DE102021003334A1 - Sensor for checking the luminescence of value documents - Google Patents

Abstract

The invention relates to a sensor for checking documents of value, which is designed to determine a luminescence index of a document of value transported past the sensor for checking, and the provision of a speed correction of the luminescence index of the document of value in the sensor. The relative movement between the document of value and the sensor results in a falsification of the measured luminescence intensities due to movement effects. A mean speed dependency of the luminescence index of a reference medium is determined with the aid of a reference sensor, which is averaged over both mutually opposite transport directions, and used to determine a speed dependency of a correction factor for the luminescence index. Based on this, the correction factor of the luminescence index that applies to the test transport speed of the value document is determined, with which the luminescence index is then corrected.

Description

The invention relates to a sensor for checking the luminescence of documents of value and the provision of a speed correction of a luminescence index in the sensor.

Sensors are usually used to check documents of value, with which the type of documents of value is determined and/or with which the documents of value are checked for authenticity or for their condition. The documents of value are checked in a device for processing documents of value, which contains one or more different sensors, depending on the properties of the documents of value to be checked. To check the documents of value, they are usually transported past the stationary sensor.

A document of value to be checked can have one or more luminescent substances, of which, for example, the decay time of the temporal intensity profile of the luminescence or spectral properties of the luminescence are checked. The luminescent substances of the document of value can be present on or in the document of value in areas or over the entire surface. To check the decay time of the luminescence, it is known to illuminate documents of value with light pulses and to detect the luminescence intensity of the document of value at different times after the end of the excitation pulse in the dark phase between the light pulses. The decay time of the luminescence, for example, is then determined from the time decay of the luminescence intensity and used to check the authenticity of value documents.

A disadvantage of the previous value document check is that, in the case of a high transport speed of the value document, a temporal intensity curve of the luminescence is detected, which is falsified in comparison to a statically detected intensity curve. At high transport speeds of the document of value, a luminescence index such as the luminescence time constant can therefore only be determined imprecisely.

An object of the present invention is to provide a sensor for checking documents of value, by means of which the luminescence of a document of value can be checked with improved accuracy.

This object is solved by the subject matter of the independent claims. Advantageous further developments and refinements of the invention are specified in dependent claims.

If the luminescence of the value document is detected statically, i.e. without relative movement between the value document and the sensor, then the detected intensity profile of the luminescence is not corrupted by movement effects. A luminescence time constant can then be determined directly from the statically detected intensity profile as a function of time. In the case of stationary documents of value, the measured luminescence time constants for different sensors of the same sensor series and for the same sensor in different installation positions agree well.

In the case of a relative movement between the document of value and the sensor, however, the detected intensity curve is corrupted due to movement effects. With sensors that are used on high-speed value-document processing devices, the value-document is displaced during the measurement by a length that is comparable to the size of the detection area and the illumination area of the sensor. Since the area of the value document excited to luminescence is partially transported out of the (stationary) detection area during detection, the measured luminescence intensities of the value document are falsified.

In the run-up to the invention, it was found that the falsification of a measured luminescence intensity at a given transport speed depends on how well the focus of the illumination area and the focus of the detection area of the sensor used match, in particular how large their offset is along the transport direction of the document of value. If the centers of gravity coincide perfectly, the falsification of the intensity depends only on the amount of the transport speed, but not on the transport direction. On the other hand, if the illumination area is slightly offset from the detection area due to mechanical tolerances, then there are differences in the measured luminescence intensities depending on the transport direction of the document of value relative to the sensor and thus also in the luminescence parameters determined therefrom for the intensity or the time behavior.

Surprisingly, it was found that with sensors of the same sensor series, the speed dependency of a luminescence index averaged over both transport directions of the document of value relative to the sensor is almost the same for sensors with poorer and better tolerances. Correction factors or a speed dependency of a correction factor can therefore be derived from the speed dependency of the luminescence index averaged over both transport directions of the document of value speed correction are used. It is often sufficient to carry out the speed correction of the luminescence index for all sensors of the same sensor series in the same way, depending only on the transport speed of the document of value.

However, it was also found that in some cases, when detecting a luminescence index on high-speed value document processing devices with different sensors of the same sensor series, measurement errors can also occur, which are also attributed to geometric tolerances in the position and possibly the angle of the lighting and the detector , in particular to a different amount of offset between the illumination and detection area in the direction perpendicular to the transport direction. The additional measurement errors may not be fully compensated for by the correction according to the invention. In such cases, in addition to the sensor-wide correction of the luminescence index with regard to the transport speed, a sensor-specific correction of the luminescence index can be carried out, which is not the same for all sensors of the same sensor series, but is different for different, nominally identical sensors of the same sensor series .

Speed correction of a luminescence index

The sensor according to the invention is set up for checking the luminescence of documents of value which are transported past the sensor along a transport direction at a checking transport speed for checking them. The sensor is set up to measure at least one luminescence intensity of the document of value while the respective document of value is transported past the sensor, and to determine at least one luminescence index of the respective document of value based on the measured at least one luminescence intensity. The luminescence index of the document of value is a characteristic variable of the measured at least one luminescence intensity of the document of value. The method described below for providing a speed correction of at least one luminescence index of a document of value to be checked is carried out on the sensor.

The sensor has at least one excitation light source for exciting a luminescence of the value document, and at least one photodetector for detecting the luminescence of the value document excited by the excitation light source. The excitation light source of the sensor is designed to illuminate an illumination area of the document of value with excitation light.

The luminescence excitation is achieved, for example, by an excitation pulse, which the excitation light source directs onto the document of value. The document of value to be checked has a security feature that contains one or more luminescent substances that emit luminescence. In response to luminescence excitation by the excitation light source, the security feature emits luminescence at one or more wavelengths.

The sensor is set up to use the photodetector to measure the at least one luminescence intensity of the value document while the value document is being transported past the sensor. The photodetector of the sensor is designed to detect the luminescence light, which emanates from a document of value brought into the measurement plane as a result of the illumination with the excitation light, in a detection area.

The sensor has an evaluation device which is designed to determine a luminescence index of the respective document of value based on the at least one luminescence intensity of the document of value measured at the test transport speed. For this purpose, the evaluation device has appropriate software, for example. The sensor uses the luminescence index to check the document of value, e.g. for a quality check of the document of value during production or for an authenticity check or classification of the document of value.

The sensor has a correction device for correcting the luminescence index with regard to the test transport speed of the document of value to be checked. In the correction device, a speed correction is/is provided for correcting the luminescence index determined with the sensor for the document of value, which when checking the luminescence of a document of value transported past the sensor at a test transport speed to correct the with the sensor for the Document of value specific luminescence index can be used. The speed correction is included in the correction facility of the sensor. The correcting device can be a processor. The speed correction can be performed by software of the correction device.

For the speed correction, a speed dependency K(v) of the correction factor is used, which is stored in the sensor, in particular a speed that applies to all sensors (that is to say that does not apply to individual sensors). Dependency K(v) of the correction factor, which preferably applies to all sensors of the same sensor series. The speed dependency of the correction factor assigns a correction factor that applies to the respective transport speed (its absolute value) to various possible transport speeds of the value document. The speed dependency of the correction factor stored in the sensor can be stored in the correction device or in the evaluation device or in a memory area of the sensor. It can be formed by discrete pairs of values, eg a table, or a mathematical function. The speed dependency of the correction factor was/is determined using the average speed dependency of the luminescence index of a reference medium assigned to the document of value to be checked, as explained below.

In order to correct the luminescence time constant of the document of value to be checked with regard to the transport speed, the correction device is set up to determine a correction factor based on a speed dependency of the correction factor stored in the sensor and using information about the test transport speed made available to the sensor, which is used for the test - Transport speed of the value document applies. To determine the correction factor, the correction factor applicable to the test transport speed is sought out from the stored speed dependency of the correction factor. If a test transport speed is used for which a correction factor is not explicitly specified in the speed dependency of the correction factor, two correction factors that apply to different other transport speeds can also be offset against each other to calculate the correction factor, e.g. interpolated or extrapolated.

For test transport speeds that differ (in terms of amount), different values for the correction factor are determined as a function of the absolute value of the test transport speed. However, regardless of the transport direction or for both opposite transport directions of the document of value relative to the sensor, the same speed dependency of the correction factor K(v) is used to correct the luminescence index determined for the document of value. An indication of the absolute value of the test transport speed is sufficient as information about the test transport speed, while information about its sign or about the test transport direction is not necessary.

The correction device is set up to correct the luminescence index determined by the sensor for the document of value using the at least one correction factor applicable to the test transport speed of the document of value in order to determine a corrected luminescence index for the document of value. To correct the luminescence index determined for the document of value, the luminescence index determined for the document of value is offset against the correction factor applicable to the test transport speed of the document of value, e.g. multiplied or divided.

If necessary, the corrected luminescence index can also be corrected by a further correction, e.g. the above-mentioned sensor-specific correction, before or after the speed correction according to the invention is carried out.

The sensor, in particular the evaluation device, is designed to check the luminescence of the respective document of value using the corrected luminescence index. For this purpose, the corrected luminescence index, which has been subjected to the above-mentioned speed correction, can be compared with one or more reference value(s) or threshold(s) expected for the respective luminescent substance of the document of value. To check the respective document of value using the corrected luminescence index, however, an index derived from one or more corrected luminescence index(es) can also be used, e.g. in the case of a speed correction at the time of measurement, a characteristic time constant determined from the intensity-time curve corrected at the time of measurement.

According to the invention, the speed of the measured luminescence index is therefore corrected as a function of the transport speed of the documents of value. In particular, the speed correction is used to correct the luminescence index with regard to the transport speed-dependent displacement of the excited area of the document of value relative to the detection area of the sensor, which occurs equally on all sensors in a sensor series.

The luminescence indexes corrected with a speed correction according to the invention, which are determined by different sensors of the same series and/or the same sensor in different installation positions, can be compared directly with one another and/or with a specified target value of the luminescence index. When comparing with the specified target value, a narrow acceptance range around the target value can be selected - in contrast to bewe tion-related falsified luminescence parameters, for which a relatively large acceptance range around the target value must be permitted. This leads to a selective security document check.

The luminescence index of the document of value to be checked can be determined in the evaluation device of the sensor using the measured luminescence intensity(s) of the document of value to be checked and transmitted to the correction device so that it carries out the speed correction. The corrected luminescence index can then be transmitted from the correction device to the evaluation device so that the latter carries out an examination of the document of value using the corrected luminescence index. The correction device can be part of the evaluation device of the sensor. Alternatively, the correction device can also be present separately from the evaluation device in the sensor.

The information about the test transport speed of the value document can be transmitted to the sensor by the value document processing device or can be determined by the sensor itself by measurement. It can be stored in the sensor. The speed dependency of the correction factor can be stored in the sensor, e.g. in a memory area of the correction device or in another memory of the sensor outside the correction device, e.g. in the form of discrete pairs of values or as a mathematical function, which assigns a correction factor to several transport speeds of a value document to be checked.

Determination of the speed dependency of the correction factor

A reference sensor and a reference medium, which has a reference luminescent substance and is assigned to the document of value to be checked, are used to determine the speed dependency of the correction factor. The reference sensor is set up to measure the luminescence of the reference medium and is assigned to the sensor in which the speed correction of the luminescence index is provided and which is to be used to check the documents of value. The reference sensor assigned to the sensor belongs in particular to the same series of sensors as the sensor in which the speed correction is made available. Preferably, the reference sensor is nominally identical (except for manufacturing tolerances) to the sensor in which the speed correction is provided. The luminescence index of the reference medium corresponds to the luminescence index of the document of value or is identical to it.

In order to determine the first and second speed dependency of the luminescence index, the luminescence index of the reference medium is determined with the reference sensor - e.g. The first speed dependency of the luminescence index applies to a first transport direction in which the reference medium is transported past the reference sensor or the document of value is transported past the sensor. The second speed dependency of the luminescence index applies to the second transport direction, which is opposite to the first transport direction and in which the reference medium is transported past the reference sensor or the document of value is transported past the sensor.

