Abstract:
A large-area touch panel utilizing carbon nanotubes (CNT units) includes a first carbon nanotube (CNT) sub-panel and a second CNT sub-panel, the second CNT sub-panel is attached to the second CNT sub-panel to form a single CNT panel assembly. Each of the first CNT sub-panel and the second CNT sub-panel includes a CNT film having a plurality of CNT units, with an orientation of the CNT units in one sub-panel being perpendicular to the CNT units of the other sub-panel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Application No. 201210304607.X, filed on Aug. 24, 2012 in the China Intellectual Property Office, the content of which is hereby incorporated by reference in its entirety. This application is related to commonly-assigned applications entitled, “CARBON NANOTUBE TOUCH PANEL HAVING TWO CARBON NANOTUBE FILMS” filed ______ (Atty. Docket No. US46691), “CARBON NANOTUBE TOUCH PANEL HAVING AT LEAST TWO CARBON NANOTUBE FILMS” filed ______ (Atty. Docket No. US46692), “CARBON NANOTUBE TOUCH PANEL AND METHOD FOR MAKING SAME” filed ______ (Atty. Docket No. US46693), “CARBON NANOTUBE TOUCH PANEL AND TOUCH DISPLAY APPARATUS USING SAME” filed ______ (Atty. Docket No. US46694), “TOUCH PANEL AND TOUCH DISPLAY APPARATUS USING SAME” filed ______ (Atty. Docket No. US46695), and “TOUCH PANEL AND TOUCH DISPLAY APPARATUS USING SAME” filed ______ (Atty. Docket No. US46960). 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to touch sensing technologies, and more particularly, to a touch panel and a carbon nanotube (CNT) touch panel and a touch display apparatus using the CNT touch panel. 
         [0004]    2. Description of Related Art 
         [0005]    Touch display apparatus normally include a display assembly and a touch panel attached to the display assembly. Carbon nanotube (CNT) touch panels are widely used because of the durability of CNT touch panels. A CNT unit is a carbon nanotube. A CNT touch panel includes a plurality of CNT units arranged in parallel on a substrate; however, conductivity of the CNT unit decreases as a length of the CNT unit increases. This characteristic is a limit in design, and making a CNT touch panel with a large size is problematic. 
         [0006]    What is needed is to provide a means that can overcome the above-described limitations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of at least one embodiment. In the drawings, like reference numerals designate corresponding parts throughout the various views. 
           [0008]      FIG. 1  is a schematic view of a touch display apparatus according to a first embodiment of the present disclosure. 
           [0009]      FIG. 2  is an exploded view of the touch display apparatus of  FIG. 1 . 
           [0010]      FIG. 3  is a detailed plan view of the touch display apparatus of  FIG. 1 . 
           [0011]      FIG. 4  is a schematic view of a CNT film of the touch display apparatus of  FIG. 1 . 
           [0012]      FIG. 5  is a plan view of a touch display apparatus according to a second embodiment of the present disclosure. 
           [0013]      FIG. 6  is a schematic view of a touch display apparatus according to a third embodiment of the present disclosure. 
           [0014]      FIG. 7  is a plan view of a touch display apparatus according to a fourth embodiment of the present disclosure. 
           [0015]      FIG. 8  is a schematic view of a touch display apparatus according to a fifth embodiment of the present disclosure. 
           [0016]      FIG. 9  is a detailed plan view of the touch display apparatus of  FIG. 8 . 
           [0017]      FIG. 10  is a detailed plan view of a touch display apparatus according to a sixth embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Reference will be made to the drawings to describe various embodiments. 
         [0019]    Referring to  FIGS. 1-2 , a touch display apparatus  10  according to a first embodiment of the present disclosure includes a base  18 , a first CNT sub-panel  11   a , and a second CNT sub-panel  11   b . The base  18  may be a transparent glass substrate or a transparent plastic substrate. The first CNT sub-panel  11   a  and the second CNT sub-panel  11   b  are placed on the base  18 , for example, the first CNT sub-panel  11   a  and the second CNT sub-panel  11   b  may be adhered to the base  18  or be mechanically mounted onto the base  18 . In particular, the base  18  may also be a display panel, such as a liquid crystal display (LCD) panel, an organic electro-luminescence display (OLED), a plasma display panel (PDP), for example. 
