Method for producing security elements having a lenticular flip

Abstract

A method for producing a security element formed as a lenticular flip, including a micro-optical layer, a carrier substrate and an image layer, wherein the image layer includes n images for n=1 to i which are visible from an n-th observation angle allocated to the n-th image, and wherein n is at least 1. The images are imaged on a photoresist with parallel light in contact print or by means of projection. After the photoresist is developed, an image layer which includes the i images is present.

Claims

1. A method for producing a security element comprising a micro-optical layer, wherein the micro-optical layer comprises an array formed from micro-optical systems, a carrier substrate and one image layer or several image layers, wherein the one image layer or several image layers comprises or comprise n partial images for n=1 to i which are visible from an n-th observation angle allocated to the n-th partial image, and wherein n is at least 1, and wherein the following method steps are provided: a) providing the carrier substrate, on the upper side of which the micro-optical layer is formed; b) applying a photoresist to the underside of the carrier substrate; c) forming a latent n-th partial image in the photoresist, wherein an n-th master image is projected onto the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein the photoresist in step b) is applied in the form of an n-th master image to the underside of the carrier substrate and wherein the photoresist is exposed through the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth; d) repeating method step c) i1 times until the i-th latent partial image is formed; e) developing the photoresist to form the image layer, wherein method steps b), c) and e) are performed with an n-th photoresist formed with an n-th color and/or an n-th sensitivity, and wherein method steps b), c) and e) are repeated (i1) times, wherein i is at least 2.

2. The method according to claim 1, wherein, after the second variant of method step c) in which the photoresist in step b) is applied in the form of an n-th master image to the underside of the carrier substrate and the photoresist is exposed through the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, method step e) is carried out before method step d).

3. The method according to claim 1, wherein the micro-optical systems in the array form a pattern formed as a security feature and/or as a decorative feature of the security element.

4. The method according to claim 1, wherein the micro-optical layer comprises differently formed arrays of micro-optical systems.

5. The method according to claim 1, wherein the micro-optical layer comprises a diaphragm layer which has transparent and opaque areas.

6. The method according to claim 1, wherein the micro-optical layer comprises an array formed from micromirrors.

7. The method according to claim 1, wherein the micro-optical layer comprises an array formed from microlenses.

8. The method according to claim 7, wherein the microlenses are formed with at least two different focal lengths.

9. A method for producing a security element comprising a micro-optical layer, wherein the micro-optical layer comprises an array formed from micro-optical systems, a carrier substrate and one image layer or several image layers, wherein the one image layer or several image layers comprises or comprise n partial images for n=1 to i which are visible from an n-th observation angle allocated to the n-th partial image, and wherein n is at least 1, and wherein the following method steps are provided: a) providing the carrier substrate, on the upper side of which the micro-optical layer is formed; b) applying a photoresist to the underside of the carrier substrate; c) forming a latent n-th partial image in the photoresist, wherein an n-th master image is placed on the micro-optical layer and is exposed with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein an n-th master image is projected onto the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein the photoresist in step b) is applied in the form of an n-th master image to the underside of the carrier substrate and wherein the photoresist is exposed through the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth; d) repeating method step c) i1 times until the i-th latent partial image is formed; and e) developing the photoresist to form the image layer, wherein the micro-optical layer has two or more micro-optical systems with a longitudinal axis and a transverse axis arranged next to each other, wherein the longitudinal axes of the micro-optical systems are arranged at an x-azimuth to the long side of the carrier substrate.

10. The method according to claim 9, wherein the longitudinal axes of the micro-optical systems are formed as a curve.

11. The method according to claim 9, wherein the micro-optical systems are formed as cylindrical lenses.

12. The method according to claim 9, wherein the x-azimuth is equal to 90.

13. The method according to claim 9, wherein, in method step b), a negative photoresist is applied.

14. The method according to claim 9, wherein, in method step b), a positive photoresist is applied.

15. The method according to claim 9, wherein, in method step b), a microstructure is formed in the underside of the photoresist facing away from the carrier substrate or in the underside of the image layer facing away from the carrier substrate.

16. The method according to claim 9, wherein, after method step e), a decorative layer is applied to the image layer.

17. The method according to claim 9, wherein, after method step e), one color layer or several color layers is or are applied to the image layer.

18. The method according to claim 9, wherein, after method step e), a metal layer and/or an HRI layer is applied to the photoresist or to the image layer.

19. The method according to claim 18, wherein the image layer is formed as an etching mask and areas of the metal layer or of the HRI layer not covered by image areas of the image layer are removed by etching.

20. The method according to claim 18, wherein the image layer is used as lift-off layer.

21. The method according to claim 9, wherein, after method step e), a multilayer structure comprising a semitransparent metal layer, a spacer layer and a reflective metal layer is applied to the image layer.

22. The method according to claim 9, wherein, after method step e), the image layer is brought into contact with a transfer ply of a transfer film and the transfer ply is transferred from the transfer film to the image layer only at the points where the image layer is located.

23. The method according to claim 9, wherein, after method step e), a volume hologram layer is applied to the image layer.

24. The method according to claim 9, wherein method steps b), c) and e) are performed with an n-th photoresist formed with an n-th color, and wherein method steps b), c) and e) are repeated (i1) times, wherein i is at least 2.

25. The method according to claim 9, wherein method step b), c) and e) are performed with an n-th photoresist formed with an n-th color and/or an n-th sensitivity, and wherein method steps b), c) and e) are repeated (i1) times, wherein i is at least 2.

26. The method according to claim 25, wherein, in method step c), the exposure is carried out with an n-th exposure level.

27. The method according to claim 23, wherein the n photoresists are applied to the underside of the carrier substrate as n layers arranged at least partially one above the other.

28. The method according to claim 27, wherein the n photoresists are applied to the underside of the carrier substrate as a striped pattern.

29. The method according to claim 9, wherein the image layer is formed from two partial images wherein, in method step c), the exposure is effected with a first incident azimuth, and wherein, in method step d), the exposure is effected with a second incident azimuth, which differs by 90 from the first incident azimuth.

30. The method according to claim 9, wherein, before method step b), a semitransparent metal layer is applied to the underside of the carrier substrate wherein the photoresist is formed as an etch resist, and wherein, after method step e) is performed, the metal layer is removed by etching in the areas not covered by the image layer.

31. The method according to claim 30, wherein the semitransparent metal layer is formed with a transmittance in the range of from 5 to 70%.

32. The method according to claim 30, wherein the semitransparent metal layer is formed with a transmittance in the range of from 1% to 95%.

33. The method according to claim 9, wherein, before method step b), a layer formed with a microstructure is applied to the underside of the carrier substrate or the underside of the carrier substrate is formed with a microstructure.

34. The method according to claim 9, wherein, in method step c), the master image is formed as an electronically controllable display.

35. The method according to claim 9, wherein, in method step c) the parallel light beams projected onto the micro-optical layer are guided through filters and/or diaphragms before striking the micro-optical layer.

36. The method according to claim 9, wherein, in method step a), a carrier substrate is provided, in which in a first area the micro-optical layer is formed on the upper side of the carrier substrate, and in which, in a second area the micro-optical layer, is formed on the underside of the carrier substrate, and wherein method steps b) to e) are carried out in the second area as in the first area, with the difference that in the second area the upper side of the carrier substrate forms the underside of the carrier substrate and vice versa.

37. The method according to claim 36, wherein the first area and the second area of the carrier substrate overlap each other in an overlap area.

38. The method according to claim 9, wherein, in a final method step, an adhesive layer is applied to the underside and/or upper side of the security element.

39. The method according to claim 9, wherein the exposure or the projection is carried out in such a way that when the security element is observed from different observation directions, by tilting and/or rotating, a continuous or quasi-continuous image sequence of the n-th partial images becomes visible.

