| 摘要 |
PROBLEM TO BE SOLVED: To obtain a laser scanning optical device in which the beam diameters of respective luminous fluxes on a photoreceptor are kept substantially equal to each other by preventing a magnification in a subscanning direction from becoming high, the device is made small-sized, the arrangement of optical elements in a rear stage where the optical path is divided is made easy, and an image curvature and a bow are excellently corrected. SOLUTION: In the laser scanning optical device, the luminous fluxes emitted from a plurality of light sources 12 are converged in a subscanning direction z with a light source optical system, guided to the deflection face 19a of a polygon mirror, respective luminous fluxes BY, BM, BC, and BK are simultaneously deflected with a single deflection face 19a, and are focused on the photoreceptor 30 with a first optical system which has a power mainly in a main scanning direction and a second optical system (scanning lenses 25Y, 25K, 25M, and 25C) which has a power mainly in the subscanning direction. Further, the first face of a scanning lens 25 has a free-form surface, and magnification in the subscanning direction of the scanning optical system is different with respect to the luminous fluxes BY and the luminous fluxes BM and BC, and magnification in the subscanning direction of the light source optical system is different. COPYRIGHT: (C)2005,JPO&NCIPI |
