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
  • G03H1/0005—Adaptation of holography to specific applications
  • G03H1/0011—Adaptation of holography to specific applications for security or authentication
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • 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
  • G03H1/0402—Recording geometries or arrangements
  • G03H1/041—Optical element in the object space affecting the object beam, not otherwise provided for
• • 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
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2249—Holobject properties
• • 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
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2286—Particular reconstruction light ; Beam properties
• • 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
  • G06K19/06046—Constructional details
• • 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
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/12—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation using a selected wavelength, e.g. to sense red marks and ignore blue marks
• • 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
  • G03H1/0402—Recording geometries or arrangements
  • G03H1/0404—In-line recording arrangement
• • 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
  • G03H1/0402—Recording geometries or arrangements
  • G03H1/0406—Image plane or focused image holograms, i.e. an image of the object or holobject is formed on, in or across the recording plane
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/0005—Adaptation of holography to specific applications
  • G03H1/0011—Adaptation of holography to specific applications for security or authentication
  • G03H2001/0016—Covert holograms or holobjects requiring additional knowledge to be perceived, e.g. holobject reconstructed only under IR illumination
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/0005—Adaptation of holography to specific applications
  • G03H1/0011—Adaptation of holography to specific applications for security or authentication
  • G03H2001/0016—Covert holograms or holobjects requiring additional knowledge to be perceived, e.g. holobject reconstructed only under IR illumination
  • G03H2001/0022—Deciphering being performed with numerical or optical key, e.g. with the optical scrambler used during recording
• • 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
  • G03H2001/0204—Object characteristics
• • 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
  • G03H1/0402—Recording geometries or arrangements
  • G03H2001/0413—Recording geometries or arrangements for recording transmission 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
  • G03H1/04—Processes or apparatus for producing holograms
  • G03H1/0402—Recording geometries or arrangements
  • G03H2001/0415—Recording geometries or arrangements for recording reflection 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
  • G03H1/04—Processes or apparatus for producing holograms
  • G03H1/0402—Recording geometries or arrangements
  • G03H2001/0415—Recording geometries or arrangements for recording reflection holograms
  • G03H2001/0417—Recording geometries or arrangements for recording reflection holograms for recording single beam Lippmann hologram wherein the object is illuminated by reference beam passing through the recording material
• • 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
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2202—Reconstruction geometries or arrangements
  • G03H2001/2223—Particular relationship between light source, hologram and observer
  • G03H2001/2231—Reflection reconstruction
• • 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
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2249—Holobject properties
  • G03H2001/2263—Multicoloured holobject
• • G—PHYSICS
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  • 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
  • G03H1/26—Processes or apparatus specially adapted to produce multiple sub- holograms or to obtain images from them, e.g. multicolour technique
  • G03H2001/2625—Nature of the sub-holograms
  • G03H2001/264—One hologram being a HOE
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2210/00—Object characteristics
  • G03H2210/20—2D object
  • G03H2210/22—2D SLM object wherein the object beam is formed of the light modulated by the SLM
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2210/00—Object characteristics
  • G03H2210/30—3D object
  • G03H2210/33—3D/2D, i.e. the object is formed of stratified 2D planes, e.g. tomographic data
• • 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
• • 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
  • G03H2210/56—Multiple objects, e.g. each in different environment
  • G03H2210/562—Holographic object, i.e. a combination of an object and holobject
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2223/00—Optical components
  • G03H2223/23—Diffractive element
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2225/00—Active addressable light modulator
  • G03H2225/60—Multiple SLMs
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2227/00—Mechanical components or mechanical aspects not otherwise provided for
  • G03H2227/05—Support holding the holographic record

Definitions

• the object of the invention is to make it difficult, even almost impossible, to reproduce and / or falsify such documents.
• Securing documents identity cards, passports, etc.
• counterfeiting and falsification is a fundamental problem facing all those involved in the field.
• the object of the invention is to produce on the document to be protected a characteristic hologram difficult to copy and carrying information otherwise printed conventionally on the document.
• a verifying agent will be able to check the document by comparing the content of the hologram with the content of the rest of the document.
• the hologram represents an image of the identity photo contained on the document. Comparing the image of the hologram and the image of the photo allows the document to be authenticated quickly and easily.
