Electrode configuration for position detection and method for position detection

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.

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.

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.

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.