Stepping motor, lens device using the same, and imaging device using the same

摘要

A stepping motor comprises first to third coil portions and first to second rotors. The first rotor has a cylindrical shape and a circumferential surface thereof is magnetically-polarized so as to alternately arrange south poles and north poles. The first rotor is disposed inside the first and second coil portions, and is rotated by magnetic fields generated at a time when the first and second coil portions are energized. The second rotor has a disk shape and a surface thereof is magnetically polarized so as to alternately arrange south poles and north poles. The second rotor is disposed such that edge areas of both surfaces thereof are interposed between the second and third coil portions. The second rotor is rotated by magnetic fields generated at a time when the second and third coil portions are energized.