40. The method according to claim 9, wherein the micro-optical layer comprises an array formed from microlenses or an array formed from microlens grids and the exposure or the projection is carried out in such a way that the n-th partial images are generated as microimages, as microimages distorted in 1 or 2 dimensions or as parts of microimages, whereby, when the security element is observed from different observation directions, by tilting and/or rotating, a continuous or quasi-continuous image sequence of the n-th partial images becomes visible.

41. A method for producing a security element comprising a micro-optical layer, wherein the micro-optical layer comprises an array formed from micro-optical systems, a carrier substrate and one image layer or several image layers, wherein the one image layer or several image layers comprises or comprise n partial images for n=1 to i which are visible from an n-th observation angle allocated to the n-th partial image, and wherein n is at least 1, and wherein the following method steps are provided: a) providing the carrier substrate, on the upper side of which the micro-optical layer is formed; b) applying a photoresist to the underside of the carrier substrate; c) forming a latent n-th partial image in the photoresist, wherein an n-th master image is placed on the micro-optical layer and is exposed with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein an n-th master image is projected onto the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein the photoresist in step b) is applied in the form of an n-th master image to the underside of the carrier substrate and wherein the photoresist is exposed through the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth; d) repeating method step c) i1 times until the i-th latent partial image is formed; and e) developing the photoresist to form the image layer, wherein the micro-optical layer has two or more micro-optical systems arranged in an x-y grid, wherein the x-axis of the x-y grid is arranged at an x-azimuth to the long side of the carrier substrate and the y-axis is arranged at a y-azimuth to the short side of the carrier substrate.

42. The method according to claim 41, wherein the micro-optical systems are arranged in a distorted grid.

43. The method according to claim 41, wherein the micro-optical systems are formed as ball lenses.

44. A method for producing a security element comprising a micro-optical layer, wherein the micro-optical layer comprises an array formed from micro-optical systems, a carrier substrate and one image layer or several image layers, wherein the one image layer or several image layers comprises or comprise n partial images for n=1 to i which are visible from an n-th observation angle allocated to the n-th partial image, and wherein n is at least 1, and wherein the following method steps are provided: a) providing the carrier substrate, on the upper side of which the micro-optical layer is formed; b) applying a photoresist to the underside of the carrier substrate; c) forming a latent n-th partial image in the photoresist, wherein an n-th master image is placed on the micro-optical layer and is exposed with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein an n-th master image is projected onto the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth, or wherein the photoresist in step b) is applied in the form of an n-th master image to the underside of the carrier substrate and wherein the photoresist is exposed through the micro-optical layer with parallel light beams incident at an n-th angle of incidence and an n-th incident azimuth; d) repeating method step c) i1 times until the i-th latent partial image is formed; and e) developing the photoresist to form the image layer, wherein the micro-optical layer comprises an array formed from microlenses, and wherein the microlenses are formed with at least two different focal lengths, and wherein the image layer is formed from a first and a second image layer, wherein the first image layer has a first partial image and the second image layer has a second partial image wherein method step b) is performed with a first photoresist wherein, after method step c), method step e) is performed to form the first image layer, and wherein the following further method steps are performed: f) applying a semitransparent reflective layer to the first image layer; g) applying a second photoresist to the semitransparent reflective layer; h) temporarily embedding the micro-optical layer in a compensation medium formed with the optical refractive index of the micro-optical systems; i) exposing the second photoresist, wherein the first image layer forms an exposure mask; k) developing the second photoresist to form a second image layer, which is formed as an etching mask; l) etching the semitransparent reflective layer; m) removing the compensation medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is now explained in more detail with reference to embodiment examples. There are shown in:

(2) FIG. 1 a schematic diagram of the structure and functioning of a security element produced according to the first method according to the invention;

(3) FIGS. 2.1 to 2.3 embodiment examples of a lens layer in FIG. 1 in schematic top views;

(4) FIGS. 3.1 to 3.5 method steps of an embodiment example for the provision of a carrier film, the upper side of which is formed as the lens layer in FIG. 1, in schematic sectional representations;

(5) FIGS. 4.1 to 4.8 method steps of a first embodiment example of the first method according to the invention in schematic sectional representations;

(6) FIG. 5.1 the method step in FIG. 4.4 in a schematic top view;

(7) FIG. 5.2 the method step in FIG. 4.6 in a schematic top view;

(8) FIGS. 6.1 to 6.6 method steps of a second embodiment example of the first method according to the invention in schematic sectional representations;

(9) FIG. 7.1 a first embodiment example of an exposure device used to perform the method steps represented in FIGS. 4.4 and 4.6 in a schematic sectional representation;

(10) FIG. 7.2 a second embodiment example of an exposure device used to perform the method steps represented in FIGS. 6.3 and 6.4 in a schematic sectional representation;

(11) FIG. 7.3 a third embodiment example of an exposure device used to perform the method steps represented in FIGS. 6.3 and 6.4 in a schematic sectional representation;

(12) FIGS. 8.1 to 8.12 method steps of a third embodiment example of the method according to the invention in schematic sectional representations;

(13) FIGS. 9.1 to 9.15 embodiment examples of a security element produced according to the first or according to the second method in schematic sectional representations;

(14) FIGS. 10.1 to 10.8 method steps of a fourth embodiment example of the method according to the invention in schematic sectional representations;

(15) FIGS. 11.1 to 11.7 method steps of a fifth embodiment example of the method according to the invention in schematic sectional representations;

(16) FIG. 12 a positive mask in schematic representation;

(17) FIG. 13 a negative mask in schematic representation;

(18) FIGS. 14a to 14c a first embodiment example of a mask;

(19) FIGS. 15a and 15b a second embodiment example of a mask;

(20) FIGS. 16a to 16c a third embodiment example of a mask;

(21) FIGS. 17a to 17c a fourth embodiment example of a mask;

(22) FIGS. 18a to 18c a first embodiment example of a diaphragm layer;

(23) FIG. 19 a second embodiment example of a diaphragm layer;

(24) FIG. 20 a third embodiment example of a diaphragm layer;

(25) FIG. 21 a fourth embodiment example of a diaphragm layer;

(26) FIG. 22 a fifth embodiment example of a diaphragm layer;

(27) FIG. 23 a sixth embodiment example of a diaphragm layer;

(28) FIG. 24 a seventh embodiment example of a diaphragm layer;

(29) FIG. 25 a sixteenth embodiment example of a security element;

(30) FIG. 26 a seventeenth embodiment example of a security element;

(31) FIG. 27 a first embodiment example of a security document;

(32) FIGS. 28a and 28b a second embodiment example of a security document;

(33) FIG. 29 a third embodiment example of a security document;

(34) FIGS. 30a and 30b a fourth embodiment example of a security document;

(35) FIGS. 31a and 31 b a fifth embodiment example of a security document;

(36) FIGS. 32a and 32b a sixth embodiment example of a security document;

(37) FIG. 33 a seventh embodiment example of a security document;

(38) FIG. 34 an eighth embodiment example of a security document;

(39) FIG. 35 a ninth embodiment example of a security document in a schematic sectional representation;

(40) FIG. 36 a tenth embodiment example of a security document.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(41) FIG. 1 shows a security element 1 comprising a micro-optical layer 11 formed as a lens layer 11l, a carrier film 13 and an image layer 14.

(42) The lens layer 11l is arranged on the upper side of the carrier film 13. The lens layer 11l has a plurality of microlenses 12, which are arranged closely spaced in a grid. The microlenses 12 are not individually recognizable with the naked eye from an observation distance of approximately 250 mm, when the grid period is less than approximately 300 m. In the embodiment example represented in FIG. 1, the grid period is approximately 35 m.

