Patent ID: 7728469

Claim:
A motor driving apparatus comprising: a rotatable rotor having a magnet that is divided into a plurality of segments along an outer peripheral surface, the magnet being magnetized so that S poles and N poles alternate with each other; a first magnetic pole member configured to face a magnetized surface of the magnet and extend; a second magnetic pole member configured to face the magnetized surface of the magnet and extend; a first coil configured to excite the first magnetic pole member; a second coil configured to excite the second magnetic pole member; a position adjustment unit configured to arrange the first magnetic pole member and the second magnetic pole member with a predetermined phase; and a magnetic detection unit movably arranged on the position adjustment unit and configured to detect a magnetic field strength generated by the magnet, wherein an angle between boundary lines of the magnetic poles of the magnet and a movable direction of the magnetic detection unit is larger than 0-degree and smaller than 90-degrees.