Image-based code readers stand poised to replace laser
scanners in a wide range of industries including food, beverage, consumer
goods, pharmaceutical and automotive, but when considering a transition from
laser scanners to image-based barcode readers, many think that the is cost too
high. Today's most advanced image-based readers have overcome the technical and
economic hurdles and now offer a more attractive alternative to industrial
laser scanners on the factory floor.
Thanks to advances in microprocessors, imaging sensors and
decoding algorithms, image-based ID readers have become not only more
affordable, but also more powerful. The logistics barcode-scanning market
breaks down into three segments. At the entry level, a mix of conventional
area-array imagers and laser scanners read codes on slow moving or stationary
objects. At the high end of the scale, fixed line scan image, based systems
handle high-speed, multi-sided barcode tunnel applications. Situated between
these two extremes, is an entire range of applications that currently rely on
an increasingly challenged generation of laser-based scanners.
Today’s most advanced image-based ID readers have overcome
the technical and economic hurdles and now offer a more attractive alternative
to industrial laser scanners on the factory floor. A laser scanner reads a
barcode by measuring the size of the printed modules using light reflected from
the code. One of the method's advantage is its simplicity as it is easy to set
up, connect, aim and can read codes fast enough to accommodate high speeds.
An unread code requires diverting the package to a manual
station where an operator directs the package to its destination or replaces
the defective barcode and resends package back through the sorting system. This
failed condition increases the labor material costs and reduces the efficiency
of sorting equipment because packages are handled more than once.
To cope with these limitations, the logistics industry has
designed special labels that maximize read rates and equipment specifically
optimized to handle high numbers of reads.
Image-based readers have several significant advantages to
traditional laser scanner technology, such as:
- An image-based reader can find and locate a barcode regardless of its orientation. This can also provide a major advantage for set up, record keeping, and diagnostic purposes.
- Imagers can use advanced software, to read 1D barcodes with significantly less contrast, which is critical for poorly printed codes or for 1D barcodes not printed on a standard white label, for instance on a corrugated box for an example.
- Imagers provide the ability to overcome the issues presented by damage or reflections in the code since the imager software can use just portions of the code to ‘reconstruct’ the data.
- The ability to use the entire 1D barcode for reading instead of just a single laser line enables image-based readers to read a code despite low resolution, voids in portions of the code, distortion, and other defects.
- Another advantage from a reliability perspective is that image-based readers have no moving parts.
- An image-based system can display the scanner image on a monitor or industrial display in real time.
- As the user sets the system up, the display shows exactly what the scanner sees, ensuring that the images will be in-focus and that the image will include all codes on any package that comes down the conveyor.
- Area array image-based readers also offer better uptime because laser scanners use motors and other mechanical mechanisms to `move' the laser spot across the code.
The logistics industry is also into the introduction of
two-dimensional (2D) codes like Data Matrix. The amount of information that 2D
codes can store makes them very attractive for a wide range of applications and
image-based scanners are required to read these symbologies. As large retailers
and internet fulfillment centers, consider capital equipment purchases to add
capacity or increase throughput, raising barcode read rates by just one per
cent could significantly shorten payback schedules and increase ROI.
