PURPOSE: To hold down the power consumption to a relatively low value, by using an auxiliary driving current pulse to compensate the rise of a driving magnetic field generated by application of a hold magnetic field.

CONSTITUTION: Driving current pulses whose phases are shifted from each other by 90° are applied to an X coil and a Y coil which are orthogonal to each other. That is, a square voltage pulse 10 is applied to the X coil, and a square voltage pulse 11 is applied to the Y coil, and further, an auxiliary driving voltage pulse 12 is applied to them so that the driving magnetic field in the direction opposite to the direction of the hold magnetic field is intensified. When driving voltage pulse are applied to X and Y coils in this manner, the driving current becomes triangular wave driving currents 13 and 13' because of inductances of coils. In this case, the driving current voltage pulse. As the result, a diamond Lissajous' waveform is attained, and the waveform is expanded in a direction -Hy to compensate the reduction of the driving force due to the hold magnetic field.