Personalizable security document and method of personalizing the same

Abstract

A personalizable security document (10) includes a first window (6) and at least one second window (3) formed in an opaque substrate layer (31) of a substrate (1). A laser-engravable material layer (2) is provided on another substrate layer (32) such that it overlaps the first window (6), but does not overlap the at least one second window (3). When an image (12) is laser engraved in the layer of laser-engravable material (2), this image can be seen together with a shape that is defined by an overlap region between the at least one second window (3) and the region in which the layer of laser-engravable material (2) is not provided. Accordingly, different security features can be interlocked with each other. A third window (2a) in the layer of laser-engravable material (2) is provided. A portion (1a) of the substrate is visible through the third window and the second window.

Description

Technical Field

[0001] The present disclosure generally relates to security features for security documents, in particular, personalizable security documents such as identification documents, driver's licenses and the like.Background

[0002] Generally, in the market of physical identification documents, a variety of different security features is used. In some applications, a laser engraved image is considered vital, as the image features are obtained inside a polycarbonate substrate rather than on the surface of the substrate. A laser engraved feature in a polycarbonate substrate may include a black and white (in particular, grayscale) image, a color image, or other special features.

[0003] Examples for other kinds of security features include the use of a combination of laser and ink to secure the document. Sometimes, different security features are provided in a transparent window extending through the document, and the different security features can be observed in a variety of different observation conditions.

[0004] Other ways to secure a document include the use of watermarks embedded inside the security document in order to secure a main portrait or a secondary portrait of a holder of the security document.

[0005] The present disclosure is directed, at least in part, to further increasing the security of personalizable security documents, without being limited to a particular type of security document.Summary of the Disclosure

[0006] According to one aspect of the present disclosure, a personalizable security document has a substrate having a first side and a second side opposite to the first side in a thickness direction of the substrate, the substrate including a plurality of first substrate layers laminated with each other. The personalizable security document further has a first window and at least one second window formed in a first substrate layer of the plurality of substrate layers. The first substrate layer is opaque when viewed under white light. The personalizable security document further has a layer of laser-engravable material provided on a second substrate layer of the plurality of substrate layers disposed above the first substrate layer. The layer of laser-engravable material is configured to have a first image laser engraved in the same from the first side. The layer of laser-engravable material covers the first window when viewed along the thickness direction. The personalizable security document further has at least one third window formed in the layer of laser-engravable material. The at least one third window is aligned with the at least one second window such that a portion of the substrate disposed below the first substrate layer is visible through the at least one third window and the at least one second window when the substrate is viewed from the first side under white light.

[0007] In another aspect of the present disclosure, a method of personalizing a security document includes the steps of providing a personalizable security document in accordance with the above aspect, the security document further having a pattern printed on a third substrate layer of the plurality of substrate layers disposed below the first substrate layer, wherein the pattern includes a laser-engravable material and is configured to have a second image laser engraved in the same from at least one of the first side and the second side, and laser engraving the second image in the layer of laser-engravable material and the pattern from the second side by varying one or more laser parameters, preferably, wherein a laser power is less than 30 W, more preferably, 20 W or less, and the second image is formed as a continuous image in the layer of laser-engravable material and the pattern.

[0008] Other features and aspects of the present disclosure will be apparent from the following description and the accompanying drawings.Brief Description of the Drawings

[0009] Fig. 1 shows a schematic cross-sectional view of a personalizable security document in accordance with the present disclosure; Fig. 2 shows plan views of two substrate layers of the personalizable security document of Fig. 1; Fig. 3 shows two plan views of the personalizable security document when viewed from the second side; Fig. 4 shows a schematic cross-sectional view of another personalizable security document in accordance with the present disclosure; Fig. 5 shows plan views of two substrate layers of the personalizable security document of Fig. 4; Fig. 6 shows to two plan views of a substrate layer of the personalizable security document of Fig. 4 and of the personalizable security document after personalization when viewed from the second side; Fig. 7 shows plan views of two substrate layers of another personalizable security document in accordance with the present disclosure; and Fig. 8 shows two plan views of a substrate layer of the personalizable security document of Fig. 7 and of the personalizable security document after personalization when viewed from the second side. Detailed Description

[0010] The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described herein are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of protection. Rather, the scope of protection shall be defined by the appended claims.

[0011] Windows formed in a security document are strong security elements of a such a security document. The windows are secured by adding security elements inside the window. Some examples include security features like Window Lock, Diamond ID, the Mirage security feature of HID, etc.

[0012] It has been realized that the security of a document can be further increased by interlocking several windows in a single security element. In particular, the windows can be interlocked inside the security document through a secondary portrait. The window interlocking makes it difficult to forge the document, as the security element can be authenticated by visual inspection of the window design. In particular, the windows can be interlocked by printing respective material layers on the front and on the back of the document.

[0013] In one aspect of the disclosure, two windows are formed by providing corresponding cutouts or through holes in an opaque layer such as a white polycarbonate (PC) layer, and laminating said opaque layer with a plurality of clear PC layers. On one of the additional layers, an ink or other material layer is printed, which covers one of the windows formed in the opaque layer, but not the other window formed in the same. This results in that, when the document is viewed in reflection from a first side, one of the windows formed in the opaque layer is visible, for example, transparent, whereas the other window that is covered by the additional material layer is hidden. Accordingly, the shape of the window that is not covered by the additional material layer can be visibly observed, and can be used in authenticating the document.

[0014] In some embodiments, a watermark, for example, a metallic watermark, is printed as an additional security feature overlapping the window that is covered by the additional material layer. If the watermark has a similar shape as the shape of the window that is not covered by the additional material layer, when the security document is viewed against white light (in transmission), both the shape of the watermark and the shape of the transparent window can be observed, and it can be verified that the shapes match. This is one example for interlocking different security features in a window formed in a security document.

[0015] In other embodiments, a further layer, for example, an ink layer can be printed on one of the substrate layers of the security document, and may be printed such that it overlaps the window of the opaque layer that is not covered by the additional material layer. When the security document is viewed from a first side in reflection, i.e., under white light, both the additional material layer covering the one window in the opaque layer, and the further ink layer can be visually observed. In particular, when the additional material layer and the further ink layer have clearly distinguishable colors, for example, red and blue, this allows for identifying both layers and the specific shape of the window in the additional material layer. This is another example for interlocking different features in a window of a security document from both sides.

[0016] Both the additional material layer and the further ink layer may be laser-engravable materials. This allows for laser-engraving one or two personalized images from one or both sides of the security document, where the engraving can advantageously be performed as a continuous engraving over both the additional material layer and the further ink layer to obtain a continuous image that extends over both layers. If both layers have clearly distinguishable colors, this creates an interlocking between three different security elements, further increasing the security of the document. Advantageously, the laser power that is used for the engraving is low enough such that regions of the opaque layer that are present between the additional material layer and the further ink layer are not visibly modified as the laser passes over the same. An additional watermark can be provided in order to enhance the security even further.

[0017] In some embodiments, the windows formed in the opaque layer can be interlocked with each other by making the one or more windows that are not covered by the additional material layer continuous with the window that is covered by the same. It is also possible to provide the further ink layer only for one of the windows that is not covered by the additional material layer, resulting in that one window remains clear, while the further ink layer can be observed through the other window.

[0018] Fig. 1 shows a schematic cross-sectional view of an exemplary personalizable security document 10 in accordance with the present disclosure. As shown in Fig. 1, security document 10 includes a substrate 1, for example, a polycarbonate (PC) or polyvinyl chloride (PVC) substrate having a substantially rectangular shape. Of course, the shape and type of security document 10 is not limited to such a configuration, and security document 10 may also be configured as a data page of a passport or the like.

