How did laser scanners change supermarket checkout systems?

Laser scanners revolutionized supermarket checkout systems by automating the identification of merchandise and the retrieval of pricing data. Previously, manual entry was required, but the introduction of barcode technology in the 1970s allowed for a more efficient process.1

In these systems, a laser scanner uses a rotating mirror to project a beam across the checkout surface. As a clerk moves a package across this beam, optical sensors detect the light reflected from the Universal Product Code (UPC) printed on the item. The scanner decodes the pattern of parallel bars—which represent binary data—and relays this information to a computer. The computer then instantly identifies the product, looks up its current price, and feeds that data into the cash register to be added to the customer's bill.12

This transition significantly increased the speed and accuracy of retail transactions, allowing for the immediate processing of detailed product information at the point of purchase.1