What are barcode scanners?
Barcode scanners are most commonly seen as the hand held devices that look like futuristic space weapons. They optically read the familiar upc bar codes found on most items sold these days. There are variations on the classical “space gun” looking barcode scanner, including the built-in plate glass scanners common to supermarkets (known as flatbed scanners), and the hand held devices with built in scanners used by delivery people (UPS, FedEx, etc.) for multiple purposes (communication, route tracking and inventory).
Scanners employ various technologies, but all are light based and depend upon a light source like a laser and typically reflection from the source, which is interpreted by a photodiode. A more advanced technology, known as charge coupled device (CCD) relies on electrical signals emitted from the reflected source. These scanners are typically referred to as LED scanners. Finally, there is a technology called 2D image scanners which is based on the CCD technology, but use an actual camera to capture the bar code and process it, rather than just a light source.
Most POS systems will rely on a hand-held scanner. These come in models referred to as straight line or omni directional. Omni directional can read from different angles. Most scanners today support USB connections as well as serial port (RS232), and keyboard wedge (PS2 Y connector). There are also wireless scanners, commonly used for scanning store inventory, or where wires are a problem. Scanners go up in price as their speed, resolution and reliability increases.