Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/225—Oblique incidence of vaporised material on substrate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
  • B42D25/29—Securities; Bank notes
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/04—Coating on selected surface areas, e.g. using masks
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/18—Diffraction gratings
  • G02B5/1847—Manufacturing methods
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
  • G03H1/0252—Laminate comprising a hologram layer
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/08—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means
  • G06K19/10—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards
  • G06K19/16—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards the marking being a hologram or diffraction grating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/328—Diffraction gratings; Holograms
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/0005—Adaptation of holography to specific applications
  • G03H1/0011—Adaptation of holography to specific applications for security or authentication
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2250/00—Laminate comprising a hologram layer
  • G03H2250/36—Conform enhancement layer

Definitions

• the invention relates to a surface element with a base layer arranged on a support and projecting from its main plane and forming a spatial, diffraction-optically effective microstructure made of a first, transparent material, the microstructure of the
• the base layer is partially provided with a coating made of a second material that has different optical properties than the first material.
• the microstructure is coated in the form of dots, strips or the like, the dimensions of these dots and strips being substantially greater than, for example, the line spacing of one formed by the microstructure
• Hologram is.
• the procedure according to the prior art has the purpose, despite the presence of a diffraction-optically effective microstructure with a reflective coating, of being able to view further information present on a carrier, for example alphanumeric information or image information, through the microstructure .
• a carrier for example alphanumeric information or image information
• a disadvantage of the prior art is that in order to achieve sufficient brightness of the holograms on the one hand and good visibility of the other information on the other hand, the ratio between the reflecting surfaces reflecting the hologram and the areas which are quasi-transparent must be selected very precisely . In addition, the design options for the known surface elements are very limited.
• the invention is based on the object of forming a surface element with a spatial microstructure in such a way that, on the one hand, if necessary it has a certain transparency, even if a reflective coating is present, on the other hand, however, a multitude of design options with regard to. of the achievable optical effects, with the possibility of machine identification of the microstructure taking into account above all.
• Areas of the microstructure are meant the areas of greatest layer thickness of the base layer having the microstructure, the projecting areas depending on the respective microstructure being able to have very different shapes. These can be line-like areas, but also point-like areas , the contour of the areas depending on the respective microstructure can be different, for example rectangular, wavy or the like.
• the surface element according to the invention is now distinguished from the prior art in that the coating of a material different from the material of the base layer is only provided where the microstructure has projecting areas. This means that the coating corresponds in structure to the structure of the microstructure and not one coating area over several elements, e.g. Grooving that stretches microstructure. Nevertheless, the transparency of the material of the base layer is retained, so that either an information carrier located under the base layer is visible through the base layer that has the microstructure and the region-by-layer coating, or a use of the surface element is possible in application areas where the effect of the microstructure in transmitted light is Validity comes.
• Base layer for example in the form of oblique vapor deposition, is achieved in a simple manner that in fact only the projecting areas of the microstructure are given a corresponding coating.
• the type and scope the coating can be changed by changing the radiation angle.
• a particular advantage of such a type of coating is that an asymmetrical coating of the projecting areas of the microstructure is also possible, namely that more coating material is deposited on the side of the projecting areas of the microstructure facing the radiation source than on the side facing away from the radiation source Page.
• This fact is of particular interest if the coating of the microstructure is a reflective coating, since different intensities of the reflected light are obtained in this way depending on the angle of reflection. For example, it can be achieved in this way that, in the case of a reflection grating serving as a microstructure, the reflection diffraction signal of the + diffraction order differs considerably in intensity from the -th diffraction order.
