Patent ID: 6246857
Filing Date: 2001-06-12
Classification: G03G,H04N

Abstract:
An image forming apparatus for forming superimposed images, comprising:a plurality of image carriers arranged along a first direction;conveying means for conveying an image receiving medium along said plurality of image carrier;a plurality of image forming means for transferring images formed on said plurality of image carriers onto the image receiving medium conveyed by said conveying means;first mark forming control means for controlling said image forming means so as to form a plurality of first marks on said conveying means by said plurality of image forming means;detecting means for detecting a first misregistration of images formed by said plurality of image forming means in the first direction and a second direction orthogonal to the first direction by detecting locations of the plurality of first marks formed on said conveying means;first image forming control means for controlling at least one of said conveying means and said plurality image forming means according to the first misregistration detected by said detecting means;second mark forming control means for controlling said image forming means so as to form a second mark simpler than the first marks on said conveying means by one of said plurality of image forming means; andsecond image forming control means for detecting a second misregistration of the second mark in either the first direction or the second direction to control at least one of said conveying means and said plurality of image forming means according to the second misregistration.