Tech Specs: Barcode Scanners

Contact Scanners

Contact scanners require direct contact with the label and barcode to be scanned. Often, these scanners are found at point-of-sale (POS) terminals, where it is relatively easy to touch the scanner to the barcode label. In a warehouse setting, where a worker may have to scan pallets off the floor or where contact is not possible or safe, contact scanners would be impractical.

Fixed-Position Scanners

Like contact scanners, fixed-position scanners are most often found at point-of-sale (POS) terminals. These are typically set on or into a counter, and items are picked up and passed in front of the scanner sensing window. These type of scanners might be impractical where items are larger than can be safely or practically picked up, or where items can't easily pass by the scanner on a conveyor system.

Handheld Scanners

These are by far the most common and cost-effective scanners for general use. They are especially useful for applications where the operator must move the scanner to read labels in unusual or non-standard positions, or where the scanning operation must be accomplished over a distance where contact with the label is not possible. They may be wireless, communicating with a linked computer by infrared or radiof frequency (RF) signals, or they may be attached by wires to the computer system. They can be used in libraries, retail stores, warehouses, etc., or on mobile delivery routes or at remote sites. These scanners can be manufactured as part of a data collection device, allowing operators to gather item data from scans which can then be processed in the device or later "dumped" via batch process to a main network computer for further processing.

Charge-Coupled Devices (CCD)

Most scanners use charge-coupled device (CCD) arrays, which consist of tightly packed rows of light receptors that can detect variations in light intensity and frequency. The scanner projects a light source onto the object to be scanned, and once the light has been received in the array, it is converted to a format the computer can use for further processing.