HK1027885A - Security element structure for documents, devices for controlling documents comprising such security elements, and method for using said security elements and devices - Google Patents

Description

Security element structure for documents, device for checking said documents and method for using same

The invention relates to a security element structure for documents, a device for checking documents with said element and a method for applying said security element and device.

Expensive optical detection methods have been used to detect security elements having diffractive optical effects. Documents with, for example, so-called diffractive optical effect security elements, or so-called OVDs (optically variable devices), cannot be detected in a document processing machine because of their high speed of operation.

DE2747156 discloses a method and a device for the anti-counterfeit detection of a holographic identification card. The Optically Variable Device (OVD) is reproducible and can be visually inspected. This method is not suitable for high-speed, efficient and human-independent detection.

In EP0042945 an apparatus for generating a scanned image with a laser, a mirror and lens system and a photodetector is described. The economic cost in this case is also very high. If the subject is not pre-classified, the cost is further increased. To avoid pre-classification, several anti-counterfeiting detection systems or repeated detection must be arranged.

A device for detecting a security tape in a banknote is described in EP0092691a 1. The material-specific absorption band of the plastic security band was measured by means of two luminescence measuring channels in the infrared range and having a wavelength of about 5 μm. In the EP mentioned above, the forgery-proof or quality-proof detection of metallic reflective diffractive optical effect forgery-proof elements, for example reflective holograms or dynamic images, is not described, so that forgery-proof or quality-proof detection of metallic reflective diffractive optical effect forgery-proof elements is not possible with the device described. The detection of the reflected light process of banknotes by line scanning cameras is known from GB2160644A, and the detection of cards with a specific laser structure by reflected light or emitted light methods is known from CH-PS 652355. Both of them compare the received image information with the original image information to detect. Both methods, reflection and marking after wear, are problematic and therefore a significant disadvantage. Automatic anti-counterfeit checking of holographic image information is described in DE-OS 3811905. The transmitter and receiver for reflected light holographic image detection described in DE-OS should be arranged directly opposite each other so that the holographic image information can be analyzed. The direct arrangement of the transmitter and the receiver in relation to one another has the disadvantage of being overloaded in the metering technology and can sometimes even damage the receiver if direct light falls into the gaps between successive banknotes. When detecting banknotes with folds, the detection is practically impossible because of irregular reflections.

According to the above known methods, accurate positioning of the detection object is required, and all the apparatuses are not suitable for a high-speed processing machine.

DE 19604856 a1 proposes the detection of the condition, quality and registration of optical security features in the form of metallic reflective layers, such as dynamic images, holographic images or the like, on counterfeit documents, in particular banknotes, by scanning the metallic reflective security features of the security documents with emitted light in a manner known per se by means of at least one electronic camera, preferably a CCD line scanning camera, and comparing the actual values determined in this manner with the required values by means of image analysis known per se for the purpose of marking banknotes with incorrect security features or for the purpose of separating used banknotes into sorting units. The device described in DE 19604856 a1 is characterized in that: a known transfer system for moving security documents in the region of an electronic camera, an infrared radiation source on the side of the security document to be measured facing the camera, and the optical axis of the camera and the optical axis of the illumination unit being at an angular offset of 180 °, is also characterized in that the transfer unit is preferably formed by transfer belts which are spaced apart from one another transversely to the transfer direction.

The apparatus and method also have disadvantages in that, for example, an extra old bill having a fold, or a bill having a broken dynamic image film and a bill having a stained surface of the dynamic image film are not detected as a genuine bill. Furthermore, although the method and associated apparatus described are automated, they are not suitable for high speed banknote counting machines which test more than 1200 banknotes per minute.

Diffractive optical security features or OVDs on security documents, such as 100 and 200 german mark banknotes, are currently being detected manually or visually for breakage, correctness of registration numbers, correct edge morphology. In the case of banknote printing, the detection is carried out visually, if necessary, in the case of sorting banknotes out of circulation. This method is time consuming and expensive.

