Method for producing a security element or security document bearing a printed image

Abstract

A method for producing a security element (01) or a security document (02) having a printed image (27), in which several image elements (28) of the printed image (27) are formed by applying printing ink to a substrate (26), in which the previously applied printing ink is removed from at least one selected location of a selected image element (28) of the printed image (27) by means of a laser beam (66) emanating from a laser (63), wherein the laser (63) is operated in pulsed mode, characterized in that a gas laser is used as the laser (63), wherein the laser (63) is operated with a pulse duration in the range between 1 ns and 40 ns, wherein a structure with a width in the range between 0.25 µm and 1 µm is formed in the selected image element (28) of the printed image (27) with the laser beam (66).wherein the at least one image element (28) with the at least one area to be freed from printing ink is formed in white printing ink.

Description

[0001] The invention relates to a method for producing a security element or security document having a printed image according to claim 1.

[0002] DE 11 2010 000 957 T5 discloses a lens array for imaging a plurality of image elements in an object plane, wherein the lens array comprises a plurality of microlenses shaped in or on one side of a transparent or translucent material with the image elements on the opposite side, wherein the lens array has a measurement thickness corresponding to the distance from the apex of each microlens to the object plane, wherein each microlens has a set of lens parameters, the measurement thickness and / or at least one lens parameter being optimized such that each microlens has a focal point size in the object plane that is substantially equal to the size of the image elements in the object plane, or that deviates from the size of the image elements by a predetermined amount. The measurement thickness of the lens array is preferably less than the focal length of all microlenses. The image elements can, for example, take the form of points or lines.The lens array of DE 11 2010 000 957 T5 is designed such that in a section plane lying parallel to the principal plane of the microlens in a cone or angle field of the light incident on the image elements in the direction of the image elements, only one of the adjacent image elements is ever arranged, whereby for a viewer looking at the printed image from a certain viewing angle, only a single frame is ever perceptible at a certain time.

[0003] WO 2007 / 042919 A2 discloses a printing unit with printing units by which the substrate to be printed is or can be printed at the same printing point on the same side simultaneously with superimposed, multicolored partial print images originating from several form cylinders.

[0004] From EP 2 996 885 B1 a method for producing a security document is known, wherein a curable material is applied to a first area of ​​the substrate on its first surface, the curable material is shaped in such a way that its surface away from the substrate follows the contours of a relief structure producing an optically variable effect, and the curable material is cured so that the relief structure is held by the cured material.

[0005] The invention is based on the objective of creating a method for producing a security element or security document having a printed image, which enables complex and / or differentiated animations by means of the security element or security document in question.

[0006] The problem is solved by a method with the features of claim 1. The dependent claims describe advantageous embodiments and / or further developments of the solution found.

[0007] Examples of implementation are shown in the drawings. They show: Fig. 1 a document with a security element having an optically representational structure; Fig. 2 a highly magnified cross-sectional view of an arrangement comprising a printed image and a single plano-convex microlens embedded in an optically imaging structure with an incidence of light from a first viewing angle; Fig. 3 the order according to the Fig. 2 with a light incidence from a second viewing angle; Fig. 4. A top view of an optically imaging structure formed in the shape of a geometric figure; Fig. 5 a top view of an optically imaging structure composed of lens arrays; Fig. 6 an optical imaging structure consisting of a group of microlenses arranged in a grid of square grid cells; Fig. 7 an optical imaging structure consisting of a group of microlenses arranged in a grid of hexagonal grid cells; Fig. 8 a picture element of a printed image underlying a microlens that is perceptible to a viewer through a microlens; Fig. 9. An image element of a printed image underlying a microlens that is not perceptible to a viewer through a microlens; Fig. 10 periodically recurring image elements in unequal phase arranged in a grid-like arrangement of microlenses; Fig. 11 a matrix for producing roughened areas between individual microlenses; Fig. 12 microlenses positioned relative to image elements of a printed image; Fig. 13 manufacturing steps for the formation of microlenses with areas not covered by these microlenses on the surface of the geometric figure, in particular areas colored white; Fig. 14 an arrangement of several superimposed levels of a security element or a security document; Fig. 15 an arrangement of masked color zones; Fig. 16 an optically imaging structure consisting of several groups of microlenses arranged in a grid; Fig. 17 an arrangement for the formation of structures in the micrometer range in an image element of a microlens to be used as a background for a printed image; Fig. 18 a schematic representation of a collating printing unit for simultaneous double-sided multicolor printing; Fig. 19 a schematic representation of a printing unit with a printing unit designed as a collective printing unit for simultaneous double-sided multicolor printing and an application device indicated upstream or downstream in the substrate path; Fig. 20 a schematic representation of a printing unit with a printing unit designed as a collective printing unit for simultaneous double-sided multicolor printing and an application device integrated inline in the substrate path.

[0008] In optics, the term "lens" refers to a component transparent to light with at least one refractive surface positioned in the path of the light rays. Here, "light" refers to the portion of electromagnetic radiation visible to the human eye. In the electromagnetic spectrum, the range of light spans wavelengths from approximately 380 nm (violet) to 780 nm (red). The following discussion focuses on converging lenses, i.e., lenses that focus incident light, particularly plano-convex lenses. Preferred designs include rotationally symmetric spherical or aspherical lenses and axially symmetric rod-shaped lenses, where the respective axis of symmetry of the lens and its optical axis coincide. The optical axis is thus typically a straight line passing through the center of curvature of a convex lens surface.For a flat lens surface, the optical axis is perpendicular to it. The curvature of a refractive surface, e.g., a convex one, is given by its radius of curvature, which originates on the optical axis. A flat lens surface is defined by an infinitely large radius of curvature.

[0009] Rod-shaped lenses are formed in the form of either a right circular cylinder or an elliptical cylinder, bisected by its rod length, with the axis of symmetry of each such lens extending orthogonally to its respective rod length. In a spherically shaped lens, the refractive surface is formed as a section of a sphere, for example, in the form of a spherical cap. An aspherically shaped lens has at least one refractive surface that deviates from a spherical or planar shape. The shape of rotationally symmetric aspherical surfaces is generally specified as a conic section (circle, ellipse, parabola, hyperbola) plus a correction polynomial for higher-order deformations.

[0010] A lens has two surfaces intersected by the path of the light rays, called enclosing surfaces. With regard to light focusing, by definition, light enters a plano-convex converging lens at its convex enclosing surface, and light exits the lens at its flat enclosing surface. These enclosing surfaces are interfaces between different media through which the light propagates. One of these media is the material of the lens itself. At least one other medium is the space, usually filled with air, in which the lens is located. Since at least two of the media in the path of the light rays have different optical material properties, the light is refracted at the interface between these adjacent media.Thus, light refraction occurs at at least one of the surfaces of each lens, particularly at its curved surface. The optical material property associated with light refraction is expressed by the refractive index of the medium in question. The refractive index is a dimensionless physical quantity that indicates by what factor the wavelength and phase velocity of light are smaller in the medium than in a vacuum. When two media with different refractive indices share a common interface, the medium with the higher refractive index is called the optically denser. The Abbe number, also known as the Abbe number, is a dimensionless quantity used to characterize the optical dispersive properties of a lens and indicates how much its refractive index changes with the wavelength of light.The property of a lens to produce an optical image of an object viewed through the lens depends on the refractive index of the material of the respective lens and on the shape of its enclosing surfaces that form interfaces between different media.

[0011] The principal plane of a lens is a plane arranged orthogonally to the lens's axis of symmetry. In the case of a thin lens, where its greatest dimension along the axis of symmetry—that is, the lens thickness—is very small compared to the radius of curvature of its convex surface (for example, because the radius of curvature of the convex surface is at least five times greater than this thickness), only a single principal plane can usually be used with sufficient accuracy to determine the lens's properties. In a plano-convex lens, this principal plane coincides with the flat lens surface. The focal length of a lens is the distance between the principal plane of the lens and its focus (focal point), where the focus is defined as the intersection of parallel light rays that are bundled by the lens.The light rays entering the lens parallel to each other do not necessarily strike it parallel to its optical axis, but rather at an arbitrary angle of incidence with respect to the principal plane of the lens, in particular an acute angle. A plane arranged orthogonally to the optical axis at the focus is called the focal plane.

[0012] The surface of the lens that receives light has two opposing points, symmetrically aligned with its optical axis, that define the boundaries of this surface, for example, in the principal plane of the lens. The distance between these two points determines the width of the lens. The aperture of a lens is its free opening or diameter, through which light rays can pass unimpeded, and is at most equal to the lens width. The point where the optical axis intersects the surface of the lens that receives light is called the vertex. This vertex is located furthest from the focus of the lens on the surface that receives light.

[0013] A rotationally symmetric spherical or aspherical lens focuses incident light into a cone, where the diameter of the base of this cone or cone is at most the lens width, and the height perpendicular to the base of this cone or cone corresponds to the focal length of the lens. An axially symmetric rod-shaped lens focuses incident light into an acute angular field, with the origin of the angular field located at the focus of this lens. The numerical aperture describes a lens's ability to focus light. It determines the minimum size of the light spot that can be produced at its focus and is therefore an important quantity that limits the resolution.

