DETERMINING PITCH AND YAW FOR TOUCHSCREEN INTERACTIONS

• US 20160231865A1
• Filed: 09/30/2015
• Published: 08/11/2016
• Est. Priority Date: 02/12/2014
• Status: Active Grant

• Current Assignee: Qeexo Co. (TDK Corporation)
• Original Assignee: Qeexo Co. (TDK Corporation)
• Inventors: XIAO, ROBERT BO, HARRISON, CHRISTOPHER, SCHWARZ, JULIA
• Granted Patent: US 9,778,783 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06T 7/136 involving thresholding
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

A method and apparatus for determining pitch and yaw of an elongated interface object as it interacts with a touchscreen surface. A touch image is received, and this touch image has at least a first area that corresponds to an area of the touchscreen that has an elongated interface object positioned at least proximate to it. The elongated interface object has a pitch and a yaw with respect to the touchscreen surface. A first transformation is performed to obtain a first transformation image of the touch image, and a second transformation is performed to obtain a second transformation image of the touch image. The first transformation differs from the second transformation. The yaw is determined for the elongated interface object based on both the first and second transformation images. The pitch is determined based on at least one of the first and second transformation images.

Claims

1. A method for determining yaw of an elongated interface object as it interacts with a touchscreen, the method comprising:

from a sensor of a touchscreen, receiving a touch image that corresponds to an area of the touchscreen that has an elongated interface object positioned at least proximate to it, wherein the elongated interface object has a pitch and a yaw with respect to a surface of the touchscreen;

performing a first transformation to obtain a first transformation image of the touch image;

performing a second transformation to obtain a second transformation image of the touch image, wherein the first transformation differs from the second transformation; and

determining the yaw for the elongated interface object based on both, the first and second transformation images.

2. The method of claim 1, wherein the yaw is determined by:

determining a theta value and a first centroid value from the first transformation image;

determining a second centroid value from the second transformation image; and

computing yaw based on the theta value and the first and second centroids.

3. The method of claim 2, wherein the first transformation is an aggressive transformation that favors strongly activated touch pixels and the second transformation is a relaxed transformation that is more inclusive of touch pixels.

4. The method of claim 3, wherein the aggressive transformation includes transforming to zero pixels that have an intensity value below a first threshold, and leaving the pixels that are above the first threshold at their original intensity values, wherein the relaxed transformation includes transforming any pixels having an intensity value above a second threshold to a first value and transforming to zero any pixels having an intensity value below the second threshold, wherein the second threshold is lower than the first threshold.

5. The method of claim 3, wherein the yaw is determined by:

determining an estimated yaw that has a theta vector that corresponds to first and second possible directions based on the theta value;

determining a vector between the first and second centroids; and

selecting the first or second possible direction of the theta vector for the yaw based on the vector between the first and second centroids, wherein the first and second transformations are selected to result in the first centroid differing from the second centroid if the interactive elongated object is not perpendicular to the surface of the touchscreen.

6. The method of claim 5, further comprising determining pitch based on distance between the first and second centroids.

7. The method of claim 3, wherein the yaw is determined by the angle of the vector between the first and second centroids.

8. The method of claim 1, further comprising determining the pitch for the elongated interface object based on a magnitude of at least first eigenvalue of at least one of the first and second transformation images.

9. A system comprising:

a touchscreen element for sensing a touch image that corresponds to an area of the touchscreen that has an elongated interface object positioned at least proximate it, wherein the elongated, interface object has a pitch and a yaw with respect to the touchscreen; and

a processor and a memory, wherein the processor and memory are configured to perform the following operations;

performing a first transformation to obtain a first transformation image of the touch linage;

performing a second transformation to obtain a second transformation image of the touch image, wherein the first transformation differs from the second transformation;

determining yaw for the elongated interface object based on both the first and second transformation images; and

determining pitch for the elongated interface object based on at least one of the first and second transformation images.

10. A method of determining pitch and yaw of an image generated by a touchscreen in response to an elongated object in at least proximate relation to the touchscreen;

the method comprising;

generating said image;

generating aggressive and relaxed transformations of the image and computing moments of intensity for the respective image transformations;

computing centroids of the respective image transformations as well as theta and eigenvalues for the aggressive transformation;

deriving pitch from a first eigenvalue;

deriving a yaw estimate from theta;

calculating a vector between the two centroids and disambiguating the yaw estimate using the vector; and

employing said pitch and yaw to derive information about said elongated object in relation to said touchscreen.

11. The method of in claim 10, wherein said aggressive transformation of the image recognizes only higher intensity image pixels.

12. The method of in claim 10, wherein said relaxed transformation of the image recognizes both higher and lower intensity image pixels.

13. The method of claim 10, wherein the aggressive transformation includes transforming to zero pixels that have an intensity value below a first threshold, and leaving the pixels that are above the first threshold at their original intensity values, wherein the relaxed transformation includes transforming any pixels having an intensity value above a second threshold to a first value and transforming to zero any pixels having an intensity value below the second threshold, wherein the second threshold is lower than the first threshold.

14. The method of claim 10, further comprising determining pitch based on distance between first and second centroids.

15. The method of claim 10, wherein the yaw is determined by the angle of the vector between first and second centroids.

16. A method for deriving information about the three-dimensional relation between an elongated object and a touchscreen to which the object is sufficiently proximate to be sensed by the touchscreen, the method comprising:

generating an image associated with said object;

transforming said image based upon a plurality of different image pixel intensity threshold criteria;

computing centroids of said image transformations and calculating said information based at least in part on the resulting centroids.

17. The method of in claim 16, wherein at least one of said centroids is based upon only higher intensity image pixels.

18. The method of in claim 16, wherein at least one of said centroids is based upon both higher and lower intensity image pixels.

19. The method of in claim 16, wherein yaw of the object is part of the derived information relative to said touchscreen.

20. The method of in claim 16, wherein pitch of the object is part of the derived information relative to said touchscreen.