Motor control device, motor control method, and optical apparatus

An optical apparatus comprising:

• a motor control device which performs drive control of a stepping motor;
• an optical member;
• and
• the stepping motor,
• wherein the motor control device comprising:
• a detection unit which detects a rotational phase of a rotor of a stepping motor;
• a generation unit which generates a driving waveform for driving the stepping motor;
• and
• a control unit which detects a phase difference between a rotational phase of the rotor and a phase of the driving waveform and controls an amplitude or a period of the driving waveform to control the phase difference,
• wherein the control unit determines a target phase difference from a variation of the phase difference with respect to a variation of the amplitude of the driving waveform to control the amplitude of the driving waveform, and
• wherein at least one processor or circuit is configured to perform a function of at least one of the units.

A motor control method executed by a motor control device that controls a stepping motor, the motor control method comprising:

• detecting a rotational phase of a rotor of the stepping motor;
• generating a driving waveform for driving the stepping motor;
• and
• detecting a phase difference between a rotational phase of the rotor and a phase of the driving waveform and controlling an amplitude or a period of the driving waveform to control the phase difference,
• determining a target phase difference from a variation of the phase difference with respect to a variation of the amplitude of the driving waveform and a step of controlling the amplitude of the driving waveform in accordance with the determined target phase difference.