Patent Publication Number: US-2009236151-A1

Title: Touch Panel Device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Taiwanese Patent Application No. 097110182, filed Mar. 21, 2008, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     1. Technical Field 
     The present invention is related to a touch panel device, and particularly to a capacitive touch panel device. 
     2. Description of the Related Art 
     In daily life, touch panels are widely used in all kinds of electronic products, such as cash machines of financial organ, guide information systems of department store, personal digital assistants (PDA), and notebooks. Generally, the touch panels are classified as resistive touch panels, capacitive touch panels, acoustic wave touch panels and optical touch panels according to their sensing principle wherein the resistive touch panel is the most extensively used touch panel with the lowest price among all, but the capacitive touch panel gains increasingly attention and popularity now. 
     Referring to  FIG. 1 , a structure of a typical capacitive touch panel device is shown. The capacitive touch panel includes a flat substrate  11 , a first electrode unit  12  formed on a top surface of the flat substrate  11  and a second electrode unit  13  formed on a bottom surface of the flat substrate  11 . A first conducting line  14  is formed on periphery area of the top surface of the flat substrate  11  and extended toward inside to electrically connect with the first electrode unit  12 . A second conducting line  15  is formed on periphery area of the bottom surface of the flat substrate  11  and extended toward inside to electrically connect with the second electrode unit  13 . A first extending wire and a second extending wire  16  and  17  are respectively electrically connected with the first and second conducting lines  14  and  15  for receiving power source or controlling signal. 
     When the power source or the controlling signal is provided to the first and second electrode units  12  and  13  via the first and second extending wires  16  and  17  and the first and second conducting lines  14  and  15 , an electric field is formed around the flat substrate  11 . When a finger of a user or a conductor is contacted or closed to the capacitive touch panel device, the electric field between the first and second electrode units  12  and  13  is correspondingly changed. Accordingly, a capacity at a touch point is changed. Thus the capacitive touch panel device can detect coordinates of the touch point according to the changes. 
     In a manufacturing process of the capacitive touch panel device, the first and second extending wires  16  and  17  are respectively formed on the periphery areas of the top and bottom surfaces of the flat substrate  11  via bonding wire for respectively connecting to the first and second conducting lines  14  and  15 . Thus the first and second extending wires  16  and  17  can electrically connected to the first and second electrodes units  12  and  13  via the first and second conducting lines  14  and  15 . However, when the first and second extending wires  16  and  17  extend outside the periphery area of the flat substrate  11 , a variable interval between the first extending wire  16  and the second extending wire  17  results in an interference signal therebetween. The interference signal can interfere with the detecting of the coordinates of the touch point, and decrease a yield rate of the capacitive touch panel device. 
     What is needed, therefore, is a touch panel device which is capable to overcome the above described problem. 
     BRIEF SUMMARY 
     Embodiments of the present invention provide a touch panel device having simple structure and being manufactured easily. 
     Embodiments of the present invention also provide a touch panel device having simple structure, and the electronic-magnetic interference comes from outside of the touch panel device can be reduced. 
     One embodiment of the present invention provides a touch panel device. The touch panel device includes a substrate, an insulating layer form on a surface of the substrate, a plurality of first electrode groups and a plurality of second electrode groups. Each first electrode group includes a plurality of first electrodes and a plurality of first connecting wires each electrically connecting two adjacent first electrodes. Each second electrode group includes a plurality of second electrodes and a plurality of bridge connecting wires each electrically connecting two adjacent second electrodes. The first electrode groups and the second electrodes of the second electrode groups are alternately formed on a surface of the insulating layer away from the substrate. The bridge connecting wires are formed on the surface of the substrate contacting with the insulating layer. 
     Another embodiment of the present invention provides a touch panel device, which comprises a transparent substrate, a transparent insulating layer and a sensing unit. The transparent insulating layer is formed on a surface of the substrate. The sensing unit comprises a plurality of first electrode groups and a plurality of second electrode groups, wherein each second electrode group comprises a plurality of electrodes and a bridge connecting wires electrically connecting two adjacent electrodes. The first electrode groups and the electrodes of the second electrode groups are alternately formed on a surface of the insulating layer to define a sensing plane corporately, the bridge connecting wires are formed between the substrate and the sensing plane. 
