Electrode Configuration for Position Detection and Method for Position Detection

• US 20150123682A1
• Filed: 09/20/2012
• Published: 05/07/2015
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: Microchip Technology Germany II GmbH & Co. KG (Microchip Technology Incorporated)
• Original Assignee: Microchip Technology Germany II GmbH & Co. KG (Microchip Technology Incorporated)
• Inventors: Burger, Stefan
• Granted Patent: US 9,958,532 B2
• Time in Patent Office: Days
• US Class Current: 324/688
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/96066 Thumbwheel, potentiometer, scrollbar or slider simulation by touch switch

Abstract

Provided is a method for detecting a position of an object relative to an electrode configuration with at least three electrodes, wherein a first electrode substantially is arranged parallel or concentrically to a second electrode, a third electrode is arranged in an acute angle or excentric relative to the first electrode, the first electrode is loaded with a first generator signal, and wherein the second electrode may be loaded with a second generator signal. The second generator signal preferably is inverse with respect to the first generator signal. In addition, provided for the method is a suitable electrode configuration with at least three electrodes.

Claims

1. A method for detecting a position of an object relative to an electrode configuration comprising at least three electrodes, wherein a first electrode is arranged substantially parallel or concentrically with respect to a second electrode, a third electrode is arranged in an acute angle or excentric relative to the first electrode, the first electrode is loaded with a first generator signal, the method comprising:

operating the second electrode as a receiving electrode and loading the third electrode with a second generator signal for determining an exposure of the electrode configuration by the object, wherein a first measurement signal is received at the receiving electrode, which is representative for a first coupling capacity between the receiving electrode and the first electrode,

operating the third electrode as a receiving electrode and loading the second electrode with the second generator signal for determining the position, wherein at the receiving electrode a second measurement signal is received, which is representative for a second coupling capacity between the receiving electrode and the first electrode, and wherein the position is determined from the ratio of the variation of the second coupling capacity to the variation of the first coupling capacity.

2. The method of claim 1, wherein the second generator signal is inverse with respect to the first generator signal.

3. The method of claim 1, wherein prior to determining the position it is determined, whether the first coupling capacity falls below a predetermined value, wherein the position only then is determined, when the first coupling capacity falls below the predetermined value.

4. The method of claim 1, wherein the variation of the first coupling capacity substantially is proportional to the exposure of the electrode arrangement by the object, and wherein the variation of the second coupling capacity substantially is proportional to the product of exposure and position of the object relative to the electrode arrangement.

5. The method of claim 1, wherein the variation of the first coupling capacity and the variation of the second coupling capacity each are determined as the variation based on the respective coupling capacity in the basic state of the electrode configuration.

6. An electrode configuration for a capacitive sensor system for detecting a position of an object relative to the electrode arrangement, wherein the electrode configuration has a first position detection electrode arrangement, which comprises a first electrode and a second electrode, wherein the first electrode is operable as a transmitting electrode and the second electrode is operable as a receiving electrode, wherein the first electrode is arranged in an acute angle relative to the second electrode, and wherein the first electrode may be loaded with a first generator signal.

7. The electrode configuration of claim 6, further comprising at least one exposure detection electrode arrangement, which comprises a third electrode and a fourth electrode, wherein the third electrode may be operated as transmitting electrode and may be loaded with the first generator signal.

8. The electrode configuration of claim 7, wherein the third electrode of the exposure detection electrode arrangement is formed by the first electrode of the position detection electrode arrangement.

9. The electrode configuration of claim 6, further comprising a second position detection electrode arrangement, which comprises a fifth electrode and a sixth electrode, wherein the fifth electrode is arranged in an acute angle relative to the sixth electrode.

10. The electrode configuration of claim 9, wherein the second electrode of the first position detection electrode arrangement substantially is arranged parallel to the fifth electrode of the second position detection electrode arrangement.

11. The electrode configuration of claim 9, wherein the sixth electrode of the second position detection electrode arrangement is formed by the second electrode of the first position detection electrode arrangement, wherein the fifth electrode may be operated as transmitting electrode and may be loaded with the first generator signal.

12. The electrode configuration of claim 9, wherein the second electrode of the first position detection electrode arrangement substantially is arranged concentrically with respect to the fifth electrode of the position detection electrode arrangement.

13. The electrode configuration of claim 9, wherein the third electrode substantially is arranged parallel to the fourth electrode.

14. The electrode configuration of claim 9, wherein the second electrode or the fourth electrode or the sixth electrode may be loaded with a second generator signal and wherein the electrodes not loaded with a generator signal may be operated as receiving electrodes.

15. The electrode configuration of claim 14, wherein the second generator signal is formed inverse with respect to the first generator signal.

16. The electrode configuration of claim 14, wherein the electrode loaded with the first or second generator signal is coupled with at least one receiving electrode via a coupling capacity, wherein the coupling capacity is configured as a discrete capacitor or as a conductor path coupling.