NL1043530B1 - Method for securing on surface applicated data elements on synthetic (polymer) documents - Google Patents

Abstract

The invention relates to a method for securing on surface applicated data elements on a data carrying synthetic document against manipulation and substitution by fusing a surface workpiece to the document, covering and sealing the data element. Fusion is being established by melting the used materials at their interface area and solidification after cooling. Laser radiation is used for generating the necessary heat by using a laser radiation absorbent layer at the joined surface interface or by combining a laser radiation transmissive material with a laser radiation absorbent material.

Description

Method for securing on surface applicated data elements on synthetic (polymer) documents The invention relates to the permanent joining of a surface workpiece or “patch” as used herein and in the appended claims, to a second workpiece, being a synthetic data carrying document. The term data carrying document or “document” as used herein and in the appended claims, is intended to include a large variety of documents and instruments such as a financial cards, identification (including a National ID or Driver's License) cards, immigration cards, electronic passport pages, gift cards, documents for holding permanent and long lasting records such as medical records or security cards, or other plastic cards used for promotion of a product or organization. The invention allows for the use of various materials.

The permanent joining of the patch to the document is to securely seal on surface applicated data elements on document or cavity embedded other elements in the document against manipulation or substitution. The data elements can be of varying nature such as alpha numeric text, symbols, barcodes and the document bearers photograph as the main element for identification.

The invention provides a better solution to presently used methods due to its permanent joining characteristic of the two components, being the patch and document In a broader view the patch can be considered and used as a separate additional security feature of its own nature and providing its own specific contribution to the security of the documents Status of technology In the generation of documents different technologies are being used.

The most common process involves mass production of blanc, generic and identical documents using different type of polymers as Polycarbonate, PVC, ABS, PET etc whereas in a later stage, and usually at another location, data elements related to the bearer, user or function of the document will be added during the so called personalization process.

A photo of the document bearer is the most important element for identification and authentication.

These blank, generic documents are produced in a well known and widely distributed process as mono layer or as sandwich multilayer construction of which the individual layers are being inter connected by thermal lamination, using adhesive materials where needed

The single layers of this sandwich construction involve coloured, usually white, materials and transparent materials, that can be of laser radiation sensitive formulation. Thickness of the layers range form several to hundreds of microns.

The sandwich construction itself varies in number of layers, depending on future function, security features used, required visual characteristics, used technology for the application of data elements and industry standards. The construction can be either opaque, transparent in various degrees or locally transparent.

Before the inter connecting lamination process takes place several layers can contain features as for instance graphical patterns created by technologies as offset printing or ink jet printing. For the personalization process, the application of data elements to the generic blank document, two basic solutions are well known and broadly in use. An embedded solution, where data elements (e.g. photo) are created within the internal document sandwich structure as by laser technology and a surface solution where data elements are added to the surface of the document. A combination of the two solutions is also possible where per data element a choice for one or even a combination of the two is made. With the embedded solution, based on laser technology and called laser engraving, one or more of the sandwich layers, made sensitive for laser radiation, is being exposed by a modulated laser beam. This controlled laser beam creates local carbonization, blackening, of the material following the laser beam travel exposure path, resulting in the image of the required data element in the related layer. This layer can be the outer layer or an underlying more internal layer. The carbonization, blackening, is irreversible, adding to the security. With the surface solution data elements are added to the surface of the document by the use of technologies as ink jet printing and dye sublimation using CMYK based concepts for colour images as known from traditional printing. The fact that these data elements are applied to the surface imposes additional risks as to manipulation and substitution as well as durability and additional measures as on top adhesive foils or varnishes to cover these data elements are necessary. In practice these foils and varnishes proof to be temper sensitive and easy to remove. Related invention provides an improved solution for the security of surface applicated data elements by creating an embedded situation after personalizeation

Description of the main principle The invention relates to a method of sealing on surface applicated data elements or in a cavity embedded other elements by fusing a covering or closing patch with the underlying document. The patch herein can vary in size, shape, thickness and material and can contain printed graphical structures, tactile structures, lens structures for optical effects optionally interacting with underlying elements or graphical structures after fusion.

Fusion of the two workpieces result from a locally created melting and solidification of the materials of the two workpieces at the interface area using laser welding technology.

