A stepping motor comprises a permanent magnet type rotor with a plurality
of poles secured to a rotating shaft and a stator having stator magnetic
poles with stator magnetic pole teeth in which excitation windings are
wound on a plurality of magnetic poles in a star or delta connection,
wherein the rotor is magnetized in different directions alternately
circumferentially to satisfy the following equation: M=4F/3 where M is the
number of poles of the rotor and F is the number of the stator magnetic
poles, the rotor is cylindrical in shape with the stator rotatably
disposed inside, disposed opposing the surfaces of the stator magnetic
pole teeth through an air gap which is of a uniform dimension throughout
the circumference between the surfaces of the stator magnetic pole teeth
of the stator and the rotor, and the surface magnetic flux distribution
thereof has a substantially sinusoidal wave form circumferentially. The
stepping motor realizes smooth rotation and simplification in the
structure of the rotor. In addition, the present invention provides a
stepping motor device using the above-mentioned stepping motor and a
method of driving the device.
