Patent Publication Number: US-2020278771-A1

Title: Multi-size touch sensor

Description:
TECHNICAL FIELD 
     This disclosure relates generally to touch sensors, and to related processes and systems. 
     BACKGROUND 
     Touch sensitive devices allow a user to conveniently interface with electronic systems and displays by reducing or eliminating the need for mechanical buttons, keypads, keyboards, and pointing devices. For example, a user can carry out a complicated sequence of instructions by simply touching an on-display touch screen at a location identified by an icon. 
     Projected capacitive touch sensing devices have been found to work well in a number of applications. In many touch sensitive devices, the input is sensed when a conductive object in the sensor is capacitively coupled to a conductive touch implement such as a user&#39;s finger. Generally, whenever two electrically conductive members come into proximity with one another without actually touching, a capacitance is formed therebetween. In the case of a capacitive touch sensitive device, as an object such as a finger approaches the touch sensing surface, a capacitance forms between the object and the sensing points in close proximity to the object. By detecting changes in capacitance at the sensing point, the sensing circuit can determine the location of the touch. 
     BRIEF SUMMARY 
     According to some embodiments, a capacitive touch sensor includes a plurality of spaced apart electrically conductive first electrodes extending along a first direction and a plurality of spaced apart electrically conductive second electrodes extending along a different second direction. The touch sensor includes plurality of electrically conductive bus lines. Each bus line corresponds to a first or second electrode. A first end of each bus line terminates at a connection region at a periphery of the touch sensor for connection to a controller. An opposite second end of each bus line, except for at least one bus line, terminates at and makes contact with a corresponding first or second electrode. The opposite second end of the at least one bus line terminates near, but does not make contact with, a longitudinal end of a corresponding first or second electrode. 
     According to some embodiments, a capacitive touch sensor comprises a flexible substrate having first and second edges extending along different respective first and second directions. A plurality of spaced apart electrically conductive first electrodes is disposed on the flexible substrate and extends longitudinally along the first direction. The first electrode nearest the first edge of the substrate is narrower than the rest of the first electrodes and extends widthwise to the first edge. A plurality of spaced apart electrically conductive second electrodes is disposed on the flexible substrate and extends longitudinally along the second direction. 
     In some embodiments, a capacitive touch sensor includes a touch sensitive viewing area with a border area surrounding the touch sensitive viewing area and having an outermost polygonal perimeter comprising a plurality of sides and vertices. A plurality of spaced apart electrically conductive first electrodes is disposed in the touch sensitive viewing area and extends along a first direction. A plurality of spaced apart electrically conductive second electrodes is disposed in the touch sensitive viewing area and extends along a different second direction. A plurality of electrically conductive bus lines is disposed in the border area for electrically coupling the pluralities of the first and second electrodes to a controller. 
     At least one first alignment feature is disposed within the border area near each of at least three vertices of the polygonal perimeter for aligning the touch sensor to a substrate. At least one second alignment feature is disposed within the border area near each of at least one side of the polygonal perimeter and away from the vertices corresponding to the side. 
     In accordance with some embodiments, a capacitive touch sensitive device includes a touch sensor that comprises a plurality of spaced apart electrically conductive first electrodes extending along a first direction. A plurality of electrically conductive first bus lines electrically connect a first end of each first electrode to a first connection region at a periphery of the touch sensor for connection to a controller. A plurality of electrically conductive third bus lines electrically connect an opposite second end of each first electrode to a different third connection region at the periphery of the touch sensor for connection to a controller. The touch sensitive device includes a flexible circuit connected to the first, but not the third, connection region. The touch sensitive device is configured to detect a location of a touch applied to the touch sensor by detecting a change in a coupling capacitance near the touch location. 
     Some embodiments are directed to a method of making a rectangular smaller touch sensor from a rectangular larger touch sensor. A first cutline extending across a viewing area of the larger touch sensor and orthogonally intersecting a first side of the larger touch sensor at a first cut location is determined. The first side terminates at first and second vertices of the larger touch sensor. A first alignment feature is formed at a first vertex of the larger touch sensor. The first alignment feature is configured to align the larger touch sensor to a larger substrate. A second alignment feature is formed near the first cut location opposite the first alignment feature. The larger sensor is cut along the first cutline into multiple cut portions. The cut portion comprising the second alignment feature is formed into a smaller touch sensor. The second alignment feature is at a vertex of the smaller touch sensor and configured to align the smaller touch sensor with a smaller substrate. 
     These and other aspects of the present application will be apparent from the detailed description below. In no event, however, should the above summaries be construed as limitations on the claimed subject matter, which subject matter is defined solely by the attached claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of a full size touch sensor that includes alignment features in accordance with some embodiments; 
         FIG. 2  is a cross sectional diagram showing alignment of the touch sensor of  FIG. 1  with a substrate in accordance with some embodiments; 
         FIG. 3  is a flow diagram illustrating processes of making a rectangular smaller touch sensor from a rectangular larger touch sensor in accordance with some embodiments; 
         FIG. 4A  depicts a top view of a cut down touch sensor in accordance with some embodiments; 
         FIG. 4B  is a more detailed view of a portion of the touch sensor of  FIG. 4A ; 
         FIG. 5  illustrates first and second electrodes comprising a metal mesh in accordance with some embodiments; and 
         FIG. 6  depicts a top view of a cut down touch sensor in accordance with some embodiments. 
     
