GB2400074A

GB2400074A - Security feature for banknote and other security documents

Info

Publication number: GB2400074A
Application number: GB0406394A
Authority: GB
Inventors: Mark Philip Crickett; Martin Douglas Raishbrook
Original assignee: De la Rue International Ltd
Current assignee: De la Rue International Ltd
Priority date: 2003-04-03
Filing date: 2004-03-22
Publication date: 2004-10-06
Anticipated expiration: 2024-03-22
Also published as: GB0406394D0; GB2400074B

Abstract

The invention relates to the use of a security feature which can be verified by rubbing together two parts of the sheet and security documents made therefrom. A sheet 10 has at least two areas 11,12 displaced laterally from each other, said areas being provided with surface relief in the form of a plurality of embossed lines raised relative to the normal plane of the sheet. The sheet is foldable to enable the at least two areas to be brought into contact with each other and rubbed relative to each other thereby giving rise to an audible sound and a distinct tactile effect.

Description

24000 74

IMPROVEMENTS IN SHEETS

The invention relates to improvements in sheets, and in particular to the use of a security feature which can be verified by rubbing together two parts of the sheet and documents made therefrom.

Bank notes and other security documents require security features that can be easily recognized and verified by the public without the need for additional verification devices. Security devices of the type described herein are intended for use on documents of value including but not limited to banknotes, fiscal cheques, travellers cheques, fiscal stamps, postal stamps, certificates of authenticity, brand protection articles, bonds, certificates, vouchers and the like.

It is widely accepted that when producing security documents, a range of security features is required.

This is both to overcome the efforts of counterfeiters and to enable inspection of the documents at a number of different levels. It is usual to consider the inspection of security documents to fall into one of three categories, public, teller assist and covert.

Inspection of documents at a public level requires the feature to be overt or not to require additional aids to verify. Examples of public features include windowed and embedded threads, cylinder mould watermarks, holographic patches and stripes, intaglio print, colourshifting or optically variable inks, thermochromic features, embossed or printed latent features. All these features will be familiar to those skilled in the art and they are also widely discussed within the patent prior art. It is important to note that several of the above features are not apparent until viewed or handled in the correct manner, e.g. latent images. Such features though not overt can still be authenticated using the human senses and handling alone and do not require the use of a secondary device or piece of equipment.

Teller assist features require the use of an additional device of piece of equipment to verify the feature. It is usual that the additional device is hand held and low cost but this is not always the case.

Examples of teller assist features include luminescent inks, microprint, magnetic inks (where only presence is determined), barcodes, REID devices and the like. Again those skilled in the art will be aware of such features and examples are widely reported within the prior art.

Covert features are usually highly secure and only detected using specialized equipment. Examples of covert features include coded magnetic threads, phosphorescent materials and specialist taggants that may be based on biological markers or specific chemical properties.

It is therefore an object of the present invention to provide a simple and effective overt security feature which can be verified without the need for additional apparatus.

The invention therefore provides a sheet having two opposing surfaces, said sheet having at least two areas displaced laterally from each other, said areas being provided with surface relief in the form of a plurality of lines raised relative to the normal plane of the sheet, the sheet being foldable to enable the at least two areas to be brought into contact with each other and rubbed relative to each other thereby giving rise to an audible sound and a distinct tactile effect.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a plan view of a sheet of paper, such as used in a banknote, having surface relief areas on the same surface at opposing short edges of the sheet; Fig. 2 is a perspective view of the sheet of Fig. 1, folded for authentication; Fig. 3 is a plan view of an alternative embodiment of the sheet of Figure 1, having the surface relief areas on opposing surfaces of the sheet; Fig. 4 is a perspective view of the sheet of Fig. 3 rolled up for authentication; Figs. 5 to 36 show alternative embodiments of a sheet of paper.

Referring to Fig. 1 there is illustrated a small sheet of paper 10, e.g. as used in a banknote, made by hand or using a known papermaking machine, such as a cylinder mould or Fourdrinier machine. A range of fibre types can be used in the making of such paper, including synthetic or natural fibres or a mixture of both. The actual preparation of the fibres is unrestricted by the invention, and will depend on what effect it is wished to produce in the finished paper. For security paper used for security documents such as banknotes, passports, and so on, these need to be hard wearing, resilient and self supporting and so an appropriate fibre mix must be selected.

