| 摘要 |
PROBLEM TO BE SOLVED: To provide an electromagnetic drive that can restrain the magnetic gap between a rotor and a yoke, and reduces the size of the electromagnetic drive and power consumption, and to provide an electromagnetic drive capable of continuously, stably, and smoothly rotating the shaft between the rotating shaft of the rotor and a bearing hole for supporting the rotating shaft, and to provide a quantity-of-light control device using the electromagnetic drive. SOLUTION: There are provided a magnet rotor that is provided at the axis center of a permanent magnet and has the rotating shaft, a coil frame having a pair of bearings for rotatably supporting both the ends of the rotating shaft, an excitation coil wound around the outer periphery of the coil frame, and a control means for controlling movement so that the magnet rotor is rotated at a prescribed angle or smaller. In the magnet rotor, a magnetic induction material made of a soft magnetic material is arranged opposingly on one cylindrical end face. The magnetic induction member is arranged at a position where the energizing force in the direction of the rotating shaft and the rotating force at the center of the rotating shaft are simultaneously given to the magnet rotor, the rotating shaft is energized to one bearing by the magnetic induction member, and the magnet rotor is held at the position of the control means. COPYRIGHT: (C)2007,JPO&INPIT
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