bar code

bar code

Commerce a machine-readable arrangement of numbers and parallel lines of different widths printed on a package, which can be electronically scanned at a checkout to register the price of the goods and to activate computer stock-checking and reordering

bar code

[′bär ‚kōd]

(computer science)

The representation of alphanumeric characters by series of adjacent stripes of various widths, for example, the universal product code.

bar code

(convention)

A printed horizontal strip of vertical bars of varying widths, groups of which represent decimal digits and are used for identifying commercial products or parts. Bar codes are read by a bar code reader and the code interpreted either through software or a hardware decoder.

All products sold in open trade are numbered and bar-coded to a worldwide standard, which was introduced in the US in 1973 and to the rest of the world in 1977. The Uniform Code Council in the US, along with the international article numbering authority, EAN International, allocate blocks of unique 12 or 13-digit numbers to member companies through a national numbering authority. In Britain this is the Article Number Association. Most companies are allocated 100,000 numbers that they can use to identify any of their products, services or locations.

Each code typically contains a leading "quiet" zone, start character, data character, optional check digit, stop character and a trailing quiet zone. The check digit is used to verify that the number has been scanned correctly. The quiet zone could be white, red or yellow if viewed by a red scanner. Bar code readers usually use visible red light with a wavelength between 632.8 and 680 nanometres.

barcode

The printed code used for recognition by a barcode scanner (barcode reader). The "bar" in barcode comes from the ubiquitous, one-dimensional (1D) UPC barcode found on countless product packages. Several two-dimensional (2D) barcodes are also in wide use, but they are not as bar-like as the UPC. The 2D codes are scanned horizontally and vertically and hold considerably more data. All the 2D examples below contain the same data: the URL for www.computerlanguage.com. See barcode scanner, mobile tagging, point of sale and AIM. Contrast with RFID.

1D Barcode

One-dimensional (1D) UPC barcodes are used on millions of consumer items as well as shipping containers. For details, see UPC.

2D QR Code

Widely used to mark products as well as identify establishments, QR codes are recognizable by their four squares with dots in the middle. For details, see QR code.

2D PDF417

Symbol Technologies' PDF417 is a general-purpose barcode that is recognizable by patterns of vertical lines on each side. For details, see PDF417.

2D DataMatrix

The DataMatrix code is used to mark small parts and holds up to 2,355 alphanumeric and 3,116 numeric characters. It is recognizable by its border with two solid lines and two alternating lines.

2D MaxiCode

The MaxiCode uses hexagonal symbols and is recognizable by its center bull's eye. Used for high-speed sorting, it holds up to 93 alphanumeric and 138 numeric characters. For more data, MaxiCodes can be chained together. (Image courtesy of AIM, Warrendale, PA, www.aimglobal.org)

2D BeeTagg

Designed for mobile tagging, this system from Switzerland accepts company logos. Recognizable by its honeycomb-like cells, BeeTaggs are also used for exchanging business card data. For more information, visit www.beetagg.com. See mobile tagging.

2D Microsoft Tag

Also developed for mobile tagging, Microsoft's system uses color. Another form of the tag allows a company logo to occupy the background. For details, see Microsoft Tag.