The Barcode
The Patent Nobody Wanted and the Packet of Gum That Proved It
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The first practical barcode reader was built in 1970 at a company called Datalogic. The technology needed a standard format to work across stores. In 1973, major retailers agreed on the Universal Product Code. This system would be tested with actual products.
On June 26, 1974, a pack of Wrigley's chewing gum was scanned for the first time in Troy, Ohio. The barcode reader worked perfectly. Anyone interested in how modern checkout systems began will find this story essential reading.
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Overview
George Joseph Laurer III was an American engineer who worked for IBM at Research Triangle Park in North Carolina. He published twenty bulletins, held twenty-eight patents, and developed the Universal Product Code, or UPC, in the early 1970s. He created the specific coding and pattern used for the UPC, building on an earlier, more general idea for barcodes by Joe Woodland. Laurer lived from September 23, 1925, to December 5, 2019.
Early life
George Joseph Laurer III was born in New York City on September 23, 1925. His family later moved to Baltimore, Maryland, where his father worked for the United States Navy as an electrical engineer. While in 11th grade, Laurer was drafted into the U.S. Army during World War II. He recovered from polio he had contracted as a teenager. After being discharged, he attended technical school to study radio and television repair. His instructor advised him to leave that program and pursue a college education instead. Laurer graduated from the A. James Clark School of Engineering at the University of Maryland in 1951. He kept up his amateur radio license throughout his life.
Career
George Laurer spent thirty-six years at IBM, starting as a junior engineer in 1951 and retiring in June 1987. By 1969, he had risen to senior engineer scientist and relocated to Research Triangle Park in North Carolina. There, he was assigned the task of developing barcodes for grocery stores. He moved away from an earlier circular design proposed by Joe Woodland in the 1940s, which didn't work well for printing. In 1971 or 1972, Laurer suggested a vertical stripe pattern instead. Working with Woodland and mathematician David Savir, he helped refine the system, including adding a check digit to correct errors. The final proposal was accepted in 1973 by a group representing grocery store companies. The barcode includes guard bars that resemble the number 666, sparking urban legends about the "mark of the beast." Laurer addressed the concern, saying it was simply a coincidence and not connected to any biblical code.
Legacy
George Laurer held 25 patents and wrote 27 technical disclosure bulletins. In 1976, he won the Raleigh Inventor of the Year Award. Seven years later, in 1980, he received IBM’s Corporate Technical Achievement award. By 2019, UPC barcodes were being scanned over 6 billion times a day, according to GS1.
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Overview
A barcode stores data visually for machine reading, starting with lines of varying widths known as linear or one-dimensional barcodes. Invented by Norman Joseph Woodland and Bernard Silver and patented in 1952, they didn't become widely used until decades later. Early industrial use included the Association of American Railroads in the late 1960s through a system called KarTrak ACI developed by General Telephone and Electronics. British Railways had built a system capable of reading barcodes on moving trains by 1962. Barcodes gained mainstream success in supermarkets, especially after Sainsbury's began using them in 1972. The Universal Product Code, developed by George Laurer, became the standard. In 1974, a scanner at Marsh supermarket in Troy, Ohio read the UPC on a pack of Wrigley's chewing gum. QR codes, a kind of two-dimensional barcode, grew popular in the 2000s with smartphone use.
History
In 1948, graduate student Bernard Silver at Drexel Institute of Technology heard Food Fair president inquire about automating checkout product reading. He shared the idea with friend Norman Joseph Woodland, and together they began experimenting with systems. Their first version used ultraviolet ink that faded quickly and cost too much. After leaving Drexel, Woodland moved to Florida, where he drew from Morse code on a beach to design lines of varying widths. To read them, he adapted a 500-watt bulb and an RCA935 photomultiplier tube from movie projectors. He later imagined a circular barcode that could be scanned in any direction. On October 20, 1949, Woodland and Silver filed a patent for "Classifying Apparatus and Method," describing both linear and bull's-eye patterns. Granted on October 7, 1952, as US Patent 2,612,994, it was later acquired by Philco and sold to RCA.
