CN103875026B - Verify method and apparatus and the application of this device of the secure file with the security feature that form is fluorescent printing element - Google Patents

Abstract

The method and apparatus that the present invention relates to a kind of secure file for verifying the security feature with the changing luminous material that form is at least one fluorescence, this changing luminous material can excite in the electromagnetic radiation of first wave length scope, so as the electromagnetic radiation launched in second wave length scope, wherein, in the first and second wave-length coverages are in visible spectral range.This device includes the mobile phone of freely programmable, and this mobile phone is with for the light source of the inspection area of the radiation of visible light secure file in the range of first wave length and with the photo sensor for shooting visible ray.This mobile phone is configured to, and is used for radiation that shot by photo sensor, that launched in the range of second wave length by changing luminous material and previously given data compare and signal represents concordance.

Description

Method and device for authenticating a security document with a security feature in the form of a fluorescent printing element and the application of this device

The invention relates to a method and a device for authenticating a security document with a security feature in the form of at least one fluorescent printing element and to the use of the corresponding device. In particular, the method can be carried out by a smartphone or the device can be an integrated part of the smartphone.

Security documents with security features in the form of luminescent substances are already known from the prior art, thereby rendering the security document counterfeit-proof or verifiable. Security documents according to the invention are in particular banknotes, travel passports, identity cards, driver's licenses, tickets or similar documents or objects in which there is a need for security against counterfeiting.

EP1673231B1 describes a value document with a value document substrate having at least two different characteristic materials for checking the value document. At least one feature material is formed by a luminescent material or a mixture of luminescent materials. Characteristic materials can be irradiated with visible or infrared radiation, with emissions occurring in the infrared spectral range. A plausibility check is performed based on the detected emissions.

EP0977670B1 discloses a printed value document with an authenticity feature in the form of a luminescent substance based on a matrix lattice doped with rare earth metals. The matrix lattice absorbs almost in the entire visible spectral range, so that all lines are suppressed in the visible spectral range of the luminescent substance. The excited region of the luminescent substance coincides with the irradiated region of a strong light source, such as a halogen lamp or a flash lamp. However, excitation by light from the visible range is also possible.

EP0991522B1 comprises a value document with a luminescent substance having an emission spectrum substantially in the infrared-spectral range, when the luminescent substance is mixed into the value document in a maximum amount that does not alter the document At this time, the luminescent substances can only be detected by conventional detectors with high measurement-technical outlay. Materials based on holmium-doped host lattices are provided as suitable substances.

EP0053183B1 discloses a document of value which has an authenticity feature in the form of a luminescent and absorbing substance which is excitable by invisible and/or visible light and which emits light only in the invisible optical spectral range.

Reference should also be made to EP0052624B1, EP0053124B1, EP0053148B1, EP0975468B1 and EP0975469B1, which likewise describe documents of value with luminous authenticity features. The excitation of the phosphor can take place both in the visible and in the invisible spectral range. As an additional safety factor, it should be noted that as far as possible no emissions should occur in the visible range.

In order to verify security documents, special testing devices are often required, most of these testing devices are inactive and are only available to a limited group of users. Furthermore, providing detectors for mobile applications has been pursued for some time.

WO2006/056268A1 and DE102004056007A1 contain a mobile authentication device for checking the authenticity of travel documents. The authentication means comprises identification means for identifying the legitimate user, opening means for opening the authentication means based on a signal of the identification means, an optical reading unit for reading the image or alphanumeric information contained on the pages of the travel document, A data processing device for processing the signals provided by the optical reading unit according to a predetermined algorithm, a display unit for displaying the read data and verification results and for encrypted transmission of the read data or verification results to Communication unit of the central station. According to a preferred embodiment, the mobile telephone can be used as graphics display unit, data processing unit and communication unit. For example, a camera is used as the optical reading unit, which preferably has an illumination device with a modulatable, in particular pulsed, light source, such as an LED or a laser diode. Security elements contained in the pigments of the printing ink can be excited by using such an illumination system, and the signals obtained here are likewise used for authenticity checks.

