A barcode scanner, also called a barcode reader, price scanner or point of sale scanner can be either hand-held or stationary. It is used to scan, capture and read information contained in a bar code. A barcode scanner consists of a scanner or reader, a decoder, which can be either built in or external, and a cable that connects the reader with a computer.
The barcode scanner is only capable of capturing and translating the barcode into numbers and/or letters, so the information must be transmitted to a computer with a corresponding software application that will subsequently translate the data into all the information contained within the barcode.
There are various ways in which a barcode scanner can be connected to a computer. One way is through a serial port, another is via a keyboard port, and another is via an interface device called a wedge. The way the barcode scanner works is by sending a beam of red light across the bar code and measuring the amount of light that is reflected back. For instance, the dark bars on a barcode reflect less light than the white spaces between them. An analog signal with varying voltage is generated from the illumination system, and the varying voltage represent the intensity (or lack thereof) from the reflection. The scanner then converts the light energy into electrical energy, or converts the analog into interpretable data, or a digital signal which the decoder then interprets, does the required math to confirm and validate that the barcode is, in fact, decipherable. If it is, it then converts it into ASCII text, formats the text and this data is forwarded to a computer which the scanner is attached to.
The five basic kinds of barcode readers are pen wands, slot scanners, Charge-Couple Device ( CCD ) scanners, image scanners, and laser scanners, and each works a little differently from the others.