(43) In the embodiment example represented in FIG. 1, the microlenses 12 are formed as cylindrical lenses or as spherical lenses or as ball lenses, which are arranged on the surface of the lens layer 11l. The microlenses 12 can also be formed as aspherical lenses.

(44) The image layer 14 is arranged on the underside of the carrier film 13 and lies in the image plane of the microlenses 12. The image plane lies in the focus or close to the focus of the microlenses 12. In the embodiment example represented in FIG. 1, the image layer 14 comprises two partial images 14l and 14r which in the case of cylindrical lenses are screened in strip-shaped image sections 14la and 14lr, wherein the image sections 14la and 14lr are arranged alternately and in register-accurate manner underneath the microlenses 12. In the case of ball lenses, dots form underneath the lens, which are lined up next to each other. With the named grid period of 35 m the image sections 14la and 14lr have a width of typically less than 17.5 m, in particular a width of from 3 m to 10 m. When the security element 1 is tilted about a tilt axis 1a which is aligned with the longitudinal axes of the image sections 14la and 14ra, an image change occurs, i.e. depending on the observation direction either the partial image 14l or the partial image 14r is visible. Between the image areas there may also be positions in which none of the images is visible. The tilt axis need not be precisely aligned with the image sections in order to recognize an image change. Thus even in the case of clear deviations, for example in the case of an angular deviation of 30, an image change becomes visible.

(45) In the embodiment example represented in FIG. 1, the partial image 14l depicts star-shaped symbols, and the partial image 14r a portrait. Such security elements are referred to as lenticular flip or image flip.

(46) The partial images 14l and 14r are macroimages, i.e. the partial images 14l and 14r have the same or approximately the same size as the partial images visible during observation.

(47) The dimensions of the layer structure are dependent on the optical arrangement of the lenses as well as the optical properties of the spacer layer. Here, the optical refractive indices of the materials used are an important parameter.

(48) With the grid period named further above of approximately 35 m, a thickness of the lens layer 11l in the range of from 20 m to 25 m and an overall thickness of the lens layer 11l and of the carrier film 14 in the range of from 35 m to 40 m, the microlenses 12 have a height of approximately 12 m.

(49) With the grid period named further above of approximately 35 m, a thickness of the lens layer 11l in the range of from 50 m to 60 m and an overall thickness of the lens layer 11l and of the carrier film 14 of approximately 70 m, the microlenses 12 have a height of approximately 7 m.

(50) FIG. 2.1 shows a first embodiment example of the lens layer 11l. The lens layer 11l has microlenses formed as cylindrical lenses 12z, the longitudinal axes of which are aligned with the tilt axis 1a.

(51) FIG. 2.2 shows a second embodiment example of the lens layer 11l. The lens layer 11l has microlenses formed as ball lenses 12k, which are arranged in longitudinal rows and transverse rows adjoining each other, wherein the longitudinal axes of the transverse rows are aligned with the tilt axis 1a.

(52) FIG. 2.3 shows a third embodiment example of the lens layer 11l. The lens layer 11l is formed like the lens layer 11l described in FIG. 2.2, with the difference that the longitudinal axes of the transverse rows 12r adjoining each other form an azimuth .sub.q with the tilt axis 1a, and that the longitudinal axes of the longitudinal rows 12l adjoining each other form an azimuth .sub.l with the tilt axis 1a. The azimuth denotes a horizontal angle in the x-y plane of the lens layer 11l. In the embodiment example represented in FIG. 2.3, the azimuth .sub.q=45, the azimuth .sub.l=135.

(53) Combinations of microlenses 12 with a different alignment can thus also be used for design purposes. The range of variation of the azimuth is in this respect important in cases where more complicated lens shapes or lens arrays are used.

(54) In one embodiment example, FIGS. 3.1 to 3.5 show a method for forming the lens layer 11l arranged on the carrier film 13. The method is described in the following as a roll-to-roll method.

(55) Alternative methods are, for example, roll-to-sheet methods or sheet-to-sheet methods. Individual production of the security elements is also possible.

(56) FIG. 3.1 shows a first method step in which the carrier film 13 is provided. The carrier film 13 can be a film made of a thermoplastic, for example polyethylene, polypropylene, polycarbonate or polyester (PET) with a thickness of approximately 20 m, which is rolled up on a supply roll. A composite of various plastic plies which are joined to each other, for example, by means of an adhesive can also be used. The thickness of the carrier film typically ranges from 6 m to 200 m, preferably from 12 m to 50 m, further preferably from 16 m to 36 m.

(57) FIG. 3.2 shows a second method step in which the upper side of the carrier film 13 is coated with a replication layer 15 made of a varnish that cures under UV light. The coating can be effected in a coating station which the carrier film 13 is guided past. The coating can be effected from a solution or solvent-free, optionally at increased temperatures. Between the layers 11 and 13 further optional single- or multilayered layers such as for example an adhesion-promoter layer or a blocking layer or barrier layer can also be provided.

(58) FIG. 3.3 shows a third method step in which a stamping die 15s is pressed onto the replication layer 15. The underside of the stamping die 15s facing the replication layer 15 has a surface structure which corresponds to the negative of the surface structure of the lens layer 11l. The stamping die 15s is formed as a stamping roller, wherein the carrier film 13 coated with the replication layer 15 is pressed onto the stamping roller using a pressure roller.

(59) FIG. 3.4 shows a fourth method step in which the stamped replication layer 15 arranged on the carrier film 13 is guided past a UV radiation source, with the result that the replication layer bonds to the lens layer 11l.

(60) Alternatively, the UV exposure can also be effected from the carrier side through the carrier film 13. A further variant is a UV exposure during the stamping process, i.e. while the stamping die 15s and the replication layer 15 are in contact such that the structure of the stamping die 15s is molded into the replication layer 15. The stamping die 15s can be formed flat, semicircular or round depending on the method used. The UV exposure can also be effected under a protective-gas atmosphere. Here, e.g. a nitrogen atmosphere or an argon gas atmosphere is generated above the replication layer 15, in order to largely exclude oxygen during the exposure.

(61) In the exposure method, particular effects can also be compensated for in advance. For example, the final product could be used on a curved surface. For this purpose, e.g. the replication layer 15 would be carried on a curved surface during the exposure process.

(62) Alternatively, the precompensation can be effected by adapting the local exposure direction. Here, the local exposure angle is modified. This can also be effected by interposition of an optical lens system with one or more optical lenses, through which the local exposure turns out differently. The precompensation can alternatively or additionally also be effected by modifying the exposure masks. The precompensation can also be effected corresponding to a mathematical function.

(63) FIG. 3.5 shows a fifth method step in which the carrier film 13 coated with the lens layer 11l is in the form of a semifinished product which is wound onto a take-up reel according to the above-described roll-to-roll method.

(64) It can also be provided to form the replication layer 15 as a plastic layer and to stamp the lens structure directly into the replication layer 15. Thus the fourth method step represented in FIG. 3.4 is dispensed with. The replication layer preferably comprises thermoplastics or varnishes. Thermoplastic elastomers can also be used.

(65) It can also be provided to print the lens layer 11l onto the carrier film 13 instead of the method steps represented in FIGS. 3.2 to 3.4.

(66) It can further be provided to form the lens layer 11l in one piece with the carrier film 13 and to stamp the lens layer 11l into the carrier film 13. Alternatively a separately produced lens layer, with lenses already formed, can also be applied to the carrier film, for example by means of gluing.

(67) FIGS. 4.1 to 4.8 show a first embodiment example of the first method according to the invention, in which the image layer 14 is formed in a contact process with a first image 14l and a second image 14r, as described further above in FIG. 1. FIGS. 4.1 to 4.8 are schematic sectional representations, wherein, for a better overview, layers are each represented as a rectangular area.

(68) FIG. 4.1 shows a first method step in which the carrier film 13, on the upper side of which the lens layer 11l is formed, is provided. The structure of the lens layer 11l is described further above.

