a panel frame 52. The display surface of the display unit 50 is rectangular here. Regarding the shape of the display surface, in addition to the rectangle, other shapes such as a circular shape, a regular octagonal shape, and a dodecagonal shape may be used. The electrophoretic display panel 5 may be a segment-driven electrophoretic display panel.

  The solar cell 3 supplies the generated power to the secondary battery. The solar cell 3 is spaced from the front side of the timepiece of the electrophoretic display panel 5, and the solar cell receiving part 22 and the panel frame 52 provided inside the timepiece case 2. It is fixed by being pinched by. The electric power stored in the secondary battery is supplied to the circuit board 42 and the electrophoretic display panel 5.

  Two LED light sources (not shown) are provided between the solar cell 3 and the electrophoretic display panel 5.

  A transparent cover 7 (windshield) made of glass or resin is provided on the front side of the watch case 2. A back cover 9 is screwed to the back side (back side) of the watch case 2. The back cover 9 and the transparent cover 7 ensure the sealing performance inside the watch case 2.

  FIG. 3 is a schematic back view of the electrophoretic display panel 5 and the panel frame 52.

  As shown in the figure, the panel frame 52 is formed in a substantially rectangular shape surrounding the periphery of the electrophoretic display panel 5. The panel frame 52 is formed so as to be in contact with the electrophoretic display panel 5 while avoiding a sealing portion described later.

  In the present embodiment, a plurality of protrusions 53 that are in contact with the side surface (outer peripheral surface) of the electrophoretic display panel 5 while avoiding the sealing portion are provided on the inner peripheral surface 54 of the panel frame 52 at a predetermined interval. .

  Here, a slight gap is generated between the protrusion 53 provided on the panel frame and the side surface of the electrophoretic display panel 5. This is because the distance between the protrusion 53 and the side surface of the electrophoretic display panel 5 is 0 when the panel frame 52 has the minimum allowable dimension and the electrophoretic display panel 5 has the maximum allowable dimension due to manufacturing errors. This is because the tolerance is set so that Therefore, when the wristwatch 1 is moved or receives an impact, the electrophoretic display panel 5 slightly moves in the horizontal direction (left-right direction or vertical direction in FIG. 3) within the panel frame 52. When the electrophoretic display panel 5 moves in the horizontal direction, the side surface of the electrophoretic display panel 5 comes into contact with the protrusion 53 provided on the inner peripheral surface 54 of the panel frame 52.

  In the example shown in FIG. 3, two protrusions 53 are provided on each of the four inner peripheral surfaces 54 of the panel frame 52, but two of the four inner peripheral surfaces 54 of the panel frame 52 that face each other. Two protrusions 53 may be provided on each of the inner peripheral surfaces 54.

  FIG. 4 is a schematic cross-sectional view schematically showing the configuration of the electrophoretic display panel 5 and the panel frame 52. In the following description, the case where the electrophoretic display panel 5 is mainly an active matrix driven electrophoretic display panel will be described as an example. However, the electrophoretic display panel 5 may be a segment driven electrophoretic display panel. .

  The electrophoretic display panel 5 includes a transparent substrate 61, a common electrode layer 62 (transparent electrode layer), an electrophoretic display layer 63, and a plurality of pixel electrodes (corresponding to drive electrodes) for driving the electrophoretic display layer 63. The pixel electrode layer 64 (corresponding to the drive electrode layer) on which is formed and the element substrate 65 (corresponding to the back substrate) are laminated from the surface side. A cover glass 66 (waterproof glass) is bonded to the surface of the transparent substrate 61. The surface side of the cover glass 66 is a display surface of the electrophoretic display panel 5.

  The common electrode layer 62 is formed as a common electrode for the electrophoretic display layer 63. On the element substrate 65, a semiconductor circuit layer for supplying a voltage to each pixel electrode is formed. In this embodiment, the semiconductor circuit layer is formed as a TFT circuit layer, and the TFT circuit layer is provided with a plurality of scanning lines and a plurality of data lines arranged orthogonally. There is provided a switching element for controlling the supply voltage to. Each pixel electrode is made of, for example, a copper foil formed on a wiring board. An input terminal (not shown) to which a drive signal supplied from the circuit board 45 is input is formed on the back surface of the element substrate 65. This input terminal is preferably arranged at a position away from the antenna 44 so as not to deteriorate the radio wave reception sensitivity. That is, in the case of the present embodiment, it is preferable to form the input terminal in the lower half region of the electrophoretic display panel 5 when the wristwatch 1 is viewed from the front.

  When the electrophoretic display panel 5 is a segment drive electrophoretic display panel, each pixel electrode is a segment electrode (corresponding to the drive electrode), and the pixel electrode layer 64 is a segment electrode layer (corresponding to the drive electrode layer). The element substrate 65 corresponds to a wiring substrate (corresponding to the rear substrate) connected to a driving circuit (not shown) by wiring.

  The element substrate 65 is, for example, an inorganic substrate such as a glass substrate, a quartz substrate, a silicon substrate, or a gallium arsenide substrate, polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA), or polycarbonate (PC). A semiconductor circuit layer (not shown) is formed on a substrate using a plastic substrate (resin substrate) composed of polyethersulfone (PES), aromatic polyester (liquid crystal polymer), or the like. In the present embodiment, it is assumed that an inorganic substrate is used as a preferable example.

  When the electrophoretic display panel 5 is a segment-driven electrophoretic display panel, the wiring substrate (corresponding to the element substrate 65) is made of, for example, polyimide or glass epoxy, and a copper foil is pasted on the surface side. A segment electrode (corresponding to a pixel electrode) is formed.

