Water Detection and Wipe Detection Algorithms for Touchscreen Proximity Sensing

• US 20160266717A1
• Filed: 03/11/2016
• Published: 09/15/2016
• Est. Priority Date: 03/13/2015
• Status: Active Grant

• Current Assignee: Parade Technologies, Ltd.
• Original Assignee: Parade Technologies, Ltd.
• Inventors: Oral, Yesim, Guzel, Tayyar
• Granted Patent: US 10,437,384 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

The various implementations described herein include systems, methods and/or devices used to enable touchscreen proximity sensing. An exemplary method is performed at a touch sensitive device and includes detecting the presence of water on a capacitive sense array (CSA). The method detects decreased electrode responses from at least a subset of a plurality of sensor electrodes of the CSA that satisfy one or more first trigger conditions. The method further includes: (1) normalizing the CSA based on the detected decrease in electrode responses to form a second baseline, (2) determining that the water is removed from the portion of the CSA based on one or more subsequent electrode responses from at least the subset of the plurality of sensor electrodes that satisfy one or more second trigger conditions, and (3) normalizing the CSA based on the detected one or more subsequent electrode responses to form a third baseline.

Claims

1. A method, comprising:

at an electronic device having a processor and a capacitive sense array that includes a plurality of sensor electrodes;

determining that a liquid is on at least a portion of the capacitive sense array based on a decrease in electrode responses from at least a subset of the plurality of sensor electrodes that differs from a first baseline by at least a first threshold amount, wherein the detected decrease in electrode responses differ from the first baseline for at least a first predefined time period;

after determining that the liquid is on at least the portion of the capacitive sense array;

normalizing the capacitive sense array based on the detected decrease in electrode responses to form a second baseline, wherein the second baseline differs from the first baseline by at least the first threshold amount;

determining that the liquid is removed from the portion of the capacitive sense array based on one or more subsequent electrode responses from at least the subset of the plurality of sensor electrodes that differ from the second baseline by at least a second threshold amount; and

normalizing the capacitive sense array based on the detected one or more subsequent electrode responses to form a third baseline, wherein the third baseline differs from the second baseline by at least the second threshold amount.

2. The method of claim 1, wherein the subsequent electrode responses differ from the second baseline for a second predefined time period.

3. The method of claim 1, further comprising:

prior to normalizing the capacitive sense array based on the detected one or more subsequent electrode responses;

identifying a peak electrode response associated with the removal of the liquid, and

identifying a subsequent decrease in electrode responses relative to the identified peak electrode response.

4. The method of claim 1, wherein determining that the liquid is on at least the portion of the capacitive sense array includes measuring self-capacitance of sensor electrodes that comprise the portion of the capacitive sense array.

5. The method of claim 1, further comprising:

while determining that the liquid is on at least the portion of the capacitive sense array;

comparing the detected decrease in electrode responses from at least the subset of the plurality of sensor electrodes against decreases in electrode responses recorded during one or more previous cycles; and

in accordance with a determination that the detected decrease in electrode responses substantially match the decreases in electrode responses recorded during the one or more previous cycles, signaling that the liquid is on at least the portion of the capacitive sense array.

6. The method of claim 1, wherein determining that the liquid is removed from the portion of the capacitive sense array includes detecting one or more increases in electrode responses followed by one or more decreases in electrode responses.

7. The method of claim 1, further comprising:

subsequent to normalizing the capacitive sense array based on the detected decrease in electrode responses to form the second baseline, detecting one or more proximity sensing events.

8. The method of claim 7, wherein electrode responses associated with each of the one or more proximity sensing events differ from the second baseline by less than the second threshold amount.

