FR2891650A1 - METHOD FOR THE HOLOGRAPHICAL SECURITY OF A DOCUMENT AND THE MANUFACTURE OF SUCH A DOCUMENT FILM FOR THE IMPLEMENTATION OF SAID METHOD AND DOCUMENT SO SECURE. - Google Patents

Abstract

The method involves superposing a marking film (1) on which a set of zero order diffraction networks are formed that are transferable on a document. The film has optically active marks that are provided in the form of numeric characters. Marks to be transferred (2, 3) are transferred on the document by applying a marking iron on the marking film. The marking iron has the shape of the marks to be transferred. The film comprises zero order diffraction networks producing their distinct optical effects. An independent claim is also included for a marking film comprising a uniform zero order diffraction network band.

Description

METHOD FOR THE HOLOGRAPHICAL SECURITY OF A DOCUMENT AND

  The present invention relates to a method for the holographic securing of a document and film for the implementation of this method. BACKGROUND OF THE INVENTION

  It relates more particularly to a method implementing the application on a support such as a bank note, a passport or an identification card of a holographic marking. The marking products of the DOVID (Diffractive Optical Variable Image Device) product family present an image whose colors change according to the observation conditions. They are made in the form of holograms or combinations of networks. These products and their manufacturing processes are known in the state of the art, for example by the components marketed under the trade names Gyrogram and Alphagram by the applicant, Hologram Industries.

  This essential feature prevents the copying or imitation of images by traditional printing and graphics software.

  As an example of the state of the art, reference is made to the international patent WO9627178 describing a security article, such as a protective packaging, revealing fraudulent manipulations, said security article comprising a support layer provided with a structure, such as a stamped hologram, which produces an effect of optical variations. Each surface of the backing layer is covered with an adhesive adhesive such that once the backing layer is adhered to a surface, it can not be removed without damaging the structure that produces an effect of variations. Optics The implementation of such products is carried out in different forms: hot stamping film for the transfer of a DOVID on paper or plastic documents, optical structures of order 0 such that they have a well-defined color when they are observed in a first direction of observation and a distinct color when they are observed at 90 (rotation in the plane of the document). These structures can be either combined to create images, or integrated with DOVID to give complex images.

  They can then be produced on hot-stamping films.

  In all these cases, it is the contrast of the different optical elements between them according to the lighting conditions and observation that defines an image. This entity is then deposited on the document in the form of a patch.

  In another field of application, typewriter ribbons which have two colors juxtaposed lengthwise so as to be able to write alternately one color or the other The object of the present invention is to propose a film allowing the simultaneous marking (preferably by hot transfer) of at least two juxtaposed signs which have distinct optical effects.

  These two elements of the marking are legible to order 0 in direct contrast with the substrate (diffusing). This solution makes it possible to eliminate the problem of the glassy reflection with the order 0 which parasitizes the reading.

  The invention more generally relates to a method of depositing a two-color optical mark for quickly identifying and authenticating a bank note document or other document carrying a composite element requiring immediate visual identification by a person without particular qualifications or expertise. This mark must not be easily reproduced or infringed. It also offers the possibility of expert level control.

  The shape of these elements is given directly by the shape of the hot stamping iron.

  The invention relates, in its most general sense, to an optical security component visible to the order 0 constituted by a film on which a plurality of optical security effects are formed, for example based on diffraction gratings transferable by hot stamping. on a support characterized in that said optical effects form after transfer at least one pair of juxtaposed signs, each of the signs of said pair producing distinct optical effects.

  Advantageously, the film has two uniform bands of distinct optical effects respectively on either side of a longitudinal line.

  Preferably, said film has a transfer layer capable of transfer by means of a marking iron, and in particular with a hot-marking iron.

  According to a particular embodiment, the film is in the form of a continuous coil with a sequence of separate security optical effect bands ordered longitudinally.

  According to another embodiment, the film is in the form of a coil containing a succession of patches, said patches consisting of several zones of separate security optical effects. In the same way, it is the iron which will draw in each zone a precise useful surface, making it possible to transfer on the 2891650 4 document distinct signs having specific optical security effects.

  The invention also relates to a method for securely marking a document, characterized in that a portion of a security optical component consisting of a transparent film on which a plurality of transferable diffraction gratings on a support are formed is superimposed. characterized in that said diffraction gratings form at least one pair of juxtaposed signs, each of the signs of said pair producing distinct optical effects, and in that at least one of the two signs of a said pair is transferred. on the adjacent document.

  According to one variant, at least the two signs of a said pair are transferred to the document to be authenticated.

  According to one variant, the shape of the hot stamping irons varies from one document to another and makes it possible to customize the authentication signs.

