Method for engraving a code pattern in a tool surface of a solid piece

Abstract

A method for engraving a tool surface of a solid piece with a plurality of code patterns of structures, wherein the plurality of code patterns comprises: a first code pattern comprising first structures having a lateral size and a pitch in the range of 20 to 500 pm, respectively; a second code pattern comprising second structures having a lateral size and a pitch in the range of 1 to 20 pm, respectively; and a third code pattern comprising third structures having a lateral size and a pitch in the range of 0.2 to 5 pm, respectively. The method comprises: providing an original base surface on a tool surface of the solid piece; polishing the original base surface to obtain a polished base surface; depositing a hard layer on the polished base surface; engraving the third code pattern in the hard layer. The method comprises engraving the first code pattern and the second code pattern prior to the step of depositing the hard layer, wherein the hard layer reproduces the topography of the first code pattern and the second code pattern.

Description

Technical Field

[0001] The present invention relates to a method for engraving at least first, second and third code patterns on the tool surface of a solid part, wherein the first, second and third code patterns respectively include corresponding first, second and third structures, wherein the lateral dimensions and spacing fall within a range of specific values ​​according to the first, second and third code patterns. Background Technology

[0002] Imprinting tools with an imprinting tool surface and an imprinting structure on the tool surface are known to be manufactured, wherein the size of the structure is in the range of 1 μm or less. Such structures will be referred to as microstructures below. International Publication WO 2012 / 1019741 A1 relates to a method for producing an imprinting tool by introducing an imprinting structure for microstructure elements in the surface of the imprinting tool. The imprinting structure is manufactured by an ultrashort laser pulse. The imprinting tool surface can be a hardened metal surface. The imprinting structure has a periodic pattern that depends on the wavelength of the laser used to generate it. The periodic pattern is a corrugated grating and can have a period of 500 nm and a depth of several hundred nm. However, the imprinting structure may not be manufactured to include sharp rectangular edges, and the only type of pattern is a grating pattern.

[0003] The present invention aims to overcome many of the shortcomings of the prior art and to provide more possibilities for obtaining precise and diverse microstructures on the tool surface of solid parts (e.g., embossing tool surface or molding tool surface), as well as other structures with dimensions several orders of magnitude larger than the microstructures. Summary of the Invention

[0004] In a first aspect, the present invention provides a method for engraving a plurality of structured code patterns on a tool surface of a solid part, wherein the plurality of code patterns comprises: a first code pattern comprising a first structure having a lateral dimension and a spacing in the range of 20 to 500 μm; a second code pattern comprising a second structure having a lateral dimension and a spacing in the range of 1 to 20 μm; and a third code pattern comprising a third structure having a lateral dimension and a spacing in the range of 0.2 to 5 μm. The method includes: providing a raw base surface on the tool surface of the solid part; polishing the raw base surface to obtain a polished base surface; depositing a hard layer on the polished base surface; and engraving the third code pattern in the hard layer. The method includes engraving the first code pattern and the second code pattern prior to the step of depositing the hard layer, wherein the hard layer reproduces the morphology of the first code pattern and the second code pattern.

[0005] In a preferred embodiment, the tool surface of the engraved solid part has cylindrical symmetry; and is configured with a first structure, a second structure, and a third structure for transferring the first code pattern, the second code pattern, and the third code pattern into a substrate, wherein the transfer is from any of the following: forming, printing, molding, handcrafting, pressing, or imprinting onto or into the substrate.

[0006] In another preferred embodiment, the tool surface of the engraved solid part is configured to serve as a forming tool for transferring the first, second, and third structures of the first, second, and third code patterns into a substrate, wherein the transfer is from any of the following: printing, molding, handcrafting, pressing, or stamping into the substrate.

[0007] In another preferred embodiment, the step of engraving the first code pattern and the second code pattern includes engraving by means of an ultrashort pulse laser beam focused on the polished base surface, the ultrashort pulse laser beam being provided by a laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W.

[0008] In another preferred embodiment, the step of engraving the third code pattern in the hard layer involves a laser and a mask projection of a third structure on the hard layer through the laser, which corresponds to the third code pattern to be engraved.

[0009] In another preferred embodiment, the step of engraving the third code pattern in the hard layer involves a laser and a beam splitter that generates multiple focal points to engrave a third structure corresponding to the third code pattern to be engraved into the hard layer.

[0010] In a second aspect, the present invention provides a method for engraving a plurality of structured code patterns on a tool surface of a solid part, wherein the plurality of code patterns comprises: a first code pattern comprising a first structure with a lateral dimension and spacing in the range of 20 to 500 μm; a second code pattern comprising a second structure with a lateral dimension and spacing in the range of 1 to 20 μm; and a third code pattern comprising a third structure with a lateral dimension and spacing in the range of 0.2 to 5 μm. The method comprises: providing a raw base surface on the tool surface of the solid part; polishing the raw base surface to obtain a polished base surface; depositing a hard layer on the polished base surface; engraving the third code pattern in the hard layer; engraving the first code pattern prior to the step of depositing the hard layer; and engraving the second code pattern into the polished base surface through the hard layer.

[0011] In another preferred embodiment, the tool surface of the engraved solid part has cylindrical symmetry; and is configured with a first structure, a second structure, and a third structure for transferring the first code pattern, the second code pattern, and the third code pattern into a substrate. The transfer is from any of the following: forming, printing, molding, handcrafting, pressing, or imprinting onto or into the substrate.

[0012] In another preferred embodiment, the tool surface of the engraved solid part is configured to serve as a forming tool for transferring the first, second, and third structures of the first, second, and third code patterns into a substrate, wherein the transfer is from any of the following: printing, molding, handcrafting, pressing, or stamping into the substrate.

[0013] In another preferred embodiment, both the step of engraving the first code pattern and the step of engraving the second code pattern include engraving by means of an ultrashort pulse laser beam focused on the polished base surface, the ultrashort pulse laser beam being provided by a laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W.

[0014] In another preferred embodiment, the step of engraving the third code pattern in the hard layer involves a laser and a mask projection of a third structure on the hard layer through the laser, which corresponds to the third code pattern to be engraved.

