| 摘要 |
PURPOSE:To adjust head height accurately and automatically without reference to hysteresis of a bimorph plate, by controlling a driving voltage to the bimorph plate in accordance with the time when the reproduction output of a roraty magnetic head crossing the recording track of the other magnetic head reaches its maximum. CONSTITUTION:Bimorph driver circuit 59 is controlled by saw-tooth signal generating circuit 58 to vary rotary head 52 in height to rotary head 51 and head 51 reproduce a signal while tracing a tranck crossing a recording track formed on magnetic tape 29. Then, when head 52 crosses the recording track and the maximum value of a reproduction output obtained by head 52 is detected through peak holding circuit 61 and comparator circuit 62, the output of circuit 62 is inverted and a voltage equivalent to heights of heads 52 and 51 is applied to circuit 59 by sample holding circuit 64 and memory 65 in accordance with a period of time from the reproduction start of head 52 until the crossing of the recording track. Therefore, the height of the heads can be adjusted accurately and automatically by the bimorph plate without reference to hysteresis of the bimorph plate. |
