Patent ID: 8749838

Claim:
An image forming apparatus, comprising: a photosensitive element; a charging unit that charges a surface of the photosensitive element; a writing unit that forms a static latent image on the photosensitive element by irradiating the charged surface of the photosensitive element with light based on input image data; a developing unit that supplies toner to the static latent image on the photosensitive element so as to form a toner image; a transfer unit that transfers the toner image onto a recording medium; and a fixing unit that fixes the toner image to the recording medium by applying heat and pressure to the toner image, wherein the writing unit includes: a data buffer unit that buffers the input image data; an image data generation unit that produces image data; a main-sub image magnification processing unit that performs image magnification processing in a main-scanning direction and a sub-scanning direction; a clock generation unit that changes a writing clock period; a correction map that retains image magnification information corresponding to a deformation of the recording medium caused by application of heat and pressure from the fixing unit; and a light-emitting device that irradiates the photosensitive element with light on the basis of drive data from the image data generation unit, and the writing unit is configured to slightly change the writing clock period so as to enlarge or shrink a formed pixel in the main-scanning direction and further perform enlargement or shrinkage in the sub-scanning direction with reference to the image magnification information of the correction map, and thus cancel an image deformation caused by the deformation of the recording medium and correct a change in an image magnification in the main-scanning direction.