1. a) Bestimmen einer ersten Geschwindigkeitsabhängigkeit L+(v) der der Lumineszenz-Kennzahl L des Wertdokuments entsprechenden Lumineszenz-Kennzahl eines zur Lumineszenzemission anregbaren Referenzmediums mit Hilfe des Referenzsensors für eine erste Transportrichtung des Referenzmediums relativ zu dem Referenzsensor, und
2. b) Bestimmen einer zweiten Geschwindigkeitsabhängigkeit L-(v) der der Lumineszenz-Kennzahl L des Wertdokuments entsprechenden Lumineszenz-Kennzahl des Referenzmediums mit Hilfe des Referenzsensors für eine zur ersten Transportrichtung entgegengesetzte zweite Transportrichtung (-x) des Referenzmediums relativ zu dem Referenzsensor, und
3. c) Mittelung der ersten Geschwindigkeitsabhängigkeit L+(v) der Lumineszenz-Kennzahl des Referenzmediums und der zweiten Geschwindigkeitsabhängigkeit L-(v) der Lumineszenz-Kennzahl des Referenzmediums bei der jeweiligen Geschwindigkeit v, um eine mittlere Geschwindigkeitsabhängigkeit Lm(v), der Lumineszenz-Kennzahl des Referenzmediums zu ermitteln, z.B. durch Berechnen einer mittleren Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl Lm(v) = (L+(v) + L-(v))/2, und
4. d) Verwenden der mittleren Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl Lm(v) des Referenzmediums zum Bestimmen einer Geschwindigkeitsabhängigkeit eines Korrekturfaktors K(v), der zur Korrektur der Lumineszenz-Kennzahl L des zu prüfenden Wertdokuments geeignet ist. Die hierbei korrigierte Lumineszenz-Kennzahl ist dieselbe Lumineszenz-Kennzahl wie die an dem Referenzmediums gemessene Lumineszenz-Kennzahl, z.B. eine Zeitkonstante oder ein Intensitätswert. Die Geschwindigkeitsabhängigkeit eines Korrekturfaktors K(v) kann z.B. direkt aus der mittleren Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl Lm(v) berechnet oder über eine Fitkurve F(v) für die mittleren Geschwindigkeitsabhängigkeit Lm(v) bestimmt werden.
5. e) Abspeichern der Geschwindigkeitsabhängigkeit des Korrekturfaktors K(v) in dem Sensor.

The following steps in particular are carried out to determine the speed dependency of the correction factor:

1. a) determining a first speed dependency L+(v) of the luminescence index corresponding to the luminescence index L of the document of value of a reference medium that can be excited to emit luminescence using the reference sensor for a first transport direction of the reference medium relative to the reference sensor, and
2. b) determining a second speed dependency L-(v) of the luminescence index of the reference medium, which corresponds to the luminescence index L of the document of value, using the reference sensor for a second transport direction (-x) of the reference medium, opposite the first transport direction, relative to the reference sensor, and
3. c) Averaging the first speed dependency L+(v) of the luminescence index of the reference medium and the second speed dependency L-(v) of the luminescence index of the reference medium at the respective speed v, by an average speed dependency Lm(v), the luminescence index of the reference medium, for example by calculating a mean speed dependency of the luminescence index Lm(v)=(L+(v)+L-(v))/2, and
4. d) using the average velocity dependence of the luminescence index Lm(v) of the reference medium to determine a velocity dependence of a correction factor K(v) used to correct the luminescence Index L of the value document to be checked is suitable. The luminescence index corrected here is the same luminescence index as the luminescence index measured on the reference medium, eg a time constant or an intensity value. The speed dependency of a correction factor K(v) can, for example, be calculated directly from the mean speed dependency of the luminescence index Lm(v) or determined using a fit curve F(v) for the mean speed dependency Lm(v).
5. e) storing the speed dependency of the correction factor K(v) in the sensor.

• - Vorbeitransportieren des zur Lumineszenzemission anregbaren Referenzmediums an dem Referenzsensor mit verschiedenen Transportgeschwindigkeiten entlang der ersten Transportrichtung und mit verschiedenen Transportgeschwindigkeiten entlang der zur ersten Transportrichtung entgegengesetzten zweiten Transportrichtung des Referenzmediums relativ zu dem Referenzsensor und
• - Messen jeweils mindestens einer Lumineszenzintensität (z.B. Lumineszenzintensität zu einem oder mehreren Messzeitpunkten, zeitlicher Verlauf der Lumineszenzintensität oder aufintegrierte Lumineszenzintensität) des Referenzmediums mittels des Referenzsensors für die verschiedenen Transportgeschwindigkeiten und Transportrichtungen, während das Referenzmedium mit der jeweiligen Transportgeschwindigkeit entlang der jeweiligen Transportrichtung an dem Referenzsensor vorbeitransportiert wird, und
• - Bestimmen der ersten Geschwindigkeitsabhängigkeit der der Lumineszenz-Kennzahl L des Wertdokuments entsprechenden Lumineszenz-Kennzahl L des Referenzmediums (z.B. Zeitkonstante oder Intensitätswert) für die erste Transportrichtung des Referenzmediums relativ zu dem Referenzsensor anhand der vom Referenzsensor für die erste Transportrichtung gemessenen mindestens einen Lumineszenzintensität des Referenzmediums, und
• - Bestimmen der zweiten Geschwindigkeitsabhängigkeit der der Lumineszenz-Kennzahl L des Wertdokuments entsprechenden Lumineszenz-Kennzahl L des Referenzmediums (z.B. Zeitkonstante oder Intensitätswert) mit Hilfe des Referenzsensors für die zweite Transportrichtung des Referenzmediums relativ zu dem Referenzsensor anhand der für die zweite Transportrichtung vom Referenzsensor gemessenen mindestens einen Lumineszenzintensität des Referenzmediums.

In order to determine the first and second speed dependency of the luminescence index of the reference medium, a luminescence index of the reference medium is determined with the reference sensor when it is transported past the reference sensor in both transport directions at different transport speeds. In particular, the following steps are carried out in steps a) and b):

• - Transporting the reference medium that can be excited to emit luminescence past the reference sensor at different transport speeds along the first transport direction and at different transport speeds along the second transport direction of the reference medium, which is opposite to the first transport direction, relative to the reference sensor and
• - Measuring at least one luminescence intensity (e.g. luminescence intensity at one or more measurement times, luminescence intensity over time or integrated luminescence intensity) of the reference medium using the reference sensor for the different transport speeds and transport directions, while the reference medium is transported past the reference sensor at the respective transport speed along the respective transport direction will, and
• - Determination of the first speed dependency of the luminescence index L of the reference medium corresponding to the luminescence index L of the document of value (e.g. time constant or intensity value) for the first transport direction of the reference medium relative to the reference sensor based on the at least one luminescence intensity of the reference medium measured by the reference sensor for the first transport direction , and
• - Determination of the second speed dependency of the luminescence index L of the reference medium corresponding to the luminescence index L of the document of value (e.g. time constant or intensity value) using the reference sensor for the second transport direction of the reference medium relative to the reference sensor based on the at least one measured for the second transport direction by the reference sensor a luminescence intensity of the reference medium.

A single reference medium can be used here, or several reference media of the same type can be used, the measured luminescence intensities of which are averaged in order to determine the first and second speed dependency of the luminescence index of the reference medium. These reference media can be specially prepared sheets provided with luminescent material or real documents of value.

With the respective transport speed and direction, exactly one luminescence intensity or several luminescence intensities of the reference medium can be measured at different measurement times and/or in different spectral channels. The measurement time refers to the time of a pulsed luminescence excitation, e.g. at the end of it.

The determination and storage of the speed dependency of a correction factor K(v) is preferably carried out by the sensor manufacturer before the sensor is delivered. This has the advantage that the sensor provided with the speed correction can be put into operation in various value-document processing devices with little effort after delivery.

Since the speed dependency of the respective luminescence index determined solely for the first and second transport direction differs only slightly from the mean speed dependency of the respective luminescence index averaged over the two transport directions, the latter can be used for the two opposite transport directions. This means that the actual transport direction of the documents of value to be checked in the respective value-document processing device or the installation position of the sensor in the respective value-document processing device does not have to be taken into account for the speed correction of the respective luminescence index. This makes it easier to put the sensor into operation in different installation positions or in different value-document processing devices.

In addition, the mean speed dependency of the respective luminescence index, averaged over the two mutually opposite transport directions, is essentially the same for different sensors of the same sensor series. This means that the average speed dependency of the luminescence index applies to all sensors of the same sensor series across all sensors. For different sensors of the same sensor series, the mean speed dependency of the luminescence index Lm(v) of the reference medium can therefore be used to determine the respective speed dependency of the correction factor K(v). The average speed dependency of the respective luminescence index of one of these sensors, which is declared as a reference sensor, is therefore representative for all sensors in this sensor series (which are nominally identical to the reference sensor, but de facto slightly different) for determining the speed dependency of the correction factor used. It is therefore sufficient to determine the mean speed dependency of the respective luminescence index on just a single reference sensor in the sensor series, ie it is not necessary to determine the speed dependency of the respective luminescence index for each individual sensor in the sensor series.

Therefore, in the case of several sensors of the same sensor series, the same speed dependency of the luminescence index of the reference medium is preferably used to determine the respective speed dependency of the correction factor K(v). In particular, the same speed correction is provided in several sensors of the same sensor series or the same speed dependence of the correction factor K(v) is stored in the respective sensor. Alternatively, with different sensors of the same sensor series, the speed dependency of the correction factor K(v) stored in the sensor can be adjusted individually for each sensor, e.g. the average speed dependency of the luminescence index can be offset against sensor-specific factors and then stored in the sensor as the speed dependency of the correction factor K(v). /be.

The speed correction according to the invention is exact for an ideal sensor of the respective sensor series that has no offset between its illumination area and its detection area. However, the correction factor that applies to all sensors also applies, at least approximately, to sensors in this sensor series with a different offset. In order to achieve an exact speed correction in the case of a large offset, it can be provided that the luminescence index determined for the document of value is not only subjected to the speed correction according to the invention, but is also additionally corrected with the aid of a sensor-specific correction factor that applies to the test transport speed of the document of value. in order to determine an even more precisely corrected luminescence index of the document of value.

Examples of the corrected luminescence metrics

The same luminescence index is preferably determined for the reference medium as for the document of value. For example, the luminescence index of the reference medium is the decay time of the reference medium and the luminescence index of the value document is the decay time of the value document, or the luminescence index of the reference medium is a specific intensity value of the reference medium and the luminescence index of the value document is the corresponding specific intensity value of the value document.

In some exemplary embodiments, the luminescence index of the reference medium or the value document, which is determined for the reference medium or for the value document to be checked for the respective transport speed and direction, is determined by the reference sensor on the reference medium using luminescence intensities measured at different measurement times or determined by the sensor on the document of value to be checked. Different measurement times are understood to mean different measurement times in relation to the pulsed luminescence excitation, e.g. different delay times in relation to the time of the excitation pulse of the pulsed excitation. That is, the luminescence index of the reference medium is determined using luminescence intensities measured by the reference sensor at different measurement times on the reference medium, and the luminescence index of the document of value is determined using luminescence intensities measured by the sensor at different measurement times on the Document of value were measured. This is the case, for example, when the time constant, the intensity ratio or an averaged or integrated intensity is used as the luminescence index.

For example, the luminescence index of the reference medium or of the document of value to be checked is a combined luminescence intensity (of the reference medium or of the document of value to be checked). This can be an integrated or averaged over different measurement times (of the reference sensor or the sensor). Luminescence intensity (of the reference medium or of the document of value to be checked). The luminescence index of the reference medium can be an integrated or averaged luminescence intensity of the reference medium over different measurement times of the reference sensor and the luminescence index of the document of value to be checked can be an integrated or averaged luminescence intensity of the document of value to be checked over the corresponding different measurement times of the sensor.