(69) FIG. 4.2 shows a second method step in which a photoresist 16 is applied to the underside of the carrier film 13. Typical starting materials for photoresists 16 are, for example, polymethyl methacrylate, novolak, polymethyl glutarimide and epoxy resins. Common solvents are, for example, cyclopentanone or gamma-butyrolactone photoresists 16 as a rule additionally contain a photosensitive component. Water-soluble photoresists 16 can also be used.

(70) The method steps of applying the photoresist 16 and applying or introducing the microlenses can also be carried out in a modified sequence or also simultaneously. The coating with the photoresist 16 can be effected over the whole surface or over part of the surface. For example, the photoresist can be applied in the form of a pattern or in the form of one or more motifs. Methods are coating or printing from solution (solvent-containing; aqueous systems); solvent-free (liquid, semiliquid), or also applying so-called dry resists by rolling, gluing.

(71) Positive photoresists 16 and/or negative photoresists 16 can be used.

(72) Depending on the subsequent process, the photoresist 16 can be colorless or pigmented and/or dyed and/or can be printed multicolored. Dissolved dyes and/or pigments, also special pigments as are used in the security field, for example UV-fluorescent pigments, are used as colorings. Pigments with small grain sizes below the layer thickness of the photoresist 16 are preferred. So-called nanopigments, i.e. pigments with grain sizes below 1 m, preferably below 0.5 m, are further preferred. The pigments can be inorganic or organic in nature or can be mixtures of the two. In addition to pigments, soluble dyes can also be used.

(73) The photoresist 16 can be transparent, semitransparent or opaque, optionally opaque only in particular wavelength ranges. Thus the colored photoresist can be largely transparent, for example in the near-UV in which the photoresist is sensitive, but can appear substantially black in the visible wavelength range. Liquid-crystalline materials can also be used as photoresists, in which, optionally additionally, spatial orientations of the liquid-crystalline molecules take place during the exposure process or curing process. The orientation of the molecules can be formed e.g. on physical structures, such as e.g. microstructures, and/or also through exposure by means of polarized light.

(74) The photoresists 16 can be applied colorless or single-colored or multicolored. They can also be applied in the form of one or more patches. The patch shape can likewise represent a motif and/or a pattern, for example a country outline, and/or can be interrupted, for example can be formed strip-shaped. Photoresists 16 can also be applied multilayered. The layers can have different forms and/or properties.

(75) FIGS. 4.3 and 4.4 show a third method step in which a first master image 14lm formed as an image mask is placed on the lens layer 11l (FIG. 4.3) and the photoresist 16 is exposed through the lens layer 11 with parallel light beams at a first angle of incidence .sub.l, which is equal to a first observation angle (FIG. 4.4). A first latent partial image is formed in the photoresist 16 by the exposure. FIG. 5.1 shows the third method step in top view. The master image 14lm can be formed as a positive mask (see FIG. 12) or as a negative mask (see FIG. 13).

(76) FIGS. 4.5 and 4.6 show a fourth method step in which a second master image 14rm formed as an image mask is placed on the lens layer 11 (FIG. 4.5) and the photoresist 16 is exposed through the lens layer 11 with parallel light beams at a second angle of incidence .sub.r, which is equal to a second observation angle (FIG. 4.6). A second latent partial image is formed in the photoresist 16 by the exposure.

(77) FIG. 5.2 shows the fourth method step in top view. The angle .sub.r here can also be 0.

(78) The parallel light beams used in the third and fourth method steps are produced in an exposure device 17 schematically represented in FIG. 7.1. The exposure device 17 comprises a radiation source 17l and a projection objective lens 17o. The radiation source 17l is a lamp which emits light in the near-UV range or in the UV range. The wavelength of the light is matched to the properties of the photoresist 16. The radiation source 17l is arranged in the focus of the projection objective lens 17o, with the result that parallel light beams exit the projection objective lens 17o.

(79) In principle, all suitable methods for producing parallel light or virtually parallel light can be used. These also include the use of lasers or laser diodes, optionally in combination with suitable optics.

(80) FIGS. 4.7 and 4.8 show a fifth method step in which the exposed photoresist 16 is developed to form the image layer 14. During the development, for example, the unexposed areas of the photoresist 16 are removed, for example by washing-off with a solvent.

(81) The exposed areas of the photoresist 16 are chemically altered by the action of the light beams such that their solubility is lower than the solubility of the exposed areas. Typical developer solutions are e.g. alkali-containing solutions. Residues of the developer solution are subsequently removed in corresponding post-treatment processes, e.g. washing with deionized water. The removal of the photoresist can be facilitated by sponges, brushes, high-pressure nozzles, etc. Organic solutions or solvents can also be used as developer solutions. There are also photoresists which use essentially water as developer solutions. Additives in the developer solution, such as for example isopropanol, serve for better wetting of the photoresist. In FIG. 4.8, the image layer 14 which comprises the partial images 14l and 14r is represented.

(82) After the development process, an additional UV exposure, optionally also at another wavelength, can be effected in order to further cure the image layer 14. A post-curing can also be effected by means of electron radiation (e-beam) and/or via a chemical cross-linking agent and/or by a post-treatment at increased temperatures. The prior application of a further layer is also possible in order to cure these together or in order to achieve a better adhesion between the layers.

(83) It is also possible to provide more than two exposure directions, for example three exposure directions.

(84) FIGS. 14a to 14c show master images suitable for this, which are formed as positive masks.

(85) FIG. 14a shows a first master image 14lm, FIG. 14b a second master image 14mm and FIG. 14c a third master image 14rm. The master images 14lm, 14mm and 14rm are each exposed from different angles. When a thus-formed security element is observed, three partial images appear successively, the motifs of which are symbolized by the letters A, B, C, which are in each case visible only at the allocated tilt angle.

(86) FIGS. 15a and 15b show a further embodiment example for master images 14lm, 14rm. When a thus-formed security element is observed, two partial images appear during tilting, the motifs of which are symbolized by the letters A, B, C and D, E, F, which are in each case visible only at the allocated tilt angle.

(87) FIGS. 16a to 16c show an embodiment example which is formed like the embodiment example described in FIGS. 14a to 14c, with the difference that when a thus-formed security element is observed, three partial images appear successively, the motifs of which are symbolized by the letters A, B, C-D, E, F-G, H, I.

(88) FIGS. 17a to 17c show an embodiment example which is formed like the embodiment example described in FIGS. 14a to 14c, with the difference that when a thus-formed security element is observed, three partial images appear successively, the motifs of which are symbolized by the letter A, which changes its rotational position.

(89) FIGS. 6.1 to 6.6 show a second embodiment example of the first method according to the invention, in which the image layer 14 is formed in a projection method with a first partial image 14l and a second partial image 14r, as described further above in FIG. 1. FIGS. 6.1 to 6.6 are schematic sectional representations, wherein, for a better overview, layers are each represented as a rectangular area.

(90) FIG. 6.1 shows a first method step in which the carrier film 13, on the upper side of which the lens layer 11l is formed, is provided. The structure of the lens layer 11l is described further above.

(91) FIG. 6.2 shows a second method step in which a photoresist 16 is applied to the underside of the carrier film 13.

(92) FIG. 6.3 shows a third method step in which a first master image 14lm is transferred by a parallel projection onto the lens layer 11 and is focused by the microlenses 12 of the lens layer 11l on the photoresist 16. The projection beams strike the lens layer 11l at a first angle of incidence .sub.l, which is equal to a first observation angle. A first latent partial image is formed in the photoresist 16 by the exposure.

(93) FIG. 6.4 show a fourth method step in which a second master image 14rm is transferred onto the lens layer 11l by a parallel projection. The projection beams pass through the lens layer 11l at a second angle of incidence r, which is equal to a second observation angle. A second latent partial image is formed in the photoresist 16 by the exposure.

