Substantially edgeless touch sensor
In one embodiment, an apparatus includes a substrate configured to extend substantially out to at least two edges of a surface of a device. The apparatus also includes a touch sensor disposed on the substrate, the touch sensor comprising an active area that is configured to extend substantially out to at least two of the edges of the surface of the device.
1. An apparatus comprising:
a substrate configured to extend substantially out to at least four edges of a first surface of a device, the substrate further configured to wrap around at least a first edge and a second edge of the at least four edges of the first surface of the device;
a touch sensor disposed on the substrate, the touch sensor comprising:
an active area that is configured to extend substantially out to the at least four edges of the first surface of the device; and
a plurality of electrodes comprising a first plurality of electrodes configurable to operate as drive electrodes and a second plurality of electrodes configurable to operate as sense electrodes, the first plurality of electrodes having a U shape and being arranged in a first plurality of columns, the second plurality of electrodes having a T shape and being arranged in the first plurality of columns, each of the first plurality of electrodes and each of the second plurality of electrodes forming a plurality of capacitive nodes at respective positions in which one of the first plurality electrodes having the U shape is interdigitated with one of the second plurality of electrodes having the T shape; and
a plurality of bond pads located at a second surface of the device, the second surface facing a different direction than the first surface and corresponding to the portions of the substrate wrapping around the first edge of the at least four edges of the first surface of the device, each of the plurality of bond pads configured to couple to a corresponding bond pad on one or more flexible printed circuits (FPCs);
wherein:
the substrate comprises a plurality of tracking areas where tracks providing connections to and from the plurality of electrodes of the touch sensor are disposed on the substrate, the tracks of the plurality of tracking areas extending to the first edge of the first surface of the device and wrapping around the first edge onto the second surface of the device to provide respective connections to and from control circuitry, the tracks including a respective track in each of the plurality of columns providing a connection to all of the first plurality of electrodes arranged in respective column of the plurality of columns; and
at least one of the plurality of tracking areas is configured to extend into the active area of the touch sensor in a gap formed between at least two adjacent columns of the plurality of columns such that multiple tracks, each providing a connection to a corresponding electrode of the second plurality of electrodes in a column, of the at least one tracking area are positioned, in plan view, in the gap formed between the at least two adjacent columns of the plurality of columns, the multiple tracks being substantially parallel in the gap along at least a portion of respective lengths of the multiple tracks, the multiple tracks of the at least one of the plurality of tracking areas configured to wrap around, with the substrate, the first edge of the first surface of the device onto the second surface of the device to provide the respective connections to or from the control circuitry, each of the multiple tracks extending in a first direction from the gap to the first edge, each of the multiple tracks configured to respectively couple to each of the plurality of bond pads at the second surface of the device, the at least two adjacent columns of the plurality of columns being adjacent in that an electrode of the first plurality of electrodes or the second plurality of electrodes is not positioned in the gap between the at least two adjacent columns of the plurality of columns.
2. The apparatus of claim 1 , wherein:
the substrate is further configured to wrap around a third edge of the at least four edges of the first surface of the device; and
the touch sensor is configured to wrap around the first, second, and third edges of the first surface of the device with the substrate, the wrapping of the touch sensor around the first, second, and third edges at least in part enabling the active area of the touch sensor to extend substantially out to the first, second, and third edges of the first surface of the device.
3. The apparatus of claim 2 , wherein one or more portions of one or more of the plurality of tracking areas are configured to be located on a third surface of the device on a side of the third edge of the device around which the substrate is configured to wrap.
4. The apparatus of claim 1 , wherein the first surface of the device is flat or curved.
5. The apparatus of claim 1 , wherein the touch sensor comprises:
a single-layer configuration with the first plurality of electrodes and second plurality of electrodes disposed only on one side of a single substrate;
a single-layer configuration with the first plurality of electrodes disposed on a first side of a single substrate and the second plurality of electrodes disposed on a second side of the single substrate opposite the first side; or
a two-layer configuration with the first plurality of electrodes disposed on one side of a first substrate and the second plurality of electrodes disposed on one side of a second substrate.
6. The apparatus of claim 1 , wherein the touch sensor is a mutual-capacitance touch sensor or a self-capacitance touch sensor.
7. The apparatus of claim 1 , wherein the plurality of electrodes comprises electrodes each made of substantially flexible conductive material comprising a conductive mesh of conductive metal lines.
8. The apparatus of claim 1 , wherein one or more portions of one or more of the tracks are made of conductive material comprising a conductive mesh of conductive metal lines.
