Combining trans-capacitance data with absolute-capacitance data for touch force estimates

Patent metadata

Field	Value
Publication number	US-10108303-B2
Application number	US-201615088026-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2016
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

Techniques for obtaining force-based data of an input device are provided. The techniques include driving sensor electrodes in transcapacitive mode and in absolute capacitive mode, obtaining profiles for each of the modes, scaling the transcapacitive profile, and subtracting the scaled transcapacitive profile from the profile for absolute capacitive sensing. The result of this subtraction is force-based data that indicates the degree of force with that input object applies to the input device.

First claim

What is claimed is:

1. A method for obtaining force-based data associated with a touch event, the method comprising:
driving a plurality of sensor electrodes in transcapacitive mode to obtain a plurality of transcapacitive measurements;
driving the plurality of sensor electrodes in absolute capacitive mode to obtain a plurality of absolute capacitive measurements; and
determining the force-based data based on differences between the plurality of transcapacitive measurements and the plurality of absolute capacitive measurements.

2. The method of claim 1 , wherein:
the plurality of sensor electrodes comprises at least one display electrode, wherein the display electrode is configured for both display updating and capacitive sensing.

3. The method of claim 1 , wherein during a touch event, an input object causes at least one sensor electrode of the plurality of sensor electrodes to move closer to a conductor within an input device that includes the plurality of sensor electrodes.

4. The method of claim 1 , wherein determining the force-based data comprises:
collapsing the plurality of transcapacitive measurements to obtain a plurality of composite transcapacitive measurements.

5. The method of claim 4 , wherein collapsing the plurality of transcapacitive measurements comprises:
combining transcapacitive measurements of the plurality of transcapacitive measurements, each such transcapacitive measurement corresponding to the same sensor electrode, to form a composite transcapacitive measurement of the plurality of composite transcapacitive measurements.

6. The method of claim 4 , further comprising:
scaling the plurality of composite transcapacitive measurements to obtain a plurality of scaled composite transcapacitive measurements.

7. The method of claim 6 , wherein determining the force-based data comprises:
subtracting the scaled composite transcapacitive measurements from the plurality of absolute capacitive measurements to obtain the force-based data.

8. A processing system for obtaining force-based data associated with a touch event, the processing system comprising:
sensing circuitry configured to:
drive a plurality of sensor electrodes in transcapacitive mode to obtain a plurality of transcapacitive measurements, and
drive the plurality of sensor electrodes in absolute capacitive mode to obtain a plurality of absolute capacitive measurements; and

a determination processor configured to:
determine the force-based data based on differences between the plurality of transcapacitive measurements and the plurality of absolute capacitive measurements.

9. The processing system of claim 8 , wherein:
the plurality of sensor electrodes comprises at least one display electrode, wherein the display electrode is configured for both display updating and capacitive sensing.

10. The processing system of claim 8 , wherein during a touch event, at least one sensor electrode of the plurality of sensor electrodes is configured to move closer to a conductor within an input device that includes the plurality of sensor electrodes in response to touch applied by an input object.

11. The processing system of claim 8 , wherein the determination processor is configured to determine the force-based data by:
collapsing the plurality of transcapacitive measurements to obtain a plurality of composite transcapacitive measurements.

12. The processing system of claim 11 , wherein the determination processor is configured to collapse the plurality of transcapacitive measurements by:
combining transcapacitive measurements of the plurality of transcapacitive measurements, each such transcapacitive measurement corresponding to the same sensor electrode, to form a composite transcapacitive measurement of the plurality of composite transcapacitive measurements.

13. The processing system of claim 11 , wherein the determination processor is further configured to:
scale the plurality of composite transcapacitive measurements to obtain a plurality of scaled composite transcapacitive measurements.

14. The processing system of claim 13 , wherein the determination processor is configured to determine the force-based data by:
subtracting the scaled composite transcapacitive measurements from the plurality of absolute capacitive measurements to obtain the force-based data.

15. An input device for obtaining force-based data associated with a touch event, the input device comprising:
a plurality of sensor electrodes; and
a processing system comprising:
sensing circuitry configured to:
drive a plurality of sensor electrodes in transcapacitive mode to obtain a plurality of transcapacitive measurements, and
drive the plurality of sensor electrodes in absolute capacitive mode to obtain a plurality of absolute capacitive measurements; and
a determination processor configured to:
determine the force-based data based on differences between the plurality of transcapacitive measurements and the plurality of absolute capacitive measurements.

16. The input device of claim 15 , wherein:
the plurality of sensor electrodes comprises at least one display electrode, wherein the display electrode is configured for both display updating and capacitive sensing.

17. The input device of claim 15 , wherein during a touch event, at least one sensor electrode of the plurality of sensor electrodes is configured to move closer to a conductor within an input device that includes the plurality of sensor electrodes in response to touch applied by an input object.

18. The input device of claim 15 , wherein the determination processor is configured to determine the force-based data by:
collapsing the plurality of transcapacitive measurements to obtain a plurality of composite transcapacitive measurements.

19. The input device of claim 18 , wherein the determination processor is configured to collapse the plurality of transcapacitive measurements by:
combining transcapacitive measurements of the plurality of transcapacitive measurements, each such transcapacitive measurement corresponding to the same sensor electrode, to form a composite transcapacitive measurement of the plurality of composite transcapacitive measurements.

20. The input device of claim 18 , wherein the determination processor is further configured to:
scale the plurality of composite transcapacitive measurements to obtain a plurality of scaled composite transcapacitive measurements.

Assignees

• Synaptics Inc

Inventors

• Shepelev Petr
• WINGARD Andrew

Classifications

• G06F2203/04107

  Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds · CPC title

• G06F3/0412

  Digitisers structurally integrated in a display · CPC title

• G06F3/044 Primary

  by capacitive means · CPC title

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/041662 Primary

  using alternate mutual and self-capacitive scanning · CPC title