| 摘要 |
PURPOSE:To actuate a servo circuit so that the servo signals sent from subsequent servo sectors are invalidated by recording a specific defective signal to a preceding servo sector to show that the sector servo signal part of a magnetic disk has a defect when a defect is detected with the sector servo signal of the disk. CONSTITUTION:When a defect 8 is detected after the position reference signal is written to a servo sector, a specific defect part indication signal 10 is recorded to an erasion zone 9 of a preceding servo sector 5b on a recording track 7. Then the signal 10 is detected when the servo sector signal is reproduced. In this case, a switching circuit is provided to a servo circuit to inhibit the working of said servo circuit for the signal sent from a servo sector following the relevant servo sector. Thus it is possible to avoid a malfunction due to a defect of a servo circuit. |
