Patent Publication Number: US-9841834-B2

Title: In-cell touch liquid crystal panels and the array substrates thereof

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to touch technology, and more particularly to an in-cell touch liquid crystal panel and the array substrate thereof. 
     2. Discussion of the Related Art 
     Touch display panel is one input media providing a simple and convenient man-machine interaction. Thus, the touch display panel has been widely adopted in a variety of electronic devices. Basing on different operations principles and the medias for transmitting information, the touch-related products may include infrared touch panels, capacitive touch panels, resistive touch panels and surface acoustic wave touch panels. The capacitive touch panels are the mainstream products due to the attributes, such as long life cycle, high light transmission rate, and providing multi-touch. 
     The capacitive touch displays include capacitive touch panels, which may include surface capacitive and projected capacitive. The projected capacitive may be further classified into self-capacitance touch screens and mutual-capacitive touch screens. With respect to the mutual-capacitive touch screens, touch driving electrodes and touch sensing electrodes are configured on a surface of the glass. Coupling capacitance is formed at the intersection of the two electrodes. When fingers touch the capacitance screen, the coupling between the two electrodes of the touch point is changed, such that the coupling capacitance between the two electrodes is changed. A coordinate of each of the touch points may be calculated in accordance with the changed capacitance. 
     With respect to the mutual-capacitive in-cell touch panels, usually, the touch driving electrode (Tx) and the touch sensing electrode (Rx) are configured directly on the array substrate or the optical filter substrate.  FIG. 1  is a schematic view of the conventional mutual-capacitive in-cell touch panel. Within the display area (AA), the touch driving electrode (Tx) and the touch sensing electrode (Rx) are respectively manufactured by two layers of ITO material. The touch driving electrode (Tx) and the touch sensing electrode (Rx) are arranged on two planes, which are non-coplanar, and the two planes are electrically insulated. This configuration is referred to as double-layers ITO mutual-capacitance screen, namely, double layer ITO touch screen (DITO). A plurality of bar-shaped touch driving electrode (Tx) are arranged along the Y-direction, and a plurality of bar-shaped touch sensing electrode (Rx) are arranged along the X-direction, wherein the X-direction is orthogonal to the Y-direction. The connection wirings  2  of the touch sensing electrode (Rx) may connect a down section of the display area (AA) with the touch control chip  1 . The connection wiring  3  of the touch driving electrode (Tx) are configured to route from the left and the right side of the display area (AA), and then extend along the Y-direction to connect to the touch control chip  1 . Thus, wiring areas  4  are at the left and right sides of the display area (AA). 
     Within the competitive display markets, differential designs is a key direction for improving unique selling points of the suppliers. Currently, the main trends include slim type and narrow border type. Such trends lead to artistic outlook and may draw consumer&#39;s focus. Nevertheless, as shown, the wiring area  4  occupies a certain space of the mutual-capacitive in-cell touch panels, and thus is adverse to the narrow-border design. 
     SUMMARY 
     In over to overcome the above-mentioned problem, the in-cell touch liquid crystal panel and the array substrate are provided. The structure of the touch screen of the array substrate is enhanced so as to reduce the width of the border of the liquid crystal panel. As such, the narrow border design may be realized. 
     In one aspect, an array substrate of in-cell touch liquid crystal panels includes: a glass substrate and at least one TFT, a common electrode layer, and at least one pixel electrode formed on the glass substrate in turn, a first insulation layer is arranged between the common electrode layer and the TFT, a passivation layer is arranged between the common electrode layer and the pixel electrode, and the pixel electrode electrically connects with the TFT via a first through hole; the common electrode layer includes a plurality of bar-shaped touch driving electrodes insulated from each other, the touch driving electrodes extend along a first direction, each of the touch driving electrodes includes a plurality of suspended electrodes arranged along the first direction, and the suspended electrodes are insulated from the touch driving electrode; a second insulation layer and a metal wiring layer are arranged between the common electrode layer and the passivation layer in sequence, wherein the second insulation layer includes a second through hole and a plurality of third through holes corresponding to each of the touch driving electrodes, each of the third through holes corresponds to one of the suspended electrodes within each of the touch driving electrodes, the metal wiring layer includes a plurality of driving electrode wirings, a plurality of suspended electrode wirings, and a plurality of touch sensing electrodes extending along the second direction, and the driving electrode wirings, the suspended electrode wirings, the touch sensing electrodes are insulated from each other; the driving electrode wirings correspond to the touch driving electrodes one by one, each of the driving electrode wirings electrically connects to one of the touch driving electrodes via the second through hole, and each of the suspended electrode wirings electrically connects to the suspended electrodes arranged along the second direction via the third through hole; and wherein the first direction is orthogonal to the second direction. 
