Touch detection at bezel edge

• US 10,185,432 B2
• Filed: 10/14/2016
• Issued: 01/22/2019
• Est. Priority Date: 06/07/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Westerman, Wayne Carl, Benbasat, Ari Y.
• Primary Examiner(s): Okebato, Sahlu
• Application Number:
  US15/294,401
• Publication Number:
  US 20170031511A1
• Time in Patent Office: 830 Days
• CPC Class Codes: G06F 2203/04108 Touchless 2D- 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 without distance measurement in the Z direction
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

This relates to a method of extrapolating proximity information to generate a border column or row of touch nodes (also known as touch pixels) and then fitting an ellipse to the contact patch including the extrapolated border touch nodes. Additionally, a contact can be identified as a thumb based on both its major axis and its distance to an edge of the touch sensing surface.

Claims

1. A method of a computing device including a touch sensing surface, the method comprising:

obtaining a proximity image from the touch sensing surface, the proximity image corresponding to a touch on the touch sensing surface;

segmenting the proximity image to identify at least a first patch including one or more touch nodes in an edge column of the proximity image, wherein the edge column corresponds to an edge of the touch sensing surface;

determining an edge centroid of the one or more touch nodes of the first patch in the edge column;

determining an adjacent centroid of one or more touch nodes of the first patch in an adjacent column of the proximity image, the adjacent column being adjacent to the edge column of the proximity image;

copying the one or more touch nodes of the first patch in the edge column to a border column in the proximity image, including offsetting the copied touch nodes in the border column based on an extrapolation of the adjacent centroid and the edge centroid; and

after the copying, using the one or more touch nodes in the border column to determine a touch metric for the touch.

2. The method of claim 1, wherein offsetting the copied touch nodes based on the extrapolation of the adjacent centroid and the edge centroid includes subtracting the adjacent centroid from the edge centroid to obtain a shift value and shifting the copied touch nodes based on the shift value.

3. The method of claim 2, wherein the shift value is a non-integer value and shifting the copied touch nodes based on the shift value includes interpolating the copied touch nodes in the border column based on the shift value.

4. The method of claim 1, further comprising:

summing the one or more touch nodes of the first patch in the edge column to obtain an edge sum;

summing the one or more touch nodes of the first patch in the adjacent column to obtain an adjacent sum; and

scaling the touch nodes in the border column based on an extrapolation of the edge sum and the adjacent sum.

5. The method of claim 4, wherein the extrapolation of the edge sum and the adjacent sum includes one of a linear extrapolation and a logistic extrapolation.

6. A non-transitory computer readable medium, the computer readable medium containing instructions that, when executed, perform a method of a computing device including a touch sensing surface, the method comprising:

obtaining a proximity image from the touch sensing surface, the proximity image corresponding to a touch on the touch sensing surface;

segmenting the proximity image to identify at least a first patch including one or more touch nodes in an edge column of the proximity image, wherein the edge column corresponds to an edge of the touch sensing surface;

determining an edge centroid of the one or more touch nodes of the first patch in the edge column;

determining an adjacent centroid of one or more touch nodes of the first patch in an adjacent column of the proximity image, the adjacent column being adjacent to the edge column of the proximity image;

copying the one or more touch nodes of the first patch in the edge column to a border column in the proximity image, including offsetting the copied touch nodes in the border column based on an extrapolation of the adjacent centroid and the edge centroid; and

after the copying, using the one or more touch nodes in the border column to determine a touch metric for the touch.

7. The non-transitory computer readable medium of claim 6, wherein offsetting the copied touch nodes based on the extrapolation of the adjacent centroid and the edge centroid includes subtracting the adjacent centroid from the edge centroid to obtain a shift value and shifting the copied touch nodes based on the shift value.

8. The non-transitory computer readable medium of claim 7, wherein the shift value is a non-integer value and shifting the copied touch nodes based on the shift value includes interpolating the copied touch nodes in the border column based on the shift value.

9. The non-transitory computer readable medium of claim 6, the method further comprising:

summing the one or more touch nodes of the first patch in the edge column to obtain an edge sum;

summing the one or more touch nodes of the first patch in the adjacent column to obtain an adjacent sum; and

scaling the touch nodes in the border column based on an extrapolation of the edge sum and the adjacent sum.

10. The non-transitory computer readable medium of claim 9, wherein the extrapolation of the edge sum and the adjacent sum includes one of a linear extrapolation and a logistic extrapolation.

11. An electronic device, comprising:

a touch sensing surface;

a processor to execute instructions; and

a memory coupled with the processor to store instructions, which when executed by the processor, cause the processor to perform operations to generate an application programming interface (API) that allows an API-calling component to perform a method of the electronic device, the method comprising;

obtaining a proximity image from the touch sensing surface, the proximity image corresponding to a touch on the touch sensing surface;

segmenting the proximity image to identify at least a first patch including one or more touch nodes in an edge column of the proximity image, wherein the edge column corresponds to an edge of the touch sensing surface;

determining an edge centroid of the one or more touch nodes of the first patch in the edge column;

determining an adjacent centroid of one or more touch nodes of the first patch in an adjacent column of the proximity image, the adjacent column being adjacent to the edge column of the proximity image;

copying the one or more touch nodes of the first patch in the edge column to a border column in the proximity image, including offsetting the copied touch nodes in the border column based on an extrapolation of the adjacent centroid and the edge centroid; and

after the copying, using the one or more touch nodes in the border column to determine a touch metric for the touch.

12. The electronic device of claim 11, wherein offsetting the copied touch nodes based on the extrapolation of the adjacent centroid and the edge centroid includes subtracting the adjacent centroid from the edge centroid to obtain a shift value and shifting the copied touch nodes based on the shift value.

13. The electronic device of claim 12, wherein the shift value is a non-integer value and shifting the copied touch nodes based on the shift value includes interpolating the copied touch nodes in the border column based on the shift value.

14. The electronic device of claim 11, the method further comprising:

summing the one or more touch nodes of the first patch in the edge column to obtain an edge sum;

summing the one or more touch nodes of the first patch in the adjacent column to obtain an adjacent sum; and

scaling the touch nodes in the border column based on an extrapolation of the edge sum and the adjacent sum.

15. The electronic device of claim 14, wherein the extrapolation of the edge sum and the adjacent sum includes one of a linear extrapolation and a logistic extrapolation.