HOVER REJECTION THROUGH DYNAMIC THRESHOLDING

• US 20180121010A1
• Filed: 10/28/2016
• Published: 05/03/2018
• Est. Priority Date: 10/28/2016
• Status: Active Grant

• Current Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Inventors: Ponnarasu, Manivannan, Nagarajan, Mythreyi
• Granted Patent: US 10,481,723 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

Disclosed herein is a touch screen controller that calculates a variance of an island in acquired touch data values. Where the variance exceeds a variance threshold, the island is validated as a representing touch. Where the variance does not exceed the variance threshold, whether the island represents a touch or a hover is determined by calculating a sharpness by applying weights to nodes of the island, where neighboring nodes adjacent to a peak node are weighted less than non-neighboring nodes not adjacent to the peak node. An island strength threshold is determined as a function of a product of the variance and the sharpness. It is determined that the island represents a touch where a highest touch data value of the island is greater than the island strength threshold, and a hover where the highest touch data value of the island is less than the island strength threshold.

Claims

1. An electronic device, comprising:

a touch screen controller configured to;

calculate a variance of an island in acquired touch data values;

where the variance exceeds a variance threshold, validate the island as a representing touch;

where the variance does not exceed the variance threshold, determine whether the island represents a touch or a hover by;

calculating a sharpness by applying weights to nodes of the island, wherein neighboring nodes adjacent to a peak node are weighted less than non-neighboring nodes not adjacent to the peak node;

determining an island strength threshold as a function of a product of the variance and the sharpness;

determining that the island represents a touch where a highest touch data value of the island is greater than the island strength threshold, and that the island represents a hover where the highest touch data value of the island is less than the island strength threshold.

2. The electronic device of claim 1, wherein the touch screen controller applies weights to nodes of the island by:

applying a first weight to the peak node;

applying a second weight to the neighboring nodes;

applying a third weight to the non-neighboring nodes;

wherein the second weight is less than the third weight.

3. The electronic device of claim 2, wherein the third weight is less than the first weight.

4. The electronic device of claim 2, wherein the touch screen controller calculates the sharpness as:

5. The electronic device of claim 4, wherein Weight1 is 1.5, Weight2 is 0.5, and Weight3 is 1.25.

6. The electronic device of claim 1, wherein the touch screen controller is further configured to normalizing the sharpness;

and wherein the touch screen controller determines the island strength threshold as a function of a product of the variance and the normalized sharpness.

7. The electronic device of claim 4, wherein the normalizing comprises a peak normalizing.

8. The electronic device of claim 7, wherein the peak normalizing comprises a five point peak normalizing.

9. The electronic device of claim 1, wherein the island is a three node by three node island.

10. An electronic device, comprising:

a touch screen;

a touch screen controller coupled to the touch screen and configured to;

identify an island in a matrix of acquired touch data values, the island comprising nodes containing adjacent touch data values indicating a potential touch of a touch screen;

calculate a variance of the island;

where the variance exceeds a variance threshold, validate the island as a representing touch;

where the variance does not exceed the variance threshold, determine whether the island represents a touch or a hover by;

calculating a sharpness by applying weights to the nodes of the island, wherein a neighboring node that is adjacent to a peak node containing a peak acquired touch data value is weighted less than a non-neighboring node that is not adjacent to the peak node;

calculating a product of the variance and the sharpness;

determining an island strength threshold as a function of the product;

determining that the island represents a touch where a highest touch data value of the island is greater than the island strength threshold;

determining that the island represents a hover where the highest touch data value of the island is less than the island strength threshold.

11. The electronic device of claim 10, wherein the touch screen controller applies weights to nodes of the island by:

applying a first weight to the peak node;

applying a second weight to the neighboring node;

applying a third weight to the non-neighboring node;

wherein the second weight is less than the third weight.

12. The electronic device of claim 11, wherein the third weight is less than the first weight.

13. The electronic device of claim 11, wherein the touch screen controller calculates the sharpness as:

14. The electronic device of claim 13, wherein Weight1 is 1.5, Weight2 is 0.5, and Weight3 is 1.25.

15. A method, comprising:

calculate a variance of an island in acquired touch data values;

where the variance exceeds a variance threshold, validate the island as a representing touch;

where the variance does not exceed the variance threshold, determine whether the island represents a touch or a hover by;

calculating a sharpness by applying weights to nodes of the island, wherein neighboring nodes adjacent to a peak node are weighted less than non-neighboring nodes not adjacent to the peak node;

determining an island strength threshold as a function of a product of the variance and the sharpness; and

determining that the island represents a touch where a highest touch data value of the island is greater than the island strength threshold, and that the island represents a hover where the highest touch data value of the island is less than the island strength threshold.

16. The method of claim 15, wherein weights are applied to nodes of the island by:

applying a first weight to the peak node;

applying a second weight to the neighboring nodes;

applying a third weight to the non-neighboring nodes;

wherein the second weight is less than the third weight.

17. The method of claim 16, wherein the third weight is less than the first weight.

18. The method of claim 16, wherein the sharpness is calculated as:

19. The method of claim 18, wherein Weight1 is 1.5, Weight2 is 0.5, and Weight3 is 1.25.

20. The method of claim 15, further comprising normalizing the sharpness;

and wherein the island strength threshold is determined as a function of a product of the variance and the normalized sharpness.

21. The method of claim 20, wherein the normalizing comprises a peak normalizing.

22. The method of claim 21, wherein the peak normalizing comprises a five point peak normalizing.