     Wherein the driving electrode wirings span over all of the touch driving electrodes along the second direction, and a hollowed area is formed by hollowing out the projected area of the touch driving electrodes that have not electrically connected with the driving electrode wirings. 
     Wherein the driving electrode wirings, the suspended electrode wirings, and the touch sensing electrodes are arranged within a non-display area of the array substrate. 
     Wherein a width of the hollowed area is not smaller than the width of the driving electrode wirings. 
     Wherein the second through holes and/or the third through hole comprise a plurality of via holes. 
     Wherein each of the driving electrode wirings includes a plurality of electrically connected metal wirings, and each of the suspended electrode wirings includes a plurality of electrically connected metal wirings. 
     Wherein a larger number of metal wirings is configured with the driving electrode wirings that are located farther from a signal input end. 
     Wherein within the second insulation layer, n number of the third through holes are configured to be corresponding to each of the suspended electrodes, and the suspended electrodes arranged in one column along the second direction is configured with n number of the suspended electrode wirings over the top of the suspended electrodes, and n is an integer larger than one. 
     In another aspect, an in-cell touch liquid crystal panel includes a TFT array substrate, a color film substrate, and a liquid crystal layer between the TFT array substrate and the color film substrate. The TFT array substrate may be the above array substrate. 
     In view of the above,by changing the touch panel structure within the array substrate, the connection wirings of the touch driving electrodes have not occupied the border area of the panel. Thus, the width of the border of the liquid crystal panel is decreased so as to realize the narrow border design. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of the conventional mutual-capacitive in-cell touch panel. 
         FIG. 2  is a schematic view of the array substrate of the in-cell touch liquid crystal panel in accordance with one embodiment. 
         FIG. 3  is a schematic view of the common electrode layer in accordance with one embodiment. 
         FIG. 4  is a schematic view of the second insulation layer in accordance with one embodiment. 
         FIG. 5  is a schematic view of the metal wiring layer in accordance with one embodiment. 
         FIG. 6  is a schematic view of the metal wiring layer in accordance with another embodiment. 
         FIG. 7  is a cross-sectional view of the hollowed area along the line (x 1 ) of  FIG. 5 . 
         FIG. 8  is a schematic view of the driving electrode wirings and the suspended electrode wirings in accordance with one embodiment. 
         FIG. 9  is an enlarged view of the area A 1  and A 2  of  FIG. 5 . 
         FIG. 10  is a schematic view of the in-cell touch liquid crystal panel in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Embodiments of the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. 
     Various example embodiments will now be described more fully with reference to the accompanying drawings in which some example embodiments are shown. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity. In the following description, in order to avoid the known structure and/or function unnecessary detailed description of the concept of the invention result in confusion, well-known structures may be omitted and/or functions described in unnecessary detail. 
     Referring to  FIGS. 2-5 , in one embodiment, an in-cell touch liquid crystal panel includes an array substrate having a touch structure embedded therein. As shown in  FIG. 2 . The array substrate  100  includes a glass substrate  10  and at least one TFT  20 , a common electrode layer  30 , and a pixel electrode  40  formed on the glass substrate  10  in turn. A first insulation layer  50  is arranged between the common electrode layer  30  and the TFT  20 . A passivation layer  60  is arranged between the common electrode layer  30  and the pixel electrode  40 . The pixel electrode  40  electrically connects with the TFT  20  via a first through hole  70 . Further, the a second insulation layer  80  and a metal wiring layer  90  is arranged between the common electrode layer  30  and the passivation layer  60  in sequence. 
