WO2025228793A1

WO2025228793A1 - Light generating system comprising first, second and third light generating devices

Info

Publication number: WO2025228793A1
Application number: PCT/EP2025/061255
Authority: WO
Inventors: Ties Van Bommel; Rifat Ata Mustafa Hikmet; Erik Petrus Johannes MALLENS
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2024-04-30
Filing date: 2025-04-24
Publication date: 2025-11-06
Anticipated expiration: 2026-10-30

Abstract

The invention provides a light generating system (1000) comprising: (A) a first device (110) having a first SSL source (10) to generate first light (11), and a first converter (2100) comprising primary and secondary first luminescent materials (2110, 2120), wherein: (A1) the primary first material (2110) converts first light (11) into primary first light (2111) having a primary first centroid wavelength, λc1,1, in range 590-690 nm; (A2) the secondary first material (2120) converts first light (11) into secondary first light (2121) having a secondary first centroid wavelength, λc1, 2, in range 590-690 nm, such that Iλc1, 2-λc1,1| ≥ 10 nm; (A3) the first device (110) generates first device light (111) comprising the primary and secondary first lights (2111, 2121); (B) a second device (120) having a second SSL source (20) to generate second light (21), and a second converter (2200) comprising primary and secondary second luminescent materials (2210, 2220), wherein: (B1) the primary second material (2210) converts second light (21) into primary second light (2211) having a primary second centroid wavelength, λc2, 1, in range 490-590 nm; (B2) the secondary second material (2220) converts second light (21) into secondary second light (2221) having a secondary second centroid wavelength, λc2, 2, in range 590-690 nm; (B3) the second device (120) generates second device light (121) comprising the primary and secondary second lights (2211, 2221) and having a second device centroid wavelength, λcd2, in range 490-590 nm; (C) a third device (130) having a third SSL source (30) to generate third light (31), and a third converter (2300) comprising a primary third luminescent material (2310), wherein: (C1) the primary third material (2310) converts third light (31) into primary third light (2311); and (C2) the third device (130) generates white light (131) comprising the primary third light (2311), wherein, in operation, the system (1000) generates white system light (1001).

Description

LIGHT GENERATING SYSTEM COMPRISING FIRST, SECOND AND THIRD LIGHT GENERATING DEVICES

FIELD OF THE INVENTION

The invention relates to a light generating system. The invention further relates to a lighting device.

BACKGROUND OF THE INVENTION

Light generating systems are known in the art. For instance, US2019341531A1 describes a solid state lighting device including at least one electrically activated solid state light emitter configured to stimulate emissions of first through third lumiphoric materials having peak wavelengths in ranges of from 485 nm to 530 nm, from 575 nm to 595 nm, and from 605 nm to 640 nm, respectively (or subranges thereof defined herein), with the third peak having a full width half maximum value of less than 60 nm. The resulting device generates aggregated emissions having a suitably high color rendering index (e.g., CRI Ra) value (e.g., at least 70), and also having a spectral power distribution with a Melanopic/Photopic ratio within a specified target range as a function of correlated color temperature, thereby providing increased perceived brightness.

SUMMARY OF THE INVENTION

Conventional light generating systems (e.g. incandescent or fluorescent lamps) are rapidly being replaced by light emitting diode (LED) based lighting solutions. LED-based lighting solutions may generally comprise a light source and a luminescent converter, wherein the luminescent converter may comprise multiple types of phosphors, such as a yellow and a red phosphor, to produce light with a suitable color temperature. Yet, known LED-based lighting solutions may suffer from low lumen per Watt efficiency, which may increase energy consumption by consumers. Additionally or alternatively, prior art solutions may have problems to provide high CRIs (especially high CRI R9 scores) and/or tunable spectral properties. Further, prior art solutions may have problems with self-absorption in the phosphor layer, wherein light emitted by a first type of phosphor is absorbed by a second type of phosphor, thereby reducing the efficiency of the system and altering one or more of the correlated color temperature, color rendering index, and color point of the system light. As such, there is a desire for lighting devices that may especially be efficient and have stable, yet tunable, spectral properties. Hence, it is an aspect of the invention to provide an alternative light generating system, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

According to a first aspect, the invention provides a light generating system comprising a first light generating device, a second light generating device, and a third light generating device. The first light generating device may comprise a first solid state light source and a first luminescent converter. Especially, the first solid state light source may be configured to generate first light source light. The first light source light may have a first peak wavelength (Api) selected from the range of 380-490 nm. Further, the first luminescent converter may comprise a primary first luminescent material and a secondary first luminescent material. The primary first luminescent material may be configured to convert part of the first light source light received by the primary first luminescent material into primary first luminescent material light. In embodiments, the primary first luminescent material light may have a primary first centroid wavelength (kci,i) selected from the range of 590-690 nm. Additionally, the primary first luminescent material light may comprise at least one emission band having a primary first full width at half maximum FWHMli of > 50 nm. Further, the secondary first luminescent material may be configured to convert part of the first light source light received by the secondary first luminescent material into secondary first luminescent material light. The secondary first luminescent material light may have a secondary first centroid wavelength ( ci,2) selected from the range of 590-690 nm. Additionally, the secondary first luminescent material light may comprise at least one emission band having a secondary first full width at half maximum FWHMh of < 30 nm. In embodiments, |kci,2-kci,i| > 10 nm. Further, the first light generating device may be configured to generate first device light, wherein the first device light may comprise the primary first luminescent material light and the secondary first luminescent material light. Additionally, the first device light may have a first device centroid wavelength ( cai) selected from the range of 590-690 nm. The second light generating device may comprise a second solid state light source and a second luminescent converter, wherein the second solid state light source may be configured to generate second light source light. Especially, the second solid state light source light may have a second peak wavelength (Xp2 selected from the range of 380-490 nm. Further, the second luminescent converter may comprise a primary second luminescent material and a secondary second luminescent material. The primary second luminescent material may be configured to convert at least part of the second light source light received by the primary second luminescent material into primary second luminescent material light. The primary second luminescent material light may especially have a primary second centroid wavelength ( c2,i) selected from the range of 490-590 nm. In embodiments, the primary second luminescent material light may comprise at least one emission band having a primary second full width at half maximum FWHM21 of > 20 nm, such as > 50 nm (and especially in embodiments > 70 nm). Similarly, the secondary second luminescent material may be configured to convert at least part of the second light source light received by the secondary second luminescent material into secondary second luminescent material light. The secondary second luminescent material light may have a secondary second centroid wavelength ( c2,2) selected from the range of 590-690 nm. Further, the secondary second luminescent material light may comprise at least one emission band having a secondary second full width at half maximum FWHM22 of < 30 nm. In embodiments, (AC2.2 - Xc2,i) > 30 nm. Further, the second light generating device may be configured to generate second device light comprising the primary second luminescent material light and the secondary second luminescent material light. The second device light may especially have a second device centroid wavelength (Zcd2) selected from the range of 490-590 nm. Further, in embodiments, (kcai - Xcd2) > 15 nm. The third light generating device may comprise a third solid state light source and a third luminescent converter. The third solid state light source may be configured to generate third light source light. The third light source light may especially have a third peak wavelength (kps) selected from the range of 435-490 nm. Further, the third luminescent converter may comprise a primary third luminescent material. The primary third luminescent material may be configured to convert at least part of the third light source light received by the primary third luminescent material into primary third luminescent material light. Further, the third light generating device may be configured to generate third device light comprising the primary third luminescent material light. In embodiments, the third device light may especially be white light having a correlated color temperature (CCT) selected from the range of > 2000 K. Further, the light generating system may be configured to generate system light. The system light may comprise one or more of the first device light, the second device light, and the third device light. Further, in a first operational mode of the light generating system, the system light may have a correlated color temperature (CCT) selected from the range of 1700-4000 K, and a color rendering index (CRI) of at least 80. The color rendering index may preferably lie in a range of 80-99, more preferably in a range of 80-97, most preferably in a range of 80-95. Hence, in specific embodiments, the invention provides a light generating system comprising a first light generating device, a second light generating device, and a third light generating device, wherein: (A) the first light generating device comprises a first solid state light source and a first luminescent converter, wherein the first solid state light source is configured to generate first light source light having a first peak wavelength (kpi ) selected from the range of 380-490 nm; wherein the first luminescent converter comprises a primary first luminescent material and a secondary first luminescent material; (B) the primary first luminescent material is configured to convert at least part of the first light source light received by the primary first luminescent material into primary first luminescent material light; wherein the primary first luminescent material light has a primary first centroid wavelength ( ci,i) selected from the range of 590-690 nm; wherein the primary first luminescent material light comprises at least one emission band having a primary first full width at half maximum FWHMli of > 50 nm; (C) the secondary first luminescent material is configured to convert at least part of the first light source light received by the secondary first luminescent material into secondary first luminescent material light; wherein the secondary first luminescent material light has a secondary first centroid wavelength ( ci,2) selected from the range of 590-690 nm; wherein the secondary first luminescent material light comprises at least one emission band having a secondary first full width at half maximum FWHMh of < 30 nm; and wherein |kci,2 - ci,i | > 10 nm; (D) the first light generating device is configured to generate first device light comprising the primary first luminescent material light and the secondary first luminescent material light; wherein the first device light has a first device centroid wavelength ( cai) selected from the range of 590-690 nm; (E) the second light generating device comprises a second solid state light source and a second luminescent converter, wherein the second solid state light source is configured to generate second light source light having a second peak wavelength (Xp2) selected from the range of 380-490 nm; wherein the second luminescent converter comprises a primary second luminescent material and a secondary second luminescent material; (F) the primary second luminescent material is configured to convert at least part of the second light source light received by the primary second luminescent material into primary second luminescent material light; wherein the primary second luminescent material light has a primary second centroid wavelength ( c2,i) selected from the range of 490-590 nm; (G) the secondary second luminescent material is configured to convert at least part of the second light source light received by the secondary second luminescent material into secondary second luminescent material light; wherein the secondary second luminescent material light has a secondary second centroid wavelength ( c2,2) selected from the range of 590-690 nm; wherein the secondary second luminescent material light comprises at least one emission band having a secondary second full width at half maximum FWHM22 of < 30 nm; and wherein (AC2.2 - Xc2,i) > 30 nm; (H) the second light generating device is configured to generate second device light comprising the primary second luminescent material light and the secondary second luminescent material light; wherein the second device light has a second device centroid wavelength (Xcd2) selected from the range of 490-590 nm; wherein ( cai - kcd2) > 15 nm; (I) the third light generating device comprises a third solid state light source and a third luminescent converter, wherein the third solid state light source is configured to generate third light source light having a third peak wavelength (kps) selected from the range of 435-490 nm; wherein the third luminescent converter comprises a primary third luminescent material; (J) the primary third luminescent material is configured to convert at least part of the third light source light received by the primary third luminescent material into primary third luminescent material light; (K) the third light generating device is configured to generate third device light comprising the primary third luminescent material light, wherein the third device light is white light having a correlated color temperature selected from the range of > 2000 K; and (L) the light generating system is configured to generate system light, wherein in a first operational mode of the light generating system the system light is white light having a correlated color temperature selected from the range of 1700-6500 K and a color rendering index of at least 80.

With such a light generating system, (different types of) luminescent materials may be divided over multiple light generating devices. This may reduce the absorption of luminescent material light from a first luminescent material by a second luminescent material, thereby increasing the efficiency of the system. Hence, such a light generating system may be more (energy -)efficient. Further, with such a light generating system, the spectral properties of the system light may be tuned (during operation) by controlling the first, second, and third light generating device. Especially, with such a light generating system, spectral properties such as the CCT may be tuned over a relatively large range. Further, a light generating system comprising a plurality of luminescent materials configured to provide luminescent material light having different centroid wavelengths may facilitate providing system light having a high color rendering index (e.g. > 80). Especially, a light generating system comprising a luminescent material configured to emit in the wavelength range of 590-690 nm in at least two of the light generating devices may especially provide system light having a high CRI R9 score. Hence, compared to prior art solutions, such a light generating system may especially provide high-quality system light with tunable optical properties at a similar or improved efficiency.

In embodiments, the light generating system may comprise the first light generating device, wherein the first light generating device may comprise a first solid state light source and a first luminescent converter. In embodiments, the first solid state light source may especially be a LED (light emitting diode), though other options are also possible (see below). The first solid state light source may be configured to generate first light source light. The first light source light may have a first peak wavelength (kpi ) selected from the range of 380-490 nm, such as from the range of 400-480 nm, especially from the range of 420-475 nm, like from the range of 430-470 nm. Hence, the first light source light may be violet light or blue light. The term “violet light”, and similar terms, may especially relate to light having a wavelength in the range of about 380-440 nm. The term “blue light”, and similar terms, may especially relate to light having a wavelength in the range of about 440- 490 nm. The term “peak wavelength” may refer to the wavelength where the radiometric emission spectrum of the light source reaches its maximum, i.e., the peak wavelength may denote the wavelength at which the largest (emission intensity) value is found in a graph of the spectral power distribution. The peak wavelength may especially be determined at room temperature.

The first light generating device may further comprise a first luminescent converter. Similarly, the second light generating device may comprise a second luminescent converter. Additionally, the third light generating device may comprise a third luminescent converter. Some general embodiments relating to the luminescent converter will be discussed below. In embodiments, the (first, second, and/or third) luminescent converter may be configured as a coating covering the respective (first, second, and/or third) solid state light source. Alternatively, the (first, second, and/or third) luminescent converter may be configured as a (self-supporting) luminescent body. In embodiments, the (first, second, and/or third) luminescent converter may be configured in physical contact with (at least part of) the respective (first, second, and/or third) solid state light source. Alternatively, the (first, second, and/or third) luminescent converter may be configured at a respective non-zero (first, second, and/or third) distance (di, d2, and/or ds, respectively) from (yet in a light receiving relationship with) the respective (first, second, and/or third) solid state light source. In embodiments, the non-zero distances di, d2, and/or ds may be (individually) selected from the range of > 5 gm, such as from the range of > 10 gm, especially from the range of > 25 gm. Further, the non-zero distances di, d2, and/or ds may be (individually) selected from the range of < 10 cm, such as from the range of < 5 cm, especially from the range of < 1 cm. In specific embodiments, the (first, second, and/or third) luminescent converter may be physically separated from the respective (first, second, and/or third) solid state light source. Further, in embodiments, the (first, second, and/or third) luminescent converter may comprise a matrix material. Luminescent materials may be configured embedded in the matrix material of the luminescent converter. In embodiments, the matrix material may especially be a light transmissive, such as light transparent, matrix material. Herein, the term “light transparent” material indicates the material may be transmissive for one or more wavelengths selected from the range of 190-1500 nm, such as for one or more wavelengths selected from the range of 200-1000 nm, especially for one or more wavelengths selected from the range of 380-780 nm (i.e. visible light). In embodiments, the matrix material may be (for each luminescent converter individually) selected from the group comprising glass, polycarbonate (PC), (clear) polyvinyl chloride (PVC), liquid silicone rubber (LSR), cyclic olefin copolymers (COC), fluorinated ethylene propylene (FEP), styrene methyl methacrylate (SMMA), polysiloxanes, and poly(methyl methacrylate) (PMMA), such as especially from the group of polysiloxanes.

The first luminescent converter may comprise a primary first luminescent material and a secondary first luminescent material. Below, some general embodiments relating to the luminescent materials are provided. These general embodiments may relate to one or more of the primary first luminescent material, the secondary first luminescent material, the primary second luminescent material, the secondary second luminescent material, the primary third luminescent material, and the secondary third luminescent material (see below). The term “luminescent material” may especially refer to a material that can convert first radiation, especially one or more of UV radiation and blue radiation, into second radiation. Herein, UV (ultraviolet) may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm, though in specific embodiments other wavelengths may also be possible. In general, the first radiation and second radiation have different spectral power distributions, with the second radiation generally having a spectral power distribution at larger wavelengths than the first radiation (i.e. “down-conversion”). In embodiments, the “luminescent material” may especially refer to a material that can convert radiation into e.g. visible and/or infrared light. The terms “visible light” or “visible emission”, and similar terms, refer to light having one or more wavelengths in the range of about 380-780 nm. Further, IR (infrared) may especially refer to radiation having a wavelength selected from the range of 780-3000 nm, such as 780-2000 nm, e.g. a wavelength up to about 1500 nm, like a wavelength of at least 900 nm, though in specific embodiments other wavelengths may also be possible.

For instance, in embodiments the luminescent material may be able to convert one or more of UV radiation and blue radiation, into visible light. Hence, upon excitation with radiation, the luminescent material may emit radiation. In general, the luminescent material will be a down converter, i.e. radiation with a smaller wavelength is converted into radiation with a larger wavelength (Xex<Xem). In embodiments, the term “luminescence” may refer to phosphorescence. In embodiments, the term “luminescence” may also refer to fluorescence. Instead of the term “luminescence”, also the term “luminescent material light” or “emission” may be applied. Hence, the terms “first radiation” and “second radiation” may refer to excitation radiation and emission (radiation), respectively. Likewise, the term “luminescent material” may in embodiments refer to phosphorescence and/or fluorescence. The term “luminescent material” may also refer to a plurality of different luminescent materials. Examples of possible luminescent materials are indicated below. Hence, the term “luminescent material” may in specific embodiments also refer to a luminescent material composition. Instead of the term “luminescent material” also the term “phosphor” may be applied. These terms are known to the person skilled in the art.

