Highly efficient and reliable blue-light-free white LED lighting equipment using ultra-high concentration KSiF phosphors.

Abstract

The present invention provides a light generation system (1000) comprising a light source (10), a first light-emitting layer (2100), and a second light-emitting layer (2200), wherein: (i) the light source (10) is configured to generate light (11); (ii) the first light-emitting layer (2100) is disposed downstream of the light source (10), wherein the first light-emitting layer (2100) comprises a first light-emitting material (2110), the first light-emitting material (2110) comprising a first light-emitting material (210), wherein the first light-emitting material (2110) comprises a first light-emitting material (210), wherein the first light-emitting material (2 ... The luminescent material (210) is configured to convert a first portion of the light source light (11) received by the first luminescent material (210) into first luminescent material light (211); (iii) a second luminescent layer (2200) is disposed downstream of the first luminescent layer (2100), wherein the second luminescent layer (2200) includes a second luminescent material (2220), wherein the second luminescent material (2220) includes M' doped with tetravalent manganese. X M 2‑2X AX6, wherein M' comprises an alkaline earth cation, wherein M comprises an alkaline cation, wherein A comprises a tetravalent cation, and wherein X comprises a monovalent anion, wherein the monovalent anion comprises at least fluorine (F); wherein the second luminescent material (220) is configured to convert a second portion of the light source light (11) received by the second luminescent material (220) into second luminescent material light (221); and wherein the second luminescent layer (2200) comprises at least 1.2 times the amount of the second luminescent material (2220) required to transmit up to 2% of the light source light (10) received by the second luminescent layer (2200); and (iv) the light generation system (1000) is configured to generate system light (1001) in a first operating mode of the light generation system (1000), the system light (1001) comprising first luminescent material light (211) and second luminescent material light (221), wherein the system light (1001) has a correlated color temperature selected from the range of 1300K-2700K.

Description

Technical Field

[0001] This invention relates to light generating systems. It also relates to lighting devices that include light generating systems. Background Technology

[0002] Light generation systems incorporating luminescent materials are known in the art. For example, US2019067532A1 describes a light-emitting device that emits secondary light with high color purity and a fast response speed. KSF phosphors and CASN phosphors, which absorb blue light and emit red light, are distributed in a resin, which seals a blue-emitting LED chip. The KSF phosphor absorbs blue light and emits red light through forbidden transitions, while the CASN phosphor absorbs blue light and emits red light through allowed transitions. Summary of the Invention

[0003] Blue-light-free LED lighting may be desired, for example, in cleanroom lighting. To generate blue-light-free LED light, light-emitting converters comprising various types of phosphors (such as yellow and red phosphors) can be used. However, existing solutions may have problems in providing efficient, reliable, and / or stable solutions. Therefore, one aspect of the present invention provides an alternative light generation system that preferably also at least partially eliminates one or more of the aforementioned disadvantages. The present invention may aim to overcome or improve at least one disadvantage of the prior art, or to provide a useful alternative solution.

[0004] According to a first aspect, the present invention provides a light generation system (“System”), comprising a light source, a first emitting layer, and a second emitting layer. The light source can be configured to generate light. In an embodiment, the light source light may have a first peak wavelength λp1 selected from the wavelength range of 400 nm to 490 nm. Furthermore, the light source may include a solid-state light source. In an embodiment, the first emitting layer may be disposed downstream of the light source. Furthermore, the first emitting layer may include a first emitting material, the first emitting material comprising a first emitting material. The first emitting material can be configured to convert a first portion of the light source light received by the first emitting material into first emitting material light. In an embodiment, the first emitting material light may have an emission band having a first centroid wavelength λc1 selected from the wavelength range of 505 nm to 590 nm. Furthermore, the first emitting material light may have an emission band having a first full width at half maximum (FWHM1) of at least 50 nm (at room temperature). In an embodiment, the second emitting layer may be disposed downstream of the first emitting layer (and the light source). Specifically, the second emitting layer may include a second emitting material, the second emitting material comprising a second emitting material. In an embodiment, the second luminescent material may include M' doped with tetravalent manganese. x M 2- 2xAX6, wherein M' comprises an alkaline earth cation, wherein M comprises a basic cation, wherein A comprises a tetravalent cation, and wherein X comprises a monovalent anion, the monovalent anion comprising at least fluorine (F). Furthermore, the second luminescent material can be configured to convert a second portion of the light source light received by the second luminescent material into second luminescent material light. In an embodiment, the second luminescent material light may have at least one emission band (in the wavelength range of 620 nm-640 nm), the at least one emission band having a second full width at half maximum (FWHM2) of up to 40 nm (at room temperature). Furthermore, in an embodiment, the second luminescent material light may have a second centroid wavelength λc2 selected from the wavelength range of 620 nm-640 nm. In an embodiment, the second luminescent layer may comprise at least 1.2 times the amount of second luminescent material required to transmit up to 2% of the light source light received by the second luminescent layer (at the first peak wavelength λp1). In an embodiment, the light generation system can be configured to generate system light in a first operating mode of the light generation system, the system light comprising the first luminescent material light and the second luminescent material light. In an embodiment, the system light may have a correlated color temperature selected from the range of 1300K-2700K. Therefore, in a specific embodiment, the present invention provides a light generation system comprising a light source, a first emitting layer, and a second emitting layer, wherein: (i) the light source is configured to generate light source light, wherein the light source light has a first peak wavelength λp1 selected from the wavelength range of 400nm-490nm; and wherein the light source comprises a solid-state light source; (ii) the first emitting layer is disposed downstream of the light source, wherein the first emitting layer comprises a first emitting material, the first emitting material comprising a first emitting material, wherein the first emitting material is configured to convert a first portion of the light source light received by the first emitting material into first emitting material light, wherein the first emitting material light has an emission band having a first centroid wavelength λc1 selected from the wavelength range of 505nm-590nm and a first full width at half maximum (FWHM1) of at least 50nm; (iii) the second emitting layer is disposed downstream of the first emitting layer, wherein the second emitting layer comprises a second emitting material, the second emitting material comprising M' doped with tetravalent manganese. x M 2-2xAX6, wherein M' comprises an alkaline earth cation, wherein M comprises a basic cation, wherein A comprises a tetravalent cation, and wherein X comprises a monovalent anion, the monovalent anion comprising at least fluorine (F); wherein the second luminescent material is configured to convert a second portion of the light source light received by the second luminescent material into second luminescent material light, the second luminescent material light having at least one emission band having a second full width at half maximum (FWHM2) of up to 40 nm, wherein the second luminescent material light has a second centroid wavelength (λc2) selected from the wavelength range of 620 nm to 640 nm; and wherein the second luminescent layer comprises at least 1.2 times the amount of the second luminescent material required to transmit up to 2% of the light source light received by the second luminescent layer; and (iv) the light generation system is configured to generate system light in a first operating mode of the light generation system, the system light comprising the first luminescent material light and the second luminescent material light, wherein the system light has a correlated color temperature selected from the range of 1300 K to 2700 K.

[0005] Using such a light generation system, system light that is essentially blue-light-free can be provided. Specifically, since the amount of the second luminescent material can be higher than the amount required to transmit up to 2% of the blue light incident on the second luminescent layer (after the light source has been partially converted in the first luminescent layer), the light generation system can provide blue-light-free light without the use of additional filters, thereby improving the efficiency of the light generation system. Furthermore, since the second luminescent material can be oversized for the light source (i.e., selected such that the amount of the second luminescent material is higher than the amount required to transmit ≤2% of the incident light), the potential degradation of the second luminescent material over time may not (significantly) (or only after a relatively long operating period) affect the amount of blue light transmitted through the second luminescent layer. Therefore, the light generation system can be stable and / or robust, and thus can have improved lifetime and / or performance. The light generation system can generate efficient and reliable (white) light. Specifically, the light generation system can generate efficient and reliable (essentially) blue-light-free (white) light.

[0006] In embodiments, the light generation system may include a light source. Specifically, the light source may include a solid-state light source. Furthermore, the light source may be configured to generate light. In embodiments, the light source light may include violet light, i.e., light having a wavelength in the range of approximately 380 nm to 440 nm. Additionally or alternatively, in embodiments, the light source light may include, for example, blue light, i.e., light having a wavelength in the range of approximately 440 nm to 490 nm. Specifically, the light source light may have a first peak wavelength λp1 selected from the 380 nm to 490 nm wavelength range, such as selected from the 400 nm to 490 nm wavelength range, and more specifically selected from the 420 nm to 475 nm wavelength range. Therefore, in a specific embodiment, the first peak wavelength λp1 may be selected from the 420 nm to 475 nm wavelength range. Light source light having a first peak wavelength λp1 selected from the 420 nm to 475 nm wavelength range can provide light source light with the highest intensity at wavelengths close to the excitation maximum of the first (layer) luminescent material and / or the second (layer) luminescent material. Therefore, such a light source (where 420nm ≤ λp1 ≤ 475nm) can be particularly beneficial for (with relatively low thermal loss) (efficiently) exciting the first (layer) luminescent material and / or the second (layer) luminescent material. Further embodiments of the light source are provided below.

[0007] In an embodiment, the light generating system may include a first light-emitting layer downstream of the light source. The terms "upstream" and "downstream" refer to the arrangement of an item or feature relative to the propagation of light from the light generating device (specifically, the light source), wherein a second position in the beam closer to the light generating device is "upstream" relative to a first position within the beam from the light generating device, and a third position in the beam farther from the light generating device is "downstream." In an embodiment, the first light-emitting layer may therefore be configured downstream of the light source. Furthermore, in an embodiment, a second light-emitting layer may be configured downstream of the first light-emitting layer (and the light source). Some general embodiments regarding the first and / or second light-emitting layers are provided herein.

[0008] In some embodiments, the light-emitting layer may be a self-supporting layer. Alternatively, in some embodiments, the light-emitting layer may be a coating. In some embodiments, the light-emitting layer may include a light-transmitting matrix in which the light-emitting material is embedded. For example, the light-emitting layer may include a polymer matrix (e.g., silicone, such as PDMS) in which the light-emitting material is embedded.

[0009] The light-emitting layer can have any shape. However, generally, the light-emitting layer can include two essentially parallel faces (i.e., a first side and a second side), which define the height of the light-emitting layer. Furthermore, the light-emitting layer can include a third side (or "edge face") that bridges the first and second sides. The edge face can be curved in one or two dimensions. The edge face can be planar. The light-emitting layer can have a rectangular or circular cross-section, but other cross-sections are also possible, such as hexagonal, octagonal, etc. Thus, the light-emitting layer can have an n-sided cross-section, where n is at least 3, such as 4 (square or rectangular cross-section), 5 (pentagonal cross-section), 6 (hexagonal cross-section), 8 (octagonal cross-section), or higher, such as up to 24. The first and second sides can also be referred to as "main faces" because they specifically provide the maximum external area of ​​the light-emitting layer. Perpendicular to the above cross-sections can be another cross-section, which in embodiments may be rectangular. Therefore, the light-emitting layer can have, for example, a cubic shape, a (non-cubic) cuboid shape, an n-sided prism shape with n at least 5 (e.g., a pentagonal prism, a hexagonal prism), and a cylindrical shape. However, other shapes are also possible. In embodiments, the light-emitting layer has a lateral dimension of width or length (W or L) or diameter (D) and a thickness or height (H). In embodiments, (i) D ≥ H or (ii) W ≥ H and / or L ≥ H. Specifically, the lateral dimension (e.g., length, width, and diameter) is at least twice the height, for example, at least five times. In a specific embodiment, the light-emitting layer has a length L, a height H, and a width W, where H ≤ 0.5. L and H≤0.5 W. In a specific embodiment, the light-emitting element may be a (small) tile. Furthermore, the light-emitting layer may be transparent or light-scattering.

[0010] Focusing on the first light-emitting layer, in this embodiment, the first light-emitting layer can be (directly) disposed on top of the light-emitting surface of the light source. That is, in this embodiment, the distance between the light source (light-emitting surface) and the first light-emitting layer (first side) can be (essentially) zero. Therefore, the first light-emitting layer can be configured to be in physical contact with the light source. Alternatively, the first light-emitting layer (first side) can be disposed at a non-zero distance d1 from the light source (light-emitting surface) (“remote configuration”). That is, the first light-emitting layer can be configured to be physically separated from the light source. For example, one or more light sources can be disposed on the inner surface of the (bottom) of the housing unit, wherein the first light-emitting layer is included by a light-emitting window, which is included by a second (top) surface of the housing unit. In this embodiment, the distance d1 can be selected from the range of ≥5µm, such as from the range of ≥15µm, specifically from the range of ≥50µm. Furthermore, the distance d1 can be selected from the range of ≤50cm, such as from the range of ≤30cm, specifically from the range of ≤10cm. Therefore, in a specific embodiment, the first light-emitting layer can be disposed at a non-zero distance d1 from the light source. Positioning the first light-emitting layer at a non-zero distance d1 from the light source can reduce the surface temperature of the first light-emitting layer because the surface of the first light-emitting layer can be physically separated from the (heat-generating) light source. Therefore, the first light-emitting layer can have improved thermal management, and thus improved lifetime and / or performance.

[0011] In an embodiment, the first light-emitting layer may include a first layer of light-emitting material, which comprises a first light-emitting material. Specifically, the first layer of light-emitting material may be a light-emitting material included in (e.g., embedded in) the first light-emitting layer. The first layer of light-emitting material may (at least) comprise a first light-emitting material. In an embodiment, the first light-emitting material may specifically be a broadband emitter. Herein, a broadband emitter may refer to a light-emitting element configured to provide an emission band having a full width at half maximum (FWHM) bandwidth ≥ 50 nm, such as a bandwidth ≥ 60 nm, specifically a bandwidth ≥ 70 nm. Furthermore, the first light-emitting material may be configured to convert a first portion of the light source light received by the first light-emitting material into first light-emitting material light. In an embodiment, the first portion of the light source light may have a spectral power selected from the range of ≥ 10% of the spectral power of the (whole) light source light, such as a range selected from ≥ 20%, specifically a range selected from ≥ 30%. Furthermore, in an embodiment, the first portion of the light source light may have a spectral power selected from the range of ≤ 65% of the spectral power of the (whole) light source light, for example, a range selected from ≤ 55%, specifically a range selected from ≤ 45%. Therefore, in embodiments, the first luminescent material can be configured to convert 10%-65%, such as 20%-55%, specifically 30%-45% of the light from the light source into light from the first luminescent material.