A system for identifying counterfeit banknotes by means of a mobile phone is described in CN1462010A. Banknotes are encrypted with the help of infrared barcodes. The barcodes are recorded in a central computer-database. After the banknotes have been put into circulation, the authenticity of the banknotes can be checked by means of the banknote recognition function of the mobile phone implemented by suitable software. For this purpose the central database is accessed via a mobile wireless connection.

CN101252612A discloses a mobile phone with a system for checking the authenticity of banknotes. The system comprises a CCD camera arranged on the mobile phone and a light source which is arranged on the same side as the CCD camera. The light source preferably includes an infrared light source and an ultraviolet light source. The system may also have an infrared filter and an ultraviolet filter which can be moved to the infrared light source or the ultraviolet light source by means of a transfer mechanism. With the described system, a CCD-camera commonly used in mobile phones can detect security features of banknotes. The disadvantage of this solution is that additional modifications are required on the mobile phone, such as setting the light source.

A mobile phone with an integrated spectroscopic sensor is known from US 2006/0279732 A1. Spectroscopic sensors include light sources and photo sensors, wherein flashlights and CMOS/CCD image sensors already present in mobile phones are used as light sources and photo sensors. Authenticity checks of objects, such as banknotes, jewellery, etc., are to be carried out by means of a mobile phone. The wavelength range of the radiation used is however not described in detail.

US2005/0100204A1 discloses a method and a device for detecting fluorescent particles to check the authenticity of documents. The device includes a mobile phone with an integrated light source and photo sensor.

US2010/144387A1 discloses a multifunctional portable electronic device with an integrated authentication function. The device can be, for example, a mobile phone or a PDA. For authenticating documents of value such as banknotes, the corresponding regions are excited, for example, by red or violet light from a light source of the device. The resulting emission can be evaluated visually and also detected by means of a camera module. A comparison is made with the given data by means of the central processing unit. The verification result is output on the display unit.

EP1986162A1 describes a device and a method for authenticity checking, wherein a target area comprising an authenticity feature is excited with visible or invisible light and is detected by means of a photo sensor in the visible or invisible spectral range launch.

EP1672668A1 studies the security features of fluorescence, which emits light in the visible spectral range. For excitation, a lighting unit with an array of LEDs can be used, which can emit light in different spectral ranges.

WO 2008/113963 A1 discloses a mobile device for authenticity checks with two oppositely arranged LEDs emitting visible light which is focused by means of a Fresnel lens and illuminates a set of security elements . The light emitted by the security element is detected by means of an image sensor and further processed by a processor. The emitted light is in the visible spectrum. The result of the inspection is signaled optically or acoustically.

WO 2010/100378 A2 describes a method for the optical analysis of substances on objects or documents. Shining an object or document with visible light to excite a substance that then emits visible light. Corresponding filter elements are used in order to visualize unique colored radiation that cannot be detected in visible light.

The technical problem to be solved by the present invention is to provide a device for verifying security documents, an application and a method of the device. In particular, the device according to the invention should be characterized in that it consists of simple, widely available components and is realized at a lower cost than conventionally used verification devices. In particular, it is desirable to design devices and methods for authenticating such security documents in such a way that they can be easily integrated into mobile phones, smartphones and similar devices.

The method for verifying security documents according to claim 1 serves to solve the technical problem according to the invention. A device for verifying security documents according to claim 4 also serves to solve the problem according to the invention. Finally, the invention provides a use of such a device for authenticating security documents according to claim 7 .

The method according to the invention for authenticating a security document comprises the steps of first exciting a pigment-like fluorescent printing element arranged in the inspection region of the security document by means of a light source which emits light in the visible spectral range. As is used in particular in modern mobile phones, LED lamps, which are used as flashlights or camera lights, are preferably used as light sources. However, excitation can also be effected by continuous light sources, for example by neon tubes, halogen radiators or LED lighting. Excitation can also be achieved by natural sunlight. In order to excite the preferably used fluorescent printing elements, blue light is usually sufficient. Light is emitted from the fluorescent printing element due to excitation. The emission of the pigmented fluorescent printing element is detected by a photo sensor and then evaluated. The evaluation is carried out by means of a dedicated application which also takes into account different light sources. The photo sensor is preferably the image sensor of the mobile phone, while the application program can be installed on the smartphone as a so-called APP.