[0015] In another preferred embodiment, the step of engraving the third code pattern in the hard layer involves a laser and a beam splitter that generates multiple focal points to engrave a third structure corresponding to the third code pattern to be engraved into the hard layer.

[0016] In a third aspect, the present invention provides an imprinting tool having a plurality of code patterns as an imprinting structure, wherein the plurality of code patterns include: a first code pattern comprising a first structure having a lateral dimension and spacing in the range of 20 to 500 μm; a second code pattern comprising a second structure having a lateral dimension and spacing in the range of 1 to 20 μm; and a third code pattern comprising a third structure having a lateral dimension and spacing in the range of 0.2 to 5 μm. The imprinting tool includes: a base; a surface of the base configured to have the first structure and the second structure disposed thereon; a hard layer disposed at least on the first structure on the surface of the base; and a surface of the hard layer comprising the third structure.

[0017] In another preferred embodiment, the base is cylindrical.

[0018] In another preferred embodiment, the base comprises a plate made of metal or composite material.

[0019] In a fourth aspect, the present invention provides an injection mold having a plurality of code patterns as a molding structure, wherein the plurality of code patterns include: a first code pattern comprising a first structure having a lateral dimension and spacing in the range of 20 to 500 μm; a second code pattern comprising a second structure having a lateral dimension and spacing in the range of 1 to 20 μm; and a third code pattern comprising a third structure having a lateral dimension and spacing in the range of 0.2 to 5 μm. The injection mold includes: a base; a surface of the base configured to have the first structure and the second structure disposed therein; a hard layer disposed at least on the first structure of the surface of the base; and a surface of the hard layer comprising the third structure.

[0020] In a fifth aspect, the present invention provides a method for certifying surface-structured products, the surface-structured products having a first code pattern area, a second code pattern area, and / or a third code pattern area on the surface of the product, wherein the first code pattern includes a first structure with a lateral dimension and spacing in the range of 20 to 500 μm; the second code pattern includes a second structure with a lateral dimension and spacing in the range of 1 to 20 μm; and the third code pattern includes a third structure with a lateral dimension and spacing in the range of 0.2 to 5 μm. The method includes the following steps: capturing an image from a first code pattern area on the product, including at least one first code pattern, using a camera associated with a first data processing device; analyzing the captured image at the first data processing device and retrieving information contained in the at least one first code pattern according to a first encoding algorithm; capturing an image from a second code pattern area on the product, including at least one second code pattern, using a camera performed by an auxiliary optical device and associated with the first data processing device; analyzing the captured image at the first data processing device and retrieving information contained in the at least one second code pattern according to a second encoding algorithm; and illuminating at least a portion of a third code pattern area, including at least one third code pattern, with a readout beam and receiving the readout beam projected through or reflected by the at least one third code pattern using a readout screen to retrieve information contained in the third code pattern. Attached Figure Description

[0021] The invention will be better understood through a detailed description of the preferred embodiments and with reference to the accompanying drawings, wherein...

[0022] Figure 1 A flowchart illustrating a method for engraving the surface of an embossing tool according to an exemplary embodiment of the present invention is included;

[0023] Figures 2-1 to 2-6 Different stages of engraving a cylindrical embossing tool using an exemplary method according to the present invention are shown;

[0024] Figure 3 A schematic diagram of a production line for manufacturing the surface of an embossing tool, including yet another exemplary embodiment of the method according to the present invention;

[0025] Figure 4 Includes a flowchart illustrating a method for engraving the surface of an embossing tool according to another exemplary embodiment of the present invention;

[0026] Figures 5-1 to 5-6 Different stages of engraving a cylindrical embossing tool using an exemplary method according to the present invention are shown;

[0027] Figure 6 A schematic diagram of a production line for manufacturing the surface of an embossing tool, including yet another exemplary embodiment of the method according to the present invention;

[0028] Figure 7 A schematic diagram of a laser engraving machine for engraving roller tools with cylindrical geometry is shown.

[0029] Figure 8 A schematic diagram of another laser engraving machine for free-form surfaces is shown;

[0030] Figure 9 A schematic diagram of yet another laser engraving machine for tool surfaces of solid parts is shown;

[0031] Figure 10 The multiplication modulation according to an example of the present invention is illustrated schematically;

[0032] Figure 11 The z-offset modulation according to an example of the present invention is illustrated schematically;

[0033] Figure 12 Additive modulation according to an example of the present invention is illustrated schematically;

[0034] Figure 13 The xy offset modulation according to another example of the invention is illustrated schematically;

[0035] Figure 14 A foil embossed with first, second, and third code patterns by the method of the present invention is illustrated schematically according to an exemplary embodiment of the present invention;

[0036] Figure 15 A mold sculpted by the method of the present invention and a molded product obtained therefrom are shown, the sculpting being carried out according to an exemplary embodiment of the present invention;

[0037] Figure 16 An exemplary embodiment of a coin-shaped product engraved according to the method of the present invention is shown;

[0038] Figure 17 A setup for reading a third code pattern from a foil embossed according to an exemplary method of the present invention is shown;

[0039] Figure 18 Two setups for reading a first code pattern and a second code pattern from a product embossed according to an exemplary method of the present invention are schematically shown;

[0040] Figure 19 This schematically illustrates the use of reading such as Figure 16 The setup of the coin-shaped product shown. Detailed Implementation

[0041] Glossary

[0042] The following defines the meanings of several terms used in this specification, unless any of these terms are interpreted differently in a particular context:

[0043] Base surface structure: The basic three-dimensional topographic structure of the carving, which has a base three-dimensional contour and is carved into the surface of the material part or tool;

[0044] Code pattern structure: The sculpted three-dimensional shape structure, whose three-dimensional contour is the result of applying the elements of the coding algorithm to the base three-dimensional contour;

[0045] Code pattern area: a spatially constrained set of structures including base surface structures and code pattern structures, which are distributed on the tool surface or material component surface according to a finite set of locations that determine the positions of the base surface structures and code pattern structures;

[0046] Encoding algorithm: includes at least one element and transcribes information (e.g., alphanumeric or image) in multiple identical basal surface structures with basal three-dimensional contours to obtain specific operations of the corresponding code pattern area;

