PERSONALIZABLE SECURITY DOCUMENT AND METHOD OF MANUFACTURING THE SAME

A personalizable security document (10) includes a security feature (3b) including a combination of a plurality of different features. In particular, the security feature (3b) may include a laser-engraved image in a first layer (16), and one or more fluorescent inks (7a, 7b) in further layers (27a, 27b), which are disposed below the first layer. Optionally, a watermark (8) may also be provided in a lower layer (18). A laser-engraving of the image is performed from a first side (S1) of the substrate (1) such that patterns formed by the inks (7a, 7b) are not affected. Under white light, the laser-engraved image can be viewed from the first side of the substrate, whereas multi-color fluorescence of the patterns can be observed from the second side (S2) under UV light.

TECHNICAL FIELD

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

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 special features like the Mirage technology of the present applicant.

There are also other approaches for providing security features for such identification documents or other security documents, for example, using fluorescent inks to provide features which are only visible under UV light. US 2014/0319817 A1 discloses a security document comprising a first pattern and a second pattern overlapping to define a security pattern. The two patterns differ in their fluorescent properties, such that upon irradiation with a first wavelength, the light emitted by the first pattern is dominant, and upon irradiation with a second wavelength, the light emitted by the second pattern is dominant. EP 3 674 099 A1 discloses laminates, identification documents, and methods for verifying identification documents. WO 2013/191762 A1 discloses a static dissipating laser engravable film.

The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems, without being limited to a particular type of security document.

SUMMARY OF THE DISCLOSURE

According to one aspect of the present disclosure, a personalizable security document comprises a substrate having a first side and a second side opposite to the first side in a thickness direction of the substrate, and a security feature formed in the substrate and extending through at least part of the substrate along the thickness direction. The security feature includes a first layer including a laser-engravable portion configured to have an image laser engraved in the same, the laser engraved image being visible when the substrate is viewed from the first side under white light, and a second layer arranged below the first layer, the second layer including a first pattern overlapping at least in part the laser-engravable portion when viewed along the thickness direction, the first pattern being visible at least in part when the substrate is viewed from the second side under UV light. The security feature further includes a third layer arranged below the second layer, the third layer including a second pattern overlapping at least in part the laser-engravable portion when viewed along the thickness direction, wherein each of the first pattern and the second pattern is visible at least in part when the substrate is viewed from the second side under UV light, the first pattern and the second pattern emitting light of a first color and a second color, respectively, upon irradiation with the UV light.

In another aspect of the present disclosure, a method of manufacturing a personalizable security document comprises the steps of providing a first substrate layer including a laser-engravable portion, providing a second substrate layer including a first pattern being visible under UV light, and arranging the second substrate layer below the first substrate layer such that the first pattern overlaps at least in part the laser-engravable portion. The method further comprises the step of combining the first layer with the second layer to form a substrate of the personalizable security document, wherein the laser-engravable portion is laser-engravable from a first side of the substrate, and the first pattern is visible at least in part when the substrate is viewed from a second side opposite to the first side in a thickness direction of the substrate under UV light. The method further comprises providing a third substrate layer including a second pattern being visible under UV light, arranging the third substrate layer below the second substrate layer such that the second pattern overlaps at least in part the laser-engravable portion, and combining the third layer with the first layer and the second layer to form the substrate, wherein each of the first pattern and the second pattern is visible at least in part when the substrate is viewed from the second side under UV light, the first pattern and the second pattern emitting light of a first color and a second color, respectively, upon irradiation with the UV light.

In yet another aspect, the present disclosure relates to a method of personalizing a security document, comprising the steps of providing a personalizable security document in accordance with the first aspect, and laser engraving a personalized image in the laser-engravable portion from the first side of the substrate.

In a further aspect, the present disclosure relates to a personalized security document obtained by the method of the previous aspect.

Other features and aspects of the present disclosure will be apparent from the following description and the accompanying drawings.

DETAILED DESCRIPTION

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.