In this evaluation, a comparison can be made with the remaining surface of the security document (comparison area) of the printing element not provided with fluorescence or with an image recording of an unexcited fluorescent printing element. The comparison data are usually stored in a database, for example stored in a mobile phone or available online. However, the data required for the comparison can also be generated during the method by illuminating the comparison region of the security document with an excited light source and detecting the emission of the comparison region. Alternatively, fluorescent printing elements can also be detected in the unexcited state and used for comparison.

In a final method step, the verification result is output, preferably on a display of the mobile phone. The verification result can be transmitted by the mobile phone to a remote recipient when required.

The security document authenticated by means of the method according to the invention has a security feature in the form of at least one pigment-like fluorescent printing element which is excitable in a first wavelength range of electromagnetic radiation in order to emit electromagnetic radiation in a second wavelength range, Wherein, the first and the second wavelength range are in the visible spectral range.

Particular preference is given to using modified forms of fine-grained, inorganic LED-converting phosphors as fluorescent printing elements which are added to printing pigments, printing inks or printing pads. The conversion phosphors used in the production of LEDs belong to this group in order to convert at least part of the emission of the semiconductor in the blue region into another color region for the generation of white light.

The device according to the invention comprises a freely programmable mobile phone with a light source for emitting light in the visible spectral range and a photo sensor for recording or measuring light in the visible spectral range. The freely programmable mobile phone is configured in such a way that it is able to compare the radiation emitted by the pigment-like fluorescent printing element, taken or measured by a photo sensor, with predetermined data and can signal a coincidence or deviation to verify the inspection The security features of the security file.

An important advantage of the authentication device according to the invention is that only one correspondingly equipped mobile phone is required. A simple and inexpensive solution is thus provided for the authenticity check of security documents. The verification device can be made available to a wider user group, which enables location-independent checking of security documents.

Smartphones are freely programmable mobile phones, which can be individually equipped with new functions by the user via additional programs (so-called apps). The light source and photo sensor required for verification are present in the smartphone as standard, so no changes to existing hardware are necessary. Smartphones often have LED-light sources for flash or lighting functions. With the aid of such so-called LED flashes, fluorescent printing elements used as security features can be excited. Smartphone photo sensors, such as CCD-sensors, CMOS-sensors or Foveon-sensors, are equipped with shutter systems in the range of 10 ms to 50 ms, especially in the range of 33 ms, in the wavelength range from about 360 nm to 1100 nm. Such photo sensors are usually designed with RGB color filters and IR blocking filters, since they are sensitive up to approximately 1100 nm and have a high sensitivity especially in the invisible range of 780 nm to 1100 nm.

An important advantage of the invention is that the emission in the visible spectral range is achieved by means of the fluorescent printing element used as a security feature. Since this emission is in the visible spectral range, it can be detected with low outlay and without special detectors, for example by a color image sensor of a smartphone. In the solutions known from the prior art, the alternatives to the above usually result in emissions in the invisible range due to the luminescent materials used, the detection of which is significantly more complex.

According to an advantageous embodiment, the first wavelength range for exciting the fluorescent printing element is between 380 nm and 500 nm. The average wavelength of the first wavelength range is preferably in the visible spectral range, wherein it is likewise preferably in the wavelength range between 380 nm and 500 nm. For some embodiments, an average wavelength between 420 nm and 470 nm or between 450 nm and 470 nm has proven to be advantageous.

The fluorescent printing element emits light in the second wavelength range, preferably in the visible spectral range. The wavelength or mean wavelength of the second wavelength range is preferably in the visible spectral range between 490 nm and 780 nm or between 550 nm and 780 nm.

The security features are usually applied to the security document by printing techniques or integrated in the security document. The printing pigments, printing inks or ink pads used preferably have a polymeric binder matrix in which the fluorescent printing elements are dispersed homogeneously. Printing pigments, printing inks or ink pads by means of suitable application methods, such as intaglio printing, gravure printing, offset printing, flexographic printing, screen printing, inkjet printing, transfer printing, retransfer printing, laser-transfer printing - Printing, flexographic printing or numbering means applied on the security document or integrated in the security document by printing the inner layer and subsequent lamination.

