Patent Publication Number: US-2013229364-A1

Title: Touch display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of China application serial no. 201210052065.1, filed on Mar. 1, 2012. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a display device. Particularly, the invention relates to a touch display device. 
     2. Description of Related Art 
     A phenomenon of electrostatic discharge can be seen everywhere in the daily living environments. Since the electron has different affinities for various objects, when any two objects are separated after contacting, it is easy to produce a phenomenon of charge transfer between the objects, which results in accumulation of static electricity. Once the static electricity in the object is accumulated to a certain degree, when the object carrying the static electricity contacts or approaches to another object with a different potential, the phenomenon of transient charge transfer is occurred, which is the so-called electrostatic discharge. 
     Taking a display panel as an example, there is a high possibility that the display panel is subjected to electrostatic discharge damage during a process of fabrication, production, assembly, transportation and even a use process after purchase. For example, when a user touches or wipes a surface of the display panel by a finger, it is easy to cause surface electrostatic charge residues to indirectly produce an electric field, which may influence arrangement of internal display media to cause a mura phenomenon. Moreover, when the components of the display panel suffer a transient high voltage electrostatic discharge, the internal circuit thereof is liable to be permanently damaged, which leads to component failure. 
     Moreover, with increasing progresses of display technology, in recent years, various electronic produces are developed towards a trend of simple operation, small size and large screen size. Especially, the portable electronic products have more strict requirements in volume and screen size. Therefore, in many electronic products, a touch panel is integrated with a display panel to save a space required by a keyboard or control buttons, so that a configuration area of the screen can be enlarged. However, since the display panel itself is a signal generation source, when a high voltage is applied to a data line of the display panel, the data line is probably coupled to a sensing pad in the touch panel, which may severely interfere a sensing signal received by the sensing pad, and lead to a poor sensing capability of the touch panel. Therefore, it is an important issue to effectively resolve the problem of static electricity on the touch panel and the display panel and between the touch panel and the display panel. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a touch display device, which is adapted to conduct static electricity on a display panel and a touch panel to ground. 
     To achieve the aforementioned advantage, the invention provides a touch display device including a display panel, a shielding electrode layer, a touch panel, a conductive element and a flexible circuit board. The display panel has a top surface. The shielding electrode layer is disposed on the display panel, and covers the top surface. The touch panel is disposed on the shielding electrode layer, and has a sensing region and a peripheral region surrounding the sensing region. The touch panel includes a substrate, a touch control element, at least one ground electrode and at least one metal wire. The touch control element is disposed on the substrate, and the touch control element includes at least one sensing electrode, at least one transmission wire and at least two pads. The sensing electrode is located in the sensing region, and the transmission wire and the pads are located in the peripheral region, and the transmission wire is located between the sensing electrode and one of the pads, and is electrically connected to the sensing electrode and one of the pads. The ground electrode is disposed in the peripheral region of the substrate. The meal wire is disposed in the peripheral region of the substrate, where the metal wire is connected between the ground electrode and another one of the pads. The conductive element is disposed between the shielding electrode layer and the touch panel, where the shielding electrode layer is electrically connected to the metal wire or the ground electrode of the touch panel through the conductive element. The flexible circuit board is disposed on the touch panel, and is located in the peripheral region, where the flexible circuit board is electrically connected to the pads, so that the sensing electrode and the metal wire are electrically connected to the flexible circuit board. 
     In an embodiment of the invention, the at least one ground electrode includes a first ground electrode and a second ground electrode. The at least one metal wire includes a first metal wire and a second metal wire. The at least two pads include a first pad, a second pad and at least one third pad located between the first pad and the second pad. The first metal wire is electrically connected to the first ground electrode and the first pad, and the second metal wire is electrically connected to the second ground electrode and the second pad. The transmission wire is connected to the third pad. 
