WO2012100309A1

WO2012100309A1 - Security perforation and method for protection against counterfeiting by means of perforation

Info

Publication number: WO2012100309A1
Application number: PCT/BG2012/000002
Authority: WO
Inventors: Zhivko Zhelev; Arkadiush Zhelev; Vitan GRANCHAROV
Original assignee: Keit Ltd.
Priority date: 2011-01-24
Filing date: 2012-01-23
Publication date: 2012-08-02
Also published as: BG66604B1; EP2768675A1; BG110837A

Abstract

The present invention relates to a high resolution perforation with color shades and a method for protection, verification and authentication of originality of products. The perforation is applied over a product with holes with the same size and the same distance between them, and the perforated holes are of the same shape or they are of different shapes for obtaining different shades.

Description

SECURITY PERFORATION AND METHOD FOR PROTECTION AGAINST

COUNTERFEITING BY MEANS OF PERFORATION

FIELD OF THE INVENTION

The present invention relates to a high resolution perforation with color shades and a method for protection, verification and authentication of originality of products.

BACKGROUND OF THE INVENTION

A number of methods and means are known for protection against counterfeiting of documents, banknotes, securities, etc by laser perforation. Document WO9718092A1 reveals a method for perforating an image by means of holes with such a size, that the image is visible in transiting light and invisible under reflected light, while US2006006236A1 describes a method, where the perforated holes have an elliptic shape , which are cross oriented in different directions in order to obtain different images depending on a viewing angle, but non of them describes a method for achieving a perforated image with high resolution and color levels(shades). Document EP0936975B1 discloses a method for obtaining the color levels by means of round holes with different diameters depending on the grey level. A major disadvantage of this method is that it is not possible to achieve a high resolution image - a high number of perforated holes with small distance in between - perforated over a very small area, because in such a case due to the small distance between the holes and the different hole diameters there will be an overlapping of holes, which will significantly deteriorate a quality of the perforated image. In addition it is possible to damage the perforated surface as a result of the large number of perforated holes with big diameters and their overlapping and the resulting material over-burning.

On the other hand none of the above-mentioned methods achieve a high quality image with high density(resolution) in case of perforation of a simple black and white image without color and light shades.

TECHNICAL DESCRIPTION OF THE INVENTION

The above described disadvantages are resolved be means of the proposed method for the image perforation, where the perforation consists of holes with the same fixed size and distance between them. In such way within the framework of fixed size it is achieved a large variety of color shades (levels) and an excellent visual perception of the perforated image. On the other hand it allows obtaining high density of the perforated holes and thus the higher resolution of the perforated image.

Considering a laser micro perforation with holes with different diameters depending on the shades of gray, where the diameters of the holes are between 80 and more than 200 μηι depending on the level of the gray shade. In this case for obtaining a high resolution image on a small perforation surface, the perforation must be carried out with the distance of 200 μιη between the hole centers which will result in the overlapping of the holes, and will lead to lower quality of the perforated image as well as to destruction of the structure of the protected object. The last can cause its rupture or breaking and destruction either during the perforation or later when the protected object is utilized.

The perforation proposed in the present invention and the method do not have such problems and disadvantages since the perforation is carried out with the same fixed size of the holes and same distance between them and at the same time the perforated image features the high density of perforated holes and resolution.

In most of the cases the security perforation represents the perforation of a certain image, like a photograph of an owner of an identity document, a logo, a number or other image. The said images have their digital format obtained by scanning, digital photographs or other means for digitalisation. The digital image represents a set of digital values, called picture elements or pixels, which describe the color shades of the image and can be different in quantity (number) depending on a image classification. For instance 256 shades of gray in so-called gray-scale digital images or 65536 colors - respectively color levels, and in some cases only two - black and white for so-called monochromatic (binary) images.

In the presence of a gray scale image or such with large number of color levels, any of the respective color levels are represented by the holes with a different shape and the same size (diameter, sides, etc.) where for a certain color level is juxtaposed a perforated hole with an exact predetermined shape and for the other level - another shape of the hole. The shape of the holes is defined in such a way, to be with rising or decreasing filling depending on the shades of the colors. When there is a level of gray 0 in the case of 255 gray shades of the gray-scale image it is juxtaposed with a figure with a certain filling, while for the level 1 such with bigger filling than the previous level and so on in the increasing order up to level 255, and at the same time all of the level-related holes remain in the frame - neither smaller nor bigger - of the fixed hole size, that is not changed for the entire perforated image along with the constant distance between the perforated holes.

In case of a simply black and white (monochromatic) image, where there is a single color shade in order to acquire high quality and high resolution perforated image, then the only one color shade is represented with a hole with the same shape and size. Respectively white or black shade is perforated with the hole with the same shape (filling) and size. The perforation is carried out in a perforation grid with constant elongation (distance) between centers of the perforated holes. Thus can be achieved high resolution perforated images and high quality of the visual perception in the transiting as well as in the reflected light.

The so-acquired high resolution and high quality perforated images serve as an unique security feature for protection against counterfeiting and forgery of a large spectrum of documents, such as passports, ID (identity) cards, driving licenses, access authorization documents (permits), Visa stickers, etc., as well as of any securities - banknote, cheques, excise labels, package lists, etc.

