| 摘要 |
PROBLEM TO BE SOLVED: To compose the optical scanning optical system, used for an optical scanning device, of a reflection type optical element and to eliminate curvature of a scanning line. SOLUTION: A specific scanned surface is scanned at an equal speed by a spherical mirror 12 with a light beam which is deflected by a polygon mirror 11, and pitch unevenness generated by a surface tilt of the polygon mirror 11 is corrected by a cylindrical mirror 11. This optical scanning optical system is provided with a light splitting means 13 which passes a light beam from the polygon mirror 11 and reflects and deflects reflected light from the spherical mirror 12 between the polygon mirror 11 and spherical mirror 12, and the spherical mirror 12 is so arranged as to reflect the light beam made incident on the spherical mirror 12 in the plane that the light beam deflected by the polygon mirror 11 draws. |
