Lighting device and method for generating an illumination light

Abstract

The invention relates to a lighting device for generating an illuminating light, comprising: o an illumination light source, o an optical interface for connecting an optical fiber to guide the illumination light, o a projection optics for projecting the illumination light source onto a projection plane in which a coupling surface of the optical fiber can be arranged, o a detection device for detecting at least one property of an optical fiber connected to the optical interface, o a control unit for controlling the illumination light source depending on the detected property of the optical fiber. In addition, a method for generating an illumination light is specified.

Description

Technical field

[0001] The invention relates to a lighting device with an optical interface for connecting an optical fiber. State of the art

[0002] From CN117768022A a training method for an artificially intelligent fiber detector is known, which is intended to detect defects in an optical fiber.

[0003] CN1869751A discloses a coupling for a fiber optic connector in which a light barrier detects whether an optical fiber is plugged in. A disadvantage is that the specification of the connected fiber cannot be detected.

[0004] JP2000019351 A discloses a coupling for a fiber optic connector in which a light barrier detects whether an optical fiber is plugged in. A disadvantage is that the specification of the connected fiber cannot be detected.

[0005] A device for determining the core diameter of an optical fiber is known from CN101846500A. However, this device is not suitable for integration into a light beam source.

[0006] From JPH10-267790 A a method for determining the core diameter of a multimode optical fiber is known.

[0007] JPS63-214638 A discloses a method for determining the core diameter of an optical fiber. In this method, a section of the fiber is bent and light is coupled into this section. The core diameter is determined from the image of the fiber's end face. However, bending the fiber can damage it.

[0008] EP1465256 A1 discloses a lighting device with multiple light-emitting diodes (LEDs). However, no fiber coupling is provided.

[0009] CN202791536 U discloses a lighting device in which the light from several light-emitting diodes is coupled together into an optical fiber. A disadvantage is that light can penetrate the fiber cladding or beside the fiber if a fiber with a core diameter that is too small is connected.

[0010] From DE10245140A1 a laser therapy device with an optical fiber connection is known, which comprises an RFID system for identifying the optical fiber.

[0011] From US2011 / 0238049 A1 a laser therapy device with an optical fiber connection is known, which comprises a sensor for identifying the optical fiber.

[0012] From EP0408160A1 a surgical laser device with an optical fiber connection is known, which comprises mechanical switches, optical switches or barcodes for identifying the optical fiber.

[0013] From US2006 / 0210228 A1 an optical fiber detector for identifying an optical fiber is known. Object of the invention

[0014] The object of the invention is to provide an energy-efficient, universally applicable lighting device for providing light via an optical fiber. Solution to the task

[0015] The object is achieved by a lighting device according to claim 1 and a method for generating an illumination light according to claim 10 and a use of a detection device according to claim 11. Advantages of the invention

[0016] The advantage of the invention lies in avoiding the disadvantages of known arrangements. The lighting device according to the invention is universally applicable and energy-efficient. Whereas previously several different lighting devices were required depending on the application, a single one is now sufficient. In particular, the lighting device can be suitable for the optional connection of optical fibers with differently sized coupling surfaces. Furthermore, the energy consumption is adapted to the respective optical fiber to be used. This increases the sustainability of the lighting device compared to known lighting devices. Description

[0017] In the following, a lighting device according to the invention together with the method according to the invention and the use are described.

[0018] The lighting device serves to generate illumination light. The lighting device comprises an illumination light source. This can advantageously be an LED light source. This can comprise a plurality of light-generating elements, for example light-emitting diodes. The light-emitting diodes can be arranged individually on a chip, in particular a semiconductor chip. However, several or all of the light-emitting diodes can also be formed as a light-emitting region on a common chip. Several or all of the light-emitting diodes can have a wavelength conversion element. With a wavelength conversion element, it can be possible, for example, to generate white LED light. The illumination light source can also comprise other light-generating elements, such as laser diodes, in particular those provided with a wavelength conversion element.

[0019] The main emission direction of the light-generating elements can be a z-direction. The light-generating elements can be arranged in an xy-plane. The x, y, and z coordinates can form a Cartesian coordinate system.

