A capstan servo with a reference locked tape speed override for a video tape recorder

摘要

A capstan servo for moving video tape with variable speed during playback controls the tape speed according to time period inputs. The input specifies the number of seconds per hour of program length, for example, that a segment of recorded video information is to be expanded or compressed compared with its normal length. The playback speed is then varied by locking the reproduced control track vertical sync signal to a synthesized time adjustable reference signal.