Patent Publication Number: US-2011069030-A1

Title: Touch Panel and Display Apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a touch panel that is disposed on a display screen such as a liquid crystal display. Further, the present invention relates to a touch panel type display device including the touch panel. 
     BACKGROUND ART 
     As an example of a screen input type display device, a display device including a touch panel is known. The touch panel is configured to detect input coordinates on the basis of a change in resistance by, for example, a pressing operation. Some touch panels have a structure in which transparent conductive films of an upper substrate and a lower substrate, respectively, are arranged to face each other. 
     In recent years, in terms of increasing the image definition and improving durability, there is proposed a touch panel that has an upper substrate made of glass, as disclosed in Japanese: Laid-open Patent Publication No. 09-146707. This touch panel is superior to a touch panel having an upper substrate made of a resin film, in terms of an image definition or durability. However, reflected glare (external light reflection) may be easily caused in the touch panel. 
     Meanwhile, an example of a technology for suppressing the reflected glare in the touch panel is disclosed in Japanese Laid-open Patent Publication No. 08-332649. According to this technology, a touch substrate to be pressed is injection molded using a transparent resin to form minute unevenness on a top surface (touch surface) of the touch substrate. 
     However, if the technique of forming the minute unevenness in the touch substrate is applied, the touch substrate may become relatively weak as compared with the case where the minute unevenness is not formed. For this reason, when the touch substrate is pressed and deformed, cracks may occur in the touch substrate and the touch substrate may easily be damaged. As a result, reliability of the touch panel may be lowered. 
     DISCLOSURE OF THE INVENTION 
     It is an object of the present invention to provide a touch panel that reduces reflected glare and improves reliability. 
     A touch panel according to an embodiment of the present invention relates to a touch panel that includes a first substrate and a second substrate. The first substrate includes a first principal surface and a second principal surface. The second principal surface is on a back side of the first principal surface. At least one recess is formed on the second principal surface. The second substrate is arranged to face the first principal surface. 
     The touch panel further includes at least one light diffusing particle. At least a portion of the light diffusing particle is positioned in the recess. 
     In the touch panel according to one embodiment of the present invention, there exists the light diffusing particles and the recesses in the first substrate. As a result, the reflected glare can be reduced. Further, in the touch panel, at least some of the light diffusing particles are arranged in the recesses of the first substrate. As a result, the pressing force that acts on the first substrate when the first substrate is deformed by a pressing operation is dispersed, and concentration of the stress at corners of the recesses can be eased. Therefore, in the touch panel, reflected glare can be reduced and reliability can be improved. 
     A touch panel type display device according to an embodiment of the present invention relates to a touch panel type display device that includes the touch panel and a display panel. 
     The touch panel type display device according to an embodiment of the present invention includes the touch panel. Therefore, the same effect as that of the above-described touch panel can be achieved. That is, in the touch panel type display device, reflected glare can be reduced and reliability can be improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded perspective view of a touch panel according to an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view taken along the line II-II of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along the line III-III of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view taken along the line IV-IV of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view illustrating a process of bonding a first base and a second base in the touch panel shown in  FIG. 1 ; 
         FIG. 6  is a cross-sectional view of a touch panel type display device including the touch panel in  FIG. 1 ; 
         FIG. 7  is a perspective view of a liquid crystal display panel of a liquid crystal display device in the touch panel type display device in  FIG. 6 ; and 
         FIG. 8  is an enlarged cross-sectional view of essential parts of the liquid crystal display panel in  FIG. 7 . 
     
    
    
     EXPLANATIONS OF LETTERS OR NUMERALS 
     
         
         
           
             X Touch panel 
             Y Touch panel type display device 
               10  First base 
               11  Transparent insulating substrate (first substrate) 
               13  Adhesive member 
               14  Polarizing film (optical film) 
               15  First principal surface 
               16  Second principal surface 
               17  Recess 
               18  Light diffusing particle 
               20  Second base 
               21  Transparent insulating substrate (second substrate) 
               40  Liquid crystal display panel 
           
         
       
    
     BEST MODE(S) FOR CARRYING OUT THE INVENTION 
     Hereinafter, a touch panel and a touch panel type display device according to an embodiment of the present invention will be described with reference to the drawings. 
     First, a touch panel according to an embodiment of the present invention will be described with reference to  FIGS. 1 to 4 . 
