Patent ID: 7898129

Claim:
A spindle motor, comprising: a magnet magnetized to a plurality of poles in a peripheral direction; a plurality of salient pole portions, a stator coil wound around each of said salient pole portions, said salient pole portions being disposed at an equiangular pitch, except for a non-equiangular pitch portion, and inner peripheral faces of said salient portions being opposed to an outer peripheral face of said magnet; a circular base portion which is formed so as to be substantially continuous with respective ends of the plurality of salient pole portions, and wherein said circular base portion has at least a portion that links the salient pole portions in the non-equiangular pitch region and that is cut out in an axial direction or a peripheral direction; and a compensating pole plate that is disposed along the vicinity of the ends of the salient pole portions opposing to an outer peripheral face of said magnet in the non-equiangular pitch region, and said compensating pole plate being formed from magnetic materials.