Abstract:
The method of the invention consists, on the one hand, in serially recording on a tape of photosensitive film a succession of volume holograms each relating respectively to an item of information of a corresponding document to be made secure, each of these holograms being accompanied by an identification and positioning code printed on the same film, in developing and in fixing the holograms thus recorded, and on the other hand in printing at the same time the identity documents with their individual identification codes which are the same as those of the respective corresponding holograms, in adding an adhesive to the holograms after their fixing, and in adhesively bonding together each hologram and the corresponding document after verifying that their respective identification codes match.

Description:
This application is a 371 of PCT/FR02/02368, filed Jul. 5th, 2002. 
   FIELD OF THE INVENTION 
   The present invention pertains to a method of serial manufacture of secure objects, as well as to a machine for implementing this method. 
   DESCRIPTION OF RELATED ART 
   The security elements used to authenticate identity documents are generally impersonal elements (arbitrary holographic figures, etc.) that are recurrent (the same for the whole of a large series of documents). They are therefore inefficient in the struggle against falsification and counterfeiting. For example, the same hologram, representing the same pattern, is found on all credit cards. In the case of identity cards, the same patterns are always found. Falsification or counterfeiting is then easy, provided that these security elements are not degraded or that they are procured. 
   The personalization of security elements considerably reduces the possibilities of falsification and renders counterfeiting very difficult. A personalized security element is a component that assumes one or more items of information from the card. Any modification of an item of information contained both on the card and in the security element, a photograph of the bearer, a name or a number for example, must be accompanied by the corresponding modification of the security element. Consequently, it is then necessary to counterfeit not only this element, but also its environment: it is necessary to have the raw material of its support and the technical skills to reproduce it. 
   Optical security elements, in particular holograms, are the most efficient against falsification and counterfeiting. Specifically, the hologram, by virtue of its physical properties, possesses the dual advantage of not being able to be copied by reprography (with the aid of toner) or any other method of photocopying, and of having a strong visual effect. However, it is currently still not known how to personalize holograms in real time. Known holograms are either stamped holograms, or volume holograms recorded within the thickness of photosensitive materials of argentic type. In both these cases, the method of recording calls upon techniques that are incompatible with industrial methods of fabricating cards. For example, the development of volume holograms recorded in argentic materials requires the use and manipulation of liquid chemical products. 
   Furthermore, it is known how to record holograms in real time through the use of novel photosensitive materials of photopolymer type, doing so by recourse to conventional industrial processes. The method of recording holograms with these novel materials has the advantage of being totally dry, unlike the other aforesaid methods, whether they call upon argentic materials or those based on dichromated gelatin. 
   A system allowing the complete fabrication of an identity document containing a personalized hologram is a complex system. This complexity makes it impossible to produce this type of document on a local scale on simple machines. Specifically, in addition to the conventional printing and laminating modules, the machine must comprise a hologram recording module composed of a laser emitter and of a sophisticated optical setup. Synchronization of all the modules is difficult to achieve. Furthermore, the recording of such an optical component necessitates stability conditions that are very constraining for the system as a whole. Finally, the hologram recording time considerably limits the rate of production of cards. The implementation and maintenance of such a system necessitate permanent monitoring by qualified operators. 
   A subject of the present invention is a method of producing hologram-secured documents in which the holograms definitely identify the documents on which they are affixed, without risk of confusion with conventional standard holograms, which method may be implemented with the aid of conventional industrial processes, in a simple and fast manner, in large series, while producing documents that are very difficult to falsify or to counterfeit. 
   A subject of the present invention is also a machine for implementing this method, which machine is fast and dependable, simple to use and requires only a minimum of servicing. 
