Patent ID: 7586816

Claim:
A playback apparatus that plays back a recording medium having a plurality of recording layers, comprising: an optical head that irradiates the plurality of recording layers with laser light using an objective lens as an output terminal, that detects reflection information on the laser light, and that reads information recorded in the plurality of recording layers; an actuator that holds the objective lens such that the objective lens is capable of moving in a focus direction and a tracking direction; focus servo means for driving the actuator in accordance with a focus error signal acquired from the reflection information read by the optical head to execute focus servo; layer movement driving means for generating a layer jump driving signal used for moving a position of the objective lens from an in-focus position for a recording layer to an in-focus position for another recording layer to drive the actuator to perform movement of the objective lens in an interlayer direction; tracking servo means for driving the actuator in accordance with a tracking error signal acquired from the reflection information read by the optical head to execute tracking servo; center-point servo means for driving the actuator in accordance with a center-point error signal functioning as an error signal for a center point position of the objective lens in the tracking direction to execute center-point servo for setting the objective lens to the center point position; and layer jump sequence control means for performing a series of layer jump operations of causing the tracking servo means to turn off the tracking servo, causing the focus servo means to turn off the focus servo to cause the layer movement driving means to perform the movement of the objective lens in the interlayer direction, causing the focus servo means to turn on the focus servo, and causing the tracking servo means to turn on the tracking servo and for causing the center-point servo means to execute the center-point servo in a predetermined time within a period during which the series of layer jump operations is performed.