A while back I wrote a blog post about barcode scanner types, and would like to follow up with some additional info.

Imagers vs. Lasers

For those of you who don’t know, there are two types of barcode scanners: imagers and lasers.

• Lasers work by shooting a laser on the barcode and sensing the reflection that comes back.  These have been around forever and work really well for 1 dimensional, standard barcode labels.
• Imagers work like a camera by basically taking a picture of the barcode and interpreting what is in the picture with software.  These are new and have the benefit of working with 2 dimensional tags like the ones you see on UPS boxes.

I took some heat from people responding to my blog when I said I don’t like imagers.  Well, I still don’t.

Headaches with Imagers

The problem we are seeing is that imagers don’t work well with long 1 dimensional barcodes.  The serial number barcodes on Dell monitors, for example, cannot be read using an imager.  At least not the ones on the Symbol devices we typically sell, even the high-end MC9090G which are about $3K a piece minimum.

This is causing a big problem for some of our customers who use primarily 1 dimensional barcodes.  You get the flexibility of supporting 2D barcodes with imagers, but if you don’t use 2D barcodes, this is of little value.  In exchange for 2D support, you have less performance with 1D barcodes and often can’t even scan the 1D barcodes in your environment.

Frustrating.

Your Priorities Should Guide your Decision

If you have high volume scanning needs and use 1D barcodes, you need a scanner that will read these tags very quickly.  If you have to press the scan trigger and move the device around for five seconds to get the device to read your tag, you will quickly become frustrated and tired after a few scans.  And if you’re performing inventory in a warehouse or receiving dock, this will be very frustrating.  In this scenario, I recommend a laser scanner.

If you require support for 2D barcodes, you have to use imagers.  Laser won’t work with 2D barcodes.  In this case, I would demand an evaluation unit from your hardware vendor before you invest a lot of money.  Test the scanner and make sure it works for your needs before spending a ton of money on hardware.

When selecting mobile devices for barcode scanning applications, take care to select the correct scanner hardware. Most devices come in multiple scanner configurations, and there are a few things to consider when choosing what type of scanner to purchase.

Scanner Types

Lasers

The traditional barcode scanner type is a laser that scans the barcode label and reflects back to the device. For one dimensional standard barcodes, lasers are my favorite. The upside is they scan at a longer distance and it is easier to target a specific barcode when a bunch of barcodes are stuck together in close proximity. The downside is they don’t support two-dimensional barcodes and cannot read damaged tags.

Imagers

The newer devices are shipping with what are called “Imagers.” These are basically cameras that take a picture of the barcode and analyze the image to “scan” the barcode. The benefit of Imagers is they support one and two dimensional barcodes so they are more flexible. Two dimensional barcodes can store more information in a smaller space. They can also be used to store multiple values within a single scan. Lastly, imagers are able to read somewhat damaged tags using fuzzy logic. This can be handy in certain environments. The downside is the scanning distance is shorter, and it often takes longer for the scanner to read the barcode. It is also difficult to isolate a single barcode when there are many close together. This can be extremely annoying in high-volume environments. You can see examples of two dimensional barcodes on UPS of Fedex packages. They look like boxes with little dots all over.

Positron Imagers

Cheap devices ship with what are called Positron imagers. These are basically one dimensional barcode readers that are imager-based. They are horrible. They don’t scan tags well at all and I highly recommend that you never purchase a device with a Positron imager, unless you are looking for a headache and an expensive paperweight.

Recommendations

If you are using high-quality one dimensional tags only, I recommend going with a laser-based scanner. You will be happier with the performance after scanning a lot of tags.

If you need to support 2D tags, then buy a high-quality Imager-based scanner. Just be certain you are not purchasing a 1D imager like a Positron. Most Motorola mobile devices ships with both configurations of Imagers. Be sure to get the 1D/2D imager version.