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Intermec EasyCoder 201 II – Technical Manual
PRINTING PRINCIPLES
The printing is produced by the thermal printhead, which consists
of a line of very small, closely spaced resistors on a ceramic tile
fitted across the paper web. When a current is led through the
resistors, commonly called “dots,” these will be heated very
quickly. The heating is controlled by a powerful 32-bit microproc-
essor. When the current is shut off, the dots cool down just as fast.
The direct thermal printing method requires a special paper coated
with a thin layer of heat-sensitive chemicals. As the paper is fed past
the dots, the heat from the dots will make the chemicals react,
producing a dark salt, which makes up the imprint under each dot.
These black imprint can be combined into patterns, which make up
letters, bar codes, or images.
The basis for all measures and positioning in the Intermec Finger-
print programming language is the size of printhead dots. For
example, in an 8 dots/mm printhead, each dot has a nominal size of
0.125 mm (4.9 mils). This means that a heated dot under standard-
ized conditions will produce a black spot which has a diameter of
0.125 mm. Depending on dot temperature, exposure time, paper
characteristics etc., the spot may actually be somewhat smaller
(weak print) or larger (black print), but that does not affect the
calculation of distances, sizes and positions.
The 6 dots/mm printhead contains 512 dots, which gives a maxi-
mum print width of 85.3 mm (3.36") for printers with a standard
sized paper roll and 80.2 mm (3.16") for “Big Roll” printers.
The 8 dots/mm printhead contains 640 dots, which gives a maxi-
mum print width of 80.0 mm (3.15") for printers with a standard
sized paper roll and 78.0 mm (3.07") for “Big Roll” printers.
The stepper motor, which feeds the paper web, is controlled in such
a way that all measures along the web should be given in dots too.
Density:
6 dots/mm (153.9 dpi)
8 dots/mm (203.2 dpi)
1 dot
0.165 mm
0.125 mm
1 dot
6.5 mils (0.0065")
4.9 mils (0.0049 ")
1 mm
6 dots
8 dots
1 inch
153.9 dots
203.2 dots
1/16 inch
9.6 dots
12.7 dots
Direct Thermal Printing
Dot Size
Conversion Table
