WO2011091963A2

WO2011091963A2 - Illumination device and sensor for checking valuable documents

Info

Publication number: WO2011091963A2
Application number: PCT/EP2011/000221
Authority: WO
Inventors: Jörg Frankenberger; Wolfgang Deckenbach; Urs Hennerkes
Original assignee: Giesecke & Devrient Gmbh
Priority date: 2010-02-01
Filing date: 2011-01-20
Publication date: 2011-08-04
Also published as: EP2531982A2; WO2011091963A3; DE102010006396A1

Abstract

The invention relates to a sensor (100) for checking valuable documents, comprising an illumination device (50) for illuminating a valuable document, an optical imaging element (25) and a detection device (30). The illumination device of the sensor contains a light source receiving element (10) comprising a plurality of light sources (15a-d) in the form of chips, having emission spectra that are different from each other. A light-absorbing casting compound (6) in which the chip-type light sources are embedded is applied to the light source receiving element. By embedding said light sources in the light-absorbing casting compound, the emission of light, at least from some of the chip-type light sources, is spatially limited in such a way that the irradiation characteristics of the light sources are adapted to each other.

Description

Illuminating device and sensor for checking value documents

The invention relates to a lighting device for illuminating value documents and a sensor for checking value documents, which has the illumination device. For the examination of value documents, sensors are usually used with which the type of value documents is determined and / or with which the value documents are checked for authenticity and / or their condition. Such sensors are used to test documents of value, e.g. Banknotes, checks, ID cards, credit cards, check cards, tickets, vouchers and the like used. The examination of the value documents takes place in a device for value document processing in which, depending on the value-document properties to be tested, one or more different sensors are included. Typically, the value documents are scanned in the test in one or more tracks, wherein the sensor and the document of value are moved relative to each other.

Value documents are often checked with the aid of optical sensors that detect the light reflected from the value documents. To illuminate a value document, some sensors have a lighting device with a plurality of differently colored light-emitting diodes, which are each equipped with a protective cap acting as a lens. The light-emitting diodes provided with the protective cap are arranged side by side on a printed circuit board. The size of the protective caps, however, leads to relatively large distances between the individual LEDs. Such a lighting device therefore has a relatively large space requirement.

In other lighting devices a plurality of different color chip-shaped light sources are applied side by side on a circuit board. The emission light of the light sources is usually by a the Light sources common light guide collected and directed out of the light guide light directed to the value document to be tested.

If a lighting device is to be equipped with a plurality of different chip-type light sources, then the chip-shaped light sources generally differ in their emission characteristic. For example, some of the chip-shaped light sources can emit a considerable portion of their emission light over their side surfaces, while in other light sources, the light emission mainly takes place over its surface. If the different light sources are arranged next to each other and their emission light is to be collected in each case with one lens, it would be necessary to use an individually fitting lens for each of the different light sources, due to the different emission characteristics. Lenses of different size and / or focal length. Because when using the same lenses for all light sources some of the lenses would be outshined or - with correspondingly large lenses - the arrangement of the lenses need a lot of space. However, the preparation and handling of various lenses, as well as their attachment within a lighting device associated with a great effort.

An object of the present invention is therefore to provide an improved illumination device for illuminating documents of value with different light sources whose emission light can be collected in each case with a lens matching the light source.

This object is solved by the subject matters of the independent claims. In dependent claims advantageous developments and refinements of the invention are given. The illumination device comprises a light source recording, on which a plurality of chip-shaped light sources are arranged, the emission spectra of which are different from one another. In addition, the illumination device has a plurality of lenses which are formed separately from the chip-shaped light sources. The lenses are arranged such that each of the chip-shaped light sources arranged on the light source receptacle is assigned exactly one lens. The emission light emitted from the respective chip-shaped light source is respectively collected by the lens associated with the chip-shaped light source. In order to obtain an unambiguous relationship between the lenses and the light sources to be arranged at the light source positions, the arrangement of the lenses and the arrangement of the light source positions or the chip-shaped light sources on the light source receptacle are the same. For example, the lenses are arranged in the same one- or two-dimensional grid as the chip-shaped light sources are arranged on the light source receptacle. The lenses associated with the chip-shaped light sources may be formed as individual lenses which are produced separately from one another or formed by a one-dimensional or two-dimensional lens array. The illumination device is designed to illuminate a value document with a plurality of different emission spectra.

