METHODS AND APPARATUS FOR CAPACITIVE SENSING

• US 20170068356A1
• Filed: 11/18/2016
• Published: 03/09/2017
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: PANCE, Aleksandar, LEUNG, Omar S., AMM, David T.
• Granted Patent: US 10,452,210 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/1616 with folding flat displays, e.g. laptop computers or notebooks having a clamshell configuration, with body parts pivoting to an open position around an axis parallel to the plane they define in closed position
• CPC Class Codes: G06F 1/1643 the display being associated to a digitizer, e.g. laptops that can be used as penpads details related to the relative motion of the display enclosure with respect to the body enclosure, e.g. to move between laptop and tablet PC configuration G06F1/1615
• CPC Class Codes: G06F 1/169 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 Class Codes: G06F 2203/04104 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 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 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 17/975 using a capacitive movable element
• CPC Class Codes: H03K 17/98 having a plurality of control members, e.g. keyboard
• CPC Class Codes: H03K 2217/96077 comprising an electrode which is floating

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.

Claims

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. 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.

12. The method of claim 11, further comprising continuously forming the conductive element portions as a surface of the electronic device.

13. The method of claim 11, further comprising performing one or more functions upon detection of the touch of the first object.

14. The method of claim 11, further comprising determining a first location of the touch of the first object.

15. The method of claim 14, further comprising detecting a touch of a second object, and determining a second location of the touch of the second object.

16. The method of claim 11, further comprising holding the conductive element portion at a ground potential.

17. The method of claim 11, further comprising forming touch-sensitive invisible buttons from the plurality of capacitive sensing regions.

18. The method of claim 11, further comprising coupling two or more of the plurality of electrodes together.

19. The method of claim 11, further comprising forming the gap from one of air or a dielectric layer.

20. 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.