Heat sink with closed logo slits for pumping cylindrical phosphor bodies

Abstract

The present invention relates to a light-generation system 1000 having a first light-generation device 110, a luminescent body 200, one or more thermal conductors 510, and one or more optical elements 400, wherein (A) the first light-generation device 110 is configured to generate a first device light 111, the first light-generation device 110 having a first light source 10 selected from the group of a superluminescent diode and a laser, (B) the luminescent body 200 has a luminescent material 210 configured to convert at least a portion of the first device light 111 into a luminescent material light 211, the luminescent body 200 having a first surface 201, a second surface 202, and a bridging surface 203 bridging the first surface 201 and the second surface 202, the second surface 202 having a second surface circle equivalent diameter D2. (C) the one or more thermal conductors (510) have (C1) a first thermal conductor portion (511) in thermal contact with at least a portion of the first surface (201) and (C2) a second thermal conductor portion (512) in thermal contact with one or more of (i) a portion of the bridging surface (203) and (ii) a portion of the second surface (202); (D) the first thermal conductor portion (511) and the second thermal conductor portion (512) define a slit-shaped opening (520) along at least a portion of the perimeter P of the bridging surface (203); and (E) the first light-generating device (110) and the one or more optical elements (400) are configured to supply the first device light (111) to the luminescent body (200) through the slit-shaped opening (520).

Description

[Technical field]

[0001] The present invention relates to a light generation system and to a lighting device comprising such a light generation system. [Background technology]

[0002] Illumination systems are known in the art. For example, US2019 / 187544 describes a first light-emitting module configured to emit at least one first color light, the at least one first color light including a first partial light and a second partial light, and a wavelength conversion unit disposed in a transmission path of the first partial light, the first partial light being focused on the wavelength conversion unit, and the second partial light passing through a location beside the wavelength conversion unit, the wavelength conversion unit converting the first partial light into a converted light, the wavelength of the converted light being greater than the wavelength of the at least one first color light. The present invention describes an illumination system having a spherical shell-shaped dichroic film arranged in a transmission path of at least one first color light between a first light-emitting module and a wavelength conversion unit, the spherical shell-shaped dichroic film being capable of transmitting at least one first color light and reflecting converted light, the converted light coming from the wavelength conversion unit being reflected by the spherical shell-shaped dichroic film and then at least partially overlapping with a second partial light, and a transparent substrate supporting the spherical shell-shaped dichroic film.

[0003] WO2010116305A discloses a lamp adapted to generate high power in laser applications. The lamp comprises a light source adapted to emit optical radiation along an optical path and a holder containing a phosphor, the holder being disposed in the optical path. A light collecting unit is provided adapted to transmit at least a portion of the optical radiation emitted by the phosphor to an output of the lamp, the phosphor having an elongated shape in a predetermined direction. Summary of the Invention [Problem to be solved by the invention]

[0004] A white LED light source, for example, has a light output of approximately 300 lm / mm 2 While static phosphor-converted laser white light sources can provide intensities up to about 20,000 lm / mm 2 It can even give an intensity of up to 1000 nm. Ce-doped garnets (e.g., YAG, LuAG) may be the most suitable luminescence converters that can be used to pump with blue laser light, since the garnet host material has a very high chemical stability. Furthermore, at low Ce concentrations (e.g., less than 0.5%), temperature quenching may only occur above about 200° C. Furthermore, the emission from Ce has a very fast decay time, and therefore the occurrence of optical saturation can be essentially prevented. Assuming, for example, a reflection mode operation, blue laser light may be incident on the phosphor. This may achieve, in embodiments, a nearly complete conversion of blue light, resulting in the emission of converted light. It is for this reason that the use of garnet phosphors with relatively high stability and thermal conductivity is proposed. However, other phosphors may also be applied. Thermal management may still be a challenge when very high power densities are used.

[0005] High brightness light sources can be used in applications such as projection, stage lighting, spot lighting, automotive lighting, etc. For this purpose, laser-phosphor technology can be used, where a laser provides the laser light and for example a (remote) phosphor converts the laser light into converted light. The phosphor may in embodiments be arranged on or inserted into a heat sink for improved thermal management and thus higher brightness.

[0006] There appears to be a need for a relatively high intensity illumination system that may preferably be relatively compact and / or relatively simple, and preferably may be highly reliable, such as spectrally stable light, regardless of intensity. However, some luminescent materials exhibit temperature dependent intensity, which may cause problems when pumping at relatively high intensities.

[0007] It is therefore an aspect of the present invention to provide an alternative light-generating device, which preferably also at least partially obviates one or more of the above disadvantages. The present invention may aim to eliminate or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [Means for solving the problem]

[0008] Thus, in a first aspect, the present invention provides a light generation system ("system") comprising a first light-generating device, a luminescent body, one or more thermal conductors, and one or more optical elements. The first light-generating device is configured to generate a first device light. The first light-generating device comprises a first light source selected from the group of a superluminescent diode and a laser. The luminescent body comprises a luminescent material configured to convert at least a portion of the first device light into luminescent material light. The luminescent body has a first surface, a second surface, and a bridging face bridging the first surface and the second surface. The second surface has a second surface circle equivalent diameter D2. In an embodiment, the bridging face has a first height (H1), where H1 / D2<1. The bridging face has a perimeter (P). The one or more thermal conductors are reflective to the first device light and the luminescent material light and have (i) a first thermal conductor portion in thermal contact with at least a portion of the first surface, and (ii) a second thermal conductor portion in thermal contact with a portion of the bridging surface and a portion of the second surface. The first thermal conductor portion and the second thermal conductor portion define a slit-shaped opening along at least a portion of the periphery (P) of the bridging surface. The first light-generating device and the one or more optical elements are configured to provide the first device light to the luminescent body through the slit-shaped opening. During operation of the light-generating system, at least a portion of the luminescent material light escapes from at least a portion of the second surface.Therefore, the present invention, in a specific embodiment, provides a light generation system having a first light-generating device, a luminescent body, one or more thermal conductors, and one or more optical elements, wherein (A) the first light-generating device is configured to generate a first device light, the first light-generating device having a first light source selected from the group of a superluminescent diode and a laser, (B) the luminescent body having a luminescent material configured to convert at least a portion of the first device light into luminescent material light, the luminescent body having a first surface, a second surface, and a bridging surface bridging the first surface and the second surface, the second surface having a second surface circle equivalent diameter D 2, the bridging surface having a first height (H1) and a perimeter (P), where H1 / D2<1; (C) the one or more thermal conductors having (C1) a first thermal conductor portion in thermal contact with at least a portion of the first surface, and (C2) a second thermal conductor portion in thermal contact with one or more of (i) the portion of the bridging surface and (ii) the portion of the second surface; (D) the first thermal conductor portion and the second thermal conductor portion define a slit-like opening along at least a portion of the perimeter (P) of the bridging surface; and (E) the first light-generating device and the one or more optical elements are configured to provide the first device light to the luminescent body through the slit-like opening.

[0009] Such a system may be capable of providing high intensity system light. Moreover, such a system may be capable of providing high intensity system light in a relatively efficient manner. Moreover, such a system may be more reliable. Thus, over time, the output may be more spectrally stable. Moreover, in embodiments, it may be possible to control the system light and thereby control one or more of the color point, color rendering index, and correlated color temperature. Moreover, such a system may be based on relatively simple components. Moreover, such a system may be capable of providing system light with good or even high CRI.

[0010] As mentioned above, the light generation system may comprise a first light generation device, a luminescent body, one or more thermal conductors, and one or more optical elements.

[0011] The first light generating device may in particular be configured to generate a first device light. In particular, the first light generating device may comprise a first light source. The first light source may in particular be configured to generate a first light source light. In an embodiment, the first device light may in particular consist of the first light source light. In a particular embodiment, the first light source may comprise a first laser device, such as a diode laser. Thus, in a particular embodiment, the first light source light may comprise a first laser device light. Hence, in a particular embodiment, the first device light may essentially consist of the first laser device light. Thus, as also shown below, in an embodiment, the light generating system may comprise a first laser device. The term "first laser device" may also refer to multiple first laser devices of essentially the same type, such as those from the same bin. Alternatively or in addition, in a particular embodiment, the first light source may comprise a first superluminescent diode. Thus, in a particular embodiment, the first light source light may comprise a first superluminescent diode light. Thus, in certain embodiments, the first device light may consist essentially of the first superluminescent diode light. Thus, as also shown below, in embodiments, the light generating system may include a first superluminescent diode. The term "first superluminescent diode" may also refer to multiple first superluminescent diodes of essentially the same type, such as from the same bin.

[0012] The term "light source" may in principle relate to any light source known in the art. It may be a conventional (tungsten) light bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light-emitting diode). In a particular embodiment, the light source comprises a solid-state LED light source (such as an LED or a laser diode (or "diode laser")). The term "light source" may also relate to a plurality of light sources, such as 2 to 200 (solid-state) LED light sources. Thus, the term LED may also refer to a plurality of LEDs. Furthermore, the term "light source" may also refer in embodiments to so-called chip-on-board (COB) light sources. The term "COB" refers in particular to an LED chip in the form of a semiconductor chip that is not encapsulated or connected, but is directly mounted on a substrate such as a PCB. Thus, several light-emitting semiconductor light sources may be arranged on the same substrate. In an embodiment, the COB is a multi-LED chip arranged together as a single lighting module.

[0013] The light source may have a light escape surface. For conventional light sources like light bulbs or fluorescent lamps, the light escape surface may be the outer surface of a glass or quartz envelope. In the case of an LED, the light escape surface may for example be the LED die or, if a resin is applied to 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 particularly relates to the part of the light source where the light actually leaves or escapes from the light source. The light source is configured to provide a light beam. This light beam escapes from the light exit surface of the light source.

[0014] Similarly, the light-generating device may include a light escape surface, such as an end window.Further, similarly, the light-generating system may include a light escape surface, such as an end window.

[0015] The term "light source" may refer to a semiconductor light emitting device such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge emitting laser, etc. The term "light source" may also refer to an organic light emitting diode (OLED), such as a passive matrix (PMOLED) or active matrix (AMOLED). In certain embodiments, the light source comprises a solid state light source (such as an LED or a laser diode). In embodiments, the light source comprises an LED (light emitting diode). The term "light source" or "solid state light source" may also refer to a superluminescent diode (SLED).

[0016] The term LED can also refer to multiple LEDs.

[0017] 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 comprise one or more micro-optical elements (array 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, for example, by multiple LEDs). In embodiments, the light source may comprise an LED with on-chip optics. In embodiments, the light source comprises a single pixelated LED (with or without optics) (in embodiments providing on-chip beam steering).

[0018] In an embodiment, the light source may be configured to provide a primary radiation to be used as such, for example a blue light source such as a blue LED, or a green light source such as a green LED, and a red light source such as a red LED. Such LEDs, which may not include a luminescent material ("phosphor"), may be denoted direct color LEDs.

