Laser and phosphor light sources with improved brightness and thermal management.

Abstract

The present invention is a light generation system 1000 having a light generation device 100, a luminescence body 200, and a first optical system 410, wherein the light generation device 100 is configured to generate device light 101, the light generation device 100 has a laser, the luminescence body 200 has a luminescence material 210, the luminescence material 210 is configured to convert at least a part of the device light 101 into luminescence material light 211, the luminescence body 200 is transparent to at least a part of the luminescence material light 211, the first optical system 410 is transparent to at least a part of the device light 101 and reflective to at least a part of the luminescence material light 211, the first optical system 410 has a primary optical surface 411 having a first surface area A1, the primary optical surface 411 is configured to be in a light receiving relationship with the light generation device 100, the luminescence body 200 is surrounded by a cavity 500 having a cavity opening 510 with a minimum cross-sectional area A2, the cavity 500 is at least partially defined by the first optical system 410, and provides a light generation system 1000 in which A2 < A1.

Description

Technical Field

[0001] The present invention relates to a light generation system and a light generation device having such a light generation system.

Background Art

[0002] An illumination device including a light source that generates blue light and a phosphor filter that converts the blue light into white light is known in the art. For example, US2018066810 describes an illumination device including a light source that generates blue light, a phosphor filter that converts the blue light into white light, and a light dispersing element that receives light and projects a plurality of scattered light points converted into white light by the phosphor filter onto a target surface. US2018066810 also describes a method for generating a plurality of scattered light points on a target surface using an illumination device including a light source, a phosphor filter, and a light dispersing element, the method including the steps of generating light using the light source, the generated light being blue light, converting the light into white light by passing the light through the phosphor filter, and incidenting the light on the light dispersing element such that the light dispersing element disperses the light and generates a plurality of individual light points on the target surface.

[0003] US2010 / 202129A1 discloses an illumination system including a wavelength conversion material and a total reflection reflector used to enhance the optical efficiency of an illumination system having a single aperture for inputting and outputting a light beam. A light guide, a micro-element plate, and an optical element having a limited output aperture are used to improve the brightness of the supplied light by reusing the light. Further, the micro-element plate can be used to control the spatial distribution of the light in terms of intensity and angle. An efficient and compact illumination system using a single light source with a deflector is also disclosed.

[0004] US2019 / 179218A1 discloses a light-emitting device including a luminescence element having a first surface and a second surface, wherein the first surface is a light input surface and a light output surface of the light-emitting device. The luminescence element receives, at the light input surface, a first light having a first spectral distribution emitted by at least one laser light source, converts at least a part of the first light having the first spectral distribution into a second light having a second spectral distribution, guides the second light having the second spectral distribution to the light output surface, and couples at least a part of the second light having the second spectral distribution outside the light output surface. A heat sink element is disposed so as to be in thermal contact with at least a part of the luminescence element.

[0005] US2021 / 104934A1 discloses that a phosphor-based lamp includes a phosphor material and a laser that excites the phosphor material. The lamp includes a recycling collar for reflecting and reusing high-angle light to increase brightness. A beam splitter redirects the direction of the laser beam to direct it through a recycling collar aperture towards the phosphor material. Light emitted by the phosphor material that exits the aperture passes through the beam splitter as the output of the lamp. Summary of the Invention Problems to be Solved by the Invention

[0006] White LED light sources can provide intensities up to, for example, about 300 lm / mm 2 whereas static phosphor-converted laser white light sources can provide intensities up to about 20,000 lm / mm 2It is possible to provide even this level of intensity. Ce-doped garnets (e.g., YAG, LuAG) may be the most suitable luminescence converters that can be used for pumping with blue laser light because the garnet matrix has very high chemical stability. Furthermore, at low Ce concentrations (e.g., less than 0.5%), thermal quenching may only occur above about 200°C. Moreover, the emission from Ce has a very fast decay time, and therefore the occurrence of light saturation can be essentially prevented. Assuming, for example, reflection mode operation, blue laser light can be incident on the phosphor. In embodiments, this may result in a nearly complete conversion of blue light, resulting in the emission of the converted light. For this reason, the use of garnet phosphors with relatively high stability and thermal conductivity is proposed. However, other phosphors may also be applicable. When extremely high power densities are used, thermal management can still be a challenge.

[0007] High-brightness light sources can be used in applications such as projection, stage lighting, spot lighting, and automotive lighting. For this purpose, laser-phosphor technology can be used in which a laser supplies laser light and a (remote) phosphor converts the laser light into converted light. In embodiments, the phosphor may be placed on or inserted into a heat sink for improved thermal management and therefore for higher brightness.

[0008] One of the problems that may be associated with such (laser) light sources is the thermal management of (ceramic) phosphors. Another problem associated with such laser light sources may be the desire to create compact, high-power devices.

[0009] Accordingly, providing an alternative luminescent element is one aspect of the present invention, which preferably further eliminates at least partially one or more of the above-mentioned disadvantages. The present invention may aim to eliminate or improve at least one of the disadvantages of the prior art, or to provide a useful alternative. [Means for solving the problem]

[0010] In a first embodiment, the present invention provides a photogenerating system ("system") having a photogenerating device ("device"), a luminescent body ("body"), and a first optical system. In particular, in embodiments, the photogenerating device may be configured to generate device light. In a particular embodiment, the photogenerating device has a laser. Furthermore, in embodiments, the luminescent body may include a luminescent material. In particular, in embodiments, the luminescent material is configured to convert at least a portion of the device light into luminescent material light. Furthermore, in a particular embodiment, the luminescent body may be transparent to at least a portion of the luminescent material light. Furthermore, in embodiments, the first optical system may be transparent to at least a portion of the device light and reflective to at least a portion of the luminescent material light. In particular, in embodiments, the first optical system has a primary optical surface having a first surface area (A1). Furthermore, in embodiments, the primary optical surface is configured to be in a light-receiving relationship with the photogenerating device. Furthermore, in embodiments, the luminescent body may be surrounded by a cavity having a cavity opening, particularly a reflective cavity. In embodiments, the cavity opening may have a minimum cross-sectional area (A2). In particular, in embodiments, the cavity may be at least partially defined by the first optical system. In certain embodiments, A2 <A1である。Therefore, in certain embodiments, the present invention provides a light generation system having a light generation device, a luminescence body, and a first optical system, wherein: (A) the light generation device is configured to generate device light, and the light generation device includes a laser; (b) the luminescence body includes a luminescence material, the luminescence material is configured to convert at least a portion of the device light into luminescence material light, and the luminescence body is transmissive to at least a portion of the luminescence material light; (c) the first optical system is transmissive to at least a portion of the device light and reflective to at least a portion of the luminescence material light, the first optical system has a primary optical surface having a first surface area (A1), and the primary optical surface is configured to be in a light receiving relationship with the light generation device; (d) the luminescence body is surrounded by a cavity having a cavity opening with a minimum cross-sectional area (A2), the cavity is at least partially defined by the first optical system, and A2 < A1.

[0011] In such a system, it may be possible to illuminate a relatively large area of the luminescence body, while the luminescence can escape from a relatively small area. Further, since the large area may be in thermal contact with a thermally conductive material such as a heat sink, the efficiency may be relatively high. Further, a relatively small device may be provided that is capable of supplying light having a relatively high intensity.

[0012] In an embodiment, the light generation device is specifically configured to generate device light. The light generation device may have a light source such as a solid light source configured to generate the device light, optionally based on conversion by a luminescence material. The light generation device includes a laser such as a solid laser. Accordingly, the device light includes laser light, and in still other specific embodiments, the device light may be laser light.

[0013] The term "light source" can refer to multiple light sources, such as 2 to 200 (solid-state) LED light sources. Therefore, the term "LED" can refer to multiple LEDs. Furthermore, in embodiments, the term "light source" can refer to a so-called chip-on-board (COB) light source. The term "COB" specifically refers to an LED chip in the form of a semiconductor chip that is not encapsulated, not connected, and directly mounted on a substrate such as a PCB. Therefore, multiple optical semiconductor light sources may be configured on the same substrate. In embodiments, the COB is a multi-LED chip configured together as a single lighting module.

[0014] The light source has a light escape surface. For conventional light sources such as incandescent bulbs or fluorescent lamps, the light escape surface may be the outer surface of a glass or quartz envelope. In the case of LEDs, the light escape surface may be, for example, the LED die, or, if a resin is coated on the LED die, the outer surface of the resin. In principle, the light escape surface may also be the end of a fiber. The term escape surface refers, in particular, to the portion of the light source from which light actually exits or escapes. The light source is configured to supply a light beam. (Thus) this light beam escapes from the light-emitting surface of the light source.

[0015] 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), and end-face emission lasers. The term “light source” may also refer to organic light-emitting diodes such as passive matrix (PMOLEDs) or active matrix (AMOLEDs). In certain embodiments, the light source has a solid-state light source (such as an LED or laser diode). In embodiments, the light source has an LED (light-emitting diode). The term “LED” may also refer to multiple LEDs. Furthermore, in embodiments, the term “light source” may refer to a so-called chip-on-board (COB) light source. The term “COB” specifically refers to an LED chip in the form of a semiconductor chip that is not encapsulated, not connected, and directly mounted on a substrate such as a PCB. Thus, multiple semiconductor light sources may be configured on the same substrate. In embodiments, the COB is a multi-LED chip configured together as a single lighting module.

[0016] The term “light source” may also refer to multiple (essentially identical (or different)) light sources, such as 2 to 2000 solid-state light sources. In embodiments, the light source may have one or more micro-optical elements (arrays of microlenses) 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, for example). In embodiments, the light source may have an LED with an on-chip optical system. In embodiments, the light source has a single pixelated LED (with or without an optical system) (which, in embodiments, provides on-chip beam steering).

[0017] The term “laser light source” specifically refers to a laser. Such a laser may be configured to produce laser light source light having one or more wavelengths in the UV, visible, or infrared range, particularly wavelengths selected from the spectral wavelength range of 200 to 2000 nm, such as 300 to 1500 nm. The term “laser” specifically refers to a device that emits light through a process of optical amplification based on stimulated emission of electromagnetic radiation.

[0018] In particular, in some embodiments, the term "laser" may refer to a solid-state laser. In certain embodiments, the terms "laser" or "laser light source," or similar terms, may refer to a laser diode (or diode laser).

