Tape speed control servo with an overriding slack takeup capability for a streaming cassette tape transport

摘要

A cassette tape transport has a tape speed control servo for driving either of a pair of tape drive motors at constant speed in response to tape speed pulses from a tape speed sensor. Upon development of a tape slack, as manifested by a decrease in the recurrence rate of the tape speed pulses, the tape speed control servo is overridden, and the pair of drive motors are simultaneously energized for rotating the cassette reels in opposite directions, thereby stretching the tape between the reels until the slack is removed. The tape transport has a microcomputer which may be factory preprogrammed to include a slack takeup routine. The microcomputer starts the slack takeup routine not only upon decrease in the recurrence rate of the tape speed pulses but also when the tape cassette is loaded in the tape transport and when no tape speed pulse is produced for a predetermined length of time.