Patent ID: 8294478

Claim:
A capacitive occupant sensor to detect an occupant seated on a vehicle seat comprising: an electrostatic sensor mat arranged inside of the vehicle seat, the mat including a base member, and a main electrode arranged on the base member so as to detect the occupant based on a capacitance variation of the mat, wherein the main electrode has a first electrode disposed on the base member, and a second electrode covering the first electrode, the second electrode being less expensive than the first electrode, the base member includes a plurality of U-shaped U-parts, each of the U-parts having two extending portions approximately linearly extending in a first direction, a bent portion which is defined by bending a part of the extending portions, and an opening which is defined by a part of the base member recessed in the first direction and surrounded by the extending portions and the bent portion, the U-parts located adjacent to each other are connected with each other so as to define an S-shaped S-part, in a manner that the openings alternately open toward a first side of the first direction or a second side of the first direction, the base member is constructed by a plurality of the S-parts, and the first electrode is located adjacent to the opening when the first electrode is patterned on the bent portion.