EP1800891A1

EP1800891A1 - Security document

Info

Publication number: EP1800891A1
Application number: EP05028337A
Authority: EP
Inventors: Gilles c/o European Central Bank Roberty
Original assignee: European Central Bank
Current assignee: European Central Bank
Priority date: 2005-12-23
Filing date: 2005-12-23
Publication date: 2007-06-27

Abstract

The invention relates to a security document, in particular a bank note 1, comprising a substrate 2 having corners A, B, C, D and sides a, b, c, d joined at the corners. At least one of the corners of the substrate of the security document according to the present invention is provided with a lined embossing pattern (4) made by an intaglio printing process. The lined corner embossing pattern (4) comprises a plurality of contacting or intersecting lines significantly improving the rigidity of the substrate so that the danger of folding or bending of the corner is reduced. According to a preferred embodiment of the invention, at least one of the sides a, b, c, d of the security document is also provided with a lined embossing pattern (5) made by an intaglio printing process so that the danger of a damage of the security document is further minimized.

Description

The present invention relates to a security document comprising a substrate having corners and sides joined at the corners, and in particular to the reinforcement of the corners of the substrate of the security document. Furthermore, the invention relates to a method for producing a security document being provided with corner reinforcement means.
The unwanted folding or bending of the corners of the substrate of security documents, e.g. bank notes, checks, stocks, bonds etc., is a long standing problem. The cause of faults in security document processing machines often lies in the existence of folded or bent corners, and the existence of folded or bent corners often results in the reduction of the life of the security documents.
Methods are known for the reinforcement of the corners of the substrates of the security documents, in particular bank notes. In order to overcome the above problem it has been proposed to increase the weight of the paper of the bank note and to provide watermarks at the corners of the paper.
It is known that watermarks altering the thickness and/or texture of the substrate have reinforcement properties. A known method for making watermarks is the embossing of the wet paper using an embossing roller, thereby impacting the mark in the paper corresponding to the embossing. A further technique resulting in an embossing of the substrate is the intaglio printing process commonly used for the production of bank notes.
It is an object of the present invention to simplify the production of security documents, in particular bank notes, comprising corner reinforcement means. A further object of the invention is to provide a security document, in particular a bank note, with corner reinforcement means having improved properties.
The above objects are solved with the features of claims 1 and 20, respectively. Preferred embodiments are the subject matter of the independent claims.
According to the present invention, at least one of the corners of the substrate of the security document, preferably all the corners are provided with a lined embossing pattern made by an intaglio printing process. The lined corner embossing pattern comprises a plurality of contacting or intersecting lines.
The contacting or intersecting lines of predetermined width, depth and distance of the lined embossing pattern at the corner of the substrate significantly improves the rigidity of the substrate so that the danger of folding or bending of the corner is reduced. By using the intaglio printing process for producing the lined embossing structures also tactile structures are provided. These tactile structures constitute a further feature which allows the identification and/or verification of the security document by the public without requiring additional tools.
In a preferred embodiment of the present invention, each of the contacting or intersecting lines of the lined corner embossing pattern describes the shape of a closed curve, in particular a circle. A shape of a circle has the advantage that the wiping of the plate of the intaglio printing machine is simplified or improved in comparison to a lined embossing pattern which comprises lines extending in the direction of the movement of the wiper of the printing machine.
In an alternative preferred embodiment, each of the contacting or intersecting lines of the lined corner embossing pattern describes the shape of a rectangle and/or square and/or triangle.
According to a further preferred embodiment, the means for reinforcement of the corner comprises a central portion at the corner of the security document and peripheral portions adjacent to the central portion, the peripheral portions extending in the direction of the sides of the security document. The advantage of the peripheral portions is the further reinforcement also of the side portions of the substrate close to the corner.
It is an important aspect of the invention that the width, distance, and depth of the lines is adapted to the tactile receptors of the human fingertips so that the lines have both reinforcement and tactile properties.
According to a further preferred embodiment, at least one of the sides, preferably all the sides of the substrate are also provided with lined embossing patterns made by an intaglio printing process so that the danger of a damage of the security document is further minimized.
The lined side embossing pattern preferably comprises a plurality of parallel lines extending between two lined corner embossing patterns. The parallel lines can be straight lines or curved lines and can be arranged parallel or orthogonal to the edges of the substrate.
In a further preferred embodiment, the lines of the side embossing pattern describe an arc of a circle. The length of the lines can differ along the edges of the substrate. The width, distance, and depth is preferably adapted to the tactile receptors of the fingertips.
A further important aspect of the invention is the method for producing the security document. The method of the invention is based on the technological advantage brought by digital intaglio plate engraving which allows among others to implement the feature designated as "bleeding-off intaglio".
It is known to print in a first method step a plurality of security documents in the same printing process on a large sheet of paper which in a second method step is cut into single security documents. For the known printing process a master die is made and then the master die is duplicated. The dies are arranged side by side in lines and columns so as to print a plurality of security documents on a common sheet of paper.
If the known intaglio printing machines are used for printing the lined embossing structures of the invention, it has been shown that in an area of some millimetres where the adjacent corners and sides border on each other an embossing is not possible because of the welding lines.
According to the invention the recently developed digital engraving systems are used for the production of the security documents comprising the means for reinforcement of the invention. The digital engraving systems allow the direct engraving of a complete sheet-size plate without the above assembly process, also known as "step and repeat process".
According to the invention, at least two security documents are provided on a common substrate side by side and adjacent corners and/or adjacent sides of the security documents are printed with a lined embossing pattern using the digital intaglio plate engraving system in the same intaglio printing process. The digital engraving system allows printing the substrate at any location, in particular at the adjacent corners and/or adjacent sides of the substrate.
For the purpose of illustrating the invention, there are shown in the accompanying drawings embodiments of the invention which are presently preferred; it being understood that the invention is not limited to the precise arrangement and instrumentalities shown.

