Symbol SE 2223, Руководство по интеграции

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2-7
Installation
Optical
The SE 2223/3223 uses a sophisticated optical system that can provide scanning
performance that matches or exceeds the performance of much larger scanners. However,
an improperly designed enclosure, or improper selection of the window material can reduce
scanner performance.
Note: This guide provides general instructions for the installation of the
scan engine into a customer's device. It is strongly recommended
that an opto-mechanical engineer perform an opto-mechanical
analysis prior to integration.
Positioning the Window
The window must be positioned so that laser light reflected off the inside of the window is
not reflected back into the collection optics of the scanner. See
Table 2-9 to determine
position and angle of the window. The window can be positioned more nearly parallel to the
face of the scanner if an anti-reflection coating is used. An improperly positioned window
can result in significant performance degradation.
Avoiding Scratched Windows
Scratches on the window can reduce the performance of the scanner. Recess the window
into the housing, or apply a scratch resistance coating to minimize scratching.
Window Material
Many window materials that look perfectly clear to the eye can contain stresses and
distortions that can reduce scanner performance. For this reason, cell cast acrylic or CR-
39 is highly recommended. Following is a description of these window materials.
Acrylic
Easily fabricated by extruding, injection-molding, or by cell-casting. Very good optical
quality and low initial cost, but surface must be protected from the environment due to its
susceptibility to attack by chemicals, mechanical stresses, and UV light. Reasonably good
impact resistance. Can be ultrasonically welded.