Technical Field

The invention relates to security document having at least one window and to a method for manufac- turing such a document, wherein a security element is placed in the window.

Background Art

Windowed documents are known in the art of security documents, e.g. from US 2005/0057036. The window or windows can be used for receiving at least one security element, such as a hologram, a reflector having spe- cial optical properties, a polarizer or other optical filter, etc.

Disclosure of the Invention

The problem to be solved by the present invention is to provide a method for manufacturing this type of document efficiently and a document manufactured in this manner.

This problem is solved by the independent claims .

Accordingly, a support sheet with a first window therein and a security element are provided. The support sheet is folded along a first folding line, thereby enclosing the security element at least partially from two opposite sides between a first and a second section of the security sheet, with at least part of said security element remaining visible through the first window. The first and second section are affixed to each other, thereby preventing an unfolding of the support sheet along the first folding line.

A corresponding security document comprises a support sheet having a first folding line, which first folding line divides the support sheet into a first and a second section. The support sheet is folded along the first folding line such that the first and second section lie on top of each other. The first and second section are affixed to each other for preventing an unfolding of the support sheet along said first folding line. At least a first window is arranged in the first section. The document further comprises a security element visible at least partially through the window and enclosed at least partially from two opposite sides between said first and second section.

Hence, the invention provides an efficient way to mount a security element in a document of this type, basically by placing the security element at the desired position and then folding the support sheet and affixing its sections to each other, thereby enclosing the security element.

In particular, the invention allows to en- close at least part or all of the edges of the security document from both sides between the first and second sections of the document, thereby making the outer surfaces of the document smoother and rendering it harder to remove the security element.

Brief Description of the Drawings

The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following de- tailed description thereof. Such description makes reference to the annexed drawings, wherein:

Fig. 1 shows a passport,

Fig. 2 shows a first manufacturing step, Fig. 3 shows a second manufacturing step, Fig. 4 shows a third manufacturing step, and Fig. 5 shows a fourth manufacturing step.

Modes for Carrying Out the Invention

The security document:

The security document of Fig. 1 is a passport in the form of a booklet 1 having a plurality of page sheets or pages 2a, 2b, 2c, .... In the embodiment shown, a first page 2a of the booklet has a window or opening 3 formed therein, with a security element 4 being placed in the window. A second page 2b, which is adjacent to first page 2a, carries a verification element 5. Security element 4 and verification element 5 are located such that, when the pages 2a, 2b are placed on top of each other, the elements 4 and 5 overlap at least partially and create a verifiable optical effect.

For example, security element 4 can be a polarizing foil and verification element 5 a reflector selectively reflecting light of only a given polarization direction in a first region and light of perpendicular polarization in a second region, thus that the two re- gions become distinct when viewing verification element 5 through security element 4. Alternatively, security element 4 and verification element 5 can be a security feature and a verification element as taught by US

2005/0057036 or vice versa. The skilled person knows other similar pairs of elements which create special optical effects when placed on top of each other, such as line structures forming Moire-patterns, or color filters in combination with color prints. Advantageously, in order to exploit a see-through effect, security element 4 is at least partially transparent.

In the following, a manufacturing technique for forming a support sheet is described. The support sheet may e.g. be used to form first page 2a and/or second page 2b of booklet 1.

The manufacturing process:

Fig. 2 depicts a support sheet 10, which is advantageously a non-transparent sheet, such as a sheet of paper, in particular security paper.

In a first step support sheet 10 is yet in a flat, unfolded state and is submitted to a punching proc- ess by means of a punching apparatus 11, the latter being shown schematically in Fig. 2. The purpose of this process is to punch and/or cut a first window 12 and a second window 13 into support sheet 10. At the same time, the support sheet is marked along a first folding line 14 and, optionally, along a second folding line 15. The punching and marking are both carried out by the same ap ^¬ paratus 11 and at the same time, which allows to create the windows and folding line(s) at accurate relative positions, thereby ensuring a mutual alignment of high pre- cision after the folding process described below. For this purpose, apparatus 11 comprises a frame or common support, schematically indicated at 16, a first cutter 17 at the location of first window 12, a second cutter 18 at the location of second window 13, a first marker tool 19 mounted at the location of the first folding line 14 and, if desired, a second marker tool 20 mounted at the location of the second folding line 15. The cutters 17, 18, and the marker tools 19, 20 are all mounted to the same frame 16, thereby assuring an accurate mutual alignment.

