| 摘要 |
PURPOSE:To transfer quickly and accurately a head from one track to the next track, by superposing a driving force due to a motor and that due to a bimorph plate, and applying them to the recording or reproducing head. CONSTITUTION:When a head access command signal (a) is generated by a head access signal source 11, a motor driving circuit 12 generates a signal (b) which drives a head feeding motor MH for a certain time, but a rise (c) is delayed because inertia is large. A bimorph driving circuit 13 receives the head access command signal to generate a driving wave (d), and a voltage (v) at the rise time is applied to a bimorph plate 7 to display a recording or reproducing head 5 by a quantity corresponding to one track pitch, and thereafter, the voltage is attenuated gradually according as the rotation quantity of the motor MH is increased with time. Thus, the overall displacement quantity of the head rises rapidly and is made approximately constant for a required time, and therefore, the head 5 is transferred quickly and accurately between recording tracks. |
