Abstract:
This conductive sheet and touch panel have a plurality of first conductive patterns arrayed in the x-direction. The first conductive patterns have: a band-shaped section extending in the y-direction; and a plurality of jutting sections that jut from the band-shaped section in both directions and are arrayed at a predetermined spacing along the y-direction. The width of the band-shaped section is at least three times the width of the jutting sections. Also, the first conductive pattern is configured by combining: a plurality of first lattices comprising fine metal wires; and a plurality of second lattices comprising fine metal wires that are larger in size than those of the first lattices. At least the jutting sections are configured from a plurality of first lattices.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY CLAIM 
       [0001]    This application is a Continuation of International Application No. PCT/JP2012/062123 filed on May 11, 2012, which was published under PCT Article 21(2) in Japanese, which is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-108325 filed on May 13, 2011, the contents all of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a conductive sheet and a touch panel suitable for use in, for example, a projected capacitive touch panel. 
       BACKGROUND ART 
       [0003]    Transparent conductive sheets containing thin metal wires have been studied as disclosed in U.S. Patent Application Publication No. 2004/0229028, International Publication No. WO 2006/001461, etc. 
         [0004]    Touch panels have attracted much attention in recent years. The touch panel has currently been used mainly in small devices such as PDAs (personal digital assistants) and mobile phones, and is expected to be used in large devices such as personal computer displays. 
         [0005]    A conventional electrode for the touch panel is composed of ITO (indium tin oxide) and therefore has a high resistance. Thus, when the conventional electrode is used in the large device in the above future trend, the large-sized touch panel has a low current transfer rate between the electrodes, and thereby exhibits a low response speed (a long time between finger contact and touch position detection). 
         [0006]    A large number of lattices made of thin wires of a metal (thin metal wires) can be arranged to form an electrode with a lowered surface resistance. Touch panels using the electrode of the thin metal wires are known from Japanese Laid-Open Patent Publication No. 05-224818, International Publication No. WO 1995/27334, U.S. Patent Application Publication No. 2004/0239650, U.S. Pat. No. 7,202,859, International Publication No. WO 1997/18508, Japanese Laid-Open Patent Publication No. 2003-099185, International Publication No. WO 2005/121940, etc. 
       SUMMARY OF INVENTION 
       [0007]    The touch panel electrode of the thin metal wires has problems with transparency and visibility because the thin metal wires are composed of an opaque material as described in the above documents relating to touch panels using electrodes of thin metal wires, such as Japanese Laid-Open Patent Publication No. 05-224818. 
         [0008]    In view of the above problems, an object of the present invention is to provide a conductive sheet and a touch panel, which can have an electrode containing a pattern of less visible thin metal wires, a high transparency, a high visibility, and an improved detection sensitivity. 
         [0009]    [1] A conductive sheet according to a first aspect of the present invention comprises a plurality of conductive patterns arranged in one direction. The conductive patterns each contain a strip and a plurality of protrusions, the strip extends in another direction approximately perpendicular to the one direction, and the protrusions extend from both sides of the strip and are arranged at predetermined intervals in the other direction approximately perpendicular to the one direction. The length of the strip in the one direction is at least 3 times larger than the length of the protrusion in the other direction approximately perpendicular to the one direction. The conductive patterns each contain a combination of a plurality of first lattices and a plurality of second lattices, the first and second lattices are composed of thin metal wires, and the second lattices are larger than the first lattices. At least the protrusions each contain a plurality of the first lattices. 
         [0010]    Since the conductive patterns each contain a combination of a plurality of the first lattices and a plurality of the second lattices, the conductive sheet can have the electrodes containing the patterns of less visible thin metal wires, a high transparency, and a high visibility. Since the protrusion contains a plurality of the first lattices, the protrusion can act as an electrode to store a signal charge corresponding to a touch position of a finger (or an input pen). Furthermore, since the length of the strip in the one direction is at least 3 times larger than the length of the protrusion in the other direction approximately perpendicular to the one direction, the strip can have an excellent conductivity to transmit the signal charge stored in the protrusion at high speed, so that the detection sensitivity can be improved. 
         [0011]    [2] In the first aspect, a portion of the strip may contain a plurality of the second lattices. 
         [0012]    [3] In the first aspect, it is preferred that the length of the protrusion is larger than ½ of the length between the adjacent strips and smaller than the length between the adjacent strips in the one direction. 
         [0013]    [4] In the first aspect, it is preferred that a specific protrusion extends from one strip toward another strip adjacent to the one strip, one protrusion extends from the other strip toward the one strip and is arranged facing the specific protrusion at a first distance L1 from the specific protrusion, another protrusion extends from the other strip toward the one strip and is arranged facing the specific protrusion at a second distance L2 from the specific protrusion, and the protrusions satisfy the inequality of L1&lt;L2. 
         [0014]    [5] In this case, it is preferred that the first distance is at most 2 times larger than the length of the protrusion in the other direction approximately perpendicular to the one direction. 
         [0015]    [6] Furthermore, it is preferred that the second distance is at least 5 times larger than the length of the protrusion in the other direction approximately perpendicular to the one direction. 
         [0016]    [7] The length of the protrusion may be smaller than ½ of the length between the adjacent strips in the one direction. 
         [0017]    [8] In this case, the ends of the protrusions extending from one strip toward another strip adjacent to the one strip and the ends of the protrusions extending from the other strip toward the one strip may be arranged facing each other. 
         [0018]    [9] It is preferred that the width of the strip is at least 3 times larger than the width of the protrusion. In this case, the strip can have an excellent conductivity to transmit the signal charge stored in the protrusion at high speed, so that the detection sensitivity can be improved. 
         [0019]    [10] A conductive sheet according to a second aspect of the present invention comprises a plurality of conductive patterns arranged in one direction. The conductive patterns each contain a plurality of electrode portions, which are connected with each other by a connection in another direction approximately perpendicular to the one direction. The length of the electrode portion is at least 2 times larger than the length of the connection in the other direction approximately perpendicular to the one direction. The conductive patterns each contain a combination of a plurality of first lattices and a plurality of second lattices, the first and second lattices are composed of thin metal wires, and the second lattices are larger than the first lattices. At least the electrode portions each contain a plurality of the first lattices. 
         [0020]    Since the conductive patterns each contain a combination of a plurality of the first lattices and a plurality of the second lattices, the conductive sheet can have the electrodes containing the patterns of less visible thin metal wires, a high transparency, and a high visibility. Since the electrode portion contains a plurality of the first lattices, the electrode portion can store a signal charge corresponding to a touch position of a finger (or an input pen). Furthermore, since the length of the electrode portion is at least 2 times larger than the length of the connection in the other direction approximately perpendicular to the one direction, the electrode portion containing a plurality of the first lattices is longer than the connection, and the entire conductive pattern can have an excellent conductivity to transmit the signal charge stored in the electrode portion at high speed, so that the detection sensitivity can be improved. 
         [0021]    [11] In the second aspect, the connection may contain a plurality of the second lattices. 
         [0022]    [12] In the first and second aspects, it is preferred that the first lattices have a side length of 30 to 500 μm. 
         [0023]    [13] Furthermore, it is preferred that the thin metal wires have a line width of 15 μm or less. In this case, a touch panel using the conductive sheet can have the electrodes containing the patterns of less visible thin metal wires, a high transparency, a high visibility, and an improved detection sensitivity. 
         [0024]    [14] A conductive sheet according to a third aspect of the present invention comprises a first conductive part and a second conductive part overlapping with each other. The first conductive part contains a plurality of first conductive patterns arranged in one direction. The second conductive part contains a plurality of second conductive patterns arranged in another direction approximately perpendicular to the one arrangement direction of the first conductive patterns. The first conductive patterns each contain a strip extending in the other direction approximately perpendicular to the one direction. The second conductive patterns each contain a plurality of electrode portions connected with each other in the one direction. The first and second conductive patterns each contain a combination of a plurality of first lattices and a plurality of second lattices, the first and second lattices are composed of thin metal wires, and the second lattices are larger than the first lattices. The length of the electrode portion is at least 2 times larger than the length of the strip in the one direction. 
         [0025]    Since the first and second conductive patterns each contain a combination of a plurality of the first lattices and a plurality of the second lattices, the conductive sheet can have the electrodes containing the patterns of less visible thin metal wires, a high transparency, and a high visibility. Since the length of the electrode portion is at least 2 times larger than the length of the strip in the one direction, the occupation area of the thin metal wires in the second conductive patterns can be increased, whereby the surface resistance of the second conductive patterns can be lowered. Consequently, when the low-resistance second conductive patterns are located closer to a display device, noise impact of an electromagnetic wave can be reduced, so that the detection sensitivity can be improved. 
         [0026]    [15] In the third aspect, it is preferred that the first lattices have a side length of 30 to 500 
         [0027]    [16] Furthermore, it is preferred that the thin metal wires have a line width of 15 μm or less. In this case, a touch panel using the conductive sheet can have the electrodes containing the patterns of less visible thin metal wires, a high transparency, a high visibility, and an improved detection sensitivity. 
         [0028]    [17] In the third aspect, it is preferred that the first and second conductive parts are stacked with a substrate interposed therebetween, and the substrate has a thickness of 50 to 350 μm. In this case, the detection sensitivity and the visibility can be improved. 
         [0029]    [18] In the third aspect, the first conductive patterns may each contain a plurality of protrusions extending from both sides of the strip, and the protrusions do not overlap with the electrode portions in the second conductive patterns. In this case, the parasitic capacitance between the protrusions and the electrode portions can be remarkably reduced to improve the detection sensitivity. 
         [0030]    [19] In the third aspect, it is preferred that in the one direction the length of the protrusion is smaller than the length of the electrode portion, and the length of the protrusion is ½ or less of the length of the electrode portion in the arrangement direction of the second conductive patterns. 
         [0031]    [20] In the third aspect, it is preferred that the length of the protrusion is larger than ½ of the length between the adjacent strips and smaller than the length between the adjacent strips in the one direction. 
         [0032]    [21] In the third aspect, it is preferred that the length of the strip in the one direction is at least 3 times larger than the length of the protrusion in the arrangement direction of the second conductive patterns. 
         [0033]    [22] In the third aspect, it is preferred that a specific protrusion extends from one strip toward another strip adjacent to the one strip, one protrusion extends from the other strip toward the one strip and is arranged facing the specific protrusion at a first distance L1 from the specific protrusion, another protrusion extends from the other strip toward the one strip and is arranged facing the specific protrusion at a second distance L2 from the specific protrusion, and the protrusions satisfy the inequality of L1&lt;L2. 
         [0034]    [23] In the third aspect, it is preferred that the first distance is at most 2 times larger than the length of the protrusion in the arrangement direction of the second conductive patterns. 
         [0035]    [24] In the third aspect, it is preferred that the second distance is at most 3 times larger than the length of the electrode portion in the arrangement direction of the second conductive patterns. 
         [0036]    [25] In the third aspect, the length of the protrusion may be smaller than ½ of the length between the adjacent strips in the one direction. 
         [0037]    [26] In this case, the ends of the protrusions extending from one strip toward another strip adjacent to the one strip and the ends of the protrusions extending from the other strip toward the one strip may be arranged facing each other. 
         [0038]    [27] In the third aspect, it is preferred that at least the protrusions each contain a plurality of the first lattices. In this case, the protrusions containing the small-sized first lattices can store a signal charge and can act as electrodes for touch position detection. 
         [0039]    [28] In the third aspect, it is preferred that a portion of the strip contains a plurality of the second lattices. 
         [0040]    [29] In the third aspect, it is preferred that the electrode portions each contain a plurality of the first lattices. In this case, the electrode portions containing the small-sized first lattices can store a signal charge and can act as electrodes for touch position detection. 
         [0041]    [30] In the third aspect, a plurality of the electrode portions may be connected with each other by a connection in the second conductive pattern, the connection may contains one or more second lattices, and as viewed from above, the connection may overlaps with the strip in the first conductive pattern. In this case, when the strip in the first conductive pattern is stacked on the connection in the second conductive pattern, the second lattices overlap with each other. Thus, a plurality of the first lattices are arranged as viewed from above, resulting in improvement of the visibility. 
         [0042]    [31] In the third aspect, in the first conductive pattern, a portion overlapping with the second conductive pattern may contain a plurality of the second lattices, and a portion not overlapping with the second conductive pattern may contain a plurality of the first lattices. Furthermore, in the second conductive pattern, a portion overlapping with the first conductive pattern may contain a plurality of the second lattices, and a portion not overlapping with the first conductive pattern may contain a plurality of the first lattices. As viewed from above, the overlap of the first conductive pattern and the second conductive pattern may contain a combination of a plurality of the first lattices. 
         [0043]    In this case, the boundaries between the first and second conductive patterns can hardly be found in the overlaps, whereby the visibility can be improved. 
         [0044]    [32] In the third aspect, it is preferred that the occupation area of the second conductive patterns is larger than the occupation area of the first conductive patterns. In this case, the second conductive patterns have a large occupation area, and thereby can exhibit a low resistance. Consequently, when the low-resistance second conductive patterns are located closer to a display device, noise impact of an electromagnetic wave can be reduced. 
         [0045]    [33] In this case, when the first conductive patterns have an occupation area A1 and the second conductive patterns have an occupation area A2, it is preferred that the conductive sheet satisfies the condition of 1&lt;A2/A1≦20. 
         [0046]    [34] It is further preferred that the conductive sheet satisfies the condition of 1&lt;A2/A1≦10. 
         [0047]    [35] It is particularly preferred that the conductive sheet satisfies the condition of 2≦A2/A1≦10. 
         [0048]    [36] In the third aspect, the first conductive patterns may each contain a plurality of protrusions extending from both sides of the strip, and the protrusions and the electrode portions may each contain a plurality of the first lattices. Thus, in the case of using a self capacitance technology or the like, even when the second conductive patterns are located closer to a display device, detection sensitivity deterioration in the electrode portion can be prevented. Furthermore, in the case of using a mutual capacitance technology, the electrode portions having the larger thin metal wire occupation area can be used as drive electrodes, the protrusions can be used as receiving electrodes, and the protrusions can exhibit a high receiving sensitivity. 
