JP2008203591A - Electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly dissipate charges accumulated on a cover glass which covers a display surface of a liquid crystal display panel. <P>SOLUTION: An electro-optical device includes: the liquid crystal display panel 10 having a liquid crystal 4 interposed between an AR substrate 1 with common electrodes 5 and pixel electrodes 8 arranged on the inside surface thereof, and a CF substrate 2 having no electrode arranged on the inside surface thereof; and the transparent cover glass 17 to cover the display surface side of the liquid crystal display panel 10. A transparent conductive layer 13 is formed on at least either surface of the transparent cover glass 17. By containing the liquid crystal display panel 10 in a casing 200, the transparent conductive layer 13 is grounded via a conductive film 200f formed on the casing 200, and the charges accumulated on the cover glass 17 are dissipated to the casing 200 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus that can efficiently release charges accumulated in a transparent cover member that covers a display panel.

  As is well known, a liquid crystal device that is representative of this type of electro-optical device is widely used in mobile terminals such as mobile phones and display portions of monitors. As this liquid crystal device, one using a horizontal electric field method is known. The horizontal electric field method is a method in which the direction of the electric field applied to the liquid crystal is substantially parallel to the substrate, and has an advantage that visual characteristics can be improved as compared with a TN (Twisted Nematic) method or the like. In addition, as a lateral electric field type liquid crystal device, an IPS (In-Plane Switching) type or an FFS (Fringe Field Switching) type is known.

  In this lateral electric field type liquid crystal device, since only one substrate has electrodes, static electricity is easily charged on the other substrate on which no electrode is formed, and the charge accumulated on the other substrate causes the vertical direction. When an electric field is generated, the alignment of the liquid crystal molecules is fixed in a specific direction, so that the alignment of the liquid crystal molecules cannot be controlled and display unevenness occurs.

  When the liquid crystal device is built in a mobile terminal such as a mobile phone, electric charge is easily accumulated on the other substrate due to friction in the mobile terminal. Therefore, it is necessary to take measures against static electricity on the other substrate not only during the manufacturing process but also after shipment.

  Here, with reference to FIG. 5, a conventional horizontal electric field type liquid crystal device with a countermeasure against static electricity will be briefly described. This liquid crystal device has a backlight illumination device (not shown) at the bottom of the figure, and a liquid crystal display panel 202 is provided on the backlight illumination device. The liquid crystal display panel 202 has a pair of transparent substrates 204 and 205 facing each other, the opposing surfaces of both transparent substrates 204 and 205 are bonded together with a sealant 207, and the liquid crystal 4 is interposed between the substrates 204 and 205. It is pinched. Reference numerals 206a and 206b denote polarizing plates.

  An electrode typified by a pixel electrode or a common electrode is formed on the surface of the transparent substrate 204 on the interface side with the liquid crystal 4, and a transparent conductive film 208 is formed on the outer surface of one transparent substrate 205. A ground wiring 204 b is formed on the projecting portion 204 a of the transparent substrate 204, and the ground wiring 204 b and the transparent conductive film 208 formed on the transparent substrate 205 are electrically connected by a conductive paste 209.

  In the liquid crystal device shown in FIG. 5, the charge accumulated in the transparent substrate 205 is released from the transparent conductive film 208 formed on the outer surface of the transparent substrate 205 to the transparent substrate 204 side through the conductive paste 209. An electric field is not generated between 205 and a good display state can be obtained.

As a similar technique, for example, in Patent Document 1 (Japanese Patent No. 2758864), a transparent conductive film 13 and a transparent substrate 1 formed on the surface of the transparent substrate 2 using a cable instead of the conductive paste described above are used. A technique for electrically connecting the ground wiring 204b formed in the cable to a ground using a cable is disclosed.
Japanese Patent No. 2758864

  By the way, when the horizontal electric field type liquid crystal device is attached to the display unit of the mobile terminal, the cover glass 201 is attached to the observation window 200a opened in the casing 200 of the mobile terminal as shown in FIG. The liquid crystal display panel 202 has a structure for protecting the display surface by disposing the display surface below the liquid crystal display panel 202.