[0019] However, in other embodiments, the light source may be configured to provide a primary radiation, and a portion of the primary radiation is converted to a secondary radiation. The secondary radiation may be based on conversion by a luminescent material. The secondary radiation may therefore also be referred to as luminescent material radiation. The luminescent material may in embodiments be included by the light source, such as an LED with a luminescent material layer or dome that includes the luminescent material. Such an LED may be referred to as a phosphor converted LED or PC LED. In other embodiments, the luminescent material may be configured at some distance ("remote") from the light source, such as an LED with a luminescent material layer that is not in physical contact with the LED die.

[0020] In embodiments, the light-generating device may comprise a luminescent material. In embodiments, the light-generating device may comprise a PC LED. In other embodiments, the light-generating device may comprise a direct LED (i.e. no phosphor). In embodiments, the light-generating device may comprise a laser device, such as a laser diode. In embodiments, the light-generating device may comprise a superluminescent diode. Thus, in certain embodiments, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED.

[0021] The light source may be configured to generate a source light having, among other things, an optical axis (O), a (beam shape), and a spectral power distribution. The source light may, in embodiments, have one or more bands having a bandwidth as known for lasers.

[0022] The term "light source" may therefore refer to a light generating element itself, e.g. a solid-state light source, or may refer to a package of one or more of said light generating elements, e.g. a solid-state light source, and an element containing a luminescent material, and (other) optics, e.g. a lens, a collimator. A light conversion element ("conversion element" or "converter") may have an element containing a luminescent material. A solid-state light source itself, e.g. a blue LED, is a light source. A combination of a solid-state light source (e.g. a light generating element) and a light conversion element optically coupled to said solid-state light source, e.g. a blue LED and a light conversion element, may also be a light source (but may also be referred to as a light generating device). A white LED is therefore a light source (but may also be referred to as a (white) light generating device).

[0023] The term "light source" as used herein may refer to light sources including solid state light sources such as LEDs or laser diodes or superluminescent diodes.

[0024] The term "light source" may therefore also refer in embodiments to a light source that is (also) based on conversion of light, such as a light source in combination with a luminescence conversion material. The term "light source" may therefore also refer to a combination of an LED and a luminescent material configured to convert at least a portion of the radiation of the LED, or a combination of a (diode) laser and a luminescent material configured to convert at least a portion of the radiation of the (diode) laser.

[0025] In embodiments, the term "light source" may refer to a combination of a light source, such as an LED, and an optical filter that may change the spectral power distribution of the light generated by the light source. In particular, the term "light-generating device" may be used to refer to a light source and further optical components, such as optical filters and / or beam shaping elements.

[0026] 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 "same light source" or "multiple identical light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from the same bin.

[0027] The terms "solid-state light source" or "solid-state material light source" and similar terms may refer, among other things, to semiconductor light sources such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes.

[0028] The term "laser source" refers in particular to a laser. Such a laser may be configured to generate laser source light having one or more wavelengths in the UV, visible or infrared, in particular having a wavelength selected from the spectral wavelength range of 200 to 2000 nm, such as 300 to 1500 nm. The term "laser" refers in particular to a device that emits light through a process of light amplification based on stimulated emission of electromagnetic radiation.

[0029] In particular, in embodiments, the term "laser" may refer to a solid-state laser. In certain embodiments, the term "laser" or "laser source" or similar terms refer to a laser diode (or diode laser). However, other embodiments may be possible.

[0030] Thus, in an embodiment, the light source comprises a laser light source. In an embodiment, the term "laser" or "solid state laser" or "solid state material laser" refers to a laser such as a cerium doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), a chromium doped chrysoberyl (alexandrite) laser, a chromium ZnSe (Cr:ZnSe) laser, a divalent samarium doped calcium fluoride (Sm:CaF2) laser, an Er:YAG laser, an erbium doped and an erbium ytterbium cobalt fluoride (Er:YAG) ... 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 yttrium orthovanadate (Nd:YVO4) lasers, Neodymium glass (Nd:glass) lasers, Neodymium YLF (Nd:YLF) solid-state lasers, Promethium 147 doped phosphate glass (147Pm 3+ : Glass) solid-state laser, ruby ​​laser (Al2O3:Cr 3+ ), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; Al2O3:Ti 3+ ) lasers, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state lasers, ytterbium-doped glass lasers (rods, plates / chips and fibers), ytterbium YAG (Yb:YAG) lasers, Yb2O3 (glass or ceramics) lasers, etc.

[0031] For example, including embodiments for second and third harmonic generation, the light source may be an F center laser, an yttrium orthovanadate (Nd:YVO4) laser, a promethium-147 doped phosphate glass (147Pm 3+ :glass), and titanium sapphire (Ti:sapphire; Al2O3:Ti 3+ ) lasers. For example, taking into account second and third harmonic generation, such a light source can be used to generate blue light.

[0032] In embodiments, the terms "laser" or "solid state laser" or "solid state material laser" may refer to one or more of semiconductor laser diodes, such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, lead-salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, and the like.

[0033] A laser may be combined with an upconverter to reach shorter (laser) wavelengths. For example, upconversion can be achieved with some (trivalent) rare earth ions or with nonlinear crystals. In another example, a laser, such as a dye laser, can be combined with a downconverter to reach longer (laser) wavelengths.

[0034] As can be derived from the following, the term "laser source" may also refer to a plurality of (different or identical) laser sources. In certain embodiments, the term "laser source" may refer to a plurality of N (identical) laser sources. In embodiments, N=2 or more. In certain embodiments, N may be at least 5, such as in particular at least 8. In this way, higher brightness may be obtained. In embodiments, the laser sources may be arranged in a laser bank (see also above). The laser bank may in embodiments include a heat sink and / or optics, e.g. a lens for collimating the laser light. Thus, in embodiments, the lasers in a laser bank may share the same optics.

[0035] The laser source is configured to generate a laser source light (or "laser light"). The source light may consist essentially of the laser source light. The source light may also comprise the laser source light of two or more (different or the same) laser sources. For example, the laser source light of the two or more (different or the same) laser sources may be coupled into a light guide to provide a single light beam comprising the laser source light of the two or more (different or the same) laser sources. Thus, in certain embodiments, the source light is in particular a collimated source light. In yet other embodiments, the source light is in particular a (collimated) laser source light.

[0036] The laser source light may, in embodiments, have one or more bands, with a bandwidth as known for lasers. In certain embodiments, the bands may be relatively sharp lines, such as having a full width half maximum (FWHM) in the range of less than 20 nm at room temperature (RT), such as 10 nm or less. Thus, the source light has a spectral power distribution (intensity in energy scale as a function of wavelength) that may include one or more (narrow) bands.

[0037] The (source light) beam may be a focused or collimated beam of (laser) source light. The term "focused" may in particular refer to converging to a small spot. This small spot may be at a discrete converter region or may be (slightly) upstream or (slightly) downstream of the discrete converter region. In particular, the focusing and / or collimation may be such that the cross-sectional shape (perpendicular to the optical axis) of the beam at the discrete converter region (at the side) is essentially not larger than the cross-sectional shape (perpendicular to the optical axis) of the discrete converter region (where the source light illuminates the discrete converter region). Focusing may be performed with one or more optical systems, such as (focusing) lenses. In particular, two lenses may be applied to focus the laser source light. Collimation may be performed with one or more (other) optical systems, such as collimation elements, such as lenses and / or parabolic mirrors. In embodiments, the beam of (laser) source light may be relatively highly collimated, such as ≦2° (FWHM), more particularly ≦1° (FWHM), most particularly ≦0.5° (FWHM). Thus, ≦2° (FWHM) may be considered as (highly) collimated source light. Optical systems may be used to provide the (highly) collimated light (see also above).

[0038] The term "solid-state material laser" and similar terms may refer to solid-state lasers such as those based on crystals or glasses doped with ions such as transition metal ions and / or lanthanide ions, fiber lasers, photonic crystal lasers, semiconductor lasers such as vertical cavity surface emitting lasers (VCSELs), and the like. The term "solid-state light source" and similar terms may refer to semiconductor light sources such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes, among others. The term "laser light source" may refer to, for example, diode lasers or solid-state lasers, and the like.

[0039] Superluminescent diodes are known in the art and can be described as semiconductor devices that potentially can emit broad-spectrum, low-coherence light like an LED, while having the brightness of a laser diode.

[0040] US2020192017, for example, indicates that "with current technology, a single SLED can emit light over a bandwidth of, for example, up to 50-70 nm in the 800-900 nm wavelength range with sufficient spectral flatness and sufficient power." In the visible range used for display applications, i.e., the 450-650 nm wavelength range, a single SLED can emit light over a bandwidth of, for example, up to 10-30 nm with current technology. These emission bandwidths are too small for display or projector applications requiring red (640 nm), green (520 nm) and blue (450 nm) emission, i.e., RGB. Furthermore, superluminescent diodes are described, inter alia, in chapter 9.3 superluminescent diodes in the book "Edge Emitting Laser Diodes and Superluminescent Diodes", https: / / doi.org / 10.1002 / 9783527825264.ch9, first published on August 3, 2020, by authors Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Najda, Thomas Slight, Piotr Perlin, and book editors Fabrizio Roccaforte, Mike Leszczynski. This book, in particular chapter 9.3, is incorporated herein by reference. In said book, inter alia, it is shown that superluminescent diodes (SLDs) are emitters that combine the characteristics of laser diodes and light-emitting diodes. SLD emitters use stimulated emission. This means that these devices operate at current densities similar to those of laser diodes. The main difference between LDs and SLDs is that in the latter case the device waveguide may be designed in a special way to prevent the formation of standing waves and lasing. Nevertheless, the presence of the waveguide ensures the emission of a high quality light beam with high spatial coherence of light, which at the same time is characterized by low temporal coherence.Currently, the most successful designs of nitride SLDs are bent, curved or tilted waveguide geometries and tilted facet geometries, while in all cases the front end of the waveguide meets the device facet at an angle, as shown in Fig. 9.10. The tilted waveguide suppresses reflection of the light from the facet to the waveguide by directing it outwards into the lossy unpumped areas of the device chip. Thus, SLDs can be semiconductor light sources, in particular where spontaneous emission is amplified by stimulated emission in the active region of the device. Such emission is called "superluminescence". Superluminescent diodes combine the high power and brightness of laser diodes with the low coherence of conventional light emitting diodes. The low (temporal) coherence of the source has the advantage that speckle is greatly reduced or invisible, and the spectral distribution of the emission is much broader compared to laser diodes, which may make it more suitable for illumination applications. In particular, by varying the current, the spectral power distribution of the superluminescent diode can be varied, and in this manner the spectral power distribution can be controlled (see also, for example, Abdullah A. Alatawi et al., Optics Express Vol. 26, Issue 20, pp. 26355-26364, https: / / doi.org / 10.1364 / OE.26.026355).