The sheet 10 may also be made of a suitable plastic material. All references hereinafter to paper should be construed to cover plastic also.

The sheet 10 is provided with at least two areas 11,12 which are displaced laterally from each other which are treated to provide them with surface relief. In this specification the phrase "surface relief" is used to mean any change on surface profile which gives rise to a change in the height or depth from the normal plane of the substrate. The preferred methods of providing surface relief can include embossment, debossment, intaglio print and thick ink films.

Embossings may be produced by the intaglio process, either with 15 or without ink 16, i.e. blind.

Alternatively the embossings may be provided by uninked die stamping. Intaglio print is inherently a combination of embossment and ink film, although in blind intaglio the surface relief simply comprises embossment. A thick ink film could, for example, be applied by a screen printing technique or thermography. Where a process such as screen printing is used, there is no embossment of the surface. Any technique which produces a surface relief effect may be used.

It should also be noted that a combination of different types of surface relief could be used in a single surface relief area 11,12 such as a combination of intaglio print and blind embossing.

In Figure 1 the surface relief area 11 comprises a plurality of raised lines, which can be brought into contact with another area 12 provided with surface relief by folding the sheet. In order to authenticate or verify a document made from the sheet 10 the user folds the sheet 10, as shown in Fig. 2 to bring the two areas 11,12 into contact and then rubs them relative to each other.

The movement can be an up and down motion, or a left to right motion. The direction of motion depends on the orientation of the lines forming the areas 11,12. This results in both a distinct tactile effect and an audible sound, as the raised lines rub against each other.

Altering the properties of the areas 11,12 allows the tactility felt and sound generated to be altered. In principle each particular type and value of document made from sheets 10 could be provided with its own unique feel by using a specifically selected combination of orientation, positioning, dimension and location of the surface relief areas 11,12, which is clearly distinguishable from the feel and sound of rubbing the two areas 11,12 together. This would be of particular benefit to people that are visually impaired as well as having benefits for those with normal sight.

In particular the invention may be used to provide a series of security documents made from sheets 10, such as banknotes, each member of the series having a different value or denomination, in which the surface relief areas 11,12 of each value or denomination makes a different sound from those of another denomination. This could be done by altering the widths of the lines making up the areas 11,12 and/or heights of the lines for each value or denomination, but retaining the same structure.

Alternatively the structure could vary for each note.

In Figure 1 area 11 is located adjacent one of a pair of opposing sides of the sheet 10 and the second area 12 is located on the opposing of the pair of sides.

In the embodiment shown, the surface relief in areas 11,12 is provided by a series of parallel lines which are printed onto the sheet 10.

In a preferred embodiment of the invention the two areas 11,12 are arranged, such that when they are folded onto each other the lines forming the surface relief area 11 interlock with those forming surface relief area 12.

The areas 11,12 may be located on the same surface of the sheet 10 as illustrated in Figures 1 and 2, or on opposing surfaces, as shown in Figures 3 and 4. In the latter embodiment, in order to rub the areas 11, 12 against each other to authenticate the sheet 10, the sheet 10 must be rolled into a tube as shown in Figure 4 to bring them together. Alternatively, a sheet may have areas 11,12 on the same and opposing surfaces, which means that the sheet 10 can be authenticated by either method.

Obviously the design, position and dimensions of the surface relief region(s) can vary and examples are shown in Figure 5 to 33. The raised lines may be straight, wavy (see Figures 27 to 29)or curved (see Figure 26)and preferably include a plurality of parallel lines. They may even constitute micro printed text or indicia (see Figure 32).

Figure 5 again shows the most basic embodiment of the invention. Here two surface relief areas 11,12 are placed at opposing edges of a note. The surface relief areas comprise a series of parallel lines running normal to the short edge of the note (or parallel to the long edge). In this example the surface relief areas are placed such that they bleed off the edge of the sheet 10.

The surface relief areas 11,12 can also be placed such that the lines do not bleed off the edge. They are also placed half way down the short edge of the sheet 10.

