Water detection and wipe detection algorithms for touchscreen proximity sensing

Patent metadata

Field	Value
Publication number	US-10437384-B2
Application number	US-201615067720-A
Country	US
Kind code	B2
Filing date	Mar 11, 2016
Priority date	Mar 13, 2015
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

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.

First claim

What is claimed is:

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 changes in electrode responses from at least a subset of the plurality of sensor electrodes that differ from a first baseline by at least a first threshold amount, wherein the detected changes 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 changes in electrode responses to form a second baseline, wherein the second baseline differs from the first baseline by at least the first threshold amount;
detecting two 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;
determining whether the two or more subsequent electrode responses satisfy an electrode response pattern associated with a liquid-removing wipe gesture, wherein the electrode-response pattern is satisfied when the two or more subsequent electrode responses vary from negative to positive with respect to the first baseline and then positive to negative with respect to the first baseline; and
in accordance with a determination that the two or more subsequent electrode responses satisfy the electrode-response pattern associated with the liquid-removing wipe gesture, normalizing the capacitive sense array, to form a third baseline, based on the detected two or more subsequent electrode responses to account for liquid removed from the capacitive sense array by the liquid-removing wipe gesture, wherein the third baseline differs from the second baseline by at least the second threshold amount.

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

3. 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.

4. 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 changes in electrode responses from at least the subset of the plurality of sensor electrodes against changes in electrode responses recorded during one or more previous cycles; and
in accordance with a determination that the detected changes in electrode responses substantially match the changes 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.

5. The method of claim 1 , further comprising:
subsequent to normalizing the capacitive sense array to form the second baseline, detecting one or more proximity sensing events, 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.

6. The method of claim 1 , further comprising, at the electronic device:
determining whether a number of sensor electrodes responsible for detecting the two or more subsequent electrode responses satisfies a sensor electrode threshold,
wherein normalizing the capacitive sense array to form the third baseline is further performed in accordance with a determination that the number of sensor electrodes responsible for detecting the two or more subsequent electrode responses satisfies the sensor electrode threshold.

7. The method of claim 1 , further comprising, at the electronic device:
in accordance with a determination that the detected two or more subsequent electrode responses do not satisfy the electrode-response pattern, ignoring the detected two or more subsequent electrode responses.

8. The method of claim 1 , wherein:
the two or more subsequent electrode responses are averaged, and
the averaged subsequent electrode response is used to determine whether the electrode-response pattern is satisfied.

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 changes in electrode responses from at least a subset of the plurality of sensor electrodes that differ from a first baseline by at least a first threshold amount, wherein the detected changes 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 changes in electrode responses to form a second baseline, wherein the second baseline differs from the first baseline by at least the first threshold amount;
detect two 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;
determine whether the two or more subsequent electrode responses satisfy an electrode response pattern associated with a liquid-removing wipe gesture, wherein the electrode-response pattern is satisfied when the two or more subsequent electrode responses vary from negative to positive with respect to the first baseline and then positive to negative with respect to the first baseline; and
in accordance with a determination that the two or more subsequent electrode responses satisfy the electrode-response pattern associated with the liquid-removing wipe gesture, normalize the capacitive sense array, to form a third baseline, based on the detected two or more subsequent electrode responses to account for liquid removed from the capacitive sense array by the liquid-removing wipe gesture, 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 changes in electrode responses from at least the subset of the plurality of sensor electrodes against changes in electrode responses recorded during one or more previous cycles; and
in accordance with a determination that the detected changes in electrode responses substantially match the changes 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 the two or more subsequent electrode responses differ from the second baseline for a second predefined time period.

13. The system of claim 9 , further comprising:
subsequent to normalizing the capacitive sense array to form the second baseline, detecting one or more proximity sensing events, 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.

Assignees

• Parade Tech Ltd

Inventors

• Oral Yesim
• Guzel Tayyar

Classifications

• G06F3/0488

  using a touch-screen or digitiser, e.g. input of commands through traced gestures · CPC title

• G06F3/044

  by capacitive means · CPC title

• G06F3/0418 Primary

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G06F3/04186 Primary

  Touch location disambiguation · CPC title