Patent ID: 8514259

Claim:
An image forming apparatus comprising: a plurality of exposure devices each having a plurality of light-emitting points arranged in a main scanning direction; a photoconductor configured to be exposed to light emitted from the exposure devices whereby an electrostatic latent image is formed thereon; and a controller configured to control emission of the exposure devices; wherein the controller includes: an end-pixel location unit configured to determine positions in the main scanning direction of points of exposure to be formed on the photoconductor by emission of light from two light-emitting points of each exposure device, the two light-emitting points being in predetermined positions near endmost light-emitting points of a predetermined number of light-emitting points the number of which corresponds to the number of pixels to be arranged in a printable width; a maximum-width exposure device identification unit configured to identify a first exposure device of which a distance between the two light-emitting points is greatest of all the exposure devices, based on the positions of the points of exposure determined by the end-pixel location unit; a light-emitting point specification unit configured to specify a subset of usable light-emitting points of a second exposure device other than the first exposure device identified by the maximum-width exposure device identification unit, the specified subset of usable light-emitting points being located in positions corresponding to a range of exposure which coincides in a width direction with a range of exposure defined by the two light-emitting points of the first exposure device; and a light-emitting point association unit configured to associate the subset of usable light-emitting points specified by the light-emitting point specification unit with pixels of input image data, wherein n pairs of adjacent usable light-emitting points of the second exposure device are each associated with one pixel, and the number n of the pairs of adjacent usable light-emitting points is obtained by subtracting the number of usable light-emitting points of the first exposure device from the number of the usable light-emitting points of the second exposure device.