| 摘要 |
PURPOSE:To improve the S/N of servo information in a recording mode with a simple circuit constitution, by providing three magnetic head cores on a magnetic disk surface to use the center head core for the detection of servo information, and head cores at both sides for record/reproduction of data information respectively. CONSTITUTION:The data supplied to a record amplifier 21 is recorded on the upper side of a magnetic disk 3 by magnetic head cores 24 at both sides of those three selected by a magnetic head core selecting circuit 13. At the same time, the center head core 25 selected by the circuit 13 reproduces both servo and data information. Then the servo information is extracted by a reproduction amplifier 22 and an LPF23. The servo information of a reproduction mode is detected in the same way by the core 25, and the data information is reproduced by the core 24 and detected via a reproduction amplifier 16 and an HPF19. Thus the S/N of servo information is improved in a recording mode with a simple circuit constitution. |