  In this case, there is a structure in which the cover glass 201 and the liquid crystal display panel 202 are integrated by bonding the back surface of the cover glass 201 to the outer surface of the liquid crystal display panel 202 through an adhesive 203 applied in a frame shape. Are known.

  In general, this type of cover glass 201 is often made of an injection-molded product of a transparent resin such as an acrylic resin or a polycarbonate resin that is lightweight, has good workability, and is excellent in impact resistance. Since the resin cover glass 201 is a dielectric, charges are likely to accumulate in the cover glass 201.

  The cover glass 201 and the liquid crystal display panel 202 are electrically connected to each other even when measures are taken to release the charges accumulated on the outer surface of the liquid crystal display panel 202 to the ground wiring as in the above-mentioned patent document. Therefore, it is conceivable that electric charges accumulate.

  The charge accumulated in the cover glass 201 is discharged by the proximity or contact of a conductive object (for example, the hand of an observer), and electrostatic noise is generated. Since charges are repeatedly accumulated in the cover glass 201, the frequency of occurrence of static noise is relatively high, and the static noise may adversely affect the display image and cause discomfort to the observer. .

  In view of the above circumstances, the present invention can quickly release the electric charge accumulated in the transparent cover member without increasing the man-hours when assembling the display panel and the transparent cover member, thereby generating electrostatic noise. An object of the present invention is to provide a liquid crystal device that can be prevented in advance and does not cause discomfort to an observer.

  In order to achieve the above object, a first electro-optical device according to the present invention includes an electro-optical device between one substrate on which the common electrode and the pixel electrode are disposed on the inner surface and the other substrate on which the electrode is not disposed on the inner surface. A transparent conductive film is formed on at least one surface of the transparent cover member, including a display panel that sandwiches the substance and a transparent cover member that covers a display surface side of the display panel.

  In such a configuration, since the transparent conductive film is formed on at least one surface of the transparent cover member that covers the display surface side of the display panel, when the display panel is housed in the casing, the transparent conductive film is not in the casing. It is grounded through the body. Alternatively, the transparent conductive film can be electrically connected to an external ground wiring. As a result, the charge accumulated in the transparent cover member can be quickly released without increasing the number of steps for assembling the display panel and the transparent cover member. Therefore, even if an object having conductivity is close to or in contact with the transparent cover member, it does not discharge, and it is possible to prevent the generation of static noise, thereby making the observer uncomfortable.

  The second electro-optical device is characterized in that, in the first electro-optical device, the transparent conductive film is formed on a surface of the transparent cover member opposite to the display panel.

  In such a configuration, since the transparent conductive film is formed on the surface of the transparent cover member opposite to the display panel, when the transparent cover member is housed from the inner side with respect to the housing, the transparent conductive film Since it is grounded through the housing, the work efficiency during assembly is improved.

  According to a third electro-optical device, in the first or second electro-optical device, the transparent conductive film is formed on a surface of the transparent cover member on the display panel side.

  In such a configuration, since the bright conductive film is formed on the surface of the transparent cover member on the display panel side, when the transparent cover member is stored from the outside with respect to the casing, the transparent conductive film is not attached to the casing. Therefore, the work efficiency during assembly is improved.

  According to a fourth electro-optical device, in the third electro-optical device, the transparent conductive film is electrically connected to a substrate transparent conductive layer formed on an outer surface of the other substrate.

  In such a configuration, the transparent conductive film formed on the display panel side surface of the transparent cover member is electrically connected to the substrate transparent conductive layer formed on the outer surface of the other substrate. When the transparent conductive layer of the substrate is a polarizing plate, if the adhesive that bonds between the polarizing plate and the transparent conductive film has conductivity, the charge accumulated on the display panel side can be transferred to the transparent cover member. Can be escaped through. Alternatively, the electric charge accumulated on the transparent cover member side can be released through the ground wiring of the display panel.

  According to a fifth electro-optical device, in the fourth electro-optical device, the transparent conductive film electrically connects the substrate transparent conductive layer formed on the outer surface of the other substrate, the other substrate, and the one substrate. It is electrically connected to a ground wiring formed on the one substrate side through a conductive portion that is electrically conductive.

