Lighting device comprising optical device and optical light guide

Abstract

A lighting device (100) comprising: a solid state light source (110) arranged to emit blue light (120); an optical arrangement (130) comprising a light conversion element (140) arranged to receive the emitted blue light, where the light conversion element comprises a green-yellow phosphor (150) configured to convert a first portion of the emitted blue light (120a) to green-yellow light (160) having a peak wavelength [lambda] GY in the range of 510-580 nm; and an optical light guide (200) wherein the optical device is configured to couple a second portion of the emitted blue light (120b) and at least a portion of the green-green light into the optical light guide wherein the optical light guide comprises a red phosphor (210) configured to convert the coupled second portion of the emitted blue light and / or the coupled yellow-green light into red light (220), and wherein the optical light guide is configured to couple out red light and yellow-green light.

Description

Technical Field

[0001] This invention generally relates to the field of lighting devices. More specifically, this invention relates to lighting devices including solid-state light sources, optical devices, and optical light guides. Background Technology

[0002] Optical fibers are known in the art. For example, US2018 / 0064322 describes an irradiation system for a surgical device, the irradiation system comprising: a tubular body made of a light-transmitting material, the tubular body including: an outer peripheral wall; a distal end; a proximal end; and at least one lumen extending between the distal end and the proximal end; a light source that generates light having at least one wavelength between 200 nm and 2000 nm; and at least one light-diffusing optical fiber disposed in the at least one lumen.

[0003] Recently, high-power white light-emitting devices combining laser diodes (LDs) and phosphors have been developed. Currently, white solid-state light sources mainly consist of blue light-emitting diode (LED) chips or combinations of blue LDs and yellow phosphors.

[0004] WO2022 / 233618 discloses a high-brightness light source comprising a blue laser pumping a green / yellow phosphor and a yellow / orange superluminescent diode pumping a red phosphor.

[0005] It should be noted that directly coupling lasers into optical fibers is subject to safety concerns and regulations, and may further lead to undesirable speckle light. Another issue is that such systems can be relatively expensive.

[0006] Therefore, it is of interest to provide a lighting device or system that can efficiently provide (white) light while meeting safety regulations and being cost-effective. Summary of the Invention

[0007] One object of the present invention is to provide a lighting device that can provide light, such as white light, while being safe and cost-effective.

[0008] This and other objectives are achieved by a lighting device having the features of the independent claim. Preferred embodiments are defined in the dependent claims.

[0009] According to the present invention, a lighting device is provided. The lighting device includes a solid-state light source and an optical device, the solid-state light source being arranged to emit light having a peak wavelength λ in the wavelength range of 400-500 nm. B The optical device emits blue light and includes a light conversion element arranged to receive the emitted blue light. The light conversion element includes a greenish-yellow phosphor configured to convert a first portion of the emitted blue light into light having a peak wavelength λ in the wavelength range of 510-580 nm.GY The illumination device further includes an optical light guide, wherein the optical device is configured to couple a second portion of the emitted blue light and at least a portion of the green-yellow light into the optical light guide. The optical light guide includes a red phosphor, which is configured to at least partially convert at least one of the coupled second portion of the emitted blue light and the coupled green-yellow light into a peak wavelength λ having a wavelength range of 600 nm to 680 nm. R The red light, wherein the optical guide is configured to couple out red light and green-yellow light.

[0010] The present invention is based on the idea of ​​providing an illumination device including a solid-state light source and an optical device, wherein a green-yellow phosphor of the optical device is provided to efficiently couple green-yellow converted light into an optical light guide including a red phosphor, so as to convert blue light and green-yellow light from the solid-state light source into red converted light.

[0011] The advantage of this invention is that the lighting device can conveniently and easily couple red and yellow-green light, wherein the coupled red and yellow-green light can be used to obtain white light.

[0012] It should be understood that the green phosphor in the optics of the lighting device affects the emitted blue light, causing it to lose coherence and intensity. Through this conversion, the emitted blue light is not dangerous when exposed to the human eye; therefore, the advantage of this invention is that it provides increased safety compared to prior art arrangements.

[0013] This shift towards lower coherence and intensity is more advantageous for the red phosphors included in the light guide. Red phosphors pumped with high-intensity light typically experience phenomena such as saturation (exceeding the phosphor's maximum capacity to absorb and convert light), thermal quenching (heat generated by the light causes the phosphor to lose its ability to emit light efficiently), and degradation over time. These effects can lead to reduced efficiency, decreased overall brightness and color quality (color shift), shortened lifespan, and degraded performance. The lighting device of the present invention mitigates these disadvantages of red phosphors.