[0019] As shown in Fig. 1, substrate 1 has a first side S1 and a second side S2 opposite to the first side in a thickness direction d of substrate 1. Substrate 1 includes a plurality of substrate layers 31, 32, 33, 34, 35. It is evident from Fig. 1 that substrate 1 may include one or more additional substrate layers between the previously mentioned substrate layers. Preferably, the additional substrate layers are transparent substrate layers, for example, clear PC layers, or other appropriate layers.

[0020] The plurality of substrate layers 31, 32, 33, 34, 35 includes a first substrate layer 31 embedded inside substrate 1, a second substrate layer 32 embedded inside substrate 1, a third substrate layer 33 embedded inside substrate 1 on an opposite side of first substrate layer 31, and a pair of transparent cover layers 34, 35 covering, for example, second substrate layer 32 and third substrate layer 33 on opposite sides of substrate 1. Each substrate layer may have a thickness between 50 µm and 150 µm, preferably around 100 µm. The plurality of substrate layers 31, 32, 33, 34, 35, as well as any additional substrate layers, if present, is laminated with each other in a known manner to form substrate 1.

[0021] As shown in Fig. 1, a first window 6 and at least one second window 3 is formed in first substrate layer 31 of the plurality of substrate layers. First substrate layer 31 is opaque when viewed under white light. As used herein, the term "opaque" means that portions of substrate 1 below first substrate layer 31 are generally not visible when substrate 1 is viewed from first side S1 under white light. In some embodiments, an opacity of first substrate layer 31 for white light may be greater than 80 %, preferably, 90 % or more. Although Fig. 1 only shows a single second window 3, any number of second windows 3 can be formed in first substrate layer 31.

[0022] Fig. 2 shows a plan view of first substrate layer 31, in which first window 6 and at least one second window 3 can be seen. In some embodiments, first window 6 and at least one second window 3 are formed as part of a security feature of the security document, in particular, a mostly transparent window formed, for example, in a corner of substrate 1 in a known manner. In some embodiments, first substrate layer 31 is a white substrate layer, in particular, a white PC layer. First window 6 and at least one second window 3 are formed in first substrate layer 31 using known cutting or punching tools. Each of first window 6 and at least one second window 3 may have a predetermined shape, for example, an oval shape for first window 6, and a hexagonal or other polygonal (or any other appropriate) shape for at least one second window 3. As shown in Fig. 2, in the present embodiment, at least one second window 3 is formed separately from first window 6, i.e., separated from first window 6 by material of first substrate layer 31. Both first window 6 and at least one second window 3 are completely surrounded by material of first substrate layer 31 and extend through the same.

[0023] As shown in Fig. 1, a layer of laser-engravable material 2 is provided on second substrate layer 32 of the plurality of substrate layers. Second substrate layer 32 is disposed above first substrate layer 31, i.e., closer to first side S1 than first substrate layer 31. The layer of laser-engravable material 2 is configured to have a first image 12 (see Fig. 2) laser engraved in the same from first side S 1. Laser-engravable material 2 may include any appropriate metallic, organic or other material, for example, materials including nanoparticles and the like, which can be laser-engraved by varying one or more laser parameters in a known manner. In particular, layer of laser-engravable material 2 may include a material that has a color-change effect upon irradiation with laser light. In such a manner, by varying the one or more laser parameters, personalized images such as a secondary portrait of a holder of security document 10, personalized data associated with the holder of security document 10, and the like can be formed by laser engraving in layer of laser-engravable material 2.

[0024] As used herein, the "color-change effect upon irradiation with laser light" means that laser light that is irradiated onto layer of laser-engravable material 2 changes at least one physical property of, for example, particles or pigments included in layer of laser-engravable material 2 in a predetermined manner, for example, depending on the intensity of the laser light and / or other laser parameters. One particular example is the ink that is used in the Mirage security feature of HID. In this technology, each pixel in laser-engraved first image 12 (see Fig. 2) has a defined color value, depending, for example, on a digital grayscale value of a grayscale image to be engraved. For example, a color value of blue corresponds to white in the digital grayscale image to be engraved, and a color value of gold corresponds to black in the digital grayscale image to be engraved. This means that, for example, a minimum or zero laser power results in that laser-engravable material 2 remains of an initial blue color, whereas increasing laser power results in a color change from the initial blue color towards a golden color at maximum laser power. In between the minimum and the maximum laser power, a color-change can be observed from blue to gold. In this manner, for example, a grayscale portrait of a holder of security document 10, for example, a negative or positive image, can be formed in a surface of laser-engravable material 2.

[0025] Here, it will be appreciated that the present application is not limited to the Mirage ink described above, and can be applied to any known laser-engravable material that exhibits a color-change effect when irradiated with laser light. However, it is important to note that the color-change effect as described herein is different from a change that is obtained when a physical structure of a material layer such as a transparent PVC layer or the like is modified by being burnt using a laser having a certain power. It will be appreciated that in such a manner a grayscale image can be formed, for example, in an image-forming region of substrate 1, however, such a formation of a grayscale image by burning of the material of the layer is not to be understood as exhibiting a color-change effect in accordance with the present disclosure. Accordingly, as used herein, a material that exhibits a color-change effect is to be considered a material which changes its color from a first, in particular, chromatic color (for example, blue) to a second, different color (for example, golden), and a change from, for example, colorless to gray or black due to burning of material with increasing laser power is not to be considered as a color-change effect.

[0026] Layer of laser-engravable material 2 may also be any other appropriately configured metallic layer exhibiting a change in reflectivity upon irradiation with laser light from first side S1. It will be appreciated that such a change in reflectivity can also be used to engrave features such as a portrait of a holder of security document 10 or other personalized information. Further, it will be appreciated that any appropriate non-metallic material, which exhibits at least one of a change in reflectivity and a color-change upon irradiation with laser light, can also be used.

[0027] Returning to Fig. 1, layer of laser-engravable material 2 covers first window 6 when viewed along thickness direction d and defines at least one third window 2a formed in layer of laser-engravable material 2. In some embodiments, layer of laser-engravable material 2 can be printed onto second substrate layer 32 in a known manner, while leaving out a portion that defines at least one third window 2a. As shown in Fig. 2, at least one second window 2a may have any desired shape, for example, a hexagonal or other polygonal shape, a circular shape, an oval shape, and the like.

[0028] At least one third window 2a is aligned with at least one second window 3 such that a portion 1a of substrate 1 disposed below first substrate layer 31 is visible through at least one third window 2a and at least one second window 3 when substrate 1 is viewed from first side S1 under white light. This is indicated by dashed lines in Fig. 1.

[0029] As used herein, at least one third window 2a being aligned with at least one second window 3 should be understood as at least one third window 2a overlapping at least in part at least one second window 3 such that a portion of substrate 1 below first substrate layer 31 is visible when substrate 1 is viewed from first side S1. At least one third window 2a and at least one second window 3 do not necessarily have to completely overlap, i.e., do not necessarily have to have the exact same size and shape. For example, at least one third window 3 may have a different shape and / or a different size from at least one second window 2a. It is immediately evident that the size of portion 1a that is visible through at least one third window 2a and at least one second window 3 is determined by the region of overlap between at least one third window 2a and at least one second window 3.

[0030] In the example that is shown in Fig. 2, at least one third window 2a and at least one second window 3 have essentially the same shape and size, and are aligned such that they are overlapping each other completely, i.e., are located at a same position when projected onto a plane perpendicular to thickness direction d. This results in that portion 1a that is visible through at least one third window 2a and at least one second window 3 has the same shape and size as said windows.

