DE19808652A1 - Verification system for a valuable and security product - Google Patents

Abstract

Described is an object of value or a security, especially one which is provided with a verification system, whereby one or more security elements are arranged thereon or embedded therein and the security elements are incorporated into the printing ink and/or the substrate in the form of small quantities of contrasting, fluorescent or luminescent substances.

Description

The invention relates to a verification system for a value and Security product according to the generic term of Claim 1, and one with the verification system processing value and security product.

Such a value and security product can e.g. Legs Banknote, an identification card and the like. According to the State of the art on this valuable and safety product or several security elements arranged and / or are embedded.

The invention is based on the general task that quick, machine verification of Security documents should be possible. So far it is only possible with such machine verifications to ensure a relatively long evaluation time. It is z. B. Known magnetic strips as security elements on the Apply security product and then magnetization to eat. It is also known to use holograms and the like. Apply structures to the security element and then the Presence of the hologram and its composition Measure evidence of light diffraction. It is also known apply magnetic colors to the security document and to measure their magnetization or a security thread to bring up the value or security document and its Conductivity, composition, imprint and other characteristics of the security thread.

In the optical machine verification of So far, security documents have only been possible such security documents in a cycle time of about 20 Process milliseconds, resulting in an evaluation rate of 50 Documents per second. Such a verification time is not for the evaluation of a large number of documents suitable.  

In particular, it is known for the verification of value and Security documents a suggestion of a fluorescent To use printing ink whose lights with a video camera (spatially resolved) or a photodiode (not spatially dissolved) is demonstrated.

However, the disadvantage of these known verification systems is that they are relatively insensitive and that they do not have a high spatial Ensure resolution with short switching times.

The invention is therefore based on the object Verification system for a value and security document of type mentioned so that a exceptional sensitivity increase at the same time high spatial resolution and at the same time short Switching time for quick optical detection of the Security elements on the value and security product should be given.

To achieve the object, the invention is by characterized technical teaching of claim 1.

An essential feature of the invention is that Using the multi-channel amplifier (MCPV detector) it now is possible for the first time, at the same time highly sensitive (lowest Concentrations of the security elements are sufficient) in high resolution (Finest structures of the security elements can be recognized extremely fast (very many documents can are verified per unit of time or signals that are in very can follow the excitation pulse for a short distance be verified) for the verification of the value and Lead safety product.

Another advantage of the multi-channel amplifier used is its compactness and the possibility of being in direct contact with the Work document. The microchannel plate replaces the Imaging optics. So there is a possibility that the Image information can be read out electronically directly.  

This is a complicated manufacturing technology connected, which complicates the replica.

So it can with the technical teaching of claim 1 in very quickly with a spatially high resolution Security feature on the value and security document be detected.

The spatial resolution of such a multi-channel amplifier is defined by the packing density of the channels used. The distance between the channels is between 10 and 20 Micrometer, so that very fine details of a security pattern on which value and security products can be measured.

In contrast to other known image sensors, the Acceleration of the electron avalanches in the channels with one High voltage, in addition to the high surface resolution, another very short switching time reached. Hence, very quickly one after the other pictures of different very dimly shining Pattern can be included, or it can Luminance distribution during an exactly defined very short time interval can be measured.

For example, with a multi-channel image intensifier Emission of a substance a few nanoseconds after the excitation of the substance can be measured with a nanosecond pulse. If the decay time of the emission of the substance also in the area less than nanoseconds, the substance can be detected only with the detector according to the invention, because only this in the Location is extremely close in time intense excitation and weak emission signals to be separated from each other and to be shown in a spatially resolved manner.

Regardless of the patented verification system, as separate invention the formation of a novel value and Security product with attached Security elements claimed as inventive.

An essential feature of this further invention is that now the value and security product one or more  Security elements are applied, which by the Addition of the smallest amounts of contrast, fluorescence or Luminescent substances in the printing ink and / or the substrate can be achieved. Absorbing luminance Distributions as a security element on the value and Security product created, the invention only detected and evaluated with multi-channel optical amplifiers can be.

