RU2155989C2 - Method and device for checking documents, which are protection against faking - Google Patents

Abstract

FIELD: security equipment. SUBSTANCE: device may be used for checking documents, which use current-conducting strip as protection element. Said current-conducting strip is designed as ribbon or filament, which conducts current along its complete length, or as strips with several current-conducting pieces, which are insulated from each other. Corresponding method uses known capacitance coupling for transmission of electric signals from transmitting antennas to receiving antennas through current- conducting protection strips. Method involves detection of temporal and amplitude characteristics of such signals, and their comparison to target characteristics, so that converting into signal characteristics ensures easy comparison of parameters. Specific selectivity of checking device is achieved by means of connection of additional selective amplifier to decoding electronic circuit. Identification which is specific for particular type of bank notes is achieved using analytic electronic circuit, so that temporal limit of amplitude of test signal, which differs from duration of amplitude characteristics of all other types of bank notes can be set using, for example, controller. EFFECT: increased reliability of protection against faking. 21 cl, 10 dwg

Description

 The invention relates to a method and devices for controlling documents protected against forgery according to the restrictive part of paragraph 1 of the claims. Numerous methods, devices, methods and control systems are known for determining the authenticity of counterfeit documents, for tracking functional suitability, for determining the position in processing machines, as well as for sorting and counting documents. DE-PS 1223594 discloses a device for capacitive reading of data carriers, in which the reading capacitors are made in the form of sensor electrodes located on both sides of the track of the data carrier. The reliability of the reading of this device is not guaranteed in relation to embedded, pressed or deposited on the surface of conductive strips, tapes or similar particles.

 In the description of the invention to the German patent DE-PS 1774290, a measuring circuit for automatically evaluating the characteristic feature of a banknote in a device for controlling the authenticity of banknotes using capacitive coupling of electrodes, which are placed in the form of a grid, is presented. This well-known measuring circuit at today's processing speeds does not provide an accurate determination of the corresponding characteristic feature and, although it slows down the monitoring process, it establishes the presence of the corresponding distinguishing feature, it is not able to determine the currently known counterfeits when using electrically conductive elements, for example, in banknotes.

 From the published application of Germany DE-OS 2619457 it is known to measure the magnetic properties of a protective strip placed in a banknote.

 Verification of the authenticity of ferromagnetic protective strips in impressions of denominations of notes by applying a magnetic field is described in German patent DE-PS 2834287. These control methods are too slow and often require accurate positioning of the controlled object or control strip.

 In the invention according to the German patent DE-PS 2760165, a technically labor-intensive verification device is described in which the authenticity of banknotes is determined mainly in the second inspection step, whereby the difference in thicknesses and fluorescent properties are measured. Checking only these properties no longer corresponds to the level of counterfeit notes in circulation. Counterfeit money with watermarks and on fluorescent paper or with fluorescent paint this device can no longer detect.

 And the reading heads described in German applications DE-OS 3236373 and 3236374 described on processing machines, which in combination with marks on documents protected against counterfeiting, form an electric capacitor and, due to the introduction of a ferroelectric between the capacitive electrodes of the reader, change the value of the capacitance in a certain way, are also not suitable for use on high-speed processing machines and for controlling European banknotes in circulation today.

 The detection of an electrically conductive security thread by mismatching the generators and oscillatory circuits according to the German patent DE 2912712 due to the low reliability of the estimates and significant technical complexity and structural complexity has not found practical application.

 US Pat. No. 5,308,992 describes a measuring device comprising optical and capacitive sensors, which however require very precise positioning of the control strip. To increase the degree of faultlessness and the possibility of distinguishing between various controlled objects (for example, different currencies), an additional use of a magnetic sensor is proposed, which makes this measuring design even more complicated and more expensive. A capacitive sensor after preliminary sorting of banknotes indicates only the presence of an electrically conductive security thread.

 A control device according to the German patent DE 4103832 is also known, in which capacitive and / or electro-optical sensors and / or millimeter-wave sensors are located along the control track for monitoring. The subject of this invention is, in addition, verification of the dielectric characteristics of banknotes.

 The German patent DE 4325027 describes a method and apparatus for checking the authenticity of banknotes, whereby when changing a high-frequency field with a metal protective strip, the changes in the field parameters are evaluated. The introduction of such a device into a bill machine is possible only at low speeds due to low sensitivity and a large influence of interference. Therefore, conducting on a plane and wet objects of control are recognized as genuine. Gaps in the metal stripes of genuine banknotes are not recognized, which leads to erroneous machine stops. Due to the low sensitivity of the device, the distance between the electrodes and the metal protective threads of the banknote is very small, which prevents the use in high-speed processing machines. The installation of several sensors is possible only at relatively large distances in relation to each other so that the sensors do not exert influence on each other.

 International publication WO 94/22114 describes a device for recognizing metallic conductive security threads. However, in this device, conductive along the plane and wet objects of control are recognized as genuine, since this is carried out as a measurement of the electrical load of the sensor electrodes. The classification of security threads of various sizes is not provided. EP 0 204 574 describes a method for recognizing magnetic printed signs by electromagnetic induction. Since conventional copiers can be equipped with magnetic inks, this control method has very limited reliability with modern fake quality.