[0019] Accordingly, in embodiments, the light source has a laser light source. In embodiments, the terms “laser” or “solid-state laser” refer to cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium-doped chrysoberyl (alexandrite) lasers, chromium-ZnSe (Cr:ZnSe) lasers, divalent samarium-doped calcium fluoride (Sm:CaF2) lasers, Er:YAG lasers, erbium-doped and erbium-ytterbium-co-doped glass. Lasers, F-center lasers, holmium (Ho:YAG) lasers, Nd:YAG lasers, NdCrYAG lasers, neodymium-doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, neodymium-doped orthovanadium yttrium (Nd:YVO4) lasers, neodymium glass (Nd:glass) lasers, neodymium YLF (Nd:YLF) solid-state lasers, promethium-147-doped phosphate glass (147Pm 3+ Solid-state laser (glass), ruby ​​laser (Al2O3:Cr 3+ ), Thulium YAG (Tm:YAG) laser, Titanium sapphire (Ti:Sapphire; Al2O3:Ti 3+This may refer to one or more of the following: lasers, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state lasers, ytterbium-doped glass lasers (rods, plates / tips, and fibers), ytterbium YAG (Yb:YAG) lasers, Yb2O3 (glass or ceramic) lasers, etc.

[0020] In embodiments, the terms “laser” or “solid-state laser” may refer to one or more semiconductor laser diodes, such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, lead salts, vertical cavity surface-emitting lasers (VCSELs), quantum cascade lasers, and hybrid silicon lasers.

[0021] Lasers may be combined with upconverters to reach shorter wavelengths. For example, upconversion can be achieved with some (trivalent) rare earth ions, or with nonlinear crystals. In other examples, lasers such as dye lasers may be combined with downconverters to reach longer wavelengths.

[0022] As can be derived from the following, the term “laser light source” may also refer to multiple (different or identical) laser light sources. In certain embodiments, the term “laser light source” may refer to multiple N (identical) laser light sources. In embodiments, N = 2 or more. In certain embodiments, N may be at least 5, particularly at least 8. In this way, higher brightness may be obtained. In embodiments, the laser light sources may be arranged in a laser bank (see also above). The laser bank may, in embodiments, include a heat sink and / or optical systems, such as lenses for collimating the laser light.

[0023] The laser light source is configured to generate laser light (or "laser light"). The light source may essentially consist of the laser light. The light source may also have laser light from two or more (different or identical) laser light sources. For example, the laser light from the two or more (different or identical) laser light sources may be coupled to an optical guide to supply a single optical beam having the laser light from two or more (different or identical) laser light sources. Thus, in certain embodiments, the light source is, in particular, collimated light. In yet another embodiment, the light source is, in particular, (collimated) laser light. The phrases "different light sources" or "multiple different light sources," and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from at least two different bins. Similarly, the phrases "identical light sources" or "multiple identical light sources," and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from the same bin.

[0024] The light source is configured to generate light source light having an optical axis (O), beam shape, and spectral power distribution. In embodiments, the light source light may have one or more bands having bandwidths known for lasers. In certain embodiments, the bands may be relatively sharp lines, such as having a full width at half maximum (FWHM) in the range of less than 20 nm at room temperature (RT), such as 10 nm or less. Thus, the light source light has a spectral power distribution (intensity in terms of energy as a function of wavelength) that may include one or more (narrow) bands.

[0025] The beam (of light from a light source) may be a focused or collimated beam of (laser) light from a light source. The term "focused" may, in particular, refer to converging into a small spot. This small spot may be in a discrete converter region, or slightly upstream or slightly downstream of the discrete converter region. In particular, focusing and / or collimation may be such that the cross-sectional shape (perpendicular to the optical axis) of the beam in the discrete converter region (on the side) is not inherently larger than the cross-sectional shape (perpendicular to the optical axis) of the discrete converter region (where the light from the light source illuminates the discrete converter region). Focusing may be performed by one or more optical systems, such as focusing lenses. In particular, two lenses may be used to focus the laser light from the light source. Collimation may be performed by one or more optical systems, such as collimation elements, such as lenses and / or parabolic mirrors. In embodiments, the beam of (laser) light source light may be relatively highly collimated, such as ≤2°(FWHM), more particularly ≤1°(FWHM), and most particularly ≤0.5°(FWHM). Thus, ≤2°(FWHM) can be considered (highly) collimated light source. Optical systems may be used to provide (high) collimation (see also above).

[0026] As described above, the photogenerating device may have one or more light sources. Furthermore, as described above, the photogenerating device may have a laser, or may be a laser. Therefore, the photogenerating device is configured to generate (polarized) laser beams.

[0027] The luminescent body may have any shape. However, generally, the luminescent body may have two essentially parallel surfaces that define its height. Furthermore, the luminescent body may have a bridge end face that connects the two essentially parallel surfaces. The end face may be curved in one or two dimensions. The end face may be planar. The luminescent body may have a rectangular or circular cross-section, but other cross-sections are also possible.

[0028] In embodiments, the body has a lateral width or length (W1 or L1) or diameter (D) and thickness or height (H1). In embodiments, (i) D ≥ H1, or (ii) W1 ≥ H1 and / or L1 ≥ H1. The luminescent tile may be transparent or light-scattering. In embodiments, the tile may have a ceramic luminescent material. In certain embodiments, L1 ≤ 10 mm, particularly L1 ≤ 5 mm, more particularly L1 ≤ 3 mm, most particularly L1 ≤ 2 mm. In certain embodiments, W1 ≤ 10 mm, particularly W1 ≤ 5 mm, more particularly W1 ≤ 3 mm, most particularly W1 ≤ 2 mm. In certain embodiments, H1 ≤ 10 mm, particularly H1 ≤ 5 mm, more particularly H1 ≤ 3 mm, most particularly H1 ≤ 2 mm. In certain embodiments, D ≤ 10 mm, particularly D ≤ 5 mm, more particularly D ≤ 3 mm, most particularly D ≤ 2 mm. In certain embodiments, the body may have a thickness in the range of 50 μm to 1 mm. Furthermore, the body may have a lateral dimension (width / diameter) in the range of 100 μm to 10 mm. In yet other specific embodiments, (i) D > H1 or (ii) W1 > H1 and W1 > H1. In particular, the lateral dimension, such as length, width, and diameter, is at least twice as large as the height, such as at least five times. In certain embodiments, the luminescent body has a first length L1, a first height H1, and a first width W1, where H1 ≤ 0.5 * L1 and H1 ≤ 0.5 * W1.

[0029] Furthermore, as described above, the luminescent body may include a luminescent material. For example, in some embodiments, the luminescent body may be a crystalline body, a ceramic body, or a luminescent material dispersed in another material such as a polymer (see also below). In particular, the luminescent material may be configured to convert at least a portion of the device light into luminescent material light.

[0030] In some embodiments, essentially all device light received by the luminescent body may be absorbed by the luminescent body. At least a portion of the absorbed light is converted into luminescent material light (depending particularly on quantum efficiency). This may be referred to as full conversion.

[0031] In other embodiments, a portion of the device light may be reflected and / or transmitted. The system light may include reflected or transmitted light. This may be referred to as a partial conversion.

[0032] The term "luminescent material" specifically refers to a material capable of converting one or more of the first radiation, particularly UV radiation and blue radiation, into the second radiation. Generally, the first and second radiations have different spectral power distributions. Therefore, the terms "luminescent converter" or "converter" may be used instead of "luminescent material." Generally, the second radiation has a spectral power distribution with greater wavelengths than the first radiation, which is the case of so-called downconversion. However, in certain embodiments, the second radiation has a spectral power distribution with greater intensity at smaller wavelengths than the first radiation, which is the case of so-called upconversion.

[0033] In an embodiment, the "luminescence material" may particularly refer to a material that can convert radiation, for example, into visible light and / or infrared light. For example, in an embodiment, the luminescence material may be capable of converting one or more of UV radiation and blue radiation into visible light. In certain embodiments, the luminescence material may convert radiation into infrared radiation (IR). Therefore, when excited by radiation, the luminescence material emits radiation. Generally, the luminescence material is a downconverter, that is, radiation with a smaller wavelength is converted into radiation with a larger wavelength (λ ex <λ em ), but in certain embodiments, the luminescence material may have an upconverter luminescence material, that is, radiation with a larger wavelength is converted into radiation with a smaller wavelength (λ ex >λ em ).

[0034] In an embodiment, the term "luminescence" may refer to phosphorescence. In an embodiment, the term "luminescence" may also refer to fluorescence. Instead of the term "luminescence", the term "light emission" may be applied. Therefore, the terms "first radiation" and "second radiation" may respectively refer to excitation radiation and light emission (radiation). Similarly, the term "luminescence material" may refer to phosphorescence and / or fluorescence in an embodiment. The term "luminescence material" may also refer to a plurality of different luminescence materials. Examples of possible luminescence materials are shown below.

[0035] In an embodiment, the luminescence materials are each selected from garnets and nitrides doped with trivalent cerium or divalent europium in particular. The term "nitride" may also refer to oxynitride or nitridosilicate, etc.

[0036] In certain embodiments, the luminescence material is A3B5O 12:Includes a Ce-type luminescent material, where A, in embodiments, includes one or more of Y, La, Gd, Tb, and Lu, particularly at least one or more of Y, Gd, Tb, and Lu, and B, in embodiments, includes one or more of Al, Ga, In, and Sc. In particular, A may include one or more of Y, Gd, and Lu, such as one or more of Y and Lu. In particular, B may include one or more of Al and Ga, more particularly at least Al, such as essentially Al only. Therefore, a particularly suitable luminescent material is a cerium-containing garnet material. Embodiments of garnet include, in particular, A3B5O 12 The material contains garnet, wherein A contains at least yttrium or lutetium, and B contains at least aluminum. Such garnet may be doped with cerium (Ce), praseodymium (Pr), or a combination of cerium and praseodymium, but may be doped with Ce in particular. In particular, B contains aluminum (Al), but B may also contain gallium (Ga) and / or scandium (Sc) and / or indium (In) in part, particularly up to about 20% of Al, and more particularly up to about 10% of Al (i.e., the B ion consists essentially of 90 mol% or more of Al and 10 mol% or less of one or more of Ga, Sc, and In). B may particularly contain up to about 10% gallium. In another modification, B and O may be replaced at least in part with Si and N. Element A may be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu), in particular. Furthermore, Gd and / or Tb are present in amounts up to about 20% of A. In certain embodiments, the garnet luminescent material is (Y 1-x Lu x )3B5O 12 :Ce is included, and x is greater than or equal to 0 and less than or equal to 1. The term ":Ce" indicates that some of the metal ions in the luminescent material (i.e., some of the "A" ions in garnet) are replaced by Ce. For example, (Y 1-x Lu x )3Al5O 12:In the case of Ce, a part of Y and / or Lu is replaced by Ce. This is known to those skilled in the art. Ce generally replaces A by 10% or less, and generally, the Ce concentration is in the range of 0.1 to 4%, particularly 0.1 to 2% (relative to A). Assuming 1% of Ce and 10% of Y, the completely correct formula can be (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 . Ce in garnet is substantially in the trivalent state or only in the trivalent state, as is known to those skilled in the art.