     A touch panel X includes a first base  10 , a second base  20 , and a conductive adhesive member  30 . 
     The first base  10  includes a transparent insulating substrate  11  (first substrate), a transparent electrode  12 , an adhesive member  13 , and a polarizing film (optical film)  14 , and is flexible as a whole. The first base  10  has a substantially rectangular shape in plan view. However, the shape of the first base  10  in plan view is not limited to the rectangular shape. 
     The transparent insulating substrate  11  performs a function of supporting the transparent electrode  12  and has a sufficient electric insulating property. The transparent insulating substrate  11  has a first principal surface  15  that faces the second base  20  and a second principal surface  16  that is positioned at an opposite side of the first principal surface  15 . The distance (thickness of the transparent insulating substrate  11 ) of the first principal surface  15  and the second principal surface  16  is set to a value between greater than or equal to 0.1 mm and less than or equal to 0.3 mm to secure sufficient shape stability and flexibility. As a material for forming the transparent insulating substrate  11 , a glass material, such as soda glass, recycled glass, crystal glass, semi-crystal glass, tempered glass, alkali-free glass, quartz glass, and borosilicate glass, is exemplified. The material for forming the transparent insulating substrate  11  is not limited to the glass material, and the transparent insulating substrate  11  may be formed of a resin material. 
     The transparent insulating substrate  11  has a light transmitting property in a thickness direction (AB direction), and has recesses  17  that are formed on the second principal surface  16 . 
     The recesses  17  are to suppress occurrence of Newton&#39;s rings, and to suppress reflected glare. The recesses  17  are scattered substantially all over the entire surface of the second principal surface  16 . For example, the recesses  17  are provided to be scattered in a region of the second principal surface  16  where the transparent electrode  12  and a transparent electrode  22  to be described below face each other and a region of the second principal surface  16  where the transparent electrode  12  and the transparent electrode  12  do not face each other. Of course, the recesses  17  may be provided only in the region of the second principal surface  16  where the transparent electrode  12  and the transparent electrode  22  face each other, as long as the occurrence of Newton&#39;s rings can be appropriately reduced. Here, if the recesses  17  are scattered substantially all over the entire surface of the second principal surface  16 , the external light reflection state or gloss in the surface of the transparent insulating substrate  11  may be homogenized. The transparent insulating substrate  11  can have constant rigidity all over the entire region of the transparent insulating substrate, and concentration of stress can be moderated. As a result, reliability can be improved. 
     The recesses  17  can be formed by etching, grinding, or abrading processing. Due to formation of the recesses  17 , the surface roughness Ra of the second principal surface  14  is between greater than or equal to 0.2 nm and less than or equal to 0.35 μm. The surface roughness Ra is measured by JIS-B-0601. 
     The transparent electrode  12  contributes to detection of potential at a contact point of the transparent electrode  12  and the transparent electrode  22  of the second base  20  to be described below, and has a light transmitting property in the AB direction. The transparent electrode  12  is formed to spread substantially all over the entire surface of the first principal surface  15  of the transparent insulating substrate  11 , using a conductive material having a predetermined electric resistance. A resistance value of the transparent electrode  12  is between greater than or equal to 200Ω/□ and less than or equal to 1500Ω/□. The thickness of the transparent electrode  12  is set to 2.0×10 −2  μm or less, in order to increase the resistance. As a material for forming the transparent electrode  12 , a light transmitting conductive material, such as indium tin oxide (ITO), antimony tin trioxide (ATO), SnO, and ZnO, is exemplified. 
     The adhesive member  13  serves to bond the polarizing film  14  to the second principal surface  16  of the transparent insulating substrate  11 . The adhesive member  13  has an adhesive material and a plurality of light diffusing particles  18  that are dispersed in the adhesive material. The light diffusing particles  18  are partially confined in the recesses  17  of the second principal surface  16 . 
     As a material for forming the adhesive member  13 , a pressure sensitive adhesive, such as an acrylic pressure sensitive adhesive, a urethane pressure sensitive adhesive, and a silicon pressure sensitive adhesive, and a water-soluble adhesive, such as a polyvinyl alcohol adhesive, are exemplified. 
