| 摘要 |
PURPOSE:To obtain a highly accurate magnetic disk device without an external mechanical sensor by detecting a track (0) with position information installed at part of a data track of a magnetic disk. CONSTITUTION:Two magnetizing inversion parts 20a and 20b of a position information area 19 used exclusively for reproducing written beforehand at part of a data track area 16 and a guard band area 17 are arranged checkeredly while a part 21 without magnetizing inversion is sandwiched so that the parts may not be equally and mutually adjacent to data track width. After a magnetic head 3 is positioned at a guard band area 17a at an outer circumference side by a positioning control circuit 26, while a comparing signal K is detected, the magnetic head 3 is shifted to an inner circumference side, a change that the comparing signal K becomes from + to ''0'' is detected and a track (0) signal E is outputted. When the comparing signal K changes from + to ''0'', the magnetic head 3 is positioned by the positioning control circuit, and then, the magnetic head 3 can be positioned on a track (0). |
