Patent Publication Number: US-2023161438-A1

Title: Touch panel and touch device

Description:
FIELD OF DISCLOSURE 
     The present disclosure relates to the field of touch technologies, in particular to a touch panel and a touch device. 
     BACKGROUND 
     In a metal mesh touch, an impedance of a channel is mainly composed of two parts, one is an impedance of an in-plane channel, and the other is a trace impedance of a bezel region. The trace impedance of the bezel region is a main impedance in the metal mesh. Too high of the trace impedance will affect a response time of a touch operation, which in turn will reduce a touch performance. 
     SUMMARY OF DISCLOSURE 
     A trace impedance of a bezel region is a main impedance in a metal mesh. If the trace impedance is too high, it will affect a response time of a touch operation and cause a touch performance to decrease. 
     Embodiments of the present disclosure provide a touch panel and a touch device, which can reduce a trace impedance of a bezel region, improve a response speed of a touch operation, and thus improve a touch performance. 
     In a first aspect, an embodiment of the present disclosure provides a touch panel, including: 
     a touch region including a plurality of transmit channels; and 
     a bezel region disposed on an edge of the touch region. The bezel region comprises a plurality of first traces, a plurality of second traces, and a plurality of conductive film layers arranged at intervals, one of the conductive film layers connects one of the first traces and one of the second traces so that the first trace and the second trace are connected in parallel, and the first trace and the second trace connected in parallel are connected to one of the transmit channels. 
     In a second aspect, an embodiment of the present disclosure also provides a touch device, and the touch device includes the touch panel described in any one of the above. 
     In the embodiments of the present disclosure, the touch panel includes the touch region and the bezel region. The touch region includes the plurality of transmit channels. The bezel region is disposed on the edge of the touch region. The bezel region includes the plurality of first traces, the plurality of second traces, and the plurality of conductive film layers arranged at intervals. One of the conductive film layers connects one of the first traces and one of the second traces so that the first trace and the second trace are connected in parallel. The first trace and the second trace connected in parallel are connected to one of the transmit channels. By arranging parallel first trace and second trace at a wiring end of each transmit channel, a trace impedance of the bezel region in the touch panel can be reduced, and a response speed of a touch operation and a touch performance of the touch panel can be improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to more clearly describe technical solutions in the embodiments of the present disclosure, the following will briefly introduce drawings needed in the description of the embodiments. Apparently, the drawings in the following description are only some embodiments of the present disclosure. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings. 
       In order to have a more complete understanding of the present disclosure and its beneficial effects, it will be described below in conjunction with the accompanying drawings. In the following description, the same reference numerals indicate the same parts. 
         FIG.  1    is a schematic diagram of a touch panel of an embodiment of the present disclosure. 
         FIG.  2    is a schematic diagram of a structure of a bezel region in the touch panel of  FIG.  1   . 
         FIG.  3    is a cross-sectional view of the bezel region of  FIG.  2    along a line A-A. 
         FIG.  4    is a schematic diagram of a touch device of an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative efforts shall fall within a protection scope of the present disclosure. 
     An embodiment of the present disclosure provides a touch panel. The touch panel is configured to touch operations. That is, a user performs operations, such as a pressing operation on a touch panel, and the touch panel can feed back a signal of the pressing operation, so that a touch device installed with the touch panel can control display or playback of the touch device according to the signal of the pressing operation. 
     Exemplarily, refer to  FIG.  1   , which is a schematic diagram of a touch panel of an embodiment of the present disclosure. The embodiment of the present disclosure provides a touch panel  100 . The touch panel  100  includes a touch region  10 , bezel regions  20 , and a metal connection element  30 . It should be noted that the touch region  10  includes a first edge and a second edge that are arranged oppositely, that is, a left edge and a right edge of the touch region  10  in  FIG.  1   . The touch panel  100  may include two bezel regions  20 . One bezel region  20  is disposed on the left edge of the touch region  10 , and the other bezel region  20  is disposed on the right edge of the touch region  10 . The metal connection element  30  can be placed in any suitable position of the touch panel  100 , and it is not limited here. For convenience of description, the embodiment of the present disclosure is described in that the metal connection element  30  is arranged at a position corresponding to the bezel region  20 . 
