Patent Publication Number: US-2017371448-A1

Title: Touch Sensing Device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. §119 of Japanese Patent Applications Nos. 2016-125319 and 2017-105646 filed on Jun 24, 2016, and May 29, 2017, respectively, the disclosures of which are expressly incorporated by reference herein in their entireties. 
     BACKGROUND OF THE INVENTION 
     Technical Field 
     The invention relates to touch sensing devices. 
     Background Art 
     A conventional mobile information terminal is disclosed in JP 2004-295730A. This mobile information terminal includes an upper casing, a lower casing, and a touch sensor disposed therebetween. The upper casing has a plurality of keys to be pressed for operation. 
     SUMMARY OF INVENTION 
     A typical conventional touch sensor has a plurality of first and second electrodes. The first electrodes are of the same shape and size and arrayed at regular intervals in X-X′ direction. The second electrodes are of the same shape and size and arrayed at regular intervals in Y-Y′ direction, such that the second electrodes orthogonally cross the first electrodes at a height different from that of the first electrodes. Some of the first electrodes (or of the second electrodes) are positioned under the keys, and others not positioned under the keys. The former is used to detect a touch of a finger onto a corresponding key, while the latter is not. This means that the first electrodes (or the second electrodes) include one or more useless electrodes that are not used for touch detection. 
     The invention is made in the above circumstance and provides a touch sensing device with a reduced number of electrodes. 
     A touch sensing device according to one aspect of the invention includes a plurality of first electrodes, at least one second electrode, and a plurality of third electrodes. The first electrodes are arrayed at a first height position, at intervals in a first direction. A vacant region is provided between two of the first electrodes or directly on a side in the first direction to an endmost one of the first electrodes. The at least one second electrode is disposed in the vacant region at the first height position. The third electrodes are arrayed at a second height position, at intervals in a second direction, and cross the first and second electrodes. The second direction crosses the first direction. The first height position and the second height position are at different heights from each other in a third direction. The third direction is orthogonal to the first and second directions. Either relation (1) or relation (2) is satisfied: 
     (1) W 2 ≧W 1 × 2 ; or (2) W 1 &lt;W 2 &lt;W 1 ×2, and W 2 ×N 1 ≧W 1 ×N 1 +W 1 . W 1  is a dimension in the first direction of each first electrode, W 2  is a dimension in the first direction of each second electrode, and N 1  is the number of the second electrodes, N 1  being an integer of two or more. In either case, the presence of the second electrode results in a reduced number of electrodes, at least by one first electrode. 
     Each of the first electrodes may include a plurality of first electrode portions. In each first electrode, the first electrode portions may be arranged in the second direction at the first height position, and each two of the first electrode portions that are adjacent to each other in the second direction may be connected to each other. The or each second electrode may include a plurality of second electrode portions being arranged in the second direction at the first height position. Each two of the second electrode portions that are adjacent to each other in the second direction may be connected to each other. Each of the third electrodes may include a plurality of third electrode portions. In each of the third electrodes, the third electrode portions may be arranged in the first direction at the second height position, and each two of the third electrode portions that are adjacent to each other in the first direction may be connected to each other. 
     Each of the third electrode portions may be disposed on one side in the third direction relative to a space defined by adjacent ones of the first electrode portions at the first height position. 
     Each of the third electrodes may further include an odd-form electrode portion. Each odd-form electrode portion may be disposed on the one side in the third direction relative to a space defined by two of the second electrode portions and two of the first electrode portions that are adjacent to each other at the first height position. Each odd-form electrode portion may be connected to one of the third electrode portions that is adjacent to the odd-form electrode portion. Each odd-form electrode portion may include a first portion and a second portion. Each first portion may be a portion of the odd-form electrode portion on a side of the corresponding second electrode portion. Each second portion may be a remaining portion of the odd-form electrode portion other than the first portion. The ratio between the dimension in the first direction of the first portion of each odd-form electrode portion and the dimension in the first direction of the second portion of the each odd-form electrode portion may be substantially the same as the ratio between the dimension in the first direction of each second electrode and the dimension in the first direction of each first electrode. 
     In the touch sensing device of this aspect, the presence of the odd-form electrode portion results in a reduced number of the third electrode portions. 
     If each third electrode does not include any odd-form electrode portions, a third electrode portion may be provided in place of the odd-form electrode portion. 
     A touch sensing device according to another aspect of the invention includes a plurality of fourth electrodes and a plurality of fifth electrodes. The fourth electrodes are arrayed at a first height position, at intervals in a first direction. The fifth electrodes are arrayed at a second height position, at intervals in a second direction, and cross the fourth electrodes. The second direction crosses the first direction. The first height position and the second height position are at different heights from each other in a third direction. The third direction is orthogonal to the first and second directions. A vacant region in which none of the fourth electrodes are present, and the vacant region is located between two of the fourth electrodes or directly on a side of an endmost one of the fourth electrodes. Either relation (1) or relation (2) is satisfied: 
     (1) W 4 ≧W 3 ×2; or (2) W 3 &lt;W 4 &lt;W 3 ×2, and W 4 ×N 2 ≧W 3 ×N 2 +W 3 . W 3  is a dimension in the first direction of each fourth electrode, W 4  is a dimension in the first direction of the vacant region, and N 2  is the number of the vacant regions, N 2  being an integer of two or more. In either case, the presence of the vacant region or regions results in a reduced number of electrodes, at least by one fourth electrode. 
     Each of the fourth electrodes may include a plurality of fourth electrode portions. In each of the fourth electrodes, the fourth electrode portions may be arranged in the second direction at the first height position, and each two of the fourth electrode portions that are adjacent to each other in the second direction may be connected to each other. Each of the fifth electrodes may include a plurality of fifth electrode portions and at least one connecting portion. The fifth electrode portions of each fifth electrode may be arranged in the first direction at the second height position such as to be positioned outside the vacant region, each two of the fifth electrode portions that are adjacent to each other may be connected to each other. Each fifth electrode portion may be positioned on the one side in the third direction relative to a space defined by adjacent ones of the fourth electrode portions that are adjacent to each other at the first height position. The connecting portion of each fifth electrode may be positioned within the vacant region at the second height position and having a dimension in the second direction that is smaller than that of each fifth electrode portion. 
     The touch sensing device according to this aspect of the invention is unlikely to incorrectly detect an approach of a detection object in the vacant region. The reason for this is as follows. Within the vacant region no fourth electrodes are present, but only the connecting portions of the fifth electrodes are. The dimension in the second direction of each connecting portion is smaller at least than that of each fifth electrode portion. Therefore, if the touch sensing device is a touch sensor of a self-capacitance type, when a detection object approaches any of the connecting portions, the detection object is unlikely to electrostatically couple with the approached connecting portion. If the touch sensing device is of a mutual capacitance type, there are no fourth electrodes to electrostatically couple with connecting portions, so that there will be no false detection of an approach of the detection object in the vacant region. 
     Each of the connecting portions may be connected to a corresponding one of the fifth electrode portions. Alternatively, each fifth electrode may further include at least one half electrode portion. Each half electrode portion may be of a shape that is substantially one half of any one of the fifth electrode portions in the first direction. Each half electrode portion may be located at the second height position, between a connecting portion and one of the fifth electrode portions, and connected to the one fifth electrode portion. Each connecting portion may be connected to a corresponding one of the half electrode portions. Each connecting portion may have a dimension in the second direction that is smaller than that of each fifth electrode portion and than that of each half electrode portion. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention can be even more fully understood with the reference to the accompanying drawings which are intended to illustrate, not limit, the present invention. 
         FIG. 1  is a schematic plan view of a touch sensing device according to a first embodiment of the invention. 
         FIG. 2A  is a cross-sectional view of the touch sensing device, taken along line  2 A- 2 A. 
         FIG. 2B  is a cross-sectional view of a first variant of the touch sensing device, taken along line  2 A- 2 A in  FIG. 1 . 
         FIG. 2C  is a cross-sectional view of a second variant of the touch sensing device, taken along line  2 A- 2 A. 
         FIG. 3A  is a schematic plan view of first and second electrodes of the touch sensing device according to the first embodiment and its variants. 