On the light source recording a light-absorbing potting compound is applied, in which the chip-shaped light sources are embedded. By embedding in the light-absorbing potting compound, the emission of emission light is spatially limited in at least some of the chip-shaped light sources such that their emission characteristics are matched to one another. In particular, the angle dependence of the beam intensity of the chip-shaped light sources is matched to one another by embedding in the light-absorbing potting compound. In comparison to their Abstrahlcharakteristika before embedding in the light-absorbing potting compound, the aligned in this way Abstrahlcharakteristika the different light sources are at least approximately equal to each other. The embedding in the light-absorbing potting compound can be carried out at each light source of the illumination device, but it can also be performed with only a subset of the light sources, for example, only those whose radiation characteristic deviates greatly from that of the other light sources. The matched radiation characteristics make it possible to use the same lenses for the different light sources. Otherwise, ie without embedding in the light-absorbing potting compound, due to the different surface and edge radiation of the different light sources, an individually fitting lens would have to be used for the different light sources. This effort can be avoided by the invention.

By embedding the chip-shaped light sources in the light-absorbing potting compound, the emission of emission light is spatially limited in at least one of the chip-shaped light sources in such a way that their emission characteristic is approximated, in particular, to the emission characteristic of a Lambert radiator. Preferably, in this way the radiation characteristic of a plurality of light sources is approximated to the emission characteristic of a Lambert radiator.

In particular, in at least one of the chip-shaped light sources, the side surfaces of the chip-shaped light source are light-tightly covered by the light-absorbent potting compound so that the emission of emission light of the chip-shaped light source to adjacent lenses adjacent to the chip-shaped light source associated lens is suppressed by the light-absorptive potting compound becomes. By the light-absorbing potting compound on the side surfaces, the emission of the emission light is at least partially suppressed on the adjacent lenses, but can also be completely suppressed. The emission of the emission light is spatially limited in at least one of the chip-shaped light sources in such a way that the proportion of the emission light of the chip-shaped light source, which would otherwise emit it to the neighboring lenses, is considerably reduced. As a result, unwanted beam paths of the emission light can be avoided, which could otherwise lead to the falsification of results of the value document test.

Preferably, the chip-shaped light sources are embedded in the light-absorbing potting compound such that the side surfaces of the respective chip-shaped light source are partially or completely covered by the light-absorbent potting compound. As a result of the fact that the side surfaces of the chip-shaped light sources are at least partially covered in a light-tight manner by the light-absorbing potting compound, an alignment of the emission characteristics can be achieved. For example, the side surfaces of some light sources of the illumination device can be completely covered and the side surfaces of other light sources of the illumination device can be partially covered by the light-absorbent potting compound. However, it can also be partially covered at each light source of the lighting device, the side surfaces or at each light source completely. In one or more light sources of the lighting device, no coverage of the side edges may be present, for example, if it is not necessary to match the radiation characteristics of the other. By partially or completely covering the side surfaces, the emission light of the chip-shaped light source is emitted substantially only to the lens associated with the respective chip-shaped light source. In particular, the chip-shaped light sources are embedded in the light-absorbing potting compound such that the surface of the respective chip-shaped light source provided for emitting the emission light is completely uncovered by the light-absorbent potting compound. The surface of the respective chip-shaped light source provided for emitting the emission light may be the entire surface of the respective chip-shaped light source or only part of the surface of the respective chip-shaped light source. The chip-shaped light sources can be embedded in the light-absorbing potting compound such that the side surfaces of the respective chip-shaped light source are only partially covered by the light-absorbent potting compound, wherein in each case an upper portion of the side surfaces, the provided to emit the emission light surface of the respective chip-shaped Light source adjacent, is uncovered by the light-absorbing potting compound. This can ensure that the potting compound, when applied to the light source recording, does not accidentally reach the surface of the chip-shaped light sources.