    
    
     The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number. 
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     A classical capacitive touch sensor is designed using a discrete film design (e.g., photomask) that is specifically designed for a touch sensor of a particular size. Each photomask may be used to create a large roll of images, which are singulated during the manufacturing process into several touch sensors of the same size and shape. Since this discrete film design typically precludes it from being used on multiple different sized touch sensors, a different roll of images is required for each different sized touch sensor. 
     It may be more cost effective to use a single photomask or fewer photomasks to fabricate multiple different sized touch sensors. Embodiments disclosed herein disclose a multi-size touch sensor that incorporates features that allow one “full size” touch sensor film to be used to produce a finished cut down touch sensor of a different size (e.g., a 24″ film design maybe cut down to make a 23″ or 21″ or 18″ touch sensor, etc.). The approaches disclosed herein reduce tooling costs associated with producing the one or more photomasks used to make the multi-size touch sensor, simplify inventory management (fewer master touch sensor rolls to manage), and provide other useful characteristics. According to some embodiments, the full size touch sensor includes alignment features and/or other features that provide for producing the cut down touch sensors. According to some embodiments, the cut down touch sensors include features that are not present in the full size touch sensor. 
       FIG. 1  is a top view of a full size capacitive touch sensor  100  that can be cut down to produce touch sensors of multiple smaller sizes. The touch sensor  100  has a touch sensitive viewing area  115  with a periphery  180  (also referred to as a “border area”) surrounding the touch sensitive viewing area  115 . The touch sensor  100  has an outermost polygonal perimeter  740  comprising a plurality of sides  700 ,  710 ,  720 ,  730  and vertices  1 ,  2 ,  3 ,  4 . In the example shown, the touch sensor  100  is rectangular but it will be appreciated that touch sensor shapes other than rectangular that include more or fewer sides and vertices are also possible. 
     The touch sensor  100  includes a plurality of spaced apart electrically conductive first electrodes  110  disposed in the touch sensitive viewing area  115  and extending along a first direction, which is designated as the x direction in  FIG. 1 . The touch sensor  100  includes a plurality of spaced apart electrically conductive second electrodes  120  disposed in the touch sensitive viewing area  115  and extending along a different second direction, which is designated as the y direction in  FIG. 1 . In some embodiments, the first  110  and/or second touch sensitive electrodes  120  may be optically transparent and/or may comprise a metallic grid. 
     The first and second touch sensitive electrodes  110 ,  120  are coupled to a plurality of electrically conductive bus lines  130 ,  140 ,  150 ,  160  disposed in the periphery  180  of the touch sensor  100 . The electrically conductive bus lines  130 ,  140 ,  150 ,  160  are configured to couple the first and second electrodes  110 ,  120  to a controller  190 . The controller  190  is configured to determine the location of a touch on the touch sensor  100  based on detected changes in capacitance sensed by the first and second electrodes  110 ,  120 . 
     The touch sensor  100  includes multiple sets of alignment features (also referred to herein as “fiducials”) that can be used to fabricate touch sensors of multiple sizes. When a touch sensitive device, such as a touch sensitive display that incorporates the touch sensor  100 , is fabricated, the touch sensor  100  is aligned with a substrate  500 , as illustrated in the cross section of  FIG. 2 . Alignment features located on the touch sensor  100  facilitate alignment of the touch sensor  100  with the substrate  500 . To accommodate the fabrication of touch sensors of multiple sizes, the full size touch sensor  100  may include multiple sets of alignment features. The touch sensor  100  may include a set of first alignment features  400 ,  410 ,  420 ,  430  respectively disposed at vertices  1 ,  2 ,  3 ,  4 , of the touch sensor  100 . The first alignment features  400 ,  410 ,  420 ,  430  provide for aligning a touch sensor of a first size, e.g. the full size touch sensor, with a substrate  500  of a touch sensitive display of a first size. In some embodiments, the substrate  500  may be optically transparent, at least in a region corresponding to the touch sensitive viewing area  115  of the touch sensor  100 . It will be appreciated that alignment of the touch sensor  100  to the substrate  500  may be accomplished with fewer than four alignment features, e.g., at least one, at least two, or at least three alignment features located respectively at one, two or three of the vertices may adequately provide for alignment of the “full-size” touch sensor to the substrate. 
     The touch sensor  100  may also include additional sets of alignment features. For example the touch sensor  100  may include one or more sets of second alignment features  440 ,  442 ,  444 ,  446  that provide for aligning a cut down touch sensor of a second size which is less than the full size touch sensor  100  with a substrate of a second size touch sensitive device. For example, the second alignment features  440 ,  446 ,  442 ,  444  allow the full size touch sensor  100  to be cut down to one or more smaller size touch sensors that can be incorporated into smaller sizes of a touch sensitive display. 