The essence of this further invention is therefore that smallest amounts of contrast, Fluorescent or luminescent substances are used only of high-resolution and highly sensitive Multi-channel amplifiers are detectable. So there is the advantage that due to the addition of the smallest amounts of substance evaluation of the security element only with highly specialized devices (namely optical Multi-channel amplifiers) is possible.

This has the advantage that the security feature itself is difficult to detect because only very small amounts are involved of contrast, fluorescent or luminescent substances as Security element can be used, which substances only can be detected by specialized measuring instruments. In addition, the use of optical multi-channel amplifiers the possibility that you can not just the presence of such a weakly concentrated Security element can prove, but you can about it out at the same time z. B. the areal distribution of this Security element on the valuable and security product prove and / or the verification period compared to Keep the period of the suggestion so short that the proof only is possible with detectors with a correspondingly short response time.

Due to the extremely high sensitivity optical Multi-channel amplifiers can adjust the concentrations of the phosphors or the contrasts are kept so low that they are one Measurements with other detectors and a visual inspection are inaccessible. Even if a spectral analysis of the  Value document with highly sensitive photomultipliers would be done is the chance to prove the signal low because the location of the phosphor is not known. Should this place will be hit by chance, it is still almost impossible the spatial distribution of the signal with a optical multi-channel amplifiers comparable, resolution measure up. Hence the re-enactment of one Luminance distribution almost impossible.

The high sensitivity of multi-channel optical amplifiers enables the detection of weak nonlinear optical Effects as a security feature.

The sharp wavelength selectivity optical Multi-channel amplifiers, which result from the physical Properties of the photocathode can advantageously be used Discrimination against background light can be used.

The high spatial resolution of multi-channel optical amplifiers enables the position of dimly glowing particles to be reduced to 20 to pinpoint exactly. For example, the distribution statically scattered fluorescent or luminescent particles measured and as an identification file on the same document can be saved. The authenticity is verified by comparing the identification data with the Glow pattern. Such a document is highly secure as it is it is extremely unlikely that a forger will succeed can, the distribution of extremely dimly glowing particles measure up. Even then it is impossible to arrange for example, approx. 100-10,000 luminous dots. A such a system is particularly suitable for film composites, because the light distributions are protected and integrated into the film can be.

An additional dimension of counterfeit security is given System based on multi-channel optical amplifiers, in which the short switching times of such image intensifiers (typical Nanoseconds). Phosphors can For example, be selected so that the excitation is very high  Top performance (ns laser or similar) requires and that Emission within nanoseconds after excitation and close the excitation wavelength. An optical one Multi-channel amplifier is then triggered so that it is at the end of the Excitation pulse opens and maps the light distribution. Detectors that cannot be triggered with such exact gate times are on the right one even when trying to measure Wavelength and in the right place from the high Excitation intensity saturated and cannot measure a signal.

The optical multi-channel amplifier can be used by others Excitation mechanisms (electric fields at Electroluminescence or the like) are triggered.

The short switching time of multi-channel optical amplifiers can be exploited, documents of value at very high speed to verify. Because of the short shutter speed Such image intensifier can, for example, by anyone with high Speed of value document transported past the detector to take a picture.

An optical multi-channel amplifier can also be used to a whole stack of value documents with one Check image recording in which a luminance distribution the value document edges from the side of a stack is verified.

Optical multi-channel amplifiers can be used via anode segments, Grid anodes or charge measurements directly electronically be read out. Because the electronic processing and Evaluation of image data a dynamically developing Technology field is becoming increasingly powerful and faster image evaluation algorithms are available. Electrostatically focused image intensifiers can Control the magnification factor of the image electronically.

Optical multi-channel amplifiers can electron, ion and X-rays directly into an amplified one without a photocathode convert visible image. Particularly interesting  Embodiments result from weak contrasts in the X-ray area can be evaluated.

The image field of a few square centimeters corresponds to that typical dimensions of a security feature. In the simplest The optical multi-channel amplifier can be used with the photocathode without the need for imaging optics in contact with the document to be verified.

