HIGH BRIGHTNESS LIGHT SOURCE COMPRISING A BLUE LASER PUMPING A GREEN YELLOW PHOSPHOR AND A YELLOW ORANGE SUPERLUMINESCENT DIODE PUMPING A RED PHOSPHOR

Abstract

The invention provides a light generating system (1000) comprising (i) a plurality of light sources (110,120, . . .), (ii) a first luminescent material (210), and (iii) a second luminescent material (220), wherein: (a) a first light source (110) is configured to generate first light source light (111) having one or more wavelengths in the blue wavelength range and having a first centroid wavelength (C1), wherein the first light source (110) is a laser; (b) the first luminescent material (210) is configured to convert at least part of the first light source light (111) into first luminescent material light (211) having one or more wavelengths in the green and/or yellow wavelength range; (c) a second light source (120) is configured to generate second light source light (121) having one or more wavelengths in the yellow and/or orange wavelength range and having a second centroid wavelength (C2), wherein C2>C1; wherein the second light source (120) is a superluminescent diode; (d) the second luminescent material (220) is configured to convert at least part of the second light source light (121) into second luminescent material light (221) having one or more wavelengths in the orange and/or red wavelength range; and (e) in an operational mode the light generating system (1000) is configured to generate system light (1001) comprising the first luminescent material light (211) and the second luminescent material light (221).

Claims

1. A light generating system comprising (i) a plurality of light sources, (ii) a first luminescent material, and (iii) a second luminescent material, wherein: a first light source is configured to generate first light source light having one or more wavelengths in the blue wavelength range and having a first centroid wavelength (.sub.C1), wherein the first light source comprises a laser; the first luminescent material is configured to convert at least part of the first light source light into first luminescent material light having one or more wavelengths in the green and/or yellow wavelength range; a second light source is configured to generate second light source light having one or more wavelengths in the yellow and/or orange wavelength range and having a second centroid wavelength (.sub.C2), wherein .sub.C2>.sub.C1; wherein the second light source comprises a superluminescent diode; the second luminescent material is configured to convert at least part of the second light source light into second luminescent material light having one or more wavelengths in the orange and/or red wavelength range; and in an operational mode the light generating system is configured to generate system light comprising the first luminescent material light and the second luminescent material light.

2. The light generating system according to claim 1, comprising a third light source configured to generate third light source light having one or more wavelengths in the blue wavelength range; wherein in the operational mode the light generating system is configured to generate white system light comprising third light source light, the first luminescent material light and the second luminescent material light.

3. The light generating system according to claim 2, wherein the third light source comprises one or more of a laser and a superluminescent diode.

4. The light generating system according to claim 1, wherein the first luminescent material comprises a luminescent material of the type A.sub.3B.sub.5O.sub.12:Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc, and/or wherein the first luminescent material comprises a luminescent material of the type A.sub.3Si.sub.6N.sub.11:Ce.sup.3+, wherein A comprises one or more of La and Y.

5. The light generating system according to claim 1, comprising a ceramic body, wherein the ceramic body comprises the first luminescent material.

6. The light generating system according to claim 1, wherein the second luminescent material comprises a luminescent material selected from the group consisting of MS:Eu.sup.2+, wherein M comprises one or more of calcium and strontium; M.sub.2Si.sub.5N.sub.8:Eu.sup.2+, wherein M comprises one or more of calcium and strontium and barium; MAlSiN.sub.3:Eu.sup.2+, wherein M comprises one or more of calcium and strontium; MLi.sub.2Al.sub.2O.sub.2N.sub.2:Eu.sup.2+, wherein M comprises strontium; MLiAl.sub.3N.sub.4:Eu.sup.2+, wherein M comprises strontium; MCaSiN.sub.2:Ce.sup.3+, wherein M comprises one or more of calcium and strontium; and M(Si,Al)N.sub.2:Ce.sup.3+, wherein M comprises calcium.

7. The light generating system according to claim 1, wherein the first light source is configured to generate first light source light having one or more wavelengths in the wavelength range of 440-495 nm, wherein the second light source is configured to generate second light source light having one or more wavelengths in the wavelength range of 570-620 nm; wherein the first luminescent material is configured to convert at least part of the first light source light into first luminescent material light having one or more wavelengths in the wavelength range of 495-590 nm, and wherein the second luminescent material is configured to convert at least part of the second light source light into second luminescent material light having one or more wavelengths in the wavelength range of 610-665 nm.

