| 摘要 |
PURPOSE:To compensate a track jump due to a defect and a flaw of a disk by detecting the flaw of the disk through a logical circuit which inputs output of a flaw detecting circuit for the disk and a time limiting device which is controlled with the output of the flaw detecting circuit to generate a signal with constant pulse width. CONSTITUTION:Once the flaw detecting circuit 6 detects the flaw of the disk 1, the time limiting device 7 is controlled with the output of the flaw detecting circuit 6 in synchronism with the flaw detection and the AND circuit 8 ANDs the outputs of both circuits, so that a flaw detection signal e0 appears at a terminal 9. When the flaw detection width of the disk 1 is shorter than the time width of the time limiting device 7, the obtained and when the flaw time width of the disk becomes longer than the output pulse width, the flaw detection signal e0 is limited to the specific value, i.e. output pulse width of the timelimiting device 7. Consequently, the flaw detection for a stain on the disk such as a fingerprint is not performed unnecessarily for a long time. |
