Arrangement for the detection of body parts by absorbing an electrical near field

A detection arrangement for detection of an approach or a presence of objects, in particular moving limbs, toward or in an observation zone, comprising:

• a circuit, a transmitter electrode coupled with a microcontroller, a receiver electrode and an isolation electrode, wherein the circuit is a resonance circuit that controls the transmitter electrode from the microcontroller, and the circuit is tuned to a carrier frequency of the transmitter electrode, wherein the transmitter electrode for an induction of an alternating electric field in the observation zone or its surrounding area, wherein the receiver electrode to detect the alternating electric field in the observation zone or its surrounding area, and wherein the isolation electrode to screen a part of the alternating electric field extending between the transmitter electrode and the receiver electrode, wherein the isolation electrode comprises a base plate that extends under the transmitter electrode and the receiver electrode and the isolation electrode comprises a ridge section which extends vertically from the base plate within a space between the transmitter electrode and the receiver electrode, wherein a height of the ridge section depends on a distance between the transmitter electrode and the receiver electrode such that the larger the distance between the transmitter electrode and the receiver electrode the smaller the height of the ridge section.