EP2011092B1 - Apparatus and method for optically examining security documents - Google Patents

Description

The invention relates to a device and a method for the optical examination of value documents as well as devices for processing value documents with an examination device according to the invention.

Here, value documents are understood to mean objects which, for example, represent a monetary value or an entitlement and should therefore not be able to be produced arbitrarily by unauthorized persons. They therefore have features which are not easy to manufacture, in particular to be copied, whose presence is an indication of the authenticity, i. the manufacture by an authorized agency. Important examples of such value documents are chip cards, coupons, vouchers, checks and in particular banknotes.

An important class of features of such value documents are optically recognizable features, which include in particular features for which luminescent substances are used which emit luminescence radiation with a characteristic spectrum when irradiated with optical radiation of predetermined wavelength. By optical radiation is meant electromagnetic radiation in the ultraviolet, visible or infrared range of the electromagnetic spectrum.

To verify the authenticity, a value document can be irradiated with suitable optical radiation. It is then checked by means of a suitable sensor device, if the optical radiation at predetermined locations on or in the value document excites luminescence radiation, for which purpose of the document of value output optical radiation is analyzed spectrally.

Such an examination should be carried out as quickly as possible and with little expenditure on equipment; In order to design space-saving devices in which an authenticity check is performed on the basis of luminescence, it is desirable that a device for testing luminescence features is very compact, but still has a sufficient spectral resolution and sensitivity to the presence to be able to recognize the characteristic luminescence spectrum.

Out DE 10 2004 035494 A1 and EP 1158 459 A1 Devices are known according to the preambles of claims 1 and 8, each having an imaging grating as spatially dispersing optical device.

Out WO 01/16870 A1 For example, a document validation method and apparatus are known. The device has a housing with a transparent opening. A broadband light source illuminates a document placed on the aperture. A converging lens and a light guide serve to collect and relay light emanating from the illuminated document. The reflected light is supplied to a diaphragm which is disposed at the focal point of a collimator lens. The collimator lens functions in conjunction with a diffraction grating to provide a range of wavelengths of light to a photosensor device. For authenticity testing, the spectrum in the visible wavelength range is compared with a given spectrum.

The present invention has for its object to provide a device for the optical examination of documents of value, which allows a very compact, space-saving design.

The object is achieved according to a first alternative by an apparatus having the features of claim 1. The apparatus for optical examination of documents of value first comprises a detection area in which the examination is a value document, and a spectrographic device for investigation coming from the detection area optical radiation. The spectrographic device comprises a spatially dispersing optical device for at least partial decomposition of optical radiation coming from the detection range into spectrally separated spectral components propagating in different directions according to the wavelength, a detection device spatially resolving in at least one spatial direction for, in particular spatially resolved, detection of the spectral components, and a collimating and focusing optics for collimating the optical radiation directed from the detection area onto the dispersing device and for focusing at least some of the spectral components formed by the dispersing device on the detection device.

The device according to the invention according to the first alternative uses a spectral decomposition of the optical radiation emanating from the detection area, in particular a value document in the detection area, for investigating a value document in the detection area, which is also referred to below as detection radiation. For this purpose, it has the spatially dispersing device which decomposes incident optical radiation at least partially into spectral components which propagate in spatially different directions depending on the wavelength of the respective spectral component. The dispersing device only needs to be able to work in a wavelength range predetermined as a function of the predetermined value documents. The presence of optical radiation in a specific spatial direction and thus of the corresponding spectral component is detected by means of the spatially resolving detection device whose detection signals can be sent to an evaluation device for at least partial detection of a spectrum of radiation emitted by the detection region and evaluated there. The detection range can be selected in particular so that a predetermined transport device for the Value documents, such as driven belts, can transport value documents to be examined into the detection area.

In particular, the detection device can have a plurality of detection elements for detecting optical radiation impinging thereon to form corresponding detection signals, which are preferably arranged in the form of a line. However, a two-dimensional array of detection elements may also be used.

Accordingly, for optically examining a value document in which optical radiation emanating from the document of value is shaped into a parallel bundle of rays by optics, in particular collimating and focusing optics, the beam is at least partially decomposed into spectral components of different wavelengths, which depend on the Spread wavelength in different directions, at least some of the spectral components are focused by the optics on a detection device, and it is the focused on the detection means spectral components detected.

The device is characterized in particular by the fact that only one optic, the collimating and focusing optics, is used in order to fulfill two tasks, namely the collimation of the optical radiation emitted by the detection area, in particular a value document therein, and the other Focusing the spectrally decomposed components on the detection device.

The proposal of this surprisingly simple structure is based on the observation that for the purpose of testing documents of value, only a moderate spectral resolution is achieved in comparison to scientific spectroscopy sufficient, which can be easily achieved with the proposed means.

The use of only one optics for collimation and focusing further allows at least one simply folded beam path to the optics, which allows a good spectral resolution with only a small space requirement.

Compared with another conceivable solution, namely the use of an imaging grating, it is a further advantage that the dispersing device and the collimating and focusing optics are comparatively simple and therefore easy and inexpensive to produce components.

In addition, only the collimating and focusing optics need to be adjusted, while in designs with separate optics for collimation and focusing, two optics need to be adjusted.

Another advantage of the proposed arrangement is that it is possible to achieve a very high numerical aperture of the beam path between the collimating and focusing optics.

Furthermore, the device is characterized in that the direction of the incident on the collimating and focusing optics radiation from the detection range is inclined relative to a plane defined by the spectral components in the region between the collimating and focusing optics and the detection device surface. This allows a particularly space-saving arrangement of the detection device.

The collimating and focusing optics can basically be designed as desired. For example, it can contain at least one imaging mirror as a collimating and focusing optical component. However, in order to achieve the simplest possible beam path and a cost-effective structure, the collimating and focusing optics preferably has at least one lens, which may be a refractive lens or a diffractive optical lens.

In order to achieve a good spectral resolution and to enable a simple evaluation and calibration of the detection device, in the device, the Kollimatiöns- and focusing optics may be achromatic. This is understood to mean that this optics in the spectral range in which the spectrographic device operates, is chromatically corrected; Preferably, the focal points are for two different wavelengths in the predetermined spectral range to each other. The use of achromatic optics has the advantage that the radiation emanating from the detection area and directed onto the dispersing device is not, in a good approximation, additionally spectrally split, and in particular when the spectral components are focused on the detection device chromatic aberrations occur at best to a small extent. In order to approximate as closely as possible the theoretical resolution limit given by the size of the aperture, for example in the case of a slit of the slit width, when using an entrance aperture or an equivalent device, the aim is to obtain the unsharp circle of a pixel which is produced by Chromasie in the spectral range to be detected or the working spectral range of the device on the detection device remains smaller than preferably 1/5, more preferably 1/10, the size of the aperture.

