BARCODE SCANNERS TECHNOLOGY GUIDE

Barcode Scanners

WHAT ARE BARCODE SCANNERS?

Barcode Scanners consist of a bright light source which illuminates the barcode symbol, a sensor which measures the light reflected from the symbol, and a decoder which translates the measurements into characters which can be used by a computer.

A SHORT HISTORY OF BARCODE SCANNERS

• Laser Scanners
• Barcode Wands
• Linear Imager Barcode Scanners
• 2D Barcode Scanners

Laser Scanners

The earliest barcode scanners used Helium-Neon lasers and the beam was scanned across the barcode by a system of moving mirrors. These scanners are known as Laser Scanners and were the first step towards the "Point and Shoot" barcode reading we all expect today.

The invention of Light Emitting Diodes (LED) provided a cheaper and smaller alternative to lasers.

Unfortunately the moving mirrors in early Laser Scanners were vulnerable to damage from rough handling and efforts were made to find mirrorless barcode scanners.

Barcode Wands

Hand-held Barcode Wands were introduced.

These devices are pen like with a light source and a photodiode in the tip.

The Wand is physically moved by hand across the barcode and signals from the photodiode are sent to a computer.

Barcode Wands have no moving parts and are well sealed against the environment.

They are still available and are relatively inexpensive.

Because the Barcode Wand tip has to be moved across the entire barcode entering from one side and leaving through the other side they are only really suitable for 1D barcodes with a fairly short symbol width and a 2cm line height.

Barcode Wands are reputed to be easy to use but in practice we found that the manual scanning method required considerable practice to use sucessfully.

Linear Imager Barcode Scanners

Next up were Linear Imager Barcode Scanners which are sometimes called CCD Scanners.

These scanners consist of a light source and hundreds of tiny photocells lined up in a row across the scanner mouth.

Signals from these photocells form a linear image of the barcode which is translated into data.

This approach is only suited to 1D barcodes but is able to provide enough resolution to read high density codes with line widths down to 3 mil.

When Linear Imagers first arrived they had a limited reading range of a few inches and a maximum code width of about 4" (12cm).

For a number of years Laser Scanners competed with Linear Imagers.

Laser Scanners were initially favoured because of increased reading range and the ability to read wider barcodes. There have been rapid developments in barcode scanners and now performance wise there would be little to choose between them.

These days there is preference for linear imagers because this technology avoids open laser beams.

However, the main drawback of both technologies is the limitation to 1D barcodes.

2D Barcode Scanners

With the introduction of 2D matrix barcodes and 2D Barcode Scanners, the world changed.

2D Barcode Scanners are effectively cameras which grab an image and decode the entire barcode symbol.

These scanners are known as Imagers and can read most 2D barcodes and also 1D barcodes in any orientation.

There is increasing interest in 2D barcodes and more 2D Barcode Scanners are becoming available.

WHAT ARE THE RECENT DEVELOPMENTS?

• Tougher Barcode Scanners
• Better Reliability
• More Versatility
• Improved Communications
• Extra Long Range
• Improved Anti-Microbial Cases
• Improved DPM Capabilities

Barcode Scanners are getting tougher

Some of the latest industrial Barcode Scanners have ratings of IP65 and IP67. This means that they are dust proof and can be immersed in water.

IP ratings appear to be improving generally for budget models and upwards.

Barcode Scanners are getting more reliable

Wireless Barcode Scanners are increasingly using inductive charging which removes reliability problems arising from damaged metal contacts.

Barcode Scanners are getting more versatile

Some hand-held imagers now have multiple scan engines with overlapping ranges which allows a single barcode scanner to be able to read printed barcodes closeup or at several metres.

Barcode Scanner communications are improving

More barcode scanners can now use Ethernet and some wireless models come with Bluetooth 5 and Wi-Fi 6.

Barcode Scanners with Extra Long Range have arrived

Some Barcode Scanners can read printed barcodes at distances of up to 24m (79').

This allows warehouse operators to audit pallets on the top level of warehouse racking without leaving the ground.

Barcode Scanners with improved anti-microbial cases are available

The recent pandemic emphasised the need for infection control.

Most Healthcare barcode scanners can be cleaned using mild agents like washing-up liquid.

Some barcode scanners can now be washed with strong bleach.

Barcode Scanners with Improved DPM capabilities are here

Some Barcode Scanners can decode barcodes directly marked on the surface of items by electrochemical etching, inkjet printing, laser engraving or percussive dot peening.

This application requires high resolution, the handling of very low contrast and lots of decoding power.

Previously some of these barcodes could be read with mid range imagers but dot peen was always a problem. Recent improvements include Adaptive Lighting, Liquid Lens Autofocus and Machine Learning.

Some Barcode Scanners can now read all DPM codes and even barcodes printed on paper.

WHAT BARCODE SCANNERS ARE AVAILABLE?

Today the actual part which does the barcode scanning is very compact.

These barcode engines are to be found in Handheld Barcode Scanners, Mobile Barcode Scanners, Mobile Computers and in Fixed Position Barcode scanners used in automation. They can also be integrated into equipment such as kiosks.

WHAT ARE THE FUTURE TRENDS?

2D barcodes are expected to become increasingly important.

Barcode Scanners are expected to become more powerful.

We are expecting to see increases in versatility such that "One Barcode Scanner does it all".

COPYRIGHT

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ERRATA

This guide is published E & OE for educational purposes and not as a Sales Document.

It is important to us that the contents are correct and easy to understand.

If you find information which is incorrect, or wish to make any suggestions, we will be pleased to receive your comments.

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