DE102009037832B4 - Identification document with two superimposed images - Google Patents

Abstract

Identification document (1), which is provided with two overlapping images (5, 6), - the images (5, 6) being applied in separate work steps, - at least one of the images being in a form inaccessible from the outside, - one of the images being a grayscale image (6), one of the images being a color image (5) which includes both color information and light / dark information, the color image (5 ) in daylight over the underlying grayscale image (6) is dominantly visible, - the color image (5) is permeable to a test radiation with which the gray scale image (6) is irradiated for testing purposes, such that the color image (5) a reading of the Image information of the grayscale image (6) is not obstructed and a transparent film (3) serves as the image carrier for the color image (5) and a layer of lacquer is applied over the transparent film (3).

Description

The invention relates to an identification document which is provided with two superimposed images and to a method for producing such an identification document. The invention also relates to a method for checking the authenticity of such an identification document.

Identification documents, such as identity cards or passports, or other recording media such as bank cards or credit cards, etc., are increasingly provided with a color image, for example with a color image of the owner. The printing methods often used in practice for printing color images, e.g. dye-sublimation printing, are considered unsafe because the dyes can be removed relatively easily due to their low penetration depth. In the past, a transparent laminate or lacquer was applied to the color image in order to increase the security of the color image.

Another possibility for increasing the security of such documents is to use a further method for applying image information with a higher degree of security in addition to the printing method. Labeling with a labeling laser is considered to be a safe labeling process due to the possible high penetration depth and the irreversible material change, so that in practice color printing is combined with laser labeling.

Such a combination is for example from the document EP 0 537 484 A1 known. In the method described there, a color image is broken down into two parts, namely a light / dark part and a colored part, the light / dark part being introduced into an image carrier in a forgery-proof manner with the help of a laser marking. The partial image generated in this way is then superimposed congruently with the color component that is printed on the image carrier for this purpose. In other words, the printed colored partial image contains only color information, while the associated light / dark information is contained in the partial image below. The two partial images thus complement each other to form the overall information stored. The forgery-proof light / dark partial image in the image carrier remains even if the printed color image is removed from the image carrier. Identification should then be possible solely on the basis of the remaining light / dark partial image.

The disadvantage of the method described, however, is that the two partial images must always be arranged exactly one above the other so that the desired overall impression is created with complete image information. For this purpose, either complex coordination of the data sets for printer and laser arrangement or a no less complex assignment of the two partial images to one another is required, in that markings provided on the image carrier are detected with the aid of optical sensors. The method described is therefore comparatively complex, especially when different printing systems are used and have to be coordinated with one another.

In addition, the increase in security is also limited. Since the colored partial image overlays the light / dark partial image congruently, the light / dark partial image is not completely visible to the naked eye, so that the image information of the light / dark component can only be verified with difficulty. In the event of manipulation of the image data, use could be made of the fact that only a portion of the image information has been stored in the light / dark partial image in a forgery-proof manner. This is because it is possible to remove the color image and use a conventional color printing system to print a new color image with different image information, which then overlays the unchanged light / dark component. Such manipulation of identification documents with photographs is made easier due to the fact that a uniform alignment of the head, the size of the image section, etc. is required in the case of photographs. Due to the high degree of similarity between the various light images, the newly applied color image can be aligned with the more clearly visible components of the light / dark partial image (e.g. eyes, nose, mouth, etc.), so that a very precise overlay of the manipulated colored partial image is possible with the existing light / dark partial image.

Out DE 10 2008 038 990 A1 an identification card is known in which, as a security feature, two images are arranged congruently on the card with respect to motif, size and position as well as rotational position, the correspondence of the two images to be recognized by a viewer. For this purpose, either the substrate of the card is transparent or the images are attached to opposite sides of the card so that the viewer has to turn the card over in order to see the correspondence of the images.

One object of the present invention is to better secure identification documents which are provided with a color image against forgery or manipulation.

This object is achieved by an identification document according to claim 1 or a method for producing such an identification document according to claim 7.

The identification document according to the invention is characterized in that it is provided with two overlapping images, that the images are applied in separate work steps, that at least one of the images is in a form inaccessible from the outside, that one of the images is a It is a grayscale image and that one of the images is a color image that includes both color information and light / dark information, the color image being dominantly visible in daylight compared to the underlying grayscale image, the color image being transparent to test radiation, with which the grayscale image is irradiated for testing purposes, in such a way that the color image does not hinder reading of the image information of the grayscale image, and with a transparent film serving as the image carrier for the color image and a layer of lacquer being applied over the transparent film.

