EP3056800B1 - Lighting device for a motor vehicle - Google Patents

Description

The invention relates to a lighting device for a motor vehicle with a laser light source for emitting a laser light beam and with a diffractive optical element, at least a portion of which is arranged in a beam path of the laser light beam.

Laser light sources for headlights are being used more and more in the automotive sector. Here, one or more laser light beams can be directed into the surroundings of a motor vehicle via a deflection system in order to illuminate them. Alternatively, the laser light beam or beams can also be directed onto a converter element, a "phosphor", which is thus excited to emit a light illuminating the surroundings of the motor vehicle in a color different from the color of the laser light beam. Micro-mirror systems or electro- or acousto-optic crystals or modulators are generally used to deflect the laser beams. However, there are other approaches to handling laser light beams in automotive lighting systems. Diffractive optical elements, which generate an optical effect via wave diffraction, can also be used with a laser light source.

For example, the DE 103 33 370 A1 a lighting device for an automobile, with a light source and a lens. The lens has a diffractive structure on one of its surfaces. A laser light source is proposed here as the light source.

In the post-published EP 3 216 650 A1 describes a lighting device comprising a coherent light source and an optical component for scattering coherent light from the light source. The optical component has a first scatter region, which the light for illuminating a first area scatters, and a second scattering region which scatters the light for displaying predetermined information in a second area.

The FR 3 009 061 A1 describes a lighting and / or signaling system with an improved shaping of scattered radiation. There, a light beam emitted by a primary light source is directed onto a disk-shaped optical element which has at least one holographic area. This optical element can also have prisms for influencing scattered radiation and is also movable, for example rotatable about an axis of rotation. The disk-shaped optical element can have a plurality of holographic regions, each of which is provided for a spatial distribution of the incident light in accordance with a predetermined beam shape.

From the WO 2010/058323 A1 a lighting device is known in which light emitted by a light source is directed from an optical element onto a screen-like element, the latter influencing at least one physical property such as the color or polarization of the light passing through.

It is the object of the present invention to provide a lighting device by means of which flexible lighting can be achieved with little mechanical and electronic effort.

This object is achieved by the subject matter of patent claim 1. Advantageous embodiments result from the dependent claims, the description and the figures.

A lighting device according to the invention for a motor vehicle has a plurality of laser light sources for emitting laser light beams and a plurality of diffractive optical elements, of which a plurality of subregions are arranged at the same time in the respective beam paths of the laser light beams. The lighting device can in particular be a headlight device. In order to achieve a flexible lighting device with little mechanical and electronic effort, provision is made, inter alia, for the diffractive optical element to be rotatable about an axis of rotation with respect to the laser light source. Thus, partial areas of this diffractive optical element of at least one of the diffractive optical elements are different, which each have different optical properties, can be rotated into the beam paths by rotation about the axis of rotation. The laser light beams can thus be influenced differently by the different partial areas, that is to say in particular deflected and / or adjusted in their intensity profiles. This has the advantage that flexible lighting is achieved, the properties of which can be set by rotating or rotating the diffractive optical element.

Different partial areas of the diffractive optical element can thus be illuminated simultaneously by one of the different laser light sources. This has the advantage that when using a plurality of laser diodes, which are required to achieve a predetermined light output or intensity of an illuminating or headlight light in the prior art, no combination of the individual laser beams ("beam combining") is required to achieve this predetermined light output is. Accordingly, the otherwise required related components can be saved here. In addition, less power is concentrated on one point, which is advantageous in terms of heat and safety. in an operation with a continuous rotation of the optical element, the frequency in which a certain partial area of the diffractive optical element is irradiated is increased even at a constant rotational speed. This can be used for improved light quality, for example reduced flicker.

If different deflection angles are assigned to the different sub-areas as defined in the previous paragraph, the use of multiple laser light beams can also influence the spatial distribution of the center of gravity and thus a deformation of a resulting light distribution.

The following statements for a single laser light beam and a single diffractive optical element can apply correspondingly to all laser light beams emitted by the plurality of laser light sources and to the diffractive optical elements.