     In the example shown in  FIG. 1 , the touch sensor  100  includes four first alignment features  400 ,  410 ,  420 ,  430 , each first alignment feature  400 ,  410 ,  420 ,  430  respectively disposed near one the four vertices  1 ,  2 ,  3 ,  4  of the polygonal perimeter  740 . The touch sensor also includes at least one second alignment feature within the peripheral area and located near the sides of the polygonal perimeter and away from the vertices corresponding to the sides. For example, as shown in  FIG. 1 , the touch sensor  100  includes second alignment features  440 ,  442 ,  444 ,  446 . Second alignment features  440 ,  442  are disposed near side  700  and away from the vertices  1  and  2 . Second alignment features  444 ,  446  are disposed near side  710  and away from vertices  2  and  3 . 
     The second alignment features  440 ,  442 ,  444 ,  446  provide for alignment of a cut down touch sensor with a substrate, the cut down touch sensor having a size that is less than the full size of the polygonal perimeter  740  of the touch sensor  100 . 
     As shown in  FIG. 1 , in some embodiments, a first side  700  of the polygonal perimeter  740  has the at least one first alignment feature  400  located near a longitudinal end of the first side  700  and at least one second alignment feature  440  near a cut location  610  on the first side  700 . The first side  700  terminates at first  1  and second  2  vertices of the touch sensor  100 . The cut location  610  is between the at least one first and second alignment features  400 ,  440 . The touch sensor  100  is adapted to be cut into a smaller size touch sensor along a cut line  600  perpendicular to and intersecting the first side  700  at the cut location  610 . The first cut line  600  may extend across the viewing area  115  of the touch sensor  100  in some cases. When the touch sensor  100  is cut along the cut line  600 , the touch sensor  100  is divided into first and second cut portions  100   a ,  100   b . The first cut portion  100   a  comprises the first alignment feature  400  and may be discarded. The second cut portion  100   b  forms a smaller touch sensor having the second alignment feature  440  near a vertex  1   b  of the smaller touch sensor  100   b . The second alignment feature  440  is adapted for aligning the smaller touch sensor  100   b  to a substrate, e.g. a smaller substrate. 
     In some embodiments, a second side  710  of the polygonal perimeter  740  has at least one first alignment feature  420  located near a longitudinal end of the second side  710  and at least one second alignment feature  446  near a cut location  810  on the second side  710 . The second side  710  terminates at second  2  and third  3  vertices of the touch sensor  100 . The cut location  810  is between the at least one first and second alignment features  410 ,  446 . The touch sensor  100  is adapted to be cut into a smaller size touch sensor along a cut line  800  that extends perpendicular to and intersecting the second side  710  at the cut location. The second cut line  800  may extend across the viewing area  115  of the touch sensor  100 . When the touch sensor  100  is cut along the cut line  800 , the touch sensor  100  is divided into third and fourth cut portions  100   c ,  100   d . The third cut portion  100   c  comprises the at least first alignment feature  410  and may be discarded. The fourth cut portion  100   d  forms a smaller touch sensor having the at least one second alignment feature  446  near a vertex  3   b  of the smaller touch sensor  100   d . The at least one second alignment feature  446  is adapted for aligning the smaller touch sensor  100   d  to a smaller substrate. 
     In some embodiments, the touch sensor  100  may be first cut along one of the cut lines  600 ,  800  and subsequently cut along the other of the cut lines  800 ,  600 . Thus, using one or both cut lines  600 ,  800 , the size of the larger touch sensor  100  may be reduced along the x axis, along the y axis or along both the x and y axes. 
     As illustrated in  FIG. 5 , the bus lines  131 ,  151 ,  152  may be connected to the electrodes  111 ,  121 ,  122  at a longitudinal end of the electrode. In some embodiments, the connection between the bus line and the electrode is made at an edge of the longitudinal end that such that a majority of the bus line  131 ,  151 ,  152  is routed over the longitudinal end of the electrode  111 ,  121 ,  122  to which it is connected. For example, in some embodiments, the bus line  131 ,  151 ,  152  is connected to the electrode  111 ,  121 ,  122  such that the bus line  131 ,  151 ,  152  is routed over more than 50%, more than 75%, more than 95% of the longitudinal end. This connection configuration provides for severing the bus line&#39;s connection to the electrode when the touch sensor is cut through that electrode. In some embodiments, the connection between the bus line and the electrode may be made at the edge of the longitudinal end that is furthermost from the connection 
     The flow diagram of  FIG. 3  illustrates processes of making a rectangular smaller touch sensor from a rectangular larger touch sensor in accordance with some embodiments. The left side of  FIG. 3  illustrates processes for a first option that involves reducing the size of the rectangular larger touch sensor along a first axis, e.g., the x-axis. The right side of  FIG. 3  illustrates additional processes for a second option that involves additionally reducing the rectangular larger touch sensor along a second axis, e.g., the y-axis. 
     Starting with  301  a rectangular larger touch sensor, a location of a first cut line is determined  302 . The first cut line may extend across a viewing area of the larger touch sensor, orthogonally intersecting a first side of the larger touch sensor at a first cut location. The first side terminates at first and second vertices of the larger touch sensor. A first alignment feature is formed  303  at a first vertex of the larger touch sensor. The first alignment feature is configured to align the larger touch sensor to a larger substrate. 