[0012] In an embodiment, the first luminescent material light may have an emission band having a first centroid wavelength λc1 selected from the wavelength range of 490nm-610nm, such as the wavelength range of 495nm-600nm, such as the wavelength range of 500nm-595nm, specifically the wavelength range of 505nm-590nm, such as the wavelength range of 535nm-590nm. In a specific embodiment, the first centroid wavelength λc1 may be selected from the wavelength range of 505nm-520nm. In an embodiment, the first luminescent material light may be essentially composed of the emission band. Therefore, in such an embodiment, the (overall) first luminescent material light may have a first luminescent material centroid wavelength λc1 selected from the wavelength range of 490nm-610nm, such as the wavelength range of 500nm-600nm, specifically the wavelength range of 505nm-590nm, such as the wavelength range of 535nm-590nm. m1 Alternatively, the light emitted by the first luminescent material may include multiple emission bands.

[0013] The term "centroid wavelength," also referred to as λc, is known in the prior art and refers to the wavelength value where half of the light energy is at the shorter wavelength and half at the longer wavelength; the value is expressed in nanometers (nm). The formula is λc = Σλ The expression I(λ) / (Σ I(λ)) represents the integral of the spectral power distribution divided into two equal parts at wavelengths, where the summation is performed over the wavelength of interest, and I(λ) is the spectral energy density (i.e., the integral of the product of wavelength and intensity over the emission band, normalized to the integral intensity). The centroid wavelength can be determined, for example, under operating conditions.

[0014] Furthermore, in an embodiment, the emission band of the first luminescent material light (having a first centroid wavelength λc1) may have a first full width at half maximum (FWHM1). That is, the first luminescent material light may include an emission band having a first full width at half maximum (FWHM1). The full width at half maximum (FWHM) of the emission band may specifically be determined at room temperature. Specifically, the full width at half maximum (FWHM) of the emission band from the luminescent material can be determined when the luminescent material has a temperature selected from the range of 20°C to 25°C (i.e., room temperature). Furthermore, the full width at half maximum (FWHM) of the emission band can be determined from the spectral power distribution of the emission band and can be defined as the width (in nm) of the emission band at half its maximum intensity. In an embodiment, the first full width at half maximum (FWHM1) may be selected from a range of at least 40 nm, such as a range selected from at least 45 nm, and specifically from a range selected from at least 50 nm. Furthermore, the first full width at half maximum (FWHM1) can be selected from a range of at least 55 nm, such as a range of at least 70 nm, and specifically a range of at least 80 nm. In addition, in embodiments, the first full width at half maximum (FWHM1) can be selected from a range of up to 150 nm, such as a range of up to 125 nm, and specifically a range of up to 100 nm. Therefore, in embodiments, the light emitted by the first luminescent material can have a first centroid wavelength (λc1) selected from a wavelength range of 505 nm to 590 nm (specifically a wavelength range of 535 nm to 590 nm) and a first full width at half maximum (FWHM1) of at least 50 nm.

[0015] Furthermore, in embodiments, the first luminescent material can be configured to convert at least a portion of the light from the source into light from the first luminescent material. In embodiments, the first luminescent material can be composed of a first luminescent material and can therefore be configured to convert 10%-65%, such as 20%-55%, specifically 30%-45%, of the light from the source into light from the first luminescent material. This leaves approximately 35%-90%, such as 45%-80%, specifically 55%-70%, of the light from the source to be received by the second luminescent layer. Alternatively, in embodiments, the first luminescent material can include the first luminescent material and one or more other luminescent materials different from the first luminescent material (e.g., different in chemical composition). The optional one or more other luminescent materials from the first luminescent layer can (individually) be selected from broadband emitters or narrowband emitters. Specifically, the first light-emitting material includes a first light-emitting material and optionally one or more other light-emitting materials included in the first light-emitting layer. The first light-emitting material can be configured to convert 15%-70%, such as 25%-60%, specifically 35%-55% of the light from the light source into light from the first light-emitting material.

[0016] Furthermore, the light emitted by the first layer of luminescent material can have a first-layer centroid wavelength λ.cL1 In this embodiment, the wavelength of the first centroid can be equal to the wavelength of the first centroid, λc1 = λc L1 Alternative site, first layer centroid wavelength λ cL1 This can be different from the first centroid wavelength λc1. Specifically, in the embodiment, 0nm ≤ |λc1-λc L1 |≤50nm, specifically 0nm≤|λc1-λc L1 |≤40nm.

[0017] Therefore, in embodiments, the first luminescent material layer may include a first luminescent material, and optionally one or more other (different) luminescent materials. Similarly, the second luminescent material layer may include a second luminescent material layer, which includes the second luminescent material and optionally one or more other luminescent materials (included by the second luminescent material layer), as further described below. First, some general aspects regarding luminescent materials are described below.

[0018] The term "luminescent material" may specifically refer to a material capable of converting one or more of a first radiation, specifically UV radiation, and blue radiation, into a second radiation. Typically, the first and second radiations have different spectral power distributions, with the second radiation generally having a spectral power distribution at wavelengths greater than the first radiation (i.e., "down-conversion"). In embodiments, "luminescent material" may specifically refer to a material capable of converting radiation into, for example, visible light and / or infrared light. For example, in embodiments, a luminescent material may be able to convert one or more of YV radiation and blue radiation into visible light. The terms "visible," "visible light," or "visible emission" and similar terms refer to light having one or more wavelengths in the range of about 380 nm to 780 nm. In this document, UV (ultraviolet) may specifically refer to wavelengths selected from the 190 nm to 380 nm range, such as the 200 nm to 380 nm range, but other wavelengths are possible in specific embodiments. Thus, when excited using radiation, a luminescent material can emit radiation. Unless it is clearly apparent from the context that the term "light" refers only to visible light, the terms "light" and "radiation" are used interchangeably herein. The terms "light" and "radiation" can therefore refer to UV radiation, visible light, and IR radiation. In specific embodiments, particularly for lighting applications, the terms "light" and "radiation" refer to (at least) visible light. In embodiments, the term "luminescence" can refer to phosphorescence. In embodiments, the term "luminescence" can also refer to fluorescence. In addition to the term "luminescence," the terms "luminescent material light" or "emission" can also be used. Therefore, the terms "first radiation" and "second radiation" can refer to excitation radiation and emission (radiation), respectively. The term "luminescent material" can also refer to several different luminescent materials. Examples of possible luminescent materials are shown below. Therefore, in specific embodiments, the term "luminescent material" can also refer to a luminescent material composition. In addition to the term "luminescent material," the term "phosphor" can also be used. These terms are known to those skilled in the art.

[0019] The following describes examples of an unrestricted number of luminescent materials.

[0020] In embodiments, the luminescent material may be selected from garnets and nitrides specifically doped with trivalent cerium or divalent europium, respectively. The term "nitride" may also refer to oxynitrides or nitrogen silicates, etc. Alternatively or additionally, (a plurality of) luminescent materials may be selected from silicates specifically doped with divalent europium. In embodiments, the luminescent material may include an oxynitride luminescent material containing divalent europium. Furthermore, in embodiments, the luminescent material may include a nitride luminescent material containing divalent europium.

[0021] In a specific embodiment, the luminescent material may include at least A3B5O. 12Ce-type luminescent materials, 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 can comprise blue light. Specifically, A may comprise one or more of Y, Gd, and Lu, such as specifically one or more of Y and Lu. Specifically, B may comprise one or more of Al and Ga, more specifically at least Al, such as substantially entirely Al. Therefore, specifically, suitable luminescent materials are garnet materials containing cerium. Examples of garnet specifically include A3B5O. 12 Garnet, wherein A comprises at least yttrium (Y) or lutetium (Lu), and wherein B comprises at least aluminum (Al). Such garnet may be doped with cerium (Ce), praseodymium (Pr), or a combination of cerium and praseodymium; however, specifically, it is doped with Ce. Specifically, B may comprise aluminum (Al); however, in addition to aluminum, B may also partially comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), specifically up to about 20% of B, more specifically up to about 10% of B; B may specifically comprise up to about 10% gallium. In another variation, B and O may be at least partially replaced by Si and N. Element A may specifically be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). Furthermore, Gd and / or Tb are specifically present only in an amount up to about 20% of A. In a specific embodiment, the garnet luminescent material comprises (Y) 1-x Lu x )3B5O 12 :Ce, where 0 ≤ x ≤ 1. The term ":Ce" indicates that the portion of the metal ions in the luminescent material (i.e., in garnet, the portion of the "A" ions) is replaced by Ce. For example, in (Y 1-x Lu x )3Al5O 12 In the case of Ce, portions of Y and / or Lu are replaced by Ce. This is well known to those skilled in the art. Typically, Ce replacement of A usually does not exceed 10%; overall, the Ce concentration will be in the range of 0.1% to 4%, specifically 0.1% to 2% (relative to A). Assuming 1% Ce and 10% Y, the complete and correct formula could be (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 As is known to those skilled in the art, Ce in garnet is essentially or only in the trivalent state. In embodiments, such luminescent materials can have suitable spectral distribution, relatively high efficiency, relatively high thermal stability, and allow for high CRI (optionally combined with light from other light sources as described herein).

[0022] In a specific embodiment, the luminescent material may only include a luminescent material selected from garnet-type luminescent materials containing cerium. In another specific embodiment, the luminescent material may include a single type of luminescent material, such as (Y x1 A' x2 Ce x3 )3(Al y1 B' y2 )5O 12 . Thus, in a specific embodiment, the luminescent material may include a luminescent material, wherein at least 85% by weight, even more specifically at least about 90 wt.%, such as even more specifically at least about 95% by weight of the luminescent material includes (Y x1 A' x2 Ce x3 )3(Al y1 B' y2 )5O 12 . Here, A' includes one or more elements selected from the group consisting of lanthanide elements, and B' includes one or more elements selected from the group consisting of Ga, In, and Sc, where x1 + x2 + x3 = 1, where x3 > 0, where 0 < x2 + x3 ≤ 0.2, where y1 + y2 = 1, where 0 ≤ y2 ≤ 0.2. Specifically, x3 is selected from the range of 0.001 - 0.1. Note that in the embodiment, x2 = 0. Alternatively or additionally, in the embodiment, y2 = 0.

[0023] The luminescent material may include a luminescent material of the A3Si6N 11 :Ce 3+ type, where A includes one or more of Y, La, Gd, Tb, and Lu, such as including one or more of La and Y in the embodiment. In the embodiment, the luminescent material may alternatively or additionally include MS:Eu 2+ and / or M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+One or more of the following, wherein M includes one or more of Ba, Sr, and Ca, specifically at least Sr in the embodiments. Therefore, in the embodiments, the luminescent material may include one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu, and (Ba,Sr,Ca)2Si5N8:Eu. As is known to those skilled in the art, in these compounds, europium (Eu) is substantially or only divalent and substitutes for one or more of the indicated divalent cations. Generally, in terms of the amount of cation, the Eu present will not exceed 10%; its presence will specifically be in the range of about 0.5% to 10% relative to the cation(s) it substitutes, more specifically in the range of about 0.5% to 5%.

[0024] In an embodiment, the luminescent material may include M' doped with tetravalent manganese. x M 2-2x The AX6 type luminescent material, wherein M' comprises an alkaline earth cation, M comprises a basic cation, and x can be selected from the range of 0-1, wherein A comprises a tetravalent cation, such as one or more of silicon and titanium, and wherein X comprises a monovalent anion, the monovalent anion comprising at least fluorine. Specifically, in embodiments, the luminescent material may comprise M' doped with tetravalent manganese. x M 2-2x AX6, wherein M' comprises an alkaline earth cation, wherein M comprises a basic cation, wherein A comprises a tetravalent cation, and wherein X comprises a monovalent anion, the monovalent anion comprising at least fluorine (F). Regardless of whether M comprises K or one or more other basic cations, M' doped with tetravalent manganese x M 2-2x AX6 type luminescent materials may also be referred to as "KSiF" or "KSF" in this article. M' doped with tetravalent manganese x M 2-2x AX6 type luminescent materials are described at least in WO2013121355A1, which is incorporated herein by reference. Paragraphs from WO2013121355A1 are also reproduced herein. The relevant alkaline earth cations (M') are magnesium (Mg), strontium (Sr), calcium (Ca), and barium (Ba), specifically one or more of Sr and Ba. The relevant basic cations (M) are sodium (Na), potassium (K), and rubidium (Rb). Alternatively, ammonium (NH4) may also be used. +M consists of potassium, lithium (Li), and / or cesium (Cs). In a preferred embodiment, M comprises at least potassium. In another embodiment, M comprises at least rubidium. In yet another preferred embodiment, M comprises at least potassium and rubidium. In one embodiment, preferably at least 80% of M (i.e., 80% of the molar number of all types of M), even more preferably at least 90%, such as 95% of M, consists of potassium and / or rubidium. Optionally, M' x M 2-2x The AX6 luminescent material has a hexagonal phase. In another embodiment, M' x M 2-2x The AX6 luminescent material has a cubic phase. In one embodiment, a combination of different basic cations can be used. In another embodiment, a combination of different alkaline earth cations can be used. In yet another embodiment, a combination of one or more basic cations and one or more alkaline earth cations can be used. For example, KRb 0.5 Sr 0.25 AX6 can be applied, where x can be selected from the range of 0-1, specifically x≤1. In a specific embodiment, x=0.

