Patent Description:
Security documents and booklets, such as passports, passbooks, identification documents, certificates, licences, cheque books and the like, commonly comprise one or more security sheets on which information is provided. A passport booklet typically comprises a cover, a plurality of internal visa pages and at least one security sheet displaying the personal data of the passport holder. Typically the visa pages are made from paper and are sewn together along a stitch line coincident with the fold of the document. The security sheet may be formed from a plastic, typically polycarbonate, and during its manufacture a number of thin plastic layers are laid over one another and laminated together, thereby forming a thicker plastic body. As this plastic body is typically rigid it is not directly attached at the stitch line or otherwise the booklet may not be able to bend effectively about the fold. Instead, the plastic body is attached about the fold using a flexible hinge or attachment layer embedded in and extending from the plastic body.

It is known to provide security features on the attachment layer. <CIT> or <CIT> discloses the application of a security print pattern and/or a security thread to a flexible band for connection to a data page and a booklet.

<CIT> discloses a security sheet comprising: a data sheet displaying data, the data sheet extending across a width from an inner edge to an outer edge; and an attachment layer attached to the data sheet, wherein the attachment layer is for attaching the data sheet in a security document, wherein the attachment layer comprises: a textile comprising a plurality of interlaced wefts and warps, wherein at least two warps and/or at least two wefts are formed from at least two yarns having different haptic and/or optical characteristics, wherein the yarns are fibrous and comprise a plurality of fibres attached together; and a hinge portion outside of the data sheet, wherein the at least two yarns having different haptic and/or optical characteristics are located on the hinge portion.

<CIT> discloses a flap being provided with a security feature such as an incision, embossing, imprint or thread. However, it is beneficial to enhance the security of documents against counterfeiting, forgery and attempts to dismantle the security documents.

Objects of the present disclosure include addressing these problems. An object of the present disclosure includes providing a strong and durable attachment between the security sheet and the rest of a security document. A further object includes increasing the difficulty of forging, counterfeiting and dismantling a security sheet including an attachment layer. Further objects include providing an improved method of manufacture of such a security sheet and a security document comprising such a security sheet.

The present disclosure therefore provides security sheets, security documents and methods in accordance with the claims. In particular, the attachment layer comprises a textile comprising at least two yarns having different haptic and/or optical characteristics. The at least two yarns having different haptic and/or optical characteristics form regions of the textile and attachment layer with the different haptic and/or optical characteristics. By having at least two yarns of different haptic and/or optical characteristics the technical complexity of recreating the security document is increased as both the haptic and/or optical characteristics and relative locations of the yarns will have to be matched.

In the present disclosure "yarns" are long, thin strand of materials forming part of the textile. For example, the yarns may comprise a material, such as a plant, mineral, animal or synthetic material, selected from at least one of cotton, wool, linen/flax, bamboo, silk, jute, modal, polyamide, polyester, viscose, glass, polypropylene, polyaramid, polyurethane, nylon, bonded nylon, rayon, acrylic, polycotton and/or other suitable fibres. Each yarn may be substantially circular, trilobal, fibrillated, grooved, dog bone or multiform in cross section. The yarns are fibrous and comprise a plurality of fibres attached together. The attachment may be mechanical and the yarns may not comprise a continuous body of plastic or the like. The yarns may comprise spun thread, in which a plurality of fibres may be twisted together. A ply structure of each yarn may be single or one-ply (i.e. single strands of fibres twisted together or single filament strands), multi-ply (i.e. a plurality of single yarns twisted together) or cord yarns (i.e. a plurality of multi-ply yarns twisted together in a twist direction). The at least two yarns may have different haptic and/or optical characteristics by virtue of being formed from different types (or compositions) or categories of yarns, each type varying from another type in the yarn material, yarn cross section, yarn ply structure, yarn twist direction, yarn diameter, yarn coating and/or yarn impregnation. The textile preferably comprises a plurality of interlaced wefts and warps formed from the at least two yarns. The textile is preferable woven or knitted. The yarns may form the textile by weaving, knitting, sewing or another interlacing method.

In the present disclosure "different optical characteristics" means that the at least two yarns are distinguishable from one another visually by the naked eye (i.e. by the human eye only without optical aids such as infrared cameras or the like). Preferably the at least two yarns are at least distinguishable from one another by the naked eye when viewed in reflected visible light incident upon them. However, in embodiments they may be additionally or alternatively distinguishable from one another by the naked eye when they are viewed in reflected non-visible light incident, in transmitted visible light and/or transmitted non-visible light. In the present disclosure "visible light" refers to light having a wavelength within the visible spectrum, which is approximately <NUM> to <NUM>, whilst "non-visible light" refers to light having wavelengths outside of this range (e.g. ultraviolet or infrared light). A user may therefore be able to authenticate the security document (i.e. confirm that it is not a counterfeit or forgery) based upon the optical sensory feedback from the human eye. If the different appearances of the at least two yarns are not identified as being correct the security document can be identified as being inauthentic. Such optical sensory feedback is achieved, in particular, by selecting yarns that have different physical characteristics that are perceptible by the human eye. The at least two yarns may therefore have different visible colours, different non-visible light properties (e.g. different luminescences), different opacities, different diameters and/or may scatter or reflect light to different degrees resulting in different levels of gloss.