     The light diffusing particles  18  perform a function of diffusing light. Preferably, the light diffusing particles  18  are substantially uniformly dispersed in the adhesive material. At least a portion of the light diffusing particles  18  are confined in the recesses  17 . For example, one of the light diffusing particles  18  may be entirely confined in one of the recesses  17 , or one of the plural light diffusing particles  18  may be partially confined in one of the recesses  17 . Alternatively, the plurality of the light diffusing particles  18  may be confined in one of the recesses  17 . If the plurality of the light diffusing particles  18  is confined in the one of the recesses  17 , a dead space between the light diffusing particles  18  and an inner surface of the recesses  17  can be reduced. 
     As a material for forming the light diffusing particles  18 , a glass material, silica, or a silicon resin can be exemplified. As the glass material for the light diffusing particles  18 , the same glass material as the material for forming the transparent insulating substrate  11  can be used. 
     As a shape of the light diffusing particles  18 , a substantially polyhedral shape and a substantially spherical shape are exemplified. A sectional area of the light diffusing particles  18  is smaller than an opening area of the recesses  17 . For example, a maximum sectional area of the light diffusing particles  18  is smaller than the opening area of the recesses  17 . If the substantially polyhedral shape is employed as the shape of the light diffusing particles  18 , a dead space between the adjacent light diffusing particles  18  or between the light diffusing particles  18  and the inner surface of the recesses  17  can be reduced. For this reason, the large amount of light diffusing particles  18  can be positioned in the recesses  17  and the transparent insulating substrate  11  can be suppressed from being damaged. Thereby, reliability of the touch panel X can be improved. 
     As the light diffusing particles  18  in the touch panel X, processing pieces that are generated by a process of grinding or polishing a portion of the transparent insulating substrate  11  may be used. 
     The polarizing film  14  selectively transmits light in a predetermined vibration direction, and is formed of, for example, an iodine material. The polarizing film  14  is formed to have the surface roughness Ra in a range between greater than or equal to 0.2 nm and less than or equal to 0.35 μm. The surface roughness Ra is measured by JIS-B-0601, as similar to the second principal surface  16 . In the touch panel X using the polarizing film  14  that has the surface roughness Ra in the above range, an optical influence due to undulating of the polarizing film  14  can be sufficiently reduced. 
     The second base  20  includes a transparent insulating substrate (second substrate)  21 , a transparent electrode  22 , line electrodes  23 ,  24 ,  25 , and  26 , and dot spacers  27 . The second base  20  is disposed to face the first base  10 . The second base  20  is also configured to have an approximately rectangular shape in plan view. However, the shape of the second base  20  in plan view is not limited to the rectangular shape, similar to the first base  10 . In the second base  20 , an external conductive region  20   a  that is a region electrically connected to a flexible printed circuit (FPC) not illustrated is provided. 
     The transparent insulating substrate  21  performs a function of supporting the transparent electrode  22 , the line electrodes  23  to  26 , and the dot spacers  27 , and has a light transmitting property and an electric insulating property in a thickness direction (AB direction). As a material for forming the transparent insulating substrate  21 , light transmitting glass or light transmitting plastic is exemplified. However, the material for forming the transparent insulating substrate  21  is preferably the light transmitting glass from the viewpoint of heat resistance. When the light transmitting glass is used as the material for forming the transparent insulating substrate  21 , the thickness of the transparent insulating substrate  21  is preferably set to 0.7 mm or more to secure sufficient shape stability. 
     The transparent electrode  22  contributes to detection of potential at a contact point of the transparent electrode  22  and the transparent electrode  12  of the first base  10 , and has a light transmitting property in a thickness direction (AB direction). As a material for forming the transparent electrode  22 , the same material as the transparent electrode  12  is exemplified. The transparent electrode  22  is formed in a region of the second base  20  corresponding to a formation region of the transparent electrode  12  of the first base  10 , in plan view. 
     Each of the line electrodes  23  and  24  performs a function of applying a voltage to the transparent electrode  12 . One end of the line electrode  23  is positioned in an end region of a connection region, in a direction of an arrow C, that is defined by a conductive connecting member  30  to be described below, in the second base  20 , and the other end of the line electrode  23  is positioned in the external conductive region  20   a  of the second base  20 . One end of the line electrode  24  is positioned in an end region of the connection region, in a direction of an arrow D, that is defined by the conductive connecting member  30  to be described below, in the second base  20 , and the other end of the line electrode  24  is positioned in the external conductive region  20   a  of the second base  20 . 