• the invention therefore relates to a document comprising at least one drawing or information produced by depositing or including optically readable pigments and / or dyes, characterized in that it also includes a hologram containing a copy of said drawing or said information.
• the invention also relates to a document security system, characterized in that it comprises an optical modulator prerecorded or electrically controllable in which the image of at least part of the document is recorded, said modulator being designed to be associated with a layer of photosensitive material, at least one first light source making it possible to transmit a first reference wave to the layer of photosensitive material and a second wave incident on said modulator and giving rise to a third object wave which is transmitted to the layer of photosensitive material to interfere in this layer with the reference wave.
• FIG. 1 represents an identity card 1 comprising information 4 indicating the identity of the owner of the card, his photograph 2 and his signature 5.
• the card comprises a hologram 3 in which, among other things, one or more elements for personalizing the card have been recorded, such as photography, signature, etc.
• FIG. 1 we have chosen to record the photograph in the hologram.
• Such a card will thus be more difficult to falsify because the hologram contains information for personalizing the card and which will change from one card to another.
• Figure 1b shows an alternative embodiment of Figure 1a.
• hologram 3 contains images which appear in different planes.
• An image 60 can be, for example in the case of an identity card, a copy of the identity photo 2, while another image 61 can be either a standard image (logo) or other information of the card such as a copy of the signature 5.
• the hologram can also include information printed on its surface. Referring to FIG. 2, a first example of a hologram recording method will be described.
• a support element 22 is coated on one of its faces with a layer of photosensitive material 21.
• An optical modulator 23 such as a transparent photographic support or a controllable modulator such as a liquid crystal screen is applied to the in the vicinity or in contact with the layer of photosensitive material.
• the modulator makes it possible to provide the content (information or image) of a part of the document to be secured. If it is a prerecorded slide type modulator, this part of the document is saved in the modulator. If it is a controllable modulator, the part of the document can be displayed by means of the modulator command.
• the support member 22 is transparent at the recording wavelength.
• a mirror 24 is placed on the side opposite the photosensitive layer with respect to the modulator 23.
• a light beam R supplied by a source S1 and conveying a coherent wave illuminates the support element 22.
• this light beam is perpendicular to the plane of the support element 22 and of the photosensitive layer 21.
• the beam R passes through the support 22, the holography layer 21. It is modulated by the modulator 23 and is transmitted to the mirror 24.
• the latter reflects the modulated beam which crosses the modulator.
• the mirror 24 is perpendicular to the direction of the beam and reflects a beam collinear with the incident beam. The reflected modulated beam interferes with the R beam in the layer of photosensitive material.
• the modulation carried by the modulated beam is therefore recorded in the photosensitive layer.
• a hologram containing information or an image which is a copy of information or an image contained in the document to be secured. If the modulator 23 contains for example the photograph of the owner of the identity card, this photo has therefore been recorded in the hologram.
• T is the modulator's transmission coefficient and that O is the wave illuminating the hologram opposite the beam R which we will call reference wave R in the following.
• the hologram records R.R.T.
• the hologram If the hologram is thick, it will rediffract during the reading of the recorded image and this for precise incidences (Bragg effect) of the illumination wave and the direction of vision.
• the modulator can integrate a diffusing function for a better reading of the hologram and to complicate any counterfeiting.
• FIG 3 shows another recording method in which two light waves of the photosensitive layer are required.
• the light modulator 23 is attached to the layer of photosensitive material 21 carried by the support 22.
• a reference illumination wave R supplied by the source S1 is transmitted to the layer of photosensitive material 21 without passing through the modulator.
• the two waves R and O interfere in the photosensitive material 21.
• the two waves O and R are counterpropagative and are perpendicular to the plane of the layer of photosensitive material 21.
• the two waves are coherent plane waves.
• the thick hologram backlit by a plane wave R will diffract an image proportional to IT, that is to say the image of the slide, provided that I is of the plane wave type like R.
• the modulator 23 of FIG. 3 can integrate a broadcasting function.
• a layer of diffusing material will be deposited on the face of the modulator situated on the side of the layer of photosensitive material.
