Paper path calibration and diagnostic system

Abstract

A plurality of scanner bars is arranged in precisely located holes in the frame of a media handling device to detect the passage of the lead and trail edge of media. The multiplicity of scanner bars, arranged linearly at a right angle to the direction of motion of the media, is sampled at some frequency. The scanner bars give not only arrival and departure time of the media from each scanner bar location, but also making some assumptions about the shape of the media, information about the orientation of the media relative to the direction of motion. This information can be used to diagnose improper media handling mechanisms upstream of the sensor or provide information to downstream corrective mechanisms. Preprinted test media, such as, ladder charts, etc., can be used to extract velocity profiles and other paper path dynamic characteristics.

Dependencies are inferred from the claim text.