WO1996030879A1 - Method and devices for checking security documents - Google Patents

Abstract

The invention concerns a method and devices for checking security documents. According to this process which uses known capacitive coupling, electrical signals are transmitted by transmitting antennae via electrically conductive security features to receiving antennae and amplified. The amplitude responses and time characteristics of the electrical signals are then evaluated and compared with existing signal responses, by being converted into signal responses having easily comparable parameters. In order to enable the testing arrangement to be specifically selective, a selective amplifier is additionally coupled to the evaluation electronics. Currency-specific definition by means of the evaluation electronics according to the invention is attained in that, for a given currency, a time limit of the test signal amplitude can be determined by means of controllers, for example, this time limit differing from the duration of the amplitude response of all the other currencies.

Description

Procedures and facilities for checking security documents

The invention relates to a method and devices for checking security documents according to the preamble of claim 1. There are various methods, devices, methods and checking systems for determining the authenticity of security documents, for monitoring the usability, for determining the position in processing machines and for determining the types and counting known. DE-PS 1223594 describes a device for capacitive scanning of record carriers, in which the scanning capacitors consist of sensor electrodes arranged on both sides of the record carrier web. The scanning security of this device is not given with regard to inserted, pressed or applied electrically conductive strips, tapes or other particles.

DE-PS 1774290 describes a measuring arrangement for the automatic evaluation of a characteristic feature of a bank note in a device for checking the authenticity of bank notes by means of capacitive coupling of electrodes which are arranged in a grid. This known measuring arrangement does not allow an exact determination of the relevant characteristic at the processing speeds required under today's conditions, and even with a slow test method, only the presence of such a characteristic is ascertained and thus does not do justice to the currently known counterfeits using electrically conductive components, for example in bank notes.

In DE-OS 2619457 magnetic properties of a test strip located in a bank note are measured.

BBATZBLÄTT (RULE 26) DE-PS 2834287 describes a genuineness test of ferromagnetic security threads in security prints with exposure to a magnetic field. These test methods are too slow and each require an exact positioning of the test object or the test strip. DE-PS 2760165 describes a technically complex test device in which the authenticity of banknotes is determined in particular in the second test section by measuring differences in thickness and fluorescence properties. The examination of only these properties no longer corresponds to the status of the false certificates in circulation. Counterfeit money with watermarks and fluorescent paper or paint can no longer be recognized as false with this device. Also the reading heads in processing machines described in DE-OS 3236373 and 3236374, which together with markings on security documents form an electrical capacitor and bring about a defined change in the capacitance value by introducing the ferroelectric between the capacitive electrodes of the reading device, are not for high-speed processing machines and not suitable for checking European banknotes currently in circulation.

Evidence of the electrically conductive security thread by detuning oscillators and resonant circuits according to DE 2912712 has not become established because of the low evaluation reliability and the great technical effort and complicated structure. US Pat. No. 5,308,992 describes a measuring arrangement made up of optical and capacitive sensors, which, however, requires exact positioning of the test strip. In order to increase the security against errors and to differentiate between different test objects (e.g. different currencies), the additional use of a magnetic sensor is proposed, which makes the measurement setup even more complicated and expensive. After presorting banknotes, the capacitive sensor only detects the presence of an electrically conductive security thread.

A test arrangement according to DE 4103832 is also known, by means of which capacitive and / or electro-optical and / or millimeter-wave sensors are used along a test section Examination are arranged. The examination of the dielectric properties of banknotes is the subject of this document.

Disadvantages of these known test methods and arrangements are primarily their high technical complexity and their inadequate security in order to find falsifications in the rapid passage of bank notes in money processing machines. A disadvantage of the known measuring arrangements for testing the capacitive properties is that a sufficiently low capacitive resistance is only achieved in the intended low frequency ranges from 10 to 220 kHz and only with very small distances between the electrodes and the metal thread. In addition, the influence of the dielectric change is still very large in this frequency range, that is to say that a substance with a large dielectric constant leads to an increase in the capacitance and thus to a reduction in the capacitive resistance between the antennas. For example, a damp false certificate would be recognized as genuine. In practice, these arrangements, in particular in the case of machine authenticity checking, have not yet proven successful.

