Patent Publication Number: US-2009225045-A1

Title: Touch panel and display using the same

Description:
This application claims the benefit of Taiwan Patent Application Serial No. 97107743, filed Mar. 5, 2008, the subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a touch panel and display using the same, and especially relates to a high sensibility touch panel and display using the same. 
     2. Description of Related Art 
     In all kinds of the consumer electric product markets, portable products, such as personal digital assistant (PDA), mobile phone, Global Positioning System (GPS) and digital media player etc., broadly use touch panel for being an interface between machines and human beings. Because of demands for thin and light products, therefore, engineers try to use touch input style instead of traditional keyboards and mouse for product design. As a result, touch panels become one of the key components. 
     As shown in  FIGS. 1A and 1B ,  FIG. 1A  is a top view of a conventional touch panel (display), wherein a resistance touch type is taken for example, and  FIG. 1B  is a cross section view of the conventional touch panel along the line I-I′ shown in  FIG. 1A . In  FIG. 1B , touch type display  1  includes touch panel  10 , liquid crystal display panel  12  and flexible printed circuit board  14  for connecting the touch panel  10  and the liquid crystal display panel  12 . Touch panel  10  is disposed on the liquid crystal display panel  12 . Adhesive  11  is used to combine the touch panel  10  and the liquid crystal display panel  12 . Touch panel  10  includes glass bases  101 ,  102 , upper electrode  103  disposed on the glass base  101 , lower electrode  104  disposed on the glass base  102 , sealant  109  assembled the glass bases  101 ,  102 , liquid crystal layer  108  or other filler filled between the glass bases  101 ,  102 , and conductor  105  connected with lower electrode  104 . Liquid crystal display panel  12  includes glass bases  121 ,  122 , sealant  123  used to assemble the glass bases  121 ,  122 , liquid crystal layer  124  filled between the glass bases  121 ,  122 , and spacers  125  disposed between the glass bases  121 ,  122  to support glass bases  121 ,  122  for forming a constant and suitable gap. 
     If finger  13  or other pressing tool presses the top surface of the glass base  101  of the touch panel  10 , top electrode  103  corresponding to the pressed location will touch specific lower electrode  104 , thereby coordinates of the touched location will be created. Then liquid crystal display panel  12  will show desired images in response to the data process conducted by the flexible printed circuit board  14  and control system (not shown) according to the coordinates. 
     When pressing the touch panel  10 , as shown in  FIGS. 1A and 1B , because area B 1  of the glass base  101  which is adjacent to the cured/hardened sealant  109  is more difficult to deform than the area B 2  which is located in the center of the glass base  101 . Area B 1  has bad sensibility. Users have to apply more enforce to press, even the worse, the area B 1  may be out of order, therefore touch type display  1  cannot operate normally and quality or capability thereof decreases. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a touch panel which has better sensibility. 
     An objective of the present invention is to increase the sensibility of the touch panel. 
     An objective of the present invention is to increase the sensibility of the location which is adjacent to the sealant. 
     In accordance with the above objectives and other objectives, the present invention provides a touch panel, a base of which including a first portion and a second portion, wherein at least one part of the second portion is substantially located between the active area and the sealant, and the thickness of the second portion is about smaller than that of the first portion. 
     In accordance with the above objectives and other objectives, the present invention provides a display, a base of which including a first portion and a second portion, wherein at least one part of the second portion is substantially located between the active area and the sealant, and the thickness of the second portion is about smaller than that of the first portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1A  is a top view of a conventional touch type display. 
         FIG. 1B  is a cress section view along line I-I′ of the touch type display in  FIG. 1A . 
         FIG. 2  is a conventional touch panel for test in an experiment of the present invention. 
         FIG. 3A  is a top view of a touch type display of the first embodiment of the present invention. 
         FIG. 3B  is a cress section view along line II-II of the touch type display in  FIG. 3A . 
         FIG. 3C  is an enlarge view of a partial part of the area B 1  of the touch type display in  FIG. 3A  when finger is pressing the area B 1  in normal force. 
         FIG. 4  is a cross section view of a touch type display of the second embodiment of the present invention. 
         FIG. 5  is a cross section view of a touch type display of the third embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     As shown in  FIG. 2  and Table 1,  FIG. 2  is a conventional touch panel for test in an experiment. Table 1 shows 9 locations of the touch panel in  FIG. 2  and corresponding desired/sufficient force which can make sensing signal create. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 location 
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 average 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 force(Kg) 
                 27 
                 23 
                 27 
                 17 
                 21 
                 48 
                 23 
                 24 
                 31 
                 27 
               
               
                   
               
            
           
         
       
     