[0031] In some embodiments, portion 1a of substrate 1 is essentially transparent when substrate 1 is viewed from first side S1. In such embodiments, at least the portions of the substrate layers below first substrate layer 31 that are below the region of overlap between at least one second window 3 and at least one third window 2a are transparent, resulting in that the region of overlap is a see-through window when substrate 1 is viewed from first side S1. As shown in Fig. 2, this see-through window, which corresponds to at least one third window 2a, can be clearly recognized when security document 10 is viewed from first side S1 under white light, i.e., in reflection. The insert in Fig. 2 shows an enlarged view of the combined window of security document 10 after personalization, i.e., after first image 12 has been laser engraved in layer of laser-engravable material 2. Here, it will be appreciated that any substrate layers that are disposed above second substrate layer 32 (more particularly, layer of laser-engravable material 2) have to be substantially transparent, such that layer of laser-engravable material 2 is visible from first side S1 and can be laser engraved without difficulty. The configuration that is shown in Fig. 2 is one example where a first security feature such as first image 12, for example, a negative portrait of a holder of security document 10, is interlocked with a second security feature, namely, the transparent window formed by at least one second window 3 and at least one third window 2a. This results in an interlocking of different features that are provided at different depths inside substrate 1 of security document 10.

[0032] In some embodiments, security document 10 further has a pattern 4 printed on third substrate layer 33, which is disposed below first substrate layer 31. Pattern 4 can be formed from any appropriate material, such as an ink that can be printed on third substrate layer 33 using techniques such as flexography, screen printing and ink jet printing. In some embodiments, the material forming pattern 4 may be a metallic material. In some embodiments, pattern 4 may be formed such that it has a thickness along thickness direction d of between 5 µm and 20 µm. In some embodiments, the material forming pattern 4 may have an easily recognizable chromatic color, for example, a red color.

[0033] In some embodiments, pattern 4 may be a watermark that is provided in a known manner on third substrate layer 33, for example, on a side that is closer to second side S2. However, it will be appreciated that pattern 4 may also be formed on the opposite side of third substrate layer 33. The material forming pattern 4 is opaque, such that a watermark effect can be obtained when substrate 1 is viewed from first side S1 against white light, i.e., in transmission. In such a case, although not shown in the figures, the shape of pattern 4 can be seen from first side S1, in combination with the portion of layer of laser-engravable material 2 that is visible from first side S1. Here, it will be appreciated that, after personalization, i.e., after laser-engraving image 12, the material forming layer of laser-engravable material 2 may have a property, in particular, an opacity and / or a thickness, such that laser engraved first image 12 disappears when security document 10 is viewed in transmission.

[0034] In some embodiments, pattern 4 has a shape that corresponds to a shape of at least one of at least one third window 2a and at least one second window 3. This is shown in Fig. 3. In Fig. 3, the top part shows second side S2 of security document 10 prior to personalization, and the bottom part shows second side S2 of security document 10 after personalization, in particular, after laser-engraving a second image 14 from second side S2, as will be described in more detail in the following.

[0035] As used herein, the expression "pattern 4 has a shape that corresponds to a shape of at least one of at least one third window 2a and at least one second window 3" is to be understood such that the shapes of pattern 4 and the at least one of at least one third window 2a and at least one second window 3 are similar or identical, while the sizes may be different, such that an observer can immediately identify a match between the different shapes. This results in that, when security document 10 is viewed from first side S1 against white light, both the shape of pattern 4 and the shape of the region of overlap between at least one second window 3 and at least one third window 2a can be observed, and it can be verified that the shapes correspond to each other. In this manner, the at least one third window 2a and the at least one second window 3 are interlocked with pattern 4. It can be immediately seen from Fig. 3 that this also applies when security document 10 is viewed from second side S2 under white light, i.e., in reflection. Also in this case, pattern 4 can be seen against the background of the portion of layer of laser-engravable material 2 covering first window 6. A further interlocking could be created by adapting the shape of first window 6 to the shape of pattern 4, i.e., such that said shapes also correspond to each other.

[0036] As mentioned above, in some embodiments, pattern 4 overlaps first window 6 when viewed along thickness direction d, and is visible when substrate 1 is viewed from first side S1 against white light.

[0037] In other embodiments, the above-described pattern is formed as a pattern 8 overlapping at least one second window 3 and at least one third window 2a when viewed along thickness direction d. This is shown in Fig. 4. Pattern 8 is visible when substrate 1 is viewed from first side S1 under white light. This is a result of pattern 8 being disposed in portion 1a of substrate 1 that is visible through at least one third window 2a and at least one second window 3 when substrate 1 is viewed from first side S1 under white light. Here, it will be appreciated that, in some embodiments, the pattern may include the previously-described pattern 4 in addition to pattern 8 shown in Fig. 4. The same effects as described above may be obtained when pattern 4 is included.

[0038] Fig. 5 shows plan views of first substrate layer 31 including first window 6 and at least one second window 3 and of second substrate layer 32, on which layer of laser-engravable material 2 is provided. In the example shown in Fig. 5, two second windows 3 and two third windows 2a are provided. Accordingly, pattern 8 is also provided as two separate portions in correspondence to the two second windows 3 and the two third windows 2a, as indicated in Fig. 4. As a result, when security document 10 is viewed from first side S1 under white light, the two portions of pattern 8 can be observed via the region of overlap between the two second windows 3 and the two third windows 2a. This is shown in the insert in Fig. 5, which again shows a portion of security document 10 after personalization by laser engraving first image 12 in layer of laser-engravable material 2.

[0039] As shown in Fig. 6, in the present embodiment, pattern 8 (and also pattern 4, if present) is visible when substrate 1 is viewed from second side S2 under white light. In Fig. 6, the top portion shows a plan view of first substrate layer 31 from second side S2, which illustrates first window 6 and the two second windows 3. The bottom portion of Fig. 6 shows second side S2 of substrate 1 after personalization by laser engraving pattern 8 and layer of laser-engravable material 2, which will be described in more detail below.

[0040] In some embodiments, pattern 4, 8 includes a laser-engravable material and is configured to have a second image 14 laser engraved in the same from at least one of first side S1 and second side S2. In the exemplary embodiments shown in Figs. 3 and 6, pattern 4, 8 is configured to have second image 14 laser engraved in the same from second side S2. In some embodiments, as shown in Figs. 2 and 5, alternatively or additionally, pattern 4, 8 is configured to have first image 12 laser engraved in the same from first side S1, in continuity with the image that is laser engraved in layer of laser-engravable material 2. If layer of laser-engravable material 2 and pattern 8 have different colors, this results in that different portions of laser engraved personalized first image 12 also have different colors, in correspondence to the different regions.

[0041] In some embodiments, layer of laser-engravable material 2 has a first chromatic color, for example, blue, as in the Mirage security feature of HID, and pattern 4, 8 has a second, different chromatic color, for example, red, when viewed under white light. This results in a clear distinction between the different portions of layer of laser-engravable material 2 and pattern 4, 8 both before and after personalization.

[0042] As shown in Figs. 3 and 6, in some embodiments, layer of laser-engravable material 2 is visible when substrate 1 is viewed from second side S2 under white light, and is configured to have a third image laser engraved in the same. In some embodiments, the third image may be different from second image 14. In some embodiments, the third image may be the same as second image 14. In other words, second image 14 may be continuously engraved in both pattern 8 and the bottom surface of layer of laser-engravable material 2 from second side S2. For example, personalized data such as a date of birth of the holder of security document 10 can be laser engraved from second side S2 in such a manner, as shown in Figs. 3 and 6. This results in an additional interlocking of different security features, because the same image 14 can be laser engraved in a continuous manner on different portions inside substrate 1, in particular, provided at different depths inside substrate 1.

