A device for measuring a surface or elevations of the surface of a rotary body provided as a cylinder, a roller, a sleeve, or a plate for a graphic industry machine, includes a first motor for rotating the rotary body about an axis of rotation and a measuring device including at least one radiation source, at least one area scan camera, and at least one computer used to take contactless measurements on the surface which is permanently sticky and/or compressible and/or porous and therefore difficult to measure. The measuring device uses a virtual reference object saved on the computer to determine the concentricity of the rotary body on the basis of the measurement results. A system including the measuring device and a flexographic printing press is also provided.

A printing plate pressure adjustment system for a can decorator including a printing plate cylinder assembly having a printing plate cylinder drive shaft, and a blanket wheel. The system, includes an actuator, a control system structured to control operation of the actuator to adjust a pressure, between the printing plate cylinder assembly and the blanket wheel, an eccentric bushing disposed around the printing plate cylinder drive shaft, wherein rotation of the eccentric bushing causes the printing plate cylinder to move toward or away from the blanket wheel, and a drive mechanism coupled between the actuator and the eccentric bushing, wherein operation of the actuator causes the drive mechanism to rotate the eccentric bushing.

A method of operating a flexographic printing press having a printing cylinder carrying a sleeve with at least one flexographic printing forme or a flexographic printing cylinder, and an impression cylinder, includes adjusting contact pressure between the printing cylinder or the flexographic printing cylinder and the impression cylinder by motor. The adjustment is made in an automated way as a function of a dot density of the flexographic printing forme, i.e. of a location-dependent density of printing elevations on the flexographic printing forme or data computationally derived therefrom. A cost-efficient way of producing high-quality prints in an industrial flexographic printing process is thus provided. In addition, the method advantageously provides further automation of the printing process. A flexographic printing press, a flexographic printing press system, and a flexographic printing forme or sleeve for a flexographic printing forme are also provided.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of dots, arranged according a screen ruling and screen angle. Said dots comprise (i) image pixels arranged as a first arc or as a plurality of arcs which together represent a first spiral, and (ii) non-image pixels arranged as a second arc or as a plurality of arcs which together represent a second spiral. Small displacements of the feed point of said dots away from the theoretical centre of a halftone dot, defined by said screen ruling and screen angle, enable a higher image quality and less patterns in said halftone raster image.

According to aspects of the embodiments, there is provided methods to measure characteristics of line width and density of printed test patterns. By printing the test patterns and capturing with an in-line scanner or optical device, the analytical results of these test patterns can be used as feedback to a control system that adjusts both impression and inking levels without the need of a skilled operator.

A method controls the color in a printing press, which includes at least one printing station printing a respective color design. The method includes the procedures of determining a control factor to color model, printing a design on a web and acquiring color characteristics corresponding to the printed design on the web. The method further includes the procedures of determining the color quality of the printed color design and determining a required change to at least one control factor when a correction to the color characteristics of the printed design is required. The change to at least one control factor is determined by determining the at least one control factor with respective color related information, which results in a reference color characteristic, according to the control factor to color model. The method returns to the procedure of printing when a correction is not required.

A method of reproducing a continuous-tone image with a printing press comprises the step of making a printing plate having a halftone raster image comprising regularly tiled halftone cells which consist of a grid of image pixels and non-image pixels; the halftone cells are obtained by digital halftoning with a single threshold array and at least a portion of the halftone cells in the raster image comprise multiple image clusters, image clusters being defined as mutually separated groups of more than 4 adjacent image pixels; the image clusters allow to obtain a printed image of the same image density with less ink than with conventional screens wherein the image pixels are grouped into a single cluster.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of dots, arranged according a screen ruling and screen angle. Said dots comprise (i) image pixels arranged as a first arc or as a plurality of arcs which together represent a first spiral, and (ii) non-image pixels arranged as a second arc or as a plurality of arcs which together represent a second spiral. Small displacements of the feed point of said dots away from the theoretical centre of a halftone dot, defined by said screen ruling and screen angle, enable a higher image quality and less patterns in said halftone raster image.

A device for measuring a surface or elevations of the surface of a rotary body provided as a cylinder, a roller, a sleeve, or a plate for a graphic industry machine, includes a first motor for rotating the rotary body about an axis of rotation and a measuring device including at least one radiation source, at least one area scan camera, and at least one computer used to take contactless measurements on the surface which is permanently sticky and/or compressible and/or porous and therefore difficult to measure. The measuring device uses a virtual reference object saved on the computer to determine the concentricity of the rotary body on the basis of the measurement results. A system including the measuring device and a flexographic printing press is also provided.

A device for measuring elevated areas of the surface of a rotary body in the form of a cylinder, a roller, a sleeve or a plate of a printing press, for example a flexographic printing plate, includes a first motor for rotating the rotary body about a rotational axis and a measuring unit for contactless measurement. The measuring unit for contactless measurement includes at least one radiation source and at least one area scan camera. The measuring unit for contactless measurement preferably includes a reference object, for example a wire tensioned in an axially parallel manner, a second motor and optionally a further second motor, for adjusting the measuring unit and/or the reference object perpendicularly to the rotational axis. The device makes it possible to measure elevated areas, for example flexographic print dots, quickly and with high precision. A system having the device is also provided.