IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an image forming apparatus which is capable of forming an electrostatic latent image on the surface of a photoreceptive drum with high positional accuracy, even when a shaft of the photoreceptive drum is eccentric.SOLUTION: The image forming apparatus includes: eccentric amount detection means for detecting the eccentric amount of a drum shaft 9 of a photoreceptive drum 100; exposure means 101 for forming an electrostatic latent image on the photoreceptive drum 100; calculation means for calculating a correction coefficient for correcting the positional deviation of the electrostatic latent image caused by the eccentricity of the drum shaft 9 of the photoreceptive drum 100; and control means for forming the latent image corrected in the eccentric amount of the drum shaft 9 on the surface of the photoreceptive drum 100 on the basis of image data after correction corrected by using the calculated correction coefficient. The eccentric amount detection means calculates the eccentric amount of the drum shaft 9 by using the detection time of a development pattern, an angular velocity corresponding to the detection time, and the pitch interval of the development pattern. The calculation means obtains the correction coefficient for correcting the eccentric amount of the drum shaft 9 by using the average value of the angular velocities corresponding to the development pattern on the photoreceptive drum 100 and the pitch interval of the development pattern.