In embodiments, luminescent materials may be selected from garnets and nitrides, especially doped with trivalent cerium or divalent europium, respectively. The term “nitride” may also refer to oxynitride or nitridosilicate, etc. Alternatively or additionally, the luminescent material(s) may be selected from silicates, especially doped with divalent europium. In embodiments, the luminescent material may comprise a divalent europium comprising oxynitride luminescent material. Further, in embodiments, the luminescent material may comprise a divalent europium comprising nitride luminescent material.

In embodiments, the luminescent material may comprise a luminescent material of the type AsBsOn 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 wherein the light source light may comprise blue light source light. Especially, A may comprise one or more of Y, Gd and Lu, such as especially one or more of Y and Lu. Especially, B may comprise one or more of Al and Ga, more especially at least Al, such as essentially entirely Al. Hence, especially suitable luminescent materials are cerium comprising garnet materials. Embodiments of garnets especially include A3B5O12 garnets, wherein A comprises at least yttrium (Y) or lutetium (Lu) and wherein B comprises at least aluminum (Al). Such garnets may be doped with cerium (Ce), with praseodymium (Pr) or a combination of cerium and praseodymium; especially however with Ce. Especially, B may comprise aluminum (Al), with optionally gallium (Ga) and/or scandium (Sc) and/or indium (In) up to about 20% of B, more especially up to about 10 % of B (i.e. the B ions essentially consist of > 90 mole % of Al and < 10 mole % of one or more of Ga, Sc, and In). B may especially comprise up to about 10% gallium. In another variant, B and O may at least partly be replaced by Si and N. The element A may especially be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Further, Gd and/or Tb are especially only present up to an amount of about 20% of A. In a specific embodiment, the garnet luminescent material comprises (Yi- _xLu_x)3B50i2:Ce, wherein 0 < x < 1. The term “:Ce”, indicates that part of the metal ions (i.e. in the garnets: part of the “A” ions) in the luminescent material is replaced by Ce. This is known to the person skilled in the art. Ce will replace A in general for not more than 10%; in general, the Ce concentration will be in the range of 0.1 to 4%, especially 0.1 to 2% (relative to A). Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art. In embodiments, such luminescent materials may have a suitable spectral distribution (see however below), have a relatively high efficiency, have a relatively high thermal stability, and allow a high CRI (optionally in combination with (the) light of other sources of light as described herein). In specific embodiments, the luminescent material may comprise (YxiA’x2Cex3)3(Al_yiB’_y2)5Oi2. Here, A’ comprises one or more elements selected from the group consisting of lanthanides, and B’ comprises one or more elements selected from the group consisting of Ga, In and Sc, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2. Especially, x3 is selected from the range of 0.001-0.1. Note that in embodiments x2=0. Alternatively or additionally, in embodiments y2=0.

In embodiments, the luminescent material may comprise a luminescent material of the type AsSieNiuCe³ , wherein A comprises one or more of Y, La, Gd, Tb and Lu, such as in embodiments one or more of La and Y. In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu²⁺ and/or LSisN^Eu² and/or MAlSiNvEu² and/or Ca2AlSi3O2Ns:Eu²⁺, etc., wherein M comprises one or more of Ba, Sr and Ca, especially in embodiments at least Sr. Hence, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations, as is known to the person skilled in the art. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions (indicated by M) is replaced by Eu (in these examples by Eu²⁺). For instance, assuming 2% Eu in CaAlSiNvEu, the correct formula could be (Cao.98Euo.o2)AlSiN3.

The term “luminescent material” herein especially relates to inorganic luminescent materials. Alternatively or additionally, also other luminescent materials may be applied. For instance quantum structures (such as e.g. quantum rods and quantum dots) and/or organic dyes may be applied and may optionally be embedded in transmissive matrices like e.g. polymers, like PMMA, or poly siloxanes, etc..

In embodiments, the luminescent material may comprise a tetravalent manganese-comprising luminescent material, i.e., a luminescent material doped with tetravalent manganese. Especially, in embodiments, the luminescent material may comprise a luminescent material of the type M’_xM2-2xAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x may be selected from the range of 0-1, wherein A comprises a tetravalent cation, for instance comprising one or more of silicon and titanium, and wherein X comprises a monovalent anion, at least comprising fluorine. Such luminescent materials may herein also be indicated as “KSiF” or “KSF”, whether or not M comprises K or one or more other alkaline cations. A luminescent material of the type M’_xM2-2xAX6 doped with tetravalent manganese is amongst others described in WO2013121355A1, which is herein incorporated by reference. Passages from WO2013121355A1 are also copied herein. In embodiments, the alkaline earth cation M’ may comprise one or more of magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba. Further, the alkaline cations M may comprise one or more of sodium (Na), potassium (K) and rubidium (Rb). Optionally, M may (further) comprise one or more of ammonium (NH ), lithium (Li), and cesium (Cs). In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. The phrase “wherein M comprises at least potassium” indicates for instance that of all M cations in a mole M’_xM2-2xAX6 , a fraction comprises K⁺ and an optionally remaining fraction comprises one or more other monovalent (alkaline) cations (see also below). In another preferred embodiment, M comprises at least potassium and rubidium. Optionally, the M’_xM2-2xAX6 luminescent material has the hexagonal phase. In yet another embodiment, the M’_xM2-2xAX6 luminescent material has the cubic phase. In an embodiment, a combination of different alkaline cations M may be applied. In yet another embodiment, a combination of different alkaline earth cations M’ may be applied. In yet another embodiment, a combination of one or more alkaline cations M and one or more alkaline earth cations M’ may be applied. For instance, KRbo.sSro^sAXe might be applied. As indicated above, x in the formula M’_xM2-2xAX6 may be selected from the range of 0-1, especially x < 1. In specific embodiments, x = 0.

The term “tetravalent manganese” refers to Mn⁴⁺. This is a well-known luminescent ion. In the formula as indicated above, part of the tetravalent cation A (such as Si) is being replaced by manganese. Hence, M’_xM2-2xAX6 doped with tetravalent manganese may also be indicated as M’xM2-2xAi-_mMn_mX6 (or M’_xM2-2xAX6:Eu). The mole percentage of manganese, i.e. the percentage it replaces the tetraval ent cation A will in general be in the range of 0.1-15 %, especially 1-12 %, i.e. m is in the range of 0.001-0.15, especially in the range of 0.01-0.12. As manganese replaces part of a host lattice ion and has a specific function, it is also indicated as “dopant” or “activator”. Hence, the hexafluorosilicate is doped or activated with manganese (Mn⁴⁺). In embodiments, A may comprise a tetravalent cation, and preferably at least comprises silicon. A may optionally (further) comprise one or more of titanium (Ti), germanium (Ge), stannum (Sn) and zinc (Zn). Preferably, at least 80%, even more preferably at least 90%, such as at least 95% of A consists of silicon. In a specific embodiment, M’_xM2-2xAX6 can also be described as (Ki-r-i-n-c-nhRbrLiiNa_nCs_c(NH4)nh)2AX6, wherein r is in the range of 0-1, wherein l,n,c,nh are each individually preferably in the range of 0-1, preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05, and wherein r+l+n+c+nh is in the range of 0-1, especially 1+n+c+nh < 1, especially < 0.2, preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05. X is preferably fluorine (F). Further, in a specific embodiment, M’_xM2-2xAX6 can also be described as MgmgCa_CaSrsrBaba(KkRbrLiiNa_nCs_c(NH4)nh)2AX6, with k, r, 1, n, c, nh each individually being in the range of 0-1, wherein mg, ca, sr, ba are each individually in the range of 0-1, and wherein mg+ca+sr+ba+k+ r+ l+n+c+nh=l. In embodiments, k=l, and the others (mg, ca, sr, ba, r, 1, n, c, nh) are zero. As indicated above, X relates to a monovalent anion, but at least comprises fluorine. Other monovalent anions that may optionally be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). Preferably, at least 80%, even more preferably at least 90%, such as 95% of X consists of fluorine. Hence, in a specific embodiment, M’_xM2-2xAX6 can also be described as M M2-2xA(Fi-_ci-b-iCl_ciBrbIi)6, wherein cl,b,i are each individually preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05, and wherein cl+b+i < 1, especially < 0.2, preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05. Hence, M’_xM2-2xAX6 can also be described as (Ki-_r-i-n-c-nh RbrLiiNanCs_c(NH4)nh)2Sii-m-t-g-s-zrMn_mTitGegSnsZrzr(Fi-_ci-b-iCl_ciBrbIi)6, with the values for r,l,n,c,nh,m,t,g,s,zr,cl,b,i as indicated above. In an embodiment, M’_xM2-2xAX6 comprises BGSiFe (indicated herein also as KSiF system). In another preferred embodiment, M’_XM2- 2xAXe comprises KRbSiFe (herein also indicated as K,Rb system). In specific embodiments, the indication M’_xM2-2xAX6 may refer to one or more of (K,Rb)2SiFe:Mn⁴⁺, (K,Rb)2TiFe:Mn⁴⁺, K2(Si,Ti)Fe:Mn⁴⁺, and Rb2(Si,Ti)Fe:Mn⁴⁺, such as one or more of K2TiFe:Mn⁴⁺, of K2SiFe:Mn⁴⁺, and of Rb2SiFe:Mn⁴⁺. As can be derived from the above, “(Si,Ti)” may indicate one or more of Si and Ti. Hence, in specific embodiments, the luminescent material may comprise one or more of (K,Rb)2SiFe:Mn⁴⁺ and K2(Si,Ti)Fe:Mn⁴⁺. The luminescent material may also be coated, as also described in WO2013121355A1.

Hence, when M’ refers to n different elements, this may imply that the relevant formula may comprise for the M’ position in the formula essentially any permutation of the n different elements. For instance, when M’=Ba,Sr,Ca or when M’ comprises one or more of Ba, Sr, Ca or when M’ refers to Ba,Sr,Ca, this may imply that in the formula Ba, Sr, Ca, (Ba_xSr_y), (Ba_xCa_y), (Ca_xSr_y), or (Ba_xSr_yCa_z), may be available, wherein in general x+y+z=l. Referring to e.g. M’_XM2-2XAX6, this may refer to e.g. one or more of K2SiFe:Mn⁴⁺, Rb2SiFe:Mn⁴⁺, and (KxRb_y)2SiFe:Mn⁴⁺, etc. Further, indications like “K,Rb” or “Ba,Sr,Ca”, and similar indications (see also above), may indicate one or more of such elements. Hence, (K,Rb)2SiFe:Mn⁴⁺, may e.g. refer to K2SiFe:Mn⁴⁺, Rb2SiFe:Mn⁴⁺, or (KxRb_y)2SiFe:Mn⁴⁺. Also herein in general x+y=l.

In embodiments, the primary first luminescent material may comprise a nitrogen-containing luminescent material, such as selected from the group of oxynitride and nitride luminescent materials. Hence, in specific embodiments, the primary first luminescent material may be selected from the group of oxynitride luminescent materials and nitride luminescent materials. Such a primary first luminescent material may provide luminescent material light having a broad (FWHM > 50 nm) emission band. As such, such a primary first luminescent material light may facilitate increasing the color rendering index (CRI) of the system light (comprising the primary first luminescent material light). Further, such a primary first luminescent material may be relatively stable.

The primary first luminescent material may be configured to convert (at least) part of the first light source light received by the primary first luminescent material into primary first luminescent material light. Especially, in embodiments, the first light source light may have a spectral power distribution, wherein the primary first luminescent material may be configured to convert > 15%, such as > 20%, especially > 25%, like > 30%, of the spectral power of the first light source light (in the wavelength range of 380-780 nm) received by the primary first luminescent material into primary first luminescent material light. Additionally or alternatively, the first light source light may have a spectral power distribution, wherein the primary first luminescent material may be configured to convert < 80%, such as < 70%, especially < 65%, like < 60%, of the spectral power of the first light source light (in the wavelength range of 380-780 nm) received by the primary first luminescent material into primary first luminescent material light.

The primary first luminescent material light may have a primary first centroid wavelength ( ci,i). The term “centroid wavelength”, also indicated as c, is known in the art, and refers to the wavelength value where half of the light energy is at shorter and half the energy is at longer wavelengths; the value is stated in nanometers (nm). It is the wavelength that divides the integral of a spectral power distribution into two equal parts as expressed by the formula Ac = X I(k) / (S I( <)), where the summation is over the wavelength range of interest, and I (A) is the spectral energy density (i.e. the integration of the product of the wavelength and the intensity over the emission band normalized to the integrated intensity). The centroid wavelength may e.g. be determined at operation conditions. In embodiments, the primary first centroid wavelength ( ci,i) may be selected from the range of 590-700 nm, such as from the range of 590-690 nm, especially from the range of 595-670 nm, like from the range of 605-650 nm. Hence, in embodiments, the primary first luminescent material light may comprise, such as be, one or more of orange light and red light, such as especially red light. The terms “orange light” or “orange emission”, and similar terms, may especially relate to light having a wavelength in the range of about 590-620 nm. The terms “red light” or “red emission”, and similar terms, may especially relate to light having a wavelength in the range of about 620-780 nm.

Further, the primary first luminescent material light may comprise at least one emission band having a primary first full width at half maximum FWHMli of > 40 nm, such as > 50 nm, especially > 60 nm, like > 75 nm. Additionally or alternatively, the primary first luminescent material light may comprise the at least one emission band having a primary first full width at half maximum FWHMli of < 200 nm, such as < 175 nm, especially < 150 nm, like < 100 nm. In embodiments, the primary first luminescent material light may comprise a plurality of emission bands, wherein at least one band may have the primary first full width at half maximum FWHMli. Alternatively, the primary first luminescent material light may comprise a single emission band, wherein said emission band may have the primary first full width at half maximum FWHMli. The term “emission band” may refer to the emission (spectral power distribution) resulting from a radiative transition of electrons from (vibrational levels of) a first higher-energy excited state to (vibrational levels of) a second lower-energy (ground) state, wherein a larger number of vibrational levels in (one or more of) the first excited state and second (ground) state results in a broader emission band (spanning a larger wavelength range). Further, the term “full width at half maximum” (or “FWHM”) refers to the width of (the spectral power distribution of) the emission band at half the maximum intensity of said emission band.

In embodiments, the secondary first luminescent material may be selected from the same type as the secondary second luminescent material. Further, in embodiments, the secondary first luminescent material may be selected from the same type as the primary third luminescent material. Hence, in embodiments, the secondary first luminescent material, secondary second luminescent material, and primary third luminescent material may (all) be selected from the same type of luminescent material. In embodiments, the secondary first, secondary second, and primary third luminescent material may be individually selected from the group of quantum structures, such as from the group comprising quantum dots and quantum rods. Especially, the secondary first luminescent material, secondary second luminescent material, and primary third luminescent material may be individually selected from the type of tetravalent manganese doped luminescent materials. In specific embodiments, the secondary first luminescent material, secondary second luminescent material, and primary third luminescent material may be individually selected from the type of M’_XM2-2XAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, A comprises a tetravalent cation, and X comprises a monovalent anion (see also above). In such embodiments, x may especially be in the range of 0-1 (and individually selected for each of the secondary first luminescent material, secondary second luminescent material, and primary third luminescent material). Further, A may comprise one or more of silicon and titanium, and X may comprise one or more of fluorine, chlorine, bromine, and iodine, wherein X may at least comprise fluorine. The composition of A and X may be individually selected for each of the secondary first luminescent material, secondary second luminescent material, and primary third luminescent material. In embodiments, at least two (such as all) of the secondary first, secondary second, and primary third luminescent materials may have the (exact) same composition. Alternatively, at least two (such as all) of the secondary first, secondary second, and primary third luminescent materials may have different compositions. The secondary first luminescent material, secondary second luminescent material, and primary third luminescent material may thus be selected from the type of M’_xM2-2x(A*,Si,Ti)i(F,Cl,Br,I)6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, A* comprises a tetravalent cation (not including silicon and titanium), and x is in the range of 0-1. Hence, in specific embodiments, the secondary first luminescent material, the secondary second luminescent material, and the primary third luminescent material may be individually selected from the type of M’_xM2-2xAX6 doped with tetravalent manganese, wherein M’ may comprise an alkaline earth cation, M may comprise an alkaline cation, and x may be in the range of 0-1, wherein A may comprise a tetravalent cation, comprising one or more of silicon and titanium, and wherein X may comprise a monovalent anion, at least comprising fluorine. Such luminescent materials may provide luminescent material light having a narrow (FWHM < 50 nm) emission band. As such, such luminescent material lights may facilitate providing high-intensity light in a narrow wavelength range, improving the brightness of the respective device light at that wavelength range. Further, such luminescent materials may be configured to convert light source light relatively efficiently. Having a luminescent material of the same type in each of the first, second, and third light generating device may further provide the benefit that each of the first, second, and third device light may have a (red) light component having similar spectral properties, and/or a relatively high CRI R9 score. As can be derived from the above, the indication “(F,Cl,Br,I)” may refer to one or more of F, Cl, Br, and I, but may especially refer to at least F, and optionally one or more of Cl, Br, and I (see also above, wherein it is indicated that cl+b+i < 1).