(94) The parallel light beams used in the third and fourth method steps are produced in an exposure device 17 schematically represented in FIG. 7.2. The exposure device 17 comprises a radiation source 17l, a condenser lens 17k, a holder 17a for the master image 14lm, 14rm and a projection objective lens 17o. The radiation source 17l is, for example, a lamp which emits light in the near-UV range or in the UV range. The wavelength of the light is matched to the properties of the photoresist 16.

(95) During projection, the master image 14lm, 14rm which can comprise one or more images, patterns, etc. is projected via the projection objective lens 17o from a defined position relative to the lens layer 11l, wherein the projection objective lens 17o and the microlenses 12 form an optical system in which a parallel beam path is formed between the projection objective lens 17o and the microlenses 12. Both a 1:1 imaging and a magnification and/or reduction in size of the master image 14lm, 14rm can be effected.

(96) If, during the projection or during the exposure, a relatively large number of different partial images or different n partial images 14l, 14r are formed, microimages with a slightly different pitch (distance of the image repetition) relative to the pitch of the array formed from micro-optical systems, preferably to the pitch of the array formed from microlenses 12, particularly preferably to the pitch of the array formed from a microlens grid, can be generated in the photoresist 16. When the security element 1 is observed from different directions, in particular by rotating and tilting the security element 1, a continuous or quasi-continuous image sequence of the generated partial images 14l, 14r can in particular be generated hereby. In particular when observing the security element 1, magnified images of the exposed n-th partial images 14l, 14r or microimages are generated hereby, wherein when tilting or rotating the security element 1, design elements that are preferably moving and/or increasing in size and/or decreasing in size and/or reversed and/or rotating become visible. This is advantageously a 1D or 2D Moir magnifier effect.

(97) The exposure or the projection is preferably carried out in such a way that when the security element 1 is observed from different observation directions, in particular by tilting and/or rotating, a continuous or quasi-continuous image sequence of the n-th partial images 14l, 14r visible.

(98) Both analog and digital methods can be provided as methods for generating the master image 14lm, 14rm. The master image 14lm, 14rm can be formed, for example, as a mask. The mask can consist, for example, of a metallic diaphragm with apertures or of a film material, which has been correspondingly blackened. The use of masks with partial images is of interest, in which the respective partial images (openings) have a selective transparency for certain wavelengths, for example a transparency for UV-A or UV-B. By using two UV exposure units with different wavelengths or wavelength ranges (example: UV-A and UV-B), a selective exposure from different angles can hereby be effected. The advantages lie in the use of only one exposure mask or in the ability to maintain the register of the two images.

(99) By register or registration, or register accuracy or registration accuracy, is meant a positional accuracy of two or more elements and/or layers relative to each other. The register accuracy is to range within a predetermined tolerance and be as low as possible. At the same time, the register accuracy of several elements and/or layers relative to each other is an important feature in order to increase the process stability. The positionally accurate positioning can be effected in particular by means of sensory, preferably optically detectable registration marks or register marks. These registration marks or register marks can either represent special separate elements or areas or layers or themselves be part of the elements or areas or layers to be positioned.

(100) Black/white representations, grayscale images, color images, images with areas of different UV absorption (color image in the UV range), half-tone images, etc. can be provided as master images 14lm, 14rm.

(101) Generation of three-dimensional images which give e.g. a depth effect to a represented object is also possible.

(102) FIG. 7.3 shows an exposure device 17 which is formed like the exposure device described in FIG. 7.2, with the difference that the master image is formed as an electronically controllable display 17d, which can be controlled via a computer 17c. The display 17d can be formed, for example, like a display known from laser projectors. The display 17d makes the introduction of individualized items of information into the photoresist or into the image layer possible. Examples of individualized items of information are serial numbers, the date of birth of a document holder or the image of a person. The radiation source 17l can advantageously be formed as a laser, with the result that the laser beam can be deflected in a suitable manner and its intensity can be modulated, for example switched on and off, in a targeted manner.

(103) A polarizer can additionally be located in the beam path, by means of which light polarized linearly or circularly can be produced.

(104) The condenser lens 17k illuminates the master image 14lm, 14rm arranged in the holder 17a evenly. The master image 14lm, 14rm is arranged with respect to the projection objective lens 17o such that the master image 14lm, 14rm is projected onto the lens array in a limited angular range.

(105) FIGS. 6.5 and 6.6 show a fifth method step which corresponds to the method step described further above in FIGS. 4.7 and 4.8. The image layer 14 which comprises the partial images 14l and 14r is represented in FIG. 6.6.

(106) The use of a line exposure or a line array as exposure unit is also possible. By a line exposure is meant an exposure unit in which the exposure is effected via a very narrow exposure line. This can be effected by exposure by means of a slit. The slit is passed here above the surface to be exposed and/or the surface to be exposed is passed underneath the linear slit. A metallic diaphragm can e.g. be used as linear slit. An arrangement of UV diodes arranged next to each other, a so-called array, can also be used as line exposure unit. The line array, preferably with high resolution, can thus be moved over the surface to be exposed during the exposure. For example, the arrangement of the individual exposure elements in the line array can correspond to a resolution of from 600 dpi to 3600 dpi. Alternatively, the surface to be exposed moves underneath the line array. The latter is advantageous in particular in the case of roll-to-roll methods.

(107) FIGS. 8.1 to 8.12 show a third embodiment example of the method according to the invention. FIGS. 8.1 to 8.12 are schematic sectional representations, wherein, for a better overview, layers are each represented as a rectangular area.

(108) FIG. 8.1 shows a first method step in which the carrier film 13, on the upper side of which the lens layer 11l is formed, is provided. The structure of the lens layer 11l is described further above.

(109) FIG. 8.2 shows a second method step in which a semitransparent metal layer 18ms is applied, preferably by vapor deposition, to the underside of the carrier film 13.

(110) FIG. 8.3 shows a third method step in which a photoresist 16 is applied to the semitransparent metal layer 18ms.

(111) FIG. 8.4 shows a fourth method step in which a first master image 14lm is transferred by a parallel projection onto the lens layer 11l and is focused by the microlenses 12 of the lens layer 11l on a first photoresist 16. The projection beams strike the lens layer 11l at a first angle of incidence .sub.l, which is equal to a first observation angle. A first latent partial image is formed in the first photoresist 16 by the exposure.

(112) FIGS. 8.5 and 8.6 show a fifth method step in which the exposed first photoresist 16 is developed to form a first image layer 14l formed as etching mask, as described further above. The first image layer 14l, which is formed from image sections 14la, is represented in FIG. 8.6.

(113) FIG. 8.7 shows a sixth method step in which the semitransparent metal layer 18ms is structured by means of etching, whereby the areas of the metal layer 18ms not covered by image elements of the first image layer 14l are removed. An aqueous lye can e.g. be used as etching medium.

(114) FIG. 8.8 shows a seventh method step in which a second photoresist 16 is applied to the first image layer 14l.

(115) FIG. 8.9 shows an eighth method step in which the lens layer 11l is covered by a compensation layer 11k. The compensation layer 11k has the same or approximately the same optical refractive index, in particular with a refractive index difference of at most 0.2, as the microlenses 12 of the lens layer 11, with the result that the optical effect of the microlenses 12 is compensated for. The compensation layer 11k can be, for example, a liquid.

(116) FIG. 8.10 shows a ninth method step in which the first image layer 14l acts as an image mask. In the embodiment example represented in FIG. 8.10, parallel projection beams strike the first image layer 14l perpendicularly, expose the second photoresist 16 arranged underneath the first image layer 14l and generate a latent partial image. It is also possible to place a translucently dyed layer in the background, in particular followed by a metal layer, in order to create the effect of a colored reflective layer.

