A cylindrical printing plate formed with high precision and used for printing on a metal can body, particularly an aluminum or aluminum alloy can body. The forming method of a printing plate forms the printing plate to be mounted on an outer periphery of a cylindrical plate cylinder, and includes a notch forming step of forming a positioning notch in a rectangular elastic material sheet in which a resin layer to be served as a plate section is formed on one surface. A cylindrical material forming step rolls the elastic material sheet in which the positioning notch is formed and overlaps both end portions of the elastic material sheet and joining them in a cylindrical shape. A plate section engraving step engraves a printing pattern on the plate section of the elastic material sheet formed into a cylinder shape.

A cylindrical printing plate formed with high precision and used for printing on a metal can body, particularly an aluminum or aluminum alloy can body. The forming method of a printing plate forms the printing plate to be mounted on an outer periphery of a cylindrical plate cylinder, and includes a notch forming step of forming a positioning notch in a rectangular elastic material sheet in which a resin layer to be served as a plate section is formed on one surface. A cylindrical material forming step rolls the elastic material sheet in which the positioning notch is formed and overlaps both end portions of the elastic material sheet and joining them in a cylindrical shape. A plate section engraving step engraves a printing pattern on the plate section of the elastic material sheet formed into a cylinder shape.

An apparatus for preparing a relief plate precursor, such as a printing plate precursor, that has to be treated. The apparatus includes a transport bar provided with at least one penetration element, preferably a plurality of penetration elements; and a plate coupling station configured for coupling a relief plate precursor to the transport bar by causing a penetration by the at least one penetration element through an unperforated area near an edge of a relief plate precursor.

An apparatus for preparing a relief plate precursor, such as a printing plate precursor, that has to be treated. The apparatus includes a transport bar provided with at least one penetration element, preferably a plurality of penetration elements; and a plate coupling station configured for coupling a relief plate precursor to the transport bar by causing a penetration by the at least one penetration element through an unperforated area near an edge of a relief plate precursor.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.

An apparatus for aligning an edge, such as a leading edge of a plate, in particular a printing plate or a printing plate precursor. The apparatus includes a support configured for supporting the plate on a support surface, and to be located upstream of a treatment station. At least two movable elements are arranged to be moved by an edge, such as a leading edge, of the plate. The at least two movable elements include a first and a second movable element; a detection means configured to detect a first and second measure representative for a first and second position of the first and second movable element, respectively, at least one controllable component configured to perform an action on the plate, and a control means configured to control the at least one controllable component based on the first and second measure.

An apparatus for aligning an edge, such as a leading edge of a plate, in particular a printing plate or a printing plate precursor. The apparatus includes a support configured for supporting the plate on a support surface, and to be located upstream of a treatment station. At least two movable elements are arranged to be moved by an edge, such as a leading edge, of the plate. The at least two movable elements include a first and a second movable element; a detection means configured to detect a first and second measure representative for a first and second position of the first and second movable element, respectively, at least one controllable component configured to perform an action on the plate, and a control means configured to control the at least one controllable component based on the first and second measure.

An apparatus for preparing a relief plate precursor, such as a printing plate precursor, that has to be treated. The apparatus includes a transport bar provided with at least one penetration element, preferably a plurality of penetration elements; and a plate coupling station configured for coupling a relief plate precursor to the transport bar by causing a penetration by the at least one penetration element through an unperforated area near an edge of a relief plate precursor.

An apparatus for preparing a relief plate precursor, such as a printing plate precursor, that has to be treated. The apparatus includes a transport bar provided with at least one penetration element, preferably a plurality of penetration elements; and a plate coupling station configured for coupling a relief plate precursor to the transport bar by causing a penetration by the at least one penetration element through an unperforated area near an edge of a relief plate precursor.

A rotogravure printing machine has a shaft that rotates and a rotogravure cylinder sleeve for rotation with the shaft. An annular end plate connects to the shaft, and the end plate has a contact surface for contact with a mating contact surface at an inner side of the cylinder sleeve.