Magazine Article | January 1, 2001

Handheld Bar Code Scanners: More Than Meets The Eye

Source: Field Technologies Magazine

Most handheld bar code scanners have a similar look on the outside. But, knowing what lies beneath can make for a much wiser investment.

Integrated Solutions, January 2001

They've become an integral part of our everyday lives. We see them at our grocery stores and shopping centers; major shipping, transportation, distribution, and healthcare companies use them. Many industry experts even predict that they will make their way into our homes in the not-so-distant future. What we're talking about are handheld bar code scanners. These ergonomically-designed Star Trek-looking devices have been around since the early '70s, but much like the famous cigarette slogan, "[They've] come a long way, baby." Getting a better understanding of this evolving technology can help determine which device(s) will be the best fit for your enterprise.

Handheld Scanners: Origin Of The Species
"Prior to the invention of bar code scanners, retailers were required to manually price merchandise on a regular basis," recalls Garrett Russell, POS product manager of Metrologic. "It was very tedious and many mistakes were made. Bar code readers came about sometime in the 1970s as a solution to these problems. With bar code scanners, if changes to prices need to be made, the user only needs to change one field of a database. All the affected product prices are updated automatically." At first, items with bar codes were swiped across a stationary scanner device. But it didn't take long for scanner companies to figure out that being able to move the scanner to the product was sometimes more convenient and practical.

Lasers, Lights, And Missing Links
"Bar code scanners use the light of either a VLD (visible laser diode) or LED (light emitting diode) to read the bar and space patterns of a common bar code label," says Larry Ru, product marketing manager of Unitech. "The bar code scanner captures the VLD or LED reflections from the bar code and converts these patterns into alpha-numeric characters. This enables it to interface with a computer which can match the alpha-numeric characters to a specific field in a database."

According to Hand Held Products' director of marketing, John Dreibelbis, there are primarily six types of scanners.

"The first kind is the laser scanner, which incorporates a miniaturized oscillating engine that projects a low-energy light beam [VLD or LED] onto the dark and light pattern of a bar code," says Dreibelbis. "It relies on an external or integrated processor to decode the bar code patterns."

The second kind of handheld bar code scanner is the CCD (charge-coupled device). This device projects a beam of light, much like the laser scanner, but it has no moving parts (i.e. no oscillating engine like the laser scanner). The downside of the CCD is that it can only read bar codes from no more than a few inches away.

The third kind of handheld bar code scanner is a CCD with fixed focus optics, also known as a linear imager. This device works similar to the CCD, but comes with the added feature of being able to read objects from greater distances (up to 14") than a normal CCD. It's like putting corrective lenses on a near-sighted person. The CCD with fixed focus optics is a solid-state device that tends to be very rugged, reads much faster than laser scanners, and can read poor quality printed codes faster than laser scanners.

The fourth kind of handheld bar code scanner is the PDT (portable data terminal). PDTs can collect data in "batch," or they can transmit data two ways via RF (radio frequency). PDTs incorporate a laser scanner or an imager to read linear or 2D bar code symbols. PDTs are used in mobile applications such as distribution, transportation, and healthcare.

The fifth kind of handheld bar code scanner is the area imager. These devices use CMOS (complementary metal oxide semiconductor) digital cameras with an integrated decoder to take a picture and decode it. These scanners not only read bar codes, but they also have OCR (optical character recognition) capability and can capture digital images.

"Area image scanners are competing with laser-based scanners," says Tom Brady, VP of AIDC (automatic identification and data capture) at UCC (Universal Code Council), "which is good for the consumer. Area imagers are useful for applications that require greater traceability. The downside to these types of scanners is that they are slower than laser scanners. Also, they are more expensive than a laser with similar bar code reading functionality," notes Brady.

"The sixth kind of handheld bar code scanner is the wand, or contact scanner," says Dreibelbis. "The wand is a pen-like device that is brushed across a bar code, reading it electro-optically and sending data to a computer. These devices are typically the least expensive of the six devices, but often have a low 'first read rate', and are limited in their application," says Dreibelbis. "For instance, you would never use a wand scanner in a warehouse setting where the user needs to be able to scan a pallet 20 feet up on a shelf."

Survival Of The Fittest Scanner
Each scanner has its strengths and weaknesses, which are magnified or diminished depending on where the device is applied. For example, a pharmacy may be a perfect fit for a pen scanner (i.e. wand scanner), whereas a retail store would probably benefit more from a laser scanner, CCD, or CCD with fixed focus optics. And for transportation, logistics, and manufacturing applications an area imager built into a PDT, which provides a higher degree of traceability and mobility, would likely be the best choice. But, even after users decide which type of scanner would be the best fit for the enterprise, they need to consider which brand is best for them. "When selecting a handheld bar code scanner, you must first be sure the scanner reads all necessary bar codes," Dreibelbis warns. There are more than 16 widely used bar code symbologies in existence today. These symbologies, like the scanners themselves, favor specific markets. And not all brands of a particular scanner will read all the bar code symbologies that a company might need. "Additionally, the device must be able to withstand the working environment," says Dreibelbis. "Some brands are better suited for temperature variations, dusty environments, and moisture. The scanner of choice must also provide an adequate operating range."

In the future, handheld bar code scanners will likely take on a whole new role for consumers in the home. Imagine going online to your grocery store and using your handheld bar code scanner to order more groceries. Or, better yet, imagine your refrigerator detecting that you are out of groceries via RFID (radio frequency identification) technology and ordering more groceries for you. When that happens we'll really be able to say, "You've come a long way, baby."

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