• the hologram 21 was recorded by adding an optical modulator to it. It is also possible, as shown in FIG. 4a, to provide a recording system in which the modulator is lit by an I wave which is modulated by the modulator and which provides an O wave. An optical device 80 images the modulator in the plane of the hologram. Furthermore, a separating plate 81 placed on the path of the O wave makes it possible to transmit a reference wave R to the photosensitive medium 21. This reference wave interferes with the O wave and allows the recording of the image provided by the modulator 23. The rereading of such a hologram requires attaching a mirror to the support 22 on the side opposite to the hologram 21.
• FIGS. 4b and 4c show variants of recording systems in which the modulator is not attached to the hologram.
• the layer of photosensitive material is illuminated by a reference wave R incident on this layer on the side opposite the modulator.
• the two waves O and R interfere in the photosensitive layer to record a hologram corresponding to the display of the modulator 23.
• the waves O and R are preferably coherent.
• FIG. 4c represents the system of FIG. 4b in which one or more additional light modulators 27, 28 are provided. These modulators are not placed in the same plane as the modulator 23. These modulators will make it possible to record, in the photosensitive layer, holograms which will not appear in the same plane as the image of the modulator 23.
• FIG. 4c makes it possible to record holograms visible in different planes is also applicable to the systems of FIGS. 2 and 3 by also providing one or more additional modulators on the path of one of the waves I or R.
• modulators will make it possible to display either a specific motif (logo) or information (signature for example) of the document to be secured.
• the means inducing a diffusion and / or aberration can be placed either on the path of the O wave, or on the path of the R wave.
• Figures 5 and 6 show variants of the systems of Figures 2 and 3 respectively in which optical aberrant devices are provided.
• an aberrator 25 is positioned, for example on the reference wave R.
• An aberrator introduces a local phase ⁇ on the R wave, that is to say transforms it into R.e
• the hologram records RR e l ⁇ T.
• the hologram records RRT e , ⁇ . This case is similar to the case of 2-wave recording treated below.
• FIG. 6 the system is lit by two distinct waves I and R supplied by sources S1 and S2 as in FIG. 3.
• the aberrator is positioned for example on the path of the R wave.
• the aberrator introduces a local phase ⁇ on the R wave, that is to say transforms it into R. e l ⁇ .
• the hologram records R. e ' ⁇ IT.
• Reading reilluminated by R, it diffracts a wave e l ⁇ IT deformed with respect to IT. The image appears disturbed to the observer as before.
• the deformation undergone by the image is the same as that resulting from the aberrator.
• an aberration correcting device 27 which we will call revealer 27, through one can read the hologram corrected for aberrations.
• the developer induces on the reading wave a phase function opposite to that of the aberrator, ie e- ⁇ i ⁇
• the incident wave on the hologram is R e-.
• the hologram having recorded RR e 2 ' ⁇ T, it diffracts a wave proportional to T.e' ⁇ then passes back through the developer which again induces e ⁇ and thus the light wave coming from the developer is proportional to T, it is that is, corresponds to the non-distorted image.
• the developer must induce - ⁇ .
• the developer is determined as in the two-wave case described below.
• the developer induces on the reading wave a phase function of e ⁇ IT. i ⁇ / 2
• the incident wave on the hologram is R. e ⁇
• the hologram having recorded R e ⁇ T, it diffracts a wave proportional to Te l ⁇ then passes back through the developer which again induces e 'lcp and thus l the light wave coming from the developer is proportional to T, that is to say corresponds to the undeformed image.
• the aberrator induces ⁇ and the developer must induce - ⁇ / 2.
• the aberrator must be chosen so as to significantly modify the vision of the image but with spatial frequencies of phase defect on the scale of the tolerated positioning accuracy.
• Recording 1 or 2 waves can be done with waves of any incidence.
• the interest is inter alia to separate the direction of observation of the recorded image compared to the specular reflection. This configuration significantly improves the contrast of the image.
• a non-specular mirror can be used in recording so as to modify the incidence of the object wave relative to that of the reference wave: separation of the direction of observation of the photo relative to specular reflection.
• the aberrator and the developer are two functions of different phases. It is possible to use the same component for both functions by re-lighting the hologram no longer with R but R *. In this case, the phase function recorded in the hologram is transformed into its conjugate by diffraction and self-corrects by crossing through this same phase law. This is the principle of phase conjugation. Such a hologram is thus made difficult to counterfeit by the presence of the aberrator during recording.
