| 摘要 |
PURPOSE:To simplify a structure by inhibiting a head arm from moving by an operating body when no magnetic media are loaded and preventing the interference of a magnetic head, and utilizing a detection part for index detection which detects the initial position of a magnetic head on a track of a magnetic medium. CONSTITUTION:A cover 15 is closed to clamp the magnetic medium 4. The closure of the cover 15 turns on a switch which is not shown in a figure to turn a motor, driving a driving spindle 2. Consequently, the magnetic medium 4 rotates and a carrier 9 slides inwardly simultaneously. At this time, a photodetecting element 19 detects light from a light emitting element 20 to generate a pulse signal when it coincides with a hole 18. This light emitting element 20 detects the number of turns and the initial position of a track of the magnetic medium 4. If there is no magnetic medium 4 loaded when the cover 15 is closed, the photodetecting element 21 still receives the light and no output from a Vcc is sent to a gate circuit 29. Therefore, such an accident that magnetic heads 13 and 14 interference with each other is prevented. |
