Patent ID: 8823310

Claim:
A stepping motor controller for controlling a stepping motor, the stepping motor controller comprising: a motor driver that is configured to drive a stepping motor; and a motor driver control unit that is configured to control the motor driver, the motor driver comprising: an excitation phase control unit that is configured to receive pulses of a clock signal and to update and output an excitation phase signal indicating an excitation phase of the stepping motor in response to each pulse of the clock signal; and a drive unit that is configured to receive the excitation phase signal and to supply a drive current to the stepping motor, the drive current corresponding to the excitation phase indicated by the received excitation phase signal, the motor driver control unit comprising: a motor driver power control unit that controls whether or not to supply electricity to the motor driver; a drive control unit that instructs the drive unit to supply the drive current to the stepping motor or to stop supplying the drive current to the stepping motor; a clock signal output unit that outputs the clock signal to the excitation phase control unit; and an excitation phase storing unit that acquires an excitation phase at a time when the motor driver power control unit stops supplying electricity to the motor driver, and stores the acquired excitation phase as a suspension excitation phase; wherein the excitation phase control unit is configured to start updating the excitation phase signal from an excitation phase signal specifying a predetermined initial excitation phase when the motor driver power control unit starts supplying electricity to the motor driver, wherein when the motor driver power control unit resumes supplying electricity to the motor driver, the drive control unit instructs the drive unit to continue stopping supply of the drive current while the excitation phase signal outputted from the excitation phase control unit is updated from the excitation phase signal specifying the predetermined initial excitation phase to an excitation phase signal specifying the suspension excitation phase, and instructs the drive unit to start supplying the drive current after the excitation phase signal has reached the excitation phase signal specifying the suspension excitation phase.