• FIG. 9 represents a device for reading a document provided with a hologram recorded with aberrations.
• This device comprises a developer 27 which must be positioned precisely with respect to the hologram to allow sufficient correction of the aberrations.
• the document which carries the hologram or the hologram support comprises positioning means such as notches 30 to 33.
• the reading device comprises lugs or studs 40 to
• the document may include optical marks 34 to 37 visible through the reading device 27.
• the latter also includes optical marks
• the function (HP) was recorded in the holographic layer 21 with an object wave obtained with the modulator 23 by means analogous to the Lipmann process and with a reference wave which is the sum of the waves transmitted by the HS component.
• the component HS is, for example, a diffraction grating providing two waves A * S , R and As, o
• component 21 requires the presence of the coding function of component HS.
• the HS network function can simply be of the fixed pitch network type or contain specific but non-personalized information: it will therefore be identical for all cards.
• the interest of the HS coding function lies in the fact that it gives the personalized hologram specific optical properties colorimetry, multiple angular ranges of visibility depending for example on the order number of the network ...
• AS. R and As.o are respectively the reference and object recording waves of the network HS and A ⁇ the incident wave on HS to record the component 21, then the recording waves of the hologram 21 are [AS.R. As.o + Ap.o The image recorded in hologram 21 will be observed without distortion if the whole (21 + HS) is illuminated by the wave A ⁇ -
• the holographic image will change color with the appearance of distortions or will disappear according to its geometrical characteristics (thickness and variation of index), a simple hologram of Lipmann does not reveal such distortions.
• the security function can contain information which will be highlighted by the continuous component reflected by the photosensitive component.
• the security function can contain information which will be highlighted by the continuous component reflected by the photosensitive component.
• the photosensitive functions can be monochrome, bichrome or tri-chromatic, .... the colorimetry of the image can be adjusted for authentication with a given light source (natural light, neon or other) or color-coded information stored in the same layer.
• photosensitive material with swelling spatially controllable by post processing makes it possible either to color code a given pattern superimposed on the personalized hologram, or to include another high-resolution function visible with an additional source.
• the hologram can be transparent to allow the reading of information located under the hologram, on the document.
• the hologram can be read either in natural light, in normal lighting light, or by means of a lamp with a range of particular wavelengths.
• the R and O light waves are preferably flat but this is not compulsory;
• the R and O light waves can be counterpropagative but this is not compulsory;
• the R and O light waves are preferably coherent with one another; - the hologram can be recorded with a single wavelength or by using several wavelengths, or even by using three wavelengths (red, green, blue) so as to diffract white light.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
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• Computer Security & Cryptography (AREA)
• General Health & Medical Sciences (AREA)
• Electromagnetism (AREA)
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• Artificial Intelligence (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Health & Medical Sciences (AREA)
• Holo Graphy (AREA)
• Credit Cards Or The Like (AREA)

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• 1999
  • 1999-07-09 FR FR9908958A patent/FR2796184B1/fr not_active Expired - Lifetime
• 2000
  • 2000-07-04 US US10/019,314 patent/US6873443B1/en not_active Expired - Fee Related
  • 2000-07-04 PL PL352800A patent/PL204975B1/pl unknown
  • 2000-07-04 WO PCT/FR2000/001914 patent/WO2001004709A1/fr active Application Filing
  • 2000-07-04 CA CA002378658A patent/CA2378658A1/fr not_active Abandoned
  • 2000-07-04 AU AU62927/00A patent/AU6292700A/en not_active Abandoned
  • 2000-07-04 TR TR2002/00005T patent/TR200200005T2/xx unknown
  • 2000-07-04 JP JP2001510055A patent/JP2003504694A/ja active Pending
  • 2000-07-04 EP EP00949629A patent/EP1196823A1/de not_active Ceased
  • 2000-07-04 KR KR1020027000346A patent/KR20020027485A/ko not_active Application Discontinuation
• 2004
  • 2004-10-25 US US10/971,136 patent/US6980336B2/en not_active Expired - Fee Related

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