9. A system comprising:

a capacitive sense array including a plurality of sensor electrodes; and

a processing device coupled to the capacitive sense array, the processing device configured to;

determine that a liquid is on at least a portion of the capacitive sense array based on a decrease in electrode responses from at least a subset of the plurality of sensor electrodes that differs from a first baseline by at least a first threshold amount, wherein the detected decrease in electrode responses differ from the first baseline for at least a first predefined time period;

after determining that the liquid is on at least the portion of the capacitive sense array;

normalize the capacitive sense array based on the detected decrease in electrode responses to form a second baseline, wherein the second baseline differs from the first baseline by at least the first threshold amount;

determine that the liquid is removed from the portion of the capacitive sense array based on one or more subsequent electrode responses from at least the subset of the plurality of sensor electrodes that differ from the second baseline by at least a second threshold amount; and

normalize the capacitive sense array based on the detected one or more subsequent electrode responses to form a third baseline, wherein the third baseline differs from the second baseline by at least the second threshold amount.

10. The system of claim 9, wherein determining that the liquid is on at least the portion of the capacitive sense array includes measuring self-capacitance of sensor electrodes that comprise the portion of the capacitive sense array.

11. The system of claim 9, wherein the processing device is further configured to:

while determining that the liquid is on at least the portion of the capacitive sense array;

compare the detected decrease in electrode responses from at least the subset of the plurality of sensor electrodes against decreases in electrode responses recorded during one or more previous cycles; and

in accordance with a determination that the detected decrease in electrode responses substantially match the decreases in electrode responses recorded during the one or more previous cycles, signal that the liquid is on at least the portion of the capacitive sense array.

12. The system of claim 9, wherein determining that the liquid is removed from the portion of the capacitive sense array includes detecting one or more increases in electrode responses followed by one or more decreases in electrode responses.

13. The system of claim 9, wherein the subsequent electrode responses differ from the second baseline for a second predefined time period.

14. The system of claim 9, further comprising:

prior to normalizing the capacitive sense array based on the detected one or more subsequent electrode responses;

identifying a peak electrode response associated with the removal of the liquid, and

identifying a subsequent decrease in electrode responses relative to the identified peak electrode response.

15. The system of claim 9, further comprising:

subsequent to normalizing the capacitive sense array based on the detected decrease in electrode responses to form the second baseline, detecting one or more proximity sensing events.

16. The system of claim 15, wherein electrode responses associated with each of the one or more proximity sensing events differ from the second baseline by less than the second threshold amount.

17. A non-transitory computer readable storage medium, storing one or more programs configured for execution by one or more processors of a sensing system, the one or more programs including instructions, which when executed by the one or more processors cause the sensing system to:

determine that a liquid is on at least a portion of the capacitive sense array based on a decrease in electrode responses from at least a subset of the plurality of sensor electrodes that differs from a first baseline by at least a first threshold amount, wherein the detected decrease in electrode responses differ from the first baseline for at least a first predefined time period;

after determining that the liquid is on at least the portion of the capacitive sense array;

normalize the capacitive sense array based on the detected decrease in electrode responses to form a second baseline, wherein the second baseline differs from the first baseline by at least the first threshold amount;

determine that the liquid is removed from the portion of the capacitive sense array based on one or more subsequent electrode responses from at least the subset of the plurality of sensor electrodes that differ from the second baseline by at least a second threshold amount; and

normalized the capacitive sense array based on the detected one or more subsequent electrode responses to form a third baseline, wherein the third baseline differs from the second baseline by at least the second threshold amount.

18. The non-transitory computer readable storage medium of claim 17, wherein determining that the liquid is on at least the portion of the capacitive sense array includes measuring self-capacitance of sensor electrodes that comprise the portion of the capacitive sense array.

19. The non-transitory computer readable storage medium of claim 17, wherein the one or more programs further include instructions, which when executed by the one or more processors cause the sensing system to:

while determining that the liquid is on at least the portion of the capacitive sense array;

compare the detected decrease in electrode responses from at least the subset of the plurality of sensor electrodes against decreases in electrode responses recorded during one or more previous cycles; and

in accordance with a determination that the detected decrease in electrode responses substantially match the decreases in electrode responses recorded during the one or more previous cycles, signal that the liquid is on at least the portion of the capacitive sense array.

20. The non-transitory computer readable storage medium of claim 17, wherein determining that the liquid is removed from the portion of the capacitive sense array includes detecting one or more increases in electrode responses followed by one or more decreases in electrode responses.