8. The light generating system according to claim 1, wherein the first light source is configured to generate first light source light having a centroid wavelength in the wavelength range of 440-495 nm, wherein the second light source is configured to generate second light source light having a centroid wavelength in the wavelength range of 570-620 nm; wherein the first luminescent material is configured to convert at least part of the first light source light into first luminescent material light having a centroid wavelength in the wavelength range of 495-590 nm, and wherein the second luminescent material is configured to convert at least part of the second light source light into second luminescent material light having a centroid wavelength in the wavelength range of 610-665 nm.

9. The light generating system according to claim 1, wherein one or more of the first luminescent material and the second luminescent material are operated in a reflective mode.

10. The light generating system according to claim 1, wherein one or more of the first luminescent material and the second luminescent material are operated in a transmissive mode.

11. The light generating system according to claim 1, comprising one or more light combining elements configured to combine in the operational mode at least the first luminescent material light and the second luminescent material light.

12. The light generating system according to claim 1, wherein the first luminescent material and the second luminescent material are supported by a thermally conductive support.

13. The light generating system according to claim 1, comprising an integrated light source package, wherein the integrated light source package comprises a common support member configured to support the plurality of light sources, the first luminescent material, and the second luminescent material, wherein common support member comprises the thermally conductive support according to claim 12.

14. The light generating system according to claim 1, comprising a control system configured to individually control (i) one or more of the one or more first light sources and (ii) one or more of the one or more second light sources, thereby controlling a spectral power distribution of the system light.

15. A light generating device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, and an optical wireless communication device, comprising the light generating system according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0120] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0121] FIGS. 1a-1c schematically depicts an embodiment and variations;

[0122] FIGS. 2a-2b schematically depict some spectral power distributions; and

[0123] FIG. 3 shows some applications.

[0124] The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0125] FIG. 1a schematically depict a number of embodiments of the light generating system 1000. All three embodiments operate the luminescent materials in the transmissive mode. However, as shown in FIG. 1c, see below, also the reflective mode may be applied. Further, it is also possible to operate one luminescent material in the transmissive mode and another one in the reflective mode. Hence, in embodiments one or more of the first luminescent material 210 and the second luminescent material 220 may be operated in a transmissive mode.

[0126] The system 1000 comprises (i) a plurality of light sources 110,120, . . . , (ii) a first luminescent material 210, and (iii) a second luminescent material 220. The phrase plurality of light sources 110,120, . . . may in embodiments indicate that the plurality of light sources may comprise at least a first type of light sources and a second type of light sources, and optionally further type of light sources.

[0127] A first light source 110 is configured to generate first light 111, especially having one or more wavelengths in the blue wavelength range and in embodiments having a first centroid wavelength .sub.C1. Especially, in embodiments the first light source 110 comprises one or more lasers (here one laser is schematically depicted). The first luminescent material 210 is configured to convert at least part of the first light source light 111 into first luminescent material light 211, especially having one or more wavelengths in the green and/or yellow wavelength range.

[0128] A second light source 120 is configured to generate second light 121 having one or more wavelengths in the yellow and/or orange wavelength range and having a second centroid wavelength .sub.C2. Especially, in embodiments .sub.C2>.sub.C1. Further, in embodiments the second light source 120 may comprise one or more superluminescent diodes (here one SLD is schematically depicted). In embodiments, the second luminescent material 220 may be configured to convert at least part of the second light 121 into second luminescent material light 221. Especially having one or more wavelengths in the orange and/or red wavelength range.

[0129] In embodiments, in an operational mode (of the system 1000) the light generating system 1000 is configured to generate system light 1001 comprising the first luminescent material light 211 and the second luminescent material light 221 (see e.g. also FIGS. 2a-2b).