         [0020]    The first CNT sub-panel  11   a  and the second CNT sub-panel  11   b  are attached to each other side-by-side, for example, the first CNT sub-panel  11   a  and the second CNT sub-panel  11   b  may abut each other to form a single CNT panel assembly, or CNT touch panel. The first CNT sub-panel  11   a  has a configuration substantially the same as the second CNT sub-panel  11   b . Each of the CNT sub-panel  11   a  and  11   b  includes a touch sensing region  110 , a first side region  111 , a second side region  112 , a third side region  113 , a fourth side region  114 , and a flexible printed circuit (FPC)  115 . The touch sensing region  110  is located in a main central region of the CNT sub-panel  11   a  or  11   b ; the first side region  111 , the second side region  112 , a third side region  113 , and the fourth side region  114  surround the touch sensing region  110 , and are arranged end to end to form a periphery of the touch sensing region  110 . The FPC  115  is mounted on and electrically connected to an edge of the third side region  113 . 
         [0021]    The first side region  111  and the second side region  112  are located adjacent to opposite ends of the touch sensing region  110 . The third side region  113  and the fourth side region  114  are located adjacent to the other two ends of the touch sensing region  110 . In other words, the first side region  111  is opposite to the second side region  112 , and is adjacent to the third side region  113  and the fourth side region  114 ; the second side region  112  is opposite to the first side region  111 , and is also adjacent to the third side region  113  and the fourth side region  114 ; the third side region  113  is opposite to the fourth side region  114 , and is adjacent to the first side region  111  and the second side region  112 ; the fourth side region  114  is opposite to the third side region  113 , and is also adjacent to the first side region  111  and the second side region  112 . 
         [0022]    In the present embodiment, the first CNT sub-panel  11   a  and the second CNT sub-panel  11   b  are arranged such that one is oriented at ninety degrees to the other. As such, the fourth side region  114  of the second CNT sub-panel  11   b  neighbors with and is attached to the first side region  111  of the first CNT sub-panel  11   a . Moreover, the first side region  111 , the second side region  112 , and the third side region  113  are defined as wiring regions, in which connection wires can be formed. 
         [0023]    Referring also to  FIGS. 3-4 , each of the first CNT sub-panel  11   a  and the second CNT sub-panel  11   b  includes a substrate  12 , a CNT film  13 , a plurality of first connection wires  14  and a plurality of second connection wires  16 . The CNT film  13 , the first connection wires  14 , and the second connection wires  16  are formed on the substrate  12 . The CNT film  13  covers the touch sensing region  110  of the CNT sub-panels  11   a ,  11   b , and senses touches applied to the touch display apparatus  10  and generates touch signals in accordance with the touches. 
         [0024]    As shown in  FIG. 4 , the CNT film  13  includes a plurality of CNT units  131 . The CNT units  131  of the CNT film  13  are arranged parallel to each other. All the CNT units  131  in the CNT film  13  extend from a first end  130  of the CNT film  13  to an opposite second end  132  of the CNT film  13 . 
         [0025]    The first connection wires  14  and the second connection wires  16  interconnect the CNT film  13  and the FPC  115 , and transmit the signals of touches generated by the CNT film  13  to the FPC  115 . The first connection wires  14  are formed on the first side region  111  of the CNT sub-panels  11   a  or  11   b , and extend onto the third side region  113  of the CNT sub-panels  11   a  or  11   b  in order to connect with the FPC  15 . The second connection wires  16  are formed on the second side region  112  of the CNT sub-panel  11   a  or  11   b , and also extend onto the third side region  113  of the CNT sub-panel  11   a  or  11   b  in order to connect with the FPC  15 . In the present embodiment, the first connection wires  14  and the second connection wires  16  of the first CNT sub-panel  11   a  are substantially symmetrical along an axis of symmetry S-S (see  FIG. 3 ); the first connection wires  14  and the second connection wires  16  of the second CNT sub-panel  11   b  are substantially symmetrical along an axis of symmetry S′-S′ (see  FIG. 3 ). The axis of symmetry S-S is perpendicular to the orientation of the CNT units  13  in the first CNT sub-panel  11   a , and the axis of symmetry S′-S′ is perpendicular to the orientation of the CNT units  13  in the second CNT sub-panel  11   b.    
