BOOK-TYPE IDENTIFICATION DOCUMENT The invention relates to a book-type identification document, in particular a passport booklet, having a plastic data page and a paper page following or preceding the plastic data page. The invention also relates to a manufacturing method for such an identification document. Passports and other book-type identification documents often take the form of a small booklet with an outer envelope cover, a sheaf of paper made up of several content pages, and a plastic data page, typically with high-value personalization features and integrated security elements. An identity document is known from the WO 2015/030575 A1, in which a data page is pivotably connected to another surface. In addition to a first image of the holder, the data page also contains a laser-generated second image. On the other surface, a third image is generated by the second image region, which corresponds to the second image and which becomes visible when the data page is folded away. The publications EP 3 279 004 A1, WO 2016/000817 A1 and WO 2015/185724 A1 relate to security elements of the prior art. Proceeding from this, the object of the invention is to provide a book-type identification document of the type mentioned at the outset with increased security against forgery. This object is achieved through the features of the independent claims. Further developments of the invention are the subject matter of the dependent claims. The invention provides an identification document according to claim 1. It is provided that - the plastic data page has a transparent window region into which a piece of window information is introduced, - an indicator substance is added to said paper page at least in a feature region that adjoins the window region of the plastic data page when the identification document is in the closed state, and - a piece of paper information that matches and is congruent with the piece of window information is introduced into said feature region. In the case of the invention, the piece of paper information of the paper page forms a type of shadow information for the piece of window information present in the data page. The congruent arrangement of the two identical pieces of information on consecutive pages that differ in material terms provides additional authentication of the identification document, which makes it significantly more difficult to reproduce the document. When the identification document is in the closed state, the plastic data page and the paper page lie directly on top of one another. The region of the paper page then lying directly above or below the window region defines said feature region of the paper page. The window information represents a laser marking and is, in particular, a piece of window information that is introduced into the window region ablation free. This means that the effect of the laser beam only changes the material properties, such as colour, refractive index or roughness of the plastic data page, but the plastic data page is not perforated. The piece of paper information can advantageously represent a laser marking. It was found that the addition of a laser-sensitive substance as an indicator to the paper page allows laser marking to be applied simultaneously to the window region of the plastic data page and the marking region of the paper page in a congruent manner. The piece of paper information can also represent a thermal marking, i.e. a marking that is not primarily generated by the effect of the laser radiation itself, but essentially by the heat generated during the laser marking of the data page and transferred to the adjacent paper page. In this variant, an indicator substance is used that does not have to be laser-sensitive, but reacts to the flow of heat and thus creates a marking that is congruent with the laser. In particular, a heat-sensitive substance is used as the indicator substance, which shows a material change, in particular a colour change, when heat is applied. According to the invention, the piece of paper information constitutes an accretion marking, i.e. a marking that is essentially produced by the accretion of a material created when laser marking the data page. For example, when a data page is laser marked, carbon black often forms, but this does not persist on an adjacent page of paper. In this variant, an indicator substance is used that does not have to be laser or heat sensitive, but rather, similar to an adhesive film, accretes and holds the formed material (specifically, for example, carbon black) and thereby produces a blackening of the paper page that is congruent with the laser marking. Kaolin, for example, can be used as an indicator substance, but a mixture of pigments made of titanium dioxide (anatase and/or rutile) and aluminium hydroxide can also be considered. The proportion of the indicator material in the paper is advantageously 1 to
15%. Depending on how the indicator material is matched to the properties of the data page and the laser conditions, the piece of paper information can be generated in the form of a laser marking, a thermal marking and/or an accretion marking. In an advantageous embodiment, said paper page has a layer structure having a paper core and a surface layer that is arranged on the side of the paper core facing the plastic data page. The surface layer is mixed with the indicator substance at least in the feature region.
The surface layer of the paper page expediently contains, for example, kaolin and/or titanium dioxide pigments and/or aluminium hydroxide.
In addition, the surface layer expediently contains binders, for example natural or synthetic polymers such as starch, polyvinyl alcohols, styrene acylate and/or polyvinyl acetate.
Alternatively, the indicator substance can be provided not only in a surface layer, but in the volume of the paper page.
In all cases, the paper page is offset with the indicator substance at least in the feature region, wherein it is possible to provide the indicator substance only in the feature region or to offset the entire paper page with the indicator substance.