     A resistance value between both ends of each of the line electrodes  23  and  24  is preferably set to be equal to or less than 1/100 of the resistance value between both ends of the transparent electrode  12 , from the viewpoint of precision in detection of the touch panel X. Here, between both ends of the transparent electrode  12  means between one end and the other end of a region of the transparent electrode  12  corresponding to the line electrodes  23  and  24 . 
     Each of the line electrodes  23  and  24  is composed of a thin metal film (width in a range between greater than or equal to 0.5 mm and less than or equal to 2.0 mm, and thickness in a range between greater than or equal to 0.5 μm and less than or equal to 2 μm), from the viewpoint of hardness and shape stability. As the thin metal film, an aluminum film, an aluminum alloy film, a laminated film of a chromium film and an aluminum film, or a laminated film of a chromium film and an aluminum alloy film is exemplified. When the transparent electrode  22  is formed with ITO, the thin metal film is preferably the laminated film of the chromium film and the aluminum film (chromium film is disposed between the ITO and the aluminum film) or the laminated film of the chromium film and the aluminum alloy film (chromium film is disposed between the ITO and the aluminum alloy film), from the viewpoint of adhesion with the ITO. As a method of forming the thin metal film, a sputtering method, a deposition method or a chemical vapor deposition (CVD) method is exemplified. 
     Each of the line electrodes  25  and  26  performs a function of applying a voltage to the transparent electrode  22 . One end of the line electrode  25  is connected to an end of the transparent electrode  22 , in a direction of an arrow E, and the other end of the line electrode  25  is positioned in the external conductive region  20   a  of the second base  20 . One end of the line electrode  26  is connected to an end of the transparent electrode  22 , in a direction of an arrow F, and the other end of the line electrode  26  is positioned in the external conductive region  20   a  of the second base  20 . Each of the line electrodes  25  and  26  is composed of a thin metal film (width in a range between greater than or equal to 0.5 mm and less than or equal to 2.0 mm, and thickness in a range between greater than or equal to 0.5 μm and less than or equal to 2 μm), similar to the line electrodes  23  and  24 . As the thin metal film, the same thin film as the thin metal film constituting the line electrodes  23  and  24  is exemplified. 
     A resistance value between both ends of each of the line electrodes  25  and  26  is preferably set to be equal to or less than 1/100 of the resistance value between both ends of the transparent electrode  22 , from the viewpoint of detection precision of the touch panel X. In this case, between both ends of the transparent electrode  22  means between one end and the other end of a region of the transparent electrode  22  corresponding to the line electrodes  25  and  26 . 
     The dot spacers  27  reduce an unnecessary contact of the transparent electrode  12  to the transparent electrode  22  at the outside of the predetermined position, in the case where the transparent electrode  12  and the transparent electrode  22  contact at the predetermined position at the time of inputting information. The dot spacers  27  are arranged in a matrix where the distance (arrangement pitch) between the adjacent dot spacers  27  is in a range between greater than or equal to 2 mm and less than or equal to 4 mm, on the transparent substrate  22 . The dot spacers  27  may be formed in the first base  10 . The dot spacers  27  preferably perform the above function in an invisible state. For example, the dot spacers  27  are formed in a semispherical shape in which the diameter is 40 μm or less and the height is in a range be between greater than or equal to 1.0 μm and less than or equal to 3.5 μm. 
     As a material for forming the dot spacers  27 , a thermosetting resin and an ultraviolet curable resin are exemplified. If the thermosetting resin is used as the material for forming the dot spacers  27 , environment resistance such as heat resistance or drug resistance can be improved, which for example surely results in high reliability during a long period. As the thermosetting resin, an epoxy resin, unsaturated polyester, a urea resin, a melanin resin or a phenol resin is exemplified. Meanwhile, if the ultraviolet curable resin is used as the material for forming the dot spacers  27 , curing time can be shortened as compared with the thermosetting resin. As a result, manufacturing efficiency can be improved. As the ultraviolet curable resin, an acrylic resin or an epoxy resin is exemplified. 
     The dot spacers  27  may include insulating particles. According to this configuration, shape stability of the dot spacers  27  can be enhanced without reducing an insulating property of the dot spacers  27 . For this reason, the function of the dot spacers  27  can be maintained over a long period. 
