| 摘要 |
PROBLEM TO BE SOLVED: To secure a stable servo function for a long period by preventing the reproduction output of a servo signal from decreasing owing to thermal fluctuations even when a discrete trak disk type vertical magnetic recording medium is used. SOLUTION: In a step 801, initial values V0(i, j) of reproduction outputs of respective servo regions are measured and in a step 802, they are recorded. In a step 803, reproduction outputs V(i, j) of the respective servo regions are measured after a specified time (e.g. three months). When a ratio of V(i, j) and VO(i, j) is smaller than a specified value (k) (<1), it is determined in a step 806 that the reproduction output of the servo signal decreases and the servo region starts remagnetization (steps 809 to 816). When a servo region having, for example, a track number (m) and a sector number (n) is remagnetized, servo control is performed in a servo region having the track number (m) and a sector number (n-1) and the magnetization is started in response to detection of a gap separating a data region and the servo region, and completed. COPYRIGHT: (C)2006,JPO&NCIPI
|