EP 589 195 A2 describes a method in which an assignment code is obtained for checking the authenticity of test objects via a detection signal obtained by scanning a scanning area with highly permeable magnetic elements with the aid of a device with an excitation coil and sensor coil, and the authenticity when the detection signal and the assignment code match is affirmed. This test method can only be used to a limited extent for plastic cards, paper documents containing magnetic or magnetizable particles and only a few non-European banknotes. Other test methods, as described in EP 204 574 A2, 553 402 AI and 560 023 AI, in which geometric and / or physical properties of test objects are classified in the comparison method, can only be used for one type of object to be tested, very much complex and have not become established in practice for processing machines because of the high speed required as the only test method for authenticity in one processing step The object of the invention is to eliminate the existing disadvantages of the known test arrangements and methods and to propose a method with which a reliable detection of a characteristic test feature is possible, for many types of banknotes and currencies, for example even when moist or deliberately moistened and / or dirty test objects can be used, can differentiate between them, requires little technical effort, the application of which is suitable for retrofitting in processing machines and corresponds to the rapid throughput of test objects in processing machines. An electrically conductive security thread or tape or a flat security feature in banknotes and securities is used as a characteristic test feature. Furthermore, it is an object to design a test device for carrying out the method in such a way that it can be connected upstream in order to carry out an authenticity check before sorting according to currencies and types.

The object of the invention for carrying out the method further consists in the development of a device for checking security documents which, as a security element, has an electrically conductive strip or thread-like strip for testing both continuously electrically conductive strips and strips which have several electrically conductive, but have mutually insulated areas. Examples of such a security document are today's US banknotes which carry electrically conductive but mutually insulated identifiers on their security thread. In today's practice, it is necessary to easily install such test systems in processing machines that not only recognize falsifications of high quality as such, but also real documents of inferior quality, since these occur quite frequently in practice and lead to false triggers that affect the operating sequence of processing machines significantly disrupt

The method according to the invention for checking security documents, using the capacitive coupling known per se, provides for electrical signals from transmit antennas to be transmitted and amplified via electrically conductive security features to receive antennas, which are then evaluated according to the amplitude and time profile and compared with existing signal profiles. by converting them into waveforms that are easy have comparable parameters. To carry out the method with its method steps to be described in more detail, a test device is proposed for banknotes, documents, securities and the like with security strips or thread or a flat security feature using the capacitive coupling, which is used in a banknote processing machine, preferably a counting machine, for example. Is used. A test sensor system in the area of optical and / or magnetic and / or format sensors is arranged on a housing assembly. The machine guides the banknotes and / or securities past the test device. The test sensor system consists of several antennas and / or electrodes. The antennas and / or electrodes have an areal longitudinal extension transverse to the transport direction of the test objects that even with a defined lateral clearance of the test objects and regardless of whether a test object with the front or rear side facing upwards passes through the test device, in any case the security strip or -sufficiently sweeps the antennas and / or electrodes. The antennas and / or electrodes of the test unit correspond to sliding devices, pressure rollers and / or conveyor belts known per se in order to space the documents to be tested during their rapid passage to the antennas and / or to press them against the electrodes. Through the assignment of the test unit according to the invention in the area of optical and / or magnetic and / or format sensors, which usually function as recognition for geometry, position, color and the like, the test sensor system is activated at the same time

One or more antennas and / or electrodes are fed with high and / or low frequency energy and / or with DC voltage, and one or more antennas and / or electrodes absorb part of the radiated energy again via a security strip or thread. The applied voltage changes at one or more receiving antennas and / or receiving electrodes.

In order to be able to make comparable test statements, for example on the authenticity, the usability of documents or the currency of banknotes, constant test conditions, such as speed, are required for the test objects to be compared. The antennas and / or electrodes supply the evaluation electronics with a voltage. The Evaluation electronics supply a slightly comparable voltage depending on the signal form of the received voltage. In order to suppress interference and external energies as well as to prevent effects of basic conductivities of test objects on the measurement result, special filters and / or phase comparators can be used. The output pulse of the evaluation electronics is independent of the throughput speed A category-related (electrically conductive security strip or security thread or any conductive markings) definition of the evaluation electronics, additional amplitude limits are set, the course of which is so close to the amplitude deflection of a test signal that the difference between the defined amplitude limit and the largest possible amplitude deflection of all objects to be tested authenticity is determined. This means that counterfeits that have appeared recently and give a signal that is usually used as an evaluator tesignal would be detected, is determined as a forgery of evaluation electronics according to the invention

A currency-specific definition by means of evaluation electronics according to the invention - for example for all banknotes of individual countries with similar security strips - is achieved according to the invention in that a time limit for the amplitude of the test signal, for example by means of a controller, can be determined for a maintenance that differs from the duration of the amplitude profile of all other currencies

If the amplitude of a test signal has the same duration, an additional test is carried out, e.g. by color detection and / or differentiation and / or magnetic and / or format test method. The detection signals supplied by light barriers, for example, are linked to the signal of the test sensor system according to the invention and become a machine-specific one Output pulse generated