In embodiments, the secondary first luminescent material, secondary second luminescent material, and primary third luminescent material may be selected from the same type of luminescent material, and may thus be configured to generate (respective) luminescent material light having similar optical properties. Especially, the secondary first luminescent material may be configured to generate secondary first luminescent material light having a secondary first centroid wavelength ( ci,2), the secondary second luminescent material may be configured to generate secondary second luminescent material light having a secondary second centroid wavelength ( c2,2), and the primary third luminescent material may be configured to generate primary third luminescent material light having a primary third centroid wavelength ( c3,i). In embodiments, the secondary first centroid wavelength (kci,2), secondary second centroid wavelength ( c2,2), and primary third centroid wavelength ( c3,i) may be individually selected from the range of 590-700 nm, such as from the range of 590-690 nm, especially from the range of 600-670 nm, like from the range of 600-650 nm. Hence, in specific embodiments, the primary third luminescent material light may have a primary third centroid wavelength ( c3,i) selected from the range of 590-690 nm. Further, the secondary first centroid wavelength ( ci,2), secondary second centroid wavelength ( c2,2), and primary third centroid wavelength ( c3,i) may be individually selected from the range of 605-640 nm, such as from the range of 610-635 nm, especially from the range of 615-630 nm. Hence, in embodiments, the secondary first luminescent material light, secondary second luminescent material light, and primary third luminescent material light may comprise, such as be, one or more of orange light and red light, such as especially red light. In embodiments, at least two (such as all) of the secondary first centroid wavelength ( ci,2), secondary second centroid wavelength ( c2,2), and primary third centroid wavelength ( c3,i) may differ by less than 15 nm, such as by less than 10 nm, especially by less than 5 nm.

Further, in embodiments, the secondary first luminescent material light, secondary second luminescent material light, and primary third luminescent material light may (each) comprise at least one emission band having a secondary first full width at half maximum FWHMh, secondary second full width at half maximum FWHM22, and primary third full width at half maximum FWHM31, respectively, (individually selected from the range) of < 30 nm, such as < 25 nm, especially < 20 nm, like < 15 nm. Hence, in specific embodiments, the primary third luminescent material light may comprise at least one emission band having a primary third full width at half maximum FWHM31 of < 30 nm. Additionally or alternatively, the secondary first luminescent material light, secondary second luminescent material light, and primary third luminescent material light may comprise the at least one emission band having a secondary first full width at half maximum FWHMh, secondary second full width at half maximum FWHM22, and primary third full width at half maximum FWHM31, respectively, (individually selected from the range) of > 2 nm, such as > 5 nm, especially > 7 nm, like > 10 nm. In embodiments, the secondary first luminescent material light, secondary second luminescent material light, and primary third luminescent material light may (each) comprise a plurality of emission bands, wherein at least one band may have the secondary first full width at half maximum FWHMh, secondary second full width at half maximum FWHM22, and primary third full width at half maximum FWHM31, respectively. Additionally or alternatively, the secondary first luminescent material light, secondary second luminescent material light, and primary third luminescent material light may (each) comprise a plurality of emission bands, wherein essentially all of the emission bands may have the secondary first full width at half maximum FWHMh, secondary second full width at half maximum FWHM22, and primary third full width at half maximum FWHM31, respectively.

Focusing on the secondary first luminescent material, the secondary first luminescent material may be configured to convert (at least) part of the first light source light received by the secondary first luminescent material into secondary first luminescent material light. Especially, in embodiments, the first light source light may have a spectral power distribution, wherein the secondary first luminescent material may be configured to convert > 20%, such as > 25%, especially > 30%, like > 35%, of the spectral power of the first light source light (in the wavelength range of 380-780 nm) received by the secondary first luminescent material into secondary first luminescent material light. Additionally or alternatively, the first light source light may have a spectral power distribution, wherein the secondary first luminescent material may be configured to convert < 80%, such as < 70%, especially < 65%, like < 60%, of the spectral power of the first light source light (in the wavelength range of 380-780 nm) received by the secondary first luminescent material into secondary first luminescent material light. Further, in embodiments, the secondary first centroid wavelength ( ci,2) may be (roughly) equal to the primary first centroid wavelength ( ci,i), such as differ by < 5 nm, especially by < 2 nm, including by (essentially) 0 nm. Alternatively, the secondary first centroid wavelength ( ci,2) may be different from the primary first centroid wavelength ( ci,i). Especially, in embodiments, |kci,2-kci,i| > 0 nm, such as |kci,2-kci,i| > 5 nm, especially |kci,2-kci,i| > 10 nm, like |kci,2-kci,i| > 20 nm. Additionally or alternatively, in embodiments, |kci,2-kci,i| < 50 nm, such as |kci,2-kci,i| < 40 nm, especially |kci,2-kci,i| < 30 nm, like |kci,2-kci,i| < 25 nm. In embodiments, the secondary first centroid wavelength ( ci,2) may be larger than (or equal to) the primary first centroid wavelength ( ci,i), i.e., ci,2 > ci,i. Alternatively, the secondary first centroid wavelength ( ci,2) may be smaller than (or equal to) the primary first centroid wavelength ( ci,i), i.e., ci,2 < kci,i.

In embodiments, the primary first luminescent material and secondary first luminescent material may be configured embedded in the first luminescent converter, such as especially in the matrix material. Hence, the first luminescent converter may comprise the primary first luminescent material in a primary first concentration Ci,i, and the secondary first luminescent material in a secondary first concentration Ci,2. In embodiments, the primary first concentration Ci,i may be selected from the range of > 5 wt.%, such as from the range of > 10 wt.%, especially from the range of > 15 wt.%. Additionally or alternatively, the primary first concentration Ci,i may be selected from the range of < 50 wt.%, such as from the range of < 40 wt.%, especially from the range of < 30 wt.%. Further, in embodiments, the secondary first concentration Ci,2 may be selected from the range of > 10 wt.%, such as from the range of > 20 wt.%, especially from the range of > 25 wt.%. Additionally or alternatively, the secondary first concentration Ci,2 may be selected from the range of < 60 wt.%, such as from the range of < 50 wt.%, especially from the range of < 35 wt.%. Further, in embodiments, Ci,2/Ci,i < 2, such as Ci,2/Ci,i < 1.5, especially Ci,2/Ci,i < 1.3, like Ci,2/Ci,i < 1.1. Additionally or alternatively, in embodiments, Ci,2/Ci,i > 0.5, such as Ci,2/Ci,i > 0.7, especially Ci,2/Ci,i > 0.8, like Ci,2/Ci,i > 0.9.

In embodiments, the first luminescent converter may further comprise one or more additional first luminescent materials, such as selected from the luminescent materials provided above. Hence, in embodiments, a first luminescent material content of the first luminescent converter may consist for at most 99 wt.%, such as at most 98 wt.%, especially at most 95 wt.%, like at most 90 wt.%, of the primary first luminescent material and the secondary first luminescent material. Alternatively, the first luminescent material content of the first luminescent converter may consist for at least 90 wt.%, such as at least 95 wt.%, especially at least 98 wt.%, including (essentially) 100 wt.%, of the primary first luminescent material and the secondary first luminescent material. Herein, the term “luminescent material content” refers to the total weight of the luminescent materials present in the luminescent converter.

In embodiments, the first light generating device comprising the first luminescent converter may be configured to generate first device light. The first device light may especially comprise the primary first luminescent material light and the secondary first luminescent material light. Optionally, the first device light may further comprise part of the first light source light. For instance, in embodiments, the first device light may have a spectral power distribution, wherein at least 2%, such as at least 3.5%, especially at least 5%, like at least 7%, of the spectral power in the wavelength range of 380-780 nm may be provided by the first light source light. Alternatively, the first device light may be (essentially) free from the first light source light. Especially, in embodiments, the first device light may have a spectral power distribution, wherein at most 5%, such as at most 2%, especially at most 1.5%, like at most 1%, including (essentially) 0%, of the spectral power in the wavelength range of 380-780 nm may be provided by the first light source light. Hence, in specific embodiments, the first device light may have a spectral power distribution, wherein at most 2% of the spectral power in the wavelength range of 380-780 nm may be provided by the first light source light. Such first device light may provide the benefit that the first device light may be (essentially) free from blue and/or violet light. Hence, such first device light may be suitable for e.g. photography dark room applications, where blue and/or violet light is undesirable due to its ability to degrade the photosensitive materials.

Further, in embodiments, the first device light may have a spectral power distribution, wherein xi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary first luminescent material light. In embodiments, xi may be selected from the range of > 20, such as from the range of > 25, especially from the range of > 30, like from the range of > 35. Additionally or alternatively, xi may be selected from the range of < 75, such as from the range of < 70, especially from the range of < 65, like from the range of < 60. Further, in embodiments, the first device light may have a spectral power distribution, wherein X2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary first luminescent material light. In embodiments, X2 may be selected from the range of > 20, such as from the range of > 25, especially from the range of > 30, like from the range of > 35. Additionally or alternatively, X2 may be selected from the range of < 75, such as from the range of < 70, especially from the range of < 65, like from the range of < 60. Further, in embodiments, X1/X2 may be selected from the range of > 0.3, such as from the range of > 0.4, especially from the range of > 0.5, like from the range of > 0.6. Additionally or alternatively, X1/X2 may be selected from the range of < 4, such as from the range of < 3, especially from the range of < 2, like from the range of < 1.5. Further, in embodiments, 0.3 < X1/X2 < 4, such as 0.4 < X1/X2 < 3, especially 0.5 < X1/X2 < 2, like 0.6 < X1/X2 < 1.5. Hence, in specific embodiments, the first device light may have a spectral power distribution, wherein xi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary first luminescent material light, wherein X2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary first luminescent material light, and wherein 0.5 < X1/X2 < 2. Such a ratio in spectral power contributions may provide the benefit that the first device light may comprise both a significant contribution of the (broadband) primary first luminescent material light and the (narrowband) secondary first luminescent material light, thereby improving both the CRI and CRI R9 score of the first device light.

In embodiments, the first device light may have a first device centroid wavelength ( cai). The first device centroid wavelength ( cai) may especially be selected from the range of 590-700 nm, such as from the range of 590-690 nm, especially from the range of 600-670 nm, like from the range of 610-650 nm. Hence, in embodiments, the first device light may especially be visible light. Further, in embodiments, the first device light may have a first color point in the CIE 1931 color space, wherein the first color point may be defined by first chromaticity coordinates [xi,yi]. The CIE 1931 color space may refer to a (two-dimensional) chromaticity diagram having a horseshoe-like shape, and may represent all of the chromaticity’s visible to the average person. The curved line around the outside of the chromaticity diagram may represent the spectral locus (displaying the spectral colors), while the straight line (connecting the ends of the horseshoe) may represent the line of purples. The CIE 1931 color space may especially be a chromaticity diagram representing the chromaticity’s visible to the average person under illumination with a CIE standard illuminant D65 (or “Des”). The CIE standard illuminant D65 may correspond to an average midday light in Western Europe / Northern Europe (comprising both direct sunlight and the light diffused by a clear sky), and may also be referred to as a daylight illuminant. The CIE standard illuminant D65 may have a color temperature of approximately 6500 K, and may have chromaticity coordinates (in the CIE 1931 color space) of x = 0.31272 and y = 0.32903. Further, in embodiments, the average person (observing a color in the CIE 1931 color space) may be represented by the CIE 1931 2° standard observer, wherein the CIE 1931 2° standard observer may be represented by three color matching functions x, y, and z representing an average human's chromatic response within a 2° arc inside the fovea. These color matching functions are known to the person skilled in the art. The chromaticity coordinates [x,y] may refer to a position within the CIE 1931 color space. In embodiments, as indicated above, the first color point of the first device light may be defined by first chromaticity coordinates [xi,yi]. In embodiments, [xi] may be selected from the range of 0.6-0.73, such as from the range of 0.63-0.71, especially from the range of 0.65-0.70. Further, in embodiments, [y i] may be selected from the range of 0.26-0.4, such as from the range of 0.28-0.35, especially from the range of 0.29-0.33.

In embodiments, the light generating system may further comprise a second light generating device. In embodiments, the second light generating device may comprise a second solid state light source and a second luminescent converter. In specific embodiments, the second solid state light source may be a LED. Further, in embodiments, the second solid state light source may be configured to generate second light source light. The second light source light may have a second peak wavelength (Xp2 selected from the range of 380-490 nm, such as from the range of 400-480 nm, especially from the range of 420-475 nm, like from the range of 430-470 nm. Hence, the second light source light may be violet light or blue light. The second light generating device may further comprise a second luminescent converter. As indicated above, the second luminescent converter may be configured as a coating (covering the second solid state light source). Alternatively, the second luminescent converter may be configured as a (self-supporting) luminescent body (optionally configured at a non-zero second distance d? from the second light source). The second luminescent converter may comprise a primary second luminescent material and a secondary second luminescent material. In embodiments, the primary second luminescent material may comprise any of the luminescent materials indicated above. Yet, especially, the primary second luminescent material may comprise a trivalent cerium-doped garnet luminescent material, such as a luminescent material of the type AsBsOn Ce³ . In such embodiments, A may comprise at least one of Y, La, Gd, Tb and Lu, and B may comprise at least one of Al, Ga, In and Sc. Hence, in specific embodiments, the primary second luminescent material may comprise a luminescent material of the type AsBsOn Ce³ ; wherein A may comprise at least one of Y, La, Gd, Tb and Lu; and wherein B may comprise at least one of Al, Ga, In and Sc.

The primary second luminescent material may be configured to convert at least part of the second light source light received by the primary second luminescent material into primary second luminescent material light. Especially, in embodiments, the second light source light may have a spectral power distribution, wherein the primary second luminescent material may be configured to convert > 50%, such as > 60%, especially > 70%, like > 75%, of the spectral power of the second light source light (in the wavelength range of 380-780 nm) received by the primary second luminescent material into primary second luminescent material light. Additionally or alternatively, the second light source light may have a spectral power distribution, wherein the primary second luminescent material may be configured to convert < 98%, such as < 95%, especially < 90%, like < 85%, of the spectral power of the second light source light (in the wavelength range of 380-780 nm) received by the primary second luminescent material into primary second luminescent material light.

The primary second luminescent material light may have a primary second centroid wavelength ( c2,i). In embodiments, the primary second centroid wavelength ( c2,i) may be selected from the range of 480-600 nm, such as from the range of 490-590 nm, especially from the range of 500-570 nm, like from the range of 515-560 nm. Hence, in embodiments, the primary second luminescent material light may comprise, such as be, one or more of green light and yellow light (including some blue or orange tones), such as especially green light. The terms “green light” or “green emission”, and similar terms, may especially relate to light having a wavelength in the range of about 490-560 nm. The terms “yellow light” or “yellow emission”, and similar terms, may especially relate to light having a wavelength in the range of about 560-590 nm.

Further, the primary second luminescent material light may comprise at least one emission band having a primary second full width at half maximum FWHM21 of > 20 nm, such as > 50 nm, especially > 70 nm. Alternatively, the primary second luminescent material light may comprise at least one emission band having a primary second full width at half maximum FWHM21 of > 40 nm, such as > 50 nm, especially > 60 nm, like > 75 nm. Additionally or alternatively, the primary second luminescent material light may comprise the at least one emission band having a primary second full width at half maximum FWHM21 of < 200 nm, such as < 175 nm, especially < 150 nm, like < 100 nm. In embodiments, the primary second luminescent material light may comprise a plurality of emission bands, wherein at least one band may have the primary second full width at half maximum FWHM21. Yet, especially, the primary second luminescent material light may comprise a single emission band, wherein said emission band may have the primary second full width at half maximum FWHM21. Hence, in specific embodiments, the primary second luminescent material light may comprise at least one emission band having a primary second full width at half maximum FWHM21 of > 50 nm.

