Per-finger force detection using segmented sensor electrodes

• US 10,088,942 B2
• Filed: 03/31/2016
• Issued: 10/02/2018
• Est. Priority Date: 03/31/2016
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Shepelev, Petr, Mackin, Thomas
• Primary Examiner(s): Bibbins, Latanya
• Application Number:
  US15/088,011
• Publication Number:
  US 20170285835A1
• Time in Patent Office: 915 Days
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04106 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 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 3/041662 using alternate mutual and self-capacitive scanning
• 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

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.

Claims

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 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.

14. The processing system of claim 12, wherein the determination processor is further configured to:

scale the first plurality of composite transcapacitive measurements to obtain a first plurality of scaled composite transcapacitive measurements; and

scale the second plurality of composite transcapacitive measurements to obtain a second plurality of scaled composite transcapacitive measurements,

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

wherein 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.

15. An input device for obtaining first and second force-based data associated with a touch event for first and second portions of the input device, the input device comprising:

a plurality of sensor electrodes comprising a first segment located within the first portion of the input device and a second segment located within the second portion of the input device; and

a 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.

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 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.

18. The input device of claim 15, 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.

19. The input device of claim 18, 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.

20. The input device of claim 18, wherein the determination processor is further configured to:

scale the first plurality of composite transcapacitive measurements to obtain a first plurality of scaled composite transcapacitive measurements; and

scale the second plurality of composite transcapacitive measurements to obtain a second plurality of scaled composite transcapacitive measurements,

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

wherein 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.