[0025] The term "tetravalent manganese" refers to Mn 4+ This is a well-known luminescent ion. In the formula indicated above, the tetravalent cation A (such as Si) is partially replaced by manganese. Therefore, M' doped with tetravalent manganese x M 2-2x AX6 can also be indicated as M' x M 2-2x A 1-m Mn m X6. The molar percentage of manganese, i.e., the percentage by which it replaces the tetravalent cation A, will generally be in the range of 0.1%–15%, specifically 1%–12%, i.e., m is in the range of 0.001–0.15%, specifically in the range of 0.01–0.12. Because manganese partially replaces the matrix lattice ions and has specific functions, it is also indicated as a "doper" or "activator." Therefore, manganese (Mn) is used in hexafluorosilicates. 4+ To dope or activate.

[0026] In the embodiments, A comprises a tetravalent cation and preferably comprises at least silicon. A may optionally (additionally) comprise one or more of titanium (Ti), germanium (Ge), tin (Sn), and zinc (Zn). Preferably, at least 80%, and even more preferably at least 90%, such as at least 95%, of A is composed of silicon.

[0027] As described above, X relates to a monovalent anion, but includes at least fluorine. Optionally, other monovalent anions that may be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). Preferably, X is composed of at least 80%, and even more preferably at least 90%, such as 95%, of fluorine. Specifically, X may be substantially composed of F (fluorine).

[0028] In one embodiment, M' x M 2-2x AX6 includes K2SiF6 (also referred to herein as a KSiF system). In another preferred embodiment, M' x M 2-2x AX6 includes KRbSiF6 (also referred to herein as a K,Rb system). In a specific embodiment, M' is indicated. x M 2-2x AX6 can refer to (K,Rb)2SiF6:Mn 4+ (K,Rb)2TiF6:Mn 4+ K2(Si,Ti)F6:Mn 4+ and Rb2(Si,Ti)F6:Mn 4+ One or more of them, such as K2TiF6:Mn 4+ K2SiF6:Mn 4+ and Rb2SiF6:Mn 4+ One or more of these. In embodiments, the luminescent material may include (K,Rb)₂SiF₆:Mn 4+ Additionally or alternatively, in embodiments, the luminescent material may include K2(Si,Ti)F6:Mn 4+ In a specific embodiment, the luminescent material may specifically include K2SiF6:Mn 4+ As can be deduced from the above, "(Si,Ti)" can indicate one or more of Si and Ti (and "(K,Rb)" can indicate one or more of K and Rb). Therefore, in a specific embodiment, the luminescent material may include (K,Rb)2SiF6:Mn 4+ and K2(Si,Ti)F6:Mn 4+ One or more of them. As described in WO2013121355A1, luminescent materials can also be coated.

[0029] The term "luminescent material" in this document specifically refers to inorganic luminescent materials. Alternatively or additionally, other luminescent materials may also be applied. For example, quantum dots, (organic and / or inorganic) perovskites and / or organic dyes may be applied and may optionally be embedded in a transmissive matrix (e.g., a polymer, such as PMMA or polysiloxane).

[0030] Furthermore, in a specific embodiment, the first luminescent material may include A3B5O. 12 Ce-type luminescent materials, wherein A includes one or more of Y, La, Gd, Tb and Lu, and wherein B includes one or more of Al, Ga, In and Sc.

[0031] Furthermore, in the embodiments, the first luminescent material may include A3B5O. 12 :Ce 3+ At least two luminescent materials of the type, such as at least (Y x11 Lu x12 A' x13 Ce x14 )3B5O 12 and (Y) x21 Lu x22 A' x23 Ce x24 )3B5O 12 In such an embodiment, the first luminescent material may include a primary first luminescent material, such as (Y) x11 Lu x12 A' x13 Ce x14 )3B5O 12 , where x 11 +x 12 +x 13 +x 14 =1, x 11 +x 12 >0, 0≤x 13 <1, 0.001≤x 14 ≤0.1, wherein A' comprises one or more of La, Gd, and Tb, and wherein B comprises one or more of Al, Ga, In, and Sc. Furthermore, in such embodiments, the first luminescent material may include a secondary first luminescent material, such as (Y) x21 Lu x22 A' x23 Ce x24 )3B5O 12 , where x 21 +x 22 +x 23 +x 24 =1, x 21 +x 22 >0, 0≤x 23 <1, 0.001≤x 24 ≤0.1, wherein A' comprises one or more of La, Gd, and Tb, and wherein B comprises one or more of Al, Ga, In, and Sc. In embodiments, the secondary first luminescent material may comprise more Lu,x in moles than the primary first luminescent material.22 >x 12 Furthermore, in the embodiments, the primary first luminescent material may contain more Y, x moles than the secondary first luminescent material. 11 >x 21 In the embodiment, x 12 It can be equal to zero. Furthermore, in the embodiments, x... 21 It can be equal to zero. Furthermore, in the embodiments, x... 12 x 13 and x 23 One or more of them can be equal to zero. In the embodiment, x 14 It can be equal to x 24 However, in the embodiments, x 14 Can be with x 24 Different, where x 14 and x 24 Both can be individually selected from the range of 0.001-0.1. Therefore, in a specific embodiment, the first luminescent material may include (Y) x11 Lu x12 A' x13 Ce x14 )3B5O 12 Type of primary first luminescent material and (Y x21 Lu x22 A' x23 Ce x24 )3B5O 12 Secondary primary luminescent materials of the type, wherein A' comprises one or more of La, Gd, and Tb, wherein B comprises one or more of Al, Ga, In, and Sc; wherein (a)x 11 +x 12 +x 13 +x 14 =1; x 11 +x 12 >0; 0≤x 13 <1; and 0.001≤x 14 ≤0.1; (b)x 21 +x 22 +x 23 +x 24 =1; x 21 +x 22 >0; 0≤x 23 <1; and 0.001≤x 24 ≤0.1; and (c)x 11 >x 21 And x 22 >x 12 . and consisting of a first luminescent material comprising (only) one type (e.g., (Y x11 Lux12 A' x13 Ce x14 )3B5O 12 Or (Y) x21 Lu x22 A' x23 Ce x24 )3B5O 12 Compared to the spectral power distribution of the first luminescent material provided by the first luminescent material, such a composition of the first luminescent material can provide a wider spectral power distribution of the first luminescent material light. For example, in an embodiment, a primary first luminescent material can be configured to provide primary first luminescent material light, and a secondary first luminescent material can be configured to provide secondary first luminescent material light, wherein the spectral power distribution (wavelength range) of the primary first luminescent material light can overlap with the spectral power distribution (wavelength range) of the secondary first luminescent material light by ≤90%.

[0032] In an embodiment, the first light-emitting layer may comprise a first layer of light-emitting material at a concentration C1. In an embodiment, the concentration C1 of the first layer of light-emitting material may be selected from the range of ≥2v / v%, such as from the range of ≥5v / v%, specifically from the range of ≥10v / v%. Alternatively or additionally, in an embodiment, the concentration C1 of the first layer of light-emitting material may be selected from the range of ≤25v / v%, such as from the range of ≤20v / v%, specifically from the range of ≤15v / v%. Here, the term "v / v%" indicates the ratio between the total volume of the first layer of light-emitting material and the total volume of the first light-emitting layer (including the volume of the first layer of light-emitting material). The remainder of the first light-emitting layer may be substantially composed of a polymeric material (e.g., silicone and / or PMMA).

[0033] Furthermore, in an embodiment, the first light-emitting layer may have a first layer height H1. In an embodiment, the first layer height H1 may be selected from a range of ≥50µm, such as a range of ≥75µm, specifically a range of ≥100µm. Additionally, the first layer height H1 may be selected from a range of ≤10mm, such as a range of ≤5mm, specifically a range of ≤3mm, for example a range of ≤2mm.

[0034] In an embodiment, the first peak wavelength λp1 and the concentration C1 of the first layer luminescent material (and the first layer height H1) can be selected such that, under vertical illumination (on the first side of the first luminescent layer), a portion of the light source light (received by the first luminescent layer) at the first peak wavelength λp1 can be transmitted through the first luminescent layer. Specifically, in an embodiment, the portion of the light source light transmitted by the first luminescent layer (under vertical illumination) at the first peak wavelength λp1 can be selected from a range of ≥45%, such as ≥50%, specifically ≥55%, of the total light source light (at the first peak wavelength λp1) received by the first luminescent layer. Furthermore, in an embodiment, the portion of the light source light transmitted by the first luminescent layer (under vertical illumination) at the first peak wavelength λp1 can be selected from a range of ≥60%, for example, selected from a range of ≥65%, specifically selected from a range of ≥70%. Additionally or alternatively, in an embodiment, the portion of the light source light transmitted by the first light-emitting layer (under vertical illumination) at the first peak wavelength λp1 can be selected from ≤80% of the (total) light source light received by the first light-emitting layer (at the first peak wavelength λp1), such as a range selected from ≤75%, specifically a range selected from ≤70%, for example a range selected from ≤65%. Therefore, in an embodiment, the portion of the light source light transmitted by the first light-emitting layer (under vertical illumination) at the first peak wavelength λp1 can be selected from 45%-80% of the (total) light source light received by the first light-emitting layer (at the first peak wavelength λp1), such as a range selected from 50%-75%, specifically a range selected from 55%-70%, for example a range selected from 60%-65%. Therefore, in a specific embodiment, the first light-emitting layer may include a first layer of light-emitting material at a first layer light-emitting material concentration C1, wherein the first light-emitting layer may have a first layer height H1; wherein the first peak wavelength λp1 and the first layer light-emitting material concentration C1 may be selected such that, under vertical illumination, 55%-70% of the light source light received by the first light-emitting layer at the first peak wavelength λp1 is transmitted by the first light-emitting layer. The first light-emitting layer, configured to transmit 55%-70% of the light source light received by the first light-emitting layer at the first peak wavelength λp1, can facilitate the provision of a substantial portion of the light source light to the second light-emitting layer, thereby promoting the generation of light from the second (layer) light-emitting material.

[0035] In an embodiment, the percentage of light transmitted through the first emissive layer at the first peak wavelength λp1 may differ from the percentage of (overall) light transmitted through the first emissive layer. That is, the first emissive layer may have an average absorption coefficient for the light source (including the wavelengths it encompasses), wherein the first absorption coefficient for the first peak wavelength λp1 may be higher or lower than the average absorption coefficient. Furthermore, in an embodiment, the light source may not illuminate the first emissive layer from a direction perpendicular to the first side of the first emissive layer. For example, the light source beam may be divergent, such that the light source beam can (at least partially) illuminate the first emissive layer at an angle ≠ 90° relative to the first side of the first emissive layer. In such an embodiment, the (average) path length of the light source beam in the first emissive layer (i.e., the distance the light source beam travels between entering and leaving the first emissive layer) may be greater than in (completely) perpendicular illumination. Therefore, the first emissive layer may be further configured to specifically transmit a portion of the light source beam (the full spectral power distribution of the light source beam) under (at least partially) non-perpendicular illumination. Specifically, in an embodiment, the first light-emitting layer may be configured to transmit 50%-85%, such as 55%-80%, specifically 55%-70%, or for example 60%-70% of the light source light received by the first light-emitting layer. Therefore, in a specific embodiment, the first light-emitting layer may be configured to transmit a range selected from 55%-70% of the light source light received by the first light-emitting layer.

[0036] In an embodiment, light transmitted through the first light-emitting layer can be incident on the second light-emitting layer. Specifically, ≥95%, such as ≥99%, specifically ≥99.5%, for example ≥99.8% (including 100%) of the light transmitted through the first light-emitting layer can be incident on the second light-emitting layer. Furthermore, in an embodiment, ≥95%, such as ≥99%, specifically ≥99.5%, for example ≥99.8% (including 100%) of the light generated by the first (layer) light-emitting material (and emitted from the second side of the first light-emitting layer) can be incident on the second light-emitting layer. Therefore, in an embodiment, the second light-emitting layer can be disposed downstream of the first light-emitting layer. Furthermore, in an embodiment, the second light-emitting layer (first side) can be configured to be in physical contact with the first light-emitting layer (second side), such as being specifically disposed at the second side of the first light-emitting layer. Alternatively, the second light-emitting layer (first side) can be configured at a second non-zero distance d2 from the first light-emitting layer (second side). That is, the second light-emitting layer can be physically separated from the first light-emitting layer (second distance d2). In an embodiment, the second distance d2 can be selected from a range of ≥5µm, such as from a range of ≥15µm, specifically from a range of ≥50µm. Furthermore, the distance d1 can be selected from a range of ≤100mm, such as from a range of ≤75mm, specifically from a range of ≤50mm. Positioning the second light-emitting layer at a second (non-zero) distance d2 from the first light-emitting layer can, for example, provide improved thermal management for both the first and second light-emitting layers by promoting airflow between them. Additionally, positioning the second light-emitting layer at a second distance d2 from the first light-emitting layer can facilitate (easier) replacement of the second light-emitting layer when, for example, the second light-emitting material degrades, with a lower risk of damage to the first light-emitting layer during the replacement process.

[0037] In an embodiment, the second light-emitting layer may include a second light-emitting material, which comprises a second light-emitting material. In an embodiment, the second light-emitting material may specifically be a narrowband emitter based on tetravalent manganese (see above). That is, the second light-emitting material may include (such as) tetravalent manganese (Mn) 4+Narrowband emitter. In this document, narrowband emitter may refer to a light-emitting element configured to provide emission having an emission band having a full width at half maximum (FWHM) of ≤50 nm, specifically ≤40 nm, for example up to 35 nm (at room temperature). Therefore, in embodiments, a second luminescent material may be configured to convert a second portion of light received by the second luminescent material into second luminescent material light having at least one emission band having a second full width at half maximum (FWHM2) of up to 50 nm, such as up to 45 nm, specifically up to 40 nm, for example up to 35 nm. Furthermore, in embodiments, the second luminescent material light may have multiple emission bands. In embodiments, multiple emission bands may have a second full width at half maximum (FWHM2) of up to 50 nm, such as up to 45 nm, specifically up to 40 nm, for example up to 35 nm. Furthermore, at least one and / or multiple emission bands may have a second full width at half maximum (FWHM2) of at least 5 nm, such as at least 10 nm, specifically at least 15 nm.

