Abstract:
Disclosed is a touch window. The touch window includes a cover substrate; a ground electrode on the cover substrate; and a circuit substrate on the cover substrate, including aground connecting part connected with the ground electrode and an open area to expose the ground connecting part, wherein the ground electrode is electrically connected to the ground connecting part through the open area.

Description:
CROSS-REFERENCES TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §119 of Korean Patent Application No. 10-2013-0111413, filed Sep. 16, 2013, which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
     Technical Field 
       [0002]    The disclosure relates to a touch window. 
         [0003]    A touch window is installed on a display surface of an image display device such as a cathode ray tube (CRT), a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electro-luminescence device (ELD), so that a user inputs predetermined information into an electronic appliance by pressing the touch panel while viewing the image display device. 
         [0004]    Due to the static electricity or ESD (Electric Static Discharge) generated from such a touch window, electrical signal interference is caused so that the accuracy of a touch is deteriorated. 
       BRIEF SUMMARY 
       [0005]    The embodiment provides a touch window having the improved reliability. 
         [0006]    A touch window according to the embodiment includes a cover substrate; a ground electrode on the cover substrate; and a circuit substrate on the cover substrate, including a ground connecting part connected with the ground electrode and an open area to expose the ground connecting part, wherein the ground electrode is electrically connected to the ground connecting part through the open area. 
         [0007]    The ground electrode is disposed on the cover substrate included in the touch window according to the embodiment. The ground electrode prevents static electricity or ESD in the touch window. That is, the static electricity or ESD moves along a path of the ground electrode, an that the static electricity or ESD can be prevented from being introduced into the touch window. The ground electrode is disposed along the edge of the cover substrate, so that the static electricity or ESD can be effectively prevented from being introduced into the touch window. The ground electrode is connected to the circuit substrate so that the ESD in the touch window can be discharged as an electrical signal. 
         [0008]    Thus, signal interference is prevented, so that accuracy and reliability of a touch can be improved. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view showing an exploded touch window according to an embodiment. 
           [0010]      FIG. 2  is a sectional view taken along tine A-A′ of  FIG. 1 . 
           [0011]      FIGS. 3 to 7  are perspective views showing exploded touch windows according to other embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    In the following description of the embodiments, it will be understood that, when a layer (or film), a region, a pattern, or a structure is referred to as being “on” or “under” another substrate, another layer (or film), another region, another pad, or another pattern, it can be “directly” or “indirectly” on the other substrate, layer (or film), region, pad, or pattern, or one or more intervening layers may also be present. Such a position of the layer has been described with reference to the drawings. 
         [0013]    The thickness and size of each layer shown in the drawings may be exaggerated, omitted or schematically drawn for the purpose of convenience or clarity In addition, the size of elements does not utterly reflect an actual size. 
         [0014]    Hereinafter, an embodiment will be described in detail with reference to accompanying drawings. 
         [0015]    First, a touch window according to an embodiment will be described in detail with reference to  FIGS. 1 and 2 .  FIG. 1  is a perspective view showing an exploded touch window according to an embodiment.  FIG. 2  is a sectional view taken along line A-A′ of  FIG. 1 . 
         [0016]    Referring to  FIGS. 1 and 2 , the touch window includes a cover substrate  100 , an electrode substrate  200  and a circuit substrate  300 . 
         [0017]    The cover substrate  100  is disposed at the uppermost position of the touch window, An input device such as a finger may be touched to a top surface of the cover substrate  100 . The cover substrate  100  may protect various elements disposed below the cover substrate  100 . For example, the cover substrate  100  may include strengthened glass, half-strengthened glass, sodalime glass or strengthened plastic. 
         [0018]    A first area  1 A and a second area  2 A surrounding the first area  1 A are defined in the cover substrate  100 . The first area  1 A may include a display area in which a real user performs a touch instruction input. 
         [0019]    The electrode substrate  200  may be disposed at a position corresponding to the first area  1 A. That is, the electrode substrate  200  may be disposed to overlap the first area  1 A. Therefore, a touch and an information input may be performed through the first area  1 A. 