A modification of the method consists in driving one or more pairs of transmitting antennas out of phase in order to check security documents capacitive coupling between one of the transmitting antennas, an electrically conductive marking on the security strip and the receiving antenna opposite to the transmitting antenna produces a authenticity-determining signal at an input of an amplifier. From a second transmitting antenna, which is driven out of phase with the first, there is no capacitive coupling of the signal to the receiving antenna, since there is no electrically conductive security strip in the effective range. This arrangement already makes it possible to test a continuously electrically conductive strip. Staggered in relation to these antenna pairs are further pairs of transmitting and receiving antennas, the dimensions and spacing of which are matched to electrically conductive markings on the security strip. By transporting the object to be tested at a defined distance from the test sensor system, characteristic amplitude and time signals and thus signals that can be evaluated are forwarded from the receiving antennas to an electronic evaluation system. A test is thus carried out which is able to recognize several electrically conductive markings which are insulated from one another and to evaluate them accordingly. It is irrelevant whether the insulation between electrically conductive markings is intended, such as. B. with a US banknote or whether the isolation z. B. by breaks in the continuous electrically conductive security strips, z. B. was called for German banknotes. A microcontroller can compare the number of these interruptions with stored values. By arranging several pairs of transmitting and receiving antennas and associated evaluation electronics, a reliable statement about the authenticity of the document is possible, since despite possible lateral displacements when the object to be tested is fed to the test device, the latter works reliably. If, according to the invention, the transmitting or receiving antennas are arranged over the entire working width of the processing machine, an authenticity check of the security documents which is neutral in position is possible. It is therefore irrelevant whether a document is fed with the front or back and / or left or right side security strips and / or shifted transversely to the transport direction. This makes it possible to check documents that can differ both in format and in the arrangement of the security strip in relation to the direction of transport. Through different types of security strips It is not only possible to classify authenticity, but also to assign different documents, e.g. different currencies, in the transport direction of the banknotes. A further test sensor system can be arranged upstream and / or downstream in the transport direction of the banknotes linked (double test) without having to change the software for the processing machine in question, for example when retrofitting with a test device according to the method of the invention

In addition to the claims, the advantageous features of the invention also emerge from the description and the drawings, the individual features representing protective versions, either individually or in groups in the form of sub-combinations, for which protection is claimed here Drawings shown Show in the drawings

1 block diagram of the evaluation circuit,

2 detection curves during the passage of a bank note at different throughput speeds, 3 detection-specific detection curves, 4 detection curves of several bank notes and falsification

Fig. 5 block diagram of the evaluation circuit in double test

Fig. 6 section through a schematic representation of a test device

Fig. 7 test sensors

8 block diagram of a test device. FIG. 9 arrangement of the test sensors in a processing machine

The method to be described in more detail below using various devices and arrangements is essentially based on the implementation of the method steps of capacitive coupling of electrical signals from transmitting antennas via electrically conductive ones Security materials for receiving antennas, amplification and conversion of the received signals in amplitude and time course into easily comparable signals and comparison of the same with existing signal courses in order to display and evaluate the authenticity of the documents to be checked in an appropriate form. A machine coupled to the test device transports the banknotes or securities into the area of the test device. The light barriers then activate the test sensors. The transmitter antenna is fed with high-frequency energy. In the present embodiment with 6 MHz. If the security strip or thread passes through the test field, the receiving antenna absorbs part of the radiated energy again. The RF voltage applied to the receiving antenna changes. As is known, the reason for this is the capacitive coupling between the transmitting and receiving antennas due to the electrical conductivity of the security strips or threads. The HF conductivity is different for the individual currencies. In order to be able to make currency-specific statements with the aid of the evaluation circuit, constant throughput conditions of all objects to be checked in one work step are required.

The test unit and its test sensors are connected in a functional unit to evaluation electronics, essentially consisting of an analog / digital converter and controller or integrator 15, trigger 16, controller, mono-flop 17 and / or AND link 18, via shielded lines. A possible evaluation electronics is shown as a block diagram in FIG. 1.