The method according to the invention for producing an identification document which is provided with two superimposed images is characterized in that one of the images is a grayscale image, that one of the images is a color image that contains both color information and also includes light / dark information, and that the color image is printed on an image carrier and the grayscale image is introduced into an image carrier by means of a controlled laser beam, the color image being predominantly visible in daylight compared to the underlying grayscale image, the color image being transparent to test radiation , with which the grayscale image is irradiated for testing purposes, in such a way that the color image does not hinder reading of the image information of the grayscale image, and wherein a transparent film is used as the image carrier for the color image and a layer of lacquer is applied over the transparent film.

In addition, the above-mentioned object is achieved by a method for checking such an identification document or the like according to claim 10.

The method according to the invention for checking the authenticity of an identification document which is provided with two superimposed images, the images being applied in separate work steps, with at least one of the images in a form inaccessible from the outside, one of the images being A grayscale image is involved, one of the images being a color image which includes both color information and light / dark information and where in daylight essentially only the color image is visible, is characterized by the following steps: irradiating the identification document or the like with a first test radiation for reading the image information of the color image, irradiating the identification document or the like with a second test radiation for reading the image information of the grayscale image, reading the image information of the color image and the grayscale image and evaluating, in particular comparing the received old picture information.

Advantageous embodiments of the invention are specified in the subclaims.

The advantages and configurations explained below in connection with the method also apply accordingly to the devices according to the invention and vice versa.

An identification document within the meaning of the invention is understood to mean not only identity cards or passports, but also other recording or data carriers, such as bank or credit cards or the like, which are not or not primarily used for identification purposes. In general, this is understood to mean a document or recording medium which is provided with images which are to be protected against manipulation or forgery.

An image is understood to be an optically readable representation of information, in which case it can in particular be photographs of people, sovereign symbols, graphic security elements, text information or other representations.

A basic idea of the invention is to take up the technology described in the prior art and to modify it in such a way that the color image comprises complete image information, that is to say both color and contrast information. It is therefore a key point of the invention not to use any partial images. Since there are always two images, each with complete image information, these can be verified more easily, so that manipulations are more easily recognized and falsification is made significantly more difficult.

The image information from one image can be completely or partially contained in the other image. In an advantageous embodiment of the invention, the grayscale image comprises all image information of the color image with the exception of the color information.

If the two images are identical or if the images differ only with regard to the color information, then they are advantageously arranged with respect to one another in such a way that they are superimposed congruently. For this purpose, both images have identical dimensions and are arranged in a precise position relative to one another. In this case, two images with maximum image information can be created be arranged in a particularly space-saving manner on a carrier. The color image is designed in such a way that it is dominantly visible to a viewer under daylight compared to the gray-scale image below. It is therefore not necessary to align the two images exactly with one another. A congruent overlay is also not absolutely necessary because the images do not have to complement each other to form overall information.

In an alternative embodiment of the invention, none of the images contains image information from the other image. In other words, it is also possible to provide the identification document with two different images. This possibility is not possible with the solution known from the prior art, in which the image information of the two partial images first have to complement each other to generate the overall image.

According to the invention, the color image is permeable to test radiation with which the grayscale image is irradiated for test purposes. This ensures that reading of the complete image information of the gray-scale image is not hindered by the color image. This enables a particularly simple check of the authenticity of the identification document.

If the color image is printed on an image carrier with a printer and the grayscale image is introduced into an image carrier by means of a controlled laser beam, in other words, the images are applied in separate work steps, then printing and labeling processes can be used that are already in practice are tried and tested. Thus, the present invention can essentially be implemented with existing machines without incurring major retrofitting costs.

It is preferably the grayscale image that is generated in a form inaccessible from the outside. The use of a controlled laser beam that writes the gray-scale image into the image carrier is particularly suitable for this purpose. A grayscale image is understood to mean an image that includes light / dark information. The number of gray levels only plays a subordinate role for the invention; in principle, the grayscale image can therefore also be a black and white image.

A transparent film, such as that used as one of the outer layers of a plastic identification document, is suitable as an image carrier. If the transparent film is used as a common carrier element for the color image and the grayscale image, the color image is printed onto the transparent film. The grayscale image is burned into the film with the help of the laser beam. To protect the color image, another protective layer in the form of a lacquer layer is applied over the transparent film.

