EP4295333A1

EP4295333A1 - Sensor for verifying the luminescence of value documents

Info

Publication number: EP4295333A1
Application number: EP22709947.0A
Authority: EP
Inventors: Wolfgang Deckenbach; Werner Heimann; Johann Wagner
Original assignee: Giesecke and Devrient Currency Technology GmbH
Current assignee: Giesecke and Devrient Currency Technology GmbH
Priority date: 2021-02-16
Filing date: 2022-02-15
Publication date: 2023-12-27
Anticipated expiration: 2042-02-15
Also published as: US20240233468A9; WO2022174979A1; US20240135768A1; EP4295333B1

Abstract

The invention relates to a sensor for verifying value documents, said sensor being designed to determine a luminescence characteristic of a value document that is moved past the sensor for verification purposes, and the provision of a velocity correction of the luminescence characteristic of the value document in the sensor. The relative movement between the value document and the sensor causes movement effects, resulting in a distortion of the measured luminescence intensities. A reference sensor is used to determine an average velocity dependency of the luminescence characteristic of a reference medium, said average velocity dependency being averaged over both opposite directions of movement and being used to determine a velocity dependency of a corrective factor for the luminescence characteristic. Said determined velocity dependency is used to determine the corrective factor for the luminescence characteristic, said corrective factor applying to the velocity of the movement of the value document during the verification process, and the luminescence characteristic is then corrected by said corrective factor.

Description

Sensor for checking the luminescence of value documents

The invention relates to a sensor for checking the luminescence of value documents 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, in which one or more different sensors are contained, depending on the properties of the document 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 in the dark phase between the light pulses at different times after the end of the excitation pulse. 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 documents of value.

A disadvantage of the previous value document check is that at 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 developments 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 falsified by movement effects. A luminescence time constant can then be determined directly from the statically detected intensity profile as a function of time. When the documents of value are at rest, 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 value document and the sensor, however, the detected intensity curve is corrupted due to movement effects. With sensors that are used on fast 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 document of value excited to luminescence is partially transported out of the (stationary) detection area during detection, the measured luminescence intensities of the document of value 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 thereof depends on how well the focal point of the illumination area and the focal point 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 value document, which are used for speed correction for all sensors of the same sensor series. It is often sufficient to correct the speed 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 due to geometric tolerances in the position and possibly the angle of the lighting and the detector be returned, in particular special attention to a different offset between the illumination and detection areas 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 inventive 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 for different, nominally identical sensors of the same sensor series is different.

Speed correction of a luminescence index

The sensor according to the invention is set up for testing the luminescence of documents of value that are transported past the sensor along a transport direction at a test transport speed for testing 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 which contains one or more luminescent substances which 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. In particular, a speed dependency of a (non-sensor-specific) correction factor is stored in the sensor, which is suitable for correcting the luminescence index of the document of value to be checked.

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 made to correct the speed with the sensor for the value do- cument specific luminescence index is provided, which can be used when checking the luminescence of a document of value transported past the sensor at a test transport speed to correct the luminescence index determined with the sensor for the document of value. The speed correction is included in the correction facility of the sensor. The correcting device can be a processor. The speed correction can be carried out by software in the correction device.

The speed dependency K(v) of the (non-sensor-individual) correction factor, which is stored in the sensor, is used for the speed correction, in particular a speed dependency K(v) of the correction factor that applies to all sensors (i.e. does not apply to individual sensors) and that preferably applies to all sensors same sensor series applies. The speed dependency of the correction factor assigns a correction factor applicable to the respective transport speed (its absolute value) to various possible transport speeds of the document of value. 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 pairs of discrete values, e.g. a table, or a mathematical function. The speed dependency of the correction factor was/is determined using the mean speed dependency of the luminescence index of a reference medium assigned to the document of value to be checked, as will be explained below.

To correct the luminescence time constant of the value document to be checked with regard to the transport speed, the correction device is set up to calculate 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 to be determined, which applies to the test transport speed of the document of value. 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 the speed dependency of the correction factor does not explicitly indicate a correction factor, two correction factors applicable to different other transport speeds can also be offset against each other to calculate the correction factor, eg 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, for example multiplied or divided. If necessary, the corrected luminescence index can also be corrected by a further correction, for example 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. However, a code derived from one or more corrected luminescence code(s) can also be used to check the respective value document using the corrected luminescence code, e.g. in the case of a speed correction for each measurement time, a characteristic time constant determined from the intensity-time curve corrected for the measurement time .

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 displacement of the excited area of the value document relative to the detection area of the sensor, which occurs equally on all sensors in a sensor series.

The luminescence parameters 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. minescence index can be compared. In the comparison with the specified target value, a narrow acceptance range around the target value can be selected—in contrast to luminescence indicators that are falsified by movement, for which a relatively large acceptance range around the target value must be allowed. This leads to a selective security document check.

The luminescence index of the document of value to be checked can be summed 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 by 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 in the sensor separately from the evaluation device.

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, the multiple transport speeds of a document of value to be checked each having one Correction factor assigned.

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 sensor series as the sensor in which the speed correction is provided. Preferably, the reference sensor is nominally identical (except for manufacturing tolerances) to that specific 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.