The reference numerals 12 denote an RF transmitter, 13 the RF receiver, which absorbs the energy radiated by the receiving antenna 9, amplifies it in the selective amplifier 14 as a currency-specific and / or authenticity useful signal, 15 an integrator, 16 a trigger, which in addition to the existing signals which receives the signals of the light barriers 20 which activate the evaluation circuit and outputs them as time-coordinated pulses via the mono-flop 17 as an output signal for test objects which are found to be genuine. As can be seen in FIG. 4 from curves a and b when bank notes are being processed, false signals 26 do not emit any output signals comparable to bank notes found to be genuine. The defined shielding of the test sensors and the evaluation electronics of electrical and electromagnetic fields as well as the arrangement of the test sensors in the area of the light barriers guarantee a high ratio of useful and interference signals and, in conjunction with the forced guidance through the conveyor belts in connection with a defined banknote throughput speed, enable a currency-specific selectivity of the test facility. Another advantage of this method according to the invention is that, for example, the moisture content and / or degree of soiling of the test objects and / or banknotes and / or securities no longer appear as a source of interference. FIG. 6 shows a schematic illustration of a test device in section, which is used in a bank note processing machine, preferably a counting machine, according to the method described above. There is a machine support 2 on the housing assembly 1, which receives a test sensor system on its horizontally extending leg 3, which is arranged in the area of light barriers 4, 5 on a non-conductive carrier material 6 of the leg 3. The carrier material 6 has cutouts and / or openings 7 for the light transfer from the light barriers 4, 5. These cutouts and / or breakthroughs 7 can be omitted if crystal-clear carrier material 6 is used.

The test sensor system consists of several strip sensors 8, 9, in this example two, namely a strip sensor 8 as a transmitting antenna and a strip sensor 9 as a receiving antenna. The strip sensors 8, 9 have such an areal longitudinal extension transversely to the transport direction of the banknotes 11 that even with a defined lateral clearance of the banknotes 11 and regardless of whether a banknote 11 with the front or back side facing upwards passes through the test device, in any case the Security strips or threads still pass over the strip sensors 8, 9 and are passed underneath them through the test device. Below the leg 3 and parallel to this, conveyor belts 10 run at such a distance from the strip sensors 8 and 9 that the bank notes are pressed against the strip sensors 8 and 9 during their rapid passage. Light barriers 4, 5 are arranged between the conveyor belts 11 perpendicular to the direction of banknote passage

The evaluation electronics are also housed in a shielded area of the processing machine, in this exemplary embodiment expediently in the area of the housing in which, for example, the paper thickness adjustment device is arranged

The defined shielding of the test sensors and the evaluation electronics of electrical and electromagnetic fields as well as the arrangement of the test sensors in the area of the light barriers 4, 5 guarantee a high ratio of useful and fault signals and enable them in connection with the forced guidance by the conveyor belt 10 in connection with a defined one Banknote throughput speed, a currency-specific selectivity of the test device Another advantage of this test device according to the invention is that, for example, the moisture content and / or degree of soiling of the test objects no longer appear as a source of disturbance a further test sensor system, for example for a magnetic test, as shown in the block diagram in FIG. 5, can be arranged upstream and / or downstream. In this case, the output signal of this sensor system is combined with the Output signal of the test sensor system according to the invention linked (double test) without having to change the software for the processing machine in question, for example when retrofitting with a test device according to the invention

The evaluation electronics connected to the test sensors and the light barriers - as shown in FIG. 2 and FIG. 3 - provide a DC voltage that is dependent on the amplitude profile of the received HF voltage. This is illustrated in the figures mentioned, the signals transmitted, shown in the respective curves a

2 shows detection curves during the passage of a bank note at different passage speeds. The curve a shows the transmitted signal and curve b the output signal of the evaluation electronics. It corresponds to v, a passage of 500 bank notes per minute and v ₂ a throughput of 1800 banknotes per minute. Curve b also illustrates how a banknote detection signal supplied by the light barriers is linked to the signal from the test sensor system and generated to form a machine-specific output pulse. This output pulse is independent of the throughput speed, as can be seen in the comparison of curves b in FIG. 2.

3 shows currency-specific acquisition curves when passing banknotes of different currencies. Curve a in turn shows the transmitted signal from the test sensor system, while curve b represents the evaluation signal of a selective amplifier, which was additionally coupled to the evaluation electronics in order to enable currency-specific selectivity of the test device without additional sensors. In FIG. 3, DE means German currency, CH Swiss currency, EG Egyptian currencies and CN Chinese yuan from the 1990 series. The amplitude profile of the received RF energy, which is different from the different type of security strip, is clearly recognizable in the banknotes of different currencies and so on detectable by the evaluation electronics. If processing of the currency-specific signal is necessary, a signal that is additionally processed by the evaluation electronics for currency-specific classification is possible, for example using a controller. Just as the different currencies can be distinguished by different security strips or threads, false certificates are also recognized - provided they have imitated security strips or threads or only a fraction of them. Fig. 4 shows detection curves of eleven banknotes in a money counter. The banknotes with the numbers 21 to 25 and 27 to 31 have been recognized as real banknotes. Test object no. 26 is a falsified certificate deliberately inserted for trial purposes. Due to the lack of a security strip or an imitated security strip, no signal was delivered by the test sensor system. In practice, if there is no signal or a signal that is not specific to banknotes, the processing machine is stopped, and the falsified product or the useless note is removed or stored separately by machine. If the test unit is additionally connected to a further test sensor system, this machine-specific output pulse indicates the detection of the respective security strip or thread and is AND-linked to the output signal of that additional test of the processing machine. If one of the two authenticity signals is missing, the machine is stopped and the operator can remove the incorrect or incorrect banknote.

