Flawless label detection at 100 parts per second

22 February 2011

Customers in the CD/DVD manufacturing sector and in the pharmaceutical sector posed a challenge for Reconcile Engineering.

For the CD/DVD application there was a requirement to verify that the right language is present on the printed packaging for CDs. The second challenge involved the counting of complex pharmaceutical labels. The only solution that was found to be suitable for both of these applications was Checker from Cognex.

Label inspection and reconciliation systems produced by Reconcile Engineering can be found in many high-speed automatic packaging lines in major optical media manufacturers throughout the world, with its tailor-made solutions for labelling and inspection applications.

Suppliers cannot afford to provide a faulty product and need to be sure of content for every product leaving their premises. Packaging needs 100% reliable inspection. Products cannot arrive with the wrong information, with missing print, in the wrong language or even with a misaligned label. This is where the Reconcile inspection solution comes in.

One customer had a requirement to be able to guarantee the inspection of their printed packaging, verifying that the correct language is present on the inlay. The customer also wanted to verify that the inlay cards were properly aligned and oriented in the right direction.

Reconcile investigated the options available for this kind of inspection and tested Checker from Cognex alongside competing systems. Checker was found to be the only product to perform successfully. Its part finding sensor proved very powerful in determining the text patterns printed on the CD boxes and as a result Checker was retrofitted onto the printing line by engineers from Reconcile.

This application would not have been possible with traditional sensors which would otherwise have required a most complex and costly multi-sensor alternative. alternative involving multiple sensors. With Checker there is no need for an external trigger so different colours or products can inspected on the machine, giving the end-user complete flexibility.

Checker is particularly useful in packaging applications because it synchronizes part rejection on variable speed lines using encoder counts instead of time to track flawed packages between the inspection and rejection points. Checker’s ability to determine what it is seeing allows it to assert it's output at the proper encoder position for each piece.

Being faced with some particularly complex pharmaceutical labels for counting also resulted in Reconcile using Checker again, as an option for all clients on their label counting machine. The labels are clear with clear backing are marked with a text, batch number etc. The fact that they are transparent and are a two-tier layer means that they pose a particular challenge for the machine when it comes to counting. Previously, Reconcile would have used an optical or ultrasonic sensor. But neither of these options could have coped with such complex labels. Checker is now fully operational on the machine, counting labels at a rate of 100 per second.

The solution is simple for the end-user too. Checker is installed on the machine and Reconcile installs a small control unit. A laser pointer connected to a PLC is mounted on the Checker permitting the operator to align the lens with the product to be ‘learned ‘ by Checker. All the operator has to do then is press a green button, ‘teach’ and the sensor is ready to go.
According to Des Farrelly, Managing Director of Reconcile Engineering; "It would have been impossible to solve this label counting application without Checkers part-finding sensor. With a successful counting rate of 100 labels a minute, we intend to include Checker as an option on our label counting machine from now on."

To view Checker in action to go: http://www.cognex.com/ApplicationsIndustries/TypesOfApplications/default.aspx?id=1214

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