[0038] In embodiments, the second luminescent material can be configured to convert a portion of the light from the light source received by the second luminescent material into light from the second luminescent material itself. This portion (light from the light source) may also be referred to herein as the "second portion". In embodiments, the second portion of the light from the light source may have a spectral power corresponding to 35%-90%, such as 45%-80%, specifically 55%-70% of the spectral power of the (overall) light from the light source (generated by the light source). Furthermore, in embodiments, the second portion of the light from the light source may have a spectral power selected from the range of ≥99%, such as the range of ≥99.5%, specifically the range of ≥99.8% (including (substantially) 100%) of the spectral power of the light from the light source received by the second luminescent material. Therefore, in embodiments, the second luminescent material can be configured to convert ≥99%, such as ≥99.5%, specifically ≥99.8% (including (substantially) 100%) of the light from the light source received by the second luminescent material into light from the second luminescent material itself. In an embodiment, the second luminescent material may (additionally) be configured to convert ≥90%, such as ≥95%, of the light source received by the second luminescent layer into second luminescent material light. Furthermore, in an embodiment, the second luminescent material may be configured to convert ≤10%, such as ≤5%, specifically ≤1%, of the light received by the second luminescent material from the first layer into second luminescent material light. In an embodiment, the second luminescent material light may have a second centroid wavelength λc2 selected from the wavelength range of 610nm-650nm, such as the wavelength range of 615nm-645nm, specifically the wavelength range of 620nm-640nm, for example, the wavelength range of 625nm-635nm.

[0039] In an embodiment, the second light-emitting material may be composed of a second light-emitting material. Alternatively, the second light-emitting material may include the second light-emitting material and one or more other light-emitting materials different from the second light-emitting material. The optional one or more other light-emitting materials from the second light-emitting layer may (individually) be selected from broadband emitters or narrowband emitters. In an embodiment, the second light-emitting material (including the second light-emitting material and optional one or more other light-emitting materials) may be configured to convert ≥99%, such as ≥99.5%, specifically ≥99.8% (including (substantially) 100%) of the light received by the second light-emitting material from the source into second-layer light-emitting material light. Furthermore, in an embodiment, the second light-emitting material may be configured to convert ≥99%, such as ≥99.5%, specifically ≥99.8% (including 100%) of the light received by the second light-emitting layer from the source into second-layer light-emitting material light. In an embodiment, the second-layer light-emitting material light may have a second-layer centroid wavelength λc. L2 In this embodiment, the wavelength of the second centroid can be equal to the wavelength of the second centroid, λc2=λc. L2 Alternative location, second-layer centroid wavelength λc L2 This can be different from the second centroid wavelength λc2. Specifically, in the embodiment, 0nm ≤ |λc2-λc L2 |≤50nm, specifically 0nm≤|λc2-λc L2 |≤40nm.

[0040] Therefore, in embodiments, the second luminescent material may include a second luminescent material, and optionally one or more other (specifically different) luminescent materials. In embodiments, the second luminescent material may include a luminescent material selected from the luminescent materials described above. Specifically, in embodiments, the second (layer) luminescent material may include M' doped with tetravalent manganese. x M 2-2x An AX6 type luminescent material, wherein M' comprises an alkaline earth cation, M comprises a basic cation, and x can be selected from the range of 0-1, wherein A comprises a tetravalent cation, such as one or more of silicon and titanium, and wherein X comprises a monovalent anion, wherein the monovalent anion comprises at least fluorine. In a specific embodiment, the second luminescent material may comprise (K,Rb)2SiF6:Mn 4+ and K2(Si,Ti)F6:Mn 4+ One or more of them. Specifically, in the embodiments, the second luminescent material may include K2SiF6:Mn 4+ Including M' x M 2-2x The second luminescent material of AX6 can exhibit relatively high efficiency and improve the color rendering index (CRI) of the system light. Furthermore, including M' x M 2-2xThe second luminescent material of AX6 can (essentially) not absorb light in the wavelength range of 505nm-590nm.

[0041] In an embodiment, the second light-emitting layer may include more second-layer light-emitting material than is required to absorb at least 98% of the light received by the second light-emitting layer (at the first peak wavelength λp1). Therefore, in an embodiment, the second light-emitting layer may include more second-layer light-emitting material than is required to transmit at most 2% of the light received by the second light-emitting layer (at the first peak wavelength λp1). Specifically, the second light-emitting layer may include at least 1.1 times, such as at least 1.2 times, for example at least 1.5 times, or specifically at least 2 times, the amount of second-layer light-emitting material required to transmit (or absorb) at most 2% (or at least 98%) of the light received by the second light-emitting layer (at the first peak wavelength λp1). Therefore, in a specific embodiment, the second light-emitting layer may include at least 1.5 times the amount of second-layer light-emitting material required to transmit at most 2% of the light received by the second light-emitting layer. A second light-emitting layer including a greater amount of second-layer light-emitting material than is required to transmit at most 2% of the light received by the second light-emitting layer can provide the beneficial effect of negligible amounts of light (e.g., (substantially) no light) being transmitted through the second light-emitting layer. Therefore, the system light may (essentially) not contain light from the source.

[0042] In an embodiment, the second light-emitting layer may (additionally) include at least five times the amount of second-layer light-emitting material required to transmit at least 2% of the light received by the second light-emitting layer (at the first peak wavelength λp1), such as at least four times, for example at least 3.5 times, specifically at least three times. Therefore, in an embodiment, the second-layer light-emitting material may include at least five times the amount of second-layer light-emitting material required to absorb at least 98% of the light received by the second light-emitting layer (at the first peak wavelength λp1), such as at least four times, for example at least 3.5 times, specifically at least three times.

[0043] In an embodiment, the second light-emitting layer may include a second light-emitting material at a concentration C2. In an embodiment, the concentration C2 of the second light-emitting material may be selected from a range of ≥3v / v%, such as from a range of ≥5v / v%, specifically from a range of ≥10v / v%. Alternatively or additionally, in an embodiment, the concentration C2 of the second light-emitting material may be selected from a range of ≤30v / v%, such as from a range of ≤25v / v%, specifically from a range of ≤20v / v%. Therefore, in an embodiment, the concentration C2 of the second light-emitting material may be selected from a range of 3v / v% to 30v / v%, such as from a range of 5v / v% to 25v / v%, specifically from a range of 10v / v% to 20v / v%. In a specific embodiment, the concentration C2 of the second light-emitting material may be selected from a range of 5v / v% to 25v / v%. The concentration C2 of this second luminescent material can be high enough that light received by the second luminescent layer will not travel along a (straight) path through the second luminescent layer without incident on the particles of the second luminescent material. Therefore, light incident on the second luminescent layer will not pass through it without incident on the second luminescent material. The remainder of the second luminescent layer can be substantially composed of polymeric materials (e.g., silicone and / or PMMA).

[0044] Furthermore, in an embodiment, the second light-emitting layer may have a second layer height H2. In an embodiment, the second layer height H2 may be selected from the range of 50µm-10 mm, such as from the range of 75µm-5 mm, and specifically from the range of 100µm-3 mm. In an embodiment, the first peak wavelength λp1 and the second layer light-emitting material concentration C2 may be selected such that under vertical illumination (on the first side of the second light-emitting layer), at least 98% of the light source light received by the second light-emitting layer at the first peak wavelength λp1 can pass through the second absorption height H2. 2a Absorbed. Therefore, the first peak wavelength λp1 and the concentration C2 of the second luminescent material can be selected such that, under vertical illumination (on the first side of the second luminescent layer), at most 2% of the light source light received by the second luminescent layer at the first peak wavelength λp1 can pass through the second absorption height H. 2a Transmitted. In an embodiment, the second absorption height H... 2a Through H 2a =0.98 / (ε2 C2) is used to determine ε2, where ε2 can be the absorption coefficient of the second luminescent material for the first peak wavelength λp1. Furthermore, in the embodiment, the height H2 of the second layer can be selected to be greater than the second absorption height H. 2a Specifically, in the embodiments, H2 ≥ 1.25 H 2a For example, H2≥1.5 H 2a , specifically H2≥2 H 2a For example, H2 ≥ 2.5 H 2a Furthermore, in the embodiments, H2 ≤ 5 H 2a Such as H2≤4 H 2a , specifically H2≤3.5 H 2a For example, H2≤3 H 2a Therefore, in a specific embodiment, the second light-emitting layer may include a second layer of light-emitting material at a second layer light-emitting material concentration C2, wherein the second light-emitting layer may have a second layer height H2; wherein the first peak wavelength λp1 and the second layer light-emitting material concentration C2 may be selected such that, under vertical illumination, at most 2% of the light source light received by the second light-emitting layer at the first peak wavelength λp1 can pass through the second absorption height H of the second light-emitting layer. 2a Transmitted, where H2 ≥ 1.5 H 2a Choose a second layer with a height H2 greater than the second absorption height H. 2a It can promote the absorption of (essentially) all of the light source light (received by the second luminescent material at the first peak wavelength λp1) by the second luminescent material.

[0045] In an embodiment, the second light-emitting layer may additionally include a secondary second absorption height H. 2a,2 In the embodiment, the secondary absorption height H 2a,2 The height of the second light-emitting layer can be defined such that at most 2% of the light received by the second light-emitting layer (within the complete spectral power distribution) can be transmitted through it. In an embodiment, 1.25 H 2a,2 ≤H2≤5 H 2a,2 Such as 1.5 H 2a,2 ≤H2≤4 H 2a,2 , specifically 2 H 2a,2 ≤H2≤3.5 H 2a,2 For example, 2.5 H 2a,2 ≤H2≤3 H 2a,2In an embodiment, the transmission (or absorption) of light from the source (at the first peak wavelength λp1) by the second light-emitting layer can be reduced (or increased) by one or more of the following: (i) increasing the height H2 of the second layer, and (ii) increasing the concentration C2 of the light-emitting material in the second layer.

[0046] In this embodiment, the height H2 of the second layer can be chosen to be greater than the height H1 of the first layer. Therefore, in this embodiment, H2 > H1, such as 0.9. H2 > H1, specifically 0.8 H2 > H1. Additionally or alternatively, in embodiments, the concentration C2 of the second layer of luminescent material can be selected to be higher than the concentration C1 of the first layer of luminescent material. Specifically, in embodiments, C2 > C1, such as 0.9. C2 > C1, specifically 0.8 C2>C1. Therefore, in a specific embodiment, for (a) the concentration C1 of the first luminescent material and the height H1 of the first layer, and (b) the concentration C2 of the second luminescent material and the height H2 of the second layer, (i) C2>C1 and (ii) H2>H1 can be applied. Choosing a second concentration C2 higher than the first concentration C1 and / or choosing a second layer height H2 greater than the first layer height H1 can provide the beneficial effect that the light from the source can be partially transmitted through the first luminescent layer, but can be (substantially) completely absorbed by the second luminescent layer.

[0047] Therefore, the light from the source can be substantially completely absorbed by both the first and second luminescent materials. Thus, in an embodiment, the system light may not include the light from the source. Alternatively, in an embodiment, the system light may include a portion of the light from the source, wherein the light from the source can provide up to 2%, such as up to 1%, specifically up to 0.5%, for example up to 0.2%, of the spectral power of the system light (in the wavelength range of 400 nm to 780 nm). In an embodiment, the system light may include the light from the first luminescent material. Furthermore, in an embodiment, the system light may include the light from the second luminescent material. The first and second luminescent material lights can (together) provide at least 99%, such as at least 99.5%, specifically at least 99.8%, for example at least 99.95% (including 100%) of the spectral power of the system light. Furthermore, in an embodiment, the first and second luminescent material lights may each have a spectral power distribution within the visible wavelength range (i.e., the range of 380 nm to 780 nm), specifically within the wavelength range of 400 nm to 780 nm. Therefore, in an embodiment, the system light can have a spectral power distribution in the visible wavelength range, such as in the 400nm-780nm wavelength range. Specifically, the system light can have a spectral power distribution in the 400nm-780nm wavelength range, wherein at least 95%, such as at least 97.5%, specifically at least 99%, for example at least 99.5% (including (substantially) 100%) of the spectral power is provided by the light from the first luminescent material and the light from the second luminescent material. Therefore, in a specific embodiment, the system light can have a spectral power distribution in the 400nm-780nm wavelength range, wherein at least 97.5% of the spectral power in the 400nm-780nm wavelength range can be provided by (i) the light from the first luminescent material generated by the first luminescent material, and (ii) the light from the second luminescent material generated by the second luminescent material.

[0048] In an embodiment, the first layer of luminescent material light may (substantially) consist of first luminescent material light. As indicated, the first luminescent material light may have a first centroid wavelength λc1 selected from the wavelength range of 505 nm to 590 nm, such as specifically selected from the wavelength range of 535 nm to 590 nm. Therefore, in an embodiment, the first luminescent material light may be yellow light or green light (or a combination thereof). Furthermore, in an embodiment, the first layer of luminescent material may include the first luminescent material and one (or more) other luminescent materials. In an embodiment, the other (or more) luminescent materials may be configured to provide orange and / or red luminescent material light. For example, the other (or more) luminescent materials may be nitrides (see above). Therefore, in an embodiment, the first layer of luminescent material light may be one or more of green, yellow, orange, and red light. Furthermore, in an embodiment, the second layer of luminescent material light may (substantially) consist of second luminescent material light having a second centroid wavelength λc2 selected from the wavelength range of 620 nm to 640 nm, such as specifically selected from the wavelength range of 625 nm to 635 nm. Therefore, in an embodiment, the second luminescent material light can be red light. Furthermore, in an embodiment, the first and second luminescent material lights can (together) provide at least 95%, such as at least 97.5%, specifically at least 99%, for example at least 99.5% (including substantially 100%) of the spectral power of the system light, specifically in the wavelength range of 400 nm to 780 nm. Therefore, in a specific embodiment, the first luminescent material light can be yellow or green light, the second luminescent material light can be red light, and the system light can have a spectral power distribution in the wavelength range of 400 nm to 780 nm, wherein at least 99% of the spectral power is provided by the first and second luminescent material lights. The system light in which at least 99% of the spectral power is provided by the first and second luminescent material lights can provide a yellow-orange system light. Such a system light can be advantageous, for example, for applications in photolithography cleanrooms, where light with a blue (and / or purple) component damages materials and / or causes unwanted reactions.

