Cylinder for aligning magnetic or magnetizable particles contained in coating agent on a substrate and machine for generating optically variable image elements

A cylinder (26) for aligning magnetic or magnetizable particles (P) contained in a coating agent (06) on a substrate (02), the cylinder comprising:

• in a region of an outer circumference of the cylinder, in a matrix-like manner, a number of n×m (where n and m are integers greater than one) magnetic elements (24) that provide magnetic fields, and which are arranged in n rows extending in an axially parallel manner and in m columns extending in a circumferential direction, and,
• in the region of the outer circumference, the cylinder further comprising a plurality of suction elements (34) with suction openings (42) pointing outwards,
• characterized in that each magnetic element (24) is combined with at least one associated suction element (34), of the plurality of suction elements (34), to form a respective modular unit (36) as an active unit (36), and as such, each active unit (36) can be positioned as a whole and independently of all other such active units (36) in the circumferential direction for positioning a plurality of the active units (36) or all of the active units (36) in one or more of the columns extending in the circumferential direction, each of the one or more columns including multiple ones of the active units (36) so that several or all of the multiple active units (36) in each column of the one or more columns are arranged one behind the other, and wherein individual active units (36) can be detached from the cylinder (26).