Fig. 1: shows a bank note comprising means for reinforcement;
Fig. 2: is a schematic view of a first embodiment of a lined corner embossing pattern;
Fig. 3: is a schematic view of second embodiment of a lined corner embossing pattern;
Fig. 4: is a schematic view of an alternative embodiment of a lined corner embossing pattern of Fig. 3;
Fig. 5: is a schematic view of a further embodiment of a lined corner embossing pattern;
Fig. 6: is schematic view of a bank note comprising both lined corner and side embossing patterns;
Fig. 7 to 9: are schematic views of further embodiments of bank notes comprising both lined corner and side embossing patterns.

Fig. 1 shows the planar front surface of a security document which is a bank note in the preferred embodiment. The bank note 1 comprises a rectangular substrate 2 made of a sheet of paper. The substrate 2 has left and right upper und lower corners A, B, C, D and left and right and upper und lower sides a, b, c, d having edges joined at the corners. A graphical design printing 3 is provided on the front and back surface of the substrate. The bank note 1 comprises means 4 for reinforcement at the left and right upper and lower corners A, B, C, D and means 5 for reinforcement at the left and right and upper and lower sides a, b, c, d of the substrate 2 which are tactile with the human fingertips, but are not visible.
Fig. 2 shows a schematic view of a first embodiment of a lined embossing pattern provided by a digital intaglio printing process at the adjacent edges A, B, C, D of the bank notes 1 printed on a large sheet of paper which is cut along the theoretical cutting lines 6, 6' into the single bank notes. The corner embossing pattern 4 comprises a plurality of crossing lines 7, 8 extending parallel and orthogonal to the edges of the bank note. The lines 7, 8 have a width in the range of 5 µm to 20 µm, a distance in the range of 5 µm to 2 mm, and a depth in the range of 5 µm to 120 µm so as to correspond to the tactile receptors of human fingertips in order to improve the tactile properties of the means for reinforcement.
The width and height of the whole corner embossing pattern 4 for the adjacent bank notes is larger than the cutting tolerance to ensure that the dimension of the embossing pattern of each bank note is sufficient independent of the position of the cutting line. However, the grid pattern has to be dimensioned to avoid any overlapping with the graphical design printing 3 on the bank note 1.
Fig. 3 shows a second embodiment of corner embossing pattern comprising a plurality of crossing lines 9, 10 extending parallel and orthogonal to the edges of the bank note. The corner embossing pattern of Fig. 2 comprises a central portion 11 having the same shape as the embossing pattern of Fig. 1 as well as peripheral portions 12 adjacent to the central portion. The peripheral portions 12 extend in the direction of the edges a, d of each bank note. Thus, the pattern has the shape of a cross.
The alternative embodiment of the corner embossing pattern as shown in Fig. 4 differs from the pattern of Fig. 3 in the length of the peripheral portions 12'. By increasing the dimension of the embossing pattern in the area of the corners A, B, C, D the stiffness of the substrate is further increased so that the danger of folding or bending of the bank note is further decreased.
Fig. 5 is a schematic view of a corner embossing pattern 4 comprising contacting lines 13 describing circles 14 arranged in a plurality of lines and columns in order to simplify or improve the wiping of the plate in the intaglio printing machine, instead of the intersecting lines of the embossing pattern as shown in Figs. 1 to 3 describing squares.
Fig. 6 is schematic view of the sheet of paper with the complete bank note 1 comprising a graphical design printing 3 and both means 4, 5 for reinforcement of the corners A; B, C, D and the sides a, b, c, d of the bank note. The bank note is provided with a plurality of parallel lines 15, 16 made by the intaglio printing process of the invention. The lines having a predetermined distance, width and depth extend parallel to the edges a, b, c, d of the bank note forming the lined embossing patterns 4 of Fig. 1 at the corners and further lined embossing patterns 5 at the sides of the bank note. The lines of the corner embossing patterns and/or the side embossing patterns can be printed with or without ink (blind lines) so that the lines are visible or not.
Fig. 7 shows a further embodiment of a bank note which is similar to the embodiment of Fig. 6. The bank note of Fig. 7 differs from the bank note of Fig. 6 in that the lined corner embossing patterns 4 comprising a plurality of squares 17 as shown in Fig. 1 are replaced with corner embossing patterns 4 comprising a plurality of circles 14 as shown in Fig. 5.
Fig. 8 is a schematic view of an alternative embodiment comprising corner embossing patterns 4 as shown in Fig. 1 as well as side embossing patterns 5 comprising parallel lines 17, 18 of predetermined distance, width, and depth. The side embossing patterns of Fig. 8 differ from the embossing patterns of Fig 7 in that the lines 17, 18 are arranged orthogonal to the edges a, b, c, d of the bank note 1.
Fig. 9 shows a further alternative embodiment of a bank note comprising corner embossing patterns 4 as shown in Fig. 1 as well as side embossing patterns 5 comprising parallel lines 19, 20. This embodiment has improved tactile properties. The side embossing patterns of Fig. 9 differ from the embossing patterns of Fig. 8 in that the lines 19, 20 are arcs of a circle. The distance between the lines of the upper und lower side embossing patterns is larger that the distance between the lines of the left and right side embossing patterns. The length of the lines of both patterns is decreasing from the corners to the middle of the sides, while the arcs of the circles on both sides of the middle of the edges have an opposite orientation.