The spectral components span a plane as a surface and the detection device comprises a row of detection elements extending in the direction of the plane which extends above or below a plane through the beam path of the radiation emanating from the detection area. The direction of the radiation from the detection area between the collimating and focusing optics and the dispersing device is inclined to an area spanned by the spectral components in the region between the collimating and focusing optics and the dispersing device.

Furthermore, in the device, at least in a section immediately in front of the collimating and focusing optics, a geometric projection of the radiation coming out of the detection area can lie on a surface area defined by the spectral components incident on the detection device and limited in this area. This results in a particularly space-saving arrangement.

Furthermore, in the device in the beam path from the detection area to the spectrographic device, a diaphragm arranged in the focal plane of the collimating and focusing optics and imaging optics for imaging the detection area can be arranged on the diaphragm. The diaphragm can be embodied in particular by a diaphragm body with an aperture or by a beam deflecting element or deflecting element, for example a mirror or a beam splitter, with a surface representing an aperture, the detection radiation at least partially reflecting surface.

Particularly preferably, the detection device can then be spaced in a direction away from the diaphragm, which is orthogonal to the direction in which the spectral components are separated. This results in a particularly compact design of the device.

In this case, the diaphragm is preferably located laterally next to the detection device in the direction of the spatial splitting of the spectral components. Laterally, depending on the orientation of the device to the ground, also mean above or below. If a detection device with a row of detection elements is used, a perpendicular from the aperture on the line preferably intersects the line itself.

In principle, the dispersing device used may be any optical component or a combination of optical components which at least partially splits incident radiation into spectral components which propagate in different directions in accordance with the respective wavelength. For example, a prism can be used. Preferably, however, the dispersing optical device of the device has an optical grating. The spectral components of the first order of diffraction may be used as spectral components, although the use of higher diffraction orders is also conceivable. This embodiment has the advantage that grids for any areas of the optical spectrum, in particular for the infrared range, are available in a simple and cost-effective manner. The grid may be any, for example, mechanically, lithographically or holographically produced, lattice.

Preferably, the grating is a reflection grating, which directs the spectral components directly back into the collimating and focusing optics, whereby a particularly compact design can be achieved.

Further, it is preferred that the grating be aligned relative to the detection means and selected so that the radiation of the zeroth diffraction order does not fall on the detection means. This has the advantage that the zeroth diffraction order can be optionally used for other investigations. In particular, a step grid can be used as the grid. Particular preference is given to using a blazed grating as step grating. This has the advantage that, by appropriate design and arrangement of the grating, the radiation of the diffraction order prescribed for forming the spectral components can obtain a particularly high intensity.

The grating may be aligned with its dispersing line structure orthogonal to the optical axis of the collimating and focusing optics. In this case, then the radiation emanating from the detection area must fall inclined to the grating against the optical axis. Preferably, however, line structures of the grating are inclined with respect to the optical axis of the collimating and focusing optics. This allows a simple adjustment of all arranged between the detection area and the collimating and focusing optics components each other.

Further, the dispersive optical device itself may be reflective or integrated with a reflective element, thereby reducing the number of optical devices. However, it is also possible that a transmission-dispersing optical device is used as the dispersing device, in which case a deflecting element, for example a mirror, is provided in order to reflect the beam components generated by the device into the collimating and focusing optics.
In a particularly preferred development, the detection device has at least two edge detection elements, which are arranged so that at least part of the detection beam path extends between them. The detection beam path from the detection area to the dispersing device extends at least partially through the detection device, resulting in an advantageously space-saving construction.

However, this space-saving construction results not only in the device according to the first alternative or when using the collimating and focusing optics.

Rather, the problem is solved according to a second alternative more generally by a device having the features of claim 8 and in particular a device for the optical examination of documents of value with a detection area, in which a Value document is, and a spectrographic device comprising a spatially dispersing optical device for at least partial decomposition of the detection area along a detection beam path of incoming optical radiation in spectrally separated, corresponding to the wavelength propagating in different directions spectral components, and in at least one spatial direction spatially resolving detection means for Detecting the spectral components comprising at least two edge detection elements arranged so that at least a portion of the detection beam path extends therebetween.

In both alternatives, the detection device may have, in addition to the two mentioned edge detection elements, further detection elements which are each arranged on the detection elements in a row. The edge detection elements need not be differentiated from any other detection elements except for their position, although this is possible. This results in a detection device with two detector lines of detection elements arranged along a line. The detector rows form a gap through which at least a portion of the detection beam path leads. The two edge detection elements are arranged on both sides of the gap.

A particularly compact structure results in the second alternative, characterized in that the device is designed so that in the region of the two edge detection elements of the detection beam path is parallel to a determined by a beam path of the spectral components surface. In particular, the detection beam path to the two edge detection elements and the beam paths of the spectral components at least partially extend in a plane, so that there is a particularly flat structure.

In principle, in the case of a device according to the second alternative, the dispersing device can be designed as described in the first alternative, but the changed beam paths must be taken into account. In particular, the dispersing device may have a reflective effect. In the case of a device according to the second alternative, if no collimating and focusing optics are used, it is particularly preferred that the spatially dispersing optical device has an imaging dispersive element which splits optical radiation which has passed through the detection region between the edge detection elements for at least one predetermined spectral range Spectral components focused on the detection device, preferably their detection elements including the edge detection elements. This embodiment offers the particular advantage that only a few components need to be used.

For the dispersing device of the device according to the second alternative, the statements apply to that of the first alternative accordingly. In particular, the dispersing optical device may preferably comprise an optical grating, which is preferably a step grating whose steps are chosen so that the radiation of the zeroth diffraction order does not fall on the detection device. The use of a grating allows a particularly variable adjustment of the splitting of the spectral components. In addition, the grid can be designed simply as a reflection grating, so that a structure with few elements results.

If the grating is a line grating, preferably the line structures of the grating are orthogonal to the detection beam path immediately in front of the optical grating. As a result, the spectral components can be redirected to the detection elements of the detection device.

In the area between the two edge detection elements no spectral component is detected. It is therefore preferred in a device according to one of the two alternatives that a beam path from the spatially dispersing device to the detection device is such that a spectral component of a predetermined wavelength between the two edge detection elements is directed. In particular, the detection device or its detection elements and the dispersing device can be arranged in a suitable manner to one another for this purpose. The wavelength can be predetermined depending on the intended use of the device. If the device is to be used, for example, for measuring luminescence or Raman radiation, the predetermined wavelength is preferably the wavelength of the excitation radiation with which the luminescence or the Raman radiation is excited.