 The disadvantages of these known control methods and devices for their implementation are, first of all, their technical complexity and lack of reliability in order to ensure the detection of fakes at a high speed of movement of banknotes in processing machines. The disadvantages of the known measuring systems for monitoring capacitive characteristics include the fact that in them a sufficiently low capacitive resistance is achieved only in the given low frequency bands from 10 to 220 kHz and only at very small distances between the electrodes and the metal thread. In addition, in this frequency range, the influence of the dielectric change is still very large, i.e. a substance with a high dielectric constant leads to an increase in capacitance and thereby to a decrease in capacitance between antennas. So, for example, a wet fake banknote can be taken for real. These schemes are still in practice, especially with machine-based authentication, have not paid off.

 In European application EP 589 195 A2, a method is described in which, to verify the authenticity of controlled objects by reading the scanned area with magnetic elements with high magnetic permeability, the obtained detection signal comes from a device with an excitation coil and a reception coil in the form of an identification code, and then the authenticity is confirmed by the coincidence of the signal detection with identification code. This control method is suitable only for plastic cards, paper documents and only for a few non-European banknotes with magnetic or magnetizable particles deposited on them. Other control methods, as described in European applications EP 204574 A2, 553402 A1 and 560023 A1, in which the geometric and / or physical characteristics of controlled objects are classified by comparison, can sometimes be used only for one or another type of controlled object, but they are very laborious and in practice do not find application in high-speed processing machines as the only method of checking for authenticity at a separate stage of processing banknotes.

 The objective of the present invention is to eliminate the existing disadvantages of known devices and control methods. To this end, a method is proposed by which it is possible to reliably recognize the characteristic control feature for many varieties of banknotes and currencies, able to distinguish them even, for example, if the controlled objects are wet or intentionally wet and / or dirty, which does not require serious technical complications, and at the same time it application is possible in the form of retrofitting of processing machines, as well as corresponding to the speed of processing machines. An electrically conductive security thread or ribbon or flat security label on banknotes or securities is used as a characteristic control feature. Further, the object of the invention is the creation of such a control device for implementing the method, which could be included so that before sorting by type of currency and type of document, an authentication check is already performed.

 The objective of the invention to implement the method is further to create a device for checking documents protected from forgery, which as a protective element contain an electrically conductive strip in the form of a ribbon or thread with continuous electrical conductivity, or such strips on which there are several electrically conductive sections isolated from each other. An example of such a document protected from counterfeiting is modern US banknotes that have protective conductive but insulated markings on an electrically conductive thread. In modern practice, it becomes necessary to easily integrate control systems into processing machines that not only recognize high-quality fakes as such, but also identify genuine documents of lower quality, since in practice they are often encountered and lead to false positives that significantly interfere the work of processing machines.

 The inventive method for monitoring counterfeit documents along with the use of the already known capacitive coupling provides that the electrical signals from the transmitting antennas are transmitted through the conductive protective tags to the receiving antennas and amplified, and then their amplitude and time characteristics are evaluated, which are compared with existing characteristics signals, and they are converted into characteristics of signals that have easily comparable parameters. To implement the method with its more detailed technological operations described below, a monitoring device for banknotes, documents, securities, etc. is proposed. with a protective strip or thread or with a flat protective label based on the use of capacitive coupling, which can be used, for example, in a banknote processing machine, mainly in a banknote counter. On the housing structural unit, monitoring sensor equipment is placed in the area of optical and / or magnetic sensors and / or format sensors. The machine passes notes and / or securities past this control device. Monitoring sensor equipment consists of several sensors in the form of antennas and / or electrodes. Antennas and / or electrodes located across the direction of transportation of the tested objects have such a planar extent that even with a certain lateral displacement of the tested objects and regardless of whether the tested object faces up or back, passing through the control device, in any case, protective the strip or thread properly crosses the antennas or electrodes. The antennas and / or electrodes of the control device correspond to known sliding devices, pinch rollers and / or conveyor belts, so that between the documents and antennas being checked, a certain distance is maintained during their fast movement and / or they are pressed against the electrodes. By attaching the control device of the invention in the area of the optical and / or magnetic and / or format sensors, which usually serve to recognize geometry, position, color, etc., the monitoring sensor equipment is simultaneously activated.

 High-frequency and / or low-frequency energy and / or constant voltage are supplied to one or several antennas and / or electrodes, and one or more antennas and / or electrodes receive a part of the radiated energy through a protective strip or thread. In this case, at one or more receiving antennas and / or receiving electrodes, the applied voltage changes.

 In order to be able to obtain comparable control answers, for example, by reliability, by the operational suitability of documents or by the value of banknotes, constant conditions for their passage, such as, for example, speed, are necessary for the objects to be compared. Antennas and / or electrodes supply voltage to the decryption electronics. The decrypting electronics provides an easily comparable voltage, depending on the waveform of the received voltage. To suppress foreign energy and interference, as well as eliminate the influence of the electrical conductivity of the base of the controlled objects on the measurement result, special filters and / or phase-matching schemes can be used.

