Patent ID: 8598824

Claim:
A motor drive circuit comprising: a drive circuit configured to drive a motor whose coil current decreases with increase in counter electromotive voltage of a motor coil; a detection circuit configured to detect whether or not a current value of the coil current is greater than a predetermined value; a first control circuit configured to control the drive circuit so that the current value of the coil current becomes smaller than or equal to the predetermined value, when it is detected that the current value of the coil current is greater than the predetermined value; and a second control circuit configured to control the first control circuit so that the first control circuit does not control the drive circuit based on a detection result of the detection circuit until a predetermined time has elapsed from a start of supply of the coil current, the second control circuit including: a charging circuit configured to charge a capacitor with a constant current when the supply of the coil current is started; a determination circuit configured to determine that the predetermined time has elapsed, when a charging voltage of the capacitor has reached a predetermined voltage, the predetermined voltage being in accordance with the predetermined time; and a third control circuit configured to operate the first control circuit based on a detection result of the detection circuit when the determination circuit determines that the predetermined time has elapsed.