Resolving multiple presences over a touch sensor array

• US 8,902,174 B1
• Filed: 03/02/2009
• Issued: 12/02/2014
• Est. Priority Date: 02/29/2008
• Status: Active Grant

• Current Assignee: Parade Technologies, Ltd.
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Peterson, Jonathan R.
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): LEE, DAVID J
• Application Number:
  US12/396,374
• Time in Patent Office: 2,101 Days
• Field of Search: 178/18.03
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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

An apparatus for and method of resolving multiple presences over a touch sensor are described. The method includes logically grouping data from a touch sensor array in order to convert the data into X-Y coordinates.

Claims

1. A method of resolving multiple substantially simultaneous presences over a touch sensor array, comprising:

measuring a plurality of sensor elements of the touch sensor array to determine a corresponding plurality of measured values;

determining whether a first measured value of a first sensor element, of the plurality of sensor elements, is above a threshold;

responsive to determining that the first measured value of the first sensor element is above the threshold, determining whether a second measured value of a second sensor element, of the plurality of sensor elements, is above the threshold;

grouping the sensor elements that neighbor one another, and have measured values above the threshold, into a plurality of grouped masses, wherein each of the plurality of grouped masses includes three or more neighboring sensor elements; and

determining, using a processing device, a center of each of the plurality of grouped masses by performing a three-dimensional center of mass calculation, wherein at least a portion of the three-dimensional center of mass calculation is performed while at least a portion of the plurality of the sensor elements is measured,

wherein the center of each grouped mass is defined by a single x-dimension value derived from a plurality of x-dimension values of positions of the grouped mass, a single y-dimension value derived from a plurality of y-dimension values of the positions of the grouped mass, and a single z-dimension value derived from a plurality of z-dimension values of the positions of the grouped mass.

2. The method of claim 1, further comprising:

interpolating the center to generate an interpolated result; and

reporting the interpolated result as an X-Y position of the touch sensor array.

3. The method of claim 2, further comprising:

filtering the center to generate a filtered result; and

reporting the filtered result as an X-Y position of the touch sensor array.

4. The method of claim 1, further comprising:

filtering the center to generate a filtered result; and

reporting the filtered result as an X-Y position of the touch sensor array.

5. The method of claim 1, wherein in performing the three dimensional center of mass calculation, each sensor element in each grouped mass is assigned a weight.

6. The method of claim 5, further comprising:

interpolating a result of the three dimensional center of mass calculation to generate an interpolated result; and

reporting the interpolated result as an X-Y position of the touch sensor array.

7. The method of claim 5, further comprising:

filtering a result of the three dimensional center of mass calculation to generate a filtered result; and

reporting the filtered result as an X-Y position of the touch sensor array.

8. The method of claim 1, wherein the single z-dimension value is a sense measurement value.

9. The method of claim 1, wherein the single z-dimension value is an amplitude value.

10. The method of claim 1, wherein the threshold is based on a noise value.

11. An apparatus to resolve multiple substantially simultaneous presences over a touch sensor array, comprising:

a processing device configured to measure a plurality of sensor elements of the touch sensor array to determine a corresponding plurality of measured values; and

responsive to determining that a first measured value of a first sensor element, of the plurality of sensor elements, is above a threshold;

determine whether a second measured value of a second sensor element, of the plurality of sensor elements, is above the threshold, the processing device configured to group the sensor elements that neighbor one another and have measured values above the threshold into a plurality of grouped masses, and determine a center of each of the plurality of grouped masses using a three-dimensional center of mass calculation, wherein each of the plurality of grouped masses includes three or more neighboring sensor elements, and wherein the processing device is configured to perform at least a portion of the three-dimensional center of mass calculation while the processing device measures at least a portion of the plurality of the sensor elements,

wherein the center of each grouped mass is defined by a single x-dimension value derived from a plurality of x-dimension values of positions of the grouped mass, a single y-dimension value derived from a plurality of y-dimension values of the positions of the grouped mass, and a single z-dimension value derived from a plurality of z-dimension values of the positions of the grouped mass.

12. The apparatus of claim 11, wherein the processing device is further configured to interpolate the center to generate an interpolated result, and to report the interpolated result as an X-Y position of the touch sensor array.

13. The apparatus of claim 11, wherein the processing device is further configured to filter the center to generate a filtered result, and report the filtered result as an X-Y position of the touch sensor array.

14. The apparatus of claim 11, wherein in performing the three dimensional center of mass calculation, the processing device is configured to assign a weight to each sensor element in each grouped mass.

15. The apparatus of claim 14, wherein the processing device is further configured to:

interpolate a result of the three dimensional center of mass calculation to generate an interpolated result,

filter the interpolated result of the three dimensional center of mass calculation to generate a filtered result, and

report the filtered result as an X-Y position of the touch sensor array.

16. The apparatus of claim 11, wherein the single z-dimension value is an amplitude value.

17. The apparatus of claim 11, further comprising the sensor array coupled to the processing device.

18. The apparatus of claim 11, wherein the threshold is based on a noise value.