High-intensity white light source with good uniformity based on multiple light sources

Abstract

The present invention relates to a light-generating system 1000 having (i) a first set 1100 including n1 first light-generating devices 110, (ii) a first optical element 410, and (iii) a luminescent body 200, wherein the n1 first light-generating devices 110 are configured to generate first device light 111, and the n1 first light-generating devices 110 may be selected from the group of lasers and superluminescent diodes, the first set 1100 having k1 first subsets 1115 of at least one first light-generating device 110 each among the n1 first light-generating devices 110, where n1≧3, in particular n1≧5 and 2≦k1≦n1, and the luminescent body 200 is configured to generate first device light 111, and the n1 first light-generating devices 110 may be selected from the group of lasers and superluminescent diodes, and the first set 1100 has k1 first subsets 1115 of at least one first light-generating device 110 each among the n1 first light-generating devices 110, where n1≧3, in particular n1≧5 and 2≦k1≦n1, a first light generating device 1000 configured to convert a portion of a first device light 111 into luminescent material light 211; and (ii) transmit a portion of the first device light 111, wherein the n1 first light generating devices 110 and the first optical element 410 are configured to provide a first beam 115 of the first device light 111 to the luminescent body 200, and wherein two or more first beams 115 of two or more first light generating devices 110 of the k1 first subsets 1115 have different first angles of incidence α1 with respect to the normal to the luminescent body 200, and in an operating mode of the light generating system 1000, a first intensity of the first device light 111 of the k1 first subsets 1115 depends on the first angle of incidence α.

Description

[Technical field]

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

[0002] The change in color temperature of the emitted light at different viewing angles to the LED is known in the art. For example, US20110001151A1 describes a common type of LED packaging in which phosphor is introduced on top of the LED known as the "glob-in-a-cup" method. The LED chip is at the bottom of a cup-shaped recess, and a phosphor-containing material (e.g., phosphor particles dispersed in an encapsulant such as silicone or epoxy) is injected into the cup, filling the cup and surrounding and sealing the LED. The encapsulant material is then cured to harden the encapsulant material around the LED. However, this packaging can result in an LED package that has a significant change in the color temperature of the emitted light at different viewing angles to the package. This color change can be caused by many factors, including differences in the path length that the light may pass through the conversion material. This problem may be exacerbated in packages where the phosphor-containing matrix material is a cup and extends above the "rim" of the cup where the LED is in the cup, resulting in a predominance of converted light emitted laterally at high viewing angles (e.g., 90 degrees from the optical axis). As a result, the white light emitted by the LED package may be non-uniform and have bands or patches of light with different colors or intensities. US20110001151A1 proposes a light emitting diode (LED) package having at least one LED that emits LED light in an LED emission profile, a first plurality of scattering particles that scatter a first target wavelength, and a second plurality of scattering particles that scatter a second target wavelength different from the first target wavelength, the first scattering particles and the second scattering particles being arranged around the LED to scatter the LED light to improve the uniformity of the LED emission profile. Summary of the Invention [Problem to be solved by the invention]

[0003] 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.

[0004] 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.

[0005] One of the problems that may be associated with such (laser) light sources is the thermal management of the (ceramic) phosphor. Another problem associated with such laser light sources may be the desire to create compact high-power devices. Furthermore, a problem with phosphor-based lighting devices, especially in transmission mode, may be color non-uniformity, also known as the color-over-angle (CoA) problem or color-over-angle effect. However, the solutions provided in the prior art may be relatively complex and susceptible to manufacturing variations. Furthermore, possible degradation of the light source, or parts of the phosphor, or scattering particles in the resin, or parts of the resin may also not be solved by the prior art solutions.

[0006] It is therefore an aspect of the present invention to provide an alternative light-generating system, 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]

[0007] In a first aspect, the present invention provides a light-generating system ("system") comprising: (i) a first set comprising n1 first light-generating devices; (ii) a first optical element; and (iii) a luminescent body. The n1 first light-generating devices may be configured to generate first device light. Furthermore, the first set may comprise a k1 first subset of at least one first light-generating device each of the n1 first light-generating devices. In an embodiment, n1≧3, in particular n1≧5. Furthermore, 2≦k1≦n1. In particular, the luminescent body is configured to convert a portion of the first device light into luminescent material light. Furthermore, in particular, the luminescent body may be configured to transmit a portion of the first device light. In an embodiment, the n1 first light-generating devices and the first optical element may be configured to provide a first beam of first device light to the luminescent body. In particular, two or more first beams of two or more first light-generating devices (from two or more different first subsets) of the k1 first subsets may have different first angles of incidence (α1) relative to a normal to the luminescent body, and in an operation mode of the light-generating system a first intensity of the first device lights of the k1 first subsets depends on the first angles of incidence (α1).In particular, the present invention therefore relates in an embodiment to a light-generating system comprising (i) a first set comprising n1 first light-generating devices, (ii) a first optical element and (iii) a luminescent body, in which (A) the n1 first light-generating devices are configured to generate first device light, (B) the first set comprises k1 first subsets of at least one first light-generating device each of the n1 first light-generating devices, where n1≧3, in particular n1≧5 and 2≦k1≦n1, and (C) the luminescent body (i) converts a portion of the first device light into luminescent material light, (i i) configured to transmit a portion of the first device light, (D) the n1 first light-generating devices and the first optical element are configured to provide a first beam of first device light to the luminescent body, and two or more first beams of two or more first light-generating devices of the k1 first subsets (particularly from two or more different first subsets) have different first angles of incidence (α1) with respect to a normal to the luminescent body, and (E) in an operation mode of the light-generating system a first intensity of the first device light of the k1 first subsets depends on the first angle of incidence (α1), wherein the n1 first light-generating devices are selected from the group of lasers and superluminescent diodes.

[0008] In such a system, it may be possible to at least partially mitigate or essentially avoid the color-over-angle problem. The intensity of the first light may be controlled in different directions, whereas the distribution of the converted light may be much less affected by the different angles at which the first light is provided to the luminescent body. The converted light may, for example, have an essentially Lambertian distribution, essentially independent of the direction in which the first light is provided to the luminescent body. However, since the path length may vary with angle, more first light may be converted at larger angles, resulting in less first light at larger angles and more first light at smaller angles. By attenuating the intensity of the first light at smaller angles compared to the first light at larger angles, the color-over-angle problem may be at least partially solved. Thus, the present invention may provide a more color-homogeneous light, substantially independent of the viewing angle.

[0009] In particular, the system may be configured to generate system light during an operational mode of the system. In particular, the system light comprises visible light. In particular embodiments, a significant portion, such as at least 95%, such as at least 85%, at least 90%, more particularly at least 95%, such as (essentially) 100%, of the spectral power of the system light may be within the visible wavelength range.

[0010] As mentioned above, the light-generating system may in particular comprise (i) a first set including n1 first light-generating devices, (ii) a first optical element, and (iii) a luminescent body.

[0011] There may be more than one set, as described below. Thus, there is at least a first set. In certain embodiments, there may be only a first set. In yet other embodiments, there may be at least a first set and a second set.