In the present disclosure the term "different haptic characteristics" means that the at least two yarns are distinguishable from one another by human touch (i.e. they are detectable as being different to one another as tactile sensory feedback by the human body). A user may therefore be able to authenticate the security document (i.e. confirm that it is not a counterfeit or forgery) based upon the tactile sensory feedback resulting from the different textures. If the different textures of the at least two yarns are not identified as being correct the security document can be identified as being inauthentic. Such tactile sensory feedback is achieved, in particular, by selecting yarns that have different physical characteristics that are perceptible by human touch. The at least two yarns may therefore have different textures resulting from different diameters, a different surface roughness, a different hardness and/or a different stiffness.

The at least two yarns preferably have different visible colours when viewed in reflected light incident upon them. The colours may result from the appropriate selection of colours resulting from the yarn material, yarn coating and/or yarn impregnation for example with dyes. For example, the at least two yarns may comprise different dyes of different visible colours. In the present disclosure, the term "visible colour" means a colour which can be seen by the naked human eye under reflected visible light. It is most preferable that the visible light is white light, i.e. contains substantially all the visible wavelengths in more or less even proportion. The term colour includes achromatic hues such as black, grey, white, silver etc., as well as chromatics such as red, blue, yellow, green, brown etc. "Different colours" are those which clearly present a contrast to one another that is visible to the naked human eye in reflected light even without a close inspection. The difference might be in terms of the colour's hue or tone or both. For example, in preferred embodiments, two colours will be considered substantially the same as one another if the Euclidean distance <MAT> between them in CIELAB colour space (i.e. the CIE <NUM>*a*b* colour space) is less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>. The value of <MAT> is measured using the formula: <MAT>.

Where ΔL*, Δa* and Δb* are the distance between the two colours along the L*, a* and b* axes respectively (see "<NPL>). Conversely, if <MAT> is greater than or equal to <NUM>, more preferably <NUM> or yet more preferably <NUM>, the two colours will be considered different. The colour difference <MAT> can be measured using any commercial spectrophotometer, such as those available from Hunterlab of Reston, Virginia, USA.

The different colours may also be a result of the materials in the yarn exhibiting different colours at different viewing angles. Examples of such materials include thin-film interference structures, interference pigments, pearlescent pigments, liquid crystal film and pigments, photonic crystals and the like.

In the present disclosure "different non-visible light properties" means that the at least two yarns are distinguishable from one another by the human eye when viewed in non-visible, reflected or transmitted, light. In particular, the at least two yarns may have different luminescent properties (e.g. fluorescent or phosphorescent) and/or different infrared absorption characteristics. In particular, when viewed in ultraviolet light (i.e. a wavelength of <NUM>-<NUM>) or infrared light (i.e. a wavelength of <NUM> to <NUM>) incident upon the at least two yarns, the at least two yarns exhibit different colours (as defined above). The at least two yarns may comprise a suitable material, coating or impregnation (such as a luminescent ink coating or impregnated in the yarn) for achieving such effects. In a particular example the at least two yarns may have a first colour combination (e.g. the same or different colours) when viewed in visible light and a second colour combination (e.g. the same or different colours, but different to those of the first colour combination) when viewed in a combination of visible and non-visible light. The at least two yarns may also comprise photochromic and/or thermochromic components that alters the colours when ultraviolet light and/or heat are applied. Suitable inks and embodiments are disclosed in <CIT>.

In the present disclosure "different opacities" means that at least one yarn is more transparent (i.e. more light can be transmitted therethrough) than at least one further yarn. The at least two yarns may have different opacities and different colours and, in particular, the at least two yarns can be non-clear and coloured. For example, at least one yarn may comprise a transparent polymer (e.g. polyester) and at least one further yarn may comprise a substantially opaque cotton or other opaque polymer.

In the present disclosure "different diameters" means that at least one yarn has a greater diameter than at least one further yarn such that the difference in diameter is distinguishable by human touch and/or by the human eye. In particular, at least one yarn may be distinguishable by human touch and/or by the human eye from at least one adjacent yarn by virtue of having the yarns having different diameters. The diameters of at least one yarn may vary along its length and the different diameters may be distinguishable where the at least one yarn has a smaller or larger diameter to at least one further yarn. In particular, the diameter of at least one yarn may be at least approximately <NUM>%, at least approximately <NUM>%, at least approximately <NUM>%, at least approximately <NUM>% or at least approximately <NUM>% of the diameter of at least one further yarn. Each yarn may have a diameter in the range of from approximately <NUM> microns up to approximately <NUM> microns.

In the present disclosure "different levels of gloss" means that at least one yarn exhibits higher specular reflection (i.e. it exhibits higher gloss) than at least one further yarn (i.e. it has a more matt appearance). The difference in levels of gloss may be implemented by appropriate selection of the yarn material, yarn coating and/or yarn impregnation. For example, at least one yarn may comprise a high gloss, polished and smooth surfaced polymer (e.g. polyester) and at least one further yarn may comprise substantially matt cotton.