[0043] As shown, for example, in Fig. 2, in some embodiments, at least one third window 2a is surrounded by laser-engravable material of layer of laser-engravable material 2. In other words, layer of laser-engravable material 2 defines the outline or shape of at least one second window 2a.

[0044] In the embodiments shown in Figs. 2 and 6, first window 6 and at least one second window 3 are formed as separate windows (cutouts, punchouts or the like) in first substrate layer 31. In other embodiments, however, as shown in Figs. 7 and 8, first window 6 and at least one second window 3 are continuous. In such embodiments, however, at least one third window 2a may still be surrounded by laser-engravable material of layer of laser-engravable material 2, as shown in the bottom portion of Fig. 7. This results in the region of overlap between at least one third window 2a and at least one second window 3 being defined by the shape of at least one third window 2a. Accordingly, this region of overlap can be observed from fist side S1 when substrate 1 is viewed under white light, as shown in the insert in Fig. 7. The same effects as those described with respect to Figs. 4 to 6 can be obtained.

[0045] In some modifications of the embodiment that is shown in Figs. 7 and 8, pattern 8 may be formed such that not all third windows 3 are covered by pattern 8. This results in that, for example, one or more of the windows defined by the region of overlap between the windows 3 and at least one third window 2a remains transparent.

[0046] As previously mentioned, the laser-engravable material of layer of laser-engravable material 2 and pattern 8 may be any appropriate material which is suitable to have an image laser engraved in the same by varying one or more laser parameters. In some embodiments, the materials of layer of laser-engravable material 2 and pattern 8 may be the same material, or they may be different materials. Each laser-engravable material may include a metallic material, preferably, a mixture of a metallic material and an organic material, more preferably with a ratio between 1:2 and 2:1. Optionally, the metallic material may include metallic pigments, for example, one or more of Al, Ag, Au, Ze, Fe and Cu pigments.Industrial applicability

[0047] With the above-described configurations, additional layers of security for a personalizable security document 10 can be provided by interlocking two or more security features provided in a window of a security document.

[0048] Personalizable security document 10 may be formed in any appropriate manner, as long as an opaque first substrate layer 31 including first window 6 and at least one second window 3 is provided, and a layer of laser-engravable material 2 is provided on a second substrate layer 32 in the above-described manner, i.e., aligned with the at least one second window 3 such that a portion 1a of substrate 1 disposed below first substrate layer 31 is visible through at least one third window 2a and at least one second window 3 when substrate 1 is viewed from first side S1 under white light. It should be noted that it is not necessary that the entire first substrate layer 31 is opaque. It is sufficient that a portion of first substrate layer 31 surrounding windows 3 and 6 is opaque. In some embodiments, first substrate layer 31 may not be made of an opaque material, but the opacity may be the result of applying a coating, such as an opaque ink, on first substrate layer 31.

[0049] An exemplary method of personalizing security document 10 in accordance with the present disclosure includes the step of providing a personalizable security document 10 having a substrate 1 having a first side S1 and a second side S2 opposite to the first side in a thickness direction d of the substrate 1, the substrate 1 including a plurality of substrate layers 31, 32, 33, 34, 35 laminated with each other, a first window 6 and at least one second window 3 formed in a first substrate layer 31 of the plurality of substrate layers, the first substrate layer 32 being opaque when viewed under white light, and a layer of laser-engravable material 2 provided on a second substrate layer 32 of the plurality of substrate layers disposed above the first substrate layer 31, the layer of laser-engravable material 2 being configured to have a first image 12 laser engraved in the same from the first side S1, the layer of laser-engravable material 2 covering the first window 6 when viewed along the thickness direction d. At least one third window 2a is formed in the layer of laser-engravable material 2. The at least one third window 2a is aligned with the at least one second window 3 such that a portion 1a of the substrate 1 disposed below the first substrate layer 31 is visible through the at least one third window 2a and the at least one second window 3 when the substrate 1 is viewed from the first side S1 under white light. The security document further has a pattern 4, 8 printed on a third substrate layer 33 of the plurality of substrate layers disposed below the first substrate layer 31. The pattern 4, 8 includes a laser-engravable material and is configured to have a second image 14 laser-engraved in the same from at least one of the first side S1 and the second side S2. The method further includes a step of laser engraving the second image 14 in the layer of laser-engravable material 2 and the pattern 4, 8 from the second side S2 by varying one or more laser parameters. Preferably, a laser power is less than 30 W, more preferably, 20 W or less, and the second image 14 is formed as a continuous image in the layer of laser-engravable material 2 and the pattern 4, 8.

[0050] Exemplary laser parameters that are used to engrave personalized image 3a are a laser wavelength between 530 nm and 1060 nm, a laser speed between 100 mm / s and 4000 mm / s, a laser repetition rate between 10 kHz and 100 kHz, and a laser power of less than 30 W, preferably less than 20 W.

[0051] It will be appreciated that the foregoing description provides examples of the disclosed systems and methods. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the general disclosure.

[0052] Recitation of ranges of values herein are merely intended to serve as a shorthand method for referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All method steps described herein can be performed in any suitable order, unless otherwise indicated or clearly contradicted by the context.

[0053] Although the preferred embodiments of the present disclosure have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.

Examples

Embodiment Construction

[0010]The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described herein are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of protection. Rather, the scope of protection shall be defined by the appended claims.

[0011]Windows formed in a security document are strong security elements of a such a security document. The windows are secured by adding security elements inside the window. Some examples include security features like Window Lock, Diamond ID, the Mirage security feature of HID, etc.

[0012]It has been realized that the security of a document can be further increased by interlocking several windows in a single securi...

Technical Field

[0001] The present disclosure generally relates to security features for security documents, in particular, personalizable security documents such as identification documents, driver's licenses and the like.Background

[0002] Generally, in the market of physical identification documents, a variety of different security features is used. In some applications, a laser engraved image is considered vital, as the image features are obtained inside a polycarbonate substrate rather than on the surface of the substrate. A laser engraved feature in a polycarbonate substrate may include a black and white (in particular, grayscale) image, a color image, or other special features.

[0003] Examples for other kinds of security features include the use of a combination of laser and ink to secure the document. Sometimes, different security features are provided in a transparent window extending through the document, and the different security features can be observed in a variety of different observation conditions.

[0004] Other ways to secure a document include the use of watermarks embedded inside the security document in order to secure a main portrait or a secondary portrait of a holder of the security document.

[0005] The present disclosure is directed, at least in part, to further increasing the security of personalizable security documents, without being limited to a particular type of security document.Summary of the Disclosure

[0006] According to one aspect of the present disclosure, a personalizable security document has a substrate having a first side and a second side opposite to the first side in a thickness direction of the substrate, the substrate including a plurality of first substrate layers laminated with each other. The personalizable security document further has a first window and at least one second window formed in a first substrate layer of the plurality of substrate layers. The first substrate layer is opaque when viewed under white light. The personalizable security document further has a layer of laser-engravable material provided on a second substrate layer of the plurality of substrate layers disposed above the first substrate layer. The layer of laser-engravable material is configured to have a first image laser engraved in the same from the first side. The layer of laser-engravable material covers the first window when viewed along the thickness direction. The personalizable security document further has at least one third window formed in the layer of laser-engravable material. The at least one third window is aligned with the at least one second window such that a portion of the substrate disposed below the first substrate layer is visible through the at least one third window and the at least one second window when the substrate is viewed from the first side under white light.