Moreover, this detection is inaccurate because, for example, diffractive optical security elements are routinely produced by chemical etching for their demetallized regions. It is well known that these methods do not produce an accurate curve of the desired structure. Typically, a "fraying" edge curve occurs.

Furthermore, in DE 19542995 a1, a method for the forgery-proof detection of data by adjusting various data variables is described.

According to this patent specification, the following possibilities exist:

-comparing the standard image of the holographic image with a storage unit,

-comparing the holographic image data of the holographic image with data in a defined range in the data carrier and/or the storage unit,

-comparing the holographic image data with data variables via an input unit,

-comparing the individual frames of the holographic image with the data of the input unit of the storage unit and/or with the data of the determined range.

This method is also time consuming and expensive. This detection is optically performed by image detection analysis by a reading device, and is not suitable for a high-speed processing or detecting machine.

As described in the DE 19734855.6 patent application, the optical effect is achieved using only diffractive optical security elements or OVDs and can only be detected by optical detection methods or visual inspection. Other detection methods, particularly for high speed processors, are not known.

The known method and device for the forgery-proof detection of objects, forgery-proof documents, especially banknotes, and the characteristic to be detected, detection areas and detection structures have the major disadvantage that the degree thereof is known. This known degree allows counterfeiters to derive a judgment from knowledge of the inspection method and apparatus and its features, inspection areas and inspection structures to be inspected. This requires completely new objects, security documents, in particular bank notes, for security detection, the solution of which must be reflected in new application systems for the detection features, detection methods and detection devices in order to avoid easy detection and copying of the information code.

It is an object of the present invention to eliminate the disadvantages of the prior art and to improve the structure of a document security element by means of an additional security element, to propose a device for detecting such a security element and a new method for applying the security element and the device, so that a counterfeiter, if not impossible, is not readily able to make a decision on the detection method and device and on the effect thereof on the security element to be checked in order to produce a counterfeit which is similar to a genuine article but not detected by the detection device.

Another object of the present invention is to provide a method for detecting a conductive ink accurately at a low cost, quickly and independently of human, by combining the conductive ink with the ink. The anti-fake feature detecting device is used in fast file processing machine and may be also used in manual detection device. In addition, it is an object of the present invention to design devices in connection with the present invention such that they detect a certain number of various security elements or features on a document, where the number of security elements to be detected differs between devices. This objective is to achieve different detection criteria based on potential cost and detectable components.

This object is solved by the following description of the invention.

The structure of the security element of the document to be examined provides a novel configuration which is not primarily a visual inspection, but is based on a detection method. This configuration, hereinafter referred to as functional configuration, is a combination of conductive and insulating structures of the same or different size, at the same or different depths from each other, and consisting of a metallized structure and/or a conductive pigment or ink. In its various and various combinations, this functional configuration obtains a coding function in all distinguishable security elements and can therefore be detected in a coded manner. According to the invention, the functional configuration can consist of a diffractive optical effect optical security element or can consist of conductive pigments or inks. If configured as a diffractive optical security element, it can be adapted optically, i.e. visually, and can even support it in its optical configuration.

Conductive colors or inks in the form of lines, dots, and patterns, etc., metallized structures that can be detected by capacitive coupling are referred to as security elements. The security elements are arranged on the document separately or in combination. A security feature comprises at least one security element, preferably a sum of security elements having the same or different configuration, size, hue and/or conductivity.

