Patent Publication Number: US-2011063240-A1

Title: Touch panel

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a touch panel used to operate various kinds of electronic devices. 
     2. Description of the Related Art 
     In recent years, various kinds of electronic devices such as cellular phones, electronic cameras or the like have become increasingly multi-functional and diverse. Therefore, devices in which touch panels having a light transmissive characteristic are mounted on the front faces of display devices such as liquid crystal display devices or the like are increasing. In such a device, there are an increasing number of cases where a user views a display on the display device placed in the rear face of the touch panel and touches the touch panel with a finger or the like for operation, such that various functions of the device are switched. Thus, it has recently become necessary to perform reliable operations at a low cost. 
     Such a touch panel in the related art will be described with reference to  FIG. 8 . In order to easily recognize constituent elements in the figure, the dimensions thereof are partially enlarged. 
       FIG. 8  is an exploded perspective view of a touch panel in the related art. In  FIG. 8 , the touch panel includes upper substrate  1 , upper conductive layers  2 , upper electrodes  3 , lower substrate  4 , lower conductive layers  5 , lower electrodes  6 , cover substrate  7 . 
     Upper substrate  1  has a film shape and a light transmissive characteristic. A plurality of substantially belt-shaped upper conductive layers  2  are arranged and formed on an upper surface of upper substrate  1  in the longitudinal direction. Upper conductive layers  2  are made of indium tin oxide or the like and have a light transmissive characteristic. Upper electrodes  3  are formed in plurality, one ends of which are connected to end portions of upper conductive layers  2  and the other ends thereof extend to the right end of the outer circumferential portion of upper substrate  1 . Upper electrodes  3  are formed in the direction (transverse direction) perpendicular to upper conductive layers  2 . Upper electrodes  3  are made of silver, carbon, or the like. 
     Lower substrate  4  has a film shape and a light transmissive characteristic. A plurality of substantially belt-shaped lower conductive layers  5  is arranged and formed on the upper surface of lower substrate  4  in the transverse direction perpendicular to upper conductive layers  2 . Lower conductive layers  5  are made of indium tin oxide or the like and have a light transmissive characteristic. Lower electrodes  6  are formed in plurality, one ends of which are connected to the end portions of lower conductive layers  5  and the other ends thereof extend to the right end of the outer circumferential portion of lower substrate  4 . Lower electrodes  6  are formed extending in the transverse direction parallel to lower conductive layers  5 . Lower electrodes  6  are made of silver, carbon, or the like. 
     Cover substrate  7  has a film shape and a light transmissive characteristic. Upper substrate  1  overlaps the upper surface of lower substrate  4 . In addition, cover substrate  7  overlaps the upper surface of upper substrate  1 . They are respectively attached to each other by adhesives (not shown) or the like. The touch panel is configured in this way. 
     The touch panel configured in this way is disposed on a front face of a display device such as a liquid crystal display device or the like and mounted on an electronic device. At this time, a plurality of upper electrodes  3  or lower electrodes  6  of the touch panel is electrically connected to electronic circuits (not shown) of the electronic device via a flexible wire board, a connector (not shown) or the like. 
     In the above-described configuration, in a state where a plurality of upper electrodes  3  and lower electrodes  6  is sequentially applied with voltages from the electronic circuits, the upper surface of cover substrate  7  is touched by a finger or the like for operation according to the display on the display device placed in the rear face of the touch panel. Thereby, a capacitance between upper conductive layers  2  and lower conductive layers  5  in the operated place varies, the electronic circuits detect the operated place, and thus various functions of the electronic device are switched. 
     In other words, for example, if a finger or the like touches the upper surface of cover substrate  7  over a desired menu in a state where a plurality of menus or the like is displayed on the display device placed in the rear face of the touch panel, a portion of charges are conducted to the finger. Thereby, a capacitance between upper conductive layers  2  and lower conductive layers  5  of the touch panel in the operated place varies. The electronic circuits detect the variation of the capacitance and thereby selection of a desired menu or the like is performed. 