[0047] Tool: A material component comprising a base surface structure and / or a code pattern structure on at least one surface to produce a surface structure, the material including, for example, a metal or ceramic in bulk or layered form, and intended to transfer the morphology of its surface structure onto another material;

[0048] Roller: A tool characterized by cylindrical symmetry and dimensions such as length <5m, diameter <1m, having a base surface structure and / or having at least one code pattern structure area with tissue on its side surface;

[0049] Hard layer: A thin layer with a thickness of less than 20 μm and a hardness preferably higher than 0.5 GPa, which uniformly covers the surface of the tool without changing its surface morphology;

[0050] Imprinting: The process of transferring a base surface structure and / or code pattern structure from at least one roller or tool onto a viscous fluid or solid substrate or onto another solid part;

[0051] Code reading: The specific process of retrieving coded information from any embossed material or engraved solid piece with a code pattern structure;

[0052] Polishing: A specific process for smoothing the surface of a material part or tool, i.e., reducing the peak-to-valley amplitude of its height profile, wherein the maximum peak-to-valley amplitude of its height profile is 0.5 or less from the expected height of the base and / or code pattern features;

[0053] Original base surface: The surface of a material part or tool before the polishing process;

[0054] Foil: refers to metal foil, polymer foil, paper, laminated paper or mixture, cardboard or other sheet products with a thickness of <1mm to be embossed.

[0055] Example embodiments of the present invention

[0056] First aspect

[0057] According to a first aspect, the present invention provides a method for engraving a plurality of code patterns on a tool surface 101 of a solid part, such as... Figure 1 As shown in the flowchart. In this example, the tool surface of the solid part is an embossing tool surface, and multiple code patterns are engraved as an embossed structure, wherein the code patterns include:

[0058] • First code pattern C-1, which includes a first structure with lateral dimensions and spacing ranging from 20 to 500 μm. Figure 1 (not shown in the image);

[0059] • Second code pattern C-2, which includes a second structure with lateral dimensions and spacing ranging from 1 to 20 μm. Figure 1 (not shown in the image); and

[0060] • Third code pattern C-3, which includes a third structure with lateral dimensions and spacing ranging from 0.2 to 5 μm. Figure 1 (Not shown in the image).

[0061] The method includes providing a raw base surface 100 on the surface 101 of the imprinting tool. The raw base surface ( Figure 1 The original base surface (not shown) is a substantially planar surface, in this sense, having no morphological elements and prepared for processing in this method for engraving. The original base surface can be, for example, the surface of a flat workpiece or the cylindrical surface of a rolled workpiece. In the next step, the method includes polishing the original base surface 102 to obtain a polished base surface. In yet another step 103, the method includes engraving a first code pattern C-1 and a second code pattern C-2 on the polished base surface. Step 103 is performed prior to the step of depositing a hard layer 104 on the polished base surface. Therefore, the hard layer is also deposited on the first code pattern C-1 and the second code pattern C-2, resulting in the hard layer also reproducing the morphology of the first code pattern C-1 and the second code pattern C-2. In yet another step 105, the method includes engraving a third code pattern C-3 in the hard layer and obtaining an engraved embossing tool surface 106.

[0062] In a preferred embodiment, the hard layer is a thin layer with a thickness of less than 20 μm and a hardness preferably greater than 0.5 GPa, which uniformly covers the surface of the solid tool without altering its surface morphology—as explained in the glossary.

[0063] In another preferred embodiment, the original base surface or the polished base surface may comprise, for example, a blocky or layered form of metal or ceramic.

[0064] like Figure 1 The different stages of the method according to the first aspect shown are illustrated in an exemplary embodiment as follows: Figures 2-1 to 2-6 The different stages of carving using cylindrical embossing tools.

[0065] Figure 2-1 A cylindrical embossing tool 200 or roller is shown, having a polished base surface 201 obtained by polishing the original base surface of the cylindrical embossing tool 200. In this example, the polished base surface is the cylindrical side surface of the cylindrical embossing tool 200.

[0066] Figure 2-2 A portion 202 of a cross-sectional view 200 of the cylindrical embossing tool 200 is shown. Note that the dimensions and proportions of the elements shown in the figure do not correspond to actual dimensions and / or proportions and have been adapted for better readability. This cross-sectional view was obtained after partially performing step 103 of the previously explained method of engraving a first code pattern C-1 on the polished base surface 202. The first code pattern C-1 is engraved in a plurality of first regions 203. An enlarged view 204 at the surface of the first region 203 shows a first structure 205 included in the first code pattern C-1.

[0067] Figure 2-3 The diagram shows portion 202 after the engraving of the second code pattern C-2 has been performed in multiple second regions 206 in method step 103. The second regions 206 differ from the first region 203. An enlarged view 207 of the surface of the second region 206 shows a second structure 208 included in the second code pattern C-2.

[0068] Figure 2-4 The portion 202 is shown after the previously explained step of depositing the hard layer 104 has been performed. The hard layer 209 is deposited on the polished base surface 201, thus covering the first structure 205 in the first region 203 and the second structure 208 in the second region 206, thereby reproducing the morphology of the first code pattern C-1 and the second code pattern C-2.

[0069] Figure 2-5 The portion 202 is shown after the previously explained step of engraving the third code pattern C-3 in the hard layer 209. The third code pattern C-3 is engraved in a third region 210, which is different from the first region 203 and the second region 206. This means that the third region 210 corresponds to the portion of the hard layer 209 that does not overlap with the first region 203 and the second region 206. Enlarged view 211 shows the third structure 212 engraved in the third region 210 corresponding to enlarged view 211.

[0070] Figure 2-6 A schematic diagram of portion 202 obtained after performing all steps of the method according to the first aspect is shown. In this particular example, at least one region 213 may be present, wherein the hard layer 209 is not engraved with the third structure 212. An enlarged view 214 of a portion of region 213 adjacent to region 206 shows a portion of the hard layer 209 without any third structure, and an adjacent portion having the second structure 208.

[0071] The main advantage of the first aspect is that the surface of the engraving tool is completely covered by a hard layer; the chemical properties, and the resistance to chemical reagents, solvents, cleaning agents, etc., will be given by the properties of the hard layer.