The diffractive optical security element according to the invention is produced with a metallized structure using production techniques known per se, rather than demetallizing a specific structure as in the prior art. In order to produce security elements to be detected with high quality, the metallized security elements according to the invention must be produced with a highly nearly required metallization structure and steep edges for adjacent insulating structures. The steepness of these edges acts as a microstructure and can be detected. As described above, the demetallized region of the diffractive optical effect security element is conventionally produced by chemical etching or the like. It is well known that such methods do not allow for sharp edges and precise lines of desired structure. Typically, a "fraying" edge is present. Such edge lines do not allow to make demetallised zones of width in the range of tenths of a millimeter for the functional configuration. Another production technique must be used to achieve the exact edge profile required for the functional configuration. It is carried out in a known high-vacuum metallizer with a special metallization process with adjoining demetallized zones. For counterfeiters, this means an increase in the cost of the counterfeiters. In addition to a more or less completely printed structure, the diffractive optical effect security element according to the invention has at least one bundle-like, lattice-like, round and/or meandering security element with a detectable line width of less than or equal to 5 mm. These security elements are also information-coding and can be detected and evaluated by the device according to the invention.

The device for detecting the special detection feature according to the invention has a capacitively operating scanner. The scanner consists of several parallel transmitting electrodes and one receiving electrode parallel to the said structure. Compared to a sensor with electrodes having a large area, the scanner has a small electrode surface, which has the advantage that the capacitive coupling between the individual electrodes is small. In a document processing machine, the scanner is arranged such that an optical or mechanical sensor in a conventional document processing machine drives the detection device according to the invention. To reduce detection and measurement errors, it is preferable to use a sensor holder that supports all sensors for detection. The distance between the sensors is minimized. In order to minimize the variation in the position of the document to be inspected, it is necessary to minimize the distance between the sensors, since the position of the document varies as it passes through the machine due to the condition of the document, the wear of the machine and the conditions of the environment, in particular the temperature and the air humidity. In the case of disadvantageous file feeds, the mutual distance between the files may vary. The wear of the transfer rollers and bearings also causes the document to twist through, which also means that the document that is only fed in may twist during transfer. As a result of the undesired position change, the defined clock is disturbed and false rejections occur. The smaller the security element, the greater the problem of its detection. The device according to the invention has a pressure-exerting device which has little resistance to the document. The pressure application device transfers the document parallel to the scanner or preferably presses the document to be examined against the scanner. But also contact the shaft of the grinding transfer roller by a sliding action. By means of such additional sliding and pressure-exerting means, reproducible detection conditions of uniform document distance or contact are ensured and the working of the sensor is fundamentally improved. The electric energy control of each transmitting electrode is performed on a time-shifted basis by an electric control system having a switching frequency in the KHz range and above. The electrical control system comprises, as main components, in addition to the power supply, a multiplex encoder, an oscillator for energizing the emitter electrode and an oscillator for controlling the multiplex encoder.

When conductive, the energy of the controlled transmitting electrode is capacitively coupled between the transmitting electrode and the receiving electrode. The signal traces on the receiving electrodes are converted into signal images. The signal image depends on the metallization structure of the diffractive optical effect security element. An electroanalytical system downstream of the receiving electrode compares the signal image of the test object with a corresponding reference signal. Basically, the electroanalytical system includes a power supply, an amplifier, a demodulator, a comparator, a microprocessor with memory, and a filter to reject interfering and undesired signals.

In addition to the software of the microprocessor, the reference signal image is stored in a memory and is compared with the signal image scanned depending on the document to be checked for the security element. Since the scanner extends over the entire document in the transverse direction, individual features of conductivity are detected by the device according to the invention. Comparison with the reference signal provides a further processed classification signal. It is thus possible to separate out counterfeit documents by stopping the detection device or by bypassing the document transfer channel. To reduce adverse effects, the sensor carrier is tightly connected to the plate supporting the electrical control and analysis system.

As a modification of the electrode arrangement, it is within the scope of the invention to arrange a long transmitting electrode parallel to several parallel receiving electrodes mounted side by side. In which case the received signal is processed by a multi-way encoder. The remainder of the electroanalytical system corresponding thereto has been described above.

Another configuration of the transmitting and receiving electrodes is to arrange the transmitting and receiving electrodes in parallel or in succession. The control and reception of the signal is according to the method of a multi-way encoder or a multi-way decoder.

