Patent ID: 7706218

Claim:
An optical pickup apparatus comprising: an objective lens that focuses light on an optical recording medium; an actuator that drives the objective lens in a direction of an optical axis of the objective lens toward or away from the optical recording medium in response to an input voltage applied to the actuator; an actuator driven distance sensor that senses a distance the actuator moves according to time or the input voltage applied to the actuator; an input voltage calculator that calculates an input voltage to be applied to the actuator that compensates for a hysteresis phenomenon that occurs during movement of the actuator based on the distance sensed by the actuator driven distance sensor; and a controller that controls the actuator to move at a constant speed according to the input voltage calculated by the input voltage calculator; wherein the input voltage calculator calculates a function of the input voltage to be applied to the actuator by deriving a function that is symmetric with a function of the motion curve about a straight line representing a linear motion curve of the actuator, wherein the motion curve represents a relation between the distance the actuator moves and the time or the input voltage applied to the actuator.