Abstract
An optical device is provided including a light-imaging component configured to focus light fed to the light-imaging component in at least one focusing spot, wherein the light fed includes at least one predefinable wavelength; and a conversion apparatus including at least one phosphor which is designed to convert light having the at least one predefinable wavelength into conversion light, wherein the conversion apparatus is arranged in such a way that the at least one phosphor is arranged in the focusing spot of the light-imaging component. The light-imaging component is configured to generate at least two focusing spots, and the conversion apparatus is arranged in such a way that the at least two focusing spots are positioned on the at least one phosphor.
Claims
1. An optical device comprising: a light-imaging component configured to focus light fed to the light-imaging component in at least one focusing spot, wherein the light fed comprises at least one predefinable wavelength; and a conversion apparatus comprising at least one phosphor which is designed to convert light having the at least one predefinable wavelength into conversion light, wherein the conversion apparatus is arranged in such a way that the at least one phosphor is arranged in the focusing spot of the light-imaging component; wherein the light-imaging component is configured to generate at least two focusing spots, and the conversion apparatus is arranged in such a way that the at least two focusing spots are positioned on the at least one phosphor.
2. The optical device as claimed in claim 1, wherein the conversion apparatus comprises at least one first and one second phosphor different than the first, wherein one of the focusing spots is positioned on the first and another of the focusing spots is positioned on the second phosphor.
3. The optical device as claimed in claim 1, wherein the light-imaging component comprises two axicons, optical axes of which are aligned coaxially with respect to one another and with respect to a light incidence axis of the light fed, wherein the axicons are arranged in such a way that conically embodied surfaces of the axicons face one another.
4. The optical device as claimed in claim 3, wherein the conversion apparatus is embodied as a conversion disk and comprises at least one first and one second phosphor different than the first, wherein the at least one first and one second phosphor are arranged on the conversion disk adjacently to one another radially in relation to the optical axis and the light-imaging component is configured to set a distance between the axicons along the optical axis in such a way that, depending on the set distance, the focusing spots are positioned in each case on the first and/or the second phosphor.
5. The optical device as claimed in claim 4, wherein the conversion disk comprises the at least one first and one second phosphor adjacent to one another in a circumferential direction of the conversion disk in relation to the optical axis.
6. The optical device as claimed in claim 1, wherein the light-imaging component comprises a lens arrangement for generating the focusing spots.
7. The optical device as claimed in claim 4, wherein the light-imaging component is configured to generate the focusing spots at least partly on a ring which is coaxial with respect to the optical axis.
8. The optical device as claimed in claim 4, wherein the conversion disk is arranged in a rotationally fixed manner.
9. The optical device as claimed in claim 1, wherein the conversion apparatus is embodied in a reflective fashion and the light-imaging component comprises on the light feeding side an optical isolation unit for isolating the light fed from the light reflected by the conversion apparatus.
10. The optical device as claimed in claim 9, wherein the conversion apparatus comprises a region for transmitting part of the light fed, and the light-imaging component comprises a light-guiding assembly configured to combine light transmitted by the conversion apparatus with the light reflected by the conversion apparatus.
11. The optical device as claimed in claim 3, wherein a light-outputting component for combining light emitted by the conversion apparatus on account of the at least two focusing spots, wherein the light-outputting component comprises an arrangement of two axicons that is mirrored in relation to the conversion apparatus in accordance with the light-imaging component.
12. The optical device as claimed in claim 11, wherein the light-outputting component is configured to set a distance between the axicons along the optical axis depending on the distance between the axicons of the light-imaging component, in order to combine light emitted by the phosphor of the conversion apparatus on account of the positioning of the focusing spots.
13. The optical device as claimed in claim 11, wherein the light-output component comprises on the conversion apparatus side a converging lens arrangement configured in accordance with a number of the focusing positions.