The secondary second luminescent material may be configured to convert (at least) part of the second light source light received by the secondary second luminescent material into secondary second luminescent material light. Especially, in embodiments, the second light source light may have a spectral power distribution, wherein the secondary second luminescent material may be configured to convert > 2%, such as > 5%, especially > 7%, like > 10%, of the spectral power of the second light source light (in the wavelength range of 380-780 nm) received by the secondary second luminescent material into secondary second luminescent material light. Additionally or alternatively, the second light source light may have a spectral power distribution, wherein the secondary second luminescent material may be configured to convert < 40%, such as < 30%, especially < 25%, like < 20%, of the spectral power of the second light source light (in the wavelength range of 380-780 nm) received by the secondary second luminescent material into secondary second luminescent material light. Further, in embodiments, the secondary second centroid wavelength ( c2,2) may be different from the primary second centroid wavelength ( c2,i), such as especially be larger than the primary second centroid wavelength ( c2,i). Especially, in embodiments, ( c2,2- c2,i) > 10 nm, such as ( c2,2- c2,i) > 20 nm, especially ( c2,2- c2,i) > 30 nm, like ( c2,2- c2,i) > 40 nm. Additionally or alternatively, in embodiments, ( c2,2- c2,i) < 150 nm, such as ( c2,2- c2,i) < 125 nm, especially ( c2,2- c2,i) < 100 nm, like ( c2,2- c2,i) < 80 nm.

In embodiments, the primary second luminescent material and secondary second luminescent material may be configured embedded in the second luminescent converter, such as especially in the matrix material. Hence, the second luminescent converter may comprise the primary second luminescent material in a primary second concentration

62.1, and the secondary second luminescent material in a secondary second concentration

62.2. In embodiments, the primary second concentration 62,1 may be selected from the range of > 10 wt.%, such as from the range of > 15 wt.%, especially from the range of > 20 wt.%. Additionally or alternatively, the primary second concentration 62,1 may be selected from the range of < 50 wt.%, such as from the range of < 40 wt.%, especially from the range of < 30 wt.%. Further, in embodiments, the secondary second concentration 62,2 may be selected from the range of > 5 wt.%, such as from the range of > 10 wt.%, especially from the range of > 15 wt.%. Additionally or alternatively, the secondary second concentration 62,2 may be selected from the range of < 30 wt.%, such as from the range of < 25 wt.%, especially from the range of < 20 wt.%. Further, in embodiments, 62,1/62,2 < 10, such as 62,1/62,2 < 8, especially 62,1/62,2 < 6, like 62,1/62,2 < 4. Additionally or alternatively, in embodiments, 62,1/62,2 > 1, such as 62,1/62,2 > 1.5, especially 62,1/62,2 > 2, like 62,1/62,2 > 3.

In embodiments, the second luminescent converter may further comprise one or more additional second luminescent materials, such as selected from the luminescent materials provided above. Hence, in embodiments, a second luminescent material content of the second luminescent converter may consist for at most 99 wt.%, such as at most 98 wt.%, especially at most 95 wt.%, like at most 90 wt.%, of the primary second luminescent material and the secondary second luminescent material. Alternatively, the second luminescent material content of the second luminescent converter may consist for at least 90 wt.%, such as at least 95 wt.%, especially at least 98 wt.%, including (essentially) 100 wt.%, of the primary second luminescent material and the secondary second luminescent material.

In embodiments, the second light generating device (comprising the second light source and the second luminescent converter) may be configured to generate second device light. As indicated above, the second device light may comprise the primary second luminescent material light and the secondary second luminescent material light. Optionally, the second device light may further comprise part of the second light source light. For instance, in embodiments, the second device light may have a spectral power distribution, wherein at least 2%, such as at least 3.5%, especially at least 5%, like at least 7%, of the spectral power in the wavelength range of 380-780 nm may be provided by the second light source light. Alternatively, the second device light may be (essentially) free from second light source light. Especially, in embodiments, the second device light may have a spectral power distribution, wherein at most 5%, such as at most 2%, especially at most 1.5%, like at most 1%, including (essentially) 0%, of the spectral power in the wavelength range of 380- 780 nm may be provided by the second light source light. Hence, in specific embodiments, the second device light may have a spectral power distribution, wherein at most 2% of the spectral power in the wavelength range of 380-780 nm may be provided by the second light source light. Such second device light may provide the benefit that (essentially) all of the spectral power (in the wavelength range of 380-780 nm) may be provided by the primary second luminescent material light and the secondary second luminescent material light. Hence, such second device light may have a second device centroid wavelength (Zcd2) located on or in close proximity to the spectral locus (in the CIE 1931 color space).

Further, in embodiments, the second device light may have a spectral power distribution, wherein yi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary second luminescent material light. In embodiments, yi may be selected from the range of > 65, such as from the range of > 70, especially from the range of > 75, like from the range of > 80. Additionally or alternatively, yi may be selected from the range of < 98, such as from the range of < 95, especially from the range of < 93, like from the range of < 90. Further, in embodiments, the second device light may have a spectral power distribution, wherein y2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary second luminescent material light. In embodiments, yi may be selected from the range of > 4, such as from the range of > 6, especially from the range of > 8, like from the range of > 10. Additionally or alternatively, yi may be selected from the range of < 35, such as from the range of < 30, especially from the range of < 25, like from the range of < 20. Further, in embodiments, y ly may be selected from the range of > 1.5, such as from the range of > 2, especially from the range of > 3, like from the range of > 4. Additionally or alternatively, y ly may be selected from the range of < 20, such as from the range of < 15, especially from the range of < 12, like from the range of < 10. Further, in embodiments, 1.5 < y lyi < 20, such as 2 < y lyi < 15, especially 3 < y lyi < 12, like 4 < y ly < 10. Hence, in specific embodiments, the second device light may have a spectral power distribution, wherein yi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary second luminescent material light, wherein y2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary second luminescent material light, and wherein 3 < yi/y2 < 12. Such a ratio in spectral power may provide the benefit that the second device light may comprise a significantly larger contribution from the primary second luminescent material light than the secondary second luminescent material light. Hence, such second device light may have optical properties more closely resembling the (green) primary second luminescent material light, and thus differing from the optical properties of the first device light.

In embodiments, the second device light may have a second device centroid wavelength ( ca2). The second device centroid wavelength ( ca ) may especially be selected from the range of 480-600 nm, such as from the range of 490-590 nm, especially from the range of 510-590 nm. Further, the second device centroid wavelength (kca2) may be selected from the range of 530-600 nm, such as from the range of 550-590 nm, especially from the range of 560-590 nm, like from the range of 575-585 nm. Hence, in specific embodiments, the second device light may have a second device centroid wavelength ( ca ) selected from the range of 575-585 nm. Such a second device centroid wavelength ( ca ) may facilitate that the second device light may be visible light, such as especially yellow light. Such yellow light may be especially suitable for providing white light having a low correlated color temperature (CCT) (when combined with other light generating devices). In embodiments, the second device centroid wavelength ( ca ) may be smaller than the first device centroid wavelength ( cdi). Especially, in embodiments, ( cdi- kcd2) > 10 nm, such as ( cdi- kcd2) > 15 nm, especially ( cdi- kcd2) > 20 nm, like ( cdi- kcd2) > 30 nm. Additionally or alternatively, in embodiments, ( cdi- kcd2) < 70 nm, such as ( cdi- kcd2) < 60 nm, especially ( cdi- kcd2) < 50 nm, like ( cdi- kcd2) < 40 nm.

In embodiments, the second device light may further have a second color point in the CIE 1931 color space, wherein the second color point may be defined by second chromaticity coordinates [x2,y2]. In embodiments, [X2] may be selected from the range of 0.35-0.6, such as from the range of 0.38-0.55, especially from the range of 0.41-0.50. Additionally or alternatively, in embodiments, [y2] may be selected from the range of 0.40- 0.65, such as from the range of 0.43-0.6, especially from the range of 0.48-0.58.

The light generating system may further comprise the third light generating device, wherein the third light generating device may comprise a third solid state light source and a third luminescent converter. In embodiments, the third solid state light source may especially be a LED, though other options are also possible (see below). The third solid state light source may be configured to generate third light source light having a third peak wavelength (kps). In embodiments, the third peak wavelength (kps) may be selected from the range of 420-490 nm, such as from the range of 435-490 nm, especially from the range of 440-475 nm, like from the range of 400-470 nm. Hence, the third light source light may be violet light or blue light, such as especially blue light.

The third light generating device may further comprise a third luminescent converter. As indicated above, the third luminescent converter may be configured as a coating (covering the third solid state light source). Alternatively, the third luminescent converter may be configured as a (self-supporting) luminescent body (optionally configured at a non-zero third distance ds from the third light source). The third luminescent converter may comprise the primary third luminescent material. The primary third luminescent material may be configured to convert (at least) part of the third light source light received by the primary third luminescent material into primary third luminescent material light. Especially, in embodiments, the third light source light may have a spectral power distribution, wherein the primary third luminescent material may be configured to convert > 5%, such as > 7%, especially > 9%, like > 11%, of the spectral power of the third light source light (in the wavelength range of 380-780 nm) received by the primary third luminescent material into primary third luminescent material light. Additionally or alternatively, the third light source light may have a spectral power distribution, wherein the primary third luminescent material may be configured to convert < 50%, such as < 45%, especially < 40%, like < 35%, of the spectral power of the third light source light (in the wavelength range of 380-780 nm) received by the primary third luminescent material into primary third luminescent material light.

Further, in embodiments, the third luminescent converter may comprise a secondary third luminescent material. In embodiments, the secondary third luminescent material may comprise any of the luminescent materials indicated above. Yet, especially, the secondary third luminescent material may comprise a trivalent cerium-doped (garnet) luminescent material. In specific embodiments, the secondary third luminescent material may comprise a luminescent material of the type AsBsOn Ce³ ; wherein A may comprise at least one of Y, La, Gd, Tb and Lu; and wherein B may comprise at least one of Al, Ga, In and Sc (see also above). Such a secondary third luminescent material may be relatively (thermally) stable. Further, such a secondary third luminescent material may be relatively efficient.

The secondary third luminescent material may be configured to convert at least part of the third light source light received by the secondary third luminescent material into secondary third luminescent material light. Especially, in embodiments, the third light source light may have a spectral power distribution, wherein the secondary third luminescent material may be configured to convert > 30%, such as > 40%, especially > 50%, like > 55%, of the spectral power of the third light source light (in the wavelength range of 380-780 nm) received by the secondary third luminescent material into secondary third luminescent material light. Additionally or alternatively, the third light source light may have a spectral power distribution, wherein the secondary third luminescent material may be configured to convert < 95%, such as < 90%, especially < 85%, like < 80%, of the spectral power of the third light source light (in the wavelength range of 380-780 nm) received by the secondary third luminescent material into secondary third luminescent material light.

The secondary third luminescent material light may have a secondary third centroid wavelength ( c3,2). In embodiments, the secondary third centroid wavelength ( c3,2) may be selected from the range of 480-600 nm, such as from the range of 490-590 nm, especially from the range of 520-580 nm, like from the range of 540-570 nm. Hence, in embodiments, the secondary third luminescent material light may comprise, such as be, one or more of green light and yellow light, such as especially yellow light. In embodiments, the secondary third centroid wavelength ( c3,2) may be different from the primary third centroid wavelength ( c3,i), such as especially smaller than the primary third centroid wavelength ( c3,i). Especially, in embodiments, ( c3,i- c3,2) > 20 nm, such as ( c3,i- c3,2) > 30 nm, especially ( c3,i- c3,2) > 40 nm, like ( c3,i- c3,2) > 45 nm. Additionally or alternatively, in embodiments, ( c3,i- c3,2) < 100 nm, such as ( c3,i- c3,2) < 75 nm, especially ( c3,i- c3,2) < 60 nm, like ( c3,i- c3,2) < 50 nm.

Further, the secondary third luminescent material light may comprise at least one emission band having a secondary third full width at half maximum FWHM32 of > 40 nm, such as > 50 nm, especially > 60 nm, like > 75 nm. Additionally or alternatively, the secondary third luminescent material light may comprise the at least one emission band having a primary third full width at half maximum FWHM32 of < 200 nm, such as < 175 nm, especially < 150 nm, like < 100 nm. In embodiments, the secondary third luminescent material light may comprise a plurality of emission bands, wherein at least one band may have the secondary third full width at half maximum FWHM32. Alternatively, the secondary third luminescent material light may comprise a single emission band, wherein said emission band may have the secondary third full width at half maximum FWHM32. Hence, in specific embodiments, the third luminescent converter may comprise a secondary third luminescent material, wherein the secondary third luminescent material may be configured to convert at least part of the third light source light received by the secondary third luminescent material into secondary third luminescent material light; wherein the secondary third luminescent material light may have a secondary third centroid wavelength ( c3,2) selected from the range of 490-590 nm; wherein the secondary third luminescent material light may comprise at least one emission band having a secondary third full width at half maximum FWHM32 of > 50 nm. Such a secondary third luminescent material may provide the benefit that the third device light may comprise a green-yellow component. Hence, such a secondary third luminescent material may provide the benefit that the first device light and third device light may have different device centroid wavelengths and spectral power distributions.

In embodiments, the primary third luminescent material and secondary third luminescent material may be configured embedded in the third luminescent converter, such as especially in the matrix material (of the third luminescent converter). Especially, the third luminescent converter may comprise the primary third luminescent material in a primary third concentration Cs,i, and the secondary third luminescent material in a secondary third concentration 63,2. In embodiments, the primary third concentration Cs,i may be selected from the range of > 5 wt.%, such as from the range of > 8 wt.%, especially from the range of > 10 wt.%. Additionally or alternatively, the primary third concentration Cs,i may be selected from the range of < 40 wt.%, such as from the range of < 35 wt.%, especially from the range of < 30 wt.%. Further, in embodiments, the secondary third concentration 63,2 may be selected from the range of > 20 wt.%, such as from the range of > 25 wt.%, especially from the range of > 30 wt.%. Additionally or alternatively, the secondary third concentration C3.2 may be selected from the range of < 60 wt.%, such as from the range of < 50 wt.%, especially from the range of < 40 wt.%. Further, in embodiments, 63,2/63,1 < 8, such as 63,2/63,1 < 6, especially 63,2/03,1 < 5, like 63,2/03,1 < 4. Additionally or alternatively, in embodiments, 03,2/63,1 > 0.5, such as 03,2/63,1 > 0.7, especially 03,2/63,1 > 0.9, like 03,2/63,1 > 1.1.

In embodiments, the third luminescent converter may further comprise one or more additional third luminescent materials, such as selected from the luminescent materials provided above. Hence, in embodiments, a third luminescent material content of the third luminescent converter may consist for at most 99 wt.%, such as at most 98 wt.%, especially at most 95 wt.%, like at most 90 wt.%, of the primary third luminescent material and the secondary third luminescent material. Alternatively, the third luminescent material content of the third luminescent converter may consist for at least 90 wt.%, such as at least 95 wt.%, especially at least 98 wt.%, including (essentially) 100 wt.%, of the primary third luminescent material and the secondary third luminescent material.

In embodiments, the third light generating device may be configured to generate third device light. The third device light may especially comprise the primary third luminescent material light. Further, the third device light may comprise the primary third luminescent material light and the secondary third luminescent material light. In embodiments, the third device light may be (essentially) free from the third light source light. Especially, in embodiments, the third device light may have a spectral power distribution, wherein at most 5%, such as at most 2%, especially at most 1.5%, like at most 1%, including (essentially) 0%, of the spectral power in the wavelength range of 380-780 nm may be provided by the third light source light. Hence, in specific embodiments, the third device light may have a spectral power distribution, wherein at most 2% of the spectral power in the wavelength range of 380-780 nm may be provided by the third light source light. Alternatively, in embodiments, the third device light may comprise part of the third light source light. Especially, in embodiments, the third device light may have a spectral power distribution, wherein at least 2%, such as at least 3%, especially at least 5%, of the spectral power in the wavelength range of 380-780 nm may be provided by the third light source light. Additionally or alternatively, the third device light may have a spectral power distribution, wherein at most 15%, such as at most 10%, especially at most 8%, of the spectral power in the wavelength range of 380-780 nm may be provided by the third light source light. Further, in embodiments, the third device light may have a spectral power distribution, wherein (selected from the range of) 2-15%, such as 3-10%, especially 5-8%, of the spectral power in the wavelength range of 380-780 nm may be provided by the third light source light.

Further, in embodiments, the third device light may have a spectral power distribution, wherein zi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary third luminescent material light. In embodiments, zi may be selected from the range of > 5, such as from the range of > 7, especially from the range of > 9, like from the range of > 11. Additionally or alternatively, zi may be selected from the range of < 50, such as from the range of < 45, especially from the range of < 40, like from the range of < 35. Further, in embodiments, the third device light may have a spectral power distribution, wherein Z2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary third luminescent material light. In embodiments, Z2 may be selected from the range of > 50, such as from the range of > 55, especially from the range of > 60, like from the range of > 65. Additionally or alternatively, Z2 may be selected from the range of < 98, such as from the range of < 95, especially from the range of < 90, like from the range of < 85. Further, in embodiments, Z1/Z2 may be selected from the range of > 0.05, such as from the range of > 0.07, especially from the range of > 0.1, like from the range of > 0.12. Additionally or alternatively, Z1/Z2 may be selected from the range of < 0.9, such as from the range of < 0.8, especially from the range of < 0.7, like from the range of < 0.6. Further, in embodiments, 0.05 < Z1/Z2 < 0.9, such as 0.07 < Z1/Z2 < 0.8, especially 0.1 < Z1/Z2 < 0.7, like 0.12 < Z1/Z2 < 0.6. Hence, in specific embodiments, the third device light may have a spectral power distribution, wherein zi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary third luminescent material light, wherein Z2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary third luminescent material light, and wherein 0.1 < Z1/Z2 < 0.7. Such a ratio in spectral power may provide the benefit that the third device light may comprise a larger contribution from the secondary third luminescent material light than the primary third luminescent material light. Hence, such third device light may especially provide significant intensity in the yellow wavelength range.