     The conductive adhesive member  30  bonds the first base  10  and the second base  20  while electrically connecting the transparent substrate  12  and the line electrodes  23  and  24 . The conductive adhesive member  30  is formed in a frame shape as a whole, and is provided to surround the transparent electrode  22  in plan view, from the viewpoint of sealing of the transparent substrate  12  and the transparent substrate  22 . However, the conductive adhesive member  30  does not necessarily need to be formed in a frame shape, as long as the function thereof can be achieved. 
     The conductive adhesive member  30  that is formed in a frame shape as a whole has an opening  30   a . The opening  30   a  is a portion through which air or the like is injected after the conductive adhesive member  30  is applied and the first base  10  and the second base  20  are bonded to each other. The opening  30   a  is sealed using the same material as that of the conductive adhesive member  30  or a non-conductive adhesive member (ultraviolet curable resin). 
     The conductive adhesive member  30  includes a first particle  31 , a second particle  32 , and an adhesive material  33 . 
     The first particle  31  performs a function of electrically connecting the transparent electrode  12  and the line electrodes  23  and  24 . In this embodiment, the first particle  31  is compressed and deformed by the first base  10  and the second base  20 , in the course of manufacturing the first particle  31 , as will be described below. However, in a state before the first particle  31  is deformed, the first particle  31  has a larger particle diameter than that of the second particle  32  to be described below. That is, the first particle  31  is compressed more strongly than the second particle  32 , between the first base  10  and the second base  20 . That is, in this embodiment, the first particle  31  has conductivity, and an elastic deformation ratio thereof is larger than that of the second particle  32 . The first particle  31  can be obtained by coating a surface of a plastic ball with a conductor material (gold or nickel). In this embodiment, as the first particle  31 , a particle having an approximately spherical shape is used from the viewpoint of damage suppression to the transparent electrode  12  and the line electrodes  23  and  24  contacting the first particle  31 . However, the shape of the first particle  31  is not limited to the above shape, and the first particle  31  may have, for example, a polyhedral shape. The particle diameter of the first particle  31  in the normal state before deformation is in a range between greater than or equal to 3 μm and less than or equal to 20 μm. 
     The second particle  32  performs a function of defining the distance between the first base  10  and the second base  20 , and has a particle diameter and an elastic deformation ratio smaller than those of the first particle  31 . As the second particle  32 , a silica sphere (spherical particle mainly made of silicon dioxide) is chosen from the viewpoint of definition easiness of the distance of the first base  10  and the second base  20 . However, the present invention is not limited thereto and glass fiber may be used as the second particle  32 . In this embodiment, as the second particle  32 , a particle having an approximately spherical shape is used from the viewpoint of damage suppression to the transparent electrode  12  and the line electrodes  23  and  24  contacting the second particle  32 . However, the shape of the second particle  32  is not limited to the above shape, and the second particle  32  may have, for example, a polyhedral shape. The particle diameter of the second particle  32  is in the range between greater than or equal to 2 μm and less than or equal to 19 μm. 
     The adhesive material  33  serves to enable bonding of the first base  10  and the second base  20 . As the adhesive material  33 , a thermosetting resin such as an epoxy resin or an ultraviolet curable resin such as an acrylic resin is exemplified. In particular, as the adhesive material  33 , the thermosetting resin is preferably used from the viewpoint of work efficiency in a manufacturing process. 
     The conductive adhesive member  30  includes the first particle  31  and the second particle  32 . However, the present invention is not limited thereto and the conductive adhesive member  30  may include only the first particle  31 . According to this configuration, since only one kind of particles may be prepared, a cost can be reduced. 
     The conductive adhesive member  30  is not limited to the configuration where the first particle  31  directly contacts the transparent electrode  12 . For example, the first particle  31  and the transparent electrode  12  may be electrically connected through lines formed on the transparent insulating substrate  11  in the above way as the line electrodes  23  and  24 . 
     Next, an example of a method of bonding the first base  10  and the second base  20  by the conductive adhesive member  30  will be described. The conductive adhesive member  30  is obtained by dispersing the first particle  31  and the second particle  32  in the adhesive material  33 . As the adhesive material  33 , the thermosetting resin is used. 
     First, the adhesive material  33  including the first particle  31  and the second particle  32  are printed in a frame shape to surround the transparent electrode  22 , on a top surface (formation surface of the line electrodes  23  and  24 ) of the second base  20 , as shown in  FIGS. 1 and 2 . 
