Bar Code Reader

 Bar Code Reader:

When information are encoded in form of parallel lines of varying thickness and spaces between them, they are called as bar codes. These codes are being used for unique identification of different types of goods in retail stores, books, postal packages, tags, etc.

          Bar codes are printed by machines (printers), which follow instructions specified by a computer program based upon certain standards and desired data to be encoded. They are used to label cartoons before shipment, or to label retail items in department stores. There is a host of bar code standards, currently in use. Prominent among them are, Plessey, UPC, Codebar, Code25, Code128A, EAN, Telepen, etc. Out of these standards UPC(Universal Product Code) is widely used. These bar code patterns are decoded as 10 digits-the first five digits identify the manufacturer/supplier of the product and the next five digits identify the specific product. Up These printers employ one of two different printing technologies: Direct Thermal Printing and Thermal Transfer Printing. Direct thermal printers use a printhead to generate heat that causes a chemical reaction in specially designed paper that turns the paper black. Thermal transfer printers also use heat, which melts a waxy substance on a ribbon that runs over the label or tag material. The heat transfers ink from the ribbon to the paper. Direct thermal printers are generally less expensive, but they produce labels that can become illegible if exposed to heat, direct sunlight, or chemical vapors.

          A barcode reader (or barcode scanner) is a computer peripheral for reading barcodes printed on various surfaces. Like a flatbed scanner, it consists of a light source(a laser beam), a lens and a photo conductor translating optical impulses into electrical ones. Infact a laser beam after stiking a pattern of bars reflect in a particular pattern which is sensed by the photo conductor. The elctrical pulse so generated goes to a decoder circuitry which analyzes the barcode's image data and sends the barcode's content to the scanner's output port.

Uses of Bar-Code:

• Practically every item purchased from a grocery store, department store, and mass merchandiser has a barcode 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. on

• Fast-selling items can be identified quickly and automatically reordered to meet consumer demand.

• Slow-selling items can be identified, preventing a build-up of unwanted stock. ing a build-up of

• The effects of repositioning a given product within a store can be monitored, allowing fast-moving and more profitable items to occupy the best space. 

• Historical data can be used to predict seasonal fluctuations very accurately.

• Items may be repriced on the shelf to reflect both sale prices and price increases.

• Document Management tools often allow for barcoded sheets to facilitate the separation and indexing of documents.

• The tracking of item movement, including rental cars, airline luggage, nuclear waste, mail and parcels are done efficiently.

• Many tickets now have barcodes that will need validated before allowing the holder to enter sports arenas, cinemas, theatres, fairgrounds, transportation etc.