公开(公告)号：BRPI0505358A

公开(公告)日：2008-01-02

申请号：BRPI0505358

申请日：2005-11-30

Applicant: XEROX CORP

Inventor： GRACE ROBERT E ,  MONGEON MICHAEL C ,  GRIFFITH HUGH W ,  LESS KRZYSTOF J ,  ENSKAT TIM

IPC: G03G15/01

Abstract: Using a document scanner or other image input device of an image or document processing system to periodically scan or image printed test images from a plurality of marking engines replaces internal sensors as a feedback means in image quality control. For example, image lightness (L*) is controlled by periodically printing mid-tone test patches, scanning the printed test patches with a main job document scanner and analyzing the scanned image to determine updated marking engine actuator set points. For instance, ROS exposure and/or scorotron grid voltages are adjusted to maintain image lightness consistency between marking engines.