| 摘要 |
<p>PURPOSE:To optimize the tape deformation form in the vicinity of a recording and reproducing head by providing a rotating body, which is rotated to a pair of upper and lower fixed drums, with spiral groups and providing a discharge part, through which air in the internal space is discharged to the outside, on the face opposite to the face, to which the recording and reproducing head is attached, of the rotating body. CONSTITUTION:Pump-out spiral groups 11 and 12 are formed in outer peripheral upper and lower face parts 4a and 4b of a rotating body 4, and the group 12 of the lower face part 4b is cut away in a partial face 4b1 to which a magnetic head 7 is fixed, and the number of groove parts 11a of the group 11 formed on a partial face 4a1 of the upper face part 4a corresponding to the opposite side is made larger than that in the other partial faces. The groove depth may be reduced without increasing the number of groove parts. By this constitution, air in the internal space generated by fixed drums 1 and 2 is discharged to the outside and the tape is run in the floating state when the rotating body 4 attached to the head 7 is rotated at a high speed by a direct drive motor.</p> |