Optical multi-channel amplifiers are compact, have a low one Power consumption and are wear-free.

The manufacture of multi-channel optical amplifiers is a extremely complicated process. Become such Multi-channel amplifiers, for example, in a special design developed, these special sensors are easy to use protect against access by counterfeiters. Besides, many would Embodiments of the invention not even a forger Use original sensor, because the security feature is not is adjustable (statistically distributed fluorescent grains etc.).

Multi-channel optical amplifiers can also be used to Evidence of characteristics of existing value documents, or to characteristics of substances that a document of value as a counterfeit unmask (wrong papers, colors etc.) to measure.

In summary, the advantages of the present invention by using multi-channel optical amplifiers as follows be summarized.

Optical multi-channel amplifiers are ideally suited as sensors for weak luminous distributions on value documents due to the following properties:

• 1) extremely high sensitivity (up to the detection of individual Photons)
• 2) extremely high spatial resolution (up to 10,000 dpi)
• 3) extremely short switching times (in the range of nanoseconds)  
• 4) Wavelength selectivity by choosing an appropriate one Photocathode and due to the work function of the photo effect ("daylight-blind" sensors)
• 5) direct detection of electron, ion and X-rays possible
• 6) the sensor surface corresponds to the characteristic dimensions of a security feature (a few cm ² )
• 7) the image section can be enlarged electronically
• 8) The luminance distribution can be done without intermediate steps be electronically read out and evaluated
• 9) small size and low power consumption
• 10) a complicated one, mastered only by a few companies Manufacturing technology of the sensors
• 11) Good suitability for use as a "black box" sensor (Self-destruction if the box is tampered with, for example Destroying the vacuum seal or by high voltage).

Such multi-channel optical amplifiers are also described below referred to as MCPBV.

Their applications in connection with a valuable and security product and this in turn in connection with a weakly dimensioned security element can be summarized as follows:
MCPBV detect very weak luminance distributions that arise across the surface of the value document, varying absorption, transmission, reflection, diffraction, scattering, emission of the other effects. Due to the high sensitivity of MCPBV, even the smallest concentrations of contrast or fluorescent materials, weak reflections, diffraction orders or the like are sufficient for reliable verification.

The concentration of the contrast or phosphors or the reflective, absorbent or diffractive surfaces (Security feature) can be kept so low that the generated luminance with other sensors undetectable are. Weak intensities of nonlinear optical effects can be used as a security feature (multi-level  Excitation processes such as two-photon absorption or the like complicate proof of the security feature).

The very weak luminance distributions contain code or Personalization information. Only MCPBV can do this Read out information since no other detector type is used at the same time over a comparable high spatial resolution and Sensitivity.

MCPBV are synchronized with the excitation process so that they a weak measurement signal from a strong excitation pulse can distinguish. Other detectors can use such a signal do not prove. Easy synchronization with Multi-step excitation is possible.

Only parts of a value document (side edges of a stack) are used for verification. The short MCPBV shutter speeds allow verification of up to a few hundred value documents / sec.

Daylight "blind" MCPBV are included with the value document in Brought in contact. Very good suppression of background light no imaging optics required (handheld device).

MCPBV evaluate X-ray contrasts. High sensitivity and spatial resolution, no photographic emulsions necessary.

MCPBV special designs are included in verification devices special photocathodes, channel cross sections or others Parameters used (example: a line-shaped MCPBV) Because of the difficult manufacturing technology, there are Detectors are not accessible to counterfeiters (therefore the in information from counterfeiters contained in one line be read out).

Another advantage of the invention is that because the short detection time a large number of documents per Second can be verified, taking up to 2000 documents can be evaluated automatically per second.  

The subject matter of the present invention results not only from the subject of the individual claims, but also from the combination of the individual claims among themselves.

All in the documentation, including the summary, Disclosed information and features, in particular those in the Drawings illustrated spatial training are considered essential to the invention, insofar as they are used individually or in Combination are new compared to the prior art.