In the present disclosure "different surface roughness" means that at least one yarn has a higher surface roughness (i.e. a higher coefficient of friction) than at least one further yarn such that the difference in surface roughness is distinguishable by human touch. Different surface roughness can be achieved by appropriate selection of the yarn material, yarn cross section, yarn ply structure, yarn twist direction and/or yarn coating. For example, fibrillated yarn generally have a higher surface roughness that smooth and polished round yarns. At least one yarn may have a higher surface roughness compared to at least one further yarn by virtue of the yarns having different, preferably opposing twist directions. For example, a yarn with a twist in a first direction would be perceived as having a lower surface roughness when rubbed in the first direction. An adjacent yarn with a twist in a second direction opposite to that of the first direction would be perceived as having a higher surface roughness when rubbed in the first direction.

In the present disclosure "different hardness" means that at least one yarn has a hardness that is distinguishable from at least one further yarn by human touch. In a particular embodiment at least one yarn is a continuous soft-touch material (e.g. thermoplastic polyurethane, polyethylene or polypropylene) which is substantially softer than at least one further yarn. In particular, the soft-touch material may have a Shore hardness in the range of from approximately 30A to approximately 95A on the Shore A scale and up to approximately <NUM> on the Shore D scale. More preferably the soft-touch material may have a Shore hardness in the range of from approximately <NUM> to approximately <NUM> on the Shore A scale. The data sheet may comprise polycarbonate, which has a typical Shore hardness of 80D on the Shore D scale. The hardness may be determined according to the test set out it ASTM D2240. Different surface hardness can be achieved by appropriate selection of the yarn material. For example, a yarn of a polymer (e.g. polyester) will generally have a higher hardness than cotton.

In the present disclosure "different stiffness" means that at least one yarn has a stiffness that is sufficiently higher than the stiffness of at least one further yarn such that they are distinguishable from one another. Human touch may distinguish between a yarn of high stiffness and a yarn of low stiffness by virtue of the differences in their resilience to bending of the textile under human touch at their respective locations. For example, a yarn of lower stiffness may comprise cotton and a yarn of higher stiffness may comprise polyester or acrylic.

In a first arrangement at least two warps and/or wefts are formed from the at least two yarns having different haptic and/or optical characteristics. Thus the at least two yarns may form part of the regular array of warps and wefts of a textile. The warps preferably extend substantially parallel to one another and the wefts preferably extend substantially parallel to one another and preferably substantially perpendicular to the warps. In the present disclose "extend substantially parallel to one another" means that the warps or wefts generally extend parallel to one another through the textile, but may extend in different directions locally at the points of interlacing, weaving, knitting or stitching.

As a result, the yarns of different haptic and/or optical characteristics may extend substantially parallel and/or perpendicular to one another and substantially between opposing edges of the attachment layer. A plurality of warps may differ from a plurality of wefts in a first haptic and/or optical characteristic (e.g. a plurality of wefts may have a smaller diameter than a plurality of warps). At least two of the plurality of warps may differ from each other in at least one second haptic and/or optical characteristic (e.g. by having different colours), which is preferably different to the first haptic and/or optical characteristic. At least two of the plurality of wefts may differ from each other in at least one third haptic and/or optical characteristic (e.g. by having different levels of gloss), which is preferably different to the first and/or second haptic and/or optical characteristic.

In a preferred embodiment the textile comprises at least three warps and the outer distal and proximal warps are different visible colours and/or the warps between the distal and proximal warps are different visible colours to the distal and/or proximal warps. In a further preferred embodiment the textile comprises at least three warps formed from at least three yarns of different visible colours such that the at least three warps form a colour progression from a first visible colour to a different second visible colour. A colour progression would assist in identifying forgeries since it would be difficult for a forger to replace any of the warp yarns with exactly the correct hue to match the colour progression. Such a colour progression may also be formed by forming the warps of different non-visible light properties such that they exhibit a colour progression between first and second colours that are visible when viewed in non-visible light.

In a further preferred embodiment the wefts comprise yarns of different diameters. In particular, connection weft yarns that extend into the data sheet may have a smaller diameter than infill weft yarns that extend between the connection weft yarns but do not extend into the data sheet. Distal and/or proximal warps of a hinge portion of the attachment layer may have a large diameter than the other warps such that they form raised edges of the hinge portion to human touch.

In a second arrangement the attachment layer comprises a textile comprising at least one motif integrated therein and a background region. The background region comprises is formed from at least one background yarn, which may form interlaced warps and wefts. The at least one motif comprises at least one motif yarn having different haptic and/or optical characteristics to the at least one background yarn. Thus the at least one motif has different haptic and/or optical characteristics to the background region. The background region at least partially surrounds the at least one motif.

By having the at least one motif embedded and integrated in the textile the at least one motif need not comprise only warps or wefts of different haptic and/or optical characteristics extending parallel and/or perpendicular to one another as in the first arrangement. The at least one motif therefore forms a, preferably complex, image or design distinguishable against the background region. The or each at least one motif may convey recognisable information to a reader and may form at least one of a pattern, symbol, flag, emblem, flower, logo, drawing, letter, pictogram, illustration, alphanumeric character, grapheme, national emblem, coat of arm, personal data, name, photograph, serial number, indicium and code.