     The touch panel device has some advantages. For example, the sensitivity of the touch panel device is improved because the first electrode groups and the electrodes of the second electrode groups are nearer to the touch surface, and the uniformity of the sensitivity is improved because the first electrode groups and the electrodes of the second electrode groups are formed on the same surface. Moreover, the structure is much simpler than some other touch panels. Furthermore, by forming the insulating layer, the first and second electrode groups are farther away from other modules (such as Liquid Crystal Display Module, LCM) such that the electronic-magnetic interference from these modules can be reduced. In another aspect, as the bridge connecting wires are covered by the insulating layer and the insulating layer can be polished to form a flat plane, the first electrode groups and the electrodes of the second electrode groups can be easily formed on the surface of the insulating layer. 
     Other objectives, features and advantages of the touch panel device will be further understood from the further technological features disclosed by the embodiments of touch panel device wherein there are shown and described preferred embodiments of this touch panel device, simply by way of illustration of modes best suited to carry out the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a cross-sectional view of a conventional touch panel device. 
         FIG. 2  is a cross-sectional view of a touch panel device according to a first embodiment. 
         FIG. 3  is a schematic vertical view of the touch panel device of  FIG. 2 . 
         FIG. 4  is a schematic, exploded view of the touch panel device of  FIG. 2 . 
         FIG. 5  is a schematic, exploded view of the touch panel device according to a second embodiment. 
         FIG. 6  is a schematic vertical view of the touch panel device of  FIG. 5 . 
         FIG. 7  is a cross-sectional view of the touch panel device of  FIG. 5 . 
         FIG. 8  is an enlarged view of the part A in  FIG. 7 . 
         FIG. 9  is a cross-sectional view of a touch panel device according to a third embodiment. 
         FIG. 10  is a enlarged view of the part B in  FIG. 9 . 
         FIG. 11  is a cross-sectional view of a touch panel device according to a fourth embodiment. 
         FIG. 12  is a cross-sectional view of a touch panel device according to a fifth embodiment. 
         FIG. 13  is a cross-sectional view of a touch panel device according to a sixth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     Referring to  FIG. 2  and  FIG. 3 , a touch panel device according to a first embodiment of the present invention is shown. The touch panel device  100  includes a substrate  110 , at least one first electrode group  120 , at least one second electrode group  130 , an insulating layer  140 , and an anti-scratch layer  150 . 
     In this embodiment, the touch panel device  100  includes a plurality of first electrode groups  120  and a plurality of second electrode groups  130 . The first electrode groups  120  and the second electrode groups  130  are disposed at a same side of the substrate  110 . The insulating layer  140  is formed on a surface of the substrate  110 . The anti-scratch layer  150  covers the first electrode groups  120  and the second electrode groups  130  for protecting them. In addition, an anti-reflection layer or other protecting layer can be formed on the anti-reflection layer  150 . 
     Each of the first electrode groups  120  includes a plurality of first electrodes  121  and a plurality of first connecting lines  122 . The first electrodes  121  are spaced arranged along a straight line. Two adjacent first electrodes  121  are electrically connected via the first connecting lines  122 . Referring to  FIG. 3 , the first electrodes  121  are diamond shapes. Two adjacent corners corresponding to short diagonal respectively belong to two adjacent diamond shaped first electrodes  121  are electrically connected via the first connecting line  122  such that the first electrodes  121  are arranged in the straight line along a direction of an X axis as shown in  FIG. 3 . Understandably, the configuration of the second electrodes  131  can also be design to other forms according to actual demand without limitation of the diamond shape in this embodiment. 
     Referring to  FIG. 2  and  FIG. 3 , each of the second electrode groups  130  includes a plurality of second electrodes  131  and a plurality of bridge connecting line-segments  132 . In each second electrode group  130 , all the bridge connecting line-segments  132  are called as bridge connecting wire. The second electrodes  131  are spaced arranged along a straight line, and two adjacent second electrodes  131  are electrically connected via a bridge connecting line-segment  132 . In this embodiment, the second electrodes  131  are diamond shapes, and two adjacent corners corresponding to long diagonal respectively belong to two adjacent diamond shaped second electrodes  131  are electrically connected via a bridge connecting line-segment  132 . Thus the plurality of second electrodes  131  are arranged in the straight line along a direction of a Y axis as shown in  FIG. 3 . Understandably, the configuration of the second electrodes  131  can also be design to other forms according to actual demand without limitation of the diamond shape in this embodiment. 