14. A light module comprising a light source and an optical device, the optical device comprising, a light-imaging component configured to focus light fed to the light-imaging component in at least one focusing spot, wherein the light fed comprises at least one predefinable wavelength; a conversion apparatus comprising at least one phosphor which is designed to convert light having the at least one predefinable wavelength into conversion light, wherein the conversion apparatus is arranged in such a way that the at least one phosphor is arranged in the focusing spot of the light-imaging component; wherein the light-imaging component is configured to generate at least two focusing spots, and the conversion apparatus is arranged in such a way that the at least two focusing spots are positioned on the at least one phosphor, wherein the light module is configured for feeding light generated by means of the light source to the optical device.
15. A method for treatment of light by means of an optical device comprising, feeding light to a light-imaging component of the optical device, which focuses the light fed to the light-imaging component in at least one focusing spot, wherein the light fed comprises at least one predefinable wavelength, and converting the fed light having the at least one predefinable wavelength into conversion light by means of at least one phosphor of a conversion apparatus, wherein the conversion apparatus is arranged in such a way that the at least one phosphor is arranged in the focusing spot of the light-imaging component, wherein at least two focusing spots are generated by means of the light-imaging component, wherein the conversion apparatus is arranged in such a way that the at least two focusing spots are positioned on the at least one phosphor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 shows, in a schematic basic view, a first embodiment of an optical device according to the invention;
[0037] FIG. 2 shows, in a plan view, a schematic illustration of a phosphor disk for the optical device in accordance with FIG. 1;
[0038] FIG. 3 shows a perspective illustration of a light-imaging component of the optical device in accordance with FIG. 1;
[0039] FIG. 4 shows a schematic side view of the phosphor disk in accordance with FIG. 2;
[0040] FIG. 5 shows a schematic sectional view of the phosphor disk in accordance with FIG. 4;
[0041] FIG. 6 shows a schematic illustration of a further phosphor disk for use in the optical device in accordance with FIG. 1, wherein the phosphors are arranged adjacent to one another in a ring in such a way that only conversion light of one phosphor is generated in each case by means of the focusing spots, and the phosphor disk is configured for rotary operation;
[0042] FIG. 7 shows, in a schematic illustration, a further embodiment of a phosphor disk as in FIG. 6 for rotary operation, wherein the phosphors are arranged adjacently to one another in a ring in such a way that white light is always generated as mixed light by means of the focusing spots;
[0043] FIG. 8 shows, in a schematic illustration, a further embodiment of a phosphor disk as in FIGS. 6 and 7, wherein the phosphor disk is configured for non-rotary operation and white light is generated as mixed light by means of the phosphors arranged adjacently to one another in a ring-shaped fashion;
[0044] FIG. 9 shows, in a schematic illustration, a light-imaging component including two coaxial axicons, which are adjustable with regard to their distance with respect to one another;
[0045] FIG. 10 shows, in a schematic illustration, a phosphor disk including two phosphor regions which are spaced apart from one another in a ring-shaped fashion and radially and in which different phosphors are arranged adjacently to one another in the circumferential direction, wherein focusing spots impinge on the outer ring in an upper illustration and on the inner ring in a lower illustration;
[0046] FIG. 11 shows, in a schematic illustration, an optical device in accordance with a further embodiment of the invention, wherein a phosphor disk is used which is embodied in a reflective fashion;
[0047] FIG. 12 shows in a schematic illustration, a further optical device in accordance with a further embodiment of the invention, in which the phosphor disk has a window through which light fed is transmitted, and by means of a light-guiding assembly for combining conversion light of the phosphor disk with light fed;
[0048] FIG. 13 shows in schematic illustration, a further optical device in accordance with a further embodiment of the invention, wherein a converging lens arrangement for combining the conversion light is provided in a departure according to FIG. 1; and
[0049] FIG. 14 shows, in a schematic illustration, a further optical device in accordance with a further embodiment of the invention on the basis of the embodiment in accordance with FIG. 13, wherein a light-outputting component is provided, by means of which the conversion light is fed to an optical integrator.
