Three-phase motor driving apparatus and three-phase motor driving method

A three-phase motor driving apparatus for controlling driving of a three-phase brushless motor using only one rotor sensor that detects a magnetic pole of a first phase of a rotor of the three-phase brushless motor, comprising:

• a motor driver that supplies a driving current to the three-phase brushless motor to drive the three-phase brushless motor and a controlling part that estimates a rotational position of the three-phase brushless motor based on a reference pulse signal output by the rotor sensor according to a rotational position of the magnetic pole of the first phase of the rotor when the three-phase brushless motor rotates, and controls the motor driver in driving patterns sequentially prescribed so as to correspond to the estimated rotational position of the three-phase brushless motor, wherein the controlling part estimates the rotational position of the three-phase brushless motor based on the reference pulse signal, a first timing, a second timing and a third timing, the first timing being estimated to correspond to a rotational position of a magnetic pole of a second phase of the rotor and prescribing a time when one third of a first reference period has elapsed from a first edge of the reference pulse signal, the second timing being estimated to correspond to a rotational position of a magnetic pole of a third phase of the rotor and prescribing a time when two thirds of the first reference period have elapsed from the first edge of the reference pulse signal, and the third timing being estimated to correspond to the rotational position of the magnetic pole of the first phase of the rotor and prescribing a time when the first reference period has elapsed from the first edge of the reference pulse signal, and the first reference period is a period between the first edge and a second edge of the reference pulse signal that immediately precedes the first edge.