In the following the invention based on several Drawings illustrating execution paths explained in more detail. Here go from the drawings and their description further features and advantages essential to the invention Invention.

Show it:

Fig. 1 plan view of a value and security certificate in a first embodiment;

Fig. 2 Schematically drawn side view of the verification device;

FIG. 3 shows schematically, a section through a microchannel image intensifier;

FIG. 4 shows the enlargement of a channel of a microchannel image intensifier showing the excitation mechanisms in the microchannel plate;

Fig. 5 The comparison of excitation pulse and response pulse in the verification of the security document;

Fig. 6 The top view of a security document with fulfillment of even higher security requirements

Fig. 7 shows another embodiment compared to Fig. 3 in the formation of a microchannel image intensifier.

In FIG. 1, various security elements 2 , 3 are arranged on a document of value 1 , and their arrangement can be carried out in any manner. In addition, one or more security strips 6 and / or one or more graphic elements (patterns) 7 can be arranged.

Such a security element 2 , 3 can, for. B. consist of an areal distribution of several pixels 4 , 5 , which form the security element 2 , 3 in a desired or random distribution.

The document of value 1 can be a bank note, an identification card or the like, the said security elements 2 , 3 or the security strip 6 and the graphic elements 7 both being embedded in the document of value 1 and also being able to be applied to the document of value itself.

A novel evaluation of such security elements for the verification of the value document 1 will now be described in more detail.

According to the invention, a so-called microchannel image intensifier 8 is used for this purpose, as is shown schematically in FIG. 2. It is important here that the security elements 2 , 3 , 6 attached to the document of value 1 emit a weak signal upon excitation, which signal is supplied to the microchannel image intensifier 8 in the direction of the arrows 11-13 , so that this weak signal can be evaluated by highly specialized evaluation devices . Here, the specified security elements 2 , 3 , 6 are excited by an excitation source 9 , which, for example, irradiates the document of value 1 in the direction of the arrow 10 .

Of course, the type and arrangement of the excitation source 9 in relation to the value document 1 is variable within free limits. The excitation source 9 can in this case be arranged on the side of the document of value, it can also be arranged on the side of the microchannel image intensifier and be directed in the same direction towards the document of value 1 , as conversely the signals from the document of value 1 are supplied to the microchannel image intensifier 8 ; the excitation source can, however, also be arranged below the value document and radiate through it.

Various excitation mechanisms come into question as excitation sources 9 , such as e.g. B. the excitation by electron beams, by laser beams, by light, by X-rays, by ionizing radiation, by alternating magnetic fields and the like. More.

Thermal excitation (IR rays) also comes into play Consideration, as well as the excitation by UV rays. In transmitted light can also be weak, through a Security product transmitted intensities detected become.

The security elements consist of the smallest quantities of Contrast, fluorescent or luminescent substances, either are arranged in the printing ink itself or in the substrate available.

Other excitation mechanisms can also be used be such. B. extremely difficult to detect bio- and chemiluminescent systems or fluorescent labeled Specialty chemicals.

The basic structure of a microchannel image intensifier is explained in more detail with reference to FIG. 3.

A window coated with a photocathode is arranged in an evacuated housing 14 , the photocathode 15 being arranged in the housing 14 for drawing reasons. A stream of light quanta 19 strikes this photocathode 15 in the direction of the arrow 18 , which eject electrons 35 from the photocathode 15 and are accelerated onto the microchannel plate 16 in the direction of the arrow 36 . The structure of the microchannel plate 16 is explained in more detail in FIG. 4. It essentially consists of an empty channel 20 , on the inner walls 22 , 23 of which the electrons appear in the direction of the arrow 21 and are passed on in a zigzag manner, as a result of which secondary electrons are released from the coating of the inner walls 22 , 23 , which are then in the form of an electron avalanche 24 from the microchannel 20 step out and be accelerated towards the fluorescent screen 17 . On this fluorescent screen 17 , the electron current is converted into a corresponding luminance distribution and further evaluated. As an evaluation device z. B. a CCD in question; the electron current can also be evaluated directly without the presence of a fluorescent screen 17 .