• a surface element according to the invention can be used for a wide variety of applications. Its use as a security element, e.g. to secure banknotes, checks, credit cards or valuable objects.
• microstructures for example holograms and diffraction structure images that appear to change depending on the viewing angle.
• the microstructure is a diffraction-optical grating structure.
• the lattice structure allows the area-by-area coating to be applied particularly uniformly by means of the oblique radiation, and in addition, precisely defined effects can be achieved by varying the radiation angle.
• lattice structures are advantageously used which have a lattice constant, i.e. a line spacing between the individual grid lines, and a structure depth, i.e. maximum dimensions between the most protruding areas of the lattice structure and the most distant areas, between 0.2 and 10 microns.
• a lattice constant i.e. a line spacing between the individual grid lines
• a structure depth i.e. maximum dimensions between the most protruding areas of the lattice structure and the most distant areas, between 0.2 and 10 microns.
• Such grating structures can be used to achieve most of the optical effects desired in the relevant field, for example color effects, movement effects, etc., the respective grating structure varying in a manner known per se over the total area of the surface element or the microstructure of the surface element from areas with each different lattice structure can be composed.
• the material used to fill the non-raised areas of the microstructure is identical to the material of the base layer, but can also be a different material. If the non-raised areas of the microstructure are filled in, a smooth surface is obtained in any case, with the result that the mechanical resistance of the coating of the microstructure or of the microstructure as a whole is improved. However, it is particularly favorable if the material used to fill the microstructure corresponds in terms of its optical properties to the first material of the base layer. In this way, one can
• Microstructure can be covered by a transparent cover layer, which primarily fulfills a protective function.
• the transparent cover layer can also be provided with a spatial microstructure, the projecting regions of the microstructure of the cover layer expediently having a coating which consists of a material whose optical properties are different from the cover layer.
• the surface element according to the invention can also be equipped with two superimposed microstructures, the advantage over the prior art, as described in US Pat. Nos. 5,128,779 and 5,145,212, primarily to be seen therein that the two microstructures are arranged extremely evenly over the surface of the surface element, and therefore undesired differences in the reflection or diffraction behavior do not result as a result of a correspondingly relatively coarse grid.
• the manufacture of the surface element according to the invention is particularly simple if
• a transparent lacquer layer is used in the base layer and possibly the top layer, into which the microstructure is embossed in a replication process, known per se, it being possible here to use the replication processes mentioned in the prior art in accordance with the aforementioned US Pat.
• the surface element according to the invention will be designed in such a way that the coating on the projecting areas of the microstructure of the base layer and / or the cover layer is reflective, the coating advantageously being made of metal, expediently applied by means of oblique vapor deposition, for example Aluminum, chrome, silver, gold or corresponding, suitable metal alloys.
• the surface element is used as a security element and accordingly on a
• the surface element is part of a transfer layer consisting of several layers and detachable from a carrier film, an embossing film, in particular a hot stamping film.
• a transfer layer consisting of several layers and detachable from a carrier film, an embossing film, in particular a hot stamping film.
• embossing foils are described, for example, in DE 34 22 908 C2 by the applicant, wherein according to the invention there is no full-surface metallization of the structure having an optical diffraction effect, but only a region-by-region coating of the regions of the microstructure which have been embossed into the corresponding lacquer layer.
• the surface element according to the invention is particularly suitable for use as
• the document of value or the object can either be equipped directly with a corresponding surface element, for example by embossing and subsequent oblique radiation with the second material, or, which should generally be preferable, the surface element is produced in a first step and then , for example by lamination or hot stamping, is transferred to the object to be secured.
• Fig. 3 shows the intensity distribution of the
• a carrier or another substrate suitable for receiving a lacquer chic as the base layer comes in as the carrier Consider, for example, a document of value, an object to be marked accordingly or the like.
• a base layer 1 is shown in each of FIGS. 1a to 1d, 2 and 4a to 6b.
