| 摘要 |
PURPOSE:To record and reproduce high-quality pictures, by discharging air from a spiral groove part to the outside through the space between end faces facing each other of a rotary cylinder and a fixed cylinder. CONSTITUTION:An overlap cylinder inside face 3a and an overlap cylinder outside face 2a which are formed in the upper part of a fixed cylinder 3 overlap each other through a space delta2 to form a center cylinder face. A spiral groove 21 is formed on the surface of the overlap cylinder outside face 2a. An upward air current is generated by the spiral groove 21 when a rotary cylinder 2 is rotated, and air discharged o the outside from the space between the rotary cylinder and the fixed cylinder gives a floating force to a magnetic tape. Uniform air films are formed for the magnetic tape on outside circumferential faces of the rotary cylinder 2 and the fixed cylinder 3, and the sliding contact between the magnetic tape and a rotary head assembly is avoided to realize smooth tape running. |
