Patent ID: 8994959
Filing Date: 2015-03-31
Classification: B41F,B41J,B65C,G01D

Abstract:
1. An apparatus for printing on containers, said apparatus comprising a first machine part, a second machine part that moves relative to said first machine part, a plurality of electrically-controllable printing heads arranged on said first machine part, each of said printing heads, in operation, engaging in the action of printing one of a corresponding plurality of images directly on a container that is rotating about an axis thereof while said container is disposed adjacent to said printing head, said plurality of printing heads comprising a first printing head that, during operation thereof, prints a first image on said container while said container is rotating about an axis thereof and disposed adjacent to said first printing head, and a second printing head that, during operation thereof, prints a second image on a container that is disposed adjacent to said second printing head and that is rotating about an axis thereof, wherein said first image, which is printed by said first printing head, is an image that is different from said second image, which is printed by said second printing head, a plurality of rotating devices arranged on said second machine part for bringing containers from said first printing head to said second printing head, each of said rotating devices comprising a cylinder that defines a rotating-device axis about which said rotating device rotates, each of said rotating devices having a rotational position that changes from a first rotational position to a second rotational position during a time interval in which said first printing head is engaged in the action of printing an image directly on a container supported by said rotating device, a plurality of sensor units arranged on said first machine part, each of said sensor units being assigned to one of said plurality of printing heads, wherein each of said sensor units is configured for detecting a rotational position of a corresponding one of said rotating devices that is adjacent to said one of said plurality of printing heads to which said sensor unit is assigned, measurement markings, and a control-and-evaluation unit, wherein said cylinder comprises a flat surface for supporting said container, said flat surface being perpendicular to said rotating-device axis, and an outer surface, said outer surface defining, at each point thereof, a surface normal vector that is perpendicular to said rotating-device axis, wherein said measurement markings are disposed on said outer surface of said cylinder, wherein said measurement markings define a circle concentric with said rotating-device axis, wherein said sensor unit is configured for contactless detection of a rotational position of said rotating device around said rotating-device axis, wherein each of said sensor units is assigned to a corresponding one of said printing heads, and wherein said control-and-evaluation unit is configured to receive a signal from said sensor unit and, based at least in part on said signal, to determine said rotational position, and to cause said rotational device to rotate said container to said first rotational position, thereby ensuring that said first image, which is printed by said first printing head, and said second image, which is printed by said second printing head, are correctly aligned.