Patent ID: 8596715

Claim:
A headrest device comprising: a headrest body which includes a headrest rear portion supported with respect to a seatback of a seat on which a passenger of a vehicle sits, and a headrest front portion configured to move within a predetermined range from a fully closed position closest to the headrest rear portion to a fully open position farthest from the headrest rear portion; a detection unit configured to detect a running state or an operation state of the vehicle; a prediction unit configured to predict a possibility of a rear vehicle collision with the vehicle on the basis of the running state or the operation state of the vehicle detected by the detection unit; a control unit configured to control a movement of a position of the headrest front portion such that a backset becomes smaller than a backset at the time of the prediction if the possibility of the rear vehicle collision is predicted by the prediction unit, the backset being a horizontal distance between the headrest front portion and a head of the vehicle passenger; and an angle detection unit configured to detect an angle of the seatback, wherein an angle of the seatback is configured to change with respect to the seat such that if: (1) the prediction unit predicts a low possibility of the rear vehicle collision with the vehicle, the control unit controls the position of the headrest front portion to move at a first speed such that the backset becomes a predetermined value on the basis of the angle of the seatback detected by the angle detection unit, and (2) the prediction unit predicts a high possibility of the rear vehicle collision with the vehicle, the control unit controls the backset to become smaller than the predetermined value, and controls the headrest front portion to move at a second speed faster than the first speed.