Editing Barcode reader (section)

==== Laser scanners ====
{{See also|Laser scanning}}
Laser barcode scanners utilize a semiconductor laser diode to produce a laser beam. This beam is directed by a deflection mirror onto a polygon mirror wheel. The design may include a focusing device, enabling the scanner to adjust the beam to scan at various distances.<ref name="scisensors">{{cite book |title=Sensors in science and technology: functionality and application areas |date=2022 |publisher=Springer |location=Wiesbaden, Germany [Heidelberg] |isbn=9783658349202 |page=340 |url=https://books.google.com/books?id=uoBaEAAAQBAJ&dq=oscillating+barcode+scanner&pg=PA340}}</ref>

The scanner deflects the laser beam using a rotating mirror wheel. This wheel deflects the beam line by line over the barcode at frequencies between 200&nbsp;Hz and 1200&nbsp;Hz in most scanners. The deflected beam exits the scanner spread at an opening angle, which is dependent on scanner design. The deflection allows it to traverse the barcode in a reading plane, effectively turning it into a "reading beam." To accommodate stationary items, laser scanners incorporate oscillating mirrors that provide additional deflection perpendicular to the main scanning line. These mirrors function at frequencies that can vary from 0.1&nbsp;Hz to about 5&nbsp;Hz, ensuring that barcodes can be read at different orientations.<ref name="scisensors"/>

Photodetector receives light through the optical system consisting of the mirror wheel and an optical filter. The reflected light, rapidly varying in brightness with a data pattern, is then converted into an electrical signal and is subsequently amplified to a usable level for digital processing.<ref name="scisensors"/>