[0049] In embodiments, the system light may therefore include a green and / or yellow component (primarily provided by the light from the first (layer) luminescent material) and a red component (primarily provided by the light from the second (layer) luminescent material). Furthermore, the system light may include (substantially) no blue component. The terms "blue light" or "blue emission" and similar terms may specifically refer to light having wavelengths in the range of about 440 nm to 490 nm. The terms "green light" or "green emission" and similar terms may specifically refer to light having wavelengths in the range of about 490 nm to 560 nm. The terms "yellow light" or "yellow emission" and similar terms may specifically refer to light having wavelengths in the range of about 560 nm to 590 nm. The terms "orange light" or "orange emission" and similar terms may specifically refer to light having wavelengths in the range of about 590 nm to 620 nm. The terms "red light" or "red emission" and similar terms may specifically refer to light having wavelengths in the range of about 620 nm to 780 nm. The phrase "light having wavelengths within a wavelength range" and similar phrases can specifically indicate that the indicated light (or radiation) has a spectral power distribution having one or more intensities at least within the indicated wavelength range. For example, a solid-state light source emitting blue light would have a spectral power distribution with intensities at least within the wavelength range of 440 nm to 495 nm. Therefore, in embodiments, system light comprising (substantially) no blue (and / or violet) component can have a spectral power distribution with no or almost no intensity in the wavelength range of 400 nm to 490 nm. Thus, in embodiments, the majority of the spectral power of the system light can be provided in the wavelength range of 490 nm to 780 nm, such as in the wavelength range of 500 nm to 780 nm, specifically in the wavelength range of 505 nm to 780 nm. Specifically, the system light can have a spectral power distribution in the wavelength range of 400 nm to 780 nm, wherein at least 95%, such as at least 97.5%, specifically at least 98%, of the spectral power is provided in the wavelength range of 490 nm to 780 nm. Furthermore, in embodiments, the system light may have a spectral power distribution in the wavelength range of 400 nm to 780 nm, wherein at least 99%, such as at least 99.5%, specifically at least 99.8% (including (substantially) 100%) of the spectral power is provided in the wavelength range of 490 nm to 780 nm.

[0050] In embodiments, light comprising a (relatively) small blue component (i.e., relatively low spectral power provided in the 440nm-490nm wavelength range) can have a lower CCT compared to light having a (relatively) large blue component. Conversely, light comprising a (relatively) large red (and / or orange) component can have a lower CCT compared to light having a (relatively) small red (and / or orange) component. Therefore, in embodiments, system light in which ≥95% of the spectral power of the system light is provided in the 490nm-780nm wavelength range can provide white light with a relatively low correlated color temperature (CCT) (small blue component). Specifically, in embodiments, the system light can have a correlated color temperature selected from the range ≤2800K, such as the range ≤2700K, specifically the range ≤2500K, for example, the range ≤2300K. Furthermore, as described above, the first luminescent material light can have an emission band having a first centroid wavelength λc1 selected from the 535nm-590nm wavelength range. Therefore, in embodiments, the system light can include a green component. Therefore, the CCT of the system light can be selected from the range of ≥1200K, such as the range of ≥1300K, specifically the range of ≥1500K, for example, the range of ≥1600K. In a specific embodiment, the CCT of the system light can be selected from the range of ≥1700K, such as the range of ≥1800K. Furthermore, in an embodiment, the correlated color temperature of the system light can therefore be selected from the range of 1200K-2800K, such as the range of 1300K-2700K, specifically the range of 1500K-2500K, for example, the range of 1500K-2300K. Therefore, in a specific embodiment, the first centroid wavelength λc1 can be selected from the wavelength range of 535nm-590nm, and the system light can have a correlated color temperature selected from the range of 1500K-2300K. System light with a CCT in the range of 1500K-2300K can be particularly advantageous for applications where blue light can be harmful to the environment. For example, in photolithography cleanrooms or chemical laboratories, blue light can cause material degradation and / or trigger unwanted reactions. Furthermore, for example, in road lighting, blue light contributes relatively more to light pollution and can affect the (natural) behavior and rhythms of wildlife. Therefore, a light generation system providing system light with a CCT of ≤2300K can have the advantage of providing (reliable) (substantially) blue-free white light for such and other applications.

[0051] Furthermore, in an embodiment, the first luminescent material light may have an emission band having a first centroid wavelength λc1 selected from the wavelength range of 505 nm to 520 nm. In such an embodiment, the system light may have a CCT selected from the range of 2000 K to 2800 K, such as from 2150 K to 2750 K, and specifically from the range of 2350 K to 2700 K. Therefore, in a specific embodiment, the first centroid wavelength λc1 may be selected from the wavelength range of 505 nm to 520 nm, and the system light may have a correlated color temperature selected from the range of 2350 K to 2700 K. Such a system light may (still) provide blue light-free illumination (i.e., light including 0% to 2% blue light), but may have a higher correlated color temperature due to the green component in the system light. Thus, such a system light may appear to have less orange-red compared to a system light with a CCT selected from the range of 1500 K to 2300 K.

[0052] In an embodiment, the correlated color temperature (CCT) of the system light can be determined (at least partially) by the percentage of light source light absorbed (and converted) by the first (layer) luminescent material. Specifically, as described above, the first (layer) luminescent material light can be yellow and / or green light, and the second (layer) luminescent material light can be red light. Furthermore, in an embodiment, ≥98% of the light source light can be absorbed by both the first (layer) and second (layer) luminescent materials. Therefore, by increasing the percentage of light source light absorbed (and converted) by the first (layer) luminescent material (providing yellow and / or green light), the CCT of the system light can be increased because a smaller percentage of the light source light can still be absorbed (and converted) by the second (layer) luminescent material to provide red second (layer) luminescent material light. For example, a light generation system in which 30% of the light source light is absorbed by the first (layer) luminescent material and ≥68% of the light source light is absorbed by the second (layer) luminescent material can provide system light with a CCT of 1750K. Conversely, a light generation system in which 39% of the light source is absorbed by the first (layer) luminescent material and ≥59% of the light source is absorbed by the second (layer) luminescent material can provide system light with a CCT of 2000K. Furthermore, in an embodiment, a light generation system in which 49% of the light source is absorbed by the first (layer) luminescent material and ≥49% of the light source is absorbed by the second (layer) luminescent material can provide system light with a CCT of 2500K. In a specific embodiment, the system light can have a CCT in the range of 1750K to 2500K or even wider (e.g., 1500K-2500K, such as 1300K-2700K).

[0053] In embodiments, the system light may additionally have a color rendering index (CRI) selected from a range of at least 35, such as a range selected from at least 40, specifically a range selected from at least 45. Furthermore, the system light may have a CRI selected from a range of at least 50, such as a range selected from at least 55, specifically a range selected from at least 60. Therefore, in specific embodiments, the system light may have a CRI of at least 50 and a correlated color temperature in the range of 1700K to 2500K. In embodiments, as known to those skilled in the art, the CRI can be determined using multiple test color samples (TCS). In embodiments, the multiple TCS may include a TCS09 with saturated red. In embodiments, TCS09 can be used to evaluate the light source's reproduction of saturated red by calculating the CRI R9 value, where a higher (positive) number indicates better reproduction of saturated red (TCS09). In embodiments, light with a relatively large red component may have a (higher) positive R9 value, while light with a relatively low red component may have a negative R9 value. In embodiments, specifically where the CCT is in the range of 1700K to 2500K, the system light can have a positive R9 value. Furthermore, in embodiments, the system light can be within 20 standard deviations (SDCM) of color matching from the blackbody trajectory (BBL), such as within 15 SDCMs from the BBL, specifically within 10 SDCMs from the BBL. In a specific embodiment, the system light can be within 10 SDCMs from the BBL and has a CCT in the range of 1700K to 2500K.

[0054] As indicated above, a light generation system may include a light source configured to generate (blue or purple) light. Some general aspects related to the light source are described below.

[0055] The term "light source" can, in principle, refer to any light source known in the art. In specific embodiments, light sources include solid-state light sources (such as light-emitting diodes (LEDs) or laser diodes (or "diode lasers")). The term "light source" can also refer to multiple (substantially identical (or different)) light sources, such as 2 to 2000 (solid-state) (LED) light sources. The phrases "different light sources" or "multiple different light sources" and similar phrases in embodiments can refer to multiple solid-state light sources selected from at least two different sorting zones. Similarly, the phrases "identical light sources" or "multiple identical light sources" and similar phrases in embodiments can refer to multiple solid-state light sources selected from the same sorting zone. Therefore, the term LED can also refer to multiple LEDs.

[0056] The light source may include a solid-state die (such as an LED) in the embodiments. The die size may be equal to or less than 2 mm, such as in the range of, for example, 0.2 mm to 2 mm. In this document, the term "light source" may also specifically refer to a small solid-state light source, such as one having a small or micro size. For example, a light source may include one or more of small LEDs and micro LEDs, such as specifically a micro LED or "microLED" or "µLED". In this document, the terms small size or small LED specifically refer to a solid-state light source having dimensions (such as die size, specifically length and width) selected from the range of 100 µm to 1 mm. In this document, the terms µ size or micro LED specifically refer to a solid-state light source having dimensions (such as die size, specifically length and width) selected from the range of 100 µm and smaller.

[0057] A light source can have a light-escape surface. For an LED, this could be, for example, the LED die, or, when resin is applied to the LED die, the outer surface of the resin. In principle, it could also be the end of an optical fiber. The term "escape surface" specifically refers to a portion of the light source where light actually leaves or escapes from the light source. The light source is configured to provide a light beam. This light beam (and therefore) escapes from the light-escape surface of the light source. Similarly, a light-generating system can include a light-escape surface, such as an end window.

[0058] The term "light source" can refer to semiconductor light-emitting devices, such as light-emitting diodes (LEDs), resonant cavity light-emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs), edge-emitting lasers, etc. The term "light source" can also refer to organic light-emitting diodes (OLEDs), such as passive substrate (PMOLEDs) or active substrate (AMOLEDs). In embodiments, the light source includes LEDs. The term "light source" or "solid-state light source" can also refer to superluminescent diodes (SLEDs). Furthermore, the term "light source" or "solid-state light source" can refer to multi-junction light-emitting diodes (or "multi-junction LEDs"). A multi-junction LED can be a single (LED) die comprising multiple junctions connected in series, and the single (LED) die can be (directly) connected to a power supply providing alternating current (AC). Specifically, the terms "solid-state light source" or "solid-state material light source" and similar terms can refer to semiconductor light sources, such as light-emitting diodes (LEDs), laser diodes, superluminescent diodes, or multi-junction LEDs. Therefore, in specific embodiments, the light source can be selected from the group consisting of light-emitting diodes, laser diodes, superluminescent diodes, and multi-junction light-emitting diodes.

[0059] In embodiments, the light source may include one or more micro-optical elements (microlens arrays) downstream of a single solid-state light source (such as an LED) or downstream of multiple solid-state light sources (i.e., shared by multiple LEDs). In embodiments, the light source may include an LED with on-chip optics. In embodiments, the light source includes pixelated individual LEDs (with or without optics) (providing on-chip beam steering in embodiments).

[0060] In embodiments, the light source can be configured to provide primary radiation, which is used as, for example, a blue light source (e.g., a blue LED), or a green light source (e.g., a green LED) and a red light source (e.g., a red LED). Such LEDs, which may not include a luminescent material (“phosphor”), can be designated as straight-color LEDs. In embodiments, the light source can be one that emits (blue) light during operation at least at a wavelength selected from the 380 nm–470 nm range. However, other wavelengths are also possible.

[0061] In one embodiment, the light source may be selected from the group consisting of laser diodes and superluminescent diodes. In other embodiments, the light source may include an LED. Specifically, the light source may be configured to generate light having an optical axis (O), (beam shape), and spectral power distribution. The light source may include one or more spectral bands in an embodiment, each having a bandwidth as known for lasers.

[0062] The term "light source" can therefore refer to the light-generating element itself, such as a solid-state light source, or the package of a light-generating element (such as a solid-state light source), as well as (other) optical devices, such as lenses and collimators. In embodiments, the term "light source" can also refer to a combination of a light source (e.g., an LED) and an optical filter that can alter the spectral power distribution of the light generated by the light source. Specifically, the term "light-generating device" can be used to refer to a light source as well as additional optical components, such as optical filters and / or beamforming elements.

[0063] In embodiments, the light generation system may include multiple light sources, such as ≥2 light sources, for example ≥4 light sources, specifically ≥6 light sources. Furthermore, in embodiments, the light generation system may include ≤2000 light sources, such as ≤1500 light sources, specifically ≤1000 light sources. In embodiments, the multiple light sources may be arranged in a chip-on-board (CoB) system. Therefore, in embodiments, the light generation system may include a chip-on-board (CoB). The term "CoB" specifically refers to an LED chip in the form of a semiconductor chip that is neither encapsulated nor connected, but directly mounted on a substrate (such as a printed circuit board (PCB)). Therefore, multiple 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. Therefore, in embodiments, a CoB may include multiple light sources. Furthermore, in embodiments, a CoB may include a first light-emitting layer. The first light-emitting layer may specifically be configured on top of the multiple light sources. In a specific embodiment, the first light-emitting layer may be (at least partially) configured to physically contact the plurality of light sources (of the CoB). Furthermore, in an embodiment, the CoB may include a second light-emitting layer. In such an embodiment, the second light-emitting layer may be specifically configured on top of the first light-emitting layer (and physically contact the first light-emitting layer). Alternatively, the first light-emitting layer may be configured on top of the plurality of light sources (and physically contact the plurality of light sources), and the second light-emitting layer may be configured at a non-zero second distance d2 from the second side of the first light-emitting layer. However, in other embodiments, the first side of the second light-emitting layer may be configured to physically contact the second side of the first light-emitting layer. Therefore, in a specific embodiment, the light generation system may include an on-board chip (CoB), wherein the on-board chip (CoB) may include (i) a plurality of light sources, (ii) a first light-emitting layer, and (iii) a second light-emitting layer, wherein the first light-emitting layer may be configured on top of the plurality of light sources, and wherein the second light-emitting layer may be configured on top of the first light-emitting layer. A light generation system including a CoB can provide the advantage that a single first (and second) light-emitting layer can be configured to cover multiple light sources. This can have the advantage of not having to provide a separate first (and second) emitting layer for each (or multiple) light source. Furthermore, since the first emitting layer can be (directly) positioned on top of multiple light sources, the risk of light from the light source being transmitted (or "leaked") after the first emitting layer can be (further) reduced.