         [0049]    [37] In the third aspect, the first conductive part may contain first auxiliary patterns between the adjacent first conductive patterns, and the first auxiliary patterns are not connected to the first conductive patterns. Furthermore, the second conductive part may contain second auxiliary patterns between the adjacent second conductive patterns, and the second auxiliary patterns are not connected to the second conductive patterns. As viewed from above, the first and second auxiliary patterns may overlap with each other to form combined patterns, and the combined patterns may each contain a combination of a plurality of the first lattices. In this case, the boundaries between the protrusions and the electrode portions can hardly be found, whereby the visibility can be improved. 
         [0050]    [38] A touch panel according to a fourth aspect of the present invention comprises a conductive sheet, which is used on a display panel of a display device. The conductive sheet contains a plurality of conductive patterns arranged in one direction. The conductive patterns each contain a strip and a plurality of protrusions, the strip extends in another direction approximately perpendicular to the one direction, and the protrusions extend from both sides of the strip and are arranged at predetermined intervals in the other direction approximately perpendicular to the one direction. The length of the strip in the one direction is at least 3 times larger than the length of the protrusion in the other direction approximately perpendicular to the one direction. The conductive patterns each contain a combination of a plurality of first lattices and a plurality of second lattices, the first and second lattices are composed of thin metal wires, and the second lattices are larger than the first lattices. At least the protrusions each contain a plurality of the first lattices. 
         [0051]    [39] A touch panel according to a fifth aspect of the present invention comprises a conductive sheet, which is used on a display panel of a display device. The conductive sheet contains a plurality of conductive patterns arranged in one direction. The conductive patterns each contain a plurality of electrode portions, and the electrode portions are connected with each other by a connection in another direction approximately perpendicular to the one direction. The length of the electrode portion is at least 2 times larger than the length of the connection in the other direction approximately perpendicular to the one direction. The conductive patterns each contain a combination of a plurality of first lattices and a plurality of second lattices, the first and second lattices are composed of thin metal wires, and the second lattices are larger than the first lattices. At least the electrode portions each contain a plurality of the first lattices. 
         [0052]    [40] A touch panel according to a sixth aspect of the present invention comprises a conductive sheet, which is used on a display panel of a display device. The conductive sheet contains a first conductive part and a second conductive part overlapping with each other. The first conductive part contains a plurality of first conductive patterns arranged in one direction. The second conductive part contains a plurality of second conductive patterns arranged in another direction approximately perpendicular to the one arrangement direction of the first conductive patterns. The first conductive patterns each contain a strip extending in the other direction approximately perpendicular to the one direction. The second conductive patterns each contain a plurality of electrode portions connected with each other in the one direction. The first and second conductive patterns each contain a combination of a plurality of first lattices and a plurality of second lattices, the first and second lattices are composed of thin metal wires, and the second lattices are larger than the first lattices. The length of the electrode portion is at least 2 times larger than the length of the strip in the one direction. 
         [0053]    As described above, the conductive sheet and the touch panel of the present invention can have the electrodes containing the patterns of less visible thin metal wires, a high transparency, a high visibility, and an improved detection sensitivity. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0054]      FIG. 1  is an exploded perspective view of a touch panel according to an embodiment of the present invention; 
           [0055]      FIG. 2  is a partially-omitted exploded perspective view of a first conductive sheet stack; 
           [0056]      FIG. 3A  is a partially-omitted cross-sectional view of an example of the first conductive sheet stack, and  FIG. 3B  is a partially-omitted cross-sectional view of another example of the first conductive sheet stack; 
           [0057]      FIG. 4  is a plan view of a pattern example of a first conductive part formed on a first conductive sheet in the first conductive sheet stack; 
           [0058]      FIG. 5  is a plan view of a pattern example of a second conductive part formed on a second conductive sheet in the first conductive sheet stack; 
           [0059]      FIG. 6  is a partially-omitted plan view of the first conductive sheet stack formed by combining the first and second conductive sheets; 
           [0060]      FIG. 7  is a plan view of a pattern example of a first conductive part formed on a first conductive sheet in a second conductive sheet stack; 
           [0061]      FIG. 8  is a plan view of a pattern example of a second conductive part formed on a second conductive sheet in the second conductive sheet stack; 
           [0062]      FIG. 9  is a partially-omitted plan view of the second conductive sheet stack formed by combining the first and second conductive sheets; 
           [0063]      FIG. 10  is a plan view of a pattern example of a first conductive part formed on a first conductive sheet in a third conductive sheet stack; 
           [0064]      FIG. 11  is a plan view of a pattern example of a second conductive part formed on a second conductive sheet in the third conductive sheet stack; 
           [0065]      FIG. 12  is a partially-omitted plan view of the third conductive sheet stack formed by combining the first and second conductive sheets; 
           [0066]      FIG. 13  is a partially-omitted exploded perspective view of a fourth conductive sheet stack; 
           [0067]      FIG. 14A  is a plan view of a pattern example of a first conductive part formed on a first conductive sheet in the fourth conductive sheet stack, and  FIG. 14B  is a plan view of a pattern example of a second conductive part formed on a second conductive sheet in the fourth conductive sheet stack; 
           [0068]      FIG. 15  is a partially-omitted plan view of the fourth conductive sheet stack formed by combining the first and second conductive sheets; 
           [0069]      FIG. 16  is a flow chart of a method for producing the conductive sheet stack of the embodiment; 
           [0070]      FIG. 17A  is a partially-omitted cross-sectional view of a produced photosensitive material, and  FIG. 17B  is an explanatory view for illustrating simultaneous both-side exposure of the photosensitive material; and 
           [0071]      FIG. 18  is an explanatory view for illustrating first and second exposure treatments performed such that a light incident on a first photosensitive layer does not reach a second photosensitive layer and a light incident on the second photosensitive layer does not reach the first photosensitive layer. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0072]    Several embodiments of the conductive sheet and the touch panel of the present invention will be described below with reference to  FIGS. 1 to 18 . It should be noted that, in this description, a numeric range of “A to B” includes both the numeric values A and B as the lower limit and upper limit values. 
         [0073]    A touch panel  100  having a conductive sheet according to an embodiment of the present invention will be described below with reference to  FIG. 1 . 
         [0074]    The touch panel  100  has a sensor body  102  and a control circuit such as an integrated circuit (not shown). The sensor body  102  contains a conductive sheet stack according to a first embodiment (hereinafter referred to as the first conductive sheet stack  12 A) and thereon a protective layer  106 . The first conductive sheet stack  12 A and the protective layer  106  can be disposed on a display panel  110  of a display device  108  such as a liquid crystal display. As viewed from above, the sensor body  102  has a touch position sensing region  112  corresponding to a display screen  110   a  of the display panel  110  and a terminal wiring region  114  (a so-called frame) corresponding to the periphery of the display panel  110 . 
         [0075]    As shown in  FIG. 2 , the first conductive sheet stack  12 A is provided by stacking a first conductive sheet  10 A and a second conductive sheet  10 B. 
         [0076]    The first conductive sheet  10 A has a first conductive part  16 A formed on one main surface of a first transparent substrate  14 A (see  FIG. 3A ). As shown in  FIG. 4 , the first conductive part  16 A contains a plurality of first conductive patterns  18 A arranged in a first direction (an x direction). 
         [0077]    The first conductive pattern  18 A contains a strip  20  and a plurality of protrusions  22 . The strip  20  extends in a second direction (a y direction, perpendicular to the first direction), and the protrusions  22  extend from both sides of the strip  20  and are arranged at regular intervals in the second direction. The length La of the protrusion  22  is larger than ½ of the length Lb between the adjacent strips  20  and smaller than the length Lb in the first direction (the x direction). In this case, the protrusion can act as an electrode to store a signal charge corresponding to a touch position of a finger (or an input pen). The length Lc of the strip  20  in the first direction (the x direction) (the width Lc of the strip  20 ) is at least 3 times as large as the length Ld of the protrusion  22  in the second direction (the y direction) (the width Ld of the protrusion  22 ). The length Lc is preferably 3 to 10 times, more preferably 3 to 7 times, particularly preferably 3 to 5 times, as large as the length Ld. In the example of  FIG. 4 , the length Lc is about 3.5 times as large as the length Ld. In this case, the strip  20  can have an excellent conductivity to transmit the signal charge stored in the protrusion  22  at high speed, so that the detection sensitivity can be improved. The length Lb between the adjacent strips  20  is at least 2 times, preferably 3 to 10 times, more preferably 4 to 6 times, as large as the width Lc of the strip  20 . In the example of  FIG. 4 , the length Lb is about 5 times as large as the width Lc. In this case, the length Le of an electrode portion  30  in the first direction (in a second conductive pattern  18 B to be hereinafter described) is at least 2 times as large as the width Lc of the strip  20 . Therefore, the occupation area of thin metal wires  24  in the second conductive pattern  18 B can be increased, and the surface resistance of the second conductive pattern  18 B can be lowered. The shape of the protrusion  22  is not limited to the example of  FIG. 4 . A plurality of protrusions may further extend from the protrusion  22 , and the end of the protrusion  22  may be branched to form a bifurcated geometric shape. The shape of the electrode portion  30  in the second conductive pattern  18 B may be selected depending on the shape of the protrusion  22 . 
         [0078]    The first conductive pattern  18 A contains a combination of a plurality of first lattices  26  and a plurality of second lattices  27 . The first lattices  26  and the second lattices  27  are composed of thin metal wires  24 , and the second lattices  27  are larger than the first lattices  26 . The first conductive sheet  10 A is stacked on the second conductive sheet  10 B such that the first conductive part  16 A and the second conductive part  16 B overlap with each other as hereinafter described. In this case, the second lattices  27  are used in the overlapping portions of the first conductive patterns  18 A and the second conductive patterns  18 B, and the first lattices  26  are used in the non-overlapping portions. Thus, in this example, at least the protrusion  22  contains a plurality of the first lattices  26 , and a part of the strip  20  contains a plurality of the second lattices  27 . 
         [0079]    The first lattice  26  and the second lattice  27  have similar rhombus (or square) shapes, and the side length of the second lattice  27  is m times longer than the side length of the first lattice  26  (in which m is a real number larger than 1). In the example of  FIG. 4 , the side length of the second lattice  27  is twice as large as that of the first lattice  26 . Of course, for example, the side length of the second lattice  27  may be 1.5, 2.5, or 3 times longer than that of the first lattice  26 . The side length of the first lattice  26  is preferably 30 to 500 μm, more preferably 50 to 400 μm, particularly preferably 100 to 350 μm. The first lattice  26  and the second lattice  27  may appropriately have an angle of 60° to 120°. 
         [0080]    The positional relationships between the protrusions  22  of the adjacent strips  20  are as follows. Thus, when a specific protrusion  22  extends from one strip  20  toward the other strip  20 , one protrusion  22  extends from the other strip  20  toward the one strip  20  and is arranged facing the specific protrusion  22  at a first distance L1 from the specific protrusion  22 , and another protrusion  22  extends from the other strip  20  toward the one strip  20  and is arranged facing the specific protrusion  22  at a second distance L2 from the specific protrusion  22 , the protrusions  22  satisfy the inequality of L1&lt;L2. 
         [0081]    Specifically, the first distance L1 is at most 2 times, preferably at most 1.8 times, more preferably at most 1.5 times, as large as the width Ld of the protrusion  22 . The second distance L2 is at least 5 times, preferably 7 to 20 times, more preferably 10 to 15 times, as large as the width Ld of the protrusion  22 . In the example of  FIG. 4 , the first distance L1 is approximately equal to the width Ld of the protrusion  22 , and the second distance L2 is approximately 13 times larger than the width Ld of the protrusion  22 . 
         [0082]    The thin metal wire  24  contains, for example, gold (Au), silver (Ag), or copper (Cu). The lower limit of the line width of the thin metal wire  24  may be 0.1 μm or more, and is preferably 1 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more. The upper limit of the line width is preferably 15 μm or less, 10 μm or less, 9 μm or less, or 8 μm or less. When the line width is less than the lower limit, the thin metal wire  24  has an insufficient conductivity, whereby the touch panel  100  using the thin metal wire  24  has insufficient detection sensitivity. On the other hand, when the line width is more than the upper limit, moire is significantly generated due to the conductive metal portion, and the touch panel  100  using the thin metal wire  24  has a poor visibility. When the line width is within the above range, the moire generated due to the conductive patterns composed of the thin metal wires  24  is improved, and the visibility is remarkably improved. It is preferred that at least the first transparent substrate  14 A has a thickness of 50 μm or more and 350 μm or less. The thickness is further preferably 80 μm or more and 250 μm or less, particularly preferably 100 μm or more and 200 μm or less. 
         [0083]    As shown in  FIG. 2 , in the first conductive part  16 A, for example, one end of each alternate odd-numbered first conductive pattern  18 A and the other end of each even-numbered first conductive pattern  18 A are each electrically connected to a first terminal wiring pattern  42   a  composed of the thin metal wire  24  by a first wire connection  40   a.    
         [0084]    As shown in  FIGS. 2 ,  3 A, and  5 , the second conductive sheet  10 B has a second conductive part  16 B formed on one main surface of a second transparent substrate  14 B (see  FIG. 3A ). As shown in  FIG. 5 , the second conductive part  16 B contains a plurality of the second conductive patterns  18 B arranged in the second direction (the y direction). 
         [0085]    The second conductive pattern  18 B contains a plurality of the electrode portions  30 , which are connected with each other by connections  28  in the first direction (the x direction). The connection  28  is located between two electrode portions  30  arranged adjacent in the first direction (the x direction). The length Le of the electrode portion  30  is at least 3 times, preferably 3 to 10 times, more preferably 4 to 6 times, longer than the length Lf of the connection  28 , in the first direction (the x direction). In the example of  FIG. 5 , the length Le is about 5 times as large as the length Lf. The second conductive pattern  18 B contains a combination of a plurality of the first lattices  26  and a plurality of the second lattices  27  similarly to the first conductive pattern  18 A. As described above, the first conductive sheet  10 A is stacked on the second conductive sheet  10 B such that the first conductive part  16 A and the second conductive part  16 B overlap with each other. In this case, the second lattices  27  are used in the overlapping portions of the first conductive patterns  18 A and the second conductive patterns  18 B, and the first lattices  26  are used in the non-overlapping portions. Thus, in this example, at least the electrode portion  30  contains a plurality of the first lattices  26 . 
         [0086]    When the first conductive part  16 A is stacked on the second conductive part  16 B, the second lattices  27  in the first conductive patterns  18 A overlap with the second lattices  27  in the second conductive patterns  18 B. In this case, a connection point of the second lattice  27  in the second conductive pattern  18 B is positioned at the center of an opening of the second lattice  27  in the first conductive pattern  18 A. 