This arrangement is preferred as it assists the user in locating the two surface relief areas on top of each other as they are placed in a region that naturally coincides when the sheet is bent or folded onto itself.

The invention is effective using a wide range of line widths, height and spacings for the lines of the embossings. The width of the lines is governed by the printing process used. The expected minimum width is 15 microns, but the width must be sufficient, in combination with the height and spacing of the lines, to provide the tactile and audible effect. It has been found that it is highly effective if the lines have widths in the range of microns to 1500 microns, and more preferably 200 to 300 microns; and heights in the range of 25 microns 120 microns, and more preferably in the range of 40 microns to 80 microns, and more preferably still in the range of microns to 80 microns.

Combinations of adjacent shallow and deep lines could also be used. The spacings of the individual lines should be slightly greater than the line width to allow the raised lines of one area 11 to rub across opposing raised lines of the other area 12 and then fall into the valley between pairs of wires. A suitable example would be 200 micron line width and 250 micron line space.

In one suitable embodiment, the areas 11,12 are provided by embossings which comprise a series of corrugations, such as repeating parallel lines spaced 1000 microns apart and each line having a width of 500 microns. The height of each line being approximately 100 microns.

Within a single embossing a combination of different line widths, spacings and heights may be used. Indeed, use of a suitable combination of dimensions and line frequency can give rise to specific audible and tactile effects.

The document may be varnished on one or both sides to improve durability of the embossings. Additionally the substrate may be coated on one or both side to improve the durability of the substrate. The embossed regions may be reinforced using a varnish layer on the front, or back of the embossing or on both the front and back of the embossing.

In Figure 6 an alternative arrangement is shown.

The surface relief areas 11,12 are essentially the same as for figure 5 but here are placed towards the top long edge of the sheet 10. The sheet 10 would be authenticated by bringing the two surface relief areas 11,12 into contact with each other and then moving them in an up/down motion.

Figure 7 shows an arrangement where the surface relief areas 11,12 are placed at the edges of the sheet as for figures 5 and 6 but are additional displaced in terms of their position on the edge. The surface relief area 11 on the left hand side is placed towards the top corner where as the surface relief area 12 on the right of the sheet 10 is placed towards the bottom corner. Here the sheet 10 would be authenticated by bringing the opposing two corners into contact with each other and moving the two surface relief areas 11,12 against each other in an up/down motion.

Figure 8 shows an arrangement similar to that shown in figure 5 but with an alternative design for the surface relief areas 11,12. Here the lines that comprise the surface relief areas 11,12 a disposed such that they are parallel to the short edge (or normal to the long edge) of the sheet 10. The sheet 10 would be authenticated by bringing the two surface relief areas 11,12 into contact with each other and then moving them in a left/right motion.

In Figure 9 surface relief areas 11,12 similar to those described for Figure 8 are placed on the long edge of the sheet 10 rather than the short edge. One of the surface relief areas 11,12 has been placed on the left hand side of the bottom long edge and the second placed on the right hand side of the top long edge.

Figure 10 is very similar to figure 9 with the exception that the surface relief areas 11,12 have been moved. Here the surface relief areas 11,12 sit on the right hand side of the bottom long edge and on the left hand side of the top long edge. In both instances the user would authenticate the sheet 10 by bringing the two corners into contact and rubbing them against each other in a left/right motion.

As a further alternative, not illustrated, the two surface relief areas 11,12 comprises a series of lines running parallel to the short edge. The first surface relief region is placed in the left hand corner on the bottom long edge and the second surface relief region is placed in the right hand corner of the bottom long edge.

Figure 11 shows another arrangement for the positioning of the surface relief areas 11,12 on the long edge. Here they are placed such that they both sit in the centre of the long edge, with one on the top long edge and the second on the bottom long edge. The sheet would be authenticated by the user folding the sheet along the centre of the short edge to bring the two regions into contact and then rubbing them against each other in a left/right motion.

Figure 12 shows an arrangement of the surface relief areas 11,12 where one of the surface relief areas 11,12 does not sit on an edge. Here a first surface relief region is positions half way up the short edge of the sheet 10 but inset into the sheet 10. The second surface - 1 0 relief region is placed halfway up on the short edge of the sheet 10.