[0064] Furthermore, in embodiments, the light generating system may include an LED filament. LED filaments are known in themselves and are described, for example, in US 8,400,051 B2, WO2020016058, WO2019197394, etc., which are incorporated herein by reference. Generally, the LED filament in embodiments may include: (i) a plurality of light-emitting diodes (LEDs), specifically arranged in a (linear) array, arranged on at least a first main surface of an elongated carrier; and (ii) an elongated package covering the plurality of LEDs and covering at least a portion of the elongated carrier. Therefore, in embodiments, the LED filament may include a plurality of light sources (of the light generating system), wherein the plurality of light sources may specifically be light-emitting diodes (LEDs). In embodiments, the plurality of light sources may be configured in an array (see below). Furthermore, the LED filament may include a first light-emitting layer. The first light-emitting layer may specifically be configured as a first elongated package. Therefore, the first light-emitting layer can be configured to surround a plurality of light sources, such as specifically covering a plurality of light sources. Furthermore, in embodiments, the LED filament may include a second light-emitting layer. In embodiments, the second light-emitting layer may be configured as a second elongated package covering the first light-emitting layer (i.e., the first elongated package). Therefore, the second light-emitting layer may be configured to surround (at least partially) the first light-emitting layer. Alternatively, in embodiments, the first light-emitting layer may be configured to cover the first elongated package of the plurality of light sources, and the second light-emitting layer may be configured away from the first light-emitting layer (i.e., at a non-zero second distance d2), for example, the second light-emitting layer may be configured in and / or at the light emanating surface of the light-generating system. Therefore, in specific embodiments, the light-generating system may include an LED filament, wherein the LED filament may include: (i) a plurality of light sources, wherein the plurality of light sources may be configured in an array, and wherein the plurality of light sources may be light-emitting diodes (LEDs); (ii) the first light-emitting layer; and (iii) the second light-emitting layer, wherein the first light-emitting layer may be configured to surround the plurality of light sources, and wherein the second light-emitting layer may be configured to surround the first light-emitting layer. Light generation systems incorporating LED filaments offer the advantage of being easily integrated into and / or used in existing light bulbs, lamps, and luminaires. Furthermore, LED filaments can be configured to provide light in all directions, allowing a single light generation system to illuminate a larger area.

[0065] In this embodiment, the LED filament can be controlled by the filament length L. F filament width W F and filament thickness T F To limit. The LED filament may also include a filament elongation axis A. F Filament elongation axis AF Specifically, the linear axis can be defined as the direction in which the LED filament is elongated. Filament elongation axis A F The shaft length L can be limited. A Where the axis length L A It can be the LED filament along the filament elongation axis A F The length of the filament. In some embodiments, the LED filament can be straight. In a straight embodiment, the filament length L F It can be (basically) equivalent to the shaft length L A In other embodiments, the LED filament can be bent. For example, the filament can have a (2D or 3D) helical shape, (e.g.) a coil shape, or other bent shapes. In bent embodiments, the axial length L A It can be less than the filament length L F Such as L A / L F ≤0.95, specifically L A / L F ≤0.75, more specifically L A / L F ≤0.55. Furthermore, LED filaments can have a relatively high aspect ratio (L / V). F / W F Or L F / T F For example, at least 5, such as at least 10, specifically at least 15, such as at least 20, more specifically at least 50. A large aspect ratio can better simulate a filament. However, in the embodiments, the aspect ratio (L) is... F / W F and / or L F / T F The number can be up to 900, such as up to 650, specifically up to 500. Therefore, in a specific embodiment, 5 W F ≤L F ≤900 W F And 5 T F ≤L F ≤900 T F In this embodiment, the LED filament may have a light-emitting surface, which may extend along the filament length L. F The light-emitting surface extends and preferably at least partially surrounds the elongation axis. In embodiments, the light-emitting surface may preferably be arranged to emit light uniformly and / or omnidirectionally.

[0066] Furthermore, as indicated, the LED filament may include an elongated carrier, a solid-state light source, and an encapsulation. Specifically, the elongated carrier may support the solid-state light source. The elongated carrier may, for example, include glass, quartz, metal, or sapphire. In other embodiments, the elongated carrier may, for example, include a polymeric material or a (flexible) metal, such as a film or foil. The elongated carrier may be rigid (self-supporting) but may also (in polymeric embodiments) be flexible. In embodiments, the elongated carrier may be light-transmitting, translucent, or transparent to light, especially visible light. Alternatively, in embodiments, the carrier may be light-reflective, specifically reflecting one or more of the light source light and the LED filament light (see below), such as reflecting at least the light source light and the LED filament light. In specific embodiments, the carrier may be diffusely reflective. The elongated carrier may have dimensions (substantially) similar to those of the LED filament. Specifically, the elongated carrier may (substantially) define the filament length L of the LED filament. F and shaft length L A The width W of the LED filament F and thickness T F It can be defined by an elongated carrier and other components of the LED filament (e.g., a solid-state light source and (first and second) encapsulations). In an embodiment, the (elongated) carrier may include a first main surface at a first side of the carrier and a second main surface at a second side of the carrier, the second side being opposite to the first side. In an embodiment, the solid-state light source may be disposed on at least one of these surfaces. Thus, in an embodiment, at least a portion (such as all) of the (plural) solid-state light sources may be mounted on the first main surface. Additionally or alternatively, at least a portion of the solid-state light source may be mounted on the second main surface. Thus, in an embodiment, the solid-state light source may be disposed, mounted, and / or mechanically coupled to / to the carrier, wherein the carrier may be specifically configured to mechanically and / or electrically support the LED.

[0067] In this embodiment, the solid-state light source may include an LED. Alternatively or additionally, in this embodiment, the solid-state light source may include a diode laser. Furthermore, the LED filament may include one or more of LEDs, laser diodes, and superluminescent diodes. Specifically, the LED filament may include multiple light-emitting diodes (LEDs). Multiple solid-state light sources may be arranged in array 100 (on an elongated carrier), specifically along (at least partially) the filament length L. F Above. The number of solid-state light sources in the array can be at least 4, such as at least 8, or even more specifically at least 12, and can, for example, up to 100, or even more. Specifically, in embodiments, the number of solid-state light sources in the array can be selected from the range of 10-2000, such as from the range of 10-1500, and specifically from the range of 10-1000. In embodiments, the solid-state light sources can be configured at filament length LF In at least a portion of the 1D (linear) array. When measured along the LED filament, the first solid-state light source and the last solid-state light source can have at least 0.5L. F or even more specifically, at least 0.7L F The mutual distance. Furthermore, in this embodiment, the solid-state light source can be configured in two 1D arrays, one 1D array on the first main surface of the elongated carrier, and the other 1D array on the second main surface. A 2D array of m solid-state light sources is also possible. In embodiments, n can be selected from the range of 1-4, such as 1-3, for example 1-2, such as 1 in one embodiment or 2 in another, and m can be selected from a range greater than n, such as specifically from a range of at least 4 (when n < 4), for example at least 6, such as at least 8. Therefore, the 2D array of solid-state light sources can specifically have a number of rows (n) smaller (m smaller) than the number of solid-state light sources (m) in these corresponding rows, such as n / m ≤ 0.2, for example n / m ≤ 0.1, specifically n / m ≤ 0.05.

[0068] In an embodiment, the LED filament may include a (first) encapsulation. The (first) encapsulation may specifically (at least partially) cover a plurality of solid-state light sources. Furthermore, the (first) encapsulation may (at least partially) cover at least a portion of an elongated carrier, such as covering at least one (partial) of a first main surface and a second main surface. Overall, the (first) encapsulation may contact the elongated carrier and may cover all solid-state light sources. Therefore, in an embodiment, the (first) encapsulation may be configured at the filament length L of the LED filament. F Most of the time (such as in filament length L) F (More than 70%). (First) The encapsulation may be located on one or both of the first and second main surfaces of the (elongated carrier) along the filament length L. F A continuous coating. Furthermore, the encapsulation may at least partially cover the solid-state light source, such as covering at least 50% of the total number of solid-state light sources in the array in the embodiments, such as at least 75%, specifically at least 95%, and up to 100%.

[0069] In an embodiment, the (first) encapsulation may include one or more of a luminescent material (specifically, a first layer of luminescent material) and a light-scattering material. One or more of the luminescent material and the light-scattering material may be specifically configured to be embedded in an encapsulation material (e.g., a (flexible) polymer material (such as silicone)). Furthermore, in an embodiment, the light-scattering material may be configured to specifically scatter (or “diffuse”) light from the source source (and / or the first layer of luminescent material) in a direction transverse to the normal to the (first and / or second) main surface. In a specific embodiment, the light-scattering material may include light-scattering particles, such as at least one of, for example, BaSO4, Al2O3, and TiO2 particles.

[0070] In an embodiment, the LED filament may further include a second encapsulation, wherein the second encapsulation may specifically include, for example, a second light-emitting layer. The second encapsulation may be configured to (at least partially) cover the first encapsulation. Therefore, in an embodiment, the second encapsulation may be configured at the filament length L of the LED filament. F Above most of (such as above ≥70%, for example above ≥80%, specifically above ≥90%), including (basically) filament length L F (100%). The second encapsulation may be located on one or both of the first and second main surfaces along the filament length L. F A continuous coating. Furthermore, the encapsulation may at least partially cover the first encapsulation (including the first light-emitting layer), such as covering at least 50% of the total surface area of ​​the first encapsulation in the embodiments, such as at least 75%, specifically at least 95%, and up to 100%.

[0071] In embodiments, an LED filament can be configured to generate filament light, which may include one or more of (scattered) light from a first layer of luminescent material and light from a second layer of luminescent material. The term "LED filament light" may refer to the light emitted by the LED filament during operation. In embodiments, system light may include LED filament light. Furthermore, in embodiments, system light may consist of LED filament light. Specifically, LED filament light may be system light. Additionally, solid-state light sources included by the LED filament can be configured to generate light source light. In embodiments, at least two (such as all) of the solid-state light sources can be configured to emit light source light with different spectral power distributions. In other embodiments, at least two (such as all) of the solid-state light sources can be configured to provide light source light having substantially the same spectral power distribution. In embodiments, an LED filament may include multiple sub-filaments.

[0072] In embodiments, the light generation system may include multiple (solid-state) light sources. The multiple light sources may include a first subset of one or more light sources, a second subset of one or more light sources, a third subset of one or more light sources, etc. In embodiments, the subsets of one or more light sources may be individually controllable. Furthermore, in embodiments, the subsets of one or more light sources may be configured, for example, in different CoB systems and / or different sub-filaments. Specifically, in embodiments, each subset of one or more light sources may be configured to have a light-providing relationship with a (separate) first emitting layer and / or a (separate) second emitting layer. Thus, the first emitting layer may include multiple first emitting layer segments, wherein each first emitting layer segment is configured to have a light-receiving relationship with a subset of one or more light sources. Similarly, the second emitting layer may include multiple second emitting layer segments, wherein each second emitting layer segment is configured to have a light-receiving relationship with a subset of one or more light sources. In embodiments, each of the first emitting layer segments and / or each of the second emitting layer segments may be configured to generate light (when illuminated by light from the light source) from first and / or second emitting materials with different optical properties. For example, the primary first luminescent layer segment may include a first luminescent material with a different composition and / or concentration compared to the secondary first luminescent layer segment. Similarly, the primary second luminescent layer segment may include a second luminescent material with a different composition (and / or concentration) compared to the secondary second luminescent layer segment. Therefore, in embodiments, the light generation system may include a plurality of light generation modules, wherein each light generation module includes: (i) one or more light sources; (ii) a first luminescent layer segment; and (iii) a second luminescent layer segment; and wherein each light generation module is configured to generate module light. In embodiments, the light generation system may include 2 to 10 light generation modules, such as 2 to 8 light generation modules, specifically 2 to 6 light generation modules.

[0073] In this document, the phrase "in a first operating mode of the light generation system" and similar phrases may refer to an embodiment in which the light generation system may have only a single operating mode, and may also refer to an embodiment in which the light generation system may have one or more other operating modes. In another operating mode, the system light may or may not include both first luminescent material light and second luminescent material light. The phrase "the system light includes first luminescent material light and second luminescent material light" may refer to an embodiment in which the system light is substantially composed of first luminescent material light and second luminescent material light, but may also refer to an embodiment in which the system light includes one or more other types of light in addition to first luminescent material light and second luminescent material light.

[0074] In embodiments, the module light from each light generation module in the light generation modules may differ in one or more of the following: radiant flux, color point, spectral power distribution, and correlated color temperature. Furthermore, in embodiments, the system light may include module light. Additionally, in embodiments, the light generation system may include a control system. The control system may be configured to control a plurality of light generation modules. Therefore, in embodiments, the control system may be configured to control the system light by adjusting the module light generated by each light generation module in the light generation modules. Specifically, the control system may be configured to control one or more of the following: radiant flux, color point, CCT, and spectral power distribution of the system light.