 The output pulse of the decrypting electronics is independent of the speed of the objects. To ensure the specific selectivity of the control device, a selective amplifier is additionally connected to the decrypting electronics. The selective amplifier converts the voltage supplied by the monitoring sensor equipment into an easily comparable voltage, depending on the amplitude characteristic of the received voltage. When category-dependent (conductive protective strips or protective threads or any conductive markings), the decryption electronics are set up with additional amplitude boundaries that go so close to the amplitude deviation of the control signal that with a difference between a clearly defined amplitude border and the greatest possible deviation of all objects being tested, definition of authenticity. This means that even the latest fakes giving a signal that would normally be perceived as a decoder signal are defined by the decryption electronics of this invention as a fake.

 A currency-specific setting using the decryption electronics according to the invention, for example, for all banknotes of individual countries with the same security strips according to the invention, is achieved in that for the currency, for example, by means of controllers, the time limit of the control signal amplitude, which differs from the amplitude duration, can be determined characteristics of all other currencies.

 For currencies with the same duration, the control signal amplitudes are additionally checked, for example, for color recognition and / or color differences and / or for checking using the format control method and / or the magnetic method. For example, recognition signals supplied by the photocells are coupled to the signal from the control sensor equipment according to the invention and processed into an output pulse characteristic of the machine.

 Another variant of the method is to include one or more pairs of phase-shifting transmit antennas. Due to the capacitive coupling of one of the transmitting antennas with one of the electrically conductive tags on the protective strip and the connection between this transmitting antenna and the receiving antenna located opposite it, an authentication signal appears at one of the inputs of the amplifier. From the second transmitting antenna, which is coupled to the first with a phase shift, there is no capacitive coupling of the signal with the receiving antenna, since there is no conductive protective strip in the interaction zone.

 Thus, thanks to this circuit, it is already possible to control a continuous conductive strip. With a shift relative to these antenna pairs, other pairs of transmitting and receiving antennas are located, which according to their size and distance are consistent with the conductive marks and the protective strip. When the controlled object is moved a certain distance to the monitoring sensor equipment, specific amplitude and time signals are transmitted further, and thereby signals for decryption from receiving antennas to decrypting electronics. Thus, a check is carried out that can recognize several electrically conductive tags isolated from each other and decrypt them accordingly. It doesn’t matter if the insulation is deliberately created between the conductive marks, such as on a US banknote, or whether it is caused by tears in the fully made conductive protective strip, such as on German banknotes. The microcontroller can compare the number of these gaps with the values stored in memory. Thanks to the installation of several pairs of transmitting and receiving antennas and corresponding decrypting electronics, it was possible to obtain a reliable message about the authenticity of the document, because despite possible lateral shifts when connecting the tested object to the control device, it works reliably. If, according to the invention, transmitting and receiving antennas are located across the entire working width of the processing machine, then position-independent authentication of counterfeit documents is possible. Thus, it does not matter whether the document is brought in front or back, and / or has protective strips on the left or right, or moves with a shift across the direction of transportation. Due to this, documents that can vary both in format and in the location of the protective strip relative to the direction of transportation become controlled. In addition, thanks to the various types of protective strips, not only classification of authenticity is possible, but also special identification of various documents, for example, various currencies.

 During the transportation of banknotes, additional monitoring sensors (additional sensor equipment) can be placed before and / or after the main control devices. In this case, the output signal of this sensor system is connected to the output signal of the monitoring sensor equipment according to the invention (double control) without the need to introduce a change in the software for the corresponding processing machine, for example, when retrofitting a control device corresponding to the inventive method.

Preferred features of this invention are contained not only in the claims, but also in the description and drawings, and sometimes the individual features themselves or in combination in the form of subordinate combinations represent protected options for which patent protection is provided here. Examples of the invention are shown in the accompanying drawings. The drawings show:
in FIG. 1: Block diagram of the decryption circuit;
in FIG. 2: Recognition curves when passing a banknote at various speeds;
in FIG. 3: Currency-specific recognition curves;
in FIG. 4: Recognition curves of several banknotes and counterfeit;
in FIG. 5: Block diagram of the decryption circuit with double control;
in FIG. 6: A schematic sectional view of a control device;
in FIG. 7: Monitoring sensory equipment;
in FIG. 8: Block diagram of a monitoring device;
in FIG. 9: Placing monitoring sensory equipment in a processing machine.

The method described below in more detail using various devices and circuits is based mainly on the following technological operations:
realizing capacitive coupling of electrical signals from transmitting antennas through electrically conductive protective materials to receiving antennas, amplifying and converting received signals with different amplitude and time characteristics into easily comparable signals and comparing them with already known signal parameters in order to demonstrate and decrypt the authenticity of the documents being verified in an appropriate form . The machine connected to the control device feeds banknotes or securities into the zone of the control device. Photocells immediately activate monitoring sensory equipment.

