Chapter 1
Quick Start
1-6
MS-850 Raster Scanner User’s Manual
1–Qui
ckst
art
Step 5 Position Scanner
Before permanent mounting:
a) Position the scanner and label, taking care to avoid excessive tilt, skew, or pitch.
Maximum tilt is determined by label characteristics and the number of scans
required. Maximum skew is
±40°
; maximum pitch is
±50°
.
b) Pitch label slightly to avoid specular reflection, the return of direct, non-diffused
light. The specular reflection zone is a narrow zone straight out from the scanner
in which direct reflected light from a label can distort the scanner’s ability to dis-
tinguish bars from spaces. For the MS-850 raster scanner, specular reflection is
avoided by pitching labels at least
5°
plus or minus from a line perpendicular to
the raster mirror.
Note:
The illustration above shows the raster pattern of scan lines as they strike the
bar code label moving in a picket fence direction. (Raster scanners are almost
always positioned to scan in the picket fence orientation.)
Note:
Another way to avoid specular reflection is to skew the scanner slightly in
relation to the label.
Scanner
Direction
of travel
Pitch
axis
Tilt
axis
Skew
axis