The intensity distribution of the laser light beam can be adapted and / or deflected almost as desired via the specific configuration of the diffractive optical element. In particular, it is possible that the intensity distribution in the laser light beam, the "beam profile", is no longer one usual Gaussian distribution, but a predetermined distribution, for example a so-called "top hat" intensity distribution, in which within a predetermined, flat area the laser light beam uniformly reaches a maximum intensity, which is limited by a sharp, almost abrupt transition to a zero intensity. Such intensity distributions or beam profiles can also be designed as a "circular flat-top beam" with a circular flat area, "linear flat-top beam" with a linear or rectangular flat area or "square flat-top beam" with a square flat area. This has the advantage that an environment of the lighting device can be illuminated particularly precisely and precisely, for example by highly precise irradiation of the known converter elements (“phosphors”) for converting the wavelengths of light rays or directly by means of the laser light beam itself. In addition, an area illuminated by the laser light beam ("spot") or an illuminated area or room area can be illuminated or irradiated in a simple manner in a very homogeneous manner.

By means of the specific configuration of the diffractive optical element or of the different partial areas, a beam expansion or beam splitting can also be implemented independently of other optical properties. This has the advantage that surfaces of different sizes, so-called “spots”, can be illuminated homogeneously by the laser light beam.

In this way it is also possible, for example, to generate a low-intensity secondary beam, for example for beam measurement, in particular for a security concept. Smoothing of a beam cross-sectional profile can also be achieved with this, as well as a large number of symmetrical or asymmetrical beam profiles of the intensity of the laser beam.

It is particularly important that the laser light beam can be deflected into different spatial areas due to the different optical properties of the different partial areas. As a result, areas that can be predetermined by the laser light beam and whose size exceeds the diameter of the laser light beam can be illuminated and scanned or scanned. This can be, for example, surface areas on a converter element or also surface areas in the vicinity of the lighting device, in particular a street.

These properties to be achieved can be combined and determined in advance by the specific configuration of the optical element. This means that they do not require any electronically or mechanically complex structures. This also enables a high degree of compactness with a very high level of accuracy. Overall, great lighting flexibility is achieved.

The diffractive optical element can be designed both as a transmissive system, for example as a glass or plastic component, and as a reflective system, for example in the form of a structured metal plate. In particular, the diffractive optical element can be implemented as a band on a carrier, which is designed, for example, as a disk that can be rotated about the axis of rotation. The approach is therefore suitable for a large number of installation space geometries.

The diffractive optical elements are annular and concentric and the axis of rotation runs through the center of the ring formed by the annular diffractive optical elements. The diffractive optical elements can thus form a ring or have the shape of a ring. For each of the diffractive optical elements, this has the advantage that a large number of different subregions of the diffractive optical element can be introduced into the beam path one after the other, and thus in a simple manner, namely by simply rotating the diffractive optical element about the axis of rotation, the laser light beam is modified according to the optical properties of the different sub-areas. The multiple concentric annular diffractive optical elements can be referred to as bands. A partial area of each annular diffractive optical element is arranged in the beam path of one of the laser light beams. In particular, the concentric annular diffractive optical elements are arranged on a common carrier. The carrier can be designed as a rotatable disc. Since the diffraction of the laser light beams in the different optical subregions of the diffractive optical elements is independent of one another, the different diffractive optical elements or their subregions can be freely assigned to the desired optical effects. These different effects can then be switched on or off by switching the assigned laser light sources on and off. This has the advantage that compared to an embodiment with a single diffractive optical element, a more compact design or a smaller maximum diameter of the rotatable diffractive optical elements or of the common carrier is achieved. In addition, a beam combiner that might otherwise be required can also be saved. Increasing the flexibility of the lighting is also achieved by switching the optical effects assigned to the laser light sources on and off.

According to the invention, it is provided that the lighting device has one converter element or several converter elements, one or more of the so-called “phosphors”, for converting a wavelength distribution. This converter element or converter elements are arranged in the beam path of the laser light beams after the diffractive optical element. This has the advantage that the laser light beam is converted in the manner of known laser headlights into a so-called “white light” with a high yellow component for illuminating an environment of the illuminating device, and thus a light that is pleasant for the human viewer to illuminate an environment of the illuminating device is produced. The use of the rotatable diffractive optical element is particularly advantageous here, since a complex mechanical and electronic control can be replaced in a deflection system for dynamic laser light applications.

In addition, the heat distribution on the phosphor, which is fundamentally problematic in the prior art, can be improved in a simple manner, since the system described is suitable for use without an additional device for beam combining ("beam combining"). Here, instead of a single laser light beam with high intensity at one point, preferably several laser light beams of lower intensity strike the phosphor at several points and excite it there to light up. The risk of local overheating and possibly damage to the phosphorus is then correspondingly reduced.