 The transmitting antenna is powered by high-frequency energy. In the considered example of execution - with a frequency of 6 MHz. If the protective strip or thread passes through the control field, the receiving antenna receives some of the radiated energy. This changes the high frequency voltage applied to the receiving antenna. The reason for this to some extent is the capacitive coupling between the transmitting and receiving antennas based on the electrical conductivity of the protective strips or threads. The high-frequency conductivity of individual bills is different. In order to be able to receive answers specific to the currency with the help of a decryption scheme, stable conditions are required for the transportation of all objects inspected in a single operation.

 With the control unit and its monitoring sensor equipment, the decryption electronics is in functional unity, consisting mainly of an analog-to-digital converter and controller or integrator 15, trigger 16, a controller, a monostable multivibrator 17, and, optionally, a logic element I 18 connected by shielded conductors. A possible decryption electronics is shown in FIG. 1 in the form of a flowchart.

 Position 12 denotes a high-frequency transmitter, 13 - a high-frequency receiver, which receives energy reflected from a receiving antenna 9, in a selective amplifier 14 amplifies a currency characteristic and / or useful authenticity signal, 15 - an integrator, 16 - a trigger that, in addition to the available signals, receives signals activating the decryption circuit of the photocell 20 and through a monostable multivibrator 17 in the form of synchronized pulses transmits as an output signal for recognized authentic controlled objects. As can be seen from those shown in FIG. 4 curves a and b, when passing banknotes, not a single signal of counterfeit 26 was issued, comparable to the signal of recognized authentic banknotes.

 Mandatory shielding of the monitoring sensor equipment and decryption electronics from electric and electromagnetic fields, as well as the placement of the monitoring sensor equipment in the photocell area provide a high noise to useful signal ratio and, in combination with forced document feed by conveyor belts and at a given banknote speed, guarantee currency-specific selectivity control device. A further advantage of the method is that, for example, the moisture content and / or the degree of contamination of the controlled objects and / or banknotes and / or securities are no longer the main sources of interference.

 In FIG. 6 schematically shows a control device in section, which is used in a banknote processing machine, mainly in a banknote counter, according to the method described above. On the housing structural unit 1 there is a machine holder 2, on the horizontal shelf 3 of which is installed monitoring sensors located in the area of photocells 4 and 5 on the non-conductive carrier material 6 of the horizontal shelf 3. The carrier material 6 has recesses and / or through holes 7 for light transmission photocells 4 and 5. These recesses and / or holes 7 are not required if transparent, like glass, carrier material 6 is used.

 Monitoring sensor equipment consists of several sensors, for example, strip sensors 8, 9 (in this example, two), namely: strip sensor 8 as a transmitting antenna and strip sensor 9 as a receiving antenna. The strip sensors 8, 9 across the direction of transportation of the banknotes 11 have such a longitudinal length that even with a given lateral clearance of the banknotes 11 and regardless of whether the banknote 11 faces up or down when passing through the device, in any case, protective strips or threads in strip sensors 8, 9 cross sufficiently and pass through them through the control device. Below the horizontal shelf 3, conveyor belts 10 run parallel to it at such a distance from the strip sensors 8 and 9, so that when the notes pass quickly, they are pressed against the strip sensors 8 and 9.

 Between the conveyor belts 11 perpendicular to the direction of passage of the banknotes are photocells 4, 5.

 Decrypting electronics is also located in the shielded area of the processing machine (in this embodiment, purposefully in the area of the casing, for example, where the adjustment device is located in accordance with the paper weight).

 The preset screening of the monitoring sensor equipment and decryption electronics from electric and electromagnetic fields, as well as the location of the monitoring sensor equipment in the area of photocells 4, 5 provide a good noise / useful signal ratio and, in combination with the forced feed of documents with conveyor belts 10 at a given speed of banknotes, guarantee a specific for currencies, selectivity of the control device. A further advantage of this device according to the invention is that, for example, the moisture content and / or the degree of contamination of the controlled objects are no longer the main sources of interference.

 In the direction of conveying banknotes — not shown in this example — additional sensory equipment, for example, for magnetic control, can be connected to the monitoring sensor equipment according to the invention, positioning it in front of and / or after it, as shown in FIG. 5.

 In this case, the output signal of this sensor equipment is combined with the output signal of the monitoring sensor equipment according to the invention (double control) without the need to change the software for the corresponding processing machine, for example, when retrofitting the monitoring device according to the invention.

 Decryption electronics associated with monitoring sensor equipment and photocells, as shown in FIG. 2 and 3, produces a voltage depending on the amplitude characteristic of the received high-frequency voltage. This is confirmed by the aforementioned figures of the transmitted signals shown in curves a.

In FIG. Figure 2 shows the recognition curves during the passage of banknotes with different speeds. Curve a shows the transmitted signal, and curve b the output signal of the decrypting electronics. The value of v ₁ corresponds to the speed of passing 500 banknotes per minute, av ₂ - the speed of passing 1800 banknotes per minute. In addition, curve b explains how the supplied banknote recognition signal is related to the signal from the monitoring sensor equipment and how it is converted to an output pulse characteristic of the machine. This output pulse, as shown by a comparison of curves b in FIG. 2, does not depend on the speed of passage of banknotes.

