Media-tracking system using thermal fluoresence quenching

摘要

A system is described for tracking a position of a receiver medium as it travels along a media path. A heat source provides heat to the receiver medium in a localized area sufficient to permanently alter a fluorescent agent in the receiver medium, thereby forming a reference mark characterized by a reduced level of fluorescence. A stimulating light source illuminates the receiver medium at a downstream position along the media path, the stimulating light source having a spectrum adapted to stimulate the fluorescent agent to fluoresce thereby producing emitted light. A sensor is used to sense the emitted light from the receiver medium thereby providing a sensed light level signal. The sensed light level signal is analyzed to determine a position of the receiver medium by detecting the reduced level of fluorescence associated with the reference mark.

主权项

1. A system for tracking a position of a receiver medium as it travels along a media path, comprising:
a heat source located at a first position along the media path adapted to provide heat to the receiver medium in a localized area, the receiver medium including a fluorescent agent that fluoresces to produce emitted light with an emission spectrum when illuminated by a light source having an appropriate excitation spectrum, wherein the provided heat is sufficient to permanently alter the fluorescent agent thereby forming a reference mark characterized by a reduced level of fluorescence; a stimulating light source that illuminates the receiver medium when it has traveled to a second position along the media path, the stimulating light source having a spectrum adapted to stimulate the fluorescent agent to fluoresce thereby producing emitted light; a sensor adapted to sense the emitted light from the receiver medium at the second position along the media path and provide a sensed light level signal; and a data processor adapted to analyze the sensed light level signal to determine a position of the receiver medium as the receiver medium passes through the second position along the media path by detecting the reduced level of fluorescence associated with the reference mark.