Since its invention in
early 1950s, bar code technology has accelerated the flow of
products and information within a business and between businesses.
As a result of improvements in data accuracy that accompanies the
adoption of bar code technology over conventional keyboard data
entry, bar code systems have become critical elements in conducting
business in today’s national and global economies. Bar code
technology comprises of the following components:
- Symbologies that encode data that can be optically read by bar
- Printing technologies that produce machine-readable symbols
- Scanners and decoders that capture visual images of the
symbologies and convert them to computer-compatible digital
data, and the verifiers that validate symbol quality.
There are many different bar code symbologies, or languages. Each
symbology has its own rules for character (e.g. letter, number,
punctuation) encoding, printing and decoding requirements, error
checking, and other features.
The various bar code symbologies differ both in the way they
represent data and in the type of data they can encode: some only
encode numbers; others encode numbers, letters, and a few
punctuation characters; still others offer encoding of the
128-character, and even 256-character, ASCII sets. The newest
symbologies include options to encode multiple languages within the
same symbol; allow user-defined encoding of special or additional
data; and can even allow (through deliberate redundancies)
reconstruction of data if the symbol is damaged.
While there were over 200 bar code symbologies, only a handful of
these are in current use and fewer still are widely used.
This refers to use of some form of electronically encoded
material that can be used for storing and accessing information
relating to a specific asset. Typically we think of our credit card
or bank card but there are other sizes and materials used for
different AIDC applications. The card can be made of plastic
(polyester, PVC, or some other material) or paper, or even some
amalgamation of materials. The essential point is that the card
includes some form of AIDC (automatic identification and data
There are currently three main technologies within card
technologies. These are
- Magnetic stripe
- Smart cards, and
- Optical cards.
Often the card will have printing on it which may involve
technologies such as Dye Diffusion Thermal Transfer (D2T2) direct to
With the advent of newer and more secure technologies, some
technology forecasters predicted the demise of magnetic stripe card.
However, given the low cost and immense investment in the current
infrastructure, magnetic stripe is not expected to disappear any
time soon. Today, card-based AIDC technologies are being used in
cellular phones, transit ticket machines, ATMs, amusement machines,
vending machines, and kiosks.
Acknowledgement: Some of the
information on AIDC pages is based on the information in AIMGlobal's
website. We would like to thank AIMGlobal for this.