US Patent 7823383 Actuator driving device

An actuator driving device includes: an actuator made of a shape metal alloy having a property that a predetermined shape is memorized in advance, and that the predetermined memorized shape is recovered when the actuator is heated to a predetermined temperature; an applier for applying, to the actuator, a pulse current or a pulse voltage at least having a predetermined current value or a predetermined voltage, and a predetermined duty ratio to heat the actuator; and a determiner for determining the current value or the voltage value, and the duty ratio of the pulse current or the pulse voltage to be applied to the actuator by the applier, wherein the determiner is operative to determine the pulse current or the pulse voltage having: the current value larger than a current value of a constant current required for displacing the actuator by a predetermined targeted displacement amount, or the voltage value corresponding thereto; and the duty ratio of making an applied current amount smaller than an applied current amount corresponding to an integrated value of the constant current in applying the constant current to the actuator.