Patent ID: 7928341

Claim:
A passenger seat device for an automotive vehicle, comprising: a seat heater that is embedded in a seat in parallel to a seat surface, electric current being supplied to the seat heater in a controlled manner from an on-board power source; an upper electrode that is embedded in the seat above the seat heater in parallel thereto; an alternating current power source that supplies an alternating voltage having a predetermined frequency to the upper electrode; and a detector that detects occupancy conditions of the seat based on changes in a capacitance between the upper electrode and a member grounded to a body of the automotive vehicle; a lower electrode embedded in the seat between the upper electrode and the seat heater in parallel thereto; wherein the upper electrode and the lower electrode are fixed directly to an upper surface and a lower surface, respectively, of an insulating film to form an integrated electrode unit; the insulating film has a generally constant thickness to maintain a generally constant distance between the upper electrode and the lower electrode; and the alternating current power source supplies to the lower electrode a shielding alternating voltage that changes in accordance with the alternating voltage supplied to the upper electrode.