The following steps in particular are carried out to determine the speed dependency of the correction factor: 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 b) determining a second Speed dependency L-(v) of the luminescence index of the reference medium corresponding to the luminescence index L of the value document 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 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), of the luminescence index of the reference medium s to be determined, e.g. by calculating an average speed dependence of the luminescence index Lm(v) = (L+(v) + L-(v))/2, and d) using the average speed dependence of the luminescence index Lm(v) des Reference medium for determining a speed dependency of a correction factor K(v), which is suitable for correcting the luminescence index L of the document of value to be checked. 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 parameter Lm(v) or determined using a fit curve F(v) for the mean speed dependency Lm(v). e) storing the speed dependency of the correction factor K(v) in the sensor. 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 the ses is transported past the reference sensor along 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 luminescence emission 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 various transport speeds and transport directions, while the reference medium is measured at the respective transport speed along the respective transport direction is transported past the reference sensor, 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 measured by the reference sensor for the first transport direction of the reference medium, and

- Determination of the second speed dependency of the luminescence index L of the document of value corresponding luminescence index L of the reference medium (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 using the for the second transport direction from the reference sensor measured at least one 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.

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 for the respective transport speed and direction. The measurement time refers to the time of a pulsed luminescence excitation, e.g. at its end.

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 value documents to be checked in the respective value document processing device or the installation position of the sensor in the respective value document processing device takes for the speed correction of the respective luminescence index not to be taken into account. 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 mean speed dependency of the luminescence index applies to all sensors in the same sensor series. 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 dependence of the respective luminescence index of one of these sensors, which is declared as the reference sensor, is therefore representative for all sensors of this sensor series (which are nominally identical to the reference sensor, but de facto slightly different) for determining the speed used depending on the correction factor. 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, i.e. 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) in the respective sensor saved. Alternatively, with different sensors of the same sensor series, the speed dependency of the correction factor K(v) stored in the sensor can be adapted to the individual sensor, e.g. the average speed dependency of the luminescence index can be offset against sensor-specific factors and then used as the speed dependency of the correction factor K(v) im be saved in the sensor.

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 also with the help of a sensor-specific correction factor that applies to the test transport speed of the document of value is corrected 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 one specific intensity value of the value document. In some exemplary embodiments, the luminescence index of the reference medium or of 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 on the basis of luminescence intensities measured at different measurement times by the reference sensor on the Reference medium 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, eg different delay times in relation to the time of the excitation pulse of the pulsed excitation. This means that the luminescence index of the reference medium is determined using luminescence intensities that were measured by the reference sensor at different measurement times on the reference medium, and the luminescence index of the value document is determined using luminescence intensities that are measured by the sensor at different measurement times were measured against the document of value. 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 a luminescence intensity (of the reference medium or of the document of value to be checked) that is integrated or averaged over different measurement times (of the reference sensor or of the sensor). 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 attack or the Luminescence cooldown. 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 from 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 speaking ratio of the luminescence intensities of the value document 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 obtained at a discrete measurement time (measurement time determined in relation to the time of a pulsed luminescence excitation) from the reference sensor on the reference medium or from the sensor on the value document measured 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 measuring 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 (from the reference sensor on the reference medium or from the sensor to the document of value) 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 for different discrete measurement times. intensity of the value document. 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 the equality of the discrete measurement times is not necessary, for example for determining a time constant.

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 various discrete measurement times, with the different discrete measurement times respectively

- 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), b) ) and

- by averaging this first and second speed dependency, the respective mean speed dependency of the respective luminescence intensity for the respective discrete measurement time is determined (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), which is used in the sensor (according to step e)) is stored and is assigned there to the respective discrete measurement time. 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

- to determine a measurement-time-specific correction factor for each of the luminescence intensities measured by the sensor on the document of value at the corresponding measurement times, based on 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 document of value, which applies to the respective 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 and for the test transport speed of the document of value, in order to determine a corrected luminescence intensity for the respective 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 a document of value is checked, several correction factors are then determined based on the information about the test transport speed, which apply to the test transport speed of the value document and to the respective measurement time, using several speed dependencies of the correction factor that are stored in the sensor and are specific to the measurement time. And the luminescence intensity of the value document measured at the respective measurement time is determined with the help of the test transport speed and for the respective measurement corrected by the correction factor applicable at the time, with 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 separate measurement time-specific and transport speed-specific correction factor is stored in the sensor for different measurement times and different transport speeds.

The correction factor for the test transport speed of the value document at the respective measurement time is determined, for example, using a first speed dependency of the first luminescence intensity of the respective measurement time determined prior to the value document test and a second speed dependency of the second luminescence intensity of the respective measurement time determined prior to the value document test , which apply to mutually oppositely directed transport directions of the document of value relative to the sensor.

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

- For the various discrete measurement times, the first and 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), b)) and

- For the various discrete measurement times, in each case by averaging this first and second speed dependency, the respective mean Ge speed dependency of the respective luminescence intensity for the respective time discrete measurement time determined (as average 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 different discrete measurement times er, by averaging over the different discrete measurement times points representative speed dependency of the correction factor is determined, which applies or is used for several or all measuring times, or which applies independently of the measuring time.

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 than the latter.

For example, to determine the representative speed dependency, the average speed dependencies of the respective luminescence intensity, which were determined for the various discrete measurement times, are combined by averaging to form a representative speed dependency of the luminescence intensity, e.g luminescence intensity. 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, you can do this first the speed dependency of the correction factor is determined for several measurement times and these are combined or averaged.