         FIG. 3B  is a schematic plan view of the third electrodes of the touch sensing device. 
         FIG. 4  is a schematic plan view of a touch sensing device according to a second embodiment of the invention. 
         FIG. 5  is a schematic plan view of a touch sensing device according to a third embodiment of the invention. 
         FIG. 6A  is a cross-sectional view of the touch sensing device, taken along line  6 A- 6 A in  FIG. 5 . 
         FIG. 6B  is a cross-sectional view of a first variant of the touch sensing device, taken along line  6 A- 6 A. 
         FIG. 6C  is a cross-sectional view of a second variant of the touch sensing device, taken along line  6 A- 6 A. 
         FIG. 7A  is a schematic plan view of the fourth electrodes of the touch sensing device according to the third embodiment and its variants. 
         FIG. 7B  is a schematic plan view of the fifth electrodes of the touch sensing device. 
         FIG. 8  is a schematic plan view of a touch sensing device according to a fourth embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The first to fourth embodiments and their variants of the invention will be hereinafter described. 
     First Embodiment 
     A touch sensing device T 1  according to a first embodiment and its variants of the invention will be described with reference to  FIG. 1  through  FIG. 3B . The touch sensing device T 1  includes a plurality of first electrodes  100   a,  at least one second electrode  100   b,  and a plurality of third electrodes  100   c.    FIGS. 1 and 2A  shows the touch sensing device T 1  according to the first embodiment,  FIG. 2B  shows a first variant thereof, and  FIG. 2C  shows a second variant thereof.  FIG. 3A  shows the layout of the first and second electrodes of the touch sensing device T 1  according to the first embodiment and its first and second variants.  FIG. 3B  shows the layout of the third electrodes of the touch sensing device T 1  according to the first embodiment and its first and second variants. 
     Here, the Y-Y′ direction shown in  FIG. 1  through  FIG. 3B  corresponds to the first direction as defined in the appended claims. The X-X′ direction shown in  FIGS. 1, 3A, and 3B  corresponds to the second direction as defined in the appended claims. The X-X′ direction may by any direction crossing the Y-Y′ direction. The X-X′ direction may be orthogonal to the Y-Y′ direction as shown in  FIGS. 1, 3A, and 3B . The Z-Z′ direction shown in  FIG. 2A  through  FIG. 2C  corresponds to the third direction as defined in the appended claims. The Z-Z′ direction is orthogonal to the Y-Y′ and X-X′ directions. It should be noted that the first electrodes  100   a  to the third electrodes  100   c  in  FIGS. 1, 3A, and 3B  are illustrated with different dot patterns for the convenience of distinction. These dot patterns are merely imaginary patterns and not actually provided on the first electrodes  100   a  to the third electrodes  100   c.    
     The first electrodes  100   a  extend in the X-X′ direction. The first electrodes  100   a  are arrayed at intervals in the Y-Y′ direction at a first height position. The first electrodes  100   a,  excluding two specific ones to be described, may or may not be arrayed at regular intervals. The first electrodes  100   a  are not in contact with each other. There is a vacant region R 1  defined between two (a pair) of the first electrodes  100   a.  There may be a plurality of vacant regions R 1 , each between a different pair of the first electrodes  100   a.  In  FIGS. 1 and 3A , a vacant regions R 1  is defined between a pair of the first electrodes  100   a,  and another vacant region R 1  is defined between another pair of the first electrodes  100   a.    
     The first electrodes  100   a  may be strip-shaped extending in the X-X′ direction. Alternatively, as best illustrated in  FIGS. 1 and 3A , the first electrodes  100   a  may each include a plurality of first electrode portions  110   a.  In each first electrode  100   a,  the first electrode portions  110   a  are arrayed along the X-X′ direction at the first height position, and each two adjacent ones in the X-X′ direction of the first electrode portions  110   a  are connected to each other. The first electrode portions  110   a  may each be of any shape. For example, the first electrode portions  110   a  may each be of a rhombic shape (see  FIGS. 1 and 3A ), any polygonal shape other than rhombic shape, a circular or other curved-sided shape, or the like. 
     The first electrodes  100   a  may each further include at least one, half electrode portion  120   a.  The, or each, half electrode portion  120   a  is of a shape that is substantially one half of a first electrode portion  110   a  (see  FIG. 3A ), and positioned at the first height position, at the X-direction end and/or the X′-direction end of the first electrode  100   a.  The, or each, half electrode portion  120   a  is connected to the adjacent inside one of the first electrode portions  110   a.  If each first electrode  100   a  includes a half electrode portion  120   a  at the X-direction end and another half electrode portion  120   a  at the X′-direction end, the two half electrode portions  120   a  are symmetrically shaped in the X-X′ direction. Alternatively, each first electrode  100   a  may include only one, half electrode portion  120   a  at the X- or X′-direction end thereof, and the other end of the first electrode  100   a  may be provided with a first electrode portion  110   a.  Still alternatively, each first electrode  100   a  may include no half electrode portions  120   a,  and each of the X- and X′-direction ends of the first electrode  100   a  may be provided with a first electrode portion  110   a.    
     The at least one second electrode  100   b  extends in the X-X′ direction. The or each second electrode  100   b  is disposed at the first height position, between the above-described pair of the first electrodes  100   a,  i.e., within the vacant region R 1 . The or each second electrode  100   b  may be parallel to the first electrodes  100   a.  The or each second electrode  100   b  is not in contact with any first electrode  100   a.  As shown in  FIGS. 1 and 3A , a plurality of second electrode  100   b  may be provided. More than one second electrode  100   b  may be disposed in a single vacant region R 1 , or each second electrode  100   b  may be disposed in a different vacant region R 1 . 
     The at least one second electrode  100   b  may each have a strip shape extending in the X-X′ direction. Alternatively, as best illustrated in  FIGS. 1 and 3A , the at least one second electrode  100   b  may each include a plurality of second electrode portions  110   b.  The second electrode portions  110   b  of the or each second electrode  100   b  are arrayed along the X-X′ direction at the first height position, and each two adjacent ones in the X-X′ direction of the second electrode portions  110   b  are connected to each other. The second electrode portions  110   b  may each be of any shape. For example, the second electrode portions  110   b  may each be of a rhombic shape (see  FIGS. 1 and 3A ), any polygonal shape other than rhombic shape, a circular or other curved-sided shape, or the like. 
     The at least one second electrode  100   b  may each further include at least one, half electrode portion  120   b.  The, or each, half electrode portion  120   b  is of a shape that is substantially one half of a second electrode portion  110   b  (see  FIG. 3A ), and positioned at the first height position, at the X-direction end and/or the X′-direction end of a respective second electrode  100   b.  The, or each, half electrode portion  120   b  is connected to the adjacent inside one of the second electrode portions  110   b.  If each second electrode  100   b  includes a half electrode portion  120   b  at the X-direction end and another half electrode portion  120   b  at the X′-direction end, the two half electrode portions  120   b  are symmetrical shaped in the X-X′ direction. Alternatively, each second electrode  100   b  may include only one, half electrode portion  120   b  at the X- or X′-direction end thereof, and the other end of the second electrode  100   b  may be provided with a second electrode portion  110   b.  Still alternatively, each second electrode  100   b  may include no half electrode portions  120   b,  and each of the X- and X′-direction ends of second electrode  100   b  may be provided with a second electrode portion  110   b.    
     Where each first electrode  100   a  has a Y-Y′ direction dimension W 1 , and the or each second electrode  100   b  has a Y-Y′ direction dimension W 2 , the dimensions W 1  and W 2  may satisfy either relation (1) or relation (2) as follows. Relation (1): W 2 ≧W 1 ×2 (the dimension W 2  is equal to, or larger than, twice the dimension W 1 ). Here, the number of second electrodes  100   b  is at least one. The total number of the first and second electrodes  100   a,    100   b  required in the touch sensing device T 1  is fewer than the total number of first electrodes  100   a  required in a first comparative example in which there are only first electrodes  100   a  arrayed at regular intervals in the Y-Y′ direction at the first height position. For example, if the dimension W 2  is twice the dimension W 1 , because of the existence of the at least one second electrode  100   b,  the touch sensing device T 1  requires one less electrode, i.e., one less first electrode  100   a,  compared to the first comparative example. If the dimension W 2  is three times the dimension W 1 , because of the existence of the at least one second electrode  100   b,  the touch sensing device T 1  requires two less electrodes, i.e., two less first electrodes  100   a,  compared to the first comparative example. If the dimension W 2  is four times the dimension W 1 , because of the existence of the at least one second electrode  100   b,  the touch sensing device T 1  requires three less electrodes, i.e., three less first electrodes  100   a,  compared to the first comparative example. 