In particular, for checking banknotes, it is often desirable to be able to detect spectrally resolved radiation in different regions of the optical spectrum, in particular in the visible and infrared part of the optical spectrum. In a device according to one of the two alternatives, it is therefore preferred that the two edge detection elements each have different spectral detection ranges. If the detection device has two detector rows, at the opposite ends of which the two edge detection elements are arranged, the detection elements of both lines preferably have identical spectral detection areas, so that the detection areas of the detection elements on the opposite sides of the gap differ. In particular, one detector row can comprise detection elements for detecting radiation at least in the visible range of optical radiation, for example based on silicon, and the other detection elements for detecting radiation in the infrared range of optical radiation, preferably with wavelengths greater than 900 nm on the basis of indium gallium arsenide semiconductors exhibit. This offers the advantage of a spectrally particularly broadband detection with only a small footprint. In particular, the disadvantage can be overcome that silicon-based detection elements in the spectral range having wavelengths greater than 1100 nm have too low a sensitivity for practical detection purposes.

In order to still be able to achieve a good signal-to-noise ratio with the shortest possible detection times, it is further preferred for a device according to one of the two alternatives that at least some detection elements of the detection device have a sensitive area of at least 0.1 mm ² . This can result in particular significant advantages compared to the use of CCD elements in terms of the signal-to-noise ratio and the detection time.

Particularly preferably, the detection device, in particular in addition to the two edge detection elements, has detection elements by means of which detection signals can be generated at the same time which reproduce a property, in particular the intensity, of the radiation incident on them. This embodiment has the advantage that the detection signals generated by the detection elements from the spectral components can be detected simultaneously, which, in particular in comparison to CCD fields, allows a high detection rate or repetition rate of the measurement. In particular, the detection elements can be independently readable or generate detection signals independently of each other.

In this case, it is particularly preferred that the device according to one of the two alternatives has an evaluation device connected via signal connections to the detection elements, which detects the detection signals formed by means of the detection elements in parallel. Such a device can preferably be used to detect at least one spectrum, preferably a temporal sequence of spectra after the emission of only one pulse, which is advantageous in particular for the investigation of luminescence phenomena.

In this case, it proves to be very advantageous if the evaluation device detects detection signals of the detection elements of the detection device as a function of a signal which reproduces the emission of a pulse of illumination radiation onto the detection area. This can be done very easily and at the same time exactly a study of luminescence, such as a banknote, since the time interval between pulse delivery and detection can be set.

In order to be able to restrict or even avoid a reduction of the signal-to-noise ratio of the detection by external radiation, in the devices according to both alternatives a filter is preferably arranged in the detection beam path between the detection area and the spatially dispersing optical device, the radiation in a predetermined spectral range suppressed. The predetermined spectral range may in turn be selected depending on the use of the device. If the device is used, for example, for measuring luminescence or Raman radiation, the predetermined spectral range can be, for example, the spectral range of the excitation radiation with which the luminescence or Raman radiation is excited. However, it is also possible to use filters which only transmit radiation in a spectral range given by the spectral components to be detected, but at least strongly attenuate radiation outside the range.

Furthermore, in the case of a device according to one of the two alternatives, it is preferable for a beam splitter to be provided in the beam path between the detection region and a gap formed by the two edge detection elements or the collimation and focusing optics, by means of which a part of the optical radiation from the detection region can be made from a Beam path to the collimating and focusing optics can be coupled out. This has the advantage that the radiation emanating from the detection area can not only be examined spectrally, but at least partially also for other examinations, for example for imaging purposes or for the spectral analysis of other spectral ranges that can not be analyzed by means of the spectrographic device. In a particularly preferred embodiment, the mentioned filter is formed by the beam splitter, which is designed accordingly.

Depending on the type of lighting, the device does not necessarily have to have an entrance slit or, more generally, an entrance slit or other device that fulfills the same function. However, according to one of the two alternatives, the device preferably has at least one component which fulfills the function of an entrance panel.

Thus, for example, the device can have an entrance aperture that lies in the plane of the detection elements at least approximately, ie in the depth of field range of the imaging elements arranged along the beam path after the entrance slit. This inlet aperture can be provided as a separate component, but it is preferably formed by the detection elements and / or one or more carriers for the detection elements. This results in a particularly simple structure. When using a beam splitter or a beam deflecting element in the detection beam path from the detection area to the dispersing device, the beam splitter or the beam deflecting Element, such as a mirror, also fulfill the function of the entrance gap. A particularly lossless transmission of the detection radiation with simultaneous shielding from external radiation can preferably be achieved in a device according to one of the two alternatives, that in the detection beam path, a light guide for guiding the detection radiation is arranged, the end of which is arranged between the two edge detection elements. The end may also preferably take over the function of an entrance panel. An optical waveguide is understood to mean, in particular, also any element for guiding and possibly also deflecting optical radiation which can be detected spectrally resolved by means of the dispersing device and the detection device. Depending on the design of these devices, the light guide can therefore also be designed in particular for the conduction of non-visible optical radiation in the infrared range.

Although in principle an illumination of the detection area with ambient light is conceivable, a device according to one of the two alternatives preferably has a radiation source for emitting optical illumination radiation in at least one predetermined wavelength range into the detection area. The illumination radiation can be used as reflected light or transmitted light.

A device according to one of the two alternatives for illuminating the detection area preferably has at least one semiconductor radiation source. The use of semiconductor radiation sources has a number of advantages. Thus, semiconductor radiation sources usually have a significantly longer life than other radiation sources. In addition, they require less input power to deliver optical radiation of a given power and generate less waste heat, which significantly reduces the cooling requirements of the device. Furthermore Semiconductor radiation sources for different wavelength ranges are available, so that simply excitation radiation can be generated in predetermined wavelength ranges. As semiconductor radiation sources, for example light emitting diodes or superluminescent diodes, but preferably semiconductor lasers into consideration. Semiconductor radiation sources are not only components based on inorganic semiconductors, but also those based on organic substances, in particular OLED.

