| 摘要 |
PROBLEM TO BE SOLVED: To provide a focusing control unit capable of executing a good focusing jump even in a multilayer disk, in which characteristics differ from layer to layer. SOLUTION: The focusing control unit is provided with an optical pickup including a detector for receiving a reflected light from an objective lens for condensing an optical beam and a multilayer recording medium, an error signal generator for generating a focusing error signal of an illumination optical beam from the detecting signal of the detector, an actuator for driving the objective lens, and a controller for driving the actuator based on the focusing error signal to control the focusing position of the optical beam. The controller obtains the intensity of a 2-layer reflected light based on the detecting signal of the detector, and thus the acceleration of focus jumping, and the timing of a deceleration signal between the two layers are controlled.
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