The luminescence index (of the reference medium or of the document of value to be checked) can also be a luminescence time constant of the luminescence (of the reference medium or of the document of value to be checked) derived from a time profile of the measured luminescence intensities, in particular the rise or decay time of the luminescence. The luminescence index of the reference medium is then a luminescence time constant, in particular the attack or decay time, of the luminescence of the reference medium, which is derived from a time profile of the luminescence intensities of the reference medium measured by the reference sensor. And the luminescence index of the document of value to be checked is a corresponding luminescence time constant, in particular the attack or decay time, of the luminescence of the document of value to be checked, which is derived from a time profile of the luminescence intensities of the document of value measured by the sensor.

The luminescence index (of the reference medium or of the document of value to be checked) can also be a ratio of two of the measured luminescence intensities (of the reference medium or of the document of value to be checked), in particular the ratio of the luminescence intensities of two different measurement times or the ratio of the luminescence intensities of two different time intervals or the ratio of the luminescence intensities measured in two different spectral channels of the reference medium or of the document of value to be checked. The luminescence index of the reference medium is then a ratio of the luminescence intensities of two different measurement times of the reference sensor or the ratio of the luminescence intensities of the reference medium measured in two different spectral channels of the reference sensor. And the luminescence index of the document of value to be checked is the corresponding ratio of the luminescence intensities of two different measurement times of the sensor or the corresponding ratio of the luminescence intensities of the document of value measured in the two different spectral channels of the sensor.

The luminescence index (of the reference medium or of the value document to be checked) can also be measured at a discrete measurement time (measurement time determined in relation to the time of a pulsed luminescence excitation) by the reference sensor on the reference medium or by the sensor on the value document be luminescence intensity. The luminescence index of the reference medium is then a luminescence intensity measured by the reference sensor on the reference medium at a discrete measurement time (e.g. in relation to the time of a pulsed luminescence excitation). And the luminescence index of the document of value to be checked is a luminescence intensity measured by the sensor on the document of value at the corresponding discrete measurement time (e.g. in relation to the time of a pulsed luminescence excitation).

Correction by measurement time

In particular, the method can be carried out on the same reference medium and the same reference sensor as well as on the same sensor and the same document of value for several different (different with respect to the point in time of the pulsed luminescence excitation) discrete measurement points in time. The luminescence intensity (by the reference sensor on the reference medium or by the sensor on the document of value) is measured for the various discrete measurement times and the luminescence index at the respective measurement time (by the reference sensor on the reference medium or by the sensor on the Value document) measured luminescence intensity used. The reference sensor measures a discrete luminescence intensity on the reference medium for different discrete measurement times, and the sensor measures a discrete luminescence intensity on the document of value for different discrete measurement times. The corresponding discrete measurement times of the document of value can be the same as the discrete measurement times of the reference medium or at least approximately correspond to them. However, they can also be different, since it is not necessary for the discrete measurement times to be identical, e.g. for determining a time constant.

• - die erste und die zweite Geschwindigkeitsabhängigkeit der zu dem jeweiligen diskreten Messzeitpunkt gemessenen Lumineszenzintensität durch den Referenzsensor an dem Referenzmedium für den jeweiligen diskreten Messzeitpunkt bestimmt wird (als erste und zweite Geschwindigkeitsabhängigkeit der der Lumineszenz-Kennzahl des Referenzmediums gemäß den Schritten a),b)) und
• - durch Mittelung dieser ersten und zweiten Geschwindigkeitsabhängigkeit die jeweilige mittlere Geschwindigkeitsabhängigkeit der jeweiligen Lumineszenzintensität für den jeweiligen diskreten Messzeitpunkt ermittelt wird (als mittlere Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl des Referenzmediums gemäß Schritt c)), und
• - (beim Bestimmen der Geschwindigkeitsabhängigkeit des Korrekturfaktors gemäß Schritt d)) für den jeweiligen diskreten Messzeitpunkt die jeweilige mittlere Geschwindigkeitsabhängigkeit der jeweiligen Lumineszenzintensität des Referenzmediums zum Bestimmen einer messzeitpunktindividuellen Geschwindigkeitsabhängigkeit des (für den jeweiligen Messzeitpunkt geltenden) Korrekturfaktors verwendet wird, der in dem Sensor (gemäß Schritt e)) abgespeichert wird und dort dem jeweiligen diskreten Messzeitpunkt zugeordnet wird.

In a first variant of the correction by measurement time, the luminescence intensity measured at the respective measurement time (by the reference sensor on the reference medium or by the sensor on the document of value) is used as the luminescence index for different discrete measurement times, with

• - The first and the second speed dependence of the respective discrete Measurement time measured luminescence intensity is determined by the reference sensor on the reference medium for the respective discrete measurement time (as a first and second speed dependence of the luminescence index of the reference medium according to steps a), b)) and
• - the respective mean speed dependency of the respective luminescence intensity for the respective discrete measurement time is determined by averaging this first and second speed dependency (as mean speed dependency of the luminescence index of the reference medium according to step c)), and
• - (When determining the speed dependency of the correction factor according to step d)) for the respective discrete measurement time, the respective average speed dependency of the respective luminescence intensity of the reference medium is used to determine a measurement time-specific speed dependency of the correction factor (applicable for the respective measurement time) that is used in the sensor (according to Step e)) is stored and assigned there to the respective discrete measurement time.

• - für jede der zu den entsprechenden Messzeitpunkten von dem Sensor an dem Wertdokument gemessenen Lumineszenzintensitäten jeweils anhand der im Sensor abgespeicherten messzeitpunktindividuellen Geschwindigkeitsabhängigkeit des Korrekturfaktors und mittels der dem Sensor zur Verfügung gestellten Information über die Prüf-Transportgeschwindigkeit des Wertdokuments, einen messzeitpunktindividuellen Korrekturfaktor zu bestimmen, der für den jeweiligen entsprechenden Messzeitpunkt und für die Prüf-Transportgeschwindigkeit des Wertdokuments gilt, und
• - die an dem Wertdokument zu dem entsprechenden Messzeitpunkt gemessene Lumineszenzintensität mit Hilfe des für den jeweiligen entsprechenden Messzeitpunkt und für die Prüf-Transportgeschwindigkeit des Wertdokuments geltenden messzeitpunktindividuellen Korrekturfaktors zu korrigieren, um eine korrigierte Lumineszenzintensität für den jeweiligen entsprechenden Messzeitpunkt des Wertdokuments zu bestimmen.

The correction device is set up (when providing the speed correction according to step f)) for the speed correction of luminescence intensities of the respective value document, which the sensor measures at corresponding measurement times on the value document, to

• - for each of the luminescence intensities measured by the sensor on the value document at the corresponding measurement times, using the measurement time-specific speed dependency of the correction factor stored in the sensor and using the information made available to the sensor about the test transport speed of the value document, to determine a measurement time-specific correction factor, which applies to the respective corresponding measurement time and to the test transport speed of the document of value, and
• - to correct the luminescence intensity measured on the document of value at the corresponding measurement time using the correction factor for the individual measurement time applicable to the respective measurement time and for the test transport speed of the document of value, in order to determine a corrected luminescence intensity for the respective corresponding measurement time of the document of value.

The sensor is designed to use the corrected luminescence intensities, which were determined for the corresponding measurement times, to check the luminescence of the respective document of value. When checking a document of value, several correction factors are then determined based on the information about the test transport speed, which apply to the test transport speed of the document of value and to the respective measurement time, using several speed dependencies of the correction factor that are specific to the measurement time and are stored in the sensor. And the luminescence intensity of the document of value measured at the respective measurement time is corrected using the correction factor applicable to the test transport speed and for the respective measurement time, different correction factors being used for the different measurement times.

The measurement time-specific speed dependency of the correction factor stored for one of the measurement times differs from the measurement time-specific speed dependencies of the correction factor stored for the other measurement times. For example, a correction factor specific to each measurement time and transport speed is stored in the sensor for different measurement times and different transport speeds.

The correction factor of the respective measurement time that applies to the inspection transport speed of the value document is determined, for example, using a first speed dependency of the first luminescence intensity of the respective measurement time, determined in advance of the value document inspection, and a second speed dependency of the second luminescence intensity of the respective measurement time, determined in advance of the value document inspection, which are mutually exclusive oppositely directed transport directions of the document of value apply relative to the sensor.

• - für die verschiedenen diskreten Messzeitpunkte jeweils die erste und die zweite Geschwindigkeitsabhängigkeit der zu dem jeweiligen diskreten Messzeitpunkt gemessenen Lumineszenzintensität durch den Referenzsensor an dem Referenzmedium für den jeweiligen diskreten Messzeitpunkt bestimmt (als erste und zweite Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl des Referenzmediums gemäß den Schritten a), b)) und
• - für die verschiedenen diskreten Messzeitpunkte jeweils durch Mittelung dieser ersten und die zweiten Geschwindigkeitsabhängigkeit die jeweilige mittlere Geschwindigkeitsabhängigkeit der jeweiligen Lumineszenzintensität für den jeweiligen diskreten Messzeitpunkt ermittelt (als mittlere Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl des Referenzmediums gemäß Schritt c)), und
• - auf Basis der mittleren Geschwindigkeitsabhängigkeiten der jeweiligen Lumineszenzintensität, die für die verschiedenen diskreten Messzeitpunkte ermittelt wurden, durch Mittelung über die verschiedenen diskreten Messzeitpunkte eine repräsentative Geschwindigkeitsabhängigkeit des Korrekturfaktors bestimmt, die für mehrere bzw. alle Messzeitpunkte gilt bzw. verwendet wird bzw. die unabhängig von dem Messzeitpunkt gilt.

In a second variant of the measurement-time-wise correction

• - For the various discrete measurement times, the first and the second speed dependency of the luminescence intensity measured at the respective discrete measurement time is determined by the reference sensor on the reference medium for the respective discrete measurement time (as the first and second speed dependency of the luminescence index of the reference medium according to steps a) , Federation
• - for the various discrete measurement times by averaging these first ones and the second speed dependency determines the respective mean speed dependency of the respective luminescence intensity for the respective discrete measurement time (as mean speed dependency of the luminescence index of the reference medium according to step c)), and
• - On the basis of the average speed dependencies of the respective luminescence intensity, which were determined for the various discrete measurement times, a representative speed dependency of the correction factor is determined by averaging over the various discrete measurement times, which applies or is used for several or all measurement times or which is independent of at the time of measurement.

The representative speed dependency of the luminescence intensity is used to determine the speed dependency of the correction factor (applicable to several or all measurement times) (according to step d)), which is stored in the sensor (according to step e)) (and there all discrete measurement times or several is assigned to discrete measurement times of the document of value). The speed correction of the second variant is not as precise as that of the first variant, but it is less complex.

For example, to determine the representative speed dependency, the mean speed dependencies of the respective luminescence intensity, which were determined for the various discrete measurement times, are summarized by averaging to form a representative speed dependency of the luminescence intensity, e.g. by averaging over the mean speed dependencies of the luminescence intensity applicable to different measurement times. Alternatively, the first and second speed dependencies of all measurement times can be combined or averaged for this purpose. Alternatively, the luminescence intensities of the different discrete measurement times, which were measured at the same transport speed, can be combined or averaged for different transport speeds. Alternatively, the speed dependency of the correction factor can first be determined for a plurality of measurement times and these can be combined or averaged.

• - für jede der von dem Sensor an dem Wertdokument zu den Messzeitpunkten gemessenen Lumineszenzintensitäten jeweils anhand der im Sensor abgespeicherten repräsentativen Geschwindigkeitsabhängigkeit des Korrekturfaktors und mittels der dem Sensor zur Verfügung gestellten Information über die Prüf-Transportgeschwindigkeit des Wertdokuments, einen repräsentativen Korrekturfaktor zu bestimmen, der für die Messzeitpunkte des Wertdokuments und für die Prüf-Transportgeschwindigkeit des Wertdokuments gilt, und
• - die an dem Wertdokument zu dem jeweiligen Messzeitpunkt gemessene Lumineszenzintensität mit Hilfe des für die Prüf-Transportgeschwindigkeit des Wertdokuments geltenden repräsentativen Korrekturfaktors zu korrigieren, um eine korrigierte Lumineszenzintensität für den jeweiligen Messzeitpunkt des Wertdokuments zu bestimmen, wobei die an dem Wertdokument zu den mehreren Messzeitpunkten gemessenen Lumineszenzintensitäten insbesondere mit Hilfe desselben, für die Prüf-Transportgeschwindigkeit geltenden repräsentativen Korrekturfaktors korrigiert werden.