By integrating the at least one motif in the textile it is much harder for a forger to alter any information or recognisability it conveys. Furthermore, if the attachment layer is removed from the security document, either from the stitching or data sheet, it is more difficult for the forger to maintain the structure of both the at least one motif and the rest of the textile. Any structural damage to the at least one motif due to such dismantling of the security document could be easily identified.

The at least one motif yarn is interlaced with, for example knitted, woven or stitched with, the at least one background yarn. Preferably the background region and at least one motif together form a structural sheet of the textile, such as a damask on a Jacquard loom.

Preferably the at least one motif is a discrete element separated from edges of the attachment layer. Preferably the attachment layer comprises a plurality of motifs. A single motif or a plurality of motifs, with spacings of background region between individual motifs, may extend between, preferably opposing, edges of the attachment layer.

In a preferred embodiment of the second arrangement the at least one motif is a different visible colour to at least one further motif and/or the background region when viewed by the naked eye in reflected visible light incident upon the attachment layer. The at least one motif may also be a covert security feature that is perceived differently by the naked eye, or is only perceivable by the naked eye, when viewed in reflected visible light as compared to reflected non-visible light by virtue of the at least one motif yarn and at least one background yarn having different non-visible light properties. In a particularly preferred embodiment the at least one motif and at least one further motif and/or the background region have a first colour combination (e.g. the same or different colours) when viewed in visible light and a second colour combination (e.g. the same or different colours, but different to those of the first colour combination) when viewed in a combination of visible and non-visible light.

In a particularly preferred embodiment, which may be formed from a two tone damask on a Jacquard loom, on a front side of the attachment layer at least one front side motif is a first colour and the front side background region is a second colour. On a reverse side of the attachment layer at least one reverse side motif is the second colour and the reverse side background region is the first colour. The motifs and backgrounds have inverse shapes of one another.

In a further preferred embodiment, which may be formed from a brocade on a Jacquard loom, the background region may comprise a structural background sheet comprising a plurality of wefts and warps formed from the at least one background yarn. The at least one motif may be formed by at least one motif yarn woven into the structural background sheet in a supplementary and non-structural arrangement (i.e. the at least one motif yarn does not substantially contribute to the maintenance of the sheet like continuous structure of the textile). If formed as a brocade, the reverse side of the attachment layer can be adapted to provide difference effects by being continuous or discontinuous.

As will be apparent from the embodiments of the detailed description, the present disclosure further includes a combination of the first and second arrangements in which the attachment layer comprises the at least one motif and the background region formed from the background and motif yarns of different haptic and/or optical characteristics and the background region itself comprises at least two background yarns forming at least two warps and/or wefts having different haptic and/or optical characteristics.

The attachment layer may, in addition to the at least one motif and/or at least two yarns having different haptic and/or optical characteristics, comprise other security features such as at least one security thread or security print. The security document may comprise one or more additional security features, such as fibres, particles, watermarks, laser perforations, threads, print, optically variable features, laser markings, tactile features, graphics, personal data, features not visible in visible light (e.g. luminescent or fluorescent features), patches and the like.

The attachment layer comprises a textile comprising at least one first region of a first textile structure and at least one second region of a second textile structure. The at least one first region and at least one second region may optionally comprise the at least two yarns of different haptic and/or optical characteristics disclosed herein such that they have the corresponding different haptic and/or optical characteristics. Warps form first regions and wefts form second regions in accordance with the first arrangement discussed above.

Due to the different first and second textile structures the first and second regions have different haptic and/or optical characteristics. The at least one first region preferably has a different texture to that of the at least one second region, the different texture being distinguishable to human touch. The different textile structures result from:.

The different textile structures may also result from:.

The attachment layer comprises a textile which may comprise at least two regions of different colours, luminescence, diameter, surface roughness, hardness, stiffness and/or gloss. The at least two regions may be formed from the at least two yarns of different types and/or haptic and/or optical characteristics disclosed herein.

The at least two yarns of different types, first and second regions of different texture or at least one motif are located on the hinge portion. The at least two yarns of different types, first and second regions of different texture or at least one motif may overlie or be separated from the fold.

By way of example only, embodiments of a security sheet, a security document and a method of manufacture in accordance with the present disclosure are now described with reference to, and as shown in, the accompanying drawings, in which:.

<FIG> and <FIG> illustrate a security document <NUM> in accordance with the present disclosure. The security document <NUM> may be of any suitable type, but may comprise a security booklet, such as a passport as illustrated, a passbook, an identification document, a certificate, a licence, a cheque book or the like. The security document <NUM> comprises a security sheet <NUM>, in this case a data page, foldable about and preferably attached along a fold <NUM> to a plurality of leaves <NUM>. The plurality of leaves <NUM> may comprise a fibrous substrate, for example paper and/or cotton and may form visa pages. The security document <NUM> also comprises a cover <NUM>, which is foldable about and attached to the fold <NUM> and/or is adhered to an outer leaf (not shown) located on the outside of the leaves <NUM> and security sheet <NUM>. The attachment is preferably stitching through the security sheet <NUM>, leaves <NUM> and/or cover <NUM> at the fold <NUM>, although other attachment means such as adhesion may be used and the attachment means may be offset from the fold <NUM>.