PREFERRED IMPLEMENTATION OF THE INVENTION
[0050] FIG. 1 shows, in a schematic basic view, an optical device 10 according to the invention including a light-imaging component 14 configured to focus light 16 fed to the light-imaging component 14 in eight focusing spots 18, two of which are illustrated in FIG. 1. In the present case, the light 16 fed is laser light having a wavelength of approximately 450 nm.
[0051] The optical device 10 furthermore includes a conversion apparatus 12, which in the present case includes three phosphors 22, 24, 26 and a transmission window 28. In the present case, the conversion apparatus 12 is embodied as a phosphor disk mounted in a rotatable fashion. Each of the phosphors 22, 24, 26 is designed to convert the light 16 fed into respective conversion light 64, 66. The conversion light of the six further focusing points is not illustrated in the present embodiment.
[0052] The phosphor disk 12 is configured for a conversion apparatus configured on the basis of transmission and is arranged in such a way that the phosphors 22, 24, 26 and the transmission window 28 are arranged in the focusing spots 18 of the light-imaging component 14.
[0053] For this purpose, the light-imaging component 14 is configured to generate the focusing spots 18, eight thereof in the present case, two of which are illustrated in FIG. 1. The phosphor disk 12 is arranged in such a way that the eight focusing spots are positioned on the phosphors 22, 24, 26 and the transmission window 28.
[0054] In the present case, the light 16 fed is light from a laser diode, which is not illustrated in further detail in the figures. The laser diode, in the same way as the optical device 10, is part of a light module (not illustrated in further detail). The light 16 fed is fed to the light-imaging component 14 with a light incidence axis 20.
[0055] FIG. 2 schematically shows the conversion apparatus 12 embodied as a phosphor disk, in a plan view. It can be discerned that the phosphors 22, 24, 26 and the transmission window 28 are arranged adjacently to one another in a ring-shaped fashion. The phosphor disk 12 is in rotation during the intended operation, such that the focusing spots 18 are positioned on the phosphors 22, 24, 26 circulating relative to said focusing spots, and on the transmission window 28. Given substantially constant rotation of the phosphor disk 12, the positions of the phosphors 22, 24, 26 and of the transmission window 28 relative to the focusing spots 18 change regularly.
[0056] As is furthermore evident from FIG. 1, the light-imaging component 14 includes two axicons 40, 42, the optical axes 36 of which are aligned coaxially with respect to one another and with respect to the light incidence axis 20 of the light 16 fed. The axicons 40, 42 are furthermore arranged in such a way that conically embodied surfaces 44, 46 of the axicons 40, 42 face one another. What is achieved by means of this arrangement of the axicons is that the light 16 fed along the light incidence axis 20 is imaged in a ring-shaped fashion. Preferably, the light ring generated by the light-imaging component 14 corresponds to the annular arrangement of the phosphors 22, 24, 26 and of the transmission window 28 of the phosphor disk 12.
[0057] It is furthermore evident from FIG. 1 that the light-imaging component 14 includes a lens arrangement 34 for generating the focusing spots 18 from the light ring generated by the axicons 40, 42. In the present case, for this purpose eight convex lenses 68 are provided, two of which are illustrated in FIG. 1. Each of the convex lenses 68 generates one of the focusing spots 18.
[0058] In the present case, the phosphor disk forming the conversion apparatus 12 is arranged in a focusing plane (not designated any further) which is arranged perpendicularly to the optical axis 36 and in which the focusing spots 18 are positioned. In the present case, the focusing spots 18 are generated on a ring which is coaxial with respect to the optical axis 36 (also cf. FIG. 2).
