| 摘要 |
Speed fluctuations are decreased with a simple method even when a stepping motor (100) having comparatively large torque fluctuations is used. A drive pulse modulating unit (112) which modulates the frequency of a drive pulse to be inputted to the stepping motor (100) is provided. The drive pulse modulating unit (112) modulates the constant frequency of the drive pulse such that the frequency of the drive pulse within excitation-phase one cycle of the stepping motor (100) is: low for a period that is, by 1/8 cycle of the excitation-phase one cycle, before an excitation phase where the vibration of the stepping motor is the maximum; and high in an excitation phase that is by 1/2 cycle subsequent to the excitation phase where the drive pulse frequency is low. |