Another possible application with a corresponding definition of the evaluation electronics results from the evaluation signals of the selective amplifier, as shown in FIG. 3. If, for example, in larger processing machines, which are also used for sorting different currencies, the amplitude limit A marked in FIG. 3 is exceeded for all currencies to be checked, then those with a speed v ₂ are displayed with a real security strip or thread responding to the test sensor system recognized. A specific time t- ^ is assigned to each currency. To distinguish between individual currencies, the times t ^ = t _j ... t ₄ to t _n must be defined as t currency-specific. For example, tf of the German currency should be chosen larger than t _{2 of} the Swiss franc or tf of the Swiss franc larger than t _{3 of} the Egyptian currency. Since tf of the German currency with tf currencies not shown in FIG. 3 may have to be chosen to be the same size, a further currency-specific check with color recognition and / or format and / or magnetic test methods known per se is required within the processing machine. Individual currencies sorted out in this way are stored in compartments or stacking containers in a known manner.

Processing machines are equipped with a test sensor system 54, as shown in FIG. 7, which consists of several transmitting and receiving antennas, all of which are arranged parallel to one another and orthogonal to the direction of transport, in particular for testing non-continuously electrically conductive security strips of documents Banknotes pass through the entire run in a processing machine, for example a banknote counting machine, onto a transport device such that the longest dimension of the security strip or thread in the banknote is approximately parallel to the direction of transport, for example a German banknote with its longest dimension The transmit antennas A2, A3 and the receive antenna AI are arranged opposite one another, offset from one another by a plurality of transmit antennas B2.i (i = 1. n) and a plurality of receive antennas Bl.i each having antenna pairs. These pairs are offset from one another to suppress coupling of a signal from a transmitting antenna Bl.i to an adjacent but not corresponding receiving antenna Bl.k (k = ln, i <> k) neighboring transmitting antennas (B2.i, B2.i + 1) and associated ones Receiving antennas (Bl.i, Bl.i + 1) are offset by a defined distance, preferably by the distance between a transmitting antenna (B2.i) and the associated receiving antenna (Bl.i). To reduce interference, the diagonally offset antenna pairs are offset preferably arranged between the transmitting antennas A2, A3 and the receiving antenna AI