[0059] FIG. 3 shows a perspective illustration of the light-imaging component 14 and the beam path brought about thereby. A diameter of the laser light 16 fed is illustrated schematically in the left-hand region of FIG. 3. Said laser light is fed to the first axicon 40 along a light incidence axis 20. A representation 70 represents the intensity of the light 16 fed in cross section. It can be discerned that a substantially homogeneous light intensity is present within a diameter of the light 16 fed and falls sharply in the direction of zero in the region of the outer diameter. The first axicon 40 diverts the fed light 16 onto the second axicon 42. The two axicons 40, 42 are arranged in a manner spaced apart coaxially with respect to one another and their conically embodied surfaces 44, 46 face one another.
[0060] This arrangement of the axicons 40, 42 generates a light ring, such as is represented in the intensity representation 72 between the second axicon 42 and a lens arrangement 34 including lenses 68 that optically succeeds said second axicon.
[0061] In the present case, the lens arrangement 34 includes the eight lenses 68 arranged in the region of the light ring. By means of the lenses 68, the ring-shaped light generated by the axicons 40, 42 is focused onto the eight focusing spots 18, as is evident on the basis of the intensity representation 74.
[0062] In the case of the embodiment in accordance with FIG. 1 it is provided that the phosphor disk 12 is configured for transmission. In the case of this embodiment, the conversion light 64, 66 is emitted on the opposite side relative to the focusing spots 18. By means of a light-outputting component 50, the conversion light 64, 66 and light transmitted through the transmission window 28 are captured and combined to form mixed light 30. In the present case, the mixed light 30 is white light.
[0063] The light-outputting component 50 includes a converging lens arrangement 56 assigned to each of the focusing spots 18. The converging lens arrangement 56 images the conversion light 64, 66 and the transmitted light of the phosphor disk 12 onto an arrangement of two axicons 52, 54. The arrangement of the axicons 52, 54 is embodied here with regard to the radiation path, in a mirrored manner with respect to the arrangement of the axicons 40, 42 of the light-imaging component 14. As a result, the conversion light 64, 66 and the transmitted light of the phosphor disk 12 are combined to form a common light beam, whereby a mixed light 30 is formed. A color combination of the mixed light 30 is chosen in such a way that white light is formed as mixed light 30. In order to improve the mixing effect, the mixed light 30 is fed to a microlens array 62.
[0064] FIG. 4 shows the phosphor disk 12 from FIG. 2 without the focusing spots 18. It can be discerned that the phosphors 22, 24, 26 are arranged in an annulus on the phosphor disk 12. Furthermore, the transmission window 28 is likewise arranged in the same ring. The phosphors 22, 24, 26 and the transmission window 28 are arranged circumferentially directly adjacently to one another, that is to say in a manner adjoining one another.
[0065] FIG. 5 shows a schematic vertical sectional view in accordance with FIG. 4 in an upper illustration on the left, wherein it is evident that the phosphor disk 12 includes a circular carrier (not designated), which is formed from sapphire in the present case. The phosphors 22, 24, 26 are applied on a surface of the carrier. The sapphire is free of phosphor in the region of the transmission window 28.
[0066] An enlarged excerpt is illustrated in a lower illustration on the right in FIG. 5. It can be discerned that a dichroic coating 60 is provided between the sapphire and the phosphor, here the phosphor 26. Said coating 60 is not provided in the region of the transmission window 28. A dichroic coating 60 that allows the short-wave light 16 fed to be transmitted, but reflects the converted light 64, 66 is arranged between the carrier composed of sapphire and the phosphors 22, 24, 26. The conversion efficiency can be improved as result. In the direction of propagation, therefore, the sapphire as carrier is arranged upstream of the dichroic coating 60 and the respective phosphor 22, 24, 26.
[0067] FIGS. 6 to 8 show further embodiments of conversion apparatuses 12 in the form of phosphor wheels. The phosphor wheels in FIGS. 6 to 8 are likewise constructed, in principle, in the manner as explained with reference to FIG. 5. Therefore, reference is supplementarily made to these explanations.