[0014] Several rotationally symmetrical or aspherical lenses, arranged in a preferably uniform grid consisting of either square or hexagonal grid cells, preferably without gaps or overlaps, form a lens group, also known as a lens array. Several axially symmetrical rod-shaped lenses, arranged orthogonally to their rod length, preferably also without gaps or overlaps, form a lens grid, also known as a lenticular. Several lenses arranged in a grid-shaped lens group and / or several lenses arranged in a lens grid, in their respective combinations, form an optically imaging structure extending over a flat or curved surface in the form of a geometric figure. The surface of the optically imaging structure can have any contour, e.g.,Rectangular, round, oval, or polygonal. In geometry, a geometric figure is understood as a set of points. With regard to the optical imaging structure, at least a subset of the points forming the geometric figure has a lens positioned on each of them.

[0015] In an optical imaging structure, either one or more lattice-shaped lens groups, or one or more lenses arranged in a lens grid, or a mixture of these two lens arrangements, can be arranged together, so that both lattice-shaped lens groups and lenses arranged in a lens grid are present in the same optical imaging structure. The lens grids formed in the optical imaging structure can, for example, each have a different orientation, with the respective orientation of the lens grid being determined by the direction of the rod length of the lenses involved in the assembly of the respective lens grid.

[0016] A microlens is a miniaturized form of a conventional lens. Here, the term microlens refers to a lens with a width of less than 100 µm, preferably between 20 µm and 65 µm. Microlenses have a focal length of less than, for example, 100 µm, preferably a maximum of 95 µm. Microlenses can now be manufactured industrially. Microlenses made of a plastic or resin can be produced, for example, using injection molding, injection embossing, or printing processes. Optically imaging structures consisting of microlenses are also called micro-optical structures.

[0017] When an optical imaging structure, particularly one composed of microlenses, is combined with a preferably planar printed image, for example by applying this optical imaging structure to a substrate bearing the printed image, various effects can be generated for a viewer observing the printed image through the optical imaging structure. For instance, an arrangement consisting of at least one printed image and at least one optical imaging structure can produce so-called flip images, spatial (i.e., three-dimensional) effects, morphing effects, zoom effects, and / or animations. These effects are perceptible to a viewer without optical aids when they view the printed image alternately from different angles.The perception presented to the viewer through different viewing angles is also called a lenticular image.

[0018] The printed image, typically a two-dimensional surface, is applied to the preferably two-dimensional substrate, for example, in an industrial manufacturing process, preferably using a printing press. The substrate is, for example, a web or a printed sheet. The printed image is applied to the substrate, for example, in a dot-like or line-like grid. The printed image therefore consists, for example, of several, and in particular a multitude, pixels and / or lines. A pixel size or line thickness is in the range of less than 100 µm, preferably less than 50 µm, and in particular less than 20 µm, for example, in the range of approximately 5 µm to 10 µm.In the following, it is assumed that the pixel size of pixels and / or the line thickness of lines, each of which are involved in the formation of a printed image used together with an optical imaging structure, are each at most as large, preferably smaller, in particular less than half as large as the respective lens width of the lenses involved in the construction of the optical imaging structure in question.

[0019] In optics, resolving power refers to the ability to distinguish fine structures, i.e., the minimum distance that, for example, two pixels or two lines must be from each other to be perceived as separate pixels or lines. The resolving power of the naked human eye varies from person to person. Normally sighted adults can usually still distinguish structures 150 µm apart at a distance of 25 cm. This corresponds to a visual angle of approximately 2 arcminutes, which is referred to as angular resolving power. At low contrasts, the visual acuity of the human eye decreases noticeably, with visual acuity being the inverse of resolving power. The lens width of a microlens is therefore typically smaller than the resolving power of the naked eye of a normally sighted adult.

[0020] To produce a colorful printed image, the substrate is printed with several printing inks; for example, the primary colors red, green, blue, and optionally black are applied to the substrate. A printed image typically consists of an arrangement of several small image elements positioned at different locations within the image. Each image element preferably comprises several pixels or lines and generally extends over a length of less than 100 µm. Each image element, or a group of adjacent image elements, forms, for example, an object viewed through a lens. The individual image elements are arranged within a printed image to form a print motif that determines the informational content of the image. Due to its limited size,Due to insufficient resolution, individual image elements used in conjunction with a microlens are not normally perceptible to the naked human eye. A person's perceived color impression of the printed image, or at least of a part of it, arises from an additive color mixing process in the eye and brain of the viewer, involving pixels and / or lines printed in different inks within the respective image elements. The superposition of any two primary colors produces the secondary colors yellow, cyan, and magenta. The superposition of all three primary colors produces the color impression white. A color register, i.e., registration accuracy, i.e.,The accuracy of the pixels and / or lines of different printing inks in their relative arrangement to each other is, in the embodiments of the invention considered here, less than 10 µm in each case and is in particular in the range of about 5 µm.

[0021] The optically imaging structure provided in connection with the embodiments of the invention considered here is preferably arranged in combination with pixels and / or lines of different printing inks. The printed image is preferably produced as or by superimposing several partial printed images, wherein several or preferably each of the partial printed images is printed, for example, in a different printing ink. The superimposition can be effected by successive overprinting onto the substrate or, preferably, by collecting the partial printed images on a printing element, e.g., on a cylinder, and simultaneously transferring them to the substrate. The partial printed images themselves each consist of pixels and / or lines, wherein the pixel size of these pixels and / or the line thickness of the respective lines are each in the micrometer range, e.g., in the range of less than 20 µm.When viewed by an observer looking at a printed image, the several partial printed images involved in this printed image overlap in their perception, e.g. to form an overall color impression.

[0022] An arrangement consisting of at least one printed image and at least one optically imaging structure allows a viewer observing the printed image to perceive several different individual images from different viewing angles. A sequence of these individual images creates, in the viewer's perception, a flip image, a spatial (i.e., three-dimensional) effect, a morphing effect, a zoom effect, and / or an animation. Each of these individual images is also referred to as a frame.The individual images perceptible to the viewer from a specific viewing angle are created by a selection, determined by the optical imaging structure, from the set of partial print images perceptible at the respective positions of the microlenses due to the at least one image element or elements present there. The overall color impression related to a position of the print image is created by superimposing all partial print images present and perceptible at that position. The optical imaging structure arranged in combination with a print image is therefore an optical masking of the partial print images involved in the respective print image, which are arranged in alignment with the surface of the optical imaging structure.

[0023] In order to allow a viewer viewing the printed image to perceive several frames simultaneously from a specific viewing angle, thereby enabling, for example, more complex and / or differentiated animations, an arrangement comprising a printed image and an optically imaging structure consisting of several plano-convex microlenses is proposed, in which several, preferably more than three, and in particular between five and ten, image elements are arranged side by side under at least one microlens of the optically imaging structure, wherein these image elements are arranged between the extent of the lens width of the microlens and its focus in a cross-sectional plane parallel to the principal plane of the microlens.wherein the cutting plane is arranged to intersect a cone or an angular field of the light incident through the lens width of the respective microlens in the direction of the adjacently arranged image elements, wherein several different image elements are arranged in a row within the cutting plane within the cone or the angular field.

[0024] This results in an arrangement comprising a printed image and an optically imaging structure consisting of several plano-convex microlenses, wherein each of these microlenses has a lens width preferably of less than 100 µm along the printed image, wherein the printed image comprises a plurality of image elements, wherein several image elements are arranged under at least one of the microlenses of the optically imaging structure, wherein these several image elements arranged under at least one of the microlenses of the optically imaging structure are arranged side by side along the lens width and each extend in the direction of the lens width over a shorter length than the lens width.wherein several, preferably at least three, and in particular more than three, different image elements are arranged in a row between the extent of the lens width of the microlens in question and its focus in a cross-sectional plane lying parallel to the principal plane of the microlens in question, within the cone or angular field of the light incident through the lens width of the microlens in the direction of the adjacently arranged image elements. With this arrangement, several frames are perceptible simultaneously to a viewer viewing the printed image from a specific viewing angle, resulting in complex and / or differentiated animations as well as, with appropriately colored image elements, smooth color transitions and / or, with different print motifs formed from the image elements, smooth frame transitions.

[0025] The substrate is, for example, a fibrous printing material, particularly paper, or a film, preferably a polymer film. The substrate can be opaque or transparent. The substrate can be single-layered or multi-layered, particularly partially multi-layered. Different layers of a multi-layered substrate can be made of different materials, for example, one layer of paper and another layer of a polymer film. The substrate, or at least each layer of this substrate, has a material thickness, i.e., a thickness, for example, of less than 100 µm, preferably less than 50 µm, particularly about 25 µm. A printed image formed on the substrate has a layer thickness, for example, of less than 10 µm, preferably less than 5 µm, particularly in the range of 1 µm to 2 µm. The substrate can be printed on one or both sides.

[0026] In a preferred embodiment of the invention, the arrangement of the printed image and the optically imaging structure is part of a security element or a document, in particular a security document. These documents include, for example, banknotes, credit cards, checks, securities, share certificates, passports, identity cards, driver's licenses, deeds of ownership, travel documents such as airline or train tickets, admission tickets, academic transcripts, and other official or governmental documents such as birth, death, or marriage certificates. This list is only exemplary and by no means exhaustive. Preferably, however, the documents in question are banknotes.

[0027] Fig. Figure 1 shows an example document 02 , in particular a security document 02 , on which at least one safety element 01 is applied. The document 02 and / or the relevant security element 01have at least a partially, preferably fully, optically imaging structure 03 on, whereby the respective optically imaging structure 03 preferably as one made of microlenses 11 trained micro-optical structure 03 is formed. The relevant optical imaging structure. 03 at least partially covers something on the document 02 formed or applied printed image 27 .

