Correcting coordinate jitter in touch screen displays due to forceful touches

Patent metadata

Field	Value
Publication number	US-9933884-B2
Application number	US-201514811884-A
Country	US
Kind code	B2
Filing date	Jul 29, 2015
Priority date	Jul 29, 2015
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

An electronic device includes a processor that acquires touch data values corresponding to different locations of a touch display, and identifies an island in the touch data that has touch data values acquired from adjacent locations of the touch display that indicate a potential touch. A first area of the island is determined from touch data values that exceed a first threshold value, and a second area of the island is determined from touch data values that exceed a second threshold value. If the first area is less than a multiple of the second area, coordinates of a location of the island are determined from the touch data values indicating the potential touch. If the first area is at least the multiple of the second area, coordinates of a location of the island are determined from the touch data values indicating the potential touch that exceed a third threshold value.

First claim

The invention claimed is:

1. An electronic device, comprising:
a touch sensitive display;
a processor coupled to the touch sensitive display and configured to:
acquire touch data values corresponding to different locations of the touch sensitive display;
identify at least one island in the touch data, the at least one island comprising touch data values acquired from adjacent locations of the touch sensitive display indicating a potential touch;
determine a first area of the at least one island from touch data values of the at least one island that exceed a first touch data threshold value;
determine a second area of the at least one island from touch data values of the at least one island that exceed a second touch data threshold value different than the first touch data threshold value;
if the first area is less than a multiple of the second area, determine coordinates of a location of the at least one island on the touch sensitive display based upon the touch data values indicating the potential touch; and
if the first area is at least the multiple of the second area, determine coordinates of a location of the at least one island on the touch sensitive display based upon the touch data values indicating the potential touch that exceeds a third touch data threshold value and not the touch data values indicating the potential touch that do not exceed the third touch data threshold value.

2. The electronic device of claim 1 , wherein the second touch data threshold value is one half a peak touch data value of the at least one island.

3. The electronic device of claim 1 , wherein the multiple of the second area is twice the second area.

4. The electronic device of claim 1 , wherein the third touch data threshold value is equal to the first touch data threshold value.

5. The electronic device of claim 1 , wherein the third touch data threshold value is greater than the first touch data threshold value.

6. The electronic device of claim 1 , further comprising a transparent layer disposed adjacent to and spaced apart from the touch sensitive display; and wherein the first area being at least the multiple of the second area indicates that the potential touch is pushing against the transparent layer with a force sufficient such that the transparent layer is bending toward the touch sensitive display.

7. The electronic device of claim 6 , wherein the processor is configured to compare the first area to the second area to determine a force with which the potential touch is pushing against the transparent layer.

8. The electronic device of claim 1 , wherein the processor is part of a touch screen controller.

9. The electronic device of claim 1 , wherein the processor is part of a system on a chip.

10. The electronic device of claim 1 , wherein the third touch data threshold value is between 70% and 95% of a peak touch data value of the at least one island.

11. An electronic device, comprising:
a touch screen controller configured to:
acquire a matrix of touch data values;
identify at least one island in the matrix, the at least one island comprising adjacent touch data values indicating a potential touch of a touch sensitive screen;
determine a first area of the at least one island based upon touch data values thereof that exceed a first threshold value;
determine a second area of the at least one island based upon touch data values thereof that exceed a second threshold value different than the first threshold value;
if the first area is less than a multiple of the second area, determine coordinates of a location of the at least one island on the touch sensitive display based upon the touch data values indicating the potential touch; and
if the first area is at least a multiple of the second area, determine coordinates of a location of the at least one island on the touch sensitive display based upon the touch data values that exceed a third threshold value but not the touch data values that do not exceed the third threshold value.

12. The electronic device of claim 11 , wherein the second threshold value is one half a peak touch data value of the at least one island.

13. The electronic device of claim 11 , wherein the multiple of the second area is twice the second area.

14. The electronic device of claim 11 , further comprising a transparent layer disposed adjacent to and spaced apart from the touch sensitive display; and wherein the first area being at least the multiple of the second area indicates that the potential touch is pushing against the transparent layer with a force sufficient such that the transparent layer is bending toward the touch sensitive display.

15. The electronic device of claim 11 , wherein the threshold value is between 70% and 95% of a peak touch data value of the at least one island.

16. A method, comprising:
acquiring touch data values corresponding to different locations of a touch sensitive display;
identifying at least one island in the touch data values, the at least one island comprising touch data values acquired from adjacent locations of the touch sensitive display indicating a potential touch;
determining a first area of the at least one island based upon touch data values thereof that exceed a first threshold value;
determining a second area of the at least one island based upon touch data values thereof that exceed a second threshold value different than the first threshold value; and
determining coordinates of a location of the at least one island on the touch sensitive display based upon the touch data values indicating that the potential touch that exceed a threshold percentage of a peak touch data value of the at least one island, when the first area is at least a multiple of the second area, thereby indicating that a transparent layer adjacent to and spaced apart from the touch sensitive display is bending toward the touch sensitive display.

17. The method of claim 16 , further comprising determining coordinates of a location of the at least one island on the touch sensitive display based upon the touch data values indicating the potential touch, when the first area is less than the multiple of the second area.

18. The method claim 16 , wherein the second threshold value is one half the peak touch data value of the at least one island.

19. The electronic device of claim 16 , wherein the multiple of the second area is twice the second area.

Assignees

• St Microelectronics Asia Pacific Pte Ltd

Inventors

• Ponnarasu Manivannan
• Lee Leo

Classifications

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0418 Primary

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

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title