Tape recording.

摘要

A helically scanned optical tape recording and replay system has a rotating drum 1 with a galvanometer mirror 2 for controlling the tracking of a number of write and read light beams during recording and replay. Dynamic focussing of the beams on the recording medium is controlled by means of a voice-coil actuator 6 operating on a lens 5 situated outside the drum. An optical rotator 20 is provided through which the write and read beams pass following beam combinations, the optical rotator being driven by a motor 21 to rotate at half the rotational velocity of the drum, and thereby present an image to the optical tape which rotates synchronously with the drum.