Patent ID: 6452147
Filing Date: 2002-09-17
Classification: G03G,H04N

Abstract:
An image forming apparatus comprising:a transfer medium which is moved in a first direction; a plurality of image forming units for forming an image respectively and for transferring the image onto the transfer medium or a recording sheet thereon, each image forming unit being capable of forming and transferring a registration mark onto the transfer medium, and at least one image forming unit being capable of forming at least one specific pattern on the transfer medium for adjustment of a registration mark detecting position; a detector for detecting the registration mark and the specific pattern, and for providing a detection signal thereof; and a controller for, based on the detection signal of the registration mark, correcting a deviation between positions at which images are transferred by the plurality of image forming units, the controller, based on the detection signal of the specific pattern, obtaining an amount of deviation in a second direction between a reference detecting position at which the detector should detect the registration mark and an actual detecting position at which the detector detects the registration mark, and adjusting relative positions of the detector and the registration mark based on the thus obtained amount of deviation, wherein the second direction is perpendicular to the first direction.