[0012] Each set may be configured to generate device light having a particular spectral power distribution, and in particular a significant portion, such as at least 95%, such as at least 85%, at least 90%, and more particularly (essentially) 100%, of the spectral power of the device light of each set may be within the visible wavelength range.

[0013] Each set may comprise a number of light-generating devices configured to generate the (respective set) device light.

[0014] Each set may have subsets. A subset may have one or more light-generating devices. Different subsets in a set may in particular be generated to generate essentially the same spectral power distribution. However, the device light of light-generating devices in different subsets may illuminate the luminescent body under different angles (see also below).

[0015] As mentioned above, the light-generating system may in particular comprise (i) a first set comprising n1 first light-generating devices.

[0016] In certain embodiments (as described further below), the light-generating system may further comprise a second set of n second light-generating devices. In particular, the second light-generating devices may be configured to generate second device light (having a different spectral power distribution than the first device light).

[0017] The first light-generating device may comprise one or more (first) light sources, more particularly one or more (first) solid-state light sources. Furthermore, the first light-generating device may comprise an optical system. Light escaping from the one or more light sources, i.e. first light source light (from the one or more first light sources), may in an embodiment be beam-shaped via the optical system. The first device light may in particular comprise the first light source light. More particularly, the first device light may consist of the (first light source) light of the one or more first light sources.

[0018] The second light-generating device may comprise one or more (second) light sources, more particularly one or more (second) solid-state light sources. Furthermore, the second light-generating device may comprise an optical system. Light escaping from the one or more light sources, i.e. second light source light (from the one or more second light sources), may in an embodiment be beam-shaped via the optical system. The second device light may in particular comprise the second light source light. More particularly, the second device light may consist of the (second light source) light of the one or more second light sources.

[0019] In the following, some general aspects regarding light sources that may be applied to (the light source of) the first light-generating device and (the light source of) the second light-generating device are described.

[0020] The term "light source" may in principle relate to any light source known in the art: it may be a conventional (tungsten) bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light-emitting diode).

[0021] In certain embodiments, the light source comprises a solid state LED light source (such as an LED or a laser diode (or "diode laser")).

[0022] 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 LED chips in the form of semiconductor chips that are not encapsulated or connected but are 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.

[0023] The light source has a light escape surface. For conventional light sources like light bulbs or fluorescent lamps, the light escape surface can be the outer surface of a glass or quartz envelope. In the case of an LED, the light escape surface can for example be the LED die or the outer surface of a resin if the resin is applied to the LED die. In principle, the light escape surface can 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 arranged to provide a light beam. This light beam escapes from the light exit surface of the light source.

[0024] 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.

[0025] 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).

[0026] The term LED may also refer to multiple 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 LED chips in the form of semiconductor chips that are not encapsulated or connected but are directly mounted on a substrate such as a PCB. Thus, multiple semiconductor light sources may be configured on the same substrate. In embodiments, a COB is a multi-LED chip configured together as a single lighting module.

[0027] 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).

[0028] 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.

[0029] However, in other embodiments, the light source may be configured to provide a primary radiation, a portion of which is converted into 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 from the light source ("remote"), such as an LED with a luminescent material layer that is not in physical contact with the LED die. Thus, in certain embodiments, the light source may be a light source that, in operation, emits light at least at a wavelength selected from the range of 380 to 470 nm. However, other wavelengths may also be possible. This light may be partially used by the luminescent material.

[0030] 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.

[0031] 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.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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).

[0040] 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.

[0041] 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 (147Pm3+ :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.

[0042] 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.

[0043] 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.

[0044] As can be derived from the following, the term "laser source" can also refer to a plurality of (different or identical) laser sources. In certain embodiments, the term "laser source" can refer to a plurality of N (identical) laser sources. In embodiments, N=2 or more. In certain embodiments, N can be at least 5, such as in particular at least 8. In this way, higher brightness can be obtained. In embodiments, the laser sources can be arranged in a laser bank (see also above). The laser bank can in embodiments include a heat sink and / or an optics, e.g. a lens for collimating the laser light.

[0045] 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.

[0046] 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.

[0047] 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).

[0048] The term "solid state 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.

[0049] 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.

[0050] 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.

[0051] 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, i.e., 450-650 nm wavelength range, used for display applications, a single SLED can emit light over a bandwidth of, for example, up to 10-30 nm in 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).

[0052] Vertical-cavity surface-emitting lasers, or VCSELs, are known in the art and may be a type of semiconductor laser diode with a laser beam emitting vertically from the top surface, as opposed to edge-emitting semiconductor lasers (in-plane lasers), which emit from a surface formed by cutting individual chips from a wafer. As is known in the art, VCSELs may have tunable emission wavelengths. See, for example, Dupont et al., Applied Physics Letters 98(16):161105 - 161105-3, DOI:10.1063 / 1.3569591, Wendi Chang et al., Applied Physics Letters 105(7):073303, DOI:10.1063 / 1.4893758, Thor Ansbaek, IEEE Journal of Selected Topics in Quantum Electronics 19(4):1702306-1702306, DOI:10.1109 / JSTQE.2013.2257164, or CJ Chang-Hasnain, IEEE Journal of Selected Topics in Quantum Electronics (Volume: 6, Issue: 6, Nov.-Dec. 2000), DOI:10.1109 / 2944.902146, all of which are incorporated herein by reference, describes tunable VCSELs, whose spectral power distribution can be changed, in particular by varying the voltage.

[0053] The light-generating device may comprise a plurality of different light sources, such as two or more subsets of light sources, each subset including one or more light sources configured to generate source light having essentially the same spectral power distribution, but with light sources of different subsets configured to generate source light having different spectral distributions. In such embodiments, the control system may be configured to control the plurality of light sources. In certain embodiments, the control system may control subsets of light sources individually (see further below).

[0054] As mentioned above, the n1 first light-generating devices are configured to generate first device light. The n1 first light-generating devices are configured to generate first device light having a wavelength selected from the range of 380 to 495 nm. In particular, the n1 first light-generating devices may be configured to generate first device light having a centroid wavelength selected from the range of 380 to 495 nm. Thus, essentially all the spectral power of the first device light, in particular at least 85%, such as at least 90%, more particularly at least 95%, such as (essentially) 100%, may be in the wavelength range of 380 to 495 nm. In an embodiment, the centroid wavelength of the first device light may be selected from the range of 380 to 440 nm (in particular may be violet light). In another embodiment, the centroid wavelength of the first device light may be selected from the range of 440 to 495 nm (in particular may be blue light).

[0055] The term "centroid wavelength", also denoted λc, is known in the art and refers to the wavelength value where half of the light energy is at the shorter wavelength and half of the light energy is at the longer wavelength, the value being given in nanometers (nm). It is the wavelength that halves the integral of the spectral power distribution as expressed by the formula λc=Σλ*I(λ) / (ΣI(λ), where the sum is over the wavelength range of interest, and I(λ) is the spectral energy density (i.e., the integral of the product of wavelength and intensity over the emission band normalized to the integrated intensity). The centroid wavelength may be determined, for example, in operating conditions.

