Operating the Scanner
3–7
Publication 2755-6.4
Dead Zone
When scanning a 1-D bar code, there is only a small specular dead
zone to avoid (+2
_
from the direct laser beam). The specular dead
zone is larger when scanning PDF417 (+9
_
from the direct laser
beam). At the same time, the scanner is not effective if its beam hits
the bar code’s surface at an angle greater than 30
_
from normal to
that surface.
1. Successful Scanning
2. Successful Scanning
Angles for Good Decodes
Bar Code
Right Angle
Normal
0
_
– 30
_
20
_
– 50
_
Tilted 0
_
– 30
_
back from surface
Tilted 20
_
– 50
_
forward toward surface
Scan Beam
Scan Beam
You can also scan successfully by tilting the scanner forward from
parallel about 20
_
to 50
_
toward the scanning surface.