  In such a configuration, the transparent conductive film is placed on the one substrate side through the substrate transparent conductive layer formed on the outer surface of the other substrate and the conductive portion that electrically connects the other substrate and one substrate. Since it is electrically connected to the formed ground wiring, the charge accumulated on the transparent conductive film side can be released through the ground wiring.

  In addition, since the first electronic apparatus according to the present invention includes any one of the first to fifth electro-optical devices in the display unit, the conductor is close to or in contact with the display unit of the electronic apparatus. However, no static noise is generated and the viewer is not uncomfortable.

  The second electronic device includes a display panel that sandwiches an electro-optical material between one substrate on which an common electrode and a pixel electrode are disposed on an inner surface and the other substrate on which an electrode is not disposed on the inner surface, and the display A transparent cover member that covers the display surface side of the panel, and a housing having an observation window that engages with the transparent cover member, a transparent conductive film is formed on at least one surface of the transparent cover member, and the transparent The conductive film is connected to the ground through the casing.

  In such a configuration, since the transparent conductive film is formed on at least one surface of the transparent cover member that covers the display surface side of the display panel, the transparent cover member is simply engaged with the observation window formed in the housing. Since the transparent conductive film is grounded via the housing, the charge accumulated in the transparent cover member can be quickly released without increasing the number of steps when assembling the display panel and the transparent cover member. . Therefore, even if an object having conductivity is close to or in contact with the transparent cover member, it does not discharge, and it is possible to prevent the generation of static noise, thereby making the observer uncomfortable.

  According to a third electronic device, in the second electronic device, the transparent conductive film is formed on a surface of the transparent cover member on the display panel side.

  In such a configuration, since the transparent conductive film is formed on the surface of the transparent cover member on the display panel side, the transparent conductive film can be formed only by engaging the transparent cover member from the outside with the observation window formed on the housing. Since it is grounded through the housing, the work efficiency during assembly is improved.

  According to a fourth electronic device, in the third electronic device, the transparent conductive film is electrically connected to a substrate transparent conductive layer formed on an outer surface of the other substrate.

  In such a configuration, the transparent conductive film formed on the display panel side surface of the transparent cover member is electrically connected to the substrate transparent conductive layer formed on the outer surface of the other substrate. When the transparent conductive layer of the substrate is a polarizing plate, if the adhesive that bonds between the polarizing plate and the transparent conductive film has conductivity, the charge accumulated on the display panel side can be transferred to the transparent cover member. Can be escaped through. Alternatively, the electric charge accumulated on the transparent cover member side can be released through the ground wiring of the display panel.

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

[First Embodiment]
1 to 3 show a first embodiment of the present invention. 1 is a perspective view of a mobile phone, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.

  A reference numeral 200 in FIG. 1 is a casing of a mobile phone as a mobile terminal that is representative of an electronic device, and an observation window 200 a is opened in the casing 200. In addition, a plurality of operation buttons 200b are provided at the lower part of the observation window 200a of the casing 200, and an earpiece 200c is provided at the upper part. Reference numeral 200d is a mouthpiece.

  The liquid crystal device 100 is accommodated in the housing 200. As shown in FIG. 2, the liquid crystal device 100 includes a liquid crystal display panel 10, and a backlight illumination device 20 is disposed on the lower side of the liquid crystal display panel 10 in the drawing. The backlight illumination device 20 includes a light guide plate 11, a light source unit 15, and a reflection sheet 14 disposed on the side of the light guide plate 11 opposite to the liquid crystal display panel 10.

  The light source part 15 is arrange | positioned at the end surface of the light-guide plate 11, and is provided with the light source 16 for illumination comprised by several LED inside. The illumination light emitted from the illumination light source 16 is guided into the light guide plate 11 from the end face of the light guide plate 11, and the direction is changed by repeating reflection between the upper and lower surfaces of the light guide plate 11, and the liquid crystal display panel 10. Emitted to the side.