[0020] The light-generating elements can be Lambertian radiators. However, it is also possible for the light-generating elements to each have a collimating element, in particular for them to be designed as collimated light-emitting diodes, i.e., those with a limited radiation divergence angle.

[0021] The illumination device also comprises an optical interface for connecting an optical fiber for conducting the illumination light. The optical fibers provided for connection can be multimode. They can have one or more fiber cores. They can be designed as step-index fibers or as gradient-index fibers. These can advantageously be glass fibers, in particular quartz glass fibers. In the lower price segment, however, plastic fibers can also be used. The connection can be made, for example, via a detachable optical fiber connection device, such as an SMA or FC / PC or ST connector. The connector can have a locking mechanism, for example, a collar or a bayonet lock. The end of the optical fiber that can be connected to the optical interface can be embedded in a ferrule.The optical interface can, for example, be arranged on a housing of the lighting device. Optical fibers designed as individual fibers with a fiber core can be provided for connection to the optical interface. The fiber core can, for example, have a round or polygonal, for example square or hexagonal, cross-section. The fiber core of the individual fiber can be surrounded by a fiber cladding. The fiber cladding can have a lower refractive index than the fiber core. An optical fiber suitable for connection can, however, also be designed as a fiber bundle made up of several individual fibers, which can be arranged next to one another as closely packed as possible. This can have the advantage that the optical fiber designed as a fiber bundle is mechanically more flexible.However, with an optical fiber designed as a fiber bundle, the effectiveness of light coupling may be lower than with an optical fiber that has only a single fiber of the same cross-sectional area.

[0022] The illumination device also comprises a projection optics for projecting the illumination light source onto a projection plane in which a coupling surface of the optical fiber can be arranged.

[0023] The light-generating elements can all be projected onto a nominal coupling area located in the projection plane using the projection optics. The nominal coupling area can be the coupling area of a connectable nominal optical fiber with a maximum coupling area. If, however, an optical fiber with a smaller coupling area than the nominal coupling area is connected, those light-generating elements whose image lies within the nominal coupling area but outside the detected coupling area can be deactivated, as described below, depending on the detected coupling area.

[0024] The coupling surface can be the surface of the fiber core of the optical fiber at the fiber end. More generally, even for an optical fiber configured as a fiber bundle, the coupling surface can be the surface at the end of the optical fiber bounded by the smallest convex envelope of all the fiber cores of the individual fibers. The coupling surface can be circular or polygonal, for example. It can be approximately circular, for example. This means that the circumscribed diameter is no more than 20% larger than the inscribed diameter, and in particular no more than 10%.

[0025] The coupling surface can, for example, be arranged at a specific location in the projection plane by connecting the optical fiber to the optical interface using a connector.

[0026] The lighting device also comprises a detection device for detecting at least one property of an optical fiber connected to the optical interface.

[0027] The illumination device also comprises a control unit for controlling the illumination light source depending on the detected property of the optical fiber.

[0028] The detection device can comprise an RFID sensor. This can detect an RFID chip attached to the optical fiber, for example, on the ferrule, on which the properties of the optical fiber can be stored or encoded. This can restrict the use of the lighting device to specific optical fibers that have an RFID chip with the corresponding coding. This technical limitation on the compatibility of the optical fibers can have the economic advantage of preventing the use of fibers from other manufacturers that are not coded in a compatible manner.

[0029] The detection device can comprise a camera. The camera can be arranged such that an image of the fiber end, in particular an image of the coupling surface, can be captured. The property of the optical fiber, for example, the diameter of the coupling surface, can be determined from the captured image. For this purpose, known methods of pattern recognition in digital images and / or image recognition methods with artificial intelligence, which have been trained to detect optical fiber end surfaces, can be used.

[0030] The detection device can comprise a photodiode. The photodiode can be arranged such that the intensity of a back reflection from the fiber end can be detected. The intensity of the back reflection can be used, for example, to determine the diameter of the coupling surface. This method can be faster and more cost-effective than camera-based methods, but may have a higher error rate.

[0031] The detection device can comprise a set of electrical coding contacts, which can be used to contact mating contacts attached to the optical fiber. The coding of the contacts can be linked to the properties of the optical fiber. This can limit the use of the lighting device to specific optical fibers, which, for example, have the corresponding coding of the mating contacts on the fiber connector.