     In order to manufacture upper substrate  1  or lower substrate  4  of the touch panel, generally, upper substrate  1  or lower substrate  4  of which an entire upper surface is provided with a thin film made of indium tin oxide or the like is immersed in an etchant, and a plurality of upper conductive layers  2  or lower conductive layers  5  having a substantially belt shape are formed on the upper surface of upper substrate  1  or lower substrate  4 . 
     Thereafter, a plurality of upper electrodes  3  or lower electrodes  6  made of silver, carbon, or the like is formed by a screen printing or the like. 
     In this way, there is completion of upper substrate  1  or lower substrate  4 , each of which the upper surface is provided with a plurality of upper conductive layers  2  or lower conductive layers  5 , and upper electrodes  3  or lower electrodes  6  having one ends connected to the end portions of the conductive layers and the other ends extending to the right end of the outer circumference thereof. 
     However, when a plurality of upper electrodes  3  or lower electrodes  6  is formed using the screen printing or the like, if the line width of upper electrode  3  or lower electrode  6  or the dimension between lines is to be reduced, spreading or scratching is easily generated. Particularly, the spreading or the scratching is especially easily generated in upper electrodes  3  which are formed thin and long in the front and rear portions of upper substrate  1  while extending in the transverse direction perpendicular to upper conductive layers  2 . Thereby, there is a case where connection to the electronic circuits of the electronic device is unstable. 
     For this reason, the line width of upper electrode  3  or the dimension between lines cannot be formed too small and thus typically is formed in the dimension of about 0.1 mm or more. Therefore, the dimension of the profile of upper substrate  1  in the longitudinal direction increases, or an operation region which can be touched by a finger or the like decreases. 
     Since unnecessary parts in the metal thin film of relatively high-priced indium tin oxide or the like formed on the entire upper surface of upper substrate  1  or lower substrate  4  are removed using an etching process to form a plurality of upper conductive layers  2  or lower conductive layers  5 , it is also difficult to realize a low price. 
     Japanese Patent Unexamined Publication No. 2009-93397 is an example of the related art. 
     However, in a touch panel in the related art, when the line width of each of a plurality of upper electrodes  3  formed thin and long in the front and rear end portions of upper substrate  1  or the dimension between lines is made small, the spreading or the scratching is easily generated, and thus it is difficult to thin the lines or to narrow the line interval. Thereby, there is a problem in that since the dimension of the profile of upper substrate  1  in the longitudinal direction increases, or the operation region which can be touched by a finger or the like decreases, it is difficult to realize overall miniaturization or an increase in the operation region. 
     SUMMARY OF THE INVENTION 
     The present invention provides a touch panel which can be reliably operated at a low cost while implementing miniaturization or an increase in an operation region. 
     A touch panel according to an embodiment of the present invention includes an upper substrate, a lower substrate opposite to the upper substrate with a predetermined gap therebetween, a plurality of belt-shaped upper conductive layers formed on the upper substrate and arranged in a predetermined direction, a plurality of upper electrodes having one ends connected to end portion of the upper conductive layers and the other ends extending to an outer circumference of the upper substrate, a plurality of belt-shaped lower conductive layers formed on the lower substrate and arranged in a direction perpendicular to the upper conductive layers with a predetermined gap between the lower conductive layers and the upper conductive layers, and a plurality of lower electrodes having one ends connected to end portion of the lower conductive layers and the other ends extending to an outer circumference of the lower substrate. At least one of the upper electrodes and the lower electrodes is formed of a copper foil. By this configuration, it is possible to miniaturize the overall touch panel and increase an operation region. Also, connection to electronic circuits of an electronic device can be stably performed and thus it is possible to obtain a touch panel which can be reliably operated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a touch panel according to a first embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the touch panel according to the first embodiment of the present invention. 
