Patent ID: 8131140

Claim:
A linear actuator, comprising: a multipolar magnet configured such that an S pole and an N pole are linearly aligned in an alternating manner; a coil body having a plurality of separate coils integrally arranged in a lengthwise direction of the coil body, the coil body being provided to be movable relatively with respect to the multipolar magnet; a magnetic sensor that detects a position of the coil body along the lengthwise direction of the coil body with respect to the multipolar magnet; and an electrifying control circuit that individually controls currents to be supplied to the plurality of separate coils based on the position of the coil body detected by the magnet sensor, wherein the electrifying control circuit comprises: a position detector configured to detect a position of each of the plurality of separate coils based on the position of the coil body detected by the magnet sensor; and an electrifying direction controller that switches a direction of currents to be supplied to each of the plurality of separate coils individually based on a detection result of the position detector.