     A second alignment feature is formed  304  along the first side of the larger touch sensor and near the first cut location opposite the first alignment feature at the first vertex. The larger touch sensor is cut  305  along a first cut line that lies along a first axis, e.g., the y-axis, into multiple cut portions. The first cut portion comprising the first alignment feature near the first vertex may be discarded. According to option  1 , the second cut portion comprising the second alignment feature disposed along the first side is formed  306  into a touch sensor that is smaller than the larger touch sensor. The second alignment feature disposed along the first side is located at a vertex of the smaller touch sensor and is configured to align the smaller touch sensor with a smaller substrate. 
     Option 2 illustrates processes for cutting the larger touch sensor along two axes, e.g., both the x and y axes. A second cut line lying along an axis, e.g., the x-axis, perpendicular to the first cut line, is determined  311 . The second cut line extends across the viewing area of the larger touch sensor and orthogonally intersects a second side of the larger touch sensor at a second cut location. The second side may be oriented orthogonally to the first side. The second side terminates at the second and third vertices of the larger touch sensor. A first alignment feature is formed  312  at the third vertex of the larger touch sensor. The first alignment feature at the third vertex is configured to align the larger touch sensor to the larger substrate. A second alignment feature is formed  313  along the second side near the second cut location opposite the first alignment feature at the third vertex. The portion of the larger touch sensor that was cut along the first cut line is additionally cut  314  along the second cut line multiple cut portions. The cut portion comprising the first alignment feature at the third vertex may be discarded. The cut portion comprising the second alignment feature along the first side and the second alignment feature along the second side is formed  315  into a smaller touch sensor. The second alignment feature disposed along the second side is located at a vertex of the smaller touch sensor and is configured to align the smaller touch sensor with a smaller substrate. 
     After the larger touch sensor is cut into a smaller touch sensor along one or more axes, the smaller touch sensor includes features that are not present in the larger touch sensor. The second alignment features previously discussed may be used to align the smaller touch sensor with a substrate, e.g., a flexible substrate. 
     According to some embodiments, the smaller touch sensor includes at least one electrode that is not connected to the bus lines that connect the electrodes to the controller. The embodiment described in conjunction with  FIGS. 4A  is directed to smaller touch sensor  101  formed from a larger touch sensor that has been cut down both the x and y-axes.  FIG. 4B  provides a more detailed view of a portion of the touch sensor  101 .  FIGS. 4A and 4B  illustrate the concepts of the embodiments based on a touch sensor that has been cut down along two axes, x and y. However, it will be appreciated that in some embodiments, as previously discussed in connection with  FIG. 3 , the cut down touch sensor may be cut down along only one axis. 
     Turning again to  FIGS. 4A and 4B , a larger touch sensor has been cut along cut lines  600 ,  800  to form a cut size touch sensor  101 . The touch sensor  101  includes a plurality of spaced apart electrically conductive first electrodes  110 ,  110   a ,  110   b  extending along a first direction, shown as the x direction in  FIGS. 4A and 4B , and a plurality of spaced apart electrically conductive second electrodes  120 ,  120   a ,  120   b  extending along a different second direction, shown as the y direction in  FIGS. 4A and 4B . The first and second directions may be orthogonal to each other, but need not be orthogonal in some embodiments. The first and second electrodes  110 ,  110   a ,  110   b ,  120 ,  120   a ,  120   b  may be optically transparent. 
     As illustrated in  FIG. 5 , in some embodiments, each of the first and second electrodes may comprise a metal mesh  220 ,  230 .  FIG. 5  shows one first electrode  111  and two second electrodes  121 ,  122 . 
     As illustrated in  FIG. 5 , in some embodiments the bus line  131  corresponding to the first electrode  111  electrically connects to the first electrode  111  at an edge  111   a  of the longitudinal end of electrode  111 . Bus lines  151 ,  152  corresponding respectively to the second electrodes  121  and  122  electrically connect to the bus lines  151 ,  152  at the edges  121   a ,  122   a  of the longitudinal ends of electrodes  121 ,  122 . In some embodiments, the bus lines are connected to the electrode at the edge of the longitudinal end that is furthermost from the connection area. Connecting the bus lines at the edges of the longitudinal ends of the electrodes ensures that if the touch sensor is cut down through an electrode, e.g., through approximately the center of an electrode, the bus line connected to that electrode will be severed by the cut so that the cut electrode cannot be connected for touch sensing. Thus, the electrodes that are connected for use in touch sensing have substantially the same width. This simplifies the controller programming for touch location determination. 
