HU203212B - Method and apparatus for protecting and identifying prints particularly securities in radio-chemical way - Google Patents

Abstract

The present invention relates to a method and apparatus for the protection and identification of printing products, in particular securities, by radiochemistry. In accordance with the present invention, a printing technique of at least one element having a characteristic X-ray line of 8 to 20 keV is applied to the printing product in a manner known per se, the labeled product of which is the scope of the description: 6 pages (including 1 sheet). EN 203 212 A -1-

Description

Scope of the description: 6 pages (including 1 page figure)

Exposure to the two X-rays or nuclear radiation and the characteristic X-ray photons emitted from the printing product are detected in a known manner.

In the apparatus according to the invention, an excited radiation source directed to a marked part of the printing product, an energy selective radiation detector, a shielding absorbent, a power amplifier connected to an energy selective radiation detector, and a composite data processing unit, and the composite data processing unit (11) comprises a control unit (9), outputs of the multi-component storage units (6) forming part of the composite data processing unit, preferably data and program storages, data evaluation unit (7), and a paper unit (10) constituting a separate unit, the input of the control unit (9) is the composite data processing unit (11) , the inputs of the containers (6) are connected to the input of the composite data processing unit (11) and to the output of the control unit (9), the outputs of the containers (6) are connected to the input of the data evaluation unit (7), the output of the data evaluation unit (7) is connected to the display (8), the input of the display (8) is connected to the control unit (9) and the data evaluation unit (7), and the input of the paper moving member (10) is connected to the output of the control unit (9).

The invention allows safe protection and identification of printing products, in particular securities.

The present invention relates to a method and apparatus for printing products, in particular securities, e.g. for the protection and identification (authenticity) of banknotes by radiochemistry. 20

Various signaling procedures are known which are widely used in each state to verify the authenticity of securities, in particular banknotes, to reduce the possibility of counterfeiting, and to provide selective divestiture by denomination. Of these, the so-called "high-end" country specific procedures that are country specific and not used by others.

Among the characteristics of the most commonly used method of identification, the size, the form of the printout, the color of the ink used and the various specific markings are worth mentioning. Among the latter, it is remarkable that the infra and the magnetic signal, because of its application, provide a special security for checking the authenticity and denomination of the banknotes, while also protecting against counterfeiting.

The most important features of the high security specific signaling modes - apart from the more detailed description of each known method - can be summarized briefly in 40 below.

First of all, it is desirable not to disclose the technical solution of the given signaling mode. It is therefore advantageous if the signaling process, the material or technology used for signaling is unknown or not feasible by others. It is also advantageous if the detection of the fact of the signal represents the main difficulty for the unauthorized imitators, while at the same time ensuring the possibility of a simple, quick and reliable identification and selective sorting by the denominator of the legitimate user.

Providing the above requirements is a technically complex task and is in all cases closely related to the state of the art technology known at that time. Based on this, it is evident that the various signaling modes generally provide complete security shortly after their introduction. Together with their popularity, the security they guarantee is reduced. In order to avoid this, it is common practice to use a combination of 60 different modes of signaling, and to introduce new signaling and identification procedures using the latest technology.

The object of the invention is to provide a solution which, on the one hand, is a special security for the printing and identification of printing products, in particular securities, especially banknotes, due to the specificity of the signaling mode and, on the other hand, the practical difficulties of detection. too.

It has been found that the above object can be achieved by applying a compound of an X-ray or nuclear radiation-emitting element to the print product to be protected and identified, and the labeled product is identified by X-ray fluorescence elemental analysis.

In accordance with the present invention, a print-ready compound of at least one element having a characteristic X-ray line of 8-20 keV is applied to the printing product in a manner known per se, exposing the labeled print product to X-ray or nuclear radiation, and the characteristic X-ray photographic images emitted from the printing material is detected in a known manner.

The most important feature of the method according to the invention is the specific mode of detection, which is based on the principle of isotopic excitation or energy-dispersive X-ray excitation X-ray fluorescence elemental analysis, which is not yet widely used in scientific workshops.

According to the present invention, the printing products, in particular the securities, are specifically identified as being protected by specific labeling and by means of energy dispersive X-ray fluorescence elemental analysis (authenticity control) as follows.

For specific labeling, bromine (Br), strontium (Sr), zirconium (Zr), molybdenum (Mo), or lead (Pb), or any combination thereof, is preferred.

For printing reasons, it is preferable to include colorless compounds of the signaling elements. Accordingly, it is preferable to use -21 for specific labeling

EN 203 212 The active compounds thus include amorphous zirconium phosphate [ZrfHPO ^ xHjO], zirconium dioxide (ZrOj), lead bromide (PbBr _2), strontium phosphate [Sr ₃ (PO ₄₎ 2], strontium hydrogen phosphate (SrHPO ₄ ), lead molybdenum (PbMoO ^).