Collins at Sylvania
David Jarrett Collins, while working at the Pennsylvania Railroad as an undergraduate, recognized the need for automatic identification of railroad cars. After earning his master's from MIT in 1959, he joined GTE Sylvania and began work on a solution. He created a system using blue, white, and red reflective stripes to encode company and car numbers, which was read by photomultiplier tubes. The Boston and Maine Railroad tested it from 1961 to 1967, when the Association of American Railroads adopted it as a standard. Installation began October 10, 1967, but slow adoption followed due to economic downturns, and it wasn't fully implemented until 1974. The system was later deemed unreliable because of dirt interference and was abandoned by the late 1970s. A new version based on radio tags wasn't introduced until the mid-1980s. Still, Collins's work found use in other areas: a toll bridge in New Jersey adapted it to spot monthly pass holders, the US Post Office used it for truck tracking, and Kal Kan requested a simpler version for pet food inventory control.
Computer Identics Corporation
In 1967, after the railway project was well underway, Collins approached Sylvania's management for funding to develop a black-and-white version of the barcode for other industries. The request was denied—they believed the railway work was already enough and saw no need to expand quickly. So Collins left Sylvania and founded Computer Identics Corporation. The company improved on early designs by switching from incandescent bulbs to helium-neon lasers and adding a mirror, allowing scanners to detect barcodes up to a meter away. This made the system more reliable and capable of reading damaged labels. In spring 1969, Computer Identics installed one of its first two scanning systems at a General Motors factory in Flint, Michigan, where it identified different types of transmissions moving on an overhead conveyor. The other system went to General Trading Company's distribution center in Carlstadt, New Jersey, helping direct shipments to the right loading bay.
Universal Product Code
In 1966, the National Association of Food Chains met to discuss automated checkout systems, and RCA, which had bought the original Woodland patent, presented its bullseye code at the meeting. The Kroger grocery chain agreed to test it. By the mid-1970s, the NAFC formed a committee to standardize product codes, working with McKinsey & Co. to create an 11-digit system. They invited several companies—including IBM, NCR, and RCA—to submit proposals. In 1971, RCA showed off its bullseye code again, prompting IBM to quickly develop their own. IBM's Alec Jablonover remembered that Woodland was still employed, so he set up a new lab at Research Triangle Park. An RCA test in a Kroger store in Cincinnati found the bullseye code unreliable due to smudged ink. In contrast, IBM's linear UPC could still be read even if ink spread. On April 3, 1973, IBM's UPC was chosen as the standard. IBM designed five versions: A through E. NCR tested the system at Marsh's Supermarket in Ohio, and on June 26, 1974, Wrigley's Juicy Fruit gum became the first item scanned using the UPC. By 1973, IBM was planning how to roll out the technology across the industry, meeting with manufacturers to promote adoption. The grocery industry projected over $40 million in savings by the mid-1970s, but early results were disappointing. Business Week even called it "The Supermarket Scanner That Failed." Sims Supermarkets became the first in Australia to use barcodes in 1979.
Industrial adoption
In 1981, the United States Department of Defense began using a system called Code 39 to mark products sold to the military. This system was known as Logistics Applications of Automated Marking and Reading Symbols, or LOGMARS. Even today, the DoD still uses this same system. Many people see LOGMARS as the moment when barcoding really started being used widely in industry.
Use
Barcodes are used everywhere, from grocery stores where UPC codes speed up checkout and help prevent shoplifting, to hospitals where they identify patients and track medications. They're found on books as ISBNs, on retail cards for customer data, and even on airline boarding passes since 2005. Barcodes help manage inventory in factories and can be read by sensors for precise positioning in machines. Some are used in art, like Scott Blake's "Barcode Jesus," and others have been used in games or to encode software in the 1970s and 1980s. Mobile devices can now read 2D barcodes to link to websites, helping shoppers compare prices.
Barcode readers
The earliest barcode scanners were simple devices using a fixed light and one photosensor moved by hand across the code. Some older models connected via RS-232 serial ports and required special software to process incoming data. Others mimicked keyboard input, often appearing as a "keyboard wedge" inserted between a PS/2 or AT keyboard and the computer. Today's scanners mostly connect through USB and function like extra keyboards, sending data as if typed. Companies such as Datalogic, Zebra Technologies, and Metrologic produce standalone readers. Meanwhile, most modern smartphones can read barcodes using their cameras—Android systems support apps like Barcode Scanner or Google Lens, while iOS 11 lets the default camera app decode QR codes and open linked URLs. Nokia's Symbian and BlackBerry's App World also included scanning tools, although they don't match the speed or accuracy of purpose-built scanners.