9. The apparatus of claim 1 , wherein one or more of the plurality of electrodes are made of indium tin oxide (ITO).
10. The apparatus of claim 1 , wherein one or more portions of one or more of the tracks are made of indium tin oxide (ITO).
11. The apparatus of claim 1 , wherein the tracks are made of fine lines of metal and have a width of approximately 100 μm or less.
12. A device comprising:
a substrate configured to extend substantially out to at least two edges of a first surface of a device, the substrate further configured to wrap around at least a first edge and a second edge of the at least two edges of the first surface of the device;
a touch sensor disposed on the substrate, the touch sensor comprising an active area that is configured to extend substantially out to the at least two of the edges of the first surface of the device;
a plurality of bond pads located at a second surface of the device, the second surface facing a different direction than the first surface and corresponding to portions of the substrate wrapping around the first edge of the at least four edges of the first surface of the device, each of the plurality of bond pads configured to couple to a corresponding bond pad on one or more flexible printed circuits (FPCs); and
one or more computer-readable non-transitory storage media embodying logic that is configured when executed to control the touch sensor;
wherein:
the substrate comprises one or more tracking areas where tracks providing drive or sense connections to or from drive or sense electrodes of the touch sensor are disposed on the substrate, the drive electrodes having a U shaped and being arranged in columns, the sense electrodes having a T shaped and being arranged in the columns, each of the drive electrodes and each of the sense electrodes forming capacitive nodes at respective positions in which one of the drive electrodes having the U shaped is interdigitated with one of the sense electrodes having a T shaped, the tracks including a respective track in each of the columns providing a connection to all of the drive electrodes arranged in a respective column of the columns; and
at least one of the one or more tracking areas is configured to extend into the active area of the touch sensor in a gap formed between two of the columns such that multiple tracks, each providing a connection to a corresponding sense electrode, of the tracking area are positioned, in plan view, in the gap formed between the two columns, the multiple tracks being substantially parallel in the gap along at least a portion of respective lengths of the multiple tracks, the multiple tracks of the at least one of the one or more tracking areas configured to wrap around, with the substrate, the first edge of the first surface of the device onto the second surface of the device to provide respective connections to or from control circuitry, each of the multiple tracks extending in a first direction from the gap to the first edge, each of the multiple tracks configured to respectively couple to each of the plurality of bond pads at the second surface of the device, the two columns being adjacent in that neither a drive electrode nor a sense electrode is positioned in the gap between the two columns.
13. The device of claim 12 , wherein:
the substrate is further configured to wrap around a third edge of the at least two edges of the first surface of the device; and
the touch sensor is configured to wrap around the first, second, and third edges of the at least two edges of the first surface of the device with the substrate, the wrapping of the touch sensor around the first, second, and third edges of the at least two edges at least in part enabling the active area of the touch sensor to extend substantially out to the first, second, and third edges of the at least two edges of the first surface of the device.
14. The device of claim 13 , wherein one or more portions of the one or more tracking areas are configured to be located on a third surface of the device on a side of the third edge of the device that the substrate is configured to wrap around.
15. The device of claim 12 , wherein the first surface of the device is flat or curved.
16. The device of claim 12 , wherein the touch sensor comprises:
a single-layer configuration with drive and sense electrodes disposed only on one side of a single substrate;
a single-layer configuration with drive electrodes disposed on a first side of a single substrate and sense electrodes disposed on a second side of the single substrate opposite the first side; or
a two-layer configuration with drive electrodes disposed on one side of a first substrate-and sense electrodes disposed on one side of a second substrate.
17. The device of claim 12 , wherein the touch sensor is a mutual-capacitance touch sensor or a self-capacitance touch sensor.
18. The device of claim 12 , wherein the touch sensor comprises drive or sense electrodes made of substantially flexible conductive material comprising a conductive mesh.
19. The device of claim 12 , wherein one or more portions of one or more of the tracks disposed on the substrate providing drive or sense connections to or from drive or sense electrodes of the touch sensor are made of conductive material comprising a conductive mesh of conductive metal lines.
20. The device of claim 12 , wherein one or more portions of one or more of the tracks disposed on the substrate providing drive or sense connections to or from drive or sense electrodes of the touch sensor are located outside a visible area of the touch sensor and are made of conductive material.
21. The device of claim 12 , wherein the touch sensor comprises drive or sense electrodes made of indium tin oxide (ITO).
22. The device of claim 12 , wherein one or more portions of one or more of the tracks disposed on the substrate providing drive or sense connections to or from drive or sense electrodes of the touch sensor are made of indium tin oxide (ITO).