[0072] According to the embodiments of the first aspect, the point to consider is homotheticity; by covering the micro-code feature C-2 with a hard layer, micro-shape deformation may occur between the engraved second structure 208 and the engraved second structure 208 coated with the hard layer 209, resulting in a loss of readability of the code pattern C-2.

[0073] Now for reference Figure 3It includes a schematic diagram of a production line for manufacturing an engraving tool surface 308 from a raw surface 301, according to a first aspect of the method of the invention. Individual machines in this production line are indicated by frames 302 to 307, and multiple frames will be referred to below as... Figures 7 to 9 The exemplary machine shown is described in detail below. Generally speaking, Figure 3 The machines used are well known in the art and require no further description. The original substrate surface 301 is treated by a polishing machine 302 to obtain a polished substrate surface. The latter is then subjected to a laser engraving machine 303, where a first code pattern and a second code pattern are engraved into the polished substrate surface. The polished substrate surface, thus engraved, is then optionally cleaned by a cleaning machine 304 before undergoing a hard layer deposition machine 305, which deposits a hard layer on the polished substrate surface including the engraved first and second code patterns. The polished substrate surface bearing the hard layer is then subjected to another laser engraving machine 306, where a third code pattern is engraved in the hard layer. Finally, an optional plasma etching machine 307 applies a final treatment to obtain an engraved surface 308.

[0074] Second aspect

[0075] According to a second aspect, the present invention provides a method for engraving a plurality of code patterns on a tool surface (in this example, an embossing tool surface 101) of a solid part, such as... Figure 4 As shown in the process diagram. Again, the embossing tool surface 101 is an example of a tool surface for a solid part. Multiple code patterns are engraved into the embossed structure, wherein the code patterns include

[0076] • First code pattern C-1, which includes a first structure with lateral dimensions and spacing ranging from 20 to 500 μm. Figure 4 (not shown in the image);

[0077] • Second code pattern C-2, which includes a second structure with lateral dimensions and spacing ranging from 1 to 20 μm. Figure 4 (not shown in the image); and

[0078] • Third code pattern C-3, which includes a third structure with lateral dimensions and spacing ranging from 0.2 to 5 μm. Figure 4 (Not shown in the image).

[0079] The method includes providing a raw base surface 100 on an impression tool surface 101. In a next step, the method includes polishing the raw base surface 102 to obtain a polished base surface. In yet another step 400, the method includes engraving a first code pattern C-1. Step 400 is performed prior to the step of depositing a hard layer 104 on the polished base surface. Thus, the hard layer is also deposited over the first code pattern C-1, which causes the hard layer to also reproduce the morphology of the first code pattern C-1. In yet another step 401, the method includes engraving a second code pattern C-2 into the polished base surface through the hard layer, and engraving a third code pattern C-3 into the hard layer, and obtaining an engraved impression tool surface 106.

[0080] Similar to the first aspect, the hard layer can be a thin layer with a thickness of less than 20 μm and a hardness preferably higher than 0.5 GPa, which uniformly covers the surface of the tool without altering its surface morphology - as explained in the glossary.

[0081] The original base surface or the polished base surface may include, for example, a blocky or layered form of metal or ceramic.

[0082] like Figure 4 The different stages of the method according to the first aspect are shown in the example as follows Figures 5-1 to 5-6 The different stages of carving using cylindrical embossing tools.

[0083] Figure 5-1 A cylindrical embossing tool 200 or roller is shown, having a polished base surface 201 obtained by polishing the original base surface of the cylindrical embossing tool 200. Note that this is in contrast to... Figure 2-1 The same type of polished base surface 201 is shown.

[0084] Figure 5-2 A portion 202 of a cross-sectional view of the cylindrical embossing tool 200 is shown. Note that the dimensions and proportions of the elements shown in the figure do not correspond to actual dimensions and / or proportions and have been adapted for better readability. This cross-sectional view was obtained after performing step 400 of the previously explained method of engraving a first code pattern C-1 on the polished base surface 202. The first code pattern C-1 is engraved in a plurality of first regions 203. An enlarged view 204 at the surface of the first region 203 shows a first structure 205 included in the first code pattern C-1.

[0085] Figure 5-3 The portion 202 is shown after the previously explained step of depositing the hard layer 104. The hard layer 209 is deposited on the polished base surface 201, thus covering the first structure 205 in the first region 203 and reproducing the morphology of the first structure 205.

[0086] Figure 5-4 shows portion 202 produced by method step 401, wherein the second code pattern C-2 has been etched into the polished base surface 201 in multiple second regions 206 through a hard layer 209. The second regions 206 are different from the first region 203. Enlarged views 500 and 502 at the surface of the second regions 206 show a second structure 208 included in the second code pattern C-2.

[0087] Figure 5-5 shows portion 202 after the previously explained step of engraving the third code pattern C-3 in hard layer 209. The third code pattern C-3 is engraved in a third region 210, which is different from the first region 203 and the second region 206. This means that the third region 210 corresponds to the portion of hard layer 209 that does not overlap with the first region 203 and the second region 206. Enlarged view 502 shows the third structure 212 engraved in the third region 210 corresponding to enlarged view 502.

[0088] Figure 5-6 A schematic diagram of portion 202 obtained after performing all the steps of the method according to the second aspect is shown. In this particular example, at least one region 213 may be present, in which the hard layer 209 is not engraved with the third structure 212. An enlarged view 503 of a portion of region 213 adjacent to region 206 shows the portion of the hard layer 209 without any third structure, and the adjacent portion having the second structure 208.

[0089] The main advantage here is the perfect readability of the second structure 208 of the code pattern C-2, which will be the result of later embossing. The invention discovers that laser parameters enable engraving through the hard layer without damaging adjacent coated areas, and without causing delamination or weak points at the boundaries of the coated areas 209.

[0090] It is important to note the grinding material of the roller, which is selected from materials with high corrosion resistance, such as stainless steel or ultrafine (e.g., particle size less than 5 μm) sintered ceramics.

