Electrode configuration for position detection and method for position detection

• US 9,958,532 B2
• Filed: 09/20/2012
• Issued: 05/01/2018
• Est. Priority Date: 09/23/2011
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): FORTICH, ALVARO E
• Application Number:
  US14/346,959
• Publication Number:
  US 20150123682A1
• Time in Patent Office: 2,049 Days
• 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 longitudinal center axis of a first electrode is arranged substantially parallel with respect to a longitudinal center axis of a second electrode, a longitudinal center axis of a third electrode is arranged in an acute angle relative to the longitudinal center axis of the first electrode, the method comprising:

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

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

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 is proportional to the coverage of the electrode configuration by the object independent of a position of the object along a length of the electrode configuration, and wherein the variation of the second coupling capacity is proportional to the product of coverage and position of the object relative to the electrode configuration.

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.

32. The electrode configuration according to claim 1, wherein each of the at least three electrodes has a rectangular shape.

6. An electrode configuration for a capacitive sensor system for detecting a position of an object relative to the electrode configuration, wherein the electrode configuration comprises:

a first position detection electrode arrangement with 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 a longitudinal center axis of the first electrode is arranged in an acute angle relative to a longitudinal center axis of the second electrode, and wherein the first electrode is loaded with a first generator signal,

and at least one exposure detection electrode arrangement, which comprises a third electrode and a fourth electrode, wherein the third electrode is operated as a transmitting electrode and is loaded with a second generator signal which is inverse to the first generator signal and wherein a longitudinal center axis of the third electrode is arranged in parallel with the longitudinal center axis of the first electrode.

7. The electrode configuration of claim 6, wherein the third electrode is arranged in parallel with the fourth electrode, wherein the third electrode is operated as a transmitting electrode and the fourth electrode is operated as a receiving electrode.

8. The electrode configuration of claim 6, wherein the third electrode is arranged in an acute angle with respect to the fourth electrode, wherein the third electrode is operated as a receiving electrode and the fourth electrode is operated as a transmitting electrode.

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 second 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.

33. The electrode configuration according to claim 6, wherein each of the first, second, third and fourth electrodes has a rectangular shape.

34. The electrode configuration according to claim 6, wherein each of the first, second, and third electrodes has a rectangular shape.

17. An electrode configuration for a capacitive sensor system for detecting a position of an object relative to the electrode configuration, wherein the electrode configuration comprises:

a first electrode, a second electrode and a third electrode, wherein the first electrode is operable as a transmitting electrode and the second electrode is operable as a receiving electrode, wherein a longitudinal center axis of the first electrode is arranged in parallel with respect to a longitudinal center axis of the second electrode, and a longitudinal center axis of the third electrode is arranged in an acute angle relative to the longitudinal center axis of the first electrode,

and a control circuit configured to

operate the second electrode as a receiving electrode and to load the first electrode with a first generator signal and the third electrode with a second generator signal during a first measurement for determining coverage of the electrode configuration by the object, wherein a first measurement signal is received from the second electrode, which is representative for a first coupling capacity between the second electrode and the first electrode,

operate the third electrode as a receiving electrode and to load the first electrode with the first generator signal and the second electrode with the second generator signal during a second measurement for determining the position, wherein at the third electrode a second measurement signal is received, which is representative for a second coupling capacity between the third electrode and the first electrode, and

wherein the control circuit determines the position from the ratio of a change of the second coupling capacity to a change of the first coupling capacity due to a presence of the object.

18. The electrode configuration of claim 17, wherein the second generator signal is inverse with respect to the first generator signal.

19. The electrode configuration of claim 17, wherein the control circuit is further configured prior to determining the position to determine, 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.

20. The electrode configuration of claim 17, wherein the variation of the first coupling capacity is proportional to the coverage of the electrode configuration by the object, and wherein the variation of the second coupling capacity is proportional to the product of coverage and position of the object relative to the electrode configuration.

21. The electrode configuration of claim 17, 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.

22. A method for detecting a position of an object relative to an electrode configuration comprising at least three electrodes being at least partially ring shaped, wherein a first electrode is arranged substantially concentrically with respect to a second electrode, and a third electrode is arranged excentric relative to the first electrode, the method comprising:

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

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

23. The method of claim 22, wherein the second generator signal is inverse with respect to the first generator signal.

24. The method of claim 22, 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.

25. The method of claim 22, wherein the variation of the first coupling capacity is proportional to the coverage of the electrode configuration by the object, and wherein the variation of the second coupling capacity is proportional to the product of coverage and position of the object relative to the electrode configuration.

26. The method of claim 22, 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.

27. An electrode configuration for a capacitive sensor system for detecting a position of an object relative to the electrode configuration, wherein the electrode configuration 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 concentrically with respect to the second electrode, and a third electrode arranged excentrically relative to the first electrode, wherein the first, second, and third electrode are at least partially ring shaped;

and a control circuit configured to

operate the second electrode as a receiving electrode and to load the first electrode with a first generator signal and the third electrode with a second generator signal during a first measurement for determining coverage of the electrode configuration by the object, wherein a first measurement signal is received from the second electrode, which is representative for a first coupling capacity between the second electrode and the first electrode,

operate the third electrode as a receiving electrode and to load the first electrode with the first generator signal and the second electrode with the second generator signal during a second measurement for determining the position, wherein at the third electrode a second measurement signal is received, which is representative for a second coupling capacity between the third electrode and the first electrode, and

wherein the control circuit determines the position from the ratio of a change of the second coupling capacity to a change of the first coupling capacity due to a presence of the object.

28. The electrode configuration of claim 27, wherein the second generator signal is inverse with respect to the first generator signal.

29. The electrode configuration of claim 27, wherein the control circuit is further configured prior to determining the position to determine, 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.

30. The electrode configuration of claim 27, wherein the variation of the first coupling capacity is proportional to the coverage of the electrode configuration by the object, and wherein the variation of the second coupling capacity is proportional to the product of coverage and position of the object relative to the electrode configuration.

31. The electrode configuration of claim 27, 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.

35. 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 concentrical with respect to a second electrode such that a capacitive coupling between the first and second electrode is independent with a position along a length of the first and second electrodes, and wherein a third electrode is arranged in an acute angle or excentrical relative to the first electrode such that a capacitive coupling between the first and third electrode is varying with respect to a position along a length of the first and third electrodes, the method comprising:

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

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

36. The method of claim 35, wherein the second generator signal is inverse with respect to the first generator signal.

37. The method of claim 35, 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.

38. The method of claim 35, wherein the variation of the first coupling capacity substantially is proportional to the coverage of the electrode arrangement configuration by the object independent of a position of the object along a length of a respective electrode, and wherein the variation of the second coupling capacity substantially is proportional to the product of coverage and position of the object relative to the electrode configuration.

39. The method of claim 35, 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.