Thermal Transfer Printing – 5
Tektronix/Xerox solid-ink printers
Printers like the Xerox Phaser 8400 uses 1 cubic inch (16 cm3) rectangular solid-state ink blocks (similar in consistency to candle wax), which are loaded into a system similar to a stapler magazine in the top of the printer. The ink blocks are melted, and the ink is transferred onto a rotating oil-coated print drum using a piezo inkjet head. The paper then passes over the print drum, at which time the image is transferred, or transfixed, to the page.
This system is similar to water-based inkjets, provided that the ink has low viscosity at the jetting temperature 60 °C (140 °F). Printout properties are similar to those mentioned above, although these printers can be configured to produce extremely high-quality results and are far more economical, as they only use the ink needed for the printout, rather than an entire ribbon panel. Costs of upkeep and ink are comparable to color laser printers, while "standby" power usage can be very high, about 200 W.
For more: https://en.wikipedia.org/wiki/Thermal-transfer_printing