Patent ID: 8441251

Claim:
A proximity sensor comprising: a first transmission coil (S 1 ), a second transmission coil (S 2 ); at least one reception coil (E); a first excitation device ( 28 ) which is connected to the first and second transmission coils (S 1 , S 2 ); and an evaluation device ( 30 ) which is connected to at least one transmission coil (S 1 , S 2 ) or to the excitation device ( 28 ) as well as to the at least one reception coil (E) and is designed to generate an evaluation signal which depends on a phase shift between a signal (U s ) of at least one transmission coil (S 1 , S 2 ) or of the excitation device ( 28 ) as well as a signal (U E ) of the at least one reception coil (E), wherein the evaluation unit signal is at least approximately proportional to the phase shift, and wherein the transmission coils (S 1 , S 2 ) are designed, arranged and excited so that and the reception coil (E) is designed and arranged so that a transfer function of the proximity sensor, which represents a relation between a signal (U E ) of the reception (E)and a signal (U S ) of a transmission coil (S 1 , S 2 ) in dependence on an approached target ( 18 ), has a zero point at a target ( 18 ) which is located at a predetermined switching distance from the proximity sensor in a direction of influence ( 14 ) of the proximity sensor.