Patent ID: 7898206

Claim:
A stepping motor drive comprising: a drive signal supply means which supplies a plurality of periodic drive signals, which construct one electric cycle by a plurality of excitation steps and have different phases from each other to generate a rotation torque in a stepping motor, wherein the drive signal supply means supplies the drive signal so that a first rotation torque generated in the stepping motor in a first phase range of one electric cycle of the drive signal becomes smaller than a second rotation torque generated in the stepping motor in a second phase range which is a remaining phase range other than the first phase range of the one electric cycle; a control means which makes the drive signal supply means supply the drive signal upon a initialization action in which a driven member connected with rotation of the stepping motor is made abut against a stopper, wherein on a condition that the driven member abuts against the stopper by a rotation in a first rotation direction in which the driven member approaches the stopper, when the drive signal supply means continues to supply the drive signal of the first rotation direction, the first phase range includes a phase range in which a rotation torque in a second rotation direction reverse to the first rotation direction is generated in the stepping motor; and a first storing means which stores a torque control parameter according to an inversion phase characteristic intrinsic to the stepping motor, wherein the control means makes the drive signal supply means supply the drive signal, in which the first and second phase ranges are set on the basis of the torque control parameter stored in the first storing means, to the stepping motor.