| 摘要 |
PURPOSE:To attain stable recording and reproduction by designing the rotary cylinder part near the magnetic head so as to have a larger diameter than other parts and providing a taper in a prescribed direction to the outer circumferential face of a rotary cylinder thereby suppressing the vertical movement without giving a damage to a recording tape medium. CONSTITUTION:An outer diameter R1 of a rotary cylinder 5A in the vicinity of a magnetic head 6 is selected to be larger than an outer diameter R2 of the other parts. Thus, the downward force exerting a recording tape medium 1 is increased locally near the magnetic head 6. Thus, an upward force caused by friction caused between the magnetic head 6 and the recording tape medium 1 near the magnetic head 6 is compensated by a downward force increased locally near the magnetic head 6 so as to suppress the vertical movement of the recording tape medium. Moreover, since the diameter of the rotary cylinder 5A is tapered while being increased from the end 504 of the stator cylinder 2 toward the other end 505, the downward force is exerted totally to the recording tape medium 1 to suppress the vertical movement totally. |
