CA2244324A1 - A method and an apparatus for fabricating a surface structure, particularly a holographic surface structure, on a substrate - Google Patents
A method and an apparatus for fabricating a surface structure, particularly a holographic surface structure, on a substrate Download PDFInfo
- Publication number
- CA2244324A1 CA2244324A1 CA 2244324 CA2244324A CA2244324A1 CA 2244324 A1 CA2244324 A1 CA 2244324A1 CA 2244324 CA2244324 CA 2244324 CA 2244324 A CA2244324 A CA 2244324A CA 2244324 A1 CA2244324 A1 CA 2244324A1
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- Canada
- Prior art keywords
- accordance
- radiation
- substrate
- surface structure
- irradiation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 31
- 239000000178 monomer Substances 0.000 claims abstract description 53
- 239000000126 substance Substances 0.000 claims abstract description 38
- 238000004049 embossing Methods 0.000 claims abstract description 21
- 239000011248 coating agent Substances 0.000 claims abstract description 17
- 238000000576 coating method Methods 0.000 claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 claims abstract description 4
- 238000005406 washing Methods 0.000 claims description 12
- 230000005855 radiation Effects 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 2
- 239000011888 foil Substances 0.000 description 27
- 239000007788 liquid Substances 0.000 description 8
- 230000001419 dependent effect Effects 0.000 description 4
- 230000001427 coherent effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001093 holography Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000005266 casting Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- 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
- G03H1/0276—Replicating a master hologram without interference recording
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
- B29C39/14—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of indefinite length
- B29C39/148—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of indefinite length characterised by the shape of the surface
-
- 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
- G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
- G03H1/0276—Replicating a master hologram without interference recording
- G03H2001/0284—Replicating a master hologram without interference recording by moulding
-
- 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
- G03H1/04—Processes or apparatus for producing holograms
- G03H1/18—Particular processing of hologram record carriers, e.g. for obtaining blazed holograms
- G03H2001/187—Trimming process, i.e. macroscopically patterning the hologram
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H2210/00—Object characteristics
- G03H2210/50—Nature of the object
- G03H2210/54—For individualisation of product
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Holo Graphy (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Coating Apparatus (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Preparing Plates And Mask In Photomechanical Process (AREA)
Abstract
A method serves the fabrication of a surface structure, in particular of a holographic surface structure, on a substrate. To allow in a simple manner an individualisedfabrication of the surface structure, the substrate (4) is coated with a radiation-curable substance, in particular a radiation-curable monomer (5). An embossing pattern is introduced into the coating, for example by a cylinder (10). The embossing pattern is cured with a modulated irradiation beam (1a, 1b) (Fig.1).
Description
A method and an apparatus for fabricating a surface structure, particularly a holographic surface structure, on a substrate The invention relates to a method for fabricating a surface structure, particularly a holographic surface structure, on a substrate and to an apparatus for the performance of such a method.
The surface structure to be fabricated is generally a relief structure. A given or defined surface structure or relief structure has to be applied to the substrate. The substrate can then be used in particular as a die (relief master) for embossing holography.
The object of the invention is to provide a method and an apparatus of the type described above with which an individualised fabrication of a surface structure,particularly of a holographic surface structure, is made possible in a simple manner.
In accordance with a first proposal, this object is solved for a method of the type described above by the substrate being coated with a radiation-curable substance, in particular with a radiation-curable monomer, by an embossing pattern being introduced into the coating and by the embossing pattern being cured with a modulated irradiation beam. The radiation-curable substance is preferably a fluid substance. This substance can preferably be cured by means of electromagnetic rays, for example W light. A regular embossing pattern can be applied. The radiation-curable substance is cured by the irradiation beam in those regions which are reached by at least one modulated irradiation beam. Naturally, the iITadiation beam(s) must be suitable to cure the radiation-curable substance.
Advantageous improvements are described in the dependent claims.
The embossing pattern is preferably applied by a cylinder. However, it may also be applied by a plane element moved intermittently. The cylinder can possess a regular relief structure on its surface.
The modulated radiation can be performed by means of a scanner, in particular bymeans of a line scanner. This is also particularly of advantage if the embossing pattern is applied by means of a cylinder. The line of the line scanner then preferably runs parallel to a circumferential line of the embossing cylinder or at a right-angle to the direction of forward movement of the scanner.
A further advantageous improvement is characterised by the fact that the irradiation is effected by an LCD. The LCD can be controlled by a PC or other computer so that the surface structure regions to be cured individually can be programmed very quickly and simply.
The method can be repeated once or several times. In this way, it is possible tofabricate one after the other on a substrate several surface structures which may differ from one another as required and which can be positioned next to one another or which may also overlap.
For example, the non-cured substance or the non-cured monomer is washed out after the irradiation or the curing.
An appalallls for the fabrication of a surface structure, in particular of a holographic surface structure, on a substrate comprises in accordance with the invention a cylinder over which a substrate coated with a radiation-curable substance, in particular with a radiation-curable monomer, can be guided and an irradiation apparatus to irradiate the coated substrate with a modulated irradiation beam.
Advantageous in~lovements are described in the further dependent claims.
Preferably, a coating apparatus for the coating of the substrate with a radiation-curable substance, in particular a radiation-curable monomer, is connected in series prior to the cylinder.