     The TFT  20  includes a gate  21 , a source  22 , a drain  23  and an active layer  24 . In the embodiment, as shown in  FIG. 2 , the active layer  24  is arranged on the glass substrate  10 , the gate  21  is arranged on the active layer  24 , and the insulation layer is arranged between the gate  21  and the active layer  24 . The source  22  and the drain  23  are arranged on the structure layer of the gate  21 , and the insulation layer is arranged between the gate  21  and the source  22 , the drain  23 . The pixel electrode  40  connects to the drain  23  via the first through hole  70 . In another example, the pixel electrode  40  connects to the source  22  via the first through hole  70 . Only one TFT  20  and one pixel electrode  40  area shown in  FIG. 2  as one example. It can be understood that there are a plurality of TFTs  20  arranged in a matrix and pixel electrodes  40 . The array substrate  100  also includes a plurality of data lines and scanning lines. The scanning lines intersect with the data line to define the pixel cells. Each of the pixel cells include one TFT  20  and one pixel electrode  40  as shown in  FIG. 4 . 
     In the embodiment, as shown in  FIG. 3 , the common electrode layer  30  includes a plurality of bar-shaped touch driving electrodes  31  insulated from each other. The touch driving electrodes  31  extend along a first direction, namely the X-direction in  FIG. 3 . In addition, the touch driving electrodes  31  are arranged along a second direction, namely, the Y-direction in  FIG. 3 . Within each of the touch driving electrodes  31 , a plurality of suspended electrodes  32  are arranged along the first direction, and the suspended electrodes  32  are insulated from the touch driving electrode  31 . Thus, within a whole area of the common electrode layer  30 , the suspended electrodes  32  are arranged in a matrix, wherein the first direction is orthogonal to the second direction. 
     In the embodiment, referring to  FIGS. 4 and 5 , the portions defined by the dashed lines are the outlook of the common electrode layer  30  below the second insulation layer  80 . As shown in  FIG. 4 , the second insulation layer  80  includes a second through hole  81  and a plurality of third through holes  82  corresponding to each of the touch driving electrodes  31 . Each of the third through holes  82  corresponds to a plurality of suspended electrodes  32  within each of the touch driving electrodes  31 . The metal wiring layer  90  includes a plurality of driving electrode wirings  91 , a plurality of suspended electrode wirings  92 , and a plurality of touch sensing electrodes  93  extending along the second direction, and the driving electrode wirings  91 , the suspended electrode wirings  92 , the touch sensing electrodes  93  are insulated from each other. The driving electrode wirings  91  corresponds to the touch driving electrodes  31  one by one. The driving electrode wirings  91  electrically connects one of the touch driving electrode  31  via the second through hole  81 . Each of the suspended electrode wirings  92  electrically connects to the suspended electrodes  32  arranged along the second direction via the third through hole  82 . It is to be noted that the second through hole  81  and the third through hole  82  may include a plurality of via holes to ensure the electrical connections between the wirings and the electrodes. For instance, as shown in  FIG. 4 , the second through hole  81  may include three via holes  81   a.    
     With respect to the array substrate  100 , when in a displaying process, an external control chip provides common voltage signals to the touch driving electrode  31  via the driving electrode wirings  91 , and provides the common voltage signals to the suspended electrodes  32  via the suspended electrode wirings  92 . In addition, the external control chip may provide the common voltage signals to the touch sensing electrodes  93  or no signals are provided to the touch sensing electrodes  93 . Preferably, during the displaying process, the external control chip provides the common voltage signals to the touch sensing electrodes  93 . During the touching sequence, the external control chip provides the touch driving signals to the touch driving electrode  31  via the driving electrode wirings  91 . The suspended electrodes  32  have not provided any signals, and the touch sensing electrodes  93  receive the touch sensing signals. 
