| 摘要 |
PROBLEM TO BE SOLVED: To suppress the vibration and noise which have a plurality of frequencies and are generated by rotating a rotatable polygon mirror. SOLUTION: An arm 90 composed of a plate member 91 and a weight 92 is fixed to a casing (a housing 50, a lid 80) on which a light deflector furnished with a polygon mirror (rotating multiface mirror) 63 is fixed. The resonance frequency (primary resonance frequency) in the primary mode of the arm 90 is substantially made to coincide with the primary rotation frequency of the polygon mirror 63, and the resonance frequency (secondary resonance frequency) in the secondary mode of the arm 90 is substantially made to coincide with the sixth rotation frequency of the polygon mirror 63. Thus the arm 90 acts as a multifreedom dynamic vibration absorber corresponding to both of the primary rotation frequency and the sixth rotation frequency of the polygon mirror 63. COPYRIGHT: (C)2005,JPO&NCIPI |