[0037] In an embodiment, the luminescence material (therefore) contains A3B5O 12 , and in a specific embodiment, up to 10% of B - O can be replaced by Si - N.

[0038] In a specific embodiment, the luminescence material contains (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 , where x1 + x2 + x3 = 1, x3>0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, 0 ≤ y2 ≤ 0.2, A' contains one or more elements selected from the group consisting of lanthanides, and B' contains one or more elements selected from the group consisting of Ga, In, and Sc. In an embodiment, x3 is selected from the range of 0.001 to 0.1. In the present invention, in particular, x1>0, such as at least 0.8, such as x1>0.2. Garnet with Y can provide an appropriate spectral power distribution.

[0039] In certain embodiments, up to 10% of B-O can be replaced by Si-N. Here, B in B-O refers to one or more of Al, Ga, In, and Sc (and O refers to oxygen), and in certain embodiments, B-O may refer to Al-O. As noted above, in certain embodiments, x3 can be selected from the range of 0.001 to 0.04. In particular, such luminescent materials have an appropriate spectral distribution (see below), have relatively high efficiency, have relatively high thermal stability, and can enable a high CRI (in combination with the first source light and the second source light (and the optical filter)). Thus, in certain embodiments, A can be selected from the group consisting of Lu and Gd. Alternatively or in addition, B can include Ga. Thus, in embodiments, the luminescent material is (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O 12 and Lu and / or Gd may be available. Even more particularly, x3 is selected from the range of 0.001 to 0.1, 0 < x2 + x3 ≤ 0.1, and 0 ≤ y2 ≤ 0.1. Further, in certain embodiments, up to 1% of B-O can be replaced by Si-N. Here, the percentages refer to moles (as is known in the art), and see also, for example, EP3149108. In still other particular embodiments, the luminescent material is (Y x1-x3 Ce x3 )3Al5O 12 where x1 + x3 = 1, 0 < x3 ≤ 0.2, and is 0.001 to 0.1, etc.

[0040] In certain embodiments, the light generating device may only include a luminescent material selected from the type of garnet containing cerium. In still other particular embodiments, the light generating device is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O12 includes a single type of luminescent material such as. Thus, in certain embodiments, the light generating device has a luminescent material, and at least 85 wt%, even more particularly at least about 90 wt%, for example even more particularly at least about 95 wt% of the luminescent material is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 . Here, A' includes one or more elements selected from the group consisting of lanthanides, B' includes one or more elements selected from the group consisting of Ga, In, and Sc, x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, and 0 ≤ y2 ≤ 0.2. In particular, x3 is selected from the range of 0.001 to 0.1. It should be noted that in an embodiment, x2 = 0. Alternatively, or in addition, in an embodiment, y2 = 0.

[0041] In certain embodiments, A may particularly include at least Y, and B may particularly include at least Al.

[0042] In an embodiment, the luminescent material may alternatively or in addition be M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+The luminescent material may include one or more of the following, where M includes one or more of Ba, Sr, and Ca, and in particular embodiments, at least Sr. In 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. In these compounds, europium (Eu) is substantially divalent or exclusively divalent and replaces one or more of the indicated divalent cations. Generally, Eu does not exist in amounts greater than 10% of the cations, and the presence of Eu is particularly in the range of about 0.5 to 10%, more particularly in the range of about 0.5 to 5%, relative to the cations that Eu replaces. The term ":Eu" means that a portion of the metal ion is Eu (in these examples, Eu 2+ This indicates that it can be replaced by (Ca). For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 ) may become AlSiN3. Divalent europium generally replaces divalent cations, such as the divalent alkaline earth cations mentioned above, particularly Ca, Sr, or Ba. The material (Ba,Sr,Ca)S:Eu may also be denoted as MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca), in particular, M in this compound includes calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced and replaces at least some of M (i.e., one or more of Ba, Sr, and Ca). Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted as M2Si5N8:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca), in particular, M in this compound includes Sr and / or Ba. In a further specific embodiment, M consists of Sr and / or Ba (the presence of Eu is not taken into consideration), and Ba 1.5 Sr 0.5Si5N8:Eu (i.e., 75% Ba; 25% Sr) consists of particularly 50 to 100%, more particularly 50 to 90% Ba, and 50 to 0%, more particularly 50 to 10% Sr. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr, and Ca). Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu may also be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca), in particular, M in this compound includes calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr, and Ca). As is known to those skilled in the art, Eu in the above-mentioned luminescent material is substantially in a divalent state, or exists only in a divalent state.

[0043] In embodiments, the red luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu, and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially divalent or exclusively divalent, replacing one or more of the indicated divalent cations. Generally, Eu is not present in amounts greater than 10% of the cations, and the presence of Eu is particularly in the range of about 0.5 to 10%, more particularly in the range of about 0.5 to 5%, relative to the cations that Eu replaces. The term ":Eu" means that a portion of the metal ion is Eu (in these examples, Eu 2+ This indicates that it can be replaced by (Ca). For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 ) can become AlSiN3. Divalent europium generally replaces divalent cations, such as the divalent alkaline earth cations mentioned above, especially Ca, Sr, or Ba.

[0044] The material (Ba,Sr,Ca)S:Eu is sometimes denoted as MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca), and in particular, in this compound, M contains calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced to replace at least some of M (i.e., one or more of Ba, Sr, and Ca).

[0045] Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted as M2Si5N8:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca), and in particular, M in this compound includes Sr and / or Ba. In further specific embodiments, M consists of Sr and / or Ba (the presence of Eu is not taken into consideration), and Ba 1.5 Sr 0.5 Si5N8:Eu (i.e., 75% Ba; 25% Sr), consisting particularly 50 to 100%, more particularly 50 to 90% Ba, and 50 to 0%, particularly 50 to 10% Sr. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr, and Ca).

[0046] Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu may also be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca), and in particular, in this compound, M comprises calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced to replace at least some of M (i.e., one or more of Ba, Sr, and Ca).

[0047] As is known to those skilled in the art, Eu in the above-mentioned luminescent material is substantially in a divalent state, or exists only in a divalent state.

[0048] The blue luminescent material is YSO(Y2SiO5:Ce 3+ ), or similar compounds, or BAM(BaMgAl 10 O 17 :EU 2+ ), or similar compounds may be included.

[0049] In this specification, the term "luminescent material" refers, in particular, to inorganic luminescent materials.

[0050] The term "phosphor" may sometimes be used instead of "luminescent material." These terms are known to those skilled in the art.

[0051] Alternatively, or in addition, other luminescent materials may be applied. For example, quantum dots and / or organic dyes may be applied and optionally embedded in a permeable matrix, such as a polymer like PMMA or polysiloxane.

[0052] Quantum dots are generally small crystals of semiconductor material with a width or diameter of only a few nanometers. When excited by incident light, quantum dots emit light of a color determined by the size and material of the crystal. Therefore, by matching the size of the dot, light of a specific color can be produced. The most well-known quantum dots that emit light in the visible range are based on cadmium selenide (CdSe) with shells such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium-free quantum dots, such as indium phosphide (InP) and copper indium sulfide (CuInS2) and / or silver indium sulfide (AgInS2), can also be used. Quantum dots exhibit a very narrow emission band, and therefore, quantum dots exhibit saturated colors. Furthermore, the emission color can be easily adjusted by matching the size of the quantum dot. In this invention, any type of quantum dot known in the art can be used. However, for reasons of environmental safety and concern, it may be preferable to use quantum dots that do not contain cadmium, or quantum dots with at least a very low cadmium content.

[0053] Other quantum confinement structures may be used instead of, or in addition to, quantum dots. In the context of this application, "quantum confinement structure" should be understood as, for example, a quantum well, quantum dot, quantum rod, tripod, tetrapod, or nanowire.

[0054] Organic phosphors can also be used. Examples of suitable organic phosphor materials include perylene derivative-based organic luminescent materials, such as compounds marketed by BASF under the name Lumogen®. Examples of suitable compounds include, but are not limited to, Lumogen® Red F305, Lumogen® Orange F240, Lumogen® Yellow F083, and Lumogen® F170.

[0055] Different luminescent materials may have different spectral power distributions for their respective luminescent material light. Alternatively, or in addition, such different luminescent materials may have different color points (or dominant wavelengths), in particular.

[0056] As described above, other luminescent materials may also be possible. Accordingly, in certain embodiments, the luminescent material is selected from the group of divalent europium-containing nitrides, divalent europium-containing oxynitrides, divalent europium-containing silicates, cerium-containing garnets, and quantum structures. Quantum structures may include, for example, quantum dots or quantum rods (or other quantum-type particles) (see above). Quantum structures may also include quantum wells. Quantum structures may also include photonic crystals.

[0057] The (inorganic) luminescent material may, in embodiments, be provided as a single crystal, as a ceramic body, or as a luminescent material dispersed in another material such as a polymer material. Organic luminescent materials and / or quantum dots may also be dispersed in another material such as a polymer material.

[0058] The luminescent body is configured to receive at least a portion of the device light. Therefore, in this embodiment, the luminescent body is configured downstream of the photogenerating device. Furthermore, the luminescent body may be configured to be in a light-receiving relationship with the photogenerating device.

[0059] The terms “upstream” and “downstream” refer to the arrangement of an item or feature with respect to the propagation of light from a light-generating means (in this case, in particular, the light source), where a second position in the light beam closer to the light-generating means is “upstream” and a third position in the light beam further away from the light-generating means is “downstream.”