[0014] Another advantage of the present invention is that the lighting device is cost-effective due to its components and structure.

[0015] The lighting device includes a solid-state light source. "Solid-state light source" herein refers to, for example, a laser source, multiple laser diodes, a light-emitting diode (LED) source, or multiple LEDs. The solid-state light source is arranged to emit light with a peak wavelength λ in the wavelength range of 400-500 nm. BThe illumination device also includes optical components, which include a light conversion element arranged to receive the emitted blue light. "Light conversion element" herein essentially refers to any element arranged or configured to convert the light directed thereon. The light conversion element includes a greenish-yellow phosphor configured to convert a first portion of the emitted blue light into light having a peak wavelength λ in the wavelength range of 510-580 nm. GY The illumination device also includes an optical light guide. "Optical light guide" herein refers to an optical element configured or arranged to guide light based on total internal reflection (TIR). The optical device is configured to couple a second portion of the emitted blue light and at least a portion of the green-yellow light into the optical light guide. Therefore, when the illumination device is in operation, the second portion of the emitted blue light and the green-yellow light are guided into the optical light guide, thereby coupling light into the optical light guide. The optical light guide includes a red phosphor, which is configured to at least partially convert at least one of the coupled second portion of the emitted blue light and the coupled green-yellow light into light having a peak wavelength λ in the wavelength range of 600-680 nm. R The red phosphor is therefore configured to at least partially convert a second portion of the coupled emitted blue light and / or coupled greenish-yellow light into a peak wavelength λ having a wavelength range of 600-680 nm. R The red light emitted. The red phosphor can be distributed along at least a portion of the optical guide (elongation direction). This portion can preferably extend along the elongation direction of the optical guide or for more than 70%, more preferably more than 80%, and most preferably more than 90% of its length.

[0016] The optical light guide can also be configured to guide a second portion of the emitted blue light and / or the coupled green-yellow light along at least that portion of the optical light guide.

[0017] The optical light guide is configured to couple red light out with green-yellow light. Therefore, the lighting device is arranged or configured to couple red light out with green-yellow light from the optical light guide.

[0018] According to an embodiment of the invention, the optical light guide can also be configured to couple out at least a portion of a second portion of the emitted blue light, wherein the following light is white light: the coupled red light, the coupled greenish-yellow light, and at least a portion of the second portion of the coupled emitted blue light, the white light having a correlated color temperature (CCT) in the range of 1700K to 6500K and a color rendering index (CRI) of at least 70 or at least 80. Therefore, the following light is white light: the coupled red light, greenish-yellow light, and a portion of the second portion of the emitted blue light, the white light having a CCT of 1700K-6500K and a CRI ≥ 80 (or CRI ≥ 70). An advantage of this embodiment is that the lighting device can couple out (obtain) white light in a safe, convenient, and easy manner. Another advantage of this embodiment is that the coupled / obtained white light with a CRI ≥ 80 is particularly suitable for illumination purposes and / or general lighting purposes.

[0019] According to one embodiment of the present invention, the solid-state light source may include a laser light source. An advantage of this embodiment is that the laser maximizes the light coupled to the optical guide. Another advantage of this embodiment is that the laser light source can pump a green-yellow phosphor with high intensity.

[0020] According to one embodiment of the present invention, a solid-state light source may include a light-emitting diode (LED) light source. The advantage of this embodiment is that LEDs offer numerous benefits, such as long lifespan, low power consumption, and high efficiency in relation to the ratio of light to heat energy.

[0021] According to one embodiment of the invention, the optical light guide may be an optical fiber comprising a core and a cladding, wherein the cladding has a lower refractive index than the core, and wherein the core is configured to guide a second portion of coupled green-yellow light and emitted blue light based on total internal reflection (TIR). The term "cladding" herein refers to the interior of the optical light guide, i.e., the lining on the inner wall of the optical light guide, whereby the "core" constitutes the central portion of the optical light guide. An advantage of this embodiment is that the ability of the core to guide green-yellow and blue light based on TIR further contributes to the efficiency of the illumination device.

