Patent ID: 7509082
Filing Date: 2009-03-24
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: a rotating member which is one of an intermediate transfer member and a rotating conveyer which conveys an image forming medium, the intermediate transfer member temporarily holds an image to be transferred onto the image forming medium; a drive roller which drives the rotating member; a plurality of image forming sections which respectively form images of different colors on the rotating member or the image forming medium; a control section which forms a pattern image in a reference color and one of the colors to be corrected, by using the image forming sections, in a space area on the rotating member arisen between a first area in which an image corresponding to a first image forming medium is formed and a second area in which an image corresponding to a second image forming medium is formed; a detection section which reads a plurality of the formed pattern images to detect an amount of misalignment of the image formation position of the color to be corrected against the image formation position of the reference color; and a correction section which corrects the image formation position of the color to be corrected according to the amount of misalignment; wherein the control section controls the image forming sections so that the image forming sections form the pattern image a number of times n (n: an integer) expressed by equation: using a predetermined integer J, the length L of the image forming medium, the width d of the space area, the conveying distance A passed by the rotating member while the drive roller rotates through one revolution, a predetermined integer m, and an approximate integer N; and wherein the control section controls the image forming sections so that if the total number of the image forming sections is S, the image forming sections form the pattern image the number of times corresponding to the smaller of n