     Relation (2): W 1 &lt;W 2 &lt;W 1 ×2, and W 2 ×N 1 ≧W 1 ×N 1 +W 1 , where N is the number of the second electrodes  100   b,  N 1  being an integer of two or more (where two or more second electrodes  100   b  are provided and the dimension W 2  is larger than the dimension W 1  and smaller than twice the dimension W 1 , W 2 × the number of the second electrodes  100   b ≧W 1 × the number of the second electrodes  100   b +W 1 ). For example, when W 1  is 1 mm, W 2  is 1.2 mm, and the number of the second electrodes  100   b  is 5, a relation “1.2×5≧1×(5+1)” is satisfied. When W 1  is 1 mm, W 2  is 1.5 mm, and the number of the second electrodes  100   b  is 2, a relation “1.5×2≧1×(2+1)” is satisfied. In either case, the total number of the first and second electrodes  100   a,    100   b  required in the touch sensing device T 1  is fewer than the total number of the first electrodes  100   a  required in the first comparative example described above. Specifically, because of the existence of the two or more second electrodes  100   b,  the touch sensing device T 1  requires one less electrode, i.e., one less first electrode  100   a,  compared to the first comparative example. 
     It should be noted that the electrode region, in which the first electrodes  100   a  and the second electrode  100   b  are arrayed at the first height position, may include at least one sensing region and the at least one vacant region R 1 . The sensing region is a part of the electrode region that is other than the vacant region R 1  and used for detecting approach (such as touch) of a detection object (finger or stylus pen) to the touch sensing device T 1 . The vacant region R 1  is a part of the electrode region in which approach (such as touch) of a detection object (finger or stylus pen) to the touch sensing device T 1  will not be detected. 
     The third electrodes  100   c  extend in the Y-Y′ direction. The third electrodes  100   c  are arrayed at intervals in the X-X′ direction at a second height position. The second height position is different from the first height position in the Z-Z′ direction. The third electrodes  100   c  may or may not be arrayed at regular intervals. The third electrodes  100   c  are not in contact with each other. The third electrodes  100   c  may preferably cross the first electrodes  100   a  and the second electrode  100   b,  at any or right angles. 
     If the first and second electrodes  100   a  and  100   b  are strip-shaped extending in the X-X′ direction, the third electrodes  100   c  may be strip-shaped extending in the Y-Y′ direction. If each first electrode  100   a  includes the first electrode portions  110   a  and the second electrode  100   b  includes the second electrode portions  110   b,  each third electrode  100   c  may include a plurality of third electrode portions  110   c.    
     In each third electrode  100   c,  the third electrode portions  110   c  are arrayed along the Y-Y′ direction at the second height position, and each two adjacent ones in the Y-Y′ direction of the third electrode portions  110   c  that are connected to each other. The third electrode portions  110   c  may each be of any shape. For example, the third electrode portions  110   c  may each be of a rhombic shape (see  FIGS. 1 and 3A ), any polygonal shape other than rhombic shape, a circular or other curved-sided shape, or other shapes. 
     Each third electrode portion  110   c  is located on the Z′-direction side relative to a respective space defined by adjacent first electrode portions  110   a  at the first height position. More specifically, each third electrode portion  110   c  is located on the Z′-direction side relative to a respective space defined by adjacent four first electrode portions  110   a  at the first height position (i.e., two first electrode portions  110   a  of one first electrode  100   a  and two first electrode portions  110   a  of another first electrode  100   a  adjacent to the one first electrode  100   a ). For any shape of the first electrode potions  110   a,  each third electrode portion  110   c  of the third electrodes  100   a  may be of substantially the same shape as that of the space defined by four adjacent first electrode portions  110   a  at the first height position. If the first electrodes  100   a  includes the half electrode portions  120   a,  each third electrode portion  110   c  at the X-or X′-direction end is located on the Z′-direction side relative to a respective space at the first height position defined by two half electrode portions  120   a  adjacent to each other in the Y-Y′ direction and two first electrode portions  110   a  adjacent to each other in the Y-Y′ direction and adjacent to these half electrode portions  120   a  in the X-X′ direction, in other words, defined by the half electrode portion  120   a  and the adjacent first electrode portion  110   a  of one first electrode  100   a  and the half electrode portion  120   a  and the adjacent first electrode portion  110   a  of another first electrode  100   a  that is adjacent to the one first electrode  100   a  in the Y-Y′ direction. 
     Each third electrode  100   c  may further include at least two odd-form electrode portions  120   c  in addition to the third electrode portions  110   c.  Each two odd-form electrode portions  120   c  are located at the second height position and on the Y- and Y′-direction sides relative to a respective second electrode  100   b.  It is preferable that each odd-form electrode portion  120   c  is preferably positioned on the Z′-direction side relative to a respective space at the first height position defined by two second electrode portions  110   b  adjacent to each other in the X-X′ direction and two first electrode portions  110   a  adjacent to each other in the X-X′ direction and adjacent to these second electrode portions  110   b  in the Y-Y′ direction. If the first electrodes  100   a  includes the half electrode portions  120   a  and the at least one second electrode  100   b  includes the half electrode portions  120   b,  each odd-form electrode portion  120   c  at the X-or X′-direction end may preferably located on the Z′-direction side relative to a respective space at the first height position defined by the half electrode portion  120   a  and the adjacent first electrode portion  110   a  of one first electrode  100   a  and the half electrode portion  120   b  and the adjacent second electrode portion  110   b  of the second electrode  100   b  that is adjacent to the one first electrode in the Y-Y′ direction. Each two odd-form electrode portions  120   c  are connected to each other, and each of the two odd-form electrode portions  120   c  is connected to the respective adjacent third electrode portion  110   c.    
     The odd-form electrode portions  120   c  may each be of a kite shape (see  FIGS. 1 and 3A ), any polygonal shape other than kite shape, a circular or other curved-sided shape, or the like. Each two odd-form electrode portions  120   c  may be symmetrically shaped with respect to each other in the Y-Y′ direction. Each odd-form electrode portion  120   c  includes a first portion  121   c  and the remaining portion, namely a second portion  122   c.  The first portions  121   c  are closer to the second electrode portions  110   b  than the second portions  122   c  are. 
     In each odd-form electrode portion  120   c,  the first portion  121   c  has a Y-Y′ direction larger than that of the second portion  122   c  and an X-X′ direction dimension that is substantially the same as that of the second portion  122   c.  The second portion  122   c  may have the same shape as that of a half of the third electrode portion  110   c  in the Y-Y′ direction . For example, if each odd-form electrode portion  120   c  is of a kite shape, each second portion  122   c  is of a triangular shape corresponding to a half of each third electrode portion  110   c  in the Y-Y′ direction, and each first portion  121   c  is of a triangular shape having an X-X′ direction dimension that is equal to that of each second portion  122   c  and a Y-Y′ direction dimension that is larger than that of each second portion  122   c.  If each odd-form electrode portion  120   c  is of a polygonal shape other than kite shape, each second portion  122   c  is of a shape corresponding to a half of each third electrode portion  110   c  in the Y-Y′ direction, and each first portion  121   c  is of a shape having an X-X′ direction dimension that is equal to that of each second portion  122   c  and a Y-Y′ direction dimension that is larger than that of each second portion  122   c.  If the odd-form electrode portion  120   c  is of a circular or curved-sided shape, the second portion  122   c  is of a semi-circular shape corresponding to a half of each third electrode portion  110   c  in the Y-Y′ direction, and each first portion  121   c  is of a semi-circular shape having an X-X′ direction dimension that is equal to that of each second portion  122   c  and a Y-Y′ direction dimension that is larger than that of each second portion  122   c.    
