| 摘要 |
PURPOSE:To improve operability by setting automatically a drum rotational speed and a tape drive speed to those at recording by a mode switching instruction when a tracking servo of 4 frequencies does not fall into the locked state after reproduction starts. CONSTITUTION:When an erroneous mode is set at reproduction and information is not reproduced normally, a tracking servo loop by 4-frequency tracking system does not fall into the locked state, because the rotational speed of a head drum and a drive speed of a magnetic tape are different from those at recording. At this time, the level of an error signal outputted from a 4F error detection circuit 20 does not lie within the prescribed range, and a mode switching instruction is issued from a mode switching instruction generator circuit 27. As a result, the output of an instruction generator circuit 4 is inverted to switch and control automatically the mode. Thus the drum rotational speed and the tape drive sped at reproduction can be automatically set to those at recording, and operability can be improved. |