[0060] The terms “radiatively coupled” or “optically coupled” may mean, in particular, that (i) a photogenerating element, such as a light source, and (ii) another item or material are related to each other such that at least a portion of the radiation emitted by the photogenerating element is received by the item or material. In other words, the item or material is configured to be in a photoreceiving relationship with the photogenerating element. At least a portion of the radiation from the photogenerating element is received by the item or material. This may be direct, such as the item or material being in physical contact with the photogenerating element (or its light-emitting surface), in an embodiment. This may be through a medium such as air, gas, or a liquid or solid light guide material. In an embodiment, one or more optical systems, such as lenses, reflectors, or optical filters, may also be configured in the optical path between the photogenerating element and the item or material.

[0061] The luminescent body is transparent to at least a portion of the luminescent material light. Since the luminescent body may be transparent, the luminescent material light (see below) generated at a position away from the cavity opening can be optionally reflected once or more times, propagate to the cavity opening, and escape from the cavity through the cavity opening.

[0062] In certain embodiments, a material may be considered transparent if, under perpendicular irradiation of radiation at or within a certain wavelength range, particularly at or within the wavelength range of radiation produced by a radiation source as described herein, the transmittance through a 1 mm thick layer of the material, particularly a 5 mm thick layer of the material, is at least 20%, such as at least 40%, at least 60%, particularly at least 80%, such as at least about 85%, and even further at least about 90%.

[0063] The light-transmitting material may have optical guide properties or wave guide properties. Accordingly, the light-transmitting material is also referred to herein as a waveguide material or optical guide material. The light-transmitting material generally has (some degree) transmittance in a direction perpendicular to the length of the light-transmitting material to one or more of (N)UV radiation, visible radiation, and (N)IR radiation, in embodiments at least visible light. In embodiments, without an activator (dopant) such as trivalent cerium, the internal transmittance in visible radiation may be close to 100%.

[0064] The transmittance of the light-transmitting material (itself) to one or more luminescence wavelengths may be at least 90% / cm, more particularly at least 95% / cm, at least 98% / cm, at least 99% / cm, or at least 80% / cm. This is, for example, 1cm 3 This means that the cubic light-transmitting material has a transmittance of at least 95% under vertical irradiation with radiation having a selected luminescence wavelength (such as the wavelength corresponding to the emission maximum of the luminescence material of the light-transmitting material).

[0065] In this specification, the transmittance values ​​refer in particular to transmittance that does not take into account Fresnel loss at the interface (e.g., with air). Accordingly, the term “transmittance” refers in particular to internal transmittance. The internal transmittance may be determined, for example, by measuring the transmittance of two or more bodies having different widths, the transmittance of which is measured over the different widths. In this case, the contribution of Fresnel reflection loss can be determined based on such measurements, and (as a result,) the internal transmittance can be determined. Accordingly, in particular, the transmittance values ​​shown herein ignore Fresnel loss.

[0066] In some embodiments, an anti-reflective coating may be applied to the luminescent body to suppress Fresnel reflection loss (during the optical incoupling process).

[0067] In addition to having high transmittance at the wavelength of interest, scattering at the same wavelength may be particularly low. Therefore, the mean free path at the wavelength of interest, taking only scattering effects into account (and thus not considering possible absorption, which should be low in any case given the high transmittance), may be at least 0.5 times the length of the body, such as at least 2 times the length of the body. For example, in an embodiment, the mean free path, taking only scattering effects into account, may be at least 5 mm, such as at least 10 mm. The wavelength of interest may, in particular, be the wavelength at the emission maximum of the luminescence of the luminescent material. The term “mean free path” is, in particular, the average distance a ray travels before experiencing a scattering event that changes its direction of propagation.

[0068] In some embodiments, the element having the light-transmitting material may be essentially made of the light-transmitting material. In some specific embodiments, the element having the light-transmitting material may be a light-transparent element.

[0069] In particular, the light-transmitting element, such as the optically transparent element, may in embodiments have an absorption length and / or scattering length of at least the length (or thickness) of the light-transmitting element, such as at least twice the length of the light-transmitting element. The absorption length can be defined as the length over which absorption reduces the intensity of light along the propagation direction by 1 / e. Similarly, the scattering length can be defined as the length along the propagation direction over which light along the propagation direction is lost due to scattering and thereby reduced by a coefficient of 1 / e. Here, the length may, in particular, refer to the distance between the first and second surfaces of the light-transmitting element comprising the light-transmitting material between the first and second surfaces.

[0070] Accordingly, in the embodiment, when the luminescent body is illuminated perpendicularly to the luminescent body with the device light, a portion of the device light (such as at least about 30% of the power of the device light) may be transmitted when it propagates parallel to the height of the luminescent body. Furthermore, in the embodiment, when the luminescent body is illuminated perpendicularly to the luminescent body with light having essentially the same wavelength as the centroid wavelength of the luminescent material light, a portion of the light (such as at least about 50% of the power of the light) may be transmitted when it propagates parallel to the height of the luminescent body. Furthermore, in the embodiment, when the luminescent body is illuminated perpendicularly to the luminescent body with light having essentially the same wavelength as the centroid wavelength of the luminescent material light, a portion of the light (such as at least about 30% of the power of the light) may be transmitted when it propagates parallel to the length of the luminescent body.

[0071] The term "centroid wavelength," also known as λc, is known in the art and refers to the wavelength value at which half of the light energy is at shorter wavelengths and half of the light energy is at longer wavelengths, and the value is expressed in nanometers (nm). It is the wavelength that bisects the integral of the spectral power distribution, as expressed by the equation λc = Σλ*I(λ) / (ΣI(λ)), where the sum spans the wavelength range 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 may be determined, for example, under operating conditions.

[0072] The system may further include a first optical system, which is transparent to at least a portion of the device light and reflective to at least a portion of the luminescent material light.

[0073] The first optical system allows excitation radiation to be irradiated to a larger portion of the luminescent body, while the cavity, with its cavity opening, essentially allows the luminescent material light to escape from the luminescent body (and the cavity) only through the cavity opening. In this manner, a relatively larger area may be excited, a relatively larger area may be cooled, and concentrated emission may be obtained.

[0074] Furthermore, the first optical system defines a portion of the cavity. Therefore, it is desirable that the first optical system be reflective to at least a portion of the luminescent material light. In this configuration, the excitation light can be transmitted into the cavity, while the luminescent material light remains within the cavity (unless it escapes through the cavity opening).

[0075] For example, in an embodiment, at least 40% of the power of the device light ("optical power") illuminating the first optical system, such as at least 50%, more particularly at least 70%, more particularly at least 80%, or at least 90%, may be transmitted under the irradiation of the device light. In an embodiment, the first optical system may be optimized to receive the device radiation perpendicularly or at a certain angle.

[0076] Therefore, in this specification, the term "power" may also refer to "light power."

[0077] For example, in one embodiment, under vertical irradiation of the luminescent material light, at least 40% of the power of the luminescent material light illuminating the first optical system may be reflected, such as at least 50%, more particularly at least 60%, more particularly at least 65%, more particularly at least 70%. It should be noted that the luminescent material light can illuminate the first optical system at various angles. However, for the sake of comparability, vertical irradiation is chosen here.

[0078] The first optical system has a primary optical surface having a first surface area (A1), and the primary optical surface is configured to be in a light-receiving relationship with the light-generating device. Therefore, at least a portion of the optical surface can be illuminated by the device light. The first optical system may also have a secondary optical surface that can be directed toward the luminescent body. Since the luminescent body can be supplied with luminescent material light during the operation of the system, the secondary optical surface may be configured to be in a light-receiving relationship with the luminescent body.

[0079] As described above, in the embodiment, the luminescent body is surrounded by a cavity. In particular, this cavity is reflective to the luminescent material light. Thus, the luminescent material light escaping from the luminescent body can be reflected by the cavity walls and returned to the luminescent body. In this manner, a kind of internal reflection may occur, and the luminescent material light may essentially only escape from the cavity through the cavity opening. In particular, at least 50% of the luminescent material light escaping from the cavity escapes through the cavity opening. Here, the percentage is relative to the power of the escaping luminescent material light. Accordingly, the luminescent body, cavity, and cavity opening may be configured such that at least 40% of the luminescent material light escaping from the cavity escapes through the cavity opening, particularly at least 40%, more particularly at least 50%, particularly at least 60%, more particularly at least 70%, and more particularly at least 80%. Thus, at least 50% of the luminescent material light escaping from the cavity escapes through the minimum cross-sectional area (A2) of the cavity opening. Here, the percentage refers to the percentage of the optical power of all the luminescent material light escaping from the cavity.

[0080] It should be noted that at least a portion of the cavity (or the cavity wall) may be defined by the first optical system. The cavity may be defined by a (reflective) wall that is reflective to the luminescent material light. Up to about 60% of the wall area may be defined by the first optical system (i.e., the secondary surface of the first optical system), such as 25 to 50% of the wall area, or in the range of 10 to 60%.

[0081] In some embodiments, the cavity may also be a cavity that is reflective to the device light.

[0082] The cavity has a cavity opening. The cavity opening has a minimum cross-sectional area (A2). The cavity opening may have a constant cross-sectional shape and size, such as a cylindrical cavity opening, for example, but the cavity opening may also have a cross-sectional size that varies over the cavity length, such as a conical cavity opening. Therefore, in this specification, the minimum cross-sectional area is selected. In an embodiment, the length of the cavity opening may be smaller than the equivalent diameter of the circle of the minimum cross-sectional area.

[0083] In an embodiment, the cavity opening may have a circular or polygonal cross-sectional shape having more than four sides, such as at least six sides (hexagon). This may be particularly useful for lighting applications.

[0084] In an embodiment, the cavity opening may have a square or rectangular cross-sectional shape. This may be particularly useful for projection applications.

[0085] In an embodiment, the first optical system and the cavity opening may have essentially the same shape, such as selected from circular, square, rectangular, hexagonal, etc.

[0086] The equivalent circle diameter (or ECD) of a two-dimensional shape (irregular shape) is the diameter of a circle of equivalent area. For example, the equivalent circle diameter of a square with side a is 2*a*SQRT(1 / π). In the case of a circle, the diameter is the same as the equivalent circle diameter. If a circle with diameter D in the xy plane is distorted into any other shape (in the xy plane) without changing the size of the region, the equivalent circle diameter of that shape will be D.

[0087] Therefore, as described above, the cavity is at least partially defined by the first optical system. Further, in an embodiment, A2 < A1. Therefore, the minimum cross-sectional area of the cavity opening is smaller than the area of the primary surface of the first optical system.