         FIG. 3  is a plan view of the touch panel according to the first embodiment of the present invention. 
         FIG. 4A  is a plan view of the touch panel according to the first embodiment of the present invention. 
         FIG. 4B  is a plan view of the touch panel according to the first embodiment of the present invention. 
         FIG. 4C  is a plan view of the touch panel according to the first embodiment of the present invention. 
         FIG. 5  is a sectional view of a touch panel according to a second embodiment of the present invention. 
         FIG. 6  is an exploded perspective view of the touch panel according to the second embodiment of the present invention. 
         FIG. 7A  is a partially sectional view of the touch panel according to the second embodiment of the present invention. 
         FIG. 7B  is a partially sectional view of the touch panel according to the second embodiment of the present invention. 
         FIG. 7C  is a partially sectional view of the touch panel according to the second embodiment of the present invention. 
         FIG. 7D  is a partially sectional view of the touch panel according to the second embodiment of the present invention. 
         FIG. 7E  is a partially sectional view of the touch panel according to the second embodiment of the present invention. 
         FIG. 8  is an exploded perspective view of a touch panel in the related art. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     Hereinafter, embodiments of the present invention will be described with reference to  FIGS. 1 to 7E . Constituent elements are partially enlarged in their dimensions in order to be easily recognized. Constituent elements the same as those described in the Description of the Related Art are given the same reference numerals and the description thereof will be simplified. The definition for directions such as front and rear, left and right, upper and lower, and the like is for explaining positional relationships between the respective constituent elements in this embodiment, and the elements are not necessarily disposed in those directions. 
     First Embodiment 
       FIG. 1  is a sectional view of a touch panel according to a first embodiment of the present invention.  FIG. 2  is an exploded perspective view of the touch panel according to the first embodiment of the present invention.  FIG. 3  is a plan view of the touch panel according to the first embodiment of the present invention. In  FIGS. 1 to 3 , the touch panel in this embodiment includes upper substrate  11 , upper conductive layers  12 , upper electrodes  13 , lower substrate  4 , lower conductive layers  5 , lower electrodes  6 , cover substrate  7 , base conductive layer  8 , base electrode  9 , and base substrate  10 . 
     Upper substrate  11  has a film shape and a light transmissive characteristic. Upper substrate  11  is made of polyethylene terephthalate, polyether sulfone, polycarbonate, or the like. A plurality of substantially belt-shaped upper conductive layers  12  is arranged and formed on an upper surface of upper substrate  11  in the longitudinal direction by a sputtering method or the like. Upper conductive layers  12  are made of indium tin oxide, tin oxide, or the like and have a light transmissive characteristic. Also, upper electrodes  13  are formed on the upper surface of upper substrate  11  in the direction (transverse direction) perpendicular to upper conductive layers  12 . Upper electrodes  13  have one ends connected to end portions of upper conductive layers  12  and the other ends extending to the right end of the outer circumference of upper substrate  11 . Upper electrodes  13  are formed at end portions in the side to which upper conductive layers  12  extend on upper substrate  11  (that is, the front end portion and the rear end portion of upper substrate  11 ). Upper electrodes  13  are formed by laminating a copper foil on indium tin oxide, tin oxide, or the like through a deposition or the like. 
     Lower substrate  4  has a film shape and a light transmissive characteristic. A plurality of substantially belt-shaped lower conductive layers  5  is arranged and formed on an upper surface of lower substrate  4  in the direction (transverse direction) perpendicular to upper conductive layers  12 . Lower conductive layers  5  are made of indium tin oxide, tin oxide, or the like and have a light transmissive characteristic. Also, a plurality of lower electrodes  6  is formed on the upper surface of lower substrate  4  in the transverse direction parallel to the lower conductive layers. Lower electrodes  6  have one ends connected to end portions of lower conductive layers  5  and the other ends extending to the right end of the outer circumference of lower substrate  4 . Lower electrodes  6  are formed at end portions in the side to which lower conductive layers  5  extend on the lower substrate  4  (the right end portion in this embodiment). Lower electrodes  6  are made of silver, carbon, or the like. 