[0032] The at least one property of the optical fiber can advantageously be a diameter or an area or a shape of the coupling surface of the optical fiber or the numerical aperture of the optical fiber. It may also be possible to detect one or more further properties, in particular further properties of the aforementioned, in addition to the at least one property.

[0033] The illumination light source has a plurality of light-generating elements grouped into at least a first group and a second group. The control unit comprises a light-generating element group selection device. This device serves to select such groups of light-generating elements based on at least the detected property, such that the light-generating elements of the selected groups can be projected onto the coupling surface of the optical fiber with an image in the projection plane. "Projectable" can be understood to mean that the image of the light-generating elements of the group lies at least partially, preferably for the majority of its area and ideally completely, within the coupling surface.For example, in the case of a connected optical fiber with a small coupling area, the light-generating element group selection device can select only the first group of light-generating elements arranged on or near the optical axis. For example, in the case of a connected optical fiber with a large coupling area, the light-generating element group selection device can select, in addition to the first group, a second group of light-generating elements arranged peripherally to the first group with respect to the optical axis. It is also possible to provide three or more groups, wherein each of the groups can be arranged peripherally to the previous group. The coupling area of the optical fiber can, for example, have an effective diameter between 0.5 mm and 10 mm.If the coupling surface is not circular, a circle with the same area as the coupling surface can be assumed as the effective diameter. The light-generating element group selection device can be implemented as a computing unit that performs the selection using a stored program.

[0034] Furthermore, the control unit can have separately controllable electrical circuits for each group of light-generating elements. The control unit can be configured to supply an operating current only to the groups of light-generating elements selected by the light-generating element group selection device. Energy can be saved by not selecting the non-projectable groups and thus not supplying them with an operating current, i.e., by allowing them to remain switched off. Furthermore, unnecessary waste heat at the optical interface and in the optical fiber can be avoided. The control unit can comprise a computing unit that uses a stored program to control the electrical driver circuits for the circuits of the groups.

[0035] Advantageously, the first group of light-generating elements may have a smallest convex envelope and the light-generating elements of the second group may lie outside the smallest convex envelope of the first group.

[0036] Advantageously, the first group can have exactly one light-generating element or exactly three or exactly four light-generating elements.

[0037] The light-generating elements of the second group may be arranged concentrically with an N-fold axis of rotation lying in a z-direction, where N is the number of light-generating elements of the second group.

[0038] The illumination device can also comprise a detection light source that provides detection light for the detection device. This can be advantageous if the detection device comprises a camera, for example. The detection light can be coupled into the beam path of the illumination device via a semi-transparent mirror. It can also be coupled via the camera path. The detection light source can also be arranged as a ring light or as an oblique light source near the optical interface. In this case, coupling into the beam path can be omitted if the detection light is guided past the beam path of the illumination light. The detection light can also be generated by means of the illumination light sources for the illumination light—possibly at reduced light output. In this case, a separate detection light source can be dispensed with.

[0039] A further aspect of the invention is a method for generating an illumination light by means of an illumination device, comprising • Providing an illumination light source with a plurality of light generating elements grouped into at least two groups, • Connecting an optical fiber with a coupling surface to an optical interface of the lighting device, • Providing a projection optics for imaging the light generating elements in a projection plane in which the coupling surface of the optical fiber is arranged, • Detection of the coupling area by means of a detection device, • Selecting such groups of light generating elements whose image in the projection plane lies at least partially within the detected coupling area, • Operating at least one of the selected group of light generating elements to generate the illumination light, • Projecting the illumination light onto the coupling surface of the optical fiber, • Conducting the illumination light from the illumination device via the optical fiber.

[0040] A further aspect of the invention is the use of a detection device for detecting a diameter of a coupling surface of an optical fiber arranged in a projection plane, which is connected to an optical interface of a lighting device comprising a plurality of light generating elements, and for deactivating those light generating elements which cannot be projected onto the coupling surface.

[0041] An effective diameter can be assumed as the diameter in the manner described above if the light entry surface is not circular.

[0042] The light-generating elements can all be projected onto a nominal coupling area located in the projection plane. The nominal coupling area can be the coupling area of a connectable nominal optical fiber with a largest coupling area. If, however, an optical fiber with a smaller coupling area than the nominal coupling area is connected, those light-generating elements whose image lies within the nominal coupling area but not within the detected coupling area can be deactivated, depending on the detected coupling area. Deactivation can be performed using a control unit.