For use in manual devices, they are likewise equipped with corresponding devices for transferring documents or scanners, which function in a manner similar to the functions of a copier, an optical autofeed image scanner or a telex unit. As a modification thereof, means are provided for determining the position of the capacitively operating scanner of the detection device according to the invention relative to the document by means of the stop element.

For a certain number of detections of the security element of a document, the device has a different number of parallel transmitting and receiving electrodes. The higher the resolution received in this way, the more security elements and codes that can be measured, the more difficult it is to create a counterfeit. In this way, simple manual devices, such as those routinely used to detect the presence of security elements such as simple security threads, can be manufactured simply, inexpensively, and easily handled. However, devices with higher resolution are able to detect additional security elements, but not security elements. This is achieved by a simple microprocessor software which is sensitive only to certain and non-public security features. The higher resolution of the suitably configured microcontroller software allows all security features to be detected. This high cost test is used by manufacturers of the security features and by users with very high levels of security to obtain the best possible test results. In this way, it is also possible to reliably detect different conductivities.

According to the invention, in addition to the entire system using special security elements and means for detecting documents, there is also provided the possibility of carrying out image detection and the condition checking of banknotes. The conductive anti-counterfeiting element can also be used for image recognition through a code, and the code is an independent code or a code support for assisting classification, and is a code for determining classification and a code for determining counterfeit goods. For the independent encoding, there are no other security elements, and conductive security elements, such as locations on the document, should be clearly discernable to minimize false rejects. For auxiliary coding support, there are other features; the code serves as a reference means for detecting the case of false rejection. The condition check is carried out by means of the detection device according to the invention, so that the conductivity of the security element can be determined as to the condition of the document, since highly worn documents, as is known from experience, cause wear of the conductive structure and thus a change in conductivity. Different degrees of wear can be classified by software. A certain file with a certain degree of wear can thus be classified. For example, wear rates may be expressed by partially damaged OVDs, damaged documents and security elements damaged thereby, or highly creased documents with breaks in the security element, etc. Thus, there are various combinations of possibilities between anti-counterfeiting detection, image detection and condition checking. In addition to the optical configuration of the security feature on the object to be examined, as described above, the security element according to the invention is also encoded, which codes, in a mathematical relationship with one another, for example as a sum, give a primary code which, in turn, determines the authenticity, condition and type of a given document from the signals or codes obtained from the synchronous metallic security threads and/or the synchronous OVD detection.

The features of the invention, which are apparent from the description and drawings, are set forth, in addition to the claims, individually or in various combinations, for the advantages which we seek, the protected configuration. Embodiments of the invention are illustrated in the drawings and are described below.

Figure 1 is a schematic view of a document having a corrugated metallized security feature,

figures 2 and 3 are schematic views of a document having a band-shaped metallized security feature,

figure 4 is a schematic view of a document having a lattice-shaped metallized security feature,

figure 5 is a schematic view of a document with multiple security features,

figure 6 is a block diagram of a detection device,

figures 7-9 are schematic diagrams of various scanners,

figure 10 is a schematic side view of a scanner and a document to be examined,

figure 11 is a schematic cross-sectional view of a metallized security element,

figure 12 is a graph of the voltage versus time of the analysis signal of figure 11,

fig. 13-15 are schematic illustrations of a scanner and a constructed security feature.

The examples shown in fig. 1 to 5 show documents with security elements according to the invention. A capacitively operating scanner according to the invention is also drawn as a schematic diagram.

Shown is a schematic structure of a security feature 1 having a metallized layer 2. The metallization layers 2 are separated by insulating regions 3. In a top view, the insulating regions 3 are wave shaped. The width of the wave-shaped insulating region 3 is greater than the minimum distance between the two electrodes. The capacitively operating scanner 4 consists of several parallel transmitting electrodes 5 and parallel receiving electrodes 6 arranged side by side.

