METHOD OF MULTI-ZONE CAPACITIVE SENSING, DEVICE AND APPARATUS IMPLEMENTING THE METHOD

• US 20160034102A1
• Filed: 04/09/2014
• Published: 02/04/2016
• Est. Priority Date: 04/15/2013
• Status: Active Grant

• Current Assignee: Quickstep Technologies, LLC (Broadcom, Inc.)
• Original Assignee: FOGALE nanotech
• Inventors: ROZIERE, Didier, LEGROS, Eric
• Granted Patent: US 10,592,046 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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

Abstract

A method is provided for capacitive detection, implementing a plurality of electrodes capable of allowing the detection of objects in their proximity by capacitive coupling, and including a step of simultaneous polarization of at least a part of the electrodes with different excitation potentials, the excitation potentials being generated with respect to a reference potential such that the scalar product over a predetermined duration of at least two of these excitation potentials is zero or very much less than the scalar product of one and/or the other of these excitation potentials with itself over the predetermined duration. A device and an appliance implementing the method are also provided.

Claims

1. A method for capacitive detection, implementing a plurality of electrodes capable of allowing the detection of objects in their proximity by capacitive coupling, comprising:

a step of simultaneous polarization of at least a part of said electrodes with different excitation potentials, said excitation potentials being generated with respect to a reference potential such that the scalar product over a predetermined duration of at least two of these excitation potentials is zero or very much less than the scalar product of one and/or the other of these excitation potentials with itself over said predetermined duration.

2. The method of claim 1, wherein the generated excitation potentials comprise at least one excitation potential that is variable over time.

3. The method of claim 1, in which the generated excitation potentials comprise periodic excitation potentials of different frequencies.

4. The method of claim 1, wherein the generated excitation potentials comprise at least one excitation potential the frequency content of which is spread over a spectral band.

5. The method of claim 1, wherein the generated excitation potentials comprise two periodic excitation potentials of the same frequency in phase quadrature.

6. The method of claim 1, wherein the generated excitation potentials comprise at least one excitation potential the scalar product of which with an interference signal is minimized.

7. The method of claim 1, wherein the generated excitation potentials comprise at least one excitation potential substantially equal to the reference potential.

8. The method according to claim 1, which also comprises a step of measuring the capacitive coupling of an electrode comprising:

acquisition of representative measurements of the electrical charge of the electrode; and

demodulation of said representative measurements of the charge by using the excitation potential of said electrode.

13. An appliance comprising:

a device for capacitive detection according to claim 9, and implementing the method according to claim 1.

14. The appliance of claim 13, which comprises on a first face a display screen and first substantially transparent electrodes polarized at a first excitation potential, and on a second face opposite to the first face, second electrodes polarized at a second excitation potential.

15. The appliance of claim 14, which is of one of the following types:

smart phone, tablet.

16. The appliance of claim 13, which comprises a plurality of modules capable of moving in relation to each other, each module comprising electrodes polarized at an excitation potential different from the other modules.

9. A device for capacitive detection, comprising plurality of electrodes capable of allowing the detection of objects in their proximity by capacitive coupling;

excitation means capable of simultaneously polarizing at least a part of said electrodes with different excitation potentials, said excitation potentials being generated with respect to a reference potential such that the scalar product over a predetermined duration of at least two of these excitation potentials is zero or very much less than the scalar product of one and/or the other of these excitation potentials with itself over said predetermined duration.

10. The device of claim 9, which also comprises measurement means referenced to the same excitation potential as the electrodes to which they are linked.

11. The device of claim 10, which also comprises demodulation means linked to the measurement means, and capable of producing a representative measurement of the capacitive coupling referenced to the reference potential.

12. The device of claim 9, which also comprises means making it possible to polarize at least one electrode:

at several different excitation potentials; and

/or

at at least one excitation potential or at the reference potential.