[0088] As can be derived from the above, the cavity opening may have an arbitrary cross-sectional shape. In particular, the cross-sectional shape may be circular or rectangular, but in an embodiment, it may be ring-shaped or the like. Further, the term "cavity opening" may refer to a plurality of cavity openings. For example, in an embodiment, there may be cavity openings on one side of the cavity and on the opposite side of the cavity. For example, in an embodiment, a grid-shaped cavity opening may be provided. It holds that A2 < A1 with respect to the cumulative cross-sectional area A2. Therefore, when there are two or more cavity openings, A2 refers to the cumulative minimum cross-sectional area of the cavity openings. Therefore, the region from which the luminescence material light can escape from the cavity is (generally) smaller than the light receiving region of the first optical system.

[0089] In a specific embodiment, 0.05 ≦ A2 / A1 ≦ 0.3. A ratio that is too small may cause loss of luminescence material light, and a ratio that is too large may not give a relatively strong spot. Therefore, within the range shown in this specification, high brightness and good efficiency can be obtained.

[0090] As described above, the cavity is at least partially defined by the first optical system. Furthermore, the cavity may be defined by a reflector or a reflective thermal conductive element such as a heat sink. Thus, the cavity opening may be formed by the first optical system or by, for example, the thermal conductive element. In certain embodiments, there is a single cavity opening that can be formed by the first optical system. In alternative embodiments, there may be multiple cavity openings, all of which are formed by the first optical system. The first optical system has the cavity opening. Note that the first surface area of ​​the first optical system is defined by the area of ​​the optical system (and does not include the area of ​​the cavity opening). Thus, for example, assuming a dichroic mirror as the first optical system (see embodiments below), the area of ​​the dichroic mirror is not defined by the cavity opening in such a dichroic mirror. Therefore, assuming a circular first optical system defined by an outer circle having a third area A3 and a (cylindrical) cavity aperture (in the first optical system) having an area A2, the area of ​​the first optical system is A1 = A3 - A2.

[0091] It should be noted that the cavity opening may, in some embodiments, generally be a physical opening, and in certain other embodiments, it may be made of an intrinsically transparent material such as glass, quartz, or ceramic. Thus, the cavity opening (itself) may have a transmittance of at least about 98%, such as at least about 99%, or 100% (in the case of a physical opening), to the luminescent material light (or the device light).

[0092] As described above, in the embodiments, the first optical system may be used to allow a relatively large area of ​​the luminescent body to be irradiated with device light, while the luminescent material light may not easily escape through the first optical system. Therefore, a considerable portion of the first optical system, in particular, may be irradiated with device light. This can further facilitate thermal management. For example, a focused laser spot may provide a strong emission spot, but it may also heat the luminescent material locally to a considerable extent. However, in the present invention, the excitation light may be dispersed across the luminescent body, while still providing a strong emission spot. This may result in less heating of the luminescent material, which may be beneficial to the efficiency and / or lifetime (of the luminescent body and / or the luminescent material).

[0093] Accordingly, the device light can, in embodiments, be broadened over at least a portion of the first optical system, or even over a substantial portion of the first optical system. This can be achieved, for example, by the properties of the photogenerating device, by using an optical system, by using multiple photogenerating devices, or by a combination of two or more of these, as are known to those skilled in the art. An optical system for influencing the beam shape of the photogenerating device may also be referred to herein as a second optical system.

[0094] Accordingly, in the embodiment, the photogenerating device and an optional second optical system may be configured to irradiate at least 25% of the first surface area (A1), such as at least 40% or at least 30% of the first surface area (A1). More particularly, in the embodiment, the photogenerating device and an optional second optical system may be configured to irradiate at least 50% of the first surface area (A1), such as at least 60% or at least 70% of the first surface area (A1).

[0095] In embodiments, at least 30% of the device light reaching the luminescent body, such as at least 40%, may be transmitted by the first optical system. Here, the percentage may refer to the percentage of the total power of the device light reaching the luminescent body, as before. In particular, at least 50% of the device light reaching the luminescent body, such as at least 60%, and at least 70% in certain embodiments, may be transmitted by the first optical system. In embodiments, at least 80% of the device light reaching the luminescent body, such as at least 95%, and at least 90%, may be transmitted by the first optical system.

[0096] In embodiments, up to approximately 70% of the device light reaching the luminescent body, such as up to approximately 60%, may reach the luminescent body through the cavity opening. In embodiments, this may be the case if the first optical system has the cavity opening. In particular, in embodiments, up to approximately 50% of the device light reaching the luminescent body, such as up to approximately 30%, may reach the luminescent body through the cavity opening. In certain embodiments, 5 to 40% of the device light reaching the luminescent body may reach the luminescent body through the cavity opening. Thus, up to 70% of the light power, such as up to 40% of the light power of the device light reaching the luminescent body, may reach the luminescent body through the cavity opening. The remaining portion may reach the luminescent body through the first optical system.

[0097] Accordingly, in certain embodiments, the light generation system may be configured such that at least 50%, particularly at least 60%, of the device light incident on the luminescent body is incident on the luminescent body after passing through the first optical system.

[0098] As described above, the cavity may be a cavity that is reflective to the luminescent material light, in particular, allowing the luminescent material light to escape from the cavity substantially only through the cavity opening. For this purpose, the cavity may have cavity walls that are reflective to the luminescent material light (see also above).

[0099] In the embodiment, at least a portion of the cavity may be provided by a reflective thermal conductive element (including a thermal conductive material) and / or by a reflector on such a thermal conductive element (including a thermal conductive material).

[0100] The thermally conductive element, in particular, has a thermally conductive material. The thermally conductive material may have a thermal conductivity of at least about 20 W / m / k, such as at least about 30 W / m / k, at least about 100 W / m / k, and especially at least about 200 W / m / k. In other specific embodiments, the thermally conductive material may have a thermal conductivity of at least about 10 W / m / k.

[0101] In embodiments, the thermally conductive material may have one or more of the following: copper, aluminum, silver, gold, silicon carbide, aluminum nitride, boron nitride, aluminum silicon carbide, beryllium oxide, silicon carbide composite, aluminum silicon carbide, copper tungsten alloy, copper molybdenum carbide, carbon, diamond, and graphite. Alternatively, or in addition, the thermally conductive material may have aluminum oxide or be composed of aluminum oxide.

[0102] Heat sinks are well known in the art. The term "heat sink" (or "heat sink") may also refer to a passive heat exchanger that transfers heat generated by a device, such as an electronic or mechanical device, to a fluid (cooling) medium, often air or a coolant. The heat is then (at least partially) dissipated away from the device. Heat sinks are designed in particular to maximize the surface area of ​​the heat sink that is in contact with the fluid cooling medium surrounding it. Therefore, heat sinks may have multiple fins. For example, the heat sink may be a body from which multiple fins extend.

[0103] A heatsink is, in particular, made of a thermally conductive material (more specifically, composed of a thermally conductive material). The term "heatsink" can also refer to multiple (different) heatsinks.

[0104] Accordingly, in the embodiment, the light generation system may further include a thermally conductive element such as a heat sink, the luminescent body is at least partially surrounded by the thermally conductive element such as the heat sink, the luminescent body is thermally coupled to the thermally conductive element such as the heat sink, and one or more of the following apply: (i) the thermally conductive element such as the heat sink is reflective to the luminescent material light, and (ii) a reflector configured between the luminescent body and the thermally conductive element such as the heat sink is reflective to the luminescent material light. Accordingly, in the embodiment, the cavity wall can be defined by one or more of the following: (i) a thermally conductive element such as a heat sink that is reflective to the luminescent material light, and (ii) a reflector configured between the luminescent body and the thermally conductive element such as the heat sink. For example, an aluminum heat sink may be sufficiently reflective to the luminescent material light. Therefore, in certain embodiments, the heat sink and the first optical system may define the cavity. The reflector may, in embodiments, be a reflective coating such as a coating of one or more of TiO2, BaSO4, or Al2O3, or other materials known to those skilled in the art.

[0105] In this embodiment, the luminescent body may be thermally coupled to a heat-conductive element such as a heat sink, but it does not have to be optically coupled.

[0106] When elements are in optical contact or optically coupled, they may, in some embodiments, be in physical contact with each other, or in other embodiments, be separated from each other by a (thin) layer of an optical material, such as an optical adhesive, or another optically transparent interface material, having a thickness of, for example, less than about 1 mm, preferably less than 100 μm. If an optically transparent interface material is not used, the (average) distance between two optically contacting elements may be, in particular, on the scale of a relevant wavelength, such as the wavelength of emission maximum. For visible wavelengths, this may be less than 1 μm, such as less than 0.7 μm, and even smaller for blue light. Therefore, an optically transparent interface material may be used when photocoupling is desired. In yet another embodiment, when an optically transparent interface material is not used, the average distance between two optically contacting elements may be, in particular, on the scale of a relevant wavelength, such as the wavelength of emission maximum. Therefore, physical contact may be present when optical contact is desired. However, even in such embodiments, there may be a non-zero average distance, in which case the average distance may be less than or equal to the wavelength of interest, such as the centroid wavelength of the laser beam.

[0107] In certain embodiments, the heat sink may have the cavity opening.

[0108] In some embodiments, the first optical system may have dichroic elements.

[0109] Alternatively, or in addition, the first optical system includes a (reflective) polarizing filter, the device light is polarized device light, and the polarizing filter and the photogenerating device are configured such that at least a portion of the polarized device light is transmitted by the polarizing filter and at least a portion of the luminescent material light is reflected by the polarizing filter. In embodiments, the device light may be polarized laser light. In embodiments, the polarizing filter may be a reflective polarizing filter. The term "polarizer" may also be used instead of "polarizing filter".

[0110] In embodiments in which the first optical system has a polarizing filter, two opposingly arranged photogenerating devices, particularly lasers, may be configured to generate polarized device light, and the photogenerating devices and the polarizing filter are configured such that at least a portion of the device light is transmitted through the polarizing filter.

[0111] In some embodiments, the polarizing filter may have two or more different polarizing filters or two or more different polarization domains. In such embodiments, different light-generating devices, such as lasers, may be configured to supply at least 50% of the device light to a particular polarizing filter or polarization domain.