     Next, as shown in  FIG. 5A , after the first base  10  is aligned with the second base  20  where the adhesive material  33  is printed, the first base  10  and the second base  20  are bonded by the adhesive material  33  and a bonding structure is manufactured. 
     Next, as shown in  FIG. 5B , the manufactured structure is pressurized in a direction in which the first base  10  and the second base  20  are in proximity to each other. In this embodiment, the pressurization is performed while the first particle  31  is deformed by the first base  10  and the second base  20  to increase an elastic deformation ratio or an aspect ratio of the first particle  31 , until the second particle  32  comes into contact with both the first base  10  and the second base  20 . 
     Next, the adhesive material  33  is heated to the hardening temperature thereof and is hardened, while a pressurization state is maintained. The first base  10  and the second base  20  are bonded by the hardening of the adhesive material  33 . Meanwhile, the transparent electrode  12  and the line electrodes  23  and  24  are electrically connected by the first particle  31  interposed therebetween. 
     In the touch panel X, there exists the light diffusing particles  18  and the recesses  17  of the first substrate  11 . Therefore, reflected glare can be reduced. Further, in the touch panel X, at least a portion of the light diffusing particles  18  is positioned in the recesses  17  of the first substrate  11 . Therefore, the pressing force that acts on the first substrate  11  when the first substrate  11  is deformed by a pressing operation is dispersed, and concentration of the stress on corners of the recesses  17  can be moderated. Thus, in the touch panel X, reflected glare can be reduced and reliability can be improved. 
     In the touch panel X, when the formation material of the light diffusing particles  18  is the same as the formation material of the first substrate  11 , even though the polarizing film  14  is bonded to the side of the second principal surface  16  of the first substrate  11  through an adhesive having a larger thermal expansion coefficient than the glass constituting the first substrate  11 , the difference of the a thermal expansion coefficient of the material existing in the recesses  17  of the first substrate  11  and a thermal expansion coefficient of the first substrate  11  can be reduced. That is, in the touch panel X, the force that acts on the inner surfaces of the recesses  17  from the material existing in the recesses  17  of the first substrate  11  due to the difference of the thermal expansion coefficients can be reduced. Accordingly, in the touch panel X, if the same material as the formation material of the first substrate  11  is used as the formation material of the light diffusing particles  18 , reliability can be improved. 
     In this case, the formation material of the light diffusing particles  18  being the same as the formation material of the first substrate  11  means that the formation material of the light diffusing particles  18  may be substantially the same as the formation material of the first substrate  11  or may be a material obtained by including an essentially necessary material in terms of manufacturing, such as an abrasive, in the formation material of the first substrate  11 . 
     Next, a touch panel type display device Y according to one embodiment of the present invention will be described with reference to  FIGS. 6 to 8 . 
     The touch panel type display device Y shown in  FIG. 6  includes a touch panel X and a liquid crystal display device Z. The liquid crystal display device Z includes a liquid crystal display panel  40 , a backlight  50 , and a casing  60 . 
     As shown in  FIGS. 7 and 8 , the liquid crystal display panel  40  has a display region P that includes a plurality of pixels to display an, image, and includes a liquid crystal layer  41 , a first base  42 , a second base  43 , and a sealing member  44 . 
     The liquid crystal layer  41  is disposed between the first base  42  and the second base  43 . The liquid crystal layer  41  has electrical, optical, mechanical or magnetic anisotropy, and includes liquid crystal that has regularity of a solid and fluidity of a liquid. As this liquid crystal, nematic liquid crystal, cholesteric liquid crystal or smectic liquid crystal is exemplified. In the liquid crystal layer  41 , a spacer (not shown in the drawings) that includes a plurality of granular members may be interposed between the first substrate  42  and the second substrate  43  to constantly maintain the thickness of the liquid crystal layer  41 . 
     The first base  42  includes a transparent substrate  421 , a light shielding film  422 , a color filter  423 , a planarizing film  424 , a transparent electrode  425 , and an alignment film  426 . 
     The transparent substrate  421  performs a function of supporting the light shielding film  422  and the color filter  423  and sealing the liquid crystal layer  41 . The transparent substrate  421  has a light transmitting property in a thickness direction (AB direction). As a material for forming the transparent substrate  421 , glass or light transmitting plastic is exemplified. 