The applied perforation itself can be a serial number of a protected object, a face image of a holder of the identity document or any other image - a logo, a coat of arms, etc. Counterfeiting will be very difficult because of the high quality and resolution of the perforated image, which facilitates its clear recognition and authentication. When identity documents are protected by means of perforation of the face image of the document owner, can his identity and the authenticity of the document be verified unambiguously, due to the high resolution and quality of the perforation even in cases of attempts to forge the owner's photograph printed over the document. At the same time, the high density of the perforated image permitting its application over smaller areas of the document creates additional difficulties to counterfeiting.

The perforation can be carried out be means of mechanical, laser, ion or any other kind of perforation - cutting holes. Laser and micro perforation are particularly appropriate in order to achieve very high resolution and quality of the perforated image over different groups of materials depending on the wavelength of the lasers. 10600 nm wavelength is used for different types of paper and plastic material, while for metals is used the 1064nm wavelength, etc.

DESCRIPTION OF THE ENCLOSED FIGURES

Fig.1. - shows a perforation of an image by means of holes with the constant size and shape and the constant distance between the holes.

Fig.2. - shows a perforation of an image by means of holes with the same size and same distance between them, where the holes have different rounded shape depending on the shade of gray.

Fig.3. - shows a perforation of an image by means of holes with the same size and same distance between them, where the holes have different non-rounded shape depending on the shade of gray.

Fig.4. - shows a perforation of an image by means of holes with the same size and shape and the same distance between the holes, where the image is converted to black and white.

EXAMPLES OF PREFERRED EMBODIMENTS

Fig.l shows an example of the invention, where the input is a black and white (monochromatic) image (1) and the said image is transformed to the resolution for perforating by resizing the image. The ready image is perforated by means of holes with the same size, which are spaced over the predefined fixed distance between them. Depending on the preferred visual perception effect will be perforated only the shade of white (2) or the shade of black (3). In the first case (white shade perforation) we obtain a negative image, that is better perceived in the transitting rather than in reflected light, and in the second case we obtain a positive perforated image, which is better perceived in reflected light. The same applies for a color image, that is at first transformed to black and white and then perforated as described above.

Another preferred embodiment is in the case of an image of gray-scale type with 256 color shades of the gray color is shown in fig.2, where depending in the color level (1) holes are perforated with a relevant shape (2) and for a group of color levels(shades) the holes are perforated with the same shape (2) in order to have the perforated image (3) for the protection of a passport (4).

The same effect is obtained in fig.3, where a high resolution image (1) with 16 bit color shades (65536 levels) is converted to the gray-scale with 256 levels(shades) of the gray (2) by means of standard transformation - (R-red +G-green +B-blue) /3). The acquired image (2) is perforated by means of the holes with different shape depending on the gray shade level (3) for obtaining the perforated image (4) over an identity card (5).

One another preferred embodiment is presented in fig.4., where from a color image (1) by means of any of the classical techniques for an image half-toning is obtained a black and white image - in this particular example is used the Floyd-Steinberg method, which is perforated for protection against counterfeiting by means of the holes with the same size, spaced over the same predefined distance and again depending on the preferences for the visual effect either only white shade (2) or only black shade (3).. Another methods can be used for obtaining of a halftone image, like Jarvis, Stucki, Cardinality-Distribution, simple thresholding, et c, which are well known and are not an object of the present invention, and to obtain a black and white image the holes are perforated with the same size and the same distance in a perforation matrix(grid) for obtaining a high resolution security perforation, like (2) and (3) for protecting a passport (4) or an identity card (5).

Claims

1. Perforation of an image over products for protection against counterfeiting, characterized in that, the perforation is with holes with the same size and distance between them, and the perforated holes represent figures with different shape for obtaining color shades.

2. Perforation of an image over products for protection against counterfeiting, characterized in that, the perforation is with holes spaced over a same distance between them and with a same size and of the same shape for obtaining a single color shade.

3. Perforation of an image over products for protection against counterfeiting according to claims 1 and 2, characterized in that, the perforation is used for protecting of documents against counterfeiting.

4. Perforation of an image over products for protection against counterfeiting according to any of the preceding claims, characterized in that, the protected document is a passport, an identity card, a banknote, a cheque, a driving license, an access authorization document, a visa sticker, a label, a packing list, an excise label and any other document.

5. Perforation of an image over products for protection against counterfeiting according to any of the preceding claims, characterized in that, the perforation represents a number, an image of a document holder/owner, a logo, a coat of arms and/or another image.

6. Perforation of an image over products for protection against counterfeiting according to any of the preceding claims, characterized in that, the perforation is a laser, a mechanical, an ion or other type of perforation.

7. Method for protection against counterfeiting of products by means of perforating an image according to claims 1, 3, 4-6, characterized in that, holes are perforated with the same size and the same distance between them and depending on the color shades the holes are perforated with different shape.

8. Method for protection against counterfeiting of products by means of perforating an image according to claims 1, 3, 4-6, characterized in that, holes are perforated with the same size and the same shape for achieving a single color shade.

9. Method according to claims 7 and 8, characterized in that, the perforated document is a passport, an identity card, a banknote, a cheque, a driving license, an access authorization document, a visa sticker, a label, a package list, an excise label or other documents.

10. Method according to claims 7 - 9, characterized in that, the perforation is obtained by means of a laser, a mechanical or other means for perforating.