[0028] Fig. Figure 2 shows, in particular as an example, an excerpt from the one in the Fig. 1 depicted safety element 01 or document 02 in a highly magnified cross-sectional view an arrangement with a single plano-convex microlens 11 , which are grouped or arranged in a grid of microlenses 11 is integrated. The microlens in question. 11 has an axis of symmetry 12on, which also forms the optical axis 12 this microlens 11 forms the microlens 11 It can be rotationally symmetrical, spherical, or aspherical, or it can be, for example, axially symmetrical and rod-shaped, whereby in the case of an axially symmetrical, rod-shaped microlens 11 the axis of symmetry 12 extends orthogonally to its rod length. The microlens 11 It is manufactured, for example, from a transparent plastic or resin using injection molding, casting, embossing, or printing techniques. The microlens 11 has a convex surface that serves to allow light to enter. 13 , wherein a bundle of parallel light rays 14 on this surface 13 hits. The microlens 11 points axially symmetric to its optical axis 12 two opposite the convex enveloping surface 13 limiting boundary points 16 ; 17on, where the distance between these two boundary points 16 ; 17 one as lens width 18 designated width of this microlens 11 determined. The lens width 18 a microlens 11 is less than 100 µm. The two boundary points 16 ; 17 the convex enveloping surface 13 lie on an orthogonal axis to the optical axis 12 the microlens in question 11 arranged plane, which is also called main plane 19 this microlens 11 is referred to. In the Fig. In the illustrated embodiment 4, the main plane forms 19 a flat surface 21 the microlens in question 11 A distance between the main plane 19 the microlens 11 and their focus 23 (Focal point) forms the focal length 22 the microlens in question 11 , with the focus 23an intersection point of the bundled, parallel into the microlens 11 incident light rays 14 is the focal length 22 a microlens 11 It is below 100 µm. One in focus 23 orthogonal to the optical axis 12 The arranged plane is called the focal plane. 24 .

[0029] In the Fig. In the illustrated embodiment 2, the microlens 11 Part of a lens array or lens grid in which, with reference to a specific surface of arbitrary contour, a plurality of microlenses are preferably arranged without gaps or overlaps. 11 are arranged. The lens array or lens grid is on a substrate. 26 arranged, wherein the substrate 26 e.g., as a fibrous printing material, e.g., with a transparent window, in particular paper, or as a film, preferably a polymer film. The substrate 26has a material thickness 29 or thickness 29 e.g., of less than 100 µm, preferably less than 50 µm, in particular about 25 µm. The substrate 26 is preferably part of a safety element 01 or a document 02 , in particular a security document 02 The substrate 26 is at least in the case of the flat surface 21 the respective microlens 11 The covered area is transparently formed. In the area in the Fig. In the embodiment shown in section 4, the substrate is located on the back side. 26 , i.e., on the side of the microlens 11 far side of this substrate 26 a printed image 27 low layer thickness 36 e.g. applied by less than 10 µm, whereby this printed image 27 a multitude of individual, each different, image elements 28 exhibits these individual image elements28 are very small and extend parallel to the lens width 18 over just a few micrometers, e.g., a maximum of 10 µm. Therefore, it is possible to use several, e.g., ten such image elements. 28a until 28j in the area of ​​the flat surface 21 the microlens 11 to arrange the covered area side by side in a row. At least one of the adjacent image elements. 28a until 28j preferably has pixels and / or lines printed in different printing colors, in particular depending on the number of adjacent image elements. 28a until 28j whose individual pixels have a pixel size and / or whose lines have a line thickness in the range of a few micrometers, preferably in the range of less than 10 µm. The printed image 27preferably consists of an overprint or superimposition of several partial print images, each printed in different inks. The area within the flat surface is defined by... 21 the microlens 11 covered area, i.e., under the microlens in question 21 adjacent image elements 28a until 28j They preferably belong to different print motifs.

[0030] The area under the microlens in question 11 adjacent image elements 28a until 28j are advantageously closer to the microlens 11 arranged as their focus 23 These image elements are preferably 28a until 28j between the microlens in question 11 and their focus 23 in a plane parallel to the main plane 19 the microlens in question 11 lying cutting plane 31arranged, wherein the cutting plane 31 a cone 32 or an angle field 32 of each through the lens width 18 the microlens in question 11 in the direction of the adjacent image elements 28a until 28j is arranged in an intersection with the incident light, with the intersection plane 31 within the cone 32 or of the angle field 32 preferably several of the image elements simultaneously 28a until 28j are arranged in a row. In the Fig. In the illustrated embodiment 2, the elements are located within the cone. 32 or of the angle field 32 at the same time, for example, the five image elements 28c until 28g arranged in a row, whereas the rest are in the area of ​​the flat surface. 21 the microlens 11 Covered area arranged image elements 28a , 28b and 28huntil 28j for one the printed image 27 observing viewer under one with the incident light rays 14 corresponding, e.g., acute first viewing angle 33 are not perceptible. If, however, the printed image is not perceptible to someone... 27 The viewing angle of the observing observer is different from the first viewing angle. 33 different, e.g. obtuse-angled second viewing angles 34 When changes occur, the image elements he can perceive also change. 28a until 28j This is in the Fig. 3 shown, the same arrangement with a printed image 27 and one consisting of several plano-convex microlenses 11 existing optically imaging structure 03 as the Fig. 2. Due to the first viewing angle 33 different second viewing angles 34 are in the Fig. 3 illustrated embodiment for a printed image 27 The viewer sees only the image elements 28d until 28h noticeable, the others not.

[0031] Fig. Figure 4 shows a top view of, for example, a safety element. 01 or a document 02 , in particular a security document 02 ( Fig. 1) applied optical imaging structure 03 in the form of a geometric Fig. 37, whose preferably flat surface, at least substantially, i.e., macroscopically considered, has, for example, a rectangular contour 38 exhibits. Which extends over the entire geometric area Fig. 37 extending optical imaging structure 03 has a plurality of preferably plano-convex microlenses 11 a first subset of these microlenses 11 in a grid consisting of, for example, square cells39 existing, in particular uniform, grids preferably arranged without gaps and without overlap, wherein these microlenses arranged in the grid 11 The grid cells are each formed with rotational symmetry, either spherically or aspherically. 39 are defined by a set of grid points 41 defined, which are interconnected by a set of grid lines 42 are connected. The specific number of grid points 41 and grid lines 42 This depends on the shape of the chosen grid. In the case of square grid cells... 39 This results in four grid points in each case. 41 and four grid lines 42 , in the case of hexagonal lattice cells 39 There are six of each. The grid points 41 are each at points from the point set of the optically imaging structure 03 descriptive geometric Fig. 37 trained. Each of the grid cells 39 spanning grid points 41 Each is a microlens 11 arranged, wherein the vertex 44 ( Fig. 2 or Fig. 3) the microlens in question 11 preferably each one coincident with the respective grid point 41 is arranged, with the vertex 44 the microlens in question 11 each at the intersection of their optical axis 12 with its convex surface that serves to allow light to enter 13 is located.

[0032] A second subset of the optically imaging structure in question 03 belonging microlenses 11 is in at least one, preferably in several lens grids 43 with several microlenses, each axially symmetrical and rod-shaped 11 arranged in a lens grid 43 arranged microlenses11 each rod is arranged orthogonally to its length, preferably without gaps or overlaps. In the case of several rods within the area of ​​the geometric Fig. 37 arranged lens grids 43 These lens grids 43 For example, each structure has a different orientation. In an advantageous arrangement, the respective orientations of different structures within the surface of the same optically imaging structure are displayed. 03 arranged lens grid 43 e.g., at right angles, acute angles, or obtuse angles to each other. In geometric terms Fig. 37 of an optically imaging structure 03 The orientation of a lens grid formed within a rectangular, especially square, area can be determined using this area. 43 They can also be arranged diagonally. The optically mapping structure within the same area 03 arranged lens grid 43They differ in their respective shape and / or in their respective area proportion, for example.

[0033] Fig. Figure 5 shows, as an example, a highly magnified top view of a lens array consisting of several lens arrays. 43 composite optical imaging structure 03 . This involves several of the microlenses, each consisting of several microlenses. 11 existing lens grid 43 each formed as a preferably square rectangular area. The lens grids formed in each rectangular area 43 are arranged in at least one row and / or at least one column, in particular without gaps or overlaps. Adjacent lens grids 43 are each arranged in different orientations to each other, with lens arrays 43 same initial orientation and different lens grids 43The first orientation differs from the second orientation, for example, by alternating them. The multiple optically mapping structures 03 forming lens grid 43 In the preferred embodiment, they together form an underlying, preferably multicolored, printed image. 27 from, whereby this printed image 27 preferably consisting of an overprint or superimposition of several partial print images, each printed in different inks, as described above, and formed in the form of several pixels and / or lines. The print image 27 For example, it is designed such that a frame, i.e., a single image of, say, an animation, is constructed from two different half-fields line by line, i.e., using interlacing. Each of the optically imaging structures 03 involved lens grid 43It has an edge length in the range of 100 µm to a maximum of 300 µm, preferably approximately 250 µm. The respective lens width 18 which in the respective lens grids 43 this optically imaging structure 03 arranged microlenses 11 The size is less than 100 µm and preferably lies in the range between 20 µm and 65 µm. Due to the limited resolving power of the naked eye of normal-sighted adults, which is around 150 µm, the multiple structures together can be visualized at a distance of, for example, 25 cm. 03 forming lens grid 43 , i.e., their respective representations of the image elements affected 28 of the underlying printed image 27 They are not perceived individually, but rather the respective ones are perceived by a specific individual lens grid. 43 depicted image elements 28 of the relevant printed image 27merge in the perception of the printed image 27 viewing viewer with at least one of the respective images of lenticular lenses 43 , which relate to this optically imaging structure 03 to the specific lens grid in question 43 are arranged adjacently. The ones in the Fig. 5. Examples in the form of a square geometric shape Fig. 37 depicted optically imaging structure 03 with a total of, for example, sixteen lens grids arranged alternately in their respective orientations 43 The side lengths are measured, for example, in the range of 0.6 mm to 1.5 mm, preferably approximately 1 mm. An advantage of the arrangement consisting of a printed image is... 27 and one corresponding to the Fig. 5 developed optical imaging structures 03 consists of using a group of one-dimensionally oriented lens arrays 43Two-dimensional lenticular images can be generated.

