초록 ▼

A device for outputting a suitable rotation torque relative to a load torque or actual torque exerted on a stepper-motor when the stepper-motor is used as a drive of an image processing device. The output torque of the stepper-motor depends on a supply current to the stepper-motor. CPU determines a

A device for outputting a suitable rotation torque relative to a load torque or actual torque exerted on a stepper-motor when the stepper-motor is used as a drive of an image processing device. The output torque of the stepper-motor depends on a supply current to the stepper-motor. CPU determines a suitable supply current using a table in ROM so that the stepper-motor is able to rotate at an optimum rotation torque. To this end, CPU sends a particular signal to the motor driver so that an appropriate supply current is supplied to the excitation phases A/B of the stepper-motor. The CPU determines the load torque based on an integrated current fed to the stepper-motor during a particular period. The CPU calculates difference between the load torque and rotation torque and determines the signal to be applied to the motor driver based on the torque difference.

대표청구항 ▼

[ What is claimed is:] [1.] A control method for a stepper-motor, comprising:(a) determining a present integrated value of a current supplied to the stepper motor;(b) determining a present load torque applied to the stepper-motor from said present integrated value determined in step (a) using a firs

[ What is claimed is:] [1.] A control method for a stepper-motor, comprising:(a) determining a present integrated value of a current supplied to the stepper motor;(b) determining a present load torque applied to the stepper-motor from said present integrated value determined in step (a) using a first table which stores a relationship between plurality of load torques of the stepper-motor and a plurality of integrated values of current supplied to the stepper-motor;(c) calculating a torque difference between a preset rotational torque of the stepper-motor and the present load torque determined in step (b);(d) determining one of a feed current or a pulse speed from said torque difference calculated in step (c) using a second table which stores a relationship between a plurality of rotational torques of the stepper-motor and one of a plurality of feed currents of the stepper-motor or a plurality of pulse speeds of the stepper-motor; and(e) controlling an output torque in response to one of the feed current and the pulse speed determined in step (d).