| 摘要 |
PURPOSE: To provide, at a low cost, a small-sized and thin type rotating polygon mirror scanning device with high reliability which is suitable to high-speed use, by employing a fluid bearing. CONSTITUTION: This rotating polygon mirror scanning device is constituted so that a sleeve 4 provided with a polygon mirror 7 assembled integrally may rotate with regard to a fixed shaft 3, whereas the position of rotational gravity center of a rotor is almost in the center of a pair of dynamic pressure radial bearings 5, 6 provided at an opposed surface between the outer periphery of the fixed shaft 3 and the inner periphery of the sleeve 4, and the length of the bearing has the following relationship: bearing 6> bearing 5. |