The correction device is used (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 (the discrete measurement times (t1, t2) of the reference medium may or may not comply), set up to

- to determine a representative correction factor 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 , which applies to the measurement times of the value document and to the test transport speed of the value document, 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 value on the value document at the several measurement times measured luminescence intensities are corrected in particular with the aid 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 document of value using the corrected luminescence intensities that are used for the measurement times of the document of value were determined, to determine a time constant of the luminescence of the value document and to check the value document using the time constant.

In a further 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, from to are assigned to documents of value to be checked, 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 test transport speed as a function of information made available to the sensor about a target 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 select that speed dependency of the correction factor from these speed dependencies as a function of information made available to the sensor about a target value of the luminescence index, e.g. the luminescence time constant, of the value document to be checked, in whose range of values lies within this target value, and to use this to determine the correction factor applicable to the test 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 valuable documents, 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 checking transport speed. For example, the device is a sorting device for documents of value.

The device can have a device which 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 set on the device for the documents of value. 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.

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: 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,

B) Providing information about the test transport speed of the document of value in the sensor, e.g. determining, possibly transmitting and storing the information in the sensor,

C) Determining a correction factor that is used for the test

Transport speed of the document of value applies, based on the speed dependency of the correction factor stored in the sensor and using the information made available to the sensor about the test transport speed,

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,

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,

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.

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 during the transport past in step A), the luminescence intensity I of the document of value is measured at different measurement times TI, T2,...

- In step D) several intensity indicators In (vP), In (vP), ... the luminescence of the document of value at the test transport speed vP an- determined using the luminescence intensities of the document of value measured at the various measurement times, with the luminescence intensity measured at the respective measurement time being determined as the respective intensity index of the respective measurement time (e.g. the first luminescence index is the luminescence intensity ITI( measured at a first measurement time TI VP), the second luminescence index is the luminescence intensity IT2(VP), ... measured at a second measurement time point T2, and

- in step F) the document of value is checked using the corrected luminescence indexes, i.e. using the corrected luminescence intensities In*(vP), Ix2*(vP), . . . , of the document of value. To check the document of value in step F), the corrected luminescence intensities In*(vP), IT2*(VP), . . . a corrected luminescence time constant t (e.g. decay or build-up time) is determined from the various measurement times TI, T2, ... (or from the time profile of the corrected luminescence intensities In*(vP), IT2*(VP), ...). , which is characteristic of the time profile of the corrected luminescence intensity of the document of value, and the document of value is checked using the corrected luminescence time constant t.

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

The invention will be explained by way of example using the following figures. Show it:

FIG. 1 shows a schematic structure of a value-document processing device with the sensor;

FIG. 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), FIG. 2b temporal progression of the luminescence intensity of the document of value at a test transport speed vP in comparison to the static case (v=0),

Figure 3a-c Velocity dependency of the luminescence index "integrated luminescence intensity" of a reference medium for the two transport directions and determined mean velocity dependency of the integrated luminescence intensity, each for a first sensor (Im(v), Fig. 3a) and for a second Sensor (I'm(v), Fig. 3b) and speed dependency K(v) of the correction factor calculated from Im(v) or Fm(v) (Fig. 3c),

Figure 4a-c Speed dependency of the luminescence index "time constant" t of a reference medium for the two transport directions and mean speed dependency of the time constant determined from this for a first sensor (tm(v), Fig. 4a) and for a second sensor (t' m(v), Fig. 4b) and speed dependence K(v) of the correction factor determined from tm(v) or t'm(v) (Fig. 4c),

Figure 5a Speed dependency of the luminescence parameters "Lu minescence intensity at time t1" and "Luminescence intensity at time t2" of a reference medium for the two transport directions and average speed dependencies of the luminescence intensity Lim(v) and I _t 2m(v) calculated from them, as well as representative ones Velocity dependency i _R m(v),

Figure 5b Speed dependencies K _ti (v) or K _t 2(v) of the mean speed dependency I _ti m(v) or

I _t 2m(v) correction factor determined for the luminescence intensity at time tl and for the luminescence intensity at time t2 and representative speed dependency KR(V) of the correction factor, 5c correction of the time profile of the luminescence intensity of the document of value for a test transport speed v=vP at the time of measurement.

Fig. 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 made available, and a separator 8, from which one value (e.g. the respective bottom or top) value is output one after the other document of the input stack is recorded and transferred to a transport device 10 (conveyor belts and/or transport rollers), which transports the documents of value in the transport direction +x past a sensor 25 - shown only schematically in the selected representation.

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

In the example shown, the sensor 25 comprises a photodetector 20 which has at least one photosensitive element which converts the luminescence intensities emitted by the document of value transported past 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 used to check the documents of value 3 in one or more measurement tracks can be formed 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 Sen sor 25 is - viewed in the transport direction x of the documents of value - arranged on the left side of the transport path. 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. In the memory area 26 further information can be stored, 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.

