Reading techniques
Leuze electronic
BCL 608i
20
5
Reading techniques
5.1
Line scanner (single line)
A line (scan line) scans the label. Due to the opt. opening angle, the reading field width is dependent on
the read distance. Through the movement of the object, the entire bar code is automatically transported
through the scan line.
The integrated code reconstruction technology permits twisting of the bar code (tilt angle) within certain
limits. These are dependent on the transport speed, the scanning rate of the scanner and the bar code
properties.
Areas of application of the line scanner
The line scanner is used:
• when the bars of the bar code are printed in the conveying direction ('ladder arrangement').
• with bar codes having very short bar lengths.
• when the ladder code is turned out of the vertical position (tilt angle).
• when the reading distance is large.
Figure 5.1: Deflection principle for the line scanner
5.2
Line scanner with oscillating mirror
The oscillating mirror deflects the scan line additionally to both sides across the scan direction at a
randomly adjustable oscillation frequency. In this way, the device can also scan larger areas or spaces for
bar codes. The reading field height (and the scan line length useful for evaluation) depends on the reading
distance due to the optical opening angle of the oscillating mirror.