     The light shielding film  422  performs a function of shielding light (maintaining the amount of transmitted light to a predetermined value or less), and is formed on a top surface of the transparent substrate  421 . The light shielding film  422  has a through-hole  422   a  that is penetrated in a thickness direction (direction of an arrow AB), in order to transmit the light in a predetermined region. As a material for forming the light shielding film  422 , a dye or a pigment having a color (for example, black) where a light shielding property is high, a resin (for example, acrylic resin) where carbon is added or Cr is exemplified. 
     The color filter  423  performs a function of selectively absorbing a predetermined wavelength of incident light and selectively transmitting only the predetermined wavelength. The color filter  423  is disposed in the through-hole  422   a  of the light shielding film  422 . As the color filter  423 , a red color filter (R) that selectively transmits a wavelength of red visible light, a green color filter (G) that selectively transmits a wavelength of green visible light or a blue color filter (B) that selectively transmits a wavelength of blue visible light is exemplified. The color filter  423  is formed by adding a dye or a pigment to an acrylic resin. 
     The planarizing film  424  performs a function of planarizing unevenness generated on a side of a top surface of the transparent substrate  421  by arranging the light shielding film  422  or the color filter  423 . As a material for forming the planarizing film  424 , a transparent resin, such as an acrylic resin, is exemplified. 
     The transparent electrode  425  performs a function of applying a predetermined voltage to the liquid crystal layer  41 , and has a light transmitting property in the AB direction. The transparent electrode  425  is formed on the planarizing film  424 . The transparent electrode  425  performs a function of propagating a predetermined signal (image signal) and has a portion that extends in a direction of an arrow CD of  FIG. 6 . As a material for forming the transparent electrode  425 , a light transmitting conductive material, such as ITO and SnO, is exemplified. 
     The alignment film  426  performs a function of aligning liquid crystal molecules of the liquid crystal layer  41  oriented in a macroscopically random direction and having low regularity in a predetermined direction. The alignment film  426  is formed on the transparent electrode  425 . As a material for forming the alignment film  426 , a polyimide resin is exemplified. 
     The second base  43  includes a transparent substrate  431 , a transparent electrode  432 , and an alignment film  433 . 
     The transparent substrate  431  performs a function of supporting the transparent electrode  432  and the alignment film  433 , and sealing the liquid crystal layer  41 . The transparent substrate  431  has a light transmitting property in a thickness direction (AB direction). As a material for forming the transparent substrate  431 , the same material as the formation material of the transparent substrate  421  is exemplified. 
     The transparent electrode  432  performs a function of applying a predetermined voltage to the liquid crystal layer  41  together with the transparent electrode  425 , and has a light transmitting property in the AB direction. The transparent electrode  432  performs a function of propagating a signal (scanning signal) to control a voltage application state (ON) or a voltage non-application state (OFF) with respect to the liquid crystal layer  41 , and has a portion that extends in an EF direction of  FIG. 6 . As a material for forming the transparent electrode  432 , the same material as the formation material of the transparent electrode  425  is exemplified. 
     The alignment film  433  performs a function of aligning liquid crystal molecules of the liquid crystal layer  41  in a predetermined direction together with the alignment film  426 , and is formed on the transparent electrode  432 . As a material for forming the alignment film  433 , the same material as the formation material of the alignment film  426  is exemplified. 
     The sealing member  44  is provided in a frame shape to be positioned between the first base  42  and the second base  43 , seals the liquid crystal layer  41 , and performs a function of bonding the first base  42  and the second base  43  in a state where the first base  42  and the second base  43  are apart from each other at a predetermined interval. As a material for forming the sealing member  44 , an insulating resin or a sealing resin is exemplified. 