As indicated above, the third device light may comprise at least part of the third light source light. Hence, the third device light may comprise a blue component (from the third light source light), a red component (from the primary third luminescent material light), and a yellow component (from the secondary third luminescent material light). In embodiments, the third device light may thus be white light. The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially between 2700 and 20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700-6500 K. In embodiments, the correlated color temperature (CCT) is especially within about 20 SDCM (standard deviation of color matching) from the BBL (black body locus), such as within 15 SDCM from the BBL, especially within 10 SDCM from the BBL, like within 5 SDCM from the BBL. In embodiments, the (white) third device light may have a CCT selected from the range of > 1500 K, such as from the range of > 1700 K, especially from the range of > 2000 K, like from the range of > 2200 K. Additionally or alternatively, in embodiments, the third device light may have a CCT selected from the range of < 4000 K, such as from the range of < 3500 K, especially from the range of < 3000 K, like from the range of < 2700 K.

In embodiments, the third device light may be white light (or colored light, see also below). Especially, the third device light may have a third color point below a line located 10 SDCM above the BBL in the CIE 1931 color space, such as below a line located 5 SDCM above the BBL, especially below a line located 2 SDCM above the BBL. Hence, in specific embodiments, the third device light may have a third color point below a line located 10 SDCM above the BBL in the CIE 1931 color space. Such a third color point may provide the benefit that, upon admixing the third device light with the second device light and/or the first device light, system light having a color point on (or within 5 SDCM of) the BBL may be provided. Further, the third device light may have a third color point on or below the BBL. In such embodiments, the third color point may especially have a distance to the BBL of at most 25 SDCM, such as at most 20 SDCM, especially at most 15 SDCM, like at most 12 SDCM. Hence, in specific embodiments, the third device light may have a third color point on or below the BBL with a distance to the BBL of at most 20 SDCM. Such a third color point may have a small enough distance to the BBL that the third device light may facilitate providing system light with a color point on the BBL (upon mixing with e.g. the second device light). In (other) embodiments, the third device light may have a third color point located below the BBL, such as with a distance to the BBL of at least 5 SDCM, such as at least 10 SDCM, especially at least 12 SDCM, like at least 15 SDCM.

Further, in embodiments, the (white) third device light may have a third color point in the CIE 1931 color space, wherein the third color point may be defined by third chromaticity coordinates [x3,ys]. In embodiments, [xs] may be selected from the range of 0.3- 0.55, such as from the range of 0.32-0.5, especially from the range of 0.35-0.45, like from the range of 0.37-0.42. Further, in embodiments, [ys] may be selected from the range of 0.25- 0.45, such as from the range of 0.28-0.4, especially from the range of 0.3-0.38. Hence, in specific embodiments, the third device light may have a third color point in the CIE 1931 color space defined by third chromaticity coordinates [x3,ys], wherein [X3] may be selected from the range of 0.35-0.45. Such a third color point may especially facilitate providing warm (white) third device light, such as especially third device light suitable for general lighting. Further, as indicated above, in embodiments the third device light may have a CCT of at least 2000 K.

In embodiments, as indicated above, the third device light may be (essentially) free from third light source light. In such embodiments, the third device light may especially be colored light. Further, in such embodiments, the third device light may have a third device centroid wavelength (Zeas). The third device centroid wavelength (Zeas) may especially be selected from the range of 530-620 nm, such as from the range of 540-610 nm, especially from the range of 550-590 nm. Hence, in embodiments, the third device light may be selected from the group of green light, yellow light, and orange light, such as especially from the group of green light and yellow light. In embodiments, the light generating system may further comprise a fourth light generating device. The fourth light generating device may comprise a fourth solid state light source. The fourth solid state light source may be configured to generate fourth light source light. In embodiments, the fourth light source light may have a fourth peak wavelength (Ap ) selected from the range of 420-490 nm, such as from the range of 435-490 nm, especially from the range of 435-470 nm, like from the range of 440-460 nm. Further, in embodiments, the fourth light generating device may be configured to generate fourth device light having a fourth device centroid wavelength ( cd4). The fourth device centroid wavelength (kcd4) may in embodiments be selected from the blue wavelength range (440-490 nm), i.e., the fourth device light may be blue light. Additionally or alternatively, the fourth device light may comprise or be violet light, i.e., the fourth device centroid wavelength ( caf) may be selected from the violet wavelength range (380-440 nm). Especially, the fourth device centroid wavelength ( caf) may be selected from the range of 420-490 nm, such as from the range of 435-490 nm, especially from the range of 435-470 nm, like from the range of 440-460 nm. In embodiments, the fourth device light may comprise the fourth light source light. Optionally, the fourth device light may further comprise luminescent material light. In such embodiments, the fourth light generating device may comprise a fourth luminescent converter comprising one or more fourth luminescent materials (e.g. selected from the luminescent materials provided above). Further, in such embodiments, the fourth device light may have a spectral power distribution, wherein at most 98%, such as at most 95%, especially at most 90%, like at most 85%, of the spectral power in the wavelength range of 380-780 nm may be provided by the fourth light source light. Yet, in specific embodiments, the fourth device light may (essentially) consist of the fourth light source light. Especially, the fourth device light may have a spectral power distribution, wherein at least 85%, such as at least 90%, especially at least 95%, like at least 98%, including (essentially) 100%, of the spectral power in the wavelength range of 380-780 nm may be provided by the fourth light source light. Hence, in specific embodiments, the light generating system may further comprise a fourth light generating device; wherein the fourth light generating device may comprise a fourth solid state light source, wherein the fourth solid state light source may be configured to generate fourth light source light; wherein the fourth light generating device may be configured to generate fourth device light having a fourth device centroid wavelength (Xcd4) selected from the range of 435-490 nm; wherein the fourth device light may have a spectral power distribution, wherein at least 90% of the spectral power in the wavelength range of 380-780 nm may be provided by the fourth light source light. Such a fourth light generating device may facilitate admixing blue light into the system light. Hence, such a fourth light generating device may provide the benefit that the CCT and/or CRI of the system light may be tuned. Further, such a fourth light generating device, wherein at least 90% of the spectral power (in the visible range) may be provided by the (blue) fourth light source light, may be more efficient than a light generating device wherein the blue light is provided by a luminescent material.

In embodiments, the fourth device light may have a fourth color point in the CIE 1931 color space defined by fourth chromaticity coordinates [x4,y4]. The fourth chromaticity coordinates [x4,y4] may especially denote a (fourth) color point on the spectral locus. Additionally or alternatively, in embodiments, [X4] may be selected from the range of 0.04-0.2, such as from the range of 0.07-0.18, especially from the range of 0.10-0.17. Further, in embodiments, [y4] may be selected from the range of 0.00-0.3, such as from the range of 0.00-0.2, especially from the range of 0.00-0.05.

In embodiments, the fourth light generating device may optionally comprise an optical coating. The optical coating may be configured covering the fourth solid state light source. Alternatively, the optical coating may be a self-supporting body (optionally configured physically separated from the fourth solid state light source). The optical coating may be configured to protect the fourth solid state light source against ingress and/or damage. Further, in embodiments, the optical coating may comprise a light scattering material, wherein the light scattering material may be configured to scatter (or “diffuse”) the fourth light source light received by the light scattering material. Hence, in embodiments, the fourth device light may comprise diffused fourth light source light. In embodiments, the light scattering material may comprise light scattering particles, such as e.g. at least one of BaSCU, A12O3 and TiCh particles.

In embodiment, the light generating system may be configured to generate system light. The system light may comprise one or more of the first device light, the second device light, the third device light, and (optionally) the fourth device light. Especially, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein > 25%, such as > 30%, especially > 35%, like > 40%, of the spectral power in the wavelength range of 380-780 nm may be provided by the first device light. Additionally or alternatively, in embodiments, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein < 65%, such as < 60%, especially < 55%, like < 50%, of the spectral power in the wavelength range of 380-780 nm may be provided by the first device light. Further, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein > 15%, such as > 20%, especially > 25%, like > 30%, of the spectral power in the wavelength range of 380-780 nm may be provided by the second device light. Additionally or alternatively, in embodiments, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein < 55%, such as < 50%, especially < 45%, like < 40%, of the spectral power in the wavelength range of 380-780 nm may be provided by the second device light. Further, in embodiments, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein > 5%, such as > 8%, especially > 12%, like > 15%, of the spectral power in the wavelength range of 380-780 nm may be provided by the third device light. Additionally or alternatively, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein < 35%, such as < 30%, especially < 25%, like < 20%, of the spectral power in the wavelength range of 380-780 nm may be provided by the third device light. Optionally, the system light may (further) comprise the fourth device light. Especially, (in an operational mode of the light generating system,) the system light may have a spectral power distribution, wherein > 0.5%, such as > 1%, especially > 2%, like > 3%, of the spectral power in the wavelength range of 380-780 nm may be provided by the fourth device light. Additionally or alternatively, in embodiments, (in the first operational mode of the light generating system,) the system light may have a spectral power distribution, wherein < 15%, such as < 10%, especially < 5%, like < 4%, of the spectral power in the wavelength range of 380-780 nm may be provided by the fourth device light.

In embodiments, the system light may be white light or colored light. Especially, in a first operational mode of the light generating system, the system light may be white light. Further, in the first operational mode of the light generating system, the system light may have a CCT selected from the range of > 1200 K, such as from the range of > 1500 K, especially from the range of > 1700 K, like from the range of > 2000 K. Additionally or alternatively, in the first operational mode of the light generating system, the system light may have a CCT selected from the range of < 8000 K, such as from the range of < 7000 K, especially from the range of < 6500 K, like from the range of < 6000 K. Hence, in the first operational mode of the light generating system, the system light may have a CCT selected from the range of 1200-8000 K, such as from the range of 1500-7000 K, especially from the range of 1700-6500 K, like from the range of 2000-6000 K. Further, in embodiments, in the first operational mode of the light generating system, the system light may have a CRI of at least 70, such as at least 80, especially at least 85, like at least 90. Additionally or alternatively, in the first operational mode of the light generating system, the system light may have a CRI R9 score of > 45, such as > 55, especially > 65, like > 70. Further, in the first operational mode of the light generating system, the system light may have a CRI R9 score of > 75, such as > 80, especially > 85.

In embodiments, the system light may have at least some intensity in the wavelength range of 380-490 nm (i.e., in the violet and/or blue wavelength range). Especially, in the first operational mode of the light generating system, the system light may have a spectral power distribution, wherein at least 1%, such as at least 2%, especially at least 5%, like at least 7%, of the spectral power may be in the wavelength range of 380-490 nm. Additionally or alternatively, in the first operational mode of the light generating system, the system light may have a spectral power distribution, wherein at most 20%, such as at most 15%, especially at most 12%, like at most 10%, of the spectral power may be in the wavelength range of 380-490 nm. In embodiments, the spectral power of the system light in the wavelength range of 380-490 nm may be provided by one or more of the first device light, second device light, third device light, and fourth device light. Especially, the spectral power of the system light in the wavelength range of 380-490 nm may be provided by one or more of the first light source light, second light source light, third light source light, and fourth light source light. In embodiments, at most 95%, such as at most 90%, especially at most 85%, like at most 80%, of the spectral power (of the system light) in the wavelength range of 380-490 nm may be provided by one or more of the third device light (especially the third light source light) and the fourth device light (especially the fourth light source light). Additionally or alternatively, in embodiments, the spectral power of the system light in the wavelength range of 380-490 nm may be (essentially) fully provided by one or more of the third device light (especially the third light source light) and the fourth device light (especially the fourth light source light). Further, in embodiments, at least 75%, such as at least 80%, especially at least 90%, like at least 95%, including (essentially) 100%, of the spectral power (of the system light) in the wavelength range of 380-490 nm may be provided by one or more of the third device light (especially the third light source light) and the fourth device light (especially the fourth light source light). Hence, in specific embodiments, in the first operational mode of the light generating system, the system light may have a spectral power distribution, wherein at least 2% of the spectral power may be in the wavelength range of 380-490 nm; wherein at least 80% of the spectral power in the wavelength range of 380- 490 nm may be provided by one or more of the third device light and the fourth device light. Such a light generating system may facilitate that the first device and second device light may be (essentially) free from violet and/or blue light, providing the benefit that the light generating system (providing system light consisting of the first and/or second device light) may be applied in e.g. photography dark rooms, where violet and/or blue light is undesired.

The light generating system may be configured to generate system light (in the first operational mode), with a luminous efficacy of > 250 lumens per watt (Im/W), such as > 275 Im/W, especially > 300 Im/W, like > 325 Im/W. Additionally or alternatively, in embodiments, the light generating system may be configured to generate system light (in the first operational mode), with a luminous efficacy of < 450 Im/W, such as < 400 Im/W, especially < 350 Im/W. Herein, the term “luminous efficacy” refers to the luminous flux generated by the light generating system per watt of (electrical) power provided to the light generating system. Further, in embodiments, (in the first operational mode) the light generating system may be configured to generate system light with an optical luminous efficacy of > 200 lumens per optical watt (lm/W_opt), such as > 225 lm/W_opt, especially > 240 lm/W_opt, like > 260 lm/W_opt. Additionally or alternatively, in embodiments, the light generating system may be configured to generate system light (in the first operational mode), with an optical luminous efficacy of < 350 lm/W_opt, such as < 325 lm/W_opt, especially < 300 lm/W_opt. Herein, the term “optical luminous efficacy” refers to the luminous flux generated by the light generating system per watt of (first, second, third, and optionally fourth) light source light emitted by the (first, second, third, and optionally fourth) solid state light sources.

In embodiments, the system light may (also) be colored light. For instance, the system light may comprise one or more of the first device light and second device light, wherein the system light may have a centroid wavelength selected from the range of <Cd2- cdi. Further, for instance, the third device light may be (essentially) free from third light source light, and the system light may comprise one or more of the first device light, second device light, and third device light. In embodiments, as indicated above, the first device light may be (orange or) red light, the second device light may be green or yellow light, the third device light may be (green) or yellow light, and the fourth device light may be blue light. Hence, in embodiments, the system light may have a color point selected from the (RGB) color gamut defined by the chromaticity coordinates [xi,yi], [x2,y?], [x3,ys], and [x4,y4].

In embodiments, the light generating system may comprise a control system. The control system may especially be configured to individually control the first light generating device, the second light generating device, the third light generating device, and (optionally) the fourth light generating device. Especially, the control system may be configured to control the intensity of the first, second, third, and (optionally) fourth device light. In embodiments, the control system may thus be configured to control the composition and intensity of the system light (by controlling the light generating devices). Especially, the control system may be configured to control one or more of the CCT, CRI, color point, and intensity of the system light. In embodiments, the control system may be configured to control a correlated color temperature (CCT) of the system light over a range of > 500 K, such as over a range of > 800 K, especially over a range of > 1000 K, like over a range of > 1500 K. Additionally or alternatively, the control system may be configured to control a CCT of the system light over a range of < 3500 K, such as over a range of < 3000 K, especially over a range of < 2500 K, like over a range of < 2000 K. Herein, the phrase “control a CCT over a range of > 1000 K”, and similar phrases, indicate that a difference between a highest (possible) CCT and a lowest (possible) CCT of the system light may be larger than 1000 K, wherein the control system may be configured to set the CCT of the system light to any value between the highest CCT and lowest CCT. Hence, in specific embodiments, the light generating system may comprise a control system, wherein the control system may be configured to individually control the first light generating device, the second light generating device, the third light generating device, and optionally the fourth light generating device; wherein the control system may be configured to control a correlated color temperature of the system light over a range of > 1000 K. Such a light generating system may provide the benefit that a user may (continuously) adjust the optical properties (especially the CCT) of the system light based on preference and/or lighting requirements. Hence, such a light generating system may be more versatile and customizable.

The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior on the element, such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc.. Beyond that, the term “controlling” and similar terms may additionally include monitoring. The controlling of the element can be done with a control system. The control system and the element may at least temporarily, or permanently, functionally be coupled. In embodiments, the control system and element may not be physically coupled. Control can be done via wired and/or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

The system, or apparatus, or device may execute an action in a “mode” or “operational mode”. The term “operational mode” may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and/or after executing the mode one or more other modes may be executed. However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term “timer” may refer to a clock and/or a predetermined time scheme. The operational mode may in embodiments also refer to a system, or apparatus, or device, that can only operate in a single operational mode (i.e. “on”, without further tunability).