[0056] In particular, the first set may comprise at least two, even more particularly at least three, such as at least five, first light-generating devices. Furthermore, the first set may comprise at least two first subsets. In a particular embodiment, the first set consists of two subsets. In other embodiments, the first set may comprise at least three first subsets. As mentioned above, the first light-generating devices in the first set may in an embodiment be essentially identical in terms of the spectral power distribution they generate during operation.

[0057] Thus, in an embodiment, the first set comprises k1 first subsets of at least one first light-generating device each of the n1 first light-generating devices, where n1≧3, in particular n1≧5 and 2≦k1≦n1. In particular, the n1 first light-generating devices may comprise lasers. Thus, in a particular embodiment, each first light-generating device may comprise a laser diode.

[0058] In particular, in an embodiment, the n1 first light-generating devices comprise vertical cavity surface-emitting lasers (VCSELs). Thus, the first light-generating devices may comprise VCSELs. In a particular embodiment, the first light-generating devices are provided by a (first) multi-channel VCSEL, such as a k1 channel VCSEL.

[0059] In the following, first some aspects and embodiments relating to the luminescent body are described and then we return to aspects and embodiments of the arrangement of the light-generating device and the luminescent body (especially in combination with a first optical element).

[0060] The luminescent body comprises a luminescent material, in particular the luminescent material is configured to convert at least a portion of the first device light into luminescent material light.

[0061] 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.

[0062] 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 >λ em ) is converted into radiation with a

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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 12The garnet includes A at least yttrium or lutetium and B 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 includes aluminum (Al), but B may also partially include gallium (Ga) and / or scandium (Sc) and / or indium (In), in particular up to about 20% of Al, more in particular up to about 10% of Al (i.e., B ions essentially consist 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 partially 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, (Y 1-x Lu x )3AlO 12 In the case of Ce, part of Y and / or Lu is replaced by Ce. This is known to those skilled in the art. Ce replaces A, generally up to 10%, and generally the Ce concentration is in the range of 0.1 to 4%, in particular 0.1 to 2% (relative to A). Assuming 1% Ce and 10% Y, the perfectly correct formula is (Y 0.1 Lu 0.89 Ce 0.01 )3AlO 12 The Ce in the garnet may be substantially or exclusively in the trivalent state, as known to those skilled in the art.

[0067] In an embodiment, the luminescence material is (therefore) A3B5O 12 and in certain embodiments, up to 10% of the B-O can be replaced by Si-N.

[0068] In certain embodiments, 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' comprises one or more elements selected from the group consisting of lanthanides, and B' comprises one or more elements selected from the group consisting of Ga, In, and Sc. 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.

[0069] In certain embodiments, up to 10% of the 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 described above, in certain embodiments, x3 can be selected from the range of 0.001 to 0.04. In particular, such a luminescence material has an appropriate spectral distribution (see below), has relatively high efficiency, has relatively high thermal stability, and can enable a high CRI (in combination with the first light source light and the second light source light (and the optical filter)). Therefore, in certain embodiments, A can be selected from the group consisting of Lu and Gd. Alternatively, or in addition, B can include Ga. Therefore, in an embodiment, the luminescence material is (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O12 including, and Lu and / or Gd may be available. Even more particularly, x3 is selected from the range of 0.001 to 0.1, 0 < x2 + x3 ≤ 0.1, and 0 ≤ y2 ≤ 0.1. Further, in certain embodiments, up to 1% of B-O can be replaced by Si-N. Here, the percentage refers to moles (as is known in the art), for example, see also EP3149108. In still other specific embodiments, the luminescence material is (Y x1-x3 Ce x3 )3Al5O 12 including, x1 + x3 = 1, 0 < x3 ≤ 0.2, and is 0.001 to 0.1, etc.

[0070] In certain embodiments, the light generating device may contain only a luminescence material selected from the type of garnet containing cerium. In still other specific embodiments, the light generating device contains a single type of luminescence material such as (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 . Thus, in certain embodiments, the light generating device has a luminescence material, and at least 85% by weight, even more particularly at least about 90% by weight, for example even more particularly at least about 95% by weight 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. Note that in embodiments, x2 = 0. Instead, or in addition, in embodiments, y2 = 0.

[0071] In certain embodiments, A may, inter alia, include at least Y, and B may, inter alia, include at least Al.

[0072] Alternatively, or in addition, the luminescent material may be A3Si6N 11 :Ce 3+ The present invention may include luminescent materials of the type A, where A includes one or more of Y, La, Gd, Tb, and Lu, such as one or more of La and Y in embodiments.

[0073] In an embodiment, the luminescent material may alternatively or additionally be 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 fact that a portion of the metal ions are 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 0.5 In 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.

[0074] 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.

[0075] 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).

[0076] 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 0.5Particularly 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).

[0077] 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).

[0078] The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0079] 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.

[0080] The term "luminescent material" as used herein relates specifically to inorganic luminescent materials.

[0081] Instead of the term "luminescent material", the term "phosphor" is sometimes applied, these terms being known to those skilled in the art.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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).

[0087] As mentioned above, other luminescent materials may be possible. Thus, in certain embodiments, the luminescent material is selected from the group of divalent europium-containing nitrides, divalent europium-containing oxynitrides, divalent europium-containing silicates, cerium-containing garnets, and quantum structures. The quantum structures may include, for example, quantum dots or quantum rods (or other quantum-type particles) (see above). The quantum structures may also include quantum wells. The quantum structures may also include photonic crystals.

[0088] The luminescent material may be selected to obtain an emission band with a full width at half maximum (of the luminescent material light) of at least 40 nm, such as at least 50 nm. For example, the luminescent material may be selected to obtain an emission band with a full width at half maximum of at least 60 nm. This may be the case, for example, for a garnet luminescent material containing trivalent cerium (as described herein). Thus, in particular, the luminescent material may include a broadband emitter. The luminescent material may also have a plurality of broadband emitters. In particular, when two or more luminescent materials are applied to convert at least a portion of the first device light and / or at least a portion of the second device light, at least two of the two or more luminescent materials may be configured to provide a respective luminescent material light having an emission band with a full width at half maximum (of the luminescent material light) of at least 40 nm, such as at least 50 nm.

[0089] In particular, the luminescent material light may include visible light. The terms "visible", "visible light" or "visible emission" and similar terms refer to light having one or more wavelengths in the range of about 380 to 780 nm. In this specification, the terms "light" and "radiation" are used interchangeably unless the context makes 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.

[0090] In particular, the luminescent material is 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 an embodiment, the luminescent body may be a ceramic body or a single crystal body. Thus, the luminescent material may be provided as a ceramic body or a single crystal body, as is possible in an embodiment for example with a garnet luminescent material containing cerium (see elsewhere herein). 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. Alternatively, 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.

[0091] The luminescent material body may be configured in the reflection mode or in the transmission mode. In the transmission mode, it may be relatively easy to mix the source light into the luminescent material light. This may be useful for generating a desired spectral power distribution. In the reflection mode, a significant portion of the luminescent body may be in thermal contact with a thermally conductive element such as a heat sink or heat spreader, so thermal management may be easier. In the reflection mode, a portion of the source light may be reflected by the luminescent material and / or a reflector, in embodiments, and mixed into the luminescent material light. The reflector may be configured downstream of the luminescent material (in the reflection mode).

