| 摘要 |
PURPOSE:To execute positioning of a track on a magnetic disk by providing a clutch between a rotation transfer means and a magnetic head position displacing member, detecting an index hole provided on the magnetic disk, and operating the clutch. CONSTITUTION:A photoswitch 34 becomes switch-on when an index hole of a magnetic disk comes, namely, once per one rotation. When two photoswitches 33, 34 become both switch-on, when a solenoid is made to conduct electrically, a movable piece 32 is detached from its detention to a rotary plate 28, and pressed to a final gear 24 side by a plate spring 30, therefore, a cam 25 starts rotation through a clutch plate 29 and executes one rotation, a carriage 18 is made to execute one reciprocating linear motion in the radial direction of the magnetic disk, and recording and reproducing are executed. Also, when giving a rotational force to the magnetic disk, it is rotated by holding it by a hub and a media holder, therefore, since no driving hole is required, a shift of a track position caused by deformation and abrasion of the driving hole does not occur at all. |