In principle, when using illumination of the detection area in reflected light, the illumination radiation can be blasted onto the value document inclined thereto. However, it is preferred that in the beam path from the detection area to the spectrographic device, a beam splitter is arranged, passes through the optical radiation of the semiconductor radiation source in or on the detection area, in particular is directed. This has the advantage that the illumination radiation can be directed orthogonally to the document of value, whereby less scattered radiation occurs, which can hinder the detection. Particularly preferably, a dichroic beam splitter is used, by means of which radiation in the region of the illumination radiation reaching the detection area is provided by the detection radiation emanating from the value document of the spectral decomposition in a predetermined wavelength range which can be selected, for example, as a function of at least one optical feature of the value document, can be separated. This increases the signal-to-noise ratio in the detection.

Another object of the invention is a device for processing documents of value with a device according to the invention according to one of the two alternatives for the examination of value documents and a transport path for value documents to be processed, in and / or by leads the detection area. The transport path may in particular have a transport device for transporting the value documents, for example driven belts. In particular, devices for counting and / or sorting banknotes, automatic pay stations for accepting and outputting value documents, in particular banknotes, as well as devices for checking the authenticity of value documents come into consideration as processing devices.

Fig. 1

eine schematische Darstellung einer Banknotensortiervorrichtung,

Fig. 2

eine schematische Draufsicht auf eine Vorrichtung zur Untersuchung von Banknoten nach einer ersten bevorzugten Ausführungsform der Erfindung,

Fig. 3

eine schematische, teilweise Seitenansicht der Vorrichtung in Fig. 2,

Fig. 4

eine schematische Draufsicht auf eine Vorrichtung zur Untersuchung von Banknoten nach einer zweiten bevorzugten Ausführungsform der Erfindung,

Fig. 5

eine schematische, teilweise Seitenansicht der Vorrichtung in Fig. 4,

Fig. 6

eine schematische Draufsicht auf eine Vorrichtung zur Untersuchung von Banknoten nach einer weiteren bevorzugten Ausführungsform der Erfindung,

Fig. 7

eine schematische, teilweise Seitenansicht der Vorrichtung in Fig. 6,

Fig. 8

eine schematische Draufsicht auf eine Vorrichtung zur Untersuchung von Banknoten nach noch einer weiteren bevorzugten Ausführungsform der Erfindung,

Fig. 9

eine schematische, teilweise Seitenansicht der Vorrichtung in Fig.8,

Fig. 10

eine schematische Draufsicht auf eine Vorrichtung zur Untersuchung von Banknoten nach einer weiteren bevorzugten Ausführungsform der Erfindung,

Fig. 11

eine schematische, teilweise Schnittansicht der Vorrichtung in Fig. 10,

Fig. 12

eine schematische perspektivische Ansicht einer Detektoranordnung mit einem Lichtleiter der Vorrichtung in Fig. 10,

Fig. 13

eine schematische Draufsicht auf eine Vorrichtung zur Untersuchung von Banknoten nach noch einer weiteren Ausführungsform der Erfindung, und

Fig. 14

eine schematische Darstellung einer Anordnung von Detektionselementen mit unterschiedlichen Breiten.

The invention will be further explained by way of example with reference to the drawings. Showing:

Fig. 1

a schematic representation of a bank note sorting device,

Fig. 2

a schematic plan view of an apparatus for examining banknotes according to a first preferred embodiment of the invention,

Fig. 3

a schematic, partial side view of the device in Fig. 2 .

Fig. 4

a schematic plan view of an apparatus for examining banknotes according to a second preferred embodiment of the invention,

Fig. 5

a schematic, partial side view of the device in Fig. 4 .

Fig. 6

a schematic plan view of an apparatus for examining banknotes according to another preferred embodiment of the invention,

Fig. 7

a schematic, partial side view of the device in Fig. 6 .

Fig. 8

a schematic plan view of an apparatus for examining banknotes according to yet another preferred embodiment of the invention,

Fig. 9

a schematic, partial side view of the device in Figure 8 .

Fig. 10

a schematic plan view of an apparatus for examining banknotes according to another preferred embodiment of the invention,

Fig. 11

a schematic, partial sectional view of the device in Fig. 10 .

Fig. 12

a schematic perspective view of a detector arrangement with a light guide of the device in Fig. 10 .

Fig. 13

a schematic plan view of an apparatus for examining banknotes according to yet another embodiment of the invention, and

Fig. 14

a schematic representation of an array of detection elements with different widths.

In- Fig. 1 For example, as an example of a device for processing value documents, a banknote sorting device 1 with an examination device according to a first preferred embodiment of the invention is shown.

The banknote sorting device 1 has in a housing 2 an input compartment 3 for banknotes BN, into which banknotes to be processed BN can be supplied as a bundle either manually or automatically, optionally after a preceding debrapping, and then form a stack there. The banknotes BN entered into the input tray 3 are withdrawn individually from the stack by a singler 4 and transported by a transport device 5, which defines a transport path, through a sensor device 6 which serves to examine the banknotes. In this exemplary embodiment, the sensor device 6 has a plurality of sensor modules accommodated in a common housing. The sensor modules serve to check the authenticity, the state and the nominal value of the checked banknotes BN. After passing through the sensor device 6, the checked banknotes BN are dependent on the examination or test results of the sensor device 6 and predetermined sorting criteria about switches 7, which are each back and forth about Weichenstellsignale between two different positions, and associated Spiralfachstapler 8 in Output compartments 9 sorted output from which they can either be removed manually or removed automatically. The control of the banknote sorting device 1, in particular the conversion of examination signals of the sensor device 6 in point setting signals for the switches 7, takes place by means of a control device 10.

As already mentioned, the sensor device 6 in this exemplary embodiment has different sensor modules, of which only the sensor module 11, a device for analyzing documents of value, in the example banknotes BN, according to a preferred embodiment of the invention, hereinafter referred to as the examination device, in the figures shown and described in more detail below. The sensor modules for detecting the condition, i. the fitness for circulation, and the denomination or denomination of banknotes BN are common sensor modules known to those skilled in the art and therefore need not be described in detail.

The examination device 11 is designed in this embodiment for the detection and analysis of luminescence radiation, which is excited when illuminated banknotes predetermined with optical radiation of predetermined wavelength, in the example in the infrared region of the spectrum.

The examination device 11 has a sensor housing 12 with a disc 13 which is transparent by an optical radiation used for the examination and closes a window to a detection area 14 in which a banknote BN is at least partially located during an examination. The sensor housing 12 with the disc 13 is formed and in particular closed so that unauthorized access to the components contained therein is not possible without damaging the sensor housing 12 and / or the disc 13.

The limited by among other things by the arrangement and properties of the optical components of the inspection device 11 detection area 14 is limited on the sensor housing 12 opposite side by a fundamentally optional plate 33, so that a banknote BN in an in Fig. 2 orthogonal to the plane extending direction T means the in Fig. 2 not shown transport means 5 can be transported past the disc 13.