[0022] The cladding may include a red phosphor, or the optical guide may include a shell that at least partially surrounds the cladding. The shell and / or the core may include a red phosphor.

[0023] Therefore, the optical light guide may include a housing that at least partially surrounds the cladding, wherein the housing includes a red phosphor, and / or the cladding of the illumination device includes a red phosphor (i.e., no housing). An advantage of this embodiment is that the cladding surrounding the optical light guide, or the housing itself, constitutes an optimal location for the red phosphor(s), resulting in more efficient red light coupling. More specifically, by providing a red phosphor in the housing and / or cladding, the guidance of the second portion of green-yellow and blue light is unimpeded, or at least only partially impeded.

[0024] According to one embodiment of the invention, the optical light guide may include an optical coupling element configured to couple one of green-yellow light, a portion of a second portion of emitted blue light, out of the optical light guide. Thus, the optical coupling element can couple either the green-yellow light or the green-yellow light to a portion of the second portion of emitted blue light out of the optical light guide. "Optical coupling element" herein essentially refers to any element or particle arranged or configured to enhance, improve, and / or facilitate the coupling of the second portion of green-yellow light and / or emitted blue light via, for example, scattering, redirection, and / or conversion. An advantage of this embodiment is that the optical coupling element achieves particularly efficient extraction of the second portion of green-yellow light and / or emitted blue light.

[0025] According to one embodiment of the present invention, the optical coupling element may include at least one of the following: light-scattering particles arranged to scatter incident light, a light-guiding structure arranged to redirect incident light, and a cladding structure. Therefore, the optical coupling element may include a structure of light-scattering particles, a light-guiding structure, and / or a cladding structure. An advantage of this embodiment is that characteristics such as scattering and (re)orientation can further improve the light extraction of the lighting device.

[0026] According to one embodiment of the invention, the optical device may further include a diffuser disposed upstream of the optical guide. "Diffuser" herein essentially refers to any element capable of, arranged, or configured to diffuse light. An advantage of this embodiment is that the diffuser can affect the light, causing it to lose its coherence, thereby conveniently increasing the safety of the lighting device. Therefore, this embodiment is particularly advantageous in situations where a laser light source is used in the lighting device.

[0027] According to one embodiment of the invention, the optical device may include at least one lens, and wherein the optical device is configured to couple a second portion of the emitted blue light and greenish-yellow light into an optical guide via the at least one lens. An advantage of this embodiment is that the lens provides optimized coupling of the second portion of the emitted blue light and greenish-yellow light into the optical guide.

[0028] According to one embodiment of the present invention, the red phosphor can be an organic red phosphor. An advantage of this embodiment is that organic red phosphors are inexpensive, thus contributing to the cost-effectiveness of the lighting device.

[0029] According to one embodiment of the present invention, the red phosphor may be doped with tetravalent manganese. Types, where M' includes alkaline earth cations, M includes basic cations, and x is in the range of 0-1, where A includes tetravalent cations, and where X includes monovalent anions, including at least fluorine. Regarding manganese-activated narrow-band red phosphors, this refers to those doped with tetravalent manganese. The luminescent material is of the type in which M' comprises an alkaline earth cation, M comprises a basic cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, such as one or more of silicon and titanium, and X comprises a monovalent anion, including at least fluorine. The relevant basic cations (M) are sodium (Na), potassium (K), and rubidium (Rb). Alternatively, lithium and / or cesium may also be used. In a preferred example, M comprises at least potassium. In yet another example, M comprises at least rubidium. The phrase "M comprises at least potassium" means, for example, in molar... Of all the M cations, a portion include K. + Optionally, the remaining portion includes one or more other monovalent (basic) cations (see also below). In another preferred example, M includes at least potassium and rubidium. Optionally, It has a hexagonal phase. In yet another example, It has a cubic phase. For x=0, the composition is M2AX6. The relevant alkaline earth cations (M') are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba.

[0030] The term "tetravalent manganese" refers to Mn 4+ This is a well-known luminescent ion. In the molecular formula described above, a portion of the tetravalent cation A (such as Si) is replaced by manganese. Therefore, doped with tetravalent manganese... It can also be expressed as The molar percentage of manganese, i.e., the percentage of its substitution for tetravalent cation A, is typically 0.1-15%, particularly 1-12%, i.e., m is in the range of 0.001-0.15, particularly in the range of 0.01-0.12.