     The ratio between the Y-Y′ direction dimension of the first portion  121   c  and that of the second portion  122   c  may preferably be substantially the same as the ratio between the Y-Y′ direction dimension of the or each second electrode  100   b  and that of each first electrode  100   a.  For example, if the dimension W 2  is twice as large as the dimension W 1 , the Y-Y′ direction dimension of the first portion  121   c  is twice as large as that of the second portion  122   c.  If W 2  is 1.5 times as large as W 1 , the Y-Y′ direction dimension of the first portion  121   c  is 1.5 times as large as that of the second portion  122   c.  For any shape of the first electrode portions  110   a  and the second electrode portions  110   b,  each odd-form electrode portion  120   c  of the third electrodes  100   c  may be of substantially the same shape as that of the space defined by two first electrode portions  110   a  adjacent to each other in the X-X′ direction and two second electrode portions  110   b  adjacent to each other in the X-X′ direction and adjacent to these first electrode portions  110   a  in the Y-Y′ direction. 
     If the third electrodes  100   c  do not include any odd-form electrode portions  120   c,  the odd-form electrode portions  120   c  may be substituted by third electrode portions  110   c,  which may be located at the second height position, among two second electrode portions  110   b  and two first electrode portions  110   a  that are adjacent to each other at the first height position. 
     Each third electrode  100   c  may further include at least one, half electrode portion  130   c.  The, or each, half electrode portion  130   c  is of a shape that is substantially one half of a third electrode portion  110   c  (see  FIG. 3B ), and is positioned at the Y-direction end or the Y′-direction end of the third electrode portion  110   c.  The, or each, half electrode portion  130   c  is connected to the adjacent inside one of the third electrode portions  110   c.  If each third electrode portion  110   c  includes a half electrode portion  130   c  at the Y-direction end and another half electrode portion  130   c  at the Y′-direction end, the two half electrode portions  130   c  are symmetrically shaped in the Y-Y′ direction. Alternatively, each third electrode  100   c  may include only one, half electrode portion  130   c  at the Y- or Y′-direction end thereof, and the other end of the third electrode  100   c  may be provided with a third electrode portion  110   c.  Still alternatively, each third electrode  100   c  may include no half electrode portions  130   c,  and each of the Y- and Y′-direction ends of the third electrode  100   c  may be provided with a third electrode portion  110   c.  If no third electrode portions  110   c  are interposed between each half electrode portion  130   c  and a corresponding odd-form electrode portion  120   c,  the each half electrode portion  130   c  and the corresponding odd-form electrode portion  120   c  may be directly connected to each other. 
     The touch sensing device T 1  may take a structure (A) in which a base  200   a  and a base  200   b  are further provided (see  FIG. 2A ), a structure (B) in which a base  200   a  is further provided (see  FIG. 2B ), or a structure (C) in which a base  200   a  and an insulation layer  300  are further provided (see  FIG. 2C ). The base  200   a  and the base  200   b  may each be a glass plate, a plastic plate, a plastic film, or the like. The base  200   a  and the base  200   b  each has a Z-direction face and a Z′-direction face. 
     In the structure (A), the first electrodes  100   a  and the second electrode  100   b  of one of the above described aspects are arrayed on the Z-direction face of the base  200   a.  The third electrodes  100   c  of one of the above described aspects are arrayed on the Z-direction face of the base  200   b.  The Z′-direction face of the base  200   a  and the Z-direction face of the base  200   b  are bonded together with an adhesion layer  400 . The Z-direction face of the base  200   a  is located at the first height position, and the Z-direction face of the base  200   b  is located at the second height position. 
     In the structure (B), the first electrodes  100   a  and the second electrode  100   b  of one of the above described aspects are arrayed on the Z-direction face of the base  200   a.  The third electrodes  100   c  of one of the above described aspects are arrayed on the Z′-direction face of the base  200   a.  The Z-direction face of the base  200   a  is located at the first height position, and the Z′-direction face of the base  200   a  is located at the second height position. 
     In the structure (C), the third electrodes  100   c  of one of the above described aspects are arrayed on the Z-direction face of the base  200   a.  The insulation layer  300  is provided on the Z-direction face of the base  200   a  so as to cover the third electrodes  100   c.  The first electrodes  100   a  and the second electrode  100   b  of one of the above described aspects are provided on the Z-direction face of the insulation layer  300 . The Z-direction face of the base  200   a  is located at the second height position, and the Z-direction face of the insulation layer  300  is located at the first height position. 
     The touch sensing device T 1  may further includes a cover panel  500 . In any of the above structures (A) to (C), the cover panel  500  may be bonded to the Z-direction face of the base  200   a  with another adhesion layer  400 . Alternatively, the cover panel  500  may be disposed separately from the base  200   a,  e.g. on the Z-direction side relative to the Z-direction face of the base  200   a.  In the latter case, the touch sensing device T 1  may further include at least one functional layer (not shown). The functional layer may function as a hard coating layer, an anti-glare layer, an antireflection layer, a low-reflection layer, a protection layer, an anti-Newtonian layer, a strength retention layer, and/or a stain-proof layer. The functional layer may preferably be positioned between the cover panel  500  and the base  200   a.  The cover panel  500  may also serve as a functional layer. It should be noted that the cover panel  500  and/or the functional layer may be omitted. 
     The touch sensing device T 1  may further include a plurality of first leader lines (not shown), at least one second leader line (not shown), and a plurality of third leader lines (not shown). The first leader lines are respectively connected to the first electrodes  100   a.  The second leader line is connected to the second electrode  100   b.  The third leader lines are respectively connected to the third electrodes  100   c.    
     The touch sensing device T 1  may further include a detector  600 , such as a detection IC, and connecting means (not shown). For example, the connecting means may be a flexible circuit board, including a plurality of conductive lines respectively connected to the first, second, and third leader lines. The detector  600  includes a plurality of connecting terminals. The connecting terminals may be pins or the like, which are respectively connected to the first, second, and third electrodes  100   a,    100   b,  and  100   c,  via the first, second, and third leader lines and the conductive lines of connecting means. 
     If the touch sensing device T 1  is of a self-capacitance type, when a detection object (finger or stylus pen) approaches at least one of the first, second, and third electrodes  100   a,    100   b,  and  100   c,  electrostatic capacitance generated between the approached electrode and the detection object changes, and in accordance with the electrostatic capacitance change, an electrical signal (voltage or current) from the electrode changes. The detector  600  sequentially detects electrical signals (voltages or currents) from the first, second, and third electrodes  100   a,    100   b,  and  100   c  and sequentially compares these signals with a threshold value. The threshold value is stored in a memory provided within or outside the detector  600 . When changes in electrical signals exceed the threshold value in at least one of the first electrodes  100   a  and at least one of the third electrodes  100   c,  the detector  600  judges that the detection object has approached the intersection of such first electrode  100   a  and such third electrode  100   c.  When changes in electrical signals exceed the threshold value in at least one of the third electrodes  100   c  and the or at least one second electrode  100   b,  the detector  600  performs cancelation or other processing, not judging that the detection object has approached the vacant region R 1 . It should be appreciated that detection time required for the detector  600  of a self-capacitance type is time required for the detector  600  to perform a cycle of sequential detection of electrical signals from the first, second, and third electrodes  100   a,    100   b,  and  100   c.    