[0130] Referring to embodiment I of FIG. 1a, in an operational mode the system light may essentially consist of first luminescent material light 211 and the second luminescent material light 221 as there may be no unconverted light source light 111,121 (e.g. 100% of the spectral power may consist of these contributions). In embodiment II of FIG. 1a, it is shown that part of the first light source light 111 may also end up in the system light 1001. In such embodiments, in an operational mode (of the system 1000), the system light may comprise first luminescent material light 211, the second luminescent material light 221, and first light source light 111. Alternatively or additionally to the first light source light 111, the system light 1001 may comprise (in the operational mode) second light source light 121. In embodiment III of FIG. 1a, a third light source 130 is applied. Hence, the system 1000 may comprise a third light source 130 configured to generate third light source light 131 having one or more wavelengths in the blue wavelength range. Here, the third light source light 131 bypasses the luminescent materials 210,220. In such embodiments, in the operational mode the light generating system 1000 is configured to generate white system light 1001 comprising third light source light 131, the first luminescent material light 211 and the second luminescent material light 221. In embodiments, the third light source 130 may comprise one or more of a (diode) laser and a superluminescent diode.

[0131] Reference 400 refers to an end window or an optical element, especially an optical element, like a beam shaping element and/or a light homogenizer (see further also below).

[0132] Reference 300 refers to a control system. Hence, the light generating system 1000 may comprise the control system 300, wherein the control system may especially be configured to individually control (i) one or more of the one or more first light sources 110 and (ii) one or more of the one or more second light sources 120. Thereby a spectral power distribution of the system light 1001 (see also FIGS. 2a-2b) may be controlled. Referring to embodiment III, when individually controlling the first light source(s) 110, the second light source(s) 120, and the third light source(s) 130, one may create system light 1001 comprising one or more of the first luminescent material light 211, the second luminescent material light 221, and third light source light 131.

[0133] FIG. 1b schematically depicts a further embodiment, wherein one or more light combining elements 420 are applied. The one or more light combining elements 420 may be configured to combine in the operational mode at least the first luminescent material light 211 and the second luminescent material light 221. The one or more light combining elements 420 may be configured to combine in the operational mode the first luminescent material light 211, the second luminescent material light 221, and the third light source light 131. The system light 1001 may escape from the system via an end window or an optical element, especially an optical element, like a beam shaping element and/or a light homogenizer (see also above).

[0134] FIG. 1c schematically depicts further embodiments, combined in a single drawing, showing the use of a support and the use of the reflective mode. Note, however, that a support may also be optically transmissive. Hence, a support may also be used in combination with the transmissive mode. FIG. 1c schematically depicts an embodiment wherein one or more of the first luminescent material 210 and the second luminescent material 220 are operated in a reflective mode. Here, both are configured/operated in the reflective mode. The support may be thermally conducive. Hence, FIG. 1c also schematically depicts an embodiment wherein the first luminescent material 210 and the second luminescent material 220 are supported by a thermally conductive support 500. Further, FIG. 1c schematically depicts an embodiment of an integrated light source package 600, wherein the integrated light source package 600 may comprise a common support member 610 configured to support the plurality of light sources 110,120, . . . , the first luminescent material 210, and the second luminescent material 220, wherein common support member 610 comprises the thermally conductive support 500. Element(s) 505 may be used to support the plurality of light sources, elements 505 and the support 500 may be a monolithic support member 610. Whether or not, elements 505 may also comprise thermally conductive material. The plurality of light source may provide their light source light with optical axes having an angle with a surface of the respective luminescent materials selected from the range of at least 20 and smaller than 90. Especially, in embodiments a may be selected from the range of 30-60.

[0135] Referring to e.g. FIGS. 1a-1c (and also 2a-2b), in embodiments, the first luminescent material 210 may comprise a luminescent material of the type A.sub.3B.sub.5O.sub.12:Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc, and/or another first luminescent material (see also above), such as a nitride based luminescent material. In embodiments, the system 1000 may comprise a ceramic body 1210, wherein the ceramic body 1210 comprises the first luminescent material 210. In embodiments, the second luminescent material 220 comprises a luminescent material selected from the group consisting of MS:Eu.sup.2+, wherein M comprises one or more of calcium and strontium; M.sub.2Si.sub.5N.sub.8:Eu.sup.2+, wherein M comprises one or more of calcium and strontium and barium; MAlSiN.sub.3:Eu.sup.2+, wherein M comprises one or more of calcium and strontium; MLi.sub.2Al.sub.2O.sub.2N.sub.2:Eu.sup.2+, wherein M comprises strontium; MLiAl.sub.3N.sub.4:Eu.sup.2+, wherein M comprises strontium; MCaSiN.sub.2:Ce.sup.3+, wherein M comprises one or more of calcium and strontium; and M(Si,Al)N.sub.2:Ce.sup.3+, wherein M comprises calcium.