  The liquid crystal display panel 10 has a pair of transparent substrates 1 and 2 made of glass or the like facing each other, and both the transparent substrates 1 and 2 are bonded together with a sealant 3 therebetween. It has a cell structure in which the liquid crystal 4 is sandwiched in a region surrounded by the sealing material 3. As will be described later, pixel electrodes 8 are arranged on the transparent substrate 1 and a ground wiring is formed on the transparent substrate 1, and the colored substrate 6 is formed on the transparent substrate 2. For convenience, the transparent substrate 1 is called an array (AR) substrate 1 and the transparent substrate 2 is called a color filter (CF) substrate 2.

  Further, polarizing plates 12a and 12b are attached to the outer surface of the AR substrate 1 (lower surface in FIG. 2) and the outer surface of the CF substrate 2 (upper side in FIG. 2). Further, a transparent resin cover glass 17 serving as a transparent cover member is applied to the upper surface of the polarizing plate 12b attached to the CF substrate 2 in a frame shape around the transparent adhesive layer or the display area (any one) (Not shown).

The display surface of the liquid crystal display panel 10 is covered and protected by a cover glass 17, and in the present embodiment, the cover glass 17 and the liquid crystal display panel 10 are integrated.

  The cover glass 17 is mounted in a state of being engaged with an observation window 200 a opened in the housing 200. That is, a stepped portion 200e is formed inside the casing on the outer periphery of the observation window 200a, and a stepped portion 17a that engages with the stepped portion 200e from the inside of the casing 200 on the upper surface of the outer periphery of the cover glass 17. Is formed. And the cover glass 17 is positioned by the observation window 200a by engaging the step part 17a of the cover glass 17 with the step part 200e of the observation window 200a.

  The cover glass 17 is an injection molded product of a transparent resin such as an acrylic resin or a polycarbonate resin, and the transparent conductive film 13 is formed on the entire outer surface. Various methods for forming the transparent conductive film 13 are conceivable. For example, a transparent conductive member such as ITO (Indium-Tin-Oxide) is used to form a film by sputtering, vapor deposition, CVD, spin coating or the like, or a transparent conductive resin is applied on the cover glass 17 by printing. It is conceivable to form the surface by coating the surface of the cover glass 17 by using a droplet discharge means.

  In addition, a conductive film 200f is formed on the step portion 200e and the inner surface of the casing 200, and the conductive film 200f is electrically connected to a ground circuit (not shown) provided in the casing 200. . The conductive film 200f is formed by, for example, resin plating.

  In such a configuration, when the cover glass 17 is attached to the observation window 200a from the inside of the housing 200 in the assembly process of the mobile phone, the stepped portions 200e and 17a are engaged and positioned. At the same time, the transparent conductive film 13 formed on the stepped portion 17a of the cover glass 17 is in surface contact with the conductive film 200f formed on the stepped portion 200e on the housing 200 side and is grounded.

  Thus, in this embodiment, the transparent conductive film 13 formed on the surface of the cover glass 17 and the conductive film 200f formed on the housing 200 are electrically connected only by attaching the cover glass 17 to the observation window 200a. As a result, the work efficiency during assembly is improved. Further, it is not necessary to electrically connect the cover glass 17 and the ground wiring on the liquid crystal display panel 10 side, and the number of manufacturing steps is not increased because the process of the liquid crystal display panel 10 and the process of assembling the mobile phone are not increased. Can be suppressed.

  In addition, since the electric charge accumulated in the cover glass 17 is released to the housing 200 side through the transparent conductive film 13, it is possible to prevent the generation of electrostatic noise that adversely affects image disturbance and the like. No discomfort.

  In this case, the transparent conductive film 13 is also formed on the surface of the cover glass 17 facing the polarizing plate 12b, and the polarizing plate 12b is a substrate transparent conductive layer having conductivity and a polarizing plate that is a substrate transparent conductive layer. 12b and the transparent conductive film 13 are bonded with a conductive adhesive layer or adhesive, and the CF substrate 2 and the AR substrate 1 are connected to each other through a conductive portion (not shown) such as a conductive pace. Connect electrically. In this way, charges accumulated on the liquid crystal display panel 10 side can be released through the conductive film 200f on the housing 200 side. Alternatively, the charge accumulated in the cover glass 17 can be released through the ground wiring formed on the AR substrate 1 of the liquid crystal display panel 10.