The light-absorbing potting compound is spectrally absorbing in such a broadband manner that it first strongly absorbs light in the spectral range of the emission light of the light sources. For example, the potting compound is colored black or black, e.g. blackened with soot. In particular, the light-absorbent potting compound is made on the basis of a casting resin, e.g. Epoxy resin, silicone resin, polyurethane resin, polyester resin or vinyl ester resin.

The lighting device has a plurality of chip-shaped light sources whose emission spectra are different from each other. For example, each of the light sources of the illumination device has a different emission spectrum than the other light sources of the illumination device. However, in addition to the light sources with different emission spectra, the illumination device can also have one or more light sources with the same emission spectrum, eg in order to obtain a sufficient illumination intensity even in a spectral range with light-weak light sources. Thus, the illumination device can also be equipped with the same light source at a plurality of the light source positions on the light source recording in order to provide one or more of the emission spectra several times. The light sources arranged on the light source receptacle provide a plurality of emission spectra in the visible spectral range and / or in the infrared spectral range and / or in the ultraviolet spectral range. Light-emitting diodes are preferably used as chip-shaped light sources, for example light emitting diodes (LEDs), in particular semiconductor light emitting diodes or organic light emitting diodes (OLED), and / or laser diodes, in particular vertical cavity surface emitting lasers (VCSEL).

On the light source recording of the illumination device a plurality of light source positions are provided, each of which is designed to receive one of the chip-shaped light sources. On the light source receptacle, e.g. a one-dimensional or a two-dimensional arrangement of light sources may be provided. In each case a light source is arranged at a plurality or at all of the light source positions of the light source holder. In some embodiments, the light source positions are the

Light source recording formed as wells, in each of which one of the chip-shaped light sources is included. In particular, the light source positions are formed by a plurality of individual recesses, in each of which exactly one of the chip-shaped light sources is received can. The wells of the light source recording can be filled individually with the light-absorbing potting compound. The filling level of the potting compound in the respective recess can be adapted in each case to the thickness of that light source which is contained in the recess. The provision of recesses as light source positions has the advantage that the filling height of the light-absorbing potting compound for the different light sources can be set individually and thus undesired light emission that emerges from the side surfaces can be optimally suppressed.

Preferably, the recesses are formed so deep relative to the surface of the light source receptacle into which the recess is inserted, that the surface of the chip-shaped light source contained in the recess, which is provided for emitting the emission light, respectively below the surface of the light source. Recording or in the plane of the surface of the light source recording is arranged. The wells of the light source receptacle are thus formed at least so deep that the depth of which corresponds at least to the thickness of that chip-shaped light source contained in the respective recess. As a result, the surface of the chip-shaped light sources can be protected against external influences. In one exemplary embodiment, the recesses of the light source receptacle have different depths with respect to the surface of the light source receptacle. The depths of the recesses are selected as a function of the thickness of the respective chip-shaped light source which is contained in the recess in order to arrange the surfaces of the light sources exactly or at least approximately in the same plane.

Preferably, the light sources and lenses are arranged relative to one another in such a way that each light source of the illumination device is separated from its associated lens. less than the focal length of this lens is removed. If the distance of the light source from its associated lens is less than the focal length of the lens, a particularly large proportion of the light emitted by the light source can be collected. Alternatively, the distance between the light source and its associated lens may be more than the simple focal length, but preferably less than twice the focal length of the lens.

