Patent ID: 7675532

Claim:
An image-forming apparatus that includes an image carrier, a laser emitting unit which emits a light beam that is wider than a single deflection surface of a rotating polygonal mirror to form a latent image on the carrier, and a developing unit which forms a toner image by developing a latent image formed by using toner, comprising: a supply unit which supplies toner to the developing unit while carrying the toner in a longitudinal direction of the developing unit; and a correction unit which corrects nonuniformity in image density in a main scanning direction that occurs when exposure by the laser emitting unit is performed, by altering amount of emitted light of the laser emitting unit from one end to the other end of the image carrier, wherein the correction unit, in emitting light with a downwardly convex alternation of amount of emitted light in which amount of emitted light decreases and then increases from one end to the other end of the image carrier, differentiates a width by which amount of emitted light decreases from a width by which amount of emitted light increases, in order to correct fluctuation in image density caused by nonuniformity, due to an angle between the deflection surface and the emitted light beam, of an upwardly convex light amount distribution in which amount of light increases in a portion between two edge portions in the main scanning direction, and by continuous alteration in charging characteristics of the toner used, from an end of the image carrier corresponding to an upstream side in a carrying direction of the toner to the other end of the image carrier corresponding to a downstream side in the carrying direction of the toner.