8 shows the block diagram of the test device according to the invention with the control of the test sensor system according to FIG. 7. If a document is fed to a processing machine that contains the test device according to the invention, it is activated by light barriers or similar position-determining sensors. The frequency generator 41 controls the transmission antenna A2 and via one Phase shifter 42 on the transmission antenna A3. The phase-shifted control prevents interference from external energy and falsified products that have no difference in electrical conductivity are recognized. This also applies to banknotes whose properties are affected, for example, by aging and / or mechanical damage and / or moisture At the same time, a number n of transmission antennas B2.i (i = ln) are controlled via a second frequency generator 43 and a second phase shifter 44, each of the transmissions which are not in series transverse to the transport direction Antennas B2.i are driven out of phase in order to reduce interference from external energies and to prevent capacitive overcoupling from a transmitting antenna B2.i to a non-corresponding receiving antenna Bl.k (k = ln, i <> k) The frequencies that the signals of the two generators are chosen so that one frequency is not a multiple of the other or a multiple of the difference between the two in order to prevent signal distortions at the receiving antennas During the test, a capacitive coupling of the signal from the transmitting antenna A2 to the receiving antenna AI takes place via a continuously electrically conductive security strip, while the signal from the transmitting antenna A3 is not capacitively coupled to the receiving antenna AI. The shortest distance between transmitting antenna A2 and receiving antenna AI is less than the longest dimension of the electrically conductive security strip in the smallest document to be checked. If the security strip is not at any time during the test in the range of effect of the transmitting antenna A2 and the receiving antenna AI, the security strip is in the range of action of the transmitting antenna A3 and the receiving antenna AI, so that the other functions are performed analogously to the case mentioned above. A signal is then present at the receiving antenna AI, which supplies a signal to the microcontroller 47 by means of a rectifier 45 and selective amplifier 46, which checks the authenticity classification by comparing the signal of the selective amplifier 46 with a signal stored in the microcontroller 47, e.g. B. causes a special threshold. If the threshold value is exceeded, the microcontroller 47 classifies the object to be checked as an object with a continuously electrically conductive security thread, ie as genuine for German banknotes. If there are electrically conductive markings in the security strip, which due to their expansion are not detected by the transmitting antenna A2 and the receiving antenna AI, the same can be recognized by the arrangement of the transmitting antennas B2.i and associated receiving antennas Bl.i according to the invention, since their spacing is around are several times smaller than the distance between the transmitting antenna A2 and the receiving antenna AI. For example, if the extension of an electrically conductive marking parallel to the document transport direction is 1.5 mm, the distance between the transmitting antenna B2.i and the receiving antenna Bl.i should be selected, for example, 1.3 mm in order to ensure reliable capacitive coupling. During testing, the security document to be tested is moved at a defined speed in the effective range of the test sensor system of the test device according to the invention. The shifted arrangement of the transmitting antennas B2.i and the receiving antennas Bl.i provides tolerance compensation for an orthogonal shift of the banknote in relation to the transport direction of the document. Signals generated at the receiving antennas Bl.i are rectified via 48..50 and Selective amplifier 51..53 fed to the microcontroller 47. Depending on the nature and position of the security thread in the document, the signals of the selective amplifiers 46, 51..53 arriving at the microcontroller 47 differ in frequency and amplitude characteristics. As a result, the document can be classified by the microcontroller 47 by frequency comparison and / or threshold value comparison with predetermined values and stored in the microcontroller 47. These values are determined by manual input, programming and / or comparison with values that have been parameterized with a comparison document that has already been classified. The microcontroller 47 generates a machine-specific signal which indicates the authenticity of the banknote to be checked. This classification signal of the microcontroller 47 is coupled to relevant display elements and / or to the corresponding interface of the processing machine for further processing. Just as the different currencies can be distinguished by different security strips or threads, false certificates are also recognized - provided they have imitated security strips or threads or only a fraction of them. The compact design of the entire test facility, in particular the sensors and evaluation electronics forming a unit, and additional shielding measures provide further possibilities for reducing interference, which are becoming increasingly important in practice. The arrangement in a processing machine is such that the usual bill transport is not affected by the test sensors. How a test device according to the invention is integrated into a conventional processing machine, for example, is shown in FIG. 9. For this purpose, the test sensor system 54, which is composed of the transmission antennas A2, A3, B2.i and the receiving antennas AI, Bl.i, is integrated into an existing guide device 56. The test sensor system 54 is tangential to the guide device 56 or tangential and offset from the transport roller 55 so that it additionally assumes its guiding function in the area of the test sensor system 54. A banknote to be checked therefore comes into the range of action of the sensors without additional pressure means. The test sensor system 54 is arranged tangentially to an existing guiding device 56 in such a way that a security document to be tested and driven by transport rollers 55 on the test sensor system 54 is at a defined distance and more defined Speed is passed. A defined distance between the transport roller 55 and the guide device 56 or the test sensor system 54 can be set by means of corresponding fastening means on the guide device 56, in particular wobble screws. The threshold values and classification variables are parameterized by switches (not shown in the figures) or by appropriate software of the microcontroller 47. As a result, the user is able to change the classification variables by simply switching over in order to check other currencies. In practice, if there is no signal or a signal that is not specific to banknotes, the processing machine is stopped and the false certificate or the useless note is removed.

The lateral expansion of the antenna arrangement over the entire document width reduces the influence of paper quality, age, moisture, etc. on the authenticity classification. This also includes the possibility of classifying, for example, falsified, genuine banknotes and banknotes with a high degree of wear. This classification is carried out by appropriate evaluation of the amplitude and time profiles of the signals emitted by the selective amplifiers 46, 51..53 and corresponding threshold value parameterizations by the evaluating microcontroller 47. The microcontroller 47 is calibrated manually, software-controlled or by checking special calibration documents, of which the authenticity classification is known. In the latter method, a calibration document is checked by the test device according to the invention as described above. Instead of comparing the signals at the outputs of the selective amplifiers 46, 51..53 with existing signals in the microcontroller 47, these are stored in the microcontroller 47 as reference variables.