General image processing systems can be used for this become.

In Fig. 5, such a suggestion is shown in connection with the impulse response. It is shown that an excitation pulse 25 of extremely short duration strikes the value document in the range of a few nanoseconds and excites the security element 2 , 3 , 6 arranged thereon, which responds with a corresponding response pulse 26 , with a time delay of Δt.

In Fig. 5 it can be seen that a relatively short evaluation time 27 is also only available in the nanosecond range, which is associated with the advantage that the security against forgery of such a value and security document is significantly improved because there are only a few devices that in are able to carry out a verification within such a short evaluation time 27 .

Most of the detectors that are known to date are otherwise unable to distinguish between the signal of the excitation pulse 25 and the signal of the response pulse 26 , ie to carry out the verification within the evaluation time 27 .

The verification method according to the invention therefore consists in exciting with an extremely short excitation pulse 25 in the nanosecond range. If a longer excitation pulse is used, then the response pulse that arises later disappears in the excitation pulse 25 and an evaluation can no longer take place.

The verification method also consists in using an excitation source 9 which is capable of generating such a short excitation pulse and, moreover, a verification unit (microchannel image intensifier 8 ) which is able to carry out the verification within the short evaluation time 27 that follows .

FIG. 6 shows a further embodiment of a document of value which takes even higher security requirements into account.

There are a number of security elements 2 , 3 arranged on a coded surface 28 , which is delimited by register marks 30 . B. be brought to light by excitation. The coordinates of the luminous and possibly also self-luminous safety elements are now determined with the previously described evaluation unit. In addition to the coordinates (position determination) of the security elements, other properties of these security elements can of course also be read out on the value document 1 , such as, for example, B. their individual specific luminance, their distribution on the document, their color, their dimensions and other properties more.

The properties read out are z. B. inscribed in a readout field 29 , which is also located on the document of value 1 .

To verify the value document 1 , the value document to be verified is now excited with the excitation source 9 and the properties of the security elements 2 , 3 are read out in the coded area 28 and compared with the information stored in the readout field 29 . In this way, a document of value with high security against forgery can be created, which can be quickly verified.

The security against forgery is further increased if there are a large number of security elements 2 , 3 which are distributed in a certain distribution on the coded areas 28 .

Otherwise, this also gives the possibility that one only certain in a precisely specified coding Valuable documents encoded to make them stand out from others to distinguish similar documents of value, e.g. B. Encode banknotes paid in the event of a kidnapping were and which are later to be recognized again.

It should also be pointed out that the presence of an excitation source 9 is not important; the security elements 2 , 3 , 6 mentioned can also be designed to be self-illuminating. Such an emission can e.g. B. done in that the security elements 2 , 3 , 6 are designed as self-radiating sources.

In Fig. 7 a further excitation possibility is shown of a further embodiment for verification, wherein the excitation occurs by an ionizing radiation source 31. Radiation-proof barriers 34 are arranged on the document of value 1 in any number and arrangement, which only allow the x-rays 32 striking the document of value to pass in a certain region 37 in the direction of the arrow 38 , while the other regions are shielded by the barriers 34 . In this way, the emission radiation specific to the document of value 1 reaches the microchannel plate 16 , which is arranged in a housing together with the fluorescent screen 17 .

In the event that an electron radiation source is selected instead of the ionizing radiation source 31 , the same explanations apply in FIG. 7, except that the housing 33 also comprises the document of value 1 and - in order to bring the document of value 1 into the housing - it is provided that the housing is flushed with an inert gas.

In this way it is possible to quickly enter the value documents 1 in the housing and bring them out again.

The inert gas is used to transport electrons in the housing to enable.

The following are nonlinear optical effects in Connection described with the novel method.

Such a suggestion exists, for. B. in that excitation with a first frequency, but that the security elements 2 , 3 , 6 emit in a different frequency range and this secondary radiation is then evaluated by the microchannel image intensifier according to the invention.

Such nonlinear effects are generally very weak and are therefore particularly suitable for evaluation in the Microchannel image intensifier according to the invention.