[0043] The purpose of use may be to save energy and / or to avoid cladding-guided light modes in the optical fiber.

[0044] The figures show the following: Fig. 1 shows a first embodiment of an illumination device with a first optical fiber in an x-projection. Fig. 2 shows the first embodiment of the lighting device with a second optical fiber. Fig. 3 shows a first example of an illumination light source. Fig. 4 shows a second example of an illumination light source. Fig. 5 shows a third example of an illumination light source. Fig. 6 shows a fourth example of an illumination light source. Fig. 7 shows a fifth example of an illumination light source. Fig. 8 shows a second embodiment of a lighting device. Fig. 9 shows an optical fiber designed as a fiber bundle. Fig. 10 shows the coupling surface of the optical fiber designed as a fiber bundle. Examples of implementation

[0045] The invention is explained below using exemplary embodiments.

[0046] Fig. 1 shows a first embodiment of an illumination device with a first optical fiber in an x-projection. The illumination device 1 serves to generate an illumination light 2. The illumination device comprises an illumination light source 4. The illumination device 1 also comprises an optical interface 9 for connecting an optical fiber 10 for conducting the illumination light 2. The connection can be made, for example, via an optical fiber connector, such as an SMA connector. For this purpose, the end of the optical fiber can be embedded in a ferrule 14. The optical interface 9 can be arranged, for example, on the housing of the illumination device 1.

[0047] The illumination device 1 further comprises projection optics 15 for projecting the illumination light source 4 onto a projection plane 20, in which a coupling surface 13 of the optical fiber 10 can be arranged. The projection optics 15 comprises a first lens group 16, which comprises one or more lenses, and a second lens group 17, which also comprises one or more lenses.

[0048] The lighting device also comprises a detection device 21 for detecting at least one property of an optical fiber 10 connected to the optical interface 9.

[0049] The illumination device also comprises a control unit 30 for controlling the illumination light source 4 depending on the detected property of the optical fiber 10.

[0050] The detection device 21 comprises an RFID sensor 25. This allows the detection of an RFID chip 26 attached to the optical fiber 10, for example to the ferrule 14, on which the property of the optical fiber 10 is stored or encoded.

[0051] The at least one property of the optical fiber 10 can advantageously be a diameter or an area or a shape of the coupling surface 13 of the optical fiber 10. It may also be possible to detect one or more further properties, in particular further of the aforementioned properties, in addition to the at least one property.

[0052] In the illustrated first embodiment, the illumination light source 4 has a plurality of light-generating elements 5, which are grouped into a first group 6 and a second group 7. The control unit 30 has a light-generating element group selection device 31 for selecting such groups 6, 7 of light-generating elements 5 based on at least the detected property, so that the light-generating elements 5 of the selected groups can be projected with an image in the projection plane 20 onto the coupling surface 13 of the optical fiber 10.

[0053] In Fig. 1, an optical fiber 10 with a fiber core 11 with a maximum fiber core diameter, for example, 5 mm, is connected to the interface 9. The coupling surface 13 can be the nominal coupling surface, i.e., the largest intended coupling surface. As can be seen from the illustrated beam path of the illumination light 2, both the first group 6 and the second group 7 of light-generating elements 5 can be projected onto the coupling surface 13. Since the coupling surface 13 extends sufficiently far around the optical axis in the x and y directions, respectively, the light from the peripherally located second group 7 also reaches the coupling surface. Thus, both the first group 6 and the second group 7 are selected by the light-generating element group selection device 31.

[0054] Furthermore, the control unit 30 has separately controllable electrical circuits with a first LED driver 32 for the first group 6 and a second LED driver 33 for the second group 7 of light-generating elements 5. The control unit 30 supplies the groups 6, 7 of light-generating elements 5 selected by the light-generating element group selection device 31 with an operating current via the LED drivers 32, 33. The arrows represent the respective signal flows.

