What is Bar Code?
Bar Code and how it is Read
Bar code is computerized information encoded in a pattern of black and white srtips. The black and white lines represent 1’s and 0’S and can be read by light. They carry encoded information- from the membership number of a sports club to the price and stock number of a packet of washing powder in a supermarket. The code is scanned by a beam of light.
When a beam of light is passed over the bar code only the white strips reflect back the light. This is picked up by a photo-detector which produces a pulse of electricity when it receives light. So the black and white Bar code is translated into on/off pulses of electricity.