[0136] Further, also referring to e.g. FIGS. 1a-1c (and also 2a-2b), in embodiments, the first light source 110 is configured to generate first light 111 having one or more wavelengths in the wavelength range of 440-495 nm. Alternatively or additionally, in embodiments the second light source 120 is configured to generate second light 121 having one or more wavelengths in the wavelength range of 570-620 nm. Further, in specific embodiments, the second luminescent material 220 is configured to convert at least part of the second light 121 into second luminescent material light 221 having one or more wavelengths in the wavelength range of 610-625 nm.

[0137] Here below, a number of embodiments are indicated:

TABLE-US-00001 FIG. 2a FIG. 2b Centroid laser (nm) (.sub.c1) 447 447 First luminescent material LuAG:Ce.sup.3+ LuAG:Ce.sup.3+ (Lu.sub.3Al.sub.5O.sub.12:Ce.sup.3+) (Lu.sub.3Al.sub.5O.sub.12:Ce.sup.3+) Centroid first luminescent material (nm) 559 559 Centroid SLD (nm) (.sub.c2) 582 570 Second luminescent material (Ca, Sr)AlSiN.sub.3:Eu2+ SrLi.sub.2Al.sub.2O.sub.2N.sub.2:Eu.sup.2+ (SCASN) (SALON:Eu.sup.2+) Centroid second luminescent material (nm) 633 622 Efficiency (Lm/W) 127 133

[0138] Here below, some further examples are provided:

TABLE-US-00002 Centroid laser (nm) (.sub.c1) 457 437 First luminescent material LSN:Ce.sup.3+ GaYAG:Ce.sup.3+ (La, Y).sub.3Si.sub.6N.sub.11:Ce.sup.3+ Y.sub.3(Al, Ga).sub.5O.sub.12:Ce.sup.3+) Centroid first luminescent material (nm) 575 554 Centroid SLD (nm) (.sub.c2) 571 561 Second luminescent material CaS:Eu.sup.2+ HP-CaSiN.sub.2:Ce.sup.3+ 660 622 Centroid second luminescent material (nm) 94 71

[0139] Referring to FIGS. 2a-2b, reference .sub.CL1 refers to the centroid wavelength of the first luminescent material light 211, and .sub.CL2 refers to the centroid wavelength of the second luminescent material light 221. Hence, .sub.C1<.sub.CL1<.sub.C2<.sub.CL2. Especially, each centroid wavelength differs at least 10 nm with the other centroid wavelengths, like at least 20 nm. Data in relation to FIGS. 2a-2b are also found in one of the tables above. Referring to FIGS. 2a-2b, when integrating the (respective) spectral power over the wavelength range of 380-780 nm, at least 90% stems from one or more of the first light source light, second light source light, the first luminescent material light, the second luminescent material light, and the third light source light. The contributions of the first light source light, second light source light, the first luminescent material light, the second luminescent material light, and the third light source light may depend upon the (respective) operational mode.

[0140] FIG. 3 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. FIG. 3 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, FIG. 3 schematically depicts embodiments of a light generating device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, and an optical wireless communication device, comprising the light generating system 1000 as described herein.

[0141] The term plurality refers to two or more.

[0142] The terms substantially or essentially herein, and similar terms, will be understood by the person skilled in the art. The terms substantially or essentially may also include embodiments with entirely, completely, all, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term substantially or the term essentially may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

[0143] The term comprise also includes embodiments wherein the term comprises means consists of.

[0144] The term and/or especially relates to one or more of the items mentioned before and after and/or. For instance, a phrase item 1 and/or item 2 and similar phrases may relate to one or more of item 1 and item 2. The term comprising may in an embodiment refer to consisting of but may in another embodiment also refer to containing at least the defined species and optionally one or more other species.

[0145] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0146] The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

[0147] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0148] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0149] Use of the verb to comprise and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to.

[0150] The article a or an preceding an element does not exclude the presence of a plurality of such elements.

[0151] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0152] The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

[0153] The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

[0154] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.