By Cindy Zeiger
Lasers have long been the cornerstone of barcode scanning technology. But in recent years, camerabased scanners have become more cost competitive—especially for warehouse and distribution center applications. Logistics managers who optimized their current laser scanning solution may be wondering if switching to cameras could lower operating costs even further. While the answer may not be a simple “yes,” a look at comparative benefits of laser and camera scanners reveals the best opportunities for cost reductions.
First, consider one huge advantage cameras have over lasers—the ability to capture an image of the whole label or scanning area. The grayscale image data can be used for much more than decoding barcodes. In fact, troubleshooting no-reads is a common use of camera images. For many high-volume distribution centers, this can lead to significant savings.
For example, suppose a DC with a throughput of 100,000 packages per day has a no-read rate of 2%. That’s 2,000 packages. If each no-read takes a worker two minutes to handle at a rate of $20 an hour, that’s an annual cost of $170,000.
By viewing a snapshot, a manager can see the reason for the no-read and address the issue. The expense of manual processing decreases, while throughput increases a percentage point or more.
The same image data can be used for video encoding and optical character recognition, further automating the process of resolving no-reads and increasing throughput.
Next, cameras typically read barcodes that are damaged or under reflective surfaces (such as plastic shrink wrap) better than lasers. A camera provides the full 2D image of the barcode so it has full
spatial information. So, if only part of the barcode is damaged, or only a part has reflection, the camera can still decode the data. In essence, the camera can take advantage of the vertical redundancy of a 1D barcode.
Finally, all other things being equal, a line camera can read barcodes faster than any other type of barcode reader. This allows for higher belt speeds and closer item spacing—in other words, higher throughput. That doesn’t necessarily mean a camera is the best choice for every application.
So, where do lasers shine? Laser scanners can handle great depth of focus for a given barcode density. This allows scanners to handle wide ranges of pitch and skew with varying sizes of packages. For example, when a retailer packages clothing in flexible polybags, the labeled surface follows the contour of the articles inside. In a similar way, flexible tags on airport bags hang from
handles at all angles and can bend as they drape onto a conveyor.
One final comparison is the cost and ease of installation. Compared side by side, most laser systems are simpler and easier to install than camera systems. Generally, cameras take longer to set up. And, if the application calls for image capture, then it must be integrated with an image server. On the other hand, new-generation camera systems with integrated decoding and illumination can actually be installed faster and at a lower cost than lasers. Here, the choice really depends on the application.
A brief article like this can’t address every relevant issue. This is a condensed look at significant advantages of each technology. Selecting barcode scanning technology is not a matter or right or wrong. Rather, the choice depends on the best fit between the needs of the application and the scanner’s performance. With help from experienced solutions providers, managers can change good to better and better to best.
Cindy Zeiger is product manager at Telford, Pa.-based Accu-Sort Systems. Visit the company’s Web site at www.accusort.com.