The evaluation device 22 determines from the intensity value(s) of the luminescence of the documents of value detected by the photodetector 20 at the measurement time(s), e.g. 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 another, 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, in a first output fold 30 documents of value are stored, which were recognized as genuine, while value documents classified as fake or suspected forgery are stored in a second output compartment 31 . At the end of the transport route shown (reference number 13), additional output compartments and/or other facilities can be provided, for example for storing or destroying valuable documents, 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 documents of value of this type 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 to the value documents processed in each case.

FIGS. 2a and 2b show the time behavior of the luminescence of a document of value, which is emitted by a luminescent security feature of the document of value. FIG. 2a shows the intensity profile of the optical excitation pulse A, which is directed at 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. FIG. 2b shows the intensity profile detected in a static measurement as a function of time after the end (t=0) of 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 value documents. In the static measurement, the detected luminescence intensity of the security feature decays with the specified luminescence time constant tO 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 tO.

If the same document of value 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 intensity profile denoted by v=vP in Figure 2b 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, the intensity curve detected in the static case with the decay time t0 is also shown in broken lines in FIG. 2b. 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 tO 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 value document thus moves relative to the detector during the measurement, and the measured intensity curve 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 dependency 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 reference sensor on the reference medium determines the speed dependency of that luminescence index L, 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 vl, 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. Then the reference medium 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 was measured by means of the reference sensor while the reference medium was being transported along at the respective transport speed is transported past the reference sensor in the second transport direction. The luminescence intensity is measured at one or more discrete measurement times, e.g. to determine the change in luminescence over time for each transport speed and direction, or measured integrated over a time interval, e.g. to determine the speed and direction for each transport speed and direction to determine the time-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 number 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 points at the several discrete measurement times Value document measured 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 the speed dependency is determined from this of the correction factor K(v) is determined. This speed dependency of the correction factor K(v) is individual sensors to which the reference sensor is assigned are stored. Then the sensors with the speed dependency of the correction factor K(v) stored therein are used to check value documents 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 determined by averaging the first speed dependency of the luminescence index applicable to the first transport direction and that applicable to the opposite second transport direction second Ge speed dependency 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 scaling factor. Alternatively, the mean 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 analogously multiplied by a factor offset (multiplied or divided) who can.

exemplary embodiments

In the first and second exemplary embodiment, the measured intensities of the luminescence of the document of value, for example from a measured intensity Time curve, a luminescence index L derived and then corrected in the manner of the invention. The thereby corrected luminescence index L is, for example, 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 an intensity measured over several measurement times -Time curve averaged intensity or its 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.

At different transport speeds v1, v2, v3 along the first transport direction (+x), a first one is respectively integrated with the reference sensor Luminescence intensity I+(v1), I+(v2), I+(v3) of the reference medium measured, see Fig. 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. 3a shows 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 average speed dependency Im(v) of the integrated luminescence intensity determined therefrom shown. The mean speed 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 using 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. The speed dependencies T+(v), T-(v) shown in FIG. 3b of the integrated luminescence intensity of the reference medium for the two transport directions (+x, -x) and the average speed dependency Tm( v) the integrated luminescence intensity.

As the comparison of FIG. 3b with FIG. 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 nominal structural identity--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 Tm(v) averaged over the two transport directions +x, -x are substantially identical (continuous curves in Fig. 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 this.

The speed dependency K(v) of the correction factor that can be used for the integrated luminescence intensity is then determined from the mean 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 the value document, see Fig 3c.

For example, the mean speed dependency K(v) of the correction factor is determined using the formula

K(v) =S/Im(v)= 2-S/ (I+(v) + I-(v)), with S as the scaling factor, i.e. the reciprocal of the average integrated luminescence intensity Im(v) determines the respective correction factor . For example, the intensity I0=lm(v=0) of the reference medium is used as the scaling factor S in a static measurement using the reference sensor. 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:

I*(nR)=I(nR) K(nR). (1)

Alternatively, the mean speed dependency K(v) of the correction factor can be determined using the formula

K(v) = Im(v)/S = (I+(v) + I-(v))/ 2-S with S as scaling factor, ie directly the (possibly scaled) integrated intensity Im(v) determines the correction factor K(v), see Fig. 3c. The intensity I0=lm(v=0) of the reference medium is used as the scaling factor S for a static Measurement using the reference sensor used. The speed correction in the respective sensor is then 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:

I*(vP)=I(vP)/K(vP) (2)

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, value documents are checked with the sensor in a value document processing device 1 . To check the documents of value, they are transported past the sensor at a checking transport speed vP. To correct the speed of the luminescence time constant, the correction device 21 uses information about the test transport speed vP of the documents of value to be tested, which is transmitted to the sensor 25 by the control device 50 of the document-of-value 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 and assigned to the check transport speed of the value document vP, see FIG.

If there is no explicit correction factor K(vP) in the sensor for the test transport speed vP of the respective value document processing device 1 is stored, it is possible, for example, to find out which of the stored transport speeds deviates the least from the test transport speed vP of the documents of value. The correction factor K(vP) assigned to this transport speed is then used to correct the integrated luminescence intensity. This can be done with the proviso that the speed deviation is below a certain threshold, eg <10%.