The correction device is (when providing the speed correction according to step f)) for the speed correction of luminescence intensities of the respective value document, which the sensor measures at several (any) measurement times on the value document (which can correspond to the discrete measurement times (t1, t2) of the reference medium or not), set up to

• - for each of the luminescence intensities measured by the sensor on the document of value at the measurement times, using the representative speed dependency of the correction factor stored in the sensor and using the information made available to the sensor about the test transport speed of the document of value, to determine a representative correction factor which the measurement times of the value document and the test transport speed of the value document apply, and
• - to correct the luminescence intensity measured on the value document at the respective measurement time using the representative correction factor applicable to the test transport speed of the value document in order to determine a corrected luminescence intensity for the respective measurement time of the value document, the values measured on the value document at the multiple measurement times Luminescence intensities are corrected in particular with the help of the same representative correction factor applicable to the test transport speed.

The sensor is designed, for example, to use the corrected luminescence intensities, which were determined for the measurement times, to check the luminescence of the respective document of value. For example, the sensor is set up to check the value document using the corrected luminescence intensities that were determined for the measurement times of the value document, to determine a time constant of the luminescence of the value document and to check the value document using the time constant.

In a development of the invention, at least two speed dependencies K(v), K'(v) of the correction factor are determined using one or more different reference media and stored in the sensor, to which different value ranges of the luminescence index, e.g. the luminescence time constant, of to be checked Are associated with documents of value or which apply to different value ranges of the luminescence index, eg the luminescence time constant, of documents of value to be checked. The correction device is/is then set up to determine the correction factor applicable to the checking transport speed as a function of information made available to the sensor about a desired value of the luminescence index, eg the luminescence time constant, of the document of value to be checked. The correction device is/is then set up to deviate from these speeds Depending on information provided to the sensor about a target value of the luminescence index, e.g. the luminescence time constant of the document of value to be checked, select that speed dependency of the correction factor in the value range of which this target value lies, and use this to determine the for the test - to use the correction factor applicable to transport speed. The speed dependencies applicable to different value ranges of the luminescence index, e.g. the luminescence time constant, can be determined, for example, using a number of reference media whose specified luminescence index, e.g. luminescence time constant, lies in the respective value range, in particular by determining the luminescence index, eg the reference medium time constant of the various reference media as a function of the transport speed.

The invention also relates to a device for processing documents of value, which has the sensor described above. The device has a transport device which is set up for transporting the document of value to be checked past the sensor along a transport direction at a test transport speed. For example, the device is a sorting device for documents of value.

The device can have a device that is set up to determine the information about the test transport speed of the document of value and whose information about the test transport speed is transmitted to the sensor and thus made available to it. This device can be the control device of the device, which has the information about the test transport speed of the documents of value set on the device. However, the device can also be a speed sensor for measuring the test transport speed of the document of value and/or use one or more light barriers for this purpose. Alternatively, the facility can also be the operator interface of the device, at which the test transport speed of the documents of value can be set by an operator of the device. Alternatively, the test transport speed can also be determined by the sensor itself and made available in this way, e.g. by means of the photodetector and, if necessary, an additional photodetector of the sensor positioned at a known distance from it, which detects the time interval between one of the value document edges transported past.

1. A) Vorbeitransportieren eines Wertdokuments an dem Sensor mit der Prüf-Transportgeschwindigkeit und Messen mindestens einer Lumineszenzintensität des Wertdokuments mittels des Sensors während des Vorbeitransportierens,
2. B) Zur Verfügung Stellen einer Information über die Prüf-Transportgeschwindigkeit des Wertdokuments in dem Sensor, z.B. Bestimmen, ggf. Übermitteln und Abspeichern der Information in dem Sensor,
3. C) Bestimmen eines Korrekturfaktors, der für die Prüf-Transportgeschwindigkeit des Wertdokuments gilt, anhand der im Sensor abgespeicherten Geschwindigkeitsabhängigkeit des Korrekturfaktors und mittels der dem Sensor zur Verfügung gestellten Information über die Prüf-Transportgeschwindigkeit,
4. D) Bestimmen einer Lumineszenz-Kennzahl des Wertdokuments bei der Prüf-Transportgeschwindigkeit anhand der bei der Prüf-Transportgeschwindigkeit gemessenen mindestens einen Lumineszenzintensität des Wertdokuments,
5. E) Korrigieren der Lumineszenz-Kennzahl des Wertdokuments mit Hilfe des für die Prüf-Transportgeschwindigkeit des Wertdokuments geltenden Korrekturfaktors, um eine korrigierte Lumineszenz-Kennzahl für das Wertdokument zu bestimmen,
6. F) Verwenden der korrigierten Lumineszenz-Kennzahl zum Prüfen des Wertdokuments, insbesondere durch Vergleichen der korrigierten Lumineszenz-Kennzahl mit für das Wertdokument erwarteten Referenzwert/en oder Schwelle/n.

The invention also relates to a method for checking documents of value using the sensor according to the invention, past which the documents of value are transported for checking them along a transport direction at a checking transport speed, with the steps:

1. A) Transporting a document of value past the sensor at the test transport speed and measuring at least one luminescence intensity of the document of value by means of the sensor while being transported past,
2. B) Providing information about the test transport speed of the document of value in the sensor, for example determining, possibly transmitting and storing the information in the sensor,
3. C) determining a correction factor, which applies to the test transport speed of the value document, using the speed dependency of the correction factor stored in the sensor and using the information about the test transport speed made available to the sensor,
4. D) determining a luminescence index of the document of value at the test transport speed based on the at least one luminescence intensity of the document of value measured at the test transport speed,
5. E) correcting the luminescence index of the document of value using the correction factor applicable to the test transport speed of the document of value in order to determine a corrected luminescence index for the document of value,
6. F) Using the corrected luminescence index to check the value document, in particular by comparing the corrected luminescence index with reference value(s) or threshold(s) expected for the value document.

• - beim Messen der Lumineszenz des Wertdokuments mittels des Sensors während des Vorbeitransportierens in Schritt A) die Lumineszenzintensität I des Wertdokuments zu verschiedenen Messzeitpunkten T1, T2,... gemessen,
• - in Schritt D) mehrere Intensitäts-Kennzahlen I_T1(vP), I_T1(vP),... der Lumineszenz des Wertdokuments bei der Prüf-Transportgeschwindigkeit vP anhand der zu den verschiedenen Messzeitpunkten gemessenen Lumineszenzintensitäten des Wertdokuments bestimmt, wobei als jeweilige Intensitäts-Kennzahl des jeweiligen Messzeitpunkts die zu dem jeweiligen Messzeitpunkt gemessene Lumineszenzintensität bestimmt wird (z.B. ist die erste Lumineszenz-Kennzahl die zu einem ersten Messzeitpunkt T1 gemessene Lumineszenzintensität I_T1(vP), die zweite Lumineszenz-Kennzahl die zu einem zweiten Messzeitpunkt T2 gemessene Lumineszenzintensität I_T2(vP),...), und
• - in Schritt F) das Wertdokument anhand der korrigierten Lumineszenz-Kennzahlen d.h. anhand der korrigierten Lumineszenzintensitäten I_T1*(vP), I_T2*(vP),... des Wertdokuments geprüft. Zum Prüfen des Wertdokuments in Schritt F) wird aus den korrigierten Lumineszenzintensitäten I_T1*(vP), I_T2*(vP) der verschiedenen Messzeitpunkte T1, T2,... (bzw. aus dem zeitlichen Verlauf der korrigierten Lumineszenzintensitäten I_T1*(vP), I_T2*(vP), ...) eine korrigierte Lumineszenz-Zeitkonstante τ (z.B. Abkling- oder Anklingzeit) bestimmt, die für den zeitlichen Verlauf der korrigierten Lumineszenzintensität des Wertdokuments charakteristisch ist, und das Wertdokument anhand der korrigierten Lumineszenz-Zeitkonstante τ geprüft.

For example, an intensity-time curve of the luminescence of the document of value can be determined to check the document of value. be there

• - when measuring the luminescence of the document of value by means of the sensor while being transported past in step A), the luminescence intensity I of the document of value is measured at different measuring times T1, T2,...
• - In step D), several intensity indicators I _T1 (vP), I _T1 (vP), ... of the luminescence of the document of value at the test transport speed vP are determined based on the luminescence intensities of the document of value measured at the various measurement times, with the respective intensities -Code of the respective measurement time determines the measured luminescence intensity at the respective measurement time (e.g. the first luminescence index is the luminescence intensity I _T1 (vP) measured at a first measurement time T1, the second luminescence index is the luminescence intensity I _T2 (vP) measured at a second measurement time T2,...), and
• - In step F), the document of value is checked using the corrected luminescence index, ie using the corrected luminescence intensities I _T1 *(vP), I _T2 *(vP), . . . of the document of value. To check the document of value in step F), the corrected luminescence intensities I _T1 *(vP), I _T2 *(vP) of the various measurement times _T1 , T2, . vP), I _T2 *(vP), ...) determines a corrected luminescence time constant τ (e.g. decay or attack time), which is characteristic of the time course of the corrected luminescence intensity of the document of value, and the document of value based on the corrected luminescence Time constant τ checked.

The value documents to be checked are e.g. banknotes, cheques, identity cards, credit cards, check cards, tickets, vouchers etc.

• 1 schematischer Aufbau einer Wertdokumentbearbeitungsvorrichtung mit dem Sensor;
• 2a Anregungspuls der Lumineszenzanregung und zeitlicher Verlauf der von einem Wertdokument emittierten Lumineszenzintensität im Fall einer statischen Prüfung (v=0),
• 2b zeitlicher Verlauf der Lumineszenzintensität des Wertdokuments bei einer Prüf-Transportgeschwindigkeit vP im Vergleich zum statischen Fall (v=0),
• 3a-c Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl „aufintegrierte Lumineszenzintensität“ eines Referenzmediums für die beiden Transportrichtungen und daraus bestimmte mittlere Geschwindigkeitsabhängigkeit der aufintegrierten Lumineszenzintensität jeweils für einen ersten Sensor (Im(v), 3a) und für einen zweiten Sensor (I'm(v), 3b) und Geschwindigkeitsabhängigkeit K(v) des aus Im(v) bzw. I'm(v) bestimmten Korrekturfaktors (3c),
• 4a-c Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahl „Zeitkonstante“ t eines Referenzmediums für die beiden Transportrichtungen und daraus bestimmte mittlere Geschwindigkeitsabhängigkeit der Zeitkonstante jeweils für einen ersten Sensor (tm(v), 4a) und für einen zweiten Sensor (t'm(v), 4b) und Geschwindigkeitsabhängigkeit K(v) des aus tm(v) bzw. t'm(v) bestimmten Korrekturfaktors (4c),
• 5a Geschwindigkeitsabhängigkeit der Lumineszenz-Kennzahlen „Lumineszenzintensität zum Zeitpunkt t1“ und „Lumineszenzintensität zum Zeitpunkt t2“ eines Referenzmediums jeweils für die beiden Transportrichtungen und jeweils daraus bestimmte mittlere Geschwindigkeitsabhängigkeiten der Lumineszenzintensität I_t1m(v) und I_t2m(v) sowie repräsentative Geschwindigkeitsabhängigkeit I_Rm(v),
• 5b Geschwindigkeitsabhängigkeiten K_t1(v) bzw. K_t2(v) des aus der jeweiligen mittleren Geschwindigkeitsabhängigkeit I_t1m(v) bzw. I_t2m(v) bestimmten Korrekturfaktors für die Lumineszenzintensität zum Zeitpunkt t1 und für die Lumineszenzintensität zum Zeitpunkt t2 und repräsentative Geschwindigkeitsabhängigkeit K_R(v) des Korrekturfaktors,
• 5c messzeitpunktweise Korrektur des zeitlichen Verlaufs der Lumineszenzintensität des Wertdokuments für eine Prüf-Transportgeschwindigkeit v=vP.