[0007] In another aspect of the present disclosure, a method of personalizing a security document includes the steps of providing a personalizable security document in accordance with the above aspect, the security document further having a pattern printed on a third substrate layer of the plurality of substrate layers disposed below the first substrate layer, wherein the pattern includes a laser-engravable material and is configured to have a second image laser engraved in the same from at least one of the first side and the second side, and laser engraving the second image in the layer of laser-engravable material and the pattern from the second side by varying one or more laser parameters, preferably, wherein a laser power is less than 30 W, more preferably, 20 W or less, and the second image is formed as a continuous image in the layer of laser-engravable material and the pattern.

[0008] Other features and aspects of the present disclosure will be apparent from the following description and the accompanying drawings.Brief Description of the Drawings

[0009] Fig. 1 shows a schematic cross-sectional view of a personalizable security document in accordance with the present disclosure; Fig. 2 shows plan views of two substrate layers of the personalizable security document of Fig. 1; Fig. 3 shows two plan views of the personalizable security document when viewed from the second side; Fig. 4 shows a schematic cross-sectional view of another personalizable security document in accordance with the present disclosure; Fig. 5 shows plan views of two substrate layers of the personalizable security document of Fig. 4; Fig. 6 shows to two plan views of a substrate layer of the personalizable security document of Fig. 4 and of the personalizable security document after personalization when viewed from the second side; Fig. 7 shows plan views of two substrate layers of another personalizable security document in accordance with the present disclosure; and Fig. 8 shows two plan views of a substrate layer of the personalizable security document of Fig. 7 and of the personalizable security document after personalization when viewed from the second side. Detailed Description

[0010] The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described herein are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of protection. Rather, the scope of protection shall be defined by the appended claims.

[0011] Windows formed in a security document are strong security elements of a such a security document. The windows are secured by adding security elements inside the window. Some examples include security features like Window Lock, Diamond ID, the Mirage security feature of HID, etc.

[0012] It has been realized that the security of a document can be further increased by interlocking several windows in a single security element. In particular, the windows can be interlocked inside the security document through a secondary portrait. The window interlocking makes it difficult to forge the document, as the security element can be authenticated by visual inspection of the window design. In particular, the windows can be interlocked by printing respective material layers on the front and on the back of the document.

[0013] In one aspect of the disclosure, two windows are formed by providing corresponding cutouts or through holes in an opaque layer such as a white polycarbonate (PC) layer, and laminating said opaque layer with a plurality of clear PC layers. On one of the additional layers, an ink or other material layer is printed, which covers one of the windows formed in the opaque layer, but not the other window formed in the same. This results in that, when the document is viewed in reflection from a first side, one of the windows formed in the opaque layer is visible, for example, transparent, whereas the other window that is covered by the additional material layer is hidden. Accordingly, the shape of the window that is not covered by the additional material layer can be visibly observed, and can be used in authenticating the document.

[0014] In some embodiments, a watermark, for example, a metallic watermark, is printed as an additional security feature overlapping the window that is covered by the additional material layer. If the watermark has a similar shape as the shape of the window that is not covered by the additional material layer, when the security document is viewed against white light (in transmission), both the shape of the watermark and the shape of the transparent window can be observed, and it can be verified that the shapes match. This is one example for interlocking different security features in a window formed in a security document.

[0015] In other embodiments, a further layer, for example, an ink layer can be printed on one of the substrate layers of the security document, and may be printed such that it overlaps the window of the opaque layer that is not covered by the additional material layer. When the security document is viewed from a first side in reflection, i.e., under white light, both the additional material layer covering the one window in the opaque layer, and the further ink layer can be visually observed. In particular, when the additional material layer and the further ink layer have clearly distinguishable colors, for example, red and blue, this allows for identifying both layers and the specific shape of the window in the additional material layer. This is another example for interlocking different features in a window of a security document from both sides.

[0016] Both the additional material layer and the further ink layer may be laser-engravable materials. This allows for laser-engraving one or two personalized images from one or both sides of the security document, where the engraving can advantageously be performed as a continuous engraving over both the additional material layer and the further ink layer to obtain a continuous image that extends over both layers. If both layers have clearly distinguishable colors, this creates an interlocking between three different security elements, further increasing the security of the document. Advantageously, the laser power that is used for the engraving is low enough such that regions of the opaque layer that are present between the additional material layer and the further ink layer are not visibly modified as the laser passes over the same. An additional watermark can be provided in order to enhance the security even further.

[0017] In some embodiments, the windows formed in the opaque layer can be interlocked with each other by making the one or more windows that are not covered by the additional material layer continuous with the window that is covered by the same. It is also possible to provide the further ink layer only for one of the windows that is not covered by the additional material layer, resulting in that one window remains clear, while the further ink layer can be observed through the other window.

[0018] Fig. 1 shows a schematic cross-sectional view of an exemplary personalizable security document 10 in accordance with the present disclosure. As shown in Fig. 1, security document 10 includes a substrate 1, for example, a polycarbonate (PC) or polyvinyl chloride (PVC) substrate having a substantially rectangular shape. Of course, the shape and type of security document 10 is not limited to such a configuration, and security document 10 may also be configured as a data page of a passport or the like.

[0019] As shown in Fig. 1, substrate 1 has a first side S1 and a second side S2 opposite to the first side in a thickness direction d of substrate 1. Substrate 1 includes a plurality of substrate layers 31, 32, 33, 34, 35. It is evident from Fig. 1 that substrate 1 may include one or more additional substrate layers between the previously mentioned substrate layers. Preferably, the additional substrate layers are transparent substrate layers, for example, clear PC layers, or other appropriate layers.

[0020] The plurality of substrate layers 31, 32, 33, 34, 35 includes a first substrate layer 31 embedded inside substrate 1, a second substrate layer 32 embedded inside substrate 1, a third substrate layer 33 embedded inside substrate 1 on an opposite side of first substrate layer 31, and a pair of transparent cover layers 34, 35 covering, for example, second substrate layer 32 and third substrate layer 33 on opposite sides of substrate 1. Each substrate layer may have a thickness between 50 µm and 150 µm, preferably around 100 µm. The plurality of substrate layers 31, 32, 33, 34, 35, as well as any additional substrate layers, if present, is laminated with each other in a known manner to form substrate 1.

[0021] As shown in Fig. 1, a first window 6 and at least one second window 3 is formed in first substrate layer 31 of the plurality of substrate layers. First substrate layer 31 is opaque when viewed under white light. As used herein, the term "opaque" means that portions of substrate 1 below first substrate layer 31 are generally not visible when substrate 1 is viewed from first side S1 under white light. In some embodiments, an opacity of first substrate layer 31 for white light may be greater than 80 %, preferably, 90 % or more. Although Fig. 1 only shows a single second window 3, any number of second windows 3 can be formed in first substrate layer 31.

[0022] Fig. 2 shows a plan view of first substrate layer 31, in which first window 6 and at least one second window 3 can be seen. In some embodiments, first window 6 and at least one second window 3 are formed as part of a security feature of the security document, in particular, a mostly transparent window formed, for example, in a corner of substrate 1 in a known manner. In some embodiments, first substrate layer 31 is a white substrate layer, in particular, a white PC layer. First window 6 and at least one second window 3 are formed in first substrate layer 31 using known cutting or punching tools. Each of first window 6 and at least one second window 3 may have a predetermined shape, for example, an oval shape for first window 6, and a hexagonal or other polygonal (or any other appropriate) shape for at least one second window 3. As shown in Fig. 2, in the present embodiment, at least one second window 3 is formed separately from first window 6, i.e., separated from first window 6 by material of first substrate layer 31. Both first window 6 and at least one second window 3 are completely surrounded by material of first substrate layer 31 and extend through the same.