     By changing the touch panel structure within the array substrate, the connection wirings of the touch driving electrodes have not occupied the border area of the panel. Thus, the width of the border of the liquid crystal panel is decreased so as to realize the narrow border design. 
     It is to be noted that  FIGS. 3-5  only demonstrate that the common electrode layer  30  may include three touch driving electrodes  31 , and each of the touch driving electrodes  31  includes three suspended electrodes  32 . Such configuration is only taken as one example, and thus the present disclosure is not limited thereto. The number of the touch driving electrode  31  and the suspended electrodes  32  may be configured in accordance with real scenarios. That is, the number of the touch driving electrode  31  and the suspended electrodes  32  may be less than or more than the above configuration. 
     The number of the wirings within the metal wiring layer  90  be described hereinafter. The number of the driving electrode wirings  91  is the same with the number of the touch driving electrode  31 . Each of the driving electrode wirings  91  corresponds to one touch driving electrode  31  electrically connected. 
     The number of the suspended electrode wirings  92  is determined by the number of the suspended electrodes  32 . As shown in  FIG. 5 , at least one column of the suspended electrodes  32  is configured with one suspended electrode wirings  92 . In another example, within the second insulation layer  80 , n number of the third through holes  82  are configured to be corresponding to each of the suspended electrodes  32 . The suspended electrodes  32  arranged in one column along the second direction is configured with n number of the suspended electrode wirings  92  over the top of the suspended electrodes  32 , and the suspended electrode wirings  92  connect to the suspended electrodes  32 , wherein n is the integer larger than one. As shown in  FIG. 6 , within the second insulation layer  80 , two third through holes  82  are configured in accordance with each of the suspended electrodes  32 . The suspended electrodes  32  of one column are configured with two suspended electrode wirings  92  over the top of the suspended electrodes  32 , and the suspended electrode wirings  92  connect with the suspended electrodes  32 . 
     The number of the touch sensing electrodes  93  is the largest one. Referring to  FIG. 5 , the metal wiring layer  90  covers the matrix of the pixel cells within the array substrate  100 . With respect to the matrix of pixel cells, a rim of each of the pixel cells corresponds to the black matrix for shielding light. The location of each of the wirings within the metal wiring layer  90  centers in the location of the black matrix. In other words, the location of each of the wirings within the metal wiring layer  90  is arranged in a non-display area of the pixels in each columns of the array substrate  100 . The Y-direction in  FIG. 5  relates to a column direction of the pixel cell matrix. The wirings within the metal wiring layer  90  may be arranged between every two adjacent pixel cell columns. Thus, except for the locations for configuring the driving electrode wirings  91  and the suspended electrode wirings  92 , the touch sensing electrodes  93  may be arranged in the remaining locations. Preferably, the touch sensing electrodes  93  are arranged in locations other than the areas having the driving electrode wirings  91  and the suspended electrode wirings  92  arranged thereon. 
     With respect to the length of the driving electrode wirings  91 , as each of the driving electrode wirings  91  correspond to one touch driving electrode  31  electrically connected therewith, the length of the driving electrode wirings  91  may be configured accordingly. As shown in  FIG. 5 , the top-left area is a starting point, and the signals are inputted from upper ends of the wirings. A first, a second, and a third touch driving electrodes  31  are arranged along a top-down direction. A first, a second, a third driving electrode wirings  91  are arranged along a left-to-right direction. The first driving electrode wirings  91  may be configured to connect only to the first touch driving electrode  31 , and thus is not extended to span the second and the third touch driving electrodes  31 . The second driving electrode wirings  91  span the first touch driving electrode  31  and then connect to the second touch driving electrode  31 , and is not extended to span the third touch driving electrode  31 . The third driving electrode wirings  91  span the first and the second touch driving electrodes  31  and connect to the third touch driving electrode  31 . It may he understood that in the above configuration, as the lengths of the driving electrode wirings  91  are different, the display performance may be affected due to the uniform transmission of the light beams. 
