Patent ID: 7586510
Filing Date: 2009-09-08
Classification: G06K

Abstract:
1. An image forming apparatus comprising: a plurality of image forming units, each of which forms an image of one color and a correction pattern to be used for correcting position deviation of the image, wherein each image forming unit forms the image on an image formed by another image forming unit to form a color image; a plurality of detectors, each of which detects the correction pattern formed by a corresponding one of the image forming units, the detectors including a first detector that is positioned at an image writing starting side, a second detector, and a third detector, the second detector positioned between the first and third detectors; a printer controller that controls only the first and third detectors to detect respective first formed correction patterns, and that corrects a total-width magnification error in the main scan direction based on results of detections by only the first detector and the third detector; and the printer controller further controls each of the first detector, second detector, and third detector to detect respective second formed correction patterns, and corrects a deviation of an image writing position in a main scan direction and corrects partial magnification errors based on a result of detection by the first detector, the second detector, and the third detector.