Commercial article printing typically occurs during the production of the article. For example, ball skins are printed with patterns or logos prior to the ball being completed and inflated. Consequently, a non-production establishment, such as a distribution site or retail store, for example, in a region in which potential product customers support multiple professional or collegiate teams, needs to keep an inventory of products bearing the logos of various teams followed in the area. Ordering the correct number of products for each different logo to maintain the inventory can be problematic.
One way to address these issues in non-production outlets would be to keep unprinted versions of the products and print the patterns or logos on them at the distribution site or retail store. Printers known as direct-to-object (DTO) printers have been developed for printing individual objects. Operating these printers with known printing techniques, such as two-dimensional (2D) media printing technology, to apply image content onto three-dimensional objects produces mixed results. As long as the surface of the objects are relatively flat, the images are acceptable. However, many products, such as mugs, water bottles, pens, and the like, have curved surfaces, which can adversely impact the printed image quality.
Challenges associated with direct-to-object printing include ejecting ink drops across large and varying gaps, locating the object and the position for the image on the object, registering the image onto the object, and holding and orienting the object for printing, for example. Given the multitude of object shapes and sizes that can be printed on, developing robust ways to hold a part and accurately determine where the faces of the printheads are relative to the surface to be printed is difficult. In other words, accurately determining the correct distance and orientation of the printheads with reference to an object surface as well as identifying the appropriate ejectors in a printhead to fire to center the image on the object is no trivial task.
These issues are exacerbated by objects that do not have a defined edge that can be used as a reference point to register an image and time the operation of the ejectors. Object holders may not present the part at an orientation that best matches the image and the area on the object selected for printing of the image may be irregular and cause distortion of the printed image. Therefore, a printing process control system that produces quality images for a wide variety of products having varying degrees of surface undulation and features would be beneficial.