| 摘要 |
PURPOSE:To record the positioning information with high efficiency, by detecting the displacement of a means which writes the positioning information on a disk and deciding the timing of writing with the output of said detection. CONSTITUTION:A position indication A which is delivered to record the positioning information is compared with the position of a head 4 which is obtained by a laser range finder through a comparator 10. Then a voice coil motor VCM 6 is driven via an error amplifier 9 on the basis of the result of the above-mentioned comparison. The output of the comparator 10 is set approximately at ''0'' when the positioning is over, and therefore an output is delivered to a comparator 11. While the output of a strain gauge 12 which detects the head oscillation is monitored by a comparator 13. When it is detected that the oscillation is within a prescribed range of allowance, a writing amplifier 15 is started with the outputs of the comparator 11 and an AND circuit 14. Then the information is recorded via the head 4. Thus it is possible to start immediately the recording when the oscillation of the head 4 gets within an allowable range. |
