Patent ID: 7307926
Filing Date: 2007-12-11
Classification: G11B

Abstract:
1. A tracking controller comprising a tracking error detecting section for generating and outputting a tracking error signal that represents how much the focal point of a light beam has shifted from a target track on a storage medium, a tracking control section for generating a drive signal in response to the tracking error signal so as to move the light beam such that the focal point of the light beam is located right on the target track, a tracking error amplitude adjusting section for multiplying the tracking error signal by a predetermined proportionality constant, and a tracking gain calculating section for calculating and storing a gain of a tracking control loop, which is defined by the tracking error detecting section, the tracking error amplitude adjusting section and the tracking control section, at an arbitrary frequency, wherein the gain of the tracking error signal is switched by changing the proportionality constant depending on whether or not the focal point of the light beam is located on a recorded area, and wherein a ratio of the gain that has been calculated by the tracking gain calculating section for the recorded area, on which the data has been written, to the gain that has been calculated by the tracking gain calculating section for an unrecorded area, on which the data has not yet been written, is used as the proportionality constant.