Reading the Future…

The age-old practice of putting data on individual items for sale or inventory depends on two interlinked processes:  Firstly, marking the data either directly onto the object, or onto a label or pack with a bar code, letters or numbers, diagram or a price; secondly, the reading or vision process, whether by human eye, a laser scanner or optical cameras to ensure the data has been placed correctly and is legible.

It may sound like stating the obvious – but we need to start with a basic principle: Effective marking and effective reading are both needed to make the data coding process reliable. Although we can seldom achieve 100% reliability in anything, better than 99% can often be reached at modern production speeds, thanks to rapid developments in both laser-based code reading and camera vision and software. Users can make the most appropriate choices with the correct advice to match budget and data needs.

Start with no compromises

Why do we need to go back to basics?  Because, marking of products can easily be compromised, for example, by challenging factory environments, poor printing or engraving, or even the skin acids on fingers. Developments in camera technology and software have widened tolerances to faulty marking and to inadequate illumination.  Nevertheless, it can be an expensive error to expect heavy investment in reading technology to compensate for inadequate marking quality; the best mark always facilitates the most reliable reading.

Achieving clarity of marking is critical to meet regulation, to avoid rejects and returns by a supermarket customer, or to ensure employee and consumer health and safety. Often driven globally by regulatory and traceability requirements such as the US Food and Drug Administration (FDA) 21CFR part 11 in pharmaceuticals and international barcode standards such as GS1, data logging and tagging are required at every stage from raw material through the manufacturing, distribution and retail to the consumer.

Depending on the application, the material and the goods, codes may be marked by a variety of methods including laser engraving, mechanical marking, often on metal substrates, or printing on a label or directly onto to a film or pack.

Choosing the right method for successful reading is, therefore, a key element of best practice. Using the wrong method could lead to poor inspection and lead to high rejection rates and low productivity through wastage and returns. The benefits of being able to offer multiple technologies will always lead to the best solution for any given task of code reading.

An inspector calls

Good procedures can minimise poor code quality but laser-based code reading or vision technology still has to overcome faults such as character damage, missing codes, bleeding, poor spacing and unreadable fonts. For optimum read reliability, parameters like spacing, contrast, font and size, location of the code, repeatability and illumination must all be considered.

It’s therefore vital that an automated process begins by inspecting the code - to verify its presence or absence, legibility and completeness and, also to ensure it is correct (e.g. not yesterday’s date but today’s!). The success of that inspection depends on optimising both code quality and the inspection performance.

If the best practice combination of marking and reading is achieved, profit yields can be improved through reduced rejects, less downtime, more efficient processes, happier customers and an improved reputation; success breeds success!

Technology Choices

Through better reading ability and improved vision algorithms, the prospects of real-time integration with faster production speeds, better reliability and more complex data sets are opening up.

With increased choice, users should be aware of their options and consider the alternatives carefully:  In particular, users can become pre-occupied between the choice between using laser scanning and or camera technology to read or view objects, as there can be a cross-over between the functionality of the two technologies.

Laser scanning is developing diverse solutions for code reading as well as shape/profile and position detection for quality control, picking, handling, and volume/pricing applications in high-speed applications. Laser scanning can also be very precise in the detection of edges and distances, and used for precision picking of complex profiles from random piles in bins.

The use of camera vision solutions has also been growing rapidly over the last few years. Cameras based on CMOS detectors for visible and UV light are ideal for quality control in terms of colour and shape as well as in reading characters, codes and artwork with the correct software.  However, they are sometimes over-complex for the task required and may not offer the best the return on investment for the quality and reliability of reading achieved.

If a vision technology manufacturer offers both laser and camera solutions, there is more likely to be an appropriate answer to the user’s requirement. After all, why hire a tractor to dig a vegetable patch when a hired rotovator would do the job as well? A hire shop that offers both options is best placed to give an honest opinion. If all you have is a hammer, you may see everything as a nail.

Camera, Laser – or both?

Most recent developments even enable cameras and laser scanners to be integrated in combined devices and offer the best features of both to enhance scanning performance for a full solution. These are now termed ‘smart’ cameras, with sophisticated software allowing real-time quality control in production lines.

RFID can also be considered as another option for data coding, enabling a data store to be attached to a product and read remotely. RFID’s potential and versatility in terms of being able to add to the attached data information, as well as being able to read it, gives even more potential value. Developments to integrate the RFID with laser-scanned data is a major breakthrough with much potential.

Machine & Alphanumeric Codes

Where machine coding is used alongside alphanumeric characters to inform retailers and consumers, supply chain scanners must be able to read the alphanumeric characters through Optical Character Recognition (OCR) software.

To verify the alphanumeric data presence and completeness, and cross check its accuracy with the machine codes, an additional function termed Optical Character Verification (OCV) is required. Reliability depends on printing and font quality, and combined OCR and OCV scanning software is undergoing intense development to compensate for poor character printing.  For example, the launch of SICK’s Lector 620 OCR scanner at the end of last year has made combined alphanumeric character and barcode reading, quality-checking and matching, faster, simpler and more reliable than was previously possible.

Connectivity in Common

As the diverse range of devices in an automated production environment expands, so technology developments are needed to improve inter-connectivity and data sharing between them. SICK’s has introduced IDpro, a major advance that successfully addresses the connectivity gap between scanners, 2D/3D vision cameras and RFID interrogators to offer seamless device intercommunication and control.

This powerful platform for SICK scanning devices offers new capabilities and functionality by leapfrogging data translation gateways, interfaces and bottlenecks in complex, multi-device data scanning and vision networks.