Head Actuator Servo for VTR Using Four Frequency Pilot Signals

A recent tendency is to employ narrower recording tracks essential for the high density video recordings. However, due to the track linearity variation caused by mechanical accuracy limitation, assurances for the tape interchangeabilties are increasing difficulties. As in Fig. l(a), unless the recording and its reproduction are performed on the same recorder, the loss of reproduced output due to the miss-tracking is unavoidable. As shown in Fig. l(b), the tracking error signal generated in this case, generally contains relatively higher frequency component above 60Hz, and since the tape transport servo mechanism is not extended to cover this higher frequencies, the heads can not trace the non-linear recorded tracks.