To supply a proper drive pulse at pulse rank-down by a simple constitution even if energy necessary for the drive of a stepping motor differs at a first terminal and at a second terminal due to a structural variation of the stepping motor.
A detection time storing/determining circuit 109 stores a peak signal detection time of an induction voltage generated when rotating the stepping motor by alternately supplying main drive pulses different in polarity to the first terminal side and the second terminal side of a coil for driving the stepping motor 102, and a control circuit 106 performs change control so that pulse reduction widths of the main drive pulses supplied to the first terminal side and the second terminal side are different from each other according to a difference between the previous peak signal detection time and the present peak detection time at the pulse count-down.
HASEGAWA TAKANORI
MANAKA SABURO
OGASAWARA KENJI
YAMAMOTO KOSUKE
