Abstract
A lighting device is disclosed with an electromagnetic radiation source for irradiating a conversion element arranged in the lighting device with an excitation radiation. The conversion element has a first element side and a second element side. The first element side delimits a first radiation space and the second element side delimits a second radiation space. At least one optical unit at least for part of the radiation emanating from the first element side is arranged in the first radiation space and at least one optical unit at least for part of the radiation emanating from the second element side is arranged in the second radiation space.
Claims
1. A lighting device comprising an electromagnetic radiation source for irradiating a conversion element arranged in the lighting device with an excitation radiation, wherein the conversion element has a first element side and a second element side, wherein the first element side delimits a first radiation space and the second element side delimits a second radiation space, wherein at least one optical unit at least for part of the radiation emanating from the first element side is arranged in the first radiation space and at least one optical unit at least for part of the radiation emanating from the second element side is arranged in the second radiation space.
2. The lighting device as claimed in claim 1, wherein the radiation emanating from the element sides is coupled out by means of the optical units.
3. The lighting device as claimed in claim 1, wherein the excitation radiation of the radiation source radiates onto the first element side, and wherein a second radiation source is provided, the excitation radiation of which radiates onto the second element side.
4. The lighting device as claimed in claim 1, wherein a reflector having an optical reflector surface is respectively provided as optical unit for each of a respective element side.
5. The lighting device as claimed in claim 1, wherein a surface normal of the first element side is approximately parallel to the excitation radiation of the assigned radiation source, and/or wherein a surface normal of the second element side is approximately parallel to the excitation radiation of the assigned radiation source.
6. The lighting device as claimed in claim 4, wherein a first shutter is provided, which is arranged in the beam path of at least part of the radiation reflected by one of the respective reflectors or which is arranged in the beam path of at least part of the radiation reflected by both of said reflectors.
7. The lighting device as claimed in claim 6, wherein the first shutter is movable and can be introduced into and withdrawn from the beam path.
8. The lighting device as claimed in claim 6, wherein a second shutter is provided, which is arranged at least in sections in the beam path between one of said reflectors assigned to the first element side and the first shutter, wherein the first shutter can be arranged in the beam path of at least part of the radiation emanating from the other of said reflectors.
9. The lighting device as claimed in claim 8, wherein the first shutter or the second shutter is arranged in such a way that it substantially separates the respective radiations emanating from the reflector.
10. The lighting device as claimed in claim 4, wherein the conversion element is inclined relative to a horizontal plane and/or relative to one or both reflector surfaces and/or relative to a direction of travel of a vehicle using the lighting device.
11. The lighting device as claimed in claim 1, wherein one optical unit is a reflector and the other optical unit is a lens or a TIR (Total Internal Reflection) collimator optical unit or a CPC (Compound Parabolic Concentrator) optical unit.
12. The lighting device as claimed in claim 1, wherein an angle rotator is provided for the emanating radiation of the first and/or the second element side.
13. The lighting device as claimed in claim 1, wherein a surface normal of the element sides points approximately in a direction of travel of a vehicle using the lighting device, wherein a reflector is provided at least for part of the radiation emanating from one element side, and wherein another optical unit is provided at least for part of the radiation emanating from the other element side.
