Dual servo system for rotating tape head control

摘要

Apparatus including a rotary head accurately reproduces a digital signal recorded on a tape, even when the tape runs at high speed. Transitions of a reproduced signal are detected, intervals corresponding to the transitions are counted on the basis of a predetermined reference signal, and the rotation of the rotary head is controlled in response to the counted value so that the relative speed between the rotary head and the tape is held constant, notwithstanding changes in the absolute speed of the tape, as in the fast-forward mode.