Labeling & Vision System Reduces Cost of Applying and Inspecting Lens 90+%

Labeling is a critical concern in the medical industry, especially in the contact lens market because one of the biggest causes of product recalls has been mislabeled products. Labeling is a particularly great challenge for SynergEyes Inc. because the high-end contact lens manufacturer produces tens of thousands of SKUs, more than an order of magnitude greater than the typical lens manufacturer. In the past, the company manually printed, affixed and inspected the labels. "This was an intensive and exhausting job and we had to manually inspect every label because the potential for error was high," says Joe Collins, vice president of manufacturing and research, and development for SynergEyes.

SynergEyes has dramatically improved the labeling process by installing an automated vial labeling and verification system (VLVS) developed and provided by code-in-motion LLC.

The system uses a Cognex DVT XS image-based ID reader that reads an inprocess 2D Data Matrix barcode label, decodes the information, and sends it off to an integrated printer that prints a final product label. Using code-in-motion's Patented "Touch & Go" rollers, the label is presented in full view to a Cognex DVT 554 vision system that rapidly inspects the printed data. The system then automatically applies the label to the vial if it passes inspection. In case of failed inspection, the operator is alerted through an integrated touch-screen PC to remove the label and print another for inspection.

"This unique automated system has reduced the cost of labeling our products by more than 90%," Collins says. "Even better, since we began using the automated system, we have not experienced a single labeling error."

Identifying What to Print

Users log into the system through a touchscreen PC. Each user ID is assigned to a security group that grants access to appropriate functions, such as those for operators, supervisors or administrators. The user interface was developed from Wonderware's In-Touch HMI (Human Machine Interface). A single easy-to-use PC interface provides users with detailed system status and inspection results, as well as access to printer settings, camera images, system parameters and system input/output values.

Vials reach the labeling system with a 2D Data Matrix barcode in-process label on their caps applied during the manufacturing process. This barcode contains all of the information needed to produce the final product label including multiple lens characteristics, expiration date and lot number. The operator loads the vials onto a ramp. The vials slide down the ramp and are individually released into an indexing starwheel.

An automated vial labeling and verification system.

"We selected Cognex cameras for this critical application primarily because Cognex's Intellect software gives us a much greater ability to develop and integrate multiple devices and controls into powerful scanning, printing and inspection applications," says Dan Popovich, vice president of operations for code-in-motion. "From within the ID reader we were able to parse out 2D barcode values of about 40 characters into individual data groupings, such as expiration, lot code, and lens characteristics. From there we could build and send out commands to a Zebra Technologies high resolution Thermal Transfer Printer that prints out a label specific to a contact lens."

Touch & Go Patent

After the 2D Data Matrix barcode is read, a label specific for that vial is printed and dispensed onto a Touch & Go Roller Grid patented by code-in-motion. Labels are dispensed sticky-side down onto these rollers that are specially coated so that adhesive will not stick to them. The roller grid with label is then moved into view of the Cognex vision system that inspects the printed label while it lies flat across closely spaced miniature rollers.

With or Without Scripting

Cognex DVT vision systems utilize predefined SoftSensors to perform specific inspection tasks without scripting. SoftSensors are software agents that extract information from selected areas in the image. SoftSensors are one of three well-defined DVT vision system configuration levels; the other two include system level and product level programming.

The system level contains parameters that affect the functionality of the vision system itself. Parameters such as communication settings and trigger mode (internal/external) are examples of system level parameters. These parameters define global settings that do not change between inspections.

Fast Label Inspection

Through custom Intellect scripting developed by code-in-motion, one camera tells the printer exactly what to print and tells another camera exactly what to inspect. The entire process of scanning the 2D barcode on the cap, printing a label, and inspecting that printed label takes only a few seconds.

Code-in-motion programmed custom scripts in the ID reader to read and process the 2D Data Matrix barcode on the vial cap. Their routines parse a barcode value of about 40 characters into multiple commands for printing the product label. Specific commands are sent to a Zebra Technologies high resolution thermal transfer printer that prints labels on-demand.

The labeling and vision verification system is controlled by an Allen-Bradley programmable logic controller (PLC). The PLC controls and orchestrates a variety of devices including pneumatics, a stepper motor for applying the labels, and an indexing starwheel that moves vials from an input chute to a labeling position, and into an output chute.

If the label fails vision inspection the operator is alerted through the touchscreen PC monitor. An ever present message log updates with an inspection failure notice. Additionally, the display shows exactly which character(s) on the label did not pass inspection or if the wrong label stock was placed into the printer. This level of detail is a great aid to the operator if, and when printing issues arise. This capability is made possible through Cognex SoftSensor standard outputs and network communications integrated into the overall code-inmotion system.

If the label passes vision inspection it is applied to the vial. A vacuum drawn tamp pad picks up the label off of the Touch & Go Patented Roller Grid. The tip of the label extends beyond the tap pad and is positioned just below a rubber roller. The label is lowered into light contact with vial so that the rubber roller is lightly depressing the label onto the vial. Meanwhile the vial is supported by two rollers within the starwheel. The rubber roller is rotated by an accurately controlled stepper motor until the label is fully applied around the vial.