Patent ID: 8371648

Claim:
An active headrest apparatus for a vehicle seat which is connected to both side frames and a upper frame of a seat back frame, comprising: a back plate connected to a lower armature and comprising slot holes formed in right and left ends of the back plate; combination pins extending through the slot holes and combined with the side frames so that the combination pins are movable along the slot holes; a back plate spring having one end connected to the side frames and the other end connected to the back plate and providing an elastic restoring force to the back plate; an upper armature combined to the lower armature and having an upper end which extends through the upper frame; and a locking cam rotatably combined to the back plate via a cam pin and comprising a pin confinement portion disposed on one end of the locking cam so that the combination pins disposed in an opposite end portion to one end portion of the slot holes are prevented from being restored to the one end portion of the slot holes.