The invention is explained below by way of example with reference to the following figures. Show it:

• 1 schematic structure of a value-document processing device with the sensor;
• 2a Excitation pulse of the luminescence excitation and time course of the luminescence intensity emitted by a document of value in the case of a static test (v=0),
• 2 B Time course of the luminescence intensity of the document of value at a test transport speed vP compared to the static case (v=0),
• 3a-c Speed dependency of the luminescence index "integrated luminescence intensity" of a reference medium for both transport directions and mean speed dependency of the integrated luminescence intensity determined from this, each for a first sensor (Im(v), 3a ) and for a second sensor (I'm(v), 3b ) and speed dependency K(v) of the correction factor ( determined from Im(v) or I'm(v) 3c ),
• 4a-c Velocity dependency of the luminescence parameter “time constant” t of a reference medium for both transport directions and mean velocity dependency of the time constant determined from this for a first sensor (tm(v), 4a ) and for a second sensor (t'm(v), 4b ) and speed dependency K(v) of the correction factor determined from tm(v) or t'm(v) ( 4c ),
• 5a Speed dependency of the luminescence parameters "luminescence intensity at time t1" and "luminescence intensity at time t2" of a reference medium for both transport directions and mean speed dependencies of the luminescence intensity I _t1 m(v) and I _t2 m(v) determined from this, as well as representative speed dependency I _Rm (v),
• 5b Speed dependencies K _t1 (v) and K _t2 (v) of the correction factor determined from the respective average speed dependency I _t1 m(v) and I _t2 m(v) for the luminescence intensity at time t1 and for the luminescence intensity at time t2 and representative Speed dependency K _R (v) of the correction factor,
• 5c correction of the time course of the luminescence intensity of the document of value for a test transport speed v=vP at the time of measurement.

1 shows an example of the schematic structure of a value-document processing device 1 with an input compartment 2, in which a stack of value documents 3 to be processed is provided, and a separator 8, from which one value document (e.g. the bottom or topmost) of the input stack is successively detected and to a transport device 10 (conveyor belts and/or transport rollers, shown only schematically in the selected illustration), which transports the documents of value in the transport direction +x past a sensor 25.

The sensor 25 is located at the value-document processing device 1 viewed along the transport direction +x in a left installation position (above the transport path). However, in other value-document processing devices, a sensor of this sensor series can also be installed in a right-hand installation position (below the transport path). This case corresponds to a reverse transport direction of the document of value relative to the sensor than in the case shown, i.e. it is equivalent to a transport direction -x of the in 1 sensor 25 shown. Therefore, a speed correction for the luminescence index of the value documents to be checked should be provided for both possible transport directions +x and -x.

In the example shown, the sensor 25 comprises a photodetector 20 which has at least one photosensitive element which emits the value document transported past Luminescence intensities converted into corresponding sensor signals. The photodetector 20 can also have a number of such photosensitive elements, for example for different spectral components of the luminescence light. The sensor 25 can also be designed to check the documents of value 3 in one or more measurement tracks on the respective document of value, with a photodetector 20 having one or more photosensitive elements being present for each of the measurement tracks. The optical excitation of the luminescence feature of the documents of value takes place, for example, by means of excitation light sources 23, 24 arranged on both sides of the photodetector 20, which illuminate the document of value with excitation light in an illumination area. The sensor 25 is arranged on the left side of the transport path, viewed in the transport direction x of the documents of value. Opposite the sensor 25, on the right side of the transport path, another sensor 29 can be arranged.

The photodetector 20 is designed to measure the luminescence of the documents of value during or after the end of the optical excitation. For this purpose, the photodetector 20 is controlled by a control device of the sensor (not shown) in such a way that it detects the luminescence of the respective document of value 3 at one or more different measurement times. The photodetector forwards the intensity values detected from the measurement location of the document of value to be checked, e.g. from a security feature of the document of value, to an evaluation device 22 of the sensor. The evaluation device 22 can be contained in the housing of the sensor 25 or outside it, e.g. in a central evaluation device of the value document processing device 1. The evaluation device 22 determines the luminescence index L based on the sensor signals detected at the measurement time(s).

The speed dependency of the correction factor K(v) is stored in a memory area 26 of the evaluation device 22 . A correction device 21 of the evaluation device 22 can access the information stored in the memory area 26 in order to use it for the speed correction of the luminescence index. Further information can be stored in the memory area 26, such as information about the test transport speed vP of the value documents, which can vary depending on the type or setting of the value document processing device 1.

From the intensity value(s) of the luminescence of the documents of value detected by the photodetector 20 at the time(s) of measurement(s), the evaluation device 22 determines, for example, a luminescence index L of a security feature of the documents of value and transfers this to the correction device 21, which carries out the speed correction according to the invention using the/the speed dependency/s K(v) of the luminescence index stored in the memory area 26 and by means of the information about the test transport speed of the documents of value vP. To do this, the correction factor K(vP) associated with vP is selected from K(v). If the test transport speed vP does not exactly match one of the transport speeds v contained in the speed dependency K(v) of the correction factor, the correction factor K(vP) applicable to vP can be determined by interpolation or extrapolation from K(v). The corrected luminescence index L*(vP) results from L(vP) e.g. by multiplying by K(vP) (L*(vP)=L(vP) K(vP)) or dividing by K(vP) (L *(vP)=L(vP)/K(vP)) and possibly multiplication or division with a further, in particular sensor-specific, factor. The evaluation device 22 then uses the luminescence index L*(vP) corrected by the correction device 21 as a test criterion for the documents of value, in particular for assessing the authenticity of the documents of value.

Depending on the authenticity of the respective value document determined by the evaluation device 22, the switches 11 and 12 along the transport route are controlled by the control device 50 in such a way that the value document is transported into one of the output compartments 30, 31 of the value document processing device 1. For example, documents of value which have been recognized as genuine are deposited in a first output compartment 30 , while documents of value classified as counterfeit or suspected of forgery are deposited in a second output compartment 31 . At the end of the transport route shown (reference number 13), further output compartments and/or other devices, for example for storing or destroying documents of value, can be provided, such as e.g. B. Cassettes for the protected storage of valuable documents or a shredder. If, for example, a document of value could not be recognized, a special output compartment can be provided for it, in which such documents of value are deposited and made available for separate treatment, for example by an operator.

In the example shown, the value document processing device 1 also includes an input/output device 40 for the input of data and/or control commands by an operator, for example using a keyboard or a touchscreen, and the output or display of data and/or information on the processing process, in particular on the each processed documents of value.

In the 2a and 2 B shows the time behavior of the luminescence of a document of value, which is emitted by a luminescent security feature of the document of value. 2a shows the intensity curve of the optical excitation pulse A, which is directed onto the document of value for luminescence excitation and ends at time t=0. The intensity profile I(t) of the luminescence then usually has a build-up of the luminescence intensity (not shown) during the excitation pulse A of the luminescence excitation and a decay of the luminescence intensity after the end of the excitation pulse of the luminescence excitation.

In 2 B shows the intensity profile detected in a static measurement as a function of time after the end (t=0) of the excitation pulse A, ie when the document of value is not moved relative to the detector (v=0). Such a static measurement is carried out, for example, during a manual check of individual documents of value. In the static measurement, the detected luminescence intensity of the security feature decays with the specified luminescence time constant t0 of the security feature. In the static measurement, the sensors 25a, 25b of the same sensor series deliver the same measurement result of the luminescence time constant t0.

If the same value document is transported past the sensor 25 at a test transport speed vP during the machine check in a value document processing device, its photodetector 20 detects the in 2 B denoted by v=vP as a function of time after the end (t=0) of the excitation pulse A emitted by the excitation light sources 23, 24. For comparison, FIG 2 B the intensity profile detected in the static case with the decay time t0 is also shown as a dashed line. The decay time t, which results from the intensity curve detected at the test transport speed v=vP, is significantly shorter than the decay time t0 of the static measurement.

The relative movement of the document of value relative to the sensor 25 causes a shorter decay time t to be determined than in the static case. This results from the fact that the documents of value are moved on by a certain length during detection, which is comparable to the size of the detection area and the illumination area. The excited area on the document of value thus moves relative to the detector during the measurement, and the measured intensity profile at the detector corresponds to a convolution of the time behavior of the luminescent substance and the movement-related change in the overlap between the excited area on the document of value and the detection area.

Determination of the speed dependency of the correction factor K(v)

The determination of the speed dependence K(v) of the correction factor, which applies to the respective luminescence index L, is usually carried out on the reference sensor before the sensors are delivered by the sensor manufacturer, e.g. at a suitable measuring station for the reference sensor or if this is in a value document processing device is installed. In order to determine the speed dependency of the correction factor K(v), the luminescence index L of a reference medium is determined at different transport speeds v using a reference sensor that belongs to the same sensor series as those sensors in which the speed correction according to the invention is provided.

First, the speed dependency of that luminescence index L is determined at the reference sensor on the reference medium, based on which the sensors used to check the documents of value are to check the documents of value to be checked. The reference medium is provided with a reference luminescent substance and is e.g. sheet-shaped.

To determine the speed dependency of the luminescence index L of the reference medium using the reference sensor, the reference medium is transported past the reference sensor at different transport speeds v1, v2, v3, ... along the first transport direction (+x) and at least one first luminescence intensity of the reference medium is measured by means of the reference sensor is measured while the reference medium is transported past the reference sensor at the respective transport speed along the first transport direction. The reference medium is then transported past the reference sensor at different transport speeds v1, v2, v3,... along the opposite second transport direction (-x) and at least one second luminescence intensity of the reference medium is measured using the reference sensor, while the reference medium is transported at the respective transport speed is transported past the reference sensor along the second transport direction. The luminescence intensity is measured at one or more discrete measurement times, eg in order to determine the change in luminescence over time for each transport speed and direction, or measured in an integrated manner over a time interval, eg in order to determine for each trans port speed and direction to determine the temporally integrated intensity.

The measured luminescence intensity itself can be used as the luminescence index L of the reference medium at the respective transport speed and direction, e.g. the luminescence intensity of the reference medium measured at a discrete measurement time or integrated over a time interval. Alternatively, the luminescence index L of the reference medium at the respective transport speed and direction can also be determined from a plurality of luminescence intensities measured in each case, such as the time constant from the chronological progression of the luminescence intensities or the ratio or the mean value of the values measured at a plurality of discrete measurement times on the document of value luminescence intensities.

Based on the at least one luminescence intensity of the reference medium measured by the reference sensor for the different transport speeds along the first and second transport direction, a speed dependency L(v) of the luminescence index L of the reference medium is determined for each transport speed and direction, and from this the speed dependency of the correction factor K(v) determined. This speed dependency of the correction factor K(v) is stored in the individual sensors to which the reference sensor is assigned. Then the sensors with the speed dependency of the correction factor K(v) stored therein are used for value document checking in value document processing devices.

In order to determine the speed dependency of the correction factor K(v), an average speed dependency Lm(v) of the luminescence index is determined, which is obtained by averaging the first speed dependency of the luminescence index applicable to the first transport direction and the second speed dependency applicable to the opposite second transport direction Speed dependence of the luminescence index is determined. The speed dependency of the correction factor K(v) is then determined from the average speed dependency Lm(v) of the luminescence index.

In order to determine the speed dependency of the correction factor K(v) based on the average speed dependency of the luminescence index Lm(v) of the reference medium, the average speed dependency of the luminescence index Lm(v) or its reciprocal value is calculated with a factor, for example (multiplied or divided): K(v)=S/Lm(v) or K(v) = Lm(v)/S with S as the scaling factor. Alternatively, the average speed dependency of the luminescence index Lm(v) can be fitted using a fit curve and the speed dependency of the correction factor K(v) can be calculated from the fit curve, with the fit curve itself or the reciprocal of the fit curve being offset by a factor (multiplied or divided) can be divided.

exemplary embodiments

In the first and second exemplary embodiment, a luminescence index L is derived from the measured intensities of the luminescence of the document of value, e.g. from a measured intensity-time curve, and this is then corrected in a manner according to the invention. The thereby corrected luminescence index L is e.g. an intensity integrated over a time interval, as in the 1st embodiment, or an index for the time behavior (e.g. build-up or decay time), as in the 2nd embodiment, or over several measurement times of the measured intensity -Time curve averaged intensity or their ratio. This first type of speed correction involves relatively little computing effort and can therefore be carried out quickly.