[0041] Therefore, in an embodiment, the first light-generating device may be configured to generate a first device light, the first light-generating device comprising a first light source selected from the group of a superluminescent diode and a laser.

[0042] At least a portion of the first device light may be used to pump the luminescent material (see further below).

[0043] The system may further comprise a luminescent body, in particular the luminescent body comprising a luminescent material configured to convert at least a portion of the first device light into luminescent material light.

[0044] Below, several embodiments of luminescent materials in general are described.

[0045] The term "luminescent material" refers in particular to a material capable of converting a first radiation, in particular one or more of UV and blue radiation, into a second radiation. Generally, the first and second radiation have different spectral power distributions. Therefore, instead of the term "luminescent material", the term "luminescence converter" or "converter" may also be applied. Generally, the second radiation has a spectral power distribution at a larger wavelength than the first radiation, which is the case of so-called down-conversion. However, in certain embodiments, the second radiation has a spectral power distribution with an intensity at a smaller wavelength than the first radiation, which is the case of so-called up-conversion.

[0046] In embodiments, the "luminescent material" may refer specifically to a material capable of converting radiation, for example to visible light and / or infrared light. For example, in embodiments, the luminescent material may be capable of converting one or more of UV radiation and blue radiation into visible light. The luminescent material may also convert radiation into infrared radiation (IR) in certain embodiments. Thus, when excited with radiation, the luminescent material emits radiation. In general, the luminescent material is a downconverter, i.e., a material capable of converting radiation of a smaller wavelength into radiation of a larger wavelength (λ ex <λ em ), in certain embodiments, the luminescent material may comprise an upconverter luminescent material, i.e., the larger wavelength radiation is converted to radiation having a smaller wavelength (λ ex >λem ) is converted into radiation with a

[0047] In embodiments, the term "luminescence" may refer to phosphorescence. In embodiments, the term "luminescence" may refer to fluorescence. Instead of the term "luminescence", the term "emission" may be applied. Thus, the terms "first radiation" and "second radiation" may refer to excitation radiation and luminescence (radiation), respectively. Similarly, the term "luminescent material" may refer to phosphorescence and / or fluorescence, in embodiments.

[0048] The term "luminescent material" may refer to a number of different luminescent materials. Examples of possible luminescent materials are provided below. Thus, the term "luminescent material" may refer to a luminescent material composition in certain embodiments.

[0049] In an embodiment, the luminescent material is selected from garnets and nitrides, in particular doped with trivalent cerium or divalent europium, respectively. The term "nitride" may also refer to oxynitrides or nitridosilicates, etc. Alternatively or in addition, the luminescent material may be selected from silicates, in particular doped with divalent europium.

[0050] In certain embodiments, the luminescent material is ABO. 12:Ce type luminescent materials, where A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, in particular (at least) one or more of Y, Gd, Tb and Lu, and B in embodiments comprises one or more of Al, Ga, In and Sc. In particular, A may comprise one or more of Y, Gd and Lu, in particular one or more of Y and Lu. In particular, B may comprise at least Al, such as one or more of Al and Ga, more in particular essentially only Al. Thus, a particularly suitable luminescent material is a cerium comprising garnet material. Garnet embodiments are in particular of the type A3B5O 12 The present invention includes a garnet, A including at least yttrium or lutetium, and B including at least aluminum. Such garnets may be doped with cerium (Ce), praseodymium (Pr), or a combination of cerium and praseodymium, but in particular with Ce. In particular, B may include aluminum (Al), but B may also include, in addition to aluminum, gallium (Ga) and / or scandium (Sc) and / or indium (In), in part, in particular up to about 20% of B, more in particular up to about 10% of B (i.e., B ions consist essentially of 90 mol % or more of Al and 10 mol % or less of one or more of Ga, Sc and In). B may in particular include up to about 10% of gallium. In another variant, B and O may be at least in part replaced by Si and N. The element A may be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). Furthermore, Gd and / or Tb are particularly present in an amount up to about 20% of A. In a particular embodiment, the garnet luminescent material is selected from the group consisting of (Y 1-x Lu x )3B5O 12 :Ce, where x is 0 or more and 1 or less. The term ":Ce" indicates that some of the metal ions in the luminescent material (i.e., in garnets, some of the "A" ions) are replaced with Ce. For example, (Y1-x Lu x )3Al5O 12 :Ce, in the case of Y and / or Lu, 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% Ce and 10% Y, the completely correct formula would be (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 It can be. Ce in garnet is substantially in the trivalent state or only in the trivalent state, as is known to those skilled in the art.

[0051] In an embodiment, the luminescence material (therefore) contains A3B5O 12 and in a particular embodiment, up to 10% of B-O can be replaced by Si-N.

[0052] In a particular embodiment, the luminescence material is (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.

[0053] 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 (optionally in combination with the light of other light sources as described herein). 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 an embodiment, the luminescent material is (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O 12 and may include Lu and / or Gd. 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 yet other particular embodiments, the luminescent material is (Y x1-x3 Ce x3 )3Al5O 12 where x1 + x3 = 1, 0 < x3 ≤ 0.2, and is, for example, from 0.001 to 0.1.

[0054] 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 luminescence material such as. Thus, in certain embodiments, the light generating device has a luminescence 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 luminescence 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.

[0055] In certain embodiments, A may particularly include at least Y, and B may particularly include at least Al.

[0056] Alternatively, or in addition, the luminescence material may include a luminescence material of the A3Si6N 11 :Ce 3+ type, and A includes one or more of Y, La, Gd, Tb, and Lu, such as one or more of La and Y in an embodiment.

[0057] In an embodiment, the luminescence material may alternatively, or in addition, be MS:Eu 2+ and / or M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+and the like, where M comprises one or more of Ba, Sr and Ca, and in particular embodiments at least Sr. Thus, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent and replaces one or more of the divalent cations indicated. Generally, Eu is not present in an amount 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 cation it replaces. The term ":Eu" refers to the presence of a portion of the metal ions that are not Eu (in these examples Eu 2+ For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 )AlSiN3. Divalent europium generally replaces divalent cations, such as the divalent alkaline earth cations mentioned above, in particular Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu may also be denoted 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 includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted 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 includes Sr and / or Ba in this compound. In a further particular embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), Ba 1.5 Sr 0.5In particular, it consists of 50-100%, more particularly 50-90% Ba and 50-0%, particularly 50-10% Sr, such as Si5N8:Eu (i.e. 75% Ba; 25% Sr), where Eu is introduced to replace 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 includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound. In particular, Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0058] In embodiments, the red 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 or exclusively divalent and replaces one or more of the divalent cations shown. Generally, Eu is not present in an amount 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 cation it replaces. The term ":Eu" indicates that a portion of the metal ions is Eu (in these examples Eu 2+ For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 )AlSiN3. Divalent europium generally replaces a divalent cation, such as the divalent alkaline earth cations mentioned above, particularly Ca, Sr or Ba.

[0059] 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 M comprises calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca).

[0060] 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 comprises Sr and / or Ba. In further particular embodiments, M consists of Sr and / or Ba (not taking into account the presence of Eu), and Ba 1.5 Sr 0.5 Particularly consisting of 50-100%, more particularly 50-90% Ba, and 50-0%, particularly 50-10% Sr, such as Si5N8:Eu (i.e., 75% Ba; 25% Sr), where Eu is introduced to replace at least a portion of M (i.e., one or more of Ba, Sr and Ca).

[0061] 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 M comprises calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca).

[0062] The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0063] The blue luminescent material is YSO (Y2SiO5:Ce 3+ ), or a similar compound, or BAM (BaMgAl 10 O 17 :EU 2+ ), or a similar compound.

[0064] The term "luminescent material" in this specification relates in particular to inorganic luminescent materials. Instead of the term "luminescent material", the term "phosphor" may also be applied. These terms are known to those skilled in the art.

[0065] Alternatively or additionally, other luminescent materials may be applied, for example quantum dots and / or organic dyes, optionally embedded in a transparent matrix, for example a polymer such as PMMA or polysiloxane.

[0066] Quantum dots are small crystals of semiconductor materials, generally with a width or diameter of only a few nanometers. When excited by incident light, quantum dots emit light with a color determined by the size and material of the crystal. Thus, by adapting the size of the dots, light of a specific color can be generated. Most known quantum dots that emit 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 very narrow emission bands, therefore they exhibit saturated colors. Moreover, the emission color can be easily tuned by adapting the size of the quantum dots. In the present invention, any type of quantum dot known in the art can be used. However, for reasons of environmental safety and concerns, it may be preferable to use cadmium-free quantum dots, or at least quantum dots that have a very low cadmium content.

[0067] Instead of or in addition to quantum dots, other quantum confinement structures may be used, where "quantum confinement structure" is to be understood in the context of this application as, for example, quantum wells, quantum dots, quantum rods, tripods, tetrapods, or nanowires.

[0068] Organic phosphors can also be used. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, such as the compounds sold 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.

[0069] Different luminescent materials may have different spectral power distributions of their respective luminescent material light. Alternatively, or in addition, such different luminescent materials may have, among other things, different color points (or dominant wavelengths).

[0070] Thus, the luminescent material may be included in a luminescent body. The luminescent body may be a layer, such as a self-supporting layer. The luminescent body may also be a coating. In particular, the luminescent body may be essentially self-supporting. In embodiments, the luminescent material may be provided as a luminescent body, such as a luminescent single crystal, a luminescent glass or a luminescent ceramic body. Such a body may be indicated as a "transducer body" or a "luminescent body". In embodiments, the luminescent body may be a luminescent single crystal or a luminescent ceramic body. For example, in embodiments, a garnet luminescent material containing cerium may be provided as a luminescent single crystal or as a luminescent ceramic body. In other embodiments, the luminescent body may comprise a light-transmitting body in which the luminescent material is embedded. For example, the luminescent body may comprise a glass body with a luminescent material embedded in the glass body, or the glass may itself be luminescent. In other embodiments, the luminescent body may comprise a polymer body with a luminescent material embedded in the polymer body. The foregoing may apply to the luminescent material.

[0071] In certain embodiments, the luminescent body may comprise a ceramic body or a single crystal.

[0072] The luminescent body may have a first surface, a second surface, and an edge bridging surface bridging the first surface and the second surface. In particular, the luminescent body is transparent at least in a direction perpendicular to the first surface and / or the second surface. In particular, the luminescent body is transparent to visible light propagating in a direction perpendicular to the first surface or the second surface. Thus, even if the luminescent body may absorb a portion of the first device light, a significant portion may not be absorbed when the first device light is provided perpendicular to one or more of the first and second surfaces. For wavelengths in the visible light that the luminescent material does not absorb, the luminescent body may be transparent not only in a direction perpendicular to the first and / or second surface, but also in a direction parallel to the first and / or second surface.

[0073] The luminescent body may be relatively thin, which may allow a relatively large area to be in contact with the thermally conductive material (see further below).

