This invention relates to the art of article classification and has particular relation to classification through the medium of identifying patterns. It is an object of the invention to provide automatic apparatus for classifying things according to photo-response to lines and/or colors which constitute classification instructions and which have been attached to, imprinted upon or caused to represent the things being classified. Another object of the invention is to provide a novel method by which classification patterns consisting of different identifying combinations within a fixed pattern area are utilized to identify different articles.
So reads the opening paragraph of US Patent 2,612,994 dated 7 October 1952.
Joseph Woodland and Bernard Silver were awarded the first patent for a barcode 60 years ago today and given the topic of this website we could hardly let it pass by without acknowledgement. According to Woodland’s personal account, his contribution consisted of combining two established technologies, the movie soundtrack and the Morse code. “I just extended the dots and dashes downward and made narrow lines out of them,” he later told a reporter. “Then I figured out how to decode the black and white stripes using a modified version of the movie sound system developed by Lee de Forest.
In the 1920s de Forest had affixed a voice-generated stripe consisting of varying shades of grey to the side of a strip of celluloid motion picture film. He then sent a beam of light through the film as it was threaded through the projector. Photoelectric cells on the back side of the film translated the variations in brightness into a corresponding waveform which was then converted into sound by loudspeakers strategically spaced around the theater. Woodland adopted the same basic principle, but the light-intensity variations in his supermarket scanners were created by reflecting bright beams of light from the alternating black-and-white stripes on his binary barcodes.
The rest is history, as they say.