However, if the test transport speed vP of the documents of value deviates more than acceptable from all transport speeds vl, v2, v3, ... stored in the sensor, at least two transport speeds vl, v2 are selected from the transport speeds stored in the sensor, e.g. the least of the test transport speed vP and the two correction factors K(v1), K(v2) assigned to them. 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). To check the authenticity of the document of value, the intensity I*(vP) which has been corrected and integrated in this way is compared with a reference value, for example, 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, for example 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 luminescence 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 a maximum of 50%, preferably by a maximum of 30%, in order to achieve a speed correction that is as accurate as possible. For example, the luminescence time constant of the value documents 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 ps is used for document of value luminescent substances with a time constant between 60 ps and 160 ps for the reference medium, and a reference luminescent substance with a time constant of between 160 ps and 350 ps for document of value luminescent substances with a time constant of 250 ps, and for value document luminescent substances with a time constant between 350 ps and 5 ms a reference luminescent substance with a time constant of 900 ps is used. Alternatively, a reference luminescent substance with a time constant of 250 ps can also be used for value document luminescent substances with a time constant between 100 ps 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, ie the reference luminescent substance and the value document luminescent substance are the same. Analogously to the first exemplary embodiment, a first luminescence time constant t+(vl), t+(v2), t+(v3) of the reference medium is measured with the reference sensor at the different transport speeds vl, v2, v3 along the first transport direction (+x) and a second luminescence time constant t-(v1), t-(v2), t-(v3) of the reference medium was measured along the opposite, second transport direction (−x), see FIG. 4a. 4a shows the speed dependencies t+(v), t-(v) of the luminescence time constant t of the reference medium for the two transport directions (+x, -x) and the mean speed dependency tm(v) of the luminescence determined therefrom - Time constant shown. The average velocity dependence of the luminescence time constant is calculated using the formula tm(v)=(t+(v)+t-(v))/2, for example.

The speed dependencies t′+(v), t′-(v) of the luminescence time constant of the reference medium for the two transport directions (+x, −x) and the resulting ones result for the above-mentioned nominally identical value document sensor in FIG. 4b determined mean velocity dependence t'm(v) of the luminescence time constant of the reference medium.

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 FIGS. 4a and 4b). The average speed dependence of the luminescence time constant tm(v), which was determined using the reference sensor, is therefore used as a representative value for the value document sensors that are nominally identical in construction. From the mean speed dependency of the luminescence time constant tm(v), which was determined using the reference sensor, the speed dependency K(v) of the correction factor that can be used for the luminescence time constant is then determined and stored in the respective sensor provided for value document testing., see figure 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, see Fig. 4c. If the speed dependency of the correction factor K(v) is only stored in the sensor in the form of discrete values K(vl), K(v2), ..., the correction factor K(vP) applicable to the test transport speed vP of the value document can can also 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)), becomes - analogously to the above formula (1) - a multiplicative correction 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 with a reference value, for example, and the document of value is classified as genuine or as a suspected counterfeit depending on this.

In addition - analogous to the mean speed dependency of the time constant tm(v) - with the reference sensor at at least one other reference ference medium with a different luminescence time constant, at least one further mean speed dependency of the time constant t ^# m(v) can be determined, which applies to documents of value with a different target value of the luminescence time constant. Based on this - in addition to the speed dependency of the correction factor K(v) indicated above - one or more other 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 value documents to be checked apply. During the value document check, 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, ie depending on the luminescence time constant expected for the document of value corrects the measured luminescence time constant either with K(vP) or with K ^# (vP).

3rd embodiment

In the third exemplary embodiment, the intensity-time curve is corrected for each measuring point. For each measurement time tl, t2, ... a separate speed dependency of the correction factor is stored in the sensor, e.g. the speed dependency of the correction factor K _ti (v) for the measurement time tl, the speed dependency of the correction factor K _t 2(v) for the measurement time t2 , ....

To determine the speed dependencies of the correction factor K _ti (v), K _t 2 (v), ... - analogously to the first and second exemplary embodiment - with the reference sensor at different transport speeds vl, v2, v3 of the reference medium along the first transport direction (+ x) in each case a first luminescence intensity In+(vl), I _ti +(v2), In+(v3) of the reference medium for a first measurement time tl after the end of the luminescence excitation and a further The first luminescence intensity I _t 2+(vl), I _t2 +(v2), I _t2 +(v3) of the reference medium is measured for a second measurement time t2 after the end of the luminescence excitation (and the same, if necessary, also for further measurement times t3, t4, ... and/or other transport speeds v4, v5, ...), see Fig. 5a. A second luminescence intensity I _ti -(vl), I _ti -(v2), I _ti -(v3) des Reference medium for the first measurement time tl and another second luminescence intensity I _t 2- (vl), I _t2 -(v2) I _t2 -(v3) of the reference medium for the second measurement time t2 ge (and the same if necessary also for further measurement times t3 , t4, ... and/or further transport speeds v4, v5, ...), cf. Fig. 5a. 5a shows the speed dependencies I _ti +(v), I _ti -(v), I _t 2+(v), I _t 2-(v) of the respectively measured luminescence intensity of the reference medium for the two transport directions ( +x, -x) and for the two measurement times tl, t2 and the mean speed dependence I _ti m(v) and I _t 2m(v) of the luminescence intensity determined therefrom for the two measurement times tl, t2 of the intensity-time -Curve shown.