         [0087]    As shown in  FIG. 2 , one ends of adjacent two second conductive patterns  18 B are combined and electrically connected to a second terminal wiring pattern  42   b  composed of the thin metal wire  24  by a second wire connection  40   b . The first conductive sheet  10 A is stacked on the second conductive sheet  10 B such that the first conductive part  16 A and the second conductive part  16 B overlap with each other as hereinafter described. In this case, the protrusions  22  of the first conductive patterns  18 A are each sandwiched by the combination of the two second conductive patterns  18 B in the second direction (the y direction). Thus, one electrode portion  30  corresponds to one protrusion  22 . 
         [0088]    As shown in  FIG. 2 , in the first conductive sheet  10 A used in the touch panel  100 , a large number of the first conductive patterns  18 A are arranged in the sensing region  112 , and a plurality of the first terminal wiring patterns  42   a  extend from the first wire connections  40   a  in the terminal wiring region  114 . 
         [0089]    In the example of  FIG. 1 , the first conductive sheet  10 A and the sensing region  112  each have a rectangular shape as viewed from above. In the terminal wiring region  114 , a plurality of first terminals  116   a  are arranged in the longitudinal center in the length direction of the periphery on one long side of the first conductive sheet  10 A. For example, the odd-numbered first wire connections  40   a  are arranged in a straight line in the x direction along one short side of the sensing region  112  (a short side closest to one short side of the first conductive sheet  10 A), and the even-numbered first wire connections  40   a  are arranged in a straight line in the x direction along the other short side of the sensing region  112  (a short side closest to the other short side of the first conductive sheet  10 A). 
         [0090]    For example, each odd-numbered first conductive pattern  18 A is connected to the corresponding odd-numbered first wire connection  40   a , and each even-numbered first conductive pattern  18 A is connected to the corresponding even-numbered first wire connection  40   a . The first terminal wiring patterns  42   a  extend from the odd-numbered and even-numbered first wire connections  40   a  to the center of one long side of the first conductive sheet  10 A, and are each electrically connected to the corresponding first terminal  116   a . Thus, for example, the 1st and 2nd first terminal wiring patterns  42   a  have approximately the same lengths, and similarly the (2n−1)-th and (2n)-th first terminal wiring patterns  42   a  have approximately the same lengths (n=1, 2, 3, . . . ). 
         [0091]    Of course, the first terminals  116   a  may be formed in a corner of the first conductive sheet  10 A or the vicinity thereof. However, in this case, as described above, the longest first terminal wiring pattern  42   a  and the first terminal wiring patterns  42   a  in the vicinity thereof are disadvantageously poor in the rate of transferring signal to the corresponding first conductive patterns  18 A. Thus, in this embodiment, the first terminals  116   a  are formed in the longitudinal center of the one long side of the first conductive sheet  10 A, whereby the local signal transfer rate deterioration is prevented, leading to increase of the response speed. 
         [0092]    As shown in  FIG. 2 , in the second conductive sheet  10 B used in the touch panel  100 , a large number of the above second conductive patterns  18 B are arranged in the sensing region  112 , and a plurality of the second terminal wiring patterns  42   b  composed of the thin metal wires  24  extend from the second wire connections  40   b  in the terminal wiring region  114 . 
         [0093]    As shown in  FIG. 1 , in the terminal wiring region  114 , a plurality of second terminals  116   b  are arranged in the longitudinal center in the length direction of the periphery on one long side of the second conductive sheet  10 B. The second wire connections  40   b  are arranged in a straight line in the y direction along one long side of the sensing region  112  (a long side closest to the one long side of the second conductive sheet  10 B). The second terminal wiring pattern  42   b  extends from each second wire connection  40   b  to the center of the one long side of the second conductive sheet  10 B, and is electrically connected to the corresponding second terminal  116   b . Thus, the second terminal wiring patterns  42   b , connected to each pair of the corresponding second wire connections  40   b  formed on the right and left of the one long side of the sensing region  112 , have approximately the same lengths. Of course, the second terminals  116   b  may be formed in a corner of the second conductive sheet  10 B or the vicinity thereof. However, in this case, the length difference between the longest second terminal wiring pattern  42   b  and the shortest second terminal wiring pattern  42   b  is increased, whereby the longest second terminal wiring pattern  42   b  and the second terminal wiring patterns  42   b  in the vicinity thereof are disadvantageously poor in the rate of transferring signal to the corresponding second conductive patterns  18 B. Thus, in this embodiment, the second terminals  116   b  are formed in the longitudinal center of the one long side of the second conductive sheet  10 B, whereby the local signal transfer rate deterioration is prevented, leading to increase of the response speed. 
         [0094]    The first terminal wiring patterns  42   a  may be arranged in the same manner as the above second terminal wiring patterns  42   b , and the second terminal wiring patterns  42   b  may be arranged in the same manner as the above first terminal wiring patterns  42   a.    
         [0095]    When the first conductive sheet stack  12 A is used in the touch panel  100 , the protective layer  106  is formed on the first conductive sheet  10 A, and the first terminal wiring patterns  42   a  extending from the first conductive patterns  18 A in the first conductive sheet  10 A and the second terminal wiring patterns  42   b  extending from the second conductive patterns  18 B in the second conductive sheet  10 B are connected to a scan control circuit or the like. 
         [0096]    A self or mutual capacitance technology can be preferably used for detecting the touch position. In the self capacitance technology, a voltage signal for the touch position detection is sequentially supplied to the first conductive patterns  18 A, and further a voltage signal for the touch position detection is sequentially supplied to the second conductive patterns  18 B. When a finger comes into contact with or close to the upper surface of the protective layer  106 , the capacitance between the first conductive pattern  18 A and the second conductive pattern  18 B in the touch position and the GND (ground) is increased, whereby signals from this first conductive pattern  18 A and this second conductive pattern  18 B have waveforms different from those of signals from the other conductive patterns. Thus, the touch position is calculated by a control circuit based on the signals transmitted from the first conductive pattern  18 A and the second conductive pattern  18 B. On the other hand, in the mutual capacitance technology, for example, a voltage signal for the touch position detection is sequentially supplied to the first conductive patterns  18 A, and the second conductive patterns  18 B are sequentially subjected to sensing (transmitted signal detection). When a finger comes into contact with or close to the upper surface of the protective layer  106 , the parallel stray capacitance of the finger is added to the parasitic capacitance between the first conductive pattern  18 A and the second conductive pattern  18 B in the touch position, whereby a signal from this second conductive pattern  18 B has a waveform different from those of signals from the other second conductive patterns  18 B. Thus, the touch position is calculated by a control circuit based on the order of the first conductive pattern  18 A supplied with the voltage signal and the signal transmitted from the second conductive pattern  18 B. Even when two fingers come into contact with or close to the upper surface of the protective layer  106  simultaneously, the touch positions can be detected by using the self or mutual capacitance technology. Conventional related detection circuits used in the projected capacitive technologies are described in U.S. Pat. Nos. 4,582,955, 4,686,332, 4,733,222, 5,374,787, 5,543,588, and 7,030,860, U.S. Patent Publication No. 2004/0155871, etc. 
         [0097]    In this embodiment, in the terminal wiring region  114 , the first terminals  116   a  are formed in the longitudinal center of the periphery on the one long side of the first conductive sheet  10 A, and the second terminals  116   b  are formed in the longitudinal center of the periphery on the one long side of the second conductive sheet  10 B. Particularly, in the example of  FIG. 1 , the first terminals  116   a  and the second terminals  116   b  are close to each other and do not overlap with each other, and the first terminal wiring patterns  42   a  and the second terminal wiring patterns  42   b  do not overlap with each other. For example, the first terminal  116   a  may partially overlap with the odd-numbered second terminal wiring pattern  42   b.    
         [0098]    Thus, the first terminals  116   a  and the second terminals  116   b  can be electrically connected to the control circuit by using a cable and two connectors (a connector for the first terminals  116   a  and a connector for the second terminals  116   b ) or one connector (a complex connector for the first terminals  116   a  and the second terminals  116   b ). 
         [0099]    Since the first terminal wiring patterns  42   a  and the second terminal wiring patterns  42   b  do not vertically overlap with each other, a parasitic capacitance is reduced between the first terminal wiring patterns  42   a  and the second terminal wiring patterns  42   b , making it possible to prevent the response speed deterioration. 
         [0100]    Since the first wire connections  40   a  are arranged along the both short sides of the sensing region  112  and the second wire connections  40   b  are arranged along the one long side of the sensing region  112 , the area of the terminal wiring region  114  can be reduced. Therefore, the size of the display panel  110  having the touch panel  100  can be easily reduced, and the display screen  110   a  can be made to seem larger. Also the operability of the touch panel  100  can be improved. 
         [0101]    The area of the terminal wiring region  114  may be further reduced by reducing the distance between the adjacent first terminal wiring patterns  42   a  or the adjacent second terminal wiring patterns  42   b . The distance is preferably 10 μm or more and 50 μm or less in view of preventing migration. 
         [0102]    Alternatively, the area of the terminal wiring region  114  may be reduced by arranging the second terminal wiring pattern  42   b  between the adjacent first terminal wiring patterns  42   a  in the view from above. However, when the pattern is misaligned, the first terminal wiring pattern  42   a  may vertically overlap with the second terminal wiring pattern  42   b , increasing the parasitic capacitance therebetween. This leads to deterioration of the response speed. Thus, in the case of using such an arrangement, the distance between the adjacent first terminal wiring patterns  42   a  is preferably 50 μm or more and 100 μm or less. 
         [0103]    As shown in  FIG. 1 , first alignment marks  118   a  and second alignment marks  118   b  are preferably formed on the corners etc. of the first conductive sheet  10 A and the second conductive sheet  10 B. The first alignment marks  118   a  and the second alignment marks  118   b  are used for positioning the sheets in the process of bonding the sheets. When the first conductive sheet  10 A and the second conductive sheet  10 B are bonded to obtain the first conductive sheet stack  12 A, the first alignment marks  118   a  and the second alignment marks  118   b  form composite alignment marks. The composite alignment marks may be used for positioning the first conductive sheet stack  12 A in the process of attaching to the display panel  110 . 
         [0104]    As shown in  FIG. 6 , when the first conductive sheet  10 A is stacked on the second conductive sheet  10 B to form the first conductive sheet stack  12 A, the second lattices  27  in the strips  20  of the first conductive patterns  18 A and the second lattices  27  in the connections  28  of the second conductive patterns  18 B overlap with each other to form combined patterns  90 . In this case, the connection point of the second lattice  27  in the second conductive pattern  18 B is positioned at the center of the opening of the second lattice  27  in the first conductive pattern  18 A. Therefore, the combined pattern  90  contains a combination of a plurality of the first lattices  26 . Thus, the boundaries between the strips  20  of the first conductive patterns  18 A and the connections  28  of the second conductive patterns  18 B are made less visible to improve the visibility. 
         [0105]    With regard to the sizes of the first conductive pattern  18 A and the second conductive pattern  18 B, the length Le of the electrode portion  30  is at least 2 times, preferably 3 to 10 times, more preferably 4 to 6 times, larger than the width Lc of the strip  20 , in the first direction (the x direction). The length La of the protrusion  22  is smaller than the length Le of the electrode portion  30  in the first direction (the x direction). The width Ld of the protrusion  22  is ½ or less, preferably ⅓ or less, more preferably ⅕ or less, of the length Lg of the electrode portion  30 , in the second direction. 
         [0106]    Thus, the occupation area of the second conductive patterns  18 B is larger than that of the first conductive patterns  18 A. In this case, when the first conductive patterns  18 A have an occupation area A1 and the second conductive patterns  18 B have an occupation area A2, the first conductive sheet stack  12 A satisfies the condition of 1&lt;A2/A1≦20, more preferably satisfies the condition of 1&lt;A2/A1≦10, and further preferably satisfies the condition of 2≦A2/A1≦10. 
         [0107]    In general, the second conductive patterns  18 B, which are located closer to the display device  108 , can act to reduce noise impact of an electromagnetic wave. Thus, a skin current flows in a particular direction to block an electric-field component of the electromagnetic wave, and an eddy current flows in a particular direction to block a magnetic-field component of the electromagnetic wave, whereby the noise impact of the electromagnetic wave can be reduced. In the first conductive sheet stack  12 A, since the occupation area of the second conductive patterns  18 B closer to the display device  108  is larger than that of the first conductive patterns  18 A, the second conductive patterns  18 B can have a low surface resistance of 70 ohm/sq or less. Consequently, the first conductive sheet stack  12 A is advantageous in the reduction of the noise impact of the electromagnetic wave from the display device  108  or the like. 
         [0108]    In this embodiment, the occupation area of the electrode portions  30  containing the first lattices  26  is larger than that of the protrusions  22  containing the first lattices  26 . In this case, when the protrusions  22  have an occupation area a1 and the electrode portions  30  have an occupation area a2, the first conductive sheet stack  12 A satisfies the condition of 1&lt;a2/a1≦20, more preferably satisfies the condition of 1&lt;a2/a1≦10, and further preferably satisfies the condition of 2≦a2/a1≦10. 
         [0109]    Therefore, in the case of using the self capacitance technology for the finger touch position detection, though the electrode portions  30  are positioned at a longer distance from the touch position than the protrusions  22 , the electrode portions  30  can store a large amount of signal charge in the same manner as the protrusions  22 , and the electrode portions  30  can exhibit a detection sensitivity approximately equal to that of the protrusions  22 . Thus, the burden of signal processing can be reduced, and the detection accuracy can be improved. In the case of using the mutual capacitance technology for the finger touch position detection, the electrode portions  30  having the larger occupation area can be used as drive electrodes, the protrusions  22  can be used as receiving electrodes, and the protrusions  22  can exhibit a high receiving sensitivity. Furthermore, even in a case where the first conductive patterns  18 A partially overlap with the second conductive patterns  18 B to form a parasitic capacitance, since the first transparent substrate  14 A has a thickness of 50 μm or more and 350 μm or less, the increase of the parasitic capacitance can be prevented, and the reduction of the detection sensitivity can be prevented. 
         [0110]    The occupation area ratios can be easily achieved by appropriately controlling the above lengths La to Lg and L1 and L2 within the above ranges. 
         [0111]    In this embodiment, the protrusions  22  and the electrode portions  30  do not overlap with each other, and a parasitic capacitance is hardly formed between the protrusions  22  and the electrode portions  30 . Meanwhile, the second lattices  27  in the first conductive patterns  18 A overlap with the second lattices  27  in the second conductive patterns  18 B to form a parasitic capacitance therebetween. Thus, only several points of the second lattices  27 , which are larger than the first lattices  26 , overlap with each other. Therefore, the thin metal wires  24  overlap with each other only at the several points, and the first transparent substrate  14 A has a thickness of 50 μm or more and 350 μm or less, so that only a small parasitic capacitance is formed between the first conductive patterns  18 A and the second conductive patterns  18 B. In addition, when the thickness of the first transparent substrate  14 A is within the above range, a desired visible light transmittance can be obtained, and the first transparent substrate  14 A can be easily handled. 
