9-1
Section
Improving Reading
196
9-1
Improving Reading
If correct reading is not performed, check the items listed below.
9-1-1
Environment and Setup
Image
Adjust the lighting and the focus to
produce a suitable image. The image can
be checked in real time by switching to a
through image.
→
Lighting
Use appropriate lighting for the application
and the reading object. The reading
accuracy can be improved significantly by
changing the lighting.
→
Field of vision
If the code image is too large, not all of it
can be read resulting in an NG reading
(because of hollowing of dots). This can be
prevented by increasing the field of vision.
If reading of a Data Matrix code made up
of dots is not possible in Normal mode, try
increasing the field of vision and thereby
reducing the influence of dots.
If the cell recognition coordinates are
incorrect, try increasing cell recognition
accuracy by decreasing the field of vision
and thereby making the code image larger.
Adjust the field of vision so that the
number of pixels per cell is at least 5. For
Data Matrix reading in Pattern mode, the
number of pixels per cell must be at least
10.
Try changing the lens configuration and
the field of vision. Under normal
conditions, it is recommended that settings
are made so that the number of pixels per
cell is between 7 and 12.
Margins
Normally, it is necessary to have a margin
around the code of at least 4 cells. For QR
Code reading in Pattern mode, however,
correct reading is possible with a margin of
only 1 cell.