[0091] Now for reference Figure 6 It includes a schematic diagram of a production line for manufacturing an engraving tool surface 610 from a raw surface 601, according to a second aspect of the method of the invention. Individual machines in this production line are indicated by frames 602 to 609, and multiple frames will be referred to below as... Figures 7 to 9 The exemplary machine shown is described in detail below. Generally speaking, Figure 6The machines used are well known in the art and require no further description. The original substrate surface 601 is treated by a polishing machine 602 to obtain a polished substrate surface. The latter is then subjected to a laser engraving machine 603, where a first code pattern is engraved into the polished substrate surface. The polished substrate surface, thus engraved, is then optionally cleaned by a cleaning machine 604 before being subjected to a hard layer deposition machine 605, where a hard layer is deposited on the polished substrate surface including the engraved first code pattern. The hard layer carrying the polished substrate surface is then subjected to another laser engraving machine 606, where a second code pattern is engraved through the hard layer into the polished substrate surface. It is then optionally subjected to a cleaning machine 607. The polished substrate surface carrying the hard layer is then subjected to another laser engraving machine 608, where a third code pattern is engraved in the hard layer. Finally, an optional plasma etching machine 609 applies a final treatment to obtain an engraved surface 610.

[0092] Example of a machine used to engrave surface structures that form code patterns.

[0093] According to international bulletin WO 2013 / 156256, Figure 7 A schematic diagram of a laser engraving machine 700 including a roller tool 701 for engraving a cylindrical geometry. This type of engraving machine can engrave a first structure of a first code pattern (not shown) and / or a second structure of a second code pattern (not shown) on the surface of the roller tool 701, on the polished base surface of the roller tool 701, or by means of a hard layer that can cover the polished base surface during engraving.

[0094] Laser 702 is typically an ultrashort pulse laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W. A laser beam 703 from laser 702 is guided by a set of dielectric mirrors 704. The laser beam 704 is modulated by an acousto-optic modulator 705, which deflects or does not deflect the laser according to a command signal from a digital controller 706. The passing laser beam 707 is sent to a beam expander 708, which increases the diameter of the laser beam 707. This allows the laser beam to be focused into a smaller spot 709 for engraving using a focusing lens 710.

[0095] The roller tool 701 is held within a set of mechanical axes 711 driven by motors (not shown), allowing rotation and translation of the roller tool 701 along its axis 712. A digital controller 706 is programmed to send signals to these motors to rotate and translate the roller tool 701 during engraving on its surface. The digital controller 702 also sends signals to a laser 702 to trigger laser pulses according to the coded pattern to be engraved.

[0096] Figure 8 A schematic diagram of a laser engraving machine 800 for a free-form surface 801 is included. This type of engraving machine can engrave a first structure of a first code pattern (not shown) and a second structure of a second code pattern (not shown) on the free-form surface 801, on its polished base surface or by means of a hard layer (not shown) that can cover the polished base surface during engraving.

[0097] Laser 802 is typically an ultrashort pulse laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W. A laser beam 803 from laser 802 is guided toward beam expander 805 by a set of dielectric mirrors 804. Beam expander 805 increases the diameter of laser beam 803. Focus shifter 806 alters the divergence of the expanded laser beam 807 to translate the focused spot 808 for engraving in the direction of the optical path, thereby following the freeform surface 801. Scanning head 809 guides laser beam 807, and f-θ lens 810 focuses the laser beam onto the freeform surface 801.

[0098] A freeform surface 801 is mounted on a 5-axis machine 811. A digital controller 812 is programmed to send signals to the 5-axis machine 811 and the scanner head 809 to correctly guide the freeform surface 801 and the focused laser spot 808, respectively. The digital controller 812 also sends signals to the laser 802 to trigger the output of laser pulses according to the code pattern to be engraved.

[0099] According to WO 2015 / 173735, Figure 9 A schematic diagram of a laser engraving machine 900 including a tool surface 901 for solid parts. The machine 900 can engrave a third structure with a third code pattern (not shown) on the surface 901 having a hard layer (hard layer not shown). The typical laser beam pulse flux used is, for example, 280 mJ / cm². 2 .

[0100] Laser 902 is typically an ultrashort pulse laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W. Laser 902 can also be an excimer laser operating at several 10 Hz with an average power between 0.5 W and 10 W. A laser beam 903 from laser 902 is guided toward beam expander 905 by a set of dielectric mirrors 904. Beam expander 905 increases the diameter of laser beam 903. Beam shaper 907 changes the profile of the expanded laser beam 906 from a Gaussian profile to a top-cap profile (profile not shown). This top-cap profile illuminates a mask 908 containing a code pattern (not shown) to engrave it on the surface 901 of a solid tool, the code pattern corresponding to the entire third code pattern or a sub-section of the third code pattern. Mask 908 can be a transparent plate with a reflective coating (not shown) removed by photolithography or direct laser etching. The mask 908 can also be a transparent plate, in which a code pattern is engraved to create opaque areas where an extended laser beam 906 is scattered. The objective lens 909 engraves the image of the mask 908 onto the surface 901 at a given magnification (between 5:1 and 100:1).

[0101] The tool surface 901 of the solid part to be engraved is fixed to a set of mechanical axes 901 controlled by a motor (not shown). A digital controller 911 is programmed to send signals to the motor and move the tool surface 901 of the solid part to engrave relative to the focused spot 912 of the laser 902. The digital controller 911 also sends signals to the laser 902 to trigger the output of laser pulses according to the code pattern to be engraved.

[0102] In another embodiment of the invention, such as Figure 9 As shown in the magnified view 914, the beam shaper 907 and the mask 908 containing the code pattern can be controlled by a beam splitter device that is also controlled by the digital controller 911. Figure 9 (Not shown in the image) is used instead. The beam splitter splits the laser beam 903 into multiple beams focused by the objective lens 909. Figure 9 (Not shown separately), multiple focal points 913 are obtained to engrave the third structure into the tool surface 901 of the solid part.

[0103] The difference between the embossing tools manufactured according to the first and second aspects

[0104] The differences in the first, second, and third structures engraved on the tool surface (e.g., the embossing tool) of a solid part using the methods and / or manufacturing processes according to the first and second aspects described above are not visible to the naked eye. To see these differences, specialized tools, such as an electron microscope, may be required. One relatively difficult-to-discern difference is that, for the first aspect, the second code pattern C-2 is ultimately covered by the hard layer 209, while for the second aspect, it is not covered by the hard layer 209. This difference has no significant impact on the capability of the embossing tool used to emboss the engraved second code pattern during the embossing process. In other words, the difference between the first and second aspects achieved in the embossing tool may not produce any distinguishing results during embossing, meaning that a product embossed using an embossing tool obtained through the first aspect has substantially the same aspects as a product embossed using an embossing tool with the same pattern but obtained through the second aspect.

