Using digital camera-based machine vision, packagers can move from decoding print and bar codes to other package and product inspection tasks.
Matrix-style or 2-D codes such as DataMatrix are increasingly favored as codes that contain more data in a smaller space compared to linear bar codes, as regulations require more information in a bar code.
Camera-based inspection systems that capture digital photos for analysis are typically required for reading these codes for content and legibility. In applications where packagers are replacing laser scanners for bar code reading with camera vision, they are typically looking for additional inspection functions for different points on a line.
Packagers could be inspecting for label tolerances, container fill levels, verifying logo correctness with pattern matching, and checking color bands on ampoules. Vision software, for example, can ensure that bar codes on containers, inserts, and cartons match up during package assembly.
Vendors have offered systems designed to be easy to use for operators untrained in camera vision, and for easy integration to peripheral equipment and production lines.
For pharmaceutical inspection applications, Microscan (www.microscan.com ) has provided its I-PAK inspection system. The PC-based system supports up to four cameras, with a GUI interface designed for pharma production tracking requirements.
Based on Microscan’s Visionscape hardware and software environment, the I-PAK is also offered as a smart camera-based system in the I-PAK HE.
“The I-PAK HE has the same functionality as the I-PAK but with the image processing in the camera with the PC used as an interface for displaying images and results,” says Dr. Jonathan Ludlow, machine vision product manager.
“There are some circumstances where the smart camera has an advantage. Companies with a single point of inspection can end up spending less money. The cameras have discrete IO capability so at the point of inspection they can send a signal that will to work a reject mechanism,” Ludlow says.
“The I-PAK HE offers exactly the same user interface with the same pharma industry compliant features (including 21 CFR Part 11 auditing, and different levels of access) supporting up to four smart cameras,” he adds.
Pharma firms have used the I-PAK as a turnkey solution for inspection functions including optical character verification (OCV) for meeting FDA inspection requirements. The OCV tool checks the content string and legibility of the lot and date codes.
The I-PAK GUI front-end displays multiple subscreens for cameras performing other tasks including error proofing and assembly verification such as presence of a safety seal, as well as 1-D and 2-D bar code reading. Bar codes are checked for legibility and content. In package assembly, the system confirms that product label, carton, and insert codes match.
With its AutoVISION software, Microscan offers a simplified solution for bar code reading and other inspection functions using its VisionHAWK and VisionMINI smart camera models.
“We have noticed that in pharma, not everyone either chooses to or is required to use an industry-specific vertical product. They may have applications not required by regulation, or choose to deal with validation issues in a different way,” Ludlow says.
AutoVISION inspects 1-D and 2-D codes, with added vision inspection capacity in a system easy to implement by operators unschooled in machine vision, says Cathy McBeth, global commercial marketing manager.
“AutoVISION is an ideal solution for companies currently using bar code inspection that are looking to do more with a single hardware device. For example, as industry regulations begin to specify 2-D codes with added information, AutoVISION ensures that the coded information matches the printed human readable printing,” McBeth says.
AutoVISION decodes human readable strings, measures distances between features, counts object presence, checks for the presence of features such as printing, and inspects label position, cap closure and seal presence.
“These are the same functions performed by I-PAK but in a more compact form where in some cases we are making the lighting and optical component decisions for the customer,” says Ludlow.
Networked via Ethernet cable, the VisionHAWK features built-in lighting, with a liquid lens for auto focus. The
camera automatically focuses to the right distance with the push of a button.
“This is typically important when setting up a system that will be reading labels on products of different sizes that are different lengths from the camera. Without auto focus, you have to twiddle the lens, and operator or technician judgment comes into play,” Ludlow says
“We are trying to remove the places where something can go wrong and make it usable by people comfortable with setting up scanners and code readers,” he adds.
A “follow-the-arrows” setup prompts to the next step as the user chooses functions—decode 2-D, count, measure distance—to add to a program. The user receives instant feed back as tools are set up and dragged to the program for downloading to the cameras.
C-Mount lenses are offered as an alternative to the VisionHAWK’s built lenses to cover all possible combinations for field of view and distance.
