Thermal Printing With Ceramic Tipped Printhead
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
A ribbon consisting of a thermal ink on a 1000-angstrom aluminum layer is driven by electrodes having a semiconductive ceramic tip which contacts the aluminum layer. The printhead is resistant to wear, and the ribbon is thin and economical. Fig. 1 illustrates standard resistive ribbon printing in which an electrode contacts a conductive polycarbonate layer, while a 1000-angstrom aluminum layer is positioned between the ink layer and the polycarbonate layer. Current passes in a relatively low resistance path from the electrode into the polycarbonate, where it creates heat primarily in the more resistive portions of the ribbon. Such printing is shown in more detail, for example, in U.S. Patent 4,345,845. Fig. 2 illustrates printing with the ceramic tipped printhead. The polycarbonate layer is eliminated.