MOTOR DRIVER, OPTICAL PICKUP FEEDING AND DRIVING APPARATUS AND METHOD THEREOF

PROBLEM TO BE SOLVED: To provide a motor driver and an optical pickup feeding and driving apparatus which have high accuracy and high torque by detecting a rotor position of rotor with an electrical method without use of an encoder. SOLUTION: This motor driver comprises a control circuit 19 for receiving a rotor position signal indicating the position of rotor of the motor to be driven, and applying a drive voltage V0 to one end of a coil 21-1 of motor depending on such position signal; a comparator 26-1 provided for comparing a potential v1 of the other end of an equalizing circuit with a potential v21 of the other end of the coil of motor by providing an equalizing circuit 22-1 which is equivalent electrically to the coil of motor; and a phase compensating circuit 33-1 for compensating for the phase of a comparison signal which is a result of comparison, and then supplying the signal to the control circuit as a rotor position signal v31 indicating the position of rotor. Accordingly, a control loop considering the present position of rotor can be formed without use of the encoder.