     Returning to  FIGS. 4A and 4B , the touch sensor  101  includes plurality of electrically conductive bus lines  130 ,  130   a ,  150 ,  150   a . The bus lines  130 ,  130   a ,  150 ,  150   a  may also comprise a metal mesh in some implementations. Each bus line  130 ,  130   a ,  150 ,  150   a  corresponds to a first or second electrode  110 ,  110   a ,  110   b ,  120 ,  120   a ,  120   b . A first end of each bus line  130   a ,  130 ,  150   a ,  150  terminates at a connection region  170 ,  174  at a periphery  180   a  of the touch sensor  101  for connection to a controller  190 . The periphery  180   a  surrounds an optically transparent viewing area  115   a  of the touch sensor  101 . At least the portion of the periphery  180   a  that includes the bus lines  130   a ,  130 ,  150   a ,  150  may be optically opaque. 
     An opposite second end of each bus line  130 ,  150 , except for at least one bus line  130   a ,  150   a , terminates at and makes contact with a corresponding first or second electrode  110 ,  110   b ,  120 ,  120   b . The opposite second end of the bus line  130   a  terminates near, but not making contact with, a longitudinal end of a corresponding first  110   a  electrode. The opposite second end of the bus line  150   a  terminates near, but not making contact with, a longitudinal end of a second  120   a  electrode. The first electrode  110   a  that is not connected to the second end of its corresponding bus line  130   a  is narrower than an adjacent first electrode  110   b  that is connected to the second end of its corresponding bus line  130 . A corresponding second electrode  120   a  that is not connected the second end of its corresponding bus line  150   a  is narrower than an adjacent second electrode  120   b  that is connected to the second end of its corresponding bus line  150 . 
     In some embodiments, the first and second electrodes  110 ,  110   a ,  110   b ,  120 ,  120   a ,  120   b  are disposed on a flexible substrate  300 . The first electrode  110   a  corresponding to truncated bus line  130   a  extends to a first edge  132  of the flexible substrate  300 . The second electrode  120   a  corresponding to truncated bus line  150   a  extends to a different edge  134  of flexible substrate  300 . 
     In some embodiments, electrical connection between the first ends of one or more of the bus lines  130 ,  150  and the controller  190  at one or more of the connection regions  170 ,  174  may be made via one or more flexible circuits  210 ,  214  assembled to the connection region  170 ,  174 . In some embodiments, electrical connection between the first ends of one more of the bus lines  130 ,  150  and the controller  190  at one or more of the connection regions  170 ,  174  may be made via a flexible circuit  210 ,  214  that is integral to and extends from the flexible substrate  300  at the connection region  170 ,  174 . 
     According to some embodiments, after the larger touch sensor  100  is cut into a smaller touch sensor  101  along one or more axes, the smaller touch sensor  101  includes at least one electrode  110   a ,  120   a  that extends to an edge of the flexible substrate  300 . As illustrated in  FIG. 4A , the cut down touch sensor  101  includes a flexible substrate having first  132  and second  134  edges extending along different respective first and second directions. The first and second directions are represented as x and y directions, respectively, in  FIGS. 4A and 4B . The plurality of spaced apart electrically conductive first electrodes  110 ,  110   a ,  110   b  disposed on the flexible substrate  300  extend longitudinally along the first direction. The first electrode  110   a  nearest the first edge  132  of the substrate  300  is narrower than the adjacent first electrode  110   b  and the other first electrodes  110 . The nearest electrode  110   a  to the first edge  132  extends widthwise to the first edge  132 . The plurality of spaced apart electrically conductive second electrodes  120 ,  120   a ,  120   b  disposed on the flexible substrate  300  extend longitudinally along the second direction. Second electrode  120   a  nearest the second edge  134  of the substrate  300  is narrower than the adjacent second electrode  120   b  and the other second electrodes  120 . The second electrode  120   a  nearest the second edge  134  extends widthwise to the second edge  134 . When the touch sensor is assembled into a touch sensitive device, such as a touch sensitive display, at least one of the first electrode  110   a  nearest the first edge  132  and/or the second electrode  120   a  nearest the second edge  134  is disposed in an opaque periphery touch sensor. For example, the opaque periphery of the touch sensor may be covered by a bezel of the assembled touch sensitive device, e.g., a touch sensitive display. As previously discussed, the touch sensor  101  includes a plurality of electrically conductive bus lines  130 ,  130   a    150 ,  150   a , each bus line  130 ,  130   a  corresponding to a first electrode  110 ,  110   a ,  110   b  or a second electrode  120 ,  120   a ,  120   b . The bus line  130   a  corresponding to the first electrode  110   a  nearest the first edge  132  terminates near, but does not make contact with the first electrode  110   a . Similarly, the bus line  150   a  corresponding to the second electrode  120   a  nearest the second edge  134  terminates near, but does not make contact with the second electrode  120   a.    
     In some embodiments, a touch sensitive device incorporating the cut down touch sensor includes a flexible circuit connected to one connection region but not another connection region. The touch sensitive device is configured to detect a location of a touch applied to the touch sensor by detecting a change in a coupling capacitance near the touch location. For example, consider the full size touch sensor  100  shown in  FIG. 1 . The full size touch sensor  100  may be cut down only along the second cut line  800  that extends along x-axis without cutting along the first cut line  600  that extends along the y-axis. Cutting touch sensor  100  along only the x-axis leaves a smaller touch sensor  102  with idle connection regions  172 ,  176  as illustrated in  FIG. 6 . 