[0023] As shown in Fig. 1, a layer of laser-engravable material 2 is provided on second substrate layer 32 of the plurality of substrate layers. Second substrate layer 32 is disposed above first substrate layer 31, i.e., closer to first side S1 than first substrate layer 31. The layer of laser-engravable material 2 is configured to have a first image 12 (see Fig. 2) laser engraved in the same from first side S 1. Laser-engravable material 2 may include any appropriate metallic, organic or other material, for example, materials including nanoparticles and the like, which can be laser-engraved by varying one or more laser parameters in a known manner. In particular, layer of laser-engravable material 2 may include a material that has a color-change effect upon irradiation with laser light. In such a manner, by varying the one or more laser parameters, personalized images such as a secondary portrait of a holder of security document 10, personalized data associated with the holder of security document 10, and the like can be formed by laser engraving in layer of laser-engravable material 2.

[0024] As used herein, the "color-change effect upon irradiation with laser light" means that laser light that is irradiated onto layer of laser-engravable material 2 changes at least one physical property of, for example, particles or pigments included in layer of laser-engravable material 2 in a predetermined manner, for example, depending on the intensity of the laser light and / or other laser parameters. One particular example is the ink that is used in the Mirage security feature of HID. In this technology, each pixel in laser-engraved first image 12 (see Fig. 2) has a defined color value, depending, for example, on a digital grayscale value of a grayscale image to be engraved. For example, a color value of blue corresponds to white in the digital grayscale image to be engraved, and a color value of gold corresponds to black in the digital grayscale image to be engraved. This means that, for example, a minimum or zero laser power results in that laser-engravable material 2 remains of an initial blue color, whereas increasing laser power results in a color change from the initial blue color towards a golden color at maximum laser power. In between the minimum and the maximum laser power, a color-change can be observed from blue to gold. In this manner, for example, a grayscale portrait of a holder of security document 10, for example, a negative or positive image, can be formed in a surface of laser-engravable material 2.

[0025] Here, it will be appreciated that the present application is not limited to the Mirage ink described above, and can be applied to any known laser-engravable material that exhibits a color-change effect when irradiated with laser light. However, it is important to note that the color-change effect as described herein is different from a change that is obtained when a physical structure of a material layer such as a transparent PVC layer or the like is modified by being burnt using a laser having a certain power. It will be appreciated that in such a manner a grayscale image can be formed, for example, in an image-forming region of substrate 1, however, such a formation of a grayscale image by burning of the material of the layer is not to be understood as exhibiting a color-change effect in accordance with the present disclosure. Accordingly, as used herein, a material that exhibits a color-change effect is to be considered a material which changes its color from a first, in particular, chromatic color (for example, blue) to a second, different color (for example, golden), and a change from, for example, colorless to gray or black due to burning of material with increasing laser power is not to be considered as a color-change effect.

[0026] Layer of laser-engravable material 2 may also be any other appropriately configured metallic layer exhibiting a change in reflectivity upon irradiation with laser light from first side S1. It will be appreciated that such a change in reflectivity can also be used to engrave features such as a portrait of a holder of security document 10 or other personalized information. Further, it will be appreciated that any appropriate non-metallic material, which exhibits at least one of a change in reflectivity and a color-change upon irradiation with laser light, can also be used.

[0027] Returning to Fig. 1, layer of laser-engravable material 2 covers first window 6 when viewed along thickness direction d and defines at least one third window 2a formed in layer of laser-engravable material 2. In some embodiments, layer of laser-engravable material 2 can be printed onto second substrate layer 32 in a known manner, while leaving out a portion that defines at least one third window 2a. As shown in Fig. 2, at least one second window 2a may have any desired shape, for example, a hexagonal or other polygonal shape, a circular shape, an oval shape, and the like.

[0028] At least one third window 2a is aligned with at least one second window 3 such that a portion 1a of substrate 1 disposed below first substrate layer 31 is visible through at least one third window 2a and at least one second window 3 when substrate 1 is viewed from first side S1 under white light. This is indicated by dashed lines in Fig. 1.

[0029] As used herein, at least one third window 2a being aligned with at least one second window 3 should be understood as at least one third window 2a overlapping at least in part at least one second window 3 such that a portion of substrate 1 below first substrate layer 31 is visible when substrate 1 is viewed from first side S1. At least one third window 2a and at least one second window 3 do not necessarily have to completely overlap, i.e., do not necessarily have to have the exact same size and shape. For example, at least one third window 3 may have a different shape and / or a different size from at least one second window 2a. It is immediately evident that the size of portion 1a that is visible through at least one third window 2a and at least one second window 3 is determined by the region of overlap between at least one third window 2a and at least one second window 3.

[0030] In the example that is shown in Fig. 2, at least one third window 2a and at least one second window 3 have essentially the same shape and size, and are aligned such that they are overlapping each other completely, i.e., are located at a same position when projected onto a plane perpendicular to thickness direction d. This results in that portion 1a that is visible through at least one third window 2a and at least one second window 3 has the same shape and size as said windows.

[0031] In some embodiments, portion 1a of substrate 1 is essentially transparent when substrate 1 is viewed from first side S1. In such embodiments, at least the portions of the substrate layers below first substrate layer 31 that are below the region of overlap between at least one second window 3 and at least one third window 2a are transparent, resulting in that the region of overlap is a see-through window when substrate 1 is viewed from first side S1. As shown in Fig. 2, this see-through window, which corresponds to at least one third window 2a, can be clearly recognized when security document 10 is viewed from first side S1 under white light, i.e., in reflection. The insert in Fig. 2 shows an enlarged view of the combined window of security document 10 after personalization, i.e., after first image 12 has been laser engraved in layer of laser-engravable material 2. Here, it will be appreciated that any substrate layers that are disposed above second substrate layer 32 (more particularly, layer of laser-engravable material 2) have to be substantially transparent, such that layer of laser-engravable material 2 is visible from first side S1 and can be laser engraved without difficulty. The configuration that is shown in Fig. 2 is one example where a first security feature such as first image 12, for example, a negative portrait of a holder of security document 10, is interlocked with a second security feature, namely, the transparent window formed by at least one second window 3 and at least one third window 2a. This results in an interlocking of different features that are provided at different depths inside substrate 1 of security document 10.

[0032] In some embodiments, security document 10 further has a pattern 4 printed on third substrate layer 33, which is disposed below first substrate layer 31. Pattern 4 can be formed from any appropriate material, such as an ink that can be printed on third substrate layer 33 using techniques such as flexography, screen printing and ink jet printing. In some embodiments, the material forming pattern 4 may be a metallic material. In some embodiments, pattern 4 may be formed such that it has a thickness along thickness direction d of between 5 µm and 20 µm. In some embodiments, the material forming pattern 4 may have an easily recognizable chromatic color, for example, a red color.

[0033] In some embodiments, pattern 4 may be a watermark that is provided in a known manner on third substrate layer 33, for example, on a side that is closer to second side S2. However, it will be appreciated that pattern 4 may also be formed on the opposite side of third substrate layer 33. The material forming pattern 4 is opaque, such that a watermark effect can be obtained when substrate 1 is viewed from first side S1 against white light, i.e., in transmission. In such a case, although not shown in the figures, the shape of pattern 4 can be seen from first side S1, in combination with the portion of layer of laser-engravable material 2 that is visible from first side S1. Here, it will be appreciated that, after personalization, i.e., after laser-engraving image 12, the material forming layer of laser-engravable material 2 may have a property, in particular, an opacity and / or a thickness, such that laser engraved first image 12 disappears when security document 10 is viewed in transmission.