         [0026]    In particular, each of the first connection wires  14  includes a first electrode  141 , a first wire body  142 , and a second electrode  143 . The first electrode  141  is electrically connected to an end of the first wire body  142 , and is attached to the first end  130  of the CNT film  13 ; the second electrode  143  is electrically connected to the other end of the first wire body  142 . Each of the second connection wires  16  includes a third electrode  161 , a second wire body  162  and a fourth electrode  163 . The third electrode  161  is electrically connected to an end of the second wire body  162 , and is attached to the second end  132  of the CNT film  13 ; the fourth electrode  163  is electrically connected to the other end of the second wire body  162 . The second electrodes  143  and the fourth electrodes  163  are arranged in parallel at a central edge of the third side region  113 . 
         [0027]    The FPC  115  includes a plurality of connection electrodes  118  all of which are arranged in parallel, and each of the connection electrodes  118  is attached to one of the second electrodes  143  or one of the fourth electrodes  163 . The attachment between the connection electrodes  118  and the electrodes  143 ,  163  enables transmission of the touch signals to the FPC  115 . 
         [0028]    When the touch display apparatus  10  is in operation, the CNT film  13  may generate touch signals in response to touches applied thereto, and the touch signals may be transmitted to the FPC  115  via the first connection wires  14  and the second connections wires  16 , and then be received by a processing unit to determine coordinates of the touches. 
         [0029]    In the foregoing touch display apparatus  10 , the touch panel is formed by the two CNT sub-panels  11   a  and  11   b  being attached to each other, thus large-sized touch panels can be created without the need of growing or creating very long CNT units. As such, the functions of the touch display apparatus  10  as provided in the present embodiment are equal to those of a larger touch display apparatus. 
         [0030]    Moreover, because the orientation of CNT units  131  in the CNT film  13  of the first CNT sub-panel  11   a  is perpendicular to the orientation of the CNT units  131  in the CNT film  13  of the second CNT sub-panel  11   b , the first CNT sub-panel  11   a  can be attached to the second CNT sub-panel  11   b  along the orientation of CNT units  131  in the CNT film  13  of the second CNT sub-panel  11   b , this maintains the necessary overall conductivity of the touch panel. 
         [0031]    Referring to  FIG. 5 , a touch display apparatus  20  according to a second embodiment of the present disclosure is similar to the above-described touch display apparatus  10  according to the first embodiment, but differs in the following aspects. An FPC  215  of a second CNT sub-panel  21   b  is mounted onto a second side region  112  of the second CNT sub-panel  21   b . In the second CNT sub-panel  21   b , a plurality of first connection wires  24  is formed at a first side region  211 , extending through a third side region  213 , and on reaching the second side region  212 , are electrically connected to the FPC  215 ; moreover, a plurality of second connection wires  26  is formed at the second side region  212  and are electrically connected to the FPC  215 . With this configuration, the FPC  215  in the second CNT sub-panel  21   b  is adjacent to an FPC  215  in a first sub-panel  21   a , this facilitates a connection between the two FPCs  215  and a main circuit board (not shown); furthermore, the two FPCs  215  may be alternatively integrated into a single unit. 