A further installation location for the test sensor system 54 results from the patent application 195 18 229.4. According to this invention, the test sensor system 54 can be arranged, for example, at the end of the circular guiding device 56, as shown in FIG. 10 here. Here, too, the necessary pressure devices for the defined spacing and / or touching passing of the test objects past the test device are eliminated This option can be used if the above-mentioned tangentially offset installation of the test sensors 54 in the region of the guide device 56 in the form of a circular arc cannot be implemented. Since pressure means such as springs and pressure rollers are eliminated according to the invention, the test object itself is also subjected to less mechanical stress by the test device.

The method according to the invention was explained on the basis of specific design variants of the test sensors and the evaluation electronics in a money counting machine. However, it should be noted that the present invention is not restricted to the details of the description in the exemplary embodiments, since changes and modifications are claimed within the scope of the patent claims. For example, Various versions of the evaluation electronics are possible, which are based on the special mode of operation of the selective amplifier.

Claims

claims 1. Procedure for checking security documents with electrically conductive Security strips, tapes, threads or flat security materials using the capacitive coupling between transmitter and receiver and downstream evaluation electronics, characterized in that in the area of optical sensors and / or magnetic sensors and / or format sensors, which are spatially connected to a test sensor system in a processing machine correspond and activate the test sensor system, several antennas and / or electrodes located in one or more levels and functioning as transmit or receive sensors form one or more test fields and, via the test object, depending on its geometry and / or its conductivity, energy in the high range - And / or low frequency and / or in direct voltage, the antennas and / or electrodes are transmitted in a coupling manner and that the transmitted energy is followed by one or more antennas and / or electrodes with the same phase position or in a different phase position n Dispense selective amplifier (14), to avoid interference energies and to suppress basic conductivities of test objects, in banknotes, for example, a phase comparator downstream of the selective amplifier (14) as well as special filters for suppressing interference and external energies and an evaluation unit are arranged so that a classification of electrically conductive security strips, tapes, threads or flat test objects, the test object is guided through the test field in an undefined lateral orientation in a forced manner during the test process. SPARE BLADES (RULE 26) 2 The method according to claim 1, characterized in that the evaluation electronics, consisting essentially of analog-digital converter and controller or integrator (15), Trigger (16), controller, mono-flop (17) and / or AND operation (18), from Signal curve at the output of the selective amplifier (14) determines the amplitude limit violation (A) and / or the currency-specific time t ^ 3 The method according to claim 1 or 2, characterized in that an authenticity classification is carried out by means of evaluation electronics by an amplitude limit (A) being set for the authenticity of the currency to be checked 4 The method according to claim 1 or 2, characterized in that by means of Evaluation electronics the classification of different banknotes and / or securities is carried out by a currency-specific time (t- ^) is preferably determined by means of a controller and the test objects with a time t _j t ^ _j , t ^ ₊ ^. t _{n to be} sorted out 5 The method according to one or more of the preceding claims, characterized in that for currencies with the same times t ^ an additional test after Authenticity test is carried out 6. The method according to one or more of the preceding claims, characterized in that a special evaluation unit, preferably one or more controllers, delivers a machine-specific signal for storing the individual classifiers in special compartments or stacking containers by time comparison and / or voltage comparison 7. The method according to one or more of the preceding claims, characterized in that the antennas and / or electrodes transversely to the transport direction of the test objects have such an areal longitudinal extent that even with a defined lateral latitude of the test objects and regardless of whether a test object with front or faces upwards through the test device, in any case the security strip or thread passes over the antennas and / or the electrodes in a defined distance. 8. The method according to one or more of the preceding claims, characterized in that an additional test is carried out and the result thereof with the signal of Evaluation electronics is linked by means of an AND gate without having to change the software of the processing machine in question. 9. Device for checking security documents with electrically conductive security strips, tape, thread or flat security materials Application of the method according to one or more of claims 1 to 8, characterized in that in the area of optical sensors and / or magnetic sensors and / or format sensors which activate a test sensor system in a processing machine, a plurality of transmitters located in one or more levels - or receiving antennas forming sensors forming one or more test fields, are arranged and are coupled via the test object depending on its geometry and / or its conductivity, energy in the radio frequency range so that one or more antennas transmit the transmitted energy with the same Submit a phase position or in different phase positions to an intermediate selective amplifier (14), one to the selective amplifier (14) to avoid interference energies and to suppress basic conductivities of test objects, for example banknotes (11), downstream phase comparators, special filters for suppression Coverage of interference and external energy and an evaluation unit, consisting essentially of analog / digital converter and controller or integrator (15), trigger (16), controller, mono-flop (17) and / or AND link (18) are and that the test object is arranged in a non-defined lateral positional orientation on the sensors in a defined contactless manner and at a defined speed by means of brushes and / or hold-down devices and / or conveyor belts (10), rollers, clamps and the like arranged in this area during the test process. 