In the third and fourth exemplary embodiment, an intensity-time curve measured on a value document is corrected measuring point by measuring point and the value document is checked using the corrected intensity-time curve, e.g. by determining a time constant or a characteristic number for the intensity from the corrected intensity-time -Curve. In this case, the correction factor depends either only on the speed (4th exemplary embodiment) or on the speed and the time of measurement (3rd exemplary embodiment). The corrected luminescence index is then the intensity value measured at a specific measuring time (=measuring point of the intensity-time curve), with several intensity values measured at different times preferably being corrected in accordance with the invention. This second type of speed correction (measurement point correction) has the advantage that more complex evaluations, e.g. of the time behavior, are possible.

1st embodiment

In the first embodiment, the luminescence index L is considered to be the luminescence intensity I integrated over a specific time interval.

With the reference sensor, a first integrated luminescence intensity I+(v1), I+(v2), I +(v3) of the reference medium measured, cf. 3a . The second integrated luminescence intensity I-(v1), I-(v2), I-(v3) of the reference medium is then measured with the reference sensor at different transport speeds v1, v2, v3 along the opposite second transport direction (-x), cf. 3a . In 3a the speed dependencies I+(v), I-(v) of the integrated luminescence intensity I of the reference medium for the two transport directions (+x, -x) and the mean speed dependency Im(v) of the integrated luminescence intensity determined from this are shown. The average velocity dependence of the integrated luminescence intensity is calculated, for example, using the formula Im(v)=(I+(v)+I-(v))/2.

For comparison, the same measurements were carried out on the same reference medium by means of a value-document sensor assigned to the reference sensor, which is to be used for value-document checking and is nominally identical to the reference sensor. For the nominally identical value document sensor, the in 3b shown speed dependency I'+(v), I'-(v) of the integrated luminescence intensity of the reference medium for the two transport directions (+x, -x) and the mean speed dependency I'm(v) of the integrated luminescence intensity determined therefrom.

Like comparing the 3b with 3a shows, the integrated intensities measured by the value document sensor differ somewhat from the integrated intensities measured by the reference sensor. This is attributed to production-related tolerances that the value-document sensor and the reference sensor--despite their nominally identical construction--have, for example in the form of a slightly different offset between the illumination and detection areas. However, the mean speed dependencies of the integrated luminescence intensity of the reference sensor Im(v) and the value document sensor I'm(v) averaged over the two transport directions +x, -x are essentially identical (solid curves in 3a and 3b ). The average speed dependency of the integrated luminescence intensity Im(v), which was determined using the reference sensor, can therefore be used as a representative for the value document sensors that are nominally identical in construction to it.

The speed dependency K(v) of the correction factor that can be used for the integrated luminescence intensity is then determined from the average speed dependency of the integrated luminescence intensity Im(v), which was determined using the reference sensor, and is stored in the respective sensor provided for checking documents of value. 3c .

mit S als Skalierungsfaktor, d.h. der Kehrwert der mittleren aufintegrierten Lumineszenzintensität Im(v) bestimmt den jeweiligen Korrekturfaktor. Als Skalierungsfaktor S wird z.B. die Intensität I0=Im(v=0) des Referenzmediums bei einer statischen Messung mittels des Referenzsensors verwendet. Dann wird die Geschwindigkeitskorrektur in dem jeweiligen Sensor so eingerichtet, dass bei der Wertdokumentprüfung eine multiplikative Korrektur der gemessenen aufintegrierten Intensität I(vP) der Lumineszenz des Wertdokuments durchgeführt wird: $$\text{I}*\left(\text{vP}\right)=\text{I}\left(\text{vP}\right)\cdot \text{K}\left(\text{vP}\right).$$

For example, the mean speed dependency K(v) of the correction factor is determined using the formula $$\text{K}\left(\text{v}\right)=\text{S}/\text{in the}\left(\text{v}\right)=2\cdot \text{S}/\left(\text{I}+\left(\text{v}\right)+\text{I}-\left(\text{v}\right)\right),$$

with S as the scaling factor, ie the reciprocal of the average integrated luminescence intensity Im(v) determines the respective correction factor. The intensity I0=Im(v=0) of the reference medium in a static measurement using the reference sensor is used as the scaling factor S, for example. Then the speed correction in the respective sensor is set up in such a way that a multiplicative correction of the measured integrated intensity I(vP) of the luminescence of the value document is carried out during the value document check: $$\text{I}*\left(\text{vP}\right)=\text{I}\left(\text{vP}\right)\cdot \text{K}\left(\text{vP}\right).$$

mit S als Skalierungsfaktor, d.h. direkt die (ggf. skalierte) aufintegrierte Intensität Im(v) bestimmt den Korrekturfaktor K(v), vgl. 3c. Als Skalierungsfaktor S wird z.B. die Intensität I0=Im(v=0) des Referenzmediums bei einer statischen Messung mittels des Referenzsensors verwendet. Dann wird die Geschwindigkeitskorrektur in dem jeweiligen Sensor so eingerichtet, dass bei der Wertdokumentprüfung eine entsprechend andere Korrekturformel (mit Division durch den Korrekturfaktor K(vP)) verwendet wird: $$\text{I}*\left(\text{vP}\right)=\text{I}\left(\text{vP}\right)\text{/K}\left(\text{vP}\right)$$

Alternatively, the mean speed dependency K(v) of the correction factor can be determined using the formula $$\text{K}\left(\text{v}\right)=\text{in the}\left(\text{v}\right)\text{/S=}\left(\text{I}+\left(\text{v}\right)+\text{I}-\left(\text{v}\right)\right)/2\cdot \text{S},$$

with S as scaling factor, ie directly the (possibly scaled) integrated intensity Im(v) determines the correction factor K(v), cf. 3c . The intensity I0=Im(v=0) of the reference medium in a static measurement using the reference sensor is used as the scaling factor S, for example. Then the speed correction in the respective sensor is set up in such a way that a correspondingly different correction formula (with division by the correction factor K(vP)) is used when checking the value document: $$\text{I}*\left(\text{vP}\right)=\text{I}\left(\text{vP}\right)\text{/K}\left(\text{vP}\right)$$

If no mathematical function but only discrete values were determined for the average speed dependency Im(v) of the integrated intensity, the average speed dependency of the correction factor K(v) can be determined from the average speed dependency Im(v) of the integrated intensity using a fit curve. For this purpose, a fit curve F(v) is first determined for the discrete function Im(v) and then the speed dependency of the correction factor K(v)) from the speed dependency of the fit curve F(v) : K(v)= S/F(v) or K(v)=F(v)/S.

After the sensor manufacturer has delivered the sensor to the customer, documents of value are checked with the sensor in a value-document processing device 1 . To check the Documents of value are transported past the sensor at a test transport speed vP. To correct the speed of the luminescence time constant, the correction device 21 uses information about the checking transport speed vP of the value documents to be checked, which is transmitted to the sensor 25 by the control device 50 of the value-document processing device 1 . During the value document check, the correction factor K(vP) is then selected from the speed dependency of the correction factor K(v) stored in the sensor, which is assigned to the check transport speed of the value document vP, cf. 3c .

If a correction factor K(vP) is not explicitly stored in the sensor for the test transport speed vP of the respective value document processing device 1, it is possible, for example, to find which of the stored transport speeds deviates the least from the test transport speed vP of the value documents. The correction factor K(vP) assigned to this transport speed is then used to correct the integrated luminescence intensity. This can be done subject to the speed deviation being below a certain threshold, e.g. <10%.

However, if the test transport speed vP of the documents of value deviates more than acceptable from all transport speeds v1, v2, v3... stored in the sensor, at least two transport speeds v1, v2 are selected from the transport speeds stored in the sensor, e.g. the least of the test -Transport speed vP deviating, and the two associated correction factors K(v1), K(v2). The correction factor K(vP) applicable to the test transport speed vP is determined from the at least two correction factors K(v1), K(v2) e.g. by interpolation.

For speed correction, the corrected integrated intensity I*(vP) is then calculated from the measured integrated intensity I(vP) of the luminescence of the document of value with K(vP) according to the above formula (1) or (2). For an authenticity check of the document of value, the intensity I*(vP) which has been corrected and integrated in this way is compared, for example, with a reference value and the document of value is classified as genuine or suspected of being a forgery depending on this.

2nd embodiment

In the second exemplary embodiment, a luminescence time constant, e.g. the decay time or build-up time of the luminescence, is considered as the luminescence index L.

To determine the speed dependency K(v) of the correction factor, a reference medium is used whose reference luminescent substance has a specified luminescence time constant that matches the document of value to be checked. Preferably, the target value of the luminescence time constant of the document of value to be checked by the sensor deviates from the specified luminescence time constant of the reference luminescent substance of the reference medium by no more than 50%, preferably by no more than 30%, in order to achieve a speed correction that is as accurate as possible. For example, the luminescence time constant of the documents of value to be checked by the sensor corresponds at least approximately to the specified luminescence time constant of the reference medium. This achieves a very precise speed correction.

For example, a reference luminescent substance with a time constant of 100 μs is used for value document luminescent substances with a time constant between 60 μs and 160 μs for the reference medium, and a reference luminescent substance with a time constant is used for value document luminescent substances with a time constant between 160 μs and 350 μs of 250 μs, and for value-document luminescent substances with a time constant between 350 μs and 5 ms a reference luminescent substance with a time constant of 900 μs is used. Alternatively, a reference luminescent substance with a time constant of 250 μs can also be used for value document luminescent substances with a time constant between 100 μs and 5 ms. For example, to determine the speed dependency K(v) of the correction factor of the respective sensor, a reference medium is used which has the same luminescent substance as the value documents to be checked with the respective sensor, i.e. the reference luminescent substance and the value document luminescent substance are the same.

Analogous to the first exemplary embodiment, a first luminescence time constant t+(v1), t+(v2), t+(v3) of the reference medium is measured with the reference sensor at the different transport speeds v1, v2, v3 along the first transport direction (+x) and along a second luminescence time constant t-(v1), t-(v2), t-(v3) of the reference medium is measured in the opposite second transport direction (-x), cf. 4a . In 4a shows the speed dependency t+(v), t-(v) of the luminescence time constant t of the reference medium for the two transport directions (+x, -x) and the average speed dependency tm(v) of the luminescence time constant determined therefrom. The middle Rate dependence of the luminescence time constant is calculated, for example, using the formula tm(v)=(t+(v)+t-(v))/2.

For the nominally identical value document sensor mentioned above, the in 4b shown speed dependency t'+(v), t'-(v) of the luminescence time constant of the reference medium for the two transport directions (+x, -x) and the mean speed dependency t'm(v) of the luminescence time constant of the reference medium determined from this .

Here, too, the luminescence time constants measured by the value-document sensor differ somewhat from the luminescence time constants measured by the reference sensor due to the manufacturing-related tolerances. However, the mean speed dependencies of the luminescence time constant of the reference sensor tm(v) and of the value document sensor t'm(v) averaged over the two transport directions are essentially identical (solid curves in 4a and 4b ). The average speed dependency of the luminescence time constant tm(v), which was determined using the reference sensor, is therefore used as a representative for the value document sensors that are nominally identical in construction to this.

The speed dependency K(v) of the correction factor that can be used for the luminescence time constant is then determined from the mean speed dependency of the luminescence time constant tm(v), which was determined using the reference sensor, and is stored in the respective sensor provided for checking documents of value. 4c .

During the value document check, the sensor then uses the information about the check transport speed vP to look for the correction factor K(vP) from the speed dependency of the correction factor K(v), which is assigned to the check transport speed of the value document vP, cf. 4c .