The present disclosure is based at least in part on the realization that it may be advantageous to provide a security feature which combines different features in a single laserable window provided in a security document, for example, a polycarbonate card which is used as an identification document. It has been realized that a specialized ink can be used, which can be laser engraved, while one or more additional inks can be included, which may not react to the laser engraving. In this manner, level1(detectable without additional equipment) and level2(requiring additional equipment to be detected) security features can be engraved in the same window, while the specific features of the additional inks are not destroyed by the laser engraving.

In addition, it has been realized that the combination of the laser-engravable ink with one or more non-laser-engravable inks provides additional security, as specific laser parameters must be used for engraving the image in the laser-engravable ink while assuring that the additional inks are not affected by the laser engraving. In other words, if a forger were to attempt to forge the security document, he might not possess the knowledge required for successfully engraving the laser engraved image without destroying either one or more of the additional features, or the entire security window of the document, for example, when the laser power is set too high.

In addition, as the additional inks, which are not engraved by the laser, are provided in respective layers of a substrate of the document, a document becomes difficult to forge. In this respect, it has also been realized that it is advantageous to provide two or more, for example, fluorescent inks in such a manner in the security window that the respective inks overlap at least in part. In this manner, a multi-color fluorescence effect can be achieved, where three or more colors are visible under UV light.

With the above configuration, it becomes possible to use only a single laser for engraving a security image, while additional security features can be achieved due to use of the fluorescent inks, and providing a watermark or the like.

In addition, it has been realized that, by using a plurality of fluorescent inks, only a single UV light having a specific wavelength range can be used for observing the fluorescence features, and it is not necessary to use particular UV wavelengths to observe the security features.

FIG.1shows a plan view of an exemplary security document10in accordance with the present disclosure. As shown in theFIG.1, security document10includes a substrate1, for example, a polycarbonate or PVC substrate having a substantially rectangular shape. In particular, as shown inFIG.1, security document10may be a personalized security document, i.e. include an image11(for example, a photograph or the like) of a person to which the document belongs. Image11may be formed in an image region2provided on a first side S1of substrate1in a known manner.

In addition, as shown inFIG.1, document10includes a security feature3formed in substrate1, for example, in the shape of a rectangular window in which one or more security features can be provided. For example, as shown inFIG.1, security feature3may include a laser engraved image5, which may correspond to image11(for example, may be an inverse or negative of image11), in a laser-engravable portion5aof security feature3.

It will be appreciated that, after manufacturing, security document10may be a personalizable security document. In other words, image region2and laser-engravable portion5amay be empty, such that security document10is not personalized. Generally, such personalization will be carried out by the respective issuers of the security documents, for example, passports, identification cards, driver's licenses or the like.

FIG.2shows a schematic sectional view of a personalizable security document10in accordance with the present disclosure. As shown inFIG.2, personalizable security document10comprises substrate1having first side S1and a second side2opposite to first side S1in a thickness direction d of substrate1. For example, substrate1is formed by stacking a plurality of layers, for example, polycarbonate or PVC layers and combining them in an appropriate manner, for example, by lamination processes or the like. This is known to the skilled person, such that a detailed description will be omitted herein.

A security feature3ais formed in substrate1and extends through at least part of substrate1along thickness direction d. In the example shown inFIG.2, security feature3aextends from the uppermost layer to the second layer from the bottom of substrate1. In some embodiments, at least the portion of each layer in which security feature3ais formed is substantially transparent or at least semi-transparent for visible light.

In the embodiment shown inFIG.2, security feature3aincludes a first layer16including laser-engravable portion5a, which is configured to have image5laser engraved in the same. For example, laser-engravable portion5ais formed by a laser-engravable ink6provided in first layer16. In one example, ink6may be formed on a bottom surface of first layer16, for example, by screen printing or the like. However, it will be appreciated that, in other embodiments, ink6may be formed on a top surface of first layer16. First layer16may be covered by one or more protective layers (not shown). In other applications, first layer16may be the top layer of the stack of layers of substrate1. In any case, first layer16is configured such that image5can be laser engraved in laser-engravable ink6by using an appropriately configured laser. This will be described in more detail below.

