Patent ID: 7847994

Claim:
An image forming apparatus comprising: a photosensitive medium on which an electrostatic latent image is formed; a developing unit to develop the electrostatic latent image; a transfer unit to transfer the electrostatic latent image developed by the developing unit; and a light scanning system comprising: a plurality of light sources to emit light; a deflector shared by the plurality of light sources, the deflector being rotatable about a rotational axis to deflect the emitted light, the emitted light being obliquely incident on a plane perpendicular to the rotational axis; one or more f-θ lenses to focus the light deflected by the deflector onto the photosensitive medium, the one or more f-θ lenses being disposed in optical paths between the plurality of light sources and a plurality of photosensitive media corresponding to the light sources, each f-θ lens satisfying −0.5<R 1 /R 2 <0.2, where R 1 is a curvature radius of an entrance surface of the respective f-θ lens in a main-scanning direction and R 2 is a curvature radius of an exit surface of the respective f-θ lens in the main-scanning direction; and a plurality of reflective mirrors to reflect the light, at least one reflective mirror being provided in an optical path between the deflector and each f-θ lens, and no reflective mirrors being provided in optical paths between the one or more f-θ lenses and the plurality of photosensitive media.