If the printing ink used for the color image is permeable to the test radiation, which is used to irradiate the grayscale image, and if a marking laser is used which emits in the same wavelength range, the "printing processes" can be in any order. In other words, either the color image or the grayscale image can be produced first. The visual impression of the visible color image is the same for both methods.

In a further embodiment of the invention, different image carriers are used for the color image and the grayscale image. If, for example, the identification document is built up in layers, as is often the case with laminated cards, then different layers of the card serve as image carriers for the color or gray-scale image.

The image carrier for the color and grayscale image can be an intermediate product in the manufacturing process of the security document. For example, the film image carrier can be arranged on a carrier substrate that serves as part of a layer structure of an identity card. However, the image carrier can also already be a finished end product.

When checking the authenticity of the identification document, it is irradiated with a first and a second test radiation, the first test radiation being used to read the image information of the color image and the second test radiation to read the image information of the grayscale image. The image information obtained is then compared, with all of the above-mentioned method steps, but in particular the comparison step, being able to run automatically in the corresponding test device.

Since the color image is transparent to the test radiation with which the grayscale image is irradiated for test purposes, it cannot be detected when using such a test radiation.

In other words, it is not possible to read the image information of the color image when using this test radiation. The grayscale image, however, is completely legible in this case. It is thus possible to check whether the color image has actually been applied with printing inks which are transparent to the test radiation. If wrong printing inks were used, the color image covers the underlying grayscale image and reading the complete image information of the grayscale image is impossible. In other words it is possible to make the grayscale image covered by the color image completely visible with the aid of the test radiation without the color image covering image information of the grayscale image.

In the test radiation with which the gray-scale image is irradiated for testing purposes, it is preferably infrared radiation, which with an infrared illumination and an infrared-sensitive detector, for. B. a CCD sensor, which can be used in picture or video cameras, can be detected. Alternatively, test radiations with other wavelengths or wavelength ranges can also be used. The prerequisite for this is that the work environment has been adapted accordingly. In particular, suitable materials must be used for the test radiation, in particular for the printing inks of the color image and the image carriers, and suitable sensors must be available for checking the image information.

The test radiation with which the color image is irradiated for test purposes is preferably light visible to the human eye, e.g. Daylight. When the identification document is irradiated with daylight, essentially only the color image is visible to a viewer.

Preferably, a detector which is sensitive to both visible and infrared light is used in conjunction with a light source which emits visible light together with infrared light. This can be both artificial light and sunlight. In this case, the color image and - if not covered by the color image - also the grayscale image can be detected at the same time.

If a filter is attached in front of this detector which only allows infrared light to pass through, then the grayscale image can be detected, since the color image is transparent to the infrared light.

Alternatively, the image carrier can optionally be illuminated with visible light and with infrared light.

The image information of the two images detected in this way can be compared with one another following the illumination and acquisition of the image information.

A manipulation or forgery can be recognized when either the color image is visible under the infrared light or the gray-scale image is not visible under the infrared light or under visible light, or the gray-scale image and the color image do not contain the expected information.

• 1 eine schematische Darstellung eines Identifikationsdokuments mit einer transparenten Folie als Bildträger (Schnittansicht),
• 2 eine schematische Darstellung eines Identifikationsdokuments mit zwei unterschiedlichen Bildträgern (Schnittansicht),
• 3 eine schematische Darstellung eines ersten Beispiel-Identifikationsdokuments bei Tageslicht (3a) und bei IR-Licht (3b),
• 4 eine schematische Darstellung eines zweiten Beispiel-Identifikationsdokuments bei Tageslicht (4a) und bei IR-Licht (4b),
• 5 eine schematische Darstellung eines dritten Beispiel-Identifikationsdokuments bei Tageslicht (5a) und bei IR-Licht (5b) und
• 6 eine schematische Darstellung eines vierten Beispiel-Identifikationsdokuments bei Tageslicht (6a) und bei IR-Licht (6b).

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Here show:

• 1 a schematic representation of an identification document with a transparent film as an image carrier (sectional view),
• 2 a schematic representation of an identification document with two different image carriers (sectional view),
• 3 a schematic representation of a first example identification document in daylight ( 3a) and with IR light ( 3b) ,
• 4th a schematic representation of a second example identification document in daylight ( 4a) and with IR light ( 4b) ,
• 5 a schematic representation of a third example identification document in daylight ( 5a) and with IR light ( 5b) and
• 6 a schematic representation of a fourth example identification document in daylight ( 6a) and with IR light ( 6b) .