Then for each measurement time tl, t2, ... a separate speed dependence of the correction factor is determined: the speed dependence of the correction factor K _ti (v) for the measurement time tl, the speed dependence of the correction factor K _t 2(v) for the measurement time t2 ( and the same, if necessary, also for further measurement times t3, t4, ...). These speed dependencies of the correction factor K _ti (v), K _t 2 (v), . . . are then stored in the respective sensor provided for checking documents of value, see FIG.

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

K(vl, tl), K(vl, t2), ... K(v2, tl), K(v2, t2), ...

The speed dependency of the correction factor can also be stored in the form of mathematical functions K _ti (v), K _t 2 (v), ... as a function of the transport speed v for different measurement times tl, t2, ... or in the form of mathematical functions K _vi (t), K _V 2(t), ... as a function of the measurement time t for different transport speeds vl, v2, ..., which are determined, for example, by means of a fit function.

When checking documents of value, the document of value sensor detects the luminescence intensity of the document of value, for example, at such measurement times TI, T2 after the end of the luminescence excitation, which correspond to the discrete measurement times tl, t2 of the reference sensor when measuring the reference medium, for which there is a speed dependency of the correction factor K _ti (v), K _t 2(v) is stored in the sensor. If the measurement times Tl, T2 of the document of value deviate from the measurement times tl, t2 of the reference medium, the corresponding speed dependencies of the correction factor Kn(v), K _T 2(V) can be calculated from the stored K _ti (v), K _t 2(v) extrapolated or interpolated and, if necessary, 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 _ti (v), K _t 2(v) are then simply used as the speed dependencies of the correction factor Kn(v), K _T 2(V). When checking documents of value, the sensor uses the information about the checking transport speed vP to determine the correction factors Kn(vP)=Ku(vP) and KT2(VP)=K _t 2(vP), which are for the measuring times Tl, T2 des Document of value and for the test transport speed vP apply, cf. Fig. 5b. The luminescence intensity ITI(VP) detected from the document of value to be checked at the measurement time T1 corrected with the correction factor Kn(vP), the luminescence intensity IT2(VP) detected at the measurement time T2 is corrected with the correction factor KT2(VP). This results in the corrected intensity values In*(vP)=Iti(nR)*Kti(nR) for the first measurement time TI of the document of value and It _2* (nR)= _IT2 (nR)*Kt ₂ (nR) for the second Measurement time T2 of the document of value, see Fig. 5c.

The luminescence of the document of value can then be checked on the basis of the corrected luminescence intensities In*(vP), It _2* (nR). To check the authenticity of the document of value, the corrected luminescence intensities In*(vP), IT2*(VP) ZB can be set in relation to one another and compared with a reference value, and the document of value can be classified as genuine or suspected of being a fake depending on this.

However, a _corrected intensity-time Curve of the luminescence of the document of value can be determined, which corresponds to a static measurement of the luminescence of the document of value, cf. Fig. 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 x of the corrected luminescence-time curve is determined and compared with a decay time specified for the document of value or with thresholds specified for this, see FIG.

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)=KR(V) is to be corrected—regardless of the measurement time the luminescence index of the document of value is used. The intensity values of the luminescence of the document of value measured at different measurement times are therefore all corrected with the same factor KR(VP).

Starting from the average speed dependencies I _ti m (v) and I _t 2m (v) of the luminescence intensity for the different measurement times tl, t2 (and possibly average speed dependencies for further measurement times - cf. third embodiment), by averaging over the various discrete measurement times, a representative speed dependency KR(V) of the correction factor, which applies to all measurement times.

For example, the average speed dependencies I _ti m(v), I t 2m(v), I _t 2m(v),

_. Then the representative speed dependency KR(V) of the correction factor (valid for all measurement times) is determined from the representative speed dependency i _R m(v) of the luminescence intensity, for example using the formula K(V)=KR(V) =S/ l _R m(v)= 2-S/ (I _ti (v) + I _t 2(v)) with S as the scaling factor. The representative speed dependency KR(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 KR(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 via km(v), the speed dependency K _ti (v), K _t 2(v) des Correction factors are determined and only these are averaged: K _R (v)=(K _ti (v), +K _t2 (v))/2.

The luminescence intensities ITI(VP), Ii ₂ (vP), which the respective sensor measures from a document of value at its measurement times TI, T2, are then corrected using the same correction factor KR(VP) applicable to the test transport speed vP, e.g. ITI *(VP)=ITI(VP)-KR(VP), IT2*(VP)=IT ₂ (VP)-KR(VP). The respective document of value can be checked on the basis of the luminescence intensities ITI*(VP), Ii2*(vP) corrected in this way in a manner analogous to the third exemplary embodiment.