The brightness and resolution of the light distribution on the converter element can also be set in an extremely simple manner. A local brightness can be increased, for example, in that, for example, adjacent partial areas of a diffractive optical element have similar properties and, for example, deflect a laser light beam onto the phosphor in almost the same area. The effect is that the laser light beam converts more slowly over the phosphor and at this point the intensity of the light emitted by the converter unit is higher. The partial regions of different diffractive optical elements can also direct laser light beams onto identical or almost identical regions of the phosphor. The local brightness can then be increased and decreased by switching the assigned laser light sources on and off. At the same time or alternatively, the resolution of the area glowing on the phosphor can be increased, for example by neighboring partial areas of the diffractive optical element deflecting a laser light beam onto respectively smaller segments of the phosphor. The phosphor can thus be used particularly efficiently through optimized beam focusing / widening.

In a further embodiment it is provided that the diffractive optical element is rotated continuously and in particular uniformly by a drive during operation of the lighting device. In particular, this can take place at a speed of more than 50 revolutions / second, preferably at a speed of between 100 and 200 revolutions / second. The numbers mentioned apply in particular to an embodiment with a laser light source and / or a laser light beam, in the beam path of which a partial region of the diffractive optical element is arranged. If there are several laser light sources and / or such laser light beams, the numbers in particular can be reduced by a corresponding factor. This applies if the corresponding laser light beams traverse or scan identical room or surface areas. If, for example, the identical surface area is traversed by four laser light beams, the speed can be reduced by a factor of four, so it only has to have more than 12.5 revolutions / second and is preferably between 25 and 50 revolutions / second. This has the advantage that the laser light beam is periodically bent in a particularly simple manner mechanically and electronically. The laser light beam is thus periodically modified in accordance with the optical properties of the partial areas. At a minimum speed of 50 revolutions / second, it is particularly easy to generate a periodic repetition that is invisible to the human eye. A speed between 100 and 200 revolutions / second is particularly suitable here, since the mechanical load on the associated component is thus also limited.

In a particularly preferred embodiment it is provided that in the different subregions of the diffractive optical element impinging laser light beam is deflected at a different angle, which is specific for the respective sub-area. The angle here can be defined relative to the beam path of the laser light beam between the laser light source and the diffractive optical element. Thus, by means of the diffractive optical element, a spatial area which is determined by the different angles can be traveled through by the laser light beam. Thus, the incident laser light beam can be deflected at a first angle by a first partial region of the diffractive optical element and the laser light beam can be deflected at a second angle different from the first in a second partial region. In this way, a space can be scanned or illuminated by the laser beam in the manner of a Braun tube or in the manner of known laser-based headlights. This has the advantage that the area can be traversed by the laser beam in a compact and low-component manner. In contrast to the known micromirror systems, there are no longer residence times of the laser beam in the edge areas of the scanned area. In a motor vehicle, this leads to a desired luminous image, since a disproportionate or disproportionate brightness is avoided in the edge areas of the light distribution. Moreover, the need for a mirror or a deflection unit for each axis in the room, as is the case in the prior art, is eliminated. The problem of beam deflection is given here by a one-piece system with a single operating parameter, namely the rotational speed of the diffractive optical element. The mechanical and electronic effort is therefore minimized.

In a particularly advantageous embodiment, it is provided here that different spatial areas can be traversed by means of the different diffractive optical elements through the assigned different laser light beams. Different light functions can thus be implemented by the different diffractive optical elements or their associated laser light sources. For example, a first laser light beam, which is deflected by a first diffractive optical element, can travel over a spatial area that corresponds to a low beam. A second laser light beam can then, for example, use a second diffractive optical element to travel exactly the area that is to be illuminated for a high beam in addition to the low beam. The spatial areas can be assigned to a converter element or an environment of the lighting device. So that the lighting device Switch between different light functions in an extremely simple manner, namely simply by switching the corresponding laser light source on or off. A mechanical control of different components or the like, however, is not necessary.

In a further advantageous embodiment, it is provided here that the one converter element or the plurality of converter elements are each arranged at least partially in the different spatial areas which are scanned by the laser light beam or the laser light beams by means of the diffractive optical element or the diffractive optical elements. One converter element or the plurality of converter elements can thus in each case be illuminated at least partially by means of different diffractive optical elements by means of different laser light beams. Correspondingly, different light functions can be assigned to the different room areas similar to the relationship described above. If several converter elements are used, the advantage here is that smaller secondary lenses can be used, so that installation space can be saved and this can be used more flexibly. This also gives more design options.