         [0112]    Consequently, even in the case of using the patterns of the thin metal wires  24  in the electrodes, the thin metal wires  24  are less visible, and the first conductive sheet stack  12 A can have a high transparency, an improved S/N ratio of detection signal, an improved detection sensitivity, and an improved detection accuracy. 
         [0113]    The sizes of the protrusion  22  and the electrode portion  30  are not particularly limited as long as they can satisfactorily detect the touch position of the human finger or input pen. 
         [0114]    Though the first lattice  26  and the second lattice  27  each have a rhombic shape in the above example, they may have another triangle or polygonal shape. The triangle shape can be easily formed e.g. by disposing a straight thin metal wire on a diagonal line of the rhombus of the first lattice  26  or the second lattice  27 . Each side of the first lattice  26  and the second lattice  27  may have a straight line shape, a curved shape, or an arc shape. In the case of using arc-shaped sides, for example, two opposite sides may have an outwardly protruding arc shape, and the other two opposite sides may have an inwardly protruding arc shape. Alternatively, each side may have a wavy shape containing outwardly protruding arcs and inwardly protruding arcs arranged continuously. Of course, each side may have a sine curve shape. 
         [0115]    Also, the sizes of the first lattices  26  (including the side lengths and the diagonal line lengths), the number of the first lattices  26  in the protrusion  22 , and the number of the first lattices  26  in the electrode portion  30  may be appropriately selected depending on the size and the resolution (the line number) of the touch panel  100 . 
         [0116]    A conductive sheet stack according to a second embodiment (hereinafter referred to as the second conductive sheet stack  12 B) will be described below with reference to  FIGS. 7 to 9 . 
         [0117]    The second conductive sheet stack  12 B has approximately the same structure as the first conductive sheet stack  12 A, but is different in that the patterns of the strip  20  in the first conductive pattern  18 A and the connection  28  in the second conductive pattern  18 B are as follows. 
         [0118]    As shown in  FIG. 8 , the connection  28  contains two second lattices  27  arranged in the second direction (the y direction). In association with the connection  28 , as shown in  FIG. 7 , the part of the second lattices  27  in the strip  20  of the first conductive pattern  18 A is larger than that in the first conductive sheet stack  12 A. As a result, the occupation area ratio (A2/A1) between the first conductive patterns  18 A and the second conductive patterns  18 B is larger in the second conductive sheet stack  12 B than in the first conductive sheet stack  12 A. Therefore, the second conductive sheet stack  12 B can more effectively act to reduce the noise impact of the electromagnetic wave from the display device  108  or the like. 
         [0119]    As shown in  FIG. 9 , when the first conductive sheet  10 A is stacked on the second conductive sheet  10 B to form the second conductive sheet stack  12 B, the second lattices  27  in the strips  20  of the first conductive patterns  18 A and the second lattices  27  in the connections  28  of the second conductive patterns  18 B overlap with each other to form combined patterns  90 . The combined pattern  90  contains a combination of a plurality of the first lattices  26 . Thus, the boundaries between the strips  20  of the first conductive patterns  18 A and the connections  28  of the second conductive patterns  18 B are made less visible to improve the visibility. 
         [0120]    A conductive sheet stack according to a third embodiment (hereinafter referred to as the third conductive sheet stack  12 C) will be described below with reference to  FIGS. 10 to 12 . 
         [0121]    The third conductive sheet stack  12 C has approximately the same structure as the first conductive sheet stack  12 A, but is different in that the patterns of the first conductive part  16 A and the second conductive part  16 B are as follows. 
         [0122]    As shown in  FIG. 10 , the first conductive part  16 A has first auxiliary patterns  32 A between the first conductive patterns  18 A. The first auxiliary patterns  32 A are not connected to the first conductive patterns  18 A. In the first auxiliary patterns  32 A, a chain pattern  34  (containing a plurality of the first lattices  26 ), a partial pattern (corresponding to a part of the first lattice  26 , such as an L-shaped pattern, a straight-line pattern, or a T-shaped pattern), and the like are arranged, so that spaces  36  between the second conductive patterns  18 B shown in  FIG. 11  (other than portions overlapping with the strips  20  and the protrusions  22  of the first conductive patterns  18 A) are filled with the arranged patterns. 
         [0123]    As shown in  FIG. 11 , the second conductive part  16 B has second auxiliary patterns  32 B between the second conductive patterns  18 B. The second auxiliary patterns  32 B are not connected to the second conductive patterns  18 B. In the second auxiliary patterns  32 B, a wavy pattern  38  (corresponding to a half of a chain pattern containing a plurality of the first lattices  26 ), a partial pattern (corresponding to a part of the first lattice  26 , such as an L-shaped pattern or a straight-line pattern), and the like are arranged, so that spaces  40  between the first conductive patterns  18 A shown in  FIG. 10  (other than portions overlapping with the connections  28  and the electrode portions  30  of the second conductive patterns  18 B) are filled with the arranged patterns. 
         [0124]    As shown in  FIG. 12 , when the first conductive sheet  10 A is stacked on the second conductive sheet  10 B to form the third conductive sheet stack  12 C, the second lattices  27  in the first conductive patterns  18 A and the second lattices  27  in the second conductive patterns  18 B overlap with each other to form first combined patterns  90 A. In this case, the connection point of the second lattice  27  in the second conductive pattern  18 B is positioned at the center of the opening of the second lattice  27  in the first conductive pattern  18 A. Therefore, the first combined pattern  90 A contains a combination of a plurality of the first lattices  26 . 
         [0125]    Furthermore, when the first conductive part  16 A is stacked on the second conductive part  16 B, the first auxiliary patterns  32 A and the second auxiliary patterns  32 B overlap with each other to form second combined patterns  90 B. In this case, the spaces  36  between the second conductive patterns  18 B shown in  FIG. 11  (other than the portions overlapping with the strips  20  and the protrusions  22 ) are filled with the first auxiliary patterns  32 A, and the first auxiliary patterns  32 A are compensated by the second auxiliary patterns  32 B. Therefore, also the second combined pattern  90 B contains a combination of a plurality of the first lattices  26 . 
         [0126]    Consequently, as shown in  FIG. 12 , the entire surface is covered with a plurality of the first lattices  26 , and the boundaries between the protrusions  22  and the electrode portions  30  can hardly be found. Then, the improved visibility can be achieved. 
         [0127]    A conductive sheet stack according to a fourth embodiment (hereinafter referred to as the fourth conductive sheet stack  12 D) will be described below with reference to  FIGS. 13 to 15 . 
         [0128]    The fourth conductive sheet stack  12 D has approximately the same structure as the first conductive sheet stack  12 A, but is different in that the patterns of the first conductive part  16 A and the second conductive part  16 B are as follows. 
         [0129]    As shown in  FIGS. 13 and 14A , in the first conductive patterns  18 A, the ends of the protrusions  22  extending from one strip  20  toward the adjacent strip  20  and the ends of the protrusions  22  extending from the adjacent strip  20  toward the one strip  20  face each other. Thus, in the first conductive patterns  18 A, the length La of the protrusion  22  extending from either side of the strip  20  is smaller than ½ of the length Lb between the adjacent strips  20  in the first direction (the x direction). For example, the length La is at least Lb/8 but less than Lb/2, preferably at least Lb/4 but less than Lb/2. 
         [0130]    Specifically, the first conductive pattern  18 A is mainly composed of a plurality of the first lattices  26 , and a first connection  28   a  in the strip  20 , which does not intersect with the protrusion  22 , contains a plurality of the second lattices  27 . The first connection  28   a  overlaps with the second connection  28   b  in the second conductive pattern  18 B to be hereinafter described. The second lattices  27  in the first connection  28   a  are different in size from the second lattices  27  in the first conductive sheet stack  12 A to the third conductive sheet stack  12 C. More specifically, the first connection  28   a  contains two types of second lattices  27   a  and  27   b . The size of one second lattice  27   a  corresponds to the total size of r first lattices  26  (in which r is an integer larger than 1) arranged in a first oblique direction (an s direction). The size of the other second lattice  27   b  corresponds to the total size of p×q first lattices  26  (in which p and q are each an integer larger than 1). Thus, the other second lattice  27   b  is provided such that p first lattices  26  are arranged in the first oblique direction and q first lattices  26  are arranged in a second oblique direction (a t direction). In the example of  FIG. 14A , r is 7, and the size of the one second lattice  27   a  corresponds to the total size of seven first lattices  26  arranged in the first oblique direction. Furthermore, p is 3 in the first oblique direction, q is 5 in the second oblique direction, and the size of the other second lattice  27   b  corresponds to the total size of fifteen first lattices  26 . 
         [0131]    The first conductive part  16 A has first auxiliary patterns  32 A along the strips  20  and the protrusions  22  in the first conductive patterns  18 A. The first auxiliary patterns  32 A are not connected to the first conductive patterns  18 A. In the first auxiliary patterns  32 A, a partial pattern (corresponding to a part of the first lattice  26 , such as an L-shaped pattern) is arranged, so that spaces  36  between the second conductive patterns  18 B shown in  FIG. 14B  (other than portions overlapping with the strips  20  and the protrusions  22  of the first conductive patterns  18 A) are filled with the arranged patterns. 
         [0132]    As shown in  FIG. 14B , in the second conductive part  16 B, the second conductive pattern  18 B contains a plurality of the electrode portions  30 , which are connected with each other by the second connections  28   b  in the first direction (the x direction). The length Le of the electrode portion  30  is at least 2 times longer than the length Lf of the second connection  28   b  in the first direction (the x direction). 
         [0133]    The second conductive pattern  18 B contains a combination of a plurality of the first lattices  26  and a plurality of the second lattices  27  similarly to the first conductive pattern  18 A. Also in this example, at least the electrode portion  30  contains a plurality of the first lattices  26 , and the second connection  28   b  contains a plurality of the second lattices  27 . The second connection  28   b  contains two types of the second lattices  27   a  and  27   b  similarly to the first connection  28   a . The size of one second lattice  27   a  corresponds to the total size of r first lattices  26  (in which r is an integer larger than 1) arranged in the second oblique direction (the t direction). The size of the other second lattice  27   b  corresponds to the total size of p×q first lattices  26  (in which p and q are each an integer larger than 1). Thus, the other second lattice  27   b  is provided such that p first lattices  26  are arranged in the second oblique direction and q first lattices  26  are arranged in the first oblique direction (the s direction). In the example of  FIG. 14B , r is 7, and the size of the one second lattice  27   a  corresponds to the total size of seven first lattices  26  arranged in the second oblique direction. Furthermore, p is 3 in the second oblique direction, q is 5 in the first oblique direction, and the size of the other second lattice  27   b  corresponds to the total size of fifteen first lattices  26 . 
         [0134]    When the first conductive part  16 A is stacked on the second conductive part  16 B, the second lattices  27  in the first conductive patterns  18 A overlap with the second lattices  27  in the second conductive patterns  18 B. In this case, the one second lattice  27   a  in the first connection  28   a  intersects with the one second lattice  27   a  in the second connection  28   b , and the other second lattice  27   b  in the first connection  28   a  intersects with the other second lattice  27   b  in the second connection  28   b.    
         [0135]    The second conductive part  16 B further has second auxiliary patterns  32 B along the electrode portions  30  in the second conductive patterns  18 B. The second auxiliary patterns  32 B are not connected to the second conductive patterns  18 B. In the second auxiliary patterns  32 B, a pattern of the first lattice  26 , a wavy pattern (containing a plurality of L-shaped patterns corresponding to a part of the first lattice  26 ), a partial pattern (corresponding to a part of the first lattice  26 , such as a cross-shaped pattern or a straight-line pattern), and the like are arranged, so that spaces  40  between the first conductive patterns  18 A shown in  FIG. 14A  (other than portions overlapping with the second connections  28   b  and the electrode portions  30  of the second conductive patterns  18 B) are filled with the arranged patterns. 
         [0136]    As shown in  FIG. 15 , when the first conductive sheet  10 A is stacked on the second conductive sheet  10 B to form the fourth conductive sheet stack  12 D, the second lattices  27  in the first connections  28   a  of the first conductive patterns  18 A and the second lattices  27  in the second connections  28   b  of the second conductive patterns  18 B overlap with each other to form first combined patterns  90 A. In this case, the one second lattice  27   a  in the first connection  28   a  intersects with the one second lattice  27   a  in the second connection  28   b , and the other second lattice  27   b  in the first connection  28   a  intersects with the other second lattice  27   b  in the second connection  28   b . Therefore, the first combined pattern  90 A contains a combination of a plurality of the first lattices  26 . 
         [0137]    Furthermore, when the first conductive part  16 A is stacked on the second conductive part  16 B, the first auxiliary patterns  32 A and the second auxiliary patterns  32 B overlap with each other to form second combined patterns  90 B. In this case, the spaces  36  between the second conductive patterns  18 B shown in  FIG. 14B  (other than the portions overlapping with the strips  20  and the protrusions  22 ) are filled with the first auxiliary patterns  32 A, and the first auxiliary patterns  32 A are compensated by the second auxiliary patterns  32 B. Therefore, also the second combined pattern  90 B contains a combination of a plurality of the first lattices  26 . 
         [0138]    Consequently, as shown in  FIG. 15 , the entire surface is covered with a plurality of the first lattices  26 , and the boundaries between the protrusions  22  and the electrode portions  30  can hardly be found. Then, the improved visibility can be achieved. 
         [0139]    Though the first conductive sheet stack  12 A to the fourth conductive sheet stack  12 D are used in the projected capacitive touch panel  100  in the above examples, they may be used in a surface capacitive touch panel or a resistive touch panel. 
         [0140]    All of the first conductive sheet stack  12 A to the fourth conductive sheet stack  12 D are hereinafter referred to as the conductive sheet stack  12 . 
         [0141]    In the above conductive sheet stack  12 , as shown in  FIG. 3A , the first conductive part  16 A is formed on the one main surface of the first transparent substrate  14 A, the second conductive part  16 B is formed on the one main surface of the second transparent substrate  14 B, and they are stacked. Alternatively, as shown in  FIG. 3B , the first conductive part  16 A may be formed on the one main surface of the first transparent substrate  14 A, and the second conductive part  16 B may be formed on the other main surface of the first transparent substrate  14 A. In this case, the second transparent substrate  14 B is not used, the first transparent substrate  14 A is stacked on the second conductive part  16 B, and the first conductive part  16 A is stacked on the first transparent substrate  14 A. In addition, another layer may be disposed between the first conductive sheet  10 A and the second conductive sheet  10 B. The first conductive part  16 A and the second conductive part  16 B may be arranged facing each other as long as they are insulated. 
         [0142]    The first conductive part  16 A and the second conductive part  16 B may be formed as follows. For example, a photosensitive material having the first transparent substrate  14 A or the second transparent substrate  14 B and thereon a photosensitive silver halide-containing emulsion layer may be exposed and developed, whereby metallic silver portions and light-transmitting portions may be formed in the exposed areas and the unexposed areas respectively to obtain the first conductive part  16 A and the second conductive part  16 B. The metallic silver portions may be subjected to a physical development treatment and/or a plating treatment to deposit a conductive metal thereon. 
         [0143]    As shown in  FIG. 3B , the first conductive part  16 A may be formed on the one main surface of the first transparent substrate  14 A, and the second conductive part  16 B may be formed on the other main surface thereof. In this case, when the one main surface is exposed and then the other main surface is exposed in the usual method, the desired patterns cannot be obtained on the first conductive part  16 A and the second conductive part  16 B occasionally. In particular, it is difficult to uniformly form the protrusions  22  extending from the strips  20  and the like as shown in  FIGS. 4 ,  7 , etc. 