(117) In a tenth method step, the compensation layer 11k is again removed from the lens layer 11l.

(118) FIGS. 8.11 and 8.12 show an eleventh method step in which the latent image formed in the second photoresist 16 is developed to form a second image layer 14r formed from flat areas such as e.g. image strips 14ra. The image strips 14ra are (permanently) visible over a very large angular range.

(119) FIGS. 10.1 to 10.8 show a fourth embodiment example of the method according to the invention.

(120) The method steps represented in FIGS. 10.1 to 10.8 are formed like the method steps described in FIGS. 4.1 to 4.8, with the difference that the exposure of the photoresist 16 is effected by a micro-optical system formed as a diaphragm layer 11b. The diaphragm layer 11b can be constructed from alternating transparent and opaque or partially opaque areas. In the simplest case, it can comprise line grids, which are e.g. printed on. However, it can also comprise more complex arrangements of transparent and opaque areas. The grid width is chosen such that it lies below the resolution of the human eye, as described further above in FIG. 1 for microlenses.

(121) FIGS. 18a to 18c show embodiment examples of diaphragm layers 11b with line grids, wherein the directional arrows shown in the figures indicate the tilting direction of the security element.

(122) In FIG. 18a, the line grid is arranged perpendicular to the tilting direction, in FIG. 18b oblique to the tilting direction and in FIG. 18c parallel to the tilting direction.

(123) FIG. 19 shows an embodiment example of the diaphragm layer 11b in which the line grid is formed from two sections which form an obtuse angle with each other, as drawn in FIG. 19.

(124) FIG. 20 shows an embodiment example of the diaphragm layer 11b in which the line grid is formed from two sections which are arranged at a right angle to each other.

(125) FIG. 21 shows an embodiment example of the diaphragm layer 11b in which the line grid is formed S-shaped.

(126) FIG. 22 shows an embodiment example of the diaphragm layer 11b in which the line grid is interrupted by linear sections running obliquely.

(127) FIG. 23 shows an embodiment example of the diaphragm layer 11b in which the line grid is interrupted by linear sections running obliquely and lines of the line grid are interrupted alternately.

(128) Instead of the line grids specified in FIGS. 18a to 24, cylindrical lenses arranged analogously can also be used.

(129) FIG. 24 shows an embodiment example of the diaphragm layer 11b in which the line grid has a star-shaped boundary, which can be perceived by an observer as a star-shaped symbol.

(130) FIGS. 11.1 to 11.7 show a fifth embodiment example of the method according to the invention.

(131) FIG. 11.1 shows a first method step in which a carrier film 13, on the upper side of which a lens layer 11l is formed, is provided. The structure of the lens layer 11l is described further above.

(132) FIG. 11.2 shows a second method step in which a photoresist 15 is applied to the underside of the carrier film 13, e.g. in the form of a field or a pattern in a defined area. The application can be effected e.g. by means of a printing process or also by transfer from a carrier by means of hot stamping or cold stamping.

(133) The method steps of applying the photoresist 15 and applying or introducing the microlenses of the lens layer 11l can also be carried out in a modified sequence or also simultaneously. Positive photoresists and/or negative photoresists can be used.

(134) Depending on the subsequent process, the photoresist 15 can be colorless or pigmented and/or dyed and/or can be printed multicolored. Dissolved dyes and/or pigments, also special pigments as are used in the security field, for example UV-fluorescent pigments, are used as colorings. Pigments with small grain sizes below the layer thickness of the photoresist 15 are preferred. So-called nanopigments, i.e. pigments with grain sizes below 1 m, preferably below 0.5 m, are further preferred. The pigments can be inorganic or organic in nature or can be mixtures of the two. In addition to pigments, soluble dyes can also be used.

(135) The photoresist 15 can be transparent, semitransparent or opaque, optionally opaque only in particular wavelength ranges. Thus a colored photoresist 15 can be largely transparent, for example in the near-UV in which the photoresist 15 is sensitive, but can appear substantially black in the visible wavelength range.

(136) Liquid-crystalline materials can also be used as photoresists 15, in which, optionally additionally, spatial orientations of the liquid-crystalline molecules take place during the exposure process or curing process. The orientation of the molecules can be formed e.g. on physical structures, such as e.g. microstructures, and/or also through exposure by means of polarized light.

(137) The photoresists 15 can be applied colorless or single-colored or multicolored.

(138) FIG. 11.3 shows a third method step in which the photoresist 15 is exposed through the lens layer 11l with parallel light beams at a first angle of incidence .sub.l, which is equal to a first observation angle. A first latent partial image is formed in the photoresist 15 by the exposure.

(139) In principle, all suitable methods for producing parallel light or virtually parallel light can be used. These also include the use of lasers or laser diodes, optionally in combination with suitable optics.

(140) FIG. 11.4 shows a fourth method step in which the exposed photoresist 15 is developed to form a first partial image 14l and optionally a fifth method step in which a further photoresist 15 is applied. The further photoresist 15 is applied to the underside of the carrier film 13, e.g. in the form of a further field or a pattern in a defined area. The further photoresist 15 can be applied next to the first partial image 14l, partially overlapping or congruent with it. In the embodiment example represented in FIG. 10.4, the further photoresist 15 is applied next to the first partial image 14l.

(141) FIG. 11.5 shows a sixth method step in which the further photoresist 15 is exposed through the lens layer 11l with parallel light beams at a second angle of incidence .sub.r, which is equal to a second observation angle. A second latent partial image is formed in the further photoresist 15 by the exposure.

(142) FIG. 11.6 shows a seventh method step in which the exposed further photoresist is developed to form a second partial image 14r.

(143) The sixth and the seventh method steps can be repeated several times.

(144) FIG. 11.7 shows a variant in which the second partial image 14r partially covers the first partial image 14l.

(145) FIGS. 9.1 to 9.15 show further embodiment examples of security elements 1, which can be produced with the above-described methods and/or by variation of the above-described methods. FIGS. 9.1 to 9.15 are schematic sectional representations, wherein, for a better overview, layers are each represented as a rectangular area.

(146) The security elements 1 can optionally be formed with a single- or multi-ply adhesive layer, not represented in FIGS. 9.1 to 9.15, on their underside. Optionally, the underside of the security element 1 represented in FIGS. 9.1 to 9.13 can also have one or more additional layers, such as e.g. a single- or multilayered bonding layer and/or primer layer. However, it can also be provided to transfer the security elements 1 onto a substrate which is coated with an adhesive layer at least in areas. Optionally, the security element can have an additional single- or multilayered protective layer, for example in the form of a PET film, on the underside. This can be glued or laminated on. The protective layer can have an additional single- or multilayered adhesive layer on the outside. The structure makes it possible to embed the security element in a substrate, for example in the form of a security thread in a document or a banknote.

(147) FIG. 9.1 shows a security element 1 in which the image layer 14 is covered by a color layer 18f. The color layer 18f can be printed on, for example. The color contrast is increased by the color layer 18f. The color layer 18f can be formed, for example, translucent or opaque and/or multicolored and/or UV-active. Opaque layers or also opaque and scattering layers are in particular preferred. The color layer 18f is visible at a plurality of observation angles when observed through the lens layer.

(148) FIG. 9.2 shows a security element 1 in which the image layer 14 is covered by a reflective layer 18r. A metal layer and/or an HRI layer can be provided as reflective layer 18r. Optionally, after applying the reflective layer 18r a structuring of the reflective layer 18r can be provided registered relative to the image layer 14, whereby the color effect is enhanced. The structuring can be effected by known methods.

