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What is a Barcode ?
Barcodes are a combination of dark and light lines of
variable widths.
The dark lines are most commonly termed as bars and the light bands as
spaces. The elements ( bars and spaces ) of these barcodes must
be consistent and proportional thickness and thinness.
What this means is that if the widest elements of the barcode can
be as thick as a pencil or a credit card but the thinness of the
thin elements has to be in proportion to the thick elements.
Barcodes are the easiest and the cheapest way of automatic data collection. i.e. Instead of an operator reading and punching the product codes by a keyboard at a retail counter, reading a barcode reads the data as well as enters the data into the host system. Thus making operations faster and efficient by reducing human errors. A Bar Code cannot be read by a human eye. Therefore it is advisable to print the data encoded in a barcode close to the barcode genrally known as human readables. So the operator can read the data and enter it manually just in case the scanner stops functioning. How do scanners scan, read and decode barcodes ? Barcodes are read by barcode readers also known as barcode scanners or imagers. These devices decode the data encoded in a barcode symbol on the principle of reflectance and absorption of light. A light of a certain wavelength is beamed across a barcode symbol. The dark elements absorb the light and the light element reflect the light. This is measured by a photoreceptor, tuned to look for light of the given wavelength which creates an electrical wave which is then sent to a electronic chip within the scanner called as the decoder. The decoder decodes and sends signals to the host (computer) which is the data. Imagers take a picture of the bar code symbol, analyse it, and create a conditioned electronic signal and decodes it. 1D Linear One Dimensional Barcode Symbologies 2D Two Dimensional Barcode Symbologies |
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