As indicated above, some general embodiments relating to the first, second, third, and fourth solid state light sources will be provided next. The term “light source” may in principle relate to any light source known in the art. In a specific embodiment, the light source may comprise a solid state light source (such as a LED or laser diode (or “diode laser”)). The term “light source” may also relate to a plurality of (essentially identical (or different)) light sources, such as 2-2000 (solid state) (LED) light sources. The phrases “different light sources” or “a plurality of different light sources”, and similar phrases, may in embodiments refer to a plurality of solid-state light sources selected from at least two different bins. Likewise, the phrases “identical light sources” or “a plurality of same light sources”, and similar phrases, may in embodiments refer to a plurality of solid-state light sources selected from the same bin. Hence, the term LED may also refer to a plurality of LEDs. Further, the term “light source” may in embodiments also refer to a so-called chip-on- board (COB) light source. The term “COB” especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of light emitting semiconductor light sources may be configured on the same substrate. In embodiments, a COB is a multi LED chip configured together as a single lighting module. The term “light source” may also refer to a chip scale package (CSP) and/or a chip scale packaged (CSP) LED. A CSP may comprise a single solid state die (such as a LED) with provided thereon a luminescent material comprising layer. The term “light source” may also refer to a midpower package. A midpower package may comprise one or more solid state die(s). The die(s) may be covered by a luminescent material comprising layer. The die dimensions may be equal to or smaller than 2 mm, such as in the range of e.g. 0.2-2 mm. Herein, the term “light source” may also especially refer to a small solid state light source, such as having a mini size or micro size. For instance, the light sources may comprise one or more of mini LEDs and micro LEDs, such as especially micro LEDs or “microLEDs” or “pLEDs”. Herein, the term mini size or mini LED especially refers to solid state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm - 1 mm. Herein, the term p size or micro LED especially refers to solid state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm and smaller.

The light source may have a light escape surface. For LEDs it may for instance be the LED die, or when a resin is applied to the LED die, the outer surface of the resin. The term escape surface especially relates to that part of the light source, where the light actually leaves or escapes from the light source. The light source is configured to provide a beam of light. This beam of light (thus) escapes from the light exit surface of the light source.

The term “light source” may refer to a semiconductor light-emitting device, such as a light emitting diode (LEDs), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc... The term “light source” may also refer to an organic light-emitting diode (OLED), such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). In an embodiment, the light source comprises a LED. The terms “light source” or “solid state light source” may also refer to a superluminescent diode (SLED). Especially, the term “solid state light source”, or “solid state material light source”, and similar terms, may refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, a superluminescent diode, or a multi -junction diode.

In embodiments, the light source may comprise one or more micro-optical elements (array of micro lenses) downstream of a single solid-state light source, or downstream of a plurality of solid-state light sources (i.e. e.g. shared by multiple LEDs). In embodiments, the light source may comprise a LED with on-chip optics. In embodiments, the light source comprises pixelated single LEDs (with or without optics) (offering in embodiments on-chip beam steering).

In embodiments, the light source may be configured to provide primary radiation, which is used as such, such as e.g. a blue light source, like a blue LED. Such LEDs, which may not comprise a luminescent material (“phosphor”) may be indicated as direct color LEDs. In other embodiments, however, the light source may be configured to provide primary radiation and part of the primary radiation is converted into secondary radiation. Secondary radiation may be based on conversion by a luminescent material. The secondary radiation may therefore also be indicated as luminescent material radiation. The luminescent material may in embodiments be comprised by the light source, such as an LED with a luminescent material layer or dome comprising luminescent material. Such LEDs may be indicated as phosphor converted LEDs or PC LEDs (phosphor converted LEDs). In other embodiments, the luminescent material may be configured at some distance (“remote”) from the light source, such as an LED with a luminescent material layer not in physical contact with a die of the LED. The term “light source” may (thus) refer to a light generating element as such, like e.g. a solid state light source, or e.g. to a package of the light generating element, such as a solid state light source, and one or more of a luminescent material comprising element and (other) optics, like a lens, a collimator. In embodiments, the term “light source” may thus also refer to a combination of a light source, like an LED, and an optical filter, which may change the spectral power distribution of the light generated by the light source. Especially, the term “light generating device” may be used to address a light source and further (optical components), like an optical filter and/or a beam shaping element, etc. Further, the term “light source” may (thus) in embodiments also refer to a light source that is (also) based on conversion of light, such as a light source in combination with a luminescent converter material. A light converter element (“converter element” or “converter”) may comprise a luminescent material comprising element. For instance, a solid state light source as such, like a blue LED, is a light source. A combination of a solid state light source (as light generating element) and a light converter element, such as a blue LED and a light converter element, optically coupled to the solid state light source, may also be a light source (but may also be indicated as light generating device).

In specific embodiments, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED or multi -junction (light emitting) diode. The light source may especially be configured to generate light source light having an optical axis (O), (a beam shape,) and a spectral power distribution. The light source light may in embodiments comprise one or more bands, having band widths as known for lasers

The term “laser light source” especially refers to a laser. Such laser may especially be configured to generate laser light source light having one or more wavelengths in the UV, visible, or infrared, especially having a wavelength selected from the spectral wavelength range of 200-2000 nm, such as from the spectral wavelength range of 300-1500 nm. The term “laser” especially refers to a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Especially, in embodiments the term “laser” may refer to a solid-state laser. In specific embodiments, the terms “laser” or “laser light source”, or similar terms, may refer to a laser diode (or diode laser). Hence, in embodiments the light source comprises a laser light source. In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of a semiconductor laser diodes, such as GaN, InGaN, AlGalnP, AlGaAs, InGaAsP, lead salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc. The term “solid state material laser”, and similar terms, may thus refer to a solid state laser like based on a crystalline or glass body dopes with ions, like transition metal ions and/or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser, etc.

In embodiments, the term “laser light source” may also refer to a plurality of (different or identical) laser light sources. In specific embodiments, the term “laser light source” may refer to a plurality N of (identical) laser light sources. In embodiments, N>2, such as N>5, especially N>8. In this way, a higher brightness (of the laser light) may be obtained. In embodiments, laser light sources may be arranged in a laser bank. The laser bank may in embodiments comprise heat sinking and/or optics (e.g. a lens to collimate the laser light). Hence, in embodiments lasers in a laser bank (or “laser array bank”) may share the same optics.

The laser light source is configured to generate laser light source light (or “laser light”). The light source light may essentially consist of the laser light source light. The light source light may also comprise laser light source light of two or more (different or identical) laser light sources. For instance, the laser light source light of two or more (different or identical) laser light sources may be coupled into a light guide, to provide a single beam of light comprising the laser light source light of the two or more (different or identical) laser light sources. In specific embodiments, the light source light is thus especially collimated (laser) light source light. The laser light source light may in embodiments comprise one or more bands, having band widths as known for lasers. In specific embodiments, the band(s) may be relatively sharp line(s), such as having full width half maximum (FWHM) in the range of <20 nm at RT, such as <10 nm. Hence, the light source light has a spectral power distribution (intensity on an energy scale as function of the wavelength) which may comprise one or more (narrow) bands. The beams (of light source light) may be focused or collimated beams of (laser) light source light. The term “focused” may especially refer to converging to a small spot. This small spot may be at the discrete converter region, or (slightly) upstream thereof or (slightly) downstream thereof. The terms “upstream” and “downstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here especially the solid state light source), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”. Focusing (of the laser light source light) may be executed with one or more optics, such as especially two (focusing) lenses. Collimation may be executed with one or more (other) optics, like collimation elements, such as lenses and/or parabolic mirrors. In embodiments, the beam of (laser) light source light may be relatively highly collimated, such as in embodiments <2° (FWHM), more especially <1° (FWHM), most especially <0.5° (FWHM).

In embodiments, the light generating system may comprise a LED package. The LED package may comprise the first light generating device, the second light generating device, the third light generating device, and optionally the fourth light generating device. Further, in embodiments, the LED package may comprise a housing, configured to house the first, second, third, and optionally fourth light generating device. Especially, the solid state light sources of the first, second, third, and optionally fourth light generating devices may be configured mounted on base of the housing (or “housing base”). The housing base may further comprise one or more electrically conductive tracks, configured to (separately) provide (electrical) power to each of the first, second, third, and optionally fourth light generating device, especially (separately) to each of the first, second, third, and optionally fourth solid state light source. In embodiments, the housing may further comprise one or more housing walls, wherein the one or more housing walls may be configured to divide the housing into four housing sections, and wherein each of the housing sections may comprise one of the first, second, third, and optionally fourth light generating device. Hence, in embodiments, the (first, second, third, and optionally fourth) solid state light sources may be mounted on housing base sections comprised by separate housing sections, wherein the corresponding (first, second, and third) luminescent converter may be configured covering the solid state light source and enclosed on at least four sides by the housing walls. In embodiments, the fourth solid state light source may be configured covered by the optical coating, optionally comprising the light scattering material. Optionally, the LED package may further comprise a transparent protective coating configured covering the first, second, and third luminescent converter (and optionally the optical coating), wherein the transparent protective coating may be configured to protect the first, second, third, and optionally fourth light generating device against e.g. moisture or ingress. Hence, in specific embodiments, the light generating system may comprise a LED package, wherein the LED package may comprise the first light generating device, the second light generating device, the third light generating device, and optionally the fourth light generating device. Such a LED package may facilitate providing the first, second, third, and optionally fourth light generating devices in a relatively compact form. Further, such a LED package may provide the benefit that a relatively narrow beam of system light may be provided without the need for optics.

Additionally or alternatively, the light generating system may comprise one or more LED filaments. The one or more LED filaments may especially comprise the first light generating device, the second light generating device, and the third light generating device. Optionally, the one or more LED filament may further comprise the fourth light generating device. Hence, in specific embodiments, the light generating system may comprise one or more LED filaments, wherein the one or more LED filaments may comprise the first light generating device, the second light generating device, the third light generating device, and optionally the fourth light generating device. A light generating system comprising one or more LED filaments may be used to provide a light generating system mimicking a conventional incandescent light bulb. Below, some general embodiments relating to a LED filament are provided.

LED filaments as such are known, and are e.g. described in US 8,400,051 B2, W02020016058, WO2019197394, etc., which are herein incorporated by reference. In general, a LED filament may in embodiments comprise (i) a plurality of LEDs, arranged on (at least a first major surface of) an elongated carrier, and (ii) an elongated encapsulant covering the plurality of LEDs and at least part of the elongated carrier. The LED filament may in embodiments be defined by a filament length LF, a filament width WF, and a filament thickness TF. Further, the LED filament may have relatively high aspect ratios (LF/WF or LF/TF), such as 10*WF < LF < 900*WF, and 10*TF < LF < 900*TF. In some embodiments, the LED filament may be straight. In other embodiments, the LED filament may be curved. For instance, the filament may have a (2D or 3D) spiraling shape, (like) a helical shape.

Further, as indicated, the LED filament may comprise an elongated carrier, solid state light sources, and an encapsulant. Especially, the elongated carrier may support the solid state light sources. The elongated carrier may e.g. comprise glass, quartz, metal, or sapphire. In other embodiments, the elongated carrier may e.g. comprise a polymeric material or (flexible) metal, e.g., a film or foil. The elongated carrier may be rigid (self-supporting), but may (in polymeric embodiments) also be flexible. In embodiments, the elongated carrier may be light transmissive, translucent, or transparent for light, especially visible light. Alternatively, in embodiments, the carrier may be light reflective, especially reflective for one or more of the light source light and the device light, such as reflective for at least the light source light and the device light. In specific embodiments, the carrier may be diffuse reflective.

In embodiments, the (elongated) carrier may comprise a first major surface at a first side of the carrier and a second major surface at a second side of the carrier, opposite to the first side. In embodiments, the solid state light sources may be arranged on at least one of these surfaces. Hence, in embodiments, at least part of, such as all of, the solid state light sources may be mounted onto the first major surface. Additionally or alternatively, at least part of the solid state light sources may be mounted onto the second major surface. Hence, in embodiments, the solid state light sources may be arranged, mounted and/or mechanically coupled on/to the carrier, wherein the carrier may especially be configured to mechanically and/or electrically support the LEDs.

In embodiments, the solid state light sources may comprise LEDs. Alternatively or additionally, in embodiments, the solid state light sources may comprise diode lasers. Further, the LED filament may comprise one or more of LEDs, laser diodes, superluminescent diodes, and multi -junction diodes. Especially, the LED filament comprises a plurality of LEDs. The (plurality of) solid state light sources may be arranged in an array (on the elongated carrier). The number of solid state light sources in the array may be at least 4, such as at least 8, even more especially at least 12, and may e.g. be up to 100, or yet even larger. Especially, in embodiments the number of solid state light sources in the array may be selected from the range of 10-2000, such as from the range of 10-1500, especially from the range of 10-1000. In embodiments, the solid state light sources may be configured in a ID (linear) array. Further, in embodiments, the solid state light sources may be configured in two ID arrays, one on the first major surface of the elongated carrier and one on the second major surface. A 2D array of solid state light sources of n*m LEDs may also be possible. In embodiments, n may be selected from the range of 1-4, such as 1-3, like 1-2, such as in embodiments 1 or in embodiments 2, and m may be selected from the range of larger than n, such as especially selected from the range of at least 4 (when n<4), like at least 6, such as at least 8. Hence, a 2D array of solid state light sources may especially have a (much) smaller number of rows (n) than the number of solid state light sources in those respective rows (m), such as n/m <0.2, like n/m <0.1, especially n/m <0.05.

In embodiments, the LED filament may comprise an encapsulant. The encapsulant may especially (at least partly) cover the plurality of solid state light sources. Further, the encapsulant may (at least partly) cover at least part of the elongated carrier, such as at least (part of) one of the first major and second major surface. In general, the encapsulant may be in contact with the elongated carrier and may cover all of the solid state light sources. The encapsulant may be a continuous coating along the filament length LF, at one or both of the first major and the second major surface. Further, the encapsulant may at least partly cover the solid state light sources, such as in embodiments at least 50% of the total number of solid state light sources in the array, such as at least 75%, especially at least 95%, up to 100%.

In embodiments, the encapsulant may comprise the luminescent converter. Alternatively, the luminescent converter may be the encapsulant, i.e., the luminescent converter may be configured as an encapsulant. Additionally or alternatively, the encapsulant may comprise a light scattering material, configured embedded in an encapsulant material, e.g. a (flexible) polymer material (such as a silicone). In embodiments, the light scattering material may be configured to scatter (or “diffuse”) the light source light and/or luminescent material light, especially in a direction transverse to a normal of the (first and/or second) major surface. In specific embodiments, the light scattering material may comprise light scattering particles, such as e.g. at least one of BaSCU, A12O3 and TiCE particles.

In embodiments, the LED filament may comprise multiple subfilaments. A LED filament comprising multiple subfilaments may in embodiments comprise one or more rows of solid state light sources configured mounted on the same elongated carrier, wherein each row and/or each section of a row (i.e., each subfilament) may be individually controllable and may be configured coated by a different encapsulant. In embodiments, at least one LED filament of the light generating system may comprise a plurality of subfilaments. Further, as indicated above, the luminescent converter may be configured as the encapsulant. Alternatively, the luminescent converter may be configured on top of the solid state light sources (e.g. as a coating), and the encapsulant may be configured covering the solid state light sources and the luminescent converter. In embodiments, a first subfilament (of the at least LED filament of the light generating system) may comprise the first light generating device. Especially, the first subfilament may comprise a plurality of the first solid state light source arranged on an elongated carrier. Further, the first subfilament may comprise a first elongated encapsulant covering the plurality of first solid state light sources(, the first luminescent converter,) and at least part of the elongated carrier, wherein the first elongated encapsulant may comprise (or cover) the first luminescent converter. The first subfilament may especially be configured to generate first device light. Further, a second subfilament (of the at least LED filament) may comprise the second light generating device. The second subfilament may comprise a plurality of the second solid state light source arranged on the (same) elongated carrier. Additionally, the second subfilament may comprise a second elongated encapsulant covering the plurality of second solid state light sources(, the second luminescent converter,) and at least part of the elongated carrier, wherein the second elongated encapsulant may optionally comprise (or cover) the second luminescent converter. The second subfilament may especially be configured to generate second device light. Similarly, a third subfilament (of the at least LED filament) may comprise the third light generating device. Especially, the third subfilament may comprise a plurality of the third solid state light source arranged on the (same) elongated carrier. Further, the third subfilament may comprise a third elongated encapsulant covering the plurality of third solid state light sources(, the third luminescent converter,) and at least part of the elongated carrier, wherein the third elongated encapsulant may optionally comprise (or cover) the third luminescent converter. The third subfilament may especially be configured to generate third device light. In embodiments, the plurality of subfilaments may optionally comprises a fourth subfilament. The fourth subfilament may comprise the fourth light generating device. Especially, the fourth subfilament may comprise a plurality of the fourth solid state light source arranged on the (same) elongated carrier. Further, the fourth subfilament may comprise a fourth elongated encapsulant covering the plurality of fourth solid state light sources and at least part of the elongated carrier. In embodiments, the fourth encapsulant may comprise the optical coating. Especially, in embodiments, the fourth encapsulant may be light transparent (and (essentially) free from light scattering materials). The fourth subfilament may especially be configured to generate fourth device light. In embodiments, the encapsulants, such as especially the fourth encapsulant, may have a curved (especially (semicircular) shape in a cross-section perpendicular to the filament length LF. The curved (shape of the) encapsulant may provide the benefit that the encapsulant may demonstrate (convex) lens-like behavior, thereby providing a more even light distribution of the device light. In embodiments, the at least one LED filament may comprise a main encapsulant, configured covering the first encapsulant, second encapsulant, third encapsulant, and optional fourth encapsulant, wherein the main encapsulant may especially be light transmissive for the first, second, third, and (optionally) fourth device light.