     In an embodiment of the invention, the ground electrode is a ring-shape ground electrode, which surrounds the sensing region and has a first end and a second end opposite to each other. The at least one metal wire includes a first metal wire and a second metal wire. The at least two pads include a first pad, a second pad and at least one third pad located between the first pad and the second pad. The first metal wire is electrically connected to the first end of the ring-shape ground electrode and the first pad, and the second metal wire is electrically connected to the second end of the ring-shape ground electrode and the second pad. The transmission wire is connected to the third pad. 
     In an embodiment of the invention, the at least one ground electrode includes a first type ring-shape ground electrode and a second type ring-shape ground electrode. The first type ring-shape ground electrode and the second type ring-shape ground electrode surround the sensing region, and the first type ring-shape ground electrode has a first end and a second end opposite to each other, and the second type ring-shape ground electrode has a third end and a fourth end opposite to each other. The at least one metal wire includes a first metal wire and a second metal wire. The at least two pads include a first pad, a second pad and at least one third pad located between the first pad and the second pad. The first metal wire is electrically connected to the first end of the first type ring-shape ground electrode and the first pad, and the second metal wire is electrically connected to the third end of the second type ring-shape ground electrode and the second pad. The second end of the first type ring-shape ground electrode is adjacent to the fourth end of the second type ring-shape ground electrode. The transmission wire is connected to the third pad. 
     In an embodiment of the invention, the at least one ground electrode includes a first ground electrode and a second ground electrode. The at least one metal wire includes a first metal wire, a second metal wire and a third metal wire. The at least two pads include a first pad, a second pad and at least one third pad located between the first pad and the second pad. The first metal wire is electrically connected to the first ground electrode and the first pad, and the second metal wire is electrically connected to the second ground electrode and the second pad. The third metal wire is electrically connected to the first ground electrode and the second ground electrode and surrounds the sensing region. The transmission wire is connected to the third pad. 
     In an embodiment of the invention, the at least one sensing electrode includes a plurality of first sensing series and a plurality of second sensing series. Each of the first sensing series extends along a first direction and includes a plurality of first sensing electrode pads and a plurality of first bridge electrodes electrically connecting the first sensing electrode pads. Each of the second sensing series extends along a second direction and includes a plurality of second sensing electrode pads and a plurality of second bridge electrodes electrically connecting the second sensing electrode pads. Each of the second bridge electrodes is insulated from the corresponding first bridge electrode through an insulation layer. The first direction is intersected with the second direction, and the first sensing series and the second sensing series are intersected with each other. The at least one transmission wire includes a plurality of transmission wires, which are disposed at peripheral of the first sensing series and the second sensing series. Each of the transmission wires is connected to one of the first sensing series and the second sensing series. 
     In an embodiment of the invention, the first sensing electrode pads, the second sensing electrode pads and the ground electrode belong to a same film layer, and the second bridge electrodes, the transmission wires and the metal wire belong to a same film layer. 
     In an embodiment of the invention, the touch display device further includes an adhesive glue disposed between the touch panel and the shielding electrode layer, where the touch panel is fixed on the display panel through the adhesive glue. 
     In an embodiment of the invention, the display panel includes a transmissive display panel, a trans-reflective display panel, a reflective display panel, a vertical alignment (VA) display panel, an in plane switch (IPS) display panel, a multi-domain vertical alignment (MVA) display panel, a twist nematic (TN) display panel, a fringe field switching (FFS) display panel or an organic light-emitting diode (OLED) display panel. 
     In an embodiment of the invention, the touch panel includes a capacitive touch panel, an acoustic wave touch panel, an infrared touch panel or an optical touch panel. 
     According to the above descriptions, the shielding electrode layer is disposed between the touch panel and the display panel, which may mitigate signal interference between the touch panel and the display panel. Moreover, the shielding electrode layer can transmit the static electricity between the touch panel and the display panel to the ground electrode or the metal wire of the touch panel through the conductive element, and the metal wire transmits the static electricity generated between the touch panel and the display panel to the ground through the electrical connection between the pad and the ground terminal of the flexible circuit board. In this way, not only sensing capability of the touch display device is effectively improved, but also the static electricity is effectively discharged to protect the electronic components inside the touch display device. 
