Patent ID: 9442175
Filing Date: 2016-09-13
CPC Classification: G01D,G01R,H03K

Claim Text:
1. A capacitive sensor device for approach and/or contact detection, comprising at least one generator electrode, at least one measurement electrode and at least one calibration electrode, wherein the at least one calibration electrode is arranged in a predefined distance adjacent to the at least one measurement electrode, wherein the at least one measurement electrode and the at least one calibration electrode are assigned to the at least one generator electrode, wherein the at least one generator electrode receives an alternating generator voltage and the at least one calibration electrode receives an alternating calibrating voltage, and wherein the at least one calibration electrode may be operated at least in a first operating mode and a second operating mode, wherein in each of the operating modes the calibrating voltage is equal to or smaller than the generator voltage, and the calibrating voltage is different in each operating mode; and further comprising an evaluation device which is configured to measure a capacitance between the measurement electrode (M) and ground while the calibration electrode is operated in the first and second operating mode, respectively and to determine a difference between the measurements, wherein the evaluation device furthermore compares the difference between the measurements with a threshold value to determine whether a calibration can be performed.