[0055] Fig. Figure 2 shows the first embodiment of the illumination device with a second optical fiber. In this figure, an optical fiber 10 with a fiber core 11 with a small fiber core diameter, for example, 2 mm, is connected to the interface 9. The coupling area 13 is now smaller than the aforementioned nominal coupling area of Fig. 1. As can be seen from the illustrated beam path of the illumination light 2, only the first group 6 of light-generating elements 5 can be projected onto the coupling surface 13. The inactive beam path 3 of the switched-off second group 7 of light-generating elements 5, shown in dashed lines, would fall onto the ferrule 14 and could not be coupled into the core 11 of the optical fiber 10 via the coupling surface 13. Thus, only the first group 6 is selected by the light-generating element group selection device 31. The control unit 30 supplies only the first group 6 with an operating current via the circuit of the first LED driver 32. The second LED driver 33 is inactive, so that the circuit of the second group 7 of light-generating elements 5 is deactivated, i.e., without operating current, and thus generates no light. By not supplying any operating current to the second non-projectable group 7, energy can be saved. Furthermore, unnecessary waste heat at the optical interface 9, 14 and in the optical fiber 10 can be avoided.

[0056] In a first modification of the example, not shown in the figure, the detection device 21 comprises a camera, see also the second embodiment in Fig. 8. The camera is arranged in such a way that an image of the fiber end, in particular an image of the coupling surface, can be captured. The properties of the optical fiber, for example, the diameter of the coupling surface, can be determined from the captured image.

[0057] In a second modification of the example (not shown in the figure), detection device 21 comprises a photodiode. The photodiode is arranged such that the intensity of a back reflection from the fiber end can be detected. The diameter of the coupling surface, for example, can be determined from the intensity of the back reflection.

[0058] In a third modification of the example, not shown in the figure, the detection device 21 comprises a set of electrical coding contacts 27. The coding of the contacts is linked to the property of the optical fiber.

[0059] In the further embodiments, the reference symbols introduced here continue to apply accordingly.

[0060] Fig. Figure 3 shows a first example of an illumination light source. The illumination light source 4 is shown in an xy view, while the main emission direction of the light from the light-generating elements 5 is the z-direction. In this illumination light source 4, the first group 6 contains exactly one light-generating element. The light-generating elements of the second group 7 are arranged around the first group 6.

[0061] The first group 6 of light-generating elements has a smallest convex envelope 36, which corresponds to the contour of the centrally shown light-generating element of the first group 5, 6. The light-generating elements of the second group 7 lie outside the smallest convex envelope 36 of the first group 6.

[0062] Fig. Figure 4 shows a second example of an illumination light source. In this illumination light source 4, the first group 6 includes four light-generating elements. The light-generating elements of the second group 7 are arranged around the first group 6. The first group 6 of light-generating elements has a smallest convex envelope 36. The light-generating elements of the second group 7 lie outside the smallest convex envelope 36 of the first group 6.

[0063] Fig. Figure 5 shows a third example of an illumination light source. In contrast to the aforementioned example of an illumination light source, the second group 7 here additionally includes smaller light-generating elements.

[0064] Fig. Figure 6 shows a fourth example of an illumination light source. The light-generating elements 5 of the second group 7 are arranged concentrically with an N-fold axis of rotation in a z-direction, where N is the number of light-generating elements 5 in the second group 7. In the figure, N=10 light-generating elements 5 are shown in the second group. However, in variations of the example, there may be more or fewer.

[0065] This figure also shows the imageable area 37 for a small coupling area, the imageable area 38 for a medium coupling area, and the imageable area 39 for a large coupling area. For example, the small coupling area can have a diameter of 2 mm, the medium coupling area 3 mm, and the large coupling area 5 mm.

[0066] If an optical fiber with the small coupling area is connected to the illumination device, only the first group 6 is supplied with an operating current. Since the light-generating elements of the first group 6 partially protrude from the imageable area 37, this portion of the light from these light-generating elements cannot be coupled into the small optical fiber.

[0067] If an optical fiber is connected to the illumination device with the central coupling surface, only the first group 6 is supplied with an operating current. Since the light-generating elements of the first group 6 are now completely located within the imageable area 38, the light from these light-generating elements can be better utilized.

[0068] If an optical fiber with the large coupling area is connected to the illumination device, both the first group 6 and the second group 7 are subjected to an operating current. Since the light-generating elements of the first group 6 are now completely located within the imageable area 38, the light from these light-generating elements can be better utilized.

