Patent ID: 8040085

Claim:
A brushless motor apparatus comprising: a stator to be fixedly arranged; a rotor to be rotated in such a manner that the stator is sequentially excited by a plurality of excitation patterns; a magnetic-pole-position detecting magnet fixedly attached to the rotor and having twice the number of poles of the rotor; and a position detecting element arranged opposite to the magnetic-pole-position detecting magnet and detecting the position of a magnetic pole of the rotor, wherein the brushless motor apparatus includes a motor drive circuit that controls rotation of the rotor such that: during normal operation, the stator is excited with excitation patterns in a series of steps in which the stator is excited by regular excitation patterns, thus causing the rotor to rotate a first rotation angle at each step during normal operation, and during a time of impedance matching, the stator is excited with excitation patterns in another series of steps in which the stator is alternately excited with one of the regular excitation patterns and another excitation pattern not used for normal operation such that, at each step of impedance matching, the rotor rotates one-half the rotation angle by which the rotator rotates during each step of normal operation, the impedance matching being carried out upon actuation of a power source.