Security feature3afurther includes a second layer17aarranged below first layer16, for example, with one or more intermediate layers provided between layers16and17a. It will be appreciated, however, that the intermediate layer(s) can also be omitted in other embodiments. Second layer17aincludes a first pattern27aoverlapping at least in part laser-engravable portion5awhen viewed along the thickness direction, as shown inFIG.2. In other words, when viewed from the first side S1or the second side S2in a direction perpendicular to the substrate surface, laser-engravable ink6at least partially covers first pattern27a, which may be formed by an ink7aexhibiting a fluorescence effect. Preferably, ink7amay be non-laserable, such that the properties of first pattern27aare not affected when laser engraving of laser-engravable ink6is performed.

First pattern27amay have any arbitrary shape, for example, comprising letters, symbols, polygonal or round or elliptic shapes, and the like. In the exemplary embodiment, ink7ais fluorescent ink, such that, upon irradiation of an excitation light having a predetermined wavelength, ink7aemits light having a different wavelength. For example, ink7amay be configured to be irradiated with UV light having a specific wavelength, and may emit light in the visible range.

Specifically, first pattern27ais provided such that it is visible at least in part when substrate1is viewed from the second side S2under UV light. In other words, when UV light having a wavelength which can excite ink7ais irradiated onto first pattern27a, first pattern27aemits visible light, which can exit from second side S2of substrate1and can be observed by an observer. In this manner, at least part of first pattern27acan be recognized under UV light.

As shown inFIG.2, as an additional feature, security feature3aalso includes a third layer17barranged below second layer17a. Again, one or more intermediate layers may be present in other embodiments. Third layer17bincludes a second pattern27boverlapping at least in part laser-engravable portion5awhen viewed along the thickness direction. In addition, second pattern27bis arranged such that each of first pattern27aand second pattern27bis visible at least in part when substrate1is viewed from second side S2under UV light. This is due to the fact that first pattern27aand second pattern27bemit light of a first color and a second color, respectively, which are different from each other, upon irradiation with UV light. This may be achieved in different manners. For example, second pattern27bmay be formed by a fluorescent ink7b, preferably also a non-laserable ink, which exhibits a fluorescence effect that is different from the fluorescence effect of ink7a. In one example, inks7aand7bmay be excitable by UV light having the same wavelength, but may emit visible light having different wavelengths. In other examples, first pattern27aand second pattern27bmay be configured to emit light in response to being irradiated with excitation light having different wavelengths. This can be achieved by using UV light including a specific wavelength range capable of generating the fluorescence of both inks7aand7b. For example, such a range may be from 254 to 354 nm, or from 100 to 400 nm. In other words, it will be appreciated that, in accordance with the present disclosure, preferably broadband UV light is used to observe security feature3a. When such broadband UV light is used, both first pattern27aand second pattern27bemit light in the visible range, which can be observed from second side S2.

Here, it is preferable that first pattern27aand second pattern27bpartially overlap when viewed along the thickness direction to define an overlap area27c, which will be described later with respect toFIG.8. Due to this overlap area, a three-color fluorescence effect can be observed from second side S2, because the color of the light emitted from overlap area27cwill appear different from the colors of light emitted by the non-overlapping parts of first pattern27aand second pattern27b. In some embodiments, first pattern27aand second pattern27bmay be formed by screen printing, flexo printing, or offset printing. It will be readily appreciated that, in other embodiments, more than two patterns can be provided in respective layers, for example, a third pattern in a third layer, a fourth pattern in a fourth layer, and so on, each exhibiting fluorescence under UV light. In this case, it will be understood that one or more additional overlap areas can be provided, such that more-than-three-color fluorescence can be obtained, if desired.