[0075] In embodiments, the control system may also be configured to monitor the spectral power distribution of the system light. Specifically, in embodiments, the control system may be configured to monitor the spectral power of the system light in the wavelength range of 400 nm to 490 nm. Furthermore, in embodiments, the control system may be configured to provide a warning and / or shut down the light generation system when a preset threshold for the spectral power (provided in the wavelength range of 400 nm to 490 nm) is exceeded. The term "control" and similar terms specifically refer at least to determining the behavior of an element or supervising the operation of an element. Thus, in this document, "control" and similar terms may, for example, refer to imposing behavior on an element, such as measuring, displaying, actuating, turning on, moving, changing temperature, etc. In addition, the term "control" and similar terms may also include monitoring. Thus, the term "control" and similar terms may include imposing behavior on an element and monitoring the element. Control of the element can be accomplished using a control system, which may also be referred to as a "controller". The control system and the element can thus be functionally coupled, at least temporarily or permanently. The element may include the control system. In embodiments, the control system and the element may not be physically coupled. Control can be achieved via wired and / or wireless control. The term "control system" can also refer to multiple different control systems that are specifically functionally coupled, where, for example, one control system can be a master control system and one or more other control systems can be slave control systems. A control system may include a user interface or may be functionally coupled to a user interface.

[0076] The control system can also be configured to receive and execute commands from a remote control. In embodiments, the control system can be controlled via an application on a device, such as a portable device like a smartphone, iPhone, or tablet. The device is therefore not necessarily coupled to the lighting system, but can be (temporarily) functionally coupled to it. In such embodiments, the control system for the lighting system can be a slave control system or controlled in slave mode.

[0077] A system, apparatus, or device may perform actions in a “mode,” “operating mode,” “mode of operation,” or “operable mode.” The term “operable mode” may also refer to “control mode.” Similarly, in a method, actions, stages, or steps may be performed in a “mode,” “operating mode,” “mode of operation,” or “operable mode.” This does not preclude the system, apparatus, or device from being adapted to provide another control mode or multiple other control modes. Similarly, this does not preclude one or more other modes from being performed before and / or after the execution of a particular mode.

[0078] However, in embodiments, a control system may be available, and the control system may be adapted to provide at least one control mode. If other modes are available, the selection of such modes may be specifically performed via a user interface; however, other options (e.g., performing modes based on sensor signals or (time) schemes) may also be possible. In embodiments, "operation mode" may also refer to a system, device, or apparatus that can operate only in a single operating mode (i.e., "on," without additional tunability). Therefore, in embodiments, the control system may be controlled based on one or more of the user interface input signals, sensor signals (sensor signals), and timers. The term "timer" may refer to a clock and / or a predetermined timing scheme.

[0079] A light generating system may be part of, or be applied to, systems such as: office lighting systems, home application systems, shop lighting systems, household lighting systems, accent lighting systems, spotlight lighting systems, theater lighting systems, fiber optic application systems, projection systems, self-emissive display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, signage systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, greenhouse lighting systems, horticultural lighting, digital projection, or LCD backlighting. A light generating system (or luminaire) may be part of, or be applied to, an optical communication system. Therefore, in another aspect, the present invention also provides lamps or luminaires that include a light generating system as defined herein. The luminaire may further include a housing, optical elements, a light-transmitting grating, etc. The lamp or luminaire may also include a housing surrounding the light generating system. The lamp or luminaire may include a light window or housing opening in the housing through which system light can escape from the housing. In another aspect, the present invention also provides projection devices that include a light generating system as defined herein. Specifically, a projection device, or "projector" or "image projector," can be an optical device that projects an image (or moving image) onto a surface (such as, for example, a projection screen). The projection device may include one or more light generating systems as described herein. Therefore, in one aspect, the invention also provides a lighting device selected from the group consisting of lamps and luminaires, the lighting device including the light generating system as defined herein. Furthermore, in embodiments, the lighting device may be selected from the group consisting of lamps, luminaires, projector devices, photochemical reactors, and optical wireless communication devices, wherein the lighting device may include the light generating system as defined herein. The lighting device may include a housing or carrier configured to house or support one or more elements of the light generating system. In a specific embodiment, the lighting device may be a lamp or luminaire for cleanroom applications. Attached Figure Description

[0080] Embodiments of the invention will now be described by way of example only, with reference to the accompanying schematic diagrams, in which corresponding reference numerals indicate corresponding parts, and in the drawings:

[0081] Figure 1 An embodiment of the light generation system is schematically depicted;

[0082] Figure 2 schematically depicts an embodiment including an LED filament and CoB, which incorporate a light generation system;

[0083] Figure 3 Another embodiment of the light generation system is schematically depicted;

[0084] Figure 4An embodiment of the system light is schematically depicted; and

[0085] Figure 5 An embodiment of a lighting device is schematically depicted.

[0086] The diagram is not necessarily drawn to scale. Detailed Implementation

[0087] Figure 1 An embodiment of the light generation system 1000 of the present invention is schematically depicted. In this embodiment, the light generation system 1000 may include a light source 10, a first light-emitting layer 2100, and a second light-emitting layer 2200. The light source 10 may be specifically configured to generate light source light 11. In this embodiment, the light source light 11 may have a first peak wavelength λp1 selected from the wavelength range of 400 nm to 490 nm. Specifically, the first peak wavelength λp1 may be selected from the wavelength range of 420 nm to 475 nm. Furthermore, the light source 10 may include a solid-state light source. Specifically, the light source 10 may be selected from the group consisting of light-emitting diodes, laser diodes, superluminescent diodes, and multi-junction light-emitting diodes. In this embodiment, the first light-emitting layer 2100 may be disposed downstream of the light source 10. Furthermore, the first light-emitting layer 2100 may include a first light-emitting material 2110, which includes a first light-emitting material 210. The first light-emitting material 210 may be configured to convert a first portion of the light source light 11 received by the first light-emitting material 210 into first light-emitting material light 211. In an embodiment, the first luminescent material 211 may have an emission band having a first centroid wavelength λc1 selected from the wavelength range of 505 nm to 590 nm. Furthermore, in an embodiment, the first luminescent material 211 may have an emission band having a first full width at half maximum (FWHM1) of at least 50 nm. In an embodiment, the second luminescent layer 2200 may be disposed downstream of the first luminescent layer 2100 (and the light source 10). In an embodiment, the second luminescent layer 2200 may include a second luminescent material 2220, which includes the second luminescent material 220. The second luminescent material 220 may specifically include M' doped with tetravalent manganese. x M 2-2x AX6, wherein M' comprises an alkaline earth cation, M comprises a basic cation, A comprises a tetravalent cation, and X comprises a monovalent anion, the monovalent anion comprising at least fluorine (F). Specifically, the second luminescent material 220 may comprise (K,Rb)2SiF6:Mn 4+ and K2(Si,Ti)F6:Mn 4+ One or more of them (wherein the second luminescent material 220 specifically includes K2SiF6:Mn) 4+Furthermore, the second luminescent material 220 can be configured to convert a second portion of the light source light 11 received by the second luminescent material 220 into second luminescent material light 221. The second luminescent material light 221 may have at least one emission band having a second full width at half maximum (FWHM2) of up to 40 nm. Furthermore, the second luminescent material light 221 may have a second centroid wavelength λc2 selected from the wavelength range of 620 nm to 640 nm. In an embodiment, the second luminescent layer 2200 may include at least 1.2 times the amount of second luminescent material 2220 required to transmit up to 2% of the light source light 11 (at the first peak wavelength λp1) received by the second luminescent layer 2200. Specifically, the second luminescent layer 2200 may include at least 1.5 times the amount of second luminescent material 2220 required to transmit up to 2% of the light source light 10 (at the first peak wavelength λp1) received by the second luminescent layer 2200. In an embodiment, the light generation system 1000 can be configured to generate system light 1001 in a first operating mode of the light generation system 1000. The system light 1001 includes a first luminescent material light 211 and a second luminescent material light 221. In an embodiment, the system light 1001 may have a correlated color temperature selected from the range of 1300K-2700K.

[0088] In an embodiment, the first luminescent material 210 may include A3B5O. 12 The luminescent material is of the Ce type, wherein A includes one or more of Y, La, Gd, Tb, and Lu, and wherein B includes one or more of Al, Ga, In, and Sc. Furthermore, in embodiments, the first luminescent material 210 may include (Y... x11 Lu x12 A' x13 Ce x14 )3B5O 12 Type of primary first luminescent material and (Y x21 Lu x22 A' x23 Ce x24 )3B5O 12 The secondary primary luminescent material of the type, wherein A' comprises one or more of La, Gd, and Tb, and wherein B comprises one or more of Al, Ga, In, and Sc. In such an embodiment, x 11 +x 12 +x 13 +x 14 =1; x 11 +x 12 >0; 0≤x 13 <1; and 0.001≤x 14 ≤0.1. Furthermore, in such an embodiment, x21 +x 22 +x 23 +x 24 =1; x 21 +x 22 >0; 0≤x 23 <1; and 0.001≤x 24 ≤0.1. Furthermore, in the embodiments, x 11 >x 21 And x 22 >x 12 In an embodiment, the first light-emitting layer 2100 may include a first layer of light-emitting material 2110 at a first layer light-emitting material concentration C1. Additionally, the first light-emitting layer 2100 may have a first layer height H1. The first peak wavelength λp1 and the first layer light-emitting material concentration C1 may be selected such that, under vertical illumination, 55%-70% (selected from the range of 55%-70%) of the light source light 11 received by the first light-emitting layer 2100 at the first peak wavelength λp1 can be transmitted through the first light-emitting layer 2100. Furthermore, the first light-emitting layer 2100 may be configured to transmit 55%-70% (selected from the range of 55%-70%) of the light source light 11 received by the first light-emitting layer 2100 (regardless of wavelength and / or illumination angle).

[0089] Similarly, the second light-emitting layer 2200 may include a second light-emitting material 2220 at a second light-emitting material concentration C2. In an embodiment, the second light-emitting material concentration C2 may be selected from the range of 5v / v% to 25v / v%. Furthermore, the second light-emitting layer 2200 may have a second layer height H2. In an embodiment, the first peak wavelength λp1 and the second light-emitting material concentration C2 may be selected such that, under vertical illumination, at most 2% of the light source light 11 received by the second light-emitting layer 2200 at the first peak wavelength λp1 can pass through the second absorption height H2 of the second light-emitting layer 2200. 2a Transmitted. Specifically, H2 ≥ 1.5 H 2a Therefore, the absorption of light source 11 by the second light-emitting layer 2200 can be adjusted by adjusting one or more of the second layer height H2 and the second layer light-emitting material concentration C2. In the embodiment, for (a) the first layer light-emitting material concentration C1 and the first layer height H1, and (b) the second layer light-emitting material concentration C2 and the second layer height H2, (i) C2>C1 and / or (ii) H2>H1 can be applied. Therefore, the second layer light-emitting material concentration C2 can be selected to be higher than the first layer light-emitting material concentration C1. Additionally or alternatively, the second layer height H2 can be selected to be higher than the first layer height H1.

[0090] Figure 2AAnother embodiment of the light generation system 1000 is schematically depicted. The light generation system 1000 may include an LED filament 4000. The LED filament 4000 may include a plurality of light sources 10. The plurality of light sources 10 may be configured in an array 100. Furthermore, the plurality of light sources 10 may be light-emitting diodes (LEDs). The light sources 10 may be specifically configured on one or more of the first and second main surfaces of the (elongated) carrier 5. Here, the plurality of light sources 10 are configured on both the first and second main surfaces of the (elongated) carrier 5. Furthermore, the LED filament 4000 may include a first light-emitting layer 2100. The first light-emitting layer 2100 may be specifically configured as an elongated encapsulation configured to cover the plurality of light sources 10. Thus, the first light-emitting layer 2100 is configured to surround the plurality of light sources 10. Furthermore, the LED filament 4000 may include a second light-emitting layer 2200. The second light-emitting layer 2200 can be configured as an elongated encapsulation, which is configured to cover the first light-emitting layer 2100. Therefore, the second light-emitting layer 2200 is configured to surround the first light-emitting layer 2100. In an embodiment, a plurality of light sources 10 can be disposed on one of the first and second main surfaces of the carrier 5. In such an embodiment, the first light-emitting layer 2100 and the second light-emitting layer 2200 can be disposed on only one of the first and second main surfaces, and may not be disposed on the other. Alternatively, a plurality of light sources 10 can be disposed on one of the first and second main surfaces of the carrier 5, and the first light-emitting layer 2100 and the second light-emitting layer 2200 can be disposed on both the first and second main surfaces. Furthermore, the light generation system 1000 may include a control system 300. The control system 300 can be configured to control one or more of the radiant flux, color point, CCT, and spectral power distribution of the system light.

[0091] Figure 2B Another embodiment of the light generation system 1000 is schematically depicted. The light generation system 1000 may include a chip-on-board (CoB) 3000. The CoB 3000 may include a plurality of light sources 10, specifically configured to be directly mounted on a substrate (such as a printed circuit board (PCB)). Furthermore, the CoB 3000 may include a first light-emitting layer 2100. The first light-emitting layer 2100 may be disposed on top of the plurality of light sources 10. In a specific embodiment, the first light-emitting layer 2100 may be configured to be in physical contact with the plurality of light sources 10. Additionally, the CoB 3000 may include a second light-emitting layer 2200. The second light-emitting layer 2200 may be specifically disposed on top of the first light-emitting layer 2100, such as in physical contact with the first light-emitting layer 2100.

[0092] Figure 3 Another embodiment 1000 of the light generation system is schematically depicted. In this embodiment, the first light-emitting layer 2100 can be disposed at a non-zero distance d1 from the light source 10. The non-zero distance d1 can be selected from the range of 5µm–50cm in this embodiment. Furthermore, as depicted herein, the first light-emitting layer 2100 (and the second light-emitting layer 2200) can be configured as the light emanating surface of the light generation system 1000. Furthermore, although the second light-emitting layer 2200 is located at… Figure 3 The light source 1000 is depicted as being in (physical) contact with the first light-emitting layer 2100, but this is not necessary. For example, the first light-emitting layer 2100 may be disposed at a non-zero distance d1 from the (surface) of the light source 10, and the second light-emitting layer 2200 may be disposed at a second non-zero distance d2 from the (side) of the first light-emitting layer 2100. Alternatively, the first light-emitting layer 2100 may be disposed on top of the light source 10, and the second light-emitting layer 2200 may be disposed at a second non-zero distance d2 from the (side) of the first light-emitting layer 2100 (e.g., at or within the light-emitting surface of the light generation system 1000).