Claims

Security document comprising a substrate (2) having corners (A, B, C, D) and sides (a, b, c, d) joined at the corners, at least one of the corners being provided with means (4) for reinforcement of the corner, wherein said means for reinforcement of the corner comprises a lined embossing pattern (4) provided by an intaglio printing process, said lined embossing pattern comprising a plurality of contacting or intersecting lines (7, 8; 9, 10; 13).
Security document according to claim 1, wherein each of the contacting or intersecting lines (13) of said lined corner embossing pattern (4) describes the shape of a closed curve.
Security document according to claim 2, wherein the closed curve is a circle (14).
Security document according to claim 1, wherein each of the contacting or intersecting lines (7, 8; 9, 10) of said lined corner embossing pattern (4) describes the shape of a rectangle and/or square (17) and/or triangles.
Security document according to any one of claims 1 to 4, wherein the contacting or intersecting lines (7, 8; 9, 10; 13) of the lined corner embossing pattern (4) are blind lines provided by an intaglio printing process without ink.
Security document according to any one of claim 1 to 5, wherein the width of the contacting or intersecting lines (7, 8; 9, 10; 13) of said lined corner embossing pattern (4) lies in a range of 5 µm to 20 µm.
Security document according to any one of claim 1 to 6, wherein the depth of the contacting or intersecting lines (7, 8; 9, 10; 13) of said lined corner embossing pattern (4) lies in a range of 5 µm to 120 µm.
Security document according to any one of claim 1 to 7, wherein the distance between adjacent contacting or intersecting lines (7, 8; 9, 10; 13) of said lined corner embossing pattern (4) lies in a range of 5 µm to 2 mm.
Security document according to any one of claim 1 to 8, wherein the means (4) for reinforcement of the corner comprises a central portion (11) at the corner (A, B, C, D) of the security document and peripheral portions (12) adjacent to the central portion, the peripheral portions extending in the direction of the sides (a, b, c, d) of the security document.
Security document according to any one of claims 1 to 9, wherein at least one of the sides of the security document is provided with means (5) for reinforcement of the side, wherein said means for reinforcement of the side is a lined embossing pattern (5) provided by an intaglio printing process.
Security document according to claim 10, wherein said lined side embossing pattern (5) comprises a plurality of parallel lines (15, 16; 17, 18; 19, 20) extending between two lined corner embossing patterns (4).
Security document according to claim 11, wherein the parallel lines (15, 16) of said lined side embossing pattern (5) are arranged parallel to the edges of the substrate.
Security document according to claim 11, wherein the parallel lines (17, 18) of said lined side embossing pattern (5) are arranged orthogonal to the edges of the substrate.
Security document according to any one of claims 11 to 13, wherein each line (19, 20) of said lined side embossing pattern (5) describe the shape of an arc of a circle.
Security document according to any one of claims 10 to 14, wherein the lines (19, 20) of said lined side embossing pattern (5) differ in the length along the edges of the substrate.
Security document according to any one of claims 10 to 15, wherein the width of the lines (15, 16; 17, 18; 19, 20) of said lined side embossing pattern (5) lies in a range of 5 µm to 20 µm.
Security document according to any one of claim 10 to 16, wherein the depth of the lines (15, 16; 17, 18; 19, 20) of said lined side embossing pattern (5) lies in a range of 5 µm to 120 µm.
Security document according to any one of claims 10 to 17 wherein the distance between the lines (15, 16; 17, 18; 19, 20) of said lined side embossing pattern (5) lies in a range of 5 µm to 2 mm.
Security document according to any one of claims 1 to 18, wherein the security document is a bank note (1).
Method for producing a security document of any one of claims 1 to 19 using a digital intaglio plate engraving system, wherein at least two security documents are provided on a common substrate side by side and adjacent corners and/or adjacent sides of the security documents are printed with a lined embossing pattern using the digital intaglio plate engraving system in the same intaglio printing process.