14. The lighting device as claimed in claim 1, wherein the conversion element is curved.
15. The lighting device as claimed in claim 1, wherein the conversion element is applied to a transparent substrate which is held by a holder, or wherein the conversion element is mounted directly on a holder.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosed embodiments. In the following description, various embodiments described with reference to the following drawings, in which:
[0045] FIGS. 1 to 15 show, in each case in a schematic illustration, a remote phosphor lighting device in accordance with various embodiments
[0046] FIGS. 16A and 16B show, in each case in a schematic illustration, a mount for a conversion element of the lighting device in accordance with one embodiment
[0047] FIG. 17 shows, in a schematic illustration, the lighting device together with the mount in accordance with one embodiment
DETAILED DESCRIPTION
[0048] In accordance with FIG. 1, a remote phosphor lighting device is shown which is used in LARP technology and is referred to hereinafter as lighting device 1. The latter has a radiation source in the form of a laser light source 2, which irradiates a conversion element 6 with an excitation radiation 4. Said conversion element includes luminescent material (phosphor) which at least partly converts the excitation radiation. The conversion element has a first element side 8 and a second element side 10. Converted and non-converted radiation then emerges from the first and second element sides 8 and 10. The first element side 8 is assigned a reflector 12 having a radiation passage 14 for the excitation radiation 4. A further reflector 15 is assigned to the second element side 10. Consequently, the radiation emanating from the first element side 8 can be reflected via the reflector 12 and the reflector surface 16 thereof and the radiation emerging from the second element side 10 can be reflected via the reflector 15 and the reflector surface 18 thereof. The first element side 8 delimits a first radiation space 20 or half-space and the second element side 10 delimits a second radiation space 22 or half-space. The element sides 8 and 10 are embodied such that they are approximately planar and approximately parallel to one another. They extend approximately horizontally or approximately in a direction of travel of a vehicle using the lighting device 1. The reflectors 12, 15 then reflect the radiation emanating from the conversion element 6 approximately in the direction of travel.
[0049] In accordance with FIG. 2, in contrast to the embodiment from FIG. 1, a further light source in the form of a laser light source 24 is provided, as a result of which the conversion element 6 can be illuminated uniformly. An excitation radiation of the conversion element 24 passes through a radiation passage 28 of the reflector 15 and impinges on the second element side 10 of the conversion element 6.
[0050] In FIG. 3, the conversion element 6 is arranged in a manner corresponding to FIGS. 1 and 2, but in this case, in contrast to the embodiments in FIGS. 1 and 2, the excitation radiation 4 of the laser light source 2 impinges on the first element side 8 approximately perpendicularly.
[0051] In accordance with FIG. 4, in contrast to FIG. 3, the further laser light source 24 is provided, wherein the excitation radiation 26 thereof likewise impinges on the second element side 10 of the conversion element 6 approximately perpendicularly. The laser light sources 2 and 24 are arranged approximately symmetrically with respect to one another in a manner corresponding to FIG. 2.
[0052] In FIG. 5, the reflectors 12 and 15 are connected or embodied integrally. The excitation radiation 4 of the single laser light source 2 impinges on the first element side 8 of the conversion element 6 approximately perpendicularly in a manner corresponding to FIG. 3. Furthermore, a shutter 30 is arranged, which is fixedly connected to the lighting device 1 and extends approximately in a vertical direction or approximately perpendicularly to the direction of travel. The shutter 30 lies in an intermediate plane 32 between the reflectors 12, 15 and a further optical unit in the form of a lens 32. The latter is disposed downstream of the reflectors 12 and 15. The shutter 30 is thus arranged in the beam path between the reflectors 12, 15 and the lens 32. An upper edge 34 of the shutter 30 as viewed approximately in a vertical direction serves as a bright-dark boundary. The reflectors 12 and 15 distribute the radiation emerging from the conversion element 6 in a near field 36. Downstream of the near field 36, the radiation is then distributed in a far field via the lens 32. The lighting device 1 in accordance with FIG. 5 can be used for example as low-beam light.
[0053] FIG. 6 shows the lighting device 1 in which the shutter 30 is pivotable about a pivoting axis 38. The shutter 30 can be pivoted at least into a first and a second position. In the first position, said shutter is arranged in sections in the beam path between the reflectors 12, 15 and the lens 32, as a result of which the lighting device 1 can be used as low-beam light. In the second position, the shutter 30 is pivoted out of said beam path, as a result of which the reflectors 12, 15 can reflect the radiation freely to the lens 32, and the lighting device 1 can be used for example as high-beam light.
