| 摘要 |
PURPOSE:To reduce a noise, vibrations, and an irregularity in rotation due to interference between air turbulence generated by the rotation of a rotary polygon mirror, and a protection cover and mass unbalance. CONSTITUTION:The generation of the air turbulence and the unbalance of mass are reduced by making the reflecting plane part 23b of the rotary polygon mirror 23, installed in the protection cover 19 which has a laser beam incidence/ projection opening part (window) 20, thinner than the columnar center part 23a. |