[0069] Fig. Figure 7 shows a fifth example of an illumination light source. The illumination light source 4 has a central light-generating element of the first group 5, 6, as well as a peripheral light-generating element of the second group 5, 7, which is annular. This can be segmented as shown, but does not have to be. Optionally, a third light-generating element of a third group 5, 8 can be provided peripherally to the second group 7.

[0070] Fig. Figure 8 shows a second embodiment of an illumination device. The illumination device 1 here additionally comprises a deflecting mirror 18, which deflects the illumination light 2 from the illumination light source 4. Therefore, the fiber coordinate system x'y' is rotated relative to the coordinate system xy of the illumination light source 4.

[0071] In this example, the detection device 21 comprises a camera with an image sensor 22, which is equipped with a partially transparent camera mirror 24 and a camera lens 23. The camera 21, 22, 23, 24 is arranged such that an image of the fiber end, in particular an image of the coupling surface 13, can be captured. The property of the optical fiber 10, for example, the diameter of the coupling surface 13, can be determined from the captured image.

[0072] A detection light source 28 for generating a detection light 29 is optionally provided for the detection device using the image sensor 22. Alternatively, the separate detection light source 28 can be omitted. Then, for example, light emitted by the illumination light source 4 can be used as the detection light.

[0073] Optionally, a second illumination light source 4b can be provided, which couples a second illumination light 2b into the beam path by means of a second deflecting mirror 18b. For this purpose, if the wavelengths of the first and second illumination light sources differ, the first deflecting mirror 18 can be dichroic. The second illumination light source 4b can have a similar grouping of the light-generating elements as the first illumination light source 4. In the optical fiber 10 shown as an example, the beam path 3b would then also be inactive.

[0074] The illustrated coding contacts 27 on the ferrule 14 are optional in the second embodiment of the lighting device.

[0075] In a first modification of the example, the detection device 21 comprises, alternatively or in addition to the camera 22, 23, 24, a set of electrical coding contacts 27. The coding of the contacts is linked to the property of the optical fiber 10.

[0076] In a second modification of the example (not shown in the figure), detection device 21 comprises a photodiode instead of camera 22. The photodiode is arranged such that the intensity of a back reflection from the fiber end can be detected. For example, the diameter of the coupling surface 13 can be determined from the intensity of the back reflection.

[0077] Fig. Figure 9 shows an optical fiber configured as a fiber bundle. The optical fiber 10 is shown in the projection plane. The optical fiber 10 comprises several individual fibers, each with a fiber core 11 and a fiber cladding 12. The individual fibers have a hexagonal cross-section. In a modification not shown in the figure, they can have a round cross-section. The individual fibers are embedded in a ferrule 14 at the end of the optical fiber located in the projection plane.

[0078] The first and second embodiments of the lighting device 1 described above can also be operated with optical fibers designed as fiber bundles instead of the optical fibers 10 shown.

[0079] Fig.Figure 10 shows the coupling area of the optical fiber designed as a fiber bundle. As already described, the coupling area 13 is limited by the smallest convex envelope of the fiber cores 11 of the individual fibers. This figure also shows that an optical fiber designed as a fiber bundle can be less efficient than an optical fiber with only one fiber core and the same coupling area. The sum of the areas of the individual fiber cores 11 of a fiber bundle is smaller than the coupling area 13. The light that does not strike one of the individual fiber cores 11 within the coupling area cannot be used. For the sake of clarity, the fiber cladding of the individual fibers is not shown in this figure.

[0080] Please note that the figures are not drawn to scale.