[0068] FIG. 6 illustrates, in a comparable illustration to FIG. 2, a phosphor disk 12 including different phosphors 22, 24, 26 arranged adjacently to one another in a ring-shaped fashion. Furthermore, transmission windows 28 are provided. The arrangement of the phosphors 22, 24, 26 and of the transmission windows 28 is such that, upon rotation of the phosphor disk 12, the eight focusing spots 18 always impinge on the same phosphor or the transmission windows 28. Thus, in a respective angular position, in each case only conversion light of a single phosphor is generated or transmission of the light 16 fed takes place. This phosphor disk 12 is provided for sequential operation. Rotation of the phosphor disk 12 ensures that the desired color combination, that is to say the sum of the colors changing over time, substantially always remains the same.
[0069] FIG. 7 shows an alternative embodiment to FIG. 6, wherein, in contrast to the configuration in accordance with FIG. 6, in the case of a specific angular position, a focusing spot 18 in each case impinges on at least one of the phosphors 22, 24, 26 used and on at least one transmission window 28. This phosphor disk 12 is provided for non-sequential operation. This phosphor disk 12, too, is provided for rotary operation. Each focusing spot 18 therefore leads to different conversion light relative to adjacent focusing spots 18. However, it is provided here, too, that the sum of the generated light is always white light.
[0070] FIG. 8 shows a further embodiment of a phosphor disk 12, which is provided for non-rotary operation and for non-sequential operation. In this embodiment, the focusing spots 18 are always positioned on the same phosphor 22, 24, 26 or the transmission window 28. Preferably, it is likewise provided here that the sum of the converted light is white light. Even if this embodiment is suitable for a non-rotating phosphor disk, nevertheless rotation can optionally be provided. The effect of the light conversion is not impaired thereby.
[0071] FIGS. 9 and 10 schematically show a further exemplary embodiment according to the invention. FIG. 10 shows a phosphor disk 12 including, circumferentially radially adjacently to one another, ring regions with phosphor 22, 24, 26 and transmission windows 28. The phosphors 22, 24, 26 and the transmission window 28 are arranged adjacently to one another in an inner ring region. Radially outward with respect thereto, a further phosphor region is provided, in which likewise the phosphors 22, 24, 26 and a transmission window 28 are provided. In the present embodiment, however, the angular ranges of the phosphors 22, 24, 26 and of the transmission window 28 differ, such that light having a different color is generated in total upon the positioning of the focusing spots 18 on the respective ring region.
[0072] In the upper illustration in accordance with FIG. 10, the focusing spots 18 are positioned on the outer ring region. In the lower illustration in FIG. 10, by contrast, the focusing spots 18 are positioned on the inner ring region.
[0073] In order to achieve these different positionings of the focusing spots 18, in this embodiment of the invention it is provided that the axicons 40, 42 are adjustable with regard to their distance with respect to one another (FIG. 9). In the upper illustration in FIG. 9, the axicons 40, 42 are spaced far apart from one another, such that a light ring is generated which, with regard to the diameter, is adapted to the outer ring region of the phosphor disk 12 from FIG. 10. With a correspondingly embodied lens arrangement 34, eight focusing points are generated, which are positioned on the outer ring region of the phosphor disk 12 in accordance with FIG. 10.
[0074] In the lower illustration in accordance with FIG. 9, by contrast, the axicons 40, 42 are spaced apart to a lesser extent compared with the upper illustration. This has the effect that the light ring generated has a smaller diameter. In the present case, it is provided that the light ring diameter generated in this case corresponds to the inner ring region of the phosphor disk 12 illustrated in FIG. 10. For this setting state, too, the lens arrangement 34 includes an adapted lens arrangement 34 which likewise generates eight focusing spots, which are positioned on the inner ring region of the phosphor disk 12.
[0075] In this way, it is possible to switch between different phosphors and color combinations. The present embodiment provides for this phosphor disk 12 also to be operated in a rotary manner during intended operation.
