Capstanless helical drive system

摘要

A capstanless helical scan recording system (14) comprises a supply reel (24); a take-up reel (26); and a media transport path (20) extending from the supply reel to the take-up reel. A drum (30) is positioned along the media transport path and has a read head (R1,R2) and a write head (W1,W2) mounted thereon for recording and reading information in helical stripes on the media. The take-up reel comprises a rotor assembly (60), a rotating hub assembly (70), and a gearing system. The rotor assembly includes a sun gear (80) which rotates at a first rotational speed. The rotating hub assembly rotates carries three planetary gears (160) and imparts a velocity to media transported in the media transport path. The gearing system meshes with the rotor assembly and with the hub assembly for causing the hub assembly to have a greater rotational speed than the rotor assembly. The gearing system preferably has a gear ratio on the order of about 8:1. A tension arm (44) protrudes into the media transport path and decouples the supply reel to compensate for reel runnout during high speed operation. The system has no further means other than the take-up reel and the supply reel for imparting impetus to the media along the media transport path.