Abstract: A headrest structure, comprising a headrest driving seat (400) fixed to a seat backrest, a lead screw motor (410), a gear mechanism (330), transmission racks (320) and a headrest part (10). The headrest structure further comprises a headrest rear cover plate (200) disposed on a rear side of the headrest part (10), wherein the headrest rear cover plate (200) is provided thereon with rear cover racks (220). The gear mechanism (330) is engaged between the rear cover racks (220) and the transmission racks (320). The lead screw motor (410) drives the gear mechanism (330) to move according to the principle of a lead screw transmission mechanism, thereby driving the headrest part (10) to move relative to the headrest driving seat (400).

Abstract: The present invention relates to a seat headrest device comprising a fixed base (30), a headrest (20) and a headrest electric motor (40). The headrest electric motor (40) drives the headrest (20) to move relative to the fixed base (30) through a composite motion mechanism comprising a screw-nut mechanism (70) and a pinion-rack mechanism (10). The present invention further discloses a seat headrest device comprising the seat headrest device. The seat headrest device has the following characteristics: a stroke of the headrest can be significantly enhanced by means of the composite movement mechanism.