[0031] As stated above, X involves monovalent anions, but includes at least fluorine. Other monovalent anions that may optionally be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I).

[0032] It should be noted that this type or composition of red phosphor does not have self-absorption properties, and this embodiment is therefore advantageous because red phosphors are particularly suitable for optical light guides in lighting devices. More specifically, the type or composition of red phosphor (virtually) does not absorb green light, and is therefore particularly suitable for the present invention.

[0033] According to one embodiment of the present invention, the red phosphor may be KSiF. According to one example, include (Also referred to here as the KSiF system). As mentioned above, in another preferred example, This includes KRbSiF6 (also referred to as the K,Rb system in this paper). As mentioned above, some silicon is replaced by manganese (i.e., the molecular formula can also be described as...). or Where m is as described above, or is respectively described as KRbSiF6:Mn and K2SiF6:Mn). Since manganese substitutes for a portion of the main lattice ions and has a specific function, it is also referred to as a "dopant" or "activator". Therefore, hexafluorosilicates are made with manganese (Mn... 4+ Doping or activation. The advantage of this embodiment is that the composition of the red phosphor has optimal characteristics regarding non-self-absorption.

[0034] According to one embodiment of the present invention, the greenish-yellow phosphor is A3B5O. 12 The 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. An advantage of this embodiment is that this material composition of the green-yellow phosphor allows it to be pumped at relatively high intensity by a solid-state light source (e.g., a (blue) laser source), resulting in a relatively large amount of green-yellow light coupled into the optical guide. Embodiments with Ce-doped garnet phosphors, particularly with LuAG and cerium concentrations in the range of 0.4-1%, may be particularly advantageous. In this way, thermal quenching is shifted to a higher temperature, and optical saturation effects are minimized. Furthermore, the laser can be focused onto a small region of emitted light with a small optical spread.

[0035] According to one embodiment of the present invention, a lighting unit is provided. The lighting unit includes a lighting device according to any of the foregoing embodiments, and a housing arranged to at least partially enclose a solid-state light source and optical devices. An advantage of this embodiment is that the housing (e.g., in the form of an enclosure) provides improved safety for the operator of the lighting device and / or any other third party. This embodiment allows for a reduction in the laser category of the lighting device and enables its use in the business-to-consumer (B2C) market.

[0036] Other objects, features, and advantages of the invention will become apparent upon studying the following detailed disclosure, drawings, and appended claims. Those skilled in the art will recognize that different features of the invention can be combined to create embodiments different from those described below. Attached Figure Description

[0037] This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate embodiments of the invention.

[0038] Figure 1 and Figure 2 This is a schematic diagram of a lighting device according to an exemplary embodiment of the present invention.

[0039] Figure 3This is a schematic diagram of the optical light guide of an illumination device according to an exemplary embodiment of the present invention.

[0040] Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 5c , Figure 6a and Figure 6b This is a schematic diagram of the cross-section of the optical light guide of the lighting device according to an exemplary embodiment of the present invention.

[0041] Figure 7a and Figure 7b This is a schematic spectrum of power per wavelength as a function of wavelength for white light emitted from a lighting device according to an exemplary embodiment of the present invention, and

[0042] Figure 8 This is a schematic diagram of a lighting unit including a lighting device according to an exemplary embodiment of the present invention. Detailed Implementation

[0043] Figure 1 This is a schematic diagram of a lighting device 100 according to an exemplary embodiment of the present invention. The lighting device 100 includes a solid-state light source 110, schematically represented by a dashed rectangle. The solid-state light source 110 may include a laser light source. The solid-state light source 110 may include an LED light source. The solid-state light source 110 is arranged to emit light having a peak wavelength λ in the wavelength range of 400-500 nm. B Blue light 120. For example, solid-state light source 110 can be arranged to emit blue light with a peak wavelength λ in the wavelength range of 430-480 nm. B The illumination device 100 also includes an optical device 130. The optical device 130 includes a light conversion element 140. Here, the light conversion element 140 is illustrated as a rectangular element, but it will be understood that many other forms or shapes of the light conversion element 140 are feasible. The light conversion element 140 is arranged to receive the blue light 120 emitted from the solid-state light source 110 during operation of the illumination device 100. The light conversion element 140 includes a greenish-yellow phosphor 150. For example, the greenish-yellow phosphor 150 may be garnet. The greenish-yellow phosphor 150 is configured to convert a first portion of the emitted blue light 120 into a peak wavelength λ having a wavelength range of 510-580 nm. GY The green-yellow light 160. For example, the green-yellow light 160 can have a peak wavelength λ in the wavelength range of 520-560 nm. GY The lighting device 100 also includes an optical guide 200, wherein the optical device 130 is configured to couple a second portion of the emitted blue light 120b and at least a portion of the green-yellow light 160 into the optical guide 200. According to... Figure 1In the example of the illumination device 100, the optical device 130 includes two lenses 400a, 400b on either side of the light conversion element 140. It should be noted that the illumination device 100 may include a single lens (or alternatively, even no lens), and the lens may have other shapes and / or positions as shown. According to the inclusion of lenses 400a, 400b... Figure 1 For example, the optical device 130 is configured to couple a second portion of the emitted blue light 120b and at least a portion of the green-yellow light 160 into the optical guide 200 via lenses 400a and 400b.