     Referring to  FIG. 6  a touch sensitive device  600  that incorporates the cut down touch sensor  102  includes a plurality of spaced apart electrically conductive first electrodes  110 ,  110   a ,  110   b  extending along the x direction and a plurality of spaced apart electrically conductive second electrodes  120  extending along the y direction. A plurality of electrically conductive first bus lines  130 ,  130   a  corresponds to the first electrodes  110 ,  110   a ,  110   b . First bus lines  130  electrically connect a first end of each of the first electrodes  110 ,  110   b  to a first connection region  170  at a periphery of the touch sensor  101  for connection to a controller  190 . Bus line  130   a  is truncated by the cut and does not connect to its corresponding first electrode  110   a.    
     A plurality of electrically conductive third bus lines  140 ,  140   a  corresponds to the first electrodes  110 ,  110   a ,  110   b . A plurality of electrically conductive third bus lines  140  electrically connects an opposite second end of each first electrode  110 ,  110   a ,  110   b  to a different third connection region  172  at the periphery of the touch sensor  102  for connection to a controller. Bus line  140   a  is truncated by the cut and does not connect to its corresponding first electrode  110   a . A flexible circuit  210  is connected to the first  170 , but not the third  172 , connection region. 
     In some embodiments, the flexible circuit  210  that is connected to the first connection region  170  is assembled to the touch sensor  102  at the first connection region  170 . In some embodiments, the flexible circuit  210  that is connected to the first connection region  170  is integral to and extends from the touch sensor  102  at the first connection region  170 . 
     A plurality of electrically conductive second bus lines  150  corresponds to the second electrodes  120 . Second bus lines  150  electrically connect a first end of each second electrode  120  to a second connection region  174  at a periphery of the touch sensor  102  for connection to a controller  190 . A plurality of electrically conductive fourth bus lines  160  corresponds to the second electrodes  120  and terminates at a fourth connection region for connection to a controller. A flexible circuit  214  is connected to the second  174 , but not the fourth  176 , connection region. 
     In some embodiments, the flexible circuit  210  that is connected to the first connection region  170  is assembled to the touch sensor  102  at the first connection region  170 . In some embodiments, the flexible circuit  210  that is connected to the first connection region  170  is integral to and extends from the touch sensor  102  at the first connection region  170 . In some embodiments, the flexible circuit  210  that is connected to the first connection region  170  is assembled to the touch sensor  102  at the first connection region  170 . Similarly, in some embodiments, the flexible circuit  214  that is connected to the second connection region  174  is integral to and extends from the touch sensor  102  at the second connection region  174 . 
     As illustrated in  FIG. 6 , the first and third connection regions  170 ,  172  may be located along adjacent edges  700 ,  740  of the touch sensor  102 . Alternatively, the first and third connection regions may be disposed along a same edge or along opposite edges of the touch sensor. According to some implementations, the first electrodes  110 ,  110   a ,  110   b  are optically transparent and/or the first and second bus lines  130 ,  130   a ,  140  are optically opaque. 
     As illustrated in  FIG. 6 , the second and fourth connection regions  174 ,  176  may be located along adjacent edges  700 ,  740  of the touch sensor  102 . Alternatively, the first and third connection regions may be disposed along a same edge or along opposite edges of the touch sensor. According to some implementations, the first electrodes  120  are optically transparent and/or the second and fourth bus lines  150 ,  160  are optically opaque. 
     As illustrated in  FIG. 6 , the first  170  and second  174  connection regions may be located along a same edge  700  of the touch sensor  102 . Alternatively, the first and second connection regions may be located along adjacent edges or along opposite edges of the touch sensor. 
     Items disclosed herein include: 
     Item 1. A capacitive touch sensor, comprising: 
     a plurality of spaced apart electrically conductive first electrodes extending along a first direction; 
     a plurality of spaced apart electrically conductive second electrodes extending along a different second direction; and 
     a plurality of electrically conductive bus lines, each bus line corresponding to a first or second electrode, a first end of each bus line terminating at a connection region at a periphery of the touch sensor for connection to a controller, an opposite second end of each bus line, except for at least one bus line, terminating at and making contact with a corresponding first or second electrode, the opposite second end of the at least one bus line terminating near, but not making contact with, a longitudinal end of a corresponding first or second electrode. 
     Item 2. The capacitive touch sensor of item 1, wherein the connection between the first ends of the bus lines to a controller at the connection region is made via a flexible circuit assembled to the connection region.
 