[0092] In particular, the luminescent body is configured in the transmission mode. The luminescent body may therefore in particular be configured downstream of the first light-generating device. The terms "upstream" and "downstream" refer to the location of an item or feature with respect to the propagation of light from a light generating means (here in particular the light source), such that with respect 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". The luminescent body may therefore be configured in a light-receiving relationship with the first light-generating device. The term "light-receiving relationship" and similar terms may indicate that an article may receive light from a light source (such as a light generating device or light generating element or light generating system) during operation of the light source. The article may therefore be configured downstream of the light source. An optical system may be configured between the light source and the article.

[0093] The luminescent body may have any shape. In general, however, the luminescent body may have two essentially parallel faces that define a height (of the luminescent body). Furthermore, the luminescent body may have end faces bridging the two essentially parallel faces. The end faces may be curved in one or two dimensions. The end faces may be planar. The luminescent body may have a rectangular or circular cross-section, although other cross-sections may be possible. The two essentially parallel faces may be denoted as "main faces", especially since they may provide the largest external area of ​​the luminescent body.

[0094] In an embodiment, the body has a lateral dimension width or length (W1 or L1) or diameter (D) and a thickness or height (H1). In an embodiment, (i) D≧H1, or (ii) W1≧H1 and / or L1≧H1. The luminescent tile may be transparent or light scattering. In an embodiment, the tile may comprise a ceramic luminescent material. In a particular embodiment, L1≦10mm, especially L1≦5mm, more especially L1≦3mm, most especially L1≦2mm. In a particular embodiment, W1≦10mm, especially W1≦5mm, more especially W1≦3mm, most especially W1≦2mm. In a particular embodiment, H1≦10mm, especially H1≦5mm, more especially H1≦3mm, most especially H1≦2mm. In a particular embodiment, D≦10mm, especially D≦5mm, more especially D≦3mm, most especially D≦2mm. In particular embodiments, the body may have a thickness in the range of 50 μm to 1 mm. Furthermore, the body may have a lateral dimension (width / diameter) in the range of 100 μm to 10 mm. In yet other particular embodiments, (i) D>H1 or (ii) W1>H1 and W1>H1. In particular, the lateral dimensions, such as length, width and diameter, are at least twice as large as the height, such as at least five times. In particular embodiments, the luminescent body has a first length L1, a first height H1 and a first width W1, where H1≦0.5*L1 and H1≦0.5*W1.

[0095] In particular, at least a portion of the first device light is transmitted through the luminescent body. Thus, in embodiments, the system light may include first device light (and luminescent material light). Thus, in embodiments, the luminescent body may be configured to (i) convert a portion of the first device light into luminescent material light, and (ii) transmit a portion of the first device light.

[0096] As mentioned above, the system may further comprise a first optical element. The term "first optical element" may also refer to a plurality of (different) first optical elements. In particular, the first light-generating device and the first optical element are configured such that at least two bundles of first device light illuminate the luminescent body under different angles. The at least two bundles of first device light may be provided by at least two first subsets of the k1 first subsets. The direction of the beam may be along the optical axis of the beam.

[0097] In particular, the optical axis may be defined as an imaginary line defining a path along which light propagates in the system starting from the light generating element, here in particular from the (first) light generating device, In particular, the optical axis may coincide with the direction of light with the highest radiant flux.

[0098] The first optical element may be configured to focus the first device light into the luminescent body. In an embodiment, the first optical element may comprise a single lens. In an embodiment, the first optical element may have an optical axis. In a particular embodiment, the optical axis of the first optical element may be configured essentially parallel to the normal of the luminescent body. The first optical element may be configured such that the parallel optical axes of two or more first light beams of two or more first light generating devices configured upstream of the first optical element acquire a mutual angle and are no longer parallel when they reach the luminescent body. Thus, the beams of first device light of the first light generating device may be provided parallel to the first optical element. However, in other embodiments, the two or more first light beams of two or more first light generating devices may be provided with a mutual angle to the first optical element. In an embodiment, the first optical element may have a focusing function, so that the mutual angle may be larger downstream of the first optical element. The normal of the luminescent body may in particular be the normal of an upstream face of the luminescent body, which in an embodiment may be one of the main faces (see also above).

[0099] Therefore, in an embodiment, the n1 first light generating devices and the first optical element may be configured to provide first beams of first device light to the luminescent body, where two or more first beams (in particular their optical axes) of two or more first light generating devices of the k1 first subsets (from two or more different first subsets) have different first angles of incidence (α1) with respect to the normal of the luminescent body. In a particular embodiment, at least two of the two or more first beams of the two or more first light generating devices of the k1 first subsets have first angles of incidence (α1) with respect to the normal of the luminescent body that differ by a mutual angle (γ) selected from the range of 5 to 175°, such as 10 to 135°, for example selected from the range of 15 to 90°, in an embodiment selected from the range of 15 to 135°.

[0100] In an embodiment, to compensate for color-over-angle effects, it may be desirable to provide beams of first radiation to the luminescent body that not only have different angles (relative to the normal), but also where the intensity of the beam may depend on the angle. In a particular embodiment, in an operating mode of the light-generating system, a first intensity of the first device light of the first subset of k1 may depend on the first angle of incidence (α1). As noted above, in an embodiment, it may be desirable that a more tilted beam of first device light may have a higher intensity than a less tilted beam, or a beam that is essentially perpendicular to the luminescent body. In the operating mode, the first intensity of the first device light of the first subset of k1 increases with increasing first angle of incidence (α1).

[0101] Thus, in certain embodiments, under normal incidence, less first device light may be illuminating the luminescent body than at larger angles, i.e., not necessarily less first device light (spatially non-uniform) in the center of the phosphor, but specifically less normal illumination (angularly non-uniform) such that unconverted first device light appears in a wider distribution.

[0102] In particular, in the embodiment, the first device light may be blue light.

[0103] In a particular embodiment, in the operating mode, a first intensity (I 1,max ) and the lowest first intensity (I 1,min ) is 1.04≦(I 1、max / I 1、min )≦10. For example, in the embodiment, 1.08≦(I 1、max / I 1、min )≦8.

[0104] In this specification, the intensities are used in particular in relation to each other. However, in embodiments determining the ratio of two intensities, the radiant flux may be applied. More particularly, the irradiance may be applied. The term "radiant flux" may refer in particular to the radiant energy emitted per unit time (by the light-generating device). Instead of the term "radiant flux", the terms "intensity" or "radiant power" may be applied. The term "radiant flux" may have units of energy, such as watts. The term "spectral power distribution" may refer in particular to the power distribution of light (in particular in watts) as a function of wavelength (in particular in nanometers), especially in embodiments spanning the human visible wavelength range (380-780 nm). In particular, the term "spectral power distribution" may refer to the radiant flux per unit frequency or wavelength, often expressed in watts / nm. Instead of the term "spectral power distribution", the term "spectral flux" may be applied. Thus, instead of the phrase "controllable spectral power distribution", the phrase "controllable spectral flux" may be applied. The spectral flux may be expressed as power (Watt) per unit frequency or wavelength. In particular, in this specification, the spectral flux is expressed as radiant flux per unit wavelength (W / nm). Furthermore, in this specification, the spectral flux and radiant flux are based on the spectral power of the device light, in particular over the wavelength range of 380 to 780 nm. The term "irradiance" may refer in particular to the radiant flux received by a surface per unit area (wherein the surface may in particular be the surface of the luminescent body).

