11
D027173_07 CR821X Dual Board Decoded Scan Engine Integration Guide
3 - Optical Considerations
D
WINDOW SIZE MUST
EXCEED WIDTH
AND HEIGHT OF
ILLUMINATION ANGLE
A
D
A
60˚ LED CONES
H
W
30.00˚
FOV
LED
30.00˚
30.00˚
30.00˚
CL
FOV CL
CL
LED CL
LED CL
4.20
[.165]
17.00
[.669]
3.1 – Window Requirements
When integrating the CR821x into your device or application, it may
be necessary to install a window in front of the optics of the Imager.
Although many different types of materials can be considered, Code
makes the following recommendations.
Placement:
Contact to 0.5 mm away from the face of the Imager,
parallel to engine face
Material:
Optically clear acrylic
Thickness:
1 mm or less
If your design constraints prevent the window from being mounted within
0.5 mm of the face of the engine, Code recommends an anti-reflective
(AR) coating be applied to both window surfaces (front and back). The AR
coating must have less than 3% reflectance from 400nm to 1000nm.
The window must be wide and tall enough so the surrounding enclosure
does not block any of the illumination from the LEDs. The following
diagram illustrates the field of illumination that must be unobstructed
by the edges of the window aperture.
CR821x Field of Illumination Diagram
Distance to
Window (D)
Illumination
Width (W)*
Illumination
Height (H)*
5 mm
22.04 mm
13.44 mm
6 mm
23.20 mm
14.60 mm
7 mm
24.36 mm
15.76 mm
8 mm
25.52 mm
16.92 mm
9 mm
26.68 mm
18.08 mm
*Window must exceed this width/height
H=1.16D+7.64
W=1.16D+16.24
UNITS = MM[INCHES]