 In FIG. Figure 3 shows recognition curves specific to a particular currency during the passage of banknotes of various nominations. Curve a again shows the signal transmitted from the monitoring sensor equipment, while curve b shows the decrypted signal of the selective amplifier, which was additionally connected to decrypting electronics to provide currency-specific selectivity of the control device without additional sensors.

 In FIG. 3 symbols denote: DE German currency, CH Swiss currency, EG Egyptian currency, CN Chinese yuan since the 1990 series.

 The amplitude characteristic of the received high-frequency energy, differently formed from dissimilar protective strips, is clearly recognized in banknotes of various currencies and, thus, is perceived by decrypting electronics. If there is a need to process a signal characterizing a currency, then an additional signal prepared by decrypting electronics is possible for classifying a currency, for example, using a controller. Just as different currencies can be distinguished thanks to different protective strips or threads, counterfeits can be recognized, since they contain these counterfeit protective strips or threads or only their pieces. In FIG. 4 shows recognition curves of eleven banknotes in one machine for counting money. Banknotes digitized from 21 to 25 and from 27 to 31 can be considered authentic. Controlled object N 26 is an intentionally falsified experimentally counterfeit. Due to the lack of a protective strip or due to a forged protective strip, the monitoring sensor equipment did not give a signal. In practice, in the absence of a signal or when a signal not characteristic of banknotes appears, the processing machine stops and the counterfeit or banknote unsuitable for circulation is removed or mechanically separated and laid aside.

 If the control device is additionally connected to another monitoring sensor equipment, this machine-specific output pulse shows the recognition of a protective strip or thread and is coupled to the output signal of an additional verification of the processing machine via logic element I. If one of these two authenticity signals is missing, the machine stops and the operator can withdraw the defective or counterfeit banknote.

Another possibility of using deciphering electronics when configured appropriately is due to the decryption signals of the selective amplifier, as shown in FIG. 3. If, for example, in larger processing machines, which are also used for sorting various currencies, the amplitude limit A for all controlled currencies is exceeded, then at speed v _{2 the} protective strips or threads read by the control sensor equipment are recognized as genuine. Each currency has its own characteristic time t _k . To distinguish between individual currencies, you must specify the time assigned to the currency t _k = t ₁ ... t ₄ and up to t _n as characteristic of the currency t _f .

So, for example, t _f German currency can be set more than t ₂ Swiss francs, or t _f Swiss francs you can choose more than t ₃ Egyptian currency. Since t _{f of the} German currency should be selected as much as possible the same as t _f not shown in FIG. 3 currencies, another currency-specific check is required using the well-known color recognition method and / or format and / or magnetic control method within the processing machine. Separate currencies sorted in this way are laid out in a known manner in boxes or piles. For example, decrypting electronics, made primarily in the form of one or more controllers, by comparing time and / or voltage produces a signal specific to a given machine, upon receipt of which, a banknote processing machine puts individual classified objects in special boxes or piles.

 The processing machines are equipped with monitoring sensor equipment 54, as shown in FIG. 7, mainly for monitoring non-through electrical conductive protective strips of documents. This sensor equipment consists of several transmitting and receiving antennas that are parallel to each other and perpendicular to the direction of transportation of documents. For verification, the banknotes are sent in a general flow to a processing machine, for example, to a conveyor device, to a banknote counting machine in such a way that the protective strip or thread in the banknote at its longest section is approximately parallel to the direction of travel, therefore, for example, a German banknote the longest part lies approximately across the direction of travel. Transmitting antennas A2, A3, as well as receiving antenna A1 are located opposite each other. Several transmitting antennas B2. i (i = 1 ... n) and several receiving antennas B1.i form antenna pairs with an offset. These pairs are offset relative to each other in order to suppress the overlapping of the signal from one of the antennas B1.i to the neighboring but not corresponding receiving antenna B1.k (k = 1.n, i <> k). Neighboring transmitting antennas (B2.i, B2i + 1) and their associated receiving antennas (B1.i, B1.i + 1) are offset by a predetermined distance, mainly by the distance between the transmitting antenna (B2.i) and the conjugate receiving antenna (B1.i). To mitigate the effects of interference, diagonally offset antenna pairs are predominantly located between the transmitting antennas A2, A3 and the receiving antenna A1.

