Patent ID: 7439640

Claim:
An actuator that uses electromagnetic drive power, comprising: an electromagnetic actuator mechanism that has a magnet unit including magnets and an electromagnetic coil unit including an electromagnetic coil, wherein relative positions of the magnet unit and the electromagnetic coil unit are variable; and a controller for controlling the electromagnetic actuator mechanism, the magnet unit including: a yoke member including a plate portion; and a first and a second magnets that are magnetically pulled onto either side of the plate portion with the identical poles of each of the magnets facing each other across the plate portion, main surfaces of the plate portion of the yoke member being set to have a size which encompasses respective surfaces of the first and second magnets that face the plate portion, thereby causing the first and second magnets being magnetically pulled onto the plate portion, the electromagnetic coil unit including a first electromagnetic coil that faces the first magnet and a second electromagnetic coil that faces the second magnet, the relative position of the maanet unit and the electromagnetic coil unit being changeable in a moving direction that is perpendicular to a direction that travels through the first electromagnetic coil, the magnet unit and the second electromagnetic coil, and the controller supplying the first and second electromagnetic coils with mutually reverse electric currents, to thereby move the electromagnetic actuator mechanism in the moving direction while maintaining the relative position of the first and second electromagnetic coils.