In a particularly advantageous embodiment it is provided that a reference marking is arranged on the diffractive optical element or on a carrier of a diffractive optical element. The reference marking can be, for example, a non-rotationally symmetrical marking, in particular in the form of an elliptical ring around the axis of rotation. The non-rotationally symmetrical marking can also have a rotationally symmetrical shape, but non-rotationally symmetrical properties, for example angle-dependent transparency or reflection properties. It can also be a rotationally symmetrical marking, such as a slip ring. It can also be a single partial area of the diffractive optical element which directs the laser light beam onto a sensor or a measuring device which is otherwise not illuminated by the laser light beam. This measuring device can be used in particular for a security concept. The angle of rotation of the diffractive optical element can thus be determined. As a result, the lighting device can be adjusted accordingly or a synchronization the rotation of the diffractive optical element with the laser light sources.

Another embodiment provides that a cooling wing is arranged on the diffractive optical element or on a carrier of the diffractive optical element. The cooling blade can in particular be one or more cooling blades or fan blades, which ensure air circulation in the manner of a fan. This has the advantage that the air circulation and thus the cooling in the lighting device is improved. In particular, the risk of the phosphor overheating is thus reduced and / or cooling of the laser light sources is promoted.

All of the features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without the frame to leave the invention. Embodiments of the invention are thus also to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, but can be derived from the explanations explained and can be generated by separate combinations of features.

Fig. 1

eine beispielhafte Ausführungsform einer erfindungsgemäßen Beleuchtungseinrichtung und

Fig. 2

eine beispielhafte Ausführungsform einer weiteren erfindungsgemäßen Beleuchtungseinrichtung.

Exemplary embodiments of the invention are explained in more detail below with the aid of schematic drawings. Show:

Fig. 1

an exemplary embodiment of a lighting device according to the invention and

Fig. 2

an exemplary embodiment of a further lighting device according to the invention.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

Fig. 1 shows an exemplary embodiment of a lighting device. The lighting device 1 comprises a laser light source 2, which emits a laser light beam 3, with the clarity here for the sake of only one laser light source 2 or one laser light beam 3 is shown. A diffractive optical element 5 with at least one partial region 6 is arranged here in a beam path 4 of the laser light beam 3. In the present case, the diffractive optical element 5 is designed as an annular band which is arranged on a carrier 7 designed as a disk. In the present case, the carrier 7 can be rotated about an axis of rotation A. The diffractive optical element 5, which is embodied here as a band and which forms a ring around the axis of rotation A, is thus also rotatable about the latter. The axis of rotation A runs through the center M of the ring formed by the diffractive optical element 5 embodied here as a band.

In the example shown, the lighting device 1 also has a converter element 8, a so-called phosphor. The converter element 8 is used for the wavelength conversion of a laser light radiated onto the converter element 8, for example on the basis of fluorescent or phosphorescent properties of the converter element 8. For ease of understanding, the converter element 8 in this illustration is in columns 8a, 8b, 8c, 8d, 8e and rows 8v, 8w, 8x, 8y, 8z divided. In the present case, the rows and columns divide the converter element 8 into converter segments 8 _ij , the converter segment 8 _av , for example, describing the segment of the converter element 8 which is in the column 8a and row 8v. The number of columns and rows here is purely exemplary. Moreover, the converter element 8 does not actually have to be divided into columns and rows with resulting converter segments 8 _ij . Rather, the converter element 8 can also be a homogeneously designed converter element 8, which, for example, is virtually divided into converter segments 8 _ij , which are then scanned by the laser light beam 3.

In the example shown, the converter element is arranged behind the diffractive optical element 5 or the carrier 7, since in the present example the diffractive optical element 5 has transmissive properties. The laser light beam 3 thus penetrates through the diffractive optical element 5 and is directed by this in a predetermined manner onto the converter element 8 or the respective converter segments 8 _ij . If, for example, the diffractive optical element 5 is not designed with transmissive but with reflective properties, the converter element 8 will continue to be arranged in the beam path 4 after the diffractive optical element 5, but then geometrically on that in comparison to the illustrated embodiment, the other side of the diffractive optical element 5.

