How, Exactly, Does a Barcode Reader Work?

How, Exactly, Does a Barcode Reader Work?

Barcode readers collect data from what look like random patterns of black and white stripes (bars) on a product box, bag, or tag. The pattern of black and white lines encodes information about a product’s country of origin, manufacturer, and item type in a highly condensed form called a Universal Product Code (UPC), or barcode. A scanner can read the barcode to record valuable data for businesses that helps manage inventory and item price changes. But how exactly does a barcode reader work?


Where Do Barcodes Come From?

An international nonprofit organization called GS1 sets standards for global trade. They provide companies with unique identification numbers (UPCs) to include on their products or in their supply chain. Sellers purchase UPC codes directly from GS1 or from a service that takes care of all the registration paperwork and follow-up for them.

Sellers then use software to encode the UPC into the barcode they place on their products. Barcodes have seven equal segments, and each digit from zero to nine has a unique pattern of black and white stripes that are a specified number of segments wide.

For example, the number two has two white stripes, one black stripe, two white stripes, and two black stripes. A barcode reader scans the pattern of lines to collect the data.


How Does a Barcode Reader Work?

Barcode readers use laser or LED light to pass over a barcode and record the light’s reflection. White bars reflect light strongly, while black bars give weak reflections. The scanner converts the pattern of reflections into a digital signal that it sends via cable or wirelessly to a decoder, then to the store or warehouse’s computerized inventory system.


Types of Barcode Readers

There are several different types of barcode readers, including pen readers, laser scanners, slot scanners, and imaging readers. Pen readers use a contact wand pressed against the lines in the barcode, while laser scanners read the data from a distance. Imaging readers, on the other hand, use cameras to capture an image of the barcode and then process it with software. Slot scanners read items drawn through them, like ID cards. Scanners can be stationary or handheld.

Knowing how barcode readers work will help you understand why an item might not scan correctly at checkout. The barcode could be damaged, blurred, or too small. As a backup, all barcodes have the numeric UPC code printed below them so a worker could enter the code manually.

Barcode readers help retailers monitor inventory and help suppliers track products going in and out of warehouses. They streamline logistics related to the supply line for multiple industries. So the next time you’re scanning away at the self-checkout, think about how that barcode reader helps keep products available and moving toward your favorite store’s shelves!

– Erik Quisling

Erik Quisling is the Founder and CEO of Started in 1999, has been featured in both The Wall Street Journal and The Washington Post and has helped more than 100,000 businesses bring their products to market with barcodes.
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