| 摘要 |
PROBLEM TO BE SOLVED: To simplify the assemblage of a turn back mirror. SOLUTION: The turn back mirror 5 turning back the scanning light L1 of a rotary polygon mirror 3 toward a rotary drum 6 is built into the mirror supporting body 10 of an optical box 7 with a spring 11 being integrated to a lid member 9. The return back mirror 5 is carried in the optical box 7 by being temporarily held in a mirror holder 12 being integrated to the lid member 9 and the lid member 9 is screwingly fixed to the optical box 7 in a state in which the turn back mirror 5 is pressurized with the spring 11. |
