When you're talking about data collection, two technologies come to mind: bar code scanning and RFID (radio frequency identification). The former has been a staple in data collection for more than 30 years. The latter, RFID, has been around for decades. However, it wasn't until recently that the AIDC (automatic identification and data collection) industry took notice. RFID is similar to the concept of bar coding, but it uses different technology to collect data. To put it simply: Bar code technology uses labels that are attached to items, and readers to scan the labels. RFID uses RFID tags to transmit data and readers to collect data via radio frequencies.
Handheld bar code scanners can be separated into two main groups: laser and linear imagers. Continual advancements and improvements have given linear technology a competitive edge over laser in an evolving market. RFID offers advantages in data collection that bar code scanners cannot. However, the price associated with RFID has played a role in the technology's slow adoption in AIDC, but that doesn't mean its potential should be underestimated. In the exploration of data collection, looking at RFID technology is just as imperative as looking at laser and linear technology. Scan speed, read range, and environment all play a role in determining which technology is best suited for your needs.
Laser's Read Range Advantage
Let's start at the very beginning of handheld scanner history - the wand. "The wand scanner has the advantage of being incredibly basic in its applications, and it's simple to use," says Dan Bodnar, director of product marketing for data capture at Intermec Technologies (Everett, WA). A wand is the most inexpensive scanner, and it requires a person to make contact with the coded item and move it across the bar code. These types of scanners are slowly dying out because they have limited capabilities. "The wand was intended for environments where there is a minimal amount of product," says Tom Ruhlman, business unit manager for handheld scanning at HHP (Skaneateles Falls, NY).
Lasers are perhaps the most recognized scanner on the market, since they've been around for more than 20 years. They are often considered the easiest of the bar code scanners to use. A laser generates a single laser beam, usually through LEDs (light emitting diodes), that is reflected onto a moving mirror. The handheld scanner then measures the reflected light. Most known for extensive read range, lasers are widely used in warehouse applications. "Lasers are a much more mature technology compared to linear and are generally used to decode at a distance up to 30 feet away," says Dick Sorenson, director of product management at LXE (Norcross, GA). "Long read ranges make it possible to scan bar codes that are located in unreachable areas in a warehouse environment."
As linear imaging technology makes new advances, such as an 80-inch read range, it is being considered comparable to a laser scanner. "The laser has relative disadvantages, such as scan rates that are lower than an image scanner, and lasers do not have the capability to read a damaged bar code as accurately as linear image bar code scanners," says Bodnar. A laser scanner has the ability to scan 30 to 50 scans per second, while imaging scanners double those speeds at more than 100 scans per second.
Image Scanner Technology Moves Forward
Image scanners are based on technology called CCD (charge coupled device). Typically, CCD scanners cost two to four times less than lasers. Two types of CCD technology are available: linear CCD and CCD imaging technology, also known as area imaging. CCD devices contain no moving parts, making them more durable than the laser that uses a moving mirror. Linear technology is limited to reading one-dimensional (1-D) bar codes. This type of handheld scanner is suited for retail, where there is no need for area imaging.
"In a retail environment, you're dealing with linear bar codes and you're conducting small- to medium-sized processes such as 5- to 10-item transactions. The time spent using a scanner is minimal, so there is no need for advanced features such as two-dimensional [2-D] imaging," says Wynn Polin, VP of marketing for Tolt Technologies (Gig Harbor, WA). For instance, when you think of the POS (point of sale) process, imagine all of the steps. Polin explains, "The actual scanning process is a small percentage of the overall function of a sales associate. You have tendering, staging, and bagging. The time spent using an input device is relatively small."
Area imagers have the ability to capture multiple 2-D bar code formats, signatures, and pictures. "An area image scanner takes a picture of a 2-D area and decodes what it sees," says Sorenson. The technology behind this type of scanner is similar to that of a digital camera. Sorenson says, "Now you can read more sophisticated bar code schemes. For instance, some shipping labels now have encoding that goes in both directions. The emerging use of area imagers is to read those bar codes." Ruhlman points to how this technology could improve efficiency. "Trucking companies have manifests with all of the information encoded in a bar code," he says. "Before 2-D technology, they would take a picture of the backs of their trucks with a camera to make sure everything was packed correctly. Then they would page scan the photo and link it to the manifest. With a CCD scanner, you can take a picture of the truck's cargo and capture information from the manifest using one device." Area 2-D scanners also could be used for signature capture purposes and receipt verification.
RFID Vs. Bar Code Scanners
RFID technology also has impacted the handheld scanner market. RFID scanners use radio waves to decode information embedded into RFID tags, known as transponders. "RFID technology doesn't use line-of-sight scanning because the radio waves are able to travel through matter," Bodnar explains. "A bar code scanner has to read a bar code by physically aligning with the code." For instance, if a store has RFID tags on products on a shelf, inventory can be calculated without having to scan a bar code or move a single item. That's because the RFID tag is sending the data back to the handheld reader. RFID tags hold much more information than a UPC (universal product code).
RFID technology can also reduce labor because there is no need for physical scanning. RFID tracking systems are already making a name for themselves in warehousing applications, and the retail vertical has recently expressed interest. Because of the cost to implement RFID technology, approximately 50 cents per tag (bar code labels cost less than 1 cent per label), it has not become a common application in retail, just yet.
As AIDC technology continues to evolve, the rivalry between lasers and linear imaging may see new competition from RFID technology. However, laser and linear will be worthy competitors. Factors such as read range, scan speed, and the environment in which it's being used will continue to be critical when asking the question: Which is better?