| 摘要 |
PROBLEM TO BE SOLVED: To realize an axes-crossing type new rotary polygon mirror.SOLUTION: A rotary polygon mirror reflects a light beam, and cyclically deflects a reflected light beam, and includes: a polygon mirror 10; a rotary drive shaft 21 fixed to the polygon mirror by a fixing member 22; and rotary drive parts 20, 30 for rotary-driving this rotary drive shaft. The polygon mirror 10 surrounds a polygon mirror shaft 11A, and is rotation-symmetrically formed with a plurality of reflection surfaces 10A to 10d, and includes a through hole 13 penetrated by the rotary drive shaft. Each of a pair of shaft surfaces 11, 12 for nipping a plurality of reflection surfaces in the polygon mirror axial direction is formed with a plane-like mounting surface portions 11a, 12a in such a manner that the normal line thereof has a tilt angle :θ for the polygon mirror shaft, and is fixed to the rotary drive shaft 21 penetrated by the through hole 13 at the mounting surface portions 11a, 12a, and plane-like mounting surface portions 11a, 12a are made orthogonal to the rotary drive shaft 21 in a state in which the polygon mirror 10 is fixed to the rotary drive shaft 21 by the fixing member.SELECTED DRAWING: Figure 1 |
