Edge registration system

摘要

A system electronically determines an edge of a copy substrate (710) to be printed on. A copy substrate (710) is inserted between a segmented linear light source array (700) and a linear sensor array (712) and a light segment of the linear light source array (700) is illuminated. An edge location of a shadow created by the copy substrate (710) intersecting the light path between the illuminated light segment and the linear sensor array (712) is measured, and the location of the edge of the copy substrate (710) is calculated based on the measured shadow location. A way of calibrating such a system uses a claibrate tool (800) inlcuding a slot of width DELTA x, and measures the shadows cast by its edges with the tool at two different heights between the light source (700) and the sensor array (712). <IMAGE>