In one embodiment, the lenses associated with the chip-shaped light sources are provided by a microlens array comprising a plurality of lenses

Contains microlenses. The microlens array is formed as a one-piece body, which preferably has attachment means. The fastening means may be formed as integral components of the microlens array, so that their position is defined very accurately relative to the microlenses. The light source receptacle has a matching to the attachment means of the microlens array counterpart. For adjustment of the illumination device, therefore, no adjustment is required. In contrast to the realization of a corresponding illumination with individual lenses, which must be supported individually and always leave gaps between them when arranged, there is hardly any space between the individual microlenses in the microlens array. Since the microlens array is formed as a one-piece body and the microlenses therefore pass directly into one another with no or at least an in-between spacing, a virtually complete light collection is achieved by the microlens array. Therefore, by the micro lens array, a lighting device having a high light collecting efficiency and being very compact can be formed.

The invention also relates to a sensor which is designed to test value documents. The sensor has the illumination described above. processing device for illuminating a value document to be checked by the sensor, as well as imaging optics and a detection device. The imaging optics allow the light emitted by the illumination device to be imaged onto the value document to be checked by the sensor. The detection device is designed to detect detection light which, when the sensor is operated when the value document is illuminated by the illumination device, starts from the value document to be checked. The sensor also has imaging optics which are designed to image the emission light of each of the light sources, after passing through the respective microlens, onto a value document to be tested by the sensor. The microlenses and the imaging optics are arranged relative to one another in such a way that the emission light of each of the light sources can be imaged by the respective associated microlens and the illumination optics onto a value document which is to be detected by the sensor. The illumination optical system preferably has one or more refractive and / or diffractive optical elements which image the illumination light onto the value document.

For the sensor, a control device is provided, which is set up to switch the light sources of the illumination device on and off again in order to illuminate the value document one after the other with a plurality of different emission spectra. In addition, the control device causes the detection device to detect a measured value during the switched-on phase of the light sources which corresponds to the light intensity emanating from the value document. Since the detection device in each case receives a measured value in synchronism with the illumination by the light sources, for those wavelengths that pass through the emission light of the light sources are predetermined, which detects the light intensity emanating from the value document. In particular, the sensor has a plurality of different light sources which, when the sensor is operated, are switched on and off one after the other in order to detect a spectral intensity distribution of the light emanating from the value document.

The detection device preferably has a spectral sensitivity which is spectrally broadband such that the emission light of each of the light sources of the illumination device can be detected by the detection device. In particular, at least visible light can be detected by the detection device. The measured values recorded by the detection device are then evaluated by an evaluation device, which may be part of the sensor or is also formed by an external evaluation device. Optionally, a detection optics can be arranged in front of the detection device, by means of which the detection light emanating from the value document is collected and directed onto the light-sensitive area of the detection device. The detection optics may be e.g. be realized by refractive or diffractive optical elements or by mirrors. The sensor preferably also has a housing in which the illumination device, the imaging optics and the detection device, optionally also the control device and detection optics, are arranged.

For checking the value document, the value document is transported past, for example, along a transport direction on the sensor. The sensor is not designed to examine the value document over the entire area, but to check the value document in a plurality of tracks on the value document, between each of which value document areas are arranged that are not checked by the sensor. The tests used to test the value document Elements illuminated areas form tracks that run parallel to each other and along the transport direction of the document of value. The traces are discretely distributed on the value document. For each of the tracks at least one illumination device, an imaging optics and a detection device according to the above description is provided. The lighting sequences preferably follow each other so quickly that the value document is examined virtually continuously along each of the tracks.

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

1 shows a lighting device with a plurality of chip-shaped light sources, in front of which a respective lens is arranged,

2a section through a lighting device according to the invention according to a first embodiment,

2b shows a section through a lighting device according to the invention according to a second embodiment,

2c section through a lighting device according to the invention according to a third embodiment,

3 shows an embodiment of a lighting device in three-dimensional representation,

Fig. 4 sensor for testing value documents, comprising the illumination device of Figure 3.