The signaling material is applied in a fixed form to the paper and then examined by means of an isotopic or energy-dispersive X-ray fluorescence measuring system to provide a reliable way of identification (authenticity) and selective sorting.

For example, it is preferred that the following isotopes be used as a radioactive source.

Name of isotope sign Nuclear data 125-iodine 125 Half-life: 60 days Emitted energy: 35 keV; 25 keV 109-cadmium 109 _α Half life: 450 days Emitted energy: 22keV

An examination for the identification and identification of the labeled printing products may be carried out with the apparatus according to the invention. The apparatus comprising an excited source of excitation, an energy selective radiant detector, a shielding absorber and a power amplifier associated with an energy selective radar detector and a composite data processing unit for the printed portion of the printing product, characterized in that the data processing unit (11) comprises a control unit (9) , the outputs of which are connected to multi-element containers (6), preferably data and program storages, (7) to the data evaluation unit, and to a paper-moving unit (10) forming part of the composite data processing unit, the input of control unit (9) is composite (11). connected to the input of the data processing unit (6), the inputs (6) are connected to the input of the composite data processing unit (11) and the output of the control unit (9), the outputs of the storage units (6) are connected to the input of the data evaluation unit (7); The output of the evaluation unit (8) is connected to the display, the display input (8) is connected to the control unit (9) and the data evaluation unit (7), and the input of the paper moving device (10) is connected to the output of the control unit (9).

The apparatus is shown in Figure 1.

In the apparatus shown in the figure as a measuring system, the excitation radiation source (which can be an X-ray tube or a radioactive isotope), the labeled print product (2), the shielding absorbent (3), the energy-selective radiation detector system (2), is the emitting radiation product (1). , (5) multipurpose containers (6) for counting electrical signals in the detector system (X-ray photon amplitude, proportional to the energy of radiation, in the energy range selected for the characteristic X-ray photons) (energy selective signal counters, a preferred embodiment may be, for example, a multi-channel amplitude analyzer), and a related data evaluation unit (7), a display unit (8), and a control unit (9) for controlling the flow of data and selectively moving the indicated print product. (10) a paper moving body. The containers (6), the data evaluation unit (7), the display (8), and the control unit (9) together form a composite data processing unit (11), the preferred embodiment of which is a suitably designed microcomputer configuration.

The excitation radiation source used in the X-ray fluorescence measuring system is 125-iodine (125 µl isotope. The energy selective radiation detector is lithium-drifted silicon, a so-called surface-sealed silicon lithium (Si / Li) semiconductor detector with a sensitive surface of about 1000 mm ² .

The speed of identification and sorting is determined by the technical specification of the sorting machines. The speed of the X-ray fluorescence method should also be adapted to this.

Starting from the condition that the maximum possible rate of exchange of banknotes in the worst case scenario does not exceed 30 db / s, the banknote residence time in the 1000 mm ² field of view of the detector - assuming the full length of the banknote used. , i.e., the measurement time to be taken as the basis for detection is at least 0.033 s.

By experimental measurements, it is possible to determine the amount of signaling required for the total counting efficiency of a given measuring system in order to measure a statistically safe handling number within a narrow energy interval near the level of X-ray photo emitted by the given signal element over a range of magnitudes of background radiation. . It should be noted that the statistically manageable signal number in this case is not the commonly used nuclear standard, because the purpose of the measurement is simply the answer. Therefore, it is sufficient that we can distinguish between the 0 and 1 responses adopted in digital technology with high reliability. In our case, the response 0 corresponds to the lack of a signal element. In this case, the measuring system counts only the background radiation, including the hair radiation, and any unspecified contaminants that may be present. However, the number of these is small in the given measuring system. However, after a finite probability of a signal coming from this, it should be assumed, despite the short detection time, that in the worst case, the system noise value may be a unit number of detected signals.

In response, when the X-ray photons emitted from the given amount of signaling are detected during the measurement time, the level of the unit response signal is recorded multiple times the level of the 0 level. Reliability tests prove that if there is an order of magnitude difference between the two levels and the unit

EN 203 212 There is a sufficient reserve for the level corresponding to the level, in practice no false indication can occur.

Accordingly, the unit level should be 10 and the detected number is at least 15. In this case both requirements are met. Returning to the previously mentioned 0.033 s detection time, this is achieved with the 450 cps (pulse / second) intensity provided by the sample. By performing the test with the exemplary detector and measuring system exemplified, the above criterion is fulfilled for Sr, Zr and Mo markers at about 1 mg. Considering that the sensitive surface of the detector is 1000 mm ² , the above amount of material must be applied to the same surface, so the required amount of the signal per unit surface is 1 g / mm ² .

In the case of values other than said sorting rate, the required amount of indicator element is determined in a similar manner to the above. In the case of a measuring system with other sensitivity data, the calculated values will be different.