Fig. 2 shows a schematic view of a security element 1, in which strip-shaped metallized regions 7 and strip-shaped insulating regions 8 are arranged alternately parallel to one another. The strip-shaped regions 7, 8 run parallel or perpendicular to the transfer path of the document, viewed from above. The latter is shown in fig. 3. The distance between the regions of the same conductivity is between 0.2 and 1.0 mm. There are differences in the width of the same conductivity region. There may also be regions of different conductivity of different widths. The combination of the features of fig. 2 and 3 is shown in fig. 4. The strip-shaped metallisation zones 7 and the insulating strip-shaped zones 8 are arranged alternately parallel to the direction of transfer of the document, the metallisation zones 7 being interrupted by strip-shaped insulating zones 9 running perpendicularly thereto.

Figure 5 shows a document with several security features. This particular combination produces another code. This increases the reliability of the detection.

Fig. 6-9 show block diagrams and various configurations of the capacitively operating scanner 4. Fig. 6 shows a block diagram of a detection device according to the invention, which consists of an electronic control system, a capacitively operating scanner 4 and an electronic analysis system. The electronic control system comprises, in addition to the power supply, basically a codec 10, an oscillator 11 for energizing the transmission electrodes, and an oscillator 12 for controlling the codec.

The electronic evaluation system is essentially composed of a power supply, an amplifier 13, a demodulator 14, a comparator 15, a microprocessor with memory and filters for suppressing interfering and undesired signals.

The transmitting and receiving electrodes are arranged in a sensor holder. They form a capacitively working scanner 4 that spans the full width of the entire document feeder. The strip-shaped receiving electrode runs transversely to the feeding direction of the document. The transmitting electrode runs parallel to the receiving electrode. The distance from the transmitting electrode to the receiving electrode is determined by the document-specific conductive security element. When the transmission electrodes are arranged side by side, it is possible to detect several conductive features on the longitudinal axis of the capacitive scanner 4 simultaneously. The resolution achievable with this arrangement depends on the number of emitter electrodes used. In this embodiment, the resolution is one scannable dot per millimeter in both the longitudinal and transverse directions. The minimum distance between adjacent transmit electrodes is limited by the interfering coupling capacitance between themselves. To avoid interfering coupling capacitances and minimize interference between adjacent transmit electrodes, the transmit electrodes are sequentially controlled by a multi-way encoder 10. By arranging the emitter electrodes over the full width of the entire document feeder, the document can be detected at any position. That is, there is no need for a pre-sorting process of several files in the file handler.

Fig. 7 shows a schematic view of a scanner 4 having several transmitting electrodes and one receiving electrode 6. The control and analysis are performed according to the block diagram shown in fig. 6.

Fig. 8 shows a schematic configuration of a capacitively operating scanner with one transmitting electrode 17 and several receiving electrodes 18. As a modification of the block diagram shown in fig. 6, the transmitting electrode 17 is controlled by an oscillator. The signals from the receive electrodes 18 are processed by a multi-way encoder. The other parts of the electronic analysis system are the same as the block diagram shown in fig. 6, and consist of a power supply, an amplifier, a demodulator, a comparator, a microprocessor with memory and filters for suppressing interfering and undesired signals.

Fig. 9 shows a schematic diagram of a capacitively operating scanner with several transmitting electrodes 19 and several receiving electrodes 20. They are alternately arranged in a straight line. The control signal of the transmitter electrode 19 and the analysis signal of the receiver electrode 20 are thus processed by means of a multiplex encoder and a multiplex decoder, respectively.

Fig. 10 shows a schematic representation of a capacitively operating scanner 4 and a side view of a document to be examined. The security feature 1 comprises a metallised line 21 and an electrically insulating carrier film 22.

Fig. 11 is a schematic cross-sectional view of a security feature having a carrier film layer 23 and a partial metallization layer 24. The partial metallization layer 24 comprises several insulating segments 25. Portions of metallization layer 26 have a greater conductivity than portions of metallization layer 24. FIG. 12 shows a voltage-time curve of the analysis signal.