         [0020]    The ground electrode  130  may be disposed in the second area  2 A. In detail, the cover substrate  100  may include one surface  100   a  through which a real user performs a touch instruction input and the opposite surface to the one surface  100   a,  and the ground electrode  130  may be disposed at an edge of the opposite surface  100   b.  Thus, the ground electrode  130  may be disposed in the remaining area except for the area in which the electrode substrate  200  is disposed. The ground electrode  130  may be disposed such that the ground electrode  130  does not make contact with the electrode substrate  200 . The ground electrode  130  may not overlap the electrode substrate  200 . 
         [0021]    The ground electrode  130  may be disposed along a border of the second area  2 A. The ground electrode  130  may have various line widths to the extent that the ground electrode  130  does not overlap with the electrode substrate  200 . 
         [0022]    Meanwhile, an outer dummy layer may be formed in the second area  2 A such that the ground electrode  130 , a wire and a circuit substrate are not seen from an outside, The outer dummy layer may be formed by coating a material having a predetermined color. The outer dummy layer may have a color suitable for an outer appearance. For example, the outer dummy layer may include a black pigment to present a black color. The outer dummy layer may be formed through a depositing, printing or wet coating scheme. In this case, the ground electrode  130  may be disposed on the outer dummy layer. 
         [0023]    The ground electrode  130  prevents static electricity or ESD in the touch window. That is, the static electricity or ESD moves along a path of the ground electrode  130 , so that the static electricity or ESD can be prevented from being introduced into the touch window, The ground electrode  130  is disposed along the edge of the cover substrate  100 , so that the static electricity or ESD can be effectively prevented from being introduced into the touch window. The ground electrode  130  may be disposed along the entire edge of the cover substrate  100 . The ground electrode  130  is connected to the circuit substrate  300 , so that the ESD in the touch window can be discharged as an electrical signal. Thus, signal interference is prevented, so that the accuracy and reliability of a touch can be improved, 
         [0024]    The ground electrode  130  may include metal. The ground electrode  130  may include low-resistance metal. For example, the ground electrode  130  may include silver (Ag), copper (Cu) or nickel (Ni). 
         [0025]    Meanwhile, the ground electrode  130  may include a carbon group material. Thus, the cost may be reduced and the circuit corrosion may be prevented. Therefore, the ground electrode  130  is usable for a touch device having various use environments. 
         [0026]    Specifically, when the ground electrode  130  includes a silver-carbon material, the ground electrode  130  may have a gray tone color. Therefore, this is useful in terms of design. 
         [0027]    The ground electrode  130  may be formed by printing metallic paste or a carbon group material. 
         [0028]    Meanwhile, a sensing electrode  210  and a wire  220  are disposed on the electrode substrate  200 . 
         [0029]    The sensing electrode  210  may sense an input device. Although the sensing electrode  210  is depicted in a bar shape in  FIG. 1 , but the embodiment is not limited thereto. Thus, the sensing electrode  210  may be formed in various shapes capable of sensing a touch of an input device such as a finger. 
         [0030]    The sensing electrode  210  may include a transparent conductive material allowing electricity to flow therethrough without interrupting the transmission of light. To this end, the sensing electrode  210  may include various materials such as indium tin oxide, indium zinc oxide, copper oxide, carbon nano tube (CNT) or an Ag nano wire. 
         [0031]    Although the sensing electrode  210  extending in one direction is depicted in  FIG. 1 , the embodiment is not limited thereto. The sensing electrode  210  may include two types of sensing electrodes, one of which extends in one direction and the other extends in another direction crossing the one direction. 
         [0032]    If the input device such as a finger is touched on such a touch window, a difference in capacitance is caused in the portion touched by the input device, and the portion having the difference in capacitance may be detected as a touch position. 
         [0033]    The wire  220  may be disposed on the electrode substrate  200  for the purpose of an electrical connection of the sensing electrode  210 . The wire  220  may include a material having excellent electrical conductivity. For example, the wire  220  may include Cr, Ni, Cu, Al, Ag and Mo, and the alloy thereof. Specifically, the wire  220  may include various metallic paste materials which may form the wire  220  through a printing process. 
