Patent ID: 8223016

Claim:
A capacitive occupant detection system which detects a condition on a seat based on a current or voltage according to differences of a weak electric field generated between a ground potential level of a vehicle and an electrode arranged inside the seat of the vehicle, comprising: a capacitive sensor provided as the electrode; a seat frame located under the capacitive sensor through a seat cushion and electrically connected with the ground potential level of the vehicle; and means for suppressing decrease in resistance of resistive component between the capacitive sensor and the seat frame, the resistance decrease resulting from water poured on the seat; wherein the seat includes a seating part, a back rest part, and a joint part which connects the seating part and the back rest part, and the suppressing means includes the seat cushion of the seating part having an upper surface which defines a plurality of grooves arranged with predetermined intervals, the grooves being formed to extend in and to be sloped along a direction between a front end of the seating part and the joint part, the upper surface of the seat cushion including surfaces of the grooves being waterproofed, and the seat cushion being formed so that the grooves are communicated to a bottom of the vehicle by penetrating the seat cushion in a downward direction at the joint part.