An Imager is a Barcode Scanner that really functions more like a digital camera than a laser scanner, and is capable of reading two-dimensional symbologies. Rather than bouncing one or several beams of intense light off of a barcode, the imager bounces a burst of light off of the barcode and back into a camera-like eye, essentially taking a picture.
Unlike a laser scanner (or human eye), the imager does not need the barcode to be oriented in anyway (other than within the scan area) in order to be legible. In fact, it doesn’t need it to be a “bar”-code at all. Two-dimensional symbologies come in a variety of styles, some resembling a chessboard or the familiar UPS code (a target with snow around it). Of course, all imagers can still read the one-dimensional codes, but usually without the greater range capability of a laser scanner. Because of their camera-like “eyes”, some imagers are designed to be capable of capturing photos, like a camera cell phone. This is a great idea for those who want a handgun scanner for barcodes with the ability to store images of, say, a signature or I.D.
This sort of scanner is actually based on the same technology as CCD scanners, but is the term generally used to refer to scanners with range comparable to Laser barcode scanners. Commonly people see these scanners as inferior to Lasers, but that’s not necessarily the case. In fact Linear Imager barcode scanners are usually able to scan smaller barcodes than Lasers, and are often considered more rugged because they have no moving parts, (Lasers almost always have moving parts inside that can misalign or break). A notable drawback to Linear Imager scanners is that they usually can’t scan in direct sunlight.