An apparatus for reproducing digital signals recorded on a magnetic or other recording tape includes a servo mechanism which is effective, when the tape is transported at a high speed in either a fast-forward or rewind mode, to maintain a relative speed between the tape and a rotary head that is substantially...http://www.google.fr/patents/US4688115?utm_source=gb-gplus-shareBrevet US4688115 - Apparatus for reproducing a digital signal