According to an advantageous embodiment, the pigmented fluorescent printing element has a d50 pigment distribution of 1 μm to 20 μm. The d50-value is a measure of the average pigment size. d50 indicates that 50% of the pigment is less than the given value. In another embodiment, it has proven to be advantageous for the d50 pigments to be distributed in the sub-μm range, in particular in the nanoscale range. Here, the d50 pigment distribution is advantageously in the range of 3 nm to 30 nm or in the range of 100 nm to 500 nm.

According to a preferred embodiment, the fluorescent printing element is formed by a luminescent material selected from the following group:

- Europium-doped alkaline earth metal orthosilicate luminescent materials and europium-doped alkaline earth metal silicate luminescent materials;

- luminescent materials of nitrides;

- Rare earth metals doped with cerium-aluminum-gallium-garnet-luminescent materials;

- red-emitting (Ca,Sr)S:Eu ²⁺ , and

- Green-emitting SrGa ₂ S ₄ :Eu ²⁺ .

Europium-doped alkaline earth metal orthosilicate phosphors or europium-doped alkaline earth metal silicate phosphors are preferably structured according to the general formula:

M ^II ₂ SiO ₄ :Eu ²⁺ where M ^II =Ca, Sr, Ba and/or

M ^II ₃ SiO ₅ :Eu ²⁺ where M ^II =Sr, Ba. When excited, Eu ²⁺ -activated orthosilicates emit broad-band in the blue spectral range with an emission wavelength maximum between 500 nm and 620 nm, depending on the specific luminescent material composition, in the yellow or orange spectrum Silicates that emit in the range between 550 nm and 610 nm have an emission spectrum with a significantly smaller half-value width.

The rare earth metal-aluminum/gallium-garnet phosphor doped with cerium is preferably structured according to the general chemical formula: M ^III ₃ (Al _1-x Ga _x ) ₅ O ₁₂ :Ce ³⁺ where M ^III =Y, Gd, Tb ,Lu and 0≤x≤1. This class of luminescent materials is characterized in that, by varying the cation and Ce3+-contents of the rare earth elements and by substitution in the anion partial lattice, that is to say by gallium-aluminum substitution, emission wavelengths can be obtained in a wide range of the visible spectrum, ie from Move within the range of 500nm to 600nm.

The red-emitting (Ca,Sr)S:Eu ²⁺ and the green-emitting strontium thiogallate SrGa ₂ S ₄ :Eu ²⁺ have lambda max values in the range of about 650 nm to about 525 nm.

Particularly preferred are printed elements which are fluorescent by means of nitride phosphors. The luminescent material is preferably doped with Eu ²⁺ or Ce ³⁺ as activator. The host lattice of the luminescent material preferably passes through the nitrided silicate of the M-Si-N structure, the silicon-based oxynitride through the M-Si-ON structure, the aluminum nitride through the M-Al-N structure, through the M - Si-Al-N structure of Si-Al-Nitride or Si-Al-O-Nitride of M-Si-Al-ON structure.

Particularly preferably, the fluorescent printing element consists of a nitride phosphor with M-Si-N, M-Si-ON, M-Al-N, M-Si-Al-N or M-Si - Al-ON structure host lattice and doped with Eu ²⁺ as activator, or with M-Si-N, La-Si-N, M-Si-Al-N or M-Si-Al-ON structure host lattice and doped with Ce3 ⁺ as activator. Here, M stands for a metal which is preferably formed by Ca, Sr and/or Ba.

Important representatives of Eu ²⁺ - or Ce ^{3+ -doped} nitride phosphors are summarized in Tables 1 and 2 below and their characteristic emission wavelengths are indicated.