   SUMMARY OF THE INVENTION 
   The method in accordance with the invention consists on the one hand, in serially recording on a tape of photosensitive film a succession of volume holograms each relating respectively to an item of information of a corresponding document to be made secure, each of these holograms being accompanied by an identification and positioning code printed on the same film, in developing and in fixing the holograms thus recorded, and on the other hand in printing at the same time the identity documents with their individual identification codes which are the same as those of the respective corresponding holograms, in adding an adhesive to the holograms after their fixing, and in adhesively bonding together each hologram and the corresponding document after verifying that their respective identification codes match, and, preferably in covering the whole with a protection which is advantageously made secure. 
   The machine in accordance with the invention comprises a holographic recording and identification code printing station, a hologram development station, a station for adding colorant film, a fixing station, a station for adding adhesive, a station for printing documents and a station for bonding the holograms to the documents and a lamination station. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     The present invention will be better understood on reading the detailed description of a mode of implementation, taken by way of nonlimiting example and illustrated by the appended drawing, the single FIGURE of which is a simplified diagram of an exemplary machine for implementing the method of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is described hereinbelow with reference to the fabrication of identity cards, but it is of course not limited solely to this application, and it may be implemented to fabricate very diverse secure documents: passports, credit cards, badges for access to protected areas, authenticity certificates, etc. 
   The machine  1  represented in the drawing comprises a first station  2  furnished with means  3  of support making it possible to receive coils  4  of photosensitive film  5 . This film  5  is protected on one of its faces by a Mylar film, and on the other face by a PVC film, for example. The film  5  passes through a pulley block  6  and arrives at a facility  7  for recording holograms, which is for example of the type described in French Patent No. 2 796 184. At the level of this facility  7 , the film  5  arrives with the said Mylar film on its upper face (as seen in the drawing), the PVC film being on its lower face. The facility  7  essentially comprises a laser emitter, a spatial light modulator controlled by the production computer  59  described later (for example of the liquid crystal cell type), lenses and optical components for guiding and concentrating the beam of the laser emitter, as well as the circuits necessary for the display by the spatial modulator of patterns provided by a database  8 . The facility  7  is followed by a facility  9 , which comprises for example a printer, and which is responsible for affixing onto the film  5  an identification mark near each hologram printed at the facility  7 . This mark may, for example, be a bar code, but it is of course possible for it to be any other type of marking allowing easy and unambiguous identification of each of the holograms from among a large number (several thousand holograms may be formed on one and the same tape of film  5 ). The facility  9  is followed by a facility  10  for irradiating the film  5 . This facility  10  comprises ultraviolet lamps applying a power of around 70 mW/cm 2  for example to the film  5 . Each of the holograms can comprise at least one of the following elements: a photograph identical to that printed on the document, a name, a number, another photograph, a code. 
   At the exit of the facility  10 , there is a roll  11  making it possible to divert the lower protective film  12  (PVC film) of the film  5  toward a take-up coiling roll  13 , while the photosensitive film together with its upper protective film (of Mylar) is conveyed to a lamination facility  14 , passing in front of a device  15  for eliminating static electricity. The facility  14  comprises two heating pressure rolls  16 ,  17  between which is made to pass the irradiated photosensitive film together with its upper protective film and a colorant film  18  which is applied against the lower face of the photosensitive film. This film  18  originates from a feed roll  19  on which this film is wound together with a protective film (of polypropylene for example). This protective film  20  is removed as and when the film  18  is used and wound on a take-up roll  21 . An antistatic device  22  is fixed around, or in proximity to, the film  18 , just downstream of the place where it is separated from the film  20 . At the exit of the facility  14  there is a pulley block  23 , which precedes a hot air circulation oven  24  in which the composite film  25  issuing from the facility  14  travels a path at even speed for a time of 8 to 20 minutes approximately, and a temperature of between 120 and 180° C. approximately, depending on the desired final color of the holograms. This film  25  comprises the following layers: the initial protective layer (of Mylar for example), the photosensitive film, the colorant film  18  and the protective film (Mylar for example) for the colorant film. At the exit of the oven  24  there is a fixing chamber  26  comprising a bank of ultraviolet radiation lamps applying a luminous power of 5 mW/cm 2  for example to the film. 
