| 摘要 |
PURPOSE:To ensure automatic tracking with high accuracy, by coating a magnetic layer on a single side of a disk-shaped substrate of a magnetic matter and providing a signal producing means at a prescribed position of a signal track formed to the magnetic layer. CONSTITUTION:For a magnetic disk, a magnetic layer 9 is provided on a single side of a disk-shaped substrate 8 of a magnetic matter and concentric or spiral signal tracks 1 are formed to the layer 9. Then epoxy resin 10 is buried into the substrate 8 with a prescribed pitch to form producing parts 5, 6 and 7 for tracking position detecting signals. Thus detecting signals of frequencies f1, f2 and f3 are generated in response to variations of the magnetic resistance. The parts 5 and 6 exchange their positions alternately at both sides of the track 1 and for each round on the basis of the part 7. Thus the parts 5 and 6 are always positioned respectively at one side and the other side centering on the track 1 within a round. |
