Overview; Overview Of Thermal Printing Technology - Hengstler eXtendo XF 4 120322 Eli Operating Manual

XF
eXtendo® Thermal Printer Family

3 Overview

3.1 Overview of Thermal Printing Technology

A brief overview of thermal printer technology might be helpful to understand how the eXtendo® XF
thermal printer family works. In most direct thermal printers, paper is fed over a soft, rotating
platen (see Pos. 4 in Figure 1 in chapter 3) and under the thermal printhead (Pos. 3). The platen acts
as a roller to advance the paper at the same time it acts as a surface against which the spring-
loaded printhead presses the paper to insure good thermal conductivity. Circuitry in the printer
determines which heating elements to activate ("fire" or "burn") to form the next row of dots on the
paper.
The thermal paper is coated with several compounds. At room temperature, these compounds are
white in color and do not react with each other. The heat from the thermal printhead acts as a
catalyst in the areas where the small printhead dots are fired, causing these compounds to react
with each other and form a new compound which is a contrasting color, usually black. The platen
then advances the paper to the position of the next dot row, and the process is repeated.
You may immediately note several of the advantages of thermal printing. First, since the printing is
done with heat, there is no noise from the printing process itself. Thermal printing is inherently
quiet compared to most other technologies, such as impact dot matrix. Also, there is only one
moving element in the thermal printer: the platen. This provides increased reliability and life when
compared to other technologies.
Part No. D-684-399 Mod. No. 4 120322 Eli page 8 of 35