     A plurality of upper conductive layers  12  and lower conductive layers  5  are formed by connecting a plurality of rectangular portions to each other in the belt shape. A plurality of substantially rectangular gap portions is provided between upper conductive layers  12  or lower conductive layers  5 . As shown in  FIG. 3 , in the state where upper substrate  11  overlaps lower substrate  4 , the rectangular portions of upper conductive layers  12  overlap the gap portions of lower electrodes  6 , and the rectangular portions of lower conductive layers  5  overlap the gap portions of upper electrodes  13 . 
     Base substrate  10  has a film shape and a light transmissive characteristic. Base substrate  10  is made of polyethylene terephthalate or the like. Base conductive layer  8  having a light transmissive characteristic is formed on the entire upper surface of base substrate  10 . Base conductive layer  8  is made of indium tin oxide, tin oxide, or the like. Base electrode  9 , which extends to the right end of the outer circumference from the front end portion and the rear end portion of base conductive layer  8 , is formed on the upper surface of base substrate  10 . Base electrode  9  is formed in substantially U shape and is made of silver, carbon, or the like. 
     Cover substrate  7  has a film shape and a light transmissive characteristic. Lower substrate  4 , upper substrate  11 , and cover substrate  7  overlap the upper surface of base substrate  10 , and they are respectively attached to each other by adhesives (not shown) such as acryl, rubber, or the like, which thus configures the touch panel. 
     In other words, in the touch panel in this embodiment, a plurality of upper conductive layers  12  arranged and formed in the longitudinal direction and lower conductive layers  5  arranged and formed in the transverse direction perpendicular to upper conductive layers  12  are disposed opposite to each other with a predetermined gap by interposing upper substrate  11  therebetween. 
     The touch panel configured in this way is disposed on a front face of a display device such as a liquid crystal display device and mounted on an electronic device. At this time, a plurality of upper electrodes  13 , lower electrodes  6 , and base electrode  9  are electrically connected to electronic circuits (not shown) of the electronic device via a flexible wire board or a connector (not shown). 
     In the above-described configuration, in the state where the electronic circuits sequentially supply voltages to a plurality of upper electrodes  13  and lower electrodes  6 , a finger or the like touches the upper surface of cover substrate  7  for operation, according to the display on the display device placed in the rear face of the touch panel. Thereby, a capacitance between upper conductive layers  12  and lower conductive layers  5  in the operated place varies. The operated place is detected by the electronic circuits based on the variation of the capacitance, and various functions of the electronic device are switched. 
     In other words, for example, if a finger or the like touches the upper surface of cover substrate  7  over a desired menu in a state where a plurality of menus or the like is displayed on the display device placed in the rear face of the touch panel, a portion of electrical charge is conducted to the finger. Thereby, a capacitance between upper conductive layers  12  and lower conductive layers  5  of the touch panel in the operated place varies. The electronic circuits detect the variation of the capacitance and thereby selection of a desired menu or the like is performed. 
     An example of manufacturing upper substrate  11  of the touch panel will be described with reference to  FIGS. 4A to 4C . As shown in  FIG. 4A , first, a thin film  12 A made of indium tin oxide is formed on the entire upper surface of upper substrate  11 . Next, copper foil  13 A is laminated on the thin film  12 A made of indium tin oxide. 
     The upper surface of copper foil  13 A is exposed and developed by a photoresist method or the like so as to mask patterns of upper electrodes  13  with a coat made of an insulating resin such as a dry film or the like. Thereafter, upper substrate  11  is immersed in an etchant to melt and remove only copper foil  13 A in unnecessary parts. Thereby, as shown in  FIG. 4B , a plurality of upper electrodes  13  is formed on the upper surface of thin film  12 A made of indium tin oxide. 