         [0144]    Therefore, the following production method can be preferably used. 
         [0145]    Thus, the first conductive part  16 A on the one main surface and the second conductive part  16 B on the other main surface can be formed by subjecting the photosensitive silver halide emulsion layers on both sides of the first transparent substrate  14 A to one-shot exposure. 
         [0146]    A specific example of the production method will be described below with reference to  FIGS. 16 to 18 . 
         [0147]    First, in step S 1  of  FIG. 16 , a long photosensitive material  140  is prepared. As shown in  FIG. 17A , the photosensitive material  140  has the first transparent substrate  14 A, a photosensitive silver halide emulsion layer formed on one main surface of the first transparent substrate  14 A (hereinafter referred to as the first photosensitive layer  142   a ), and a photosensitive silver halide emulsion layer formed on the other main surface of the first transparent substrate  14 A (hereinafter referred to as the second photosensitive layer  142   b ). 
         [0148]    In step S 2  of  FIG. 16 , the photosensitive material  140  is exposed. In this exposure step, a simultaneous both-side exposure, which includes a first exposure treatment for irradiating the first photosensitive layer  142   a  on the first transparent substrate  14 A with a light in a first exposure pattern and a second exposure treatment for irradiating the second photosensitive layer  142   b  on the first transparent substrate  14 A with a light in a second exposure pattern, is carried out. In the example of  FIG. 17B , the first photosensitive layer  142   a  is irradiated through a first photomask  146   a  with a first light  144   a  (a parallel light), and the second photosensitive layer  142   b  is irradiated through a second photomask  146   b  with a second light  144   b  (a parallel light), while conveying the long photosensitive material  140  in one direction. The first light  144   a  is arranged such that a light from a first light source  148   a  is converted to the parallel light by an intermediate first collimator lens  150   a , and the second light  144   b  is arranged such that a light from a second light source  148   b  is converted to the parallel light by an intermediate second collimator lens  150   b . Though two light sources (the first light source  148   a  and the second light source  148   b ) are used in the example of  FIG. 17B , only one light source may be used. In this case, a light from the one light source may be divided by an optical system into the first light  144   a  and the second light  144   b  for exposing the first photosensitive layer  142   a  and the second photosensitive layer  142   b.    
         [0149]    In step S 3  of  FIG. 16 , the exposed photosensitive material  140  is developed to prepare e.g. the conductive sheet stack  12  shown in  FIG. 3B . The conductive sheet stack  12  has the first transparent substrate  14 A, the first conductive part  16 A formed in the first exposure pattern on the one main surface of the first transparent substrate  14 A, and the second conductive part  16 B formed in the second exposure pattern on the other main surface of the first transparent substrate  14 A. Preferred exposure time and development time for the first photosensitive layer  142   a  and the second photosensitive layer  142   b  depend on the types of the first light source  148   a , the second light source  148   b , and a developer, etc., and cannot be categorically determined. The exposure time and development time may be selected in view of achieving a development ratio of 80% to 100%. 
         [0150]    As shown in  FIG. 18 , in the first exposure treatment in the production method of this embodiment, for example, the first photomask  146   a  is placed in close contact with the first photosensitive layer  142   a , the first light source  148   a  is arranged facing the first photomask  146   a , and the first light  144   a  is emitted from the first light source  148   a  toward the first photomask  146   a , so that the first photosensitive layer  142   a  is exposed. The first photomask  146   a  has a glass substrate composed of a transparent soda glass and a mask pattern (a first exposure pattern  152   a ) formed thereon. Therefore, in the first exposure treatment, areas in the first photosensitive layer  142   a , corresponding to the first exposure pattern  152   a  in the first photomask  146   a , are exposed. A space of approximately 2 to 10 μm may be formed between the first photosensitive layer  142   a  and the first photomask  146   a.    
         [0151]    Similarly, in the second exposure treatment, for example, the second photomask  146   b  is placed in close contact with the second photosensitive layer  142   b , the second light source  148   b  is arranged facing the second photomask  146   b , and the second light  144   b  is emitted from the second light source  148   b  toward the second photomask  146   b , so that the second photosensitive layer  142   b  is exposed. The second photomask  146   b , as well as the first photomask  146   a , has a glass substrate composed of a transparent soda glass and a mask pattern (a second exposure pattern  152   b ) formed thereon. Therefore, in the second exposure treatment, areas in the second photosensitive layer  142   b , corresponding to the second exposure pattern  152   b  in the second photomask  146   b , are exposed. In this case, a space of approximately 2 to 10 μm may be formed between the second photosensitive layer  142   b  and the second photomask  146   b.    
         [0152]    In the first and second exposure treatments, the emission of the first light  144   a  from the first light source  148   a  and the emission of the second light  144   b  from the second light source  148   b  may be carried out simultaneously or independently. When the emissions are simultaneously carried out, the first photosensitive layer  142   a  and the second photosensitive layer  142   b  can be simultaneously exposed in one exposure process to reduce the treatment time. 
         [0153]    In a case where both of the first photosensitive layer  142   a  and the second photosensitive layer  142   b  are not spectrally sensitized, a light incident on one side may affect the image formation on the other side (the back side) in the both-side exposure of the photosensitive material  140 . 
         [0154]    Thus, the first light  144   a  from the first light source  148   a  reaches the first photosensitive layer  142   a  and is scattered by silver halide particles in the first photosensitive layer  142   a , and a part of the scattered light is transmitted through the first transparent substrate  14 A and reaches the second photosensitive layer  142   b . Then, a large area of the boundary between the second photosensitive layer  142   b  and the first transparent substrate  14 A is exposed to form a latent image. As a result, the second photosensitive layer  142   b  is exposed to the second light  144   b  from the second light source  148   b  and the first light  144   a  from the first light source  148   a . When the second photosensitive layer  142   b  is developed to prepare the conductive sheet stack  12 , the conductive pattern corresponding to the second exposure pattern  152   b  (the second conductive part  16 B) is formed, and additionally a thin conductive layer is formed due to the first light  144   a  from the first light source  148   a  between the conductive pattern, so that the desired pattern (corresponding to the second exposure pattern  152   b ) cannot be obtained. This is true also for the first photosensitive layer  142   a.    
         [0155]    As a result of intense research in view of solving this problem, it has been found that when the thicknesses and the applied silver amounts of the first photosensitive layer  142   a  and the second photosensitive layer  142   b  are selected within particular ranges, the incident light can be absorbed by the silver halide to suppress the light transmission to the back side. In this embodiment, the thicknesses of the first photosensitive layer  142   a  and the second photosensitive layer  142   b  may be 1 μm or more and 4 μm or less. The upper limit is preferably 2.5 μm. The applied silver amounts of the first photosensitive layer  142   a  and the second photosensitive layer  142   b  may be 5 to 20 g/m 2 . 
         [0156]    In the above described contact both-side exposure technology, the exposure may be inhibited by dust or the like attached to the film surface to generate an image defect. It is known that the dust attachment can be prevented by applying a conductive substance such as a metal oxide or a conductive polymer to the film. However, the metal oxide or the like remains in the processed product, deteriorating the transparency of the final product, and the conductive polymer is disadvantageous in storage stability, etc. As a result of intense research, it has been found that a silver halide layer with reduced binder content exhibits a satisfactory conductivity for static charge prevention. Thus, the volume ratio of silver/binder is controlled in the first photosensitive layer  142   a  and the second photosensitive layer  142   b . The silver/binder volume ratios of the first photosensitive layer  142   a  and the second photosensitive layer  142   b  are 1/1 or more, preferably 2/1 or more. 
         [0157]    In a case where the thicknesses, the applied silver amounts, and the silver/binder volume ratios of the first photosensitive layer  142   a  and the second photosensitive layer  142   b  are selected as described above, the first light  144   a  emitted from the first light source  148   a  to the first photosensitive layer  142   a  does not reach the second photosensitive layer  142   b  as shown in  FIG. 18 . Similarly, the second light  144   b  emitted from the second light source  148   b  to the second photosensitive layer  142   b  does not reach the first photosensitive layer  142   a . As a result, in the following development for producing the conductive sheet stack  12 , as shown in  FIG. 3B , only the conductive pattern corresponding to the first exposure pattern  152   a  (the pattern of the first conductive part  16 A) is formed on the one main surface of the first transparent substrate  14 A, and only the conductive pattern corresponding to the second exposure pattern  152   b  (the pattern of the second conductive part  16 B) is formed on the other main surface of the first transparent substrate  14 A, so that the desired patterns can be obtained. 
         [0158]    In the production method using the above one-shot both-side exposure, the first photosensitive layer  142   a  and the second photosensitive layer  142   b  can have both of the satisfactory conductivity and both-side exposure suitability, and the same or different patterns can be formed on the surfaces of the one first transparent substrate  14 A by the exposure, whereby the electrodes of the touch panel  100  can be easily formed, and the touch panel  100  can be made thinner (smaller). 
         [0159]    In the above production method, the first conductive part  16 A and the second conductive part  16 B are formed using the photosensitive silver halide emulsion layers. The other production methods include the following methods. 
         [0160]    A photosensitive layer to be plated containing a pre-plating treatment material may be formed on the first transparent substrate  14 A and the second transparent substrate  14 B. The resultant layer may be exposed and developed, and may be subjected to a plating treatment, whereby metal portions and light-transmitting portions may be formed in the exposed areas and the unexposed areas respectively to form the first conductive part  16 A and the second conductive part  16 B. The metal portions may be further subjected to a physical development treatment and/or a plating treatment to deposit a conductive metal thereon. 
         [0161]    The following two processes can be preferably used in the method using the pre-plating treatment material. The processes are disclosed more specifically in Japanese Laid-Open Patent Publication Nos. 2003-213437, 2006-64923, 2006-58797, and 2006-135271, etc. 
         [0162]    (a) A process comprising applying, to a transparent substrate, a plating base layer having a functional group interactable with a plating catalyst or a precursor thereof, exposing and developing the layer, and subjecting the developed layer to a plating treatment to form a metal portion on the plating base material. 
         [0163]    (b) A process comprising applying, to a transparent substrate, an underlayer containing a polymer and a metal oxide and a plating base layer having a functional group interactable with a plating catalyst or a precursor thereof in this order, exposing and developing the layers, and subjecting the developed layers to a plating treatment to form a metal portion on the plating base material. 
         [0164]    Alternatively, a photoresist film on a copper foil disposed on the first transparent substrate  14 A or the second transparent substrate  14 B may be exposed and developed to form a resist pattern, and the copper foil exposed from the resist pattern may be etched to form the first conductive part  16 A or the second conductive part  16 B. 
         [0165]    A paste containing fine metal particles may be printed on the first transparent substrate  14 A or the second transparent substrate  14 B, and the printed paste may be plated with a metal to form the first conductive part  16 A or the second conductive part  16 B. 
         [0166]    The first conductive part  16 A or the second conductive part  16 B may be printed on the first transparent substrate  14 A or the second transparent substrate  14 B by using a screen or gravure printing plate. 
         [0167]    The first conductive part  16 A or the second conductive part  16 B may be formed on the first transparent substrate  14 A or the second transparent substrate  14 B by using an inkjet method. 
         [0168]    A particularly preferred method, which contains using a photographic photosensitive silver halide material for producing the first conductive sheet  10 A or the second conductive sheet  10 B of this embodiment, will be mainly described below. 
         [0169]    The method for producing the first conductive sheet  10 A or the second conductive sheet  10 B of this embodiment includes the following three processes different in the photosensitive materials and development treatments. 
         [0170]    (1) A process comprising subjecting a photosensitive black-and-white silver halide material free of physical development nuclei to a chemical or thermal development to form the metallic silver portions on the photosensitive material. 
         [0171]    (2) A process comprising subjecting a photosensitive black-and-white silver halide material having a silver halide emulsion layer containing physical development nuclei to a solution physical development to form the metallic silver portions on the photosensitive material. 
         [0172]    (3) A process comprising subjecting a stack of a photosensitive black-and-white silver halide material free of physical development nuclei and an image-receiving sheet having a non-photosensitive layer containing physical development nuclei to a diffusion transfer development to form the metallic silver portions on the non-photosensitive image-receiving sheet. 
         [0173]    In the process of (1), an integral black-and-white development procedure is used to form a transmittable conductive film such as a light-transmitting conductive film on the photosensitive material. The resulting silver is a chemically or thermally developed silver in the state of a high-specific surface area filament, and thereby shows a high activity in the following plating or physical development treatment. 
         [0174]    In the process of (2), the silver halide particles are melted around and deposited on the physical development nuclei in the exposed areas to form a transmittable conductive film such as a light-transmitting conductive film on the photosensitive material. Also in this process, an integral black-and-white development procedure is used. Though high activity can be achieved since the silver halide is deposited on the physical development nuclei in the development, the developed silver has a spherical shape with small specific surface. 
         [0175]    In the process of (3), the silver halide particles are melted in the unexposed areas, and are diffused and deposited on the development nuclei of the image-receiving sheet, to form a transmittable conductive film such as a light-transmitting conductive film on the sheet. In this process, a so-called separate-type procedure is used, the image-receiving sheet being peeled off from the photosensitive material. 
         [0176]    A negative or reversal development treatment can be used in the processes. In the diffusion transfer development, the negative development treatment can be carried out using an auto-positive photosensitive material. 
         [0177]    The chemical development, thermal development, solution physical development, and diffusion transfer development have the meanings generally known in the art, and are explained in common photographic chemistry texts such as Shin-ichi Kikuchi, “ Shashin Kagaku  ( Photographic Chemistry )”, Kyoritsu Shuppan Co., Ltd., 1955 and C. E. K. Mees, “ The Theory of Photographic Processes,  4th ed.”, Mcmillan, 1977. A liquid treatment is generally used in the present invention, and also a thermal development treatment can be utilized. For example, techniques described in Japanese Laid-Open Patent Publication Nos. 2004-184693, 2004-334077, and 2005-010752 and Japanese Patent Application Nos. 2004-244080 and 2004-085655 can be used in the present invention. 
         [0178]    The structure of each layer in the first conductive sheet  10 A and the second conductive sheet  10 B of this embodiment will be described in detail below. 
       [First Transparent Substrate  14 A and Second Transparent Substrate  14 B] 
       [0179]    The first transparent substrate  14 A and the second transparent substrate  14 B may be a plastic film, a plastic plate, a glass plate, etc. 
