"[In] 1974, the first product with a barcode [chewing gum] was scanned at a checkout counter."
Russ Adams, author
The development of barcodes stemmed from comments made by a food-chain president to a university dean at the Drexel Institute of Technology, Philadelphia, in 1948, and overheard by graduate student Bernard Silver (1924-1962). The company wanted some sort of system to collect product information at the checkout automatically, but the dean had little interest in initiating such research. Silver decided that he and his friend Norman Woodland (b. 1921) should pursue a solution. Eventually the pair turned to a combination of movie soundtrack technology invented by Lee De Forest in the 1920s and Morse code dots and dashes; "I just extended the dots and dashes downward and made narrow lines and wide lines out of them," said Woodland.
De Forest's film included a varying transparency pattern on its edge. When a light was shined through it, sensing equipment on the other side converted the changes in brightness into electronic waveforms that translated into sound. Woodland adapted this system by reflecting light off his wide and narrow lines and coupling the sensor to an oscilloscope. They had invented the first electronic reader of printed data. The advent of affordable, low-power, laser light sources, and "compact" computers to process the captured data, did not occur until several years later.
