| 摘要 |
PURPOSE:To expand the range of driving frequencies by providing a varying means to gradually increasing or decreasing the level of an output signal from a specified level, and increasing or decreasing the driving frequency of a pulse motor by using said output. CONSTITUTION:A pulse motor 18 which drives an arm device and the like in a reproducing device for a recording disk is driven by the frequency signal obtained by dividing the output of a reference oscillating circuit 36 by a frequency dividing circuit 38 during the time of playing. At the time of quick sending, the pulse motor 18 is driven by gradually increasing or decreasing the signal level formed in a boot- strap circuit and the like via a sawtooth-wave generating circuit 45, and further increasing or decreasing the oscillating frequency by a voltage control oscillating circuit 46. Therefore, when the number of revolution of the motor is changed instantaneously from the playing state to the quick sending state, the operating range of the driving frequency can be expanded to the maximum continuous response frequency, and the operability can be enhanced. |