     Also referring to  FIG. 2  and  FIG. 3 , each second electrode group  130  includes a plurality of bridge connecting line-segments  132  respectively connected between two adjacent second electrodes  131 . Each bridge connecting line-segment  132  includes a first conductive part  133  and two second conductive parts  134  respectively connected to two ends of the first conductive part  133 . In this embodiment, each first conductive part  133  is a connecting line-segment. A length of the connecting line-segment is approximately equal to an interval of two adjacent second electrodes  131 . The two ends of the first conductive part  133  are electrically connected to two adjacent second electrodes  131  respectively via the two second conductive parts  134 . 
     Referring to  FIG. 4  together, in each second electrode group  130 , a plurality of first conductive parts  133  are spaced arranged along a straight line and formed on a surface  111  of the substrate  110 . In other words, the first conductive parts  133  cover a part of the surface  111  of the substrate  110 . The insulating layer  140  is formed on the surface  111  of the substrate  110  to cover the first conductive parts  133  and a part of the surface  111  without the first conductive parts  133  formed thereon. The insulating layer  140  has a flat insulating surface  141  opposite to the surface  111  of the substrate  110 . Due to the flat insulating surface  141  of the insulating layer  140 , a process for forming the first electrode groups  120  and the second electrodes  131  of the second electrode groups  130  on the insulating layer  140  is relatively simple. 
     Furthermore, the insulating layer  140  defines a plurality of through holes  142  therein. Each pair of through holes  142  correspond to two ends of each first conductive part  133 . The second conductive parts  134  are formed by filling conductive materials in the through holes  142 . Such that one end of the second conductive part  134  is electrically connected to the first conductive part  133  and the other end of the second conductive part  134  forms a conducting pad on the insulating surface  141  of the insulating layer  140 . The conducting pads are configured for electrically connecting the second electrodes  131  when the second electrodes  131  are formed on the insulating surface  141  of the insulating layer  140  to cover the conducting pads. 
     The second electrodes  131  is formed on the insulating surface  141  and positions of the second electrodes  131  correspond with the first conductive parts  133  and the second conductive parts  134  such that two adjacent second electrodes  131  are electrically connected with each other via the corresponding first conductive part  133  and the second conductive parts  134 . In further description, the plurality of first conductive parts  133  are arranged on the surface  111  of the substrate  110  according to a predetermined demand. Two second conductive parts  134  are respectively disposed on the two ends of the first conductive part  133 . The plurality of second electrodes  131  are formed on the insulating layer  141  corresponding to two ends of the first conductive parts  133  and electrically connected with the first conductive parts  133  via the second conductive parts  134 . Thus, the bridge connecting line-segments  132  including the first conductive parts  133  and the second conductive parts  134  are formed in the insulating layer  140 . In other words, the second electrodes  131  and the bridge connecting line-segments  132  are located in different layers. That is, the plurality of second electrodes  131  on the insulating surface  141  can be electrically connected to each other by a bridge connecting manner via the bridge connecting line-segments  132  including the first conductive parts  133  and the second conductive parts  134  formed in the insulating layer  140 . 
     Referring back to  FIG. 2 , since the plurality of first electrodes  121  and the plurality of first connecting lines  122  are also formed on the insulating surface  141  of the insulating layer  140 , the first electrode groups  120  and the second electrodes  131  of the second electrode groups  130  are formed on the insulating surface  141  of the insulating layer  140 , in another word, are located in a same layer to define a sensing plane corporately. 
     The first electrode groups  120  arranged in straight lines are paralleled to each other on the insulating surface  141  of the insulating layer  140 . The second electrodes  131  of the second electrode groups  130  arranged in straight lines are also paralleled to each other on the insulating surface  141  of the insulating layer  140 . The first electrode groups  120  and the second electrode groups  130  are alternately arranged. In this embodiment, the first electrodes  121  arranged in straight lines and the second electrodes  131  arranged in straight lines are alternately arranged to form a matrix. In the matrix formed by the first electrodes  121  and the second electrodes  131 , the first electrodes  121  do not cross or overlap with the second electrodes  131  such that the first electrodes  121  and the second electrodes  131  are separated with each other and alternately formed on the insulating surface  141  of the insulating layer  140 . 