Preferably, the irradiation apparatus is located outside the cylinder. In this case, the substrate is translucent for the rays of the irradiation apparatus. The irradiation apparatus can, however, also be located within the cylinder. In this case, the surface of the cylinder is transparent for the irradiation beams.
Preferably, the irradiation apparatus comprises a light modulator, for example ascanner, in particular a line scanner, and/or an LCD.
Preferably, several apparatuses are located in series one after the other. The substrate passes through these apparatuses one after the other. In this way, several surface structures, which may differ as required, can be fabricated one after the other on the substrate which surface structures are then located next to one another and/or overlapping on the substrate.
For example, a washing unit is connected subsequent to the cylinder to wash out the non-cured substance or the non-cured monomer.
The object forming the subject of the invention is solved for a method of the type described above in accordance with a second proposal for which independent protection is claimed by a radiation-curable substance, in particular a radiation-curable monomer, being applied to the substrate in accordance with the surface structure to be fabricated and the substance being irradiated with an irradiation beam. In this case, therefore, the radiation-curable substance is not applied to the whole surface region of the substrate, but only to that region where the surface structure should later be located. There, the substance is then irradiated and thus cured. One advantage of this procedure consists of a washing out of any liquid substance in those areas where no surface structure should be located no longer being necessary.
The two methods in accordance with the invention differ by means of the following: in accordance with the method first given, the radiation-curable substance is first applied to the whole substrate or, however, at least to regions of the substrate which are greater than that region on which the surface structure should later be located. The surface structure is then manufactured in that only those regions on which the surface structure should later appear are irradiated wlth an irradiation beam. In contrast, in the second method, the radiation-curable substance is from the beginnin~ only applied to the substrate where the surface structure should later appear. Here, the curing beam does not need to be modulated (as long as no additional hologram is irradiated).
Advantageous improvements are described in the further dependent claims.
The radiation-curable substance or the radiation-curable monomer can be applied to the substrate by specific application, for example by spraying or imprinting or by another method. In accordance with another advantageous improvement, the radiation-curable substance or the radiation-curable monomer can be applied to a cylinder with surface relief and subsequent to curing by irradiation be applied to the substrate from this. In this case, the radiation-curable substance or the radiation-curable monomer is, for example, applied individually to the embossing cylinder by means of inkjet nozzles. For the curing, only uniform, unmodulated radiation is required.
The method can be repeated once or several times to apply different surface structures to the substrate as required and this to regions of the substrate which are next to one another or which overlap.
An apparatus to fabricate a surface structure, in particular a holographic surface structure, on a substrate comprises in accordance with the second proposal of the invention an application apparatus to apply a radiation-curable substance, in particular a radiation-curable monomer, to the substrate in accordance with the surface structure to be fabricated and an irradiation apparatus to irradiate the substance.
Advantageous improvements are described in the further dependent claims.
The apparatus preferably comprises a cylinder. The application apparatus comprises, for example, inkjet nozzles to apply the radiation-curable substance or the radiation-curable monomer to the substrate andlor to the cylinder. It is advantageous if several apparatuses are connected in series in order to fabricated different surface structures to the substrate as required, and this to regions of the substrate which are next to one another and/or which overlap.
By means of the invention, in particular holographic surface structures can be fabricated. However, it is also possible to fabricate other surface structures, for example, optical gratings. The surface structures are manufactured in the form of casting or moulding.
Embodiments of the invention are described in detail below by means of the enclosed drawing in which Fig. 1 shows an apparatus for fabricating a surface structure on a substrate with a cylinder in a side view;
Fig. 2 shows the apparatus shown in Fig. 1 with, in addition, a coating apparatus and a line scanner in a perspective view;
Fig. 3 shows a modification of the apparatus shown in Fig. 2 with an LCD
Fig. 4 shows a washing unit in a side view;
Fig. S shows two apparatuses from Fig.2 connected in series one after the other;
Fig. 6 shows an apparatus for fabricating a surface structure on a substrate with inkjet nozzles in a perspective view; and Fig. 7 shows an apparatus for fabricating a surface structure on a substrate with inkjet nozzles to apply thé surface structure to a cylinder in a perspective view.
In the apparatus shown in schematic form in Fig. 1, a foil 4, which is coated with a liquid, radiation-curable monomer 5, is supplied to a rotating cylinder 10. The cylinder . 10 comprises a cylindrical surface (cylinder wall) 3 to whose outside a surface structure 2 is applied. It is, for example, a hologram surface structure. The foil 4 is first guided round a first guide roller 7. It then comes into contact with the surface structure 2 in such a way that the liquid, radiation-curable monomer 5 is positioned on the side of the foil 4 facing the surface structure 2. The feed rate 11 of the foil 4 is precisely the same as the circumferential speed of the cylinder wall 3. Then, the foil is deflected by a further guide roller 7' and transported away.
While the foil 4 is in contact with the surface structure 2, the embossing pattern is applied to the monomer coating 5 of the foil 4, that is the (negative) embossing pattern of the surface structure 2. This embossing pattern is irradiated with a modulated irradiation beam la and/or lb. The irradiation can be effected by a modulated irradiation beam la from the inside, that is from the interior of the cylinder. In this case, the cylinder wall 3 must be translucent. However, the irradiation can also be effected by means of a modulated irradiation beam lb from the outside or the inside.
In the case of irradiation from the outside, the foil 4 should be translucent; in the event of irradiation from the inside, the embossing cylinder be translucent in order to allow an irradiation and curing of the monomer 5.