  The transparent substrate 61 is a substrate that holds the electrophoretic display layer 63, and is a substrate made of a material having high light transmittance such as polyethylene terephthalate (PET), polyethersulfone (PES), polycarbonate (PC), and the like.

  The common electrode layer 62 is made of a transparent electrode material such as ITO (Indium Tin Oxide). The pixel electrode of the pixel electrode layer 64 is provided for each pixel, but the common electrode layer 62 is common to each pixel.

  The electrophoretic display layer 63 includes a plurality of microcapsules 63a and a binder material (not shown) for holding the microcapsules 63a. The binder material may also function as an adhesive between the transparent electrode layer 62 and the pixel electrode layer 64 and the microcapsule 63a. The binder material is preferably an adhesive having good affinity for the capsule wall film of the microcapsule 63a, excellent adhesion to the transparent electrode layer 62 and the pixel electrode layer 64, and good insulation.

  The electrophoretic display layer 63 may further include an adhesive layer (not shown) for improving the adhesion with the pixel electrode layer 64 on the back surface side (pixel electrode layer 64 side). The adhesive layer is preferably an adhesive that has excellent adhesion to the pixel electrode layer 64 and has good insulating properties.

  The microcapsule 63a encloses an electrophoretic particle dispersion in which a large number of charged particles are dispersed. In the electrophoretic particle dispersion liquid, black electrophoretic particles (hereinafter referred to as black particles) and white electrophoretic particles (hereinafter referred to as white particles) are dispersed, and an electrophoretic layer of a two-color powder fluid system. Is configured. These black particles and white particles are charged with different polarities, and in this embodiment, the black particles are negatively charged and the white particles are positively charged.

  The electrophoretic display layer 63 is interposed between the transparent substrate 61 and the element substrate 65 by a sealing material 67 (sealing portion) made of epoxy resin or the like provided in a region including the peripheral portion of the electrophoretic display layer 63. Is sealed. Thereby, the electrophoretic display layer 63 is protected from a moist environment, and the characteristic change of the electrophoretic particles is suppressed. Further, a sealing material 67 is also provided on the peripheral portion of the pixel electrode layer 64, thereby preventing the pixel electrode layer 64 from being corroded.

  Here, in the present embodiment, a protrusion 53 is provided on the inner peripheral surface of the panel frame 52, and the protrusion 53 is formed so as to contact a rigid element substrate 65 (back substrate) while avoiding the sealing material 67. Has been. That is, the protrusion 53 is provided at a position on the inner peripheral surface of the panel frame 52 at a height equal to or lower than the height of the boundary surface 67 a between the sealing material 67 and the element substrate 65.

  In this way, even if the electrophoretic display panel 5 is moved in the right direction in FIG. 4 due to the impact of the wristwatch 1 or the like, the projection 53 provided on the panel frame 52 comes into contact with the back substrate 65. Since the panel frame 52 does not contact the sealing material 67, it is possible to prevent a load from being applied to the sealing material 67 due to an impact or the like. That is, it is possible to prevent the sealing portion 76 from being peeled off from the boundary surface 67a due to a load due to impact or the like, and to prevent moisture (humidity) from entering the electrophoretic display layer 63.

  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 case where the projection 53 that contacts the element substrate 65 is provided on the panel frame 52 while avoiding the sealing material 67 has been described as an example. A groove for avoiding the contact may be provided. The panel frame 52 may be formed so that a portion other than the portion provided with the groove of the panel frame 52 is in contact with the element substrate 65.

  In the above embodiment, the case where a microcapsule type electrophoretic display layer is used has been described as an example. However, the present invention is not limited to this, and other electrophoretic display layers are used. In the case of using, for example, a display layer of a horizontal movement type electrophoresis method or a vertical movement type electrophoresis method is also applicable.

  In the present embodiment, the case where the electrophoretic display device is applied to a watch such as a wristwatch has been described as an example. However, the present invention is not limited thereto, and the electrophoretic display device may be used as an electrophoretic display device for other electronic devices. Is possible.

  Here, the electronic device means any device including the above-described electrophoretic display device as a display unit, and includes a display device, a television device, an electronic book, an electronic paper, an electronic notebook, a calculator, a mobile phone, and portable information. Includes terminals.

DESCRIPTION OF SYMBOLS 1 Wristwatch, 2 Watchcase (exterior case), 3 Solar cell, 4 Circuit case, 5 Electrophoretic display panel, 7 Transparent cover, 8 LED light source, 9 Back cover, 10 Operation button, 11 Operation button, 22 Solar cell receiving part , 42 circuit board, 44 antenna, 50 display unit, 52 panel frame, 53 protrusion, 54 inner peripheral surface, 60 cover glass, 61 transparent substrate, 62 common electrode layer, 64 pixel electrode layer (drive electrode layer), 65 element substrate (Back substrate), 67 Sealing material (sealing part)

Claims (3)

A transparent substrate, a common electrode layer on which a common electrode is formed, an electrophoretic display layer, a drive electrode layer on which a drive electrode for driving the electrophoretic display layer is formed, and a back substrate are formed from the front side. Stacked electrophoretic display panels;
A panel frame of the electrophoretic display panel,
The electrophoretic display layer is sealed between the transparent substrate and the back substrate by a sealing portion provided in a region including a peripheral portion of the electrophoretic display layer,
Said panel frame, an electrophoretic display device provided with a projection in contact with the side surface of the rear substrate while avoiding the sealing portion. A timepiece comprising the electrophoretic display device according to claim 1 . An electronic apparatus comprising the electrophoretic display device according to claim 1 .

Images