Claims

P a te nt claims

1. A method for providing a speed correction of at least one luminescence index (L, I, t, In, hz) 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, In, Lz) 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) determining a first speed dependency (L+(v), I+(v), t+(v), I _ti +(v), I _t 2+(v)) of the luminescence index (L, I, t, Iu, L2) 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 relative to the R reference sensor, and b) determining a second speed dependency (L-(v), I-(v), t-(v), Li-(v), I _t 2-(v)) of the luminescence index (L, I , t, Iu, L2) 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, 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 _ti +(v), I _t 2+(v)) of the luminescence index of the reference medium and the second velocity dependence (L-(v), I -(v), t-(v)„ I _ti -(v), I _t 2-(v)) 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 _ti m(v), I _t 2m(v)) of the luminescence index of the reference medium, and d) using the average velocity dependence of the luminescence index (Lm(v) , Im(v), tm(v), I _ti m(v), I _t 2m(v)) of the reference medium for determining a speed dependency of a correction factor (K(v)) which is suitable for correcting the luminescence index (L, I, t, In, fc) of the value document to be checked, e) storing the speed dependency of the correction factor (K(v) ) in the sensor (25), f) providing a speed correction which, when checking the luminescence of the value document transported past the sensor (25) at a checking transport speed (vP), to correct the luminescence determined with the sensor for the value document code (L, I, t, In, Lz) can be used in a correction device (21) of the sensor, the correction device being used for the speed correction of the luminescence code (L, I, t, In, IT2) of the document of value is set up to

- 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 is used for the test - Transport speed (vP) of the value document applies, and

- to correct the luminescence code number (L, I, t, ITI, K2) 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 correct a To determine the luminescence index (L*(vP), I*(vP), t*(vP), ITI*(VP), IT2*(VP)) for the document of value, the sensor being designed to detect the corrected luminescence -Key number to use for examining the luminescence of the value document.

2. The method according to claim 1, characterized in that in the case of several sensors of the same sensor series, the same mean speed dependency of the luminescence index (Lm(v), Im(v), tm(v), In m(v), I _t 2m( v)) of the reference medium for determining the respective speed dependency of the correction factor (K(v)) is used, which is used for the respective sensor for the correction structure of the luminescence index (L, I, t, In, I ₁₂ ) of the value document to be checked is used, with the same speed correction being provided in particular in several sensors of the same sensor series or the same speed dependence of the correction factor (K(v)) being stored and is used to correct the luminescence index (L, I, t, In, Lz) determined with the respective sensor for the document of value.

3. The method according to any 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 by the reference sensor on the reference medium or by the sen sor on the document of value to be checked.

4. The method according to any 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 the sensor integrated or averaged luminescence intensity (I) of the reference medium or of the document of value to be checked.

5. The method according to any 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 The reference medium or the document of value to be checked is, in particular, the build-up time or the decay time of the respective luminescence.

6. The method according to any 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 from two different measurement times or the ratio of the luminescence intensities from two different time intervals or the ratio of the luminescence intensities of the reference medium or the value document to be checked measured in two different spectral channels.

7. The method according to any one of the preceding claims, characterized in that the luminescence index (L) of the reference medium or the value document to be checked at a discrete measurement time (tl, t2 or TI, T2) from the reference sensor on the Reference medium (In, L2) or luminescence intensity (In, I12) measured by the sensor on the value document.

8. The method as claimed in one of the preceding claims, characterized in that the method is carried out for a number of different discrete measurement times (t1, t2 or Tl, T2), with the luminescence index (L) being used for each of the different discrete measurement times Luminescence intensity (Iu, L2) measured by the reference sensor on the reference medium at the respective measurement time or luminescence intensity (In, Lz) measured by the sensor on the document of value at the respective measurement time is used.

9. The method according to any one of the preceding claims, characterized in that for the different discrete measurement times (tl, t2) respectively

- the first and the second speed dependency (Iu+(v), I _ti -(v) or I _t 2+(v), I _t 2-(v)) of the luminescence intensity measured at the respective discrete measuring time (t1, t2). is determined by the reference sensor on the reference medium for the respective discrete measurement time (t1, t2), and - By averaging this first and second speed dependency (I _ti +(v), I _ti -(v) or I _t 2+(v), I _t 2-(v)), the respective mean speed dependency (I _ti m(v), I _t 2m(v)) of the respective luminescence intensity for the respective discrete measurement time (t1, t2) is determined, and

- For the respective discrete measurement time (tl, t2), the respective mean speed dependency (I _ti m(v), I _t 2m(v)) of the respective luminescence intensity of the reference medium to determine a measurement time-specific speed dependency (K _ti (v), K _t 2(v)) a correction factor applicable 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 (In(vP), IT2(VP)) of the respective document of value, which the sensor measures at corresponding measuring times (T1, T2) on the document of value, is set up for this purpose,

- for each of the luminescence intensities (In(vP), I _T2 (vP)) measured by the sensor on the document of value at the corresponding measurement times (Tl, T2) based on the speed dependency (K _ti (v), K _t 2(v)) of the correction factor and using the information made available to the sensor about the test transport speed (vP) of the document of value, to determine a measurement-time-individual correction factor (Kn(vP), KT2(VP)) for the respective ligen corresponding measurement time (Tl, T2) of the document of value and for the test transport speed (vP) of the document of value applies, and

- the luminescence intensity (ITI(VP), IT2(VP)) measured on the value document at the corresponding measurement time using the measurement time applicable to the respective corresponding measurement time (Tl, T2) and to the test transport speed (vP) of the value document individual correction factor (Kn(vP), KT2(VP)) TO correct in order to obtain a corrected luminescence intensity (ITI*(VP), IT2*(VP)) for the respective corresponding to determine the corresponding measurement time (TI, T2) of the document of value, the sensor being designed to determine the corrected luminescence intensities (ITI*(VP), IT2*(VP)) that were determined for the corresponding measurement times (TI, T2), to use to check the luminescence of the respective document of value.