In some embodiments, security feature3amay further include a fourth layer18arranged below third layer17b, as shown inFIG.3. For example, fourth layer18may include a watermark8or the like formed in the same and overlapping at least in part laser-engravable portion5awhen viewed along the thickness direction. Watermark8is visible when substrate1is viewed from second side S2under white light and/or when substrate1is viewed from first side S1against white light, as will be described in more detail below. For example, watermark8may be printed onto fourth layer18by screen printing or offset printing or the like. The use and forming of such watermarks is well known to the skilled person, such that a detailed description will be omitted herein. The remaining configuration of the embodiment shown inFIG.3is the same as the configuration of the embodiment shown inFIG.2.

As previously mentioned, laser-engravable portion5ais formed by a laser-engravable ink6, the transparency of which can be changed by irradiation of laser light of a particular wavelength and having different laser intensity. In some examples, a grayscale image may be engraved by varying the laser power between a minimum value and a maximum value corresponding to grayscale values between 0 and 255. In this manner, for example, a negative (inverted) image of image11shown inFIG.1can be engraved in laser-engravable ink6by an appropriate laser engraving apparatus. It will be appreciated that ink6is not particularly limited, as long as it is suitable for laser engraving. For example, ink6may be the ink which is used in the Mirage technology of the present applicant. In the Mirage technology, each pixel in the engraved image has a different color value, depending on the grayscale value of a grayscale image to be engraved. For example, a color value of blue corresponds to white in the grayscale image to be engraved, and a color value of gold corresponds to black in the grayscale image to be engraved. In other words, a minimum laser power results in that ink6remains blue, whereas a maximum laser power results in that ink6turns golden.

An exemplary method of engraving laser-engraved image5is schematically shown inFIG.4. As shown inFIG.4, laser light L1is irradiated from first side S1of substrate1in the thickness direction to change the properties of laserable ink6(for ease of illustration, the respective layers and inks are not shown inFIG.4). Here, it is important to use a laser power which is not too high, but sufficient to change the properties of laserable ink6. If the power of laser light L1were too high, at least part of security feature3shown inFIG.4would be destroyed. Accordingly, individual features, which will be described in more detail in the following, could no longer be observed.

An appropriately configured (personalized) security document10in accordance with the present disclosure can exhibit the following effects. In other words, once laser-engraved image5has been successfully engraved in first layer16, image5aand patterns27a,27b, which are included in the respective layers17a,17b, as well as watermark8provided in fourth layer18, if present, can be observed.

For example, as shown inFIGS.5and6, substrate1can be viewed from first side S1and second side S2under white (visible) light, i.e. light which is perceived by the human eyes as white, for example, sunlight. Accordingly, when viewed from first side S1, laser-engraved image5formed in first layer16can be recognized as part of security feature3. However, first and second patterns27a,27bare generally not visible under white light. In addition, watermark8also cannot be observed from first side S1under white light.

Upon observation under white light from second side S2, however, watermark8can be observed. On the other hand, image5generally cannot be seen from second side S2. This is due to the laser engraving of portion5agenerally only affecting the top portion of ink6, but not the bottom portion of the same. Therefore, in embodiments where ink6is not transparent for visible light, the light is reflected by the rear surface of ink6, which appears as a uniform background. It should be noted that, for ease of illustration, the window including security feature3is shown at the same position in both the front view and the rear view inFIGS.5and6. Of course, it will be appreciated that the position of the security feature is in fact mirrored when substrate1is turned. The same applies toFIGS.7to10, and to any feature that is visible from both sides, as will be described below.

The situation is different when substrate1is viewed under UV light. In this case, when viewed from first side S1, image5can no longer be recognized, as ink6is generally not excited by UV light. On the other hand, when viewed from second side S2, multi-color fluorescence due to patterns27aand27bcan be observed. In the example shown, first pattern27ais a set of lines, and second pattern27bmay, for example, be formed between said lines. In addition, watermark8may still be visible under UV light, for example, may appear black. In addition, as shown inFIG.8, overlap area27c, in which first pattern27aand second pattern27boverlap, is also visible, but with a color which is different from the first color of light emitted by first pattern27aand the second color of light emitted by second pattern27b. In the example, overlap area27cis the letter “A” in the center. Therefore, a combination of a multi-color fluorescence and the watermark8is visible from second side S2under UV light.

