CDM excitation on full in-cell matrix sensor array with reduced background capacitance
Embodiments described herein include a method for detecting a presence of an input in a capacitive sensing device that includes a sensing region and a plurality of sensor electrodes. The method includes driving a first column of transmitter sensor electrodes at a first potential and driving a second column of transmitter sensor electrodes at a second potential different than the first potential. The method includes acquiring a measurement from each row of sensor electrodes, where a first sensing node includes the first column of transmitter sensor electrodes and a third column of receiver sensor electrodes, and a second sensing node includes the second column of transmitter sensor electrodes and a fourth column of receiver sensor electrodes. The method also includes determining, using the measurements from each row of sensor electrodes, a first set of transcapacitive measurements corresponding to the plurality of sensor electrodes.
1. A method for detecting a presence of an input in a capacitive sensing device, wherein the capacitive sensing device comprises a sensing region comprised of a plurality of sensor electrodes, comprising:
driving a first column of transmitter sensor electrodes at a first potential;
driving a second column of transmitter sensor electrodes at a second potential different than the first potential;
acquiring a measurement from each row of sensor electrodes, wherein the first column of transmitter sensor electrodes and a third column of receiver sensor electrodes comprise a first sensing node, and the second column of transmitter sensor electrodes and a fourth column of receiver sensor electrodes comprise a second sensing node, wherein the columns of transmitter sensor electrodes are substantially parallel to their respective columns of receiver sensor electrodes; and
determining, using the measurements from each row of sensor electrodes, a first set of transcapacitive measurements corresponding to the plurality of sensor electrodes.
2. The method of claim 1 , wherein the first sensing node and the second sensing node each comprise two columns of transmitter sensor electrodes and one column of receiver sensor electrodes.
3. The method of claim 1 further comprising:
determining a second set of transcapacitive measurements corresponding to the plurality of sensing electrodes by driving the first column of transmitter sensor electrodes at the second potential according to a code division multiplexing pattern.
4. The method of claim 3 , wherein the first set of transcapacitive measurements, the second set of transcapacitive measurements, and one or more additional sets of transcapacitive measurements are collected and used to determine a horizontal profile of the input in the sensing region.
5. The method of claim 1 , where the first potential and the second potential are determined by a code division multiplexing pattern.
6. The method of claim 1 , wherein each receiver sensor electrode in a row of receiver sensor electrodes is routed to an analog front end input of a touch display driver.
7. The method of claim 6 , wherein a vertical profile of the input in the sensing region is determined by a measurement from one or more analog front end inputs.
8. An input device for capacitive sensing, comprising:
a capacitive touch sensor configured to:
sense a presence of an input in a sensing region comprising a plurality of sensor electrodes; and
a processing system configured to:
drive a first column of transmitter sensor electrodes at a first potential;
drive a second column of transmitter sensor electrodes at a second potential different than the first potential;
acquire a measurement from each row of sensor electrodes, wherein the first column of transmitter sensor electrodes and a third column of receiver sensor electrodes comprise a first sensing node, and the second column of transmitter sensor electrodes and a fourth column of receiver sensor electrodes comprise a second sensing node, wherein the columns of transmitter electrodes are substantially parallel to their respective columns of receiver electrodes; and
determine, using the measurements from each row of sensor electrodes, a first set of transcapacitive measurements corresponding to the plurality of sensor electrodes.
9. The input device of claim 8 , wherein the first sensing node and the second sensing node each comprise two columns of transmitter sensor electrodes and one column of receiver sensor electrodes.
10. The input device of claim 8 , further comprising:
determining a second set of transcapacitive measurements corresponding to the plurality of sensing electrodes by driving the first column of transmitter sensor electrodes at the second potential according to a code division multiplexing pattern.
11. The input device of claim 10 , wherein the first set of transcapacitive measurements, the second set of transcapacitive measurements, and one or more additional sets of transcapacitive measurements are collected by the processing system and used to determine a horizontal profile of the input in the sensing region.
12. The input device of claim 8 , where the first potential and the second potential are determined by a code division multiplexing pattern.
13. The input device of claim 8 , wherein each receiver sensor electrode in a row of receiver sensor electrodes is routed to an analog front end input of a touch display driver.
14. The input device of claim 13 , wherein a vertical profile of the input in the sensing region is determined by a measurement from one or more analog front end inputs.
15. A processing system for a capacitive sensing device, the processing system comprising:
a sensor module configured to:
sense a presence of an input in a sensing region comprising a plurality of sensor electrodes; and
processing circuitry configured to:
drive a first column of transmitter sensor electrodes at a first potential;
drive a second column of transmitter sensor electrodes at a second potential different than the first potential;
acquire a measurement from each row of sensor electrodes, wherein the first column of transmitter sensor electrodes and a third column of receiver sensor electrodes comprise a first sensing node, and the second column of transmitter sensor electrodes and a fourth column of receiver sensor electrodes comprise a second sensing node, wherein the columns of transmitter electrodes are substantially parallel to their respective columns of receiver electrodes; and
determine, using the measurements from each row of sensor electrodes, a first set of transcapacitive measurements corresponding to the plurality of sensor electrodes.
16. The processing system of claim 15 , wherein the first sensing node and the second sensing node each comprise two columns of transmitter sensor electrodes and one column of receiver sensor electrodes.
17. The processing system of claim 15 , wherein the processing circuitry is further configured to:
determine a second set of transcapacitive measurements corresponding to the plurality of sensing electrodes by driving the first column of transmitter sensor electrodes at the second potential according to a code division multiplexing pattern.
18. The processing system of claim 17 , wherein the first set of transcapacitive measurements, the second set of transcapacitive measurements, and one or more additional sets of transcapacitive measurements are collected by the processing system and used to determine a horizontal profile of the input in the sensing region.
19. The processing system of claim 15 , where the first potential and the second potential are determined by a code division multiplexing pattern.
20. The processing system of claim 15 , wherein each receiver sensor electrode in a row of receiver sensor electrodes is routed to an analog front end input of a touch display driver.