| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk device etc. which realizes precise focus jump while properly avoiding collision between an optical disk and a focusing lens. SOLUTION: The optical disk device comprises a light source, a focusing part for focusing light from a light source, a moving part which varies the position of the focusing part in a direction vertical to the information surface of the optical disk based on a control signal to move the focal point of the light, a photodetection part which receives reflected light from the information surface in a plurality of areas for generating a plurality of signals according to a photodetective quantity in each area, a signal generation part for generating a focus error signal based on the plurality of signals, and a control part for generating a control signal based on the focus error signal. The control signal is a signal for moving the focal point of the light to a range where focus control is possible with respect to the information surface. A control part generates the control signal for decelerating the focal point with a first acceleration with respect to the information surface and thereafter decelerating the focal point with a second acceleration. The absolute value of the second acceleration is smaller than that of the first acceleration. COPYRIGHT: (C)2004,JPO&NCIPI
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