Unformatted text preview: rly used for unique
identification of all types of goods, books, postal packages, badges, tags, etc.
A bar-code reader is a device used for reading (decoding) bar-coded data. It may be a
hand-held scanner, or may be embedded in a stationary scanner. It scans a bar-code
image and converts it into an alphanumeric value, which is then fed to the computer to
which the bar-code reader is connected, just as though the alphanumeric value had been
typed on a keyboard.
A bar-code reader uses a laser-beam scanning technology. The laser beam is stroked
across the pattern of bars of a bar code. Different bar codes having different patterns of
bars reflect the beam in different ways, which is sensed by a light-sensitive detector.
Reflected light patterns are converted into electrical pulses and then transmitted to
recognition logic circuits which convert it into an alphanumeric value.
Just as there are a variety of internal bit encoding systems, there are a variety of barcoding systems. The most widely known bar-coding system is the Universal Product
Code (UPC), which now appears on almost all retail packages in USA. The UPC,
originally used for supermarket items, is now being printed on other consumer goods
also. The UPC bar-code patterns are decoded as 10 digits. The first 5 of these digits
identify the manufacturer or supplier of the product and the next 5 digits identify a
specific product of the manufacturer (see Figure 9.13).
Bar code readers are commonly found in supermarkets and department stores. When a
customer picks up a product for purchasing and/brings it to the cash counter for payment,
the sales person at the counter uses a bar code reader to scan the bar code printed on the
product. The bar-code reader converts the bar code into an alphanumeric value and feeds
it to the computer that looks up the price of the product, possibly updates inventory and
sales records, and uses the price and description information to prepare a purchase bill for
the customer. Postal delivery services also...
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This document was uploaded on 04/07/2014.
- Spring '14