[0074] Thus, in an embodiment, the luminescent body has a first surface, a second surface, and a bridging surface bridging the first surface and the second surface.

[0075] The second surface may have a second surface equivalent circle diameter D2. Furthermore, the first surface may have a first surface equivalent circle diameter D1. In an embodiment, D1=D2. In other embodiments, D1≠D2. In the case of a cylindrical shape or a cylindrical-like shape, such as a hexagonal prism, D1=D2. In the case of a cone shape or a cone-like shape, such as a truncated cone, D1≠D2. Thus, in a particular embodiment, the luminescent body has a cylindrical shape or a cylindrical-like shape, such as a hexagonal prism, and D1=D2.

[0076] The equivalent circle diameter (or ECD) of a (irregularly shaped) two-dimensional shape is the diameter of a circle with equivalent area. For example, the equivalent circle diameter of a square with side a is 2xaxSQRT(1 / π). For a circle, the diameter is the same as the equivalent circle diameter. If a circle with diameter D in the xy plane is distorted to any other shape (within said xy plane) without changing the size of the area, the equivalent circle diameter of that shape is D.

[0077] The distance between the first surface and the second surface may be constant in embodiments. This distance may be referred to as a height. Thus, in embodiments, the bridge surface has a first height (H1).

[0078] In a particular embodiment, the luminescent body has a height smaller than at least one of the equivalent diameters, in particular the height smaller than the equivalent diameter of the first face. This may allow a good thermal contact of the one or more heat conductors with the first face. Thus, in particular, H1 / D2<1 may apply. For example, in an embodiment, 0.01≦H1 / D2≦0.5, such as 0.02≦H1 / D2≦0.5. In particular, H1 may be selected from the range of 0.1 to 10 mm and / or D1 may be selected from the range of 1 to 20 mm, more in particular, H1 may be selected from the range of 0.2 to 2 mm and / or D1 may be selected from the range of 2 to 10 mm.

[0079] In embodiments, the luminescent body may have a cross-sectional shape selected from (a) a k-gon, where k≧4, and (b) a cylindrical shape. For example, the luminescent body may have a hexagonal shape (k=6), an octagonal shape (k=8), a decagonal shape (k=10), etc. However, in embodiments, k is selected from the range of 4 to 24, such as 6 to 24. However, in other embodiments, the cross-sectional shape is circular (k may be considered as ∞). In embodiments in which the luminescent body has a k-gonal cross-section, the bridging surface may include k facets.

[0080] The bridging surface defines a perimeter, which has a length that is 2×π×R in the case of a circular cross section, and a height H1, i.e. the height of the bridging surface. Instead of the terms "perimeter" or "bridging surface", the term "side" may also be used. The term "perimeter" in this specification may refer to the bridging surface itself as well as the length of the bridging surface. Thus, the bridging surface may have a perimeter (P).

[0081] The luminescent body may have a body axis, which may be perpendicular to the first surface (and / or the second surface), and which may further coincide with an optical axis (see also below).

[0082] As described above, the first surface may be in thermal contact with a thermal conductor. Thus, the system may include one or more thermal conductors. At least one of the one or more thermal conductors may be in thermal contact with the first surface, such as in physical contact with the first surface.

[0083] The thermal conductor comprises 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), such as at least about 100 W / (m×K), such as at least about 200 W / (m×K). In yet other specific embodiments, the thermally conductive material may have a thermal conductivity of at least about 10 W / (m×K). In embodiments, the thermally conductive material may comprise one or more of 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 comprise or consist of aluminum oxide.

[0084] An element may be considered to be in thermal contact with another element if the element is capable of exchanging energy through a thermal process. The elements may therefore be thermally coupled. In an embodiment, thermal contact may be achieved by physical contact. In an embodiment, thermal contact may be achieved via a thermally conductive material, such as a thermally conductive adhesive. Thermal contact between two elements may also be achieved if the two elements are disposed at a distance of about 10 μm or less relative to each other, although larger distances, such as up to 100 μm, may be possible. The shorter the distance, the better the thermal contact. In particular, the distance is 10 μm or less, such as 1 μm or less, such as 5 μm or less. The distance may be the distance between two respective surfaces of each element. The distance may be an average distance. For example, the two elements may be in physical contact at one or more locations, such as a plurality of locations, while at one or more, particularly a plurality of, other locations the elements are not in physical contact. This may be the case, for example, if one or both elements have a rough surface. Thus, in an embodiment, the distance between the two elements may be, on average, 10 μm or less (although a larger average distance, such as up to 100 μm, may be possible). In an embodiment, the two surfaces of the two elements may be kept at a distance by one or more distance holders. When the two elements are in thermal contact, they may be in physical contact or may be arranged at a small distance, such as up to 1 mm, such as up to 10 μm, from each other. When the two elements are arranged at a distance from each other, an intermediate material may be arranged between them, but in other embodiments, the distance between the two elements may be filled with a gas, liquid, or may be a vacuum. If an intermediate material is available, the greater the distance, the higher the thermal conductivity available for the thermal contact between the two elements may be. However, the smaller the distance, the lower the thermal conductivity of the intermediate material may be (although of course higher thermally conductive materials may also be used).

[0085] The one or more thermal conductors may have one or more thermal conductors or may consist of one or more thermal conductors. The one or more thermal conductors may consist of two thermal conductor parts that are physically connected. In particular, the one or more thermal conductors herein have a first thermal conductor part in thermal contact with at least a portion of the first surface and / or a second thermal conductor part in thermal contact with one or more of (i) a portion of the bridging surface and (ii) a portion of the second surface. In particular, in an embodiment, the one or more thermal conductors have (a) a first thermal conductor part in thermal contact with at least a portion of the first surface and (b) a second thermal conductor part in thermal contact with one or more of (i) a portion of the bridging surface and (ii) a portion of the second surface.

[0086] In embodiments, at least 50% of the area of ​​said first surface may be in thermal contact with said first thermal conductor, such as at least 80% of the area, such as at least 90% of the area.

[0087] When the second thermal conductor part is configured in thermal contact with the bridging surface, the second thermal conductor part is configured in thermal contact with a part of the bridging surface in consideration of incoupling of light (see also below).When the second thermal conductor part is configured in thermal contact with the second surface, the second thermal conductor part is configured in thermal contact with a part of the second surface in consideration of outcoupling of light (see also below).

[0088] In particular, the one or more heat conductors comprise a reflective material or have a reflective coating. The reflectivity may be at least 50%, such as at least 85%, such as at least 70% under normal illumination. The one or more heat conductors may be reflective to the first device light and / or to the luminescent material light.

[0089] In this manner, the first thermal conductor portion and the second thermal conductor portion may define a slit-like opening along at least a portion of the periphery (P) of the bridging surface.

[0090] The slit-shaped opening may have a length defined along the periphery that is at least 80%, such as at least 90%, or even 100%, of the length of the periphery. For example, the luminescent body may be sandwiched between the first thermal conductor portion and the second thermal conductor portion, thereby providing a slit-shaped opening along the periphery that has a length equal to the length of the periphery.

[0091] The opening may have a relatively small height, equal to, and in some embodiments smaller than, the first height H1, hence the term "slit-like opening".

[0092] A first device light may be guided through the slit-shaped opening to generate the luminescent material light. The generated luminescent material light may escape through at least a portion of the second surface. The entire second surface may be available if the second thermal conductor is not in thermal contact with the second surface, or a portion of the second surface may be available if the second thermal conductor is in thermal contact with the second surface. In particular, at least about 70%, such as at least about 80%, more particularly at least about 90%, of the area of ​​the second surface may be available for outcoupling of the luminescent material light. Thus, in an embodiment, less than about 50%, such as less than about 20%, such as less than about 30%, particularly less than about 10%, of the area of ​​the second surface may be in thermal contact with the second thermal conductor.

[0093] Thus, in an embodiment, the second thermal conductor part may have an opening, such that at least a part of the second surface is not in thermal contact with the second thermal conductor part, whereby light may escape from the luminescent body through the second surface to outside the system.

[0094] Thus, in embodiments, the second thermal conductor part may have a ring shape and / or in embodiments, the first thermal conductor part may have a (substantially closed) cylindrical shape.

[0095] During operation, at least a portion of the luminescent material light may (and therefore) escape from at least a portion of the second surface and exit the system via the second thermal conductor portion (and optional optics, for example).

[0096] To guide the first device light through the slit-like opening, it may be desirable for the device light to be provided as a substantially circular beam that focuses to a ring located about the cross-linking surface (or circumference). Focusing may be at the cross-linking surface, or at a short distance upstream of the cross-linking surface, such as within + / - 5% of D1 around the circumference, such as within + / - 10% of D1 around the circumference, or at a short distance from the cross-linking surface into the luminescent body. Thus, the first light-generating device and the one or more optical elements may be configured to provide the first device light to the luminescent body through the slit-like opening.

[0097] The slit-like opening may define a portion of the bridging surface that is accessible by the device light. This portion may also be denoted as light incoupling portion. This may be essentially 100% if the luminescent body is (only) sandwiched between the first and second thermal conductor portions. However, if one of the first and second thermal conductor portions is in thermal contact with a portion of the bridging surface, the portion of the bridging surface that is accessible by the device light may be less than 100% of the bridge (area). Similarly, this percentage may be smaller if a bridging element is present between the first and second thermal conductor portions.

[0098] In particular, however, the light incoupling portion may be arranged over the entire periphery (P).

[0099] To define the light in-coupling portion, a portion of the bridge surface may be taken that is accessible by light propagating parallel to the first surface (and / or the second surface), which may therefore be light traveling perpendicular to the optical axis and / or the body axis of the luminescent body.

[0100] The bridging surface may have a third area A3. The light incoupling portion may have an area A1 or a first area. In an embodiment, 100% of the third area may be accessible by the device light. In such an embodiment, A1=A3. However, in other embodiments, the area of ​​the light incoupling portion may be smaller. However, it may be less desirable for the area of ​​the light incoupling portion to be significantly smaller than the area A3 of the bridging surface. Thus, in an embodiment, 0.25≦A1 / A3≦1, more particularly 0.5≦A1 / A3≦1, such as 0.75≦A1 / A3≦1.

[0101] Thus, in certain embodiments, the optical incoupling portion is configured over the entire circumference (P). Hence, in embodiments, the slit-shaped opening may define an optical incoupling portion of the bridging surface configured to receive the first device light, the optical incoupling portion being configured over the entire circumference (P).

[0102] In particular, a significant portion of the light incoupling portion is illuminated by the device light. Thus, assuming a fourth area A4 to be the area of ​​the bridging surface that receives the device light, A4 may in particular be at least 50%, such as at least about 70%, more in particular at least about 80%, such as at least about 90%, of the light incoupling area A1. In particular, 0.25≦A4 / A3≦1, more in particular 0.5≦A1 / A3≦1, such as 0.75≦A1 / A3≦1.