     As shown in Table 1, locations  1 ,  3 ,  6  and  9  which are adjacent to sealant  209  need greater force than other locations, 27, 27, 48 and 31 KG, respectively. As we know, if we want locations which are near sealant  209  to sense, greater force must be applied. In other words, it is possible that locations which are near sealant  209  may be out of order or week sensibility. Therefore, when touch panel  20  is under operation, users have to pay more attention to provide greater force or do additional checks to see if the sensing signal is normal, so operative convenience and capability of touch panel  20  would be influenced. 
     Display or touch panel of the present invention is shown as following in detail and incorporated with FIGs for explaination. 
     First Embodiment 
     As shown in  FIGS. 3A and 3B ,  FIG. 3A  is a top view of the display according to the first embodiment of the present invention, and  FIG. 3B  is a cross section view along line II-II of the display in  FIG. 3A  according to the first embodiment of the present invention. 
     In  FIG. 3B , touch type display  3  includes touch panel  30 , liquid crystal display panel  32  and circuit board  34  for electrically connected between the touch panel  30  and the liquid crystal display panel  32 . Circuit board  34  may be a flexible printed circuit board, for example. Liquid crystal display panel  32  is disposed beneath the touch panel  30 . Adhesive  31  is used for connected the touch panel  30  and the liquid crystal display panel  32 . 
     Touch panel  30  includes bases  301 ,  302 ; upper electrode  303  disposed on the base  301 ; lower electrode  304  disposed on the base  302 ; sealant  309  connected with the bases  301 ,  302 ; liquid crystal layer  108  or other filler filled between the bases  301 ,  302 ; and conductor  305  connected with the lower electrode  304 . Materials of bases  301 ,  302  may be glass or quartz, for example. Materials of upper electrode  303  and lower electrode  304  may be transparent conductive materials, such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO), for example. Upper electrode  303  and lower electrode  304  define/form an active area AA. Active area AA is for showing images from liquid crystal layer  108  and/or for conducting most sensing function. Materials of sealant  309  may be light-curing glue or heat-curing glue. Base  301  includes first portion  3011  and second portion  3012 . Second portion  3012  is located substantially around the first portion  3011 . At least one part of the second portion  3012  is substantially located between the active area AA and sealant  309 . Thickness of the second portion  3012  is about smaller than that of the first portion  3011 . For example, thickness of the second portion  3012  may be about 60% to about 80%, and preferably, about 65% to about 75%. Distance d 1  which is between the sealant  309  and the edge of the first portion  3011  is about 1 millimeter to about 1.5 millimeter, and preferably about 1.2 millimeter to about 1.5 millimeter. 
     Liquid crystal display panel  32  includes bases  321 ,  322 ; sealant  323  is for assembling bases  321  and  322 ; a liquid crystal layer  324  filled between the bases  321 ,  322 ; and spacers  325  for supporting bases  321  and  322  and for keeping constant and suitable gap therebetween. 
       FIG. 3C  shows enlarge of a partial of area B 1  when finger  33  apply normal/usual force to touch area B 1  of touch type display  3 . As shown, because thickness of the second portion  3012  is smaller than that of the first portion  3011 , the deformable level of the second portion  3012  is greater than that of the first portion  3011 . Even the touched area is adjacent cured/hardened sealant  309 , touch panel  30  can successfully operate sensing function. In other words, upper electrode  303  therein can contact corresponding/specific lower electrode  304 . 
     Second Embodiment 
     As shown in  FIG. 4 ,  FIG. 4  is a cross section view of the touch type display according to the second embodiment of the present invention. 
     Unlike the first embodiment, touch type display  4  is a display integrating touch panel and liquid crystal display panel. Thickness and weight thereof is smaller than that of the touch type display  3  of the first embodiment. 
     Touch type display  4  includes bases  401  and  402 ; upper electrode  403  disposed on the base  401 ; lower electrode  404  disposed on the base  402 ; sealant  409  connected with the bases  401  and  402 ; and liquid crystal layer  408  disposed between the bases  401  and  402 . Materials of bases  401 ,  402  may be glass or quartz, for example. Materials of upper electrode  403  and lower electrode  404  may be transparent conductive materials, such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO), for example. Materials of sealant  409  may be light-curing glue or heat-curing glue. 
     Color filter array is disposed between the base  401  and the upper electrode  403 . Color filter array includes light-shielding layer  430  and color resists, such as red resist R, green resist G and blue resist etc. Light-shielding layer  430  is substantially located between adjacent color resists. Insulating layer  420  is formed on the color filter array. Materials of the insulating layer  420  may be organic materials, for example. Bumps  46  and upper electrode  403  are formed on the insulating layer  420 . Upper electrode  403  is formed on the bumps  46 . Spacers include main-spacers  44  and sub-spacers  45  disposed between the bases  401  and  402  for supporting and keeping a constant or suitable gap. For example, number of sub-spacers  45  is about greater than that of the bumps  46 , and number of the bumps  46  is about greater than that of the main-spacers  44 . 
     Active device array  410  is disposed between the base  402  and lower electrode  404 . Active device array  410  is a thin film transistor array, for example. Sensing pads  411  are formed on the active device array  410  or integrated with the active device array  410 . Lower electrode  404  is formed on the sensing pads  411 . Liquid crystal layer  408  is disposed between the upper electrode  403  and lower electrode  404 . 