Hence, in specific embodiments, at least one LED filament may comprise a plurality of subfilaments, wherein: (A) a first subfilament may comprise the first light generating device, wherein the first subfilament may comprise (i) a plurality of the first solid state light source arranged on an elongated carrier, and (ii) a first elongated encapsulant covering the plurality of first solid state light sources and at least part of the elongated carrier, wherein the first elongated encapsulant may comprise the first luminescent converter; (B) a second subfilament may comprise the second light generating device, wherein the second subfilament may comprise (i) a plurality of the second solid state light source arranged on the elongated carrier, and (ii) a second elongated encapsulant covering the plurality of second solid state light sources and at least part of the elongated carrier, wherein the second elongated encapsulant may comprise the second luminescent converter; (C) a third subfilament may comprise the third light generating device, wherein the third subfilament may comprise (i) a plurality of the third solid state light source arranged on the elongated carrier, and (ii) a third elongated encapsulant covering the plurality of third solid state light sources and at least part of the elongated carrier, wherein the third elongated encapsulant may comprise the third luminescent converter; and (D) the plurality of subfilaments may optionally comprise a fourth subfilament, wherein the fourth subfilament may comprise the fourth light generating device, wherein the fourth subfilament may comprise (i) a plurality of the fourth solid state light source arranged on the elongated carrier, and (ii) a fourth elongated encapsulant covering the plurality of fourth solid state light sources and at least part of the elongated carrier. Such a LED filament comprising subfilament may provide the benefit that all light generating devices may be provided on the same LED filament, removing the need for multiple separate components comprising light generating devices. Further, a LED filament comprising subfilaments may be more decorative (due to the multi-colored appearance).

Additionally or alternatively, in embodiments, the light generating system may comprises a plurality of LED filaments. In such embodiments, a first LED filament may comprise the first light generating device, wherein the first LED filament may comprise a plurality of the first solid state light source arranged on an elongated carrier. Further, the first LED filament may comprise a first elongated encapsulant covering the plurality of first solid state light sources(, the first luminescent converter,) and at least part of the elongated carrier. In embodiments, the first elongated encapsulant may comprise the first luminescent converter. Further, the plurality of LED filaments may comprise a second LED filament. The second LED filament may especially comprise the second light generating device, wherein the second LED filament may comprise a plurality of the second solid state light source arranged on a (different) elongated carrier. Further, the second LED filament may comprise a second elongated encapsulant covering the plurality of second solid state light sources(, the second luminescent converter,) and at least part of the elongated carrier. In embodiments, the second elongated encapsulant may comprise the second luminescent converter. In embodiments, the plurality of LED filaments may comprise a third LED filament. The third LED filament may comprise the third light generating device, wherein the third LED filament may comprise a plurality of the third solid state light source arranged on an elongated carrier. Further, the third LED filament may comprise a third elongated encapsulant covering the plurality of third solid state light sources(, the third luminescent converter,) and at least part of the elongated carrier. In embodiments, the third elongated encapsulant may comprise the third luminescent converter. The plurality of LED filaments may optionally comprise a fourth LED filament. The fourth LED filament may comprise the fourth light generating device, wherein the fourth LED filament may comprise a plurality of the fourth solid state light source arranged on an elongated carrier. Further, the fourth LED filament may comprise a fourth elongated encapsulant covering the plurality of fourth solid state light sources and at least part of the elongated carrier. The fourth encapsulant may comprise the optical coating (optionally comprising the light scattering material). Further, the (first, second, third, and/or) fourth encapsulant may especially have a curved shape in a cross-section perpendicular to the filament length LF.

Hence, in specific embodiments, the light generating system may comprises a plurality of LED filaments, wherein: (A) a first LED filament may comprise the first light generating device, wherein the first LED filament may comprise (i) a plurality of the first solid state light source arranged on an elongated carrier, and (ii) a first elongated encapsulant covering the plurality of first solid state light sources and at least part of the elongated carrier, wherein the first elongated encapsulant may comprise the first luminescent converter; (B) a second LED filament may comprise the second light generating device, wherein the second LED filament may comprise (i) a plurality of the second solid state light source arranged on an elongated carrier, and (ii) a second elongated encapsulant covering the plurality of second solid state light sources and at least part of the elongated carrier, wherein the second elongated encapsulant may comprise the second luminescent converter; (C) a third LED filament may comprise the third light generating device, wherein the third LED filament may comprise (i) a plurality of the third solid state light source arranged on an elongated carrier, and (ii) a third elongated encapsulant covering the plurality of third solid state light sources and at least part of the elongated carrier, wherein the third elongated encapsulant may comprise the third luminescent converter; and (D) the plurality of LED filaments may optionally comprise a fourth LED filament, wherein the fourth LED filament may comprise the fourth light generating device, wherein the fourth LED filament may comprise (i) a plurality of the fourth solid state light source arranged on an elongated carrier, and (ii) a fourth elongated encapsulant covering the plurality of fourth solid state light sources and at least part of the elongated carrier. A light generating system comprising a plurality of LED filaments may provide the benefit that the ratio of light generating device in the light generating system may be adjusted throughout use of the light generating system (e.g., additional first LED filaments may be added depending on user requirements). Further, upon damage to one of the LED filaments, only part of the system may need to be replaced, reducing replacement costs.

The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems.

In yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc... The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system as defined herein. Especially, in a second aspect, the invention provides a lighting device selected from the group of a lamp and a luminaire, comprising the light generating system as defined herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system.

The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light.

BRIEF DESCRIPTION OF THE DRAWINGS

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:

Fig. 1 schematically depicts an embodiment of the light generating system;

Fig. 2 schematically depicts an embodiment of the first, second, third, and fourth device light;

Fig. 3 schematically depicts an embodiment of the LED package; Fig. 4 schematically depicts an embodiment of the system light; Fig. 5 schematically depicts an embodiment of the LED package; Fig. 6 schematically depicts embodiments of the one or more LED filaments; Fig. 7A-B schematically depict embodiments of the one or more LED filaments; and

Fig. 8 schematically depicts an embodiment of the lighting device. The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS Fig. 1 schematically depicts an embodiment of the light generating system 1000. The light generating system 1000 may comprise a first light generating device 110, a second light generating device 120, and a third light generating device 130. The first light generating device 110 may comprise a first solid state light source 10 and a first luminescent converter 2100. The first solid state light source 10 may especially be configured to generate first light source light 11, wherein the first light source light 11 may have a first peak wavelength (kpi) selected from the range of 380-490 nm. Further, the first luminescent converter 2100 may comprise a primary first luminescent material 2110 and a secondary first luminescent material 2120. The primary first luminescent material 2110 may be configured to convert part of the first light source light 11 received by the primary first luminescent material 2110 into primary first luminescent material light 2111. The primary first luminescent material light 2111 may especially have a primary first centroid wavelength ( ci,i) selected from the range of 590-690 nm. Further, the primary first luminescent material light 2111 may comprise at least one emission band having a primary first full width at half maximum FWHMli of > 50 nm. The secondary first luminescent material 2120 may be configured to convert part of the first light source light 11 received by the secondary first luminescent material 2120 into secondary first luminescent material light 2121. In embodiments, the secondary first luminescent material light 2121 may have a secondary first centroid wavelength ( ci,2) selected from the range of 590-690 nm. Further, the secondary first luminescent material light 2121 may comprise at least one emission band having a secondary first full width at half maximum FWHMh of < 30 nm. In embodiments, | ci,2- ci,i | > 10 nm. The first light generating device 110 may be configured to generate first device light 111 comprising the primary first luminescent material light 2111 and the secondary first luminescent material light 2121. Especially, the first device light 111 may have a first device centroid wavelength ( cai) selected from the range of 590-690 nm.

The second light generating device 121 may comprise a second solid state light source 20 and a second luminescent converter 2200. Especially, the second solid state light source 20 may be configured to generate second light source light 21 having a second peak wavelength (Xp2) selected from the range of 380-490 nm. Further, the second luminescent converter 2200 may comprise a primary second luminescent material 2210 and a secondary second luminescent material 2220. The primary second luminescent material 2210 may be configured to convert at least part of the second light source light 21 received by the primary second luminescent material 2210 into primary second luminescent material light 2211. The primary second luminescent material light 2210 may especially have a primary second centroid wavelength ( c2,i) selected from the range of 490-590 nm. Further, the secondary second luminescent material 2220 may be configured to convert at least part of the second light source light 21 received by the secondary second luminescent material 2220 into secondary second luminescent material light 2221. The secondary second luminescent material light 2221 may have a secondary second centroid wavelength ( c2,2) selected from the range of 590-690 nm. Further, the secondary second luminescent material light 2221 may comprise at least one emission band having a secondary second full width at half maximum FWHM22 of < 30 nm. In embodiments, (Xc2,2 - Xc2,i) > 30 nm. The second light generating device 120 may be configured to generate second device light 121 comprising the primary second luminescent material light 2211 and the secondary second luminescent material light 2221. The second device light 121 may especially have a second device centroid wavelength (^Cd2) selected from the range of 490-590 nm. In embodiments, (kcai- cd2) > 15 nm.

The third light generating device 130 may comprise a third solid state light source 30 and a third luminescent converter 2300. The third solid state light source 30 may be configured to generate third light source light 31 having a third peak wavelength (kps) selected from the range of 435-490 nm. Further, the third luminescent converter 2300 may comprise a primary third luminescent material 2310. In embodiments, the secondary first luminescent material 2120, the secondary second luminescent material 2220, and the primary third luminescent material 2310 may be individually selected from the type of M’_xM2-2xAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. Further, the primary third luminescent material 2310 may be configured to convert at least part of the third light source light 31 received by the primary third luminescent material 2310 into primary third luminescent material light 2311. Additionally, the third light generating device 130 may be configured to generate third device light 131 comprising the primary third luminescent material light 2311. The third device light 131 may especially be white light having a correlated color temperature selected from the range of > 2000 K. Further, the light generating system 1000 may be configured to generate system light 1001. The system light 1001 may comprise one or more of the first device light 111, the second device light 121, and the third device light 131. Further, in a first operational mode of the light generating system 1000, the system light 1001 may have a correlated color temperature selected from the range of 1700-6500 K and a color rendering index of at least 80. The color rendering index may thus lie in a range of 80-99, more preferably in a range of 80-97, most preferably in a range of 80-95.

The third luminescent converter 2300 may further comprise a secondary third luminescent material 2320. The secondary third luminescent material 2320 may be configured to convert at least part of the third light source light 31 received by the secondary third luminescent material 2320 into secondary third luminescent material light 2321. Especially, the secondary third luminescent material light 2321 may have a secondary third centroid wavelength ( c3,2) selected from the range of 490-590 nm. Further, the secondary third luminescent material light 2321 may comprise at least one emission band having a secondary third full width at half maximum FWHM32 of > 50 nm.

The light generating system 1000 may further comprise a fourth light generating device 140. The fourth light generating device 140 may comprise a fourth solid state light source 40, configured to generate fourth light source light 41. Further, the fourth light generating device 140 may be configured to generate fourth device light 141 having a fourth device centroid wavelength ( caf) selected from the range of 435-490 nm. In embodiments, the fourth device light 141 may have a spectral power distribution, wherein at least 90% of the spectral power in the wavelength range of 380-780 nm may be provided by the fourth light source light 41. Optionally, the fourth light generating device 140 may further comprise an optical coating 600. The optical coating 600 may in embodiments comprise a light scattering material 610, configured to scatter (or “diffuse”) the fourth light source light 41. Further, the light generating system 1000 may comprise a control system 300. The control system 300 may be configured to individually control the first light generating device 110, the second light generating device 120, the third light generating device 130, and optionally the fourth light generating device 140. Further, the control system 300 may be configured to control a correlated color temperature of the system light 1001 over a range of > 1000 K.

Fig. 2 schematically depicts an embodiment of the primary first luminescent material light 2111, the secondary first luminescent material light 2121, the primary second luminescent material light 2211, the secondary second luminescent material light 2221, the primary third luminescent material light 2311, the secondary third luminescent material light 2321, and the first, second, third, and fourth light source light 11,21,31,41. In embodiments, the second device light 121 (comprising the primary second luminescent material light 2211 and the secondary second luminescent material light 2221) may have a second device centroid wavelength (Xca?) selected from the range of 575-585 nm. Further, the third device light 131 (comprising the primary third luminescent material light 2311, the secondary third luminescent material light 2321, and optionally the third light source light 31) may have a third color point in the CIE 1931 color space defined by third chromaticity coordinates [x3,ys], wherein [xs] may be selected from the range of 0.35-0.45. Additionally or alternatively, the third device light 131 may have a color point below a line located 10 SDCM above the BBL in the CIE 1931 color space.

Fig. 3(1) schematically depicts an embodiment of the first device light 111 comprising the primary first luminescent material light 2111 and secondary first luminescent material light 2121. The primary first luminescent material light 2111 may have the primary first centroid wavelength ( ci,i), and may comprise at least one band having the primary first full width at half maximum FWHMli of > 50 nm. Similarly, the secondary first luminescent material light 2121 may have the secondary first centroid wavelength ( ci,2), and may comprise at least one band having the secondary first full width at half maximum FWHMh of < 30 nm. Further, the first device light 111 (having a first device centroid wavelength ( cdi)) may have a spectral power distribution, wherein xi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary first luminescent material light 2111, and wherein X2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary first luminescent material light 2121. In embodiments, 0.5 < X1/X2 < 2.

Fig. 3(11) schematically depicts an embodiment of the second device light 121 comprising the primary second luminescent material light 2211 and secondary second luminescent material light 2221. The primary second luminescent material light 2211 may have the primary second centroid wavelength ( c2,i), and may comprise at least one band having the primary second full width at half maximum FWHM21 of > 20 nm, especially > 50 nm. Similarly, the secondary second luminescent material light 2221 may have the secondary second centroid wavelength ( c2,2), and may comprise at least one band having the secondary second full width at half maximum FWHM22 of < 30 nm. Further, the second device light 121 (having a second device centroid wavelength ( ca2)) may have a spectral power distribution, wherein yi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary second luminescent material light 2211, and wherein y2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary second luminescent material light 2221. In embodiments, 3 < yi/y2 < 12.

Fig. 3(111) schematically depicts an embodiment of the third device light 131 comprising the primary third luminescent material light 2311 and secondary third luminescent material light 2321. The primary third luminescent material light 2311 may have the primary third centroid wavelength ( c3,i) selected from the range of 590-690 nm. Further, the primary third luminescent material light 2311 may comprise at least one emission band having a primary third full width at half maximum FWHM31 of < 30 nm. Similarly, the secondary third luminescent material light 2321 may have the secondary third centroid wavelength ( c3,2), and may comprise at least one band having the secondary third full width at half maximum FWHM32 of > 50 nm. Further, the third device light 131 may have a spectral power distribution, wherein zi% of the spectral power in the wavelength range of 380-780 nm may be provided by the primary third luminescent material light 2311, and wherein Z2% of the spectral power in the wavelength range of 380-780 nm may be provided by the secondary third luminescent material light 2321. In embodiments, 0.1 < Z1/Z2 < 0.7.

Fig. 4 schematically depicts an embodiment of the system light 1001. The system light 1001 may comprise one or more of the first device light 111, the second device light 121, and the third device light 131. Optionally, the system light 1001 may further comprise the fourth device light 141. In the embodiment depicted in Fig. 4, the system light 1001 comprises the fourth device light 141, yet this need not be the case. Further, in embodiments, the first, second, third, and fourth device light 111,121,131,141 may contribute to the spectral power of the system light 1001 (in the wavelength range of 380-780 nm) to different extents. Two examples of spectral power compositions of the system light 1001 are provided in Table 1. Here, the percentages refer to what percentage of the spectral power of the system light 1001 in the wavelength range of 380-780 nm is provided by the respective device light 111,121,131,141. The CCT of the resulting system light 1001 is also provided. Table 1: examples of spectral power compositions of the system light 1001.

