John L Vaught: Ink dispenser with "frozen" solid ink. Hewlett Packard Company, Jeffery B Fromm, December 25, 1984: US04490731 (162 worldwide citation)

A new type of apparatus for dispensing "frozen" solid ink and the ink for use therein for printing on paper is disclosed. The ink dye vehicle is chosen to have a melting point above room temperature, so that the ink which is melted in the apparatus will not be subject to evaporation or spillage duri ...