Touch sensor having jumpers
Examples are disclosed herein that relate to sensing touch input and applied force at a common sensor using a common controller. One example provides a touch sensor with (1) a plurality of electrodes forming a transmit electrode array and a receive electrode array; (2) drive circuitry configured to drive the transmit electrode array; (3) receive circuitry coupled to at least the receive electrode array; (4) and one or more jumpers electrically coupling respective pairs of the electrodes, the one or more jumpers having an electrical resistance that varies with applied force. The touch sensor may include a controller configured to determine, based on output from the receive circuitry, a location of a touch input and an applied force of the touch input based on a capacitance associated with the output and on a resistance associated with the output.
1. A touch sensor, comprising:
a plurality of electrodes forming a transmit electrode array and a receive electrode array;
drive circuitry configured to drive the transmit electrode array;
receive circuitry coupled to at least the receive electrode array;
one or more jumpers electrically coupling respective pairs of the electrodes, the one or more jumpers having an electrical resistance that varies with applied force; and
a controller configured to determine, based on output from the receive circuitry, a location of a touch input and an applied force of the touch input based on a capacitance associated with the output and on a resistance associated with the output,
where an impedance of a capacitive path induced by driving the transmit electrode array is substantially equal to an impedance of a resistive path of the one or more jumpers.
2. The touch sensor of claim 1 , where the output is a function of a complex impedance, and where the controller is configured to solve for the capacitance and the resistance which yield the complex impedance based on a magnitude and a phase of the complex impedance.
3. The touch sensor of claim 1 , where the respective pairs of electrodes electrically coupled by the one or more jumpers each include a transmit electrode of the transmit electrode array and a receive electrode of the receive electrode array.
4. The touch sensor of claim 1 , where the respective pairs of electrodes electrically coupled by the one or more jumpers each include one of a transmit electrode pair of the transmit electrode array and a receive electrode pair of the receive electrode array.
5. The touch sensor of claim 1 , where the receive circuitry is further coupled to the transmit electrode array, and where the respective pairs of electrodes coupled by the one or more jumpers each include a transmit electrode pair of the transmit electrode array.
6. The touch sensor of claim 5 , where, for each respective pair of electrodes, the drive circuitry is configured to drive a first transmit electrode of the electrode pair, and where the controller is configured to receive output from a second transmit electrode of the electrode pair.
7. The touch sensor of claim 1 , where the respective pairs of electrodes coupled by the one or more jumpers each include a receive electrode pair of the receive electrode array, where, for each respective pair of electrodes, the drive circuitry is configured to drive a first receive electrode of the electrode pair, and where the controller is configured to receive output from a second receive electrode of the electrode pair.
8. The touch sensor of claim 7 , where, for each respective pair of electrodes, the drive circuitry is configured to drive a first receive electrode of the electrode pair, and where the controller is configured to receive output from a second receive electrode of the electrode pair.
9. The touch sensor of claim 1 , where each of the one or more jumpers is coiled.
10. The touch sensor of claim 1 , further comprising a pressure-sensitive layer having an electrical resistance that varies with the applied force, and where the resistance associated with the output is a function of the electrical resistance of the one or more jumpers and the electrical resistance of the pressure-sensitive layer.
11. A method of input sensing, comprising:
driving a transmit electrode array;
receiving output from a receive electrode array, the transmit and receive electrode arrays formed by a plurality of electrodes; and
determining from the output a location of a touch input based on a capacitance associated with the output, and an applied force of the touch input based on a resistance associated with the output,
where one or more jumpers electrically couple respective pairs of electrodes, the one or more jumpers having an electrical resistance that varies with the applied force, and
where an impedance of a capacitive path induced by driving the transmit electrode array is substantially equal to an impedance of a resistive path of the one or more jumpers.
12. The method of claim 11 , where the output is a function of a complex impedance, and where determining the location and the applied force of the touch input includes solving for the capacitance and the resistance which yield the complex impedance based on a magnitude and a phase of the complex impedance.
13. The method of claim 11 , further comprising driving the receive electrode array.
14. The method of claim 11 , further comprising receiving output from the transmit electrode array.
15. The method of claim 11 , where the respective pairs of electrodes electrically coupled by the one or more jumpers each include a transmit electrode of the transmit electrode array and a receive electrode of the receive electrode array.
16. The method of claim 11 , where the respective pairs of electrodes electrically coupled by the one or more jumpers each include one of a transmit electrode pair of the transmit electrode array and a receive electrode pair of the receive electrode array.
17. A touch sensor, comprising:
a plurality of electrodes forming a transmit electrode array and a receive electrode array;
drive circuitry coupled to at least some of the electrodes;
receive circuitry coupled to at least some of the electrodes;
the drive circuitry being configured to drive one or more electrodes of the transmit electrode array to induce, via capacitive coupling to the receive electrode array, an output on one or more electrodes of the receive electrode array that is processed by the receive circuitry to determine a location of a touch input; and
one or more jumpers electrically coupling jumpered pairs of the plurality of electrodes, the one or more jumpers having a resistance that varies with applied force,
where for a given jumpered pair of the electrodes, the drive circuitry is configured to drive one electrode of the jumpered pair to induce an output on the other electrode of the jumpered pair, such output being processed at the receive circuitry to determine an applied force of the touch input, and
where an impedance of a capacitive path induced by driving the transmit electrode array is substantially equal to an impedance of a resistive path of the one or more jumpers.
18. The touch sensor of claim 17 , where the jumpered pairs include a first transmit electrode and a second transmit electrode.
19. The touch sensor of claim 17 , where the jumpered pairs include a first receive electrode and a second receive electrode.