An precisely focused and finely bundled laser beam is used as a light source for the laser scanner’s reading system. The laser beam is deflected by a rotating polygon mirror, creating an upandlandy laser beam. This is forwarded to the barcode carrier and then projected onto a photo receiver as a reflecting beam of varying degrees via a mirror and lens system. There, the optical pulses are converted into binary electrical signals. Laser scanners allow a relatively large depth of field due to the sharp beam bundling and the parallelism of the light and are able to read a low-density code at a distance of 1.5 m. Mandatory safety measures must be met when installing laser light sources. Today, laser scanners are not only used as stationary systems (e.B. on conveyor belts), but also in the form of mobile laser guns, with which the conveyed material can be scanned directly from the driver’s seat of a forklift and thus identified.
For more information about the design of a barcodeso that it can be read by the scanner, see Designing a bar code.
Image source: © Kitch Bain – Fotolia.com
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