     The substrate  110  can be made from transparent materials, such as glass, polymeric methyl methacrylate (PMMA), polyvinylchloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphtalate (PEN), polycarbonate (PC) or other appropriate transparent materials. The substrate  110  can also be made from opaque materials. The first electrode groups  120  and the second electrode groups  130  can be made from transparent conductive materials such as indium tin oxide (ITO) or other opaque materials. The insulating layer  140  can be made from transparent insulating materials such as silicon dioxide or opaque insulating materials. 
     In other words, the substrate  110 , the first electrode groups  120 , the second electrode groups  130  and the insulating layer  140  can all made from transparent materials. In an alternative embodiment of the present invention, the substrate  110 , the first electrode groups  120 , the second electrode groups  130  and the insulating layer  140  can all made from opaque materials. In a further alternative embodiment of the present invention, the substrate  110 , the first electrode groups  120 , the second electrodes  131  of the second electrode groups  130  and the insulating layer  140  are made from transparent materials and the bridge connecting line-segments  132  of the second electrode groups  130  are made of an opaque material such as sliver or copper. As long as sizes of the bridge connecting line-segments  132  of the second electrode groups  130  are small enough, the touch panel device  100  can also be employed in a transparent environment. The touch panel device  100  made from transparent materials can be used in different touch devices having touch screen, such as mobile telephones, personal digital assistants (PDA), global position systems (GPS) etc. The touch panel device  100  can also be made from printed circuit board (PCB) or flexible printed circuit (FPC) when it is employed in other applications. 
     The above described anti-scratch layer  150  covers the first electrode groups  120  and the second electrodes  131  for preventing them from damages from an external force. The anti-scratch layer  150  includes a touch surface  151  configured for being contacted with the finger or other conductive element. 
     Comparing with the conventional touch panel device, the touch panel device  100  provided in above described embodiment has the following advantages. Firstly, because the first electrode groups  120  and the second electrode groups  130  are closed to the touch surface  151 , the sensitivity of the touch panel device  100  are correspondingly increased. Secondly, because the first electrode groups  120  and the second electrodes  131  of the second electrode groups  130  are disposed in the same layer, an even sensitivity can be achieved when the conductive element is closed to or contacted with the touch surface  151 . In addition, due to the first electrode groups  120  and the second electrodes  131  of the second electrode groups  130  are disposed in the same layer, the configuration of the touch panel device  100  becomes relatively simple, thus, the manufacturing process of the touch panel device  100  is simplified. Thirdly, because of the existence of the insulating layer  140 , the first electrode groups  120  and the second electrodes  131  are far away from a light control module (LCM) which is disposed at another side of the substrate  110  opposite to the insulating layer  140 . An interference of a sensing process of the touch panel device  100  generated by the LCM can be depressed. Fourthly, flat surface of the touch panel device  100  is propitious to perform a latter optical adjusting method such as reflecting the light. Lastly, because the bridge connecting line-segments  132  of the second electrode groups  130  are disposed in the insulating layer  140  and the insulating layer  140  includes a flat insulating surface  141 , it is easy for the first electrode groups  120  and the second electrodes  131  of the second electrode group  130  to be formed on the insulating surface  141 . 
     Referring to  FIG. 5  to  FIG. 8 , a touch panel device  200  according to a second embodiment of the present invention is shown. The touch panel device  200  is similar to the touch panel device  100  except for the configurations of second electrode groups  230 . The touch panel device  200  includes a plurality of second electrode groups  230 . Each second electrode group  230  includes a plurality of second electrodes  231  and a bridge connecting wire  232  for electrically connecting two adjacent second electrodes  231 . The bridge connecting wire  232  includes a first conductive part  233  and a plurality of second conductive parts  234  electrically connected to the first conductive part  233 . The first conductive part  233  is a line-shaped conducting line corresponding to the plurality of second electrodes  231 . The number of the second conductive parts  234  is equal to the number of the second electrodes  231  such that the second conductive parts  234  respectively correspond to the second electrodes  231 . Each second electrode  231  is electrically connected to the first conductive part  233  via a corresponding second conductive part  234 . Thus the second electrodes  231  are electrically connected in series. In this embodiment, an end of each second conductive part  234  is connected to the first conductive part  233  and the other end of each second conductive part  234  is connected to an end of each second electrode  231 . 