[0044] like Figure 1 As shown, the optical guide 200 of the illumination device 100 extends along the main optical path of the second portion of the emitted blue light 120b and / or the greenish-yellow light 160. The optical guide 200 includes a red phosphor 210, which is configured to at least partially convert the coupled second portion of the emitted blue light 120b and / or the coupled greenish-yellow light 160 into a peak wavelength λ having a wavelength range of 600-680 nm. R Red light 220. For example, red light 220 can have a peak wavelength λ in the wavelength range of 610-650 nm. R Optical guide 200 is configured to couple out red light 220 and green-yellow light 160, such as... Figure 1 As shown in (i) of the invention. In an example of the lighting device 100 according to the invention, the optical guide 200 may also be configured to couple out at least a portion of the second portion of the emitted blue light 120b. The following light is white light WL: the coupled red light 220, the coupled greenish-yellow light 160, and at least a portion of the second portion of the coupled emitted blue light 120b, as shown in (i). Figure 1 As shown in (ii) above. White light WL has a correlated color temperature (CCT) in the range of 1700K to 6500K and a color rendering index (CRI) of at least 80.

[0045] Figure 2 This is a schematic diagram of a lighting device 100 according to an exemplary embodiment of the present invention. It should be understood that... Figure 2 The lighting device 100 and Figure 1 The lighting device 100 shown and the related text share the same concepts, and references are also made herein to enhance understanding of the lighting device 100. Figure 1 .exist Figure 2 In the illumination device 100, two solid-state light sources 110 (e.g., laser light sources) are arranged to emit light with a peak wavelength λ in the wavelength range of 400-500 nm. BThe illumination device 100 also includes an optical device 130, indicated by a dashed rectangle. The optical device 130 includes a light conversion element 140 arranged to receive blue light 120 emitted from the solid-state light source 110 when the illumination device 100 is in operation. The light conversion element 140 includes a greenish-yellow phosphor configured to convert a first portion of the emitted blue light 120a into a peak wavelength λ having a wavelength range of 510-580 nm. GY The green-yellow light is 160.

[0046] The illumination device 100 also includes a diffuser 380, wherein the diffuser 380 is arranged in transmission mode to diffuse a second portion of the emitted blue light 120b. The second portion of the emitted blue light 120b and the greenish-yellow light 160 are coupled to an optical guide 200 via a reflector 390. The optical guide 200 includes a red phosphor 210, which is configured to at least partially convert the second portion of the emitted blue light 120b and / or the greenish-yellow light 160 into a peak wavelength λ having a wavelength range of 600 nm to 680 nm. R The red light 220. The optical guide 200 is configured to couple out the red light 220 and the green-yellow light 160, as... Figure 2 As shown in (i) in the diagram.

[0047] Figure 3 This is a schematic diagram of an optical guide 200 of an illumination device according to an exemplary embodiment of the present invention. The optical guide 200 may be an optical fiber comprising a core 300 and a cladding 310 surrounding or enclosing the core 300. The cladding 310 is disposed inside the optical guide 200 as a liner, etc. The core 300 constitutes the central portion of the optical guide 200. The cladding 310 may have a lower refractive index than the core 300. The core 300 of the optical guide 200 may be configured to guide a second portion of coupled green-yellow light 160 and emitted blue light 120b based on total internal reflection (TIR) ​​(as schematically indicated by the dashed arrow). The optical guide 200 may also include a shell at least partially surrounding the cladding 310. The cladding 310 and / or the shell of the cladding 310 may include a red phosphor 210. The optical guide 200 may include an optical output element configured to couple a portion of the green-yellow light 160 or the green-yellow light 160 to a portion of a second portion of the emitted blue light 120b and output the optical guide 200.