The Irradiation beam la and/or lb is modulated in such a way that only certain predetermined regions of the embossing pattern are irradiated with light. These regions are shown in black in Fig. 1. In these regions, the monomer 5 is cured. In this way, the predetermined surface structure is formed on the foil with monomer 6 cured by means of irradiation. Liquid monomer 5 can still be found between the cured reglons.
In Fig. 2, the coating apparatus positioned prior to the cylinder is shown which coating apparatus comprises a tank 8 filled with liquid monomer, a lower coating roller 9 and an upper coating roller 9'. The lower coating roller 9 dips into the liquid monomer in the tank 8. It rotates counter-clockwise and is in contact with the upper coating roller 9' which rotates clockwise and whose circumferential speed is the same as the transportation rate 11 of the film 4.
In the embodiment of Fig.2, irradiation is effected with the mo~ te-l irradiation beam 1 by means of a line scanner 2 which consists of a rotating polygon mirror and which is irradiated by the beam source 3 with modulation capability. The line of the line scanner 2 runs parallel to a circumferential line of the cylinder 10. In this way, regions 14 with cured monomer are applied to the foil 4.
The version shown in Fig. 3 differs from that in Fig. 2 in that the line scanner has been replaced by an irradiation apparatus with an LCD 23 which irradiation apparatus is irr~ te~l by an expanded irradiation beam 1 through a lens system 22. The predetermined surface structure is fabricated on the LCD 23. The expanded irradiation beam 1 is guided onto the LCD 23 by the lens system 22 and modulated there. The LCD is located above the cylinder 10 parallel and at a distance to one of its circumferential lines.
In Fig.4, a washing unit for the non-irradiated monomer is shown. It consists of a washing drum 34 which rotates in a container with washing solution 33. The foil 31, on which regions with cured monomer and with liquid monomer are located, is led via a first rubber scraper 32 to a guide roller 35. From there, the foil 31 comes to the outside circumference of the washing drum 34 in such a way that the monomer regions are located on the outside circumference. In the washing solution 33, the liquid monomer is then removed from the foil 1. The foil 31 washed in this way is then guided through a rubber roller 36 after one wrap around the washing drum 34. By means of the rubber roller 36, which is in contact with the washing drum 34, anysolvent still adhering to the foil 31 is simultaneously squeezed off.
The foil 37 with cured monomer is subsequently led to further rubber scrapers 32 on both sides of the foil 37 which scrape off any residues of monomer andlor solvent.
Following on from these are hot-air nozzles 38 on both sides of the foil 31 which blow off any monomer and/or solvent residues still rem~ining.
Fig. 5 shows two a~palaluses of the type shown in Fig. 2 connected one after theother. Identical parts are identified by the same symbols so that they do not need to be described again. By means of the first inscription beam 1, a first surface structure 14 is applied to the foil 4. The second inscription beam 1 ' applies a second surface structure 14' to the film 4. In the embodiment of Fig. 5, the regions 14 and 14' are next to each other. However, they may also overlap in full or in part.
In Figs. 6 and 7, embodiments in accordance with the second solution in accordance with the invention are shown. In the embodiment of Fig. 6, a radiation-curable monomer is applied in accordance with the surface structure 44 to the foil 4 by inkjet nozzles 41. It is then found on the foil 4 as a sprayed monomer 42 in the pre-determined surface structure. This pre-determined surface structure is fabricated by means of a corresponding control ofthe inkjet nozzles 41. While passing the cylinder 10, the foil 4 is irradiated with the expanded irradiation beam 43. In this way, the monomer located at the pre-determined areas is cured. On the regions 44, cured monomer is then found on the foil 4.
Fig. 7 shows a modified embodiment in which the inkjet nozzles 41 do not apply the monomer directly to the foil 4, but first to the cylinder 10 provided with a regular surface structure or relief structure. The inkjet nozzles 41 are located below the cylinder. After one rotation of the cylinder 10, its surface is irradiated by an expanded irradiation beam 52. The inkjet nozzles 41 have applied the monomer to the cylinder 10 only on those pre-determined areas on which the surface structure 57 should be fabricated. There, the monomer is then cured by the expanded irradiation beam 52.
Subsequently, it is transferred to the foil 4.
-The foil 4 is first deflected downwards by a guide roller 55 which is located above thecylinder 10. It is brought into contact with the surface of the cylinder 10 by a pressure roller 56. The foil 4 is then guided away by a further guide roller 55.
As in the embodiments of Figs. 6 and 7, the monomer is only applied to the pre-determined areas on which the surface structure should be fabricated, no washing unit is required.
By means of the invention, the copying capability and the imitation of security holograms is made substantially more difficult. It is possible to fabricate microstructures which make counterfeiting difficult in a simple manner. These microstructures can be fabricated by means of an individ~ tion such as a numbering, a bar code, personal images (for I.D.s, etc.) or similar.
By means of the invention, a method and an apparatus are provided for the individualised transfer of surface structures onto translucent and non-translucent substrates. No expensive holographic equipment is needed. In particular, among other things, the irradiation can be effected with a non-coherent light source. The individll~ ation of the information to be transferred can be performed with very low effort and by the utilisation of existing technologies such as LCD displays (projectors), modulated lasers (laser printers), inkjet monomer application (inkjet printers),electron beam scanners (welding, drilling), electro-mechanically adjustable masks, thermal transfer technology (printers, facsimile machines) and/or electrostatic discharging with laser scanners (laser printers).
