Abstract:
An in-cell touch panel is disclosed. The in-cell touch panel includes a plurality of pixels. Each pixel has a laminated structure bottom-up including a substrate, a TFT layer, a liquid crystal layer, a color filter layer, and a glass layer. The TFT layer is disposed on the substrate. A first conductive layer and a common electrode are disposed in the TFT layer. The first conductive layer is arranged in mesh type. The liquid crystal layer is disposed on the TFT layer. The color filter layer is disposed on the liquid crystal layer. The glass layer is disposed on the color filter layer. The design of touch electrodes and their trace layout in the in-cell touch panel of the application is simple and it can effectively reduce cost and reduce the RC loading of the common electrode.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a touch panel, especially to an in-cell touch panel having lower RC loading. 
         [0003]    2. Description of the Related Art 
         [0004]    In general, there are several different laminated structures of the capacitive touch panel; for example, an in-cell capacitive touch panel or an on-cell capacitive touch panel. 
         [0005]    Please refer to  FIG. 1  and  FIG. 2 .  FIG. 1  and  FIG. 2  illustrate two different laminated structures of the in-cell capacitive touch panel and the on-cell capacitive touch panel respectively. As shown in  FIG. 1 , the laminated structure  1  of the on-cell capacitive touch panel includes a substrate  10 , a thin-film transistor layer  11 , a liquid crystal layer  12 , a color filtering layer  13 , a glass layer  14 , a touch sensing layer  15 , a polarizer  16 , an adhesive  17  and top lens  18 . As shown in  FIG. 2 , the laminated structure  2  of the in-cell capacitive touch panel includes a substrate  20 , a thin-film transistor layer  21 , a touch sensing layer  22 , a liquid crystal layer  23 , a color filtering layer  24 , a glass layer  25 , a polarizer  26 , an adhesive  27  and top lens  28 . 
         [0006]    After comparing  FIG. 1  with  FIG. 2 , it can be found that the touch sensing layer  22  of the in-cell capacitive touch panel is disposed under the liquid crystal layer  23 ; that is to say, the touch sensing layer  22  is disposed in the liquid crystal display module of the in-cell capacitive touch panel. On the other hand, the touch sensing layer  15  of the on-cell capacitive touch panel is disposed above the glass layer  14 ; that is to say, the touch sensing layer  15  is disposed out of the liquid crystal display module of the on-cell capacitive touch panel. Compared to the conventional one glass solution (OGS) and on-cell capacitive touch panel, the in-cell capacitive touch panel can achieve thinnest touch panel design and widely used in portable electronic products such as mobile phones, tablet PCs, and notebooks. 
         [0007]    Therefore, the invention provides an in-cell touch panel to reduce the effects of resistance and parasitic capacitance through its novel layout to enhance the entire performance of the in-cell touch panel. 
       SUMMARY OF THE INVENTION 
       [0008]    A preferred embodiment of the invention is an in-cell touch panel. In this embodiment, the in-cell touch panel includes a plurality of pixels. A laminated structure of each pixel includes a substrate, a thin-film transistor (TFT) layer, a liquid crystal layer, a color filtering layer, and a glass layer. The TFT layer is disposed above the substrate. A first conductive layer and a common electrode are disposed in the TFT layer, and the first conductive layer is arranged in mesh type. The liquid crystal layer is disposed above the TFT layer. The color filtering layer is disposed above the liquid crystal layer. The glass layer is disposed above the color filtering layer. 
         [0009]    In an embodiment, the in-cell touch panel is an in-cell self-capacitive touch panel, and touch electrodes of the in-cell self-capacitive touch panel are formed by the first conductive layer arranged in mesh type. 
         [0010]    In an embodiment, the first conductive layer and the common electrode are separated by an insulating layer. 
         [0011]    In an embodiment, the touch electrodes are not connected with each other and there is a specific distance between the touch electrodes. 
         [0012]    In an embodiment, the specific distance is an integral multiple of pixel or sub-pixel. 
         [0013]    In an embodiment, a part of the first conductive layer not forming the touch electrodes is electrically connected with the common electrode through a via. 
