| 摘要 |
PURPOSE: To decrease the number of parts, to obtain a structure to prevent splashing of oil mists which is easy to be assembled, and to reduce the size over the entire part. CONSTITUTION: This rotary polyhedral mirror type optical deflector has ball bearings 9a, 9b which are set to a stationary shaft 8, a hub 4 which is freely rotatably supported by these ball bearings 9a, 9b and has a driving magnet 6 fixed to it and a polygon mirror 1 which is fixed to this hub 4 and rotates integrally therewith. A labyrinth ring 2 is fixed to one end side of the stationary shaft 8. The outer peripheral surface 12 of this labyrinth ring 2 and the inner peripheral surface 11a of the polygon mirror 1 face each other by forming a microspacing C in a radial direction. |
