| 摘要 |
PROBLEM TO BE SOLVED: To realize with high precision a constitution in which an optical diaphragm is arranged close to a rotary polygon mirror, without increasing the cost. SOLUTION: The optical diaphragm 3 is integrally formed with an optical box 12. Furthermore, the rotary polygon mirror 4 side of this optical diaphragm 3 is made to a curved surface, or, its right and left direction or up and down direction in reference to an optical axis is inclined by an angleθ. |