   At the exit of the chamber  26  there is a pair of rolls  27 ,  28  gripping the film and making it possible to delaminate the protective film  29  from the colorant film. This film  29  is wound onto a take-up roll  30 . Downstream of the rolls  27 ,  28  are heating pressure rolls  31 ,  32  making it possible to add an adhesive film  33 , in place of the protective film  29  that had just been removed, to the composite film arriving thereat. The adhesive film  33  originates from a feed roll  34 . On this roll  34 , the film  33  was wound together with an upper protective film  35  which is removed immediately after passing between two rolls  36 ,  37  and wound onto a take-up roll  38 . Antistatic devices  39 ,  40  are placed immediately downstream of the rolls  27 ,  28  and  31 ,  32  respectively. 
   Downstream of the rolls  31 ,  32  is placed a pulley block  41  followed by two rider rolls  41 A,  41 B and by a roll  42  onto which the remaining lower protective film  43  for the adhesive  33  is wound. The resulting composite film then passes through a facility  45  for cutting out the holograms that it contains, the cutting out leaving behind the upper protective film, which thus serves as support for transporting the holograms. After cutting out, what remains, that is to say the now useless part  46  of the composite film (the part referred to as the “skeleton”), is wound onto a take-up roll  47 . The “skeleton” comprises several layers formed of parts of films whose surface has not been used for the holograms, these films being: the photosensitive film, the adhesive film, the colorant film and the upper protective film for the photosensitive film. 
   According to a variant of the invention (represented by dashed lines in the drawing), the film  48 , comprising the said upper protective film and the holograms, passes between rolls  48 A,  48 B which make it possible to add a protective film  48 C thereto, originating from a roll  48 D, this protective film being bonded adhesively to the holograms. The resulting composite film  48 E is wound onto a take-up roll  48 F, so as to be used subsequently in a station  48 G for printing documents and for transferring holograms, in a manner analogous to that described hereinbelow with reference to the description of the elements  49  to  58 . The elements  48 A to  48 G constitute, like the elements  49  to  58 , a station for completing production of secure documents. 
   If the variant just described is not implemented, the assembly  48  of the said upper protective film and of the holograms passes through a facility  49  for checking and for transferring holograms onto documents to be made secure. This facility  49  essentially comprises a device for comparing identification codes and a device for transferring holograms onto the documents. These documents are printed in a printing facility  50  and transported to the facility  49 . At the exit of the facility  49 , the documents furnished with their holograms pass through a laminating facility  51  in which they are laminated between heating lamination rolls  52 A,  52 B with an upper protective film  53  and a lower protective film  54  originating from rolls  55 ,  56 , respectively. The laminated tape thus obtained passes through a cutting facility  57 , and the individual secure documents are stored temporarily in a take-up facility  58 . 
   A processor  59  manages all the elements described hereinabove in tempo with the images to be recorded: advancing of the films and tapes, irradiation, oven and developing banks, printing of the holograms from the database  8 , printing of the identification codes and of the documents, etc. 
   The operation of the machine described hereinabove is as follows. The photosensitive film  5 , stored on the feed roll  3 , is pulled in a discontinuous manner by a stepper motor (not represented) acting for example on the rolls  16 ,  17 . The pulley block  6  prevents jerks during the unwinding of the film  5  which unwinds in a continuous manner from the roll  3 , while the pulley block  23  allows the film to pass in a continuous manner through the oven  24  and beyond, up to the pulley block  41 . The film  5  passes firstly through the facility  7 , where it is held on a holographic “master” by suction and/or under the effect of a roll which keeps it hard against this “master”. At this facility  7 , the photosensitive film is irradiated by a laser beam passing through a liquid crystal cell, to which the database  8  dispatches on each occasion an item of unique personalization information (for example the photograph of the bearer of each corresponding identity card fabricated by the machine  1 ). The “master” is a holographic mirror containing recurrent information (logos, text, etc) in three dimensions and possibly optical security features invisible to the naked eye. The operation of this recording facility will not be described in greater detail, since it is the same as that described in the aforesaid French patent No. 2 976 184. After having been irradiated in the facility  7 , the photosensitive film receives at the facility  9  a placement and identification mark (bar code for example with a tag making it possible to pinpoint the exact location of the hologram with respect to the tape). These marks may be printed with an inkjet or thermal printer, for example. The identification marks make it possible to unambiguously identify the corresponding holograms, in the same manner as the marks of the documents printed by the printer of the facility  50  are identified, and hence to assemble each hologram with the corresponding document. 
