Three-pass thermal dye transfer color printer with continuous web print

Abstract

A three-pass thermal color printer for printing a color image on a continuous web of thermal print media consists of a thermal printhead having an upstream side adjacent the roll of print media and an opposite downstream side. The printer further consists of an associated printhead platen, and a set of drive rollers positioned between the printhead and the roll of print media. The drive rollers are operative for drawing the print media through the printhead in an upstream direction, i.e. toward the roll of print media, and advancing the print media in a downstream direction. In operation, the drive rollers draw the print media in an upstream direction whereby the printhead prints an image on the print media starting from a mid-point on the print media to the terminal end thereof. The drive rollers then advance the print media in a downstream direction so that the next printing operation can be overlayed onto the first printed image. The printer reciprocates the print media back and forth until three separate color images are overlayed to achieve a full-color image. The drive rollers are further operative for advancing the print media in a downstream direction to eject the printed image form the printer. The instant printing arrangement has no wasted print media when the printed image is severed from the continuous web.