     In order to make the aforementioned and other features and advantages of the invention comprehensible, several exemplary embodiments accompanied with figures are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a cross-sectional view of a touch display device according to an embodiment of the invention. 
         FIG. 2A  is a bottom view of a touch panel and a flexible circuit board of  FIG. 1 . 
         FIG. 2B  is a partial enlarged bottom view of a touch control element of the touch panel of  FIG. 2A  according to another embodiment. 
         FIG. 2C  is a cross-sectional view of  FIG. 2B  along a line I-I. 
         FIG. 3  is a bottom view of a touch panel and a flexible circuit board of  FIG. 1  according to another embodiment. 
         FIG. 4  is a bottom view of a touch panel and a flexible circuit board of  FIG. 1  according to still another embodiment. 
         FIG. 5  is a bottom view of a touch panel and a flexible circuit board of  FIG. 1  according to yet another embodiment. 
         FIG. 6  is a bottom view of a touch panel and a flexible circuit board of  FIG. 1  according to still another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
       FIG. 1  is a cross-sectional view of a touch display device according to an embodiment of the invention.  FIG. 2A  is a bottom view of a touch panel and a flexible circuit board of  FIG. 1 . Referring to  FIG. 1  and  FIG. 2A , in the present embodiment, the touch display device  100  includes a display panel  200 , a shielding electrode layer  300 , a touch panel  400   a,  a conductive element  500  and a flexible circuit board  600 . 
     In detail, the display panel  200  has a top surface  202 . The display panel  200  is, for example, a transmissive display panel, a trans-reflective display panel, a reflective display panel, a vertical alignment (VA) display panel, an in plane switch (IPS) display panel, a multi-domain vertical alignment (MVA) display panel, a twist nematic (TN) display panel, a fringe field switching (FFS) display panel or an organic light-emitting diode (OLED) display panel, which is not limited by the invention. 
     The shielding electrode layer  300  is disposed on the display panel  200 , and covers the top surface  202  of the display panel  200 , where a material of the shielding electrode layer  300  is, for example, a transparent conductive material, for example, indium tin oxide (ITO) or indium zinc oxide (IZO). 
     Referring to  FIG. 2 , the touch panel  400   a  is disposed on the shielding electrode layer  300 , and has a sensing region  402  and a peripheral region  404  surrounding the sensing region  402 . When a user operates the touch panel  400   a,  the user may directly press or touch the sensing region  402  to execute a required instruction or function. In detail, the touch panel  400   a  includes a substrate  410 , a touch control element  420   a,  at least one ground electrode  430   a  (only one ground electrode is schematically illustrated in  FIG. 2A ) and at least one metal wire  440   a  (only one metal wire is schematically illustrated in  FIG. 2A ). The touch control element  420   a  is disposed on an insulation layer  460  (referring to  FIG. 1 ) on the substrate  410 , and the touch control element  420   a  includes at least one sensing electrode  422  (a plurality of sensing electrodes is schematically illustrated in  FIG. 2A ), at least one transmission wire  424  (a plurality of transmission wires is schematically illustrated in  FIG. 2A ) and at least two pads  426   a,  where the pads  426   a  are a first pad  426   a   1  and at least one second pad  426   a   2  (a plurality of second pads is schematically illustrated in  FIG. 2A ). The sensing electrodes  422  are located in the sensing region  402 , and the transmission wires  424  and the pads  426   a  are located in the peripheral region  404 , and the transmission wires  424  are located between the sensing electrodes  422  and the second pads  426   a   2 , and are structurally and electrically connected to the sensing electrodes  422  and the second pads  426   a   2 . The ground electrode  430   a  is disposed in the peripheral region  404  of the substrate  410 . The meal wire  440   a  is disposed in the peripheral region  404  of the substrate  410 , where the metal wire  440   a  is connected between the ground electrode  430   a  and the first pad  426   a   1 . 