     A coat is formed on the upper surface of thin film  12 A made of indium tin oxide by the photoresist method or the like in order to cover the patterns of upper electrodes  13 . Next, upper substrate  11  is immersed in an etchant different from the above-described etchant to melt and remove thin film  12 A in unnecessary parts. Thereby, upper substrate  11  is formed as shown in  FIG. 4C . That is to say, on the upper surface of upper substrate  11 , there are formed a plurality of substantially belt-shaped upper conductive layers  12 , and a plurality of upper electrodes  13  having one ends connected to end portions of upper conductive layers  12  and the other ends extending to the right end of the outer circumference of upper substrate  11 . Copper foil  13 A is laminated on thin film  12 A made of indium tin oxide to form upper electrodes  13 . 
     In other words, a plurality of substantially belt-shaped upper electrodes  13  disposed at the front end portion and the rear end portion of upper substrate  11  in the thin and long manner is formed of the copper foil using the etching process or the like, and thereby upper electrodes  13  can have the line width or the line interval of about 0.03 mm to 0.05 mm. That is to say, the upper electrodes can be formed thinner and thus the interval between the electrodes can be further narrowed. 
     A plurality of upper electrodes  13  is formed of the copper foil using the etching process or the like, and thereby it is possible to thin upper electrodes  13  or to narrow the interval therebetween. For this reason, it is possible to miniaturize the overall touch panel or to increase an operation region. Since upper electrodes  13  can be formed without the spreading or the scratching, the stable connection to the electronic circuits of electronic device is enabled and therefore an operation can be reliably performed. 
     Base substrate  10  provided with base conductive layer  8  is attached to the entire lower surface of lower substrate  4 . By this configuration, it is possible to remove, using base conductive layer  8 , electronic noise generated from the touch panel when a finger or the like touches the upper surface of cover substrate  7  or electronic noise from the display device placed in the rear face of the touch panel. Therefore, it is possible to perform a more stable input operation without introducing errors. 
     Furthermore, only upper electrodes  13  are formed of the copper foil, and lower electrodes  6  or base electrode  9  are respectively formed using the screen printing or the like, and thereby the touch panel can be manufactured at a relatively low cost. 
     A plurality of lower electrodes  6  of lower substrate  4  may be also formed of the copper foil like upper electrodes  13  using the etching process or the like although the touch panel is manufactured at a slightly high cost. Thereby, since there is no need for heating for drying lower substrate  4 , which is accompanied by the screen printing or the like, it is possible to prevent a misalignment with upper substrate  11  due to the contraction of lower substrate  4 . 
     As described above, according to this embodiment, a plurality of substantially stripe-shaped upper electrodes  13  extending from upper conductive layers  12  in the perpendicular direction or lower electrodes  6  extending from lower conductive layers  5  are formed of the copper foil, and thereby it is possible to form upper electrodes  13  or lower electrodes  6  which realize a thinned line or narrowed line interval without the spreading or the scratching by using the etching process or the like. Therefore, the overall miniaturization or increase in an operation region cannot only be implemented, but stable connection to the electronic circuits of the device can be also performed, thereby obtaining the touch panel which can be reliably operated. 
     Second Embodiment 
     Hereinafter, a touch panel according to a second embodiment of the present invention will be described with reference to  FIGS. 5 to 7E . In addition, the constituent elements the same as those in the first embodiment are given the same reference numerals and the detailed description thereof will be omitted. 
       FIG. 5  is a sectional view of a touch panel according to the second embodiment of the present invention.  FIG. 6  is an exploded perspective view of the touch panel according to the second embodiment of the present invention. 