By means of a combination or overlapping of different structures, complex structures can be manufactured simply in one workstep. Even structures with a large area can be manufactured with minimum equipment effort. The invention allows a simple and direct preparation of relief masters for embossing holography with and without the use of coherent lasers and holographic equipment. By mixing in different dyestuffs, fluorescent dyestuffs, reversible thermal dyestuffs and/or ferro-magnetic substances in micro-encapsulated form (or also directly) to the monomer, imitation or counterfeiting is made more difficult. By means of a multiple application onto overlapping regions, elevations or relief structures can be fabricated on the substrate.
In accordance with the first solution in accordance with the invention, the substrate is coated with a radiation-curable substance, in particular with a radiation-curable monomer. This process step can, however, be omitted if a pre-coated substrate is used for the process. In this case, the embossing pattern is applied to the coating of the pre-coated substrate and this embossing pattern is then irradiated with the modulated or unmodulated irradiation beam.
In the multiple application of monomer shown in Fig. 5, elevations of the cured monomer layer can be fabricated if the regions which are coated in each case overlap.
These elevations can be tangible or measurable by means of which an additional authenticity feature is created. In addition, it is possible to provide the first cylinder 10 with a first structure and the second cylinder 10' with a second or multiple structures.
The structures can correspond to a first and a second colour.
The surface structure to be fabricated is generally a relief structure. A given or defined surface structure or relief structure has to be applied to the substrate. The substrate can then be used in particular as a die (relief master) for embossing holography.
The object of the invention is to provide a method and an apparatus of the type described above with which an individualised fabrication of a surface structure,particularly of a holographic surface structure, is made possible in a simple manner.
In accordance with a first proposal, this object is solved for a method of the type described above by the substrate being coated with a radiation-curable substance, in particular with a radiation-curable monomer, by an embossing pattern being introduced into the coating and by the embossing pattern being cured with a modulated irradiation beam. The radiation-curable substance is preferably a fluid substance. This substance can preferably be cured by means of electromagnetic rays, for example W light. A regular embossing pattern can be applied. The radiation-curable substance is cured by the irradiation beam in those regions which are reached by at least one modulated irradiation beam. Naturally, the iITadiation beam(s) must be suitable to cure the radiation-curable substance.
Advantageous improvements are described in the dependent claims.
The embossing pattern is preferably applied by a cylinder. However, it may also be applied by a plane element moved intermittently. The cylinder can possess a regular relief structure on its surface.
The modulated radiation can be performed by means of a scanner, in particular bymeans of a line scanner. This is also particularly of advantage if the embossing pattern is applied by means of a cylinder. The line of the line scanner then preferably runs parallel to a circumferential line of the embossing cylinder or at a right-angle to the direction of forward movement of the scanner.
A further advantageous improvement is characterised by the fact that the irradiation is effected by an LCD. The LCD can be controlled by a PC or other computer so that the surface structure regions to be cured individually can be programmed very quickly and simply.
The method can be repeated once or several times. In this way, it is possible tofabricate one after the other on a substrate several surface structures which may differ from one another as required and which can be positioned next to one another or which may also overlap.
For example, the non-cured substance or the non-cured monomer is washed out after the irradiation or the curing.
An appalallls for the fabrication of a surface structure, in particular of a holographic surface structure, on a substrate comprises in accordance with the invention a cylinder over which a substrate coated with a radiation-curable substance, in particular with a radiation-curable monomer, can be guided and an irradiation apparatus to irradiate the coated substrate with a modulated irradiation beam.
Advantageous in~lovements are described in the further dependent claims.
Preferably, a coating apparatus for the coating of the substrate with a radiation-curable substance, in particular a radiation-curable monomer, is connected in series prior to the cylinder.
Preferably, the irradiation apparatus is located outside the cylinder. In this case, the substrate is translucent for the rays of the irradiation apparatus. The irradiation apparatus can, however, also be located within the cylinder. In this case, the surface of the cylinder is transparent for the irradiation beams.
Preferably, the irradiation apparatus comprises a light modulator, for example ascanner, in particular a line scanner, and/or an LCD.
Preferably, several apparatuses are located in series one after the other. The substrate passes through these apparatuses one after the other. In this way, several surface structures, which may differ as required, can be fabricated one after the other on the substrate which surface structures are then located next to one another and/or overlapping on the substrate.
For example, a washing unit is connected subsequent to the cylinder to wash out the non-cured substance or the non-cured monomer.
The object forming the subject of the invention is solved for a method of the type described above in accordance with a second proposal for which independent protection is claimed by a radiation-curable substance, in particular a radiation-curable monomer, being applied to the substrate in accordance with the surface structure to be fabricated and the substance being irradiated with an irradiation beam. In this case, therefore, the radiation-curable substance is not applied to the whole surface region of the substrate, but only to that region where the surface structure should later be located. There, the substance is then irradiated and thus cured. One advantage of this procedure consists of a washing out of any liquid substance in those areas where no surface structure should be located no longer being necessary.
The two methods in accordance with the invention differ by means of the following: in accordance with the method first given, the radiation-curable substance is first applied to the whole substrate or, however, at least to regions of the substrate which are greater than that region on which the surface structure should later be located. The surface structure is then manufactured in that only those regions on which the surface structure should later appear are irradiated wlth an irradiation beam. In contrast, in the second method, the radiation-curable substance is from the beginnin~ only applied to the substrate where the surface structure should later appear. Here, the curing beam does not need to be modulated (as long as no additional hologram is irradiated).