     The touch region  10  includes a plurality of transmit channels  110 . The plurality of transmit channels  110  are arranged side by side on a same layer. Traces in each transmit channel  110  can be formed in a metal mesh structure. Since any touch region  10  of the touch panel  100  can realize sensing of a touch operation, forming the transmit channels  110  to the metal mesh structure can make the transmit channels  110  have a wide distribution range. On the other hand, an impedance of the metal mesh structure of the transmit channels  110  is lower than that of a conventional structure of the transmit channels. In the conventional structure, for example, the traces in the transmit channels are a plurality of metal traces that are not connected in parallel and are arranged side by side. The metal mesh structure can realize a parallel connection of the plurality of metal traces, which can reduce a trace impedance, thereby improving a response speed of the touch panel  100  and improving a touch performance. 
     In a metal mesh touch, an impedance of a channel is mainly composed of a channel impedance in the touch region  10  and a trace impedance of the bezel region  20 , that is: 
     
       
      
       R 
       TX 
       =R 
       ch 
       +R 
       trace  
      
     
     R TX  represents the impedance of the channel; 
     R ch  represents the channel impedance in the touch region  10 ; 
     R trace  represents a total trace impedance of the bezel region  20 . 
     For the traces of bezel region  20 , a total impedance of the traces in one side is: R trace =2*R s *W/W line . A total impedance of the traces in three sides is: R trace =R s *W/W line . 
     R s  is a square resistance of each trace; 
     W is a width of the bezel region  20 ; 
     W line  is a width of the trace. 
     In other words, no matter how the traces are arranged, the total trace impedance R trace  of the bezel region  20  is related to the square resistance of each trace. Moreover, the higher the square resistance of the trace, the larger the total trace resistance R trace  of the bezel region  20 . Too high impedance will increase a charging time of a touch capacitor, and the response speed of the touch operation will decrease accordingly. Therefore, the trace impedance of the bezel region  20  needs to be optimized. The embodiment of the present disclosure provides an optimized structure of the trace impedance of the bezel region  20 , which will be described below. 
     In order to fully understand a structure of the bezel region  20  of the touch panel  100  in the embodiment of the present disclosure, the bezel region  20  will be described in detail below. 
     For details, referring to  FIG.  2    and  FIG.  3   ,  FIG.  2    is a schematic diagram of a structure of a bezel region in the touch panel of  FIG.  1   , and  FIG.  3    is a cross-sectional view of the bezel region of  FIG.  2    along a line A-A. The bezel region  20  includes a plurality of first traces  210 , a plurality of second traces  220 , and a plurality of conductive film layers  230  arranged at intervals. One of the conductive film layers  230  connects one of the first traces  210  and one of the second traces  220 , so that the corresponding first trace  210  and second trace  220  are connected in parallel. The first trace  210  and the second trace  220  connected in parallel are connected to one of the transmit channels  110 . By setting the first trace  210  and second trace  220  in parallel on a trace end of each transmit channel  110 , the trace impedance of the bezel region  20  in the touch panel  100  can be reduced, and the response speed of the touch operation and the touch performance of the touch panel can be improved. 
     Two ends of the first trace  210  and the second trace  220  connected in parallel are respectively connected to the corresponding transmit channel  110  and the metal connection element  30 , so that the transmit channel  110  is connected to the metal connection element  30  through the first trace  210  and second trace  220  connected in parallel. The metal connection element  30  is connected to a touch chip, so that control signals, such as judgment, feedback, and control signals, of the touch chip are transmitted to the transmit channel  110  through the first trace  210  and the second trace  220 . 
     One of the first traces  210  is disposed between two of the second traces  220 . The plurality of first traces  210  are arranged on a same plane at intervals. Alternatively, a distance between two adjacent first traces  210  is equal. The plurality of second traces  220  are arranged on a same plane at intervals. Alternatively, a distance between two adjacent second traces  220  is equal. It should be noted that the plane where the first traces  210  is located and the plane where the second traces  220  is located are parallel and non-overlapping planes. That is, the first traces  210  and the second traces  220  can be arranged in different layers. Alternatively, the distance between two adjacent second traces  220  is greater than the distance between two adjacent first traces  210 . 
