Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/06009—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with optically detectable marking
  • G06K19/06037—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with optically detectable marking multi-dimensional coding
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/08—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means
  • G06K19/10—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/08—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means
  • G06K19/10—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards
  • G06K19/16—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards the marking being a hologram or diffraction grating

Definitions

• the present invention relates to a method and a device for forming objects with variable optical characteristics and an object thus obtained.
• the present invention aims to remedy all or part of these disadvantages.
• the present invention relates to an object having:
• a second surface separated from the first surface and not lying in a plane common to the first surface, of which at least one zone carries a second network configured to polarize light
• At least one of said zones carrying a nanostructuration having a periodic structure having a period between a hundred and a thousand nanometers, carried out by a laser beam, said nanostructuring realizing a said network or reducing the polarization of a said network.
• the demonstration of the existence of periodic structures having a period of a few hundred nanometers has been scientifically performed (see, for example, the document by Messrs. GUILLERMIN, F. GARRELIE, N. SANNER, E. AUDOUARD, H. SODER "Mono- and multi-pulse formation of surface structures under static femtosecond irradiation" Accepted at Appl., Sc.253, 8075-879 - 2007).
• nanostructuring is a modification of a polarizing network or a polarizing network, with a dispersion of optical characteristics related to the interaction between the laser beam and the material of a surface of the object. According to whether the object is illuminated so that an observation is made by transparency through two zones of the two surfaces or by reflection of light rays on such a zone, a message or effects of dispersion of optical characteristics. It is therefore possible to authenticate the object by these observations or by analysis of the dispersion of optical characteristics.
• said nanostructuring realizes a said network for polarizing light.
• said nanostructuring achieves polarization reduction of said network.
• said nanostructuring represents a message
• said message is readable by the naked eye.
• said nanostructuring forms random or unpredictable defects locally.
• the structure of nanostructures formed by ultrafast laser irradiation is not only characterized by a periodicity of the order of a few hundred nanometers. Finer features, or irregularities, such as the number of bifurcations between lines of pseudoperiodic nanostructures, the average length of the lines between two bifurcations, the shapes of the bifurcation figures, are also analyzed and quantified by image analysis algorithms. adapted. From a figure of nanostructures, can then be obtained a unique digital signature of a particular interaction between the laser and the material (in the manner of a fingerprint for a human being). This characteristic is stored for use in identification, authentication and traceability procedures.
• said two surfaces are two parallel outer faces of an at least partially transparent object.
• At least one of said surfaces has a metallized layer.
• the present invention provides an object forming device of the present invention, which comprises a source of polarized laser radiation.
• the structure of nanostructures formed by ultrafast laser irradiation is characterized by a periodicity of the order of a few hundred nanometers.
• the device of the present invention comprises two sources of laser radiation face to face surrounding the object being processed and forming two images in correspondence on two parallel surfaces of said object.
• At least one said laser radiation source is a picosecond laser.
• At least one said laser radiation source forms a document number on a surface of said object.
• the present invention relates to a method of marking an object, which comprises:
• a second step of forming a network configured to polarize the light, on a second surface of the object, separated from the first surface and not included in a common plane with the first surface and
• At least one nanostructuration step of a said surface by a laser beam at least one nanostructuration step of a said surface by a laser beam.
• FIG. 1 represents, schematically and in section, a particular embodiment of an object which is the subject of the present invention
• FIG. 2 represents, schematically and in section, a particular embodiment of a device which is the subject of the present invention.
• FIG. 3 represents, in the form of a logic diagram, steps of a particular embodiment of the method that is the subject of the present invention.
• FIG. 1 shows an object 10 comprising a transparent layer 11 and a metallized layer 12.
• the transparent layer 11 is made of polyethylene.
• a first surface 14 carries, including at least one zone, a first network 13 configured to polarize the light.
• a second surface 16, here the contact surface of the metallized layer 12 on the transparent layer 1 1, separated from the first surface 14, carries, in at least one zone, a second network 15 configured to polarize the light for at least one wavelength for which the grating 13 is polarizing.
• At least one of the zones 13 and 15 carries a nanostructuration carried out by a laser beam, said nanostructuration realizing a said network or reducing the polarization of a said network.