         [0014]    In an embodiment, the first conductive layer is formed after the common electrode. 
         [0015]    In an embodiment, the first conductive layer is formed before the common electrode. 
         [0016]    In an embodiment, the color filtering layer includes a color filter and a black matrix resist and the black matrix resist has good light resistance, and the first conductive layer is disposed under the black matrix resist. 
         [0017]    In an embodiment, the first conductive layer overlaps a source line in the TFT layer. 
         [0018]    In an embodiment, a touch mode and a display mode of the in-cell touch panel are driven in a time-sharing way, and the in-cell touch panel is operated in the touch mode during a blanking interval of a display period of the in-cell touch panel. 
         [0019]    In an embodiment, when the in-cell touch panel is operated in the display mode, the common electrode is maintained a DC voltage or an AC voltage, and the touch electrodes are maintained a DC voltage, an AC voltage or a voltage related to the common electrode or the touch electrodes are in a floating state. 
         [0020]    In an embodiment, the common electrode has a common electrode region overlapping the touch electrodes, when the in-cell touch panel is operated in the touch mode, the touch electrodes are provided a touch sensing signal and the common electrode is provided a touch-related signal having same frequency, same amplitude and same phase with the touch sensing signal. 
         [0021]    In an embodiment, the common electrode has a common electrode region overlapping the touch electrodes, when the in-cell touch panel is operated in the touch mode, the touch electrodes are provided a touch sensing signal and the common electrode is disconnected with a signal source or in a floating state. 
         [0022]    In an embodiment, the common electrode has common electrode regions overlapping the touch electrodes respectively, when the in-cell touch panel is operated in the touch mode, the touch electrodes are provided touch sensing signals and the common electrode regions are correspondingly provided touch-related signals having same frequency, same amplitude and same phase with the touch sensing signals in order, or the common electrode regions are correspondingly disconnected with a signal source or in a floating state in order. 
         [0023]    In an embodiment, the common electrode has a common electrode region overlapping the touch electrodes, when the in-cell touch panel is operated in the touch mode, the touch electrodes are provided a touch sensing signal and a source line or a gate line in the thin-film transistor layer is provided a touch-related signal having same frequency, same amplitude and same phase with the touch sensing signal. 
         [0024]    In an embodiment, the common electrode has common electrode regions overlapping the touch electrodes respectively, when the in-cell touch panel is operated in the touch mode, the touch electrodes are provided touch sensing signals in order and a source line or a gate line in the thin-film transistor layer is correspondingly provided touch-related signals having same frequency, same amplitude and same phase with the touch sensing signals in order. 
         [0025]    In an embodiment, a second conductive layer is disposed in the thin-film transistor layer and the second conductive layer is electrically connected with the first conductive layer. 
         [0026]    In an embodiment, the second conductive layer and a source electrode and a drain electrode of the thin-film transistor layer are formed simultaneously. 
         [0027]    In an embodiment, the second conductive layer and the first conductive layer are overlapped and coupled in parallel. 
         [0028]    In an embodiment, the second conductive layer forms a bridge structure through a via to across the first conductive layer. 
         [0029]    In an embodiment, when the laminated structure has a half source driving (HSD) structure, the laminated structure has an additional space which is originally occupied by a source line, and the second conductive layer electrically connected with the first conductive layer is disposed in the additional space as traces of the touch electrodes. 
         [0030]    In an embodiment, the second conductive layer not used as traces or signal lines is electrically connected with the first conductive layer not used as touch electrodes through a via and further electrically connected with the common electrode through the via to enhance a conductivity of the common electrode. 
         [0031]    In an embodiment, driving times of a touch mode and a display mode of the in-cell touch panel are at least partially overlapped. 
         [0032]    In an embodiment, when the in-cell touch panel is operated in the touch mode, the touch electrodes are provided a touch sensing signal, the common electrode or a source line is in a floating state in a part of time and provided a touch-related signal having same frequency, same amplitude and same phase with the touch sensing signal in another part of time. 
