Per-finger force detection using segmented sensor electrodes

Patent metadata

Field	Value
Publication number	US-10088942-B2
Application number	US-201615088011-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2016
Publication date	Oct 2, 2018
Grant date	Oct 2, 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. These techniques may be used with an input device in which a plurality of sensor electrodes are divided into two or more segments. Independent sets of force-based data can be obtained for each segment, which allows for determination of a location associated with each set of force-based data.

First claim

What is claimed is:

1. A method for obtaining first and second force-based data associated with a touch event for first and second portions of an input device, the method comprising:
driving a first segment of a plurality of sensor electrodes located within the first portion of the input device in transcapacitive mode to obtain a first plurality of transcapacitive measurements;
driving a second segment of the plurality of sensor electrodes located within the second portion of the input device in transcapacitive mode to obtain a second plurality of transcapacitive measurements;
driving the first segment of the plurality of sensor electrodes in absolute capacitive mode to obtain a first plurality of absolute capacitive measurements;
driving the second segment of the plurality of sensor electrodes in absolute capacitive mode to obtain a second plurality of absolute capacitive measurements;
determining the first force-based data based on differences between the first plurality of transcapacitive measurements and the first plurality of absolute capacitive measurements; and
determining the second force-based data based on differences between the second plurality of transcapacitive measurements and the second 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 the touch event, an input object causes at least one of a sensor electrode of either the first segment of the plurality of sensor electrodes or the second segment of the plurality of sensor electrodes to move closer to a conductor within the input device.

4. The method of claim 1 , wherein:
determining the first force-based data comprises collapsing the first plurality of transcapacitive measurements to obtain a first plurality of composite transcapacitive measurements for the first segment of the plurality of sensor electrodes; and
determining the second force-based data comprises collapsing the second plurality of transcapacitive measurements to obtain a second plurality of composite transcapacitive measurements for the second segment of the plurality of sensor electrodes.

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

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

7. The method of claim 6 , wherein:
determining the first force-based data comprises subtracting the first scaled composite transcapacitive measurements from the first plurality of absolute capacitive measurements to obtain the first force-based data for the first portion of the input device; and
determining the second force-based data comprises subtracting the second scaled composite transcapacitive measurements from the second plurality of absolute capacitive measurements to obtain the second force-based data for the second portion of the input device.

8. The method of claim 7 , wherein:
subtracting the first scaled composite transcapacitive measurements from the first plurality of absolute capacitive measurements comprises subtracting, from a first absolute capacitive measurement of the first plurality of absolute capacitive measurements, a scaled composite transcapacitive measurement generated based on data from a sensor electrode associated with the first absolute capacitive measurement; and
subtracting the second scaled composite transcapacitive measurements from the second plurality of absolute capacitive measurements comprises subtracting, from a second absolute capacitive measurement of the second plurality of absolute capacitive measurements, a scaled composite transcapacitive measurement generated based on data from a sensor electrode associated with the second absolute capacitive measurement.

9. A processing system for obtaining first and second force-based data associated with a touch event for first and second portions of an input device, the processing system comprising:
sensor circuitry configured to:
drive a first segment of a plurality of sensor electrodes located within the first portion of the input device in transcapacitive mode to obtain a first plurality of transcapacitive measurements,
drive a second segment of the plurality of sensor electrodes located within the second portion of the input device in transcapacitive mode to obtain a second plurality of transcapacitive measurements,
drive the first segment of the plurality of sensor electrodes in absolute capacitive mode to obtain a first plurality of absolute capacitive measurements, and
drive the second segment of the plurality of sensor electrodes in absolute capacitive mode to obtain a second plurality of absolute capacitive measurements; and

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

10. The processing system of claim 9 , 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.

11. The processing system of claim 9 , wherein the sensor electrode is configured such that during the touch event, an input object causes at least one of a sensor electrode of either the first segment of the plurality of sensor electrodes or the second segment of the plurality of sensor electrodes to move closer to a conductor within the input device.

12. The processing system of claim 9 , wherein:
determining the first force-based data comprises collapsing the first plurality of transcapacitive measurements to obtain a first plurality of composite transcapacitive measurements for the first segment of the plurality of sensor electrodes; and
determining the second force-based data comprises collapsing the second plurality of transcapacitive measurements to obtain a second plurality of composite transcapacitive measurements for the second segment of the plurality of sensor electrodes.

13. The processing system of claim 12 , wherein:
collapsing the first plurality of transcapacitive measurements comprises combining transcapacitive measurements of the first plurality of transcapacitive measurements, each such transcapacitive measurement corresponding to the same sensor electrode, to form a composite transcapacitive measurement of the firs

Assignees

• Synaptics Inc

Inventors

• Shepelev Petr
• Mackin Thomas

Classifications

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0414

  using force sensing means to determine a position · CPC title

• G06F2203/04106

  Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection · CPC title

• G06F2203/04105

  Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position · CPC title

• G06F3/044

  by capacitive means · CPC title