• This base layer 1 is expediently a layer of a lacquer suitable for receiving a microstructure, with respect to the lacquers that can be used, their thickness and the embossing of the microstructure are expressly referred to the explanation in DE 34 22 908 C2.
• other lacquers and other layers which can be deformed by means of an embossing matrix to form a microstructure can also be used as the base layer.
• the base layer 1 is attached, at least during the production of the surface element according to the invention, with the underside 2 on the carrier, not shown.
• the base layer 1 On its side opposite the flat surface 2, which corresponds to the main plane of the surface element, the base layer 1 is provided with a microstructure, generally designated by the reference number 3, the design of the microstructure being different.
• the microstructure is e.g. from a regular triangular lattice structure.
• the microstructure 3 is of irregular design, the microstructure 3 of FIG. 1b being a hologram structure, for example.
• the microstructure 3 is in each case a rectangular grating, although the ratio between the grating constant g and the structure depth t of the grating (see FIG. 2) in each case can be different.
• the different rectangular grids differ in the respective relationships between web width a and web spacing b, the ratio a / b being large in FIG. 1c and small in FIG. 1d.
• the coating 4 being able to be formed, for example, by a vapor-deposited metal layer while the coating 4a (FIG. 4b) is formed by a dielectric which has different optical properties than the first material from which the base layer 1 is made.
• the coating 4 is found only in the area of the tips 5 of the base layer 1.
• FIG. 1 b where only the most protruding “waves” 5 a of the hologram microstructure have a coating 4.
• the coating 4, 4a is essentially only present on the end faces 6 of the grid webs 7 opposite the surface 2.
• This type of coating of the base layer 1 is achieved according to the invention in that particles of the material forming the coating 4, 4a are sprayed onto the base layer at a predetermined angle.
• This spraying of the particles forming the coating at an angle leads to the areas of a Lattice web or the microstructure, which are covered by an adjacent web or projection during spraying, are not coated.
• the respective coated surface depends on the one hand on the exact shape of the microstructure 3 and on the other hand on the irradiation angle, it generally being the case that the larger the irradiation angle, the larger the coated surface.
• the surface elements according to FIGS. 1c and 1d differ essentially only in that the ratio between web width a and web spacing b is different, while the radiation angle ⁇ coincides.
• a coating 4 is obtained which actually covers essentially only the end face 6 of the lattice webs 7 and extends only to a very small extent into the space between the lattice webs 7.
• the coating 4 in the microstructure according to FIG. 1d extends significantly further into the space between the grid bars, which can only be attributed to the greater distance between the grid bars 7 compared to FIG. 1c, because in this case the grid bars less the respectively adjacent grid bar cover.
• a thicker coating of the one (in the figure right) side surface 9 of the lattice webs 7 is provided, which thereby What is achieved is that the irradiation angle at which the particles of the coating material strike the microstructure 3 of the base layer 1 is significantly increased in comparison to FIGS. 1a to 1d.
• a surface element according to the invention can have special optical properties in the sense of a clear asymmetry. It is obvious that a grating of a design according to FIG. 2 reflects light relatively strongly in the Oth order or, because the regions between the webs are transparent, also transmits it strongly. With reflection - and possibly also transmission - of the light and the corresponding diffraction are then obtained in the + lth or -lth order of strongly different light intensities, as is sketched in FIG. 3.
• This property of the surface element according to FIG. 2 can, for example, be used to great advantage to ensure the authenticity of a document or the like. to be checked by machine. It is possible without great difficulty to measure the light beams of the + lth and -lth order at the same time and then to check their intensity ratio, which ratio can be used as a security feature.
• each lattice in which - when using metal as a coating - alternating, metallized, opaque and conductive sections on the one hand and non-metallized, translucent and non-conductive subareas are present on the other hand. This is indicated in Fig. 4a by the arrows.
• a dielectric as the coating 4a, as in 4b, areas corresponding to alternately different optical properties are obtained.
• FIGS. 1c to 4a show the production of a special surface element according to the invention.
• the base layer is provided with a microstructure 3, for example a rectangular lattice structure, in a conventional manner, for example by molding.
• This microstructure 3 is then provided with a coating 4 in the manner explained in connection with FIGS. 1 a to 2, for example by oblique vapor deposition with a metal, oblique vapor deposition processes e.g. for films or other substrates are generally known.