         [0032]    Referring to  FIG. 6 , a touch display apparatus  30  according to a third embodiment of the present disclosure is similar to the above-described touch display apparatus  10  according to the first embodiment, but differs in the following aspects: a second CNT sub-panel  31   b  of the touch display apparatus  30  does not include a fourth side region, and instead, a touch sensing region  310  of the second CNT sub-panel  31   b  is directly attached to a first side region  311  of the first CNT sub-panel  31   a . With this configuration, a touch-insensitive gap between the touch sensing regions  310  of the first and second CNT sub-panels  31   a  and  31   b  can be narrower. 
         [0033]    Referring to  FIG. 7 , a touch display apparatus  40  according to a fourth embodiment of the present disclosure is similar to the above-described touch display apparatus  10  according to the first embodiment, but differs in the following aspects: an FPC  415  in a second CNT sub-panel  41   b  is mounted adjacent to an FPC  415  in a first sub-panel  41   a ; in addition, a second CNT sub-panel  41   b  of the touch display apparatus  40  does not include a fourth side region, instead, a touch sensing region  410  of the second CNT sub-panel  41   b  is directly attached to a first side region  411  of the first CNT sub-panel  41   a.    
         [0034]    Referring to  FIGS. 8-9 , a touch display apparatus  50  according to a fifth embodiment of the present disclosure is similar to the above-described touch display apparatus  10  according to the first embodiment, but differs in the following aspects: in addition to a first CNT sub-panel  51   a  and a second CNT sub-panel  51   b , the touch display apparatus  50  further includes a third CNT sub-panel  51   c  and a fourth CNT sub-panel  51   d . Configurations of the first CNT sub-panel  51   a , the second CNT sub-panel  51   b , the third CNT sub-panel  51   c  and the fourth CNT sub-panel  51   d  remain substantially the same. The first CNT sub-panel  51   a , the second CNT sub-panel  51   b , the third CNT sub-panel  51   c  and the fourth CNT sub-panel  51   d  are arranged anticlockwise as a two-plus-two sub-panel array, and two adjacent CNT sub-panels are attached to each other side-by-side to form a single CNT panel assembly. 
         [0035]    In the touch display apparatus  50 , the second CNT sub-panel  51   b  is oriented at ninety degrees relative to the first CNT sub-panel  11   a , the third CNT sub-panel  51   c  is oriented at one hundred and eighty degrees relative to the first CNT sub-panel  11   a , and the fourth CNT sub-panel  51   d  is oriented at two hundred and seventy degrees relative to the first CNT sub-panel  11   a . Accordingly, a first side region  511  of the fourth CNT sub-panel  51   d  is the neighbor of, and is attached to, a fourth side region  514  of the first CNT sub-panel  51   a . A fourth side region  514  of the third CNT sub-panel  51   c  is the neighbor of, and attached to, a first side region  511  of the second CNT sub-panel  51   b , and a first side region  511  of the third CNT sub-panel  51   c  is the neighbor of, and attached to, a fourth side region  514  of the fourth CNT sub-panel  51   d.    
         [0036]    Moreover, an orientation of CNT units in a CNT film  53  of the second CNT sub-panel  51   b  is perpendicular to an orientation of the CNT units of the first CNT-panel  51   a . An orientation of CNT units in a CNT film  53  of the third CNT sub-panel  51   c  is parallel to the orientation of the CNT units of the first CNT-panel  51   a , and an orientation of CNT units in a CNT film  53  of the fourth CNT sub-panel  51   d  is perpendicular to the orientation of the CNT units of the first CNT-panel  51   a.    
         [0037]    Referring to  FIG. 10 , a touch display apparatus  60  according to a sixth embodiment of the present disclosure is similar to the above-described touch display apparatus  50  according to the fifth embodiment, but differs in the following aspects: an FPC  615  in a second CNT sub-panel  61   b  is mounted adjacent to an FPC  415  in a first sub-panel  61   a , and an FPC  615  in a fourth CNT sub-panel  61   d  is mounted adjacent to an FPC  415  in a third sub-panel  61   c.    
         [0038]    It is to be understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in the matters of shape, size, and arrangement of parts, within the principles of the embodiments, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.