     If the touch sensing device T 1  is of a mutual capacitance type, one of the electrodes set at the first height position (i.e., the first electrodes  100   a  and the second electrode  100   b ) and the electrode set at the second height position (i.e., the third electrodes  100   c ) serves as drive electrodes, and the other electrode set serves as detection electrodes (sensor electrodes). Each drive electrode and each sensor electrode intersecting in the Z-Z′ direction forms an electrostatically coupled pair. When a detection object approaches at least one intersecting pair of the drive and sensor electrodes, the approach changes electrostatic capacitance generated between the or each intersecting pair of drive and sensor electrodes, and the electrostatic capacitance change results in a change in electrical signals (voltage or current) from the sensor electrode. The detector  600  sequentially supplies drive pulses to the drive electrodes, sequentially detects electrical signals (voltages or currents) from the sensor electrodes, and sequentially compares these signals with a threshold value. The threshold value is stored in a memory within or outside the detector  600 . The detector  600  is configured to judge that a detection object has approached at the intersection of a drive electrode and a sensor electrode when the detector  600  detects a change in electrical signals exceeding the threshold value from the sensor electrode while supplying drive pulses to the drive electrode. If the at least one second electrode  100   b  is a sensor electrode, when a change in electrical signals from the second electrode  100   b  exceeds the threshold value, the detector  600  may perform cancelation or other processing, not judging that the detection object has approached the vacant region R 1 . Alternatively, if the at least one second electrode  100   b  is a drive electrode, the detector  600  may preferably supply drive pulses to the second electrode  100   b.  In this case, when changes in electrical signals from any of the third electrodes  100   c  (sensor electrodes) exceed the threshold value, the detector  600  may perform cancelation or other processing, not judging that the detection object has approached the vacant region R 1  provided with the second electrode  100   b  to which the drive pulse has been supplied. It should be appreciated that detection time required for the detector  600  of a mutual capacitance type is time required for the detector  600  to perform a cycle of sequential detection of electrical signals (voltage or current) from the sensor electrodes. 
     The touch sensing device T 1  is able to distinguish the first touch from the second touch defined as follows. By “first touch” is meant approach of a detection object (e.g., a finger) to an area spanning the vacant region R 1 , a region on the Y-direction side relative to the vacant region R 1  (which may be hereinafter referred to simply as the “Y-direction-side region”), and a region on the Y′-direction-side region relative to the vacant region R 1  (which may be hereinafter referred to simply as the “Y′-direction-side region”). By “second touch” is meant approach of two detection objects (e.g., two fingers) respectively to the Y-direction-side region and the Y′-direction-side region, substantially simultaneously, avoiding the vacant region R 1 . Here, the Y-direction-side region and the Y′-direction-side region form part of the sensing region. 
     If the touch sensing device T 1  is of a self-capacitance type, when the first touch is made, i.e., when a detection object (e.g., a finger) approaches the vacant region R 1 , the Y-direction-side region, and the Y′-direction-side region, the following changes (1) to (3) occur in electrical signals: (1) There are changes exceeding the threshold value in electrical signals from the second electrode  100   b  positioned within the vacant region R 1  as viewed from the Z direction and from at least one of the third electrodes  100   c  whose odd-form electrode portion  120   c  or third electrode portion or portions  110   c  is positioned within the vacant region R 1  as viewed from the Z direction. (2) There is a change exceeding the threshold value in electrical signals from at least one of the first electrodes  100   a  positioned within the Y-direction-side region as viewed from the Z direction and from at least one of the third electrodes  100   c  whose third electrode portion or portions  110   c  are positioned within the Y-direction-side region as viewed from the Z direction. (3) There are changes exceeding the threshold value in electrical signals from at least one of the first electrodes  100   a  positioned within the Y′-direction-side region as viewed from the Z direction, and from at least one of the third electrodes  100   c  whose third electrode portion or portions  110   c  are positioned within the Y′-direction-side region as viewed from the Z direction. When the above changes (1) to (3) occur, the detector  600  judges that the first touch has been made. 
     If the touch sensing device T 1  is of a mutual capacitance type, when the first touch is made, i.e., when a detection object (e.g., a finger) approaches the vacant region R 1 , the Y-direction-side region, and the Y′-direction-side region, the following changes (4) to (6) occur in electrical signals: (4) There is a change exceeding the threshold value in electrical signals either from the second electrode  100   b  (sensor electrode) positioned within the vacant region R 1  as viewed from the Z direction, or from at least one of the third electrodes  100   c  (sensor electrodes) whose odd-form electrode portion(s)  120   c  or third electrode portion(s)  110   c  is positioned within the vacant region R 1  as viewed from the Z direction. (5) There is a change exceeding the threshold value in electrical signals either from at least one of the first electrodes  100   a  (sensor electrodes) positioned within the Y-direction-side region as viewed from the Z direction, or from at least one of the third electrodes  100   c  (sensor electrodes) whose third electrode portion(s)  110   c  is positioned within the Y-direction-side region as viewed from the Z direction. (6) There is a change exceeding the threshold value in electrical signals either from at least one of the first electrodes  100   a  (sensor electrodes) positioned within the Y′-direction-side region as viewed from the Z direction, or from at least one of the third electrodes  100   c  (sensor electrodes) whose third electrode portion(s)  110   c  is positioned within the Y′-direction-side region as viewed from the Z direction. When the above changes (4) to (6) occur, the detector  600  judges that the first touch has been made. 
     If the touch sensing device T 1  is of a self-capacitance type, when the second touch is made, i.e., when a detection object (e.g., a finger) approaches the Y-direction-side region and the Y′-direction-side region, there are electrical signal changes of types (2) and (3) above. When electrical signal changes of both the types (2) and (3) exceed the threshold value, the detector  600  judges that the second touch has been made. 
     If the touch sensing device T 1  is of a self-capacitance type, when the second touch is made, i.e., when a detection object (e.g., a finger) approaches the Y-direction-side region and the Y′-direction-side region, there are electrical signal changes of types (5) and (6) above. When electrical signal changes of both the types (5) and (6) exceed the threshold value, the detector  600  judges that the second touch has been made. 
     The touch sensing device T 1  described above has at least the following technical features. Firstly, as described above, the touch sensing device Ti has a reduced number of electrodes, at least by a first electrode  100   a,  because of the presence of the at least one second electrode  100   b.  This results in reduction of at least one first leader line to be connected to a first electrode  100   a  and at least one connecting terminal of the detector  600 . Therefore, it is possible to save an area for mounting the detector  600  if the detector  600  is mounted on connecting means, such as a flexible circuit board. Further, the reduced number of the electrodes results in reduction of the processing time of the detector  600 . 
     Secondly, the touch sensing device T 1  is able to distinguish the first touch from the second touch as described above. 
     Thirdly, if the third electrodes  100   c  include the odd-form electrode portions  120   c,  the touch sensing device T 1  has a reduced number of third electrodes  100   c  for the reason below. In each odd-form electrode portion  120   c,  the ratio between the Y-Y′ direction dimension of the first portion  121   c  and that of the second portion  122   c  is substantially the same as the ratio between the Y-Y′ direction dimension of the or each second electrode  100   b  and that of each first electrode  100   a  Accordingly, each odd-form electrode portion  120   c  has a Y-Y′ direction dimension larger than that of each third electrode portion  110   c.    
     Second Embodiment 
     The following describes a touch sensing device T 1 ′ according to the second embodiment of the invention with reference to  FIG. 4 . The touch sensing device T 1 ′ has the same configuration as the touch sensing device T 1 , except for the following differences (1) and (2). Difference (1): At least one vacant region R 1 ′ and at least one second electrode  100   b  are provided at different positions from those of the vacant region R 1  and the second electrode  100   b  of the touch sensing device T 1 . Difference (2): The third electrodes  100   c ′ have different configurations from those of the third electrodes  100   c  of the touch sensing device T 1 . These differences will be described in detail, without repeating descriptions on the touch sensing device T 1 ′ that overlap with those of the touch sensing device T 1 .  FIG. 4  shows the Y-Y′ and X-X′ directions in a similar manner to  FIG. 1 . With regard to the Z-Z′ direction in this embodiment, reference should be made to  FIG. 2A  to  FIG. 2C . 
     The at least one vacant region R 1 ′ is located, not between two first electrodes  100   a,  but directly on the Y-direction side with respect to the first electrode  100   a  at the Y-direction end and/or directly on the Y′-direction side to the first electrode  100   a  at the Y′-direction end. In other words, the or each vacant region R 1 ′ is located on an outer side of the array of the first electrodes  100   a.    
     The at least one second electrode  100   b  is provided, not between two first electrodes  100   a,  but directly on the Y-direction side to the first electrode  100   a  at the end in the Y direction (i.e., within the vacant region R 1 ′ on the Y-direction side) and/or directly on the Y′-direction side to the first electrode  100   a  at the end in the Y′ direction (i.e., within the vacant region R 1 ′ on the Y′-direction side). In other words, the or each second electrode  100   b  is located on an outer side of the array of the first electrodes  100   a.    
