| 摘要 |
PURPOSE:To eliminate the rotation irregularity of a polygon mirror by allowing the turning force of a motor to operate directly on a hub and rotating a mirror together with the hub. CONSTITUTION:A polygon mirror driving device has a U-sectioned cylindrical hub 2 fitted around an L-sectioned cylindrical support shaft 13, and a shaft 10 whose end part pierces the top surface of the hub 2 fixedly is supported rotatably inside of the shaft 13. Then, the polygon mirror 1, an upper rotor plate 4, and a lower roller plate 20 are fixed to the outer circumference of the hub 2 horizontally at right angles to the hub 2. Further, an upper rotor magnet 5 attached to the plate 4, a stator substrate 7 supported horizontally on a lower case, and a lower rotor magnet 5' attached to the plate 20 are put opposite to the winding group 6 of the substrate 7 with a gap between. Then, the mirror 1 provided to the outer circumference of the hub 2, plates 4 and 20, magnets 5 and 5', hub 2, and shaft 10 rotate together freely in the cavity formed of the upper and lower cases 9 and 8. |