For this purpose it can even be provided that the primary beam filtered or through a suitable training of Photocathode is not visible to this. So it just becomes that nonlinear optical signal evaluated.  

Reference list

1

Value document

2nd

Security element

3rd

Security element

4th

pixel

5

pixel

6

Security strip

7

graphic elements (pattern)

8th

Microchannel image intensifier

9

Source of inspiration

10th

Arrow direction

11

Arrow direction

12th

Arrow direction

13

Arrow direction

14

evacuated housing

15

Photocathode

16

Microchannel plate

17th

Fluorescent screen

18th

Arrow direction

19th

Light quant

20th

channel

21

Arrow direction

22

inner space

23

inner space

24th

Electron avalanche

25th

Excitation pulse

26

Response impulse

27

Evaluation time

28

coded area

29

Readout field

30th

Register mark

31

Radiation source

32

X-rays

33

casing

34

barrier

35

electron

36

Arrow direction

37

Area

38

Arrow direction

Claims (19)

1. Verification system for a value and security product, on which one or more security elements are arranged, which consist of weakly emitting, patterned and excitable substances with defined spectral properties, the emission of which is made visible with an optical imaging device, characterized in that the optical imaging device is a multi-channel amplifier (MCBV). 2. Verification system according to claim 1, characterized in that the multi-channel amplifier has a spatial resolution due to the packing density of the channels ( 20 ), which is in the range between about 10 and 20 microns. 3. Verification system according to claim 2, characterized characterized in that at the output of the multi-channel amplifier Input of an electronic camera is arranged.   4. Verification system according to claim 3, characterized characterized in that in an image field of the to be verified Value and security document of 1-3 qcm the exit of the Multi-channel amplifier directly with the photocathode electronic camera is in a light-conducting connection. 5. Value and security product, in particular with verification system according to one of claims 1-4, on which one or more security elements are arranged and / or embedded, characterized in that the security elements ( 2 , 3 ) as an admixture of the smallest amounts of contrast, Fluorescent or luminescent substances are formed in the printing ink and / or the substrate. 6. Value and security product according to claim 5, characterized in that a certain areal distribution of the security elements ( 2 , 3 ) is provided. 7. Value and security product according to claim 5 or 6, characterized in that a reference surface ( 28 ) is provided which is delimited by one or more register marks ( 30 ). 8. value and security product according to claim 7, characterized in that in addition a read-out field ( 29 ) is present in which a checksum is stored for the reference surface ( 28 ). 9. Value and security product according to one of the preceding Claims, characterized in that the security elements as alien luminous markings that need stimulation are trained. 10. Value and security product according to claim 9, characterized in that the security elements ( 2 , 3 ) have an extremely short response time. 11. Value and security product according to claim 9 or 10, characterized in that the security elements ( 2 , 3 ) require a high excitation energy. 12. Value and security product according to one of claims 9 to 11, characterized in that the security elements ( 2 , 3 ) emit an extremely short response signal. 13. Value and security product according to one of claims 9 to 12, characterized in that the response signal in a different frequency range than the excitation signal. 14. Value and security product according to one of the preceding claims, characterized in that at least one of the security elements ( 2 , 3 ) is attached to the edge or on an edge of the value document ( 1 ). 15. Procedure for evaluating and checking a value and Security product according to one of the preceding Claims, characterized by the use of an optical Multi-channel amplifier. 16. The method according to claim 15, characterized in that a parallel evaluation and testing of several valuable and security products ( 1 ) takes place simultaneously. 17. The method according to claim 15 or 16, characterized characterized in that the optical multi-channel amplifier Has sensor surface in characteristic dimensions a security element is adapted to 3. 18. The method according to any one of claims 15 to 17, characterized characterized in that the optical multi-channel amplifier has a high Sensitivity, high resolution and short switching times having. 19. The method according to any one of claims 1 to 18, characterized characterized that an adjustment of the optical  Multi-channel amplifier to a certain wavelength by choice a suitable photo cathode is provided.