| 摘要 |
<p>Prior to reproducing an optical disk (11), the peak of a focus error signal is detected, and a reference value of a focus error signal is set based on this value. When executing a layer jump, a kick signal with respect to an objective lens (13a) halts when a focus error signal exceeds a reference value. A brake signal is output when a focus error signal exceeds a reference value in a reversed polarity. A brake signal output time is set based on a kick signal output time. After the suspension of a brake signal, a focus servo (21) is turned on pending the peak of a focus error signal. Accordingly, a high-stability layer jump technique accommodating variations in error levels and changes in surrounding environments is provided.</p> |