Laser welding of plastics is a known form patent US2007/0051461 A1 and US656315 B2 and a registered trademark as for instance Clearweld® and is based on combining two workpieces in a joined fashion of which one is laser radiation transmissive and the other laser radiation absorbent. Controlled laser radiation passes through the transmissive workpiece into the absorbent workpiece, generating heat at the interface area, and melting the workpieces at the joint interface area which upon cooling solidifies.

The process requires a strict tuning between material characteristics as to laser absorption and the wavelengths from the used lasers. Material laser absorption characteristics can be influenced by additives however could have influence on the material's colour.

Absorption characteristics are not by default a function of colour. Most application use lasers operating in the Near Infra Red range, such as diode and Nd:YAG lasers. For applications where materials are being used that are transparent within the visual spectrum and where colour deviation is not allowed another solution is available. Herein an absorbent layer is applied to the interface area of the two workpieces. Laser radiation is now generating heat in this absorbent layer allowing for the welding process. Related intervention is primarily based on the use of such absorbent layer but not limited to and applies also for materials with absorbent resins and additives. The range of materials suitable for this type of welding is known within the industry and information is readily and free available.

Description of the invention For clarification reference is made to enclosed drawings. All drawings being schematically only and solely exemplary and not limited to, showing an example based on a surface applicated photograph as data element on a document and with a rectangular patch with a patch outline area absorbent layer as explained later.

Figure 1 shows a document (1} with a surface aplicated data element (2) and the rectangular transparent patch (3) with absorbent layer (4) at the patch outline to be positioned over the designated area to seal. Figure 2. shows a cross section of the generic document (1) with on surface applicated data element (2), as per the used personalization system applied on the document outer transparent layer (5), before sealing off by the patch (3) through laser welding using the absorbent layer (4).

Figure 3. shows the next step, preferably within the same personalization system but not limited to, where the patch (3) is mechanically positioned on the document (1} in the right position and rotation angle. Controlled laser radiation (6) is started then, creating a local melting point (7) following the predefined laser exposure travel path (8). Figure 4, shows the same cross section of the document (1), in the fused status with welded patch (3) permanently and indissolubly connected to the outer transparent layer (5) of the documents along the welded area.

The applied patch is pre manufactured in the material of choice, defined size and shape, thickness and optionally with a tactile structure, lens structure or other graphical elements. Depending on the material various production methods as lamination, extrusion, thermoforming are available for producing the patch Using the absorbent layer solution gives several options for the process setup as to the way of application of the absorbent layer and the laser radiation exposure principle.

The professional system design specialist has several options for designing the system setup to obtain the optimized solution for the designated product: - Deciding on the way of application of the absorbent layer - Deciding on what workpiece to apply the absorbent layer on - Deciding on what surface coverage design principle to use at applying the absorbent layer - Deciding on what laser radiation exposure design principle to use Deciding on the way of application of the absorbent layer: Several options for the way of application of the absorbent layer are available to the manufacturer of the personalized document. The options are dispensing unit, spraying with optional use of masking, applying film or by use of inkjet technology as known from patent WQ002083798 A1 Deciding on what workpiece to apply the absorbent layer on: 5 The professional specialist has the system design option as to on which of the two workpieces the absorbent layer is applied. Options as dispensing, spraying or film are best suitable as way of application to the patch in the pre manufacturing phase of the patch itself. The Inkjet based option is best suitable as way of application on the document whereas integration in the personalization system can be as part of or extension of the data element applying inkjet system within the personalization system.

Deciding on what surface coverage design principle to use at applying the absorbent layer: Applying the absorbent layer can follow different basic coverage design principles as full area coverage of the patch shape area, the patch shape area outline and the data element image outline area coverage. As an example figure 5 shows a table with the coverage design principles based on a photograph as on surface applicated data element and a rectangular shaped patch The full area coverage is best suited for application on the patch during pre-manufacturing of the patch but not limited to and also allow for solution using the inkjet technology on the document in the personalization system after having applicated the data element.

The patch shape area outline coverage can be used in both ways, on the pre-manufactured patch or on the document in he personalization system. The data element image outline coverage principle is best suited for application on the document by the ink jet system within the personalization system for optimized positioning alignment in relation to the applicated data element itself.