The examination apparatus 11 has an illumination device 15 for emitting illumination radiation into the detection area 14 and in particular to a value document at least partially located in the detection area 14, in the example a banknote BN, and a spectrographic device 16 for the examination and in particular spectrally resolved detection of the Detection area 14 or a value document outgoing optical radiation. In the example, the detection radiation comprises luminescence radiation in a wavelength range predetermined by the type of value documents, for example infrared luminescence radiation. This optical radiation emanating from the detection area 14 in the direction of the pane 13 is also referred to below as detection radiation. A detection optical unit 17 serves to transmit optical radiation, which passes from the detection area 14 through the pane 13 into the sensor housing 12, i. the detection radiation to couple into the spectrographic device 16.

The illumination device 15 has a semiconductor radiation source 18 in the form of a semiconductor laser, which in the example emits optical radiation in the visible range, and illumination optics. In other embodiments, the semiconductor laser may also be designed to emit radiation in the infrared region. The illumination optics has in a illumination beam path a first collimator optics 19 for forming an illumination beam or parallel illumination beam 20 from the optical radiation emitted by the semiconductor radiation source 18, a dichroic beam splitter 21 which is reflective for the radiation of the illumination beam or illumination beam 20 and illuminates the illumination beam or light beam The illumination beam 20 in the example 90 ° deflects the disc 13, and a first condenser optics 22 for focusing the illumination radiation through the likewise forming part of the illumination optics disc 13 in the detection area 14, in particular a value document BN in the detection area 14th

The detection optics 17 comprise along a detection beam path, which extends from the detection area 14 or the value document BN therein into and into the spectrographic device 16, next to the pane 13, the first condenser optics 22, which originate from a point on the value document BN in the Detection area 14 collects outgoing radiation in a parallel beam, the beam splitter 21, which is transparent to the spectrographic device 16 to be supplied radiation, but as scattered radiation in the detection beam path reaching illumination radiation filtered by reflection from the detection beam path, and a second condenser 23 for focusing the parallel Detection radiation on an inlet opening of the spectrographic device 16. Between the second condenser 23 and the spectrographic device 16 are optionally a filter 24 for filtering unwanted spectral components from the detection beam path, in particular in the wavelength range of the illumination radiation, as well as a deflection element 25, in the example a mirror, for deflecting the detection radiation by a predetermined angle, in the example 90 °. In other embodiments, the filter 24 may be disposed in the parallel beam path in front of the second condenser optics 23. This has the advantage that, for example, interference filters can be easily used.

The spectrographic device 16 has an entrance aperture 26 with a slot-shaped aperture 27 in the exemplary embodiment, the longitudinal extent of which extends at least approximately orthogonally to the plane defined by the detection beam path.

Detection radiation entering through the aperture 27 is bundled by an achromatic collimating and focusing optics 28 of the spectrographic device 16 in the example. The collimating and focusing optics 28 are shown only symbolically as lenses in the figures, but in fact will often be embodied as a combination of lenses. Assuming that this optic is achromatic, it is understood that it is corrected for chromatic aberrations in the wavelength range in which the spectrographic device 16 operates. A corresponding correction in other wavelength ranges is not necessary. The entrance aperture 26 and the collimating and focusing optics 28 are arranged so that the aperture 27 lies, at least to a good approximation, in the entrance aperture side focal surface of the collimating and focusing optics 28.

The spectrographic device 16 further comprises a spatially dispersing device 29, in the example an optical grating, the incident detection radiation, i. from the detection range coming optical radiation, at least partially separated into spectrally separated, according to the wavelength propagating in different directions spectral components.

A detection device 30 of the spectrographic device 16 serves for spatially resolving detection of the spectral components in at least one spatial direction. Detection signals formed during the detection are supplied to an evaluation device 31 of the spectrographic device 16, which detects the detection signals and, on the basis of the detection signals, performs a comparison of the detected spectrum with predetermined spectra. The evaluation device 31 is connected to the control device 10 connected in order to transmit the result of the comparison via corresponding signals.

The spatially dispersing device 29 in the present example is a reflection grating having a line structure whose lines extend parallel to a plane through the longitudinal direction of the aperture 27 and an optical axis of the collimating and focusing optics 28. The line spacing is chosen so that the detection radiation can be spectrally decomposed in a given spectral range, in the example in the infrator. The dispersing device 29 is so aligned that the separate spectral components, in the example, the first diffraction order by the collimating and focusing optics 28 are focused on the detection device 30. In order to obtain the best possible signal-to-noise ratio, the line spacing and the position of the dispersing device 29 are chosen such that non-spectrally dispersed portions of the detection radiation, in the example the zeroth diffraction order, do not fall into the collimating and focusing optics 28, but instead to a radiation trap, not shown in the figures, for example, a plate absorbing for the detection radiation.

The detection device 30 has a line-shaped arrangement of detection elements 32 for the spectral components, for example a row of CCD elements which are at least approximately parallel to the direction of the spatial splitting of the spectral components, ie in this case the surface S spanned by the spectral components, in this case more precisely a plane that is aligned. The plane S is in Fig. 3 illustrated by a dashed line.

In order to achieve the most compact possible structure, on the one hand the dispersing device 29 is arranged in two directions in relation to the detection device 30 and the direction of the incident detection radiation the collimating and focusing optics and the reflective component causing the convolution of the beam path, in this case the dispersing device 29, are inclined. Since, in the exemplary embodiment, the direction of the detection radiation between the collimating and focusing optics 28 and the reflective device, ie the dispersing device 29, is parallel to the optical axis O of the collimating and focusing optics 28, firstly the plane reflection grating 29 and thus also its line structure are opposite the optical axis O of the collimating and focusing optics 28 inclined in the plane of the detection beam path. Therefore, at least in the region between the dispersing device 29 and the collimating and focusing optics 28, the area S produced by the spectral components, in the example a plane, is opposite the direction of the detection radiation or the optical axis O of the collimating and focusing optics by the angle β inclined. In particular, a normal to the plane reflection grating 29 in the plane of the detection beam path by an angle β relative to the optical axis O of the collimating and focusing optics 28 is inclined (see. Fig. 3 ). Secondly, the dispersing device 16, more precisely the specular reflection incidence slot, ie here the normal to the plane of the line structure of the reflection grating 29, is at an angle α to the direction of the detection radiation or the optical axis O between the collimating and focusing optics 28 and the dispersing device 29 inclined.