The security sheet <NUM> is illustrated in further detail in <FIG>. The security sheet <NUM> comprises a data sheet <NUM>, which preferably comprises plastic and may be formed from a plurality of plastic body layers connected together, comprising data <NUM> and an attachment layer <NUM> attached to the data sheet <NUM>. The data sheet <NUM> extends across a width from an inner edge <NUM>, located proximate the fold <NUM>, to an outer edge <NUM>, distal to the fold <NUM>. The data sheet <NUM> extends across a thickness between substantially planar first and second outer surfaces <NUM>, <NUM>. The data sheet <NUM> may comprise at least one of a thermoplastic polymer, polycarbonate, polybutylene terephthalate, polyester, polyethylene, polypropylene, polyvinyl chloride, a co-polymer comprised of any of the previous thermoplastic polymers, a fibrous substrate and the like.

The attachment layer <NUM> is configured to securely connect the attachment layer <NUM> to the data sheet <NUM> and to the rest of the security document <NUM>. The attachment layer <NUM> is thus preferably flexible, substantially resistant to plastic deformation and tear resistant and may comprise a substantially elongate sheet or body as illustrated. The attachment layer <NUM> comprises a connection portion <NUM> extending from a hinge portion <NUM>. The connection portion <NUM> is at least partially located in or on and attached to the data sheet <NUM> and outer edge <NUM>). The hinge portion <NUM> is located outside of the data sheet <NUM>. The fold <NUM> and/or attachment means discussed above extend through the hinge portion <NUM>.

The attachment layer <NUM> (or preferably at least the hinge portion <NUM> thereof) comprises a textile having a mesh of interlaced, knitted, woven, stitched, overlapping or otherwise integrated wefts <NUM> and warps <NUM>. The warps <NUM> may extend substantially parallel to one another and/or the fold <NUM>. The wefts <NUM> may extend substantially parallel to one another and/or may be substantially perpendicular to the warps <NUM> and/or fold <NUM>. The connection portion <NUM> may comprise at least portions of wefts <NUM>, referred to as connection wefts <NUM>, as illustrated in <FIG>. The plurality of connection wefts <NUM> are separated from an adjacent connection weft <NUM> by a spacing <NUM>. The connection wefts <NUM> may comprise portions of the wefts <NUM> extending out of and forming the hinge portion <NUM> as in <FIG>. The connection portion <NUM> is therefore firmly connected to the data sheet <NUM> by a frictional force applying a resistance to the attempted removal of the attachment layer <NUM> from the data sheet <NUM>. The connection portion <NUM> may instead comprise a mesh of both wefts <NUM> and warps <NUM>, rather than only the connection wefts <NUM>, such that the entire attachment layer <NUM> is a meshed textile. Although the connection wefts <NUM> are preferably part of the textile, they may instead comprise strips, a film and/or other elongate bodies extending from the hinge portion <NUM>.

The textile of the attachment layer <NUM> comprises at least one motif <NUM> (which may also be referred to as a first region) integrated with a background region <NUM> (which may also be referred to as a second region) in accordance with the second arrangement of the disclosure as discussed above. In <FIG> the attachment layer <NUM> comprises motifs <NUM> representing the letters "D", "L", "R" and a logo. The at least one motif <NUM> or first region may have a first textile structure that is different to a second textile structure of the background region <NUM> or second region. In particular, the at least one motif <NUM> is formed by at least one motif yarn interlocked with, knitted, woven and/or stitched and extending through at least one background yarn forming the background region <NUM>. The at least one motif yarn and at least one background yarn, and therefore the at least one motif <NUM> and a background region <NUM>, have different haptic and/or optical characteristics selected from those set out above. The at least one motif yarn may extend multiple times between the outer surfaces of the attachment layer <NUM> to form the pattern of the at least one motif <NUM>. The background region <NUM> and at least one motif <NUM> may together form the mesh (e.g. by each forming wefts <NUM> and warps <NUM>) of the textile. The background yarn forms wefts <NUM> and/or warps <NUM> of the background region <NUM> and the at least one motif yarn is interlocked with the textile by being looped around the wefts <NUM> and/or warps <NUM>. The background region <NUM> may be a single, substantially continuous colour. The at least one motif <NUM> and background region <NUM> may be formed using the Jacquard process on a Jacquard loom.

By virtue of the at least one motif yarn and at least one background yarn being different visible colours, the at least one motif <NUM> may be a different visible colour to at least part of the background region <NUM> adjacent to the at least one motif <NUM> when viewed by the naked eye in reflected light incident upon the attachment layer <NUM>. For example, the background region <NUM> may appear substantially as at least one first colour (e.g. white) at least partially around the at least one motif <NUM> whilst the at least one motif <NUM> may be at least one different second colour (e.g. non-white). A single motif <NUM>, or each of a plurality of motifs <NUM>, may comprise a plurality of different colours when viewed by the naked eye in reflected light incident upon the attachment layer <NUM>. For example, the at least one motif <NUM> may comprise different colours corresponding to the image or design it represents.