         [0034]    A pad part  230  is disposed at an end of the wire  220 . The pad part  230  may be connected to the circuit substrate  300 . The pad part  230  may be connected to a connecting part  310  of the circuit substrate  300 . 
         [0035]    Various types of circuit substrates may be applied as the circuit substrate  300 . For example, a flexible printed circuit board (FPCB) may be applied as the circuit substrate  300 . 
         [0036]    Although not shown in the drawings, a connector and a driving chip may be mounted on the circuit substrate  300 , 
         [0037]    The circuit substrate  300  may include a top coverlay  360  and a bottom coverlay  340 . The wire and ground connecting parts  310  and  320  may be formed in the circuit substrate  300 . In detail, wire and ground connecting parts  310  and  320  may be formed in the bottom coverlay  340 . 
         [0038]    The wire and ground connecting parts  310  and  320  may be disposed on mutually different surfaces of the bottom coverlay  340 . That is, the wire and ground connecting parts  310  and  320  may be disposed on both surfaces of the bottom coverlay  340 , respectively. The wire connecting part  310  may be disposed to face the electrode substrate  200 . The ground connecting part  320  may be disposed to face the cover substrate  100 , 
         [0039]    The wire connecting part  310  may be connected to the wire  220 . In detail, the wire connecting part  310  may be connected to the pad part  230  disposed at the end of the wire  220 . Thus, the wire connecting part  310  may be electrically connected to the pad part  230  so that the wire connecting part  310  may be transferred to the pad part  230 , 
         [0040]    The ground connecting part  320  may be connected to the ground electrode  130 . The ground connecting part  320  may be connected to the ground electrode  130  through an adhesive layer  400  and an open area OA. 
         [0041]    In detail, the circuit substrate  300  includes the open area OA. The open area OA is disposed at a portion of the circuit substrate  300 . The open area OA is disposed in the top coverlay  360 . The open area OA is disposed over the ground connecting part  320 . 
         [0042]    The ground connecting part may be exposed through the open area OA. In addition, the open area OA may expose a portion of the adhesive layer  400 . Thus, the ground connecting part  320 , the adhesive layer  400  and the ground electrode  130  may be connected to each other through the open area OA. In this case, the adhesive layer  400  may include a conductive material. 
         [0043]    Although the ground connecting unit  320 , the open area OA of the circuit substrate  300  and the adhesive layer  400  are depicted in  FIG. 2  as spaced apart from each other, the ground connecting part  320 , the adhesive layer  400  and the ground electrode  130  may really make contact with each other through the open area OA. Titus, the ground connecting part and the ground electrode  130  may be electrically connected to each other, 
         [0044]    Therefore, while the adhesive layer  400  adheres to the cover substrate  100  and the circuit substrate  300 , the adhesive layer  400  may electrically connect the ground electrode  130  to the ground connecting part  320 . 
         [0045]    Hereinafter, a touch window according to another embodiment will be described with reference to  FIGS. 3 to 7  In the following description about the touch window according to another embodiment, the parts similar or identical to those of the previously described embodiment will be omitted for the purpose of clear and brief description. 
         [0046]    Referring to FIG,  3 , the ground electrode  130 , which is disposed on a lower surface of the cover substrate  109 , may have a ring shape. That is, the ground electrode  130  may include a curved line. However, the embodiment is not limited thereto, and the ground electrode  130  may have various shapes. 
         [0047]    Referring to  FIG. 4 , a first ground electrode  130  is disposed on the lower surface of the cover substrate  100 , First and second electrode substrates  201  and  202  are disposed on the lower surface of the cover substrate  100 . 
         [0048]    A first sensing electrode  211  is disposed on the first electrode substrate  201  and a second ground electrode  249  is disposed adjacently to the first sensing electrode  211 . In detail, the second ground electrode  240  may be disposed at the outmost portion of the first sensing electrode  211 . That is, the second ground electrode  240  may be disposed at an outer portion of the first electrode substrate  201 . Meanwhile, the second ground electrode  240  may be disposed in the first area  1 A which is a display area. Similarly with the first ground electrode  130 , the second ground electrode  240  prevents static electricity or ESD in the touch window. in addition, the second ground electrode  249  may prevent signal interference of the first sensing electrodes  211 . 
