Input Devices : Barcodes

Barcodes are often printed on products that you can buy and are used by shops and supermarkets to produce bills for customers. A barcode is made up of a sequence of bars of different widths. Different groups of bars are used to represent different numbers. A printed barcode is therefore simply a way of representing a number. The number is often printed above or below the barcode so that humans can read it.

Barcodes are read into the computer using a wand or a fixed scanner. Barcodes are not easily damaged and can normally still be read if they are creased or not stuck onto a flat surface. They can be printed using a normal printer and ink and so are cheap to produce. The information normally included on a barcode for a product is country of origin, manufacturer and item code. The price is not included in the barcode.

A scanner can read a barcode number incorrectly. A check digit is included in the barcode number to reduce the likelihood of this happening.

GCSE ICT Companion 04 - (C) P Meakin 2004