         [0180]    Examples of materials for the plastic film and the plastic plate include polyesters such as polyethylene terephthalates (PET) and polyethylene naphthalates (PEN); polyolefins such as polyethylenes (PE), polypropylenes (PP), polystyrenes, and EVA; vinyl resins; polycarbonates (PC); polyamides; polyimides; acrylic resins; and triacetyl celluloses (TAC). 
         [0181]    The first transparent substrate  14 A and the second transparent substrate  14 B are preferably a film or plate of a plastic having a melting point of about 290° C. or lower, such as PET (melting point 258° C.), PEN (melting point 269° C.), PE (melting point 135° C.), PP (melting point 163° C.), polystyrene (melting point 230° C.), polyvinyl chloride (melting point 180° C.), polyvinylidene chloride (melting point 212° C.), or TAC (melting point 290° C.). The PET is particularly preferred from the viewpoints of light transmittance, workability, etc. The conductive film such as the first conductive sheet  10 A or the second conductive sheet  10 B used in the conductive sheet stack  12  is required to be transparent, and therefore the first transparent substrate  14 A and the second transparent substrate  14 B preferably have a high transparency. 
       [Silver Salt Emulsion Layer] 
       [0182]    The silver salt emulsion layer for forming the conductive portions of the first conductive sheet  10 A and the second conductive sheet  10 B (including the first conductive patterns  18 A, the first auxiliary patterns  32 A, the second conductive patterns  18 B, and the second auxiliary patterns  32 B) contains a silver salt and a binder and may further contain a solvent and an additive such as a dye. 
         [0183]    The silver salt used in this embodiment may be an inorganic silver salt such as a silver halide or an organic silver salt such as silver acetate. In this embodiment, the silver halide is preferred because of its excellent light sensing property. 
         [0184]    The applied silver amount (the amount of the applied silver salt in the silver density) of the silver salt emulsion layer is preferably 1 to 30 g/m 2 , more preferably 1 to 25 g/m 2 , further preferably 5 to 20 g/m 2 . When the applied silver amount is within this range, the resultant conductive sheet stack  12  can exhibit a desired surface resistance. 
         [0185]    Examples of the binders used in this embodiment include gelatins, polyvinyl alcohols (PVA), polyvinyl pyrolidones (PVP), polysaccharides such as starches, celluloses and derivatives thereof, polyethylene oxides, polyvinylamines, chitosans, polylysines, polyacrylic acids, polyalginic acids, polyhyaluronic acids, and carboxycelluloses. The binders show a neutral, anionic, or cationic property depending on the ionicity of a functional group. 
         [0186]    In this embodiment, the amount of the binder in the silver salt emulsion layer is not particularly limited, and may be appropriately selected to obtain sufficient dispersion and adhesion properties. The volume ratio of silver/binder in the silver salt emulsion layer is preferably ¼ or more, more preferably ½ or more. The silver/binder volume ratio is preferably 100/1 or less, more preferably 50/1 or less. Particularly, the silver/binder volume ratio is further preferably 1/1 to 4/1, most preferably 1/1 to 3/1. As long as the silver/binder volume ratio of the silver salt emulsion layer falls within this range, the resistance variation can be reduced even under various applied silver amount, whereby the conductive sheet stack can be produced with a uniform surface resistance. The silver/binder volume ratio can be obtained by converting the silver halide/binder weight ratio of the material to the silver/binder weight ratio, and by further converting the silver/binder weight ratio to the silver/binder volume ratio. 
       &lt;Solvent&gt; 
       [0187]    The solvent used for forming the silver salt emulsion layer is not particularly limited, and examples thereof include water, organic solvents (e.g. alcohols such as methanol, ketones such as acetone, amides such as formamide, sulfoxides such as dimethyl sulfoxide, esters such as ethyl acetate, ethers), ionic liquids, and mixtures thereof. 
         [0188]    In this embodiment, the ratio of the solvent to the total of the silver salt, the binder, and the like in the silver salt emulsion layer is 30% to 90% by mass, preferably 50% to 80% by mass. 
       &lt;Other Additives&gt; 
       [0189]    The additives used in this embodiment are not particularly limited, and may be preferably selected from known additives. 
       [Other Layers] 
       [0190]    A protective layer (not shown) may be formed on the silver salt emulsion layer. The protective layer used in this embodiment contains a binder such as a gelatin or a high-molecular polymer, and is disposed on the photosensitive silver salt emulsion layer to improve the scratch prevention or mechanical property. The thickness of the protective layer is preferably 0.5 μm or less. The method of applying or forming the protective layer is not particularly limited, and may be appropriately selected from known applying or forming methods. In addition, an undercoat layer or the like may be formed below the silver salt emulsion layer. 
         [0191]    The steps for producing the first conductive sheet  10 A and the second conductive sheet  10 B will be described below. 
       [Exposure] 
       [0192]    In this embodiment, the first conductive part  16 A and the second conductive part  16 B may be formed in a printing process, and may be formed by exposure and development treatments, etc. in another process. Thus, a photosensitive material having the first transparent substrate  14 A or the second transparent substrate  14 B and thereon the silver salt-containing layer or a photosensitive material coated with a photopolymer for photolithography is subjected to the exposure treatment. An electromagnetic wave may be used in the exposure. For example, the electromagnetic wave may be a light such as a visible light or an ultraviolet light, or a radiation ray such as an X-ray. The exposure may be carried out using a light source having a wavelength distribution or a specific wavelength. 
       [Development Treatment] 
       [0193]    In this embodiment, the emulsion layer is subjected to the development treatment after the exposure. Common development treatment technologies for photographic silver salt films, photographic papers, print engraving films, emulsion masks for photomasking, and the like may be used in the present invention. The developer used in the development treatment is not particularly limited, and may be a PQ developer, an MQ developer, an MAA developer, etc. Examples of commercially available developers usable in the present invention include CN-16, CR-56, CP45X, FD-3, and PAPITOL available from FUJIFILM Corporation, C-41, E-6, RA-4, D-19, and D-72 available from Eastman Kodak Company, and developers contained in kits thereof. The developer may be a lith developer. 
         [0194]    In the present invention, the development process may include a fixation treatment for removing the silver salt in the unexposed areas to stabilize the material. Fixation treatment technologies for photographic silver salt films, photographic papers, print engraving films, emulsion masks for photomasking, and the like may be used in the present invention. 
         [0195]    In the fixation treatment, the fixation temperature is preferably about 20° C. to 50° C., more preferably 25° C. to 45° C. The fixation time is preferably 5 seconds to 1 minute, more preferably 7 to 50 seconds. The amount of the fixer used is preferably 600 ml/m 2  or less, more preferably 500 ml/m 2  or less, particularly preferably 300 ml/m 2  or less, per 1 m 2  of the photosensitive material treated. 
         [0196]    The developed and fixed photosensitive material is preferably subjected to a water washing treatment or a stabilization treatment. The amount of water used in the water washing or stabilization treatment is generally 20 L or less, and may be 3 L or less, per 1 m 2  of the photosensitive material. The water amount may be 0, and thus the photosensitive material may be washed with storage water. 
         [0197]    The ratio of the metallic silver contained in the exposed areas after the development to the silver contained in the areas before the exposure is preferably 50% or more, more preferably 80% or more by mass. When the ratio is 50% or more by mass, a high conductivity can be achieved. 
         [0198]    In this embodiment, the tone (gradation) obtained by the development is preferably more than 4.0, though not particularly restrictive. When the tone is more than 4.0 after the development, the conductivity of the conductive metal portion can be increased while maintaining the high transmittance of the light-transmitting portion. For example, the tone of 4.0 or more can be obtained by doping with rhodium or iridium ion. 
         [0199]    The conductive sheet is obtained by the above steps. The surface resistance of the resultant first conductive sheet  10 A or second conductive sheet  10 B is preferably within a range of 0.1 to 100 ohm/sq. The lower limit is preferably 1 ohm/sq or more, 3 ohm/sq or more, 5 ohm/sq or more, or 10 ohm/sq or more. The upper limit is preferably 70 ohm/sq or less or 50 ohm/sq or less. When the surface resistance is controlled within this range, the position detection can be performed even in a large touch panel having an area of 10 cm×10 cm or more. The first conductive sheet  10 A and the second conductive sheet  10 B may be subjected to a calender treatment after the development treatment to obtain a desired surface resistance. 
       [Physical Development Treatment and Plating Treatment] 
       [0200]    In this embodiment, to increase the conductivity of the metallic silver portion formed by the above exposure and development treatments, conductive metal particles may be deposited thereon by a physical development treatment and/or a plating treatment. In the present invention, the conductive metal particles may be deposited on the metallic silver portion by only one of the physical development and plating treatments or by the combination of the treatments. The metallic silver portion, subjected to the physical development treatment and/or the plating treatment in this manner, is also referred to as the conductive metal portion. 
         [0201]    In this embodiment, the physical development is such a process that metal ions such as silver ions are reduced by a reducing agent, whereby metal particles are deposited on a metal or metal compound core. Such physical development has been used in the fields of instant B &amp; W film, instant slide film, printing plate production, etc., and the technologies can be used in the present invention. 
         [0202]    The physical development may be carried out at the same time as the above development treatment after the exposure, and may be carried out after the development treatment separately. 
         [0203]    In this embodiment, the plating treatment may contain electroless plating (such as chemical reduction plating or displacement plating), electrolytic plating, or a combination thereof. Known electroless plating technologies for printed circuit boards, etc. may be used in this embodiment. The electroless plating is preferably electroless copper plating. 
       [Oxidation Treatment] 
       [0204]    In this embodiment, the metallic silver portion formed by the development treatment or the conductive metal portion formed by the physical development treatment and/or the plating treatment is preferably subjected to an oxidation treatment. For example, by the oxidation treatment, a small amount of a metal deposited on the light-transmitting portion can be removed, so that the transmittance of the light-transmitting portion can be increased to approximately 100%. 
       [Conductive Metal Portion] 
       [0205]    In this embodiment, the lower limit of the line width of the conductive metal portion (the thin metal wire  24 ) may be 0.1 μm or more as described above. The lower limit of the line width is preferably 1 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and the upper limit thereof is preferably 15 μm or less, 10 μm or less, 9 μm or less, or 8 μm or less. When the line width is less than the lower limit, the conductive metal portion has an insufficient conductivity, whereby a touch panel using the portion has insufficient detection sensitivity. On the other hand, when the line width is more than the upper limit, moire is significantly generated due to the conductive metal portion, and a touch panel using the portion has a poor visibility. As long as the line width falls within the above range, the moire of the conductive metal portion is improved, and the visibility is remarkably improved. The side length of the first lattice  26  is preferably 30 μm or more and 500 μm or less, more preferably 50 μm or more and 400 μm or less, most preferably 100 μm or more and 350 μm or less. The conductive metal portion may have a part with a line width of more than 200 μm for the purpose of ground connection, etc. 
         [0206]    In this embodiment, the opening ratio of the conductive metal portion is preferably 85% or more, more preferably 90% or more, most preferably 95% or more, in view of the visible light transmittance. The opening ratio is the ratio of the light-transmitting portions other than the conductive portions (including the first conductive patterns, the first auxiliary patterns, the second conductive patterns, and the second auxiliary patterns) to the entire conductive part. For example, a square lattice having a line width of 15 μm and a pitch of 300 μm has an opening ratio of 90%. 
       [Light-Transmitting Portion] 
       [0207]    In this embodiment, the light-transmitting portion is a portion having light transmittance, other than the conductive metal portions in the first conductive sheet  10 A and the second conductive sheet  10 B. The transmittance of the light-transmitting portion, which is herein a minimum transmittance value in a wavelength region of 380 to 780 nm obtained neglecting the light absorption and reflection of the first transparent substrate  14 A and the second transparent substrate  14 B, is 90% or more, preferably 95% or more, more preferably 97% or more, further preferably 98% or more, most preferably 99% or more. 
         [0208]    The exposure is preferably carried out using a glass mask method or a laser lithography pattern exposure method. 
       [First Conductive Sheet  10 A and Second Conductive Sheet  10 B] 
       [0209]    In the first conductive sheet  10 A and the second conductive sheet  10 B of this embodiment, the thicknesses of the first transparent substrate  14 A and the second transparent substrate  14 B are preferably 50 to 350 μm, more preferably 80 to 250 μm, particularly preferably 100 to 200 μm. When the thicknesses are within the range of 50 to 350 μm, a desired visible light transmittance can be obtained, the substrates can be easily handled, and the parasitic capacitance between the first conductive patterns  18 A and the second conductive patterns  18 B can be lowered. 
         [0210]    The thickness of the metallic silver portion formed on the first transparent substrate  14 A or the second transparent substrate  14 B may be appropriately selected by controlling the thickness of the coating liquid for the silver salt-containing layer applied to the first transparent substrate  14 A or the second transparent substrate  14 B. The thickness of the metallic silver portion may be selected within a range of 0.001 to 0.2 mm, and is preferably 30 μm or less, more preferably 20 μm or less, further preferably 0.01 to 9 μm, most preferably 0.05 to 5 μm. The metallic silver portion is preferably formed in a patterned shape. The metallic silver portion may have a monolayer structure or a multilayer structure containing two or more layers. When the metallic silver portion has a patterned multilayer structure containing two or more layers, the layers may have different wavelength color sensitivities. In this case, different patterns can be formed in the layers by using exposure lights with different wavelengths. 
         [0211]    In the case of using the first conductive sheet  10 A or the second conductive sheet  10 B in a touch panel, the conductive metal portion preferably has a smaller thickness. As the thickness is reduced, the viewing angle and visibility of the display panel are improved. Thus, the thickness of the layer of the conductive metal on the conductive metal portion is preferably less than 9 μm, more preferably 0.1 μm or more but less than 5 μm, further preferably 0.1 μm or more but less than 3 μm. 
         [0212]    In this embodiment, the thickness of the metallic silver portion can be controlled by changing the coating thickness of the silver salt-containing layer, and the thickness of the conductive metal particle layer can be controlled in the physical development treatment and/or the plating treatment, whereby the first conductive sheet  10 A and the second conductive sheet  10 B having a thickness of less than 5 μm (preferably less than 3 μm) can be easily produced. 
         [0213]    The plating or the like is not necessarily carried out in the method for producing the first conductive sheet  10 A and the second conductive sheet  10 B of this embodiment. This is because the desired surface resistance can be obtained by controlling the applied silver amount and the silver/binder volume ratio of the silver salt emulsion layer in the method. The calender treatment or the like may be carried out if necessary. 
         [0000]    (Film Hardening Treatment after Development Treatment) 
         [0214]    It is preferred that after the silver salt emulsion layer is developed, the resultant is immersed in a hardener and thus subjected to a film hardening treatment. Examples of the hardeners include dialdehydes (such as glutaraldehyde, adipaldehyde, and 2,3-dihydroxy-1,4-dioxane) and boric acid, described in Japanese Laid-Open Patent Publication No. 02-141279. 
       [Conductive Sheet Stack] 
       [0215]    An additional functional layer such as an antireflection layer or a hard coat layer may be formed in the conductive sheet stack  12 . 
         [0216]    The present invention may be appropriately combined with technologies described in the following patent publications and international patent pamphlets shown in Tables 1 and 2. “Japanese Laid-Open Patent”, “Publication No.”, “Pamphlet No.”, etc. are omitted. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
             
