Tapered platen roller for thermal printer

An improved platen roller for a thermal printing apparatus, the printing apparatus having a registration wall, a print deck, a thermal print head mounted to the registration wall and extending over the deck to define a print station, a platen roller support assembly for supporting the platen roller parallel to the thermal print head and causing the platen roller to bias an envelope against the thermal print head and causing the envelope to traverse the thermal print head during a print cycle of the thermal printing apparatus, the platen roller improvement comprising:

• said platen roller being segmented into a plurality of equal axial segments "N" of between 25 to 35 durometer cellular urethane, each of said segments segment having a segment thickness "X.sub.s " between 0.06 and 1.5 inches and a gap distance "Z" of between 0.005 and 0.75 inches having
• a first end section of conical configuration with an outer end of "R+h" and an inner end of radius "R" where "R" is less than "R+h", and having a surface taper angle "A" of between -2.0.degree. degrees and -3.0.degree. degrees, and having a axial length of "L" wherein:
• h=L * tangent (.vertline.A.vertline.)
• and;
• axial length L is equal to or greater than 1.0 inches.