In a conventional active headrest device, in order to protect a head etc. at the time of collision, a headrest ascends, and an ascent stroke is secured. However, it was proven that this construction is a little unsatisfactory in terms of ascent speed or distance in following the movement of a head, etc. at the time of the collision. Further, it is considered that this ascent speed or distance incurs a risk of a second accident and causes a new problem.
In light of the above circumstance, the active headrest of the invention includes individual means provided in a seat back. The individual means includes a lower unit which operates by an impact given to a frame, a wire which elevates/lowers inside the seat back linked to the lower unit, a solenoid to which the wire is locked and/or an upper unit having the solenoid, and a headrest device linked to a lifter or a connecting portion of the upper unit. At the time of collision, the wire is tensioned downward, the lifter or connecting portion of the upper unit ascends or tilt forward, and the ascent and forward tilting of the headrest are performed instantaneously. As a result, this headrest can secure the ascent stroke and forward tilting which can follow the movement of a head, etc. at the time of collision, and can protect a head, etc.