History of Bar Code

Retail applications drove the early technological development of bar coding, but industrial applications soon followed. We will first trace the retail roots.

Wallace Flint, son of a Massachusetts grocery wholesaler, wrote his 1932 master’s thesis at Harvard on a system for automating supermarket checkout counters. Flint’s proposed system used flow racks and punched cards to automatically dispense products to customers. The proposal was economically unfeasible, but this was the first time that the benefits of an automated checkout had been completely documented. Forty years later, Flint was the vice presi¬dent of the National Association of Food Chains, and he actively supported the standardization effort that led to the Universal Product Code and its associated symbology.

In the late 1940s, foe Woodland and Berny Silver were investigating technical approaches that would allow prices of grocery items to automatically be read at the checkout stand. Several approaches were pursued, and their developments culminated in the filing of U.S. Patent 2,612,994 in 1949.

The Woodland and Silver patent describes a circular printed pattern that resembles a miniature archery target. This format is often referred to as a bull’s- eye code. The concentric rings of the target are, however, simply bars and spaces curved into a circular form. Conceptually, bull's-eye coding and bar coding are the same. Technology and retail economics were still not ready for bar code, but twenty years later Joe Woodland, then an IBM engineer, was part of the team that developed the precursor to the UPC bar code symbol.

In the late 1950s and early 1960s, several inventors proposed the construction of stylized human-readable characters that would look like bar code to the automatic scanner but appear like numerals or letters to a person. Typical of these inventors was Girard Feissel, who filed a U.S. patent in 1959 depicting the numerals 0 through 9, each constructed from seven parallel bar segments. Unfortunately, such arrangements are more difficult for machines to read than true bar code and less pleasant for humans to read than traditional type fonts.

Serious efforts toward developing a standard for automating the supermarket point-of-sale began in 1968. RCA developed a bull’s-eye symbol and scanner that operated in a Kroger store in Cincinnati for an 18-month period beginning in 1972. This test store provided much valuable data for cost benefit analysis and system refinement. Meanwhile, in mid-1970 a grocery industry ad hoc committee was formed under the chairmanship of R. Bert Gookin to select a standard code and symbol for that industry. This ad hoc committee subsequently established guidelines and a symbol selection subcommittee to select an industry standard symbol. Proposals were solicited from interested manufacturers of computers and point-of-sale equipment. Seven equipment manufacturers respond¬ed with proposed symbols, several of which are illustrated:

Proposed Symbols. Bar code technology has its roots in the late 1960s and early 1970s. At the time of the definition of the grocery industry's UPC (Universal Product Code) symbology in the early 1970s, many proposals from different organizations were examined. Some of the originally proposed bar code symbologies are shown here.

A massive symbol evaluation was undertaken that included laboratory tests by Battelle Memorial Institute, printing tolerance tests assisted by the Graphic Arts Technical Foundation, printability tests by participating grocery manufacturers, and store tests of complete working systems. This effort concluded with selection of the UPC symbol as the industry standard on April 3, 1973. This final symbol closely resembles the one that had been proposed by IBM.

The early success of UPC in U.S. and Canadian supermarkets encouraged foreign, particularly European, interest in the system. This interest led to the adoption of the EAN (European Article Numbering) code and symbol in December 1976.

Industrial applications of bar code can be traced back to the early 1960s. In 1962 E. F. Brinker of Westinghouse Air Brake filed a patent that described a bar code attached to the side of a railroad car. In the late 1960s, North American Railroads adopted a system invented by Sylvania that used retroreflective red, blue, and white bars; 95 percent of U.S. freight cars had been labeled by the time the system was abandoned in 1974 because of insufficient training, maintenance, and equipment investment.

Several companies pursued warehouse and related applications following the initial railroad experience. In 1971 the Plessey Company developed a bar code and reading system for library checkout. Codabar was developed by Monarch Marking Systems in 1972. This symbology continues to be used in blood collection applications as well as in its original library usage.

Before 1974, bar codes could only encode numeric digits plus a few special characters. In 1974, Dr. David C. Allais of Intermec developed Code 39, the first commercial alphanumeric bar code symbology.

During the 1970s, bar coding became increasingly practical and economical with the advent of low-cost electronics—microprocessors in particular—and the availability of smaller, lower cost lasers. Inventors in many companies devised their own bar code symbology and associated scanning equipment. This resulted in the proliferation of several dozen different bar code symbologies with no commonly accepted standards. Subsequent adoption patterns and standardization activities have sharply narrowed the field. In retail applications, the UPC/EAN symbol is pervasive. On the industrial side, Code 39 is clearly dominant, but Interleaved 2 of 5 and Codabar continue to enjoy reasonably broad usage. Several other symbologies are currently used in specific applications.

As bar code became technically and economically more viable during the 1970s, the UPC retail system provided stability and acted as a stimulant for industrial acceptance. This acceptance has given rise to standardization of bar code symbologies and specifications. Military Standard 1189 (Code 39) was adopted in January 1982. This was closely followed by ANSI Standard MH10.8M in 1983 covering Code 39, Interleaved 2 of 5, and Codabar. The UPC Shipping Container symbol (Interleaved 2 of 5) was adopted in 1984. The Automotive Industry Action Group in the same time frame standardized on Code 39 and developed a well-thought-out format for its shipping container label. In the same year the health industry established its HIBC standard (Code 39). Other industries including paper, aluminum, electronics, telecommunications, and furniture have developed their own standards using Code 39.

The early 1980s brought two attempts to reduce the amount of space required for a bar code symbol. Code 128 was introduced in 1981 and Code 93 in 1982. Using these symbologies allowed labels to be approximately 30 percent shorter than if Code 39 was used. Very few applications are currently using Code 93. Code 128 has seen modest adoption, and its use is now increasing in distribution applications

In late 1987, Dr. David C. Allais introduced Code 49, a nonconventional symbology that offers significant density advantages over more traditional bar code symbologies. One year after the announcement of Code 49, Ted Williams introduced a similar multirow symbology called Code 16K. In 1990, Symbol Technologies announced PDF417, a multirow symbology offering even higher density

As these various standards evolved, manufacturers and users saw the need for greater precision, technical refinement, and uniformity. Responding to this need, the Automatic Identification Manufacturers (AIM), a trade organization, chartered its Technical Symbology Committee to come up with a family of AIM Uniform Symbol Specifications (USS). These were developed and published for Code 39, Interleaved 2 of 5, Codabar, Code 93, Code 128, Code 49, and Code 16K.