Fig. 13-15 are schematic views of scanners 33, 34, 35 and one constituent security feature 36. The structure of the security feature 36 consists of a round metallised security element 37, a strip-shaped metallised security element 38 and two rectangular metallised security elements 39, 40. The detection reliability is achieved by the clearly visible high edge steepness of the metallization, since the production costs in this way are very high. A simple manual device comprises a scanner 33 according to fig. 13. The resolution is so low that only the security element 38 in the form of a band can be detected. Such manual devices are suitable for everyday use because of their ease of manufacture, low cost and ease of operation. The high-resolution device according to fig. 14 consists of a scanner 34 which, in addition to the strip-shaped security element 38, can also detect additional security elements, here circular security elements 37. The rectangular security elements 39, 40 are not detected. This is achieved by simple microprocessor software which is sensitive only to certain security elements. The rectangular security elements 39, 40 are not referenced in the memory.

The higher resolution of the suitably configured microprocessor software is shown in fig. 15. It can detect all security features. In order to maintain the superiority of the security element with optical effect, the microstructure is produced by a special metallization process. In this way very sharp edges to the non-metallised structure can be produced.

In order to achieve the object of the invention, a new system of application of a security element and a detection device is proposed, in order to avoid the effects of the detection method and device being known or becoming rapidly known, and the use of a security element with a corresponding method of use, including a device according to the invention, is described below.

In order to apply the invention on a large scale, it is necessary to identify groups of persons to be tested, who have purposefully acquired a certain knowledge about the testing system, to carry out anti-counterfeiting tests with specific tests, and to carry out image tests and condition tests. This detection system is illustrated by group A, B, C below.

Group A:

it is well known that national banks publish valid security features for banknotes so that users can test themselves according to specifications. This publication relates to a detection method without an auxiliary device and a detection method with an auxiliary device. The scanner sensor is mounted in a personal fixture. The electrical conductivity of certain security elements can be detected by this manual means and a special software.

The software is modified so that the conductivity of the security element of the scanner driven by the optical sensor must be at a certain value as soon as the length of the banknote passing through and measured. The end of the banknote is determined by the optical sensor and then the scanner sensor is switched off. The position of the conductive security element on the detection target can thus be determined. The stored data may be used by the controller to compare and analyze the data.

Group B:

group B has machines that process banknotes. These machines are equipped with special sensors that detect different features. Currently, these machines are equipped with sensors in the optical field and/or sensors for magnetic property detection and/or for measuring the passage length by means of capacitive sensors, with which it is possible to measure the presence of conductive features longer than 6 mm. They cannot detect several conductive security elements across the length. In addition, the different conductivities within the detection zone cannot be detected. Nor can the structure inside the security feature be detected. These detections can be made by special scanner sensors so that group B can make higher quality detections.

The software of group B is designed so that the scanner sensor is driven by the optical sensor and then detects the ring-shaped metallized security element 37 and the band-shaped metallized security feature 38. The conductivity value is fixed. A deviation of ± 30% was rejected.

Group C:

the software is designed to detect all security elements. The scanning sensor is driven by an optical sensor. The pass width of security feature 36, ring-shaped metallized security element 37, band-shaped security element 38, and rectangular security elements 39, 40 are detected. The conductivity values are given. A deviation of ± 30% was rejected.

In particular, the overall detection system may vary for group B and group C applications. Particularly for detecting euros, can be modified nationally for its purpose. Because the security features to be tested, such as those in euro, are the same across countries, the detection method and detection apparatus can be modified in different ways across countries at successive time intervals depending on their purpose.

The above security element and detection device are used as follows: the image can be detected by a code of a special metallization. The image detection can be used for various purposes, in particular for classification, value assignment and anti-counterfeiting detection. Another advantage of this detection method is the condition check. Conductivity measurements allow a determination to be made of the condition of the banknote. Highly damaged banknotes severely reduce the conductivity.

The invention relates to the construction of security elements and to devices for detecting said elements, in particular embodiments. It should be noted, however, that the invention is not restricted to the details described in the embodiments, since modifications and variations are included within the framework of the patent claims. While other conductive detection features such as conductive security threads can be classified by the detection device according to the present invention.