[0103] Thus, the slit-shaped opening may define an optical incoupling portion of the cross-linking surface configured to receive the first device light, the optical incoupling portion being configured along at least a portion of the outer periphery (P), and the optical incoupling portion having an optical incoupling portion area A1.

[0104] In an embodiment, the light in-coupling portion may have a second height (H2). In particular, in an embodiment, 0.1≦H2 / H1≦1.

[0105] The area of ​​the light incoupling portion and the area of ​​the second surface, i.e., the second area A2, may be related.

[0106] To improve the light in-coupling, the area A1 of the light in-coupling portion may be larger than the second area A2 of the second surface in the range of 1.1≦A1 / A2≦8, in an embodiment 1.25≦A1 / A2≦8, such as more particularly 1.5≦A1 / A2≦8.

[0107] However, to improve light outcoupling, it may be desirable for the second area A2 of the second surface to be larger than the area A1 of the light incoupling portion.Thus, in other embodiments, 0.05≦A1 / A2≦1.1, such as in an embodiment 0.1≦A1 / A2≦1, such as in an embodiment 0.25≦A1 / A2≦1, in particular 0.25≦A1 / A2≦0.75.

[0108] To provide a substantially circular beam, various solutions may be possible. Some solutions may create a substantially circular beam with one or more light-generating devices. Some embodiments are described below.

[0109] In a first set of embodiments, the one or more optical elements comprise one or more first optical elements. In particular, the light generation system may comprise a first light generation device and n sets (or arrangements) of the one or more first optical elements. In an embodiment, the first light generation device and the one or more first optical elements may be configured to provide the first device light to the luminescent body through the slit-like opening. In an embodiment, n≧1, such as n≧4, such as n≧2. In particular, 3≦n≦72, such as 3≦n≦24, although of course other values ​​of n may be possible. Thus, in an embodiment, the one or more optical elements comprise one or more first optical elements, and the light generation system comprises a first light generation device and n sets of the one or more first optical elements, and the first light generation device and the one or more first optical elements are configured to provide the first device light to the luminescent body through the slit-like opening, and n≧1. With a first light-generating device and a multiple array of the one or more first optical elements, in embodiments a substantially circular beam may be provided that may illuminate at least 50%, such as at least 60%, more particularly at least 70%, such as at least 80%, of the area of ​​the cross-linking surface.

[0110] In certain embodiments, the one or more first optical elements may comprise a first cylindrical lens arranged downstream of the first light-generating device and a first half-cylindrical lens arranged downstream of the first cylindrical lens, which may be a relatively simple way to create a narrow beam that can enter the slit-like aperture.

[0111] In particular, in an embodiment, n≧2, and the optical axis O of the set s The mutual angle α between sm is α sm ≠ 360° / n, where n is an even number. This may prevent a first set from illuminating a second set and the second set from illuminating the first set, which may damage one or more elements of these sets.

[0112] Alternatively or in addition, the one or more optical elements may comprise one or more second optical elements, the one or more second optical elements comprising a first axicon lens arranged downstream of the first light-generating device and a second cylindrical reflector arranged downstream of the first axicon lens. In particular, the first light-generating device and the one or more second optical elements may be arranged to focus a ring-shaped beam of first device light onto the luminescent body through the slit-shaped opening. In particular, in an embodiment, the second cylindrical reflector may comprise a truncated compound parabolic reflector. With the first light-generating device and the one or more second optical elements, in an embodiment, a substantially circular beam may be provided, which may illuminate at least 50%, such as at least 60%, more particularly at least 70%, such as at least 80%, of the area of ​​the bridge surface.

[0113] The luminescent body may, in embodiments, be relatively transparent, particularly for light propagating within the luminescent body in a direction parallel to the body axis. However, absorption of the first device light may be relatively high when propagating within the luminescent body in a direction perpendicular to the body axis. For example, in embodiments, the material and dimensions of the luminescent body, such as the activator concentration, may be selected such that only a small portion of the first device light may escape the luminescent body again through an end face. Thus, in embodiments, absorption of the first device light through the luminescent body parallel to the first face may be selected such that at least 90% (such as at least 95%, or even at least about 98%) of the first device light propagating in a direction (parallel to one or more of the first face and the second face) from a portion of the cross-linking face to an opposite portion of the cross-linking face may be absorbed by the luminescent body. In certain embodiments, the diameter (D) of the luminescent body may be at least four times the absorption length of the first device light. If the luminescent body has a k-gon shape, the width (perpendicular to the body axis) may be chosen instead of the diameter.

[0114] In embodiments, the luminescent body may comprise a light outcoupling structure configured to outcouple a portion of the first device light via the second surface. This may allow mixing of the luminescent material light and the first device light in the system light (see also below). The outcoupling structure may in embodiments comprise a depression in one or more of the first and second surfaces and / or a particulate material in the luminescent body, as known in the art.

[0115] In embodiments, the light generation system may further comprise a dichroic layer on at least a portion of the cross-linking surface. The dichroic layer may be configured to transmit the first device light and reflect the luminescent material light. This may reduce escape of the luminescent material light through the cross-linking surface and therefore may promote escape of the luminescent material light from the luminescent body through the second surface.

[0116] In embodiments, the one or more thermal conductors comprise one or more heat sinks or the one or more thermal conductors are included in a heat sink. In particular, the first thermal conductor may be a heat sink or may be included in a heat sink. In other embodiments, at least one of the one or more thermal conductors may be in thermal contact.

[0117] During operation, the system may generate a system light which may in particular comprise the luminescent material light and optionally comprise the first device light, however alternatively or in addition, the system light may also comprise the second device light, which may be mixed into the system light downstream of the luminescent body or which may be generated upstream of the luminescent body and transmitted through (or reflected by) the luminescent body.

[0118] The terms "upstream" and "downstream" relate to the positioning of an item or feature relative to the propagation of light from a light generating means (here, in particular the light source), such that relative to a first position in the light beam from the light generating means, 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".

[0119] In particular, the second device may generate a second device light. In certain embodiments, the second device light may be generated upstream of the luminescent body and may be transmitted through the luminescent body. To this end, the first thermal conductor part may have an opening, also denoted herein as a "first thermal conductor part opening". Such an opening may be a pinhole. The cross-sectional area of ​​the first thermal conductor part opening may in embodiments be less than or equal to 10% of the area of ​​the first face.

[0120] Therefore, in an embodiment, the light generation system may further comprise a second light generating device configured to generate a second device light having a different spectral power distribution than one or more of (i) the first device light and (ii) the luminescent material light, the first thermal conductor portion having a first thermal conductor portion opening, the second light generating device configured to illuminate the first side of the luminescent body through the first thermal conductor portion opening, and an absorption of the second device light through the luminescent body perpendicular to the first side (and / or the second side) is selected such that at least 90% of the second device light propagating in a direction from the first side to the second side is transmitted through the luminescent body. In particular, in such an embodiment, the first height (H1) of the luminescent body may be less than 0.5 times the absorption length of the second device light.

[0121] In an embodiment, the first light generating device may be configured to generate blue first device light.

[0122] The term "purple light" or "purple emission" particularly relates to light having a wavelength in the range of about 380 to 440 nm. The term "blue light" or "blue emission" particularly relates to light having a wavelength in the range of about 440 to 495 nm (including some purple and cyan hues). The term "green light" or "green emission" particularly relates to light having a wavelength in the range of about 495 to 570 nm. The term "yellow light" or "yellow emission" particularly relates to light having a wavelength in the range of about 570 to 590 nm. The term "orange light" or "orange emission" particularly relates to light having a wavelength in the range of about 590 to 620 nm. The term "red light" or "red emission" particularly relates to light having a wavelength in the range of about 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 about 490 to 520 nm. The term "amber" may refer to one or more wavelengths selected from a range of about 585-605 nm, such as about 590-600 nm. The phrase "light having one or more wavelengths within a wavelength range" and similar phrases may specifically indicate that the light (or radiation) being indicated has a spectral power distribution with at least one or more intensities at those one or more wavelengths within the wavelength range being indicated. For example, a blue-emitting solid-state light source has a spectral power distribution with intensities at one or more wavelengths within a wavelength range of 440-495 nm.

[0123] The emission of the luminescent material, and optionally the first device light, may have a spectral power distribution that may be desirable for some applications, but may be undesirable for some other applications.Thus, in an embodiment the system may further comprise a second light source, in particular the second light generating device.

[0124] In particular, the second light source may be configured to generate a second light having a different spectral power distribution from (a) the first device light and (b) the emission of the luminescent material. In particular, the difference may be in a color point. Thus, the spectral power distributions are different. Thus, further, the difference may be in a centroid wavelength in an embodiment. In an embodiment, the second light source is a light having a different color from the color of the emission of the luminescent material or provides a light having a different color from the color of the emission of the luminescent material. For example, in an embodiment, (a) the second light source, (b) the emission of the luminescent material, and (c) the first device light may be selected from green, yellow, orange and red. For example, in an embodiment, the second light source may be selected from orange and red, and the emission of the luminescent material may be one or more of yellow and green. However, other combinations may also be possible.

[0125] In particular embodiments, the colors or color points of the first and second types of light may differ if the respective color points of said first and second types of light differ by at least 0.01 with respect to u' and / or at least 0.01 with respect to v', even more particularly at least 0.02 with respect to u' and / or at least 0.02 with respect to v'. In even more particular embodiments, the respective color points of said first and second types of light may differ by at least 0.03 with respect to u' and / or at least 0.03 with respect to v', where u' and v' are the color coordinates of the light in the CIE 1976 UCS (Uniform Chromaticity) diagram.

[0126] Thus, (a) the second light source, and (b) the emission of the luminescent material and the first device light, in embodiments, may differ by at least 0.02 in terms of u' and / or at least 0.02 in terms of v', or more.

[0127] Spectral power distributions of different light sources that have centroid wavelengths that differ by at least 10 nm, such as at least 20 nm, or even at least 30 nm, may be considered different spectral power distributions, eg, different colors.

[0128] However, the second light-generating device may optionally be used to generate essentially the same light as the first device light, such as blue light, for example, since the first device light that enters the luminescent body via the cross-linking surface may essentially be absorbed by the luminescent material.

[0129] In particular embodiments, the color or color point of the first type of light and the second type of light may be essentially the same if the respective color points of the first type of light and the second type of light differ by at most 0.1 with respect to u' and / or at most 0.1 with respect to v', and even more particularly at most 0.05 with respect to u' and / or at most 0.05 with respect to v'. In more particular embodiments, the color or color point of the first type of light and the second type of light may be essentially the same if the respective color points of the first type of light and the second type of light differ by at most 0.03 with respect to u' and / or at most 0.03 with respect to v', and even more particularly at most 0.02 with respect to u' and / or at most 0.02 with respect to v'. In even more particular embodiments, the respective color points of the first type of light and the second type of light may differ by at most 0.01 with respect to u' and / or at most 0.01 with respect to v', where u' and v' are the color coordinates of the light in the CIE 1976 UCS (Uniform Chromaticity) diagram.

