| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk device in which focus pull-in to a target recording layer is properly performed even in an optical disk with a large number of recording layers. <P>SOLUTION: When carrying out focus search, a search signal is supplied from a search voltage generation part 9a to a driver 34, and an objective lens 108 is driven to a focus direction. Then, a gain scale factor signal from a gain scale factor generation part 9b is supplied to a VCA (Voltage Control Amp) 24 so that a gain scale factor of a focus-error signal changes according to a search position. Accordingly, amplitude of an S-shaped curve which may become smaller than a sensing threshold is extended to become larger than the sensing threshold. Then, a miscount of the S-shaped curve is suppressed and pull-in of a laser beam to a target recording layer may be smoothly and correctly performed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
