METHOD AND APPARATUS FOR CONTROLLING STEPPER MOTOR

摘要

PURPOSE: To set a moving body to an origin position so as not to be locked with reference to a lead screw by means of a simple constitution by a method wherein a stepper motor in a reset mode is driven at a driving torque which is smaller than that in an ordinary operating mode. CONSTITUTION: In a stepper motor 11, a moving body 15 which is screwed to a lead screw 13 is moved rectlinearly by means of the lead screw 13 which is formed on a shaft. A reset mode in which an origin position is set when the moving body 15 is brought into contact with a criterion face 16 which is arranged in the criterion position of the moving body 15 and an ordinary operating mode in which the moving body 15 is separated from the criterion face 16 and in which the moving body 15 is moved within an operating range not coming into contact with the criterion face 16 are prepared. Then, the stepper motor 11 in the reset mode is driven at a driving torque which is smaller than that in the ordinary operating mode.