In the course of performing a print job, printers periodically or continuously advance print media (e.g. paper) along a paper path. Such advancement must be made with precision; inaccuracies in the advancement will result in lessened print quality.
In some applications, one step in the advancement of the print media involves recognizing features defined on the print media, such as specific fibers which form the surface of the print media. Once recognized, a specific fiber can be used as a landmark, allowing the print media to be advanced with great precision.
However, where the print media is illuminated with poor uniformity, print media advancement which is based on recognition of features defined on the print media is impaired. For example, a feature defined on the print media may be recognized under a first lighting condition. Subsequently, the print media may be advanced to a degree that the recognized feature is located in a region having different lighting characteristics. Under the different lighting characteristics, a feature recognition module or feature recognition algorithm may be unable to locate the recognized feature. This may result in less precise control over the advancement of the print media.
Compound lighting systems, using more than one light source, have been developed in an attempt to provide more uniform lighting. However, such lighting systems have failed to provide the uniformity desired to better control the advancement of print media along the paper path in a printer. Accordingly, systems and methods which result in more uniform lighting are needed.