         [0049]    The second ground electrode  240  may be disposed to surround an outer portion of the first electrode substrate  201 . However, differently from those depicted in the drawings, when long and short sides of the first electrode substrate  201  are defined, the second ground electrode  240  may extend along the long side of the first electrode substrate  201 . That is, the first ground electrode  130  may extend in the same direction as the first sensing electrode  211 . 
         [0050]    A pad part  250  may be disposed at an end of the second ground electrode  240 , so that the pad part  250  may be connected to a connecting part  350  of the circuit substrate  300 . 
         [0051]    Meanwhile, the second electrode substrate  202  may be disposed on a lower surface of the first electrode substrate  201 . In addition, a second sensing electrode  212  is disposed on the second electrode substrate  202  and a third ground electrode  241  is disposed adjacently to the second sensing electrode  212 . In detail, the third ground electrode  241  may be disposed at the outmost portion of the second sensing electrode  212 . That is, the third ground electrode  241  may be disposed at an outer portion of the second electrode substrate  202 . Similarly with the first ground electrode  130 , the third ground electrode  241  also prevents static electricity or ESD in the touch window. in addition, the third ground electrode  241  may prevent signal interference of the second sensing electrodes  212 . 
         [0052]    The third ground electrode  241  may be disposed to surround an outer portion of the second electrode substrate  202 . However, differently from those depicted in the drawings, when long and short sides of the second electrode substrate  202  are defined, the third ground electrode  241  may extend along the long side of the second electrode substrate  202 . The first ground electrode  130  may extend in a direction crossing the extension direction of the second sensing electrode  212 . 
         [0053]    A pad part  251  may he disposed at an end of the third ground electrode  241 , so that the pad part  251  may be connected to a connecting part  351  of the second circuit substrate  301 . 
         [0054]    Next, referring to  FIG. 5 , sensing electrodes  210  may be disposed on the electrode substrate  200  and second ground electrodes  240  may be interposed between the sensing electrodes  210 . In this case, the second ground electrodes  240  may be transparently formed. Thus, the second ground electrodes  240  may he prevented from being seen in the first area IA which is a display area. In addition, a width of a bezel may be reduced, so that a wider display area may be achieved, thereby overcoming a limitation in terms of design. 
         [0055]    Referring to  FIG. 6 , the first sensing electrode  211  may be formed directly on the lower surface of the cover substrate  100 . Thus, an electrode substrate for forming the first sensing electrode  211  may be omitted, so that the thickness of the touch window may be reduced. 
         [0056]    In this case, the top coverlay  360  may include the first and second open areas OA 1  and OA 2 . 
         [0057]    The ground connecting part  320  and the wire connecting part  310  may be disposed on the same plane on the bottom coverlay  360 . Meanwhile, the second wire connecting part  311  may be disposed on an opposite surface of the bottom coverlay  360 . The second wire connecting part  311  may face the second electrode substrate  202 . 
         [0058]    The first open area OA 1  may expose the ground connecting part  320 . Thus, the ground connecting part.  320  and the ground electrode  130  may be connected to each other. 
         [0059]    The second open area OA 2  may expose the wire connecting part  310 . Thus, the wire connecting part  310  and the pad part  230  may be connected to each other. Referring to FIG.  7 , the first sensing electrode  211  may he disposed on an upper surface of the electrode substrate  201  and the second sensing electrode  212  may he disposed on a lower surface of the electrode substrate  200 . Thus, the sensing electrodes  211  and  212  may be formed on a single electrode substrate, so that the thickness of the touch window may be reduced. 
         [0060]    Such a touch window may be disposed on a display panel which is a driving part. The touch window and the display panel may be combined with each other so that a touch device may be produced. 
         [0061]    The touch window may be applied to a vehicle as well as a touch device of a mobile terminal. That is, the touch window is applied to a dashboard as well as a PND (Personal Navigation Display) such as a vehicle navigation, so that a CID (Center Information Display) may be implemented. However, the embodiment is not limited to the above, and the touch device may be used for various electronic appliances. 
         [0062]    Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to affect such feature, structure, or characteristic in connection with other ones of the embodiments. 
         [0063]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.