On the other hand, the line of detection elements 32 of the detection device 30 at least approximately in a plane with the aperture 27 and in a direction orthogonal to the plane defined by the propagation directions of the spectral components S plane of the aperture 27 is spaced, in Fig. 3 above the aperture 27, arranged. In the FIGS. 2 and 3 For clarity, the entrance aperture 26 and the receiving surfaces of the detection elements 32 are parallel to Focal plane of the collimating and focusing optics 28 are shown spaced apart, but in fact they are substantially in a common plane in this example. Viewed in the direction parallel to the line of the detection elements 32, the aperture 27 is located approximately in the middle of the line.

This also shows how Fig. 2 can be removed that in the section between the entrance aperture 26 and the collimating and focusing optics 28, ie, in particular also immediately before the collimating and focusing optics 28, a geometric projection of the coming of the detection range 14 detection radiation to a falling through the detection device 30 Spectral components spanned and limited area A, which is trapezoidal in this case, lie in this area. This results in a particularly space-saving arrangement.

In this embodiment, the detection device 30, the entrance aperture 26, the collimating and focusing optics 28 and the dispersing device 29 are formed and arranged so that they are in a circular cylindrical space region whose cylinder axis through the optical axis of the collimating and focusing optics 28, and whose cylinder diameter is given by the diameter of the collimating and focusing optics 28, or the lens or largest lens therein. The length of the circular cylindrical space region is preferably less than 50 mm, in the example 40 mm. This results in a particularly small space requirement for the spectrographic device, wherein at the same time a large numerical aperture compared to the extent can be achieved.

For the optical examination of a value document, here a banknote BN in the detection area 14, the value document with illumination radiation, in the example for the excitation of luminescence radiation, is suitable Radiation of the semiconductor radiation source 18, illuminated and emanating from the document of value optical radiation, here luminescence radiation, formed by the detection optics 17 and the collimating and focusing optics 28 to a parallel detection beam. This is at least partially decomposed into spectral components of different wavelengths, which propagate in different directions depending on the wavelength. In Fig. 2 For example, the zeroth diffraction order reflected without spectral splitting is represented by a solid line and spectral components given by the first diffraction order for two different wavelengths by dotted and dashed lines, respectively. The spectral components are focused by the collimating and focusing optics 28 onto the detection device 30, more precisely the line with detection elements 32, and detected spatially resolved by them. Each detection element 32 is associated with a propagation direction and thus as a function of the wavelength of a spectral component. The evaluation device 31 therefore forms in each case from the positions of the detection elements 32 and the respectively detected by these intensities a spectrum that can then be compared with comparison spectra.

A second preferred embodiment in the FIGS. 4 and 5 differs from the first embodiment on the one hand in the nature of the dispersing device and on the other hand, the arrangement of the illumination device. For identical components, therefore, the same reference numerals are used and the explanations to the first embodiment apply accordingly here.

Instead of the flat reflection grating 29, a blazed grating 29 'is now used whose steps are inclined so that the first order of diffraction is in the direction of the specular reflection. As a result, a higher intensity of the spectral components can be achieved.

In principle, in the first exemplary embodiment, the illumination device can be rotated about the optical axis of the first condenser optics 22 without the function changing. In order to be able to achieve a compact design as possible, the semiconductor radiation source 18 and the collimator optics 19 are therefore arranged next to the collimating and focusing optics 28 in this embodiment.

Further embodiments differ from the first and second embodiments in that, instead of the deflecting element 25, a deflecting element 25 'is used which replaces the inlet aperture 26. A corresponding modification of the first embodiment is in Fig. 6 and Fig. 7 shown. Therein, the same reference numerals as in the first embodiment are used for the same elements and the explanations on these in the first embodiment also apply here. The deflection element 25 'is now a mirror of the size of the aperture 27 in the first embodiment and arranged in the focal plane of the collimating and focusing optics 28.

Still further preferred embodiments differ from the previously described embodiments in that the detection device 30 and the entrance aperture 26 are integrated. For this purpose, the aperture is formed in a circuit board, which also carries the detection elements 32.

In other embodiments, the illumination device 15 has a light-emitting diode, a super-luminescent diode or an OLED instead of the laser diode 18 as the radiation source.

Further, in other embodiments, the illumination device 15 may include at least two semiconductor radiation sources that receive optical radiation at different centroid wavelengths, i. the weighted average emission value over the emission wavelengths, deliver and can be independently switched on and off. This allows successive investigations at different wavelengths.

In other preferred embodiments, the entrance panel 26 can be omitted entirely. The illumination device 15 is then designed such that it illuminates only a narrow, elongated area in the detection area, for which purpose the first condenser optics 19 can contain a cylindrical lens.

Still other embodiments differ from the previously described embodiments in that further lenses are arranged in the detection beam path in order to reduce aberrations caused by the elements of the detection optics and the collimating and focusing optics 28 or to improve the illumination.

Further exemplary embodiments differ from the previously described exemplary embodiments in that the deflecting element 25 or 25 'is a beam splitter, so that portions of the detection radiation passing through it can be coupled out, for example, to produce an image of the value document.

In further embodiments, a lighting in transmission can be used.

Further, it is not necessary to use a reflective dispersing optical device such as the reflection grating 29. So it is in a further embodiment, which only in this respect of the embodiment in the 6 and 7 differs, it is possible to arrange a transmission grating 29 "in the detection beam path after the collimation and focusing optics 28, which at least partially decomposes the detection radiation into spectral components The spectral components can then be detected by at least one reflective component 34, for example a mirror, against the spectrometer components Plane is inclined to be thrown back into the collimating and focusing optics 28.

By folding the beam path after the collimating and focusing optics, a substantially more compact design is achieved than in a possible device in which a focusing optics and the detection device are arranged behind the transmission grating instead of the mirror.

In other embodiments, the sensor housing 12 and / or the plate 33 may also be designed differently or omitted altogether.

Furthermore, in other embodiments, the evaluation device 31 may be integrated in the control device 10.

Other preferred embodiments differ from the previously described embodiments in that instead of the detection device instead of a row of CCD elements line-arranged photodetection elements, for example CMOS elements, or photodetection elements for the detection of optical radiation in other wavelength ranges.

An exemplary embodiment of such an examination device, which, like all other examination devices described, for example, in the device for processing value documents in Fig. 1 can be used in the FIGS. 10 to 12 shown.

