| 摘要 |
<p>PURPOSE:To always and uniformly keep a contact state between a head and a tape by forming part of the outer ring of a drum in an axial direction in a sectional cylindrical part with a diameter smaller than the outer diameter of the drum, and forming a window for protruding the head on the cylindrical part. CONSTITUTION:The outer circumference of the prescribed part of a rotary drum 1 separated from a drum side plane that is a tape sliding plane is formed in cylindrical shape having the diameter smaller than the outer diameter of the drum which forms the tape sliding plane. And the window 3 for protruding the head is formed at the cylindrical part with the small diameter. Therefore, an air layer can be always held between the drum and the tape 4 by rotating the rotary drum 1. In such a way, it is possible to suppress fluctuation in air pressure due to the window 3 for protruding the head or a gap in the drum, and to hold the contact state between the head and the tape stably.</p> |
