A stepping motor includes a magnet ring 1 whose outer peripheral surface is circumferentially divided to form radial protrusions and recesses and whose outer peripheral surface consists of a cylindrical permanent magnet magnetized to the same polarity, first and second cylindrical coils 2 and 3, a first outer magnetic pole portion 8 excited by the first coil, a second outer magnetic pole portion 9 excited by the second coil, and an output shaft 10 formed of a soft magnetic material and fixed to the inner peripheral portion of the magnet ring, the output shaft 10 being opposed to at least one of the first outer magnetic pole portion and the second outer magnetic pole portion in a predetermined axial range and equipped with an inner magnetic pole portion excited by at least one of the first coil and the second coil. Accordingly, a low-cost, high output, and high resolution stepping motor can be provided without hindering miniaturization.

 
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> Rule-based data reproduction system and method

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