Barcode

What is a bar code?

A bar code is a data carrier, made of an optical pattern. This pattern contains data which can be read by a machine.

The reading equipment (a scanner or a camera system) measures the light which is reflected by the black bars and the white spaces and interprets the content of the bar code. Most bar codes are made of a series of parallel bars and spaces in various widths.

History of the bar code
As early as 1949 the first patent for a bar code was granted in the USA. In Switzerland, Zellweger in Uster started a project in conjunction with the retail chain Migros in the early seventies. However, the semi-circled product code was not successful. Walmart in the USA put pressure on their suppliers and in 1973 the UPC-code, developed by IBM, was introduced. Europe followed in 1976 with the EAN-code.

In the middle of the eighties, a considerable part of the consumer goods in Switzerland was already marked with an EAN-code, while there were still few cash registers with scanners. The break-through of the scanning came when the other processes along the supply chain started to benefit from the advantages of the EAN-system as well.

Besides the consumer goods bar codes EAN and UPC other bar codes were developed, some of them for very specific purposes or branches. Codabar was for many years the standard bar code for blood donations, and Code 39 established itself in libraries and industrial applications, notably in the automotive industry.

As time went on, the demands on automatic data capturing were growing and new symbologies were invented or existing bar codes were further developed. Code 128 can show the full ASCII character set and two-dimensional codes have a high densitiy of information plus an error correction.

The continuous success of the bar code is based on three characteristics: simplicity, reliability and an excellent cost/benefit ratio. A bar code is easy to produce, whether it is printed, laser engraved or woven. The reading is simple too, any off-the-shelf scanner can read the standard bar codes. The high level of security in capturing data by means of a bar code makes this system one of the most reliable methods of all. Countless logistic, medical and production applications rely totally on bar code technology because it is faster and safer than any data entry by hand. This security combined with the simplicity of use account for a favorable cost/benefit ratio. While other technologies might fail in a harsh, industrial environment, bar codes can be used even under extreme conditions.