         [0033]    Compared to the prior arts, the in-cell touch panel and its trace layout of the invention have following advantages: 
         [0034]    (1) The laminated structure of the in-cell touch panel of the invention is simple and easy to be manufactured to reduce costs. 
         [0035]    (2) Designs of the touch electrodes, common electrodes and their traces in the in-cell touch panel of the invention are very simple. 
         [0036]    (3) The aperture ratio of the LCD touch panel will not be affected by the novel trace layout method of the invention. 
         [0037]    (4) The RC loading of the common electrode can be effectively reduced. 
         [0038]    (5) When the in-cell touch panel is operated in the touch mode, the common electrode is controlled simultaneously to reduce the entire RC loading of the in-cell touch panel. 
         [0039]    The advantage and spirit of the invention may be understood by the following detailed descriptions together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]    So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
           [0041]      FIG. 1  and  FIG. 2  illustrate schematic diagrams of the laminated structure of the conventional in-cell capacitive touch panel and on-cell capacitive touch panel respectively. 
           [0042]      FIG. 3A ,  FIG. 3B ,  FIG. 3C  and  FIG. 3D  illustrate schematic diagrams of the laminated structures of the in-cell self-capacitive touch panel in different embodiments of the invention respectively. 
           [0043]      FIG. 4A  illustrates a schematic diagram of the touch electrodes of the in-cell self-capacitive touch panel and their traces. 
           [0044]      FIG. 4B  illustrates a schematic diagram of a part of first conductive layer not used as touch electrode electrically connecting with the common electrode through the via. 
           [0045]      FIG. 5A  illustrates a schematic diagram of the common electrode having a common electrode region overlapping the first touch electrode, the second touch electrode and the third touch electrode. 
           [0046]      FIG. 5B ,  FIG. 5C  and  FIG. 5D  illustrate timing diagrams of the signals of the in-cell self-capacitive touch panel operated in the display mode and touch mode in different embodiments of the invention. 
           [0047]      FIG. 6A  illustrates a schematic diagram of the common electrode having common electrode regions overlapping the first touch electrode, the second touch electrode and the third touch electrode respectively. 
           [0048]      FIG. 6B  illustrates a timing diagram of the signals of the in-cell self-capacitive touch panel of  FIG. 6A  operated in the display mode and touch mode. 
           [0049]      FIG. 7A  illustrates a schematic diagram of the second conductive layer electrically connecting with the first conductive layer through the via in the laminated structures of the in-cell self-capacitive touch panel. 
           [0050]      FIG. 7B  illustrates a schematic diagram of the second conductive layer electrically connecting with the first conductive layer through the via and further electrically connecting with the common electrode through the via in the laminated structures of the in-cell self-capacitive touch panel. 
           [0051]      FIG. 7C  illustrates an embodiment of the pixel design in the in-cell self-capacitive touch panel. 
           [0052]      FIG. 8  illustrates a schematic diagram of the traces formed by the second conductive layer and the signal lines are interlaced and different touch electrodes are bridged by the via through the traces in the in-cell self-capacitive touch panel. 
           [0053]      FIG. 9A ,  FIG. 9B  and  FIG. 9C  illustrate schematic diagrams of the touch electrodes having different shapes formed by the first conductive layer aligned in mesh-type. 
       
    
    
     DETAILED DESCRIPTION 
       [0054]    A preferred embodiment of the invention is an in-cell capacitive touch panel. In practical applications, the in-cell capacitive touch panel can achieve thinnest touch panel design; therefore, it can be widely used in portable electronic products such as mobile phones, tablet PCs, and notebooks. 
         [0055]    In this embodiment, the in-cell capacitive touch panel can be suitable for displays using in-plane switching liquid crystal (IPS) technology, fringe field switching (FFS) technology, or advanced hyper-viewing angle (AHVA) technology, but not limited to these cases. 
         [0056]    In general, the most popular capacitive touch sensing technology in nowadays should be the projected capacitive touch sensing technology including a mutual-capacitive type and a self-capacitive type. As to the mutual-capacitive touch sensing technology, when a touch occurs, capacitive coupling will be generated between two electrode layers adjacent to the touch point, and the capacitance change between the two electrode layers will be used to determine the touch point. As to the self-capacitive touch sensing technology, when a touch occurs, capacitive coupling will be generated between the touch item and the electrode, and the capacitance change of the electrode will be used to determine the touch point. 
