| 摘要 |
PURPOSE:To effectively prevent attraction of a rotor to a yoke or axial run-out by forming the pole ends of a yoke to apply electromagnetic driving force to the rotor as a pair of pole pieces which sandwich the turning locus of the rotor from above and below along the axial direction of a torsion bar. CONSTITUTION:The torsion bar 16 is fixed and held to supporting arms 12, 14 provided at both ends of a base plate 10 and the rotor 22 is fixed to nearly the central part thereof. The yoke 25 having an approximately U-shaped plane section is disposed to the position corresponding to the rotor 22. The pole ends 26, 27 formed to a pair of the pole pieces sandwiching the turning locus of the rotor 22 from above and below along the axial direction of the torsion bar 16 are provided to the yoke 25. Electromagnetic driving power is applied from the ends 26, 27 to the rotor 22 by the electric current flowing in an excitation coil 28 and a light beam 100 projected to a reflecting mirror 24 according to the rotating angle of the rotor 22 is reflected as scanning light 200. Generation of a trouble such as the axial run-out of the rotor 22 or the attraction of the rotor to the yoke 25 is obviated.
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