[0130] Therefore, in certain embodiments, the second light-generating device is configured to generate second device light having a spectral intensity in one or more of a blue wavelength range and a red wavelength range, and the light-generating system is configured to generate system light including the luminescent material light and the second device light.

[0131] In embodiments, the light-generating system may be configured to provide white system light in an operating mode of the light-generating system. This does not mean that the light-generating system necessarily always produces white system light. In other embodiments, the light-generating system may be configured to provide colored system light in another operating mode.

[0132] The term "white light" and similar terms in this specification are known to those skilled in the art. The white light may particularly refer to light having a correlated color temperature (CCT) in the range of about 2000K to 20000K, particularly between about 1800K and 20000K, such as 2700K to 20000K, and in the case of general illumination, particularly in the range of about 2000K to 7000K, such as in the range of 2700K to 6500K. In embodiments, for example in the case of backlight applications or other applications, the correlated color temperature (CCT) may particularly be in the range of about 7000 to 20000K. In yet other embodiments, the correlated color temperature (CCT) is particularly within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), particularly within about 10 SDCM from the BBL, and even more particularly within about 5 SDCM from the BBL.

[0133] In certain embodiments, the correlated color temperature (CCT) may be selected from the range of 6000K to 12000K, such as at least 8000K, such as selected from the range of 7000K to 12000K. In still other embodiments, the correlated color temperature (CCT) may be selected from the range of 6000K to 12000K, such as selected from the range of 7000K to 12000K, in combination with a CRI of at least 70. In certain embodiments, the system light is white light and has a correlated color temperature selected from the range of 1800K to 12000K and a color rendering index of at least 70.

[0134] The term "secondary light-generating device" may also refer to multiple secondary light-generating devices. The term "secondary light-generating device" may also refer to multiple different secondary light-generating devices. The light of the secondary light-generating devices may be mixed into the system light at the same location or at different locations (see also above for some examples of locations).

[0135] In embodiments, the second light generating device may be configured to generate red device light, such as red laser light, and / or the first light generating device may be configured to generate blue first device light, such as blue laser light.

[0136] The light-generating system may further comprise a control system (see also above), which may be configured to control (i) the first light-generating device, or (ii) the optional second light-generating device.

[0137] The phrase "controlling the first light-generating device" and similar phrases may refer to embodiments where there is a single first light-generating device, but in other embodiments may include controlling two or more (essentially the same) first light-generating devices, such as lasers from the same bin. Similarly, the phrase "controlling the second light-generating device" and similar phrases may refer to embodiments where there is a single second light-generating device, but in other embodiments may include controlling two or more (essentially the same) second light-generating devices, such as lasers from the same bin.

[0138] The term "control" and similar terms refer in particular to at least determining the behavior of an element or supervising the operation of an element. Thus, in this specification, the term "control" and similar terms may refer to imposing a behavior on the element (determining the behavior of an element or supervising the operation of an element), such as, for example, measuring, indicating, activating, opening, shifting, changing temperature, etc. The term "control" and similar terms may further include monitoring as well. Thus, the term "control" and similar terms may include imposing a behavior on an element and may include imposing a behavior on an element and monitoring the element. The control of the element may be performed by a control system, which may be denoted as a "controller". Thus, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may comprise the control system. In an embodiment, the control system and the element may not be physically coupled. The control may be performed via wired and / or wireless control. The term "control system" may also refer to a number of different control systems, particularly those that are functionally coupled, for example one control system of the number of different control systems may be a master control system and one or more other control systems may be slave control systems. A control system may have a user interface or may be functionally coupled to a user interface.

[0139] The control system may also be configured to receive and execute instructions from a remote control device. In an embodiment, the control system may be controlled via an app on a device, such as a smartphone or portable device, such as an iPhone, tablet, etc. Thus, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0140] Thus, in an embodiment, the control system may (also) be configured to be controlled by an app on a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or may control in slave mode. For example, the lighting systems may be identifiable by a code, in particular a unique code for each lighting system. The control system of the lighting system may be configured to be controlled by an external control system that accesses the lighting system based on knowledge entered by a user interface comprising an optical sensor (e.g. a QR code reader) of the (unique) code. The lighting system may also have means for communicating with other systems or devices, such as based on Bluetooth, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0141] The system, or apparatus, or device may perform an operation in a "mode" or "operational mode" or "mode of operation" or "operable mode". The term "operational mode" may also be indicated as "control mode". Similarly, in a method, an operation, or a stage, or a step may be performed in a "mode" or "operational mode" or "mode of operation" or "operable mode". This does not exclude that the system, or apparatus, or device may also be adapted to provide another control mode or multiple other control modes. Similarly, this may not exclude that one or more other modes may be performed before and / or after performing the mode.

[0142] However, in embodiments, a control system may be available that is adapted to provide at least said control mode. If other modes are available, the selection of such modes may in particular be performed via a user interface, although other options may also be possible, such as performing the mode depending on a sensor signal or a (time) scheme. The operating mode may also refer in embodiments to a system, or apparatus, or device that can only operate in a single operating mode (i.e. "on", without further adjustability).

[0143] Thus, in an embodiment, the control system may be dependent on one or more of a user interface input signal, a sensor signal (of a sensor), and a timer, where the term "timer" may refer to a clock and / or a predefined timing scheme.

[0144] Such a system may be capable of providing light with a controllable spectral power distribution. Moreover, such a system may be capable of providing light with a controllable correlated color temperature and / or a controllable color rendering index. Moreover, such a system may be capable of providing a spectral power distribution that is partially or substantially conformal to the spectral power distribution (within the visible range) of a (light emission of) a black body radiator. The fact that the light-generating system may be configured to generate (white) system light does not exclude embodiments of the system in which the system may also operate or be able to be operated in other operation modes. In particular, in embodiments, the spectral power distribution of the system light may be controllable. Thus, in an embodiment, in a first operation mode (of the light-generating system), the light-generating system may be configured to generate the white system light and in a second operation mode (of the light-generating system), the light-generating system may be configured to generate a non-white system light.

[0145] Hence, in an embodiment, the light-generating system may further comprise a control system configured to control the spectral power distribution of the system light.

[0146] In particular, the control system may be configured to control the correlated color temperature of the system light to a value selected from the range of 1800 to 12000 K, such as a value selected from the range of 1800 to 6500 K, although other values ​​are not excluded in this specification (see also above).

[0147] In certain embodiments, the correlated color temperature of the system light may be controllable over a CCT control range of at least 500 K, such as a CCT control range of at least 1000 K, within a range of 1800 to 12000 K, such as selected from a range of 1800 to 6500 K. For example, the CCT of the system light may be controllable between 2700 to 4000 K (i.e. over a CCT control range of 1300 K), or over a range of 2000 to 4500 K (i.e. over a CCT control range of 2500 K). Thus, in embodiments, the CCT (of the white system light) may be controlled from a first value T1 to a second value T2, where |T2-T1|≧500 K, more particularly |T2-T1|≧1000 K.

[0148] In an embodiment, the R9 (of the (white) system light) may be at least 0, particularly at least 20, or even more particularly at least 30. In another example, the R9 value may be controllable over a range of at least 20, such as between 20 and 40. In a particular embodiment, the control system may be configured to control the R9 value of the system light (in the first operational mode (of the light generating system)) to a value of at least 30, and the R9 value of the system light may be controllable over an R9 control range of at least 30, the R9 control range at least partially overlapping with a range of at least 30. Furthermore, in a particular embodiment, the color rendering index of the system light (in the first operational mode (of the light generating system)) may be at least 80. In an embodiment, the control system may be configured to control the R9 value of the system light to a value of at least 30.

[0149] In an embodiment, the control system may be configured to control the color rendering index (CRI) of the system light to at least 60, more particularly at least 70, even more particularly at least 80. In an embodiment, the R9 value (of the white system light) may be controlled from a first R9 value R9.1 to a second R9 value R9.2, where |R9.2-R9.1|≧30. It is noted that the CRI may also depend on the spectral power composition. Thus, different types of white light may have different CRI values ​​and / or different R9 values. In an embodiment, the control system may be configured to control (in an operational mode) the CRI value of the system light within a predefined CRI range.

[0150] In embodiments, the system may include a light exit, such as an end window or (other) optical element opening, through which the system light may escape outside the system. The system may include a housing containing such a light exit. The housing may at least partially enclose one or more light-generating devices and one or more (other) optical elements.

[0151] The system may comprise optics for combining and / or blending light from different light sources. Such optics may for example be arranged downstream of the luminescent body.

[0152] The term "optical system" may refer in particular to (one or more) optical elements. Thus, the terms "optical system" and "optical element" may refer to the same thing. The optical system may include one or more of mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, diffraction gratings, dichroics, arrays of one or more of the foregoing, etc. Alternatively or in addition, the term "optical system" may refer to a holographic element or a mixing rod. In an embodiment, the optical system may include one or more of beam expander optics and zoom lens optics. In an embodiment, the optical system may include an integrator, such as a "Köhler integrator" (or "Köhler integrator"). In particular, the optical system may be used for beam shaping and / or light mixing of the first device light, the second device light, the luminescent material light, and optionally the third device light.

[0153] In an embodiment, a semi-transparent mirror may be applied to combine the different light beams.

[0154] In certain embodiments, for example, a compact package may be provided. For example, in embodiments, the system may include an integrated light source package having a common support member configured to support one or more of: (i) the first light generating device, (ii) at least one of the one or more thermal conductors, (iii) the luminescent body, (iv) optional optics, (v) optional the second light generating device, etc. Optionally, the common support member may include a thermally conductive support. The thermally conductive support may include one or more of a heat sink, a heat spreader, and a vapor chamber.

[0155] The light generating system may be part of or used in, for example, an office lighting system, a home application system, a shop lighting system, a domestic lighting system, an accent lighting system, a spot lighting system, a theatre lighting system, a fiber optic 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, a horticultural lighting, digital projection, or an LCD backlight. The light generating system (or the luminaire) may be part of or used in, for example, an optical communication system or a disinfection system.

[0156] In yet another aspect, 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 in the housing, or a housing opening, through which the system light may escape from the housing. In yet another aspect, the present invention also provides a projection device having a light generating system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or a moving image) onto a surface, such as a projection screen. The projection device may include one or more light generating systems as described herein. Thus, the present invention also provides, in one aspect, an illumination device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, the illumination device having a light generating system as defined herein. The lighting device may have a housing configured to accommodate or a carrier configured to support one or more elements of the light generation system, for example, in an embodiment, the lighting device may have a housing configured to accommodate or a carrier configured to support one or more of the first laser device, the third laser device, and the fourth laser device.