         [0057]    It should be noted that the self-capacitive touch sensing technology can be used in the in-cell capacitive touch panel of this embodiment. The touch electrodes of the in-cell capacitive touch panel are formed by the first conductive layer arranged in mesh type, and it provides novel layout method to reduce the electrical and optical effects caused by the in-cell touch elements of the in-cell capacitive touch panel. 
         [0058]    Next, the laminated structure of the in-cell self-capacitive touch panel in this embodiment will be introduced as follows. 
         [0059]    As shown in  FIG. 3A , in an embodiment, the laminated structure  3 A of the in-cell self-capacitive touch panel includes a substrate  30 , a thin-film transistor (TFT) layer  31 , a liquid crystal layer  32 , a color filtering layer  33 , a glass layer  34 . 
         [0060]    The TFT layer  31  is disposed above the substrate  30 . A first conductive layer M 3  and a common electrode CITO are disposed in the TFT layer  31 . The first conductive layer  31  is arranged in mesh type. The liquid crystal layer  32  including liquid crystal units LC is disposed above the TFT layer  31 . The color filtering layer  33  is disposed above the liquid crystal layer  32 . The glass layer  34  is disposed above the color filtering layer  33 . 
         [0061]    In fact, the first conductive layer M 3  can be formed by metal or any other conductive material; the common electrode CITO can be formed by an indium tin oxide (ITO) layer, but not limited to this. 
         [0062]    The color filtering layer  33  includes a color filter CF and a black matrix resist BM. The black matrix resist BM has good light resistance and it can be used in the color filtering layer  33  to separate three different color filters including a red (R) color filter, a green (G) color filter, and a blue (b) color filter, but not limited to this. In this embodiment, the first conductive layer M 3  arranged in mesh type is disposed under the black matrix resist BM and shielded by the black matrix resist BM. 
         [0063]    It should be noticed that, in the laminated structure  3 A of the in-cell self-capacitive touch panel shown in  FIG. 3A , the first conductive layer M 3  is formed after the common electrode CITO; the first conductive layer M 3  and the common electrode CITO are separated by an insulating layer ISO, and the first conductive layer M 3  cannot be electrically connected with the common electrode CITO. 
         [0064]    In another embodiment, in the laminated structure  3 B of the in-cell self-capacitive touch panel shown in  FIG. 3B , the first conductive layer M 3  is also formed after the common electrode CITO; the first conductive layer M 3  and the common electrode CITO are separated by the insulating layer ISO, but the first conductive layer M 3  can be electrically connected with the common electrode CITO through a via VIA. 
         [0065]    In addition, in the laminated structure  3 C of the in-cell self-capacitive touch panel shown in  FIG. 3C , the first conductive layer M 3  is formed before the common electrode CITO; the first conductive layer M 3  and the common electrode CITO are separated by an insulating layer ISO, so that the common electrode CITO will not be electrically connected with the first conductive layer M 3 . 
         [0066]    In another embodiment, in the laminated structure  3 D of the in-cell self-capacitive touch panel shown in  FIG. 3D , the first conductive layer M 3  is also formed before the common electrode CITO; the first conductive layer M 3  and the common electrode CITO are separated by an insulating layer ISO; the common electrode CITO is electrically connected with the first conductive layer M 3  through a via VIA. 
         [0067]    Then, as shown in  FIG. 4 , touch electrodes TE of the in-cell self-capacitive touch panel TP 1  are formed by the first conductive layer M 3  arranged in mesh type; the touch electrodes TE are not connected and there is a specific distance between the touch electrodes TE. The touch electrodes TE and the common electrode CITO are not connected. In fact, the specific distance can be an integral multiple of pixel or sub-pixel, but not limited to this. 