     In  FIGS. 5 and 6 , the second embodiment is the same as the first embodiment in that upper conductive layers  15  are arranged and formed on the upper surface of upper substrate  11  in the longitudinal direction. However, unlike the first embodiment, a plurality of conductive metal thin lines  15 B such as silver or the like having a diameter of about 10 to 100 nm and a length of about 1 to 15 μm is dispersed in ultraviolet curable resin  15 A in predetermined parts such as acryl or the like having the thickness of about 0.1 to 20 μm, thereby forming upper conductive layers  15 . 
     Upper electrodes  13  have one ends connected to end portions of upper conductive layers  15  and the other ends extending to the right end of the outer circumference of upper substrate  11 . Upper electrodes  13  are formed of a copper foil having the thickness of about 20 nm to 10 μm. A plurality of upper electrodes  13  is formed extending in the transverse direction perpendicular to upper conductive layers  15 . Upper electrodes  13  are formed at end portions in the side to which upper conductive layers  15  extend in upper substrate  11 . 
     Lower substrate  16  has a film shape and a light transmissive characteristic like upper substrate  11 . Lower conductive layers  17  are formed by dispersing a plurality of conductive metal thin lines  17 B in ultraviolet curable resin  17 A like upper conductive layers  15 . A plurality of substantially belt-shaped lower conductive layers  17  is arranged and formed on the upper surface of lower substrate in the transverse direction perpendicular to upper conductive layers  15 . Lower conductive layers  17  have a light transmissive characteristic. 
     Lower electrodes  18 , like upper electrodes  13 , are formed of a copper foil. Lower electrodes  18  have one ends connected to end portions of lower conductive layers  17  and the other ends extending to the right end of the outer circumference, and a plurality of lower electrodes  18  is formed extending in the parallel direction (transverse direction) to lower conductive layers  17 . Lower electrodes  18  are formed in the side to which lower conductive layers  17  extend in lower substrate  16 . 
     A plurality of upper conductive layers  15  and lower conductive layers  17  have a plurality of substantially rectangular portions connected in a belt shape like the first embodiment. A plurality of substantially rectangular gap portions is provided between upper conductive layers  12  or lower conductive layers  5 . In the state where upper substrate  11  and lower substrate  16  overlap each other, the rectangular portions of upper conductive layers  15  overlap the gap portions of lower electrodes  18 , and the rectangular portions of lower conductive layers  17  overlap the gap portions of upper electrodes  13 . 
     Base substrate  10  is provided with base conductive layer  19  having a light transmissive characteristic the same as upper conductive layers  15  or lower conductive layers  17 , on its entire upper surface. Base electrode  9  is formed in a substantially U shape so as to extend from the front end portion and the rear end portion of base conductive layer  19  to the right end of the outer circumference of base substrate  10 . 
     Lower substrate  16 , upper substrate  11 , and cover substrate  7  sequentially overlap the upper surface of base substrate  10 , and the touch panel is configured by attaching them to each other, which is the same as the first embodiment. 
     In other words, in this embodiment, a plurality of upper conductive layers  15  arranged and formed in the longitudinal direction and lower conductive layers  17  arranged and formed in the transverse direction perpendicular thereto are formed of ultraviolet curable resin  15 A or  17 A in which conductive metal thin lines  15 B or  17 B are dispersed. Upper conductive layers  15  and lower conductive layers  17  are disposed opposite to each other with a predetermined gap by interposing upper substrate  11  therebetween. Upper electrodes  13  extending from upper conductive layers  15  and lower electrodes  18  extending from lower conductive layers  17  are formed of the copper foil. 
     A method of manufacturing, for example, upper substrate  11  of the touch panel will be described with reference to  FIGS. 7A to 7E .  FIGS. 7A to 7E  are partially sectional views of the touch panel according to the second embodiment of the present invention. 
     As shown in  FIG. 7A , first, ultraviolet curable resin  15 A and copper foil  13 A are sequentially laminated on the upper surface of upper substrate  11 . A plurality of conductive metal thin lines  15 B is entirely dispersed in ultraviolet curable resin  15 A. 