Advantageous improvements are described in the further dependent claims.
The radiation-curable substance or the radiation-curable monomer can be applied to the substrate by specific application, for example by spraying or imprinting or by another method. In accordance with another advantageous improvement, the radiation-curable substance or the radiation-curable monomer can be applied to a cylinder with surface relief and subsequent to curing by irradiation be applied to the substrate from this. In this case, the radiation-curable substance or the radiation-curable monomer is, for example, applied individually to the embossing cylinder by means of inkjet nozzles. For the curing, only uniform, unmodulated radiation is required.
The method can be repeated once or several times to apply different surface structures to the substrate as required and this to regions of the substrate which are next to one another or which overlap.
An apparatus to fabricate a surface structure, in particular a holographic surface structure, on a substrate comprises in accordance with the second proposal of the invention an application apparatus to apply a radiation-curable substance, in particular a radiation-curable monomer, to the substrate in accordance with the surface structure to be fabricated and an irradiation apparatus to irradiate the substance.
Advantageous improvements are described in the further dependent claims.
The apparatus preferably comprises a cylinder. The application apparatus comprises, for example, inkjet nozzles to apply the radiation-curable substance or the radiation-curable monomer to the substrate andlor to the cylinder. It is advantageous if several apparatuses are connected in series in order to fabricated different surface structures to the substrate as required, and this to regions of the substrate which are next to one another and/or which overlap.
By means of the invention, in particular holographic surface structures can be fabricated. However, it is also possible to fabricate other surface structures, for example, optical gratings. The surface structures are manufactured in the form of casting or moulding.
Embodiments of the invention are described in detail below by means of the enclosed drawing in which Fig. 1 shows an apparatus for fabricating a surface structure on a substrate with a cylinder in a side view;
Fig. 2 shows the apparatus shown in Fig. 1 with, in addition, a coating apparatus and a line scanner in a perspective view;
Fig. 3 shows a modification of the apparatus shown in Fig. 2 with an LCD
Fig. 4 shows a washing unit in a side view;
Fig. S shows two apparatuses from Fig.2 connected in series one after the other;
Fig. 6 shows an apparatus for fabricating a surface structure on a substrate with inkjet nozzles in a perspective view; and Fig. 7 shows an apparatus for fabricating a surface structure on a substrate with inkjet nozzles to apply thé surface structure to a cylinder in a perspective view.
In the apparatus shown in schematic form in Fig. 1, a foil 4, which is coated with a liquid, radiation-curable monomer 5, is supplied to a rotating cylinder 10. The cylinder . 10 comprises a cylindrical surface (cylinder wall) 3 to whose outside a surface structure 2 is applied. It is, for example, a hologram surface structure. The foil 4 is first guided round a first guide roller 7. It then comes into contact with the surface structure 2 in such a way that the liquid, radiation-curable monomer 5 is positioned on the side of the foil 4 facing the surface structure 2. The feed rate 11 of the foil 4 is precisely the same as the circumferential speed of the cylinder wall 3. Then, the foil is deflected by a further guide roller 7' and transported away.
While the foil 4 is in contact with the surface structure 2, the embossing pattern is applied to the monomer coating 5 of the foil 4, that is the (negative) embossing pattern of the surface structure 2. This embossing pattern is irradiated with a modulated irradiation beam la and/or lb. The irradiation can be effected by a modulated irradiation beam la from the inside, that is from the interior of the cylinder. In this case, the cylinder wall 3 must be translucent. However, the irradiation can also be effected by means of a modulated irradiation beam lb from the outside or the inside.
In the case of irradiation from the outside, the foil 4 should be translucent; in the event of irradiation from the inside, the embossing cylinder be translucent in order to allow an irradiation and curing of the monomer 5.
The Irradiation beam la and/or lb is modulated in such a way that only certain predetermined regions of the embossing pattern are irradiated with light. These regions are shown in black in Fig. 1. In these regions, the monomer 5 is cured. In this way, the predetermined surface structure is formed on the foil with monomer 6 cured by means of irradiation. Liquid monomer 5 can still be found between the cured reglons.
In Fig. 2, the coating apparatus positioned prior to the cylinder is shown which coating apparatus comprises a tank 8 filled with liquid monomer, a lower coating roller 9 and an upper coating roller 9'. The lower coating roller 9 dips into the liquid monomer in the tank 8. It rotates counter-clockwise and is in contact with the upper coating roller 9' which rotates clockwise and whose circumferential speed is the same as the transportation rate 11 of the film 4.
In the embodiment of Fig.2, irradiation is effected with the mo~ te-l irradiation beam 1 by means of a line scanner 2 which consists of a rotating polygon mirror and which is irradiated by the beam source 3 with modulation capability. The line of the line scanner 2 runs parallel to a circumferential line of the cylinder 10. In this way, regions 14 with cured monomer are applied to the foil 4.
The version shown in Fig. 3 differs from that in Fig. 2 in that the line scanner has been replaced by an irradiation apparatus with an LCD 23 which irradiation apparatus is irr~ te~l by an expanded irradiation beam 1 through a lens system 22. The predetermined surface structure is fabricated on the LCD 23. The expanded irradiation beam 1 is guided onto the LCD 23 by the lens system 22 and modulated there. The LCD is located above the cylinder 10 parallel and at a distance to one of its circumferential lines.