     It should be noticed that although a plurality of sensing electrodes  422  and a plurality of transmission wires  424  are illustrated in  FIG. 2A , in other embodiments that are not illustrated, a single sensing electrode  422  or a single transmission wire  424  can also be used to construct the touch control element  420   a  of the touch panel  400   a.  Namely, the numbers of the sensing electrodes  422  and the transmission wires  424  are not limited to be one or plural. Moreover, a shape of the sensing electrode  422  is not limited to that illustrated in  FIG. 2A . 
     For example,  FIG. 2B  is a partial bottom enlarged view of the touch control element of the touch panel of  FIG. 2A  according to another embodiment.  FIG. 2C  is a cross-sectional view of  FIG. 2B  along a line I-I. Referring to  FIG. 2B  and  FIG. 2C , the sensing electrode  422   a  includes a plurality of first sensing series  423   a  (only one first sensing series is schematically illustrated in  FIG. 2B ) and a plurality of second sensing series  425   a  (only one second sensing series is schematically illustrated in  FIG. 2B ). Each of the first sensing series  423   a  extends along a first direction D 1  and includes a plurality of first sensing electrode pads  423   a   1  and a plurality of first bridge electrodes  423   a   2  electrically connecting the first sensing electrode pads  423   a   1 . Each of the second sensing series  425   a  extends along a second direction D 2  and includes a plurality of second sensing electrode pads  425   a   1  and a plurality of second bridge electrodes  425   a   2  electrically connecting the second sensing electrode pads  425   a   1 . Each of the second bridge electrodes  425   a   2  is insulated from the corresponding first bridge electrode  423   a   2  through an insulation layer  427 . The first direction D 1  is intersected with the second direction D 2 , and the first sensing series  423   a  and the second sensing series  425   a  are intersected with each other. A plurality of transmission wires  424   a  is disposed at peripheral of the first sensing series  423   a  and the second sensing series  425   a,  and each of the transmission wires  424   a  is connected to one of the first sensing series  423   a  and the second sensing series  425   a,  where the transmission wires  424   a  can be shielded by a light shielding layer  429 . It should be noticed that the ground electrode  430   a  (referring to  FIG. 2A ), the first sensing electrode pads  423   a   1  and the second sensing electrode pads  425   a   1  belong to a same film layer, i.e. the ground electrode  430   a,  the first sensing electrode pads  423   a   1  and the second sensing electrode pads  425   a   1  are simultaneously formed in a same fabricating process. The metal wire  440   a  (referring to  FIG. 2A ), the second bridge electrodes  425   a   2 , and the transmission wires  424   a  belong to a same film layer, i.e. the metal wire  440   a,  the second bridge electrodes  425   a   2  and the transmission wires  424   a  are simultaneously formed in a same fabricating process. In this way, fabrication cost is effectively saved. 
     Moreover, in other embodiments that are not illustrated, the sensing electrodes  422  can be a whole electrode layer formed in the sensing region  402 , or can be electrode series formed by a plurality of diamond, rectangular and polygonal electrodes. Certainly, the sensing electrodes  422  can also be bar-shape electrodes formed in the sensing region  402 . The touch panel  400   a  is, for example, a capacitive touch panel, an acoustic wave touch panel, an infrared touch panel or an optical touch panel, which is not limited by the invention. 
     Referring to  FIG. 1 , the conductive element  500  is disposed between the shielding electrode layer  300  and the touch panel  400   a,  where the shielding electrode layer  300  is structurally and electrically connected to the metal wire  440   a  or the ground electrode  430   a  of the touch panel  400   a  through the conductive element  500 . As shown in  FIG. 1 , the shielding electrode layer  300  is structurally and electrically connected to the metal wire  440   a  of the touch panel  400   a  through the conductive element  500 . Here, the conductive element  500  is, for example, a silver adhesive layer or a conductive adhesive tape. The flexible circuit board  600  is disposed on the touch panel  400   a,  and is located in the peripheral region  404 , where the flexible circuit board  600  is electrically connected to the pads  426   a  of the touch control element  420   a,  so that the sensing electrode  422  and the metal wire  440   a  are electrically connected to the flexible circuit board  600  (referring to  FIG. 2A ). Moreover, the touch display device  100  of the present embodiment further includes an adhesive glue  700  disposed between the touch panel  400   a  and the shielding electrode layer  300 , where a pattern of the adhesive glue  700  is, for example, a □-shape glue, and the touch panel  400   a  is fixed on the display panel  400   a  through the adhesion glue  700 . 