Figure 13 shows a further development of this where both surface relief areas 11,12 are inset from the short edge. This example shows the surface relief areas 11,12 being made up of lines parallel to the long edge, these can be replaced by lines parallel to the short edge.

Likewise it is perfect reasonable for the surface relief areas 11,12 to be placed inset from the long edge rather than inset from the short edge, not shown.

In a further example, shown in figure 14, the surface relief area 11 on the left hand side has been produced using short lines and the surface relief area 12 on the right has been produced using long lines. This approach is beneficial as it provides some assistance when locating the two surface relief areas 11,12 onto each other.

Thus far all examples have shown the surface relief areas 11,12 comprising lines that are parallel to either the long edge or short edge of the sheet 10. It is also within the scope of the current invention to provide the surface relief lines at an angle such that they are not parallel to either the short edge or the long edge.

Figure 15 shows surface relief areas 11,12 provided with lines angled at 45 with respect to the edges of the sheet 10. They are also situated such that they sit essentially within opposite corners of the sheet 10.

In all the figures shown so far the surface relief areas 11,12 have comprised parallel continuous straight lines, this need not be the case. Figure 16 shows a further alternative where the surface relief areas 11, 12 have an outer line in the shape of a crescent with a second inner crescent and final a single line running parallel to the short edge. The line widths, spacings and heights are in keeping with those previously described.

In Figure 17 the surface relief areas 11,12 are essentially as described within figure 5 but additionally provided with an outer perimeter line defining a symbol, in this case an arrow.

In Figure 18 the surface relief areas 11,12 are essentially as described within figure 5 but this time the lines are broken and thus not continuous.

Thus far the surface relief areas 11,12 have been provided in localised areas. Figure 19 illustrates an example of where the surface relief areas 11,12 are provided such that they extend over a larger area, thus aiding the process of authentication. Here a series of lines are provided running the full width of the sheet 10 and parallel to the short edge. A similar arrangement is shown in Figure 20, here lines are provided running the full length and parallel to the long edge.

In the majority of illustrations shown so far the surface relief areas 11, 12 have comprised lines having substantially equally spacings. As mentioned previously it is possible to provide surface relief areas 11,12 having lines where the widths, heights and spacings can vary. Figures 21 and 22 illustrate examples where the line widths vary within the surface relief areas 11,12.

Figure 23 illustrates an example where the line widths vary. It should be noted that, whereas in the illustrative examples both surface relief areas 11,12 are shown to have varying line widths and/or spacings, this need not be the case. One of the surface relief areas 11,12 could be provided with lines having a constant line width or spacing.

In a further illustration, Figure 24, the surface relief areas 11,12 are provided as series of short lines parallel to the short edge but extending for a much greater distance across the length of the long edge so that they converge into a single greater region.

However, the region must be of sufficient length or width that it can be folded onto itself.

Figure 26 illustrates an example where a first surface relief area 15 is printed as a series of lines and the second surface relief area 16 is printed as a solid area with uninked regions. This embodiment is referred to as a lock and key approach. The spacings in the substantially solid area are such that they match with the dimensions of the printed lines 11 on the opposite edge of the sheet 10.

Figure 27 is essentially the same as illustrated in Figure 3 but the straight lines have been replaced with wavy lines.

Figure 28 is essentially the same as illustrated in Figure 8 but the straight lines have been replaced with wavy lines.

Figure 29 is essentially the same as Figure 15 but the straight lines have been replaced with wavy lines and surface relief areas 11,12 have been placed in each of the four corners.

Figure 29 illustrates an example where the surface relief areas 11,12 comprise concentric circles.

Figure 30 illustrates an example where two types of surface relief areas 11,12 are provided on the same sheet 10. The two different types of surface relief areas 11,12 may be designed such that when authenticated they both produce the same noise or alternatively different noises.

Figure 31 illustrates an example where the surface relief areas 11,12 comprise concentric circles.

Figure 32 illustrates an example where the surface relief region comprises microtext. The microtext is arranged such as to define lines, the height of the microtext essentially being the width of the line. The microtext may comprise characters, text numerals, simple geometric symbols or patterns.