  Next, the internal structure of the horizontal electric field type liquid crystal display panel 10 will be briefly described with reference to FIG. 2A is an enlarged sectional view of the liquid crystal display panel 10 in one subpixel, and FIG. 2B is a plan view thereof.

  FIG. 3 shows an FFS (Fringe Field Switching) type liquid crystal display panel 10. As shown in FIG. 2A, a common electrode 5 is formed on the entire surface (opposite surface) of the AR substrate 1 with the liquid crystal 4 from a transparent conductive member such as ITO. A pixel electrode 8 is formed on the common electrode 5 with an insulating layer 7 and a transparent conductive member such as ITO. Although not shown, an alignment film is formed on the uppermost layer on the opposite surface of the AR substrate 1.

  On the other hand, a colored pixel 6 is formed on the surface (facing surface) of the CF substrate 2 on the interface side with the liquid crystal 4. An alignment film 9 is formed on the uppermost layer of the facing surface.

  As shown in FIG. 3B, in the pixel electrode 8, a plurality of conductive portions 8a to 8e are arranged in a comb-like shape at regular intervals, and the conductive portions 8a to 8e are electrically connected to each other on the base side. Are connected together. The liquid crystal display panel 10 generates a horizontal electric field (lateral electric field) E between the conductive portions 8 a to 8 e and the common electrode 5.

  The pixel electrode 8 is electrically connected to some terminals of a driver IC (not shown) through wiring (not shown) formed on the AR substrate 1. Further, the common electrode 5 is electrically connected to a common potential terminal (COM terminal) of the driver IC through another wiring formed on the AR substrate 1. The driver IC controls the magnitude of the electric field E based on a control signal supplied from an external electronic device. In the horizontal electric field type liquid crystal display panel 10, by controlling the magnitude of the electric field E, the alignment state of the liquid crystal molecules in the liquid crystal 4 is changed, and the gradation on the display screen is changed.

[Second Embodiment]
FIG. 4 is a sectional view corresponding to FIG. 2 according to a second embodiment of the present invention. In the first embodiment described above, the cover glass 17 is integrated with the liquid crystal display panel 10 in advance and then attached to the mobile phone casing 200 from the inside. However, in this embodiment, the cover glass 17 is integrated. The liquid crystal display panel 10 is attached to the housing 200 from the outside. In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the present embodiment, the inner periphery of the observation window 200a is formed in a size that allows the liquid crystal display panel 10 to be inserted from the outside to the inside. Note that the light source unit 15 of the backlight illumination device 20 may be retrofitted, or the observation window 200a may be formed in a size that allows the light source unit 15 to be inserted.

  A step portion 200e is formed on the outer side of the outer periphery of the observation window 200a. Further, a step portion 17 a that engages with the step portion 200 e from the outside of the housing 200 is formed on the lower surface of the outer periphery of the cover glass 17. Further, the transparent conductive film 13 is formed on the inner surface of the cover glass 17, that is, the entire surface on the liquid crystal display panel 10 side. The material of the cover glass 17, the forming method, and the forming method of the transparent conductive film 13 are the same as those in the first embodiment.

  A conductive film 200f is formed from the stepped portion 200e of the housing 200 to the inner surface by resin plating or the like, and this conductive film 200f is electrically connected to a ground circuit (not shown) provided in the housing 200. It is connected to the.

  In such a configuration, in the process of assembling the mobile phone, the liquid crystal display panel 10 integrally having the cover glass 17 is inserted from the outside into the observation window 200a. Then, the stepped portion 17a formed on the outer periphery of the cover glass 17 is positioned by engaging with the stepped portion 200e formed on the inner periphery of the observation window 200a, and is formed on the stepped portion 17a of the cover glass 17. The transparent conductive film 13 is in surface contact with the conductive film 200f formed on the step portion 200e on the housing 200 side and is grounded. As a result, the electric charge accumulated in the cover glass 17 is released through the conductive film 200f formed in the housing 200.