In Fig.4, a washing unit for the non-irradiated monomer is shown. It consists of a washing drum 34 which rotates in a container with washing solution 33. The foil 31, on which regions with cured monomer and with liquid monomer are located, is led via a first rubber scraper 32 to a guide roller 35. From there, the foil 31 comes to the outside circumference of the washing drum 34 in such a way that the monomer regions are located on the outside circumference. In the washing solution 33, the liquid monomer is then removed from the foil 1. The foil 31 washed in this way is then guided through a rubber roller 36 after one wrap around the washing drum 34. By means of the rubber roller 36, which is in contact with the washing drum 34, anysolvent still adhering to the foil 31 is simultaneously squeezed off.
The foil 37 with cured monomer is subsequently led to further rubber scrapers 32 on both sides of the foil 37 which scrape off any residues of monomer andlor solvent.
Following on from these are hot-air nozzles 38 on both sides of the foil 31 which blow off any monomer and/or solvent residues still rem~ining.
Fig. 5 shows two a~palaluses of the type shown in Fig. 2 connected one after theother. Identical parts are identified by the same symbols so that they do not need to be described again. By means of the first inscription beam 1, a first surface structure 14 is applied to the foil 4. The second inscription beam 1 ' applies a second surface structure 14' to the film 4. In the embodiment of Fig. 5, the regions 14 and 14' are next to each other. However, they may also overlap in full or in part.
In Figs. 6 and 7, embodiments in accordance with the second solution in accordance with the invention are shown. In the embodiment of Fig. 6, a radiation-curable monomer is applied in accordance with the surface structure 44 to the foil 4 by inkjet nozzles 41. It is then found on the foil 4 as a sprayed monomer 42 in the pre-determined surface structure. This pre-determined surface structure is fabricated by means of a corresponding control ofthe inkjet nozzles 41. While passing the cylinder 10, the foil 4 is irradiated with the expanded irradiation beam 43. In this way, the monomer located at the pre-determined areas is cured. On the regions 44, cured monomer is then found on the foil 4.
Fig. 7 shows a modified embodiment in which the inkjet nozzles 41 do not apply the monomer directly to the foil 4, but first to the cylinder 10 provided with a regular surface structure or relief structure. The inkjet nozzles 41 are located below the cylinder. After one rotation of the cylinder 10, its surface is irradiated by an expanded irradiation beam 52. The inkjet nozzles 41 have applied the monomer to the cylinder 10 only on those pre-determined areas on which the surface structure 57 should be fabricated. There, the monomer is then cured by the expanded irradiation beam 52.
Subsequently, it is transferred to the foil 4.
-The foil 4 is first deflected downwards by a guide roller 55 which is located above thecylinder 10. It is brought into contact with the surface of the cylinder 10 by a pressure roller 56. The foil 4 is then guided away by a further guide roller 55.
As in the embodiments of Figs. 6 and 7, the monomer is only applied to the pre-determined areas on which the surface structure should be fabricated, no washing unit is required.
By means of the invention, the copying capability and the imitation of security holograms is made substantially more difficult. It is possible to fabricate microstructures which make counterfeiting difficult in a simple manner. These microstructures can be fabricated by means of an individ~ tion such as a numbering, a bar code, personal images (for I.D.s, etc.) or similar.
By means of the invention, a method and an apparatus are provided for the individualised transfer of surface structures onto translucent and non-translucent substrates. No expensive holographic equipment is needed. In particular, among other things, the irradiation can be effected with a non-coherent light source. The individll~ ation of the information to be transferred can be performed with very low effort and by the utilisation of existing technologies such as LCD displays (projectors), modulated lasers (laser printers), inkjet monomer application (inkjet printers),electron beam scanners (welding, drilling), electro-mechanically adjustable masks, thermal transfer technology (printers, facsimile machines) and/or electrostatic discharging with laser scanners (laser printers).
By means of a combination or overlapping of different structures, complex structures can be manufactured simply in one workstep. Even structures with a large area can be manufactured with minimum equipment effort. The invention allows a simple and direct preparation of relief masters for embossing holography with and without the use of coherent lasers and holographic equipment. By mixing in different dyestuffs, fluorescent dyestuffs, reversible thermal dyestuffs and/or ferro-magnetic substances in micro-encapsulated form (or also directly) to the monomer, imitation or counterfeiting is made more difficult. By means of a multiple application onto overlapping regions, elevations or relief structures can be fabricated on the substrate.
In accordance with the first solution in accordance with the invention, the substrate is coated with a radiation-curable substance, in particular with a radiation-curable monomer. This process step can, however, be omitted if a pre-coated substrate is used for the process. In this case, the embossing pattern is applied to the coating of the pre-coated substrate and this embossing pattern is then irradiated with the modulated or unmodulated irradiation beam.
In the multiple application of monomer shown in Fig. 5, elevations of the cured monomer layer can be fabricated if the regions which are coated in each case overlap.
These elevations can be tangible or measurable by means of which an additional authenticity feature is created. In addition, it is possible to provide the first cylinder 10 with a first structure and the second cylinder 10' with a second or multiple structures.
The structures can correspond to a first and a second colour.