[0105] The luminescent body may be specifically configured to convert at least a portion of the first device light, although it may be desirable for at least a portion of the first device light to be transmitted through the luminescent body. Thus, the luminescent body may be relatively transmissive or even transparent to the first device light. Hence, the luminescent body may have a relatively low scattering for the first device light. In certain embodiments, the luminescent body has a body height (H1) and a scattering mean free path (ls) of the first device light, in certain embodiments ls>1 / 5*H1. For example, in embodiments, the scattering mean free path (ls) of the first device light may be selected from the range of 1 / 4*H1 to H1, such as selected from the range of 1 / 4*H1 to 1 / 3*H1. Furthermore, in certain embodiments, the luminescent body may have a transmission in the range of 5 to 20% for vertically provided first device light.

[0106] Thus, the luminescent body may have an upstream face (see also above) configured to be in a light receiving relationship with the n1 first light-generating devices, and a downstream face from which (a) the first device light after being transmitted through the luminescent body and (b) the luminescent material light escape during the operation mode. In particular, in an embodiment, the light-generating system may be configured to generate a system light, which in the operation mode comprises the first device light and the luminescent material light, and the first angle of incidence (α1) and the first intensity in the operation mode are selected such that in a plane perpendicular to the downstream side, the change in color in u' over an angle β of at least 90° (in that plane) or the change in color in v' over said angle is at most 0.03. In a particular embodiment, this may apply to two perpendicular planes (perpendicular to each other (and in particular both perpendicular to the downstream side)).

[0107] To reduce color-over-angle effects, the intensity of the vertical beam may be lower than the intensity of the more tilted beam. In certain embodiments, it may be desirable to control said intensity. This allows adapting said intensity (such as radiant flux) over time. However, this may also allow not only an operating mode in which color-over-angle effects are reduced or substantially absent, but also (on the contrary) an operating mode in which color-over-angle effects are reduced. In such an operating mode, the intensity of the vertical beam may be higher than the intensity of the more tilted beam.

[0108] Where the intensity of the beam is controlled, a control system may be included in the system or operatively coupled to the system.

[0109] In a particular embodiment, the system may further comprise a control system, wherein the k1 first subsets (of at least one first light-generating device each of the n1 first light-generating devices) are individually controllable, the control system being configured to control the k1 first subsets. In particular, the control system may be configured to control the radiant flux of the first light-generating devices of the first subset.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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).

[0115] 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.

[0116] In embodiments, it may be desirable to collimate the first device light from the first light-generating devices. For example, this may be desirable when using laser diodes, which may have relatively wide beams (relatively large beam angles). Thus, in certain embodiments, the light-generating system may further comprise a second optical element, which in embodiments may comprise (i) a lens array with m1 lenslets, or (ii) a collimator element. In particular, the m1 lenslets or the collimator element may be configured downstream of the n1 first light-generating devices and upstream of the first optical element. Furthermore, in certain embodiments, m1=n1. Furthermore, in embodiments, the m1 lenslets or the collimator element may be configured in particular to collimate the first device light of the n1 first light-generating devices. The second optical element may comprise one or more of a collimator, a lens, and a lens array, for example downstream of each first light-generating device. Such lenses may be relatively small and may be denoted lenslets.

[0117] In certain embodiments, the luminescent body may be configured to convert at least a portion of the first device light to green or yellow (or amber) light. In certain embodiments, the luminescent body may be configured to convert a portion of the first device light to luminescent material light having a wavelength within 495-605 nm. In certain embodiments, a substantial portion, such as at least 95%, such as at least 85%, at least 90%, more particularly (essentially) 100%, of the spectral power of the system light may be within the wavelength range of 495-650 nm. In embodiments, the centroid wavelength may be configured within the wavelength range of 495-605 nm. The centroid wavelength may be configured more particularly within the wavelength range of 510-590 nm, and even more particularly within the wavelength range of 570-590 nm. Thus, in certain embodiments, the first device light may be blue light and the luminescent material light may be yellow light or may have a combination of yellow and red light.

[0118] As mentioned above, the light-generating system may further comprise a second set comprising n2 second light-generating devices. In particular, the second light-generating devices may be configured to generate second device light (having a different spectral power distribution than the first device light). In particular, the second set may comprise k2 second subsets of at least one second light-generating device each of the n2 second light-generating devices. In particular embodiments, n2≧3, in particular n2≧5. In further embodiments, 2≦k2≦n2. Furthermore, in particular embodiments, the luminescent body may have a transmittance of at least 50% for vertically delivered second device light, such as at least about 60%, in embodiments at least about 65%, or even at least about 70%. In particular, the n2 second light-generating devices and the first optical element may be configured to provide second beams of second device light to the luminescent body, and two or more second beams of two or more second light-generating devices (from two or more different second subsets) of the k2 second subsets may have different second angles of incidence (α2) with respect to the normal to the luminescent body. In a particular embodiment, in an operation mode of the light-generating system, a second intensity of the second device light of the k2 second subsets may depend on the second angle of incidence (α2).Therefore, the present invention relates to a method for manufacturing a luminescent body having a second set comprising n2 second light-generating devices, wherein (a) the second light-generating devices are configured to generate second device light, (b) the second set comprises k2 second subsets of at least one second light-generating device each of the n2 second light-generating devices, where n2≧3, in particular n2≧5 and 2≦k2≦n2, and (c) the luminescent body has a luminance of at least 5%, such as at least about 60%, in embodiments at least about 65%, or even at least about 70%, relative to the vertically supplied second device light. 0% transmittance; (d) the n2 second light-generating devices and the first optical element are configured to provide a second beam of second device light to the luminescent body, and two or more second beams of two or more second light-generating devices (from two or more different second subsets) of the k2 second subsets have different second angles of incidence (α2) with respect to the normal to the luminescent body; and (e) in an operating mode of the light-generating system, a second intensity of the second device light of the k2 second subsets depends on the second angle of incidence (α2).

[0119] In an embodiment, the n2 second light-generating devices may be configured to provide second device light having a wavelength within 605 to 780 nm. In particular, the n2 second light-generating devices may be configured to generate second device light having a centroid wavelength selected from the range of 605 to 780 nm. Thus, essentially all the spectral power of the second device light may be within the wavelength range of 605 to 780 nm, in particular at least 85%, such as at least 90%, more particularly at least 95%, such as (essentially) 100%. In particular, the centroid wavelength may be within the wavelength range of 605 to 680 nm, such as within the wavelength range of 610 to 650 nm.