     In the touch display device  100  of the present embodiment, by configuring the shielding electrode layer  300  between the touch panel  400   a  and the display panel  200 , the display panel  200  is coupled to the shielding electrode layer  300 , so as to prevent the display panel  200  from coupling to the sensing electrode  422  in the touch panel  400   a.  In this way, an interference signal generated by the display panel  200  is prevented from influencing a touch signal sensed by the sensing electrode  422 , so that sensing capability of the touch display device  100  is improved. Moreover, since the shielding electrode layer  300  of the present embodiment can transmit the static electricity between the touch panel  400   a  and the display panel  200  to the ground electrode  430   a  or the metal wire  440   a  of the touch panel  400   a  through the conductive element  500 , and the metal wire  440   a  transmits the static electricity generated between the touch panel  400   a  and the display panel  200  to the ground through the electrical connection between the pad  426   a  and a ground terminal  602  of the flexible circuit board  600 . In this way, not only the sensing capability of the touch display device  100  is effectively improved, but also the static electricity is effectively discharged to protect the electronic components (not shown) inside the touch display device  100 . 
     It should be noticed that the numbers and patterns of the ground electrodes  430   a  and the metal wires  440   a  of the touch panel  400   a  are not limited by the invention, and in the present embodiment, the number of the ground electrode  430   a  is one and a shape thereof is a rectangle, and the number of the metal wire  440   a  is one and the metal wire  440   a  is only located between the ground electrode  430   a  and the pad  426   a.  A plurality of embodiments is provided below to describe touch panels  400   b,    400   c,    400   d  and  400   e.  It should be noticed that the referential numbers and a part of content of the aforementioned embodiment are adopted in the following embodiments, in which the same reference numbers denote the same or like components, and descriptions of the same technical contents are omitted. The aforementioned embodiment can be referred for descriptions of the omitted part, and details thereof are not repeated. 
       FIG. 3  is a bottom view of the touch panel and the flexible circuit board of  FIG. 1  according to another embodiment. Referring to  FIG. 3 , the touch panel  400   b  of the present embodiment is similar to the touch panel  400   a  of  FIG. 2A , and a main difference there between is that a ground electrode  430   b  of the touch panel  400   b  of the present embodiment includes a first ground electrode  432   b  and a second ground electrode  434   b,  the metal wire  440   b  includes a first metal wire  442   b  and a second metal wire  444   b,  and the pads  426   b  includes a first pad  426   b   1 , a second pad  426   b   2  and at least one third pad  426   b   3  (a plurality of the third pad is schematically illustrated in  FIG. 3 ) located between the first pad  426   b   1  and the second pad  426   b   2 . The first metal wire  442   b  is electrically connected to the first ground electrode  432   b  and the first pad  426   b   1 , and the second metal wire  444   b  is electrically connected to the second gound electrode  434   b  and the second pad  426   b   2 . The transmission lines  424  of the touch control element  420   b  are electrically connected to the third pads  426   b   3 . 
       FIG. 4  is a bottom view of the touch panel and the flexible circuit board of  FIG. 1  according to still another embodiment. Referring to  FIG. 4 , the touch panel  400   c  of the present embodiment is similar to the touch panel  400   a  of  FIG. 2A , and a main difference there between is that a ground electrode  430   c  of the touch panel  400   c  of the present embodiment is a ring-shape electrode, which surrounds the sensing region  402  and has a first end  433   c  and a second end  435   c  opposite to each other. The metal wire  440   c  includes a first metal wire  442   c  and a second metal wire  444   c.  The pads  426   c  include a first pad  426   c   1 , a second pad  426   c   2  and at least one third pad  426   c   3  (a plurality of the third pad is schematically illustrated in  FIG. 4 ) located between the first pad  426   c   1  and the second pad  426   c   2 . The first metal wire  442   c  is electrically connected to the first end  433   c  of the ring-shape ground electrode  430   c  and the first pad  426   c   1 , and the second metal wire  444   c  is electrically connected to the second end  435   c  of the ring-shape ground electrode  430   c  and the second pad  426   c   2 . The transmission wires  424  of the touch control element  420   c  are connected to the third pads  426   c   3 . 