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Overview
A barcode reader is an optical scanner that reads printed barcodes and sends their data to a computer. It works much like a flatbed scanner, using a light source, a lens, and a light sensor to turn optical impulses into electrical signals. The device also includes decoder circuitry that analyzes the image data from the sensor and transmits the barcode's content through the scanner’s output port.
Pen-type readers
A pen-type barcode reader looks like a regular pen, with a light source and a photodiode placed close together at the tip. To scan a barcode, someone moves the tip across the bars and spaces at a steady pace. The photodiode detects how much light is reflected back from each part—dark bars absorb light, while white spaces reflect it. This creates a voltage waveform that mirrors the pattern of the barcode. The scanner then interprets this waveform, much like decoding Morse code dots and dashes, to figure out what the barcode says.
Laser scanners
A laser barcode scanner uses a semiconductor laser diode to generate a beam of light, which then travels through a deflection mirror and hits a polygon mirror wheel. This wheel spins and redirects the beam in a sweeping motion across the barcode, typically at frequencies between 200 and 1200 times per second. Some scanners include a focusing device to adjust the beam for different distances. The beam spreads out as it exits the scanner, and this movement creates what’s called a reading beam that scans line by line. To read barcodes on stationary items, the scanner also uses oscillating mirrors that move the beam back and forth perpendicular to the main scan line, operating at slower speeds from 0.1 to about 5 times per second. A photodetector captures the reflected light, converting it into an electrical signal that gets amplified for digital processing.
CCD readers (also known as LED scanners)
A CCD reader uses a row of hundreds of incredibly small light detectors, each one checking the brightness right in front of it as the barcode moves past. These sensors generate a voltage pattern that mirrors the barcode’s dark and light sections. What sets CCD readers apart from pen or laser scanners is that they detect ambient light coming from the barcode itself, rather than sending out their own light and reading what bounces back. Some LED scanners now use CMOS sensors instead and are replacing older laser-based models.
Camera-based readers
Two-dimensional imaging scanners represent a newer kind of barcode reader, using camera technology and image processing to decode barcodes. Video camera readers rely on CCD technology, but instead of a single row of sensors, they use hundreds of rows arranged in a grid to form a complete image. Some systems capture multiple barcodes at once with high-resolution industrial cameras, decoding them instantly through tools like ImageID patents and code creation, or via plugins such as the Barcodepedia, which used a flash application and webcam to query a database.
Omnidirectional barcode scanners
Omnidirectional barcode scanners work by sending out a complex pattern of light—either straight or curved lines arranged like a starburst or Lissajous curve—so that no matter how a barcode is angled, at least one beam will cross all its bars and spaces. Most use a laser, and while simpler scanners rely on just one line, these project multiple beams at once. They often use a single rotating mirror and several fixed ones to create this variety of angles. You might recognize them from supermarket checkout lines, where packages slide over a glass or sapphire window. These scanners can read barcodes from a few centimeters away up to a couple meters out, and they're especially good at picking up information even when the barcode is faded, wrinkled, or torn.
Housing
Barcode readers come in several forms, each built for different jobs. A handheld scanner has a handle and usually a trigger button to turn on its light, and it's often used in factories and farms for checking quality and managing shipments. There’s also the PDA scanner, which is basically a personal digital assistant equipped with a barcode reader or connected to one. For high-volume tasks like processing lots of documents, automatic readers are used in back offices and can handle up to 50,000 barcodes per hour. And then there are cordless scanners, powered by batteries inside them, which move freely without being plugged into the wall and send data wirelessly to devices like computers.
Serial interfaces
Early barcode scanners, no matter the format, mostly relied on the RS-232 serial interface, which was easy to wire and didn’t need complicated software—though that software did have to be written specifically for each computer and its serial port. As personal computers evolved with new standard connections, barcode readers began using keyboard interfaces instead. The first “keyboard wedge” hardware would sit between a PS/2 port and the keyboard, making it seem like the scanner’s input was just typed in as if from the user. Today, the term covers any device that can plug in and add data to what comes “from the keyboard.” These days, USB versions are common, with some offering choices between HID or CDC types of connections.
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