10. The method according to any 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 document of value is used as the luminescence index for several different discrete measurement times, whereby

- For the various discrete measurement times (tl, t2), the first and the second speed dependency (Iu+(v), I _ti -(v) or I _t 2+(v), I _t 2-(v)) of the to the luminescence intensity measured at the respective discrete measurement time (t1, t2) is determined by the reference sensor on the reference medium for the respective discrete measurement time (t1, t2), and

- For the various discrete measurement times (tl, t2) by averaging this first and second speed dependency (In+(v), Li-(v) or I _t 2+(v), I _t 2-(v)) the respective average velocity dependence (In m(v), I _t 2m(v)) of the respective luminescence intensity for the respective discrete measurement time is determined, and

- based on the mean speed dependencies (In m(v), I _t 2m(v)) of the respective luminescence intensity, which were determined for the various discrete measurement times (tl, t2), a representative speed dependency by averaging over the various discrete measurement times (KR(V)) of the correction factor is determined, which applies regardless of the time of measurement,

- that the correction device for the speed correction of luminescence intensities (In (vP), I _T 2 (VP)) of the respective document of value, which the sensor measures at several measuring times (T1, T2) on the document of value, since it is set up, - for each of the luminescence intensities (In (vP), I _T 2 (VP)) measured by the sensor on the document of value at the measurement times (TI, T2) based on the representative speed dependence (KR(V)) stored in the sensor of the correction factor and by means of the information provided to the sensor about the test

Transport speed (vP) of the document of value, a representative correction factor (KR(VP)) ZU, which applies to the measurement times (TI, T2) of the document of value and to the test transport speed (vP) of the document of value, and

- Correct the luminescence intensity (In (vP), IT2 (VP)) measured on the value document at the respective measurement time using the representative correction factor (KR(VP)) applicable to the test transport speed (vP) of the value document, in order to corrected luminescence intensity (In*(vP), IT2*(VP)) for the respective measurement time (TI, T2) of the document of value, the sensor being designed to determine the corrected luminescence intensities (In*(vP), IT2*( VP)), which were determined for the measurement times (TI, T2) of the document of value, for checking the luminescence of the respective document of value.

11. The method according to any one of claims 8 to 10, characterized in that the sensor is set up to check the document of value using the corrected luminescence intensities (ITI*(VP), IT2*(VP)) that are available for the respective measurement times (TI , T2) of the document of value were determined, to determine a time constant (x) of the luminescence of the document of value and to check the document of value using the time constant (x).

12. Sensor (25) for checking documents of value (3), which are transported past the sensor for checking them along a transport direction (x) at a checking transport speed (vP), the sensor - Has 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 value document excited by the excitation light source,

- is set up to measure at least one luminescence intensity of the value document while the value document is being transported past the sensor by means of the at least one photodetector, and

- has an evaluation device (22) which is designed to generate a luminescence index (L, I, t, In, I _T 2) of the respective document of value based on the at least one luminescence intensity measured at the test transport speed (vP). to determine value document, and

- has a correction device (21) in which a speed correction for correcting the luminescence index (L, I, t, In, I12) determined with the sensor for the value document, in particular according to one of Claims 1-11, ready 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, In, IT2) can be used, and wherein a speed dependency of a correction factor (K(v)) is stored in the sensor, which is suitable for correcting the luminescence index (L, I, t, ln, I _T 2) of the document of value to be checked, and wherein the correction device (21) is set up for the speed correction of the luminescence index (L, I, t, ln, K2) of the document of value transported past the sensor at a test transport speed (vP),

- 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 is the test transport speed (vP) of the value document applies, and - to correct the luminescence index (L, I, t, hi, I _T 2) 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, to determine a corrected luminescence index (L*(vP), I*(vP), t*(vP), In*(vP), IT2*(VP)) for the document of value, and wherein the sensor is designed for this to use the corrected luminescence index to check the luminescence of the document of value.

13. Sensor according to claim 12, characterized in that the luminescence index of the reference medium or of the value document to be checked

- is a combined luminescence intensity of the reference medium or of the document of value to be checked, or

- is a luminescence time constant of the reference medium or of the document of value to be checked, derived from a time profile of the measured luminescence intensities, or

- is 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

- is a luminescence intensity measured at a discrete measurement point in time by the reference sensor on the reference medium or by the sensor on the document of value, or that for several different discrete measurement points in each case as a luminescence characteristic number at the respective measurement point in time from the reference sensor on the reference medium or from the sensor on the document of value measured luminescence intensity is used.

14 device (1) for processing documents of value with

- a sensor (25) according to any one of claims 12 to 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 check transport speed (vP).

15. A method for checking documents of value using the sensor according to one of claims 12 to 13, the following steps being carried out:

A) Transporting a value document to be checked past the sensor (25) along a transport direction (x) at a checking transport speed (vP) and measuring at least one luminescence intensity of the value document 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, In, Lz) of the value document at the test transport speed (vP) based on the at least one luminescence intensity of the value document measured at the test transport speed (vP),

E) Correcting the luminescence index (L, I, t, In, In) of the value document using the correction factor (K(vP)) applicable to the test transport speed (vP) of the value document, by a corrected luminescence index (L *(vP), I*(vP), t*(vP), In*(vP), IT2*(VP)) for the document of value,

F) Using the corrected luminescence index to check the document of value.