Sheet deskewing method and apparatus

摘要

A method and apparatus for correcting skew of an advancing sheet responsive to the detection of one or the other of aligned fiducial marks located near each of the opposite side edges adjacent the sheet leading edge. Upon detection of a first of the fiducial marks, the advance of the side edge of the sheet associated with the detected fiducial mark is repeatedly dithered rearward and then forward while the opposite side edge of the sheet continues to advance. The dithering of one side edge while continuing the advance of the opposite side edge continues until the other of the fiducial marks is detected after which the advance of the sheet is resumed.