[0081] The reference symbols used consistently in all figures are as follows: 1 lighting device 2 Illumination light 3 Inactive beam path 4 Light source 5 Light generating element 6 First group 7 Second group 8 Third group 9 Optical interface 10 optical fibers 11 Fiber core 12 fiber sheath 13 Coupling area 14 Ferrule 15 Projection optics 16 First lens group 17 Second lens group 18 deflecting mirrors 19 Optical axis 20 image plane 21 Detection device 22 image sensor 23 Camera lens 24 camera mirrors 25 Fiber type detector 26 RFID elements 27 Coding contact 28 Detection light source 29 Detection light 30 Control unit 31 Computing unit, light-generating element group selection device 32 First LED driver 33 Second LED driver 34 Projection optics 35 Optical axis 36 Smallest convex envelope of the first group 37 Imageable area for a small fiber core 38 Imageable area for a medium fiber core 39 Imageable area for a large fiber core

Claims

[1] Lighting device (1) for generating an illuminating light (2), comprising: • An illumination light source (4), • An optical interface (9) for connecting an optical fiber (10) for guiding the illumination light (2), • A projection optics (15) for projecting the illumination light source (4) onto a projection plane (20), in which a coupling surface (13) of the optical fiber (10) can be arranged, • a detection device (21) for detecting at least one property of an optical fiber (10) connected to the optical interface (9), • a control unit (30) for controlling the illumination light source (4) depending on the detected property of the optical fiber (10), wherein • the illumination light source (4) comprises a plurality of light generating elements (5) which are grouped in at least a first group (6) and a second group (7) and • the control unit (30) has a light-generating element group selection device (31) for selecting such groups (6, 7, 8) of light-generating elements (5) based on at least the detected property, so that the light-generating elements (5) of the selected groups can be projected with an image in the projection plane (20) onto the coupling surface (13) of the optical fiber (10), and • the control unit (30) has separately controllable electrical circuits (32, 33) for each of the groups (6, 7, 8) of light-generating elements (5), the control unit (30) is designed to supply an operating current only to the groups (6, 7, 8) of light-generating elements (5) selected by the light-generating element group selection device (31). [2] Lighting device (1) according to claim 1, wherein the detection device (21) comprises at least one RFID sensor (25) and / or a camera (22, 23) and / or a photodiode and / or a set of electrical coding contacts (27). [3] Lighting device (1) according to one of the preceding claims, wherein the at least one property of the optical fiber (10) is a diameter or an area or a shape of the coupling surface (13) of the optical fiber (10) or the numerical aperture of the optical fiber (10). [4] Lighting device (1) according to one of the preceding claims, wherein the illumination light source (4) has a plurality of light generating elements (5) which are designed as Lambertian radiators or each have a collimation optic for reducing divergence. [5] Lighting device (1) according to one of the preceding claims, which is provided for connecting an optical fiber (10) designed as a fiber bundle comprising a plurality of individual fibers to the optical interface (9). [6] Lighting device (1) according to one of the preceding claims, wherein the first group (6) of light-generating elements (5) has a smallest convex envelope and the light-generating elements (5) of the second group (7) lie outside the smallest convex envelope of the first group (6). [7] Lighting device (1) according to one of the preceding claims, wherein the first group (6) comprises exactly one light-generating element (5) or exactly three or exactly four light-generating elements (5). [8] Lighting device (1) according to one of the preceding claims, wherein the light-generating elements (5) of the second group (7) are arranged concentrically with an N-fold axis of rotation lying in a z-direction, where N is the number of light-generating elements (5) of the second group (7). [9] Method for generating an illuminating light (2) by means of an illuminating device (1), comprising • Providing an illumination light source (4) with a plurality of light generating elements (5) which are grouped in at least two groups (6, 7, 8), • Connecting an optical fiber (10) with a coupling surface (13) to an optical interface (9) of the lighting device (1), • Providing a projection optics (15, 16, 17) for imaging the light generating elements (5) in a projection plane (20) in which the coupling surface (13) of the optical fiber (10) is arranged, • detecting the coupling surface (13) by means of a detection device (21, 22, 23, 25, 26), • Selecting such groups (6, 7, 8) of light-generating elements (5) whose image in the projection plane (20) lies at least partially within the detected coupling surface (13), • Operating at least one of the selected group (6, 7, 8) of light generating elements (5) to generate the illumination light (2), • Projecting the illuminating light (2) onto the coupling surface (13) of the optical fiber (10), • Conducting the illumination light (2) from the illumination device (1) via the optical fiber (10). [10] Use of a detection device (21) for detecting a diameter of a coupling surface (13) of an optical fiber (10) arranged in a projection plane (20), which is connected to an optical interface (9) of a lighting device (1) comprising a plurality of light generating elements (5), and for deactivating those light generating elements which cannot be projected onto the coupling surface (13).

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