Figure 33 shows an example where three surface relief areas 11,12 have been provided on the same sheet 10. When surface relief area 11 is moved against surface relief area 12 a first noise is generated. When surface relief area 11 is moved against surface relief area 14 a second noise audibly different to the first noise is generated.

The pattern of the lines could be formed into indicia, such as indicating the value or denomination of the document, as shown in Figures 34 to 36.

The areas 11,12 can be the same or different in appearance. They can also be disposed in a symmetric or asymmetric manner with respect to their position on the sheet 10.

It should be noted that the examples shown in the Figures are not exhaustive and other permutations may be possible.

By angling the lines of the surface relief areas 11,12 to the edge of the sheet 10, or producing areas 11,12 with lines extending in different directions, it is possible to produce a feature which can be authenticated by moving the areas 11,12 over each other in an up/down or left/right motion.

In a further embodiment, the areas 11,12 maybe inset into the sheet 10, there being a gap or border between the edge of the sheet 10 and the surface relief areas 11,12.

Although all of the figures show a pair of areas 11,12, this is only a minimum requirement. Alternative embodiments may have more than two areas. Where three or more areas are used, they can be provided in such a manner that a different audible noise is generated depending on which two areas are brought into contact and moved against each other.

It should be noted that in this specification the

reference to a sheet can include an individual sheet which is printed to form the bank note. Alternatively, it can comprise the larger sheet, which is subsequently cut to form the aforementioned smaller document sized sheets.

Claims

CLAIMS: 1. A sheet having two opposing surfaces, said sheet having at

least two areas displaced laterally from each other, said areas being provided with surface relief in the form of a plurality of lines raised relative to the normal plane of the sheet, the sheet being foldable to enable the at least two areas to be brought into contact with each other and rubbed relative to each other thereby giving rise to an audible sound and a distinct tactile effect.
2. A sheet as claimed in claim 1 in which the at least two areas are provided on the same surface of the sheet.
3. A sheet as claimed in claim 1 in which the at least two areas are provided on opposing surfaces of the sheet.
4. A sheet as claimed in claim 1 or claim 2 in which the at least two areas merge to form a single larger region.
5. A sheet as claimed in claim 1 or claim 2 or claim 3 in which the areas are discrete from each other and located at opposing edges of the sheet.
6. A sheet as claimed in any one of the preceding claims in which the lines of the surface relief areas are straight.
7. A sheet as claimed in any one of claims 1 to 5 n which the lines of the surface relief areas are curved or wavy.
8. A sheet as claimed in any one of the preceding claims in which the lines substantially extend at an angle of 90 to at least one of the edges of the sheet.
9. A sheet as claimed in any one of the preceding claims in which the lines substantially extend parallel to a pair of edges of the sheet.
10. A sheet as claimed in any one of the preceding claims in which the width of the lines lies in the range of 100 to 1500 microns.
11. A sheet as claimed in claim 10 in which the width of the lines lies in the range of 200 to 700 microns.
12. A sheet as claimed in any one of the preceding claims in which the height of the lines lies in the range of 25 to 120 microns.
13. A sheet as claimed in claim 12 in which the height of the lines lies in the range of 40 to 80 microns.
14. A sheet as claimed in claim 13 in which the height of the lines lies in the range of 70 to 80 microns.
15. A sheet as claimed in any one of the preceding claims in which the lines are provided by an intaglio process.
16. A sheet as claimed in claim 15 in which the intaglio embossings are uninked.
17. A sheet as claimed in claim 15 in which the intaglio embossings are inked.
18. A sheet as claimed in any one of the preceding claims in which the lines are provided by die stamping.
19. A security document made from a sheet according to any one of the preceding claims.
20. A banknote made from a sheet according to any one of the preceding claims.
21. A series of security documents as claimed in claim 19 or claim 20 each having a different value, the surface relief areas of each member of the series being selected such as to provide s different audible sound from each other member of the series.
22. A series of security documents as claimed in claim 21 in which the series of documents is a series of banknotes, each of a different denomination.
23. A sheet substantially as hereinbefore described with reference to or as shown in the accompanying drawings.