         [0068]    In addition, as shown in  FIG. 4B , in the in-cell self-capacitive touch panel TP 2 , a part of the first conductive layer M 3  not forming the touch electrodes TE can be electrically connected with the common electrode CITO through the via VIA to be traces of the common electrode CITO. It should be noted that the touch electrodes TE in  FIG. 4B  are also formed by the first conductive layer M 3 , but the first conductive layer M 3  used as the touch electrodes TE and their traces will not be electrically connected with the common electrode CITO. A part of the first conductive layer M 3  not forming the touch electrodes TE can be electrically connected with the common electrode CITO through the via VIA to be traces of the common electrode CITO. 
         [0069]    Then, please refer to  FIG. 5A . In the in-cell self-capacitive touch panel TP, the first conductive layer M 3  arranged in mesh type forms the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  respectively; the common electrode CITO has a common electrode region VCOM overlapping the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3 , but the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are not electrically connected with the common electrode CITO. A part of the first conductive layer M 3  not forming the touch electrodes TE can be electrically connected with the common electrode CITO through the via VIA to be traces of the common electrode CITO disposed among the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  respectively. 
         [0070]    It should be noticed that a touch mode and a display mode of the in-cell self-capacitive touch panel TP of the invention can be driven in a time-sharing way, and the in-cell self-capacitive touch panel TP can be operated in the touch mode during a blanking interval of a display period of the in-cell self-capacitive touch panel TP, but not limited to this. In fact, the driving times of the touch mode and the display mode of the in-cell self-capacitive touch panel TP of the invention can be at least partially overlapped. 
         [0071]    In an embodiment, as shown in  FIG. 5B , when the in-cell self-capacitive touch panel TP is operated in the display mode, the common electrode region VCOM can be maintained a DC voltage or an AC voltage, and the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are maintained a DC voltage, an AC voltage or a voltage related to the common electrode region VCOM or the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are in a floating state. When the in-cell self-capacitive touch panel TP is operated in the touch mode, the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are provided touch sensing signals TS 1 -TS 3  and the common electrode region VCOM is provided a touch-related signal having same frequency, same amplitude and same phase with the touch sensing signals TS 1 -TS 3 . 
         [0072]    In another embodiment, as shown in  FIG. 5C , when the in-cell self-capacitive touch panel TP is operated in the touch mode, the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are provided touch sensing signals TS 1 -TS 3 , but the common electrode region VCOM is disconnected with a signal source or in a floating state. 
         [0073]    In another embodiment, as shown in  FIG. 5D , when the in-cell self-capacitive touch panel TP is operated in the touch mode, the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are provided touch sensing signals TS 1 -TS 3 , but the source lines S 1 -S 3  and gate lines G 1 -G 3  in the TFT layer are provided a touch-related signal having same frequency, same amplitude and same phase with the touch sensing signals TS 1 -TS 3 . 
         [0074]    Except the above-mentioned embodiments, the common electrode CITO can have common electrode regions overlapping different touch electrodes respectively. 
         [0075]    Please refer to  FIG. 6A . As shown in  FIG. 6A , the common electrode CITO has the first common electrode region VCOM 1 , the second common electrode region VCOM 2  and the third common electrode region VCOM 3  overlapping the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  respectively. 
         [0076]    When the in-cell self-capacitive touch panel TP is operated in the touch mode, the first touch electrode TE 1 , the second touch electrode TE 2  and the third touch electrode TE 3  are provided the first touch sensing signal TX 1 , the second touch sensing signal TX 2  and the third touch sensing signal TX 3  in order, and the first common electrode region VCOM 1 , the second common electrode region VCOM 2  and the third common electrode region VCOM 3  can be correspondingly provided touch-related signals having same frequency, same amplitude and same phase with the first touch sensing signal TX 1 , the second touch sensing signal TX 2  and the third touch sensing signal TX 3  in order. In another embodiment, the first common electrode region VCOM 1 , the second common electrode region VCOM 2  and the third common electrode region VCOM 3  can be correspondingly disconnected with a signal source or in a floating state in order. 
         [0077]    It should be noticed that, in practical applications, when the in-cell self-capacitive touch panel TP is operated in the touch mode, the single common electrode region VCOM, the first common electrode region VCOM 1 , the second common electrode region VCOM 2  and the third common electrode region VCOM 3 , or the source lines can be in a floating state in a part of time and provided a touch-related signal having same frequency, same amplitude and same phase with the touch sensing signal in another part of time, but not limited to this. 
