thermal sublimation printer
Sublimation is the transition of a solid substance into a gaseous state, whereby one aggregate state, the liquid, is skipped. The dye sublimation printer is based on this principle.
In this thermal printer, the inks are located one after the other as wax inks on a special carrier foil. Depending on the color model, the colors are cyan, magenta and yellow, CMY, or, if black is included, CMYK. The wax inks are brought to a gaseous state by the action of heat and vaporized into the special paper. Depending on the color model, the paper is pulled under the print head three or four times and printed line by line.
In the case of the dye-sublimation printer, the wax inks, which are located on a polyester film, are heated to temperatures between 300 °C and 400 °C using many controllable heating elements. By controlling the temperature, the individual color dots can be changed in their intensity and thus all color shades of the corresponding color model can be produced. This control mechanism distinguishes the dye sublimation printer from the thermal transfer printer. Semiconductor elements located on a thermal rail serve as heating elements; their number and size determine the print resolution.
Dye-sublimation printers, like all printers, work according to the CMY or CMYK color model and are characterized by high-quality color prints with high color saturation. This high quality, equivalent to that of photos, is achieved even at the relatively low resolution of 300 dpi and above. This is due to the fact that the prints are not screened, but the color tones are achieved via halftone control. With this halftone control, each of the three colors of a print dot can be represented with 8 bits, which corresponds to a color gamut of up to 16.8 million colors.
The thermal transfer paper used for printing is a special paper that can be printed with vaporized heating wax inks.