[0048] Red phosphor 210 can be an organic red phosphor. Furthermore, red phosphor 210 can be doped with tetravalent manganese. The type, wherein M' comprises an alkaline earth cation, M comprises a basic cation, and x is in 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, including at least fluorine. The relevant basic cations (M) are sodium (Na), potassium (K), and rubidium (Rb). Optionally, lithium and / or cesium may also be used. In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. The phrase "wherein M comprises at least potassium" means, for example, in molar... Of all the M cations, some include K. + And optionally, the remaining portion includes one or more other monovalent (basic) cations (see also below). In another preferred embodiment, M includes at least potassium and rubidium. Optionally, The luminescent material has a hexagonal phase. In yet another embodiment, The luminescent material has a cubic phase. For x=0, the composition is M2AX6. The relevant alkaline earth cations (M') are magnesium (Mg), strontium (Sr), calcium (Ca), and barium (Ba), particularly one or more of Sr and Ba. The term "tetravalent manganese" refers to Mn. 4+ This is a well-known luminescent ion. In the molecular formula described above, a portion of the tetravalent cation A (e.g., Si) is replaced by manganese. Therefore, doped with tetravalent manganese... It can also be expressed as The molar percentage of manganese, i.e., the percentage by which it substitutes for the tetravalent cation A, is typically 0.1-15%, particularly 1-12%, i.e., m is in the range of 0.001-0.15, particularly 0.01-0.12. As mentioned above, X relates to a monovalent anion, but includes at least fluorine. Other monovalent anions that may optionally be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). In one embodiment, This includes K2SiF6 (also referred to herein as the KSiF system). As described above, in another preferred embodiment, This includes KRbSiF6 (also referred to as the K,Rb system in this paper). As mentioned above, some silicon is replaced by manganese (i.e., the molecular formula can also be described as...). or Where m is as described above, or is respectively described as KRbSiF6:Mn and K2SiF6:Mn). Since manganese substitutes for a portion of the main lattice ions and has a specific function, it is also referred to as a "dopant" or "activator". Therefore, hexafluorosilicates are made with manganese (Mn... 4+ Doping or activation. In specific embodiments, the luminescent material may include (K,Rb)₂SiF₆:Mn 4+ Alternatively or additionally, in embodiments, the third luminescent material may include K2SiF6:Mn4+ Alternatively or additionally, in embodiments, the third luminescent material may include K2TiF6:Mn 4+ In an embodiment, the third luminescent material may include K2(Si,Ti)F6:Mn 4+ From the above, we can conclude that "Si, Ti" can represent one or more of Si and Ti.

[0049] Red phosphor 210 can be, for example, KSiF.

[0050] Greenish-yellow phosphor 150 can be A3B5O 12 The luminescent material is of the Ce type, wherein A in the embodiments comprises one or more of Y, La, Gd, Tb, and Lu, particularly at least one or more of Y, Gd, Tb, and Lu, and wherein B in the embodiments comprises one or more of Al, Ga, In, and Sc. Specifically, A may comprise one or more of Y, Gd, and Lu, for example, particularly one or more of Y and Lu. Specifically, B may comprise one or more of Al and Ga, more particularly at least Al, for example, substantially entirely Al. Therefore, cerium-containing garnet materials are particularly suitable. Examples of garnet particularly include A3B5O. 12 Garnet, wherein A comprises at least yttrium or lutetium, and wherein B comprises at least aluminum. This garnet may be doped with cerium (Ce), praseodymium (Pr), or a combination of cerium and praseodymium; however, Ce is particularly preferred. 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), particularly up to about 20% B, more particularly up to about 10% B (i.e., the B ions are essentially composed of more than 90 mol% Al and less than 10 mol% of one or more of Ga, Sc, and In); B may particularly comprise up to about 10% gallium. In another variant, B and O may be at least partially replaced by Si and N. Element A may be selected, in particular, from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). Furthermore, Gd and / or Tb are particularly present only in amounts up to about 20% of A. In a specific embodiment, the garnet luminescent material includes , where x is equal to or greater than 0 and equal to or less than 1. The term ":Ce" indicates that a portion of the metal ions in the luminescent material (i.e., in garnet: a portion of the "A" ions) are replaced by Ce. For example, in (Y 1-x Lu x )3Al5O 12In the case of Ce, a portion of Y and / or Lu is replaced by Ce. This is known to those skilled in the art. Ce will generally replace no more than 10% of A; typically, the concentration of Ce (relative to A) is in the range of 0.1-4%, particularly 0.1-2%. Assuming 1% Ce and 10% Y, the perfectly correct molecular formula could be... Ce in garnet is essentially or only in the trivalent state, as is known to those skilled in the art.