Item 3. The capacitive touch sensor of item 1, wherein the connection between the first ends of the bus lines to a controller at the connection region is made via a flexible circuit integral to and extending from the touch sensor at the connection region.
 
Item 4. The capacitive touch sensor of any of items 1 through 3, wherein each first and second electrode is optically transparent.
 
Item 5. The capacitive touch sensor of any of items 1 through 4, wherein the first and second directions are orthogonal to each other.
 
Item 6. The capacitive touch sensor of any of items 1 through 5, wherein each of the first and second electrodes comprises a metal mesh.
 
Item 7. The capacitive touch sensor of any of items 1 through 6, wherein each bus line comprises a metal mesh.
 
Item 8. The capacitive touch sensor of any of items 1 through 7, wherein the at least one bus line comprises first and second bus lines in the plurality of bus lines, the opposite second end of the first bus line terminating near, but not making contact with, a longitudinal end of a corresponding first electrode, the opposite second end of the second bus line terminating near, but not making contact with, a longitudinal end of a corresponding second electrode.
 
Item 9. The capacitive touch sensor of item 8, wherein the corresponding first electrode is narrower than an adjacent first electrode, and the corresponding second electrode is narrower than an adjacent second electrode.
 
Item 10. The capacitive touch sensor of item 8, wherein the first and second electrodes are disposed on a flexible substrate, the corresponding first electrode extending to a first edge of the substrate, the corresponding second electrode extending to a different edge of the flexible substrate.
 
Item 11. The capacitive touch sensor of any of items 1 through 10, wherein at least a portion of the periphery is optically opaque and at least partially surrounds an optically transparent viewing area.
 
Item 12. A capacitive touch sensor, comprising:
 
     a flexible substrate having first and second edges extending along different respective first and second directions; 
     a plurality of spaced apart electrically conductive first electrodes disposed on the flexible substrate and extending longitudinally along the first direction, the first electrode nearest the first edge of the substrate being narrower than the rest of the first electrodes and extending widthwise to the first edge; and 
     a plurality of spaced apart electrically conductive second electrodes disposed on the flexible substrate and extending longitudinally along the second direction. 
     Item 13. The capacitive touch sensor of item 12, wherein the first electrode nearest the first edge is disposed in an opaque periphery of the touch sensor.
 
Item 14. The capacitive touch sensor of any of items 12 through 13, wherein the second electrode nearest the second edge of the substrate is narrower than the rest of the second electrodes and extends widthwise to the second edge.
 
Item 15. The capacitive touch sensor of any of items 12 through 14, wherein the second electrode nearest the second edge is disposed in an opaque periphery of the touch sensor.
 
Item 16. The capacitive touch sensor of any of items 12 through 15, wherein each first and second electrode is optically transparent.
 
Item 17. The capacitive touch sensor of any of items 12 through 16, further comprising a plurality of electrically conductive bus lines, each bus line corresponding to a first electrode, the bus line corresponding to the first electrode nearest the first edge terminating near, but not making contact with the first electrode.
 
Item 18. A capacitive touch sensor, comprising:
 
     a touch sensitive viewing area; 
     a border area surrounding the touch sensitive viewing area and having an outermost polygonal perimeter comprising a plurality of sides and vertices; 
     a plurality of spaced apart electrically conductive first electrodes disposed in the touch sensitive viewing area and extending along a first direction; 
     a plurality of spaced apart electrically conductive second electrodes disposed in the touch sensitive viewing area and extending along a different second direction; 
     a plurality of electrically conductive bus lines disposed in the border area for electrically coupling the pluralities of the first and second electrodes to a controller; 
     at least one first alignment feature within the border area near each of at least three vertices of the polygonal perimeter for aligning the touch sensor to a substrate; and 
     at least one second alignment feature within the border area near each of at least one side of the polygonal perimeter and away from the vertices corresponding to the side. 
     Item 19. The capacitive touch sensor of item 18, wherein: 
     the border area has an outermost rectangular perimeter comprising four sides and four vertices; 
     at least one first alignment feature is disposed within the border area near each vertex of the polygonal perimeter; and 
     at least one second alignment feature is disposed within the border area near each of two adjacent sides of the polygonal perimeter and away from the vertices corresponding to the side. 
     Item 20. The capacitive touch sensor of any of items 18 through 19, wherein each first and second electrode is optically transparent.
 
Item 21. The capacitive touch sensor of any of items 18 through 20 wherein the at least one first alignment feature is for aligning the touch sensor to a substrate, the substrate being optically transparent at least in a region corresponding to the touch sensitive viewing area.
 
Item 22. The capacitive touch sensor of any of items 18 through 21, wherein a first side of the polygonal perimeter has the at least one first alignment feature near a longitudinal end of the first side and the at least one second alignment feature near a cut location on the first side, the cut location between the at least one first and second alignment features, the touch sensor adapted to be cut into a smaller size touch sensor along a cutline perpendicular to and intersecting the first side at the cut location, such that when the touch sensor is cut along the cutline, the touch sensor is divided into first and second cut portions, the second cut portion forms a smaller touch sensor having the at least second alignment feature near a vertex of the smaller touch sensor, the at least one second alignment feature adapted for aligning the smaller touch sensor to a smaller substrate.
 
Item 23. The capacitive touch sensor of item 18, wherein each electrically conductive bus line is electrically connected to a corresponding first or second electrode at an edge of a longitudinal end of the corresponding electrode such that the bus line is routed over a majority of the longitudinal end.
 
