Practically every item purchased from a grocery store, department store, and mass merchandiser has a barcode on it. This greatly helps in keeping track of the large number of items in a store and also reduces instances of shoplifting (since shoplifters could no longer easily switch price tags from a lower-cost item to a higher-priced one). Since the adoption of barcodes, both consumers and retailers have profited from the savings generated.

Rental car companies keep track of their cars by means of barcodes on the car bumper.

Airlines track passenger luggage with barcodes, reducing the chance of loss.

Recently, researchers have placed tiny barcodes on individual bees to track the insects` mating habits.

NASA relies on barcodes to monitor the thousands of heat tiles that need to be replaced after every space shuttle trip.

The movement of nuclear waste can be tracked easily with a bar-code inventory system.

More recently, barcodes have even started appearing on humans. Fashion designers stamp barcodes on their models to help coordinate fashion shows. The codes store information about what outfits each model should be wearing and when they are due on the runway.

In the late 1990s in Tokyo, there was a fad for temporary barcode shaped tattoos among high school girls.

http://en.wikipedia.org/wiki/Barcode

Technology and Engineering

laser scanners : typical scanners utilise a 650nm laser diode, leveraging on the economies of scale of diodes manufactured for CD/DVD drives. The diode is normally housed in a metal casing for heat dissipation. The laser light emitted is focused through a lens and reflected off a rotating polygonal mirror, or an oscillating mirror. This produces a line or raster pattern which may be aimed at a barcode. The light reflected off the barcode is captured onto a photodiode whereby the current is amplified and interpreted by the decoding circuit. The signal obtained is the modulation of the laser spot (whose profile approximates that of a Gaussian beam), over the alternating black and white lines of the barcode. The performance of the scanner is a function of:

the signal to noise ratio (determined by the laser power, the size of the laser spot, reflectivity/transmittivity of the optical parts, receiving light collection area, distance to the barcode, the level of optical noise such as sunlight, fluorescent light as well as the ability to filter out that noise, etc). The laser power is usually limited by CDRH Class I/II safety requirements.

the scan speed of the device. Basically a trade-off between decode speed and the size of the decode zone.

the barcode (determined by difference in refectance of the barcode`s alternating black & white stripes--print contrast ratio, defects, the size of the barcode, and the barcode`s orientation in relation to the scanner). Generally, the laser has to pass a certain amount of the `quiet zone` on the barcode before it hits the line patterns, in order to decode.

the decoding circuit`s ability to decode and to handle errors in the barcode, optical noise as well as the range of frequencies at which the signal is modulated.

http://en.wikipedia.org/wiki/Barcode_reader#Technology_and_Engineering

Barcode Reader Manufacturers

Metrologic Instruments

Hand Held Products

Intermec

NCR

Symbol Technologies

PSC

http://en.wikipedia.org/wiki/Barcode_reader#Barcode_Reader_Manufacturers

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