[0034] As shown, the printed image results for one 27 in combination with the optically imaging structure 03 The viewer may experience very complex animations, e.g., different animations for different directions, if they are, for example, in the form of a geometric pattern. Fig. 37 developed optical imaging structures 03 with at least some of the based on the Fig. 4 or Fig. The 5 features shown are used. If within the area of ​​a geometric shape Fig. 37 trained optical imaging structures 03 differently oriented lens grids 43 used as described in the Fig. 4 and Fig. As shown in example 5, the printing process in the manufacturing process must be carried out in such a way that the underlying printed image 27of the type described above, whose color register is maintained two-dimensionally, e.g., both in the transport direction of the substrate moving through the printing press and perpendicular to it. This results in the registration accuracy of the print image in question. 27 The distance between the pixels and / or lines printed in different inks in two orthogonal directions is less than 10 µm and is in particular in the range of about 5 µm.

[0035] Fig. Figure 6 shows an optically imaging structure 03 consisting of a group of microlenses, each with rotational symmetry, either spherically or aspherically shaped 11 , which are in a grid of square grid cells 39 are arranged without gaps or overlaps, i.e., boundary points 16 ; 17 adjacent microlenses 11 are in physical contact. The square grid cells39 show four grid points 41 on, which are connected by two pairs of parallel grid lines 42 are connected. Each of the grid cells is connected. 39 spanning grid points 41 Each is a microlens 11 arranged, wherein the vertex 44 the microlens in question 11 each coinciding with the respective grid point 41 is arranged. Based on the area of ​​the square grid cell. 39 This results in a maximum packing density of π / 4 ≈ 78.5%, which means that at least approximately 21% of the area of ​​the respective grid cell 39 no contribution to the imaging of one of the microlenses in question 11 underlying printed image 27 can afford, but in one case the printed image 27 through the optically imaging structure 03 It creates a rather undesirable and disturbing perception for the observing viewer.

[0036] How Fig. As can be seen in section 7, an optically imaging structure is also possible. 03 consisting of a group of microlenses, each with rotational symmetry, either spherically or aspherically shaped 11 , which, unlike the Fig. 6 in a grid of hexagonal grid cells 39 are arranged without gaps or overlaps, i.e., boundary points 16 ; 17 adjacent microlenses 11 are in contact, the problem identified is the area between the microlenses 11 This does not resolve the rather undesirable and disturbing perception originating from this source. While the packing density here reaches a maximum of π / 6 √3 ≈ 90.6%, this still means that approximately 10% of the area of ​​each grid cell is occupied by [unclear text]. 39 no contribution to the imaging of one of the microlenses in question 11 underlying printed image 27 can afford it.

[0037] The undesirable optical effects of the limited packing density of microlenses arranged in a group, each rotationally symmetric spherically or rotationally symmetrically aspherically shaped 11 will be in the Fig. 8 and Fig. 9 illustrates this. In the two-part sections Fig. 8 and Fig. Figure 9 is a simplified representation of what a viewer perceives when looking through the same group of microlenses from two different viewing angles. 11 on the microlenses 11 underlying print image 27 looks, whereby this printed image 27 at least two different image elements 28a ; 28b exhibits, whereby in the Fig. 8 and Fig. 9 each on an optically neutral substrate 26 Each at least one first image element 28a each from the convex enveloping surface 13 the microlens in question 11is completely covered and at least one other second image element 28b each at the same position in a corner of, for example, a square grid cell 39 arranged and therefore by the microlens in question 11 is not covered or is only partially covered with a share of less than 50%.

[0038] According to the Fig. 8. The viewer looks, for example, perpendicularly through the microlens in question. 11 and takes that from the microlens in question 11 covered and thus depicted at least one first image element 28a True, since that is at least one of the first microlenses in question. 11 captured image element 28a lies in the beam path of the viewer and the microlens 11 visually appears to fill the space. The situation is different in the... Fig. Situation 9 is shown. Due to the oblique viewing angle of the viewer, e.g., at the viewing angle 33 ( Fig. 2) the beam path concerning it does not focus at least one first beam from the microlens in question 11 completely covered image element 28a or rather, the beam path doesn't even hit it, so that the viewer doesn't get an image of at least one first image element. 28a through the microlens in question 11 perceives. The microlens in question. 11 remains in the Fig. 9 situation depicted against the background of the optically neutral substrate 26 visually inactive. In both in the Fig. 8 and Fig. However, in the 9 situations depicted, at least one other second image element remains. 28b , each in the same position in a corner of, for example, a square grid cell 39 arranged and therefore by the microlens in question 11 only partially covered, perceptible to the viewer. Image elements arranged in this way. 28b, which are outside the convex enclosing surface 13 the microlens in question 11 If the images are arranged on an area that is at least almost completely covered, they lead to optical disturbances in the viewer's perception, such as so-called ghost images, a crosstalk effect, or a loss of contrast or sharpness with respect to the perceptible printed image intended as the useful signal. 27 Low-contrast and / or blurry moiré patterns can also occur if the printed image 27 Periodically recurring image elements 28 exhibits, however, the microlenses arranged in a uniform grid. 11 are not arranged in phase, but rather parts of at least some periodically recurring image elements are arranged differently. 28 are each arranged outside the area enclosed by the respective convex surface 13 the microlenses in question 11at least almost completely covered. The latter is due to the Fig. 10 through the periodically recurring star-shaped image elements 28 in their non-phase relationship to the lattice-like arrangement of the microlenses 11 illustrated.

[0039] To reduce and / or avoid the aforementioned undesirable disturbing perceptions, it is proposed to use an arrangement of several rotationally symmetric spherical or rotationally symmetric aspherical microlenses. 11 , which are in a grid of cells 39 existing grids are arranged on at least one, e.g., between adjacent microlenses 11 formed area that is separated from the respective convex enclosing surface 13 the microlenses in question 11 is not covered, incident light rays 14to reflect diffusely and thus scatter in a multitude of different spatial directions. The microlenses arranged in a group 11 form an optically imaging structure 03 in the form of a geometric Fig. 37 with at least one of the respective convex enveloping surface 13 the microlenses in question 11 uncovered area of ​​any shape, e.g. rectangular contour 38 from, wherein the respective convex surface 13 the microlenses in question 11 Uncovered area, incident light rays 14 It is diffusely reflective, i.e., scattering. The reflectance of this surface is in the range of, for example, 30% to 99%, preferably more than 60%.

[0040] The incident light rays 14A diffusely reflecting surface is, for example, roughened, i.e., this surface exhibits roughness structures with a roughness depth that depends on the respective wavelength of the incident light rays. 14 or, with reference to the spectrum of the incident light, is of the same order of magnitude and thus has a value in the range of, for example, 380 nm to 780 nm. Preferably, the roughness of the diffusely reflecting surface, specified, for example, by a mean roughness value Ra or an average roughness depth Rz of the surface in question (each, for example, according to DIN EN ISO 4288:1998-04), is approximately exactly the same as the wavelength of the incident light rays. 14 The roughness structures typically exhibit a large number of scattering centers for the incident light rays, distributed across the surface. 14 on.

[0041] The roughening of at least one incident light ray 14A diffusely reflecting surface can be created, for example, using an embossing or casting process, which is used to produce the multiple microlenses. 11 exhibiting optically imaging structure 03 is used, are manufactured or designed in such a way that the microlenses 11 embossing or casting, e.g., metallic die 46 e.g., areas roughened by grinding, lapping, honing, sandblasting, pickling, etching, or any other abrasive process 49 between the hollows 47 for the microlenses to be trained in each case 11 with a roughness in a range corresponding to the wavelength of the incident light rays 14 They are formed on a comparable scale, so that the roughness structures of these areas 49 e.g. when embossing the microlenses 11 using this die 46 on the one for these microlenses 11 intended blank48 or semi-finished products 48 to depict or, for example, when watering onto a substrate 26 train. This blank 48 or this semi-finished product 48 is made, for example, from a UV-curable plastic or resin. This approach is made possible by the Fig. Figure 11 illustrates this. The microlenses 11 uncovered roughened areas 49 on the surface of the geometric Fig. 37 appear dull and / or pale and / or whitish to an observer due to diffuse reflection, i.e., light scattering.