[0157] The terms "visible", "visible light" or "visible emission" and similar terms refer to light having one or more wavelengths within the range of about 380-780 nm. As used herein, UV may refer specifically to wavelengths selected from the range of 190-380 nm, such as 200-380 nm. As used herein, the terms "light" and "radiation" are used interchangeably unless the context makes it clear that the term "light" refers only to visible light. Thus, 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 (at least) visible light. [Brief description of the drawings]

[0158] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which: [Figure 1] Several embodiments and aspects are illustrated diagrammatically. [Figure 2a] Several embodiments are illustrated diagrammatically. [Figure 2b] Several embodiments are illustrated diagrammatically. [Diagram 3] Some application examples are illustrated diagrammatically.

[0159] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0160] Referring to FIG. 1, in an embodiment, a light-generation system 1000 may comprise a first light-generation device 110, a luminescent body 200, one or more thermal conductors 510, and one or more optical elements 400.

[0161] The first light-generating device 110 may be configured to generate a first device light 111. The first light-generating device 110 may comprise a first light source 10 selected from the group of superluminescent diodes and lasers (in particular diode lasers / laser diodes).

[0162] The luminescent body 200 may comprise a luminescent material 210 configured to convert at least a portion of the first device light 111 to luminescent material light 211 .

[0163] The luminescent body 200 may have a first surface 201, a second surface 202, and a bridging surface 203 bridging the first surface 201 and the second surface 202. The second surface 202 has a second surface equivalent circle diameter D2. The bridging surface 203 has a first height H1 and a perimeter P. In particular, H1 / D2<1.

[0164] The one or more thermal conductors 510 have a first thermal conductor portion 511 in thermal contact with at least a portion of the first surface 201, and / or a second thermal conductor portion 512 in thermal contact with one or more of (i) a portion of the bridging surface 203 and (ii) a portion of the second surface 202.

[0165] The first thermal conductor portion 511 and the second thermal conductor portion 512 may define a slit-like opening 520 along at least a portion of the periphery (P) of the bridging surface 203 .

[0166] The first light-generating device 110 and the one or more optical elements 400 may be configured to provide the first device light 111 to the luminescent body 200 via the slit-like opening 520 .

[0167] Embodiments I and IV show embodiments as further described below. Embodiment I shows a side view or a cross section, for example along the optical axis O1 of the light-generating device 110. Embodiment IV shows a top view or a cross section, in a plane perpendicular to the body axis. The reference BA indicates the body axis of the luminescent body 200.

[0168] Embodiment II shows examples of a k-gonal luminescent body 200, where k=6, and a luminescent body 200 with a circular cross section.

[0169] The slit-like opening 520 may define a light in-coupling portion 251 of the bridging surface 203 configured to receive the first device light 111. The light in-coupling portion 251 may be configured along at least a portion of the perimeter P. The light in-coupling portion 251 has a light in-coupling portion area A1. The second surface 202 has a second area A2. In an embodiment, 0.5≦A1 / A2≦8, such as 1.5≦A1 / A2≦8. In another example embodiment, 0.05≦A1 / A2≦1.5.

[0170] In an embodiment, the bridging surface 203 has a third area A3. In an embodiment, 0.5≦A1 / A3≦1.

[0171] The area A4 of the light incoupling portion 251 may be smaller than the area of ​​the bridging surface 203, as shown in the embodiment III. In this embodiment, the second heat conductor portion 512 may be in thermal contact with a part of the bridging surface 203 and a part of the second surface 202, as an example.

[0172] The second thermal conductor portion 512 may have an opening 522 such that at least a portion of the second surface is not in thermal contact with the second thermal conductor portion 512 and allows light to escape from the luminescent body 200 through the second surface 202 to the outside of the system.

[0173] The luminescent body 200 may comprise a ceramic body or a single crystal. 12 A may comprise one or more of the following luminescent materials: Y, La, Gd, Tb and Lu, and B may comprise one or more of the following: Al, Ga, In and Sc.

[0174] In an embodiment, the luminescent body 200 has a cross-sectional shape selected from: (a) a k-gon, where k≧4; and (b) a cylindrical shape.

[0175] The one or more optical elements 400 comprise one or more first optical elements 410. The light-generation system 1000 may comprise n sets 1110 of the first light-generation device 110 and one or more first optical elements 410. The first light-generation device 110 and the one or more first optical elements 410 are configured to provide first device light 111 to the luminescent body 200 via a slit-like opening 520, where N≧1. Embodiments I and IV illustrate such embodiments in a schematic manner.

[0176] In an embodiment, the one or more first optical elements 410 comprise a first cylindrical lens 411 arranged downstream of the first light-generating device 110 and a first semi-cylindrical lens 412 arranged downstream of the first cylindrical lens 411 .

[0177] In an embodiment, n≧2, and the optical axis O of the set 1110 s The mutual angle α between sm is α sm ≠ 360° / n, where n may be an even number.

[0178] A cylindrical / semi-cylinder solution may be a relatively simple solution. However, other lens / mirror optical solutions may be possible, such as using (as)pherical aplanatic (or astigmatic) elements to create a line-shaped focus from a diode laser. For example, in an embodiment, instead of two separate lenses as described here, a single lens may be used, which may have cylindrical entrance and exit faces with their respective cylindrical axes oriented orthogonally.

[0179] In an embodiment, the one or more optical elements 400 comprise one or more second optical elements 420. The one or more second optical elements 420 comprise a first axicon lens 421 arranged downstream of the first light-generating device 110 and a second cylindrical reflector 422 arranged downstream of the first axicon lens 421. The first light-generating device 110 and the one or more second optical elements 420 are arranged to focus a ring-shaped beam of the first device light 111 into the luminescent body 200 through a slit-shaped aperture 520. In an embodiment, the second cylindrical reflector 422 may comprise a truncated compound parabolic reflector. This is illustrated diagrammatically in FIG. 2a.

[0180] In an embodiment, the absorption of the first device light 111 passing through the luminescent body 200 parallel to the first surface 201 may be selected such that at least 90% of the first device light 111 propagating in a direction from one portion of the cross-linking surface 203 to an opposite portion of the cross-linking surface 203 (parallel to one or more of the first surface 201 and the second surface 202) may be absorbed by the luminescent body 200.

[0181] In an embodiment, the axicon may provide a continuous ring of the first light. With facetted prismatic elements (like facets in diamond), a discrete number of sub-beams may also be possible. This may be desirable for k-gonal luminescent bodies.

[0182] In an embodiment, the diameter D of the luminescent body may be at least four times the absorption length of the first device light 111 .

[0183] 1 and 2a, in an embodiment, the first light generating device 110 and one or more optical elements 400 may be configured to provide the first device light 111 to the luminescent body 200 through a slit-like opening 520. Furthermore, to guide the first device light through the slit-like opening, it may be desirable for the device light to be provided as a substantially circular beam that focuses into a ring located about the cross-linking surface (or circumference). The focusing may be on the cross-linking surface, or a short distance upstream of the cross-linking surface, such as within + / - 5% of D1 to the circumference, within + / - 10% of D1 to the circumference, or a short distance into the luminescent body from the cross-linking surface.

[0184] In an embodiment, the luminescent body 200 may have a light outcoupling structure 205 configured to outcouple a portion of the first device light 111 via the second surface 202. This is illustrated diagrammatically in embodiment I of Fig. 2b.

[0185] In an embodiment, the light generation system 1000 may further comprise a dichroic layer 206 on at least a portion of the cross-linking surface 203. This is illustrated diagrammatically in Figure 2b. In an embodiment, the dichroic layer 206 may be configured to transmit the first device light 111 and reflect the luminescent material light 211. Figure 2b therefore diagrammatically illustrates several embodiments that are not necessarily combined.

[0186] In an embodiment, the light in-coupling portion 251 may be arranged over the entire periphery P (see also embodiment II of FIG. 2b).

[0187] In an embodiment, the light in-coupling portion 251 has a second height H2, where 0.1≦H2 / H1≦1.

[0188] In an embodiment, one or more of the thermal conductors 510 may comprise one or more heat sinks or the one or more of the thermal conductors 510 may be included in a heat sink.

[0189] In certain embodiments, the light-generating system 1000 may further comprise a second light-generating device 120. The second light-generating device 120 may be configured to generate a second device light 121 having a different spectral power distribution than one or more of (i) the first device light 111 and (ii) the luminescent material light 211. The first thermal conductor portion 511 may have a first thermal conductor portion opening 521. The second light-generating device 120 may be configured to illuminate the first surface 201 of the luminescent body 200 through the first thermal conductor portion opening 521.

[0190] The absorption of the second device light 121 through the luminescent body 200 perpendicular to the first surface 201 (and / or the second surface 202) may be selected such that at least 90% of the second device light 121 propagating in the direction from the first surface 201 to the second surface 202 may be transmitted through the luminescent body 200.

[0191] In an embodiment, the first height (H1) of the luminescent body may be less than 0.5 times the absorption length of the second device light 121.

[0192] In an embodiment, the second light generating device 120 may be configured to generate second device light 121 having a spectral intensity in one or more of the blue and red wavelength ranges.

[0193] The light generation system 1000 may be configured to generate a system light 1001 that includes a luminescent material light 211 and a second device light 121 .

[0194] The system light 1001 may be a white light, having a correlated color temperature selected from the range of 1800K to 12000K and a color rendering index of at least 70.

[0195] Fig. 3 illustrates diagrammatically an embodiment of a luminaire 2 including a light-generating system 1000 as described above. Reference number 301 indicates a user interface that may be functionally associated with a control system 300 included by or functionally associated with the light-generating system 1000. Fig. 3 also illustrates diagrammatically an embodiment of a lamp 1 including the light-generating system 1000. Reference number 3 indicates a projector device or projector system that may be used to project an image onto a wall or the like, said projector device or projector system may also include the system 1000. Thus, Fig. 3 illustrates diagrammatically an embodiment of a lighting device 1300 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light-generating system 1000 as described herein. In an embodiment, such a lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Illumination device light escaping the illumination device 1300 is indicated with reference numeral 1301. The illumination device light 1301 may essentially consist of the system light 1001, and therefore may be the system light 1001 in certain embodiments.

[0196] In particular, a light-generating system is proposed for providing system light, the system comprising a (yellow) (ceramic) phosphor tile, a heat sink, optical components, and a (blue) laser providing (blue) laser light. In an embodiment, the light-incoupling surface extends circumferentially around the ceramic phosphor tile as a closed-loop surface (around a main axis of extension).

[0197] The laser light can impinge on the light-incoupling surface in a closed-loop manner by using optical components.

[0198] Since the ceramic phosphor tile can be pumped circumferentially around the phosphor tile like a closed ring, hot spots of the (focused) laser light on the ceramic phosphor plate can be reduced.

[0199] In an embodiment, the columnar phosphor may be illuminated through a slit.

[0200] In an embodiment, separate diode lasers with fast and slow axes may be applied, and further, collimators with different focuses may be applied.