             
               
                 2004-221564 
                 2004-221565 
                 2007-200922 
                 2006-352073 
                 2007-129205 
               
               
                 2007-235115 
                 2007-207987 
                 2006-012935 
                 2006-010795 
                 2006-228469 
               
               
                 2006-332459 
                 2009-21153 
                 2007-226215 
                 2006-261315 
                 2007-072171 
               
               
                 2007-102200 
                 2006-228473 
                 2006-269795 
                 2006-269795 
                 2006-324203 
               
               
                 2006-228478 
                 2006-228836 
                 2007-009326 
                 2006-336090 
                 2006-336099 
               
               
                 2006-348351 
                 2007-270321 
                 2007-270322 
                 2007-201378 
                 2007-335729 
               
               
                 2007-134439 
                 2007-149760 
                 2007-208133 
                 2007-178915 
                 2007-334325 
               
               
                 2007-310091 
                 2007-116137 
                 2007-088219 
                 2007-207883 
                 2007-013130 
               
               
                 2005-302508 
                 2008-218784 
                 2008-227350 
                 2008-227351 
                 2008-244067 
               
               
                 2008-267814 
                 2008-270405 
                 2008-277675 
                 2008-277676 
                 2008-282840 
               
               
                 2008-283029 
                 2008-288305 
                 2008-288419 
                 2008-300720 
                 2008-300721 
               
               
                 2009-4213 
                 2009-10001 
                 2009-16526 
                 2009-21334 
                 2009-26933 
               
               
                 2008-147507 
                 2008-159770 
                 2008-159771 
                 2008-171568 
                 2008-198388 
               
               
                 2008-218096 
                 2008-218264 
                 2008-224916 
                 2008-235224 
                 2008-235467 
               
               
                 2008-241987 
                 2008-251274 
                 2008-251275 
                 2008-252046 
                 2008-277428 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
             
             
               
                 2006/001461 
                 2006/088059 
                 2006/098333 
                 2006/098336 
                 2006/098338 
               
               
                 2006/098335 
                 2006/098334 
                 2007/001008 
               
               
                   
               
             
          
         
       
     
       EXAMPLES 
       [0217]    The present invention will be described more specifically below with reference to Examples. Materials, amounts, ratios, treatment contents, treatment procedures, and the like, used in Examples, may be appropriately changed without departing from the scope of the present invention. The following specific examples are therefore to be considered in all respects as illustrative and not restrictive. 
       First Example 
       [0218]    In First Example, in each of the conductive sheet stacks  12  of Examples 1 to 9, the side length of the first lattice  26 , the line width of the thin metal wire  24 , and the surface resistance of the representative second conductive pattern  18 B were measured, and the moire and visibility were evaluated. The properties and evaluation results of Examples 1 to 9 are shown in Table 3. 
       Examples 1 to 9 
     (Photosensitive Silver Halide Material) 
       [0219]    An emulsion containing an aqueous medium, a gelatin, and silver iodobromochloride particles was prepared. The amount of the gelatin was 10.0 g per 150 g of Ag, and the silver iodobromochloride particles had an I content of 0.2 mol %, a Br content of 40 mol %, and an average spherical equivalent diameter of 0.1 μm. 
         [0220]    K 3 Rh 2 Br 9  and K 2 IrCl 6  were added to the emulsion at a concentration of 10 −7  (mol/mol-silver) to dope the silver bromide particles with Rh and Ir ions. Na 2 PdCl 4  was further added to the emulsion, and the resultant emulsion was subjected to gold-sulfur sensitization using chlorauric acid and sodium thiosulfate. The emulsion and a gelatin hardening agent were applied to the first transparent substrate  14 A or the second transparent substrate  14 B having a thickness of 150 μm, both composed of a polyethylene terephthalate (PET). The amount of the applied silver was 10 g/m 2 , and the Ag/gelatin volume ratio was 2/1. 
         [0221]    The PET support had a width of 30 cm, and the emulsion was applied thereto into a width of 25 cm and a length of 20 m. The both end portions having a width of 3 cm were cut off to obtain a roll photosensitive silver halide material having a width of 24 cm. 
       (Exposure) 
       [0222]    An A4 (210 mm×297 mm) sized area of the first transparent substrate  14 A was exposed in the pattern of the first conductive sheet  10 A shown in  FIG. 4 , and an A4 sized area of the second transparent substrate  14 B was exposed in the pattern of the second conductive sheet  10 B shown in  FIG. 5 . The exposure was carried out using a parallel light from a light source of a high-pressure mercury lamp and patterned photomasks. 
       (Development Treatment) 
       [0223]      
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Formulation of 1 L of developer 
                   
               
               
                   
                 Hydroquinone 
                  20 g 
               
               
                   
                 Sodium sulfite 
                  50 g 
               
               
                   
                 Potassium carbonate 
                  40 g 
               
               
                   
                 Ethylenediaminetetraacetic acid 
                  2 g 
               
               
                   
                 Potassium bromide 
                  3 g 
               
               
                   
                 Polyethylene glycol 2000 
                  1 g 
               
               
                   
                 Potassium hydroxide 
                  4 g 
               
               
                   
                 pH 
                 Controlled at 10.3 
               
               
                   
                 Formulation of 1 L of fixer 
               
               
                   
                 Ammonium thiosulfate solution (75%) 
                 300 ml 
               
               
                   
                 Ammonium sulfite monohydrate 
                  25 g 
               
               
                   
                 1,3-Diaminopropanetetraacetic acid 
                  8 g 
               
               
                   
                 Acetic acid 
                  5 g 
               
               
                   
                 Aqueous ammonia (27%) 
                  1 g 
               
               
                   
                 pH 
                 Controlled at 6.2 
               
               
                   
                   
               
             
          
         
       
     
         [0224]    The exposed photosensitive material was treated with the above treatment agents using an automatic processor FG-710PTS manufactured by FUJIFILM Corporation under the following conditions. A development treatment was carried out at 35° C. for 30 seconds, a fixation treatment was carried out at 34° C. for 23 seconds, and then a water washing treatment was carried out for 20 seconds at a water flow rate of 5 L/min. 
       Example 1 
       [0225]    In the conductive parts (including the first conductive patterns  18 A and the second conductive patterns  18 B) of the prepared first conductive sheet  10 A and second conductive sheet  10 B, the side length of the first lattice  26  was 30 μm (i.e. the side length of the second lattice  27  was 60 μm) and the line width of the thin metal wire  24  was 1 μm. 
       Example 2 
       [0226]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 2 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 40 μm (i.e. the side length of the second lattice  27  was 80 μm) and the line width of the thin metal wire  24  was 3 μm. 
       Example 3 
       [0227]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 3 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 50 μm (i.e. the side length of the second lattice  27  was 100 μm) and the line width of the thin metal wire  24  was 4 μm. 
       Example 4 
       [0228]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 4 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 80 μm (i.e. the side length of the second lattice  27  was 160 μm) and the line width of the thin metal wire  24  was 5 μm. 
       Example 5 
       [0229]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 5 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 100 μm (i.e. the side length of the second lattice  27  was 200 μm) and the line width of the thin metal wire  24  was 8 μm. 
       Example 6 
       [0230]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 6 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 250 μm (i.e. the side length of the second lattice  27  was 500 μm) and the line width of the thin metal wire  24  was 9 μm. 
       Example 7 
       [0231]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 7 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 350 μm (i.e. the side length of the second lattice  27  was 700 μm) and the line width of the thin metal wire  24  was 10 μm. 
       Example 8 
       [0232]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 8 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 400 μm (i.e. the side length of the second lattice  27  was 800 μm) and the line width of the thin metal wire  24  was 15 μm. 
       Example 9 
       [0233]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 9 were produced in the same manner as Example 1 except that the side length of the first lattice  26  was 500 μm (i.e. the side length of the second lattice  27  was 1000 μm) and the line width of the thin metal wire  24  was 15 μm. 
       (Surface Resistance Measurement) 
       [0234]    In each of the first conductive sheets  10 A and the second conductive sheets  10 B, the surface resistivity values of randomly selected 10 points were measured by LORESTA GP (Model No. MCP-T610) manufactured by Dia Instruments Co., Ltd. utilizing an in-line four-probe method (ASP), and the average of the measured values was obtained to evaluate the detection accuracy. 
       (Moire Evaluation) 
       [0235]    In Examples 1 to 9, the first conductive sheet  10 A was stacked on the second conductive sheet  10 B to prepare the conductive sheet stack  12 , and the conductive sheet stack  12  was attached to the display screen of the display device  108  (liquid crystal display) to produce the touch panel  100 . The touch panel  100  was fixed to a turntable, and the display device  108  was operated to display a white color. The moire of the conductive sheet stack  12  was visually observed and evaluated while turning the turntable within a bias angle range of −45° to +45°. 
         [0236]    The moire was observed at a distance of 1.5 m from the display screen  110   a  of the display device  108 . The conductive sheet stack  12  was evaluated as “Good” when the moire was not visible, as “Fair” when the moire was slightly visible to an acceptable extent, or as “Poor” when the moire was highly visible. 
       (Visibility Evaluation) 
       [0237]    Before the moire evaluation, the touch panel  100  was fixed to the turntable, the display device  108  was operated to display the white color, and whether a thickened line or a black point was formed or not in the touch panel  100  and whether boundaries between the first conductive patterns  18 A and the second conductive patterns  18 B and between the strips  20  and the connections  28  were visible or not in the touch panel  100  were evaluated by the naked eye. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                   
                 Line width 
                 Thickness of 
                   
