Cushman, Darby & Cushman
Method of controlling positioning of rotor of stepping motor
 A method of controlling the positioning of a rotor of a stepping motor is disclosed. During the last step in a movement of the rotor to a desired rest position thereof, the windings of the stepping motor are energized so as to produce a first magnetic vector, a position indicated by the first magnetic vector being displaced from the desired rest position in the direction of the movement of the rotor by a predetermined amount. This displacement of the first magnetic vector causes the rotor to overshoot the desired rest position by such an amount that a positioning error of the rotor due to a hysteresis characteristic of the rotor in the direction of the movement thereof is compensated. The windings are then energized to produce a second magnetic vector with the position indicated by this second magnetic vector coinciding with the desired rest position of the rotor. The energization of the windings may be performed in small steps to effect a vernier driving of the rotor. 
Tokiko, Ltd.
H
H02P
inventional
Makoto
Nishimura