[0034] In some embodiments, pattern 4 has a shape that corresponds to a shape of at least one of at least one third window 2a and at least one second window 3. This is shown in Fig. 3. In Fig. 3, the top part shows second side S2 of security document 10 prior to personalization, and the bottom part shows second side S2 of security document 10 after personalization, in particular, after laser-engraving a second image 14 from second side S2, as will be described in more detail in the following.

[0035] As used herein, the expression "pattern 4 has a shape that corresponds to a shape of at least one of at least one third window 2a and at least one second window 3" is to be understood such that the shapes of pattern 4 and the at least one of at least one third window 2a and at least one second window 3 are similar or identical, while the sizes may be different, such that an observer can immediately identify a match between the different shapes. This results in that, when security document 10 is viewed from first side S1 against white light, both the shape of pattern 4 and the shape of the region of overlap between at least one second window 3 and at least one third window 2a can be observed, and it can be verified that the shapes correspond to each other. In this manner, the at least one third window 2a and the at least one second window 3 are interlocked with pattern 4. It can be immediately seen from Fig. 3 that this also applies when security document 10 is viewed from second side S2 under white light, i.e., in reflection. Also in this case, pattern 4 can be seen against the background of the portion of layer of laser-engravable material 2 covering first window 6. A further interlocking could be created by adapting the shape of first window 6 to the shape of pattern 4, i.e., such that said shapes also correspond to each other.

[0036] As mentioned above, in some embodiments, pattern 4 overlaps first window 6 when viewed along thickness direction d, and is visible when substrate 1 is viewed from first side S1 against white light.

[0037] In other embodiments, the above-described pattern is formed as a pattern 8 overlapping at least one second window 3 and at least one third window 2a when viewed along thickness direction d. This is shown in Fig. 4. Pattern 8 is visible when substrate 1 is viewed from first side S1 under white light. This is a result of pattern 8 being disposed in portion 1a of substrate 1 that is visible through at least one third window 2a and at least one second window 3 when substrate 1 is viewed from first side S1 under white light. Here, it will be appreciated that, in some embodiments, the pattern may include the previously-described pattern 4 in addition to pattern 8 shown in Fig. 4. The same effects as described above may be obtained when pattern 4 is included.

[0038] Fig. 5 shows plan views of first substrate layer 31 including first window 6 and at least one second window 3 and of second substrate layer 32, on which layer of laser-engravable material 2 is provided. In the example shown in Fig. 5, two second windows 3 and two third windows 2a are provided. Accordingly, pattern 8 is also provided as two separate portions in correspondence to the two second windows 3 and the two third windows 2a, as indicated in Fig. 4. As a result, when security document 10 is viewed from first side S1 under white light, the two portions of pattern 8 can be observed via the region of overlap between the two second windows 3 and the two third windows 2a. This is shown in the insert in Fig. 5, which again shows a portion of security document 10 after personalization by laser engraving first image 12 in layer of laser-engravable material 2.

[0039] As shown in Fig. 6, in the present embodiment, pattern 8 (and also pattern 4, if present) is visible when substrate 1 is viewed from second side S2 under white light. In Fig. 6, the top portion shows a plan view of first substrate layer 31 from second side S2, which illustrates first window 6 and the two second windows 3. The bottom portion of Fig. 6 shows second side S2 of substrate 1 after personalization by laser engraving pattern 8 and layer of laser-engravable material 2, which will be described in more detail below.

[0040] In some embodiments, pattern 4, 8 includes a laser-engravable material and is configured to have a second image 14 laser engraved in the same from at least one of first side S1 and second side S2. In the exemplary embodiments shown in Figs. 3 and 6, pattern 4, 8 is configured to have second image 14 laser engraved in the same from second side S2. In some embodiments, as shown in Figs. 2 and 5, alternatively or additionally, pattern 4, 8 is configured to have first image 12 laser engraved in the same from first side S1, in continuity with the image that is laser engraved in layer of laser-engravable material 2. If layer of laser-engravable material 2 and pattern 8 have different colors, this results in that different portions of laser engraved personalized first image 12 also have different colors, in correspondence to the different regions.

[0041] In some embodiments, layer of laser-engravable material 2 has a first chromatic color, for example, blue, as in the Mirage security feature of HID, and pattern 4, 8 has a second, different chromatic color, for example, red, when viewed under white light. This results in a clear distinction between the different portions of layer of laser-engravable material 2 and pattern 4, 8 both before and after personalization.

[0042] As shown in Figs. 3 and 6, in some embodiments, layer of laser-engravable material 2 is visible when substrate 1 is viewed from second side S2 under white light, and is configured to have a third image laser engraved in the same. In some embodiments, the third image may be different from second image 14. In some embodiments, the third image may be the same as second image 14. In other words, second image 14 may be continuously engraved in both pattern 8 and the bottom surface of layer of laser-engravable material 2 from second side S2. For example, personalized data such as a date of birth of the holder of security document 10 can be laser engraved from second side S2 in such a manner, as shown in Figs. 3 and 6. This results in an additional interlocking of different security features, because the same image 14 can be laser engraved in a continuous manner on different portions inside substrate 1, in particular, provided at different depths inside substrate 1.

[0043] As shown, for example, in Fig. 2, in some embodiments, at least one third window 2a is surrounded by laser-engravable material of layer of laser-engravable material 2. In other words, layer of laser-engravable material 2 defines the outline or shape of at least one second window 2a.

[0044] In the embodiments shown in Figs. 2 and 6, first window 6 and at least one second window 3 are formed as separate windows (cutouts, punchouts or the like) in first substrate layer 31. In other embodiments, however, as shown in Figs. 7 and 8, first window 6 and at least one second window 3 are continuous. In such embodiments, however, at least one third window 2a may still be surrounded by laser-engravable material of layer of laser-engravable material 2, as shown in the bottom portion of Fig. 7. This results in the region of overlap between at least one third window 2a and at least one second window 3 being defined by the shape of at least one third window 2a. Accordingly, this region of overlap can be observed from fist side S1 when substrate 1 is viewed under white light, as shown in the insert in Fig. 7. The same effects as those described with respect to Figs. 4 to 6 can be obtained.

[0045] In some modifications of the embodiment that is shown in Figs. 7 and 8, pattern 8 may be formed such that not all third windows 3 are covered by pattern 8. This results in that, for example, one or more of the windows defined by the region of overlap between the windows 3 and at least one third window 2a remains transparent.

[0046] As previously mentioned, the laser-engravable material of layer of laser-engravable material 2 and pattern 8 may be any appropriate material which is suitable to have an image laser engraved in the same by varying one or more laser parameters. In some embodiments, the materials of layer of laser-engravable material 2 and pattern 8 may be the same material, or they may be different materials. Each laser-engravable material may include a metallic material, preferably, a mixture of a metallic material and an organic material, more preferably with a ratio between 1:2 and 2:1. Optionally, the metallic material may include metallic pigments, for example, one or more of Al, Ag, Au, Ze, Fe and Cu pigments.Industrial applicability

[0047] With the above-described configurations, additional layers of security for a personalizable security document 10 can be provided by interlocking two or more security features provided in a window of a security document.