                   
                   
               
               
                   
                 Side length 
                 of thin 
                 transparent 
                 Surface 
               
               
                   
                 of first lattice 
                 metal wire 
                 substrate 
                 resistance 
                 Moire 
                 Visibility 
               
               
                   
                 (μm) 
                 (μm) 
                 (μm) 
                 (Ω/sq) 
                 evaluation 
                 evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Example 1 
                 30 
                 1 
                 150 
                 90 
                 Good 
                 Good 
               
               
                 Example 2 
                 40 
                 3 
                 150 
                 85 
                 Good 
                 Good 
               
               
                 Example 3 
                 50 
                 4 
                 150 
                 80 
                 Good 
                 Good 
               
               
                 Example 4 
                 80 
                 5 
                 150 
                 75 
                 Good 
                 Good 
               
               
                 Example 5 
                 100 
                 8 
                 150 
                 65 
                 Good 
                 Good 
               
               
                 Example 6 
                 250 
                 9 
                 150 
                 50 
                 Good 
                 Good 
               
               
                 Example 7 
                 350 
                 10 
                 150 
                 45 
                 Good 
                 Good 
               
               
                 Example 8 
                 400 
                 15 
                 150 
                 40 
                 Good 
                 Good 
               
               
                 Example 9 
                 500 
                 15 
                 150 
                 40 
                 Fair 
                 Fair 
               
               
                   
               
             
          
         
       
     
         [0238]    As shown in Table 3, among Examples 1 to 9, the conductive sheet stacks  12  of Examples 1 to 8 had excellent conductivity, transmittance, moire, and visibility properties. The conductive sheet stack  12  of Example 9 was inferior to those of Examples 1 to 8 in the moire and visibility properties. However, in Example 9, the moire was only slightly visible to an acceptable extent, and an image on the display device  108  could be observed without any difficulty. 
         [0239]    Therefore, it is clear that the side length of the first lattice  26  is preferably 30 to 500 μm, more preferably 50 to 400 μm, particularly preferably 100 to 350 μm. Furthermore, it is clear that the lower limit of the line width of the thin metal wire  24  is preferably 1 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and the upper limit is preferably 15 μm or less, 10 μm or less, 9 μm or less, or 8 μm or less. 
       Second Example 
       [0240]    In Second Example, in the conductive sheet stacks  12  of Examples 11 to 17 and Reference Examples 11 and 12, the thickness of the first transparent substrate  14 A was changed to evaluate the detection sensitivity and the visibility. The properties and evaluation results of Examples 11 to 17 and Reference Examples 11 and 12 are shown in Table 4. 
       Example 11 
       [0241]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 11 were produced in the same manner as Example 1 except that, in the conductive parts (including the first conductive patterns  18 A and the second conductive patterns  18 B), the side length of the first lattice  26  was 80 μm (i.e. the side length of the second lattice  27  was 160 μm), the line width of the thin metal wire  24  was 5 μm, and the thickness of the first transparent substrate  14 A was 50 μm. 
       Example 12 
       [0242]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 12 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 80 μm. 
       Example 13 
       [0243]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 13 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 100 μm. 
       Example 14 
       [0244]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 14 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 150 μm. 
       Example 15 
       [0245]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 15 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 200 μm. 
       Example 16 
       [0246]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 16 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 250 μm. 
       Example 17 
       [0247]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 17 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 350 μm. 
       Reference Example 11 
       [0248]    The first conductive sheet  10 A and the second conductive sheet  10 B of Reference Example 11 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 30 μm. 
       Reference Example 12 
       [0249]    The first conductive sheet  10 A and the second conductive sheet  10 B of Reference Example 12 were produced in the same manner as Example 11 except that the thickness of the first transparent substrate  14 A was 400 μm. 
       (Transmittance Measurement) 
       [0250]    The transmittance value of the light-transmitting portion in the first conductive sheet  10 A and the second conductive sheet  10 B was measured by a spectrophotometer to evaluate the transparency of the first transparent substrate  14 A. 
       (Detection Sensitivity Evaluation) 
       [0251]    A finger was moved in a predetermined direction on each touch panel  100  to obtain a detection waveform. The detection sensitivity was evaluated based on the detection waveform. The touch panel  100  was evaluated as “Excellent” when the detection sensitivity was more than 110% of a predetermined threshold value, as “Good” when it was 90% or more and 110% or less of the threshold value, or as “Fair” when it was less than 90% of the threshold value. 
         [0252]    The results of Examples 11 to 17 and Reference Examples 11 and 12 are shown in Table 4. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                   
                 Line 
                   
                 Transmittance 
                   
                   
               
               
                   
                 Side 
                 width of 
                 Thickness of 
                 of light- 
               
               
                   
                 length of 
                 thin metal 
                 transparent 
                 transmitting 
               
               
                   
                 first lattice 
                 wire 
                 substrate 
                 portion 
                 Detection 
                 Visibility 
               
               
                   
                 (μm) 
                 (μm) 
                 (μm) 
                 (%) 
                 sensitivity 
                 evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Reference 
                 80 
                 5 
                 30 
                 99 
                 Fair 
                 Good 
               
               
                 Example 11 
               
               
                 Example 11 
                 80 
                 5 
                 50 
                 99 
                 Good 
                 Good 
               
               
                 Example 12 
                 80 
                 5 
                 80 
                 99 
                 Good 
                 Good 
               
               
                 Example 13 
                 80 
                 5 
                 100 
                 97 
                 Excellent 
                 Good 
               
               
                 Example 14 
                 80 
                 5 
                 150 
                 97 
                 Excellent 
                 Good 
               
               
                 Example 15 
                 80 
                 5 
                 200 
                 95 
                 Excellent 
                 Good 
               
               
                 Example 16 
                 80 
                 5 
                 250 
                 95 
                 Good 
                 Good 
               
               
                 Example 17 
                 80 
                 5 
                 350 
                 90 
                 Good 
                 Good 
               
               
                 Reference 
                 80 
                 5 
                 400 
                 80 
                 Poor 
                 Poor 
               
               
                 Example 12 
               
               
                   
               
             
          
         
       
     
         [0253]    As shown in Table 4, though the conductive sheet stack  12  of Reference Example 11 had a good visibility, it had a low detection sensitivity. It was likely that because the first transparent substrate  14 A had a small thickness of 30 μm, a large parasitic capacitance was formed between the first conductive patterns  18 A and the second conductive patterns  18 B, and the detection sensitivity was deteriorated due to the parasitic capacitance. The conductive sheet stack  12  of Reference Example 12 was poor in both of the detection sensitivity and the visibility. It was likely that because the first transparent substrate  14 A had a remarkably large thickness of 400 μm, the finger touch position was hardly detected by the second conductive patterns  18 B in the self capacitance technology, and signals from the drive electrodes were hardly received by the receiving electrodes in the mutual capacitance technology. The visibility was deteriorated because the first transparent substrate  14 A had a remarkably large thickness of 400 μm, whereby the light-transmitting portions had a low transmittance of 80% to lower the transparency. 
         [0254]    In contrast, the conductive sheet stacks  12  of Examples 11 to 17 had high detection sensitivities and high visibilities. Particularly the conductive sheet stacks  12  of Examples 13 to 15 had excellent detection sensitivities. 
         [0255]    Therefore, it is clear that the thickness of the transparent substrate (the first transparent substrate  14 A) disposed between the first conductive part  16 A and the second conductive part  16 B is preferably 50 μm or more and 350 μm or less, further preferably 80 μm or more and 250 μm or less, particularly preferably 100 μm or more and 200 μm or less. 
       Third Example 
       [0256]    In Third Example, in the conductive sheet stacks  12  of Examples 21 to 28 and Reference Examples 21 and 22, the ratio (A2/A1) of the occupation area A2 of the second conductive patterns  18 B to the occupation area A1 of the first conductive patterns  18 A was changed to evaluate the surface resistance of the first conductive pattern  18 A, the surface resistance of the second conductive pattern  18 B, and the detection sensitivity. The properties and evaluation results of Examples 21 to 28 and Reference Examples 21 and 22 are shown in Table 5. 
       Example 21 
       [0257]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 21 were produced in the same manner as Example 1 except that, in the conductive parts (including the first conductive patterns  18 A and the second conductive patterns  18 B), the side length of the first lattice  26  was 80 μm (i.e. the side length of the second lattice  27  was 160 μm), the line width of the thin metal wire  24  was 5 μm, the thickness of the first transparent substrate  14 A was 150 μm, and the occupation area ratio A2/A1 was 2. 
       Example 22 
       [0258]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 22 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 3. 
       Example 23 
       [0259]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 23 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 5. 
       Example 24 
       [0260]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 24 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 7. 
       Example 25 
       [0261]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 25 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 8. 
       Example 26 
       [0262]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 26 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 10. 
       Example 27 
       [0263]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 27 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 15. 
       Example 28 
       [0264]    The first conductive sheet  10 A and the second conductive sheet  10 B of Example 28 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 20. 
       Reference Example 21 
       [0265]    The first conductive sheet  10 A and the second conductive sheet  10 B of Reference Example 21 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 1. 
       Reference Example 22 
       [0266]    The first conductive sheet  10 A and the second conductive sheet  10 B of Reference Example 22 were produced in the same manner as Example 21 except that the occupation area ratio A2/A1 was 25. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 5 
               
               
                   
                   
               
               
                   
                   
                   
                 Surface 
                   
               
               
                   
                   
                 Surface 
                 resistance of 
               
               
                   
                   
                 resistance of 
                 second 
               
               
                   
                 Occupation 
                 first conductive 
                 conductive 
               
               
                   
                 area ratio 
                 pattern 
                 pattern 
                 Detection 
               
               
                   
                 (A2/A1) 
                 (Ω/sq) 
                 (Ω/sq) 
                 sensitivity 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Reference 
                 1 
                 75 
                 75 
                 Fair 
               
               
                 Example 21 
               
               
                 Example 21 
                 2 
                 75 
                 70 
                 Good 
               
               
                 Example 22 
                 3 
                 76 
                 70 
                 Good 
               
               
                 Example 23 
                 5 
                 78 
                 60 
                 Excellent 
               
               
                 Example 24 
                 7 
                 80 
                 50 
                 Excellent 
               
               
                 Example 25 
                 8 
                 82 
                 40 
                 Excellent 
               
               
                 Example 26 
                 10 
                 85 
                 35 
                 Good 
               
               
                 Example 27 
                 15 
                 90 
                 30 
                 Good 
               
               
                 Example 28 
                 20 
                 100 
                 20 
                 Good 
               
               
                 Reference 
                 25 
                 150 
                 10 
                 Fair 
               
               
                 Example 22 
               
               
                   
               
             
          
         
       
     
         [0267]    As shown in Table 5, the conductive sheet stacks  12  of Reference Examples 21 and 22 had low detection sensitivities. In Reference Example 21, the second conductive patterns  18 B had a high surface resistance of 75 ohm/sq, and it was likely that the second conductive patterns  18 B could not reduce the noise impact of the electromagnetic wave. In Reference Example 22, though the second conductive patterns  18 B had a significantly low surface resistance, the first conductive patterns  18 A had a high surface resistance of 150 ohm/sq. It was likely that the detection sensitivity of the receiving electrodes was deteriorated due to the high surface resistance. 
         [0268]    In contrast, the conductive sheet stacks  12  of Examples 21 to 28 had high detection sensitivities. Particularly the conductive sheet stacks  12  of Examples 23 to 25 had excellent detection sensitivities. 
         [0269]    Therefore, it is clear that the ratio of the occupation area A2 of the second conductive patterns  18 B to the occupation area A1 of the first conductive patterns  18 A preferably satisfies 1&lt;A2/A1≦20, further preferably satisfies 1&lt;A2/A1≦10, and particularly preferably satisfies 2≦A2/A1≦10. 
         [0270]    The occupation area ratio can be easily controlled by appropriately changing the lengths La to Lg and L1 and L2 within the above-described ranges. 
         [0271]    It is to be understood that the conductive sheet and the touch panel of the present invention are not limited to the above embodiments, and various changes and modifications may be made therein without departing from the scope of the present invention.