June 26, 1974: By Gum! There's a New Way to Buy Gum

By Randy Alfred Email 06.26.08
Norman Joseph Woodland, one of the inventors of the UPC symbol, got his idea by first scratching elongated Morse code symbols into the sand on a beach.
Courtesy Erin Silversmith

1974: A supermarket cashier scans a multipack of chewing gum across a bar-code scanner in Troy, Ohio. It's the first product ever checked out by Universal Product Code.

Some readers may be unable to remember when grocery clerks had to put price stickers on nearly every item in the store. And retail cashiers had to read a price tag by eye and key in the price by hand. But that's the way things were. The process was not only laborious, but it left the store manager with no idea of how much of each of thousands of different products had been sold and how much remained in stock.

There were four main methods of keeping tabs of inventory: Look for empty spots on the shelves and in storerooms, conduct a labor-intensive inventory during overnight downtime every week or so, take whatever the chain-store regional managers wanted to send you, or just guess. Good guessers at the local level got promoted to make regional guesses.

Even so, the supermarket bar code was a long time coming. It was an idea that needed to find a practical technology as well as appropriate application for it.

Drexel University graduate students Bernard Silver and Norman Joseph Woodland began working in 1948 on a retail-checkout system that would keep track of inventory. They started with ink patterns that would glow in ultraviolet light. Expensive. Hard to make the ink long-lasting.

Woodland left Philadelphia to work on the problem at his grandfather's apartment in Florida. He thought Morse code would be a good way to mark inventory, but optical readers would require the checker to line up the code at a specific angle. Not practical.

While on the beach one day, Woodland punched some dots and dashes into the sand, then idly lengthened them into vertical lines and bars. Voilà! Those elongated marks would be readable from nearly any angle.

Woodland and Silver coupled this with an idea from movie technology: Lee de Forest's 1920s sound-on-film system. They used light from a very hot 500-watt bulb to reflect off the printed lines and create patterns that could be read by a photomultiplier tube.

It worked, but it was too big, it was too hot, computers were still enormous and expensive, and lasers hadn't been invented yet. The duo tweaked the tech, using bull's-eye patterns instead of lines, for better readability. And they patented it. IBM was interested, but didn't offer the inventors enough money. They eventually sold the patent to Philco, which later sold it to RCA.

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