| 摘要 |
PURPOSE:To attain the high density of tracks by winding a steel belt around a pulley of a step motor whose diameter is changed partially. CONSTITUTION:The steel belt 12 whose both ends are fixed ends 13, 14 is wound around a barrel-shaped pulley 11 fitted to a step motor shaft and a head carriage 15 is moved left and right. When the pulley 11 is driven clockwise, the belt 12 is wound to the smaller diameter part of the pulley 12 and when driven counterclockwise, the belt 12 is wound around the larger diameter part. Thus, in setting the counterclockwise turning of the pulley 11 to the movement of a head toward the outer circumferential direction, the track pitch is increased for the outer tracks with respect to the same step angle of the step motor. |