[0120] In particular, the second set may comprise at least two, even more particularly at least three, such as at least five, second light-generating devices. Furthermore, the second set may comprise at least two second subsets. In a particular embodiment, the second set consists of two subsets. In other embodiments, the second set may comprise at least three second subsets. As mentioned above, the second light-generating devices in the second set may in an embodiment be essentially identical in terms of the spectral power distribution they generate during operation.

[0121] In particular, the n2 second light-generating devices may comprise lasers. Thus, in a particular embodiment, each second light-generating device may comprise a laser diode. In particular, in an embodiment, the n2 second light-generating devices comprise vertical-cavity surface-emitting lasers (VCSELs). Thus, the second light-generating devices may comprise VCSELs. In a particular embodiment, the second light-generating device is provided by a (second) multi-channel VCSEL, such as a k1-channel VCSEL. Thus, one or more of (i) the n1 first light-generating devices comprising vertical-cavity surface-emitting lasers and (ii) the n2 second light-generating devices comprising vertical-cavity surface-emitting lasers may be applied.

[0122] In embodiments, it may be desirable to collimate the first device light from the first light-generating device. For example, this may be desirable when using a laser diode. For this purpose, a second optical element as described above may also be applied, in which case the second optical element may be specifically dedicated to the second light-generating device.

[0123] In contrast to the first device light, in the (first) operating mode, the second device light may be provided at a higher intensity under essentially normal angles and at a lower intensity at more tilted angles. In a particular embodiment, in the operating mode, the second intensity of the second device lights of the second subset of k2 decreases with increasing second angle of incidence (α2).

[0124] The first device light and the second device light may be combined before reaching the first optical element. Thus, in certain embodiments, the system may further comprise a third optical element, which may comprise a beam combiner, the third optical element being configured downstream of the n1 first light generating devices and the n2 second light generating devices and upstream of the first optical element, the third optical element being configured to combine the first device light and the second device light. In embodiments, the beam combiner may comprise a polarizing beam splitter. In embodiments, the beam combiner may comprise a dichroic beam combiner. Furthermore, in embodiments, the beam combiner may comprise a diffraction grating.

[0125] The system light may have a white light in the operating mode in an embodiment. More particularly, in a further particular embodiment, the system light may be a white light in the operating mode. The term "white light" in this specification is known to those skilled in the art. The white light particularly relates to light having a correlated color temperature (CCT) between about 2000K and 20000K, particularly between 2700K and 20000K, particularly between about 1800K and 20000K, such as between about 2700K and 6500K for general illumination. In an embodiment, for backlight applications, the correlated color temperature (CCT) may particularly be within about 7000K and 20000K. In yet another embodiment, 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.

[0126] 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.

[0127] 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 a light generating device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, and an optical wireless communication device, the light generating device having a light generating system as defined herein. The light generating device may have a housing configured to accommodate or a carrier configured to support one or more elements of the light generating system. For example, in an embodiment, the light generating device may have a housing configured to accommodate or a carrier configured to support one or more of the first light generating device, the first light generating device, the first optical element and the luminescent body, and optionally also one or more of the second light generating device and one or more further optical elements.

[0128] 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 to 780 nm. As used herein, UV may specifically refer to wavelengths selected from the range of 200 to 380 nm.

[0129] As used herein, the terms "light" and "radiation" are used interchangeably, unless it is clear from the context that the term "light" refers only to visible light. Thus, the terms "light" and "radiation" can 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.

[0130] The term "purple light" or "purple emission" and similar terms particularly refers to light having a wavelength in the range of about 380 to 440 nm. In certain embodiments, the purple light may have a center wavelength in the range of 380 to 440 nm. The term "blue light" or "blue emission" and similar terms particularly refers to light having a wavelength in the range of about 440 to 490 nm (including some purple and cyan hues). In certain embodiments, the blue light may have a center wavelength in the range of 440 to 490 nm. The term "green light" or "green emission" and similar terms particularly refers to light having a wavelength in the range of about 490 to 560 nm. In certain embodiments, the green light may have a center wavelength in the range of 490 to 560 nm. The term "yellow light" or "yellow emission" and similar terms particularly refers to light having a wavelength in the range of about 560 to 590 nm. In certain embodiments, the yellow light may have a central wavelength in the range of 560 to 590 nm. The terms "orange light" or "orange emission" and similar terms particularly relate to light having a wavelength in the range of about 590 to 620 nm. In certain embodiments, the orange light may have a central wavelength in the range of 590 to 620 nm. The terms "red light" or "red emission" and similar terms particularly relate to light having a wavelength in the range of about 620 to 750 nm. In certain embodiments, the red light may have a central wavelength in the range of 620 to 750 nm. The terms "cyan light" or "cyan emission" and similar terms particularly relate to light having a wavelength in the range of about 490 to 520 nm. In certain embodiments, the cyan light may have a central wavelength in the range of 490 to 520 nm. The terms "amber light" or "amber emission" and similar terms particularly relate to light having a wavelength in the range of about 585 to 605 nm, such as about 590 to 600 nm. In certain embodiments, the amber light may have a centroid wavelength in the range of 585 to 605 nm.

[0131] In particular embodiments, the colors or color points of the first type of light and the second type of light may differ if the respective color points of the first type of light and the second type 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 the first type of light and the second type 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. In particular, different spectral power distributions may refer to light having different color points in embodiments.

[0132] The phrase "light having one or more wavelengths in a wavelength range" and similar phrases may specifically indicate that the light (or radiation) shown has a spectral power distribution with at least one or more intensities at those one or more wavelengths in the wavelength range shown. For example, a blue-emitting solid-state light source has a spectral power distribution with intensities at one or more wavelengths in the wavelength range of 440 to 495 nm. [Brief description of the drawings]

[0133] 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] 1 illustrates an embodiment diagrammatically. [Figure 2a] Several embodiments are illustrated diagrammatically. [Figure 2b] Several embodiments are illustrated diagrammatically. [Diagram 3] 1 illustrates a schematic diagram of an embodiment of a light-generating system; [Figure 4] Several embodiments and applications are illustrated diagrammatically.

[0134] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0135] FIG. 1 illustrates a schematic embodiment of a light-generating system 1000 having (i) a first set 1100 including n1 first light-generating devices 110, (ii) a first optical element 410, and (iii) a luminescent body 200.

[0136] The n1 first light-generating devices 110 are configured to generate a first device light 111. The first set 1100 may include k1 first subsets 1115 of at least one first light-generating device 110 each of the n1 first light-generating devices 110. In particular, n1≧3, in particular n1≧5, and 2≦k1≦n1. Here, two subsets 1115 are illustrated diagrammatically, one designated as a first subset 1115a and one designated as a second subset 1115b. Here, in this schematic cross-sectional view. The first subset 1115a comprises at least a single first light-generating device 110, and the second subset 1115b comprises at least two first light-generating devices 110.

[0137] In an embodiment of the light-generating system 1000, the n1 first light-generating devices 110 comprise lasers.