     Each of the third electrodes  100   c ′ may further include at least one odd-form electrode portion  140   c,  in addition to a plurality of third electrode portions  110   c  and at least one odd-form electrode portion  120   c.  The at least one odd-form electrode portion  140   c  is of the same shape as that of the first portion  121   c  of each odd-form electrode portion  120   c  and may preferably be positioned at the Y-direction end and/or at the Y′-direction end in each third electrode  100   c ′. Each odd-form electrode portion  140   c  is connected to the adjacent inside one of the odd-form electrode portion  120   c.  If each third electrode  100   c ′ includes two odd-form electrode portion  140   c  at the Y-direction end and the Y′-direction end, these odd-form electrode portions  140   c  are symmetrically shaped in the Y-Y′ direction. The odd-form electrode portions  140   c  may be omitted and replaced with odd-form electrode portions  120   c  or third electrode portions  110   c.    
     The touch sensing device T 1 ′ described above provides similar technical effects as those of the touch sensing device T 1 . 
     Third Embodiment 
     The following describes a touch sensing device T 2  according to a third embodiment and its variants of the invention with reference to  FIG. 5  through  FIG. 7B . The touch sensing device T 2  includes a plurality of fourth electrodes  100   d  and a plurality of fifth electrodes  100   e.    FIGS. 5 and 6A  shows the touch sensing device T 2  according to the third embodiment,  FIG. 6B  shows a first variant thereof, and  FIG. 6C  shows a second variant thereof.  FIG. 7A  shows the layout of the fourth electrodes of the touch sensing device T 2  according to the third embodiment and its first and second variants.  FIG. 7B  shows the layout of the fifth electrodes of the touch sensing device T 2  according to the first embodiment and its first and second variants. 
     The Y-Y′ direction shown in  FIG. 5  through  FIG. 7B  corresponds to the first direction as defined in the appended claims. The X-X′ direction shown in  FIGS. 5, 7A, and 7B  corresponds to the second direction as defined in the appended claims. The X-X′ direction may be any direction crossing the Y-Y′ direction. The X-X′ direction may be orthogonal to the Y-Y′ direction as shown in  FIGS. 5, 7A, and 7B . The Z-Z′ direction shown in  FIG. 6A  through  FIG. 6C  corresponds to the third direction as defined in the appended claims. The Z-Z′ direction is orthogonal to the Y-Y′ and X-X′ directions. It should be noted that the fourth electrodes  100   d  and the fifth electrodes  100   e  in  FIGS. 5, 7A, and 7B  are illustrated with different dot patterns for the convenience of distinction. These dot patterns are merely imaginary patterns and not actually provided on the fourth electrodes  100   d  and the fifth electrodes  100   e.    
     The fourth electrodes  100   d  may have similar configuration and arrangement to those of the first electrodes  100   a,  except for the following differences. The fourth electrodes  100   d  may be strip-shaped extending in the X-X′ direction. Alternatively, the fourth electrodes  100   d  may each include a plurality of fourth electrode portions  110   d.  The fourth electrodes  100   d  may each further include at least one, half electrode portion  120   d.    
     There is a vacant region R 2  defined between two (a pair) of the fourth electrodes  100   d.  None of the fourth electrodes  100   d  are present within the vacant region R 2 . There may be a plurality of vacant regions R 2 , each between a different pair of the fourth electrodes  100   d.  In  FIGS. 5 and 7A , the vacant regions R 2  are defined between a pair of the fourth electrodes  100   d,  and another vacant region R 2  is defined between another pair of the fourth electrodes  100   d.    
     Where each fourth electrode  100   d  has a Y-Y′ direction dimension W 3 , and the or each vacant region R 2  has a Y-Y′ direction dimension W 4 , the dimensions W 3  and W 4  may satisfy either relation (1) or relation (2) as follows. Relation (1): W 4 ≧W 3 ×2 (the dimension W 4  is equal to, or larger than, twice the dimension W 3 ). Here, the number of vacant regions R 2  is at least one. The total number of the fourth electrodes  100   d  required in the touch sensing device T 2  is fewer than the total number of fourth electrodes  100   d  in a second comparative example in which there are only fourth electrodes  100   d  arrayed at regular intervals in the Y-Y′ direction at the first height position. For example, if the dimension W 4  is twice the dimension W 3 , because of the existence of the at least one vacant region R 2 , the touch sensing device T 2  requires one less electrode, i.e., one less fourth electrode  100   d,  compared to the second comparative example. If the dimension W 4  is three times the dimension W 3 , because of the existence of the at least one vacant region R 2 , the touch sensing device T 2  requires two less electrodes, i.e., two less fourth electrodes  100   d,  compared to the second comparative example. If the dimension W 4  is four times the dimension W 3 , because of the existence of the at least one vacant region R 2 , the touch sensing device T 2  requires three less electrodes, i.e., three less fourth electrodes  100   d,  compared to the second comparative example. 
     Relation (2): W 3 &lt;W 4 &lt;W 3 ×2, and W 4 ×N 2 ≧W 3 ×N 2 +W 3 , where N 2  is the number of the vacant region R 2 , N 2  being an integer of two or more (where two or more vacant regions R 2  are provided and the dimension W 4  is larger than the dimension W 3  and smaller than twice the dimension W 3 , W 4 × the number of the vacant regions R 2 ≧W 3 × the number of the vacant regions R 2 +W 3 ). For example, when W 3  is 1 mm, W 4  is 1.2 mm, and the number of the vacant region R 2  is 5, a relation “1.2×5≧1×5+1” is satisfied. When W 3  is 1 mm, W 4  is 1.5 mm, and the number of the vacant region R 2  is 2, a relation “1.5×2≧1×2+1” is satisfied. In either case, the total number of the fourth electrodes  100   d  required in the touch sensing device T 2  is fewer than the total number of the fourth electrodes  100   d  required in the second comparative example described above. Specifically, because of the existence of the two or more vacant regions R 2 , the touch sensing device T 2  requires one less electrode, i.e., one less fourth electrode  100   d,  compared to the second comparative example. 
     It should be noted that the electrode region or regions in which the fourth electrodes  100   d  are arrayed at the first height position serves as a sensing region or regions for detecting approach (such as touch) of a detection object (finger or stylus pen) to the touch sensing device T 2 . The vacant region R 2  is a region in which approach (such as touch) of a detection object (finger or stylus pen) to the touch sensing device T 2  will not be detected. 
     The fifth electrodes  100   e  extend in the Y-Y′ direction. The fifth electrodes  100   e  are arrayed at intervals in the X-X′ direction at a second height position. The second height position is different from the first height position in the Z-Z′ direction. The fifth electrodes  100   e  may or may not be arrayed at regular intervals. The fifth electrodes  100   e  are not in contact with each other. The fifth electrodes  100   e  may preferably cross with the fourth electrodes  100   d,  at any or right angles. 
     If the fourth electrodes  100   d  are strip-shaped extending in the X-X′ direction, the fifth electrodes  100   e  may be strip-shaped extending in the Y-Y′ direction. If each fourth electrode  100   d  includes the fourth electrode portions  110   d,  each fifth electrode  100   e  may include a plurality of fifth electrode portions  110   e.    
     In each fifth electrode  100   e,  the fifth electrode portions  110   e  are arrayed along the Y-Y′ direction at the second height position, and each two adjacent ones in the Y-Y′ direction of the fifth electrode portions  110   e  are connected to each other. The fifth electrode portions  110   e  may each be of any shape. For example, the fifth electrode portions  110   e  may each be of a rhombic shape (see  FIGS. 5 and 7A ), any polygonal shape other than rhombic shape, a circular or other curved-sided shape, or other shapes. 