As mentioned, support sheet 10 is "marked" at first folding line 14 and, if desired, at second folding line 15. Advantageously, this marking comprises a me- chanical working of support sheet 10 in order to simplify a later folding along the folding line(s). Advantageously, it comprises an embossing or partial cutting of support sheet 10 along the folding line(s).

As can be seen from Fig. 2, first folding line 14 divides support sheet 10 into a first section 22 and a second section 23. First window 12 is advantageously fully located within first section 22, while second window 13 is fully located in second section 23, even though one or both windows may also overlap with first folding line 14 and extend into both sections 22, 23.

In a next step, security element 4 is placed on support sheet 10. In the embodiment shown in Fig. 3, security element 4 is placed on first section 22 at the location of first window 12. It can then be fixed to support sheet 10 in that location in order to hold it in place during the next processing step. Such fixing can e.g. be carried out by gluing, e.g. using conventional glue, an adhesive film or a hotmelt process.

In a next step, support sheet 10 is folded along first folding line 14 such that first section 22 and second section 23 come to lie on top of each other. The two sections are now affixed to each other in order to prevent an unfolding along folding line 14. Such af- fixing can e.g. be carried out by a gluing process, again based on conventional glue, adhesive film or a hotmelt process. However, other adhesive or mechanical means for affixing the two sections to each others can be used as well, such as stitching or stapling technigues.

In an advantageous embodiment, a glue is applied by inkjet to select areas of first and/or second section 22, 23, such as along the edges of the sections 22, 23, and the edges of the windows 12, 13.

Advantageously, security element 4 is affixed to both sections 22, 23, e.g. during the above gluing process, in order to render its removal more difficult. The support sheet 10 as manufactured by the previous steps is shown in Fig. 5. As can be seen, security element 4 remains visible through at least one, preferably both windows 12, 13.

The folded support sheet 10 can now be used for forming two pages (i.e. leaves) of booklet 1, such as pages 2a and 2d. As it is known, such a booklet can be formed by a plurality of sheets, with each sheet being folded along the spine of the booklet. The corresponding folding line at the spine coincides with second folding line 15 of support sheet 10. In most applications, only a single sheet used for manufacturing booklet 10 is a support sheet as shown in Fig. 5, while the other sheets are conventional sheets of e.g. paper or plastics. However, it is possible to use more than a single support sheet 10 for manufacturing a booklet.

As shown in Fig. 5, not only first section 22 but also second section 23 of support sheet 10 extend at least to or over second folding line 15, thus that the edge of the folded part of support sheet 10 does not come to lie within the surface of the page carrying the first or second window 12, 13.

Booklet 10 is manufactured by placing a plurality of sheets, including support sheet 10, on top of each other. The sheets are then bound and folded at the location of folding line 15. Now, the outer edge regions of the pages of booklet 10 are cut in order to ensure that the edges of all pages are located exactly on top of each other. In Fig. 5, line 26 denotes a location where such cutting may take place. During this cutting process, the part of the support sheet 10 that comprises the first folding line 14 is advantageously removed.

Notes:

The terms "first page" and "second page" when used to refer to pages in a booklet are to be understood as designating different page sheets of the booklet. "First", "second", etc., however, are not to be understood to refer to any numbering of the pages, nor to any mutual order of the pages, unless explicitly specified. For example, the "first page" may be the page sheet that carries page number 17 and 18 at its front and back, while the "second page" carries page numbers 15 and 16.

The support sheet 10 may form one or two pages of this type within booklet 1.

In the embodiment above, a first and a second window 12, 13 are formed in support sheet 10, thereby forming window or opening 3 of the booklet of Fig. 1. It must be noted, though, that if security element 4 has to be visible from one side only, either first window 12 or second window 13 can be omitted.

If two windows 12, 13 are used, they can have the same shape and size or different shape and size, but they should overlap if the document is to be transparent at the given location.

The window or windows can optionally be cov- ered by transparent foils in addition to security element 4. For simplicity, though, it is advantageous if the first and/or second window 12, 13 forms an unobstructed opening reaching to security element 4.

In the example above, the security document is a passport. The present invention can, however, also be used with other types of security documents . Such security documents can be a booklet 1 as shown in Fig. 1, but they may also be formed by a single sheet, such as the folded support sheet of Fig. 5, in which case the se- curity document may e.g. be a cheque, identity card or banknote .

While there are shown and described presently preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.