Claims (23)
1. A method for the fabrication of a surface structure, in particular of a holographic surface structure on a substrate, characterised in that the substrate is coated with a radiation-curable substance, in particular a radiation-curable monomer (5), an embossing pattern is introduced into the coating and the embossing pattern is cured with a modulated irradiationbeam (1a, 1b).
2. A method in accordance with claim 1 wherein the embossing pattern is applied by a cylinder (10).
3. A method in accordance with either of claims 1 or 2 wherein the irradiation is effected from the side of the substrate facing away from the coating.
4. A method in accordance with any of the preceding claims wherein the irradiation is effected by a scanner, in particular by a line scanner (12).
5. A method in accordance with any of the preceding claims wherein the irradiation is effected by an LCD (23).
6. A method in accordance with any of the preceding claims wherein the process is repeated once or several times.
7. A method in accordance with any of the preceding claims wherein the non-cured substance or the non-cured monomer is washed out.
8. An apparatus for fabricating a surface structure, in particular a holographic surface structure, to a substrate, comprising a cylinder (10) over which a substrate (4) coated with a radiation-curable substance (5), in particular a radiation-curable monomer, can be guided and an irradiation apparatus (1a, 1b) for the irradiation of the coated substrate with a modulated irradiation beam.
9. An apparatus in accordance with claim 8 wherein a coating apparatus (8, 9, 9') for the coating of the substrate with a radiation-curable substance, in particular a radiation-curable monomer, is connected in series prior to the cylinder (10).
10. An apparatus in accordance with either of claims 8 or 9 wherein the irradiation apparatus is located outside the cylinder 10.
11. An apparatus in accordance with any of claims 8 to 10 wherein the irradiation apparatus is located inside the cylinder.
12. An apparatus in accordance with of claims 8 to 11 wherein the irradiation apparatus comprises a scanner, in particular a line scanner (12).
13. An apparatus in accordance with any of claims 8 to 12 wherein the irradiation apparatus comprises an LCD (23).
14. An apparatus in accordance with any of claims 8 to 13 wherein several apparatuses are connected in series one after the other.
15. An apparatus in accordance with any of claims 8 to 14 wherein a washing unit(33, 34) to wash out the non-cured substance or the non-cured monomer is connected in series after the cylinder (10).
16. A method for fabricating a surface structure, in particular a holographic surface structure, to a substrate characterised in that a radiation-curable substance, in particular a radiation-curable monomer, is applied to the substrate (4) in accordance with the surface structure (44, 57) to be fabricated and in that the substance is irradiated with a radiation beam (43, 52).
17. A method in accordance with claim 16 wherein the radiation-curable substance or the radiation-curable monomer is applied to the substrate (4) by specific application, for example by spraying, imprinting, etc.
18. A method in accordance with claim 16 wherein the radiation-curable substance or the radiation-curable monomer is applied to a cylinder (10) with a surface relief and applied from there to the substrate (4) after curing by irradiation (52).
19. A method in accordance with any of claims 16 to 18 wherein the process is repeated once or several times.
20. An apparatus for fabricating a surface structure, in particular a holographic surface structure, to a substrate comprising an application apparatus for the application of a radiation-curable substance, in particular a radiation-curable monomer, to the substrate (4) in accordance with the surface structure (44, 57) to be fabricated and an irradiation apparatus (43, 52) to irradiate the substance.
21. An apparatus in accordance with claim 20 characterised by a cylinder (10).
22. An apparatus in accordance with either of claims 20 or 21 wherein the application apparatus comprises, for example, ink-jet nozzles (41) for the application of the radiation-curable substance or the radiation-curable monomer to the substrate (4) and/or the cylinder (10).
23. An apparatus in accordance with any of claims 20 to 22 wherein several apparatuses are connected in series one after the other.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19733746 | 1997-08-04 | ||
| DE19733746.5 | 1997-08-04 | ||
| DE19802585A DE19802585A1 (en) | 1997-08-04 | 1998-01-23 | Method and device for producing a surface structure, in particular a holographic surface structure, on a substrate |
| DE19802585.8 | 1998-01-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2244324A1 true CA2244324A1 (en) | 1999-02-04 |
Family
ID=26038862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2244324 Abandoned CA2244324A1 (en) | 1997-08-04 | 1998-07-28 | A method and an apparatus for fabricating a surface structure, particularly a holographic surface structure, on a substrate |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0896259A3 (en) |
| JP (1) | JPH11147059A (en) |
| CN (1) | CN1209590A (en) |
| CA (1) | CA2244324A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7767273B2 (en) | 2005-03-09 | 2010-08-03 | 3M Innovative Properties Company | Apparatus and method for producing two-sided patterned web in registration |