The examination device 11 "differs from the examination device 11 in addition to the type of detection elements Fig. 1 in that now the detection beam path between two edge detection elements of a detection device occurs and reaches the dispersing device. In particular, the examination devices differ only in that the detection device 30 is replaced by a detection device 34, the deflection element 25 by a light guide 35 and the evaluation device 31 by a modified evaluation device 31 '. In addition, the dispersing device 29 is oriented differently from the detection device 30. Since the examination device otherwise does not differ from that of the first embodiment, the same reference numerals are used for the same components and the statements on this in the description of the first embodiment also apply here accordingly.

In the Fig. 12 Detection device 34 shown in more detail now has a carrier 36, in the example a ceramic substrate, on which first detection elements 37 are arranged in a first line-shaped arrangement 39 and second detection elements 38 are arranged in a second line-shaped arrangement 39 '. In this embodiment, the detection elements 37 and 38 are arranged along only one straight line. In Fig. 12 Below the detection element 37 or 38 are electrically connected to the detection elements via an amplifier stage formed on the carrier Contacting elements 40, which are connected to signal connections to Auswerteschaltungen or devices.

The detection elements 37 and 38 are located on opposite sides of a recess or opening 41 in the carrier 36, which is rectangular in this embodiment. So there is a gap between the two edge detection elements 42 and 43.

The detection elements 37 differ from the detection elements 38 by their spectral detection range.

The detection elements 37 are detection elements for detecting optical radiation in the visible and near infrared, i. up to a wavelength of 1100 nm. In this exemplary embodiment, they have a usable spectral detection range between 400 nm and 1100 nm. For example, silicon-based detection elements can be used here.

The detection elements 38 are detection elements for detecting optical radiation in the infrared. Their usable spectral detection range in the exemplary embodiment is between 900 nm and 1700 nm. For example, here detection elements based on InGaAs can be used, which are sensitive in the spectral range above 900 nm.

The detective elements 37 and 38 are arranged relative to the dispersing means 29 so that spectral components from the dispersing means at wavelengths above 900 nm are directed to the detection elements 38 and those at wavelengths below 900 nm onto the detection elements 37.

Compared to CCD arrays, only a significantly smaller number of detection elements 37 and 38, for example between ten and thirty, are used, but they have a larger detection area and a reduced proportion of non-photosensitive areas. The detection surface is determined by the fact that only incident on this optical radiation is detected.

The detection surfaces preferably have an area of at least 0.1 mm ² , in the example they have a height of 2 mm and a width of 1 mm, non-photosensitive areas between adjacent detection elements having an extension of about 50 μm.

In this embodiment, the detection elements 37 and 38 are individually independently of each other and in particular readable in parallel.

In this embodiment, for this purpose, the already mentioned amplifier stage for each of the detection elements includes an analog / digital converter, which converts analog signals from the respective detection element into a digital detection signal which represents the intensity of the radiation dropped on the detection surface.

In the detection beam path, the light guide 35 made of a suitable transparent material is arranged, which leads detection radiation entering it at least in the spectral range detectable by the examination device and deflects in the direction of the dispersing device 29.

An end 44 of the light guide 35, through which the detection radiation emerges from this, is in the opening 41 and thus in the focal surface of the collimation and focusing optics 28 are arranged. The detection beam path therefore passes between the two edge detection elements 42 and 43. The exit surface or the end 44 of the light guide 35 form an entrance aperture or an entrance slit for the spectrographic device.

The light guide 35 is aligned relative to the optical axis O of the collimating and focusing optics 28 that the radiation emitted by the end 44 averaged over the beam cross section at least approximately parallel to the optical axis O and orthogonal to the surface of the carrier 36 and in particular the line-shaped arrangements of the detection elements runs.

As in Fig. 11 recognizable, the dispersing device 29, in particular their grid lines, in the in Fig. 11 level shown aligned orthogonal to the optical axis O. In the to the level in Fig. 11 orthogonal, in Fig. 10 on the other hand, the line structure given by the grid lines is inclined to the optical axis O.

The spectral components generated by the dispersing device 29 are therefore focused by the collimating and focusing optics 28 on the detection device 34, more precisely the detection elements 37 and 38, which then detect the corresponding spectral components.

The selected arrangement of light guide 35, collimating and focusing optics 28, dispersing device 29 and detection device 34 ensures that the detection beam path runs parallel or partially in the area determined by the spectral components generated by means of the dispersing device 29.

The angle α is chosen so that a spectral component corresponding to a predetermined wavelength, in this example given by the application for luminescence measurements, the excitation wavelength for the luminescence, focused in the gap between the two edge detection elements 42 and 43 and thus not detected.

As an option, the evaluation device 31 'is modified relative to the evaluation device 31 on the one hand in that the detection signals of the detection elements or of the detection device can be detected substantially in parallel. Substantially parallel is understood to mean that the detection signals may differ at least to the extent that they are necessary for the transmission to the evaluation device 31 ', for example by means of a multiplexing method via a bus.

Furthermore, the evaluation device 31 'is configured to detect the detection signals of the detection device 34 in response to a time interval predetermined in dependence on the expected luminescence, in response to a pulse output signal for the semiconductor radiation source 18.

The parallel read-out of the detection elements 37 and 38 thus made possible short integration times and, in particular, a high repetition frequency of the measurements. This measure also contributes to an increase in the signal-to-noise ratio.

In particular, this examination device can be used to perform a so-called "single-shot" measurement in which a single measurement of the spectral properties of the luminescence radiation is carried out on only one illumination or excitation pulse, which has sufficient accuracy for the evaluation.

Furthermore, the evaluation device 31 'can optionally be designed so that the examination device can be used to record the detection signals of the detection elements and thus several spectra after delivery of an excitation pulse by the semiconductor radiation source in time sequence and thus to carry out an evaluation of the time evolution of the spectrum.

Yet another embodiment in Fig. 13 differs from the last-described embodiment in the FIGS. 10 to 12 only in that the collimating and focusing optics 28 and the dispersing device 28 are replaced in the form of a plane reflection grating by an imaging dispersive element 45, which takes over their function. All other components and components are unchanged, so that the same reference numerals are used for them and the comments on the last embodiment apply here as well.

As an imaging dispersive element, a holographic grating 45 is now used, which images the entrance aperture 44, in the example, the end 44 of the light guide 35 onto the detection elements 37 and 38 in a spectrally resolved manner.

In the example, the imaging grating 24 preferably has more than about 300, particularly preferably more than about 500 bars or lines per mm, ie diffraction elements, in order to still allow sufficient dispersion of the luminescence radiation onto the detector element 21, despite the compact construction. In this case, the distance between the imaging grating 45 and the detection device 34 is preferably less than about 70 mm, particularly preferably less than about 50 mm.