 In FIG. 8 shows a block diagram of a control device according to the invention with control of the monitoring sensor equipment of FIG. 7. When the document is fed to a processing machine containing a control device according to the invention, it is activated by photocells or similar position-sensing sensors. The frequency generator 41 starts the transmitting antenna A2 and, through the phase shifter 42, the transmitting antenna A3. Thanks to the phase-shifted control, the influence of interference from extraneous energy sources is prevented and fakes that do not have differences in electrical conductivity are recognized. This also applies to banknotes whose properties have changed, for example, due to aging, and / or mechanical damage, and / or due to moisture. At the same time, several transmitting antennas B2.i (i = 1. ... n) are launched by the second frequency generator 43 and the second phase shifter 44. Accordingly, the transmitting antennas B2.i located across the direction of banknote movement not in the same row are adjusted in phase to weaken the influence of extraneous interference and prevent capacitive overlapping of one transmitting antenna B2.i with one of the non-corresponding receiving antennas B1. k (k = 1..n, i <> k). The frequencies of the signals from two generators are selected so that one frequency is not a multiple of the other or their difference is single, in order to prevent signal distortion at the receiving antennas.

 During the test, a capacitive interposition of the signal of the transmitting antenna A2 with the antenna A1 occurs through the protective strip with continuous conductivity, while the signal of the transmitting antenna A3 is connected to the receiving antenna A1 by non-capacitive coupling. The shortest distance between the transmitting antenna A2 and the receiving antenna A1 is less than the longest length of the conductive protective strip in the smallest document to be monitored. If at none of the test times the protective strip is in the area of interaction of the transmitting antenna A2 and the receiving antenna A1, then the protective strip is in the area of interaction of the transmitting antenna A3 and receiving antenna A1, so that the other functions are performed similarly to the case described above. Then, a signal is received at the receiving antenna A1, which, through the rectifier 45 and the selective amplifier 46, supplies a signal to the microcontroller 47, which classifies the authenticity by comparing the signal of the selective amplifier 46 with the signal recorded in the microcontroller 47, for example, with a special threshold value. If the threshold value is exceeded, then the microcontroller 47 classifies the inspected object as an object with a through conductive protective strip, which means that for German banknotes this object is recognized as genuine. If there are electrically conductive tags in the protective strip which, due to their length, are not detected by the transmitting antenna A2 and receiving antenna A1, then you can recognize them by using the location of the transmitting antennas B2.i and the corresponding receiving antennas B1.i according to the invention, since the distance between them is half that than the distance between the transmitting antenna A2 and the receiving antenna A1. If, for example, the length of the electrically conductive mark parallel to the direction of movement is 1.5 mm, then the distance between the transmitting antenna B2.i and the receiving antenna B1.i can be set equal to 1.3 mm to ensure reliable capacitive overlap. During verification, a controlled document protected from forgery is forcibly moved at a predetermined speed in the range of the monitoring sensor equipment of the control device according to the invention. Due to the shifted arrangement of the transmitting antennas B2.i and the receiving antennas B1.i with orthogonal shift of the banknote relative to the direction of transportation of the document, tolerance compensation is obtained. The signals arising at the B1.i receive antennas through the rectifiers 48 ... 50 and the selective amplifiers 51 ... 53 are fed to the microcontroller 47. Depending on the quality and location of the protective strip in the document, the signals of the selective amplifiers 46, 51 are received at the input of the microcontroller 47. ..53 differ in frequency and amplitude response. Due to this, it is possible to classify the document by the microcontroller 47 by comparing frequencies and / or comparing the threshold value with predetermined and recorded values in the microcontroller 47. These values are determined by manual input, programming and / or comparison with values that have been parameterized with an already classified reference document. Microcontroller 47 generates a machine-specific signal that confirms the authenticity of a controlled banknote. This classifying signal of the microcontroller 47 is transmitted to its corresponding indicator elements and / or sent for further processing to the corresponding interface of the processing machine. Just as different currencies can be distinguished from each other by the differences in their protective strips or threads, so are fakes if they have copied protective strips or threads, or their segments. Thanks to the compact design of the entire control device, especially thanks to the integrated sensor and decryption electronics unit, as well as additional shielding measures, new possibilities have been discovered for reducing interference, which in practice are of increasing importance. The placement of the control device in the processing machine is carried out so that the monitoring sensory equipment does not affect the traditional transportation of banknotes.

 How the control device of the invention is integrated in a conventional processing machine is shown by way of example in FIG. 9. For this purpose, the monitoring sensor equipment 54 consisting of transmitting antennas A2, A3, B2.i and receiving antennas A1, B1.i is integrated into the guide device 56. At the same time, the monitoring sensor equipment 54 is located tangentially relative to the guide device 56 or tangentially with a shift relative to the drive roller 55 in such a way that it additionally maintains its leading function in the area of the monitoring sensor equipment 54. Therefore, the banknote to be checked falls into the range of the sensors without the participation of additional clamping means. The monitoring sensor equipment 54 is located tangentially relative to the existing guide device 56 so that a controlled document protected from counterfeit, driven by the drive rolls 55, moves past the monitoring sensor equipment 54 at a predetermined distance and at a given speed. The predetermined distance between the drive roller 55 and the guide device 56 or the monitoring sensor equipment 54 can be adjusted using appropriate fastening means, mainly with deflection screws. Threshold values and classification values are parameterized by switches not shown in the drawing, or by the corresponding microcontroller programs 47. Thus, the operator can change the classification values to switch to checking different currencies by simply switching. In practice, in the absence of one of the signals or when a signal that is not characteristic of a banknote appears, the processing machine stops, and a fake or unfit note is withdrawn.

