Hybrid force measurement

• US 10,095,341 B2
• Filed: 06/30/2016
• Issued: 10/09/2018
• Est. Priority Date: 06/30/2016
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Solven, Derek
• Primary Examiner(s): Moon, Patrick
• Application Number:
  US15/199,777
• Publication Number:
  US 20180004332A1
• Time in Patent Office: 831 Days
• Field of Search: None
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

Hybrid force sensing includes acquiring absolute capacitance measurements of the absolute capacitance of at least one frame side electrode, acquiring mutual capacitance measurements of the mutual capacitance between the at least one frame side electrode and at least one display side electrode. Hybrid force sensing further includes determining an absolute capacitance derived force from the absolute capacitance measurements, determining a mutual capacitance derived force from the mutual capacitance measurements, and combining the absolute capacitance derived force and the mutual capacitance derived force to obtain a combined force. Hybrid force sensing further includes performing an action based on the combined force.

Claims

1. A method for hybrid force sensing comprising:

acquiring a plurality of absolute capacitance measurements of an absolute capacitance of at least one frame side electrode disposed between a conductive frame and at least one display side electrode,

wherein the at least one display side electrode is disposed between a display and the at least one frame side electrode,

wherein acquiring the plurality of absolute capacitance measurements comprises modulating the at least one frame side electrode with a reference voltage and measuring the absolute capacitance of the at least one frame side electrode, and

wherein the absolute capacitance is based on a distance of the at least one frame side electrode to the conductive frame;

acquiring a plurality of mutual capacitance measurements of a mutual capacitance between the at least one frame side electrode and the at least one display side electrode;

determining an absolute capacitance derived force from the plurality of absolute capacitance measurements;

determining a mutual capacitance derived force from the plurality of mutual capacitance measurements;

combining the absolute capacitance derived force and the mutual capacitance derived force to obtain a combined force; and

performing an action based on the combined force.

2. The method of claim 1, wherein combining the absolute capacitance derived force and the mutual capacitance derived force comprises totaling the absolute capacitance derived force and the mutual capacitance derived force.

3. The method of claim 1, wherein acquiring a plurality of mutual capacitance measurements comprises using the at least one frame side electrode as a transmitter electrode and the at least one display side electrode as a receiver electrode, wherein the transmitter electrode transmits sensing signals and the receiver electrode receives resulting signals based on the sensing signals.

4. The method of claim 1, wherein acquiring the plurality of mutual capacitance measurements comprises using the at least one frame side electrode as a receiver electrode and the at least one display side electrode as a transmitter electrode, wherein the transmitter electrode transmits sensing signals and the receiver electrode receives resulting signals based on the sensing signals.

5. An input device comprising:

a display;

a conductive frame;

at least one frame side electrode;

at least one display side electrode, wherein the at least one display side electrode is disposed between the display and the at least one frame side electrode, and wherein the at least one frame side electrode is disposed between the conductive frame and the at least one display side electrode;

a first compressible layer, wherein the at least one display side electrode is interposed between the display and the first compressible layer; and

a processing system that is configured to;

acquire a plurality of absolute capacitance measurements of an absolute capacitance of at least one frame side electrode;

acquire a plurality of mutual capacitance measurements of a mutual capacitance between the at least one frame side electrode and at least one display side electrode;

determine an absolute capacitance derived force from the plurality of absolute capacitance measurements;

determine a mutual capacitance derived force from the plurality of mutual capacitance measurements;

combine the absolute capacitance derived force and the mutual capacitance derived force to obtain a combined force; and

perform an action based on the combined force.

6. The input device of claim 5, wherein the first compressible layer is a foam.

7. The input device of claim 5, further comprising:

a first substrate attached to the display,

wherein the at least one display side electrode is interposed between the first substrate and the first compressible layer.

8. The input device of claim 5, further comprising:

a second compressible layer,

wherein the second compressible layer is interposed between the at least one frame side electrode and the conductive frame.

9. The input device of claim 5, wherein the conductive frame is a metal housing.

10. The input device of claim 5, wherein the conductive frame is a mid-frame of the input device.

11. The input device of claim 8, further comprising a second substrate mounting the at least one frame side electrode.

12. The input device of claim 8, wherein the second compressible layer is air.

13. The input device of claim 8, wherein the second compressible layer is foam.

14. The input device of claim 5, wherein the at least one display side electrode is comprised in the display.

15. A processing system for hybrid force sensing comprising:

sensor circuitry with functionality for;

acquiring a plurality of absolute capacitance measurements of an absolute capacitance of at least one frame side electrode,

wherein the at least one frame side electrode is disposed between a conductive frame and at least one display side electrode,

wherein acquiring the plurality of absolute capacitance measurements comprises modulating the at least one frame side electrode with a reference voltage and measuring the absolute capacitance of the at least one frame side electrode, and

wherein the absolute capacitance is based on a distance of the at least one frame side electrode to the conductive frame, and

acquiring a plurality of mutual capacitance measurements of a mutual capacitance between the at least one frame side electrode and the at least one display side electrode, wherein the at least one display side electrode is disposed between a display and the at least one frame side electrode; and

processing circuitry with functionality for;

determining an absolute capacitance derived force from the plurality of absolute capacitance measurements,

determining a mutual capacitance derived force from the plurality of mutual capacitance measurements,

combining the absolute capacitance derived force and the mutual capacitance derived force to obtain a combined force, and

performing an action based on the combined force.

16. The processing system of claim 15, wherein combining the absolute capacitance derived force and the mutual capacitance derived force comprises totaling the absolute capacitance derived force and the mutual capacitance derived force.

17. The processing system of claim 15, wherein acquiring a plurality of mutual capacitance measurements comprises using the at least one frame side electrode as a transmitter electrode and the at least one display side electrode as a receiver electrode, wherein the transmitter electrode transmits sensing signals and the receiver electrode receives resulting signals based on the sensing signals.

18. The processing system of claim 15, wherein acquiring a plurality of mutual capacitance measurements comprises using the at least one frame side electrode as a receiver electrode and at least one display side electrode as a transmitter electrode, wherein the transmitter electrode transmits sensing signals and the receiver electrode receives resulting signals based on the sensing signals.