(149) FIG. 9.3 shows a security element 1 in which a multilayer structure is applied to the image layer 14. In the embodiment example represented in FIG. 9.3, the multilayer structure comprises a semitransparent metal layer 18mt as absorber layer, a spacer layer 18a and a reflective layer 18r. The semitransparent metal layer 18mt is arranged on the underside of the image layer 14. In the case of the thus-formed security element 1 a color change effect is visible as background. A structure in which the reflective layer 18r is located on the underside of the image layer 14 (reverse structure), followed by a spacer layer and a semitransparent layer is also possible. In the case of the last-named structure a color change effect is visible from the side facing away from the lens layer 11. Embodiments in which the color change is visible from both sides of the security element 1 are also possible.

(150) FIG. 9.4 shows a security element 1 which is produced according to the first method described further above (FIGS. 4.1 to 4.8 and FIGS. 6.1 to 6.6), with the difference that instead of the image layer 14 firstly a first image layer 14l is formed, and then a further photoresist 16 is deposited and a second image layer 14r is formed after exposure and development. The two image layers 14l and 14r can advantageously have different colors. It is also possible to apply the two photoresists in a strip grid, to expose and to develop them together.

(151) FIG. 9.5 shows a security element 1 which is formed like the security element represented in FIG. 9.4, with the difference that the two photoresists 16 are formed with different sensitivity. For example, the first photoresist 16 can be formed with a higher sensitivity than the second photoresist 16.

(152) By using differently colored photoresists it is possible to form mixed colors, for example the mixed color magenta from the colors red and blue.

(153) It can further be provided to arrange the security element on a substrate or product, e.g. a security document, with an arrangement of cylindrical lenses running obliquely to the horizontal or vertical tilt axis of the security element. This arrangement results in an image flip in the case of tilting both via the horizontal and vertical tilt axis.

(154) FIG. 9.6 shows a security element 1 in which a microstructure 13s is molded into the underside of the carrier film 13. The microstructure 13s can also be introduced into a further layer applied to the carrier film 13. The microstructure 13s can form different optical effects, for example a KINEGRAM or 2D/3D or 3D structure-based effects. The image layer 14 is coated with a reflective layer 18r. The coating can optionally be provided.

(155) A combination of a microstructure with a structure analogous to FIG. 8.7 is also possible.

(156) FIG. 9.7 shows a security element 1 in which a semitransparent metal layer 18ms is arranged on the underside of the carrier film 13, wherein the metal layer 18ms was partially demetallized after the formation of the image layer 14 formed as etching mask. The security element 1 thus has an image layer 14 metallically coated from the observation side. Optionally, an additional color layer can be applied to the rear side of the image layer in order to increase the contrast and/or in order to produce colored areas. It is also possible to place a second metal layer, e.g. dyed a different color with a translucent color varnish layer, in the background, analogously to the embodiment described in FIG. 8.7.

(157) FIG. 9.8 shows a security element 1 in which the rear side of the security element 1 is formed by a structured metal layer 18m. The structured metal layer 18m has areas removed in the lift-off method which are congruent with the structured image layer 14. For this, the image layer 14 was vapor-deposited with the metal layer 18m and the image layer 14 was then removed in the exposed areas in the lift-off method, wherein a positive photoresist was used in this embodiment example. Optionally, the structured metal layer 18m can have a color layer placed behind it. It is also possible to place a translucently dyed layer in the background, in particular followed by a metal layer, in order to create the effect of a colored reflective layer.

(158) FIG. 9.9 shows a security element 1 in which a transfer ply 18u of a transfer film is arranged on the image layer 14. The image layer 14 is formed as a thermal adhesive which, after heating, is brought into contact with the transfer ply 18u formed on the transfer film, and, after cooling, the transfer ply adheres to the image layer by means of the thermal adhesive. Then the security element 1 is detached from the transfer film, wherein the areas of the transfer ply 18u glued to the image layer 14 are detached. In this embodiment of the security element 1 a wide variety of designs are possible. Thus, for example, a continuous color gradient or a true color image can be formed or optical structures can be transferred onto the image layer 14.

(159) FIG. 9.10 shows a security element 1 in which a volume hologram 18v is arranged on the image layer 14.

(160) FIG. 9.11 shows a security element 1 in which a partially metallized layer 18mp is arranged between the underside of the carrier film 13 and the dyed image layer 14. The security element 1 forms a color-metal flip. The effect can occur by tilting the security element 1 or by rotation through 180. A continuous metal/color transition can be formed in one exposure. Optionally, a metal/color flip can be formed by two exposures and structuring. Continuous transition: an exposure and utilization of the colored photoresist as coloring in one area and for the further structuring of the metal layer partially produced beforehand in the other area. Metal/color image flip: first structuring of a metal layer by means of a first exposure, then structuring of a separately applied colored photoresist by means of a second exposure.

(161) FIG. 9.12 shows a further security element 1 which was produced according to the method described further above in FIGS. 8.1 to 8.12.

(162) FIG. 9.13 shows a security element 1 in which a functional layer 18v is arranged underneath the carrier film 13, on the side of which facing away from the carrier film 13 there is arranged a multilayered image layer comprising a first image layer 14, a reflective layer 18r and a second image layer 14.

(163) FIG. 9.14 shows a security element 1 which is formed like the security element described in FIG. 1, with the difference that the security element 1 has a first area which is formed as described in FIG. 1, and that the security element 1 has a second area which is formed as a mirror image of the first area. In the second area, the lens layer 11l is arranged on the underside of the security element 1. The image layer 14 is arranged on the upper side of the security element 1. The security element 1 can be arranged, for example, in a window of a security document, wherein different optical effects can be formed when the front side and the rear side of the security element 1 are observed. It can also be provided to form the window in the security document 1 such that it only enables the second area to be viewed. The first and/or the second area can have partial areas not connected to each other. For example, the partial areas can be formed as elements of a grid.

(164) FIG. 9.15 shows a security element 1 which was produced by combining two security elements corresponding to FIG. 4.8 and FIG. 9.1.

(165) The production can be effected, for example, by laminating the two security elements by means of an adhesive 19.

(166) FIGS. 25 and 26 show security elements 1 in which the micro-optical layer is formed as a prism layer 11p, wherein the prism layer is formed trapezoidal in cross section in FIG. 26.

(167) The security elements described in FIGS. 9.1 to 9.15, 25 and 26 can form many and varied optical effects, wherein it is also possible to form combinations of the security elements represented in FIGS. 9.1 to 9.15 as well as 25 and 26.

(168) It is possible to form stereoscopic effects when the two partial images 14l and 14r form a stereoscopic pair of images.

(169) It is further possible to generate quasi-continuous movements of the images, wherein the movement, i.e. the positional change of the images, can occur when the observation position is continuously changed.

(170) A morphing effect can be achieved in a similar way, wherein a first image is transformed via various stages into a second image.

(171) The security elements 1 can be observed in reflection and/or in transmission.

(172) The image layer or image layers can represent a static image on the side facing away from the micro-optical elements.

(173) Following the production of the image layer 14 further layers can be applied over the whole surface or partially, e.g. by printing or by transfer of a transfer ply from a carrier, in particular by hot stamping and/or cold stamping. A partial removal after the application, e.g. a so-called demetallization, is also possible. The layers can be metals, for example aluminum, HRI layers, colorless or dyed (e.g. dyed to complement the color of the image layer 14) single- or multi-ply plastic layers, primer layers of inorganic or organic nature, adhesive layers, etc.

(174) The sequence is as far as possible as desired. Layers can also appear several times. The application of further layers to the rear side of the image layer 14 is of interest because different effects from the front and rear side can thus be realized.

(175) By using several differently dyed photoresists, e.g. color images, in particular true color images, can be generated.

(176) It is also possible to introduce optical structures into the image layer or into additional layers, e.g. by replication (thermal replication or UV replication). Optical structures can, however, also be introduced into a spacer layer before the image layer is applied.

