DEFLECTION SCANNING DEVICE

摘要

PURPOSE:To suppress the rise in the temperature of a bearing part and a stator coil by providing pleated parts in the vicinity of the dynamic fluid bearing of a deflection scanning device. CONSTITUTION:The dynamic fluid bearing part is constituted in a sleeve 32 and a rotary shaft 31 is rotatably fitted; and the sleeve 32 is provided integrally with pleated parts at eight places. The sleeve 32 is fixed in a housing 37 and a motor substrate 38 is fixed on the housing 37. A rotary polygon mirror 40 is fixed on a flange 39 fixed on the rotary shaft 31 and a rotor yoke 42 is fixed on the reverse side of the flange 39. A magnet 43 is fixed on the reverse surface of the rotor yoke 42 and the stator coil 44 is arranged on the motor substrate 38 while being opposed to the magnet 43. Heat generated by the dynamic fluid bearing is emitted to the air from the pleated parts 32a provided on the sleeve 32.