| 摘要 |
PURPOSE:To provide a motor control method through which abnormality in a motor or the control system therefor is detected and the motor and the control system are protected against breakdown due to runaway caused by the abnormality. CONSTITUTION:In digital control of a motor 8 performing feedback control based on the output from an incremental encoder 9, control output value at every sampling period is compared each other and if the comparison result is constant over predetermined times, the motor 8 for causing subscanning of an image scanner 801 is stopped. Consequently, when the signal from the encoder is normal but a control circuit such as a CPU or a control numeric value is abnormal or when the signal from the encoder 9 is abnormal due to overload being applied onto the motor or failure of the encoder 9 itself, the abnormality is detected and runaway of the motor or breakdown of control circuit system is prevented. |
