Calculating correction factors for subsequent printing operations by weighting measured alignment differences

摘要

A position of a first registration mark printed on a substrate during an earlier printing operation is detected. A second registration mark is printed on the substrate during a current printing operation at a position on the substrate relative to the first registration mark based on the detected position of the first registration mark and a correction factor. An alignment difference between the position of the first registration mark and the position of the second registration mark is measured. A new correction factor for a subsequent printing operation is calculated by weighting the measured alignment difference according to a difference between the measured alignment difference and a previous measured alignment difference.