Touch Panel Deformation Compensation

• US 20140253488A1
• Filed: 03/05/2013
• Published: 09/11/2014
• Est. Priority Date: 03/05/2013
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Simmons, Martin John, Golbourn, Darren, Hersee, Andrew, Vukovic, Predrag
• Granted Patent: US 9,864,463 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

In one embodiment, a method includes receiving, from a touch sensor of a device, one or more signals corresponding to touch or proximity inputs within a touch-sensitive area of the touch sensor. The touch sensor comprising one or more nodes. The method also includes applying an offset to one or more of the signals. The offset corresponding to a variation in a distance between a touch panel and a ground plane or display of the device. The method also includes determining whether a touch input to the touch sensor has occurred based at least in part on the signals and the offset as applied.

Claims

1. A method comprising:

receiving, from a touch sensor of a device, one or more signals corresponding to touch or proximity inputs within a touch-sensitive area of the touch sensor, the touch sensor comprising one or more nodes;

applying an offset to one or more of the signals, the offset corresponding to a variation in a distance between a touch panel and a ground plane or display of the device; and

determining whether a touch input to the touch sensor has occurred based at least in part on the signals and the offset as applied.

2. The method of claim 1, wherein applying the offset comprises subtracting the offset from the signal of each node.

3. The method of claim 1, wherein the offset is determined along orthogonal axes of the touch sensor.

4. The method of claim 3, wherein applying the offset comprises separately applying the offset to one or more of the signals measured along each orthogonal axis.

5. The method of claim 1, wherein the offset is determined based at least in part on a difference between one or more signals without the touch input of each node relative to one or more neighboring nodes, fitting a mathematical curvature function to the signals without the touch input, or determining a maximum value in the signals without the touch input.

6. The method of claim 1, wherein the offset is determined at least in part on filtering one or more signals without the touch input higher than a pre-determined threshold value or removing the signals without the touch input of each node with a difference relative to one or more neighboring nodes higher than the pre-determined threshold value.

7. The method of claim 1, wherein the offset is stored as a two-dimensional kernel and each element of the kernel corresponds to the variation in a distance between the touch panel and the ground plane or display of the device for each node.

8. The method of claim 7, wherein applying the offset comprises performing a convolution operation of the signal of each node with the kernel.

9. A computer-readable non-transitory storage medium embodying logic configured when executed to:

receive, from a touch sensor of a device, one or more signals corresponding to touch or proximity inputs within a touch-sensitive area of the touch sensor, the touch sensor comprising one or more nodes;

apply an offset to one or more of the signals, the offset corresponding to a variation in a distance between a touch panel and a ground plane or display of the device; and

determine whether a touch input to the touch sensor has occurred based at least in part on the data and the offset as applied.

10. The medium of claim 9, wherein the logic is further configured to subtract the offset from the signal of each of the nodes.

11. The medium of claim 9, wherein the offset is determined along orthogonal axes of the touch sensor.

12. The medium of claim 11, wherein the logic is further configured to separately apply the offset to one or more of the signals measured along each orthogonal axis.

13. The medium of claim 9, wherein the offset is determined based at least in part on a difference between one or more signals without the touch input of each node relative to one or more neighboring nodes, fitting a mathematical curvature function to the signals without the touch input, or determining a maximum value in the signals without the touch input.

14. The medium of claim 9, wherein the offset is determined at least in part on filtering one or more signals without the touch input higher than a pre-determined threshold value or removing the signals without the touch input of each node with a difference relative to one or more neighboring nodes higher than the pre-determined threshold value.

15. The medium of claim 9, wherein the offset is stored as a two-dimensional kernel and each element of the kernel corresponds to the variation in a distance between the touch panel and the ground plane or display of the device for each node.

16. The medium of claim 15, wherein applying the offset comprises performing a convolution operation of the signal of each node with the kernel.

17. A device comprising:

a measurement circuit; and

a computer-readable non-transitory storage medium coupled to the measurement circuit and embodying logic configured when executed to;

receive, from a touch sensor of a device, one or more signals corresponding to touch or proximity inputs within a touch-sensitive area of the touch sensor, the touch sensor comprising one or more nodes;

apply an offset to one or more of the signals, the offset corresponding to a variation in a distance between a touch panel and a ground plane or display of the device; and

determine whether a touch input to the touch sensor has occurred based at least in part on the signals and the offset as applied.

18. The device of claim 17, wherein the logic is further configured to subtract the offset from the signal of each of the nodes.

19. The device of claim 18, wherein the offset is determined along orthogonal axes of the touch sensor.

20. The device of claim 18, wherein the logic is further configured to separately apply the offset to one or more of the signals measured along each orthogonal axis.