By selecting different haptic and/or optical characteristics for the motif and/or background yarns, various effects can be achieved with the embodiment of <FIG>. In particular, the at least one motif yarn may have a different surface roughness, hardness, stiffness and/or diameter to the at least one background yarn. As a result, the at least one motif <NUM> can be distinguished by human touch by virtue of having a higher or lower surface roughness, diameter, stiffness and/or hardness to the at least partially surrounding background region <NUM>. A particularly preferred effect can be achieved by the at least one motif yarn having a greater diameter than the at least one background yarn, which results in the outer surface of the at least one motif <NUM> being raised above the at least partially surrounding outer surface of the background region <NUM>. The resulting raised texture is easily distinguishable to human touch and also creates a three dimensional effect visible to the naked human eye. The effect can be further developed by having a plurality of motif yarns of different diameters such that the outer surface of the motif itself is textured with different contours, thereby forming complex three dimensional effects visible to the human eye.

By having different textile structures the at least one motif <NUM> has a different texture to the background region <NUM> such that they are distinguishable from one another by human touch. In particular, the presence of the at least one motif yarn in the at least one motif <NUM> is detectable as providing a texture distinguishable to the texture of the background region <NUM>. Such a different texture is also achieved if the at least one motif yarn and at least one background yarn have substantially the same haptic and/or optical characteristics.

As illustrated in <FIG>, the at least one motif <NUM> may be not extend over the fold <NUM> and/or attachment means or stitch line such that the entire at least one motif <NUM> can be viewed when the security document <NUM> is open at the security sheet <NUM>. The at least one motif <NUM> may extend over the fold <NUM>. If the fold <NUM> is offset from the attachment means, such as by being offset from the stitch line, the at least one motif <NUM> may extend over the fold <NUM> and/or attachment means. In such arrangements the difficulty of attempting to adapt the at least one motif <NUM> is increased since the adaptation will require the entire removal of the security sheet <NUM> from the security document <NUM> to reach the area under the fold <NUM> or attachment means.

As illustrated in <FIG>, the at least one motif <NUM> may be located only in the hinge portion <NUM> such that it is located and visible outside of the data sheet <NUM>. However, the at least one motif <NUM> may be at least partially located on the connection portion <NUM> and/or at least partially located within or on the data sheet <NUM>. Thus the at least one motif <NUM> may be difficult to reach during an attempted adaptation.

As illustrated in <FIG>, the at least one motif <NUM> may be separated from the edges of the attachment layer <NUM> such that it is a discrete element entirely surrounded by the background region <NUM>. In particular, the at least one motif <NUM> may not extend between opposing edges of the attachment layer <NUM> and may be in contact with fewer than three edges of the attachment layer <NUM>. The or each at least one motif <NUM> may extend across less than approximately <NUM>% of the area of the hinge portion <NUM>, less than approximately <NUM>% of the area of the hinge portion <NUM> or less than approximately <NUM>% of the area of the or hinge portion <NUM>. The surface area of the at least one motif <NUM> may be less than approximately <NUM>%, <NUM>% or <NUM>% of the surface area of the background region <NUM>.

However, as illustrated in the embodiment of <FIG> and <FIG>, the at least one motif <NUM> (in the form of a sinusoid in this example) may extend between opposing edges of the attachment layer <NUM> (in this case three edges of the attachment layer <NUM> and four edges of the hinge portion <NUM>). <FIG> and <FIG> also illustrate how the colours of the at least one motif <NUM> and background region <NUM> can be a first colour combination on a front side (as in <FIG>) of the attachment layer <NUM> and a second colour combination, which is the inverse of the first colour combination, on a reverse side (as in <FIG>) of the attachment layer <NUM>. In the illustrated example the front side motif <NUM> is black and the front side background region <NUM> is white. On the reverse side there are correspondingly positioned and shaped reverse side illustrated example the front side motif <NUM> is black and the front side background region <NUM> is white. On the reverse side there are correspondingly positioned and shaped reverse side motif <NUM> and reverse side background region <NUM>, the reverse side motif <NUM> being white and the reverse side background region <NUM> being black. Such an inverse colour arrangement can be achieved by forming a two tone damask on a Jacquard loom in which the at least one front side motif <NUM> and reverse side background region <NUM> are formed from the at least one motif yarn of the first colour and the front side background region <NUM> and at least one reverse side motif <NUM> are formed from the at least one background yarn of the second colour.