10. Device according to claim 9, characterized in that the sensors acting as transmitting or receiving antennas are designed as strip sensors (8; 9) in one plane or in two planes opposite and / or mirror-like. 11. The device according to claim 9 or 10, characterized in that the strip sensors (8; 9) have recesses and / or openings and / or windows (7) or those are arranged in close proximity to the strip sensors (8; 9). 12. Device according to one or more of the preceding claims 9 to 11, characterized in that sensors in test units are arranged in mirror image with the test zones and / or security strips, threads and / or tapes of objects to be checked, preferably banknotes, securities and packaging are. 13. A device for checking security documents with an electrically conductive security strip, tape, thread or flat security materials for applying the method according to one or more of claims 1 to 8, characterized in that several transmitting antennas (A2, A3, B2.1. .B2.n) and several receiving antennas (AI, Bl.L.Bl.n) forming a test sensor system (54) are arranged in such a way that both continuously conductive and strips can be tested that have several electrically conductive but mutually insulated areas within of a security strip, the test sensor system (54) being arranged tangentially parallel to an arcuate guiding device (56) or tangentially, parallel to a transport roller (55), and in that two transmitting antennas (A2, A3 ) orthogonal to the longest direction of expansion of a security strip and orthogonal to the direction of movement of a document to be checked and one or more receiving antennas (AI) parallel to the transmitting antennas (A2, A3) opposite and between these several transmitting antennas (B2.1..B2.n) parallel to the transmitting antennas (A2, A3) and a plurality of receiving antennas (Bl.L.Bl.n) are arranged parallel to the transmitting antennas (B2.1..B2.n), with adjacent transmitting antennas (B2.i, B2.i + 1) and associated receiving antennas (Bl. i, Bl.i + 1) are arranged offset by a defined distance, preferably by the distance between a transmitting antenna (B2.i) and associated receiving antenna (Bl.i) and the shortest distance between a transmitting antenna (B2.i) and the associated receiving antenna (Bl.i) is smaller than the shortest distance between one of the transmitting antennas (A2, A3) and the receiving antenna (AI). 14. Device according to claim 13, characterized in that a plurality of transmitting antennas (A2, A3, B2.1..B2.n) and a plurality of receiving antennas (AI, Bl.L.Bl.n) are arranged over the entire document feed width of the processing machine. 15. The device according to claim 13 or 14, characterized in that the transmitting antennas (A2, A3, B2.1..B2.n) and the receiving antennas (AI, Bl.L.Bl.n) so side by side, parallel and offset in are arranged on one level so that the documents are authentically checked independently of the page and independently of the edge with respect to two parallel document edges. 16. Device according to one or more of the preceding claims 13 to 15, characterized in that receiving antennas (Bl.L.Bl.n) and transmitting antenna (B2.1..B2.) Which are offset in parallel and / or in a row transversely to the transport direction. n) are arranged so that each security feature to be checked, regardless of its arrangement in the document, covers at least one receiving antenna (Bl.L.Bl.n) and an associated transmitting antenna (B2.1..B2.n). 17. The device according to one or more of the preceding claims 13 to 16, characterized in that the longest side of a transmitting antenna (B2.i) and the longest side of the associated receiving antenna (Bl.i) corresponds to the width of a conductive marking of the security strip. 18. Device according to one or more of the preceding claims 13 to 17, characterized in that operable or software-controlled switching and setting elements, in particular microcontrollers (47) after rectifier (45, 48..50) and selective amplifier (46, 51..53 ) are arranged so that the output signals of the selective amplifier (46, 51..53) can be combined or logically combined. 19. Device according to one or more of the preceding claims 13 to 18, characterized in that operable or software-controlled switching and setting elements, in particular microcontrollers (47) after rectifier (45, 48..50) and selective amplifier (46, 51..53 ) are arranged so that switching between different document types, types and degrees of wear takes place without changing the sensor arrangement. 20. Device according to one or more of the preceding claims 13 to 1, characterized in that the shortest distance between two in a row Transmitting antennas (B2.i) is greater than the shortest distance between two electrically conductive, mutually insulated markings of the security thread and that switching elements are arranged so that the antenna (A3) either as a transmitting or receiving antenna, depending on the supply of the test item Document is used. 21. Device according to one or more of the preceding claims 13 to 20, characterized in that software and / or manually controlled switching elements are arranged such that one or more transmitting antennas (B2.i) and the corresponding receiving antennas (Bl.i) are optional can be activated or deactivated.