[0042] Another solution for reducing and / or avoiding the aforementioned undesirable and disturbing perceptions is, for example, the use of microlenses manufactured using casting or stamping techniques. 11 in their manufacturing process relative to image elements 28 an underlying printed image 27 to position. This is achieved through the Fig. Figure 12 illustrates this solution. It is suitable for microlenses manufactured using casting or stamping techniques, for example. 11 their respective each on at least one image element 28 an underlying printed image 27 related position set or at least adjustable in their manufacturing process, wherein these microlenses are arranged in a group 11 an optically imaging structure 03 in the form of a geometric Fig. 37 form.

[0043] The aforementioned undesirable and disturbing perceptions can, for example, be reduced and / or avoided by using microlenses 11 on the surface of the geometric Fig. 37 uncovered areas 49 especially white. The coloration, especially the whitening of the microlenses 11 on the surface of the geometric Fig. 37 uncovered areas 49This occurs, for example, in connection with the production of these microlenses. 11 and is based on the Fig. 13 explained. Fig. Figure 13 shows, by way of example, in four partial illustrations a to d, successive manufacturing steps for the formation of microlenses. 11 with these microlenses 11 on the surface of the geometric Fig. 37 uncovered areas, especially those colored white 49 In the first manufacturing step (a), troughs are formed. 47 one for the production of microlenses 11 used die 46 , i.e., a mold, e.g., filled with a UV-curable plastic or resin. Then the parts between the cavities are filled. 47 the die 46 arranged bridges 51 at the microlenses 11 uncovered areas 49 e.g., colored especially white by using a particularly white printing ink 52 load-bearing pressure beam 53on these from the microlenses 11 uncovered areas 49 The first part of the illustration shows the pressure applied, as indicated by the directional arrow. The second part, b), shows the process used to manufacture the microlenses. 11 die used 46 each with troughs filled with, for example, a plastic or resin 47 and in particular white-colored bridges 51 , after the white printing ink 52 load-bearing pressure beams 53 - as indicated by the directional arrow - from the die 46 has been removed again. According to the third partial representation c), the matrix 46 with their respective troughs filled with, for example, a plastic or resin 47 and their respective, in particular, white-colored bridges 51 in the direction of the arrow onto a substrate 26 pressed down, whereby the white printing ink 52 on the footbridges 51is still in a damp state. Both those on the walkways 51 the die 46 applied, especially white, printing ink 52 as well as the castings, e.g. made of plastic or resin, for the production of the microlenses 11 are applied to the substrate 26 transferred. As the fourth partial representation d) shows, the matrix is 46 with their emptied skips 47 and after the transfer of the printing ink, especially white ink 52 from the substrate 26 lifted, as indicated by the directional arrow. The manufacturing steps exemplified in the four partial illustrations a) to d) produce an array of several microlenses. 11 existing optically imaging structure 03 in the form of a geometric Fig. 37 formed, wherein the microlenses 11 on the surface of the geometric Fig. 37 uncovered areas49 are especially white. The microlenses 11 on the surface of the geometric Fig. 37 uncovered areas, especially those colored white 49 They also exhibit, for example, roughness structures with a roughness depth that is related to the respective wavelength of the incident light rays. 14 or is of the same order of magnitude with respect to the spectrum of the incident light, so that these areas 49 as a result of their color and surface texture, they are each diffusely reflective, i.e., scattering.

[0044] To create complex and / or differentiated animations and / or with appropriately colored image elements 28 smooth color transitions and / or from the image elements 28 To create smooth frame transitions between the different printed motifs, it is necessary to place microlenses under the microlenses. 11an optically imaging structure 03 each of several, preferably more than three, in particular between five and ten or even more image elements side by side 28 to arrange the individual image elements 28 in a printed image 27 are arranged to form a printed motif. Since the lens width 18 of each microlens 11 less than 100 µm and preferably in the range between 20 µm and 65 µm, this means that the individual image elements 28 Each of these printing-processed image elements has extremely small dimensions, on the order of just a few micrometers. As a rule, each of these image elements is composed of 28 composed of several pixels and / or lines, wherein the pixel size of these pixels and / or the line thickness of these lines is preferably less than half the respective lens width. 18the structure of the optical imaging structure in question 03 involved microlenses 11 . In the case of differently colored, especially the same, microlens 11 underlaid image elements 28Their pixels and / or lines are arranged with a color register of less than 10 µm each, particularly in the range of approximately 5 µm. The formation of pixels and / or lines in the aforementioned size range of only a few micrometers and / or their registration accuracy presents a significant printing challenge in an industrial manufacturing process, especially since, at these dimensions and / or accuracy requirements, factors such as printing-related deformation of the substrate and, preferably, rheological properties of the printing ink used, particularly its spreading (i.e., its areal distribution and propagation on the surface of the substrate), become significant influences on the formation of such pixels and / or lines.

[0045] In the preferred embodiment, the arrangement consists of a printed image. 27 and optically imaging structure 03 component of a safety element01 or a security document 02 The safety element is... 01 or the security document 02 For example, it is composed of several superimposed levels or layers, where the term "level" will be used in the following. One layer covers the viewer of the security element. 01 or the security document 02 upper level facing the viewer of the security element, at least partially, at least one level below it. 01 or the security document 02 lower level facing away from the viewer. In the direction of the security element. 01 or the security document 02 The upper plane facing the other side contains at least one or more microlenses. 11 exhibiting optically imaging structure 03 This upper level is formed as a substrate. 26e.g. formed in the form of a transparent polymer film, with on this substrate 26 Microlenses made of plastic or resin, e.g. cast or stamped. 11 are arranged. At least one lower level has a further substrate. 26 on, which differs in its material from, for example, the upper layer. The substrate 26 consists, for example, of a substrate containing fibers, in particular paper, wherein a printed image is formed in one of the lower levels, for example, on the substrate. 27 is at least partially covered by the upper layer. The upper layer and the at least one lower layer are preferably joined together in the printing press during the manufacturing process, preferably after printing on the substrate forming one of the lower layers. In a further embodiment, it can be provided that the substrate 26the upper level is printed on the reverse side, i.e., on the side facing at least one lower level, before being joined with the lower level in question.

[0046] Since this arrangement uses an optically imaging structure 03 the respective lens width 18 each individual microlens 11 and the respective dimensions of each image element involved in the print design 28 of the optically imaging structure 03 underlying printed image 27 Each of these particles is smaller than the resolving power of the naked eye of a normally sighted adult, which is around 150 µm, and cannot be perceived by a viewer of the printed image. 27 individual microlenses 11 and / or individual image elements 28 Each element is not perceived individually, i.e., as recognizable as such. Rather, the viewer of the printed image perceives it. 27 only one group of several microlenses at a time11 with these microlenses 11 underlaid image elements 28 perceived as a graphic element (pixel), whereby this perception relating to the respective pixel with regard to its shape and / or color is an integration via the image elements that cannot be individually resolved by the eye. 28 is.

[0047] Fig. Figure 14 shows a schematic and greatly enlarged arrangement of several, e.g. three, lower levels of a safety element arranged one above the other. 01 or a security document 02 , specifically in a first representation a) in a section and in a second representation b) in a corresponding top view. A corresponding structure covering the lower planes, which optically depicts the structure. 03 upper level, which is visible to a viewer of the security element 01 or the security document 02 is turned towards is in Fig. 14 is not shown for clarity. Regarding possible configurations of this visually representational structure. 03 will be directed to Fig. 2 to Fig. 13 are referenced, each with its corresponding descriptive text. As the lowest element, and thus the one most visible to the viewer of the security element. 01 or the security document 02 The furthe most distant level is according to Fig. 14 a) a substrate 26 e.g. in the form of a fibrous substrate on which a multi-colored printed image is applied. 27 applied or arranged. The printed image 27 In accordance with its print motif, it consists of several, usually different, especially differently colored, image elements. 28 together, which are on the substrate 26 are partly arranged in different pressure layers on top of each other. In a first embodiment, for example, directly on the substrate. 26 a lower pressure layer 54applied or arranged, wherein in this lower printing layer 54 several, i.e., different, each with several pixels and / or lines, widths, especially different colored color zones 61 each is preferably arranged next to each other without gaps or overlaps. On this lower printing layer 54 is at least one upper printing layer 56 arranged or applied, in which preferably several different, in particular differently colored, image elements are arranged or applied. 28 each on the color zones 61 For example, they are arranged next to each other at even intervals. The color zones 61 are preferably strip-shaped or rectangular; however, they can also have any other surface geometry. The upper printing layer 56 arranged image elements 28are at most half as wide as those extending in the same direction in the lower pressure layer 54 arranged color zones 61 , preferably the width of the in the upper printing layer is 56 arranged image elements 28 each less than 30% of the parallel width of the relevant layer in the lower printing layer 54 arranged color zone 61 This means that at least two of these are in the upper printing layer. 56 arranged image elements 28 such on one of the lower pressure layer 54 arranged color zone 61 arranged that in a top view of the safety element 01 or security document 02 between at least two in the upper printing layer 56 each of the image elements arranged at a distance from one another 28 each of these image elements 28 in the lower printing layer 54arranged color zone 61 is visible. As seen through the Fig. 14 b) shows that the top view of this safety element reveals 01 or security document 02 an arrangement in which the lower pressure layer appears to 54 formed image elements 28 and actually through the upper pressure layer 56 formed image elements 28 They are arranged alternately in a row. This arrangement results in several different pairs of image elements, each arranged alternately. 28 , each consisting of one through the respective color zone 61 depicted image element 28 the lower pressure layer 54 and an image element 28 the upper pressure layer 56 are formed. In the top view of the Fig. 14 b) are pairs of image elements formed by the same printing inks 28Examples of different frames 57 a to 57e summarized, with each of these frames 57a until 57e in combination with the microlenses arranged in the upper plane 11 existing optically imaging structure 03 for one the printed image 27 This creates a two-color flip image for the viewer. Another embodiment of the design described in the Fig. The arrangement shown in 14 may include an upper level that is visible to an observer of the safety element. 01 or the security document 02 is facing the front and is formed, for example, from a transparent polymer film, with the optically imaging structure on the front side. 03 features and on the reverse side first with the image elements, which are spaced apart from each other and are of different colors. 28 is printed, whereby these individual image elements 28 then with larger color zones61 overprinted. In this way, a multi-layered arrangement is also created, but unlike the first described embodiment, it does not have a substrate. 26 The printing material must be, for example, made of paper. This second embodiment thus leads, for example, to a safety element. 01 or a security document 02 reduced material thickness. Both embodiments have in common that the respective individual image elements 28 They can be applied or arranged with relatively high position tolerance, since the underlying color zones 61 compared to these image elements 28 are formed over a larger area. This is particularly true given the dimensions of the image elements, which are in the micrometer range. 28 very advantageous with regard to the manufacturing process for such a safety element 01 or security document 02 .

