Electronic timepiece, movement, and motor control circuit

A movement comprising:

• a motor with a coil;
• a driver that is controlled to an on state supplying drive current to the coil, and an off state not supplying the drive current;
• a current detector configured to detect a current value flowing through the coil;
• a controller configured to control the driver to the on state or the off state according to the current value detected by the current detector;
• a detection signal output device configured to output a detection signal in response to at least one of (i) an on time, which is a continuous time of the on state of the driver, meeting a first predetermined condition and (ii) an off time, which is a continuous time of the off state of the driver, meeting a second predetermined condition, the first predetermined condition and the second predetermined condition being for changing a polarity of the current flowing to the coil;
• a drive pulse counter configured to count a number of times the polarity is changed and output a drive step count of the number of times the polarity is changed;
• a reference signal output device configured to output a reference signal used as a reference of a drive speed of the motor;
• a reference pulse counter configured to count pulses of the reference signal and output a reference step count of the pulses of the reference signal;
• and
• a drive cycle adjuster configured to compare the drive step count to the reference step count and, each time the polarity is changed,
• determine that a pulse of the detection signal occurs after a pulse of the reference signal,
• based on the comparison between the drive step count and the reference step count and in response to the determination that the pulse of the detection signal occurs after the pulse of the reference signal, shorten a drive cycle of the motor compared with the drive cycle of the motor when the pulse of the detection signal occurs before the pulse of the reference signal,
• determine that the pulse of the detection signal occurs before the pulse of the reference signal, and
• based on the comparison between the drive step count and the reference step count and in response to the determination that the detection signal occurs before the pulse of the reference signal, lengthen the drive cycle of the motor compared with the drive cycle of the motor when the pulse of the detection signal occurs after the pulse of the reference signal.

A motor control circuit comprising:

• a driver that is controlled to an on state supplying drive current to a coil of a motor, and an off state not supplying the drive current;
• a current detector configured to detect a current value flowing through the coil;
• a controller configured to control the driver to the on state or the off state according to the current value detected by the current detector;
• a detection signal output device configured to output a detection signal in response to at least one of (i) an on time, which is a continuous time of the on state of the driver, meeting a first predetermined condition and (ii) an off time, which is a continuous time of the off state of the driver, meeting a second predetermined condition, the first predetermined condition and the second predetermined condition being for changing a polarity of the current flowing to the coil;
• a drive pulse counter configured to count a number of times the polarity is changed and output a drive step count of the number of times the polarity is changed;
• a reference signal output device configured to output a reference signal used as a reference of a drive speed of the motor;
• a reference pulse counter configured to count pulses of the reference signal and output a reference step count of the pulses of the reference signal;
• and
• a drive cycle adjuster configured to compare the drive step count to the reference step count and, each time the polarity is changed,
• determine that a pulse of the detection signal occurs after a pulse of the reference signal,
• based on the comparison between the drive step count and the reference step count and in response to the determination that the pulse of the detection signal occurs after the pulse of the reference signal, shorten a drive cycle of the motor compared with the drive cycle of the motor when the pulse of the detection signal occurs before the pulse of the reference signal,
• determine that the pulse of the detection signal occurs before the pulse of the reference signal, and
• based on the comparison between the drive step count and the reference step count and in response to the determination that the pulse of the detection signal occurs before the pulse of the reference signal, lengthen the drive cycle of the motor compared with the drive cycle of the motor when the pulse of the detection signal occurs after the pulse of the reference signal.