         [0078]    As shown in  FIG. 7A , in another embodiment, in the laminated structure  7 A of the in-cell self-capacitive touch panel, the second conductive layer M 2  is disposed in the TFT layer  71  and the second conductive layer M 2  is electrically connected with the first conductive layer M 3  through the via VIA. In fact, the second conductive layer M 2  and the source lines S and drain lines D in the TFT layer  71  can be formed at the same time; the first conductive layer M 3  and the source lines S in the TFT layer  71  can be overlapped, but not limited to this.  FIG. 7C  illustrates an embodiment of the pixel design in the in-cell self-capacitive touch panel, but also not limited to this. 
         [0079]    In practical applications, the second conductive layer M 2  and the first conductive layer M 3  can be overlapped and coupled in parallel; the second conductive layer M 2  can form a bridge structure through the via VIA to across the first conductive layer M 3 , but not limited to this. 
         [0080]    In practical applications, when the laminated structure of the in-cell self-capacitive touch panel has a half source driving (HSD) structure, the laminated structure will have an additional space which is originally occupied by a source line, and the second conductive layer M 2  electrically connected with the first conductive layer M 3  can be disposed in the additional space as the traces of the touch electrodes TE, but not limited to this. 
         [0081]    In this embodiment, as shown in  FIG. 8 , the traces M 2 (Touch) and the signal lines M 2 (Data) formed by the second conductive layer M 2  are interlaced; therefore, the number of the second conductive layer M 2  can be reduced by half. The second conductive layer M 2  and the first conductive layer M 3  can be overlapped completely, and different touch electrodes TE can be bridged by the via VIA through the traces M 2 (Touch); therefore, the touch electrodes TE formed by the first conductive layer M 3  arranged in mesh type can cover larger area to reduce the area of the touch sensing dead zone, and the effective touch sensing area of the in-cell self-capacitive touch panel TP can be increased accordingly. 
         [0082]    It should be noticed that, when the touch sensing is performed in this embodiment, the signal control of the common electrodes CITO, the source lines S and the gate lines G can be the same with any above-mentioned embodiments without any specific limitations. Furthermore, similar to the above-mentioned embodiments, the first conductive layer M 3  not used as the touch electrodes can be also electrically connected with the common electrode CITO through the via VIA to increase the conductivity of the common electrode CITO. And, as shown in  FIG. 7B , the second conductive layer M 2  not used as traces or signal lines can be also electrically connected with the first conductive layer M 3  not used as touch electrodes through the via VIA and further electrically connected with the common electrode CITO through the via VIA to further enhance the conductivity of the common electrode CITO. 
         [0083]    Please refer to  FIG. 9A ,  FIG. 9B  and  FIG. 9C . As shown in  FIG. 9A ,  FIG. 9B  and  FIG. 9C , the shapes of the touch electrodes TE formed by the first conductive layer M 3  arranged in mesh type is not limited to the conventional rectangle or square, in practical applications, the shapes of the touch electrodes TE can be triangle (as shown in  FIG. 9A ), hexagonal (as shown in  FIG. 9B ), circular (as shown in  FIG. 9C ) or any other geometries without any specific limitations. 
         [0084]    Compared to the prior arts, the in-cell touch panel and its trace layout of the invention have following advantages: 
         [0085]    (1) The laminated structure of the in-cell touch panel of the invention is simple and easy to be manufactured to reduce costs. 
         [0086]    (2) Designs of the touch electrodes, common electrodes and their traces in the in-cell touch panel of the invention are very simple. 
         [0087]    (3) The aperture ratio of the LCD touch panel will not be affected by the novel trace layout method of the invention. 
         [0088]    (4) The RC loading of the common electrode can be effectively reduced. 
         [0089]    (5) When the in-cell touch panel is operated in the touch mode, the common electrode is controlled simultaneously to reduce the entire RC loading of the in-cell touch panel. 
         [0090]    With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.