     Each fifth electrode portion  110   e  is located between adjacent fourth electrode portions  110   d  at the first height position. More specifically, each fifth electrode portion  110   e  is located on the Z′-direction side relative to a respective space defined by four fourth electrode portions  110   d  adjacent to each other at the first height position (i.e., two fourth electrode portions  110   d  of one fourth electrode  100   d  and two fourth electrode portions  110   d  of another fourth electrode  100   d  adjacent to the one fourth electrode  100   d ). For any shape of the fourth electrode potions  110   d,  each fifth electrode portion  110   e  of the fifth electrodes  100   e  may be of substantially the same shape as that of the space defined by four adjacent fourth electrode portions  110   e  at the first height position. If the fourth electrodes  100   d  include the half electrode portions  120   d,  each fifth electrode portion  110   e  at the X-or X′-direction end is located on the Z′-direction side relative to a respective space at the first height position defined by two half electrode portions  120   d  adjacent to each other in the Y-Y′ direction and two fourth electrode portions  110   d  adjacent to each other in the Y-Y′ direction and adjacent to these half electrode portions  120   d  in the X-X′ direction, in other words, defined by the half electrode portion  120   d  and the adjacent fourth electrode portion  110   d  of one fourth electrode  100   d  and the half electrode portion  120   a  and the adjacent fourth electrode portion  110   d  of another fourth electrode  100   d  that is adjacent to the one fourth electrode  100   d  in the Y-Y′ direction. 
     Each fifth electrode  100   e  may further include at least a pair of half electrode portions  120   e  and at least one connecting portion  130   e  in addition to the fifth electrode portions  110   e.  Each half electrode portion  120   e  is of a shape that is substantially one half of a fifth electrode portion  110   e  (see  FIG. 7B ). The or each pair of half electrode portions  120   e  are positioned at the second height position, on the Y- and Y′-direction sides with respect to the or a respective vacant region R 2 . The half electrode portions  120   e  in each pair are respectively connected to the fifth electrode portions  110   e  directly on the Y- and Y′-direction sides thereof. In each pair, the half electrode portion  120   e  on the Y-direction side and the half electrode portion  120   e  on the Y′-direction side are symmetrical shaped in the Y-Y′ direction. Each half electrode portion  120   e  may preferably be located on the Z′-direction side relative to a respective space defined by a respective vacant region R 2  and two fourth electrode portions  110   d  that are adjacent to each other in the X-X′ direction at the first height position. If the fourth electrodes  100   d  include the half electrode portions  120   d,  each half electrode portions  120   e  at the X-or X′-direction end may preferably be located on the Z′-direction side relative to a respective space defined by a vacant region R 2 , and a half electrode portion  120   d,  and the fourth electrode portion  110   d  that is adjacent to the half electrode portion  120   d  in the X-X′ direction at the first height position. 
     The or each connecting portion  130   e  of each fifth electrode  100   e  is positioned within the vacant region R 2  and connects two half electrode portions  120   e.  Each connecting portion  130   e  has an X-X′ direction dimension smaller at least than that of each fifth electrode portion  110   e.  The X-X′ direction dimension of the connecting portion  130   e  may be smaller than that of each half electrode portions  120   e.  It should be appreciated that if the touch sensing device T 2  is of a mutual capacitance type, the or each vacant region R 2  includes no fourth electrodes  100   d.  Specifically, as the vacant region R 2  includes no electrodes to couple with the connecting portions  130   e,  each connecting portion  130   e  may have any X-X′ direction dimension without limitation. If the touch sensing device T 1  is of a self-capacitance type, the connecting portions  130   e  per se may serve as electrode portions in the vacant region R 2  for detecting approach of a detection object. If a threshold value for a detector  600 ′ (to be described) is set as X % of a maximum change value in electrostatic capacitance (i.e., the maximum change value of electrical signals from the fifth electrodes  100   e ) of the fifth electrode portions  110   e,  the X-X′ direction dimension of each connecting portion  130   e  may preferably be smaller than X % of the X-X′ direction dimension of the fifth electrode portions  110   e.  For example, if a threshold value for the detector  600 ′ is set as 50% of the maximum change value in electrostatic capacitance of the fifth electrode portions  110   e  (i.e., a maximum change value in electrical signals from the fifth electrodes  100   e ), each connecting portion  130   e  may preferably have an X-X′ direction dimension that is smaller than a half (smaller than 50%) of the X-X′ direction dimension of each fifth electrode  100   e.  In this case, when a detection object approaches a vacant region R 2  to cause the electrostatic capacitance of the corresponding connecting portion  130   e  (electrical signal from the fifth electrode  100   e ) to change to the maximum value, this value does not reach the threshold value. Therefore, the detector  600 ′ does not judge that the detection object has approached the vacant region R 2 . 
     Each of the fifth electrodes  100   e  may further include at least one half electrode portion  140   e.  The, or each, half electrode portion  140   e  is of a shape that is substantially one half of a fifth electrode portion  110   e  (see  FIG. 7B ), and positioned at the second height position, at the Y-direction end and/or the Y′ -direction end of the fifth electrode  100   e.  The, or each, half electrode portion  140   e  is connected to the adjacent inside one of the fifth electrode portions  110   e.  If each fifth electrode  100   e  includes a half electrode portion  140   e  at the Y-direction end and another half electrode portion  140   e  at the Y′-direction end, the two half electrode portions  140   e  are symmetrically shaped in the Y-Y′ direction. Alternatively, each fifth electrode  100   e  may include only one, half electrode portion  140   e  at the Y- or Y′-direction end thereof, and the other end of the fifth electrode  100   e  may be provided with fifth electrode portion  110   e.  Still alternatively, each fifth electrode  100   e  may include no half electrode portions  140   e,  and each of the Y- and Y′-direction ends of the fifth electrode  100   e  may be provided with a third electrode portion  110   e.  If no fifth electrode portions  110   e  are interposed between each half electrode portion  140   e  and a corresponding half electrode portion  120   e,  the each half electrode portion  140   e  and the corresponding half electrode portion  120   e  may be connected to each other. 
     The touch sensing device T 2  may take any one of the structures (A), (B), or (C) as described for the touch sensing device T 1  f shown in  FIGS. 6A, 6B, and 6C , respectively. 
     Particularly, in the structure (A), the fourth electrodes  100   d  of one of the above described aspects are arrayed on the Z-direction face of a base  200   a.  The fifth electrodes  100   e  of one of the above described aspects are arrayed on the Z-direction face of a base  200   b.  The Z′-direction face of the base  200   a  and the Z-direction face of the base  200   b  are bonded together with an adhesion layer  400 . The Z-direction face of the base  200   a  is located at the first height position, and the Z-direction face of the base  200   b  is located at the second height position. 
     In the structure (B), the fourth electrodes  100   d  of one of the above described aspects are arrayed on the Z-direction face of a base  200   a.  The fifth electrodes  100   e  of one of the above described aspects are arrayed on the Z′-direction face of the base  200   a.  The Z-direction face of the base  200   a  is located at the first height position, and the Z′-direction face of the base  200   a  is located at the second height position. 
     In the structure (C), the fifth electrodes  100   e  of one of the above described aspects are arrayed on the Z-direction face of a base  200   a.  Over the Z-direction face of the base  200   a,  an insulation layer  300  is disposed so as to cover the fifth electrodes  100   e.  The fourth electrodes  100   d  of one of the above described aspects are provided on the Z-direction face of the insulation layer  300 . The Z-direction face of the base  200   a  is located at the second height position, and the Z-direction face of the insulation layer  300  is located at the first height position. 
     The touch sensing device T 2  may further includes a cover panel  500 . The cover panel  500  has the same configuration as that of the touch sensing device T 1 . The touch sensing device T 2  may further include at least one functional layer (not shown) with the same configuration as that of the touch sensing device T 1 . The touch sensing device T 2  may further include a plurality of fourth leader lines (not shown)and a plurality of fifth leader lines (not shown). The fourth leader lines are respectively connected to the fourth electrodes  100   d.  The fifth leader lines are respectively connected to the fifth electrodes  100   e.  The touch sensing device T 2  may further include a detector  600 ′, such as a detection IC and connecting means (not shown). For example, the connecting means may be a flexible circuit board, including a plurality of conductive lines respectively connected to the fourth and fifth leader lines. The detector  600 ′ includes a plurality of connecting terminals. The connecting terminals may be pins or the like, which are respectively connected to the fourth electrodes  100   d  and the fifth electrodes  100   e  via the fourth and fifth leader lines and the conductive lines of connecting means. 