[0048] Alternatively to the one in the Fig. The arrangement shown in 14 is proposed to be located on a lower level of a safety element. 01 or a security document 02 arranged substrate 26 in a lower pressure layer 54 several differently colored color zones 61 to be arranged side by side, with one running perpendicular to the longitudinal direction of the respective color zone 61 extending width preferably of the lens width 18 corresponds, whereby these color zones are formed, for example, in the printing inks red, green and blue, whereby these different colored color zones 61 through an upper pressure layer 56 are masked. The masking is achieved, for example, by the fact that the upper printing layer 56 an arrangement of holes 59 or slits 59 exhibits.

[0049] Fig. Figure 15 shows the lower printing layer in a top view on the left. 54with several, e.g. three, each the width of a lens 18 formed, e.g., parallel, preferably differently colored color zones 61 , on which lower printing layer 54 - indicated by the plus sign - the one on the right in the Fig. 15 masks shown 58 , especially shadow mask or stripe mask as the upper printing layer 56 is arranged. The color zones 61 are formed, for example, by the printing inks R (red); G (green); B (blue). Into the mask 58 is assigned to the respective color zones 61 each with an individual pattern of holes 59 or slits 59 inserted through which holes 59 or slots 59 through which the respective printing ink R; G; B of the underlying color zone 61 becomes perceptible. Each of the color zones, preferably formed in different printing inks R, G, and B, is perceptible. 61one different from the other color zones 61 various patterns of holes 59 or slits 59 assigned so that all holes 59 or slots 59 in their respective individual positions depending on the color zone 61 differ from each other. All these holes 59 or slots 59 point at least perpendicular to the longitudinal direction of the respective color zone 61 , i.e. in the direction of the width of the color zone in question 61 each extension is smaller than the respective lens width. 18 of those microlenses 11 is the one that this mask 58 cover up. In addition, it shows Fig. 15, how the color zone varies 61 differently masked, preferably differently colored, three color zones 61 in combination with the mask 58 represent. Fig. 15 shows that the differently colored color zones 61 through the different patterns of holes 59 or slits 59 the mask 58 be coded in a unique way. The holes 59 or slots 59 the mask 58 are, for example, arranged in a grid of preferably square grid cells, wherein this grid preferably corresponds in shape and / or size to the grid in which the microlenses are arranged. 11 the optically imaging structure 03 are arranged. This is in the Fig. 15 indicated by the dashed lines that form the mask 58 Divide into rows and columns.

[0050] One advantage in masking color zones 61 consists of the fact that only these color zones 61to be printed in register, and only in a single direction, namely orthogonal to its longitudinal extent, whereby the requirements for the color register are also not nearly as high as in the embodiment of the Fig. 14. The image elements were there. 28 the lower pressure layer 54 and the image elements 28 the upper pressure layer 56 to position them in a very precise color register relative to each other in order to selectively create specific alternating images or other perceptions. In the embodiment of the Fig. 15, however, only needs to be ensured that the respective holes 59 or slots 59 the masking in the selected assignment to the relevant lenses, each in lens width 18 Color zones formed from, for example, 20 µm to 65 µm 61This is significantly easier to achieve in a printing manufacturing process than maintaining a color register in the range of less than 10 µm, rather around 5 µm.

[0051] The optically imaging structure 03 facing surface of the mask 58 is preferably white, in particular formed by a white printing ink, to be visible to a viewer of the printed image 27 to reduce or avoid unwanted disturbing perceptions that would occur with a different color scheme consisting of areas between the rotationally symmetric microlenses arranged in a group. 11 could result.

[0052] Fig. Figure 16 shows an optically imaging structure 03 in the form of a geometric shape, e.g. a rectangle Fig. 37, wherein the optically imaging structure 03 several groups of rotationally symmetric microlenses 11exhibits, with these groups arranged in a grid consisting of rows and columns. These groups of microlenses 11 are, for example, uniformly shaped, with several microlenses each. 11 Each group is arranged, for example, into a rectangle, and in particular a square. Between the individual groups of microlenses 11 Examples include footbridges. 62 trained, which are free of microlenses 11 are. In the in the Fig. The embodiment shown in 16 is rotationally symmetric, preferably plano-convex microlenses. 11 each with a lens width 18 of e.g. 20 µm in preferably square groups of several in each dimension, e.g. six by six microlenses 11arranged, wherein these groups are in turn arranged in a rectangular grid consisting of several, i.e., a multitude of columns and several, i.e., a multitude of rows. The formation of the optically imaging structure. 03 according to Fig. 16 leads to each group of microlenses 11 in the perception of a viewer who sees the optically representing structure 03 underlying print image 27 considered as a graphic element (pixel), since each of these groups of microlenses 11 in both dimensions, each extending over a length in the range of 120 µm to 150 µm, which is approximately within the resolving power of the naked eye of a normally sighted adult. If such an optically imaging structure exists... 03 on a white mask 58 The individual groups of microlenses are arranged as follows: 11white bridges between each other 62 This improves the contrast between individual pixels. Of course, optically imaging structures can also be used. 03 according to the Fig. 4 or Fig. 5 in conjunction with the arrangements according to the Fig. 14 or Fig. 15 can be used.

[0053] Based on Fig. 17 now describe an arrangement for the formation of structures in the micrometer range in an image element. 28 a microlens 11 to be underlaid print image 27 as well as explaining a method for applying to a substrate 26 applied image elements 28 a printed image 27 can be coded, whereby the printed image 27 after the encoding of at least some of its image elements 28 one of several microlenses 11 exhibiting optically imaging structure 03 for the formation of a safety element 01or a security document 02 is supported. In this arrangement and this method, a laser is used in each case. 63 , preferably a gas laser, in particular an excimer laser 63 used to selectively remove printing ink from a selected image element 28 to remove. One of the laser 63 outgoing laser beam 66 is through a mask 64 on the image element to be edited 28 directed, whereby this mask 64 e.g. in a laser beam 66 orthogonal plane a coding in the form of a in this mask 64 exhibits a developed pattern, whereby this pattern determines at which points of the selected image element 28 The mask is used to selectively remove printing ink. 64 It is, for example, made of a semi-transparent quartz, in which the pattern is created by appropriately positioned openings for the laser beam. 66is trained. This in the mask 64 The established pattern is thus transferred to the image element being processed. 28 , as per the pattern of the mask 64 in this image element 28 Printing ink upon impact of the laser beam 66 e.g., selectively removed by evaporation. The image element in question. 28 exhibiting substrate 26 The laser thus removes the previously applied printing ink from certain areas. 63 , especially excimer lasers 63 It is preferably operated in pulsed mode with a pulse duration in the range of, for example, 1 ns to 40 ns, preferably around 20 ns. The wavelength of the laser beam 66 It is preferably located in the ultraviolet spectral range, e.g., in the range between 100 nm and 360 nm. With an excimer laser 63 Structures with a width in the range of 0.25 µm to 1 µm can be formed, so that in one image element28 The finest patterns can be created from selectively removed areas.