[0051] Organic red phosphors are typically dissolved in a matrix (e.g., a polymer matrix of PMMA, PC, or PET) in a molecular manner.

[0052] Figure 4a and Figure 4b This is a schematic cross-sectional view of the optical guide 200 of the lighting device according to an exemplary embodiment of the present invention, and for a better understanding of the optical guide 200 of the lighting device 100, please refer to... Figures 1-3 .exist Figure 4a In the optical guide 200, the fiber core 300 includes (schematically shown) phosphor particles 340. The phosphor particles 340 can be arranged to convert incident light (exemplified by 340a, and further indicated by asterisks). The phosphor particles 340b and 340c, which are schematically indicated, are arranged to scatter the incident light (indicated by the symbol "^"). Therefore, Figure 4a The phosphor particles 340 in the light can (to a large extent) convert light or (to a smaller extent) scatter incident light. Figure 4b In the optical guide 200, the fiber core 300 includes (schematically shown) phosphor particles 340d arranged to convert incident light, and optical coupling elements 350, wherein the optical coupling elements 350 are illustrated as two light scattering elements 350a and 350b arranged to scatter incident light.

[0053] Figures 5a-5c This is a schematic cross-sectional view of an optical light guide 200 of an illumination device according to an exemplary embodiment of the present invention. The optical light guide 200 includes a cladding 310 surrounding a fiber core 300. Figure 5a In the cladding 310, phosphor particles 340 are disposed, wherein the phosphor particles 340 are arranged to convert or scatter incident light. Figure 5b In this optical guide 200, phosphor particles are arranged in the cladding 310, while optical coupling elements 350a-c, arranged as non-luminescent light scattering elements that convert or scatter incident light, are disposed in the core 300 of the optical guide 200. Figure 5c In this process, all particles, including phosphor particles and light scattering elements, are disposed in the cladding 310 of the optical guide 200.

[0054] Figure 6a and Figure 6b This is a schematic cross-sectional view of an optical light guide 200 of an illumination device according to an exemplary embodiment of the present invention. The optical light guide 200 includes a housing 330 that at least partially surrounds a cladding 310, which in turn at least partially surrounds a fiber core 300. Phosphor particles 340 are disposed within the housing 330 of the optical light guide 200. An optical coupling element 350, arranged in the form of light-scattering particles that scatter incident light, is disposed within the cladding 310 of the optical light guide 200. Figure 6a The optical guide 200 also includes structures schematically shown in the cladding 310, which may be examples of the optical coupling element 350. This structure may include element 360a, such as... Figure 6a As shown on the left-hand side. Alternatively, the structure may include or constitute damage, (irregular) patterns, etc., to the cladding 310, such as... Figure 6a As shown in 360b on the right side. Figure 6b An example of an optical coupling element 350 is shown, which is arranged at the interface between the core and cladding of the optical guide 200, thereby enhancing the light extraction of the optical guide 200.

[0055] It should also be noted that, for the optical guide 200 illustrated in Figures 4-6, bending of the optical guide 200 can lead to (further) optical coupling.

[0056] Figure 7a and Figure 7b This is a schematic spectrum of power per wavelength as a function of wavelength for white light emitted from a lighting device according to an exemplary embodiment of the present invention. The greenish-yellow phosphor of the light conversion element of the lighting device's optical element is of the LuAG type, having 0.5% Ce and lumen red emission. Figure 7a In the spectrum, CCT=3000K and CRI=87 are observed, including a significant peak at approximately 600 nm. Figure 7b In the spectrum, CCT=4000K and CRI=90 are shown, including a significant peak at a wavelength of about 460 nm and a significant peak at a wavelength of about 600 nm.