Claims (17)

1. A structure of a security element with diffractive optical effect according to the document DE 19734855.6, characterized in that it has an electrical information coding with beam-like, lattice-like, curved and/or circular conductive structures having steep edges parallel to the non-metallised structure, where the detectable minimum line width of the conductive structures is 5 mm or less.

2. A security element structure according to claim 1, characterized in that there is an electrical information coding with bunched, latticed, curved and/or rounded metallization structures, said structures having steep edges parallel to the non-metallization structures, where the smallest line width of the detectable metallization structures is 5 mm or less.

3. A security element construction according to any of the preceding claims, characterized in that the individual metallized security elements have different electrical conductivities.

4. A security element structure according to any of the preceding claims, characterized in that at least two structures in the security feature have different metallisation coating thicknesses.

5. A security element construction according to any of the preceding claims, characterized in that the width of the metallization structure with constant conductivity corresponds to the width of at least two detection electrodes of the detection device.

6. A security element structure according to any of the preceding claims, characterized in that the distance between two metallization structures of the same or different conductivity is at least 0.1 mm.

7. Device for the detection of documents with diffractive optical effect security elements with a metallic reflective layer according to patent application DE 19734855.6, characterized in that a capacitively operating scanner (4, 33-35) detects a metallized security element (39, 40) which is arranged in the metallized security element (37) by means of a plurality of parallel electrodes which are arranged side by side along one or several straight lines and which are analyzed by an electronic control and analysis system arranged in the scanner (4, 33-35) for comparing the signal profile of the document to be measured with a corresponding reference signal profile.

8. A device according to claim 7, characterized in that two adjacent electrodes are arranged in an electrically connected manner.

9. Device according to claim 7 or 8, characterized in that the electronic control system consists of a power supply, a multiplex encoder (10), an oscillator (11) for supplying power to the emitter electrode (5) and an oscillator (12) for controlling the multiplex encoder (10).

10. Apparatus according to any of claims 7 to 9, characterised in that the electronic analysis system consists of a power supply, an amplifier (13), a demodulator (14), a comparator (15), a microprocessor (16) with memory and filters to suppress interfering or undesired signals.

11. A device according to any one of claims 7 to 10, characterized in that the minimum distance between the two transmitting electrodes (5) is less than 0.5 mm.

12. A device according to any one of claims 7 to 11, characterized in that the distance between one transmitting electrode (5) and the receiving electrode (6) is at least 0.5 mm.

13. Device according to any of claims 7 to 12, characterized in that the device has a pressing device for guiding the document to be measured parallel to the transmitting and receiving electrodes, preferably for pressing the document against the scanner.

14. Apparatus according to any one of claims 7 to 13, wherein the shaft of the document transport roller is abraded in sliding operative contact.

15. An arrangement according to any one of claims 7 to 14, characterized in that the arrangement is arranged in a high-speed document handler.

16. A device according to any one of claims 7 to 15, characterized in that the device is arranged in a human setting.

17. Method for the application of a diffractive optical effect security element with a metallic reflective layer with a structure according to one or more of claims 1 to 6 in a document according to patent application DE 19734855.6, and a device according to one or more of claims 7 to 16, characterized in that metallized detection elements are arranged in the form of metallized layers (2, 24, 26), metallized zones (7), metallized lines (21) or metallized security elements (37 to 40) on the document to be examined in size, shape, number, tone and spacing such that

-at least one conductive structure is detected by the group a population by means of a scanner (33) designed as a manual device;

-at least two conductive structures are detected by a smaller group B population by means of a scanner (34) equipped with software different from the software designed for group a population and installed in a high speed processing machine;

-at least three conductive structures are detected by a very small group C population by means of a scanner (34) installed in a high speed processor (35) and loaded with software different from the software designed for group B population; and

the conductive structures represent codes which can also be perceived visually by group a, by group B and by software coding, and by group C, mainly by software decoding not available to group a and group B.