[0048] Personalizable security document 10 may be formed in any appropriate manner, as long as an opaque first substrate layer 31 including first window 6 and at least one second window 3 is provided, and a layer of laser-engravable material 2 is provided on a second substrate layer 32 in the above-described manner, i.e., aligned with the at least one second window 3 such that a portion 1a of substrate 1 disposed below first substrate layer 31 is visible through at least one third window 2a and at least one second window 3 when substrate 1 is viewed from first side S1 under white light. It should be noted that it is not necessary that the entire first substrate layer 31 is opaque. It is sufficient that a portion of first substrate layer 31 surrounding windows 3 and 6 is opaque. In some embodiments, first substrate layer 31 may not be made of an opaque material, but the opacity may be the result of applying a coating, such as an opaque ink, on first substrate layer 31.

[0049] An exemplary method of personalizing security document 10 in accordance with the present disclosure includes the step of providing a personalizable security document 10 having a substrate 1 having a first side S1 and a second side S2 opposite to the first side in a thickness direction d of the substrate 1, the substrate 1 including a plurality of substrate layers 31, 32, 33, 34, 35 laminated with each other, a first window 6 and at least one second window 3 formed in a first substrate layer 31 of the plurality of substrate layers, the first substrate layer 32 being opaque when viewed under white light, and a layer of laser-engravable material 2 provided on a second substrate layer 32 of the plurality of substrate layers disposed above the first substrate layer 31, the layer of laser-engravable material 2 being configured to have a first image 12 laser engraved in the same from the first side S1, the layer of laser-engravable material 2 covering the first window 6 when viewed along the thickness direction d. At least one third window 2a is formed in the layer of laser-engravable material 2. The at least one third window 2a is aligned with the at least one second window 3 such that a portion 1a of the substrate 1 disposed below the first substrate layer 31 is visible through the at least one third window 2a and the at least one second window 3 when the substrate 1 is viewed from the first side S1 under white light. The security document further has a pattern 4, 8 printed on a third substrate layer 33 of the plurality of substrate layers disposed below the first substrate layer 31. The pattern 4, 8 includes a laser-engravable material and is configured to have a second image 14 laser-engraved in the same from at least one of the first side S1 and the second side S2. The method further includes a step of laser engraving the second image 14 in the layer of laser-engravable material 2 and the pattern 4, 8 from the second side S2 by varying one or more laser parameters. Preferably, a laser power is less than 30 W, more preferably, 20 W or less, and the second image 14 is formed as a continuous image in the layer of laser-engravable material 2 and the pattern 4, 8.

[0050] Exemplary laser parameters that are used to engrave personalized image 3a are a laser wavelength between 530 nm and 1060 nm, a laser speed between 100 mm / s and 4000 mm / s, a laser repetition rate between 10 kHz and 100 kHz, and a laser power of less than 30 W, preferably less than 20 W.

[0051] It will be appreciated that the foregoing description provides examples of the disclosed systems and methods. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the general disclosure.

[0052] Recitation of ranges of values herein are merely intended to serve as a shorthand method for referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All method steps described herein can be performed in any suitable order, unless otherwise indicated or clearly contradicted by the context.

[0053] Although the preferred embodiments of the present disclosure have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.

Examples

Embodiment Construction

[0010]The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described herein are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of protection. Rather, the scope of protection shall be defined by the appended claims.

[0011]Windows formed in a security document are strong security elements of a such a security document. The windows are secured by adding security elements inside the window. Some examples include security features like Window Lock, Diamond ID, the Mirage security feature of HID, etc.

[0012]It has been realized that the security of a document can be further increased by interlocking several windows in a single securi...

Claims

1. A personalizable security document (10) comprising: - a substrate (1) having a first side (S1) and a second side (S2) opposite to the first side in a thickness direction (d) of the substrate (1), the substrate (1) including a plurality of substrate layers (31, 32, 33, 34, 35) laminated with each other; - a first window (6) and at least one second window (3) formed in a first substrate layer (31) of the plurality of substrate layers, the first substrate layer (32) being opaque when viewed under white light; - a layer of laser-engravable material (2) provided on a second substrate layer (32) of the plurality of substrate layers disposed above the first substrate layer (31), the layer of laser-engravable material (2) being configured to have a first image (12) laser engraved in the same from the first side (S1), the layer of laser-engravable material (2) covering the first window (6) when viewed along the thickness direction (d); and - at least one third window (2a) formed in the layer of laser-engravable material (2), wherein the at least one third window (2a) is aligned with the at least one second window (3) such that a portion (1a) of the substrate (1) disposed below the first substrate layer (31) is visible through the at least one third window (2a) and the at least one second window (3) when the substrate (1) is viewed from the first side (S1) under white light.

2. The security document of claim 1, wherein the portion (1a) of the substrate (1) is substantially transparent when the substrate (1) is viewed from the first side (S1).

3. The security document of claim 1 or 2, further comprising a pattern (4, 8) printed on a third substrate layer (33) of the plurality of substrate layers disposed below the first substrate layer (31).

4. The security document of claim 3, wherein the pattern (4, 8) has a shape that corresponds to a shape of at least one of the at least one third window (2a) and the at least one second window (3).

5. The security document of claim 4, wherein the pattern (4) overlaps the first window (6) when viewed along the thickness direction (d), the pattern (4) being visible when the substrate (1) is viewed from the first side (S1) against white light.

6. The security document of any one of claims 3 to 5 when depending on claim 1, wherein the pattern (8) overlaps the at least one second window (2a) and the at least one third window (3) when viewed along the thickness direction (d), the pattern (8) being visible when the substrate (1) is viewed from the first side (S1) under white light.

7. The security document of any one of claims 3 to 6, wherein the pattern (4, 8) is visible when the substrate (1) is viewed from the second side (S2) under white light.

8. The security document of any one of claims 3 to 7, wherein the pattern (4, 8) includes a laser-engravable material and is configured to have a second image (14) laser engraved in the same from at least one of the first side (S1) and the second side (S2).

9. The security document of any one of claims 3 to 8, wherein the pattern (4, 8) has been printed on the third substrate layer (33) by flexography, screen printing or inkjet printing, and has a thickness along the thickness direction (d) of between 5 µm and 20 µm.

10. The security document of any one of claims 3 to 9, wherein the layer of laser-engravable material (2) has a first chromatic color, for example, blue, and the pattern (4, 8) has a second, different chromatic color, for example, red, when viewed under white light.

11. The security document of any one of claims 1 to 10, wherein the layer of laser-engravable material (2) is visible when the substrate (1) is viewed from the second side (S2) under white light and configured to have a third image laser-engraved in the same from the second side (S2).

12. The security document of any one of claims 1 to 11, wherein the at least one third window (2a) is surrounded by laser-engravable material of the layer of laser-engravable material (2).

13. The security document of any one of claims 1 to 12, wherein the first window (6) and the at least on second window (3) are continuous.

14. The security document of any one of claims 1 to 13, wherein the laser-engravable material includes a metallic material, preferably a mixture of a metallic material and an organic material, more preferably with a ratio between 1:2 and 2:1, optionally, wherein the metallic material includes metallic pigments, for example, one or more of Al, Ag, Au, Zn, Fe and Cu pigments.

15. A method of personalizing a security document (10), comprising: - providing a personalizable security document (10) in accordance with claim 8 or any one of claims 9 to 14 when depending on claim 8; and - laser engraving the second image (14) in the layer of laser-engravable material (2) and the pattern (4, 8) from the second side (S2) by varying one or more laser parameters, preferably, wherein a laser power is less than 30 W, more preferably, 20 W or less, and the second image (14) is formed as a continuous image in the layer of laser-engravable material (2) and the pattern (4, 8).

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