[0054] This results, for example, in a method for producing a printed image. 27 exhibiting safety element 01 or a security document 02 , in which several image elements 28 of the printed image 27 by applying printing ink to a substrate 26 be trained using a laser 63 outgoing laser beam 66 at least one selected location of a selected image element 28 of the printed image 27 The previously applied printing ink is removed. This is done using a laser. 63 e.g. a gas laser, in particular an excimer laser 63 used. With the laser beam 66 will be in the selected image element 28 of the printed image 27a structure with a width preferably in the range between 0.25 µm and 1 µm is formed, wherein these structures are e.g. similar to those in the Fig. 12 or Fig. 16 can be similar. The laser 63 It is advantageously operated in pulsed mode with a pulse duration in the range between 1 ns and 40 ns and / or with a wavelength in the range between 100 nm and 360 nm. The at least one point where the laser beam... 66 in the selected image element 28 of the printed image 27 The previously applied printing ink is preferably removed by selecting a path in which the laser beam is inserted. 66 a mask 64 with at least one opening for the laser beam 66 is arranged, whereby there is at least one opening in the mask 64 corresponding to the at least one area in the selected image element that needs to be freed from printing ink 28 of the printed image 27is positioned. The printed image 27 of the safety element 01 or the security document 02 In particular, one of several microlenses will be used. 11 exhibiting optically imaging structure 03 underlaid, whereby this printed image 27 at least one image element 28 with at least one each using the laser 63 outgoing laser beam 66 has an area free of printing ink, with the respective lens width 18 the microlenses 11 less than 100 µm and preferably in the range between 20 µm and 65 µm. The printing ink for forming the at least one image element. 28 of the printed image 27 is applied to an opaque or transparent substrate 26 applied and from there by means of the laser 63 outgoing laser beam 66 selectively ablated. The microlenses 11exhibiting optically imaging structure 03 They are manufactured, for example, using injection molding, casting, stamping, or printing techniques. The microlenses 11 the optically imaging structure 03 are preferably made of a plastic or a resin. Advantageously, the at least one image element is 28 with at least one area to be cleaned of printing ink, formed in white printing ink. The at least one image element 28 In a preferred embodiment, a color zone is formed with at least one area to be freed from printing ink. 61 e.g., underlined in one of the printing colors red, green, or blue, which differs from the printing color of at least one image element. 28 with the at least one area to be freed from printing ink being formed in a different color, so that the area freed from printing ink of the at least one image element 28this image element 28 reveals a differently colored, underlying color zone.

[0055] The safety features outlined 01 or documents 02 , in particular security documents 02 with the optically imaging, especially micro-optical structure 03 These images can, in principle, be produced using a wide variety of printing presses and / or printing processes. One particular advantage is an embodiment in which several or all of the aforementioned partial images are printed onto the substrate. 26 applied or printed on, while being guided by the same guide element 118 ; 119 guided, for example on the same guide element 118 ; 119 e.g. a belt or belt system or preferably a transport cylinder 118 ; 119 , superimposed, by a printing mechanism 101 ; 102is promoted. That is, the printing of the substrate. 26 The transfer of at least two sub-images, preferably of different colors, on the same page with the different frames takes place on a transport path section with a continuous transport means, i.e. without an intermediate transfer of the substrate. 26 between different means of transport.

[0056] Preferably, the printing with at least two or more partial print images is carried out simultaneously and / or at the same printing point. 103 ; 104 , by first superimposing them on each other and then transferring them as a whole to the substrate in an indirect process 26 to be handed in.

[0057] In a preferred version, the safety element is located in the production path. 01 or document 02 underlying substrate 26 a printing press 100 with at least one printed work 101 ;102 provided through which the substrate 26 at least on one side, e.g., on the side that contains the micro-optical structure 03 in the completed security element 01 or document 02 opposite, at the same pressure point 103 ; 104 simultaneously with at least two or more imaging printing cylinders 106 ; 107 e.g., shaped cylinders 106 ; 107 , originating from, preferably multicolored printed images, dhog partial printed images, is printable (see e.g. Fig. 18, Fig. 19 and Fig. 20). The substrate 26 is thus - preferably based on at least its micro-optical structure 03 in the completed security element 01 or document 02 opposite side - at the same pressure point 103 ; 104 on the same side simultaneously with several forming cylinders 106; printed with 107 overlapping and preferably differently colored partial print images. Such a printed work 101 ; 102 will also be referred to below as a collective publication. 101 ; 102 designated.

[0058] The collective publication 101 ; 102 includes the pressure point 103 ; 104 for the substrate to be printed 26 supplying printing cylinders 108 ; 109 , through which substrate brought along a transport path 26 through the contact between the printing cylinder 108 ; 109 and substrate 26 It can be printed with the ink of the image previously applied to its surface. The printed image is a superimposition of several partial images, which are produced by multiple image-forming printing cylinders. 106 ; 107 , especially shaped cylinders 106 ; 107 , of the printed work 101, 102 originate and on this the pressure point 103 ; 104 supplying printing cylinder 108 ; 109 or are superimposed on each other upstream of the ink flow to form the printed image. This requires two or more image-forming printing cylinders. 106 ; 107 e.g., shaped cylinders 106 ; 107 , includes, for example, the handling of the cylinder that collects the partial print images, in particular the printing point 103 ; 104 forming printing cylinder 108 ; 109 , arranged one behind the other and attachable or positioned to these. Preferably, for the formation of the pressure point 103 ; 104 the relevant printing cylinder 108 ; 109 and one as a counter-pressure cylinder 118 ; 119 effective additional printing cylinder 118 , 119 about the substrate 26They are arranged or can be arranged next to each other. For example, this is another printing cylinder. 118 , 119 as the substrate 26 conveying transport cylinder 118 ; 119 trained and also simultaneously provides the aforementioned leadership element 118 ; 119 depict on which the substrate 26 is supported or guided while being printed by at least two or more partial print images.

[0059] In preferred version of the printed work 101 ; 102 is the pressure point 103 ; 104 forming printing cylinder 108 ; 109 simultaneously as the collecting cylinder that collects the partial print images 108 ; 109 , especially color collecting cylinders 108 , 109 , designed and preferably as transmission or blanket cylinders 108 ; 109executed. It features one or more printing blankets arranged one behind the other around its circumference, each with a compressible and / or elastic layer.

[0060] Those with the same collecting cylinder 108 ; 109 cooperating imaging printing cylinders 106 ; 107 are in the area of ​​their effective surface by respective color units 111 ; 112 colored, which can in principle be designed in any way. Preferably, however, they are designed as lift inking units. The image-forming printing cylinders 106 ; 107 and the associated dye works 111 ; 112The comprehensive printing unit sections can, in principle, operate entirely or partially according to a dry offset printing process, i.e., without a dampening system and / or using printing plates for dry offset printing. Preferably, however, all or at least two of the printing unit sections are designed to operate according to wet offset printing, i.e., with their respective dampening systems. 113 ; 114 and / or using printing forms for wet offset printing.

[0061] In a preferred embodiment, at least two of the imaging cylinders 106 ; 107 The surface area is formed and / or equipped with a printing form whose structure enables or permits printing with image elements of a specified pixel size or line thickness. When printing two partial images, the specified security elements are incorporated during the manufacturing process. 01 or documents 02- possibly including - image elements with a line thickness of less than 100 µm, preferably less than 50 µm, in particular less than 20 µm on the substrate 26 printed. For example, the registration accuracy of these two partial print images in the transport direction is considered, with a maximum relative deviation of less than 20 µm, preferably less than 10 µm. In the case of a printing form designed as a relief printing plate, this includes, for example, raised ridges effective for printing with a width of less than 100 µm, preferably less than 50 µm, and in particular less than 20 µm, at the outer end. In the case of a printing form designed as a flat printing plate for wet offset printing, this includes, for example, hydrophilic printing plate areas effective for printing with a width of less than 100 µm, preferably less than 50 µm, and in particular less than 20 µm.

[0062] In an advantageous alternative embodiment, which is not detailed here, the printing with the partial print images to be superimposed is carried out in the production path of the substrate underlying the security element or document. 26 a printing press 100 provided with at least one printing unit operating according to a non-impact process, i.e. without a printing form, e.g. an inkjet printing unit, through which the substrate 26 At least on one side, e.g., the side opposite the micro-optical structure in the finished security element or document, it is printed in multiple colors using a printing-form-less printing process, e.g., inkjet printing. Preferably, this is also carried out in the manner described above on a transport path section with a continuous transport means, i.e., without an intermediate transfer of the substrate. 26between different means of transport. The printheads and / or their arrangement in the printing unit are designed or usable, for example, for printing with a resolution of at least 600 dpi, preferably at least 1200 dpi, and in particular at least 2400 dpi. During the manufacture of the aforementioned safety elements... 01 or documents 02 For example, two or more partial print images are printed onto the substrate by printheads with a resolution of at least 600 dpi, preferably at least 1200 dpi, and in particular at least 2400 dpi. 26 printed.

[0063] In the production path of the safety element 01 or document 02 underlying substrate 26 is - fundamentally independent of the design of the printing press 100 included printing mechanism, but advantageous in conjunction with a version as described above - furthermore at least one application device 116 ; 117provided in which the substrate 26 with a micro-optical structure 03 is subject to or can be subjected to. This includes the collective print work. 101 ; 102 and the application setup 116 ; 117 basically in separate, decoupled processes or inline in an overall process encompassing both processes one after the other, for example a printing press 100 with a printed work 101 ; 102 and an application device 116 ; 117 , be provided for. The application setup can be used for this purpose. 116 ; 117 The process generally takes place either before or after printing by the printing machine. 101 ; 102 , especially a collective publication 101 ; 102 , are planned.

[0064] In a first group of embodiments, for example, two separate units are used for application and printing, namely the collective printing unit. 101 ; 102 comprehensive printing unit and application device 116 ; 117 planned (see e.g. Fig. 2) Such a composite print can be placed on only one side of the substrate path or on both sides of the substrate path. 101 ; 102 with two or more forming cylinders 106 ; 107 be provided for. In the second case, these can be implemented in a double printing unit and between their respective color collecting cylinders. 108 ; 109form a double printing point. In a first embodiment, the two units can, for example, be provided in separate machines, so that printing and application take place in separate steps, or in a second embodiment, they can be integrated inline in a common machine.