   After the facility  9 , the film is driven towards the facility  10  in which the rays containing ultraviolet fix the information recorded in the photosensitive material. At the facility  14 , a colorant film  18  is added to the photosensitive film. This photosensitive film is generally green after fixing, and in order to improve the contrast and readability thereof, this colorant film is added thereto, doing so by lamination between the heating rolls  16 ,  17 , at 120° C. for example. The said stepper motor may for example drive these rolls  16 ,  17 . 
   The composite film thus obtained at the exit of the rolls  16 ,  17  is treated in the oven  24 , at a temperature, of between 120° C. and 180° C., which is dependent on the desired final color of the hologram. The continuous advancing of the composite film through the oven makes it possible to limit the deformations of the film in contact with the rolls over which it passes in this oven. According to an example of production, the heating in the oven is effected by circulation of hot air with a minimum overall flow rate of approximately 50 l/min, this air being recycled within the oven so as to enhance its thermal stability and its thermal homogeneity. The oven  24  is furnished with a “dancer”  24 A, which is an adjustable-position roll, thereby making it possible to tailor the residence time of the composite film in the oven to the production speed of the machine  1  by adjusting the length traveled by the film in the oven and to determine the final color of each hologram. The bank  26  of ultraviolet lamps makes it possible to stop the reaction activated in the oven  24  and thus to fix the color of the hologram. The rolls  31  and  32  make it possible to add the adhesive film  33  to the composite film and to advance the film continuously downstream of the pulley block  23 , these rolls being propelled by a continuous-rotation motor. 
   The exit rolls  41 A,  41 B of the pulley block  41  are propelled by a stepper motor, this making it possible to present the film to the facility  45  hologram by hologram so as to be able to cut out each hologram, after having removed the adhesive&#39;s protective film. 
   To match each identity card up with its proper hologram, the facility  49  comprises means for reading bar codes and reticules, a comparator for comparing each code read on the identity card which arrives at this facility with the code read on the hologram which arrives thereat at the same time, and it also comprises means controlling the advancing of the film supporting the holograms so that the correct hologram is brought face-on to the identity card which is present thereat. This comparator triggers means of signaling or of alarm if the hologram present is not the correct one, or else it can instruct the subsequent reprinting of the identity card for which the corresponding hologram is not found, and even the corresponding hologram, so as not to have to stop the machine. The reticules printed on the film of holograms serve to position each of the holograms face-on to the location that it must occupy on the appropriate identity card. When a hologram is thus correctly positioned, a “wedge” or a heating roll applies it against the identity card. After the hologram has been put in place in this way, each identity card thus completed is conveyed to the laminating rolls of the facility  51 . 
   Of course, the steps of putting the holograms in place on the identity cards may be effected in an equivalent manner by implementing other steps known per se. For example, the operations of cutting out the holograms and of putting them in place on the identity cards may be coupled, thereby making it possible to keep the upper protective film (Mylar) of each hologram. As a variant, this protective film may be cut out partially to 99% for example) so as to guide the holograms better. 
   It will be readily seen by one of ordinary skill in the art that the present invention fulfills all of the objects set forth above. After reading the foregoing specification, one of ordinary skill will be able to affect various changes, substitutions of equivalents and various other aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by the definition contained in the appended claims and equivalents thereof.