[0105] Therefore, the exemplary engraving and embossing products described in the following paragraphs can be obtained indistinguishably by using the tool surface of a solid part manufactured according to the first or second aspect.

[0106] Example of code pattern implementation

[0107] According to a preferred embodiment, the first and / or second code pattern structures are arranged according to an ordered graph generated by an encoding algorithm, which allows it to know where each code pattern structure can be found in order to reconstruct and retrieve the encoded information. In a preferred embodiment, for example, an ordered graph of 33 rows and 33 columns includes, within itself, a small set of, for example, 64 code pattern structures representing specific information. During optical information retrieval, an image sensor acquires an image of at least a portion of the ordered graph and subsequently sends the image to an image processor. The image processor is programmed to know where the code pattern structures can be found on the engraved surface, and it recovers the information encoded on the engraved surface and / or information about the product imprinted thereon.

[0108] The following example illustrates the modulation of preferred elements used in the encoding algorithm, which is typically used to obtain the contours of the first and / or second code pattern structures from the base contours of the base surface structure based on the information to be encoded.

[0109] Multiplicative modulation allows for high modulation or polarity reversal (positive to negative, and vice versa) of the complete basal surface structure. (See reference) Figure 10 This includes a schematic example of multiplicative modulation by a factor a, depicting two cases: one where a < 1 and the other where a > 1. In the example where a < 1, height modulation reduces the height of the base structure 1000 to obtain a modulation structure 1001 with reduced amplitude, and in the example where a > 1, height modulation increases the height of the base structure 1000 to obtain a modulation structure 1002.

[0110] Offset modulation allows for height modulation of the entire base surface structure. Figure 11 An example of z-offset modulation of a hemispherical base surface structure is shown, wherein the center 1103 is modulated by a vector in the z-direction. The base structure 1000 is translated to the new center 1101. Therefore, the base structure 1000 is translated to raise the vector. The amount is used to obtain the modulation structure 1100. This assumes that the base structure 1000 has a virtual shape below the surface from which the base structure rises.

[0111] Additive modulation, which also covers subtraction cases, allows position-dependent structures to be added to the base surface structure. Figure 12 Three examples are shown, in which one or more cone-shaped structures are added at various locations to the hemispherical base surface structure 1200, resulting in three different code pattern structures. Figure 12 In the example shown in the upper part, the conical structure 1201 added to the base structure 1200 results in a modulation structure 1202 having a conical cavity 1203 on the top of the hemispherical shape. Figure 12 In the middle section, another conical structure 1204, shaped as a positive structure, is added to the base structure 1200, causing the conical structure to merge into the right side 1205 of the hemispherical shape. Figure 12 In the lower part, two additional conical structures 1206 are formed as two positive structures that are far apart from each other by a base diameter smaller than that of the base structure 1200, resulting in the conical structures merging into the corresponding left and right sides 1207 and 1208 of the hemispherical shape.

[0112] Figure 13 Another offset modulation is shown, in which the code pattern structure 1301 is represented as a laterally shifted version of the base surface feature 1300 in the (x, y) plane, wherein the lateral shift vector and / or

[0113]

[0114] Various types of modulation can also be combined by modulating more than one parameter. This may be desirable in order to produce stronger effects when needed, for example, a more significant effect on the intensity of light reflected from the modulation structure thus obtained, so as to facilitate readout and retrieval by means of a software-driven image sensor / processor combination.

[0115] According to a preferred embodiment of the present invention, an iterative Fourier transform algorithm can be used to calculate the third structure of the third code pattern, the iterative Fourier transform algorithm using a computer-generated random optical phase and a computer-generated blank image as input.

[0116] In the first iteration step, a first complex image is calculated from the random optical phase and the blank image. A Fourier transform is applied to this first complex image and the corresponding optical phase is extracted.

[0117] In the second iteration step, the first extracted optical phase is combined with the image information to be encoded, and a second complex image is calculated. An inverse Fourier transform is then applied to the second complex image to extract the corresponding optical phase.

[0118] The extracted optical phase is combined with a computer-generated blank image to obtain a third complex image. A Fourier transform is then applied to the third complex image to extract the corresponding optical phase.

[0119] Repeat this process until the extracted optical phase no longer changes (e.g., from 10 to 100 times), and obtain the final composite image and final phase.

[0120] The final phase is used to obtain the height profile of the third structure according to the following formula:

[0121]

[0122] Where h represents the profile height, It is the optical phase, and λ is the wavelength of the read beam 1703.

[0123] Examples of embossed products

[0124] A typical application derived from engraving the surface of an embossing tool using the method according to the invention and then embossing a product using the embossing tool surface is to authenticate the embossed product by taking an image of its embossed surface, processing the image to identify possible code pattern areas, and retrieving information contained in such code pattern areas.

[0125] refer to Figure 14 The product 1400 obtained by utilizing the preferred embodiments of the invention as explained in the preceding paragraph may include an embossed foil 1404, the embossed foil including an embossed base surface structure (e.g., having a hemispherical shape and regularly aligned on a grid). Figure 14 (Not shown in the image), the imprinted base surface structure surrounds the first code pattern C-1 region, which in turn includes the imprinted first structure 1401. In a particular implementation, the imprinted first structure 1401 is obtained from the base surface imprinted structure using an additive modulation coding algorithm, allowing position-dependent structures to be added to the base surface structure. Figure 12 An example of this additive modulation is shown, in which a conical feature is added to a hemispherical base surface structure.

[0126] The product 1400 further includes a second code pattern C-2 area that constructs the word "LOGO" and has an embossed second structure 1402 that forms the texture of each letter. In a particular implementation, the embossed second structure 1402 can be obtained from the base surface embossing structure using an offset modulation coding algorithm, wherein the code pattern structure is represented as a laterally shifted version of the base surface structure in the (x,y) plane of the foil surface, wherein the laterally shifted vector... and / or like Figure 13 As shown in the image.