• a surface element is then obtained which basically corresponds to that of FIGS. 1c, 1d, 2 and 4a.
• the surface element according to FIG. 5c is now modified compared to the surface element according to FIG. 5b in that the spaces 10 between the lattice webs 7 are filled, as a result of which a smooth surface 11 is formed on the side of the base layer 1 opposite the surface 2.
• the material used to fill the gaps 10 may vary depending on the desired effect. In any case, the material should be transparent. However, it is particularly expedient if the intermediate spaces 10 are filled with a material that corresponds to the material of the base layer 1, because then the interfaces 12 (dashed lines in FIG. 5c) between the original base layer 1 and the filled material 10 are not visible.
• the surface element according to FIG. 5d thus gives the impression that lattice structures formed by the coating 4 are only present in the region of the surface 11, without the surface 11 in any way spatially, i.e. is three-dimensional. 5c therefore acts like an amplitude grating.
• a particular advantage of the surface element of FIG. 5c can be seen in the fact that there is no possibility of transferring the structures of the surface 11 by molding, for example for the purpose of forgery.
• a transparent cover layer 13 can be attached to the surface elements of FIGS. 1a to 5c on the side of the base layer facing away from surface 2, which covers the microstructure and e.g. protective purposes only.
• FIGS. 6a and 6b A particularly advantageous embodiment of such a cover layer 13 is shown in FIGS. 6a and 6b.
• the cover layer 13 according to FIGS. 6a and 6b is also with a Provided microstructure, for example also in the form of a rectangular grid with different grid parameters than the grid of FIGS. 5a, 5b, wherein, as shown in FIG. 6b, the grid structure 14 of the cover layer 13 can also be provided with a coating 15.
• the coating 15 of the lattice structure 14 of the cover layer 13 can match the coating 4 of the base layer 1, but can consist of a different material. E.g. one of the coatings 4, 15 could be made of metal, the other of a dielectric.
• a surface element according to FIG. 5c is first created in the manner explained above, whereby not only the gaps 10 between the lattice webs 7 are filled in one work step, but the cover layer 13 is simultaneously applied. This is possible if the cover layer 13 is made of the same material that is also used to fill the spaces 10. If a different material is provided for the cover layer 13, only that
• the further microstructure 14 e.g. by means of a suitable embossing die.
• the further coating 15 is then applied to the microstructure 14 of the cover layer 13, it being assumed in FIG. 6b that the
• Coating 15 is produced by correspondingly oblique radiation of the microstructure 14 of the cover layer 13.
• the radiation angle is chosen to be correspondingly large, usually about 90 °.
• the surface element according to FIG. 6b comprises two optically effective microstructures which can certainly produce different optical effects. This ensures that either the optical effect produced by the coating 4 through the regionally coating 15 of the microstructure 14 is visible or, conversely, the optical effect generated by the microstructure 14 with the coating 15 is visible through the regionally coating 4, provided that for the Cover layer 13 or the base layer 1 can be used in accordance with transparent materials. If only reflection effects are to be observed, the base layer 1 could possibly be non-transparent, provided that the surface element of FIG. 6b is observed from the side of the coating 15.
• microstructure 14 and, if necessary, the coating 15 of the cover layer 13 with a further material layer, which may also only fill the depressions of the microstructure 14 in order to achieve a smooth surface.
• the base layer 1 or cover layer 13 is provided with a lattice structure as a microstructure
• the lattice structure expediently having a lattice constant g and a structure depth t between 0.2 and 10 ⁇ m should have.
• a coating in certain areas is expediently achieved in that the irradiation of the lattice webs 7 or projecting Areas of the microstructure 3 with particles of the coating material take place at an angle between 5 and 60 ', which can be achieved by appropriate alignment of the carrier with the base layer with respect to the source of the coating composition.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Business, Economics & Management (AREA)
• Optics & Photonics (AREA)
• Manufacturing & Machinery (AREA)
• Accounting & Taxation (AREA)
• Finance (AREA)
• Theoretical Computer Science (AREA)
• Credit Cards Or The Like (AREA)
• Holo Graphy (AREA)
• Diffracting Gratings Or Hologram Optical Elements (AREA)

Priority Applications (1)

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Citations (2)

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• 1994
  • 1994-06-18 DE DE4421407A patent/DE4421407C1/de not_active Expired - Fee Related
• 1995
  • 1995-05-24 TW TW084105210A patent/TW320604B/zh active
  • 1995-06-08 AU AU26680/95A patent/AU2668095A/en not_active Abandoned
  • 1995-06-08 WO PCT/DE1995/000776 patent/WO1995035553A1/de not_active Ceased

Patent Citations (2)

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