[0112] In some embodiments, n1 lasers may be arranged at an angle of 360 / n relative to each other. In some specific embodiments, n1 may be 4. Two or more of the n1 lasers may supply device light with different polarizations. For example, one or more of the n1 lasers may supply device light with p polarization, and one or more other of the n1 lasers may supply device light with s polarization. For example, when n1=4, in some embodiments, two lasers may supply device light with p polarization, and two lasers may supply device light with p polarization.

[0113] In embodiments, the device light may be supplied to the first optical system at an angle, rather than under perpendicular illumination. However, combinations are also applicable. Thus, in certain embodiments, the photogenerating system may have n1 photogenerating devices configured to generate the device light having an optical axis (O) at an angle α with the primary optical plane, where the angle α is at least 40° and less than 90°. In particular embodiments, α may be selected from the range of 50 to 80°. Furthermore, in embodiments, n1 ≥ 1. In certain embodiments, n1 ≥ 2, such as 4 ≤ n1 ≤ 8, such as 3 ≤ n1 ≤ 12. However, more photogenerating devices may also be possible.

[0114] The system may supply system light during operation. The system light may, in the operating mode, include at least the luminescent material light. Other light may be mixed into this light. This may be done downstream of the luminescent body. However, along with the luminescent material light, device light may also propagate away from the luminescent body, for example by reflection in the first optical system and / or reflection within the cavity, and escape through the cavity opening (and / or the first optical system).

[0115] Accordingly, in certain embodiments, the photogenerating system may be configured to generate system light (the luminescent material is configured to convert a portion of the device light into luminescent material light), and during operation, at least a portion of the device light escapes from the cavity through the cavity opening, and the system light includes the device light and the luminescent material light.

[0116] The system, apparatus, or device may perform an operation in a certain “mode,” “operating mode,” or “mode of operation.” Similarly, in a method, an operation, or a stage, or a step may be performed in a certain “mode,” “operating mode,” or “mode of operation,” or “operable mode.” The term “mode” may also be expressed as “control mode.” This does not exclude the fact that the system, apparatus, or device may be adapted to provide another control mode, or more other control modes. Similarly, this does not exclude the fact that one or more other modes may be performed before and / or after the execution of the mode.

[0117] In embodiments, the photogenerating device may be configured to generate device light having a first centroid wavelength λ1, for example in blue, and the luminescent material light may have a second centroid wavelength λ2, for example in green, yellow, orange, or red, where λ2-λ1 ≥ 50 nm. In embodiments, 50 nm ≤ λ2-λ1 ≤ 250 nm, such as 50 nm ≤ λ2-λ1 ≤ 200 nm. In embodiments, λ2-λ1 ≥ 70 nm, and in particular, λ2-λ1 ≥ 90 nm, such as a difference of at least 110 nm, such as a difference of at least 100 nm.

[0118] In this embodiment, the luminescent body may have a ceramic body.

[0119] Further embodiments and aspects are described below.

[0120] In this specification, the terms “light” and “radiation” are used interchangeably unless the context makes it clear that “light” refers only to visible light. Therefore, the terms “light” and “radiation” may refer to UV radiation, visible light, and IR radiation. In certain embodiments, particularly for lighting applications, the terms “light” and “radiation” refer to visible light.

[0121] In certain embodiments, the term UV radiation may refer to near-UV radiation (NUV). Therefore, in this specification, the term "(N)UV" is also used to refer to UV in general and to NUV in certain embodiments. In certain embodiments, the term IR radiation may refer to near-IR radiation (NIR). Therefore, in this specification, the term "(N)IR" is also used to refer to IR in general and to NIR in certain embodiments.

[0122] The luminescent material layer may have multiple different luminescent materials. The term "layer" may also refer to a multilayer. In particular, the luminescent material layer has a ceramic body. In certain embodiments, the term "ceramic body" may refer to multiple ceramic bodies. Therefore, in certain embodiments, the luminescent material layer may have a ceramic body containing the luminescent material. Furthermore, in certain embodiments, the luminescent material may be A3B5O 12 :Includes a Ce-type luminescent material, where A includes one or more of Y, La, Gd, Tb, and Lu, and B includes one or more of Al, Ga, In, and Sc. Examples of luminescent materials are described below.

[0123] As described above, the photogenerating system is configured to generate system light, which includes at least the luminescent material radiation, in its operating mode. The system light may also include unabsorbed device light, unless filtered out or (in the case of total conversion) there is no unabsorbed device light. Furthermore, other photogenerating devices not described herein may be available that generate light that may be included by the system light in its operating mode. Furthermore, multiple photogenerating devices may be available that have different spectral power distributions of the device light and optionally include associated optical systems, following the same principles as described herein. Accordingly, the term “system” may, in embodiments, refer to multiple systems, and in particular embodiments, refer to multiple systems that may share one or more elements, such as one or more optical systems. In particular, such multiple systems that may share one or more elements may share at least radiation exit windows, such as openings in the housing or end windows of light-transmitting (solid) material.

[0124] In particular embodiments, the device radiation may have one or more of UV and visible radiation. In certain embodiments, the device radiation is essentially visible radiation, such as blue light. In particular embodiments, the luminescent material radiation may have one or more of visible radiation and IR radiation. In certain embodiments, the luminescent material radiation is essentially visible radiation, such as yellow and / or red light, where up to 20%, such as up to 10%, of the power in the spectral power distribution of the luminescent material radiation is at wavelengths above 780 nm.

[0125] In some embodiments, the system may be configured to generate white light in the operating mode. This will be further explained below.

[0126] In one embodiment, the luminescent body and the light-generating device may be configured in a reflective mode. In another embodiment, the luminescent body and the light-generating device may be configured in a transmissive mode.

[0127] Furthermore, the system may have a control system, or may be functionally coupled to a control system. The control system may control the photogenerating device, or may optionally control other devices as described above.

[0128] The term “white light” as used herein is known to those skilled in the art. The white light relates in particular to light having a correlated color temperature (CCT) between about 1800K and 20000K, such as between about 2000K and 20000K, particularly between 2700K and 20000K, and in the case of general illumination, particularly in the range of about 2700K to 6500K. In embodiments, for backlight applications, the correlated color temperature (CCT) may be particularly in the range of about 7000 to 20000K. Further embodiments, the correlated color temperature (CCT) may be particularly within about 15 SDCM (standard deviation of color matching) from the blackbody locus (BBL), particularly within about 10 SDCM from the BBL, and even more particularly within about 5 SDCM from the BBL.

[0129] The terms “visible,” “visible light,” or “visible emission,” and similar terms, refer to light having one or more wavelengths in the range of approximately 380 to 780 nm. In this specification, UV may refer in particular to wavelengths selected from the range of 200 to 380 nm.

[0130] The term “violet light” or “violet emission” particularly refers to light having a wavelength in the range of approximately 380 to 440 nm. The term “blue light” or “blue emission” particularly refers to light having a wavelength in the range of approximately 440 to 495 nm (including some violet and cyan hues). The term “green light” or “green emission” particularly refers to light having a wavelength in the range of approximately 495 to 570 nm. The term “yellow light” or “yellow emission” particularly refers to light having a wavelength in the range of approximately 570 to 590 nm. The term “orange light” or “orange emission” particularly refers to light having a wavelength in the range of approximately 590 to 620 nm. The term “red light” or “red emission” particularly refers to light having a wavelength in the range of approximately 620 to 780 nm. The term “pink light” or “pink emission” refers to light having a blue component and a red component. The term “cyan” may refer to one or more wavelengths selected from the range of approximately 490 to 520 nm. The term "amber" can refer to one or more wavelengths selected from the range of approximately 585 to 605 nm, such as approximately 590 to 600 nm.

[0131] The terms “control” and similar terms particularly mean at least determining the behavior of an element or supervising the operation of an element. Accordingly, in this specification, “control” and similar terms may mean imposing behavior on the element (determining the behavior of an element or supervising the operation of an element), such as measuring, displaying, operating, opening, shifting, changing temperature, etc. The terms “control” and similar terms may further include monitoring. Accordingly, the terms “control” and similar terms may include imposing behavior on an element, and may include imposing behavior on an element and monitoring the element. Control of the element may be performed by a control system, which may be referred to as a “controller.” Accordingly, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may have the control system. In embodiments, the control system and the element may not be physically coupled. Control may be performed via wired and / or wireless control. The term "control system" may also refer to multiple different control systems that are functionally coupled, for example, one of the multiple different control systems may be a master control system, and one or more other control systems may be slave control systems. The control system may have a user interface, or may be functionally coupled to a user interface.

[0132] Accordingly, in embodiments, the control system may be controlled by relying on one or more of the following: input signals from a user interface, sensor signals (from a sensor), and timers. The term "timer" may refer to a clock and / or a predetermined time scheme.

[0133] As described above, the light generation system further comprises a luminescent body. In particular, the luminescent body has a luminescent material and is configured to be in a light-receiving relationship with the n laser light sources, and the luminescent material is configured to convert at least a portion of the laser light source light into luminescent material light. In particular, the luminescent material light has visible light such that it has a color point in yellow or green.

[0134] The luminescent material is configured to convert at least a portion of a first radiation (selected from one or more of UV radiation and visible radiation) into luminescent material light. In particular, in embodiments, the luminescent material may be configured to convert at least a portion of blue light (as radiation) into luminescent material light. In particular, if the blue light is partially converted, the blue light can be used as a blue light source (for the device light) and as excitation light that can be converted by the luminescent material. The first radiation may be supplied in particular by a (solid) light source (see further below).

[0135] When various luminescent materials are used, one or more luminescent materials may be configured to convert the laser light source into one or more of green and yellow luminescent material light, and one or more other luminescent materials may be configured to convert the laser light source into one or more of orange and red luminescent material light.

[0136] In certain embodiments, the luminescent body has a ceramic body containing the luminescent material. In other examples, the luminescent body has a single crystal. In yet other specific embodiments, various types of luminescent bodies may be used. Thus, the body can be selected from single crystals and ceramic bodies in particular. The latter can be manufactured more easily than the former, but nevertheless may have good optical and / or thermal properties. Thus, in embodiments, the body may be a ceramic body. However, in certain embodiments, a combination of single crystals and ceramic bodies may also be used. In particular, the luminescent body has a ceramic luminescent body. Thus, in certain embodiments, the luminescent body is defined by a ceramic luminescent material. Therefore, in certain embodiments, the luminescent material is a luminescent material on which a ceramic luminescent body can be provided. Thus, the luminescent body may include a ceramic luminescent body.