FIG. 1 shows a lighting device with a plurality of chip-shaped light sources 15a-d, which are arranged side by side on a common light source receptacle 10. In front of each of the chip-shaped light sources 15a-d, a lens 2 is arranged, which collects the emission light of the respective light sources 15a-d. The light sources 15a and 15c emit mainly via the respective chip surface. Some of the light sources, namely the light sources 15b and 15d, emit their emission light but not only on their chip surface, but also on their chip side surfaces 17. The broader radiation characteristics of these light sources 15b and 15d causes the light sources 15b, 15d associated lenses 2 with the emission light These light sources are outshone. In addition, a portion of the emission light of the light sources 15b, 15d is incident on the two adjacent lenses 2 associated with the adjacent light sources 15a, 15c. In the case of a sensor for checking documents of value, this may cause a proportion of the emission light of the light sources 15b and 15d to fall on a detection device of the sensor via an undesired beam path.

FIG. 2a shows a first exemplary embodiment of the illumination device 5 according to the invention with a light source receptacle 10, on which a plurality of light source positions 11 are provided, on each of which a chip-shaped light source 15a-d is arranged. At the light source positions 11, the chip-shaped light sources 15a-d are attached, for example, by bonding, gluing or soldering. For example, the light sources 15a-d emit different emission spectra in the visible and / or infrared spectral range. In front of each of the chip-shaped light sources 15a-d, a lens 2 is arranged, which collects the emission light of the respective light source 15a-d. The light source receptacle 10 is designed, for example, as a printed circuit board and has an electrical wiring structure required for operating the light sources 15a-d (not shown), which permits selective activation of each individual light source 15a-d. The light source positions 11 are defined, for example, by the electrical contacts required to operate the light sources. The light sources 15a-d are embedded in a light-absorbing potting compound 6, which has a uniform thickness D. The side surfaces 17 of the chip-shaped light sources 15a-d are partially covered by the light source in this example. absorbent potting compound 6, leaving an upper portion of the side surface uncovered. The surfaces 16a-d of the light sources 15a-d are also completely uncovered. The potting compound 6 absorbs portions of emission light from the light sources 15a-d, which would otherwise be emitted via the side surfaces 17 of the light sources 15a-d.

FIG. 2 b shows a second exemplary embodiment of the illumination device 5 according to the invention. In contrast to the first embodiment, the light source positions 11 are formed here as recesses 12, in each of which one of the chip-shaped light sources 15a-d is included. The recesses 12 have, relative to the surface 13 of the light source receptacle 10, all the same depth T. The bottoms of the light sources 15a-d are therefore all in one plane El. In the example shown, different chip-shaped light sources 15a-d are used which have different thicknesses D1-D3. Due to the different thicknesses D1-D3 of the light sources 15a-d, it can be used to suppress the

Be light emission at the side surfaces 17 of the light sources 15a-d be advantageous to choose 12 different filling heights of the light-absorbing potting compound 6 in the different wells. In the recess 12 in which the light source 15b having the largest thickness D2 is arranged, the light-absorbing potting compound 6 is sealed e.g. introduced to a greater filling level than the other wells 12th

The recesses 12 of the light source receptacle 10 may according to a third embodiment of the illumination device 5 but also have different depths relative to the surface 13 of the light source receptacle 10, see. Figure 2c. The depth of the depressions can be selected, for example, as a function of the thickness D1-D4 of the chip-shaped light sources 15a-d. This is particularly advantageous if the thicknesses D1-D4 of the chipför Might light sources 15a-d are very different. For example, the large-thickness light sources (eg, the light source 15b) are inserted into a deep-depth well, while a low-depth well is selected for the light-thickness light sources (eg, the light source 15d). By adapting the depth of the depression 12 to the thickness D1-D4 of the respective light source 15a-d, it can be achieved that the surfaces 16a-d of the light sources 15a-d lie exactly or at least approximately in the same plane E2. Thereby, the distances between the respective light emitting surface 16a-d of the light source 15a-d and the respective lens 2 can be made equal to each other.