(177) The spacer layer can be a volume hologram layer.

(178) Between the lens layer 11 and the image layer 14, a plurality of additional materials can be present, for example dyed layers (over the whole surface or in areas); pigmented layers (security pigments, for example UV-fluorescent pigments); printed layers (over the whole surface or in areas); layers which can be inscribed by means of a laser; layers with polarizing properties; HRI layers, for example made of ZnS.

(179) The security elements can be formed with further elements which can serve, for example, as in particular static optical reference points, lines, etc. for the movement. Further elements could be additional Moir elements, further printed or optically variable or metallic representations, which supplement or complement the image flip. The image flip represented can also be represented by one or more further technologies, for example by an optically variable element. Here, the image flip can be effected synchronously, asynchronously or inversely.

(180) Elements of the image layer can also be used as markings, in particular as register marks and/or control marks for controlling further process steps, in particular for applying further layers and/or elements.

(181) Combinations with further security elements or decorative elements can further be provided, which can be formed, for example, as a hologram, a Kinegram, a lens effect, a volume hologram, security print, a decorative print, a UV-fluorescent print, a print of upconverters (IR upconverters), an OVI (Optically Variable Ink) print and as machine-detectable pigments (3rd line features). The combinations can be arranged next to each other. They can also be arranged interlaced in each other or overlapping. Image elements as well as data etc. contained therein can be complementary to each other, can supplement each other or can be repeated in various technologies.

(182) The partial images contained in the image layer can be supplemented with further images or items of information of the security element 1. Thus the partial images of the image layer can present, with printed items of information outside the security element 1, an overall image or overall images. Here, a part of the overall image would be variable in particular through the lenticular flip.

(183) Through a combination with an optically variable element, different overall partial images could be generated by partial items of information from lenticular flip and optically variable elements, which would be visible at different observation angles.

(184) A further example would be the combination with an optically variable printing ink. Thus the colors of the optically variable ink, occurring at different observation angles, could be visible synchronously with the colors of the lenticular flip.

(185) The security elements can provide additional functions such as machine-readability in addition to the optical effects. A lenticular flip or a Moir magnifier can be machine-readable, wherein different barcodes or positive/negative barcodes can be displayed. These codes can be used for authentication/verification.

(186) The image layer 14 can contain a Moir encoding, i.e. one or more images of the image flip can additionally be analyzed using a Moir analyzer or via an image capture and processing. The capture of a Moir effect can also be effected from the side facing away from the lenses.

(187) A lenticular flip can contain Moir magnifier information which is analyzed by a second analyzer, wherein the Moir analyzer is positioned above the lens layer.

(188) The above-described security elements can be used, for example, in the following security documents: state or non-state personal documents (passport, identity card, visa, driver's license, birth certificate, motor vehicle license plate, gun licenses, etc. banknotes, checks, certificates credit cards; articles of value; tickets; access identity cards

(189) The security elements are in particular suitable in so-called documents with window technology with transparent areas for observation in transmitted light and/or observation from the front and rear side. So-called window banknotes can be banknotes with physical openings in the substrate or, for example, polymer banknotes with transparent polymer areas. The security elements 1 can partially or completely cover the window area, wherein an observation in the window area both from the front and the rear side of the banknote is possible in reflection and/or in transmission. In the case of polymer banknotes, the security element can also be constructed directly on the substrate, i.e. the polymer substrate would represent the carrier substrate.

(190) The security element can likewise be part of a plastic card, wherein the security element 1 is applied to a plastic card or is produced as an embedded and/or integral part of the plastic card.

(191) The above-described elements can, however, also be used outside the field of security documents or outside the security field for decorative articles and advertising materials or as functional elements, for example as components of displays and spectacles.

(192) The security elements are particularly suitable for products with so-called see-through elements, such as e.g. window banknotes, security thread applications for banknotes and/or documents with transparent areas, etc.

(193) The security elements can be applied to objects or introduced (embedded) into objects.

(194) FIGS. 27 to 36 show embodiment examples of security documents which are formed with one or more of the above-described security elements.

(195) FIG. 27 shows a security document 2 formed as a banknote, which has a strip-shaped security element 1.

(196) FIGS. 28a and 28b show a security document 2 formed as a banknote, which has a strip-shaped security element 1, at different tilt angles. The image motifs of the security element 1, symbolized by letters, change from A, B, C to D, E, F.

(197) FIG. 29 shows a security document 2 formed as a banknote, which has a strip-shaped security element 1, which is formed in sections with different image effects:

(198) A: lenticular flip element based on microlenses

(199) B: 2D/3D hologram

(200) C: Kinegram

(201) D: lenticular flip element based on opaque strips

(202) E: optically variable ink print

(203) The areas A to E can be arranged adjacent to each other and/or overlapping each other.

(204) FIG. 30a shows a security document 2 formed as a banknote, which has a window 2f1.

(205) FIG. 30b shows the security document represented in FIG. 30a, which is formed with a strip-shaped security element 1 laminated onto its front side which covers the window 2f. The security element 1 has a first motif symbolized by the letter X which is arranged above the window 2f, and a second motif symbolized by the letter Y which is arranged underneath the first motif outside the window 2f.

(206) FIGS. 31a and 31 b show a security document 2 which is formed like the security document described in FIG. 30b, with the difference that a first motif symbolized by the letter A which is arranged above the window 2f is visible when the security document 2 is tilted about a perpendicular axis in a first tilting position and is invisible in a second tilting position, and that a second motif symbolized by the letter B which is arranged underneath the first motif outside the window 2f is invisible in the first tilting position and is visible in the second tilting position.

(207) FIGS. 32a and 32b show a security document 2 which is formed like the security document described in FIGS. 31a and 31b, with the difference that the motif arranged above the window 2f and symbolized by the letter A is visible in both tilting positions when observed from the rear side.

(208) FIGS. 33 and 34 show a security document 2 with a window 2f formed in the card format ID1.

(209) FIG. 34 shows a security document 2 which is formed like the security document described in FIG. 33, with the difference that a strip-shaped security element 1 which covers the window 2f is laminated onto the front side of the security document 2. The security element 1 has a heart-shaped lenticular flip element which is arranged above the window 2f, as well as a star-shaped hologram which is arranged underneath the window 2f.

(210) FIG. 35 shows a security document 2 with a window 21 in a schematic cross section, in which a lens layer 11l and a carrier substrate 13 of a security element 1 are arranged on the front side of the security document 2 above the window 21, wherein an image layer 14 corresponding to the lens layer 11l is arranged on the rear side of the security document 2.

(211) FIG. 36 shows a security document 2 which is formed like the security document described in FIG. 35, with the difference that the image layer 14 is arranged on the rear side of the carrier substrate 13.

LIST OF REFERENCE NUMBERS

(212) 1 security element 1a tilt axis 2 security document 2f window 11 micro-optical layer 11b diaphragm layer 11k compensation layer 11l lens layer 11p prism layer 12 microlens 12l longitudinal row 12k ball lens 12r transverse row 12z cylindrical lens 13 carrier substrate; carrier film 13s microstructure 14, 14 image layer 14l first partial image 14la image section of the first partial image 14lm first master image 14m master image 14mm third master image 14r second partial image 14ra image section of the second partial image 14rm second master image 15 replication layer 15s stamping die 16 photoresist 17 exposure device 17c computer 17d display 17l radiation source 17k condenser lens 17o projection objective lens 18a spacer layer 18f, 18fl, 18fr color layer 18r reflective layer 18m metal layer 18mp partially metallized layer 18ms semitransparent metal layer 18mt transparent metal layer 18u transfer ply 18v functional layer 19 adhesive layer .sub.e incident azimuth .sub.l x-azimuth .sub.q y-azimuth .sub.e angle of incidence .sub.el first angle of incidence .sub.er second angle of incidence