<FIG> illustrates an embodiment of the security sheet <NUM> in accordance with the first arrangement discussed above, and in accordance with the claims, in which the attachment layer <NUM> comprises a textile comprising at least two yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of different haptic and/or optical characteristics. <FIG> illustrates the attachment layer <NUM> in an exploded view in order to illustrate its composition, but in practice will be tightly pulled together and may comprise significantly more connection wefts <NUM> (e.g. at least twenty or fifty connection wefts <NUM>). <FIG> is an illustration of a portion of an exemplary security sheet <NUM> formed according to the embodiment of <FIG>. The hinge portion <NUM> comprises at least one yarn <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> extending at least partially through the hinge portion <NUM> to form the wefts <NUM> and warps <NUM>. In particular, a plurality of wefts <NUM> and/or warps <NUM> may comprise a single continuous yarn <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The attachment layer <NUM> comprises at least one connection weft yarn <NUM>, first infill weft yarn <NUM>, second infill weft yarn <NUM> and warp yarn <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

The outer warps <NUM> are formed from a distal warp yarn <NUM> and a proximal warp yarn <NUM>. The distal warp yarn <NUM> is located adjacent to the inner edge <NUM> of the data sheet <NUM>, the proximal warp yarn <NUM> is located adjacent the free proximal edge (i.e. the top edge of <FIG>) of the attachment layer <NUM> and infill warp yarns <NUM>, <NUM>, <NUM> are located therebetween. The hinge portion <NUM> may have a width between its outer warps <NUM> (i.e. between the distal and proximal warp yarns <NUM>, <NUM>) of at least approximately <NUM> or at least approximately <NUM> and/or optionally up to approximately <NUM> or approximately <NUM>. The hinge portion <NUM> comprises only five warps <NUM> or warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as in the illustrated embodiment, but may comprise five or fewer warps <NUM>, ten or fewer warps <NUM> or fifteen or fewer warps <NUM>. At least two of the adjacent warps <NUM> or warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the hinge portion <NUM> are separated from one another (in particular separated in a direction perpendicular to the inner edge <NUM>, optionally also the attachment line and/or fold <NUM>) by at least approximately <NUM>, and optionally by at least approximately <NUM>, at least approximately <NUM>, at least approximately <NUM> or at least approximately <NUM>. By virtue of this separation adjacent warps <NUM> form first regions of a first textile structure whilst the wefts <NUM> extending between the adjacent warps <NUM> form a second textile structure. Due to the separation being relatively large, it is possible to detect the gap or separation between the adjacent warps <NUM> by human touch.

The at least one connection weft yarn <NUM> forms the connection wefts <NUM>. The at least one connection weft yarn <NUM> extends at least partially into the hinge portion <NUM> and is interlaced with at least one or warp <NUM>, but is not interlaced with itself. The connection weft yarn(s) <NUM> preferably comprises a plurality of ends by comprising a plurality of adjacent, substantially parallel, yarns, strips, threads or filaments. In particular, the connection weft yarn(s) <NUM> may comprise a synthetic yarn, such as nylon, and may comprise a plurality of monofilaments. Preferably the connection weft yarn(s) <NUM> is substantially clear or transparent in a similar manner to the at least one body layer such that it is substantially hidden in the data sheet <NUM> after formation and such that the connection weft yarn(s) <NUM> have different optical characteristics compared to other yarns of the textile <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The first infill weft yarn <NUM>, second infill weft yarn <NUM> and/or warp yarn <NUM> may comprise polyester. The first and second infill weft yarns <NUM>, <NUM> continuously form infill wefts <NUM>, which extend between the connection wefts <NUM>, of the hinge portion <NUM> by looping within the hinge portion <NUM> between the between the distal and proximal warp yarns <NUM>, <NUM>. The connection weft yarn(s) <NUM> may have a smaller diameter than the first infill weft yarn <NUM>, second infill weft yarn <NUM> and/or at least one warp yarn <NUM>, <NUM>, <NUM>, <NUM>, <NUM> such that the connection wefts <NUM> have a smaller diameter than the infill wefts <NUM> and/or warps <NUM> of the hinge portion <NUM>. As a result, the connection weft yarn(s) <NUM> have different haptic characteristics and are distinguishable to human touch to the other yarns of the textile <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The connection weft yarns <NUM> are therefore individually identifiable in the attachment layer <NUM> and thus any tampering thereof is difficult to hide. In addition, the hinge portion <NUM> therefore comprises relatively strong yarns to prevent ripping or other damage along the attachment line whilst the connection wefts <NUM> add little bulk to the data sheet <NUM> and are therefore more discreet. The connection weft yarn <NUM> may be less than approximately <NUM> denier, less than approximately <NUM> denier and is preferably approximately <NUM> denier. The first infill weft yarn <NUM>, second infill weft yarn <NUM> and/or warp yarn <NUM> may be at least approximately <NUM> decitex, at least approximately <NUM> decitex and is preferably approximately <NUM> decitex.

The interlacing between the weft and warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is not shown in <FIG>, but preferably they are interlocked to one another, such as by knitting. In particular, the warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be knitted into at least one weft yarn <NUM>, <NUM>, <NUM> such that they are attached to one another by a stitch. In the present disclosure "knitting" refers to forming closed, interlocked loops between yarns. Preferably the knitting is crochet knitting and each interlock comprises a crochet knitting stitch. Using knitting as the interlacing method rather than weaving results in an attachment layer <NUM> that is harder for a forger to unpick and remove from the security document <NUM>. During manufacture, a plurality of warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be fed by a machine into contact with the weft yarns <NUM>, <NUM>, <NUM> for interlacing therewith. Preferably the machine is a knitting machine and more preferably a crochet knitting machine.