Item 24. A capacitive touch sensitive device comprising:
 
     a touch sensor, comprising:
         a plurality of spaced apart electrically conductive first electrodes extending along a first direction;   a plurality of electrically conductive first bus lines electrically connecting a first end of each first electrode to a first connection region at a periphery of the touch sensor for connection to a controller;   a plurality of electrically conductive third bus lines for electrically connecting an opposite second end of each first electrode to a different third connection region at the periphery of the touch sensor for connection to a controller; and   a flexible circuit connected to the first, but not the third, connection region, wherein the touch sensitive device is configured to detect a location of a touch applied to the touch sensor by detecting a change in a coupling capacitance near the touch location.
 
Item 25. The capacitive touch sensitive device of item 24, wherein the flexible circuit that is connected to the first connection region is assembled to the touch sensor at the first connection region.
 
Item 26. The capacitive touch sensitive device of any of items 24 through 25, wherein the flexible circuit that is connected to the first connection region is integral to and extends from the touch sensitive device at the first connection region.
 
Item 27. The capacitive touch sensitive device of any of items 24 through 26, wherein the first and third connection regions are along a same edge of the touch sensor.
 
Item 28. The capacitive touch sensitive device of any of items 24 through 26, wherein the first and third connection regions are along adjacent edges of the touch sensor.
 
Item 29. The capacitive touch sensitive device of any of items 24 through 26, wherein the first and third connection regions are along opposite edges of the touch sensor.
 
Item 30. The capacitive touch sensitive device of any of items 24 through 29, wherein the first electrodes are optically transparent and the first and third bus lines are optically opaque.
 
Item 31. The capacitive touch sensitive device of any of items 24 through 30, wherein the touch sensor further comprises:
       

     a plurality of spaced apart electrically conductive second electrodes extending along a different second direction; 
     a plurality of electrically conductive second bus lines electrically connecting a first end of each second electrode to a second connection region, different than the first and third connection regions, at the periphery of the touch sensor for connection to a controller; and 
     a plurality of electrically conductive fourth bus lines for electrically connecting an opposite second end of each second electrode to a fourth connection region, different than the first, second, and third connection regions, at the periphery of the touch sensor for connection to the controller. 
     Item 32. The capacitive touch sensitive device of item 31, wherein the second and fourth connection regions are along a same edge of the touch sensor.
 
Item 33. The capacitive touch sensitive device of item 31, wherein the second and fourth connection regions are along adjacent edges of the touch sensor.
 
Item 34. The capacitive touch sensitive device of item 31, wherein the second and fourth connection regions are along opposite edges of the touch sensor.
 
Item 35. The capacitive touch sensitive device of item 31, further comprising a flexible circuit connected to the second, but not the fourth, connection region.
 
Item 36. The capacitive touch sensitive device of item 31, wherein the first and second connection regions are along a same edge of the touch sensor.
 
Item 37. The capacitive touch sensitive device of item 31, wherein the first and second connection regions are along adjacent edges of the touch sensor.
 
Item 38. The capacitive touch sensitive device of item 31, wherein the first and second connection regions are along opposite edges of the touch sensor.
 
Item 39. A method of making a rectangular smaller touch sensor from a rectangular larger touch sensor, comprising:
 
     providing a rectangular larger touch sensor; 
     determining a first cutline extending across a viewing area of the larger touch sensor and orthogonally intersecting a first side of the larger touch sensor at a first cut location, the first side terminating at first and second vertices of the larger touch sensor; 
     forming a first alignment feature at a first vertex of the larger touch sensor, the first alignment feature configured to align the larger touch sensor to a larger substrate; 
     forming a second alignment feature near the first cut location opposite the first alignment feature; 
     cutting the larger sensor along the first cutline into multiple cut portions; 
     forming the cut portion comprising the second alignment feature into a smaller touch sensor, the second alignment feature being at a vertex of the smaller touch sensor and configured to align the smaller touch sensor with a smaller substrate. 
     Item 40. The method of item 39, further comprising discarding the cut portion comprising the first alignment feature.
 
Item 41. The method of any of items 39 through 40, wherein forming the cut portion comprising the second alignment feature into the smaller touch sensor comprises:
 
     determining a second cutline extending across the viewing area of the larger touch sensor and orthogonally intersecting a second side, orthogonal to the first side, of the larger touch sensor at a second cut location, the first side terminating at the second and a third vertices of the larger touch sensor; 
     forming a third alignment feature at the third vertex of the larger touch sensor, the third alignment feature configured to align the larger touch sensor to the larger substrate; forming a fourth alignment feature near the second cut location opposite the third alignment feature; 
     cutting the larger sensor along the second cutline into multiple cut portions; and 
     forming the cut portion comprising the second and fourth alignment features into a smaller touch sensor, the fourth alignment feature being at a vertex of the smaller touch sensor and configured to align the smaller touch sensor with the smaller substrate. 
     Item 42. The method of item 41, further comprising discarding the cut portion comprising the third alignment feature. 
     Various modifications and alterations of this invention will be apparent to those skilled in the art and it should be understood that this scope of this disclosure is not limited to the illustrative embodiments set forth herein. For example, the reader should assume that features of one disclosed embodiment can also be applied to all other disclosed embodiments unless otherwise indicated.