     If the touch sensing device T 2  is a touch sensor of a self-capacitance type, when a detection object (finger or stylus pen) approaches at least one of the fourth and fifth electrodes  100   d  and  100   e,  electrostatic capacitance generated between the approached electrode and the detection object changes, and in accordance with the electrostatic capacitance change, an electrical signal (voltage or current) from the electrode changes. The detector  600 ′ sequentially detects electrical signals (voltages or currents) from the fourth and fifth electrodes  100   d  and  100   e,  and sequentially compares these signals with a threshold value. The threshold value is stored in a memory provided within or outside the detector  600 ′. When changes in electrical signals exceed the threshold value in at least one of the fourth electrodes  100   d  and at least one of the fifth electrodes  100   e,  the detector  600  judges that the detection object has approached the intersection of such fourth electrode  100   d  and such fifth electrode  100   e.  When a detection object approaches a vacant region R 2 , the detector  600 ′ detects no changes in electrical signal from the fourth electrodes  100   d.  On the other hand, the detector  600 ′ is able to detect changes in electrical signals from the fifth electrodes  100   e,  but the changes do not exceed the threshold value. It should be appreciated that detection time required for the detector  600 ′ of a mutual capacitance type is time required for the detector  600 ′ to perform a cycle of sequential detection of electrical signals (voltage or current) from the fourth and fifth electrodes  100   d  and  100   e.    
     If the touch sensing device T 2  is of a mutual capacitance type, the fourth electrodes  100   d  and the fifth electrodes  100   e  serves as drive electrodes and sensor electrodes, respectively, or as sensor electrodes and drive electrodes, respectively. Each drive electrode and each sensor electrode intersecting in the Z-Z′ direction forms an electrostatically coupled pair. When a detection object approaches at least one intersecting pair of the drive and sensor electrodes, electrostatic capacitance generated between the or each intersecting pair of drive and sensor electrodes changes, and in accordance with the electrostatic capacitance change, an electrical signal (voltage or current) from the sensor electrode changes. The detector  600 ′ sequentially supplies drive pulses to the drive electrodes and also sequentially detects electrical signals (voltages or currents) from the sensor electrodes and sequentially compares these signals with a threshold value. The threshold value is stored in a memory within or outside the detector  600 ′. The detector  600 ′ is configured to judge that a detection object has approached at the intersection of a drive electrode and a sensor electrode when the detector  600 ′ detects a change in electrical signals exceeding the threshold value from the sensor electrode while supplying drive pulses to the drive electrode. When a detection object approaches a vacant region R 2 , the detector  600 ′ detects no changes in electrical signals from the sensor electrodes. It should be appreciated that detection time required for the detector  600 ′ to perform a cycle of sequential detection of electrical signals (voltage or current) from the sensor electrodes. 
     The touch sensing device T 2  described above has the following technical features. Firstly, as described above, the touch sensing device T 2 , has a reduced number of electrodes, at least by a fourth electrode  100   d,  because of the presence of the at least one the vacant region R 2 . As a result, the touch sensing device T 2  provides the same effects as those of the touch sensing device T 1 . 
     Secondly, for the following reasons, the touch sensing device T 2  is unlikely to incorrectly detect an approach of a detection object in the vacant region R 2 . Within a vacant region R 2  no fourth electrodes  100   d  are present, but only the connecting portions  130   e  of the fifth electrodes  100   e  are. The X-X′ direction dimension of each connecting portion  130   e  is smaller at least than that of each fifth electrode portion  110   e.  Therefore, if the touch sensing device T 2  is of a self-capacitance type, when a detection object approaches any of the connecting portions  130   e,  the detection object is unlikely to electrostatically couple with the approached connecting portion  130   e.  If the touch sensing device T 2  is of a mutual capacitance type, there are no fourth electrodes  100   d  to electrostatically couple with connecting portions  130   e,  so that there will be no false detection of an approach of the detection object in the vacant region R 2 . 
     Thirdly, the touch sensing device T 2  is easy to bend. As described above, only the connecting portions  130   e  are present in the vacant region R 2 , it is easy to bend the touch sensing device T 2  at the part corresponding to the vacant region R 2 . In particular, flexibility of the touch sensing device T 2  can be increased by punching holes in the touch sensing device T 2  at the part corresponding to the vacant region R 2  to form the device with holes in this part. Specifically, the holes may be provided in at least one of the cover panel  500 , the base  200   a,  the base  200   b,  the insulation layer  300 , the adhesion layer  400 , and the functional layer of the touch sensing device T 2 , at the part corresponding to the at least one vacant region R 2 . 
     Fourth Embodiment 
     The following describes a touch sensing device T 2 ′ according to the fourth embodiment of the invention with reference to  FIG. 8 . The touch sensing device T 2 ′ has the same configuration as the touch sensing device T 2 , except for the following differences (1) and (2). Difference (1): At least one vacant region R 2 ′ is provided at different positions from those of the vacant region R 2  of the touch sensing device T 2 . Difference (2): The fifth electrodes  100   e ′ have different configurations from those of the fifth electrodes  100   e  of the touch sensing device T 2 . These differences will be described in detail, without repeating descriptions on the touch sensing device T 2 ′ that overlap with those of the touch sensing device T 2 .  FIG. 8  shows the Y-Y′ and X-X′ directions in a similar manner to  FIG. 5 . With regard to the Z-Z′ direction in this embodiment, reference should be made to  FIGS. 6A to 6C . 
     The at least one vacant region R 2 ′ is located, not between two fourth electrodes  100   d,  but directly on the Y-direction side of the endmost fourth electrode  100   d  at the Y-direction end and/or directly on the Y′-direction side of the endmost fourth electrode  100   d  at the Y′-direction end. In other words, the or each vacant region R 2 ′ is located on an outer side of the array of the fourth electrode  100   d.    
     Each of fifth electrodes  100   e ′ may include a plurality of fifth electrode portions  110   e,  at least one half electrode portions  120   e,  and at least one connecting portion  130   e.  The or each connecting portion  130   e  includes a first end (Y-direction end or Y′-direction end) and a second end opposite to the first end. The first end of each connecting portion  130   e  is connected to the corresponding half electrode portion  120   e.  The second end of each connecting portion  130   e  is not connected to a half electrode portion  120   e,  but may be connected to a fifth leader line. In each fifth electrode  100   e ′, the connecting portion  130   e  is positioned at or Y-direction end and/or at or Y′-direction end. In each fifth electrode  100   e ′, one of the half electrode portions  120   e  may be replaced with a fifth electrode portion  110   e.  This fifth electrode portion  110   e  is located directly on an inner side of and connected to the corresponding connecting portion  130   e.    
     The touch sensing device T 2 ′ described above provides similar technical effects as those of the touch sensing device T 2 . 
     It should be noted that the touch sensing device described above is not limited to the above embodiments but may be modified in any manner within the scope of the appended claims. 
     It should be appreciated that the touch sensing devices of the above embodiments and variants thereof are described above by way of examples only. The materials, shapes, dimensions, numbers, arrangements, and other configurations of the constituents of the touch sensing devices may be modified in any manner if they can perform similar functions. The configurations of the embodiments and the variants described above may be combined in any possible manner. The first direction of the invention may be any direction in which the first electrodes of the invention are arrayed at intervals. The second direction of the invention may be any direction crossing the first direction. The third direction of the invention may be any direction orthogonal to the first and second directions. 
     REFERENCE SIGNS LIST 
     T 1 , T 1 : touch sensing device 
       100   a:  first electrode 
       110   a:  first electrode portion 
       120   a:  half electrode portion 
     R 1 , R 1 ′: vacant region 
       100   b:  second electrode 
       110   b:  second electrode portion 
       120   b:  half electrode portion 
       100   c:  third electrode 
       110   c:  third electrode portion 
       120   c:  odd-form electrode portion 
       121   c:  first portion 
       122   c:  second portion 
       130   c:  half electrode portion 
     T 2 , T 2 ′: touch sensing device 
       100   d:  fourth electrode 
       110   d:  fourth electrode portion 
       120   d:  half electrode portion 
     R 2 , R 2 ′: vacant region 
       100   e,    100   e ′: fifth electrode 
       110   e:  fifth electrode portion 
       120   e:  half electrode portion 
       130   e:  connecting portion 
       140   e:  half electrode portion 
       200   a:  base 
       200   b:  base 
       300 : insulation layer 
       400 : adhesion layer 
       500 : cover panel 
       600 ,  600 ′: detector