[0065] The application setup - intended for inline or offline use 116 In a first version, it can be achieved by a device for applying and connecting 116 of the substrate 26 with a structure that optically maps 03 forming and / or encompassing layer, e.g. a plastic film or film elements with the lenses 11 or with the micro-optical structure 03 This application setup 116 The device for connecting the partial print images can be included in the production path before or after printing. 116as a hot stamping device 116 executed, through which the micro-optical structure 03 comprehensive layer, e.g. plastic film, onto the printed or to-be-printed substrate 26 is applicable.

[0066] In a second group of embodiments that are advantageous with regard to the production process and / or accuracy (see e.g. Fig. 3) the printing – in particular simultaneous – with at least two partial print images and the application of the micro-optical structure takes place. 03 while passing through the same guide element 118 ; 119 guided, for example on the same guide element 118 ; 119 e.g. a belt or belt system or preferably a transport cylinder 118 ; 119 , lying flat, is conveyed through the machine. That is, the printing of the substrate. 26on the same page with at least two partial images, as well as the application of the micro-optical structure 03 on the same or the opposite side of the substrate 26 This takes place on a transport path section with a continuous means of transport, i.e., without an intermediate transfer of the substrate. 26 between different means of transport. As mentioned above, the printing with at least two partial print images preferably takes place simultaneously.

[0067] In the second group of embodiments, the application can also be carried out, in principle, by applying a micro-optical structure. 03 A comprehensive layer, e.g., a film-like layer, is used. Preferably, however, a device for forming the micro-optical structure is required. 03 on the substrate 26 provided for, by which on the substrate 26a layer of uncured, e.g. polymer-containing plastic material, e.g. a plastic containing natural or synthetic resin, can be applied and is at least in one or more areas still liquid or soft in the micro-optically effective structure. 03 It is malleable. For example, the material is applied selectively or over the entire surface using an application device. 121 e.g. a printing or coating plant 121 , in particular a screen printing machine 121 , onto the substrate 26 applied and used to shape the structure 03 with the previously actuated side guided over an embossing tool, which imprints a pattern on the surface corresponding to the micro-optical structure. 03 complementary pattern of depressions, e.g., matrix 46 , exhibits. In a preferred embodiment, this is achieved during the printing of the substrate guide. 26 serving guide element 119 as an embossing tool, e.g. embossing cylinder119 , executed and has a matrix on its surface 46 with the indentations. Printing on the substrate. 26 It can, in principle, be determined by the scope of the guide element. 119 The initial drying process takes place before the application of the plastic material, but preferably in the circumferential direction of the guide element es119 after the application of the material to be formed and optionally a preferably UV-based intermediate drying stage. The common guide element is... 119 not only as transport cylinders 110 effective, but equally as an embossing cylinder 119 and serves the color collection cylinder 109 of the collective publication 102 executed printed work 102 as a counter-pressure cylinder 119 .

[0068] The application and shaping of the micro-optical structure 03 and printing with multiple partial print images on the same guide element 119This can be followed by further single- or double-sided printing, preferably also by a gang printing unit. 101 ; 101' ; 102 This occurs on the input side of the printing press. 100 can a feed device 122 e.g. a stack feeder, through which the substrate may be fed. 26 in the form of a printing material 04 , e.g. a web of printed material or preferably in the form of sheets of printed material 04 , is supplied. Across the width of the substrate. 04 For example, several of the above documents will then be... 02 as so-called uses printed side by side simultaneously and with the structure 03 provided. In a receiving facility 123 , e.g. sheet layout, the intermediate products containing the benefits are grouped into packages.

[0069] In this last embodiment, the safety element is manufactured using a specific process. 01or security document 02 the single- or multi-layered substrate 26 via the same guide element 119 guided and thereby both with the micro-optical structure 03 as well as being loaded with at least two partial print images. This meets the highest demands regarding the registration and alignment between the partial images on the one hand, and between the partial images and the position of the micro-optical structure on the other. 03 on the other hand.

[0070] Regardless of whether the application of the micro-optical structure 03 The substrate is formed by applying a solid layer, e.g., plastic film, or by applying and molding soft or liquid plastic. 26 in at least one area of ​​the structure 03 comprehensive layer of covered substrate 26 transparent, by being embedded in the substrate 26either made transparent itself or having a transparent window into the otherwise opaque substrate in this area. 26 is or will be integrated. Reference symbol list 01 Safety element 02 Security document 03 optical imaging structure; micro-optical structure 04 Printing material, sheet 05 - 06 - 07 - 08 - 09 - 10 - 11 Microlens 12. Axis of symmetry; optical axis 13 convex enveloping surfaces 14 Light beam 15 - 16 Edge point 17 Edge point 18 lens width 19 Main Level 20 - 21 flat surface 22 Focal length 23 Focus 24 Focal plane 25 - 26 Substrat 27 Print image 28 Image element ( 28a (up to age 28) 29 Material thickness; thickness 30 - 31 Section plane 32 cones; angle field 33 first viewing angle 34 second viewing angle 35 - 36 layer thickness 37 geometric figure of an optically imaging structure ( 03 ) 38 contour 39 grid cell 40 - 41 grid point 42 grid line 43 lens grids 44 Vertex 45 - 46 die 47 trough 48 blanks; semi-finished products 49 roughened area 50 - 51 Bridge 52 printing inks 53 printing plates 54 lower printing layer 55 - 56 upper printing layer 57 Frame ( 57a until 57e ) 58 Mask 59 holes; slot 60 - 61 Color Zone 62 Bridge 63 Lasers; Excimer lasers 64 Mask 65 - 66 Laser beam 100 printing presses 101 Printed matter, collated printing matter 102 Printed matter, collating printing matter 103 Pressure point 104 Pressure point 105 - 106 printing cylinders, imaging cylinders, form cylinders 107 printing cylinders, imaging cylinders, form cylinders 108 printing cylinders, ink collection cylinders, transfer cylinders 109 printing cylinders, ink collection cylinders, transfer cylinders 110 - 111 Dyeing unit, lift dyeing unit 112 inking unit, lift inking unit 113 Humidification system 114 Humidification system 115 - 116 Application setup 117 Application device 118 Guide element, transport cylinder 119 Guide element, transport cylinder, embossing cylinder 120 - 121 Printing unit, coating unit, screen printing unit 122 Feed device 123 Acceptance device QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 112010000957 T5

[0002] WO 2007 / 042919 A2

[0003] EP 2996885 B1

[0004] Cited non-patent literature

[0000] DIN EN ISO 4288:1998-04

[0040]

Claims

[1] Method for producing a security element (01) or a security document (02) having a printed image (27), wherein several image elements (28) of the printed image (27) are formed by applying printing ink to a substrate (26), wherein the previously applied printing ink is removed by means of a laser beam (66) emanating from a laser (63) at least at one selected location of a selected image element (28) of the printed image (27). [2] Method according to claim 1, characterized by , that a gas laser, in particular an excimer laser (63), is used as the laser (63). [3] Method according to claim 1 or 2, characterized by , that with the laser beam (66) a structure with a width in the range between 0.25 µm and 1 µm is formed in the selected image element (28) of the printed image (27). [4] Method according to claim 1 or 2 or 3, characterized by, that the laser (63) is operated in pulsed mode with a pulse duration in the range between 1 ns and 40 ns and / or with a wavelength in the range between 100 nm and 360 nm. [5] Method according to claim 1 or 2 or 3 or 4, characterized by , that the at least one location where the previously applied printing ink is removed by means of the laser beam (66) in the selected image element (28) of the printed image (27) is selected by means of a mask (64) with at least one opening for the laser beam (66) being arranged in the beam path of the laser beam (66), wherein the at least one opening in the mask (64) is positioned according to the at least one location to be freed of printing ink in the selected image element (28) of the printed image (27). [6] Method according to claim 1 or 2 or 3 or 4 or 5, characterized by, that the printed image (27) of the security element (01) or the security document (02) is overlaid on an optically imaging structure (03) having microlenses (11), wherein this printed image (27) has at least one image element (28) with at least one area freed from ink by means of the laser beam (66) emanating from the laser (63). [7] Method according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized by , that the printing ink is applied to an opaque or transparent substrate (26) to form at least one image element (28) of the printed image (27) and is selectively removed from there by means of the laser beam (66) emanating from the laser (63) and / or that the optically imaging structure (03) having microlenses (11) is produced by injection molding, casting, stamping or printing. [8] Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7, characterized by, that the microlenses (11) of the optical imaging structure (03) are made of a plastic or a resin. [9] Method according to claim 6 or 7 or 8, wherein the substrate is printed on a first side, in particular simultaneously and / or at the same printing point, with several superimposed partial print images by at least one printing unit (101; 102), and on the same or preferably other side of the substrate (26) by an application device (116; 117), in particular inline, the optically imaging structure (03) comprising the microlenses (11) is applied. [10] Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9, characterized by , that the at least one image element (28) with the at least one area to be freed from printing ink is formed in white printing ink. [11] Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, characterized by , that a color zone (61) is placed under the at least one image element (28) with the at least one area to be freed from printing ink, wherein the color zone (61) is formed in a different color than the printing ink of the at least one image element (28) with the at least one area to be freed from printing ink, so that the differently colored color zone (61) placed under this image element (28) is exposed by the area freed from printing ink.

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