[0137] Many of the above-mentioned luminescent materials, particularly garnet materials, can be supplied as ceramics (ceramic bodies or ceramic slabs). At least this is the case with A3B5O. 12 :Ce, or A3B'5C''3O 12 The alternative formula written as :Ce is applicable (see also below).

[0138] Ceramic bodies are known in the art. In particular, the ceramic material may be obtained by sintering and / or hot pressing, which is optionally followed by annealing in a (slightly) oxidizing atmosphere. The term "ceramic" is used in particular to refer to inorganic materials, and especially to 10 -8The present invention relates to inorganic materials obtained by heating (polycrystalline) powder at a temperature of at least 800°C, particularly at least 500°C, particularly at least 1400°C, particularly at least 1000°C, particularly at least 1000°C, under reduced pressure, atmospheric pressure, or high pressure, particularly under uniaxial pressure or isostatic pressure, particularly under isostatic pressure. A specific method for obtaining ceramics is hot isostatic pressing (HIP), and the HIP treatment may be post-sintering HIP, capsule HIP, or composite sintering HIP treatment, such as under the temperature and pressure conditions described above. The ceramics obtained by such a method may be used as is or may be further treated (such as polishing). The ceramics have a density of at least 90% (see below), particularly in the range of 97% to 100%, particularly at least 95% of the theoretical density (i.e., the density of a single crystal). Ceramics can still be polycrystalline, but the volume between grains (compressed or compressed aggregated grains) is reduced or significantly reduced. Heating under high pressure, such as HIP, can be carried out in an inert gas containing, for example, one or more of N2 and argon (Ar). In particular, prior to heating under high pressure, there is a sintering treatment at a temperature selected from the range of 1400 to 1900°C, such as 1500 to 1800°C. Such sintering is 10 -2The process may be carried out under reduced pressure, such as a pressure of Pa or less. Such sintering can already yield a density of at least 95%, and more particularly, at least 99%, of the theoretical density. After both pre-sintering and heating, especially under high pressure, such as HIP, the density of the light-transmitting material can approach that of a single crystal. However, the difference is that since the light-transmitting material is polycrystalline, grain boundaries are available in the light-transmitting material. Such grain boundaries can be detected, for example, by optical microscopy or SEM. Thus, in this specification, the light-transmitting material refers in particular to a sintered polycrystalline material having substantially the same density as a single crystal (of the same material). Thus, such a light-transmitting material is (especially Ce 3+ (Excluding absorption by light-absorbing species such as [specific species]) it may have high transparency to visible light.

[0139] The light generation system may be, for example, part of or used in an office lighting system, a home application system, a store lighting system, a home lighting system, an accent lighting system, a spot lighting system, a theater lighting system, an optical fiber application system, a projection system, a self-lit display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indicator sign system, a decorative lighting system, a portable system, an automotive application, an (outdoor) road lighting system, an urban lighting system, a greenhouse lighting system, horticultural lighting, digital projection, or an LCD backlight. The light generation system (or the lighting fixture) may be, for example, part of an optical communication system or a disinfection system, or used in or used in such a system.

[0140] In yet another embodiment, the present invention also provides a lamp or luminaire having a light-generating system as defined herein. The luminaire may further include a housing, optical elements, louvers, etc. The lamp or luminaire may further include a housing enclosing the light-generating system. The lamp or luminaire may have a light window or housing opening in the housing, through which the system light can escape from the housing. In yet another embodiment, the present invention also provides a projection device having a light-generating system as defined herein. In particular, the projection device or “projector” or “image projector” may be an optical device that projects an image (or video) onto a surface such as a projection screen. The projection device may include one or more light-generating systems as described herein. The light-generating system may also be used for disinfection or optical wireless communication. Accordingly, in some embodiments, the present invention also provides a photogenerating device selected from the group of lamps, lighting fixtures, projector devices, disinfection devices, and optical wireless communication devices, which has a photogenerating system as defined herein. [Brief explanation of the drawing]

[0141] Herein, embodiments of the present invention will be described with reference to the accompanying schematic drawings, where corresponding reference numerals indicate corresponding parts, as merely one example. [Figure 1a] Embodiments and modified examples are schematically illustrated. [Figure 1b] Embodiments and modified examples are schematically illustrated. [Figure 2a] Several embodiments and aspects are schematically illustrated. [Figure 2b] Several embodiments and aspects are schematically illustrated. [Figure 2c] Several embodiments and aspects are schematically illustrated. [Figure 2d] Several embodiments and aspects are schematically illustrated. [Figure 2e] Several embodiments and aspects are schematically illustrated. [Figure 2f] Several embodiments and aspects are schematically illustrated. [Figure 3] Here are a few examples of its application.

[0142] The schematic drawings are not necessarily to scale. [Modes for carrying out the invention]

[0143] Laser-based light sources are attracting considerable interest due to their potential to deliver extremely high intensity. Products such as automotive headlights and projection televisions, where lasers are used to pump phosphors, are already on the market.

[0144] Ce-doped garnets (e.g., YAG, LuAG) are suitable luminescence transducers for this purpose because the garnet matrix has the highest chemical stability and thermal quenching only occurs above 200°C at Ce concentrations below 0.5%. For this purpose, sizes from 0.04 mm × (0.2 mm × 0.2 mm) to 16 mm are suitable. × Phosphorescent ceramics up to (4mm*4mm) in size can be used.

[0145] In reflection mode, blue laser light is incident on the phosphor, achieving a nearly complete conversion of the blue light and resulting in the emission of the converted light. For this reason, the use of garnet phosphors, which possess relatively high stability and thermal conductivity, is proposed. However, thermal management remains a challenge when extremely high power densities are used.

[0146] To achieve high brightness, using the smallest possible phosphor tiles may be beneficial. However, as size decreases, brightness is limited by thermal quenching. Furthermore, as size decreases, pumping the phosphor tiles becomes more difficult, resulting in a complex and costly laser-phosphor architecture.

[0147] Herein, we propose, in particular, that a phosphor be placed on a highly reflective heat sink, with a dichroic reflector on the opposite side for yellow / green (and optionally red) light. The phosphor can be irradiated with (multiple) lasers on its top surface through a dichroic mirror. In embodiments, the dichroic reflector has a (central) physical light-emitting hole for the intentional escape of phosphor emission through such a hole. In embodiments, the irradiation on the top surface, for example at multiple points, is preferably near the edges. The phosphor may, in embodiments, be a (ceramic) (polycrystalline / monocrystalline) (disc-shaped) tile (the sides may also be disposed within the heat sink). The ratio of the surface area of ​​the light-emitting hole (A2) to the top surface area (A1) may, in embodiments, be in the range of 0.05 to 0.3. The phosphor tile may be molded (into a cone shape) to obtain light directionality in the transducer.

[0148] Figures 1a and 1b schematically illustrate an embodiment of a photogenerating system 1000 having a photogenerating device 100, a luminescent body 200, and a first optical system 410.

[0149] The photogenerating device 100 is configured to generate device light 101. In certain embodiments, the photogenerating device 100 has, or is, a laser. Therefore, in embodiments, the device light 101 may be laser light. Figure 1 schematically illustrates an embodiment comprising n1 = 8 photogenerating devices. In embodiments, illumination on the top surface at, for example, multiple points may be particularly near the edges. Referring, for example, to Figures 1a to 1b, the system 1000 may therefore include n1 photogenerating devices 100 configured to generate device light 101 having an optical axis O that makes an angle α with the primary optical plane 411. In embodiments, the angle α is at least 40° and less than 90°. In particular, α can be selected from the range of 50 to 80°. Furthermore, in certain embodiments, n1 ≥ 2. However, n1 may also be 1.

[0150] System 1000 further comprises a luminescent body 200 containing a luminescent material 210. The area shown by the larger circle may be a cylindrical luminescent body 200, with only the central part of the luminescent body 200 visible (see below for further details).

[0151] The luminescent material 210 is configured to convert at least a portion of the device light 101 into luminescent material light 211. In particular, the luminescent body 200 is transparent to at least a portion of the luminescent material light 211.

[0152] Reference numeral 410 indicates the first optical system. As seen from above, in this embodiment, the first optical system 410 covers a portion (a significant portion) of the luminescent body 200. Therefore, unless the first optical system 410 is transparent to the device light 101, such light may not reach the luminescent body 200 through the first optical system, or may reach it only at a reduced intensity.

[0153] Figure 1a schematically shows the (eight) spots of device light 101 on the primary surface 411 of the first optical system 410.

[0154] In this embodiment, the photogenerating device 100 and an optional second optical system (see below) may be configured to irradiate at least 50% of the first surface area A1 with device light 101.

[0155] Furthermore, in embodiments, the light generation system 1000 may be configured such that at least 60% of the device light 101 incident on the luminescent body 200 is incident on the luminescent body 200 after passing through the first optical system 410. In embodiments, a portion of the device light 101, such as up to about 40% of the device light 101 that reaches the luminescent body 200, may also be incident through the cavity opening 510.

[0156] As can be seen in Figure 1b, the device light 101 may have an optical axis that intersects with the first optical system. Therefore, there may be no device light 101 at all, or only a small amount, that directly reaches the luminescent body through the cavity aperture 510 (see below for further details).

[0157] In particular, the first optical system 410 is transparent to at least a portion of the device light 101 and reflective to at least a portion of the luminescent material light 211.

[0158] The first optical system 410 has a primary optical surface 411 oriented away from the luminescent body 200 and a secondary optical surface 412 oriented toward the luminescent body 200. The primary optical surface 411 has a first surface area A1. As schematically illustrated in Figures 1a to 1b, the primary optical surface 411 may be configured to be in a light-receiving relationship with the light-generating device 100.

[0159] In this embodiment, it should be noted that the primary optical system 410 and the cavity aperture 510 may have essentially the same shape (circular in this case).

[0160] As schematically illustrated, the luminescence body 200 is surrounded by a cavity 500 having a cavity opening 510. The cavity opening has a minimum cross-sectional area A2. Note that in these schematically illustrated embodiments, the cavity 500 is at least partially defined by an optical system 410. Further, as schematically illustrated, A2 < A1. In certain embodiments, 0.05 ≦ A2 / A1 ≦ 0.3.

[0161] In the schematically illustrated embodiment, the first optical system 410 has the cavity opening 510.