     Base  401  includes first portion  4011  and second portion  4012 . Second portion  4012  is located substantially around the first portion  4011 . At least one part of the second portion  4012  is substantially located between the active area AA and sealant  409 . Thickness of the second portion  4012  is about smaller than that of the first portion  4011 . For example, thickness of the second portion  4012  may be about 60% to about 80%, and preferably, about 65% to about 75%. Distance d 1  which is between the sealant  409  and the edge of the first portion  4011  is about 1 millimeter to about 1.5 millimeter, and preferably about 1.2 millimeter to about 1.5 millimeter. Smallest distance d 2  which is between the bump  46  and the edge of the first portion  4011  is about 500 micrometer to about 600 micrometer. 
     When finger  43  or other pressing tools presses the active area of the touch type display  4 , because thickness of the second portion  4012  is smaller than that of the first portion  4011 , the deformable level of the second portion  4012  is greater than that of the first portion  4011 . Even the touched area is adjacent cured/hardened sealant  409 , touch type display  4  can successfully operate sensing function. In other words, upper electrode  403  on the bump  46  therein can contact corresponding/specific lower electrode  404 . Then coordinates of corresponding touched location can be created and touch type display  4  can display images thereafter. 
     Third Embodiment 
     As shown in  FIG. 5 ,  FIG. 5  shows a cross section view of a touch type display according to the third embodiment of the present invention. 
     Unlike the first embodiment, touch type display  5  is a display integrating touch panel and liquid crystal display panel. Thickness and weight thereof is smaller than that of the touch type display  3  of the first embodiment. 
     Touch type display  5  includes bases  501  and  502 ; upper electrode  503  disposed on the base  501 ; lower electrode  504  disposed on the base  502 ; sealant  509  connected with the bases  501  and  502 ; and liquid crystal layer  508  disposed between the bases  501  and  502 . Materials of bases  501 ,  502  may be glass or quartz, for example. Materials of upper electrode  503  and lower electrode  504  may be transparent conductive materials, such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO), for example. Materials of sealant  509  may be light-curing glue or heat-curing glue. 
     Color filter array is disposed between the base  501  and the upper electrode  503 . Color filter array includes light-shielding layer  530  and color resists, such as red resist R, green resist G and blue resist etc. Light-shielding layer  530  is substantially located between adjacent color resists. Insulating layer  520  is formed on the color filter array. Materials of the insulating layer  520  may be organic materials, for example. Bumps  56  and upper electrode  503  are formed on the insulating layer  520 . Upper electrode  503  is formed on the bumps  56 . Spacers includes main-spacers  54  and sub-spacers  55  disposed between the bases  501  and  502  for supporting and keeping a constant or suitable gap. For example, number of sub-spacers  55  is about greater than that of the bumps  56 , and number of the bumps  56  is about greater than that of the main-spacers  54 . 
     Active device array  510  is disposed between the base  502  and lower electrode  504 . Active device array  510  is a thin film transistor array, for example. Sensing pads  511  are formed on the active device array  510  or integrated with the active device array  510 . Lower electrode  404  is formed on the sensing pads  511 . Liquid crystal layer  508  is disposed between the upper electrode  503  and lower electrode  504 . 
     Base  501  includes first portion  5011 , second portion  5012  and third portion  5013 . Second portion  5012  is located around the first portion  5011 . Third portion  5013  is located around the second portion  5012 . Second portion  5012  is substantially located between the active area AA and the sealant  509 . Sealant  509  is disposed on the third portion  5013 . Thickness of the second portion  5012  is about smaller than that of the first portion  5011 . For example, thickness of the second portion  5012  is about 60% to about 80% of that of the first portion  5011 , and preferably about 65% to about 75%. Distance d 1  which is between the sealant  509  and the edge of the first portion  5011  is about 1 millimeter to about 1.5 millimeter, and preferably about 1.2 millimeter to about 1.5 millimeter. Thickness of the third portion  5013  is smaller than or equal to the first portion  5011 . 
     When finger  53  or other pressing tools presses the active area of the touch type display  5 , because thickness of the second portion  5012  is smaller than that of the first portion  5011  and third portion  5013 , the deformable level of the second portion  5012  is greater than that of the first portion  5011 . Even the touched area is adjacent cured/hardened sealant  509 , touch type display  5  can successfully operate sensing function. In other words, upper electrode  503  on the bump  56  therein can contact corresponding/specific lower electrode  504 . Then coordinates of corresponding touched location can be created and touch type display  5  can display images thereafter. 
     As shown, present invention provides a touch panel and touch type display. Using a base having two or more portions with different thickness. If the portion adjacent to the sealant has less thickness, sensibility therein can be almost as good as other sensing area. Therefore, when conducting a touch panel or touch type display, users can easily provide normal/usual force to touch the panel or display to successfully perform touch process. As a result, capability thereof can increase and operational stability or convenience can be better as well. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.