[0054] In accordance with FIG. 7, in contrast to FIG. 6, a shutter 40 is additionally provided, which shutter is firmly fixed in the lighting device 1 approximately in a horizontal direction or in the direction of travel. As a result, the radiation reflected by the reflectors 12, 15 can be separated from one another at least partly. The shutter 40 then delimits (a lower) radiation channel 42 in which substantially the radiation emanating from the second element side 10 and reflected by the reflector 15 radiates. The radiation channel 42 can then be opened and closed with control by the pivotable shutter 30. Furthermore, the shutter 40 delimits an (upper) radiation channel 44 for the radiation of the first element side 8. In the case of use as low-beam light, the radiation channel 42 is closed, as a result of which only radiation from the upper radiation channel 44 radiates to the lens 32. If the lighting device 1 is used as high-beam light, then the lower radiation channel 42 can be released by the shutter 30.
[0055] In accordance with FIG. 8, the lighting device 1 has only the shutter 40 arranged approximately horizontally. In this case, an optical unit embodied as a lens 46 is embodied in such a way that substantially the radiation of the upper radiation channel 44 radiates to the lens 46. A reflector 48 is provided for the radiation of the second element side 10 of the conversion element 6, which reflector then images the radiation directly in the far field. The reflector 48 is advantageously a multifaceted freeform reflector.
[0056] FIG. 9 shows the lighting device 1 in which the conversion element 6 is inclined relative to a horizontal plane or the direction of travel. In this case, the first element side 8 faces approximately away from a main beam direction of the lighting device 1 and the second element side 10 faces approximately in said main beam direction. The reflectors 12 and 15 reflect the radiation emanating from the element sides 8, 10 directly into a far field. The reflectors 12 and 15 can once again be multifaceted freeform surfaces. As a result of the inclination of the conversion element 6, the reflector 12 assigned to the first element side 8 can be irradiated more efficiently, wherein the radiation emanating from the first element side 8 can have a higher luminous flux proportion of the total luminous flux in comparison with the radiation emanating from the second element side 10. The radiation reflected by the reflector 12 can then be used for example as low-beam light. The radiation then reflected by the reflector 15, that is to say in particular the radiation of the second element side 10, can then serve for example in a supporting fashion as road sign illumination function or the reflectors 12 and 15 are used jointly for a high-beam light. For the use as high-beam light or low-beam light, a shutter 50 is then provided, which shutter is movable. For a low-beam light, the shutter 50 is then arranged in the beam path between the second element side 10 and the reflector 15. If the shutter 50 is reflective in this case, then the radiation emanating from the second element side 10 can be reflected to the reflector 12 and/or back to the conversion element 6. If the shutter 50 in this case is configured concavely with its side facing the conversion element 6, then the reflecting toward the conversion element 6 is improved. For the high-beam light, the shutter 50 is led out of the beam path between the second element side 10 and the reflector 15.
[0057] In accordance with FIG. 10, in contrast to FIG. 9, the lighting device 1 does not have a reflector 15 assigned to the second element side 10, but rather a refractive optical unit in the form of a lens 52. The shutter 50 from FIG. 9 can additionally be provided.
[0058] In FIG. 11, in contrast to FIG. 10, the lighting device 1 does not have a lens, but rather a TIR collimator optical unit 54. An exit surface 56 of the optical unit 54 is planar, curved or has a multifaceted freeform shape. An entrance surface 58 of the optical unit 54 is configured in a concave fashion and arranged adjacent to the second element side 10.
[0059] In accordance with FIG. 12, in contrast to FIG. 1, the lighting device 1, for the second element side 10, does not have a reflector 15, but rather a CPC (Compound Parabolic Concentrator) 60. The latter is arranged directly on the second element side 10 in accordance with FIG. 12 and can be used for downstream optical units or light functions (e.g. cornering light).
