| 摘要 |
PROBLEM TO BE SOLVED: To provide a focus searching method and an optical disk device capable of speedily shifting to the data reproducing operation after focus searching by making the moving range small for an objective lens, and thereby shortening the time for shifting the objective lens. SOLUTION: On the basis of detection information AS-cd from a photo-detector when the objective lens 73 is focused on the signal surface of an optical disk in the middle of raising or lowering the objective lens 73 placed on standby at the lens midpoint between a temporarily set lens bottom point and a temporarily set lens top point according to a temporarily set lens bottom point voltageαand a temporarily set lens top point voltageβ, a focus search driving voltage R corresponding to a signal surface 12 of an optical disk 10 is acquired, and based on the focus search driving voltage R and predetermined factors, a lens bottom point voltageγand a lens top point voltageδat the time of starting the device are obtained by using an arithmetic operation program, and then a lens bottom point corresponding to the lens bottom point voltageγis set nearer to the lens midpoint side than the temporarily set lens bottom point while a lens top point corresponding to the lens top point voltageδis set nearer to the lens midpoint side than the temporarily set lens top point. COPYRIGHT: (C)2005,JPO&NCIPI
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