If the speed dependency of the correction factor K(v) is only stored in the sensor in the form of discrete values K(v1), K(v2), ..., the correction factor K(vP) applicable to the test transport speed vP of the value document can also can be calculated from these discrete values K(v1), K(v2), ... by interpolating or extrapolating.

For the speed correction, the corrected luminescence time constant t*(vP) is then calculated from the measured luminescence time constant t(vP) of the document of value with K(vP). For example, if the reciprocal of the mean luminescence time constant tm(v) was used for the correction factor (K(v) =S/tm(v)= 2*S/(t+(v) + t-(v)), then - analogous to the above formula (1) - a multiplicative correction is carried out t*(vP)=t(vP)*K(vP).

To check the authenticity of the document of value, the luminescence time constant t*(vP) corrected in this way is compared, for example, with a reference value and the document of value is classified as genuine or as a suspected forgery depending on this.

In addition - analogously to the average speed dependency of the time constant tm(v) - with the reference sensor on at least one other reference medium with a different luminescence time constant at least one further average speed dependency of the time constant t ^# m(v) can be determined, which for documents of value with a different Target value of the luminescence time constant applies. Based on this - in addition to the speed dependency of the correction factor K(v) specified above - one or more further speed dependencies K ^# (v) of the correction factor can also be determined and stored in the sensor, each for a different value range of the luminescence time constant of the to be tested Value documents apply. When checking the value document, the respective speed dependency of the correction factor K(v), K ^# (v) is then used for speed correction, which applies to the luminescence time constant of the respective value document to be checked, i.e. depending on the luminescence time constant expected for the value document measured luminescence time constant corrected with either K(vP) or K ^# (vP).

3rd embodiment

In the third exemplary embodiment, the intensity-time curve is corrected for each measurement point. For each measurement time t1, t2, ... a separate speed dependency of the correction factor is stored in the sensor, e.g. the speed dependency of the correction factor K _t1 (v) for the measurement time t1, the speed dependency of the correction factor K _t2 (v) for the measurement time t2. ..

To determine the speed dependencies of the correction factor K _t1 (v), K _t2 (v), ... - analogously to the first and second exemplary embodiment - with the reference sensor at different transport speeds v1, v2, v3 of the reference medium along the first transport direction (+x ) each have a first luminescence intensity I _t1 + (v1), I _t1 + (v2), I _t1 + (v3) of the reference medium for a first measurement time t1 after the end of the luminescence excitation and a further first luminescence intensity I _t2 + (v1), I _t2 +(v2), I _t2 +(v3) of the reference medium for a second measurement time t2 measured after the end of the luminescence excitation (and the same, if necessary, also for further measurement times t3, t4, ... and/or further transport speeds v4, v5, ...), cf. 5a . A second luminescence intensity I _t1 -(v1), I _t1 -(v2), I _t1 -(v3) of the reference medium for measured the first measurement time t1 and a further second luminescence intensity I _t2 -(v1), I _t2 -(v2), I _t2 -(v3) of the reference medium for the second measurement time t2 (and the same, if necessary, also for further measurement times t3, t4, ... and/or other transport speeds v4, v5, ...), cf. 5a . In 5a is the speed dependency I _t1 +(v), I _t1 -(v), I _t2 +(v), I _t2 -(v) of the respectively measured luminescence intensity of the reference medium for the two transport directions (+x, -x) and for the two measurement times t1, t2 and the average speed dependency I _t1 m(v) and I _t2 m(v) of the luminescence intensity determined from this is shown for the two measurement times t1, t2 of the intensity-time curve.

Then for each measurement time t1, t2, ... a separate speed dependency of the correction factor is determined: the speed dependency of the correction factor K _t1 (v) for the measurement time t1, the speed dependency of the correction factor K _t2 (v) for the measurement time t2 (as well as the same Also for further measurement times t3, t4, .... These speed dependencies of the correction factor K _t1 (v), K _t2 (v), ... are then stored in the respective sensor provided for checking documents of value, cf. 5b .

The speed dependency of the correction factor can be stored, for example, in the form of one or more matrix-like tables K(v,t), with numerical values for each $$\begin{array}{l}\text{K}\left(\text{v1},\text{t1}\right),\text{K}\left(\text{v1},\text{t2}\right),...\\ \text{K}\left(\text{v2},\text{t1}\right),\text{K}\left(\text{v2},\text{t2}\right),...\\ ...\end{array}$$

However, the speed dependency of the correction factor can also be stored in the form of mathematical functions K _t1 (v), K _t2 (v), . . . as a function of the transport speed v for different measuring times t1, t2, K _v1 (t), K _v2 (t), . . . as a function of the measurement time t for different transport speeds v1, v2, .

When checking the value document, the value document sensor detects the luminescence intensity of the value document, for example at such measurement times T1, T2 after the end of the luminescence excitation, which correspond to the discrete measurement times t1, t2 of the reference sensor when measuring the reference medium, for which a speed dependency of the correction factor K _t1 (v ), K _t2 (v) is stored in the sensor. If the measurement times T1, T2 of the document of value deviate from the measurement times t1, t2 of the reference medium, the corresponding speed dependencies of the correction factor K _T1 (v), K _T2 (v) can be extra from the stored K _t1 (v), K _t2 (v). - or interpolated and possibly stored in the sensor.

It is assumed below that the measurement times of the document of value and the measurement times t1, t2 of the reference medium are at least approximately the same. The speed dependencies of the correction factor K _t1 (v), K _t2 (v) are then simply used as the speed dependencies of the correction factor K _T1 (v), K _T2 (v). When checking documents of value, the sensor uses the information about the checking transport speed vP to determine the correction factors K _T1 (vP)=K _t1 (vP) and K _T2 ( _V P)=K _t2 (vP), which are for the measuring times T1 , T2 of the document of value and for the test transport speed vP apply, cf. 5b . The luminescence intensity I _T1 (vP) detected by the value document to be checked at the measurement time T1 is corrected with the correction factor K _T1 (vP), the luminescence intensity I _TZ (vP) detected at the measurement time T2 is corrected with the correction factor K _T2 (vP). This results in the corrected intensity values I _T1 *(vP)= I _T1 (vP) K _T1 (vP) for the first measurement time T1 of the document of value and I _T2 *(vP)= I _T1 (vP).K _T2 (vP) for the second measurement time T2 of the document of value, cf. 5c .

The luminescence of the document of value can then be checked on the basis of the corrected luminescence intensities I _T1 *(vP), I _T2 *(vP). To check the authenticity of the document of value, the corrected luminescence intensities I _T1 *(vP), I _T2 *(vP) can be related to one another and compared to a reference value, and the document of value classified as authentic or as a suspect forgery depending on this.

_However , _{a corrected intensity} Time curve of the luminescence of the document of value are determined, which corresponds to a static measurement of the luminescence of the document of value, cf. 5c . The luminescence of the document of value can then be checked on the basis of this corrected intensity-time curve. For this purpose, for example, a decay time τ of the corrected luminescence-time curve is determined and with a decay specified for the document of value time or compared with thresholds specified for this purpose, cf. 5c .

4th embodiment

In the fourth exemplary embodiment, too, a correction of the intensity-time curve is carried out for each measurement point. But in contrast to the third exemplary embodiment, only a single speed dependency of the correction factor K(v)=K _R (v) is used—independent of the measurement time—to correct the luminescence index of the document of value. The intensity values of the luminescence of the document of value measured at different measurement times are therefore all corrected with the same factor K _R (vP).

Starting from the average speed dependencies I _t1 m(v) and I _t2 m(v) of the luminescence intensity for the different measurement times t1, t2 (and, if necessary, average speed dependencies for further measurement times - cf. third exemplary embodiment), by averaging over the various discrete measurement times a representative speed dependency K _R (v) of the correction factor is determined, which applies to all measurement times.

For example, the average velocity dependencies _Itim (v), I _t2 m(v), . . . of the respective luminescence intensity for the various discrete measurement times t1, t2, . . summarized, which applies to the reference medium regardless of the time of measurement, cf. 5a . Then, from the representative speed dependency I _Rm (v) of the luminescence intensity, the representative speed dependency K _R (v) of the correction factor (valid for all measurement times) is determined, e.g. using the formula K(v)=K _R (v) =S/I _R m(v)= 2*S/(I _t1 (v) + I _t2 (v)) with S as scaling factor. The representative speed dependency K _R (v) of the correction factor is then stored in the sensor and the sensor is set up in such a way that the representative speed dependency K _R (v) is used in the speed correction for all discrete measurement times T1, T2 of the document of value.

As an alternative to the calculation using I _R m(v), the speed dependency K _t1 (v), K _t2 (v) of the correction factor could also be determined first for the individual measurement times t1, t2 and only these could be averaged: $${\text{K}}_{\text{R}}\left(\text{v}\right)=\left({\text{K}}_{\text{t1}}\left(\text{v}\right),+{\text{K}}_{\text{t2}}\left(\text{v}\right)\right)/2.$$

The luminescence intensities I _T1 (vP), I _T2 (vP), which the respective sensor measures from a document of value at its measurement times T1, T2, are then corrected using the same correction factor K _R (vP) applicable to the test transport speed vP, eg I _T1 *(vP)=I _T1 (vP)·K _R (vP), I _T2 *(vP)=I _T2 (vP)·K _R (vP). The respective document of value can be checked on the basis of the luminescence intensities I _T1 *(vP), I _T2 *(vP) corrected in this way in a manner analogous to the third exemplary embodiment.

Claims (15)