[0076] FIG. 11 schematically shows a further embodiment of the invention, wherein there is no need for a separate light-outputting component like the light-outputting component 50 in accordance with FIG. 1. The phosphor disk 12 provided in this embodiment is embodied in a reflective fashion. That is to say that the light-imaging component 14 serves both for feeding the light 16 fed and for outputting the conversion light 64, 66. In this regard, the corresponding light-imaging component 14 again has a construction as in FIG. 1. Therefore, in this regard reference is supplementarily made to the explanations concerning FIG. 1.
[0077] In order to isolate the fed light 16 from the conversion light 64, 66, a dichroic mirror 32 is provided on the input side, said dichroic mirror being reflective for the light 16 fed, but transmissive for the conversion light 64, 66. Blue light 80 is additionally fed to the dichroic mirror 32, said blue light likewise being reflected at the dichroic mirror 32 and being combined with the conversion light 64, 66 in order to form the light 30 provided for the illumination. In an alternative embodiment, a design including a dichroic mirror in which blue light is transmitted and conversion light is reflected is possible.
[0078] FIG. 12 schematically shows a further embodiment of the invention, which is based on the exemplary embodiment in accordance with FIG. 11. In order to avoid the separate feeding of blue light 80 in accordance with FIG. 11, in this embodiment it is provided that the phosphor disk 12 has a transmission window (not illustrated in FIG. 12) through which part of the light 16 fed is transmitted by the phosphor disk 12 and is guided by means of a light-guiding unit 48 to the dichroic mirror 32, where, as described above with regard to FIG. 11, it is fed to the conversion light 64, 66 in order to form the light 30 for lighting purposes. In this embodiment, too, as in FIG. 11, it is provided that the conversion light 64, 66 uses the light-imaging component 14 counter to the light 16 fed.
[0079] Further embodiments of the invention are illustrated schematically in accordance with FIGS. 13 and 14, said further embodiments being based on the exemplary embodiment in accordance with FIG. 1. Therefore, reference is supplementarily made to the explanations concerning said example. In contrast to the embodiment in accordance with FIG. 1, the embodiment in accordance with FIG. 13 includes, in the light-outputting assembly 50, a converging lens 82 instead of the axicons 52, 54, by means of which converging lens the converted light 64, 66 is fed to a concave lens 84.
[0080] A further embodiment is shown in FIG. 14, which differs from the embodiment in accordance with FIG. 13 in that, instead of the converging lens 82, a converging lens 86 is provided which focuses the conversion light 64, 66 onto an entrance surface of an optical integrator 88. In the present case, the optical integrator 88 is formed by a cylindrical, in particular rectangular or hexagonal, glass rod or else mirror tunnel.
[0081] In principle, the number of focusing spots 18 can be chosen as desired and adapted as required. Furthermore, it is possible, of course, for a different number of focusing spots in each case to impinge on the different phosphors, in order thereby to influence the composition of the conversion light. For this purpose, it may furthermore be provided that the phosphors are arranged on surface regions of different sizes.
[0082] The invention allows the optical device to be able to be adapted simply and rapidly as required. As a result, it is possible not only to change spent phosphor wheels, but also to adapt color spaces as required. The invention furthermore allows the power of a single focusing spot on the phosphor to be reduced since this can be compensated for on account of the number of focusing spots. As a result, a lower heat loss is generated locally in the phosphor, such that the phosphor as such can be operated at a higher efficiency.
[0083] The embodiments explained above serve merely for explaining the invention and are not restrictive for the invention. The invention can be used for any lighting purposes, for example room lighting, area lighting but also in projectors, spotlights/headlights or the like.
[0084] Finally, features of the claims and description can, of course, be combined with one another in virtually any desired manner in order to arrive at further embodiments within the scope of the invention. It should further be noted that the advantages and features and also embodiments described for the device according to the invention equally apply to the light module according to the invention and respectively the corresponding method, and vice versa. Consequently, corresponding method features can be provided for device features, and vice versa.