 Due to the lateral extension of the antenna device over the entire width of the document, the influence of paper quality, age, humidity, etc., is weakened. on the classification of authenticity. This also includes the possibility of classifying, for example, counterfeits, genuine banknotes and banknotes with a high degree of wear. This classification is carried out by appropriate decoding of the amplitude and time characteristics of the signals emitted by selective amplifiers 46, 51. ..53, and appropriate parameterization of the threshold values by the decrypting microcontroller 47. The calibration of the microcontroller 47 is carried out manually using software control or by monitoring using special calibration documents, of which the classification of authenticity becomes known. Using the latter method, the calibration document is checked by the control device of the invention as described above. Instead of comparing the signals at the outputs of the selective amplifiers 46, 51 ... 53 with the signals available in the microcontroller 47, they are entered into the microcontroller 47 as reference values.

 Another option for embedding monitoring sensor equipment 54 is known from the German patent application 19519 229.4. According to this invention, the monitoring sensor apparatus 54 can, for example, be positioned at the end of an arcuate guide apparatus 56, as shown in FIG. 10. Also, clamping devices are not required for pulling the objects to be checked in compliance with the specified clearance and / or with touching the control device. This possibility can be used if it is not possible to carry out the above tangentially shifted integration of the monitoring sensor equipment 54 into the arcuate zone of the guide apparatus 56. Since, according to the invention, there is no need for clamping devices, for example, springs, pressure rollers, etc., then the inspected object experiences less mechanical load from the control device.

 The method according to the invention is described on the basis of specific embodiments of monitoring sensor equipment and decryption electronics in a machine for counting money. However, it should be noted that the present invention is not limited to the details of the description in 20 examples of execution, since changes and deviations are possible within the scope of the claims. So, for example, the most diverse versions of decrypting electronics are possible, focusing on the special principle of operation of a selective amplifier.

Claims (21)