Method for providing a speed correction of at least one luminescence index (L, I, t, I _T1 , I _T2 ) of a value document to be checked in a sensor (25) which is set up to measure at least one luminescence intensity of the value document, while the respective value document is transported past the sensor, and which is set up to determine at least one luminescence index (L, I, t, I _T1 , I _T2 ) of the respective document of value based on the measured at least one luminescence intensity and to check the luminescence of the respective document of value, with the Steps: a) Determination of a first speed dependency (L+(v), I+(v), t+(v), I _t1 +(v), I _t2 +(v)) of the luminescence index (L, I, t, I _t1 , I _t2 ) of a reference medium that can be stimulated to emit luminescence, which corresponds to the luminescence index of the document of value, with the aid of a reference sensor assigned to the sensor for a first transport direction (+x) of the reference medium rel ative to the reference sensor, and b) determining a second speed dependency (L-(v), I-(v), t-(v), I _t1 -(v), I _t2 -(v)) of the luminescence index ( L, I, t, In, I _t2 ) of the reference medium, which corresponds to the luminescence index of the document of value, using the reference sensor for a second transport direction (-x) of the reference medium, which is opposite to the first transport direction, relative to the reference sensor, and c) averaging the first speed dependency (L+(v), I+(v), t+(v), I _t1 +(v), I _t2 +(v)) of the luminescence index of the reference medium and the second speed dependency (L-(v), I-(v), t-(v), ), I _t1 -(v), I _t2 -(v)) of the luminescence index of the reference medium at the respective velocity (v) to obtain an average velocity dependence (Lm(v ), Im(v), tm(v), I _t1 m(v), I _t2 m(v)) of the luminescence index of the reference medium, and d) using the mean velocity dependence of the luminescence index (Lm(v ), Im(v), tm(v ), I _t1 m(v), I _t2 m(v)) of the reference medium to determine a speed dependency of a correction factor (K(v)) used to correct the luminescence index (L, I, t, I _T1 , I _T2 ) of the value document to be checked is suitable, e) storing the speed dependency of the correction factor (K(v)) in the sensor (25), f) providing a speed correction that is used when checking the luminescence of the document of value transported past the sensor (25) at a checking transport speed (vP). can be used to correct the luminescence index (L, I, t, I _T1 , I _T2 ) determined with the sensor for the document of value, in a correction device (21) of the sensor, the correction device for the speed correction of the luminescence index (L , I, t, I _T1 , I _T2 ) of the document of value is set up for this purpose - using the speed dependency of the correction factor (K(v)) stored in the sensor and using information made available to the sensor about the test transport speed (vP) of the Document of value to determine a correction factor (K (vP)), which applies to the test transport speed (vP) of the document of value, and - from the sensor for the document of value ment-specific luminescence index (L, I, t, I _T1 , I _T2 ) using the correction factor (K(vP)) applicable to the test transport speed (vP) of the document of value, in order to obtain a corrected luminescence index (L *(vP), I*(vP), t*(vP), I _T1 *(vP), I _T2 *(vP)) for the document of value, wherein the sensor is designed to use the corrected luminescence index To use examination of the luminescence of the value document. procedure after claim 1 , characterized in that with several sensors of the same sensor series, the same mean speed dependence of the luminescence index (Lm(v), Im(v), tm(v), I _t1 m(v), I _t2 m(v)) of the reference medium for Determination of the respective speed dependency of the correction factor (K(v)) is used, which is used in the respective sensor to correct the luminescence index (L, I, t, _IT1 , _IT2 ) of the document of value to be checked, in particular in several Sensors of the same sensor series the same speed correction is provided or the same speed dependence of the correction factor (K(v) is stored and used to correct the luminescence index (L, I, t, _IT1 , _IT2 ) determined for the value document with the respective sensor. Method according to one of the preceding claims, characterized in that the luminescence index (L) of the reference medium or the document of value, which is determined for the reference medium or for the document of value to be checked for the respective transport speed and direction, in each case based on Luminescence intensities measured at different measurement times is determined by the reference sensor on the reference medium or by the sensor on the document of value to be checked. Method according to one of the preceding claims, characterized in that the luminescence index (L) of the reference medium or of the document of value to be checked is a combined luminescence intensity of the reference medium or of the document of value to be checked, in particular one over different measurement times of the reference sensor or of the sensor integrated or averaged luminescence intensity (I) of the reference medium or of the document of value to be checked. Method according to one of the preceding claims, characterized in that the luminescence index (L) of the reference medium or of the document of value to be checked is a luminescence time constant (t) of the luminescence of the reference medium or of the document of value to be checked, in particular the build-up time or the decay time of the respective luminescence. Method according to one of the preceding claims, characterized in that the luminescence index (L) of the reference medium or of the document of value to be checked is a ratio of two of the measured luminescence intensities of the reference medium or of the document of value to be checked, in particular the ratio of the luminescence intensities of two different measurement times or the ratio of the luminescence intensities of two different time intervals or the ratio of the luminescence intensities measured in two different spectral channels of the reference medium or of the document of value to be checked. Method according to one of the preceding claims, characterized in that the luminescence index (L) of the reference medium or of the value document to be checked is one at a discrete measurement time (t1, t2 or T1, T2) from the reference sensor on the reference medium (I _t1 , I _t2 ) or luminescence intensity (I _T1 , I _T2 ) measured by the sensor on the document of value. Method according to one of the preceding claims, characterized in that the method is carried out for a plurality of different discrete measurement times (t1, t2 or T1, T2), wherein for the different discrete measurement times the luminescence index (L) at the respective measurement time of the reference sensor on the reference medium measured luminescence intensity (I _t1 , I _t2 ) or at the respective measurement time by the sensor on the value documentation ment measured luminescence intensity (I _T1 , I _T2 ) is used. Method according to one of the preceding claims, characterized in that for the different discrete measurement times (t1, t2) in each case - the first and the second speed dependency (I _t1 +(v), I _t1 -(v) or I _t2 +(v ), I _t2 -(v)) of the luminescence intensity measured at the respective discrete measurement time (t1, t2) by the reference sensor on the reference medium for the respective discrete measurement time (t1, t2), and - by averaging these first and second Speed dependency (I _t1 +(v), I _t1 -(v) or I _t2 +(v), I _t2 -(v)) the respective average speed dependency (I _t1 m(v), I _t2 m(v)) of the respective luminescence intensity for the respective discrete measurement time (t1, t2) is determined, and - for the respective discrete measurement time (t1, t2) the respective mean speed dependency (I _t1 m(v), I _t2 m(v)) of the respective luminescence intensity of the reference medium to determine a measurement time-specific G speed dependency (K _t1 (v), K _t2 (v)) of a correction factor that applies to the respective measurement time is used, which is stored in the sensor and is assigned there to the respective discrete measurement time (t1, t2), and - that the correction device for the speed correction of luminescence intensities (I _T1 (vP), I _T2 (vP)) of the respective document of value, which the sensor measures on the document of value at corresponding measurement times (T1, T2), is set up for this purpose - for each of the at the corresponding measurement times ( T1, T2) luminescence intensities (I _T1 (vP), I _T2 (vP)) measured by the sensor on the document of value, each based on the measurement time-specific speed dependency (K _t1 (v), K _t2 (v)) of the correction factor stored in the sensor and by means the information made available to the sensor about the test transport speed (vP) of the document of value, a correction factor (K _T1 (vP), K _T2 (vP)) that is specific to the measurement time, e.g determine u, which applies to the respective corresponding measurement time (T1, T2) of the value document and to the test transport speed (vP) of the value document, and - the luminescence intensity (I _T1 (vP), I _T2 measured on the value document at the corresponding measurement time (vP)) using the measurement time-specific correction factor (K _T1 (vP), K _T2 (vP)) applicable to the respective measurement time (T1, T2) and for the test transport speed (vP) of the document of value, in order to correct a corrected To determine the luminescence intensity (I _T1 *(vP), I _T2 *(vP)) for the respective corresponding measurement time (T1, T2) of the document of value, the sensor being designed to detect the corrected luminescence intensities (I _T1 *(vP), I _T2 *(vP)), which were determined for the corresponding measurement times (T1, T2), to use to check the luminescence of the respective document of value. Method according to one of the preceding claims, characterized in that the luminescence intensity measured at the respective measurement time by the reference sensor on the reference medium or by the sensor on the value document is used as the luminescence index for several different discrete measurement times, wherein - for the different discrete measurement times (t1, t2) the first and the second speed dependency (I _t1 +(v), I _t1 -(v) or I _t2 +(v), I _t2 -(v)) at the respective discrete measurement time (t1, t2) measured luminescence intensity is determined by the reference sensor on the reference medium for the respective discrete measurement time (t1, t2), and - for the different discrete measurement times (t1, t2) in each case by averaging this first and second speed dependency (I _t1 + (v), I _t1 -(v) or I _t2 +(v), I _t2 -(v)) the respective mean velocity dependence (I _t1 m(v), I _t2 m(v)) of the respective luminescence intensity is determined for the respective discrete measurement time, and - on the basis of the mean speed dependencies (I _t1 m(v), I _t2 m(v)) of the respective luminescence intensity, which were determined for the different discrete measurement times (t1, t2), by averaging over the various discrete measurement times, a representative speed dependency (K _R (v)) of the correction factor is determined, which applies independently of the measurement time, - that the correction device for the speed correction of luminescence intensities (I _T1 (vP), I _T2 (vP)) of the respective document of value, which the sensor measures on the document of value at a plurality of measurement times (T1, T2), is set up for this purpose, - for each of the luminescence intensities (I _T1 (vP)) measured by the sensor on the document of value at the measurement times (T1, T2), I _T2 (vP)) based on the representative speed dependency (K _R (v)) of the correction factor stored in the sensor and using the S ensor information about the test transport speed (vP) of the document of value to determine a representative correction factor (K _R (vP)) which is used for the measurement time (T1, T2) of the document of value and for the test transport speed (vP) of the value document applies, and - the luminescence intensity measured on the value document at the respective measurement time (I _T1 (vP), I _T2 (vP)) using the representative correction factor (K _R (vP) applicable to the test transport speed (vP) of the value document ) to correct a corrected luminescence intensity (I _T1 *(vP), I _T2 *(vP)) for the respective measurement time (T1, T2) of the document of value, the sensor being designed to determine the corrected luminescence intensities (I _T1 *(vP), I _T2 *(vP)), which were determined for the measurement times (T1, T2) of the document of value, for checking the luminescence of the respective document of value. Procedure according to one of Claims 8 until 10 , characterized in that the sensor is set up to check the document of value using the corrected luminescence intensities (I _T1 *(vP), I _T2 *(vP)), which were determined for the respective measurement times (T1, T2) of the document of value, to determine a time constant (τ) of the luminescence of the value document and to check the value document on the basis of the time constant (τ). Sensor (25) for checking documents of value (3) which are transported past the sensor in a transport direction (x) at a checking transport speed (vP) for checking them, the sensor - at least one excitation light source (23, 24) for exciting a luminescence of the respective document of value (3), and - has at least one photodetector (20) for detecting the luminescence of the document of value excited by the excitation light source, - for measuring at least one luminescence intensity of the document of value while the document of value is being transported past the sensor is set up by means of the at least one photodetector, and - has an evaluation device (22) which is designed to determine a luminescence index (L, I, t, I _T1 , I _T2 ) of the respective value document based on the test transport speed ( vP) to determine at least one measured luminescence intensity of the document of value, and - a correction device (21) a ufweis, in which a speed correction to correct the determined with the sensor for the document of value luminescence number (L, I, t, _IT1 , _IT2 IT), in particular according to one of Claims 1 - 11 , is provided, which when checking the luminescence of a document of value transported past the sensor (25) at a checking transport speed (vP) to correct the luminescence code number (L, I, t, 1 _T1 , I _T2 ) can be used, and wherein a speed dependency of a correction factor (K(v)) is stored in the sensor, which is used to correct the luminescence index (L, I, t, I _T1 , I _T2 ) of the document of value to be checked is suitable, and wherein the correction device (21) for the speed correction of the luminescence index (L, I, t, I _T1 , I _T2 ) of the document of value transported past the sensor at a test transport speed (vP) is set up to - a correction f to determine the actuator (K(vP)), which applies to the test transport speed (vP) of the document of value, and the luminescence code number (L, I, t, _IT1 , _IT2 ) determined by the sensor for the document of value Using the correction factor (K(vP)) applicable to the test transport speed (vP) of the document of value, in order to obtain a corrected luminescence index (L*(vP), I*(vP), t*(vP), I _T1 *(vP), I _T2 *(vP)) for the value document, and wherein the sensor is designed to use the corrected luminescence index to check the luminescence of the value document. sensor after claim 12 , characterized in that the luminescence index of the reference medium or of the document of value to be checked - is a combined luminescence intensity of the reference medium or of the document of value to be checked, or - a luminescence time constant of the reference medium or of the document of value to be checked, or - a ratio of the luminescence intensities of two different measurement times of the reference medium or of the document of value to be checked or the ratio of the luminescence intensities of the reference medium or of the document of value to be checked measured in two different spectral channels, or - one at a discrete measurement time luminescence intensity measured by the reference sensor on the reference medium or by the sensor on the document of value, or that for a number of different discrete measurement times each as a luminescence characteristic number at the respective measurement time of the reference sensor on the reference medium or the luminescence intensity measured by the sensor on the document of value is used. Device (1) for processing documents of value with - a sensor (25) according to one of Claims 12 until 13 , and - a transport device (10) for transporting the respective document of value (3) to be checked past the sensor (25) along a transport direction (x) at a checking transport speed (vP). Method for checking documents of value by the sensor according to one of Claims 12 until 13 , wherein the following steps are carried out: A) a document of value to be checked is transported past the sensor (25) along a transport direction (x) at a test transport speed (vP) and measurement of at least one luminescence intensity of the document of value by means of the sensor while it is being transported past, B) Providing information about the test transport speed (vP) of the document of value in the sensor (25), C) determining a correction factor (K(vP)), which applies to the test transport speed (vP) of the document of value, based on the Speed dependency of the correction factor (K(v)) stored in the sensor and using the information made available to the sensor about the test transport speed (vP), D) determining at least one luminescence index (L, I, t, _IT1 , _IT2 ) of the document of value at the test transport speed (vP) based on the at least one luminescence measured at the test transport speed (vP). intensity of the document of value, E) correcting the luminescence index (L, I, t, I _T1 , I _T2 ) of the document of value using the correction factor (K(vP)) applicable to the test transport speed (vP) of the document of value by one to determine the corrected luminescence index (L*(vP), I*(vP), t*(vP), I _T1 *(vP), I _T2 *(vP)) for the document of value, F) using the corrected luminescence Code for checking the value document.

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