In other embodiments, it may also be provided that individual detection elements 45 have different dimensions, in particular in the dispersion direction of the spectral components, as shown by way of example in FIG Fig. 14 is shown. Since usually not all wavelengths of the spectrum or only wavelength ranges of the same width, but specifically only individual wavelengths or wavelength ranges of different widths are evaluated, the detection elements can be adapted in their width parallel to the plane defined by the spectral components on the respective wavelengths to be evaluated (ranges) be designed.

In yet further exemplary embodiments, in particular in those in which a collimating and focusing optics is used, a cylindrical lens may be arranged in front of the detection device or a line with detection elements, the detection radiation focused on the detection elements and the cylinder axis thereof aligned parallel to the line ,

By means of such a cylindrical lens, the portion of the detection area used for detection in a direction corresponding to a direction orthogonal to the cylinder axis of the cylindrical lens can be increased and thus the intensity available for detection can be increased.

Claims (16)

1. An apparatus for optically analysing value documents (BN) by measuring and analysing luminescence radiation which is excited upon illumination of the value documents with optical radiation of a given wavelength, having a recording area (14) in which a value document (BN) is located during analysis,
   a semiconductor radiation source (18) for illuminating the value documents with optical radiation suitable for exciting the luminescence radiation, and
   a spectrographic device (16) which has:

   a spatially dispersing optical device (29) for at least partly decomposing optical luminescence radiation coming from the recording area (14) into spectrally separate spectral components propagating in different directions according to the wavelength,

   a detection device (30; 34) locally resolving in at least one spatial direction for detecting the spectral components,

   characterized in

   that the apparatus has a collimating and focusing optic (28) for collimating the optical radiation directed from the recording area (14) onto the dispersing device (29) and for focusing at least some of the spectral components formed by means of the dispersing optical device (29) onto the detection device (30; 34), and

   that the direction of the radiation from the recording area (14) falling on the collimating and focusing optic (28) is inclined from a surface spanned by the spectral components in the area between the collimating and focusing optic (28) and the detection device (30).
2. The apparatus according to claim 1, wherein the collimating and focusing optic (28) is achromatic.
3. The apparatus according to claim 1 or claim 2, wherein at least in a portion immediately before the collimating and focusing optic (28), a geometric projection of the radiation coming from the recording area (14) onto a surface (A) spanned and limited by the spectral components falling on the detection device (30) is located in said surface.
4. The apparatus according to any of the previous claims, wherein a diaphragm (26) disposed in the caustic surface of the collimating and focusing optic (28) and an imaging optic (22, 23) for imaging the recording area (14) onto the diaphragm (26) are disposed in the beam path from the recording area (14) to the spectrographic device (16).
5. The apparatus according to claim 4, wherein the detection device (30; 34) is spaced from the diaphragm (26) in a direction which extends orthogonally to the direction in which the spectral components are separated.
6. The apparatus according to any of the previous claims, wherein the dispersing optical device (29) has an optical grating, and wherein preferably the grating (29) is so configured and so selected that the radiation of the zeroth diffraction order does not impinge on the detection device (30; 34).
7. The apparatus according to claim 6, wherein the line structures of the grating (29) are inclined from the optical axis (O) of the collimating and focusing optic (28).
8. An apparatus for optically analysing value documents by measuring and analysing luminescence radiation which is excited upon illumination of the value documents with optical radiation of a given wavelength, having a recording area (14) in which a value document (BN) is located during analysis,
   a semiconductor radiation source (18) for illuminating the value documents with optical radiation suitable for exciting the luminescence radiation, and
   a spectrographic device (16) which has:

   a spatially dispersing optical device (29) for at least partly decomposing optical luminescence radiation coming from the recording area (14) along a detection ray path from the recording area (14) to the dispersing device (29) into spectrally separate spectral components propagating in different directions according to the wavelength, and

   a detection device (34) locally resolving in at least one spatial direction for detecting the spectral components,

   characterized in

   that the detection device (34) has as at least two edge detection elements (42, 43) which are so disposed that at least part of the detection beam path extends therebetween,

   that in the area of the two edge detection elements (42, 43) the detection beam path extends parallel to a surface determined by a beam path of the spectral components, and

   that the spectral components impinging on the edge detection elements (42, 43) propagate toward the edge detection elements (42, 43) in a plane spanned by these spectral components.
9. The apparatus according to claim 8, which further has a collimating and focusing optic (28) for collimating the optical radiation directed from the recording area (14) onto the dispersing device (29) and for focusing at least some of the spectral components formed by means of the dispersing optical device (29) onto the detection device (30; 34).
10. The apparatus according to claim 8, wherein the spatially dispersing optical device has an imaging dispersing element which focuses optical radiation that has passed from the recording area between the edge detection elements, split into spectral components for at least one given spectral range, onto the detection device.
11. The apparatus according to any of claims 8 or 9, wherein the dispersing optical device (29) has an optical grating which is so aligned and so selected that the radiation of the zeroth diffraction order of the grating (29) does not impinge on the detection device (30; 34), the grating preferably being an echelon grating.
12. The apparatus according to any of claims 8 to 11, wherein a beam path from the spatially dispersing device (29) to the detection device (30; 34) extends such that a spectral component of a given wavelength is directed between the two edge detection elements (42, 43), and wherein preferably the at least two edge detection elements (42, 43) have in each case different spectral detection ranges.
13. The apparatus according to any of claims 1 to 7, wherein a filter is disposed in the detection beam path between the recording area and the spatially dispersing optical device (29), which filter suppresses radiation in a given spectral range, preferably the spectral range of the optical radiation for exciting the luminescence radiation, and/or wherein a beam splitter (25) by means of which part of the optical radiation from the recording area (14) can be coupled out of the detection beam path is provided in the detection beam path between the recording area (14) and the collimating and focusing optic (28).
14. The apparatus according to any of the previous claims, wherein the detection device (34) has, in particular in addition to the two edge detection elements (42, 43), detection elements (32, 37, 38, 42, 43) by means of which detection signals can be generated simultaneously which represent a property, in particular the intensity, of the radiation impinging thereon.
15. The apparatus according to any of the previous claims, wherein a beam splitter (21) via which optical radiation from the semiconductor radiation source (18) passes into or onto the recording area (14) is disposed in the beam path from the recording area (14) to the spectrographic device (16).
16. An apparatus for processing value documents (BN) with an apparatus according to any of the previous claims and a transport path (5) for value documents (BN) to be processed which leads into and/or through the recording area (14).

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