SPINDLE MOTOR FOR A LASER BEAM PRINTER

摘要

A spindle motor for a laser beam printer is provided to secure a stable driving characteristic by firmly supporting a top surface of a polygon mirror through a rotor assembly to prevent movement of the polygon mirror. A bearing holder(120) is fixed to a plate(110) and has an armature(140) on an outer peripheral surface. A bearing(130) is fixed to an inner peripheral surface of the bearing holder. A rotary shaft(150) is inserted in an inner diameter part of the bearing to be rotatably supported by the bearing. A rotor assembly(160) is coupled with the rotary shaft, has a magnet(190) facing the armature, and supports top and bottom surfaces of a polygon mirror(170). A fixing member(180) is interposed between the polygon mirror and the rotor assembly to fix the polygon mirror to the rotor assembly and presses the polygon mirror in an axial direction of the rotary shaft.