  The invention also relates to a method for preparing a security component, characterized in that a film comprising a transparent substrate, an embossing layer, a layer of high optical refractive index, an optional contrast layer, is prepared. a thin layer of preferably opaque colored varnish and that said film is etched to form a series of bands having distinct optical effects with a configuration for producing two distinct optical effects for said adjacent signs of a pair when using the film.

  Finally, the invention relates to a document secured by an optical security component consisting of at least 2 distinct signs having different optical effects visible to order 0 transferred to said document by hot stamping.

  The present invention will be better understood on reading the description which follows, with reference to the accompanying drawings in which: FIG. 1 represents a marking film according to the prior art; FIG. 2 represents a marking film according to the invention; FIG. 3 represents an example of a document marked according to the prior art; FIG. 4 represents an example of a document marked according to the invention.

  Figure 1 shows a solution known in the state of the art. The security component is in the form of a film 1 having optically active signs 5, here in the form of numerical characters. The two characters 2 and 0 may, in the prior art be identical or different as to the optical effects they produce.

  During heat transfer, the entire area 6 is deposited on the document. This zone includes, besides the 2 characters, a transparent zone which reflects the light in the order zero, parasitic by the same the readability of the characters. One of the objectives of the invention is to delete this area.

  The film 1 is in the form of a coil consisting of differentiated patches.

  In the solution according to the invention presented in FIG. 2, the film has the same general structure. However, the diffracting gratings spread uniformly along the coil on either side of the center line. The choice of the form of hot stamping will make it possible to carry out at the moment of transfer the characters here 2 and 3 suggested by the dotted lines. Each of the characters having the predefined optical effect of each band.

  The invention offers the possibility with the same film to mark distinct signs by simply changing the marking tool and limit the stock to a single stock of consumable.

  It also allows the apposition of two separate effects in a single pass on machine.

  FIG. 3 represents an example of a document marked according to the prior art.

  The marking is in the form of a transfer of an optically variable component 7 having two configurations 15, 25, of different colors possibly, but embedded in the transparent varnish deposited simultaneously at the time of transfer and which disturbs the reading at the same time. order O. FIG. 4 represents an exemplary document marked according to the invention.

  The marking is in the form of a transfer of two optically variable components 2, 3, possibly of different colors, and producing distinct optical effects. They are directly transferred onto a diffusing paper substrate. The optical effect is for example obtained with a maximum intensity according to two different orientations, specific to each of the signs forming the pair 2, 3. Their readability is increased by the fact that they are no longer embedded in an important glassy reflection zone but they stand out directly on the paper that is diffusing it.

Claims (10)

  1 security optical component constituted by a transparent film 1 on which are formed a plurality of transferable diffraction gratings on a support characterized in that said diffraction gratings form at least one pair of signs 2, 3 juxtaposed, each of the signs 2, 3 of said pair producing distinct optical effects.   2 optical security component according to claim 1, characterized in that the film has a plurality of pairs of signs 2, 3 respectively disposed on either side of a longitudinal line.   3 optical security component according to claim 1, characterized in that said signs 2, 3 have a transfer layer capable of transfer by means of a marking iron.   4 optical security component according to claim 1, characterized in that said signs 2, 3 have a transfer layer suitable for transfer using a hot stamping iron.     Optical safety component according to claim 1, characterized in that the film 1 is in the form of a continuous coil with a succession of pair of signs 2, 3 ordered longitudinally.   6 optical security component according to claim 1, characterized in that the film 1 is in the form of a coil containing a succession of 2891650 8 patches, said patches consisting of several separate zones of optical security effects.   7 A method for securely marking a document, characterized in that a part of a security optical component consisting of a transparent film 1 on which a plurality of transferable diffraction gratings are formed on a support is superimposed, characterized in that said diffraction gratings form at least one pair of signs 2, 3 juxtaposed, each of the signs 2, 3 of said pair producing distinct optical effects, and in that at least one of the two signs of a pair is transferred. said pair on the adjacent document.   The method of security marking according to claim 7, characterized in that at least the two signs of said pair are transferred to the adjacent document.   9 method of security marking according to claim 7, characterized in that the delimitation of the signs 2, 3 producing specific security optical effects is performed by a iron ensuring the transfer.   Process for the preparation of a security component, characterized in that a film comprising a transparent substrate, a stamping layer, a layer of high optical refractive index, a thin layer 4bis of a preferably colored varnish is prepared. translucent and an aluminum layer and that said film is stamped to form a series of adjacent sign pairs with a pattern for producing two distinct optical effects for said adjacent signs of a pair.   Secure document characterized in that it consists of a security optical component comprising a transparent film 1 on which is formed a plurality of diffraction gratings transferable on a support, said diffraction gratings forming at least one pair of signs. 2, 3 juxtaposed, each of signs 2, 3 of said pair producing distinct optical effects.