  Thus, in the present embodiment, the transparent conductive film formed on the surface of the cover glass 17 simply by mounting the liquid crystal display panel 10 integrally including the cover glass 17 on the observation window 200a of the housing 200 from the outside. 13 and the conductive film 200f formed in the housing 200 can be electrically connected.

  Accordingly, it is not necessary to electrically connect the cover glass 17 and the ground wiring on the liquid crystal display panel 10 side, and it is not necessary to increase the steps of the liquid crystal display panel 10 and the process of assembling the mobile phone, and the number of manufacturing steps is reduced. Increase can be suppressed. Furthermore, since the electric charge accumulated in the cover glass 17 is immediately released, it is possible to prevent the occurrence of electrostatic noise that adversely affects image disturbance and the like, thereby preventing the viewer from feeling uncomfortable.

  In this case, the polarizing plate 12b bonded to the outer surface of the CF substrate 2 is a conductive substrate transparent conductive layer, and the conductive bonding between the polarizing plate 12b and the cover glass 17 is performed. Adhere with a layer or adhesive. Further, the CF substrate 2 and the AR substrate 1 are electrically connected through a conductive portion such as a conductive paste. In this way, the charge accumulated on the liquid crystal display panel 10 side can be released to the housing 200 side. Alternatively, the charge accumulated in the cover glass 17 can be released through the ground wiring formed on the AR substrate 1 of the liquid crystal display panel 10.

  Electronic devices to which the liquid crystal device 100 according to the present invention can be applied include, in addition to mobile phones, personal computer monitors, liquid crystal televisions, viewfinder type / direct monitor type video tape recorders, car navigation devices, pagers, and electronic devices. There are notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, and the like.

The perspective view of the mobile telephone by 1st Embodiment A-A 'sectional view of FIG. 3 shows sub-pixels of the liquid crystal device, in which (a) is a sectional view thereof and (b) is a plan view thereof. Sectional drawing equivalent to FIG. 2 by 2nd Embodiment An enlarged cross-sectional view of the main part of a conventional liquid crystal device with countermeasures against static electricity

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AR board | substrate, 2 ... CF board | substrate, 4 ... Liquid crystal, 5 ... Common electrode, 8 ... Pixel electrode, 10 ... Liquid crystal display panel, 13 ... Transparent electrically conductive film, 17 ... Cover glass, 17a ... Step part, 200 ... Housing , 200a ... observation window, 200e ... step, 200f ... conductive film

Claims (9)

A display panel that sandwiches an electro-optic material between one substrate on which the common electrode and the pixel electrode are disposed on the inner surface and the other substrate on which the electrode is not disposed on the inner surface;
A transparent cover member covering the display surface side of the display panel,
An electro-optical device, wherein a transparent conductive film is formed on at least one surface of the transparent cover member. The electro-optical device according to claim 1, wherein the transparent conductive film is formed on a surface of the transparent cover member opposite to the display panel. The electro-optical device according to claim 1, wherein the transparent conductive film is formed on a surface of the transparent cover member on the display panel side.   4. The electro-optical device according to claim 3, wherein the transparent conductive film is electrically connected to a substrate transparent conductive layer formed on the outer surface of the other substrate.   The transparent conductive film is disposed on the one substrate side through the substrate transparent conductive layer formed on the outer surface of the other substrate and a conductive portion that electrically connects the other substrate to the one substrate. The electro-optical device according to claim 4, wherein the electro-optical device is electrically connected to the formed ground wiring.   An electronic apparatus comprising the electro-optical device according to claim 1 in a display unit. A display panel that sandwiches an electro-optic material between one substrate on which the common electrode and the pixel electrode are disposed on the inner surface and the other substrate on which the electrode is not disposed on the inner surface;
A transparent cover member covering the display surface side of the display panel;
A housing having an observation window engaged with the transparent cover member,
A transparent conductive film is formed on at least one surface of the transparent cover member,
The electronic device, wherein the transparent conductive film is connected to ground through the casing. The electronic device according to claim 7, wherein the transparent conductive film is formed on a surface of the transparent cover member on the display panel side.   9. The electronic apparatus according to claim 8, wherein the transparent conductive film is electrically connected to a substrate transparent conductive layer formed on the outer surface of the other substrate.

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