     A distance between a projection of one first trace  210  on a plane formed by the plurality of second traces  220  and two adjacent second traces  220  ranges from 2 micrometers to 3 micrometers. In this way, the first traces  210  and the second traces  220  do not overlap each other and thus achieve insulation from each other. Moreover, the small distance between the first traces  210  and the second traces  220  can save a material of the conductive film layers  230 . 
     It should be noted that a width of the first trace  210  may range from 3 micrometers to 10 micrometers. A thickness of the first trace  210  may range from 0.2 micrometers to 0.7 micrometers. A width of the second trace  220  may range from 3 micrometers to 10 micrometers. A thickness of the second trace  220  may range from 0.2 micrometers to 0.7 micrometers. Setting the first trace  210  and the second trace  220  to flat and wide line shapes can ensure conductivities of the first trace  210  and the second trace  220  when the thickness of the trace is small. 
     Both the first trace  210  and the second trace  220  may be made of metal. Preferably, they may be made of metal with lower impedance. For example, the first trace  210  and the second trace  220  are made of a silver material. In addition, the first trace  210  and the second trace  220  are both metal mesh structures. 
     It should be noted that an impedance of the second trace  220  and an impedance of the first trace  210  may be equal or not equal. If the impedance of the second trace  220  is less than or equal to the impedance of the first trace  210 , the impedance of the second trace  220  and the impedance of the first trace  210  in parallel are smaller. That is, the trace impedance of bezel region  20  is more obviously reduced, the touch response speed is higher, and the touch performance is better. 
     In order to further illustrate positions and connection relationships between the first trace  210  and the second trace  220  of the bezel region  20  and the conductive film layers  230 , following specific descriptions will be made with reference to the cross-sectional view of the bezel region  20  in  FIG.  3    along the line A-A. 
     The bezel region  20  includes a glass layer  260 , a first insulating layer  240 , and a second insulating layer  250  that are sequentially stacked. A plurality of the first traces  210  are arranged on one side of the first insulating layer  240  at intervals. A plurality of the second traces  220  are arranged on the other side of the first insulating layer  240  at intervals. One side of the first insulating layer  240  and the other side of the first insulating layer  240  are arranged opposite to each other. It can be understood that one side of the first insulating layer  240  includes a plane where the plurality of first traces  210  are set. The other side of the first insulating layer  240  includes another plane where the plurality of second traces  220  are set. That is, there is a setting plane on each side of the first insulating layer  240 . 
     The first insulating layer  240  is provided with a plurality of first via holes  242 . The second insulating layer  250  is provided on the plurality of second traces  220 . The second insulating layer  250  is provided with a plurality of second via holes  252  and a plurality of third via holes  254 . One of the third via holes  254  is formed between two of the second via holes  252 . One of the third via holes  254  is connected to one of the first via holes  242 . One of the conductive film layers  230  connects on the plurality of the first traces  210  and on the plurality of the second traces  220  through on the plurality of the first via holes  242 , on the plurality of the second via holes  252 , and on the plurality of the third via holes  254 . 
     A sum of depths of the first via hole  242  and the connected third via hole  254  is greater than a depth of the second via hole  252 . It is understandable that since the first via hole  242  and the connected third via hole  254  are formed to extend from the second insulating layer  250  to the first insulating layer  240 , and the second via hole  252  only perforates the second insulating layer  250 , the sum of the depths of the first via hole  242  and the connected third via hole  254  is greater than the depth of the second via hole  252 . 
     It should be noted that when making the traces, the insulating layer, and the glass layer  260  of the touch panel  100 , following steps can be performed. A layer of the glass layer  260  is provided, and then a layer of metal mesh trace is formed. The plurality of transmit channels  110  and the plurality of first traces  210  that are arranged at intervals are obtained through a photolithography process. One of the first traces  210  is correspondingly connected to one of the transmit channels  110 . Then, a layer of the first insulating layer  240  is coated, and then a layer of metal mesh trace is formed. A plurality of sensing channels and the plurality of second traces  220  that are arranged at intervals are obtained through the photolithography process. The second traces  220  are insulated from the sensing channels. Then, the second insulating layer  250  is coated. Finally, the first via holes  242  and the third via holes  254  are formed at corresponding positions of the first traces  210 , and the second via holes  252  are formed at corresponding positions of the second traces  220 . The conductive film layer  230  connects the first trace  210  and the second trace  220  through the first via hole  242 , the third via hole  254 , and the second via hole  252 . It can be understood that two ends of the conductive film layer  230  are respectively connected to the transmit channel  110  and the metal connection element  30 . 
