Patent ID: 7994777

Claim:
A proximity sensor comprising: a housing having a face and the housing defined in part by a longitudinal axis; electronics within the housing; at least a first pair of inductive coils disposed within the housing, the first pair of inductive coils disposed on opposite sides of the longitudinal axis, the first pair of inductive coils electrically coupled with the electronics; one of the first pair of inductive coils is opposite in polarity from another one of the first pair of inductive coils; at least a second pair of inductor coils disposed within the housing, the second pair of inductive coils disposed on opposite sides of the longitudinal axis, the second pair of inductive coils electrically coupled with the electronics, and one of the second pair of inductive coils is opposite in polarity from another one of the second pair of inductive coils; and a third pair of inductor coils, the third pair of inductor coils disposed on opposite sides of the longitudinal axis.