| 摘要 |
<p>PURPOSE:To prevent the flawing of a tape by flanges and to obtain good jitter performance by molding the roller of the revolving guide of a plastic resin and coating the outer peripheral surface thereof with a thin film made of a metal or ceramics. CONSTITUTION:A bearing part 3b in contact with a guide shaft 2 of the roller 3 of the revolving guide 1 is molded of a polyacetal resin having excellent slidability. The roller 3a molded of an ABS resin on which a metallic film is liable to fix is concentrically laminated on the outer peripheral surface of this bearing part 3b. A chrome plating 12 is applied on the outer peripheral surface of this roller 3a. The increase rate of the inertia moment of this time is set at <=1.2 as compared with the roller which is not coated with the metallic thin film. Since the metallic thin film having a low coefft. of friction is used, the transfer force that the tape receives in an axial direction decreases and the flawing by the flanges 4, 5 is prevented. The increase rate of the inertia moment is low and the longitudinal vibration frequency remains high and less affects the jitter.</p> |
