| 摘要 |
An optical scanning device includes a light source which emits a light beam, a deflector, an incident optical system and one scanning lens. The deflector reflects and then deflects/scans the light beam emitted from the light source. The scanning lens includes a first face facing the deflector and a second face on an opposite side to the first face, and performs imaging of the deflected/scanned light beam on a surface to be scanned. When a curvature radius of the first face in a main scanning direction cross section is R1, a curvature radius of the second face in a main scanning direction cross section is R2, a lens thickness in an optical axis direction at a center of the scanning lens in the main scanning direction is d, and a refractive index of the scanning lens is n, following Formula (1) and Formula (2) are satisfied: 0<R2<R1(1) 0>R2-R1>-(n-1)d/n(2). |
