Barcode Scanners

Barcode scanners are devices which use some sort of light-emitting device and a photo conductor to read barcodes. They are usually designed to attach to a computer, via either PS2 or some other interface, though they may also be used on their own and store the data for future retrieval by a computer.

Barcode scanners typically utilize a laser scanner, though LED and imaging varieties also exist. Light is shot out of the barcode scanner onto the barcode, then reflected back, picked up by a photodiode in the scanner and decoded. The decoded information is then transmitted to the computer that the scanner is hooked up to.

Barcode scanners may be completely handheld, in which case they usually look almost like a science-fiction era gun, with a laser emitting from the barrel, and a trigger to turn the light on or off. These are found in some stores, and consumer-level barcode scanners are most often of this variety. Barcode scanners may also be built into a surface such as a register counter, so that barcodes can be read by swiping them across the laser. These types of barcode scanners are most typically found in supermarkets because of their ease of use and speed.

Smaller barcode scanners, often shaped like small pens, are also in use. This variety is often found in video stores or book stores. Their smaller, usually lower-quality light source does not allow for the same consistency of reading as larger scanners, but is often adequate for simple uses.