However, the elements present in the trace amount always mean that their presence is not detected by other non-destructive procedures, so that the unauthorized imitator cannot recognize the signaling mode; on the other hand, the legitimate user will become the holder of a specific and selective signaling and sorting process and equipment.

In another preferred embodiment of the apparatus according to the invention, the energy-selective radiation detector system (4) has a particular design. The material may be, for example, thallium-activated sodium iodide (NaI / Tl) or a thallium-activated cesium iodide (CsI / T1) single crystal as a scintillation detector. In this case, the light pulses are converted into electrical signals by a photoelectric multiplier fitted to the detector.

For this device, due to the detector properties, lower eneigia selectivity and higher background value due to scattering should be expected.

The widespread method of improving the eneigia selectivity and reducing the impulse from diffuse radiation is the use of so-called pairs of filters for this type of measurement system. Filters suitably selected on the basis of the upper and lower edges of the absorption edge improve the energy selectivity of the measuring system as a function of "differential differential discriminator".

However, the higher value of the gross count efficiency in these detectors results in a significant increase in the number of useful signals that can be measured during the detection time relative to the silicon semiconductor detector measuring system. As a result, the reliability of high speed identification and selective sorting increases.

An advantage of the present invention is that it significantly enhances the secure identification of securities, in particular banknotes, by means of elemental detection techniques utilized in trace amounts and by means of isotope excitation or energy-dispersive X-ray excitation techniques, and at the same time provides a fast instrument selection for the legal user4.

The specific marking and sorting of the different denominations is basically possible by the geometrically well-determined position of the applied marker.

The combined use of two or more signaling elements at known ratios, and the possibility of energy selective detection of X-ray photons, have many variations. In this way, the strictly determined value of the measured number of signals at the selected energy intervals, and their relative ratio to the given measuring system reliably guarantee the different signaling and selective sorting of each denomination. The particular advantage of this method is that it is only the X-ray fluorescence measuring system alone that can detect the fact of the signal. And that makes it almost impossible to improperly print.

The following examples illustrate the invention.

Example 1

For marking banknotes, amorphous zirconium phosphate is applied under pressure to the paper in a 10x80 mm strip. For the identification of the indicated banknotes, 109 isotopes are used as excitation sources. Identification is performed by energy selective detection of X-ray photons emitted by the signaling element with a silicon lithium (Si / Li) semiconductor detector. The energy of the zirconium x-rays: E _Kal -15,774 keV, E _Kpi -17,666 ke V.

Example 2

For marking securities, zirconium dioxide is applied in a 10x80 mm strip. Identification is carried out as in Example 1, except that 125 _t isotope is used as excitation radiation radiation.

Example 3

For securities, lead bromide is applied in a 9x150 mm strip under pressure. The labeled papers are selected from a mixed set by irradiation with 125j, emitted X-ray photons are detected with a thallium activated sodium iodide (NaI / T1) by a crystal scintillation detector. Characteristics of lead emitted X-ray photos: -9.6 keV, E |

-10.5 keV.

Example 4

For marking securities, strontium phosphate is applied in 9x150 mm strips. 109 _α excitation radiation sources were used for identification and emitted X-ray photons were detected with a thallium activated cesium iodide (CsI / Tl) single crystal scintillation detector. The energy of the strontium X-ray photons: E _Kal -14,164 keV, E _{Kf) 1} -15,834 keV.

Example 5

Lead molybdate is applied in 9x150 mm strips to mark securities. It is inspiring for identification

The source is a 50 mA excitation current and 500 V excitation tungsten cathode x-ray tube. The emitted X-ray photons are detected by a silicon lithium (Si / Li) semiconductor detector. The lead x-rays are characterized by the energy levels mentioned in Example 3, while the energy of the molybdenum X-ray photons is E _Kol -17,478 keV, E _KfJ , -19,667 keV.

Claims (2)

PATENT CLAIMS A method for the radiochemical protection and identification of printing products, in particular securities, characterized in that the printing compound of at least one element having an X-ray characteristic of at least one of 8-20 keV is applied to the printing product in a manner known per se, x-rayed or nuclear and detecting characteristic X-rays emitted from the printing product in a known manner. 2. Apparatus for the radiochemical examination, in particular verification and identification, of printed printed matter comprising an excitation radiation source, an energy selective radiation detector, a shield absorber and a preamplifier and power supply unit associated with an energy selective radiation detector, the composite data processing unit (11) comprising a control unit (9) as a subassembly, the outputs of which are for the main elements (6), preferably the data and program storage units, the data evaluation unit (7) and the paper handling unit (10). connected, the input of the control unit (9) is connected to the input of the composite data processing unit (11), the inputs of the storage units (6) to the input of the composite data processing unit (11) and connected to the output of the control unit (9), the outputs of the storage units (6) are connected to the input of the data evaluation unit (7), the output of the data evaluation unit (7) is connected to the display (8) is connected to the unit (7) and the input of the paper conveyor (10) is connected to the output of the control unit (9).