A second tracking error detector detects the displacement between the track and the light beam and outputs a second displacement detection result based on the comparison of the reproduction signals between first and second pit strings respectively. A second tracking error controller corrects a target position for push-pull control based on the second displacement detection result. A third tracking error controller calculates a correction data of a first displacement detection result based on the correction amount of the target position by the second tracking error controller, and corrects the first displacement detection result based on the calculated correction data.