     As shown in  FIG. 7B , upper substrate  11  is exposed and developed by the photoresist method or the like so as to mask the upper surface of copper foil  13 A with coats  21  made of insulating resin such as a dry film or the like. Thereby, parts forming patterns of upper conductive layers  15  are covered by coats  21 . 
     Next, upper substrate  11  is immersed in an etchant such as ammonium persulfate diluted aqueous solution or the like. Thereby, only copper foil  13 A in unnecessary parts which are not covered by coats  21  is melted and removed. Thereafter, upper substrate  11  is immersed in an etchant such as a dilute aqueous solution where phosphoric acid and nitric acid are mixed with each other, and thereby conductive metal thin lines  15 B and ultraviolet curable resin  15 A placed under the parts where copper foil  13 A is removed are melted and removed. Thereby, as shown in  FIG. 7C , a plurality of conductive metal thin lines  15 B is arranged in a predetermined direction in ultraviolet cured resin  15 A to form upper substrate  11  provided with copper foil  13 A on ultraviolet curable resin  15 A. 
     Thereafter, as shown in  FIG. 7D , the upper surface of a predetermined copper foil  13 A is exposed and developed by the photoresist method or the like to be masked with coats  21  again. 
     Next, upper substrate  11  is immersed in an etchant such as ammonium persulfate diluted aqueous solution or the like to melt and remove copper foil  13 A in unnecessary parts which are not covered by coats  21 . Thereby, as shown in  FIG. 7E , there is completion of upper substrate  11  provided with a plurality of upper conductive layers  15  arranged in a predetermined direction by conductive metal thin lines  15 B in ultraviolet curable resin  15 A, and a plurality of upper electrodes  13  extending therefrom. 
     Lower substrate  16  may be manufactured by fundamentally the same method as upper substrate  11 . 
     The touch panel configured in this way is disposed on a front face of a display device such as a liquid crystal display device or the like and mounted on an electronic device. A plurality of upper electrodes  13 , lower electrodes  18 , and base electrode  9  of the touch panel are electrically connected to electronic circuits (not shown) of the electronic device via a flexible wire board or a connector (not shown). 
     In the above-described configuration, in the state where the electronic circuits sequentially supply voltages to a plurality of upper electrodes  13  and lower electrodes  18 , a finger or the like touches the upper surface of cover substrate  7  for operation, according to the display on the display device placed in the rear face of the touch panel. Thereby, a capacitance between upper conductive layers  15  and lower conductive layers  17  in the operated place varies. The operated place is detected by the electronic circuits based on the variation of the capacitance, and various functions of the electronic device are switched. 
     In other words, for example, if a finger or the like touches the upper surface of cover substrate  7  over a desired menu in a state where a plurality of menus or the like is displayed on the display device placed in the rear face of the touch panel, a portion of electrical charge is conducted to the finger. Thereby, a capacitance between upper conductive layers  15  and lower conductive layers  17  of the touch panel in the operated place varies. The electronic circuits detect the variation of the capacitance and thereby selection of a desired menu or the like is performed. 
     Upper conductive layers  15  or lower conductive layers  17 , and base conductive layer  19  of the touch panel are formed of ultraviolet curable resin  15 A or  17 A in which a plurality of conductive metal thin lines  15 B or  17 B is dispersed, and thereby it is possible to configure the touch panel at a low cost as compared with a case where they are formed of a metal thin film made of a high-priced indium tin oxide or the like. 
     By forming upper conductive layers  15  or lower conductive layers  17  as in this embodiment, light transmittance is 91 to 92% higher than a case where upper conductive layers  15  or lower conductive layers  17  are formed of the metal thin film made of indium tin oxide or the like. For this reason, the display on the liquid crystal display device or the like placed in the rear face of the touch panel can be easily viewed and thus visibility becomes better, thereby easily performing an operation. 
