| 摘要 |
PURPOSE:To detect or adjust circumferential direction accuracy with high accuracy, by constituting a titled medium so as to have a magnetic signal whose position in the circumferential direction is matched with both recording faces. CONSTITUTION:A part of a reference track 2 on a recording medium 1 is cut with high accuracy in the direction orthogonal to the reference track, for instance, by a laser knife, and a cut groove 4A whose width is several mum is formed. In a sectional drawing on the track 2 of this cut groove 4A, magnetic layers 6, 7 formed on a medium base material 5 are magnetized uniformly in one direction. When the cut groove 4A is formed in such a recording medium 1, a line of magnetic force 8 and 9 running uniformly in the inside of the magnetic layer 6 and 7 collapse, and a leakage magnetic flux 10 and 11 are generated in the cut groove 4A. By detecting this leakage magnetic flux, a position shift in the circumferential direction of the upper and lower magnetic heads can be approved. |
