| 摘要 |
PURPOSE:To rotate a magnetic head smoothly and quickly at the time of activating a device after a power source is turned on and to rotate it securely even when a magnetic head adheres to a magnetic disk and the disk will not rotate by stopping a command to a magnetic disk rotating means when a signal of a rotation detecting means of a magnetic disk is not inputted and simultaneously by giving the command to a magnetic head shifting means. CONSTITUTION:When a signal from a rotation detection means 28 to detect a rotation of a magnetic disk 13 is not inputted, the command to stop a spindle motor 15 is outputted. Then, a pulse voltage is impressed to a solenoid 24, and a lock mechanism is securely released. Then the command is outputted to a step motor 1, and a magnetic head 8 is shifted by several tracks (for instance, 7-8 tracks) in the radius direction of the magnetic disk 13. The rotation command is given to the spindle motor 15 again, and after the elapse of appropriate time, the magnetic disk is decided whether it is rotated or not. At this time, the magnetick disk 13 can rotate if the adhesion of the magnetic head 8 is released by shifting the magnetic head 8; therefore a control circuit 27 reads and writes normal information to the magnetic disk 13. |
