| 摘要 |
<p>PURPOSE:To secure the effective head touch of a tape at the time of rotating rapidly and slowly a rotary drum by forming grooves for attenuating an air film on prescribed positions corresponding to rapid rotation heads on the tape traveling face of the rotary drum. CONSTITUTION:Four tape adhesion preventing grooves 7 are vertically formed at equal intervals on a range from the center part of the outer periphery 2a of the rotary drum 2 up to the position opposed to the vicinity of NRSC recording/reproducing heads 4. In addition, four air film attenuating grooves 8 continued to respective grooves 7 are formed on the position opposed to the vicinity of HD recording/reproducing 3. Since the air film thickness at the rapid rotation is almost similar to that of slow rotation, the change of the air film thickness can be prevented at the time of rotating rapidly and slowly a rotary drum and the effective head touch of the tape can be secured.</p> |