At least two of the yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the hinge portion <NUM> have different visible colours such that they have different optical characteristics. In preferred embodiments at least two warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and preferably at least the distal and proximal warp yarns <NUM>, <NUM>, are different colours. For example, the distal warp yarn <NUM> may be a first colour and the proximal warp yarn <NUM> may be a different second colour. In the case of at least three (preferably at least five or at least <NUM>) warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> they may also form a colour progression from the first colour to the different second colour. The colour progression may be formed by the at least one infill warp yarn <NUM>, <NUM>, <NUM> having at least one further different colour formed by a colour mixture of the first and second colours. Thus the hue of the colour of the warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may graduate from the first colour at the distal warp yarn <NUM>, through the infill warp yarns <NUM>, <NUM>, <NUM> to the second colour at the proximal warp yarn <NUM>. One of more of the infill warp yarns <NUM>, <NUM>, <NUM> may form a third colour and the colour progression may be a variance in hues from the first colour to the third colour and from the third colour to the second colour. Fourth and further colours may be added. Thus the colours of the warps <NUM> and warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may form a rainbow, iris or ombre, which are difficult for a counterfeiter to replicate.

In alternative embodiments the distal and proximal warp yarns <NUM>, <NUM> may be a first colour whilst the infill warp yarns <NUM>, <NUM>, <NUM> may be a second colour or form a graduation of hue between the first colour of the distal and proximal warp yarns <NUM>, <NUM>. The warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may also have at least one different colour to at least one of the at least one connection weft yarn <NUM>, first infill weft yarn <NUM> and second infill weft yarn <NUM>.

The security sheet <NUM> may be formed by the connection together of the attachment layer <NUM> and at least one plastic body layer forming the data sheet <NUM> by, for example, lamination, adhesion, welding and/or any other suitable method. During lamination or welding heat and/or pressure are applied to fuse or push the plurality of body layers together and the plastic of at least one body layer is pushed through the at least one spacing <NUM> between the connection wefts <NUM>, through mesh openings of the mesh or through the textile (depending upon the construction of the connection portion <NUM>). The attachment layer <NUM> may be pressed into the first or second outer surface <NUM>, <NUM> formed by the outer body layers such that the connection portion <NUM> is at least partially attached at or adjacent to and overlapping the first outer surface <NUM> of the data sheet <NUM>. At least one strip <NUM> may overlap at least part of the connection portion <NUM> and is attached to or embedded within the data sheet <NUM> such that it forms part of the first outer surface <NUM> of the data sheet <NUM>. Alternatively the connection portion <NUM> may be attached between adjacent body layers prior to lamination such that it is located within the thickness of the data sheet <NUM>. The lamination may be performed using any suitable method and may be a substantially in-line method, similar to that of <CIT> and <CIT>, in which a plurality of security sheets <NUM> are formed continuously.

Various alternatives to the embodiments discussed above fall within the scope of the present disclosure. The at least one motif <NUM> discussed in respect of <FIG> may be included in the security sheet <NUM> of <FIG> and the different coloured warp yarns <NUM>, <NUM>, <NUM>, <NUM>, <NUM> discussed in respect of <FIG> may be included in the security sheet <NUM> of <FIG>.

In a particular arrangement the at least one motif <NUM> may be formed from at least one motif yarn that does not have different optical and/or haptic characteristics as the at least one background yarn forming the background region <NUM>. The aforementioned description of <FIG>, <FIG> and <FIG> equally applies to this arrangement, but without the yarns having different optical and/or haptic characteristics. The at least one motif <NUM> may be visible and/or detectable by human touch by virtue of the textile structure in the at least one motif <NUM> being different to the textile structure in the background region <NUM> in any of the manners listed in the Summary. For example, the thread count in the at least one motif <NUM> may be higher than in the background region <NUM> such that it is distinguishable by appearing to have a denser concentration of warps <NUM> and/or wefts <NUM>.

Claim 1:
A security sheet (<NUM>) comprising:
a data sheet (<NUM>) displaying data (<NUM>), the data sheet (<NUM>) extending across a width from an inner edge (<NUM>) to an outer edge (<NUM>); and
an attachment layer (<NUM>) attached to the data sheet (<NUM>), wherein the attachment layer (<NUM>) is for attaching the data sheet (<NUM>) in a security document (<NUM>), wherein the attachment layer (<NUM>) comprises:
(a) a textile comprising a plurality of interlaced wefts (<NUM>) and warps (<NUM>), wherein at least two warps (<NUM>) and/or at least two wefts (<NUM>) are formed from at least two yarns (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having different haptic and/or optical characteristics, wherein the yarns are fibrous and comprise a plurality of fibres attached together; and
(b) a hinge portion (<NUM>) outside of the data sheet (<NUM>), wherein the at least two yarns having different haptic and/or optical characteristics are located on the hinge portion (<NUM>),
characterised in that at least two adjacent warps (<NUM>) of the hinge portion (<NUM>) are separated from one another in a direction perpendicular to the inner edge (<NUM>) by at least <NUM>.