[0093] Figure 4An embodiment of system light 1001 is schematically depicted. System light 1001 may include a first layer of luminescent material light 2111 and a second layer of luminescent material light 2221, the first layer of luminescent material light 2111 including first luminescent material light 211, and the second layer of luminescent material light 2221 including second luminescent material light 221. In an embodiment, the first luminescent material light 211 may be yellow or green light. Additionally or alternatively, the second luminescent material light 221 may be red light. In an embodiment, system light 1001 may not include light source light 11. Therefore, system light 1001 may have a spectral power distribution in the wavelength range of 400nm-780nm, wherein at least 99% of the spectral power is provided by the first luminescent material light 211 and the second luminescent material light 221. Alternatively, the system light 1001 may have a spectral power distribution in the wavelength range of 400 nm to 780 nm, wherein at least 97.5% of the spectral power in the wavelength range of 400 nm to 780 nm is provided by: (i) first-layer luminescent material light 2111 generated by the first-layer luminescent material 2110, and (ii) second-layer luminescent material light 2211 generated by the second-layer luminescent material 2210. Specifically, the system light 1001 may have a spectral power distribution in the wavelength range of 400 nm to 780 nm, wherein at least 97.5% of the spectral power is provided in the wavelength range of 490 nm to 780 nm. As indicated, the first centroid wavelength λc1 may be selected from the wavelength range of 505 nm to 590 nm, such as specifically selected from the wavelength range of 535 nm to 590 nm. Furthermore, the second centroid wavelength λc2 may be selected from the wavelength range of 620 nm to 640 nm, such as specifically selected from the wavelength range of 625 nm to 635 nm. Therefore, in an embodiment, the system light 1001 may have a correlated color temperature selected from the range of 1300K-2700K, such as specifically selected from the range of 1500K-2300K. Alternatively, in an embodiment, the first centroid wavelength λc1 may be selected from the wavelength range of 505nm-520nm, and the system light 1001 may have a correlated color temperature selected from the range of 2350K-2700K.

[0094] like Figure 4 The description in the text refers to (doped) Mn. 4+The characteristic narrow-band emission of (some luminescent materials, such as the second luminescent material 220) can include multiple relatively narrow spectral bands (sometimes referred to as "spectral line emission"). Each of these narrow spectral bands, centered at approximately 632 nm, can have a (second) FWHM (2) of up to 40 nm (at room temperature). Note that some of these narrow spectral bands can partially overlap. Due to this effect and the resolution aspect related to the device, the narrow spectral bands may appear wider. However, when measured at sufficient resolution (at room temperature) and when deconvolve the overlapping spectral bands, the overall FWHM will be (just) below 40 nm.

[0095] Figure 5 An embodiment of a luminaire 2 is schematically depicted, which includes the light generating system 1000 as described above. Reference numeral 301 indicates a user interface that may be functionally coupled to a control system 300, which is included in or functionally coupled to the light generating system 1000. Figure 5 An embodiment of a lamp 1 including a light generating system 1000 is also schematically depicted. Reference numeral 3 indicates a projector device or projector system, which can be used, for example, to project images onto a wall, and may also include the light generating system 1000. Therefore, Figure 5 An embodiment of a lighting device 1200 selected from the group consisting of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and a wireless optical communication device, as described herein, is schematically depicted. In the embodiment, such a lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or a wireless optical communication device. The lighting device light emanating from the lighting device 1200 is indicated by reference numeral 1201. The lighting device light 1201 may consist substantially of system light 1001, and therefore may be system light 1001 in a particular embodiment. Reference numeral 1300 refers to a space, such as a room. Reference numeral 1305 refers to a floor and reference numeral 1310 refers to a ceiling; reference numeral 1307 refers to a wall.

[0096] The term "multiple" refers to two or more.

[0097] The terms "substantially" or "basically" and similar terms used herein will be understood by those skilled in the art. The terms "substantially" or "basically" may also include embodiments with words such as "completely," "entirely," "all," etc. Therefore, in embodiments, the adjectives "substantially" or "basically" may also be removed. Where applicable, the terms "substantially" or "basically" may also refer to 90% or higher, such as 95% or higher, specifically 99% or higher, or even more specifically 99.5% or higher, including 100%.

[0098] The term "comprising" also includes embodiments in which the term "comprising" means "consisting of". The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or". For example, the phrase "item 1 and / or item 2" and similar phrases can refer to one or more of item 1 and item 2. The term "comprising" in one embodiment can mean "consisting of", but in another embodiment it can also mean "containing at least the defined substance and optionally one or more other substances".

[0099] Furthermore, the terms first, second, third, etc., used in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe a sequential or chronological order. It should be understood that such terms are interchangeable where appropriate, and the embodiments of the invention described herein can operate in sequences other than those described or illustrated herein.

[0100] The equipment, apparatus, or system described herein may refer to the process of operation. As will be apparent to those skilled in the art, the invention is not limited to the method of operation, or the equipment, apparatus, or system in operation.

[0101] It should be noted that the above embodiments are illustrated but not limited to the present invention, and those skilled in the art will be able to devise many alternative embodiments without departing from the scope of the appended claims.

[0102] In the claims, any reference numerals placed between parentheses should not be construed as limiting the claims.

[0103] The use of the verb "comprising" and its variations does not exclude the presence of elements or steps other than those stated in the claims. Unless the context explicitly requires otherwise, throughout the specification and claims, the words "comprising," "including," etc., should be interpreted in a sense of inclusion, not exclusion or exhaustion; that is, in the sense of "including but not limited to."

[0104] The article "one" or "a" preceding an element does not preclude the existence of multiple such elements.

[0105] This invention can be implemented by hardware comprising several different elements, and by a suitably programmed computer. In the device claims, apparatus claims, or system claims enumerating several means, several means of the apparatus can be embodied by the same item of hardware. The fact that certain measures are recited in mutually different dependent claims does not indicate that combinations of these measures cannot be advantageously used. In another aspect, the invention (therefore) provides a software product that, when run on a computer, enables the provision of one or more embodiments of the methods described herein.

[0106] The present invention also provides a control system that can control a device, apparatus, or system, or that can perform the methods or processes described herein. Furthermore, the present invention provides a computer program product that, when run on a computer (which is functionally coupled to or included by the device, apparatus, or system), controls one or more controllable elements of the device, apparatus, or system.

[0107] The present invention also applies to devices, apparatuses, or systems that include one or more of the characterizing features described in the specification and / or shown in the accompanying drawings. The present invention also relates to methods or processes that include one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.

[0108] The various aspects discussed in this patent can be combined to provide additional advantages. Furthermore, those skilled in the art will understand that embodiments can be combined, and more than two embodiments can also be combined. Additionally, some features can form the basis of one or more divisional applications.

Claims

1. A light generation system (1000), the light generation system (1000) comprising a light source (10), a first light-emitting layer (2100), and a second light-emitting layer (2200), wherein: The light source (10) is configured to generate light source light (11), wherein the light source light (11) has a first peak wavelength (λ) selected from the wavelength range of 400 nm to 490 nm. p1 ); and the light source (10) therein includes a solid-state light source; The first light-emitting layer (2100) is disposed downstream of the light source (10), wherein the first light-emitting layer (2100) comprises a first light-emitting material (2110), wherein the first light-emitting material (210) comprises a first light-emitting material (210), wherein the first light-emitting material (210) is configured to convert a first portion of the light source light (11) received by the first light-emitting material (210) into first light-emitting material light (211), wherein the first light-emitting material light (211) has an emission band having a first centroid wavelength (λ) selected from the wavelength range of 505 nm to 590 nm. c1 ) and at least 50nm of first half-height full width (FWHM1); The second light-emitting layer (2200) is disposed downstream of the first light-emitting layer (2100), wherein the second light-emitting layer (2200) includes a second light-emitting material (2220), wherein the second light-emitting material (2220) includes a second light-emitting material (220), wherein the second light-emitting material (220) includes M' doped with tetravalent manganese. x M 2-2x AX6, wherein M' comprises an alkaline earth cation, wherein M comprises a basic cation, wherein A comprises a tetravalent cation, and wherein X comprises a monovalent anion, the monovalent anion comprising at least fluorine (F); wherein the second luminescent material (220) is configured to convert a second portion of the light source light (11) received by the second luminescent material (220) into second luminescent material light (221), the second luminescent material light (221) having at least one emission band having a second full width at half maximum (FWHM2) of up to 40 nm, wherein the second luminescent material light (221) has a second centroid wavelength (λc2) selected from the wavelength range of 620 nm to 640 nm; and wherein the second luminescent layer (2200) comprises at least 1.2 times the amount of the second luminescent material (2220) required to transmit up to 2% of the light source light (10) received by the second luminescent layer (2200); and The light generation system (1000) is configured to generate system light (1001) in a first operating mode of the light generation system (1000), the system light (1001) comprising first luminescent material light (211) and second luminescent material light (221), wherein the system light (1001) has a correlated color temperature selected from the range of 1300K to 2700K.

2. The light generation system (1000) according to claim 1, wherein the first peak wavelength (λ) p1 The wavelength range is selected from 420 nm to 475 nm, and the second luminescent material (220) comprises (K,Rb)2SiF6:Mn 4+ and K2(Si,Ti)F6:Mn 4+ One or more of them.

3. The light generation system (1000) according to any one of the preceding claims, wherein the first centroid wavelength (λc1) is selected from the wavelength range of 535 nm to 590 nm; wherein the system light (1001) has a correlated color temperature selected from the range of 1500 K to 2300 K.

4. The light generation system (1000) according to claim 1 or 2, wherein the first centroid wavelength (λc1) is selected from the wavelength range of 505 nm to 520 nm; wherein the system light (1001) has a correlated color temperature selected from the range of 2350 K to 2700 K.

5. The light generation system (1000) according to any one of the preceding claims, wherein the second light-emitting layer (2200) comprises at least 1.5 times the amount of the second light-emitting material (2220) required to transmit up to 2% of the light source light (10) received by the second light-emitting layer (2200).

6. The light generation system (1000) according to any one of the preceding claims, wherein: The light emitted by the first luminescent material (211) is yellow or green; The light emitted by the second luminescent material (221) is red light; and The system light (1001) has a spectral power distribution in the wavelength range of 400 nm to 780 nm, wherein at least 99% of the spectral power is provided by the first luminescent material light (211) and the second luminescent material light (221).

7. The light generation system (1000) according to any one of the preceding claims, wherein the second light-emitting layer (2200) comprises a second light-emitting material (2220) at a second light-emitting material concentration (C2), wherein the second light-emitting layer (2200) has a second layer height H2; wherein the first peak wavelength (λp1) and the second light-emitting material concentration (C2) are selected such that, under vertical illumination, at most 2% of the light source light (11) received by the second light-emitting layer (2200) at the first peak wavelength (λp1) is transmitted through the second absorption height H of the second light-emitting layer (2200). 2a Where H2≥1.5 H 2a .

8. The light generation system (1000) according to claim 7, wherein the concentration (C2) of the second luminescent material is selected from the range of 5 v / v% to 25 v / v%; and wherein the second luminescent material (220) comprises K2SiF6:Mn 4+ .

9. The light generating system (1000) according to any one of the preceding claims, wherein the first light-emitting material (210) comprises A3B5O. 12 Ce-type luminescent materials, wherein A includes one or more of Y, La, Gd, Tb and Lu, and wherein B includes one or more of Al, Ga, In and Sc.

10. The light generation system (1000) according to any one of the preceding claims, wherein the first light-emitting layer (2100) comprises a first layer light-emitting material (2110) at a first layer light-emitting material concentration (C1), wherein the first light-emitting layer (2100) has a first layer height (H1); wherein the first peak wavelength (λ) p1 The concentration of the first luminescent material (C1) and the concentration of the first luminescent material (C1) are selected such that, under vertical illumination, the light received by the first luminescent layer (2100) at the first peak wavelength (λ) p1 55% to 70% of the light source light (11) at the location is transmitted by the first light-emitting layer (2100).

11. The light generation system (1000) according to any one of the preceding claims, wherein for (a) the concentration C1 of the first layer luminescent material and the height H1 of the first layer as defined in claim 10 and (b) the concentration C2 of the second layer luminescent material and the height H2 of the second layer as defined in any one of claims 6 to 7, (i) C2>C1 and (ii) H2>H1.

12. The light generation system (1000) according to any one of the preceding claims, wherein the first light-emitting layer (2100) is disposed at a non-zero distance (d1) from the light source (10).

13. The light generation system (1000) according to any one of claims 1 to 11, wherein the light generation system (1000) comprises a chip-on-board (CoB) (3000), wherein the chip-on-board (CoB) (3000) comprises (i) a plurality of light sources (10), (ii) a first light-emitting layer (2100) and (iii) a second light-emitting layer (2200), wherein the first light-emitting layer (2100) is disposed on top of the plurality of light sources (10), and wherein the second light-emitting layer (2200) is disposed on top of the first light-emitting layer (2100).

14. The light generating system (1000) according to any one of claims 1 to 11, wherein the light generating system (1000) comprises an LED filament (4000), wherein the LED filament (4000) comprises (i) a plurality of light sources (10), wherein the plurality of light sources (10) are arranged in an array (100), and wherein the plurality of light sources (10) are light-emitting diodes (LEDs); (ii) a first light-emitting layer (2100); and (iii) a second light-emitting layer (2200), wherein the first light-emitting layer (2100) is configured to surround the plurality of light sources (10), and wherein the second light-emitting layer (2200) is configured to surround the first light-emitting layer (2100).

15. A lighting device (1200) selected from the group consisting of lamps (1) and luminaires (2), the lighting device (1200) comprising a light generating system (1000) according to any one of the preceding claims.

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