Method and apparatus for servo-control of tape tension in high speed tape transporter

摘要

A vacuum column (34) is used in a closed loop, high-speed tape transporter (10) to maintain constant tension on a moving loop of tape as it is delivered to a pick-up head (20) of the transporter (10). A motor driven capstan (35) intermediate a tape storage bin (23) and the vacuum column (34) pulls the loop of tape from bin (23) and delivers it to the vacuum column (34). A servo-control (39), (40), (41) senses changes in the position of the tape within the vacuum column (34) caused by tension changes of the tape within the bin (23) and sends a signal responsive to the change of position of the tape in the vacuum column (34) to the capstan motor (31), thereby changing its speed sufficient to maintain the position of the tape within capstan (34) at a relatively constant level. Sensing can be by means of a vacuum slot (34), an ultrasonic proximity indicator (42) or a series of photo-optical sensors (44), (45).