| 摘要 |
PURPOSE:To simplify the structure of the moving mechanism of a head rum by providing a cam whose displacement varies linearly and reciprocating the head rum in an axial direction by this cam. CONSTITUTION:The reciprocating motion in the upper and lower direction of a rotary head drum 10 is synchronized with the rotary movement of the drum 10, the timing performing an electrification to a magnetic head 12 is postponed according to the vertical movement of the drum 10 and a track is thus formed on the surface of a magnetic tape. When the movement is performed up to the upper end part of a magnetic tape by recording along a track down or up by the magnetic head 12, the displacement of a cam 31 is reversed and a track is recorded to the upper or lower part his time. And when coming to the lower end, the displacement of the cam 31 is again reversed. When a motor 29 is rotated in a fixed direction at a constant speed, the drum 10 and a stationary drum 13 perform a reciprocating motion in the axial direction at a constant speed and the reciprocating motion can be achieved without reversing the motor 29. No wear, etc., are caused because the displacement of the cam 31 is received with a roller contact by a cam follower 32. |