| US7804649B2 (en) | 2003-09-09 | 2010-09-28 | 3M Innovative Properties Company | Microreplicated achromatic lens |
| US7931841B2 (en) | 2005-03-09 | 2011-04-26 | 3M Innovative Properties Company | Microreplicated article |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE270615T1 (en) * | 1998-11-19 | 2004-07-15 | Nilpeter As | METHOD AND DEVICE FOR ROTATIONAL MOLDING OF STRUCTURES WITH SURFACE RELIEF |
| WO2000030869A1 (en) * | 1998-11-19 | 2000-06-02 | E.I. Du Pont De Nemours And Company, Inc. | Method for decoratively shaping a painted substrate surface |
| CN1104529C (en) * | 1999-12-14 | 2003-04-02 | 张君伟 | Holographic card paper making process |
| GB0207944D0 (en) | 2002-04-05 | 2002-05-15 | Univ Cambridge Tech | Method of detection |
| EP1526963A1 (en) * | 2002-08-09 | 2005-05-04 | Leonhard Kurz Gmbh & Co. | Laser-supported reproduction method |
| DE10236597A1 (en) * | 2002-08-09 | 2004-02-19 | Leonhard Kurz Gmbh & Co. Kg | The laser assisted security marking assembly, for individual markings on a substrate, has a laser beam directed at the replicating surface to form shaping zones to be imposed on the substrate by pressure |
| DE10247011A1 (en) * | 2002-10-09 | 2004-04-29 | Leonhard Kurz Gmbh & Co. Kg | Multi-layer film with UV lacquer layer |
| US7070406B2 (en) * | 2003-04-29 | 2006-07-04 | Hewlett-Packard Development Company, L.P. | Apparatus for embossing a flexible substrate with a pattern carried by an optically transparent compliant media |
| DE10333469A1 (en) | 2003-07-22 | 2005-02-10 | Giesecke & Devrient Gmbh | security element |
| US7245406B2 (en) | 2003-09-17 | 2007-07-17 | Dai Nippon Printing Co., Ltd. | Method for forming fine concavo-convex patterns, method for producing optical diffraction structure, and method for copying optical diffraction structure |
| DE102004009422A1 (en) * | 2004-02-24 | 2005-09-08 | Metronic Ag | Method and device for applying diffractive elements to surfaces |
| JP4563213B2 (en) * | 2004-02-25 | 2010-10-13 | 大日本印刷株式会社 | An optical diffraction structure including an optical diffraction structure replicated by the optical diffraction structure replication method and the replication method. |
| DE602006019834D1 (en) | 2005-03-09 | 2011-03-10 | 3M Innovative Properties Co | DEVICE AND METHOD FOR PRODUCING A MICROREPLICED OBJECT |
| ATE424986T1 (en) * | 2005-03-09 | 2009-03-15 | 3M Innovative Properties Co | APPARATUS AND METHOD FOR PRODUCING A MICROREPLICATED ARTICLE |
| DE102006048768A1 (en) * | 2006-10-12 | 2008-04-17 | Hologram Industries Research Gmbh | Production process for holograms and documents with hologram |
| RU2415024C1 (en) * | 2006-12-14 | 2011-03-27 | Колгейт-Палмолив Компани | Topographic image that appears on package |
| CN103722917B (en) * | 2013-01-31 | 2016-09-07 | 汕头市依明机械股份有限公司 | A kind of transparent roller for laser imprinting and a kind of laser imprinting device |
| DE102015015378A1 (en) * | 2015-11-27 | 2017-06-01 | Giesecke & Devrient Gmbh | Embossing device for embossing micro- or nanostructures |
| DE102015015407A1 (en) * | 2015-11-27 | 2017-06-01 | Giesecke & Devrient Gmbh | Embossing process for embossing micro- or nanostructures |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5242084B2 (en) * | 1974-06-06 | 1977-10-22 | ||
| GB8829697D0 (en) * | 1988-12-20 | 1989-02-15 | Ciba Geigy Ag | Copying holograms |
| EP0408283B1 (en) * | 1989-07-12 | 1995-09-27 | Canon Kabushiki Kaisha | Apparatus for producing substrate sheet for optical recording mediums and process for producing substrate sheet for optical recording mediums making use of it, apparatus for producing optical recording medium and process for producing optical recording medium making use of it. |
| EP0439050B1 (en) * | 1990-01-18 | 1996-04-03 | E.I. Du Pont De Nemours And Company | Method for making optically readable media containing embossed information |
| DE4404128A1 (en) * | 1993-02-19 | 1994-08-25 | Gao Ges Automation Org | Security document and method for its manufacture |
| DE19530495A1 (en) * | 1995-08-18 | 1997-02-20 | Giesecke & Devrient Gmbh | Data carrier with at least in partial areas transparent plastics layer |
-
1998
- 1998-07-28 CA CA 2244324 patent/CA2244324A1/en not_active Abandoned
- 1998-08-03 EP EP98114562A patent/EP0896259A3/en not_active Withdrawn
- 1998-08-04 JP JP22037698A patent/JPH11147059A/en active Pending
- 1998-08-04 CN CN 98116879 patent/CN1209590A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7804649B2 (en) | 2003-09-09 | 2010-09-28 | 3M Innovative Properties Company | Microreplicated achromatic lens |
| US7767273B2 (en) | 2005-03-09 | 2010-08-03 | 3M Innovative Properties Company | Apparatus and method for producing two-sided patterned web in registration |
| US7931841B2 (en) | 2005-03-09 | 2011-04-26 | 3M Innovative Properties Company | Microreplicated article |
| US8740599B2 (en) | 2005-03-09 | 2014-06-03 | 3M Innovative Properties Company | Apparatus and method for producing two-sided patterned web in registration |
| US8968629B2 (en) | 2005-03-09 | 2015-03-03 | 3M Innovative Properties Company | Apparatus and method for producing two-sided patterned web in registration |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0896259A3 (en) | 1999-07-28 |
| CN1209590A (en) | 1999-03-03 |
| EP0896259A2 (en) | 1999-02-10 |
| JPH11147059A (en) | 1999-06-02 |
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