All figures show the invention only schematically and with its essential components. The same reference symbols correspond to elements with the same or comparable function.

The schematic representation of the printer or the printing method for printing the color image and the schematic representation of the laser arrangement or the method for controlling the laser beam on the one hand and the schematic representation of the test method or the test device are omitted, since this information is either familiar to the person skilled in the art or result in sufficient clarity from the following description.

A schematic representation of an identification document in the form of an identity card 1 is in 1 pictured. The ID card 1 comprises a polymer carrier 2 and one serving as a cover layer on the support 2 arranged transparent plastic film 3 as an image carrier for two superimposed images.

The two pictures are in separate steps on the slide 3 applied or in the film 3 brought in. On the one hand, this is an on the surface 4th the slide 3 printed color image 5 and on the other hand around one in the slide 3 burned-in grayscale image 6 , which is therefore in a form inaccessible from the outside. The color images are superimposed 5 and the grayscale image 6 .

The color picture 5 is applied with the help of a dye sublimation printer. Bringing in of the grayscale image 6 takes place with the help of a (near) infrared laser beam working with a wavelength of 1064 nm, which irreversibly discolors the processed material starting from the surface inside through local burning or sooting and thus irreversibly and thus forgery-proof.

The color picture 5 is characterized by the fact that it includes both color information and light / dark information. The underlying grayscale image 6 includes all image information of the color image 5 except for the color information. To generate the grayscale image 6 is preferably the color image 5 into a grayscale image 6 converted so that all image information with the exception of the color information is retained.

In 2 is another identification document, also in the form of an identity card 1 , shown. Different layers of the ID card, which is built up in layers, are used 1 as an image carrier. The color picture 5 is on an upper layer 7th imprinted while the grayscale image 6 with a controlled laser beam in an underlying, directly to the upper layer 7th adjacent lower layer 8th is introduced. An exact assignment of the two layers 7th , 8th to each other such that the color image 5 and the grayscale image 6 are arranged congruently to one another is not absolutely necessary, since each image already contains complete image information and an exact synopsis of the two images is not necessary.

To protect the color image 5 is in both cases a protective layer over the image carrier of the color image 17th provided in the form of a clear laminate.

In both cases the color image is 5 permeable to infrared radiation, which is used as test radiation for irradiating the grayscale image 6 serves.

When checking the authenticity of the ID card 1 the ID card is irradiated 1 with daylight for reading the image information of the color image 5 and irradiating with infrared light to read the image information of the grayscale image 6 . The image information of the color image 5 and that of the grayscale image 6 read with the help of suitable sensors and fed to an evaluation unit for evaluation, in particular for comparing the image information obtained.

This in 3 illustrated first example identification document 9 is with a color picture 10 , namely the photograph of a woman. This image information is visible in daylight, as in 3a shown. Irradiate this document 9 with infrared light, you get that in 3b shown grayscale image 11 which contains the same image information as the color image with the exception of the color information 10 . When evaluating the image information read, here in particular in the form of a comparison of the image information of the color image 10 with the image information of the grayscale image 11 occurs, this match is determined. There is no forgery or manipulation of the color image 10 in front.

This in 4th illustrated second example identification document 12 is again provided with a colored photograph of a woman. This image information is visible in daylight, as in 4a shown. If you irradiate this document with infrared light, you get that in 4b shown grayscale image 13 depicting a photograph of a man. An evaluation of the read image information shows that the image information does not match. The document 12 belongs to a male person. The color picture 10 was faked.

This in 5 illustrated third example identification document 14th As in the cases described above, it is provided with a photograph of a woman. This image information is again visible in daylight, as in 5a shown. Irradiate this document 14th with infrared light, one finds, as in 5b shown, no grayscale image. It is therefore a forged document 14th , in which only a color image 10 was printed. The forgery-proof grayscale image, however, is missing. This is determined when evaluating the image information.

This in 6 illustrated fourth example identification document 15th As in the cases described above, it is provided with a photograph of a woman. This image information is again visible in daylight, as in 6a shown. The document 15th differs from the documents shown above in that color formation and grayscale image do not contain identical image information. Instead, it is provided that a numerical code is written under the color image, in this case the date of birth of the document holder. A forgery would therefore be recognized immediately if the number code was missing. If you now irradiate this document 15th with infrared light, one finds, as in 6b shown, a grayscale image 16 showing the numeric code. Still, as in 4th , Color image and grayscale image differ from one another, it can be assumed at first glance that there is no forgery. To confirm this statement, a subsequent evaluation of the image information, in particular an evaluation of the numerical code and checking of the date of birth, is necessary.

