That Vision Thing, Postpress Style
While I didn’t have a whole lot of time to stroll around the show floor during last week’s GRAPH EXPO 2012 in Chicago, one technology caught my eye. Vision, as in machine vision. When we think of finishing solutions, that capability is not something that springs to mind. But the advances in camera technology and software—along with variable-data print—have raised it’s importance.
Let me give you an example from the mailing sector. Back in the day, we inserted all of the necessary pieces into the envelope and wished it well on it’s journey through the postal system. But it’s quite common in today’s high-volume transactional and billing mail processing centers to capture a picture of every single finished mail piece coming off the inserter. Images are then stored on servers so that proof of mailing can be supplied if needed.
Then there is the case of postpress operations on continuous-web digital systems. Almost every postpress manufacturer offers a web-inspection system. These units employ multiple cameras to inspect selected areas of the printed web to check print and barcode integrity in real time.
Some saddlestitchers designed for digital print also use multiple cameras to verify the sheet sequence and to inspect the finished booklet. In most cases, inclusion of the proper components is verified by a barcode reader, but for critical high-integrity applications (such as examination booklets), the vision units used can be both quite complex and expensive.
In the “traditional” bindery, vision systems have become more common over the years. They have been used to verify that the correct signature has been loaded into the feeder by the operator. The reduction in “do-overs” due to badly collated books can easily justify the system’s cost. On co-mailing machines, cameras will verify that the correct mailing address has been applied to the right publication for that recipient.
Vision systems are not made of cameras alone, but are integrated with processors, and sophisticated software specifically designed for a variety of character and code recognition tasks. They can even be used for checking book trim and adhesive application quality.
Vision technology offers round-the-clock inspection consistency, with no lunch breaks. Such systems are another tool that can be used to ensure consistent, high-quality finished products.