[0201] In the example, a diode laser with a beam angle of 14x46° is focused with a cylindrical lens to a narrow focus in the vertical plane (fast axis, YZ). A semi-cylindrical lens focuses the beam to a wide focus in the horizontal plane (slow axis, XY). In this way, the laser beam is imaged as a line onto the cylindrical surface of the phosphor. The phosphor can be cylindrical, hexagonal, square, etc. The optics used can be a relatively simple (cylindrical) lens.

[0202] Thus, in such an embodiment, the point light source may be transformed into a line light source.

[0203] In another example, for example, a single diode laser may be applied in conjunction with an axicon lens and a compound parabolic reflector.

[0204] The axicon lens can generate a ring-shaped beam from a collimated blue laser beam.

[0205] A (truncated) compound parabolic reflector can focus the ring beam onto the (cylindrical) surface of the phosphor.

[0206] In an embodiment, the ceramic phosphor tile may preferably have a cylindrical shape (or a polygonal shape having k faces, where k≧6).

[0207] In an embodiment, the light incoupling area (up to about 2·π·r·H1) is preferably less than the area of ​​the bottom of the ceramic phosphor tile (π·r 2 ) The phosphor concentration and diameter can be configured to ensure full conversion of the laser light.

[0208] A closed annular slit may be disposed within the heat sink that extends circumferentially around the ceramic phosphor tile as a closed annular surface about the primary axis of extension.

[0209] Alternatively, or in addition, the light in-coupling surface may be covered by a dichroic mirror to transmit the laser light while reflecting (most of) the converted light. The heat sink at the bottom of the ceramic phosphor tile may have a pinhole for injecting red laser light (via an optical component, e.g., a lens) into the ceramic phosphor tile.

[0210] The light in-coupling surface may be arranged such that a portion of the blue laser light escapes through the top surface of the ceramic phosphor tile.

[0211] In another example, one or more of red and blue light may be added downstream of the ceramic phosphor tile.

[0212] With the present invention it may be possible to at least partially or substantially prevent the formation of hot spots in laser-pumped phosphors. The phosphor disk (or phosphor tile) may be in good thermal contact with a reflective heat sink at the bottom and may be clamped from above by a heat sink with a hole from which the converted light is collected. The heat sink may thus have a narrow circumferential slit. The phosphor disk may be pumped through its cylindrical wall by two or more lasers through the narrow circumferential slits.

[0213] In an embodiment, the shape of each laser beam passes through a slit and is elliptical (ie, a short line rather than a dot) to spread out the pump energy.

[0214] If only a single laser is used, a hot spot can occur where the pump beam enters the luminescent body. If two lasers are used, the hot spot can be (already) wider. With even more lasers, the hot spot can be even wider.

[0215] In an embodiment, the slits in the heat sink may be all around the periphery of the luminescent body.

[0216] In an embodiment, optics may be used to shape the laser beam into an elliptically elongated spot. In an embodiment, for the fast axis, a cylindrical lens may be used to narrow the wide vertical beam angle of the laser and focus it through a narrow slit. In an embodiment, for the slow axis, a semi-cylindrical lens may be used to create a wide elongated focus on the crosslinked surface of the luminescent body.

[0217] In a second embodiment, the (collimated) laser beam may be sent through an axicon lens to generate a ring-shaped beam, in which a truncated compound parabolic reflector can then focus the ring-shaped beam onto the cylindrical edge of the phosphor disk.

[0218] In an embodiment, the phosphor disc may be clamped within a heat sink (see also above) and the converted light may be collected downstream of the second surface.

[0219] In an embodiment, the pump laser may be a single laser or may be multiple co-linear lasers.

[0220] The term "plurality" refers to two or more.

[0221] The terms "substantially" or "essentially" and similar terms herein will be understood by those of skill in the art. The terms "substantially" or "essentially" may also include embodiments with "entirely," "completely," "all," and the like. Thus, in embodiments, the adjectives substantially or essentially may be omitted. Where applicable, the terms "substantially" or "essentially" may also relate to 90% or more, including 100%, such as 95% or more, particularly 99% or more, and even more particularly 99.5% or more.

[0222] The term "comprises" also includes embodiments in which the term "comprises" means "consisting of."

[0223] The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or." For example, the phrase "item 1 and / or item 2," and similar phrases, can refer to one or more of item 1 and item 2. The term "comprising" can refer in some embodiments to "consisting of," while in other embodiments it can refer to "including at least the specified species, and optionally one or more other species."

[0224] Moreover, in the specification and claims, the terms first, second, third, etc. are used to distinguish between similar elements and are not necessarily used to describe a sequential or chronological order. The terms so used are interchangeable under appropriate circumstances, and it is to be understood that the embodiments of the invention described herein are capable of operation in orders other than those described or illustrated herein.

[0225] The present specification may describe, among other things, devices, apparatus, or systems in operation. As will be apparent to one of ordinary skill in the art, the present invention is not limited to methods of operation or devices, apparatus, or systems in operation.

[0226] It should be noted that the above-described embodiments are illustrative of the invention rather than limiting, and that those skilled in the art will be able to design many other embodiments without departing from the scope of the appended claims.

[0227] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0228] The use of the verb "to have" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the specification and claims, words like "to have" and the like should be interpreted in their inclusive sense, i.e., "including, but not limited to," as opposed to their exclusive or exhaustive sense.

[0229] The singular reference of an element does not exclude the presence of a plurality of such elements.

[0230] The invention may be implemented by means of hardware comprising several distinct elements, or by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. (Thus) in yet another aspect, the invention provides software which, when executed on a computer, is capable of implementing (one or more embodiments of) the method as described herein.

[0231] The present invention also provides a control system that may control a device, apparatus or system or that may perform the methods or processes described herein. Still further, the present invention also provides a computer program product that, when executed on a computer operatively coupled to or included in a device, apparatus or system, controls one or more controllable elements of such a device, apparatus or system.

[0232] The invention further applies to a device, an apparatus or a system having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.The 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.

[0233] Various aspects described in this patent can be combined to provide additional advantages. Moreover, those skilled in the art will appreciate that embodiments can be combined, and that more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

[0234] In particular, the present invention can provide a heat sink having a closed annular slit for pumping a cylindrical (ceramic) phosphor tile in a closed annular manner at its edge.

Claims

1. A light generating system having a first light generating device, a luminescent body, one or more thermal conductors, and one or more optical elements, the first light-generating device is configured to generate a first device light, the first light-generating device having a first light source selected from the group of a superluminescent diode and a laser; the luminescent body comprises a luminescent material configured to convert at least a portion of the first device light into luminescent material light, the luminescent body has a first surface, a second surface, and a bridging surface bridging the first surface and the second surface, the second surface having a second surface circle equivalent diameter D2, the bridging surface having a first height H1 and a circumference, H1 / D2<1; the one or more thermal conductors are reflective to the first device light and to the luminescent material light; a first thermal conductor portion in thermal contact with at least a portion of the first surface; a second thermal conductor portion in thermal contact with a portion of the bridge surface and a portion of the second surface; the first thermal conductor portion and the second thermal conductor portion define a slit-like opening along at least a portion of the periphery of the bridging surface; the first light generating device and the one or more optical elements are configured to provide the first device light to the luminescent body through the slit-shaped opening; the slit-shaped opening defines a light in-coupling portion of the cross-linking surface configured to receive the first device light; during operation of the light generating system, at least a portion of the luminescent material light escapes through at least a portion of the second surface; the optical incoupling portion is configured along at least a portion of the outer periphery; A light generating system, wherein the light incoupling portion has a light incoupling portion area A1 and the second surface has a second area A2, where 1.1≦A1 / A2≦8, or 0.05≦A1 / A2≦0.

75.

2. 2. The light-generating system of claim 1, wherein 1.5≦A1 / A2≦8, or 0.25≦A1 / A2≦0.

75.

3. 3. The light-generating system of claim 2, wherein the cross-linked surface has a third area A3, where 0.5≦A1 / A3≦1.

4. 2. The light generation system of claim 1, wherein the slit-like opening defines a light in-coupling portion of the cross-linking surface configured to receive the first device light, the light in-coupling portion being configured around the entire periphery.

5. 5. The light generation system of claim 1, wherein the one or more optical elements comprise one or more first optical elements, and the light generation system comprises n sets of a first light generating device and the one or more first optical elements, the first light generating device and the one or more first optical elements being configured to supply the first device light to the luminescent body through the slit-shaped opening, where n≧1.

6. 6. The light-generating system of claim 5, wherein the one or more first optical elements comprise a first cylindrical lens arranged downstream of the first light-generating device and a first semi-cylindrical lens arranged downstream of the first cylindrical lens.

7. n≧2, and the optical axis O of the set ｓ The mutual angle α between ｓｍ But, α ｓｍ 7. The light generating system of claim 5, wherein ≠ 360° / n is satisfied, n being an even number.

8. 5. The light-generating system of claim 1, wherein the one or more optical elements comprises one or more second optical elements, the one or more second optical elements comprising a first axicon lens configured downstream of the first light-generating device and a second cylindrical reflector configured downstream of the first axicon lens, the first light-generating device and the one or more second optical elements being configured to focus a ring-shaped beam of first device light onto the luminescent body via the slit-shaped opening.

9. The light production system of claim 8 , wherein the second cylindrical reflector comprises a truncated compound parabolic reflector.

10. 10. The light generation system of claim 1, wherein the absorption of the first device light through the luminescent body parallel to the first surface is selected such that at least 90% of the first device light propagating in a direction from one portion of the cross-linking surface to an opposite portion of the cross-linking surface is absorbed by the luminescent body.

11. 11. The light generation system of claim 1, wherein the luminescent body has a cross-sectional shape selected from (a) a k-gon, where k>4, and (b) a cylindrical shape, and the luminescent body comprises a ceramic body or a single crystal.

12. The luminescent material is ３ B ５ O １２ 12. The light generating system of claim 1, comprising a luminescent material of type A:Ce, A comprises one or more of Y, La, Gd, Tb and Lu, B comprises one or more of Al, Ga, In and Sc, and the one or more thermal conductors have one or more heat sinks or are included in a heat sink.

13. 13. The light-generating system of claim 1, further comprising a second light-generating device configured to generate a second device light having a different spectral power distribution than one or more of (i) the first device light and (ii) the luminescent material light, the first heat conductor portion having a first heat conductor portion opening, the second light-generating device configured to illuminate the first side of the luminescent body through the first heat conductor portion opening, and an absorption of the second device light through the luminescent body perpendicular to the first side is selected such that at least 90% of the second device light propagating in a direction from the first side to the second side is transmitted through the luminescent body.

14. 14. The light generating system of claim 13, wherein the second light generating device is configured to generate second device light having a spectral intensity in one or more of a blue wavelength range and a red wavelength range, and the light generating system is configured to generate system light comprising the luminescent material light and the second device light, the system light being white light and having a correlated color temperature selected from the range of 1800K to 12000K and a color rendering index of at least 70.

15. 15. An illumination device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising a light generation system according to any one of claims 1 to 14.

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