Patent ID: 8573700

Claim:
A head restraint position adjusting device, comprising: at least one upper sensing electrode provided in an upper portion of a front portion of a head restraint provided on a seat of a vehicle, and configured to sense a capacitance between a human body sitting on the seat and the head restraint; at least one lower sensing electrode provided in a lower portion of the front portion of the head restraint, and configured to sense a capacitance between the human body and the head restraint; a detection circuit configured to detect a position of a top of a head of the human body based on sensing signals from the upper sensing electrode and the lower sensing electrode; and position adjusting means configured to, in accordance with a detection result from the detection circuit, adjust a position of the head restraint relative to the seat to an appropriate position for the head, the appropriate position being based on the position of the top of the head, the detection circuit being configured to detect the position of the top of the head by comparing a capacitance value indicated by a capacitance, based on the sensing signal from the upper sensing electrode, between a vicinity of the top of the head and the head restraint, with a capacitance value indicated by a capacitance, based on the sensing signal from the lower sensing electrode, between a portion of the human body other than the vicinity of the top of the head and the head restraint.