The Bar Code's Origins
The invention of the bar code is most widely credited to Norman Joseph Woodland who developed the idea in the late 1940s. Woodland wanted to streamline processes at supermarkets and invent an automated method to capture product information at checkout. He developed the bar code system, which converts Morse code into a linear, two-dimensional system, by representing the code’s dots with thin bar lines and its dashes with thick bar lines. Although bar code structures have changed since then, its basic functionality remains the same.
While almost everyone has used a bar code in one way or another, few understand how it actually works. Retail Universal Product Code (UPC) bar codes consist of a minimum of two sections of scannable information. The sections are divided by three sets of slightly longer lines. These sets of long lines do not interpret numbers, but are used to help the scanner read the entire bar code. The first section of short lines represents the numbers listed below the section, which correspond to the retail company or manufacturer of the product. The second section of short lines represents the numbers that correspond to the product’s identification code or other product information, such as price or weight. In the above bar code, the first section of short lines represents 76950, which identifies the company selling the product. The second section of short lines represents 40547, which identifies the product. The last piece of code, represented in this bar code with the number 9, is the check digit. The check digit is a direct mathematical sum when all of the previous numbers are entered into a checking formula. The purpose of the check digit is to verify the entire bar code is correct and without errors.
The entire sequence of code creates a unique part number for the company and product. When bar codes were first introduced, there were more than enough unique codes for each company. Since then, however, commerce has expanded and the number of companies using UPC has skyrocketed. Soon, the UPC will have exhausted all available company prefixes, prompting the bar code to evolve in order to overcome its limitations.
As of January 1st, 2005, all North American retailers should have expanded their UPC data structure capabilities through the Sunrise 2005 initiative to process 13-digit field lengths, including EAN-13 symbols. Furthermore, Global Standards (GS1) recommended database expansions to accept 14-digit data structures, which will support the Global Trade Item Number (GTIN) for efficient and seamless global trade.