     The backlight  50  shown in  FIG. 6  irradiates light propagated in an A direction onto the liquid crystal display panel X. The backlight  50  includes a light source  51  and a light guiding plate  52 . The backlight  50  adopts an edge light type where the light source  51  is disposed on the side of the light guiding plate  52 . The light source  51  performs a function of emitting light to the light guiding plate  52 . As the light source  51 , a cathode fluorescent lamp (CFL), a light emitting diode (LED), a halogen lamp, a xenon lamp, or electro-luminescence (EL) is exemplified. The light guiding plate  52  performs a function of approximately equally guiding light from the light source  51  over the entire bottom surface of the liquid crystal display panel  40 . The light guiding plate  52  generally includes a reflection sheet (not shown in the drawings) that is provided on a back surface thereof, a diffusion sheet (not shown in the drawings) that is provided on a surface thereof, and a prism sheet (not shown in the drawings) that is provided on the surface thereof. The reflection sheet reflects light, the diffusion sheet diffuses light to perform uniform surface emitting, and the prism sheet condenses light in an approximately constant direction. As a material for forming the light guiding plate  52 , a transparent resin, such as an acrylic resin and a polycarbonate resin, is exemplified. The backlight  50  is not limited to the edge light type, and may adopt other type, such as a direct type, in which the light source  51  is disposed on the side of the back surface of the liquid crystal display panel  40 . 
     The casing  60  performs a function of storing the liquid crystal display panel  40  and the backlight  50 , and includes an upper casing  61  and a lower casing  62 . As a material for forming the casing  60 , a resin such as a polycarbonate resin or a metal such as stainless (SUS) and aluminum is exemplified. 
     Next, an example of a method of fixing the touch panel X to the liquid crystal display panel Z will be described. In the description below, a fixing member using a double-sided tape T is described, but the present invention is not limited to the fixing method using a double-sided tape T. For example, the method of fixing the touch panel X to the liquid crystal display panel Z may be a fixing method using an adhesive member, such as a thermosetting resin and an ultraviolet curable resin, or a method that physically fixes the touch panel X and the liquid crystal display device Z. 
     First, one surface of the double-sided tape T is bonded to a predetermined region on a top surface of the upper casing  61  of the liquid crystal display device Z. In this embodiment, the predetermined region is a region R that is positioned to surround the display region P of the liquid crystal display device Z (refer to  FIG. 7 ). 
     Next, after the touch panel X is aligned to the liquid crystal display device Z where the double-sided tape T is bonded, the transparent insulating substrate  21  of the touch panel X and the upper casing  61  of the liquid crystal display device Z are bonded through the double-sided tape T. Thereby, the touch panel X is fixed to the liquid crystal display device Z. 
     Since the touch panel type display device Y according to the embodiment of the present invention includes the touch panel X, the same effect as the effect of the above-described touch panel X can be achieved. That is, in the touch panel type display device Y, reflected glare can be reduced and reliability can be improved. 
     The specific embodiment of the present invention has been described. However, the present invention is not limited thereto and various changes can be made without departing from the spirit of the present invention. 
     In the touch panel X, instead of the polarizing film  14 , an optical function film (for example, AR (anti-reflection) film, a phase-difference film or a laminate thereof) or an HC (Hard coat) film may be formed. 
     In the touch panel X, a film that is subjected to anti-glare processing or reflection prevention coating may be further disposed in at least one of the first base  10  and the second base  20 . According to this configuration, external light reflection can be reduced. 
     The transparent insulating bases  11  and  21  of the touch panel X may be replaced by any one of the phase-difference film, the polarizing film, and the film subjected to the anti-glare processing or the reflection prevention coat processing. 
     In the touch panel X, a phase-difference film may be further disposed in at least one of the first base  10  and the second base  20 . The phase-difference film performs a function of converting a state of linearly polarized light whose state is converted into an elliptical polarization state by birefringence (phase shift) of the liquid crystal from the elliptical polarization state to a state similar to a linear polarization state. As a material for forming the phase-difference film, polycarbonate (PC), polyvinyl alcohol (PVA), polyarylate (PA), polysulfone (Psu) or polyolefin (PO) is exemplified. However, as the material for forming the phase-difference film, the PC is preferable from the viewpoint of consistency with wavelength dispersion of the liquid crystal, and the PO that has a photoelastic coefficient smaller than that of the PC is preferable from the viewpoint of adaptability with respect to a circularly polarizing plate. According to this configuration, a contrast ratio of a display image can be increased. 
     In the touch panel X, instead of the resistive type, other type, such as a capacitance type, an surface elastic wave type, an infrared type or an electromagnetic induction type, may be used. 
     In the touch panel type display device Y, instead of the liquid crystal display panel described above, a display panel, such as an EL (electro luminescence) display panel or a plasma display panel, which has a different display format, may be used as a display panel.