       FIG. 5  is a bottom view of the touch panel and the flexible circuit board of  FIG. 1  according to yet another embodiment. Referring to  FIG. 5 , the touch panel  400   d  of the present embodiment is similar to the touch panel  400   a  of  FIG. 2A , and a main difference there between is that a ground electrode  430   d  of the touch panel  400   d  of the present embodiment includes a first type ring-shape ground electrode  432   d  and a second type ring-shape ground electrode  434   d.  The first type ring-shape ground electrode  432   d  and the second type ring-shape ground electrode  434   d  surround the sensing region  402 , and the first type ring-shape ground electrode  432   d  has a first end  433   d  and a second end  435   d  opposite to each other, and the second type ring-shape ground electrode  434   d  has a third end  437   d  and a fourth end  439   d  opposite to each other. The metal wire  440   d  includes a first metal wire  442   d  and a second metal wire  444   d.  The pads  426   d  include a first pad  426   d   1 , a second pad  426   d   2  and at least one third pad  426   d   3  (a plurality of the third pad is schematically illustrated in  FIG. 5 ) located between the first pad  426   d   1  and the second pad  426   d   2 . The first metal wire  442   d  is electrically connected to the first end  433   d  of the first type ring-shape ground electrode  432   d  and the first pad  426   d   1 , and the second metal wire  444   d  is electrically connected to the third end  437   d  of the second type ring-shape ground electrode  434   d  and the second pad  426   d   2 . The second end  435   d  of the first type ring-shape ground electrode  432   d  is adjacent to the fourth end  439   d  of the second type ring-shape ground electrode  434   d.  The transmission wires  424  of the touch control element  420   d  are connected to the third pads  426   d   3 . 
       FIG. 6  is a bottom view of the touch panel and the flexible circuit board of  FIG. 1  according to still another embodiment. Referring to  FIG. 6 , the touch panel  400   e  of the present embodiment is similar to the touch panel  400   a  of  FIG. 2A , and a main difference there between is that a ground electrode  430   e  of the touch panel  400   e  of the present embodiment includes a first ground electrode  432   e  and a second ground electrode  434   e.  The metal wire  440   e  includes a first metal wire  442   e,  a second metal wire  444   e  and a third metal wire  446   e.  The pads  426   e  include a first pad  426   e   1 , a second pad  426   e   2  and at least one third pad  426   e   3  (a plurality of the third pad is schematically illustrated in  FIG. 6 ) located between the first pad  426   e   1  and the second pad  426   e   2 . The first metal wire  442   e  is electrically connected to the first ground electrode  432   e  and the first pad  426   e   1 , and the second metal wire  444   e  is electrically connected to the second ground electrode  434   e  and the second pad  426   e   2 . The third metal wire  446   e  is electrically connected to the first ground electrode  432   e  and the second ground electrode  434   e  and surrounds the sensing region  404 . The transmission wires  424  of the touch control element  420   e  are connected to the third pads  426   e   3 . 
     In summary, the shielding electrode layer is disposed between the touch panel and the display panel, which may mitigate signal interference between the touch panel and the display panel. Moreover, the shielding electrode layer can transmit the static electricity between the touch panel and the display panel to the ground electrode or the metal wire of the touch panel through the conductive element, and the metal wire transmits the static electricity generated between the touch panel and the display panel to the ground through the electrical connection between the pad and the ground terminal of the flexible circuit board. In this way, not only sensing capability of the touch display device is effectively improved, but also the static electricity is effectively discharged to protect the electronic components inside the touch display device. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.