Capacitive Sensor Device And Method For Operating A Capacitive Sensor Device

• US 20150288361A1
• Filed: 01/12/2012
• Published: 10/08/2015
• Est. Priority Date: 01/12/2011
• Status: Active Grant

• Current Assignee: Microchip Technology Germany GmbH (Microchip Technology Incorporated)
• Original Assignee: Microchip Technology Germany GmbH (Microchip Technology Incorporated)
• Inventors: Kaltner, Claus
• Granted Patent: US 9,954,524 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2017/9615 using three electrodes per touch switch
• CPC Class Codes: H03K 2217/960705 Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe
• CPC Class Codes: H03K 2217/960775 Emitter-receiver or "fringe" type detection, i.e. one or more field emitting electrodes and corresponding one or more receiving electrodes

Abstract

A capacitive sensor device for approach and/or contact detection can be coupled with an electric circuit (10) and has a sensor electronics (20) and a device for potential separation (30), which with the sensor electronics (20) is coupled and by which the capacitive sensor device can be coupled with the electric circuit (10). In a method for operating a capacitive sensor device which has a sensor electronics, the sensor electronics can be coupled with an electric circuit and the sensor electronics is coupled with the electric circuit in a separable way with respect to the potential.

Claims

1. Capacitive sensor device for approach and/or contact detection, which can be coupled with an electric circuit, comprising

an electrode configuration, having at least one transmission electrode, at least one compensation electrode and at least one receiving electrode, in which at the transmission electrode and at the compensation electrode each an alternating electrical field can be emitted, which can be coupled into the receiving electrode,

a sensor-electronics which can be coupled with the electrode configuration and which, at least during a measuring interval, supplies the transmission electrode and the compensation electrode each with an electric alternating signal and taps an electrical value at the receiving electrode, and

a device for potential separation, which is coupled with the sensor electronics and by means of which the capacitive sensor device can be coupled with the electric circuit.

2. Sensor device according to claim 1, wherein the device for potential separation, at least during the measuring interval, galvanically separates the capacitive sensor device from the electric circuit.

3. Sensor device according to claim 1, wherein the device for potential separation galvanically separates the capacitive sensor device from the electric circuit in a time-division multiplex method.

4. Sensor device according to claim 1, wherein the device for potential separation comprises a filter for the frequency-selective separation of the capacitive sensor device from the electric circuit, preferably during the measuring interval.

5. Sensor device according to claim 1, wherein the device for potential separation comprises at least one of optical coupling device, capacitive coupling device, and inductive coupling device, in order to couple the capacitive sensor device with the electric circuit.

6. Sensor device according to claim 1, wherein the device for potential separation presents at least one electric switch, by which the sensor-electronics can be coupled with the electric circuit.

7. Sensor device according to claim 1, wherein the sensor-electronics further supplies the transmission electrode with an electric alternating signal, which is phase-shifted with respect to the electric alternating signal supplied at the compensation electrode.

8. Sensor device according to claim 1, wherein the electric circuit is part of an electric hand-held device, especially of a mobile phone, a two-way radio, a computer mouse, a remote control device, a digital camera, a game controller, a movable minicomputer, or a tablet PC.

9. Method for operating a capacitive sensor device, which comprises a sensor-electronics and an electrode configuration that can be coupled with it, wherein the sensor-electronics can be coupled with an electric circuit, in which

a transmission electrode and a compensation electrode of the electrode configuration are each time supplied with an electric alternating signal in order to emit at them each time an alternating electrical field, which can be coupled into a receiving electrode of the electrode configuration, at the receiving electrode an electrical value being tappable, and

the sensor electronics is coupled with the electric circuit in a separable way with respect to the potential.

10. Method according to claim 9, in which at least during the measuring interval the capacitive sensor device is galvanically isolated from the electric circuit.

11. Method according to claim 9, wherein the capacitive sensor device is galvanically isolated from the electric circuit in a time-division multiplex method.

12. Method according to claim 9, wherein the potential separation is done with a device, which comprises at least one of optical coupling device, capacitive coupling device, inductive coupling device, and electric switch.

13. Mobile device comprising a capacitive sensor device for approach and/or contact detection, which can be coupled with an electric circuit of the mobile device, comprising

an electrode configuration, having at least one transmission electrode, at least one compensation electrode and at least one receiving electrode, in which at the transmission electrode and at the compensation electrode each an alternating electrical field can be emitted, which can be coupled into the receiving electrode,

a sensor-electronics which can be coupled with the electrode configuration and which, at least during a measuring interval, supplies the transmission electrode and the compensation electrode each with an electric alternating signal and taps an electrical value at the receiving electrode, and

a device for potential separation, which is coupled with the sensor electronics and by means of which the capacitive sensor device can be coupled with the electric circuit.

14. Mobile device according to claim 13, wherein the device for potential separation, at least during the measuring interval, galvanically separates the capacitive sensor device from the electric circuit.

15. Mobile device according to claim 13, wherein the device for potential separation galvanically separates the capacitive sensor device from the electric circuit in a time-division multiplex method.

16. Mobile device according to claim 13, wherein the device for potential separation comprises a filter for the frequency-selective separation of the capacitive sensor device from the electric circuit, preferably during the measuring interval.

17. Mobile device according to claim 13, wherein the device for potential separation comprises at least one of optical coupling device, capacitive coupling device, and inductive coupling device, in order to couple the capacitive sensor device with the electric circuit.

18. Mobile device according to claim 13, wherein the device for potential separation presents at least one electric switch, by which the sensor-electronics can be coupled with the electric circuit.

19. Mobile device according to claim 13, wherein the sensor-electronics further supplies the transmission electrode with an electric alternating signal, which is phase-shifted with respect to the electric alternating signal supplied at the compensation electrode.

20. Mobile device according to claim 13, wherein the mobile device is a mobile phone, a two-way radio, a computer mouse, a remote control device, a digital camera, a game controller, a laptop computer, or a tablet PC.