If kaolin is used as an indicator substance, the proportion of kaolin in the feature region of the paper page, in particular the proportion of kaolin in the feature region of the surface layer, is advantageously between 1% and 10%. The proportion of kaolin can be determined, for example, as the proportion of ash (loss on ignition according to ISO 2144). The data page is advantageously formed by a polycarbonate layer or contains one or more polycarbonate layers.
In principle, the window region can have any shape.
For example, the window region may be rectangular on the inside of the data page, or it may be in the form of a longitudinal or transverse strip extending across the entire data page.
The piece of window information and the piece of paper information advantageously represent a personalization feature that is different for each identification document.
The piece of window information and the piece of paper information can represent an image motif, in particular a portrait, a logo or a code, such as a barcode, or an alphanumeric character string.
Specifically, the piece of window information and the piece of paper information can represent an access number of the identification document, the name of the document holder or the signature of the document holder.
In an advantageous embodiment, the piece of paper information can form hidden information on the paper page.
For example, a suitable background print on the paper page can ensure that the piece of paper information that is congruent with the window information is not always visible, but only appears from special viewing directions or only when using tools such as a strong light source or a magnifying glass.
The authenticity protection is further reinforced as a result, since the presence of the piece of paper information corresponding to the piece of window information is not immediately recognizable for a potential forger.
In a further variant of the invention, the piece of paper information and the background print on the paper page are advantageously formed by structural elements of the same type.
For example, the piece of paper information and the background print can each be formed by line patterns and/or dot patterns, so that the piece of paper information supplements the background print with structural elements (lines and/or dots) of the same type.
The paper information preferably represents a personalization feature that differs in each identification document, while the background print is the same in all identification documents.
The individual piece of paper information, for example in the form of an individual line or dot pattern, is then hidden in the background print, which is correspondingly designed in the form of a line or dot pattern common to all documents.
The overall pattern formed by the piece of paper information and the background print then appears identical for all documents at first glance because of the common background component, but differs from document to document on closer inspection due to the individual piece of paper information.
In relation to the reading direction of the identification document, the paper page can be both the paper page following the plastic data page and the paper page preceding the plastic data page.
If the paper page represents the page following the plastic data page, the piece of paper information appears on the front side of the paper page on the right when viewed separately from the piece of window information.
In the case of a preceding page, on the other hand, the piece of paper information appears on the back of the paper page as a mirror image of the piece of window information.
The invention also includes a method of manufacturing a book-type identification document according to claim 11, wherein the method simultaneously generates the piece of window information in the transparent window region and the piece of paper information in said paper page by laser impingement on the window region of the plastic data page.
To generate the piece of window information and the piece of paper information, a laser beam, for example a pulsed laser beam, can be guided over the surface of the window region in the pattern of the desired information.
Alternatively, a large-area laser beam can also be used advantageously together with a suitable mask.
Since the laser impingement always occurs through the window region into the adjacent paper page, when the piece of paper information is introduced into the paper page that follows in the identification document, the result is a right-sided display on its front side, and if it is introduced into the paper page that precedes it in the identification document, it results in a reversed display on its back.
The latter variant can be used advantageously in the case of hidden paper information in particular. In an advantageous method, the laser impingement of the window region of the plastic data page simultaneously generates the piece of window information in the form of a laser marking, and the piece of paper information in the form of a thermal marking is generated by the heat generated during the laser marking of the plastic data page and transferred to the adjacent paper page. In another, also advantageous method, the window region of the plastic data page is simultaneously generated through the laser impingement in the form of a laser marking, and during the laser marking of the plastic data page, a material, in particular carbon black, is formed, which is accreted and retained on the paper page to form the piece of paper information. Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, which are not shown to scale and proportions in order to improve clarity. In the drawings:
Fig. 1 shows a schematic perspective view of a passport booklet according to the invention with several paper pages and a plastic data page, and
Fig. 2 shows a schematic cross-section of the passport booklet of Fig. 1 in the window region of the plastic data page during the laser impingement step, wherein (a) shows the state before and (b) shows the state after the laser impingement. The invention will now be explained using a passport booklet as an example. Fig. 1 shows a schematic perspective view of a passport booklet 10 according to the invention, which contains several paper pages 12, 14 and a plastic data page 20 in an envelope cover 16. The plastic data page 20 of the booklet has, in addition to other personalization and security features, a transparent window region 22 into which a piece of window information 24 is introduced, which is shown in the exemplary embodiment by the number sequence "33550336" for illustration purposes. The piece of window information 24 can be, for example, an access number (CAN), the name of the passport holder or their signature. The page in the passport booklet 10 following the plastic data page 20 in the reading direction represents a paper page 12 in which a piece of paper information 34 is introduced in a feature region 32. The piece of paper information 34 corresponds to the piece of window information 24, i.e. it represents the same sequence of digits. In addition, the piece of paper information 34 and the piece of window information 24 are arranged congruently with one another, so that when the passport book pages 20, 12 lie one on top of the other, they lie exactly in the list one on top of the other. This congruent arrangement of the two pieces of information 24, 34 with the same content in different passport book pages 20, 12 provides additional authentication of the passport booklet 10. In order to be able to produce a passport booklet with this additional protection, the paper page 12 must be designed in a special way and, in addition, during the production of the booklet, laser radiation must be applied at the same time as the plastic data page 20 and through its window regions 22, as explained in more detail below with reference to the illustration in Fig. 2.