     In the embodiment, as shown in  FIG. 5 , the driving electrode wirings  91  span all of the touch driving electrodes  31  along the second direction. That is, the first driving electrode wirings  91  connect to the first touch driving electrode  31  and expend downward to span the second and the third touch driving electrodes  31 . The second driving electrode wirings  91  span the first touch driving electrode  31  and connect to the touch driving electrode  31 , and then span downward to the third touch driving electrode  31 . The third driving electrode wirings  91  span the first and the second touch driving electrodes  31  and then connect to the third touch driving electrode  31 . This may prevent from the optical issues caused by different lengths of the driving electrode wirings  91 . 
     However, as the driving electrode wirings  91  span over the touch driving electrode  31  that has not been connected therewith, the driving electrode wirings  91  may impact the signals of the touch driving electrode  31 . In the embodiment, referring to  FIGS. 3-5, and 7 ,  FIG. 7  is a cross-sectional view of the  FIG. 5  along the line “x 1 .” A hollowed area  33  is formed by hollowing out the projected area of the touch driving electrodes  31  that have not electrically connected with the driving electrode wirings  91 . Taking the first driving electrode wirings  91  as one example, the first driving electrode wirings  91  connects to the first touch driving electrode  31 , and thus the hollowed area  33  is formed by hollowing out the projected area of the second and the third touch driving electrodes  31  with respect to the first driving electrode wirings  91 . By configuring the hollowed area  33 , the touch driving electrode  31  that has not connected to the driving electrode wirings  91  is prevented from being affected by the driving electrode wirings  91 . In addition, as shown in  FIG. 7 , the width (d 1 ) of the hollowed area  33  is not smaller than the width (d 2 ) of the driving electrode wirings  91  to obtain a better effect. 
     In the embodiment, as shown in  FIG. 8 , each of the driving electrode wirings  91  include a plurality of electrically connected metal wirings  91   a.  each of the suspended electrode wirings  92  include a plurality of electrically connected metal wirings  92   a.  In addition, with respect to the driving electrode wirings  91  transmitting the touch driving signals, the transmitted distances of the different driving electrode wirings  91  are different, i.e., the distance from a signal input end to the corresponding suspended electrodes  32 . In order to provide better matched impedance, a larger number of metal wirings  91   a  is configured for the driving electrode wirings  91  that are located farther from a signal input end. In an example, referring to  FIGS. 5 and 9 , if the first driving electrode wirings  91  include three metal wirings  91   a,  the second driving electrode wirings  91  may be configured to include four or more metal wirings  91   a.  Similarly, the number of the metal wirings  91   a  configured with the third driving electrode wirings  91  is larger than the number of the driving electrode wirings  91  configured with the second driving electrode wirings  91 . 
     In the embodiment, an in-cell touch liquid crystal panel, as shown in  FIG. 10 , includes the TFT array substrate  100  in the above embodiments. The in-cell touch liquid crystal panel also includes a color film substrate  200  opposite to the array substrate  100 , and a liquid crystal layer  300  between the array substrate  100  and the color film substrate  200 . 
     In view of the above, by changing the touch panel structure within the array substrate, the connection wirings of the touch driving electrodes have not occupied the border area of the panel. Thus, the width of the border of the liquid crystal panel is decreased so as to realize the narrow border design. 
     It should be noted that the relational terms herein, such as “first” and “second”, are used only for differentiating one entity or operation, from another entity or operation, which, however do not necessarily require or imply that there should be any real relationship or sequence. Moreover, the terms “comprise”, “include” or any other variations thereof are meant to cover non-exclusive including, so that the process, method, article or device comprising a series of elements do not only comprise those elements, but also comprise other elements that are not explicitly listed or also comprise the inherent elements of the process, method, article or device. In the case that there are no more restrictions, an element qualified by the statement “comprises a . . . ” does not exclude the presence of additional identical elements in the process, method, article or device that comprises the said element. 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.