Methods and apparatus for capacitive sensing

Patent metadata

Field	Value
Publication number	US-10452210-B2
Application number	US-201615356215-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Oct 24, 2008
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

The present disclosure addresses methods and apparatus facilitating capacitive sensing using a conductive surface, and facilitating the sensing of proximity to the conductive surface. The sensed proximity will often be that of a user, but can be another source of a reference voltage potential. In some examples, the described systems are capable of sensing capacitance (including parasitic capacitance) in a circuit that includes the outer conductive surface, and where that outer conductive surface is at a floating electrical potential. In some systems, the systems can be switched between two operating modes, a first mode in which the system will sense proximity to the conductive surface, and a second mode in which the system will use a capacitance measurement to sense contact with the conductive surface.

First claim

What is claimed is:

1. An electronic device comprising:
a plurality of capacitive sensing regions arranged at different locations across the electronic device, the plurality of capacitive sensing regions including a plurality of electrodes separated by a gap from a plurality of conductive element portions held at a first potential;
wherein each of the plurality of capacitive sensing regions is configured to change the gap between the electrode and the conductive element portion when a first object contacts the conductive element portion; and
sensing circuitry coupled to the electrode in each of the plurality of capacitive sensing regions, the sensing circuitry configured to determine a change in capacitance between the electrode and the conductive element portion due to the change in the gap and detect a touch of the first object.

2. The electronic device of claim 1 , wherein the conductive element portions are continuously formed as a surface of the electronic device.

3. The electronic device of claim 1 , further comprising a processor coupled to the sensing circuitry and capable of performing one or more functions upon detection of the touch of the first object.

4. The electronic device of claim 1 , further comprising a processor coupled to the sensing circuitry and capable of determining a first location of the touch of the first object.

5. The electronic device of claim 4 , wherein the sensing circuitry is further configured to detect a touch of a second object, and wherein the processor is further capable of determining a second location of the touch of the second object.

6. The electronic device of claim 1 , wherein the first potential is a ground potential.

7. The electronic device of claim 1 , wherein the plurality of capacitive sensing regions comprise one or more touch-sensitive invisible buttons.

8. The electronic device of claim 1 , wherein two or more of the plurality of electrodes are coupled together.

9. The electronic device of claim 1 , wherein the gap comprises one of air or a dielectric layer.

10. The electronic device of claim 1 , incorporated into a portable computing device.

11. The electronic device of claim 1 , wherein the plurality of conductive element portions form a part of an external surface of the electronic device.

12. A method of capacitive touch sensing at an electronic device, comprising:
forming each of a plurality of capacitive sensing regions by separating an electrode and a conductive element portion by a gap, and holding the conductive element portion at a first potential;
arranging the plurality of capacitive sensing regions at different locations across the electronic device;
changing the gap between the electrode and the conductive element portion of a particular capacitive sensing region when a first object contacts the conductive element portion of the particular capacitive sensing region;
determining a change in capacitance between the electrode and the conductive element portion due to the change in the gap; and
detecting a touch of the first object based on the determined change in capacitance.

13. The method of claim 12 , further comprising continuously forming the conductive element portions as a surface of the electronic device.

14. The method of claim 12 , further comprising performing one or more functions upon detection of the touch of the first object.

15. The method of claim 12 , further comprising determining a first location of the touch of the first object.

16. The method of claim 15 , further comprising detecting a touch of a second object, and determining a second location of the touch of the second object.

17. The method of claim 12 , further comprising holding the conductive element portion at a ground potential.

18. The method of claim 12 , further comprising forming touch-sensitive invisible buttons from the plurality of capacitive sensing regions.

19. The method of claim 12 , further comprising coupling two or more of the plurality of electrodes together.

20. The method of claim 12 , further comprising forming the gap from one of air or a dielectric layer.

21. The method of claim 12 , wherein the conductive element portions form a part of an external surface of the electronic device.

22. An electronic device comprising:
a touch-sensitive surface;
one or more capacitive touch sensing regions cooperatively arranged with the touch-sensitive surface, each capacitive touch sensing region including a first electrode and a second electrode separated by a gap, the second electrode being held at a first potential;
sensing circuitry coupled to the first electrode in each of the one or more capacitive touch sensing regions, the sensing circuitry configured for generating a first signal indicative of a capacitance between the first electrode and the second electrode; and
a processor cooperatively coupled to the sensing circuitry and capable of receiving the first signal and sensing a touch by detecting a change in the first signal caused by a change in a gap between the first electrode and the second electrode, the change in the gap caused by an object in contact with the touch-sensitive surface.

23. The electronic device of claim 22 , wherein the second electrode forms an external surface of the electronic device.

Assignees

• Apple Inc

Inventors

• Pance Aleksandar
• Leung Omar S
• Amm David T

Classifications

• H03K17/975

  using a capacitive movable element · CPC title

• H03K17/9622

  using a plurality of detectors, e.g. keyboard · CPC title

• G06F1/169

  the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes (G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033) · CPC title

• H03K17/98

  having a plurality of control members, e.g. keyboard · CPC title

• G06F2203/04104

  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 title