• the nanostructures have a periodic structure, having a period of a few hundred nanometers.
• the structure of nanostructures formed by ultrafast laser irradiation is not only characterized by a periodicity of the order of a few hundred nanometers. Finer features, or irregularities, such as the number of bifurcations between lines of pseudo-periodic nanostructures, the average length of the lines between two bifurcations, the shapes of the bifurcation figures, are also analyzed and quantified by analysis algorithms. image adapted. From a nanostructure figure can then be obtained a signature unique digital system of a particular interaction between the laser and the material (in the manner of a fingerprint for a human being). This characteristic is stored for use in identification, authentication and traceability procedures.
• the two surfaces carrying polarizing networks are not included in a common plane, so that a light ray can cross the two polarizing networks.
• the two surfaces are two parallel outer faces of an at least partially transparent object.
• a polarizing network or a modification of a polarizing network is produced with a dispersion of optical characteristics related to the interaction between the laser beam and the material of a surface of the object.
• a dispersion of optical characteristics related to the interaction between the laser beam and the material of a surface of the object.
• a message or effects of dispersion of optical characteristics are observed. It is therefore possible to authenticate the object by these observations or by analysis of the dispersion of optical characteristics.
• said nanostructuring realizes a said network for polarizing light.
• said nanostructuring achieves a polarization reduction of a said polarizing grating.
• said nanostructuring represents a message, for example a readable message to the naked eye.
• said nanostructuring forms random or unpredictable defects locally. These defects take, for example, the form of irregularities of ripples formed by the impact of a picosecond laser on a surface, as explained above.
• an object forming device 20 of the present invention comprises a first source of polarized laser radiation 23, a second source of polarized laser radiation, sources 23 and 24 lying face to face on both sides of the object 20 and forming two images 21 and 22, in correspondence, on two parallel surfaces of the object 20.
• at least one said laser radiation source is a picosecond laser.
• At least one said laser radiation source forms a document number on a surface of the object 20.
• a substrate carries a network (in English "grating") polarizing.
• This network can be formed by known techniques or by illumination with a laser causing a nanostructuration.
• a laser emitting pulses of the order of one picosecond is implemented.
• a transparent layer for example made of polyethylene carries a metallized layer whose inner surface (contact with the transparent layer) or the outer layer has the polarizing network.
• the outer surface of the transparent layer is also provided with a polarizing network, preferably oriented at 90 ° of the network formed on the metal layer.
• zones do not carry the polarizing network, to constitute a message, positive or negative.
• the reflection presents a diffraction of the light and the appearance of a color, even of a message in color, especially when the angle of incidence deviates from the normal to the surface.
• the crossing of the polarization angles causes the appearance of a message in the areas where one of the networks is not formed.
• a surface pre-structuring is performed and then a message is added by local destruction of a polarizing network.
• a surface pre-structuring is performed and then noise, that is to say random or locally unpredictable defects, is added by local destruction of one of the polarizing arrays.
• this noise is achieved by laser nanostructuration by putting a picosecond laser.
• FIG. 3 shows, in a particular embodiment, a method of marking an object, which comprises:
• a message to be formed on non-coplanar surfaces of the object is determined, for example a serial number, a code, etc.
• step 50 the formation of at least part of the message is carried out by nanostructuring a first surface
• step 55 the formation of at least part of the message is carried out by nanostructuring a second surface
• a nanostructuration step of at least one surface, in or outside a polarizing array is carried out by a laser beam, to form random irregularities and / or unpredictable locally, for example ripple irregularities,
• a capture of at least one image of a surface is carried out by reflection illumination, that is to say positioned on the same side of the object as the image sensor; ,
• step 70 at least one image is captured by backlighting, the light source being, with respect to the image sensor, on the opposite side of the object and
• the captured images or single fingerprints obtained by processing these images and representing random irregularities and / or unpredictable locally, for example their locations on the object or respectively between them and, possibly, respectively, are memorized , their types.
• the two message portions made in steps 50 and 55 complement each other to form an intelligible message or a coherent code.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Laser Beam Processing (AREA)
• Polarising Elements (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=50549159

Family Applications (1)

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Family Cites Families (3)

• 2014
  • 2014-02-28 FR FR1451620A patent/FR3018126B1/fr not_active Expired - Fee Related
• 2015
  • 2015-02-27 EP EP15707135.8A patent/EP3111375A1/de not_active Withdrawn
  • 2015-02-27 WO PCT/EP2015/054193 patent/WO2015128489A1/fr active Application Filing

Non-Patent Citations (1)

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