[0127] The product 1400 also includes a third code pattern C-3 area, which covers the surface of the inner circle of the two letters "O" in the word "LOGO". These third code pattern C-3 areas include an embossed third structure 1403.

[0128] The encoding algorithm can be used for each type of structure, i.e., for the first, second, and third structures. Different specific encoding algorithms can be selected and used for the corresponding types of the first, second, and third structures. Therefore, for example, three different encoding algorithms can be used.

[0129] Now for reference Figure 15 The invention discloses an example of an injection-molded part comprising two halves 1500 and 1501 that can be used for molding a product 1503. The first half 1500 of the injection mold is etched according to any method of the invention and thus includes a second code pattern area, which includes at least a second code pattern C-2 having a second structure and a shaped letter "B". The shaped letter "B" includes a third code pattern area in one of its inner surfaces, which includes at least a third code pattern C-3 having a third structure. The surface 1502 constituting the letter "B" has no code pattern and is configured as an embossed light diffraction surface. The molded product 1503 itself includes corresponding embossed structures of at least one second code pattern C-2 and at least one third code pattern C-3, and an embossed surface corresponding to the surface 1502 and thus configured to diffract light falling thereon.

[0130] Now for reference Figure 16 The illustration shows an example of a coin-shaped product 1600 engraved according to any method of the present invention. Thus, the surface of the coin-shaped product 1600 includes at least an embossed first code pattern C-1 having a first structure, and letters constituting the word "LOGO," the surface of which is at least textured with an engraved second code pattern C-2 having a second structure. The oval inner surfaces of the two letters "O" are engraved with at least one embossed third code pattern C-3 having a third structure.

[0131] Example of a reading process for reading and identifying various embossed codes on a product.

[0132] Reading and retrieving information from the first code pattern

[0133] Preferably, the encoding algorithm for generating the engraved encoded features (i.e., the first structure) of the first code pattern is designed such that these features have a size that can still be observed and focused by the optical system of a common device that serves as a reading device (such as a smartphone or camera). The reading device handles the decoding algorithm and is able to

[0134] - Acquire an image of the first code pattern area, including the first code pattern;

[0135] - Process the image and identify coded features;

[0136] - Analyze these features and retrieve the encoded information.

[0137] For example, in the case of a smartphone, the built-in camera will be used for image acquisition, and the initially loaded software will process the acquired images and retrieve the encoded information.

[0138] Reading and retrieving information from the second code pattern

[0139] Complementing the first code pattern, the encoding algorithm for the etched coded features (i.e., the second structure) used to generate the second code pattern is designed such that these features have dimensions that are indistinguishable by common devices (such as the built-in optics of a smartphone or a camera). Additional optical devices are then required to resolve and focus the coded features, such as a clamp-on magnifying lens (e.g., 10×) for a smartphone or a portable microscope.

[0140] This fact allows the target audience of the second code pattern to shift from a broad consumer base for a given product to a more specialized audience.

[0141] The reading device handles additional optical devices and decoding algorithms, and is capable of...

[0142] - Acquire a clear image of the second code pattern area, including the second code pattern;

[0143] - Process the image and identify coded features;

[0144] - Analyze these features and retrieve the encoded information.

[0145] Reading and retrieving information from third-code patterns

[0146] The premise of the third code pattern may rely on the physical phenomenon of light diffraction on at least one surface grating. The encoding algorithm calculates at least one grating, which retrieves encoded information when illuminated with a readout beam (e.g., a laser beam).

[0147] Therefore, the third code is preferably aimed at the professional public who handle and know how to use such a reading device, such as a laser beam from a commercial laser pointer.

[0148] To retrieve information encoded in the third code area pattern, a reading device and a reading screen are used, which transmit a reading beam. The reading beam illuminates the surface area containing the third code pattern, and the latter reflects the incident light in such a way that the encoded information is reproduced on the reading screen.

[0149] In the following text, by viewing Figure 17 , 18 Here are a few examples of settings used to read code patterns, and 19.

[0150] refer to Figure 17 It illustrates the setup for reading the third code pattern C-3 from a foil 1700 embossed according to an exemplary method of the present invention. The foil may be, for example, similar to... Figure 14 The foil shown and marked 1400 includes a third code pattern C-3 area covering the inner circle of the two letters "O" in the word "LOGO". These third code pattern C-3 areas, as shown in the enlarged view 1701, include an embossed third structure. As described above, a laser 1702 serves as a reading device, emitting a reading beam 1703 that illuminates the surface area containing the third code pattern C-3, whereby the surface area is translucent to the reading beam, and the transmitted light is projected onto a screen 1704, whereby the coded information is reproduced at least by projection 1705.

[0151] Now for reference Figure 18 The illustration schematically depicts two setups for reading two different types of code patterns from a product 1800 embossed according to an exemplary method of the present invention. The embossed product includes an embossed second code pattern C-2 and an embossed first code pattern C-1. Figure 18 Examples of the different systems 1801 and 1802 explained above are shown, which are respectively configured to read the imprinted second code pattern C-2 and the imprinted first code pattern C-1. Each system 1801 and 1802 includes a smartphone 1803 as a reading device, but system 1801 additionally includes a magnifying lens 1804 clipped onto a standard lens of system 1801. Figure 18 Viewpoints 1805 and 1806 corresponding to systems 1801 and 1802 are also schematically shown.

[0152] Figure 19 This schematically illustrates the use of reading such as Figure 16The coin-shaped product 1900 shown is configured as follows. The coin-shaped product 1900 includes at least a third code pattern C-3 area that covers the surface of the inner circle of the two letters "O" in the word "LOGO," as can be seen in magnified view 1901. This at least one third code pattern C-3 area includes an engraved third structure. As explained above, a laser 1702 serves as a reading device, emitting a reading beam 1703 that illuminates the surface area containing the third code pattern C-3, whereby the surface area reflects the reading beam 1703, and the reflected light is projected onto a screen 1704, whereby the coded information is reproduced at least by projection 1902.

