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The picture at the right is an
exploded
view
of
the
previous
scanned
image.
Again notice the ink bleed
and how it affects the ratio
of the dark to the light bar
widths.
Using
the
ADD
SPACE parameter gives the
user the ability to minimize
this effect.
Trial and error is necessary
to find the correct settings to
be
used.
The
substrate
material is the governing
factor in deciding what the
correct settings are.
The second concept that the
pictures show is the overall
consistency in bar width
across
the
image.
All
scanners have the capability
of
accepting
a
certain
amount of bar growth but
must be kept to a minimum.
Bar growth will be seen in
non-linear production lines.
Normally with a consistent
running
production
line,
there is no need for an
external
encoder.
Where
there is an acceleration or
deceleration component in
the production line, it is
absolutely necessary to use
an encoder. Even with an
encoder a code can deviate
from the proper aspect ratio.
This deviation is caused by
slippage
of
the
product
against the production line.
Bar growth will also lead to a less dense dark bar due to the fact the printed
vertical columns will print further apart then previous dark bars. This may also be
seen when not using an encoder and the line speed of the printer is set slower
than the actual line speed of the production line.
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EVOLUTION LX SYSTEM MANUAL Issue 1.0 5 DEC 2009