When the lighting device 1 is in operation, the laser light source 2 now radiates the laser beam 3 onto the partial area 6 of the diffractive optical element 5 at the time shown. The partial area 6 of the diffractive optical element 5 is designed in the example shown so that it deflects the laser light beam 3, specifically in the illustration exactly on the converter segment 8 _{av of} the converter element 8. This is thus excited here to emit white light radiation. Since the diffractive optical element 5 on the carrier 7 is rotated continuously and preferably at a uniform speed in the direction of the arrow in operation in the present case, another subarea 6 ′ with optical properties different from the first subarea 6 is rotated into the beam path 4 next. In the example shown, the further partial region 6 ′ is configured in such a way that deflection of the laser light beam 3 onto the converter segment 8 _bv , which is arranged here adjacent to the first converter segment 8 _av , is deflected. In this sense, the deflection of the laser light beam 3 also takes place through further subareas, which are not shown here for reasons of clarity. Because of the rotation of the diffractive optical element 5 in the arrow direction on the converter element 8, the laser light beam 3 also moves in the arrow direction and thus moves the converter element 8 line by line in the present case. The entire converter element 8 can thus be scanned with the laser light beam 3 and excited to light over a number of different partial areas 6, 6 'on the diffractive optical element 5. In an alternative embodiment, the converter element 8 can also be omitted, for example, and instead an area of the lighting device 1 can be scanned directly by the laser light beam 3 and thus illuminated.

Fig. 2 shows a further exemplary embodiment of a lighting device. The lighting device 1 here comprises a plurality of, in the present case twelve, laser light sources 2a to 2l which emit respective laser light beams 3a to 3l. The lighting device 1 also comprises several, in the present case six, diffractive optical elements 5a to 5f. In the present case, these diffractive optical elements 5a to 5f are arranged as ring-like bands on the carrier 7 designed as a disk. The diffractive optical elements 5a to 5f are arranged as concentric rings around the center M of the carrier 7. Also runs through the center point M. the axis of rotation A ( Fig. 1 ). In the example shown, the diffractive optical elements 5a to 5f are each subdivided into a plurality of subregions 5 _ij, each of which has different optical properties in this example. The laser light sources 2a to 2l or their associated beam paths 4a to 4l and the disk 7 or the diffractive optical elements 5a to 5f arranged on the disk 7 are now arranged in such a way that different partial areas 5 _{ij of} the diffractive optical elements 5a to 5f are Laser light sources 2a to 2f are irradiated. In the example shown, each of the diffractive optical elements 5a to 5f is assigned two laser light sources 2a to 2f, that is to say at the same time two different subregions 5 _ij or segments of a respective diffractive optical element 5a to 5f are assigned to the respective diffractive optical element 5a by the two to 5f associated laser light sources 2a to 2l irradiated. Correspondingly, the laser light beams 3a to 3l reflected or transmitted by the respective subregions 5 _{ij of} the diffractive optical elements 5a to 5f, but in any case diffracted and in the present case deflected, are deflected independently of one another and can thus be used to, for example, a converter element 8 as shown in FIG Fig. 1 is shown, or to drive or illuminate an environment of the lighting device 1.

Since the carrier 7 with the diffractive optical elements 5a to 5f is rotated around the center point M of the disk in relation to the stationary laser light sources 2a to 2l during operation of the illumination device 1, different partial areas 5 _{ij of} the diffractive optical elements 5a to 5f are illuminated at successive times. Since the different sub-areas 5 _{ij have} different optical properties, in the present case a different deflection behavior of an incident light, the resulting deflected, that is to say reflected or transmitted, laser light beams 3 a to 3 l will move in the room and traverse a respective area of the room. It can be realized, for example, that the respective laser light beams 3a to 3l have different segments 8a to 8j ( Fig. 1 ) of a converter element 8 ( Fig. 1 ) depart. Since such a converter element 8 ( Fig. 1 ) is then irradiated at many points at the same time, a heat output is spatially distributed and a cooling problem that frequently occurs in the prior art is reduced. Moreover, combining ("beam-combining") the different laser light beams 3a to 3l, as is known from the prior art, is also superfluous. The use of a variety of inexpensive laser light sources 2a to 2l with a proportionate Low beam power is therefore also technically advantageous compared to the use of fewer, but more expensive, high-power laser light sources.

By means of the different diffractive optical elements 5a to 5f, predetermined spatial areas, for example said segments 8 _{ij of} the converter element 8 ( Fig. 1 ), be driven and illuminated. Different light functions can thus also be assigned to the different diffractive optical elements 5a to 5f, for example by traversing spatial areas by the laser light beams 2a to 2l which correspond to a high beam or low beam function. To activate or deactivate the corresponding light function, only the corresponding laser light source 2a to 2l then has to be switched off or on. A changed mechanical control of mechanical components, however, is not necessary. Corresponding control components can be designed to be cheap and durable.