     In other words, upper conductive layers  15  or lower conductive layers  17 , and base conductive layer  19  are formed of ultraviolet curable resin  15 A or  17 A in which relatively low-priced conductive metal thin lines  15 B or  17 B are dispersed, and thereby upper conductive layers  15  or lower conductive layers  17  can be formed comparatively simply using the etching process or the like. Therefore, it is possible to obtain the touch panel which can be reliably operated at a low cost. 
     A plurality of upper electrodes  13  or lower electrodes  18  are formed of the copper foil using the etching or the like, and thereby it is possible to form upper electrodes  13  or lower electrodes  18  having the electrode width or the interval between electrodes of about 0.03 to 0.05 mm. That is to say, it is possible to thin upper electrodes  13  or lower electrodes  18  or to narrow the interval therebetween. 
     In other words, it is possible to thin upper electrodes  13  or lower electrodes  18  or to narrow the interval therebetween by forming a plurality of upper electrodes  13  or lower electrodes  18  using the copper foil. Therefore, it is possible to miniaturize the overall touch panel or to increase an operation region. Also, since upper electrodes  13  or lower electrodes  18  can be formed without the spreading or the scratching, the stable connection to the electronic circuits of electronic device is enabled and therefore an operation can be reliably performed. 
     The above description has been made of the configuration where upper conductive layers  15 , lower conductive layers  17 , and base conductive layer  19  are all formed of ultraviolet curable resin  15 A or  17 A in which conductive metal thin lines  15 B or  17 B are dispersed. However, base conductive layer  19 , which is formed on the entire upper surface of base substrate  10  and for which removal by the etching process or the like is hardly necessary, may be made of indium tin oxide, tin oxide, or the like by the sputtering method or the like. Even when only either upper conductive layers  15  or lower conductive layers  17  are formed of the ultraviolet curable resin in which the conductive metal thin lines are dispersed, the present invention can be implemented. 
     The above description has been made of the configuration where both of upper electrodes  13  and lower electrodes  18  are formed of the copper foil. However, lower electrodes  18 , which are formed extending in the transverse direction parallel to lower conductive layers  17  and have some margin in the line width or the line interval as compared with upper electrodes  13 , may be made of silver, carbon, or the like by screen printing. In other words, even when only upper electrodes  13  extending in the perpendicular direction to upper conductive layers  15  are formed of the copper foil, the touch panel in this embodiment can be manufactured at a low cost. 
     In this way, according to this embodiment, at least one of upper conductive layers  15  or lower conductive layers  17  is formed of ultraviolet cured resin  15 A or  17 A in which conductive metal thin lines  15 B or  17 B are dispersed, and thereby it is possible to relatively simply form upper conductive layers  15  or lower conductive layers  17  using the etching process or the like. In addition, it is possible to obtain the touch panel which can be reliably operated at a low cost. 
     At least one of a plurality of upper electrodes  13  extending from upper conductive layers  15  and a plurality of lower electrodes  18  extending from lower conductive layers  17  is formed of the copper foil to thin the electrodes or narrow the interval therebetween, thereby miniaturizing the overall touch panel or increasing an operation region. Further, it is possible to prevent the electrodes from being spread or scratched, thereby realizing stable connection to the electronic circuits of the electronic device. 
     The above description has been made of the configuration where lower substrate  4  or lower substrate  16  is attached to the lower surface of upper substrate  11 . However, upper substrate  11  and lower substrate  4  or lower substrate  16  may be placed upside down, and upper substrate  11  may be attached to the lower surface of lower substrate  4  or lower substrate  16 . Even when upper conductive layers  12  or upper conductive layers  15 , and lower conductive layers  5  or lower conductive layers  17  are respectively formed on the upper and lower surfaces of upper substrate  11  instead of lower substrate  4  or lower substrate  16 , the present invention can be implemented. 
     According to the embodiments of the present invention, there are advantages in that it is possible to obtain the touch panel which can be reliably operated at a low cost, and the touch panel is suitable for operation of various kinds of electronic devices.