[0057] Figure 8 This is a schematic diagram of an illumination unit 500 including an illumination device 100 according to an exemplary embodiment of the present invention. The illumination unit 500 also includes a housing 510, for example in the form of an outer shell, which is provided or arranged to at least partially enclose the solid-state light source 110 (schematically indicated by a dashed ellipse) and the optical device 130 (schematically indicated by a dashed ellipse).

[0058] Those skilled in the art will recognize that the invention is by no means limited to the preferred embodiments described above. Rather, many modifications and variations are possible within the scope of the appended claims. For example, optical devices 130, optical guides 200, etc., may have different shapes, sizes, and / or dimensions than those depicted / described.

Claims

1. A lighting device (100), comprising A solid-state light source (110) is arranged to emit a peak wavelength λ in the wavelength range of 400 nm to 500 nm. B Blue light (120). Optical device (130) includes a light conversion element (140) arranged to receive the emitted blue light, wherein the light conversion element includes a green phosphor (150) configured to convert a first portion of the emitted blue light (120a) into a peak wavelength λ having a wavelength range of 510 nm to 580 nm. GY The greenish-yellow light (160), and An optical guide (200), wherein the optical device is configured to couple a second portion (120b) of the emitted blue light and at least a portion of the green-yellow light into the optical guide. The optical guide includes a red phosphor (210) configured to at least partially convert at least one of the following into a peak wavelength λ in the wavelength range of 600 nm to 680 nm. R Red light (220): The second portion of the emitted blue light coupled in, and The coupled green-yellow light, and The optical guide is configured to couple out the red light and the green-yellow light.

2. The lighting device of claim 1, wherein the optical guide is further configured to couple out at least a portion of the second portion of the emitted blue light, wherein the light is white light WL: The red light that is coupled out, The coupled green-yellow light, and At least a portion of the second part of the emitted blue light, coupled out. The white light has a correlated color temperature (CCT) in the range of 1700K to 6500K and a color rendering index (CRI) of at least 80.

3. The lighting device according to claim 1 or 2, wherein the solid-state light source includes a laser light source.

4. The lighting device according to any one of the preceding claims, wherein the solid-state light source comprises a light-emitting diode (LED) light source.

5. The lighting device according to any one of the preceding claims, wherein the optical light guide is an optical fiber comprising a core (300) and a cladding (310), wherein the cladding has a lower refractive index than the core, and wherein the core is configured to guide the second portion of the coupled green-yellow light and the emitted blue light based on total internal reflection (TIR).

6. The lighting device according to claim 5, wherein... (i) The cladding (310) includes the red phosphor, or (ii) The optical guide further includes a housing (330) that at least partially surrounds the cladding, wherein the housing and / or the core includes the red phosphor (340).

7. The lighting device according to any one of the preceding claims, wherein the optical light guide includes an optical coupling element (350) configured to couple out one of the following from the optical light guide: The green-yellow light, and A portion of the second part of the emitted blue light and the green-yellow light.

8. The lighting device according to claim 7, wherein the optical coupling element comprises at least one of the following: Light scattering particles (350) are arranged to scatter incident light. A light redirection structure is arranged to redirect incident light, and The structure of the cladding (360).

9. The lighting device according to any one of the preceding claims, wherein the optical device further comprises a diffuser (380) disposed upstream of the optical light guide.

10. The lighting device according to any one of the preceding claims, wherein the optical device comprises at least one lens (400a, 400b), and wherein the optical device is configured to couple the second portion of the emitted blue light and the green-yellow light into the optical guide via the at least one lens.

11. The lighting device according to any one of the preceding claims, wherein the red phosphor is an organic red phosphor.

12. The lighting device according to any one of the preceding claims, wherein the red phosphor is doped with tetravalent manganese. The type, wherein M' includes alkaline earth cations, M includes basic cations, and x is in the range of 0 to 1, wherein A includes tetravalent cations, and wherein X includes monovalent anions, wherein the monovalent anions include at least fluorine.

13. The lighting device according to claim 12, wherein the red phosphor is KSiF.

14. The lighting device according to any one of the preceding claims, wherein the greenish-yellow phosphor is A3B5O. 12 :Ce type, where A includes one or more of Y, La, Gd, Tb and Lu, and where B includes one or more of Al, Ga, In and Sc.

15. A lighting unit (500), comprising: The lighting device according to any one of the preceding claims, and The housing (510) is arranged to at least partially surround the solid-state light source and the optical device.

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