Abstract:
A touch panel includes a first electrically conductive substrate, a second electrically conductive substrate; and a plurality of insulators located between the first electrically conductive substrate and the second electrically conductive substrate. The second electrically conductive substrate includes a first carbon nanotube film facing the first electrically conductive substrate, and a second carbon nanotube film exposed outside the touch panel.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to touch panels, and particularly to a touch panel having carbon nanotube films, and a touch display device using the touch panel. 
         [0003]    2. Description of Related Art 
         [0004]    A typical touch panel includes a first electrically conductive substrate, a second electrically conductive substrate, and a number of insulators located between the first and second substrates. One of the first and second substrates faces outside and flexibly electrically contacts the other if a pressure is applied thereon. 
         [0005]    However, the exposed substrate may be easily damaged and wear out too easily over time. 
         [0006]    What is needed, therefore, is a touch panel and a touch display device using same, which can overcome the above shortcomings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the present touch panel and touch display device can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present touch panel and touch display device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0008]      FIG. 1  is a schematic view of a touch panel in accordance with a first embodiment, the touch panel including a first electrically conductive substrate and a second electrically conductive substrate. 
           [0009]      FIG. 2  is an enlarged view of the circled portion II of the second electrically conductive substrate shown in  FIG. 1 . 
           [0010]      FIG. 3  is an enlarged view of a second electrically conductive substrate in accordance with a second embodiment. 
           [0011]      FIG. 4  is an enlarged view of a second electrically conductive substrate in accordance with a third embodiment. 
           [0012]      FIG. 5  shows a touch display device in accordance with a fourth embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Embodiments of the present touch panel and touch display device will now be described in detail below and with reference to the drawings. 
         [0014]    Referring to  FIGS. 1 and 2 , a touch panel  80  in accordance with a first embodiment, is provided. The touch panel  80  includes a first electrically conductive substrate  82 , a second electrically conductive substrate  84 , and a number of insulators  83  sandwiched between the first substrate  82  and the second substrate  84 . Too improve ruggedness and other properties of the touch panel  80 , carbon nanotube films described below are provided. 
         [0015]    The first substrate  82  is made of a transparent electrically conductive material, e.g., indium tin oxide. The insulators  83  can be formed into spheres and made of transparent dielectric material such as plastic to help keep a separation between the first and second substrates  82 ,  84  when no pressure from a touch is applied. 
         [0016]    The second substrate  84  is flexible. The second substrate  84  includes a first carbon nanotube film  842  that faces the first substrate  82  and is in contact with the insulators  83 , and a second carbon nanotube film  844  exposed outside the touch panel  80 . In the present embodiment, the second electrically conductive substrate  84  further includes a flexible transparent layer  843 , the first carbon nanotube film  842  is formed on a bottom surface of the flexible transparent layer  843 , and the second carbon nanotube film  844  is formed on a top surface of the flexible transparent layer  843 . 
         [0017]    The carbon nanotubes of the first carbon nanotube film  842  are in an array, and a lengthwise direction of each of the carbon nanotubes is substantially perpendicular to the bottom surface of the flexible transparent layer  843 . In actual production, the flexible transparent layer  843  can serve as a substrate for growing the carbon nanotubes on the bottom surface thereof, thus the carbon nanotubes are substantially perpendicular to the bottom surface. The carbon nanotubes in the second carbon nanotube film  844  are substantially parallel with the top surface of the flexible transparent layer  843 . The carbon nanotubes herein and after may be referred to as carbon nanotube sections. 
         [0018]    Carbon nanotubes have electrical conductivity along the lengthwise directions thereof. The carbon nanotubes of the first carbon nanotube film  842  have quick response time and allow for precisely identifying location of a touched portion if a pressure is applied on the second substrate  84  causing it to electrically contact the first substrate  82 . 
         [0019]    The carbon nanotubes of the second carbon nanotube film  844  each have a diameter in a range about 10 nm to 50 nm. Within this diameter range, the carbon nanotubes of the second carbon nanotube film  844  allow sufficient flexibility of the film while retaining a rugged characteristic that can better withstand repeated use than previous touch screens. 
         [0020]    The carbon nanotubes of the first carbon nanotube film  842  and the second carbon nanotube film  844  can be single-walled carbon nanotubes for better light penetrability. Thickness of the second substrate  84  can be made according to a desire level of light penetrability. 
         [0021]    Referring to  FIG. 3 , a second electrically conductive substrate  85  of a touch panel in accordance with a second embodiment, is provided. The second substrate  85  includes a flexible transparent layer  853 , a first carbon nanotube film  852  formed on the bottom surface of the flexible transparent layer  853 , and a second carbon nanotube film  854  formed on the top surface of the flexible transparent layer  853 . The carbon nanotubes of both the first and second carbon nanotube films  852 ,  854  are substantially parallel with the flexible transparent layer  853 . Because the carbon nanotubes also have electrically conductivity along a radial direction, the first carbon nanotube film  852  can also be used to electrically conduct the first substrate of the touch panel (not shown). 
         [0022]    Referring to  FIG. 4 , a second electrically conductive substrate  86  of a touch panel in accordance with a third embodiment, is provided. The second substrate  86  is comprised of a number of carbon nanotube films stacked one on another. The second substrate  86  has a thickness greater than 100 microns and is still flexible. The second substrate  86  also includes a first carbon nanotube film  862  at the inner side, and a second carbon nanotube film  864  at the outer side. In the present embodiment, the carbon nanotubes of the carbon nanotube films are substantially parallel with the first substrate of the touch panel (not shown). 
         [0023]    Referring to  FIG. 5 , a touch display device  100  in accordance with a fourth embodiment, is provided. The touch display device  100  includes a display panel assembly and a touch panel  80  mounted at a front side thereof. The display panel assembly includes in sequence a light emitting element  10 , a light reflecting plate  20 , a light diffusing plate  30 , a brightness enhancement film  35  formed on a light output surface of the light diffusing plate  30 , a lower polarizing plate  40 , a lower glass substrate  45 , a thin-film transistor module  50 , a liquid crystal layer  55 , a common electrode  60 , a filter  65 , an upper glass substrate  70  and an upper polarizing plate  75 . The upper polarizing plate  75  is adjacent to the touch panel  80 . 
         [0024]    The light emitting element  10  has a multiple quantum well structure. The multiple quantum well structure includes two different semiconductor materials staggered and stacked one on another. The light reflecting plate  20  is configured to reflect light to the light diffusing plate  30 . The light diffusing plate  30  has scattering dots formed thereon to allow light uniform. The cooperation of the lower polarizing plate  40  and the upper polarizing plate  75  can adjust light output. The liquid crystal layer  55  acts as a light switch based on voltages applied thereon. The thin-film transistor module  50  controls the liquid crystal layer  55  by applying the different voltages thereon. 
         [0025]    It is understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiments and methods without departing from the spirit of the disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.