Claims

1. A method for engraving a plurality of structured code patterns on the tool surface of a solid part, wherein, The plurality of code patterns include: A first code pattern, the first code pattern comprising a first structure with a lateral dimension and a spacing in the range of 20 to 500 μm; The second code pattern includes a second structure with a lateral dimension and spacing in the range of 1 to 20 μm; and The third code pattern includes a third structure with a lateral dimension and spacing in the range of 0.2 to 5 μm; The method includes: The original base surface is provided on the tool surface of the solid part; Polish the original base surface to obtain a polished base surface; A hard layer is deposited on the polished base surface; The third code pattern is engraved in the hard layer; The method is characterized in that it further includes: The first code pattern and the second code pattern are engraved prior to the step of depositing the hard layer. The hard layer reproduces the morphology of the first code pattern and the second code pattern.

2. The method according to claim 1, wherein, Tool surface for carving solid parts: It has cylindrical symmetry; and A first structure, a second structure, and a third structure configured to transfer the first code pattern, the second code pattern, and the third code pattern onto a substrate. The transfer is any one of the following: printing, molding, handcrafting, pressing, or molding into the substrate.

3. The method according to claim 1, wherein, Tool surface for carving solid parts: It has cylindrical symmetry; and A first structure, a second structure, and a third structure configured to transfer the first code pattern, the second code pattern, and the third code pattern onto a substrate. The transfer is formed onto the substrate.

4. The method according to claim 1, wherein, The tool surface of the solid piece being carved: It is configured to be used as a molding tool for transferring the first structure, the second structure, and the third structure of the first code pattern, the second code pattern, and the third code pattern onto a substrate. The transfer is any one of the following: printing, molding, handcrafting, pressing, or molding into the substrate.

5. The method according to claim 1, wherein, The steps of engraving the first code pattern and the second code pattern include engraving by means of an ultrashort pulse laser beam focused on the polished base surface, the ultrashort pulse laser beam being provided by a laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W.

6. The method according to claim 1, wherein, The step of engraving the third code pattern in the hard layer involves using a laser and a mask projection of a third structure onto the hard layer through the laser, wherein the mask projection of the third structure corresponds to the third code pattern to be engraved.

7. The method according to claim 1, wherein, The step of engraving the third code pattern in the hard layer involves a laser and a beam splitter that generates multiple focal points to engrave a third structure corresponding to the third code pattern to be engraved into the hard layer.

8. A method for engraving a plurality of structured code patterns on the tool surface of a solid part, wherein, The plurality of code patterns include: A first code pattern, the first code pattern comprising a first structure with a lateral dimension and spacing in the range of 20 to 500 μm; The second code pattern includes a second structure with a lateral dimension and spacing in the range of 1 to 20 μm; and The third code pattern includes a third structure with a lateral dimension and spacing in the range of 0.2 to 5 μm; The method includes: The original base surface is provided on the tool surface of the solid part; Polish the original base surface to obtain a polished base surface; A hard layer is deposited on the polished base surface; The third code pattern is engraved in the hard layer; The method is characterized in that it further includes: The first code pattern is etched before the step of depositing the hard layer, and The second code pattern is etched into the polished base surface through the hard layer.

9. The method according to claim 8, wherein, Tool surface for carving solid parts: It has cylindrical symmetry; and A first structure, a second structure, and a third structure configured to transfer the first code pattern, the second code pattern, and the third code pattern onto a substrate. The transfer is any one of the following: printing, molding, handcrafting, pressing, or molding into the substrate.

10. The method according to claim 8, wherein, Tool surface for carving solid parts: It has cylindrical symmetry; and A first structure, a second structure, and a third structure configured to transfer the first code pattern, the second code pattern, and the third code pattern onto a substrate. The transfer is formed onto the substrate.

11. The method according to claim 8, wherein, Tool surface for carving solid parts: It is configured to be used as a molding tool for transferring the first structure, the second structure, and the third structure of the first code pattern, the second code pattern, and the third code pattern onto a substrate. The transfer is any one of the following: printing, molding, handcrafting, pressing, or molding into the substrate.

12. The method according to claim 8, wherein, Both the step of engraving the first code pattern and the step of engraving the second code pattern involve engraving by means of an ultrashort pulse laser beam focused on the polished base surface, the ultrashort pulse laser beam being provided by a laser operating between 100 kHz and 10 MHz with an average power between 1 W and 500 W.

13. The method according to claim 8, wherein, The step of engraving the third code pattern in the hard layer involves using a laser and a mask projection of a third structure onto the hard layer by the laser, wherein the mask projection of the third structure corresponds to the third code pattern to be engraved.

14. The method according to claim 8, wherein, The step of engraving the third code pattern in the hard layer involves a laser and a beam splitter that generates multiple focal points to engrave a third structure corresponding to the third code pattern to be engraved into the hard layer.

15. An embossing tool having a plurality of code patterns as embossing structures, wherein, The plurality of code patterns include: A first code pattern, the first code pattern comprising a first structure with a lateral dimension and spacing in the range of 20 to 500 μm; The second code pattern includes a second structure with a lateral dimension and spacing in the range of 1 to 20 μm; and The third code pattern includes a third structure with a lateral dimension and spacing in the range of 0.2 to 5 μm; The imprinting tool includes: Base; The surface of the base is configured to have the first structure and the second structure disposed thereon; A hard layer, the hard layer being disposed at least on the first structure on the surface of the base; and The surface of the hard layer includes the third structure.

16. The embossing tool according to claim 15, wherein, The base is cylindrical.

17. The embossing tool according to claim 15, wherein, The base comprises a plate made of metal or composite material.

18. An injection mold having a plurality of code patterns as a molding structure, wherein, The plurality of code patterns include: A first code pattern, the first code pattern comprising a first structure with a lateral dimension and spacing in the range of 20 to 500 μm; The second code pattern includes a second structure with a lateral dimension and spacing in the range of 1 to 20 μm; and The third code pattern includes a third structure with a lateral dimension and spacing in the range of 0.2 to 5 μm; The injection mold includes: Base; The surface of the base is configured to have the first structure and the second structure disposed therein; A hard layer, the hard layer being disposed at least on the first structure on the surface of the base; The surface of the hard layer includes the third structure.

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