Motor-control device for image forming apparatus

摘要

Motor-control device for an image forming apparatus includes a motor, an encoder, a microcomputer, and a driving circuit. The encoder generates a pulse signal in response to rotation of the motor. The microcomputer includes a CPU, a RAM and a ROM. The CPU detects actual rotational speed of the motor based upon the pulse signal generated by the encoder. The CPU cyclically provides a driving signal by comparing the actual rotational speed with a predetermined target rotational speed of the motor. An operating cycle is proportional to a cycle of the pulse signal generated by the encoder. The driving circuit drives the motor based upon the driving signal provided by the CPU. The CPU determines the operating cycle based upon the predetermined target rotational speed. The CPU also determines whether the motor condition is normal or abnormal by comparing the driving signal with a predetermined reference driving signal.