Patent ID: 7256519

Claim:
A linear actuator comprising: a driving part comprising: an inner yoke; an outer yoke which is disposed around the inner yoke such that a first gap space and a second gap space separated in an axial direction are formed between an outer peripheral face of the inner yoke and the outer yoke; and a coil for generating an alternating magnetic field in the first gap space and the second gap space with the outer yoke, the first gap space, the inner yoke, the second gap space and the outer yoke as a magnetic path; and a movable body provided with a magnet which is disposed between the inner yoke and the outer yoke, the movable body being reciprocated in the axial direction in cooperation with the alternating magnetic field; wherein the movable body is formed in a tubular shape having an aperture edge part with at least one end opened, and the aperture edge part or a portion near the aperture edge part is disposed between the inner yoke and the outer yoke and is positioned closer to the inner yoke side than to the outer yoke side.