[0138] In particular, the n1 first light-generating devices 110 are configured to generate first device light 111 having a wavelength selected from the range of 380 to 495 nm.

[0139] The luminescent body 200 may be configured to (i) convert a portion of the first device light 111 into luminescent material light 211, and (ii) transmit a portion of the first device light 111.

[0140] The n1 first light generating devices 110 and the first optical element 410 are configured to provide first beams 115 of first device light 111 to the luminescent body 200, where the two or more first beams 115 of the two or more first light generating devices 110 of the k1 first subsets 1115 (from two or more different first subsets 1115) have different first angles of incidence α1 with respect to the normal of the luminescent body 200. The first beam 115a may be based on the first light generating devices 110 of the first subset 1115a and the second beam 115b may be based on the first light generating devices 110 of the second subset 1115b. The beams 115 downstream of the first optical element 410 may be characterized by an optical axis of said beams 115, where the optical axis may have a respective first angle of incidence α1 with respect to the normal of the luminescent body 200. The first angle of incidence α1 is essentially 0° for the first beam 115a, and in this schematic drawing the first angle of incidence α1 may be approximately 25°.

[0141] In an operating mode of the light-generating system 1000, a first intensity of the first device lights 111 of the first subset k1 1115 may depend on the first angle of incidence α. In a particular embodiment (of the light-generating system 1000), in an operating mode, the first intensity of the first device lights 111 of the first subset k1 1115 increases with increasing first angle of incidence α1. Schematically, the tilted beam 115b is illustrated with a thicker arrow indicating a higher intensity compared to the beam 115a propagating essentially parallel to the normal.

[0142] In particular, at least two of the two or more first beams 115 of the two or more first light-generating devices 110 of the k1 first subsets 1115 have a first angle of incidence (α1) with respect to the normal of the luminescent body that differs at a mutual angle γ selected in the range of 15 to 135°. Note that here three angles of incidence, i.e. three optical axes, are shown, with two beams having an angle α1 with respect to the normal. Note that it is not necessary that these two beams have the same angle of incidence. However, in an embodiment a symmetrical configuration may be chosen.

[0143] In a particular embodiment, in the operation mode, the highest first intensity (I 1,max ) and the lowest first intensity (I 1,min ) is 1.04≦(I 1、max / I 1、min )≦10.

[0144] In an embodiment, the luminescent body 200 has a body height H1 and a scattering mean free path (ls) of the first device light 111. In particular, ls>1 / 4*H1. The width is indicated with the reference W1. In a particular embodiment, the width W1 may be a diameter D. In a rectangular embodiment, there may be a length L1 perpendicular to the width W1 and the height H1 (see also FIG. 2b).

[0145] In an embodiment, the luminescent body 200 may comprise a single crystal body or a ceramic body.

[0146] In an embodiment, the luminescent body 200 has a transmittance for normally-fed first device light 111 in the range of 5 to 20%.

[0147] The luminescent body 200 may be configured to convert a portion of the first device light 111 to luminescent material light 211 having a wavelength within 495 to 605 nm.

[0148] In particular, the luminescent body 200 has an upstream face 201 configured to be in a light receiving relationship with the n1 first light generating devices 110, and a downstream face 202 from which (a) the first device light 111 after being transmitted through the luminescent body 200 and (b) the luminescent material light 211 escape during an operational mode. The upstream face 201 and the downstream face 202 may also be denoted as main faces. The main faces may be bridged by edges. A cross section of the luminescent body 200 parallel to one of the main faces may be, for example, circular or rectangular.

[0149] The light generating system 1000 may be configured to generate a system light 1001. In an operational mode, the system light 1001 may comprise a first device light 111 and a luminescent material light 211. In an embodiment, in an operational mode, the system light 1001 may be white light.

[0150] In certain embodiments, the light-generating system 1000 may further include a control system 300 .

[0151] In an embodiment, the k1 first subsets 1115 (of at least one first light-generating device 110 each of the n1 first light-generating devices 110) may be individually controllable. The control system 300 may be configured to control the k1 first subsets 1115.

[0152] Referring also to FIG. 2a, in an embodiment the first angle of incidence (α1) and the first intensity in the operating mode are selected such that in a plane perpendicular to the downstream side, the change in color in u' over an angle β of at least 90° (in that plane) or the change in color in v' over said angle can be at most 0.03.

[0153] Figure 2b (see also Figure 1) illustrates diagrammatically a top view of a possible luminescent body 200, with the dashed line indicating a plane perpendicular to the downstream side 202 of the luminescent body. On the left side a rectangular luminescent body 200 is illustrated, and on the right side a circular luminescent body 200 is illustrated. Other shapes may be possible. The dashed circle indicates the luminescent light and device light escaping from the downstream side 202 of the luminescent body 200. This may be the system light 1001.

[0154] 3, in an embodiment, the light-generating system 1000 may further comprise a second optical element 420. The second optical element 420 may comprise a lens array with m1 lenslets 425, or a collimator element 426. The m1 lenslets 425, or the collimator element 426 may be configured downstream of the n1 first light-generating devices 110 and upstream of the first optical element 410. In an embodiment, m1=n1. In an embodiment, the m1 lenslets 425, or the collimator element 426 may be configured to collimate the first device light 111 of the n1 first light-generating devices 110.

[0155] In certain embodiments, the light-generating system 1000 may further comprise a second set 1200 including n2 second light-generating devices 120. The second light-generating devices 120 may be configured to generate second device light 121 (having a different spectral power distribution than the first device light 111).

[0156] The second set 1200 may comprise k2 second subsets 1125 of at least one second light-generating device 120 each of the n2 second light-generating devices 120. In an embodiment, n2≧3, in particular n2≧5. In a particular embodiment, 2≦k2≦n2.

[0157] In an embodiment, the luminescent body 200 has a transmittance of at least 50% for normally-fed second device light 111 .

[0158] The n 2 second light-generating devices 120 and the first optical element 410 are configured to provide a second beam 125 of second device light 121 to the luminescent body 200 .

[0159] The two or more second beams 125 of the two or more second light-generating devices 120 (from two or more different second subsets 1125) of the k2 second subsets 1125 have different second angles of incidence α2 with respect to the normal to the luminescent body 200.

[0160] In an operation mode of the light-generating system 1000, a second intensity of the second device lights 121 of the second subset 1125 of k2 may depend on the second angle of incidence α2. In particular, in an operation mode, the second intensity of the second device lights 121 of the second subset 1125 of k2 may decrease with increasing second angle of incidence α2. This is shown diagrammatically by the dashed lines, with a higher intensity for a more perpendicular beam and a lower intensity for a more tilted beam.

[0161] In an embodiment, the n2 second light-generating devices 120 comprise lasers.

[0162] Here, by way of example, the first set 1100 has collimator element 426 arranged downstream thereof, and the second set 1200 has m1 lenslets 425 arranged downstream thereof. Of course, other embodiments may also be possible.

[0163] With particular reference to Figures 1 and 3, one or more of (i) n1 first light-generating devices 110 having vertical cavity surface-emitting lasers, and (ii) n2 second light-generating devices 120 having vertical cavity surface-emitting lasers may be applied.