     It should be noted that the touch panel  100  usually includes a transmit channel layer and a sensing channel layer that are stacked and insulated. Existing touch panels usually do not reserve second traces  220  when forming sensing channels. The embodiments of the present disclosure reserve the second traces  220  when fabricating the sensing channel layer. Moreover, the second traces  220  and the first traces  210  are connected in parallel through the conductive film layers  230 . At this time, R trace-new =1/2*R trace . In comparison with a traditional trace pattern which only includes the first traces  210 , the embodiments of the present disclosure increase conductive paths of the traces. Therefore, the impedance of the traces in the bezel region can be reduced, the touch response speed can be improved, and the touch performance can be improved. 
     Positions of the first insulating layer  240  corresponding to the first traces  210  can form a plurality of protrusions during production, because the formation of the plurality of first traces  210  will make a surface after coating the first insulating layer  240  uneven. Similarly, positions of the second insulating layer  250  corresponding to the second traces  220  will also form a plurality of protrusions. In addition, since the first via holes  242  are formed at the positions of the first insulating layer  240  corresponding to the first traces  210 , the second via holes  252  are formed at the positions of the second insulating layer  250  corresponding to the second traces  220 , and the third via holes  254  are formed at the positions of the second insulating layer  250  corresponding to the first via holes  242 , structures of the first insulating layer  240  and the second insulating layer  250  shown in  FIG.  3    are formed. 
     The conductive film layer  230  includes a first section  232 , a second section  234 , and a third section  236 . The first section  232  is disposed on a wall of the first via hole  242  and a wall of the third via hole  254 . The second section is disposed on a wall of the second via hole  252 . The third section  236  is disposed on the second insulating layer  250 , and the third section  236  connects the first section  232  and the second section  234 . 
     The conductive film layers  230  may be made of high light-transmitting materials, such as transparent indium tin oxide (ITO) materials. It should be noted that if the conductive film layers  230  are manufactured, an ITO film can be coated on the conductive glass to form the conductive film layers  230 . 
     In some embodiments, please refer to  FIG.  4   , which is a schematic diagram of a touch device of an embodiment of the present disclosure. The embodiment of the present disclosure provides a touch device  1000 . The touch device  1000  includes the touch panel  100  and a display panel  200 . The display panel  200  at least partially overlaps the touch panel  100 . That is, an area of the display panel  200  is greater than or equal to an area of the touch panel  100 . For example, as shown in  FIG.  4   , the touch panel  100  and the display panel  200  partially overlap. In order to enable touch operations in all regions of the display panel  200 , preferably, the touch panel  100  overlaps the display panel  200 . That is, the area of the touch panel  100  is equal to the area of the display panel  200 . The structure of the touch panel  100  can refer to the structure of the touch panel  100  described in the foregoing embodiments, which will not be repeated here. 
     The touch device in the embodiments of the present disclosure may be a mobile terminal such as a mobile phone or a tablet computer. The touch device may also be a device with a touch panel, such as a gaming equipment, an augmented reality (AR) equipment, a virtual reality (VR) equipment, an in-vehicle computer, a laptop, a data storage device, an audio playback device, a video playback device, a wearable device, etc. The wearable device may be a smart bracelet, smart glasses, etc. 
     In the foregoing embodiments, the description of each embodiment has its own focus. For a part that is not described in detail in some embodiments, reference may be made to related descriptions of other embodiments. 
     In the description of the present disclosure, terms, such as “first” and “second”, are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating a number of indicated technical features. Thus, features defined as “first” and “second” may explicitly or implicitly include one or more plurality of features. It should be understood that the “plurality of” mentioned in this specification refers to two or more. 
     The touch panel and the touch device of the embodiments of the present disclosure have been described in detail above. In this specification, specific examples are used to illustrate principles and implementations of the present disclosure. The description of the above embodiments is only used to help understand methods and core ideas of the present disclosure. Also, for those skilled in the art, based on the ideas of the present disclosure, there will be changes in the specific implementations and the scope of application. In summary, the content of this specification should not be construed as a restriction on the present disclosure.