In the above-mentioned second and third embodiments, the respective filling level of the potting compound is e.g. chosen approximately equal to the thickness D1-D3 and D1-D4 of the respective light source 15a-d, cf. FIGS. 2b-c. However, the filling height can also be chosen to be somewhat smaller than the thickness of the respective light source 15a-d, e.g. in order to avoid a running of the potting compound 6 on the chip surface 16a-d when introducing the potting compound 6. The fill level can in each case be set in a targeted manner such that a certain upper section of the respective chip side faces 17 remains free. In the second and third embodiments, however, the light-absorbing potting compound 6 may also have the same fill level in a plurality of the depressions 12 or in all wells 12, if this is sufficient to suppress the unwanted light emission at the side surfaces 17 of the chip-shaped light sources 15a-d.

The sections of an illumination device 5 shown in FIGS. 2a-2c each show four light sources 15a-d which are each arranged at one of the light source positions 11 of the light source receptacle 10. In the exemplary embodiments of FIGS. 2a-c, on the light source Recording 10 but also other light source positions 11, 12 with corresponding further chip-shaped light sources 15a-d be present. For example, LEDs and / or OLEDs and / or VCSELs can be used as chip-shaped light sources. In each of the three embodiments, all chip-shaped light sources of the illumination device may have the same thickness, but some or all chip-shaped light sources may also have different thicknesses. The thicknesses and depths shown in FIGS. 2a-c are not drawn to scale, but only by way of example.

Figure 3 shows a lighting device 50, which represents a possible embodiment of the above-described second or third embodiment, in three-dimensional view. In the example of FIG. 3, the illumination device 50 has a microlens array 20 which belongs to the light source receptacle 10 and has a plurality of microlenses 21. The light source receptacle 10 and the microlens array 20 are matched to one another such that each of the light sources 15 is assigned exactly one of the microlenses 21. For this purpose, the microlenses 21 are arranged within the microlens array 20 in the same two-dimensional grid as the light sources 15 are arranged on the light source receptacle 10. The light sources 15 are contained in recesses 12 of the light source receptacle, wherein the side surfaces are covered with the light-absorbing potting compound 6. The microlens array 20 is formed as a one-piece body and is formed for example by a glass body or by a transparent plastic body. The diameter of the individual microlenses is for example in the μιη range or in the mm range. For fixing the microlens array 20, the body of the microlens array 20 is provided with attachment pins 22 which are inserted into mating holes in the light source receptacle 10. The sensor for checking value documents is explained below using the example of a remission sensor. However, the sensor according to the invention can also be designed as a transmission sensor. For this purpose, the detection device is arranged opposite the illumination device, so that the illumination light transmitted through the value document is detected.

The illumination device 50 is installed in a sensor 100, which is designed to test documents of value, cf. FIG. 4 shows the depths of the depressions 12 and the thicknesses of the chip-shaped light sources 15 in FIG. 4 in order to simplify the illustration. The light emitted by the light-emitting device 50 is imaged onto the value document 1 by an imaging lens 25. In order to direct the light emitted by the illuminating device 50 onto the document of value 1, other optical components can also be used as imaging optics, alternatively to the imaging lens 25, for example lens systems, diffractive optical components, eg a Fresnel lens, or imaging mirrors. Depending on the optical properties of the value document 1, portions of the illumination light are remitted by the value document 1. The light remitted from the value document 1 is detected by means of a detection device 30 having a photosensitive region 31. The detection device 30 may be formed, for example, by a photodiode or a phototransistor. Optionally, a detection optics 35 can be arranged in front of the detection device 30, by means of which the light reflected from the value document 1 is collected and directed onto the photosensitive region 31. In the example shown, the illumination light is imaged perpendicular to the value document 1 and the detection device 30 detects the light reflected at an oblique angle. alternatives The lighting can also be carried out at an oblique angle and / or the detection device can detect the light emitted in the vertical direction. For collecting the remission light, it is also possible to provide a plurality of identical detection devices 30, eg in order to detect the remission light over a larger angular range, or to expand several different detection devices 30, for example by the detectable spectral range.

