Motor control device and image forming apparatus

A device comprising:

• an application unit configured to apply a voltage to a motor including a plurality of coils to apply a current to the plurality of coils;
• a detection unit configured to detect the current;
• an estimation unit configured to estimate a coil temperature based on the detected current;
• and
• a control unit configured to control driving of the motor based on the coil temperature,
• wherein the estimation unit estimates a first coil temperature in a state where the motor is stopped, and a second coil temperature in a state where the motor is driven, and
• wherein the control unit controls the driving of the motor based on the first coil temperature and the second coil temperature,
• wherein, when estimating the first coil temperature while the motor is stopped, the estimation unit is configured to:
• cause the application unit to apply, to an excitation phase of the motor, a measurement voltage pattern for temperature estimation and for measuring a peak value of an excitation current, thereby causing the excitation current to flow;
• measure, as a physical quantity that changes according to an inductance of at least one of the plurality of coils, the peak value of the excitation current detected by the detection unit in response to the measurement voltage pattern;
• and estimate the first coil temperature from the measured peak value, and
• wherein, when estimating the second coil temperature while the motor is being driven, the estimation unit is configured to:
• set an initial value of a temperature rise amount used to estimate the second coil temperature based on the first coil temperature or a coil temperature rise value obtained from the first coil temperature;
• update the temperature rise amount based on the current detected by the detection unit while the motor is being driven;
• and estimate the second coil temperature based on the updated temperature rise amount.