[0164] In a particular embodiment, the n2 second light-generating devices 120 may be configured to provide second device light 121 having a wavelength within 605 to 780 nm.

[0165] 3, the light generation system 1000 may further include a third optical element 430. The third optical element may include a beam combiner. The third optical element 430 may be configured downstream of the n1 first light generation devices 110 and the n2 second light generation devices 120 and upstream of the first optical element 410. The third optical element 430 may be configured to combine the first device light 111 and the second device light 121.

[0166] Optical modelling has been performed which indicates that a significant reduction in the colour over-angle effect can be obtained.

[0167] Fig. 4 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. 4 illustrates diagrammatically an embodiment of a lighting device 1200 selected from the group of lamps 1, luminaires 2, projector devices 3, disinfection devices and optical wireless communication devices, 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 from the illumination device 1200 is indicated with reference numeral 1201. The illumination device light 1201 may essentially consist of the system light 1001, and therefore may be the system light 1001 in certain embodiments.

[0168] 1 to 3, in a particular embodiment, in an operating mode, a first intensity of the first device light 111 of the k1 first subset 1115 may increase with an increase in the first angle of incidence (α1), the n1 first light-generating devices 110 may comprise lasers, and the light-generating device 1200 may be configured to generate white light 1201 having a CCT selected from the range of 2700 to 4000K and a CRI of at least 80.

[0169] The term "plurality" refers to two or more.

[0170] 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.

[0171] The term "comprises" also includes embodiments in which the term "comprises" means "consisting of."

[0172] 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."

[0173] 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.

[0174] 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.

[0175] 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.

[0176] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0177] The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the specification and claims, words like "comprise" 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.

[0178] The singular reference of an element does not exclude the presence of a plurality of such elements.

[0179] 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.

[0180] 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.

[0181] 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.

[0182] 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.

Claims

1. A light-generating system having (i) a first set including n1 first light-generating devices, (ii) a first optical element, and (iii) a luminescent body, the n1 first light-generating devices are configured to generate first device light, the n1 first light-generating devices are selected from the group consisting of lasers and superluminescent diodes, and the n1 first light-generating devices are configured to generate first device light having a wavelength selected from the range of 380 to 495 nm; the first set comprises k1 first subsets of at least one first light-generating device each of the n1 first light-generating devices, where n1≧3 and 2≦k1≦n1; the luminescent body is configured to (i) convert a portion of the first device light into luminescent material light, and (ii) transmit a portion of the first device light; the n1 first light-generating devices and the first optical element are configured to provide first beams of first device light to the luminescent body, and two or more first beams of two or more first light-generating devices from two or more different first subsets of the k1 first subsets have different first angles of incidence with respect to a normal to the luminescent body; in an operating mode of the light-generating system, a first intensity of the first device light of the k1 first subset increases with an increasing first angle of incidence; the luminescent body having an upstream surface configured to be in a light-receiving relationship with the n1 first light-generating devices, and a downstream surface from which, during the operating mode, (a) first device light after transmission through the luminescent body and (b) luminescent material light escape, the light-generation system configured to generate system light, wherein in the operating mode, the system light comprises the first device light and the luminescent material light, and the first angle of incidence and the first intensity in the operating mode are selected such that, in a plane perpendicular to the downstream side, the change in color in u' over an angle β of at least 90° or the change in color in v' over the angle is at most 0.

03.

2. 2. The light-generating system of claim 1, wherein in the operating mode, at least two of the two or more first beams of the two or more first light-generating devices of the k1 first subsets have first angles of incidence with respect to the normal of the luminescent body that differ by a mutual angle selected from the range of 15 to 135°.

3. In the operating mode, the highest first intensity I of the first device light of the k1 first subsets upstream of the luminescent bodies １，ｍａｘ and the lowest first intensity I １，ｍｉｎ The ratio of １、ｍａｘ / I １、ｍｉｎ 3. The light-generating system of claim 1 or 2, wherein the ratio of the number of light-generating units to the number of light-generating units is selected from the range of 10 to 120.

4. 3. The light-generating system of claim 1 or 2, wherein the n1 light-generating devices are selected from the group of lasers.

5. 3. The light-generating system of claim 1 or 2, wherein the luminescent body has a body height H1 and a scattering mean free path ls for the first device light, where ls>1 / 3*H1.

6. 3. The light-generating system of claim 1 or 2, wherein the luminescent body has a transmittance in the range of 5 to 20% for vertically supplied first device light, and the luminescent body is configured to convert a portion of the first device light into luminescent material light having a wavelength within 495 to 605 nm.

7. 3. The light-generating system of claim 1 or 2, wherein the luminescent body comprises a luminescent material, the luminescent material comprising a luminescent material of A3B5O12:Ce type, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and B comprises one or more of Al, Ga, In and Sc.

8. 3. The light-generating system of claim 1 or 2, further comprising a control system, wherein the k1 first subsets are individually controllable, and the control system is configured to control the k1 first subsets.

9. 3. The light-generating system of claim 1, further comprising a second optical element, the second optical element comprising a lens array with m1 lenslets or a collimator element, the m1 lenslets or the collimator element being arranged downstream of the n1 first light-generating devices and upstream of the first optical element, where m1 = n1.

10. a second set including n2 second light-generating devices; the second light-generating device is configured to generate second device light; the second set comprises k2 second subsets of at least one second light-generating device each of the n2 second light-generating devices, where n2≧3 and 2≦k2≦n2; the luminescent body has a transmittance of at least 65% for normally supplied second device light; the n2 second light-generating devices and the first optical element are configured to provide second beams of second device light to the luminescent body, and two or more second beams of two or more second light-generating devices from two or more different second subsets of the k2 second subsets have different second angles of incidence with respect to the normal to the luminescent body; 3. The light-generating system of claim 1 or 2, wherein in an operating mode of the light-generating system, second intensities of the second device lights of the second subset of k2 light sources depend on the second angle of incidence.

11. 11. The light generation system of claim 10, wherein in the operating mode, the second intensity of the second device light of the second subset of k2 light beams decreases with increasing second angle of incidence.

12. 11. The light-generating system of claim 10, wherein one or more of (i) the n1 first light-generating devices comprising vertical cavity surface-emitting lasers, and (ii) the n2 second light-generating devices comprising vertical cavity surface-emitting lasers, the n2 second light-generating devices being configured to provide second device light having a wavelength within 605 to 780 nm.

13. 12. The light-generating system of claim 11, further comprising a third optical element, the third optical element comprising a beam combiner, the third optical element being configured downstream of the n1 first light-generating devices and the n2 second light-generating devices and upstream of the first optical element, the third optical element being configured to combine the first device light and the second device light.

14. A light-generating device selected from the group of a lamp, a luminaire, a projector device, a disinfection device and an optical wireless communication device, comprising a light-generating system according to claim 1 or 2.

15. the n1 first light-generating devices each comprising a laser; 15. The light-generating device of claim 14, configured to generate white light having a CCT selected from the range of 2700 to 4000K and a CRI of at least 80.

Images