| 摘要 |
PROBLEM TO BE SOLVED: To prevent a temperature rise in a cover covering a rotary polygon mirror. SOLUTION: This rotary polygon mirror 3 is covered by a cover 12 to prevent wind whistle noise, and the scanning light of the rotary polygon mirror 3 is taken out of an aperture 12a of the cover 12 through a dust-proof glass 13. The cover 12 is exposed from the opening part of a cover member 20, and a heat conductive member 14 is abutted on the top of the cover 12. The temperature rise in the cover 12 is prevented by directly emitting the heat of the cover 12 from a heat radiator 15 into a main body frame 30 via the heat conductive member 14. |