 1. The method of checking documents protected from forgery using capacitive coupling between the transmitter and the receiver, which consists in transferring energy between the transmitter and the receiver by blocking the electromagnetic field with electrically conductive protective strips, tapes, threads or flat protective materials and using decryption electronics, characterized in that zone of known optical sensors available in the processing machine, which in the processing machine are spatially correlated with the control sensor equipment and activate the monitoring sensor equipment, several located in one or more planes and functioning as transmitting or receiving sensors of the antennas and / or electrodes form control fields, and through the object being tested, depending on its geometry and / or electrical conductivity, transmit electromagnetic energy through these antennas with overlapping, while several antennas are configured at least in different phase positions and transmit the transferred energy to the included consequently a selective amplifier for eliminating energy interference and suppressing the conductivity of the basis of the objects under test, for example, in banknotes, a phase comparing device included after the selective amplifier, as well as filters for suppressing interference and foreign energies and one block of decrypting electronics are located in such a way that classification of conductive protective strips is possible, ribbons, threads or flat protective materials, and the inspected object during the verification process forcibly passes through the counter ol field in an undefined lateral position. 2. The method according to claim 1, characterized in that the decoding electronics, which consists of an analog-to-digital converter and a controller or integrator connected by conductors, a trigger, a controller, a monostable multivibrator and, if necessary, an AND logic element, determines the intersection by the characteristic of the signal at the output of the selective amplifier the boundaries of the amplitude A of the control signal and / or the time t _k, characteristic of the currency.  3. The method according to claim 2, characterized in that by means of decrypting electronics, the classification of authenticity is carried out by setting the boundary of the specified amplitude A for the authenticity of the verified currencies. 4. The method according to claim 1 or 2, characterized in that by means of decrypting electronics, various banknotes and / or securities are classified, moreover, the currency characteristic time t _{k is} set mainly by the controller, and the objects to be checked are sorted by time t ₁ ... t _k-1 , t _{k + 1} , ..., t _n , characteristic of currencies. 5. The method according to claim 4, characterized in that for currencies with the same time t _k, after verification, an additional check is performed using the controller on various protective strips or threads.  6. The method according to claim 1, characterized in that the decrypting electronics, made primarily in the form of one or more controllers, by comparing the time and / or comparing the voltage produces a signal characteristic of the machine for stacking individual classified objects in special boxes or piles.  7. The method according to claim 1 or 2, characterized in that the antennas and / or electrodes across the direction of transportation of the inspected objects have such a length in the plane as with a certain lateral gap of the inspected objects and regardless of whether the object being checked is facing or reverse side up when passing through the control field, in any case, the protective strip or thread at a given distance crosses the antennas and / or electrodes in contact with them.  8. The method according to claim 5, characterized in that the result of the additional verification is connected to the signal of the decrypting electronics using the logical element AND without the need to make changes to the program of the corresponding processing machine.  9. A device for checking documents protected against counterfeiting with elements for capacitive coupling when the electromagnetic field is blocked by electrically conductive protective strips, ribbons, threads or plane protective materials with decryption electronics for implementing the method according to claim 1, characterized in that the device contains optical sensors in a processing machine, for activating capacitive monitoring sensor equipment, control fields formed by several in one or more planes sensors that are active and functioning as transmitting or receiving antennas, a selective amplifier, a phase comparing device sequentially connected behind it, a filter for suppressing interference and extraneous energies, and also a decoding electronics consisting of conductors connected by an analog-to-digital converter and controller or integrator, trigger, controller, monostable multivibrator, a test object with an indefinite lateral position, passing at a given speed using clamps placed in this zone and / and and conveyor belts, rolls, located No touching sensors.  10. The device according to claim 9, characterized in that the sensors acting as transmitting or receiving antennas are made in the form of strip sensors and are placed in one or two planes and / or are mirrored.  11. The device according to claim 10, characterized in that the strip sensors are provided with recesses and / or through holes and / or windows.  12. The device according to one of claims 9 to 11, characterized in that the sensors are located mirror-image relative to the monitored zones and / or protective strips, threads, and / or ribbons of the objects being checked, mainly banknotes, securities and packages. 13. A device for checking documents protected against counterfeiting with electrically conductive protective strips, ribbons, threads or plane protective materials for implementing the method according to claim 1, characterized in that several transmitting antennas A ₂ , A ₃ , B2.1, B2.n and several receiving antennas A ₁ , B1.1, ..., B1.n, forming the monitoring sensory equipment, are located with the ability to control both protective strips with through conductivity, and such protective strips that have several electrically conductive but isolated from each other d uga of the areas within the protective strip, and the monitoring sensor equipment is located so that the checked document protected from counterfeiting, driven by the drive rolls, moves past the monitoring sensor equipment at a given distance and at a given speed, while two antiphase ones configured for low or high A frequency of transmission antennas _2, A ₃ are installed perpendicular to the longitudinal direction of the protective strip and perpendicular to the direction of movement of the inspected protected oddelki document and one or more receiving antennas A ₁ are arranged in parallel opposing transmission antennas A _2, A _3, and between them there are multiple transmit antennas B2.1, B2. n parallel to the transmitting antennas A ₂ , A ₃ , and several receiving antennas B1.1, ..., B1.n located parallel to the transmitting antennas B2.1, ..., B2n, and the transmitting antennas B2.i adjacent to them , ..., B2i + 1 and the receiving antennas B1.i, ..., B1.i + 1 associated with them are offset by a predetermined distance, preferably by a distance between the transmitting antenna B2.i and the receiving antenna B1 associated with it .i, and the shortest distance from the transmitting antenna B2.i to the conjugate receiving antenna B1.i is less than the shortest distance between one of the transmitting antennas nn A2, A3 and the receiving antenna A1.  14. The device according to item 13, wherein the several transmitting antennas A2, A3, B2.1 ... B2.n and receiving antennas A1, B1.1 ... B1.n are located across the entire width of the documents of the processing machine .  15. The device according to item 13, or 14, characterized in that the transmitting antennas A2, A3, B2.1 ... B2.n and receiving antennas A1, B1.1 ... B1.n are parallel to each other and with an offset in one plane so that the authenticity of documents is controlled, independent of the position of the sides and edges of two parallel edges of the documents.  16. The device according to p. 13, characterized in that the receiving antennas B1.1 ... B1.n and the transmitting antennas B2.1 ... B2.n are parallelly offset and / or arranged in the same row across the transport direction distance from each other that any security feature to be checked crosses at least one receiving antenna B1.1 regardless of its spatial position in the document. .. B1.n and one transmitting antenna B2.1 ... B2.n associated with it  17. The device according to p. 13, characterized in that the longest side of one transmitting antenna B2. i and the longest side of the receiving antenna B1.i associated with it correspond to the width of one conductive label of the protective strip.  18. The device according to p. 13, characterized in that it contains manually controlled or software-controlled switching and regulating elements, in particular microcontroller 47 after rectifiers 45, 48 ... 50 and selective amplifiers 46, 51 ... 53 arranged so that the output signals of selective amplifiers 46, 51 ... 53 can be combined or logically connected.  19. The device according to item 13, characterized in that it contains manually controlled or software-controlled switching and regulating elements, in particular microcontroller 47 after rectifiers 45, 48 ... 50 and selective amplifiers 46, 51 ... 53 arranged in such a way that switching between different types and types of documents is carried out without changing the location of the sensors.  20. The device according to p. 18 or 19, characterized in that the shortest distance between two transmitting antennas B2.i located in the same row is greater than the shortest distance between two electrically conductive, insulated marks of the protective strip, and that these switching elements are placed so that antenna A3 can be used either as a transmitter or as a receiver, depending on the input of the document to be checked.  21. The device according to item 13, characterized in that it contains manually controlled or software-controlled switching elements located in such a way that one or more transmitting antennas B2.i and associated receiving antennas B1.i can be alternately initiated or de-initiate. Priority on points:
03/30/95 according to claims 1 to 12;
02/29/96 according to claims 13-21.

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