Table 1

Form 2

The various luminescent materials exemplarily listed here should not represent limitations. It is also possible to use other suitable phosphors which, after excitation, emit visible light in the blue or visible spectral range, as well as mixtures of different phosphors. Furthermore, a preferred embodiment consists in that, in particular, those conversion phosphors which are also used for producing white-emitting LEDs are suitably modified by changing the lattice composition, the activator concentration and/or by co-doping other different properties The rare earth metal ions are modified and used in this form as phosphor printing elements according to the invention.

Claims (7)

1. the method using the mobile phone authenticating security documents of freely programmable, wherein, this safety File include the printed element of the fluorescence of at least one pigment shape as security feature, this printed element arrange In inspection area and can excite in the electromagnetic radiation of first wave length scope, in order to launch second wave length model Electromagnetic radiation in enclosing, wherein, the first and second wave-length coverages are in visible spectral range, and Wherein, the fluorescent printing element of described pigment shape is consisted of the luminescent material of nitride, this luminescent material There is the substrate of M-Si-N, M-Si-O-N, M-Al-N, M-Si-Al-N or M-Si-Al-O-N structure Lattice and the Eu that adulterates²⁺As activator, or have M-Si-N, La-Si-N, M-Si-Al-N or The parent lattice of M-Si-Al-O-N structure and the Ce3 that adulterates⁺As activator, wherein, M represents metal,

Said method comprising the steps of:

-glisten by means of the LED-of the mobile phone of the freely programmable of luminescence in the range of first wave length Excite the printed element of fluorescence；

-sending out by the printed element of the photo sensor detection fluorescence of the mobile phone of freely programmable Penetrate；

-by means of the App of mobile phone of freely programmable by comparing with previously given data Relatively assess the transmitting of detection, fluorescence printed element in the range of second wave length；

-according to the result of the comparison output the result carried out.

2. the method for claim 1, it is characterised in that the method is further comprising the steps of:

-illuminate the comparison domain of secure file by means of the light source of luminescence in the range of visible spectrum, its In, this comparison domain does not comprise the printed element of the fluorescence being arranged in inspection area；

-by the transmitting of photo sensor detection comparison domain；

-launching of the comparison domain that detects is used as the detecting of printed element at assessment fluorescence The previously given data used during transmitting.

3. include an application for the device of the mobile phone of freely programmable, the movement of this freely programmable Phone is with the LED-for the inspection area with the radiation of visible light secure file in the range of first wave length Glisten and with the photo sensor for shooting visible ray, wherein the mobile phone of freely programmable is joined Be set to, by means of freely programmable mobile phone App for by that shot by photo sensor, The radiation launched in the range of second wave length by the printed element of fluorescence is compared with previously given data Relatively and signal represents concordance, in order to authenticating security documents, this secure file includes that form is at least one The security feature of the printed element of the fluorescence of individual pigment shape, wherein, the fluorescent printing element of described pigment shape Constituted by the luminescent material of nitride, this luminescent material have M-Si-N, M-Si-O-N, M-Al-N, The parent lattice of M-Si-Al-N or M-Si-Al-O-N structure and the Eu that adulterates²⁺As activator, or There is the parent lattice of M-Si-N, La-Si-N, M-Si-Al-N or M-Si-Al-O-N structure and mix Miscellaneous Ce3⁺As activator, wherein, M represents metal,

Wherein, the printed element of described fluorescence is arranged in the inspection area of secure file and can be visible Spectral range in first wave length scope in excite, and due to the visible spectral range of this excitation-emission In second wave length scope in electromagnetic radiation.

Apply the most as claimed in claim 3, it is characterised in that described first wave length scope is at 380nm Between 500nm and/or described second wave length scope is between 490nm to 780nm.

5. the application as described in claim 3 or 4, it is characterised in that described security feature is to print skill Art is applied on secure file or/and be integrated in secure file, wherein, and the printing unit of the fluorescence of pigment shape Part is dispersed in the binder matrix of polymerization.

6. the application as described in claim 3 or 4, it is characterised in that the print of the fluorescence of described pigment shape Brush element has the d50-pigment distribution in 1 μm to 20 μ m.

Apply the most as claimed in claim 5, it is characterised in that the printing unit of the fluorescence of described pigment shape Part has the d50-pigment distribution in 1 μm to 20 μ m.