The sensor 100 has a housing 90, on the underside of which a transparent window 101 is arranged. The light emitted by the illumination device 50 is imaged through the window 101 onto a value document 1 to be checked, which is transported past the sensor 100 along a transport direction T. The illumination device 50, in particular the light sources 15, and the detection device 30 are actuated by a control device 60, which in this example is arranged inside the housing 90. The control device 60 switches the light sources 15 on and off in succession, so that, for example, only one light source 15 is switched on at any one time. During the switched-on phase of the light sources, the detection device 30 acquires in each case a measured value which corresponds to the light intensity remitted by the value document 1. The value document 1 is successively illuminated with the different emission spectra of the different light sources 15. Since the detection device 30 in each case receives a measured value in synchronism with the illumination by the light sources 15, the light intensity remitted by the value document 1 is measured in each spectral range which the light sources 15 specify.

The controller 60 controls the light sources 15 so that the lighting sequence with which the light sources 15 on and off are repeated periodically to sequentially detect the remitted light for several detection areas 3 on the value document 1 in each case. For example, the controller 60 may be programmed so that each light source 15 of the lighting device 50 is turned on and off exactly once during each lighting sequence. Alternatively, a light source 15 can also be activated several times per illumination sequence, for example in order to compensate for the low intensity of an intensity-weak light source 15 by multiple measurements. A lighting sequence can either involve the activation of all the light sources 15 present in the lighting device 50 or only a subset of the existing light sources 15. After a lighting sequence, ie after a measured value has been recorded under illumination with each emission spectrum intended for the measurement, the light starts Next lighting sequence in which a measured value is again recorded under illumination with each emission spectrum, which is intended for the measurement, etc. The measured values obtained during a lighting sequence, for example, provide a spectral dependence of the remission of the respective detection area 3.

Claims

Patency

1. illumination device (5, 50) for illuminating value documents, comprising:

a plurality of chip-shaped light sources (15a-d, 15) whose emission spectra are different from one another,

- A light source recording (10) on which a plurality of light source positions (11, 12) is provided, on each of which one of the chip-shaped light sources (15a-d, 15) is arranged, and

a plurality of lenses (2, 21) which are formed separately from the chip-shaped light sources (15a-d, 15) and are arranged such that the light sources (15a-d, 15) arranged on the light source receptacle (10) because exactly one of the lenses (2, 21) is associated with and that emission light emitted from the respective chip-shaped light source (15a-d, 15) through the chip-shaped light source (15a-d, 15) associated lens (2, 21 ) can be collected

characterized in that on the light source recording (10) a light-absorbing potting compound (6) is applied, in which the chip-shaped light sources (15a-d, 15) are embedded, wherein by embedding in the light-absorbing potting compound (6) the emission of Emission light in at least some of the chip-shaped light sources (15a-d, 15) is spatially limited such that their emission characteristics are matched to each other.

2. Lighting device (5, 50) according to claim 1, characterized in that the chip-shaped light sources (15a-d, 15) are respectively embedded in the light-absorbing potting compound (6) in such a way that the sending the emission light provided surface (16) of the respective chip-shaped light source (15a-d, 15) is completely uncovered by the light-absorbing potting compound (6).

3. Lighting device (5, 50) according to any one of the preceding claims, characterized in that the emission of emission light in at least one of the chip-shaped light sources (15a-d, 15) is spatially limited by embedding in the light-absorbing potting compound (6), that their emission characteristic is approximated to the radiation characteristic of a Lambert radiator.

