| 摘要 |
<p>PURPOSE:To secure the effective head touch of a tape at the time of rotating both rapidly and slowly by perforating air holes for attenuating an air film on a rotary drum, closing the air holes by valves at the time of slow rotation of the drum, or opening them at the time of rapid rotation. CONSTITUTION:A pair of upper and lower air holes 6, 6 for attenuating the air film are perforated on the upper part of each of HD recording/reproducing heads 3 and NTSC recording/reproducing heads 4 formed on the peripheral wall part 2b of the rotary drum 2. At the time of slow rotation of the drum 2 which is NTSC recording/reproducing, respective valve bodies 8a of valves 8 are abutted upon one ends of stoppers 9 and respective air holes 6, 6 are closed, or at the time of rapid rotation to be NTSC recording/reproducing, the valve bodies 8a are abutted upon the other ends of the stoppers 9 and respec tive air holes are opened. Thus, the air film can be prevented from being changed at its thickness at the time of rotating both rapidly and slowly the rotary drum 2 and the effective head touch of the tape can be secured.</p> |