Deciding on what laser radiation exposure design principle to use: The path the laser will travel for initiating the welding is predetermined by the related data element and the radiation exposure design principle. Similar to the coverage design principle for the application of the absorbent layer the laser can also do a full patch area exposure, a patch shape area outline exposure and a data element image outline area exposure.

Asan example figure 5 shows a table with the exposure design principles based on a photograph as on surface applicated data element and a rectangular shaped patch.

The combinations of area coverage of the absorbent layer and the area exposure of the laser allows for an optimized solution towards the data element to be secured and its possible interaction between various element as the absorbent layer, laser exposure or any optional other features within the relevant area. Other considerations could be process time versus output or cost requirements of the personalization system As for both laser engraving and the laser welding process NIR lasers as Nd: Yag lasers, operating at 1064nm, are used a combined function within the personalization system is feasible.

The use of the same type of laser offers an additional optional design combination as reflected in figure 5, table options A4 and AS.

Known and regularly used, several on surface applicated photograph solutions, based on inkjet technology, generate the coloured image from the CMY combination only and adding the black(K) contrast component from laserengraving a grey scale derived image of the same photograph underneath the colour image in the underlying layer. This laser engraving of the underlying greyscale image can be combined with the laser radiation exposure used for fusing the patch to the document. This is refelected in the pixel facial image in figure 5.

Additional claims The invention also allows for a configuration which the on surface applicated data element is positioned in a surface indent of the document, created during the manufacturing process of the blank generic document during lamination, milling or any other means, allowing for a less protruding patch or to allow for better focal length alignment with the underlying layer in case of lens structure. See figure 6 The invention also allows for effectively using the patch as an additional separate security feature of its own nature, optionally personalized, being applied to the document during the personalization process.

The invention also allows for a configuration in which the patch can effectively configured and used as an insert in a blank generic document, or in its constructive core layer as one of the components for the sandwich construction before lamination, to create a locally fully transparent area, and subsequent derivatives, as security feature. Figure 7. Provides an example of a possible construction. Here the sandwich contains a central core layer of transparent material (10). All other layers are punched through and in the first steps the resulting cavities are being filled with a smaller patch (11) also with an absorbent layer (12} to allow welding to the core layer {10}. This process needs to be repeated for the other side of the document. Final closure is done by a larger patch (3) also having an absorbent layer (4) to allow for welding to the earlier installed patches. Also here the process requires repetition for the other side.

The invention allows also for a configuration in which the patch can effectively used as a seal to close a pre-manufactured cavity in a document, or in its constructive core layer as one of the components for the sandwich construction before lamination, encapsulating an embedded mechanical element (9) See figure 8. In this case the patch could be of opaque visual nature. The need for absorbent layer is depending on the absorption characteristics of the materials in which cavity is created.

Claims (4)

Conclusions Claims 1. A method for protecting the surface layer (5) of a data-carrying polymer document (1) applied data elements (2) of various possible types against manipulation and substitution by applying a covering and sealing surface element (3) which, by fusing the materials of both components, leads to a homogeneous and inseparable whole. The fusion makes the invention distinctive and an improvement over other methods. Fusing is achieved by using laser welding technology in which focused laser radiation is converted into heat in the contact surface of both components by using an applied laser absorbing layer (4) or by using a combination of a laser transmissive material with a laser absorbing material. The covering surface element may comprise various sizes, shapes, thicknesses and configurations. The invention can be used for a wide range of materials. The invention describes the possibilities for the skilled person with regard to choices for combinations of application of the absorbent layer and method of laser exposure in the process of personalization 2. The invention can be used for a document according to claim 1, wherein the data element is arranged in a recessed area of the document surface (Figure 6) and wherein after application of the covering surface element, the data element may or may not be recessed or less protruding towards the surface. relative to or flush with the document surface. With a surface element with a lens structure, this offers opportunities to optimize the focus length of the lens relative to lower layers for intended interactions. 3. The invention can be used for a document according to the foregoing claims, wherein the surface element itself functions as an independent additional, whether or not personalized, security element. 4. The invention can be used for a document wherein, according to one or more preceding claims, a surface element is used as a filling element in previously created cavities in the document in order to obtain a locally fully transparent part. The invention can be used for a document in which, according to one or more of the foregoing claims, the surface element serves to cover and close a cavity and a placed element (9), which has been applied at an earlier stage. See figure 8.