In the example shown, a reference marking 9 is also applied to the disk-shaped carrier 7. In the present case, this is designed as an elliptical optical marking, which can be detected by an optical sensor. A rotation angle or the position of the carrier 7 and thus the diffractive optical elements 5a to 5f can thereby be determined. An alternative possibility for such a reference marking is also to design, for example, one or more of the partial areas 5 _{ij in} accordance with the known laws of optics such that an incident laser light beam does not, for example, lead to a converter element 8 ( Fig. 1 ) or another area to be illuminated by the lighting device 1, but to a corresponding detector, which then detects this laser light beam. This signal can then also be evaluated and a position of the diffractive optical elements 5a to 5f or of the carrier 7 can be determined.

Claims (8)

1. Illumination device (1) for a motor vehicle, with

   - a plurality of laser light sources (2, 2a-2l) for the emission of a laser light beam (3, 3a-3l) in each case, and

   - a plurality of concentric annular diffractive optical elements (5, 5a-5f), of which at least a partial region (5_ij, 6, 6') of each is arranged in a beam path (4, 4a-4l) of one of the laser light beams (3, 3a-3l), wherein simultaneously a plurality of the partial regions (5_ij, 6, 6') of at least one of the diffractive optical elements (5, 5a-5f) are arranged in respective beam paths (4, 4a-4l) associated with the laser light sources (2, 2a-2l),

   the diffractive optical elements (5, 5a-5f) are arranged to be rotatable with respect to the laser light sources (2, 2a-2l) about an axis of rotation (A) and to be continuously rotatable by a drive, so that different partial regions (5_ij, 6, 6') of the diffractive optical elements (5, 5a-5f) each having different optical properties are rotatable into the beam paths (4, 4a-4l) by means of a rotation about the axis of rotation (A) and by the continuous rotation of the diffractive optical elements (5, 5a-5f), the laser light beams (3, 3a-3l) are deflectable into different spatial regions corresponding to different light functions, and surface regions pre-determinable by the laser light beams (3, 3a-3l) are scannable, wherein the axis of rotation (A) passes through the centre (M) of the ring formed by the annular diffractive optical elements (5, 5a-5f),
   wherein
   the illumination device (1) has a converter unit (8) or a plurality of converter units (8) for converting a wavelength distribution which is or are arranged in the beam path (4, 4a-4l) of at least one of the laser light beams (3, 3a-3l) after one of the diffractive optical elements (5, 5a-5f).
2. Illumination device (1) according to one of the preceding claims, characterised in that the diffractive optical elements (5, 5a-5f) are continuously rotatable by a drive during operation of the illumination device (1), in particular at more than 50 revolutions per second, preferably at between 100 and 200 revolutions per second.
3. Illumination device (1) according to one of the preceding claims,
   characterised in that
   in the different partial regions (5_ij, 6, 6') at least one of the diffractive optical elements (5, 5a-5f) deflects the incident laser light beam (3, 3a-3l) in each case at a different angle which is specific for the respective partial region (5_ij, 6, 6'), so that by means of the at least one diffractive optical element (5, 5a-5f) a spatial region can be traversed by the laser light beam (3, 3a-3l).
4. Illumination device (1) according to claim 1,
   characterised in that
   the plurality of concentric annular diffractive optical elements (5, 5a-5f) are arranged on a common support (7).
5. Illumination device (1) according to claim 3,
   characterised in that,
   by means of the different diffractive optical elements (5, 5a-5f), the different spatial regions can be traversed by the different laser light beams (3, 3a-3l).
6. Illumination device (1) according to claim 5,
   characterised in that
   the one converter unit (8) or the plurality of converter units are each arranged at least partially in the different spatial regions.
7. Illumination device (1) according to any one of the preceding claims,
   characterised in that
   a reference mark (9) is arranged on at least one of the diffractive optical elements (5, 5a-5f) or on a support (7) of the at least one diffractive optical element (5, 5a-5f).
8. Illumination device (1) according to any one of the preceding claims,
   characterised in that
   at least one of the diffractive optical elements (5, 5a-5f) or a cooling vane is arranged on a support (7) of the at least one diffractive optical element (5, 5a-5f).

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