Patent ID: 8773482

Claim:
An exposure apparatus comprising: a light source for emitting a light beam with a light quantity corresponding to an amount of current supplied thereto; a rotating polygon mirror with a plurality of reflection planes, the rotating polygon mirror configured to rotate in such a manner that the light beam emitted from the light source and reflected off a reflection plane of the plurality of reflection planes scans a photosensitive body; a beam magnifying unit for expanding the light beam emitted from the light source in a manner that the light beam is irradiated onto the rotating polygon mirror with a beam width exceeding a width of the reflection plane of the rotating polygon mirror in a scanning direction; a setting unit for setting a target light quantity of the light beam irradiated onto the photosensitive body according to the light beam irradiation duration per unit pixel; and a current supplying unit for, if a first target light quantity is set by the setting unit, supplying the light source with first correction current such that a light quantity of the light beam irradiated onto the photosensitive body is substantially constant in a main scanning direction and, if a second target light quantity is set by the setting unit, supplying the light source with second correction current such that the light quantity of the light beam irradiated onto the photosensitive body is substantially constant in the main scanning direction.