Patent ID: 8143817

Claim:
An electromagnetic actuator driving method for driving an electromagnetic actuator including a stator and a movable body, the stator including a core provided with a plurality of magnetic poles and a coil wound on at least one of the magnetic poles, the movable body including a permanent magnet arranged to oppose tip end surfaces of the magnetic poles through a magnetic gap, the movable body being supported on the electromagnetic actuator in such a manner as to make reciprocating movement in a direction perpendicular to a direction in which the permanent magnet opposes the magnetic poles, the method comprising: the movable body being reciprocated upon applying an alternating voltage to the coil, performing feedback control of the alternating voltage in which the alternating voltage is applied to the coil during a first half of a control period, in which the coil is in a non-magnetized state during a second half of the control period; and wherein a control signal is detected from an induced electromotive force generated in the coil during the second half of the control period.