4. lighting device (5, 50) according to any one of the preceding claims, characterized in that in at least one of the chip-shaped light sources (15a-d, 15), the side surfaces () of the chip-shaped light source (15a-d, 15) by the light-absorbing potting compound ( 6) are covered in such a light-tight manner that the emission of emission light from the chip-shaped light source (15a-d, 15) to neighboring lenses (2) adjacent to the chip-shaped light source (15a-d, 15) associated lens (2) are arranged , is suppressed by the light-absorbing potting compound (6).

5. lighting device (5, 50) according to any one of the preceding claims, characterized in that the chip-shaped light sources (15a-d, 15) are embedded in the light-absorbing potting compound (6) such that the side surfaces (17) of the respective chip-shaped light source ( 15a-d, 15) are partially or completely covered by the light-absorbing potting compound (6).

Illumination device (5, 50) according to one of the preceding claims, characterized in that the chip-shaped light sources (15a-d, 15) are embedded in the light-absorbing potting compound (6) such that the side surfaces (17) of the respective chip-shaped light source (15a) d) are partly covered by the light-absorbing potting compound (6), wherein in each case an upper portion of the side surfaces (17), the (16a-d) provided for emitting the emission light surface of the respective chip-shaped light source (15a-d, 15 ) is adjacent, of the light-absorbing potting compound (6) is uncovered.

Lighting device (5, 50) according to one of the preceding claims, characterized in that the light source positions (11) of the light source receptacle (10) are formed as recesses (12), in each of which one of the chip-shaped light sources (15a-d, 15) is included.

Lighting device (5, 50) according to claim 7, characterized in that the recesses (12) of the light source recording (10) individually with the light-absorbing potting compound (6) are filled, so that the filling level of the potting compound (6) in the respective recess (12) each to the thickness (Dl, D2, D3, D4) of that chip-shaped light source (15a-d, 15) can be adjusted, which is contained in the recess (12).

Lighting device (5, 50) according to any one of claims 7 to 8, characterized in that the recesses (12) relative to the surface (13) of the light source recording (10) are formed so deep that the intended for emitting the emission light surface ( 16) of the chip-shaped light source (15a-d, 15) contained in the recess (12) respectively below the surface (13) of the light source receptacle (10) or in the plane of the surface (13) of the light source receptacle (10) is arranged.

10. Lighting device (5, 50) according to any one of claims 7 to 9, character- ized in that the recesses (12) of the light source recording (10) have different depths (T) relative to the surface (13) of the light source receptacle (10). 10), the depth (T) of the depressions (12) being selected as a function of the thickness (D1, D2, D3, D4) of the chip-shaped light sources (15a-d) in order to provide the surfaces intended for emitting the emission light (FIG. 16a-d) of the light sources (15a-d) to be arranged exactly or at least approximately in the same plane (E2).

11. Lighting device (5, 50) according to any one of the preceding claims, characterized in that the light sources (15a-d, 15) and the lenses (2, 21) are arranged to each other that each light source (15a-d, 15) is less than the focal length of the lens (2, 21) away from its associated lens (2, 21).

12. Lighting device (5, 50) according to any one of the preceding claims, characterized in that the lenses (2, 21) by a microlens array (20) is provided, which is preferably formed as a one-piece body.

13. Lighting device (5, 50) according to claim 12, characterized in that the microlens array (20) has fastening means (22) for fastening the microlens array (20) to the light source receptacle (10).

14. Sensor (100) for checking value documents (1) comprising:

- A lighting device (5, 50) according to one of claims 1 to 13, and

an imaging optics (25) by which the light emitted by the illumination device (5, 50) can be imaged onto a value document (1) which, when the sensor (100) is operated, is to be detected by the sensor (00), and

- A detection device (30), which is designed to detect Detekti- onslicht, which, when operating the sensor (100), from the by the illumination device (5, 50) illuminated value document (1) emanates.

15. Sensor (100) according to claim 14, characterized in that the sensor (100) has a plurality of different light sources (15a-d, 15) which, upon operation of the sensor (100), are switched on and off one after the other Value document successively to illuminate with several different emission spectra.