| 摘要 |
PURPOSE:To position efficiently and highly accurately a head by dividing a recording area of a disc into two parts, and embedding and forming servo information in respective areas. CONSTITUTION:The 1st and 2nd areas 12, 13 are formed on the inner peripheral part and the outer peripheral part of the disc 11. The area 12 is divided into plural sectors and each sector consists of a servo sector 15 and a data sector 16 and embeds servo information. On the other hand, the area 13 is divided into sectors which are several times of the number of sectors of the area 12 and servo information is embedded in each sector 17. Therefore, the volume of servo information formed in the area 13 is larger than that of the area 12. The head is positioned on the basis of the servo information obtained from the area 13 and the one obtained from the area 12. Consequently, positioning can be attained efficiently and highly accurately. |