For both examples, the resulting system light 1001 has a CRI of ~93, and a CRI R9 score of ~85. Further, for both examples, the light generating system 1000 is configured to generate the respective system light 1001 with a luminous efficacy of -320 Lm/W. Hence, the light generating system 1000 may be configured to generate system light 1001 having similar optical properties either with or without (a spectral power contribution from) the fourth device light 141. The spectral power distribution of the system light 1001 resulting from example 2 is depicted in Fig. 4.

As indicated above, in the first operational mode of the light generating system 1000, the system light 1001 may have a spectral power distribution, wherein at least 2% of the spectral power may be in the wavelength range of 380-490 nm. Especially, at least 80% of the spectral power in the wavelength range of 380-490 nm may be provided by one or more of the third device light 131 (especially the third light source light 31) and the fourth device light 141 (especially the fourth light source light 41). Further, in the first operation mode of the light generating system 1000, the system light 1001 may be white light having a correlated color temperature selected from the range of 1700-6500 K and a color rendering index of at least 80. Table 2 indicates several embodiments of the system light 1001 at different CCTs, including the corresponding (optical) luminous efficacy and CRI (R9) scores. Table 2: embodiments of the system light 1001 at different CCTs.

Fig. 5 schematically depicts an embodiment of the light generating system 1000 comprising a LED package 500. The LED package 500 may comprise the first light generating device 110, the second light generating device 120, and the third light generating device 130. Optionally, the LED package may further comprise the fourth light generating device 140. The LED package 500 may comprise several housing sections, wherein each housing section may comprise one of the first, second, third, and (optional) fourth light generating device 110,120,130,140. In Fig. 5, the first, second, third, and fourth solid state light sources 10,20,30,40 are indicated by dashed boxes, and are configured covered by the first, second, and third luminescent converter 2100,2200,2300 and optical coating 600, respectively.

Fig. 6 schematically depicts embodiments of the light generating system 1000 comprising one or more LED filaments 4000. The one or more LED filaments 4000 may especially comprise the first light generating device 110, the second light generating device 120, the third light generating device 130, and optionally (also) the fourth light generating device 140.

Fig. 6(1) schematically depicts an embodiment of the light generating system 1000 comprising a plurality of LED filaments 4000. Herein, a first LED filament 4100 may comprise the first light generating device 110. Especially, the first LED filament 4100 may comprise (i) a plurality of the first solid state light source 10 arranged on an elongated carrier 5 (see Fig. 7A), and (ii) a first elongated encapsulant 4150 (see Fig. 7A) covering the plurality of first solid state light sources 10 and at least part of the elongated carrier 5. The first elongated encapsulant 4150 may comprise the first luminescent converter 2100. Further, a second LED filament 4200 may comprise the second light generating device 120. Especially, the second LED filament 4200 may comprises (i) a plurality of the second solid state light source 20 arranged on an elongated carrier 5, and (ii) a second elongated encapsulant 4250 (see Fig. 7A) covering the plurality of second solid state light sources 20 and at least part of the elongated carrier 5. The second elongated encapsulant 4250 may comprise the second luminescent converter 2200. Further yet, a third LED filament 4300 may comprise the third light generating device 130. Especially, the third LED filament 4300 may comprise (i) a plurality of the third solid state light source 30 arranged on an elongated carrier 5, and (ii) a third elongated encapsulant 4350 (see Fig. 7A) covering the plurality of third solid state light sources 30 and at least part of the elongated carrier 5. The third elongated encapsulant 4350 may comprise the third luminescent converter 2300.

Fig. 6(11) schematically depicts another embodiment of the light generating system 1000 comprising a plurality of LED filaments 4000. Herein, the plurality of LED filaments 4000 may further comprise a fourth LED filament 4400. The fourth LED filament 4400 may comprise the fourth light generating device 140. Especially, the fourth LED filament 4400 may comprise (i) a plurality of the fourth solid state light source 40 arranged on an elongated carrier 5, and (ii) a fourth elongated encapsulant 4450 (see Fig. 7A) covering the plurality of fourth solid state light sources 40 and at least part of the elongated carrier 5.

Fig. 6(111) schematically depicts an embodiment of the light generating system 1000, wherein at least one LED filament 4000 may comprise a plurality of subfilaments 400. Herein, a first subfilament 410 may comprise the first light generating device 110, wherein the first subfilament 410 may especially comprise (i) a plurality of the first solid state light source 10 arranged on an elongated carrier 5 (see Fig. 7B), and (ii) a first elongated encapsulant 415 (see Fig. 7B) covering the plurality of first solid state light sources 10(, the first luminescent converter 2100,) and at least part of the elongated carrier 5. The first elongated encapsulant 415 may comprise the first luminescent converter 2100. Further, a second subfilament 420 may comprise the second light generating device 120, wherein the second subfilament 420 may especially comprise (i) a plurality of the second solid state light source 20 arranged on the (same) elongated carrier 5, and (ii) a second elongated encapsulant 425 (see Fig. 7B) covering the plurality of second solid state light sources 20(, the second luminescent converter 2200,) and at least part of the elongated carrier 5. In embodiments, the second elongated encapsulant 425 may comprise the second luminescent converter 2200. Further yet, a third subfilament 430 may comprise the third light generating device 130, wherein the third subfilament 430 may especially comprise (i) a plurality of the third solid state light source 30 arranged on the (same) elongated carrier 5, and (ii) a third elongated encapsulant 435 (see Fig. 7B) covering the plurality of third solid state light sources 30(, the third luminescent converter 2300,) and at least part of the elongated carrier 5. In embodiments, the third elongated encapsulant 435 may comprise the third luminescent converter 2300. The plurality of subfilaments 400 may optionally further comprise a fourth subfilament 440 (as depicted in the center LED filament 4000 of Fig. 6(111)). The fourth subfilament 440 may comprise the fourth light generating device 140, wherein the fourth subfilament 440 may especially comprise (i) a plurality of the fourth solid state light source 40 arranged on the (same) elongated carrier 5, and (ii) a fourth elongated encapsulant 445 (see Fig. 7B) covering the plurality of fourth solid state light sources 40 and at least part of the elongated carrier 5.

Fig. 7A schematically depicts a detailed view of a LED filament 4000, such as especially of the first LED filament 4100, the second LED filament 4200, the third LED filament 4300, and/or the fourth LED filament 4400. The first, second, third, and/or fourth LED filament 4100,4200,4300,4400 may especially comprise a plurality of the corresponding solid state light source 10,20,30,40 arranged on an elongated carrier 5, wherein the plurality of solid state light sources 10,20,30,40 and at least part of the elongated carrier 5 may be covered by the corresponding encapsulant 4150,4250,4350,4450. The plurality of solid state light sources 10,20,30,40 may be configured on both major surfaces of the elongated carrier 5 (as depicted in Fig. 7A), or on only one of the major surfaces of the elongated carrier 5. Similarly, the encapsulant 4150,4250,4350,4450 may (at least partially) cover both major surfaces of the elongated carrier 5 (as depicted in Fig. 7A), or on only one of the major surfaces of the elongated carrier 5.

Fig. 7B schematically depicts a detailed view of a cross-section perpendicular to the filament length LF (and parallel to the filament width WF) of a LED filament 4000 comprising a plurality of subfilaments 400, such as especially the first subfilament 410, the second subfilament 420, the third subfilament 430, and the fourth subfilament 440. In the embodiment depicted in Fig. 7B, the first, second, and third encapsulant 415,425,435 may comprise the first, second, and third luminescent converter 2100,2200,2300, respectively, though this need not be the case. As indicated for the first, second, and third subfilament 410,420,430, the encapsulants 415,425,435 may have a square shape in a cross-section perpendicular to the filament length LF. Alternatively, and especially for the fourth encapsulant 445 (as depicted in Fig. 7B), the encapsulants 415,425,435,445 may have a curved or (semi-)circular shape in a cross-section perpendicular to the filament length LF.

Fig. 8 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. 8 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. 8 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may especially be a lamp 1 or a luminaire 2. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001, and may in specific embodiments thus be system light 1001. Reference 1300 refers to a space, such as a room. Reference 1305 refers to a floor and reference 1310 to a ceiling; reference 1307 refers to a wall.

The term “plurality” refers to two or more. 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%. The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’. 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”. 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”. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

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.

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

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. In yet a further aspect, the invention (thus) provides a software product, which, when running on a computer is capable of bringing about (one or more embodiments of) the method as described herein. 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. 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.

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.

Claims

CLAIMS:

1. A light generating system (1000) comprising a first light generating device

(110), a second light generating device (120), and a third light generating device (130), wherein: the first light generating device (110) comprises a first solid state light source (10) and a first luminescent converter (2100), wherein the first solid state light source (10) is configured to generate first light source light (11) having a first peak wavelength (kpi) selected from the range of 380-490 nm; wherein the first luminescent converter (2100) comprises a primary first luminescent material (2110) and a secondary first luminescent material (2120); the primary first luminescent material (2110) is configured to convert at least part of the first light source light (11) received by the primary first luminescent material (2110) into primary first luminescent material light (2111); wherein the primary first luminescent material light (2111) has a primary first centroid wavelength ( ci,i) selected from the range of 590-690 nm; wherein the primary first luminescent material light (2111) comprises at least one emission band having a primary first full width at half maximum FWHMh of > 50 nm; the secondary first luminescent material (2120) is configured to convert at least part of the first light source light (11) received by the secondary first luminescent material (2120) into secondary first luminescent material light (2121); wherein the secondary first luminescent material light (2121) has a secondary first centroid wavelength ( ci,2) selected from the range of 590-690 nm; wherein the secondary first luminescent material light (2121) comprises at least one emission band having a secondary first full width at half maximum FWHMh of < 30 nm; and wherein |kci,2 - ci,i | > 10 nm; the first light generating device (110) is configured to generate first device light (111) comprising the primary first luminescent material light (2111) and the secondary first luminescent material light (2121); wherein the first device light (111) has a first device centroid wavelength ( cai) selected from the range of 590-690 nm; the second light generating device (120) comprises a second solid state light source (20) and a second luminescent converter (2200), wherein the second solid state light source (20) is configured to generate second light source light (21) having a second peak wavelength (kps) selected from the range of 380-490 nm; wherein the second luminescent converter (2200) comprises a primary second luminescent material (2210) and a secondary second luminescent material (2220); the primary second luminescent material (2210) is configured to convert at least part of the second light source light (21) received by the primary second luminescent material (2210) into primary second luminescent material light (2211); wherein the primary second luminescent material light (2211) has a primary second centroid wavelength ( c2,i) selected from the range of 490-590 nm; the secondary second luminescent material (2220) is configured to convert at least part of the second light source light (21) received by the secondary second luminescent material (2220) into secondary second luminescent material light (2221); wherein the secondary second luminescent material light (2221) has a secondary second centroid wavelength ( c2,2) selected from the range of 590-690 nm; wherein the secondary second luminescent material light (2221) comprises at least one emission band having a secondary second full width at half maximum FWHM22 of < 30 nm; and wherein (kc2,2 - c2,i) > 30 nm; the second light generating device (120) is configured to generate second device light (121) comprising the primary second luminescent material light (2211) and the secondary second luminescent material light (2221); wherein the second device light (121) has a second device centroid wavelength (kcas) selected from the range of 490-590 nm; wherein (kcai - kcas) > 15 nm; the third light generating device (130) comprises a third solid state light source (30) and a third luminescent converter (2300), wherein the third solid state light source (30) is configured to generate third light source light (31) having a third peak wavelength (kps) selected from the range of 435-490 nm; wherein the third luminescent converter (2300) comprises a primary third luminescent material (2310); the primary third luminescent material (2310) is configured to convert at least part of the third light source light (31) received by the primary third luminescent material (2310) into primary third luminescent material light (2311); the third light generating device (130) is configured to generate third device light (131) comprising the primary third luminescent material light (2311), wherein the third device light (131) is white light having a correlated color temperature selected from the range of > 2000 K; and the light generating system (1000) is configured to generate system light (1001), wherein in a first operational mode of the light generating system (1000) the system light (1001) is white light having a correlated color temperature selected from the range of 1700-6500 K and a color rendering index of at least 80.

2. The light generating system (1000) according to any one of the preceding claims, wherein the primary third luminescent material light (2311) has a primary third centroid wavelength ( c3,i) selected from the range of 590-690 nm; wherein the primary third luminescent material light (2311) comprises at least one emission band having a primary third full width at half maximum FWHM31 of < 30 nm.

3. The light generating system (1000) according to any one of the preceding claims, wherein the third luminescent converter (2300) comprises a secondary third luminescent material (2320), wherein the secondary third luminescent material (2320) is configured to convert at least part of the third light source light (31) received by the secondary third luminescent material (2320) into secondary third luminescent material light (2321); wherein the secondary third luminescent material light (2321) has a secondary third centroid wavelength ( c3,2) selected from the range of 490-590 nm; wherein the secondary third luminescent material light (2321) comprises at least one emission band having a secondary third full width at half maximum FWHM32 of > 50 nm.

4. The light generating system (1000) according to any one of the preceding claims, wherein the third device light (131) has a spectral power distribution, wherein zi% of the spectral power in the wavelength range of 380-780 nm is provided by the primary third luminescent material light (2311), wherein Z2% of the spectral power in the wavelength range of 380-780 nm is provided by the secondary third luminescent material light (2321), and wherein 0.1 < Z1/Z2 < 0.7.

5. The light generating system (1000) according to any one of the preceding claims, wherein: the third device light (131) has a third color point in the CIE 1931 color space defined by third chromaticity coordinates [x3,ys], wherein [xs] is selected from the range of 0.35-0.45; and the third device light (131) has a third color point below a line located 10 SDCM above the BBL in the CIE 1931 color space.

6. The light generating system (1000) according to any one of the preceding claims, wherein the secondary first luminescent material (2120), the secondary second luminescent material (2220), and the primary third luminescent material (2310) are individually selected from the type of M’_xM2-2xAX6 doped with tetraval ent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, comprising one or more of silicon and titanium, and wherein X comprises a monovalent anion, at least comprising fluorine.

7. The light generating system (1000) according to any one of the preceding claims, wherein the first device light (111) has a spectral power distribution, wherein xi% of the spectral power in the wavelength range of 380-780 nm is provided by the primary first luminescent material light (2111), wherein X2% of the spectral power in the wavelength range of 380-780 nm is provided by the secondary first luminescent material light (2121), and wherein 0.5 < X1/X2 < 2.

8. The light generating system (1000) according to any one of the preceding claims, wherein the primary second luminescent material light (2211) comprises at least one emission band having a primary second full width at half maximum FWHM21 of > 50 nm; wherein the second device light (121) has a second device centroid wavelength (<Cd2) selected from the range of 575-585 nm.

9. The light generating system (1000) according to any one of the preceding claims, wherein the second device light (121) has a spectral power distribution, wherein yi% of the spectral power in the wavelength range of 380-780 nm is provided by the primary second luminescent material light (2211), wherein y2% of the spectral power in the wavelength range of 380-780 nm is provided by the secondary second luminescent material light (2221), and wherein 3 < yi/y2 < 12.

10. The light generating system (1000) according to any one of the preceding claims, wherein the light generating system (1000) further comprises a fourth light generating device (140); wherein the fourth light generating device (140) comprises a fourth solid state light source (40), wherein the fourth solid state light source (40) is configured to generate fourth light source light (41); wherein the fourth light generating device is configured to generate fourth device light (141) having a fourth device centroid wavelength (Xcd-t) selected from the range of 435-490 nm; wherein the fourth device light (141) has a spectral power distribution, wherein at least 90% of the spectral power in the wavelength range of 380-780 nm is provided by the fourth light source light (41).

11. The light generating system (1000) according to any one of the preceding claims, wherein in the first operational mode of the light generating system (1000) the system light (1001) has a spectral power distribution, wherein at least 2% of the spectral power is in the wavelength range of 380-490 nm; wherein at least 80% of the spectral power in the wavelength range of 380-490 nm is provided by one or more of the third device light (131) and the fourth device light (141) as defined in claim 10.

12. The light generating system (1000) according to any one of the preceding claims, wherein the light generating system (1000) comprises a LED package (500), wherein the LED package (500) comprises the first light generating device (110), the second light generating device (120), the third light generating device (130), and optionally the fourth light generating device (140) as defined in claim 10.

13. The light generating system (1000) according to any one of the preceding claims, wherein the light generating system (1000) comprises one or more LED filaments (4000), wherein the one or more LED filaments (4000) comprise the first light generating device (110), the second light generating device (120), the third light generating device (130), and optionally the fourth light generating device (140) as defined in claim 10.

14. The light generating system (1000) according to any one of the preceding claims, wherein the light generating system (1000) comprises a control system (300), wherein the control system (300) is configured to individually control the first light generating device (110), the second light generating device (120), the third light generating device (130), and optionally the fourth light generating device (140) as defined in claim 10; wherein the control system (300) is configured to control a correlated color temperature of the system light (1001) over a range of > 1000 K.

15. A lighting device (1200) selected from the group of a lamp (1) and a luminaire

(2), comprising the light generating system (1000) according to any one of the preceding claims.