| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk reading device performing the focus search and the layer jump between plural recording layers by using the past focus error signal, etc. SOLUTION: This optical disk reading device is provided with a focus search circuit 27 for outputting a driving signal to an actuator part 21 of an optical pickup, a focus error detecting circuit 23 for generating a focus error signal, a switch 29 for changing over the ON/OFF of the focus servo loop which is maintained based on this signal, a memory part 30 for extracting and storing the parameter based on the focus error signal at the time of focus servo loop, and a control part 28 for making the focus servo loop to be OFF with respect to a changeover circuit, controlling the focus search circuit so as to move an objective lens by deciding the moving amount of it by the focus error signal obtained again based on the parameter from the memory, and controlling the focus servo loop to be made ON after the movement.
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