The situation is again different when substrate1is viewed against white light, i.e. in transmission. In this case, as shown inFIG.9, watermark8can be observed from first side S1in the usual manner. In addition, one or both of fluorescent patterns27aand27bmay also be visible despite not being excited to be fluorescent. In the example shown inFIG.9, overlap area27ccan be recognized. The same applies when substrate1is viewed against white light from second side S2. In this case, watermark8can again be recognized, as can overlap area27c.

Although not shown in the figures, a further effect, which may be achieved in accordance with the present disclosure, is that first and/or second pattern27aand27bmay result in a small color shift which can be observed in security feature3when substrate1is provided on different surfaces and viewed under white light. For example, the color of image5may vary slightly due to the presence of inks7aand7bbelow laser-engravable portion5a, at least when patterns27aand27boverlap laser-engravable portion5ato a large extent.

INDUSTRIAL APPLICABILITY

With the above-described configurations, a security document such as an ID card, a driver's license or the like having a security feature which includes a combination of different features can be obtained. In particular, the combination of a specific laser engraving process with the presence of one or more additional features such as fluorescent inks and a watermark results in an increased security and makes it very difficult for a potential forger to create a valid security document or modify an existing security document.

An exemplary method of manufacturing a personalizable security document as described above comprises the following steps: in a first step, a first substrate layer including a laser-engravable portion is provided. Then, a second substrate layer including a first pattern being visible under UV light is provided, and the second substrate layer is arranged below the first substrate layer such that the first pattern overlaps at least in part the laser-engravable portion. Here, it will be appreciated that one or more intermediate layers can be provided between first substrate layer16and second substrate layer17a. In a further step, first layer16is combined with second layer17ato form substrate1of the personalizable security document. The resulting personalizable security document is configured such that laser-engravable portion5ais laser-engravable from a first side of substrate1, and first pattern27ais visible at least in part when substrate1is viewed from second side S2. Here, it will be appreciated that one or more intermediate layers or cover layers can be provided between and/or on top of first substrate layer16and/or second substrate layer17a, as long as laser-engravable portion5acan be laser engraved from first side S1, and first pattern27ais visible at least in part when substrate1is viewed from second side S2under UV light.

The method further comprises the step of providing a third substrate layer including second pattern27bbeing visible under UV light. The substrate layer17bmay be arranged below second substrate layer17asuch that second pattern27boverlaps at least in part laser-engravable portion5a. Third layer17bmay again be combined with first layer16and second layer17ato form substrate1, with one or more intermediate layers or cover layers to be provided, if desired. Again, first pattern27aand second pattern27bare visible at least in part when substrate1is viewed from second side S2under UV light, with first pattern27aand second pattern27bemitting light of different colors upon irradiation with UV light.

Optionally, a fourth substrate layer can be provided, with a watermark being printed onto fourth layer18, for example, by screen printing or offset printing or the like. Fourth substrate layer18is arranged below third substrate layer such that the watermark overlaps at least in part the laser-engravable portion5a. The fourth layer is then combined with the first layer16, the second layer17aand the third layer17bto form substrate1. The watermark is visible when substrate1is viewed from second side S2under white light and/or when substrate1is viewed from the first side S1against white light. In addition, watermark8may also be visible from second side S2under UV light. Here, it will be appreciated that the watermark may be printed onto fourth layer18before combining the same with first layer16, second layer17aand third layer17b. In other embodiments, however, the watermark may also be printed onto fourth layer18after combining the same with the other layers.

A personalizable security document obtained with the above-described methods may be personalized by laser engraving a personalized image5in laser-engravable portion5afrom first side S1of substrate1, as described above with reference toFIG.4. As a result, a personalized security document10can be obtained, which includes security feature3having the above-described features.

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.

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.

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.