Fig. 2 shows a schematic cross-section of the passport booklet 10 in the window region 22 of the plastic data page 20 during the laser impingement step. The plastic data page and the following paper page 12 are shown a small distance apart for the sake of clarity, but in practice lie directly on top of one another when the laser impingement occurs. Referring first to Fig. 2(a), the plastic data page 20 of the passport 10 is made of polycarbonate, for example, and typically contains several personalization and security features that are not essential to the present invention and are therefore not shown in the figure. The plastic data page 20 has a transparent window region 22, which is rectangular in the exemplary embodiment and is arranged inside the data page. The page of the passport booklet 10 following the plastic data page 20 represents a paper page 12 that has a layered structure made up of a paper core 36 and a surface layer 38 facing the data page 20. The surface layer 38 contains a mixture of titanium dioxide and aluminium hydroxide and, as a special feature, the filler kaolin in a proportion of, for example, 5%. The plastic data page 20, together with the underlying paper page 12, is exposed to laser radiation 40 in the window region 22 in order to inscribe the desired piece of window information 24 in the window region 22 (Fig. 2(a)). For this purpose, for example, a pulsed laser beam 40 can be guided over the surface of the window region 22 in the pattern of the desired piece of window information. The inventor has now surprisingly found that the surface layer 38 can be sensitized by adding an indicator substance, so that the laser impingement 40 not only generates the piece of window information 24 in the window region of the data page 20, but also a marking in the adjacent surface layer 38 of the paper page 12 and thus leads to the generation of the piece of paper information 34. Depending on the transmission properties of the data page and the laser conditions, the piece of paper information 34 can be in the form of a laser marking, which is generated by the laser radiation penetrating the data page, can be in the form of a thermal marking, which is not caused by laser radiation but by the laser marking of the data page and heat transmitted to the adjacent paper side, or is produced according to the invention in the form of an accretion marking which is not produced by laser radiation or heat but by the accretion of a material such as carbon black resulting from the laser marking of the data page.
Since the plastic data page 20 and the paper page 12 lie directly on top of one another when the laser impingement occurs, the information 24, 34 is generated simultaneously in both passport book pages 20, 12 with identical information content and congruently with one another, as shown in Fig. 2(b). The piece of paper information 34 thus forms a kind of shadow information of the window information 24 in the finished passport booklet 10, as already shown and described in connection with Fig. 1. If the paper information 34 is to form hidden information, the paper page 12 can be provided with a camouflaging background layer in the marking region, for example, which conceals the presence of the piece of paper information under normal viewing conditions.
For example, the background layer can be black, but have a different gloss behaviour than the laser-marked paper information 34, so that it is only visible in grazing light.
It can also be provided that the individualizing piece of paper information 34 forms a line or dot pattern and the background layer on the paper side 12 also shows a line or dot pattern, which together with the piece of paper information 34 forms an overall pattern.
While the pattern of the background layer is identical for all passport booklets 10, the individualizing paper information 34 is different for each booklet.
The overall pattern therefore always looks the same on superficial inspection because of the common background pattern, but differs on closer examination due to the individual paper information, so that a hidden marking of authenticity is created.
List of reference signs Passport booklet 12,14 Paper pages 16 Envelope cover Plastic data page 22 Transparent window region 24 Window information 32 Feature region
34 Paper information 40 Laser radiation