| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of a longer accessing time caused by a rapid reduction in a disk rotation speed by an axial loss and a windage loss during the accessing of high-speed rotation or in a free run state to prevent a problem caused by a disk damage, a partially bad grade RF signal or the like in a disk playback device. SOLUTION: In a free run state such as an accessing time, a changeover switch 13 is switched to a pseudo synchronous signal detector 12 side, the output thereof is input to a synchronous signal cycle pair voltage converter 21, and a voltage proportional to the pseudo synchronous signal is generated. Simultaneously, a spindle motor control changeover switch 22 does not supply an output from a CLV error detector 15 to a spindle motor driver 16, and a playback driving controller 18 applies the output of the synchronous signal cycle pair voltage converter 21 to the spindle motor driver 16. Since a track-on state is realized again, and a rotational speed is not reduced until servo pulling-in, recovery is made within a short time. COPYRIGHT: (C)2005,JPO&NCIPI
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