Customers using AutoVISION can scale up if inspection requirements grow in complexity by licensing the Visionscape programming environment.
“We don’t make a walled garden around the product. If you start on the Vision HAWK, and decide you need to move to a PC-based system, the AutoVISION application runs on the PC based-system. You don’t need to switch to a new software platform and rewrite your jobs. So you are protecting your investment,” McBeth says.
As the distributor of scanware vision products, Pharmaworks Inc. (www.pharmaworks.com ) provides solutions that integrate product handling with vision system requirements. From Scanware Electronic GmbH, scanware vision supports complete line inspection including print inspection with the Lynx-Signum HR and product inspection with the Lynx-Spectra and Lynx Spectra 3D. And scanware can manage all quality control functions on a line encompassing product verification and reject functions. A PLC with shift register control tracks the product. Networked peripheral devices such as printers and reject stations are managed from a single interface. The industrial PC-based system supports high resolution inspection at high speeds, says Peter Buczynsky, president.
“In certain applications, we are looking across 300 mm webs with ten pockets across, inspecting 2-D codes and lot dates on blister lidding material with high accuracy at line speed,” Buczynsky says.
Manufacturers can avoid the costly process of having the line machinery OEMs reprogram and revalidate machine PLCs for integrating vision functions with networked devices.
TAKING OVER QUALITY CONTROL
“Scanware systems are unique in that they are designed to retrofit the product inspection systems on existing packaging machinery without the need to modify the existing machine’s control system. Many lines have non-networked, locally controlled cameras and printers. There are still many lines out there running on old controller boards without a PLC [at all],” Buczynsky says.
The scanware vision system serves as a master interface for customers’ existing quality control functions, and supports adding new functions.
“Many times, when we install a scanware system, the customer may be adding additional inspection functions, such as pinhole detection or bar code verification, for example, and then realize that the vision system will call for additional functions, such as inspecting for product or material over-heating or seal over-loads,” he says.
Customers can start with a lower-cost solution and scale up, such as moving from inspection for pattern matching and gross defects with a single camera, to multicameras for inspecting wider webs, and materials with more print in smaller fonts.
“You can multiplex cameras together under one of our hoods. We do the image stitching on external hardware rather than through software, which compromises the speed. So we are doing high-resolution image processing without any compromise to speed,” Buczynsky says,
For product inspection applications, Pharmaworks has installed the Lynx-Spectra 3D solution at several companies recently. The applications include solid doses with very low contrast between the product and foil background and inspection of different products having the same color and diameter but varying heights.
“Since the pocket needs to be larger in cold form packages, you have an issue with detecting doubles in low product/background contrast applications, and often the product color shade changes when the product is sitting in the pocket at an angle. The only way you
can inspect for these differences is with a volume measuring system,” Buczynsky says.
Optel Vision (www.optelvision.com ) provides a suite of camera-based solutions for inspecting bottle and blister contents and packaging. Its VialSafe for vials and ampoule inspection features 360-degree inspection of human readable strings and bar codes.
“This is an advanced pre-set vision tool for doing OCV/OCR on human readable print and DataMatrix codes that may not be planar on the cap crimp. You don’t have to worry about the vial’s orientation when presented to the system,” says Mario Petitclerc, vision specialist.
Images of a print string that runs around a cap crimp are captured by two or more cameras and stitched, or combined, to capture the complete code.
VialSafe has specialized tools for checking for chipped glass at the neck and crimp integrity. It also inspects for label presence and color bands on ampoules. The same tool is used with dark field lighting to inspect for label orientation and fill level. Back lighting is used to verify container transparency and color variations.
Optel Vision’s LabelProof system is combined with VialSafe for the character and bar code inspection verifying bar code content and
“Vial codes are typically placed on the top of the cap or the neck. Our customers are using human readable or DataMatrix. But every solution is different from customer to customer, so our turnkey solutions are customizable,” says Ken Fallu, marketing manager.
To avoid cross contamination, an identification code can be printed on the unlabeled vials just after filling, then this code can be reread just prior to labeling to ensure there was no proodcts mix between filling and labeling.