[0060] FIG. 13 shows the lighting device 1 in which the conversion element 6 extends approximately in a vertical direction or approximately perpendicularly to the direction of travel. In this case, surface normals of the element sides 8, 10 can then point approximately in the direction of travel. In this case, the first element side 8, which faces away from the direction of travel, for example, is assigned the reflector 12, which distributes the radiation directly in a far field. The other element side 10 is assigned the TIR collimator optical unit 54. The latter is arranged approximately centrally with respect to the reflector 12, as a result of which the latter can reflect the radiation emanating from the first element side 8 substantially in such a way that said radiation radiates past the optical unit 54. The laser light source 2 is arranged in such a way that the excitation radiation 4 impinges on the conversion element 6 approximately parallel to the surface normal of the first element side 8.
[0061] In accordance with FIG. 14, in contrast to FIG. 13, the lighting device 1 has a differently shaped reflector 12. The latter is configured approximately in a W-shaped fashion as viewed in cross section, as a result of which a larger portion of the radiation which emanates from the first element side 8 can radiate past the TIR collimator optical unit 54. Furthermore, the optical unit 54 has an exit surface 62 configured as a multifaceted freeform surface.
[0062] In FIG. 15, the lighting device 1 has a conversion element 64 configured in a curved fashion. The first element side 8 is configured in a convex fashion and the second element side 10 in a concave fashion. An axis of symmetry of the conversion element 64 points approximately in a direction of travel or extends approximately in a horizontal direction. Consequently, the first element side 8 substantially faces away from the direction of travel. The first element side 8 is assigned the reflector 12, which is configured for example as a multifaceted freeform reflector. The curved or concave second element side 10 concentrates the radiation emanating from it. Part of this radiation impinges on the downstream optical unit 66 and part is radiated back into the conversion element 8. Only radiation 68 which emanates from the second element side 10 and impinges neither on the conversion element 8 nor on the optical unit 66 cannot be used further. It is conceivable, however, to configure the reflector 12 in such a way that the latter can also reflect the radiation 68. Further reflectors 70 can also be provided for the radiation 68. The elements 70 could also include refractive optical units or the solid angle covered by the radiation 68 can be covered by a sensor element 70. The laser light source 2 is arranged in such a way that the excitation radiation 4 radiates onto the conversion element 64 approximately in the direction of the axis of symmetry of said conversion element.
[0063] FIG. 16A illustrates the mount of the conversion element 6. In this case, the conversion element 6 is applied to a transparent, thermally conductive substrate 72. In accordance with FIG. 16B, both the conversion element 6 and the substrate have an approximately rectangular cross section. In this case, the conversion element 6 is arranged approximately centrally with respect to the substrate 72 on the large side 74 thereof. The substrate 72 is then inserted into a holder 76. In the latter, the substrate 72 is supported at least in sections firstly by its circumferential wall 78 and secondly by its further large side 80. In this case, the holder 76 is configured in such a way that, in accordance with FIG. 16A, a central region 82 of the large side 80 is not covered by said holder. As a result, radiation emerging from the second element side 10 can radiate without hindrance to a downstream optical unit.
[0064] It would also be conceivable to secure the conversion element 6 directly in the holder 76.
[0065] FIG. 17 illustrates the holder 76 together with the reflectors 12 and 15. These can be produced together in an injection-molding method, wherein the holder 76 is then arranged as an insert in an injection-molding tool. In accordance with FIG. 17, the holder 76 has cooling ribs 84. It is conceivable for the section 86 of the holder 76 that projects into the reflectors 12, 15 to be used as a horizontal shutter; see FIG. 7, for example. Furthermore, it is conceivable to use an end face 88—facing in the direction of travel—of the holder 76 for arranging further elements, such as auxiliary light sources or small optical units, for example, or to realize or to support light functions such as a flashing indicator function and/or a daytime running light function, for example.
[0066] What is disclosed is a remote phosphor lighting device including an electromagnetic radiation source, with which a conversion element can be irradiated with an excitation radiation. The conversion element has two element sides. In this case, each element side is assigned an optical unit, by means of which the radiation emanating from the conversion element is coupled out.
[0067] While the disclosed embodiments have been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosed embodiments as defined by the appended claims. The scope of the disclosed embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.