[0162] In an embodiment, the first optical system 410 has a dichroic element. In an alternative embodiment, the first optical system 410 may have a reflective polarizing filter, the device light 101 is polarized device light 101, and the polarizing filter and the light generation device 100 are configured such that at least a portion of the polarized device light 101 is transmitted by the polarizing filter and at least a portion of the luminescence material light 211 is reflected by the polarizing filter.

[0163] Reference numeral 1001 indicates the system light of the system 1000, which may include the luminescence material light 211.

[0164] Thus, the light generation system 1000 is configured to generate, in particular, the system light 1001, the luminescence material 210 is configured to convert a portion of the device light 101, and during operation, at least a portion of the device light 101 escapes from the cavity 500 through the cavity opening 510, and the system light 1001 includes the luminescence material light 211 and optionally includes the device light 101.

[0165] Reference numeral 600 indicates a heat sink or other thermally conductive element. Note that in this embodiment, the heat sink (or other thermally conductive element) 600 defines at least a portion of the cavity 500. The heat sink (or other thermally conductive element) may be at least partially reflective to luminescent material light 211 (and device light (101)).

[0166] Referring to the embodiments in Figures 2a and 2b, the angle α may also be 90°. In such embodiments, a third optical system 430, particularly a dichroic one, may be used that can transmit or reflect device radiation 101 and reflect or transmit luminescent material radiation 211 (see embodiments I and II in Figure 2a). However, embodiment I in Figure 2b also shows that a simple reflector, shown as the third optical system 430 in this embodiment, may be used.

[0167] Embodiment II in Figure 2b shows that a second optical system 420, such as a lens, may be used to control the beam shape of the device light 101.

[0168] Figure 2c shows that other shapes of the luminescent body 200 are also possible. For example, the phosphor tile may be shaped (conical) to obtain directionality of light in the transducer. The dashed areas schematically show the cavity 500 and cavity opening 510 for the purpose of illustrating these embodiments.

[0169] Referring to Figure 2d, and also to Figures 1a to 2c, an embodiment of the light generation system 1000 having a heat sink 600 is schematically illustrated. The luminescent body 200 is surrounded at least partially by the heat sink 600. In particular, the luminescent body 200 may be thermally coupled to the heat sink 600. Furthermore, embodiments are illustrated in which one or more of the following are true: (i) the heat sink 600 is reflective to the luminescent material light 211 (see Figures 1a to 2c), and (ii) the reflector 610 configured between the luminescent body 200 and the heat sink 600 is reflective to the luminescent material light 211 (see Figure 2d). Accordingly, in the embodiment, at least a portion of the reflector 610 may define the cavity wall of the cavity 500.

[0170] Therefore, in this embodiment, the heat sink 600 and the first optical system 410 define the cavity 500. In yet another embodiment, the first optical system 410 and one or more of the reflector 610 and the heat sink 600 may define the cavity 500.

[0171] Figure 2e schematically illustrates several alternative embodiments, in which Embodiment I appears to have two or more cavity openings 510, where the cavity openings 510 are, in the case of a ring-shaped cavity opening 510, one identical opening. Embodiment I in Figure 2e shows that A1 may be defined by several parts (e.g., an outer ring and an inner ring), and A2 may be defined by, for example, a ring-shaped cavity opening 510 (or multiple cavity openings).

[0172] Embodiment II in Figure 2e schematically illustrates an embodiment in which the heat sink 600 has a cavity opening 510.

[0173] Figure 2f schematically illustrates several embodiments of the shape of the luminescent body 200. The luminescent body 200 may have a first length L1, a first height H1, and a first width W1. In particular, H1 ≤ 0.5 * L1 and H1 ≤ 0.5 * W1. Note that in the case of a circular cross-section, W1 = L1 = D1 (diameter). If the length, width, or diameter varies over the height H1 (see Embodiment III), the average value averaged over the height H1 may be applied.

[0174] In the embodiment, the photogenerating device 100 is configured to generate device light 101 having a first centroid wavelength λ1, and the luminescent material light 211 has a second centroid wavelength λ2, where λ2-λ1≧50nm. Furthermore, in the embodiment, the luminescent material 210 is A3B5O 12 : Containing a Ce-type luminescent material, A contains one or more of Y, La, Gd, Tb, and Lu, and B contains one or more of Al, Ga, In, and Sc.

[0175] Figure 3 schematically illustrates an embodiment of a lighting fixture 2 including the light generation system 1000 described above. Reference numeral 301 indicates a user interface that can be functionally coupled to a control system 300 which is included in or functionally coupled to the light generation system 1000. Figure 3 also schematically illustrates an embodiment of a lamp 1 having the light generation system 1000. Reference numeral 3 indicates a projector device or projector system that can be used to project an image onto a wall or the like, and the projector device or projector system may also include system 1000.

[0176] The term "plural" refers to two or more things.

[0177] The terms “substantially” or “essentially” as used herein, and similar terms, will be understood by those skilled in the art. The terms “substantially” or “essentially” may also include embodiments that include “overall,” “completely,” “all,” etc. Accordingly, in embodiments, the adjectives “substantially” or “essentially” may be omitted. Where applicable, the terms “substantially” or “essentially” may also refer to 90% or more, including 100%, 95% or more, especially 99% or more, and even more specifically 99.5% or more.

[0178] The term "to possess" also includes embodiments in which the term "to possess" means "to consist of".

[0179] The term "and / or" refers in particular 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 may refer to one or more of item 1 and item 2. The term "having" may in one embodiment mean "consisting of", but in another embodiment it may mean "including at least the specified species and optionally including one or more other species".

[0180] Furthermore, terms such as "first," "second," and "third" in the specification and claims are used to distinguish similar elements and are not necessarily used to describe a sequential or chronological order. Such terms are interchangeable under appropriate circumstances, and it should be understood that embodiments of the invention described herein may operate in an order other than that described or illustrated herein.

[0181] In the claims, no reference numerals placed in parentheses should be construed as limiting the claims.

[0182] The use of the verb "to have" and its inflections does not exclude the existence of elements or steps other than those indicated in the claims. Unless the context clearly requires a different meaning, throughout the specification and claims, words such as "to have" should be interpreted in a comprehensive sense, as opposed to an exclusive or exhaustive sense, i.e., "including, but not limited to."

[0183] The singular notation of an element does not exclude the possibility of multiple instances of that element.

[0184] The present invention also provides control systems capable of controlling devices, apparatus, or systems, or of performing methods or processes described herein. Furthermore, the present invention also provides computer program products that, when executed on a computer functionally coupled to or included in such devices, apparatus, or systems, control one or more controllable elements of such devices, apparatus, or systems.

[0185] The present invention further relates to a device, apparatus, or system having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings. The present invention further relates to a method or process having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.

Claims

1. A light generation system comprising a light generation device, a luminescent body, a heat sink, and a first optical system, The photo-generating device is configured to generate device light, and the photo-generating device has a laser, The luminescent body comprises a luminescent material, the luminescent material is configured to convert at least a portion of the device light into luminescent material light, and the luminescent body is transparent to at least a portion of the luminescent material light. The first optical system is transparent to at least a portion of the device light and reflective to at least a portion of the luminescent material light, and the first optical system has a primary optical surface having a first surface area A1, and the primary optical surface is configured to be in a light-receiving relationship with the light-generating device. The luminescent body is at least partially surrounded by the heat sink, and the luminescent body is thermally coupled to the heat sink. The luminescent body is surrounded by a cavity having a cavity opening with a minimum cross-sectional area A2, the cavity is defined by the first optical system and the heat sink, and the first optical system has the cavity opening, where A2 < A1. A light generation system in which the cavity is reflective to the light of the luminescent material, and during operation, at least 70% of the light of the luminescent material is emitted from the cavity through the cavity opening.

2. The photogenerating system according to claim 1, wherein the photogenerating device is configured to irradiate at least 50% of the first surface area A1 with the device light.

3. The photogenerating system according to any one of claims 1 to 2, further comprising a second optical system configured to influence the beam shape of the photogenerating device.

4. The light generation system according to any one of claims 1 to 3, wherein the light generation system is configured such that at least 60% of the device light incident on the luminescent body is incident on the luminescent body after passing through the first optical system.

5. A light generation system according to any one of claims 1 to 3, wherein one or more of the following are met: (i) the heat sink is reflective to the light of the luminescent material, and (ii) the reflector configured between the luminescent body and the heat sink is reflective to the light of the luminescent material.

6. The photogenerating system according to any one of claims 1 to 3, wherein the first optical system has a dichroic element.

7. The light generation system according to any one of claims 1 to 3, wherein the first optical system includes a reflective polarizing filter, the device light is polarizing device light, and the polarizing filter and the light generation device are configured such that at least a portion of the polarizing device light is transmitted by the polarizing filter and at least a portion of the luminescent material light is reflected by the polarizing filter.

8. A photogenerating system according to any one of claims 1 to 3, wherein 0.05 ≤ A2 / A1 ≤ 0.

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9. The photogenerating system according to any one of claims 1 to 3, comprising n1 photogenerating devices configured to generate device light having an optical axis that makes an angle α with the primary optical surface, wherein the angle α is at least 40° and less than 90°, and n1 ≥ 2.

10. The photo-generating system according to any one of claims 1 to 3, wherein the photo-generating system is configured to generate system light, and during operation, at least a portion of the device light escapes from the cavity through the cavity opening, and the system light comprises device light and luminescent material light.

11. The photo-generating device is configured to generate device light having a first centroid wavelength λ1, and the luminescent material light has a second centroid wavelength λ2, wherein λ2 - λ1 ≥ 50 nm, according to any one of claims 1 to 3.

12. The luminescent body has a ceramic body, and the luminescent material is A ３ B ５ O １２ A photogenerating system according to any one of claims 1 to 3, comprising a Ce-type luminescent material, wherein A comprises one or more of Y, La, Gd, Tb, and Lu, and B comprises one or more of Al, Ga, In, and Sc.

13. The light generation system according to any one of claims 1 to 3, wherein the luminescent body has a first length L1, a first height H1, and a first width W1, and H1 ≤ 0.5 × L1 and H1 ≤ 0.5 × W1.

14. The photogenerating system according to claim 1, wherein the heat sink has the cavity opening.

15. A photogenerating device selected from the group consisting of lamps, lighting fixtures, projector devices, disinfection devices, and optical wireless communication devices, the photogenerating device having the photogenerating system described in any one of claims 1 to 3.

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