     Understandably, the position of connections between the second conductive parts  234  and the second electrodes  231  are not limited to the end of the second electrodes  23   1 . In an alternative embodiment of the present invention, the second conductive parts  234  can be electrically connected to any portion of the second electrodes  231 . For example, referring to  FIG. 9  to  FIG. 10 , a touch panel device  300  according to a third embodiment of the present invention is similar to the touch panel device  200 . A difference therebetween is that an end of each second conductive part  334  is connected to the first conductive part  233  and the other end of each second conductive part  334  is connected to a middle portion of the second electrodes  231 . 
     Comparing with the conventional touch panel device, the touch panel devices  200 ,  300  have advantages same with that of the touch panel device  100 . Furthermore, because the touch panel devices  200 ,  300  only have one line-shaped first conductive part  233 ,  333  respectively, which respectively correspond to the plurality of second electrodes  231 ,  331 , a manufacturing process of the touch panel device  200 ,  300  is further simplified. 
     Referring to  FIG. 11 , a touch panel device  400  according to a fourth embodiment of the present invention is shown. The touch panel device  400  is similar to the touch panel device  100  except for configurations of the second electrode groups  430 . The touch panel device includes a plurality of second electrode groups  430 . Each second electrode group  430  includes a plurality of second electrodes  431  and a plurality of bridge connecting wires  432 . Two adjacent second electrodes  431  are electrically connected to each other via a bridge connecting wires  432 . Each bridge connecting wire  432  includes a first conductive part  433  and two second conductive parts  434  respectively connected to two ends of the first conductive part  433 . The first conductive part  433  and two second conductive parts  434  are integrated into one body. In this embodiment, the first conductive part  433  and two second conductive parts  434  are integrated into one body to form each U-shaped bridge connecting wire  432 . 
     Comparing with the conventional touch panel device, the touch panel device  400  has advantages same with that of the touch panel device  100 . Furthermore, because each bridge connecting wire  432  are integrated into one body by the first conductive part  433  and two second conductive parts  434 , a reliability of the electrical conductivity of the bridge connecting wires  432  is increased. Moreover, a process of forming the though holes in the insulating layer and filling the conductive materials in the through holes can be omitted. Therefore, a manufacturing process of the touch panel device  400  is further simplified. 
     In the above-described embodiments, the elements employed in the first electrode groups and the second electrode groups such as the electrodes, the connecting lines and the first and second conductive parts of the bridge connecting line-segments can be made from same materials such as ITO. 
     Referring to  FIG. 12  and  FIG. 13 , touch panel devices  500 ,  600  according to a fifth and a sixth embodiments are respectively shown. The touch panel devices  500 ,  600  are similar to the touch panel device  100 . The touch panel device  500  showing in  FIG. 12  further includes a conductive layer  180  on a surface of the substrate opposite to the insulating layer. The touch panel device  600  showing in  FIG. 13  further includes a conductive layer  182  formed in the insulating layer  140  adjacent to the bridge connecting line-segments or bridge connecting wires. The conductive layer  180 ,  182  are configured for shielding interference of the LCM to the sensing electrode of the touch panel devices  500 ,  600 . The conductive layer  180  can also be formed in a net-shape to decrease the capacitance thereof. In an alternative embodiment, the conductive layer  180 ,  182  can both be employed in a touch panel device. Understandably, such shielding structure can also be applied in other touch panel devices as described above. 
     To sum up, the configuration of the bridge connecting line of the touch panel devices does not be limited by the illustrated embodiments. The touch panel device can be achieved as long as the first electrode groups and the second electrodes of the second electrode groups are disposed in a same layer or defined a sensing plane corporately, and the bridge connecting line-segments or bridge connecting wires are disposed in a layer different to the sensing plane. In other words, the bridge connecting line-segments or bridge connecting wires are disposed on the substrate and are insulated with the first electrode groups by the insulating layer. 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including configurations ways of the electrodes and materials and/or designs of the electrode. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.