Conventional devices for checking the authenticity of identification documents mostly already include the assemblies necessary for carrying out the checking method according to the invention, in particular a lighting unit for irradiating the identification document 1 with a first test radiation (eg daylight) for reading the image information of the color image 5 and / or for irradiating the identification document 1 with a second test radiation (eg infrared light) to read the image information of the gray-scale image 6 and an evaluation unit for evaluating, in particular for comparing the image information obtained. To carry out the method according to the invention, therefore, only one adaptation of the evaluation algorithms is generally necessary.

Deviations from the example shown are possible. For example, the color image 5 can also be applied with the help of another printing process, provided that this allows the use of infrared-permeable printing ink. In another variant, the grayscale image 6 instead of a birthday a different one from the color picture 5 contain various image information, for example a serial number, a coat of arms or another national emblem or the like.

All of the features shown in the description, the following claims and the drawing can be essential to the invention both individually and in any combination with one another.

List of reference symbols

1

Identification card

2

carrier

3

foil

4th

Foil surface

5

Color image

6th

Grayscale image

7th

Upper layer

8th

Lower class

9

first document

10

Color image

11

Grayscale image

12

second document

13th

Grayscale image

14th

third document

15th

fourth document

16

Grayscale image

17th

Protective layer

Claims (11)

Identification document (1) which is provided with two overlapping images (5, 6), - The images (5, 6) are applied in separate work steps, - with at least one of the images in a form inaccessible from the outside, - one of the images being a grayscale image (6), - One of the images is a color image (5) which includes both color information and light / dark information, - wherein the color image (5) is dominantly visible in daylight compared to the underlying grayscale image (6), - The color image (5) being permeable to a test radiation with which the gray-scale image (6) is irradiated for test purposes, in such a way that the color image (5) does not hinder reading of the image information of the gray-scale image (6) and - A transparent film (3) serving as the image carrier for the color image (5) and a layer of lacquer being applied over the transparent film (3). Identification document (1) Claim 1 wherein at least portions of the image information of one image are contained in the other image. Identification document (1) Claim 1 or 2 wherein the grayscale image (6) comprises all image information of the color image (5) with the exception of the color information. Identification document (1) according to one of the Claims 1 to 3 , whereby the images (5, 6) overlap congruently. Identification document (1) Claim 1 , wherein none of the images (5, 6) contain image information of the respective other image. Identification document (1) according to one of the Claims 1 to 5 , the grayscale image (6) being in a form inaccessible from the outside. Method for producing an identification document (1) which is provided with two overlapping images (5, 6), - one of the images being a grayscale image (6), - one of the images being a color image (5) acts, which includes both color information and light / dark information, the color image (5) being printed on an image carrier (3; 7) and the gray-scale image (6) being introduced into an image carrier (3; 8) by means of a controlled laser beam, - the color image (5) being compared to the underlying gray-scale image (5) in daylight. 6) is dominantly visible, - the color image (5) being permeable to a test radiation with which the gray-scale image (6) is irradiated for testing purposes, in such a way that the color image (5) does not hinder reading of the image information of the gray-scale image (6) and - a transparent film (3) serving as the image carrier for the color image (5) and a layer of lacquer being applied over the transparent film (3). Procedure according to Claim 7 , wherein the image carrier (3) for the color image (5) is at the same time the image carrier (3) for the grayscale image (6). Procedure according to Claim 7 wherein the image carriers are different, preferably directly adjacent layers (7, 8) in the layer structure of the identification document (1). Method for checking the authenticity of an identification document (1) which is provided with two overlapping images (5, 6), the images (5, 6) being applied in separate work steps, at least one of the images in a form inaccessible from the outside is present, one of the images being a grayscale image (6), one of the images being a color image (5) comprising both color information and light / dark information, and being essentially in daylight only the color image is visible with the steps: - irradiating the identification document (1) with a first test radiation for reading the image information of the color image (5), - irradiating the identification document (1) with a second test radiation for reading the image information of the gray-scale image (6), - Reading the image information of the color image (5) and the grayscale image (6) and Evaluation, in particular comparison, of the image information obtained. Procedure according to Claim 10 , wherein the second test radiation is infrared radiation.

Images