Direct thermal media and registration sensor system and method for use in a color thermal printer

A system for use in a color direct thermal printer comprising:

• a laterally striped direct thermal media comprising a repeating alternating pattern of at least 2 sets of stripes wherein each stripe set contains a thermochromic leuco dye producing one color when thermally imaged and each of the other stripe sets contain a thermos chromic leuco dye producing a unique and different color when thermally imaged, and wherein one stripe set also contains a fluorophore and is fluorescent under excitation light of a defined wavelength range;
• an optical registration system configured to correspond with the optical properties of the fluorophore and comprising a confocal excitation light source configured to cause the fluorophore carrying stripe to fluoresce with an anamorphic optical return path to filter and focus the emitted fluorescence light pattern by the fluorescent stripe as an image on a sensor;
• and
• an image processing unit configured to determine the position of each fluorescent stripe on the array sensor and configured to output a signal when a fluorescent stripe is detected at a predetermined position on the array sensor.